Sample records for natural circulation loop

  1. Experimental Study of a Nitrogen Natural Circulation Loop at Low Heat Flux

    NASA Astrophysics Data System (ADS)

    Baudouy, B.

    2010-04-01

    A natural convection circulation loop in liquid nitrogen, i.e. an open thermosiphon flow configuration, has been investigated experimentally near atmospheric pressure. The experiments were conducted on a 2 m high loop with a copper tube of 10 mm inner diameter uniformly heated over a length of 0.95 m. Evolution of the total mass flow rate of the loop and the pressure difference along the tube are described. We also report the boiling curves where single phase and two-phase flows are identified with increasing heat flux. We focus our heat transfer analysis on the single phase regime where mixed convection is encountered. A heat transfer coefficient correlation is proposed. We also examine the boiling incipience as a function of the tube height.

  2. Design of Complex Systems to Achieve Passive Safety: Natural Circulation Cooling of Liquid Salt Pebble Bed Reactors

    NASA Astrophysics Data System (ADS)

    Scarlat, Raluca Olga

    This dissertation treats system design, modeling of transient system response, and characterization of individual phenomena and demonstrates a framework for integration of these three activities early in the design process of a complex engineered system. A system analysis framework for prioritization of experiments, modeling, and development of detailed design is proposed. Two fundamental topics in thermal-hydraulics are discussed, which illustrate the integration of modeling and experimentation with nuclear reactor design and safety analysis: thermal-hydraulic modeling of heat generating pebble bed cores, and scaled experiments for natural circulation heat removal with Boussinesq liquids. The case studies used in this dissertation are derived from the design and safety analysis of a pebble bed fluoride salt cooled high temperature nuclear reactor (PB-FHR), currently under development in the United States at the university and national laboratories level. In the context of the phenomena identification and ranking table (PIRT) methodology, new tools and approaches are proposed and demonstrated here, which are specifically relevant to technology in the early stages of development, and to analysis of passive safety features. A system decomposition approach is proposed. Definition of system functional requirements complements identification and compilation of the current knowledge base for the behavior of the system. Two new graphical tools are developed for ranking of phenomena importance: a phenomena ranking map, and a phenomena identification and ranking matrix (PIRM). The functional requirements established through this methodology were used for the design and optimization of the reactor core, and for the transient analysis and design of the passive natural circulation driven decay heat removal system for the PB-FHR. A numerical modeling approach for heat-generating porous media, with multi-dimensional fluid flow is presented. The application of this modeling approach to the PB-FHR annular pebble bed core cooled by fluoride salt mixtures generated a model that is called Pod. Pod. was used to show the resilience of the PB-FHR core to generation of hot spots or cold spots, due to the effect of buoyancy on the flow and temperature distribution in the packed bed. Pod. was used to investigate the PB-FHR response to ATWS transients. Based on the functional requirements for the core, Pod. was used to generate an optimized design of the flow distribution in the core. An analysis of natural circulation loops cooled by single-phase Boussinesq fluids is presented here, in the context of reactor design that relies on natural circulation decay heat removal, and design of scaled experiments. The scaling arguments are established for a transient natural circulation loop, for loops that have long fluid residence time, and negligible contribution of fluid inertia to the momentum equation. The design of integral effects tests for the loss of forced circulation (LOFC) for PB-FHR is discussed. The special case of natural circulation decay heat removal from a pebble bed reactor was analyzed. A way to define the Reynolds number in a multi-dimensional pebble bed was identified. The scaling methodology for replicating pebble bed friction losses using an electrically resistance heated annular pipe and a needle valve was developed. The thermophysical properties of liquid fluoride salts lead to design of systems with low flow velocities, and hence long fluid residence times. A comparison among liquid coolants for the performance of steady state natural circulation heat removal from a pebble bed was performed. Transient natural circulation experimental data with simulant fluids for fluoride salts is given here. The low flow velocity and the relatively high viscosity of the fluoride salts lead to low Reynolds number flows, and a low Reynolds number in conjunction with a sufficiently high coefficient of thermal expansion makes the system susceptible to local buoyancy effects Experiments indicate that slow exchange of stagnant fluid in static legs can play a significant role in the transient response of natural circulation loops. The effect of non-linear temperature profiles on the hot or cold legs or other segments of the flow loop, which may develop during transient scenarios, should be considered when modeling the performance of natural circulation loops. The data provided here can be used for validation of the application of thermal-hydraulic systems codes to the modeling of heat removal by natural circulation with liquid fluoride salts and its simulant fluids.

  3. Numerical simulation of velocity and temperature fields in natural circulation loop

    NASA Astrophysics Data System (ADS)

    Sukomel, L. A.; Kaban'kov, O. N.

    2017-11-01

    Low flow natural circulation regimes are realized in many practical applications and the existence of the reliable engineering and design calculation methods of flows driven exclusively by buoyancy forces is an actual problem. In particular it is important for the analysis of start up regimes of passive safety systems of nuclear power plants. In spite of a long year investigations of natural circulation loops no suitable predicting recommendations for heat transfer and friction for the above regimes have been proposed for engineering practice and correlations for forced flow are commonly used which considerably overpredicts the real flow velocities. The 2D numerical simulation of velocity and temperature fields in circular tubes for laminar flow natural circulation with reference to the laboratory experimental loop has been carried out. The results were compared with the 1D modified model and experimental data obtained on the above loop. The 1D modified model was still based on forced flow correlations, but in these correlations the physical properties variability and the existence of thermal and hydrodynamic entrance regions are taken into account. The comparison of 2D simulation, 1D model calculations and the experimental data showed that even subject to influence of liquid properties variability and entrance regions on heat transfer and friction the use of 1D model with forced flow correlations do not improve the accuracy of calculations. In general, according to 2D numerical simulation the wall shear stresses are mainly affected by the change of wall velocity gradient due to practically continuous velocity profiles deformation along the whole heated zone. The form of velocity profiles and the extent of their deformation in its turn depend upon the wall heat flux density and the hydraulic diameter.

  4. Numerical study of air ingress transition to natural circulation in a high temperature helium loop

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Franken, Daniel; Gould, Daniel; Jain, Prashant K.

    Here, the generation-IV high temperature gas cooled reactors (HTGRs) are designed with many passive safety features, one of which is the ability to passively remove heat under a loss of coolant accident (LOCA). However, several common reactor designs do not prevent against a large break in the coolant system and may therefore experience a depressurized LOCA. This would lead to air entering into the reactor system via several potential modes of ingress: diffusion, gravity currents, and natural circulation. At the onset of a LOCA, the initial rate of air ingress is expected to be very slow because it is governedmore » by molecular diffusion. However, after several hours, natural circulation would commence, thus, bringing the air into the reactor system at a much higher rate. As a consequence, air ingress would cause the high temperature graphite matrix to oxidize, leading to its thermal degradation and decreased passive heat (decay) removal capability. Therefore, it is essential to understand the transition of air ingress from molecular diffusion to natural circulation in an HTGR system. This paper presents results from a computational fluid dynamics (CFD) model to study the air ingress transition behavior. These results are validated against an h-shaped high temperature helium loop experiment. Details are provided to quantitatively predict the transition time from molecular diffusion to natural circulation.« less

  5. Numerical study of air ingress transition to natural circulation in a high temperature helium loop

    DOE PAGES

    Franken, Daniel; Gould, Daniel; Jain, Prashant K.; ...

    2017-09-21

    Here, the generation-IV high temperature gas cooled reactors (HTGRs) are designed with many passive safety features, one of which is the ability to passively remove heat under a loss of coolant accident (LOCA). However, several common reactor designs do not prevent against a large break in the coolant system and may therefore experience a depressurized LOCA. This would lead to air entering into the reactor system via several potential modes of ingress: diffusion, gravity currents, and natural circulation. At the onset of a LOCA, the initial rate of air ingress is expected to be very slow because it is governedmore » by molecular diffusion. However, after several hours, natural circulation would commence, thus, bringing the air into the reactor system at a much higher rate. As a consequence, air ingress would cause the high temperature graphite matrix to oxidize, leading to its thermal degradation and decreased passive heat (decay) removal capability. Therefore, it is essential to understand the transition of air ingress from molecular diffusion to natural circulation in an HTGR system. This paper presents results from a computational fluid dynamics (CFD) model to study the air ingress transition behavior. These results are validated against an h-shaped high temperature helium loop experiment. Details are provided to quantitatively predict the transition time from molecular diffusion to natural circulation.« less

  6. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Knížat, Branislav, E-mail: branislav.knizat@stuba.sk; Urban, František, E-mail: frantisek.urban@stuba.sk; Mlkvik, Marek, E-mail: marek.mlkvik@stuba.sk

    A natural circulation helium loop appears to be a perspective passive method of a nuclear reactor cooling. When designing this device, it is important to analyze the mechanism of an internal flow. The flow of helium in the loop is set in motion due to a difference of hydrostatic pressures between cold and hot branch. Steady flow at a requested flow rate occurs when the buoyancy force is adjusted to resistances against the flow. Considering the fact that the buoyancy force is proportional to a difference of temperatures in both branches, it is important to estimate the losses correctly inmore » the process of design. The paper deals with the calculation of losses in branches of the natural circulation helium loop by methods of CFD. The results of calculations are an important basis for the hydraulic design of both exchangers (heater and cooler). The analysis was carried out for the existing model of a helium loop of the height 10 m and nominal heat power 250 kW.« less

  7. Pretest analysis of natural circulation on the PWR model PACTEL with horizontal steam generators

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kervinen, T.; Riikonen, V.; Ritonummi, T.

    A new tests facility - parallel channel tests loop (PACTEL)- has been designed and built to simulate the major components and system behavior of pressurized water reactors (PWRs) during postulated small- and medium-break loss-of-coolant accidents. Pretest calculations have been performed for the first test series, and the results of these calculations are being used for planning experiments, for adjusting the data acquisition system, and for choosing the optimal position and type of instrumentation. PACTEL is a volumetrically scaled (1:305) model of the VVER-440 PWR. In all the calculated cases, the natural circulation was found to be effective in removing themore » heat from the core to the steam generator. The loop mass flow rate peaked at 60% mass inventory. The straightening of the loop seals increased the mass flow rate significantly.« less

  8. Flow rate and temperature characteristics in steady state condition on FASSIP-01 loop during commissioning

    NASA Astrophysics Data System (ADS)

    Juarsa, M.; Giarno; Rohman, A. N.; Heru K., G. B.; Witoko, J. P.; Sony Tjahyani, D. T.

    2018-02-01

    The need for large-scale experimental facilities to investigate the phenomenon of natural circulation flow rate becomes a necessity in the development of nuclear reactor safety management. The FASSIP-01 loop has been built to determine the natural circulation flow rate performance in the large-scale media and aimed to reduce errors in the results for its application in the design of new generation reactors. The commissioning needs to be done to define the capability of the FASSIP-01 loop and to prescribe the experiment limitations. On this commissioning, two scenarios experimental method has been used. The first scenario is a static condition test which was conducted to verify measurement system response during 24 hours without electrical load in heater and cooler, there is water and no water inside the rectangular loop. Second scenario is a dynamics condition that aims to understand the flow rate, a dynamic test was conducted using heater power of 5627 watts and coolant flow rate in the HSS loop of 9.35 LPM. The result of this test shows that the temperature characterization on static test provide a recommendation, that the experiments should be done at night because has a better environmental temperature stability compared to afternoon, with stable temperature around 1°C - 3°C. While on the dynamic test, the water temperature difference between the inlet-outlets in the heater area is quite large, about 7 times the temperature difference in the cooler area. The magnitude of the natural circulation flow rate calculated is much larger at about 300 times compared to the measured flow rate with different flow rate profiles.

  9. Operation of a cascade air conditioning system with two-phase loop

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Feng, Yinshan; Wang, Jinliang; Zhao, Futao

    A method of operating a heat transfer system includes starting operation of a first heat transfer fluid vapor/compression circulation loop including a fluid pumping mechanism, a heat exchanger for rejecting thermal energy from a first heat transfer fluid, and a heat absorption side of an internal heat exchanger. A first conduit in a closed fluid circulation loop circulates the first heat transfer fluid therethrough. Operation of a second two-phase heat transfer fluid circulation loop is started after starting operation of the first heat transfer fluid circulation loop. The second heat transfer fluid circulation loop transfers heat to the first heatmore » transfer fluid circulation loop through the internal heat exchanger and includes a heat rejection side of the internal heat exchanger, a liquid pump, and a heat exchanger evaporator. A second conduit in a closed fluid circulation loop circulates a second heat transfer fluid therethrough.« less

  10. Transient boiling in two-phase helium natural circulation loops

    NASA Astrophysics Data System (ADS)

    Furci, H.; Baudouy, B.; Four, A.; Meuris, C.

    2014-01-01

    Two-phase helium natural circulation loops are used for cooling large superconducting magnets, as CMS for LHC. During normal operation or in the case of incidents, transients are exerted on the cooling system. Here a cooling system of this type is studied experimentally. Sudden power changes are operated on a vertical-heated-section natural convection loop, simulating a fast increase of heat deposition on magnet cooling pipes. Mass flow rate, heated section wall temperature and pressure drop variations are measured as a function of time, to assess the time behavior concerning the boiling regime according to the values of power injected on the heated section. The boiling curves and critical heat flux (CHF) values have been obtained in steady state. Temperature evolution has been observed in order to explore the operating ranges where heat transfer is deteriorated. Premature film boiling has been observed during transients on the heated section in some power ranges, even at appreciably lower values than the CHF. A way of attenuating these undesired temperature excursions has been identified through the application of high enough initial heating power.

  11. Design Construction and Operation of a Supercritical Carbon Dioxide (sCO 2) Loop for Investigation of Dry Cooling and Natural Circulation Potential for Use in Advanced Small Modular Reactors Utilizing sCO 2 Power Conversion Cycles.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Middleton, Bobby D.; Rodriguez, Salvador B.; Carlson, Matthew David

    This report outlines the work completed for a Laboratory Directed Research and Development project at Sandia National Laboratories from October 2012 through September 2015. An experimental supercritical carbon dioxide (sCO 2 ) loop was designed, built, and o perated. The experimental work demonstrated that sCO 2 can be uti lized as the working fluid in an air - cooled, natural circulation configuration to transfer heat from a source to the ultimate heat sink, which is the surrounding ambient environment in most ca ses. The loop was also operated in an induction - heated, water - cooled configuration that allows formore » measurements of physical parameters that are difficult to isolate in the air - cooled configuration. Analysis included the development of two computational flu id dynamics models. Future work is anticipated to answer questions that were not covered in this project.« less

  12. RELAP5 Analysis of the Hybrid Loop-Pool Design for Sodium Cooled Fast Reactors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hongbin Zhang; Haihua Zhao; Cliff Davis

    2008-06-01

    An innovative hybrid loop-pool design for sodium cooled fast reactors (SFR-Hybrid) has been recently proposed. This design takes advantage of the inherent safety of a pool design and the compactness of a loop design to improve economics and safety of SFRs. In the hybrid loop-pool design, primary loops are formed by connecting the reactor outlet plenum (hot pool), intermediate heat exchangers (IHX), primary pumps and the reactor inlet plenum with pipes. The primary loops are immersed in the cold pool (buffer pool). Passive safety systems -- modular Pool Reactor Auxiliary Cooling Systems (PRACS) – are added to transfer decay heatmore » from the primary system to the buffer pool during loss of forced circulation (LOFC) transients. The primary systems and the buffer pool are thermally coupled by the PRACS, which is composed of PRACS heat exchangers (PHX), fluidic diodes and connecting pipes. Fluidic diodes are simple, passive devices that provide large flow resistance in one direction and small flow resistance in reverse direction. Direct reactor auxiliary cooling system (DRACS) heat exchangers (DHX) are immersed in the cold pool to transfer decay heat to the environment by natural circulation. To prove the design concepts, especially how the passive safety systems behave during transients such as LOFC with scram, a RELAP5-3D model for the hybrid loop-pool design was developed. The simulations were done for both steady-state and transient conditions. This paper presents the details of RELAP5-3D analysis as well as the calculated thermal response during LOFC with scram. The 250 MW thermal power conventional pool type design of GNEP’s Advanced Burner Test Reactor (ABTR) developed by Argonne National Laboratory was used as the reference reactor core and primary loop design. The reactor inlet temperature is 355 °C and the outlet temperature is 510 °C. The core design is the same as that for ABTR. The steady state buffer pool temperature is the same as the reactor inlet temperature. The peak cladding, hot pool, cold pool and reactor inlet temperatures were calculated during LOFC. The results indicate that there are two phases during LOFC transient – the initial thermal equilibration phase and the long term decay heat removal phase. The initial thermal equilibration phase occurs over a few hundred seconds, as the system adjusts from forced circulation to natural circulation flow. Subsequently, during long-term heat removal phase all temperatures evolve very slowly due to the large thermal inertia of the primary and buffer pool systems. The results clearly show that passive safety PRACS can effectively transfer decay heat from the primary system to the buffer pool by natural circulation. The DRACS system in turn can effectively transfer the decay heat to the environment.« less

  13. Natural circulation in a liquid metal one-dimensional loop

    NASA Astrophysics Data System (ADS)

    Tarantino, M.; De Grandis, S.; Benamati, G.; Oriolo, F.

    2008-06-01

    A wide use of pure lead, as well as its alloys (such as lead-bismuth, lead-lithium), is foreseen in several nuclear-related fields: it is studied as coolant in critical and sub-critical nuclear reactors, as spallation target for neutron generation in several applications and for tritium generation in fusion systems. In this framework, a new facility named NAtural CIrculation Experiment (NACIE), has been designed at ENEA-Brasimone Research Centre. NACIE is a rectangular loop, made by stainless steel pipes. It consists mainly of a cold and hot leg and an expansion tank installed on the top of the loop. A fuel bundle simulator, made by three electrical heaters placed in a triangular lattice, is located in the lower part of the cold leg, while a tube in tube heat exchanger is installed in the upper part of the hot leg. The adopted secondary fluid is THT oil, while the foreseen primary fluid for the tests is lead-bismuth in eutectic composition (LBE). The aim of the facility is to carry out experimental tests of natural circulation and collect data on the heat transfer coefficient (HTC) for heavy liquid metal flowing through rod bundles. The paper is focused on the preliminary estimation of the LBE flow rate along the loop. An analytical methodology has been applied, solving the continuity, momentum and energy transport equations under appropriate hypothesis. Moreover numerical simulations have been performed. The FLUENT 6.2 CFD code has been utilized for the numerical simulations. The main results carried out from the pre-tests simulations are illustrated in the paper, and a comparison with the theoretical estimations is done.

  14. Decay Heat Removal from a GFR Core by Natural Convection

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Williams, Wesley C.; Hejzlar, Pavel; Driscoll, Michael J.

    2004-07-01

    One of the primary challenges for Gas-cooled Fast Reactors (GFR) is decay heat removal after a loss of coolant accident (LOCA). Due to the fact that thermal gas cooled reactors currently under design rely on passive mechanisms to dissipate decay heat, there is a strong motivation to accomplish GFR core cooling through natural phenomena. This work investigates the potential of post-LOCA decay heat removal from a GFR core to a heat sink using an external convection loop. A model was developed in the form of the LOCA-COLA (Loss of Coolant Accident - Convection Loop Analysis) computer code as a meansmore » for 1D steady state convective heat transfer loop analysis. The results show that decay heat removal by means of gas cooled natural circulation is feasible under elevated post-LOCA containment pressure conditions. (authors)« less

  15. Reflux cooling experiments on the NCSU scaled PWR facility

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Doster, J.M.; Giavedoni, E.

    1993-01-01

    Under loss of forced circulation, coupled with the loss or reduction in primary side coolant inventory, horizontal stratified flows can develop in the hot and cold legs of pressurized water reactors (PWRs). Vapor produced in the reactor vessel is transported through the hot leg to the steam generator tubes where it condenses and flows back to the reactor vessel. Within the steam generator tubes, the flow regimes may range from countercurrent annular flow to single-phase convection. As a result, a number of heat transfer mechanisms are possible, depending on the loop configuration, total heat transfer rate, and the steam flowmore » rate within the tubes. These include (but are not limited to) two-phase natural circulation, where the condensate flows concurrent to the vapor stream and is transported to the cold leg so that the entire reactor coolant loop is active, and reflux cooling, where the condensate flows back down the interior of the coolant tubes countercurrent to the vapor stream and is returned to the reactor vessel through the hot leg. While operating in the reflux cooling mode, the cold leg can effectively be inactive. Heat transfer can be further influenced by noncondensables in the vapor stream, which accumulate within the upper regions of the steam generator tube bundle. In addition to reducing the steam generator's effective heat transfer area, under these conditions operation under natural circulation may not be possible, and reflux cooling may be the only viable heat transfer mechanism. The scaled PWR (SPWR) facility in the nuclear engineering department at North Carolina State Univ. (NCSU) is being used to study the effectiveness of two-phase natural circulation and reflux cooling under conditions associated with loss of forced circulation, midloop coolant levels, and noncondensables in the primary coolant system.« less

  16. Thermohydraulic behavior of the liquid metal target of a spallation neutron source

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Takeda, Y.

    1996-06-01

    The author presents work done on three main problems. (1) Natural circulation in double coaxial cylindircal container: The thermohydraulic behaviour of the liquid metal target of the spallation neutron source at PSI has been investigated. The configuration is a natural-circulation loop in a concentric double-tube-type container. The results show that the natural-circulation loop concept is valid for the design phase of the target construction, and the current specified design criteria will be fulfilled with the proposed parameter values. (2) Flow around the window: Water experiments were performed for geometry optimisation of the window shape of the SINQ container for avoidingmore » generating recirculation zones at peripheral area and the optimal cooling of the central part of the beam entrance window. Flow visualisation technique was mainly used for various window shapes, gap distance between the window and the guide tube edge. (3) Flow in window cooling channels: Flows in narrow gaps of cooling channels of two different types of windows were studied by flow visualisation techniques. One type is a slightly curved round cooling channel and the other is hemispherical shape, both of which have only 2 mm gap distance and the water inlet is located on one side and flows out from the opposite side. In both cases, the central part of the flow area has lower velocity than peripheral area.« less

  17. Circulating heat exchangers for oscillating wave engines and refrigerators

    DOEpatents

    Swift, Gregory W.; Backhaus, Scott N.

    2003-10-28

    An oscillating-wave engine or refrigerator having a regenerator or a stack in which oscillating flow of a working gas occurs in a direction defined by an axis of a trunk of the engine or refrigerator, incorporates an improved heat exchanger. First and second connections branch from the trunk at locations along the axis in selected proximity to one end of the regenerator or stack, where the trunk extends in two directions from the locations of the connections. A circulating heat exchanger loop is connected to the first and second connections. At least one fluidic diode within the circulating heat exchanger loop produces a superimposed steady flow component and oscillating flow component of the working gas within the circulating heat exchanger loop. A local process fluid is in thermal contact with an outside portion of the circulating heat exchanger loop.

  18. Laboratory formation of non-cementing, methane hydrate-bearing sands

    USGS Publications Warehouse

    Waite, William F.; Bratton, Peter M.; Mason, David H.

    2011-01-01

    Naturally occurring hydrate-bearing sands often behave as though methane hydrate is acting as a load-bearing member of the sediment. Mimicking this behavior in laboratory samples with methane hydrate likely requires forming hydrate from methane dissolved in water. To hasten this formation process, we initially form hydrate in a free-gas-limited system, then form additional hydrate by circulating methane-supersaturated water through the sample. Though the dissolved-phase formation process can theoretically be enhanced by increasing the pore pressure and flow rate and lowering the sample temperature, a more fundamental concern is preventing clogs resulting from inadvertent methane bubble formation in the circulation lines. Clog prevention requires careful temperature control throughout the circulation loop.

  19. Influence of cross-sectional ratio of down comer to riser on the efficiency of liquid circulation in loop air lift bubble column

    NASA Astrophysics Data System (ADS)

    Yamamoto, Tatsumi; Kawasaki, Hiroyuki; Mori, Hidetoshi

    2017-11-01

    Loop type bubble columns have good performance of liquid circulation and mass transfer by airlift effect, where the liquid circulation time is an important measurable characteristic parameter. This parameter is affected by the column construction, the aspect ratio of the column, the cross-sectional area ratio of down comer to riser (R), and the superficial gas velocity in the riser (UGR). In this work, the mean gas holdup and the liquid circulation time (TC) have been measured in four types of loop airlift type bubble column: concentric tube internal loop airlift type, rectangular internal loop airlift type, external loop airlift type, external loop airlift with separator. Air and tap water were used as gas and liquid phase, respectively. The results have demonstrated that the mean gas holdup in riser increases in proportion to UGR, and that it in downcomer changes according to the geometric parameters of each bubble column. TC has been found to conform to an empirical equation which depends on UGR and the length of draft tube or division plate in the region of 0.33 < R < 1.

  20. Performance and stability analysis of gas-injection enhanced natural circulation in heavy-liquid-metal-cooled systems

    NASA Astrophysics Data System (ADS)

    Yoo, Yeon-Jong

    The purpose of this study is to investigate the performance and stability of the gas-injection enhanced natural circulation in heavy-liquid-metal-cooled systems. The target system is STAR-LM, which is a 400-MWt-class advanced lead-cooled fast reactor under development by Argonne National Laboratory and Oregon State University. The primary loop of STAR-LM relies on natural circulation to eliminate main circulation pumps for enhancement of passive safety. To significantly increase the natural circulation flow rate for the incorporation of potential future power uprates, the injection of noncondensable gas into the coolant above the core is envisioned ("gas lift pump"). Reliance upon gas-injection enhanced natural circulation raises the concern of flow instability due to the relatively high temperature change in the reactor core and the two-phase flow condition in the riser. For this study, the one-dimensional flow field equations were applied to each flow section and the mixture models of two-phase flow, i.e., both the homogeneous and drift-flux equilibrium models were used in the two-phase region of the riser. For the stability analysis, the linear perturbation technique based on the frequency-domain approach was used by employing the Nyquist stability criterion and a numerical root search method. It has been shown that the thermal power of the STAR-LM natural circulation system could be increased from 400 up to 1152 MW with gas injection under the limiting void fraction of 0.30 and limiting coolant velocity of 2.0 m/s from the steady-state performance analysis. As the result of the linear stability analysis, it has turned out that the STAR-LM natural circulation system would be stable even with gas injection. In addition, through the parametric study, it has been found that the thermal inertia effects of solid structures such as fuel rod and heat exchanger tube should be considered in the stability analysis model. The results of this study will be a part of the optimized stable design of the gas-injection enhanced natural circulation of STAR-LM with substantially improved power level and economical competitiveness. Furthermore, combined with the parametric study, this research could contribute a guideline for the design of other similar heavy-liquid-metal-cooled natural circulation systems with gas injection.

  1. Verification of RELAP5-3D code in natural circulation loop as function of the initial water inventory

    NASA Astrophysics Data System (ADS)

    Bertani, C.; Falcone, N.; Bersano, A.; Caramello, M.; Matsushita, T.; De Salve, M.; Panella, B.

    2017-11-01

    High safety and reliability of advanced nuclear reactors, Generation IV and Small Modular Reactors (SMR), have a crucial role in the acceptance of these new plants design. Among all the possible safety systems, particular efforts are dedicated to the study of passive systems because they rely on simple physical principles like natural circulation, without the need of external energy source to operate. Taking inspiration from the second Decay Heat Removal system (DHR2) of ALFRED, the European Generation IV demonstrator of the fast lead cooled reactor, an experimental facility has been built at the Energy Department of Politecnico di Torino (PROPHET facility) to study single and two-phase flow natural circulation. The facility behavior is simulated using the thermal-hydraulic system code RELAP5-3D, which is widely used in nuclear applications. In this paper, the effect of the initial water inventory on natural circulation is analyzed. The experimental time behaviors of temperatures and pressures are analyzed. The experimental matrix ranges between 69 % and 93%; the influence of the opposite effects related to the increase of the volume available for the expansion and the pressure raise due to phase change is discussed. Simulations of the experimental tests are carried out by using a 1D model at constant heat power and fixed liquid and air mass; the code predictions are compared with experimental results. Two typical responses are observed: subcooled or two phase saturated circulation. The steady state pressure is a strong function of liquid and air mass inventory. The numerical results show that, at low initial liquid mass inventory, the natural circulation is not stable but pulsated.

  2. Buoyancy Driven Coolant Mixing Studies of Natural Circulation Flows at the ROCOM Test Facility Using ANSYS CFX

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hohne, Thomas; Kliem, Soren; Rohde, Ulrich

    2006-07-01

    Coolant mixing in the cold leg, downcomer and the lower plenum of pressurized water reactors is an important phenomenon mitigating the reactivity insertion into the core. Therefore, mixing of the de-borated slugs with the ambient coolant in the reactor pressure vessel was investigated at the four loop 1:5 scaled ROCOM mixing test facility. Thermal hydraulics analyses showed, that weakly borated condensate can accumulate in particular in the pump loop seal of those loops, which do not receive safety injection. After refilling of the primary circuit, natural circulation in the stagnant loops can re-establish simultaneously and the de-borated slugs are shiftedmore » towards the reactor pressure vessel (RPV). In the ROCOM experiments, the length of the flow ramp and the initial density difference between the slugs and the ambient coolant was varied. From the test matrix experiments with 0 resp. 2% density difference between the de-borated slugs and the ambient coolant were used to validate the CFD software ANSYS CFX. To model the effects of turbulence on the mean flow a higher order Reynolds stress turbulence model was employed and a mesh consisting of 6.4 million hybrid elements was utilized. Only the experiments and CFD calculations with modeled density differences show a stratification in the downcomer. Depending on the degree of density differences the less dense slugs flow around the core barrel at the top of the downcomer. At the opposite side the lower borated coolant is entrained by the colder safety injection water and transported to the core. The validation proves that ANSYS CFX is able to simulate appropriately the flow field and mixing effects of coolant with different densities. (authors)« less

  3. A Self-Circulating Heat Exchanger for Use in Stirling and Thermoacoustic-Stirling Engines

    NASA Astrophysics Data System (ADS)

    Backhaus, Scott; Reid, Robert S.

    2005-02-01

    A major technical hurdle to the implementation of large Stirling engines or thermoacoustic engines is the reliability, performance, and manufacturability of the hot heat exchanger that brings high-temperature heat into the engine. Unlike power conversion devices that utilize steady flow, the oscillatory nature of the flow in Stirling and thermoacoustic engines restricts the length of a traditional hot heat exchanger to a peak-to-peak gas displacement, which is usually around 0.2 meters or less. To overcome this restriction, a new hot heat exchanger has been devised that uses a fluid diode in a looped pipe, which is resonantly driven by the oscillating gas pressure in the engine itself, to circulate the engine's working fluid around the loop. Instead of thousands of short, intricately interwoven passages that must be individually sealed, this new design consists of a few pipes that are typically 10 meters long. This revolutionary approach eliminates thousands of hermetic joints, pumps the engine's working fluid to and from a remote heat source without using moving parts, and does so without compromising on heat transfer surface area. Test data on a prototype loop integrated with a 1-kW thermoacoustic engine will be presented.

  4. Numerical Simulation in a Supercirtical CFB Boiler

    NASA Astrophysics Data System (ADS)

    Zhang, Yanjun; Gaol, Xiang; Luo, Zhongyang; Jiang, Xiaoguo

    The dimension of the hot circulation loop of the supercritical CFB boiler is large, and there are many unknowns and challenges that should be identified and resolved during the development. In order to realize a reasonable and reliable design of the hot circulation loop, numerical simulation of gas-solid flow in a supercritical CFB boiler was conducted by using FLUENT software. The working condition of hot circulation loop flow field, gas-solid flow affected by three unsymmetrical cyclones, air distribution and pressure drop in furnace were analyzed. The simulation results showed that the general arrangement of the 600MWe supercritical CFB boiler is reasonable.

  5. Laser beam pulse formatting method

    DOEpatents

    Daly, T.P.; Moses, E.I.; Patterson, R.W.; Sawicki, R.H.

    1994-08-09

    A method for formatting a laser beam pulse using one or more delay loops is disclosed. The delay loops have a partially reflective beam splitter and a plurality of highly reflective mirrors arranged such that the laser beam pulse enters into the delay loop through the beam splitter and circulates therein along a delay loop length defined by the mirrors. As the laser beam pulse circulates within the delay loop a portion thereof is emitted upon each completed circuit when the laser beam pulse strikes the beam splitter. The laser beam pulse is thereby formatted into a plurality of sub-pulses. The delay loops are used in combination to produce complex waveforms by combining the sub-pulses using additive waveform synthesis. 8 figs.

  6. ANALYSIS OF BORON DILUTION TRANSIENTS IN PWRS.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    DIAMOND,D.J.BROMLEY,B.P.ARONSON,A.L.

    2004-02-04

    A study has been carried out with PARCS/RELAP5 to understand the consequences of hypothetical boron dilution events in pressurized water reactors. The scenarios of concern start with a small-break loss-of-coolant accident. If the event leads to boiling in the core and then the loss of natural circulation, a boron-free condensate can accumulate in the cold leg. The dilution event happens when natural circulation is re-established or a reactor coolant pump (RCP) is restarted in violation of operating procedures. This event is of particular concern in B&W reactors with a lowered-loop design and is a Generic Safety Issue for the U.S.more » Nuclear Regulatory Commission. The results of calculations with the reestablishment of natural circulation show that there is no unacceptable fuel damage. This is determined by calculating the maximum fuel pellet enthalpy, based on the three-dimensional model, and comparing it with the criterion for damage. The calculation is based on a model of a B&W reactor at beginning of the fuel cycle. If an RCP is restarted, unacceptable fuel damage may be possible in plants with sufficiently large volumes of boron-free condensate in the cold leg.« less

  7. Numerical study on the Welander oscillatory natural circulation problem using high-order numerical methods

    DOE PAGES

    Zou, Ling; Zhao, Haihua; Kim, Seung Jun

    2016-11-16

    In this study, the classical Welander’s oscillatory natural circulation problem is investigated using high-order numerical methods. As originally studied by Welander, the fluid motion in a differentially heated fluid loop can exhibit stable, weakly instable, and strongly instable modes. A theoretical stability map has also been originally derived from the stability analysis. Numerical results obtained in this paper show very good agreement with Welander’s theoretical derivations. For stable cases, numerical results from both the high-order and low-order numerical methods agree well with the non-dimensional flow rate analytically derived. The high-order numerical methods give much less numerical errors compared to themore » low-order methods. For stability analysis, the high-order numerical methods could perfectly predict the stability map, while the low-order numerical methods failed to do so. For all theoretically unstable cases, the low-order methods predicted them to be stable. The result obtained in this paper is a strong evidence to show the benefits of using high-order numerical methods over the low-order ones, when they are applied to simulate natural circulation phenomenon that has already gain increasing interests in many future nuclear reactor designs.« less

  8. LMFBR system-wide transient analysis: the state of the art and US validation needs

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Khatib-Rahbar, M.; Guppy, J.G.; Cerbone, R.J.

    1982-01-01

    This paper summarizes the computational capabilities in the area of liquid metal fast breeder reactor (LMFBR) system-wide transient analysis in the United States, identifies various numerical and physical approximations, the degree of empiricism, range of applicability, model verification and experimental needs for a wide class of protected transients, in particular, natural circulation shutdown heat removal for both loop- and pool-type plants.

  9. ISP33 standard problem on the PACTEL facility

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Purhonen, H.; Kouhia, J.; Kalli, H.

    ISP33 is the first OECD/NEA/CSNI standard problem related to VVER type of pressurized water reactors. The reference reactor of the PACTEL test facility, which was used to carry out the ISP33 experiment, is the VVER-440 reactor, two of which are located near the Finnish city of Loviisa. The objective of the ISP33 test was to study the natural circulation behaviour of VVER-440 reactors at different coolant inventories. Natural circulation was considered as a suitable phenomenon to focus on by the first VVER related ISP due to its importance in most accidents and transients. The behaviour of the natural circulation wasmore » expected to be different compared to Western type of PWRs as a result of the effect of horizontal steam generators and the hot leg loop seals. This ISP was conducted as a blind problem. The experiment was started at full coolant inventory. Single-phase natural circulation transported the energy from the core to the steam generators. The inventory was then reduced stepwise at about 900 s intervals draining 60 kg each time from the bottom of the downcomer. the core power was about 3.7% of the nominal value. The test was terminated after the cladding temperatures began to rise. ATHLET, CATHARE, RELAP5 (MODs 3, 2.5 and 2), RELAP4/MOD6, DINAMIKA and TECH-M4 codes were used in 21 pre- and 20 posttest calculations submitted for the ISP33.« less

  10. Experimental and analytical study of stability characteristics of natural circulation boiling water reactors during startup transient

    NASA Astrophysics Data System (ADS)

    Woo, Kyoungsuk

    Two-phase natural circulation loops are unstable at low pressure operating conditions. New reactor design relying on natural circulation for both normal and abnormal core cooling is susceptible to different types of flow instabilities. In contrast to forced circulation boiling water reactor (BWR), natural circulation BWR is started up without recirculation pumps. The tall chimney placed on the top of the core makes the system susceptible to flashing during low pressure start-up. In addition, the considerable saturation temperature variation may induce complicated dynamic behavior driven by thermal non-equilibrium between the liquid and steam. The thermal-hydraulic problems in two-phase natural circulation systems at low pressure and low power conditions are investigated through experimental methods. Fuel heat conduction, neutron kinetics, flow kinematics, energetics and dynamics that govern the flow behavior at low pressure, are formulated. A dimensionless analysis is introduced to obtain governing dimensionless groups which are groundwork of the system scaling. Based on the robust scaling method and start-up procedures of a typical natural circulation BWR, the simulation strategies for the transient with and without void reactivity feedback is developed. Three different heat-up rates are applied to the transient simulations to study characteristics of the stability during the start-up. Reducing heat-up rate leads to increase in the period of flashing-induced density wave oscillation and decrease in the system pressurization rate. However, reducing the heat-up rate is unable to completely prevent flashing-induced oscillations. Five characteristic regions of stability are discovered at low pressure conditions. They are stable single-phase, flashing near the separator, intermittent oscillation, sinusoidal oscillation and low subcooling stable regions. Stability maps were acquired for system pressures ranging 100 kPa to 400 kPa. According to experimental investigation, the flow becomes stable below a certain heat flux regardless of the inlet subcooling at the core and system pressure. At higher heat flux, unstable phenomena were indentified within a certain range of inlet subcooling. The unstable region diminishes as the system pressure increases. In natural circulation BWRs, the significant gravitational pressure drop over the tall chimney section induces a Type-I instability. The Type-I instability becomes especially important during low power and pressure conditions during reactor start-up. Under these circumstances the effect of pressure variations on the saturation enthalpy becomes significant. An experimental study shows that the flashing phenomenon in the adiabatic chimney section is dominant during the start-up of a natural circulation BWR. Since flashing occurs outside the core, nuclear feedback effects on the stability are small. Furthermore, the thermal-hydraulic oscillation period is much longer than power fluctuation period caused by void reactivity feedback. In the natural circulation system increasing the inlet restriction reduces the natural circulation flow rate, shifting the unstable region to higher inlet subcooling.

  11. Inherent Safety Characteristics of Advanced Fast Reactors

    NASA Astrophysics Data System (ADS)

    Bochkarev, A. S.; Korsun, A. S.; Kharitonov, V. S.; Alekseev, P. N.

    2017-01-01

    The study presents SFR transient performance for ULOF events initiated by pump trip and pump seizure with simultaneous failure of all shutdown systems in both cases. The most severe cases leading to the pin cladding rupture and possible sodium boiling are demonstrated. The impact of various features on SFR inherent safety performance for ULOF events was analysed. The decrease in hydraulic resistance of primary loop and increase in primary pump coast down time were investigated. Performing analysis resulted in a set of recommendations to varying parameters for the purpose of enhancing the inherent safety performance of SFR. In order to prevent the safety barrier rupture for ULOF events the set of thermal hydraulic criteria defining the ULOF transient processes dynamics and requirements to these criteria were recommended based on achieved results: primary sodium flow dip under the natural circulation asymptotic level and natural circulation rise time.

  12. Natural circulation decay heat removal from an SP-100, 550 kWe power system for a lunar outpost

    NASA Technical Reports Server (NTRS)

    El-Genk, Mohamed S.; Xue, Huimin

    1992-01-01

    This research investigated the decay heat removal from the SP-100 reactor core of a 550-kWe power system for a lunar outpost by natural circulation of lithium coolant. A transient model that simulates the decay heat removal loop (DHRL) of the power system was developed and used to assess the system's decay heat removal capability. The effects of the surface area of the decay heat rejection radiator, the dimensions of the decay heat exchanger (DHE) flow duct, the elevation of the DHE, and the diameter of the rise and down pipes in the DHRL on the decay heat removal capability were examined. Also, to determine the applicability of test results at earth gravity to actual system performance on the lunar surface, the effect of the gravity constant (1 g and 1/6 g) on the thermal behavior of the system after shutdown was investigated.

  13. Cooling system for a nuclear reactor

    DOEpatents

    Amtmann, Hans H.

    1982-01-01

    A cooling system for a gas-cooled nuclear reactor is disclosed which includes at least one primary cooling loop adapted to pass coolant gas from the reactor core and an associated steam generator through a duct system having a main circulator therein, and at least one auxiliary cooling loop having communication with the reactor core and adapted to selectively pass coolant gas through an auxiliary heat exchanger and circulator. The main and auxiliary circulators are installed in a common vertical cavity in the reactor vessel, and a common return duct communicates with the reactor core and intersects the common cavity at a junction at which is located a flow diverter valve operative to effect coolant flow through either the primary or auxiliary cooling loops.

  14. Laser beam pulse formatting method

    DOEpatents

    Daly, Thomas P.; Moses, Edward I.; Patterson, Ralph W.; Sawicki, Richard H.

    1994-01-01

    A method for formatting a laser beam pulse (20) using one or more delay loops (10). The delay loops (10) have a partially reflective beam splitter (12) and a plurality of highly reflective mirrors (14) arranged such that the laser beam pulse (20) enters into the delay loop (10) through the beam splitter (12) and circulates therein along a delay loop length (24) defined by the mirrors (14). As the laser beam pulse (20) circulates within the delay loop (10) a portion thereof is emitted upon each completed circuit when the laser beam pulse (20) strikes the beam splitter (12). The laser beam pulse (20) is thereby formatted into a plurality of sub-pulses (50, 52, 54 and 56). The delay loops (10) are used in combination to produce complex waveforms by combining the sub-pulses (50, 52, 54 and 56) using additive waveform synthesis.

  15. The NICMOS Cooling SYSTEM-5 Years of Successful On-Orbit Operation

    NASA Astrophysics Data System (ADS)

    Swift, W. L.; Dolan, F. X.; Zagarola, M. V.

    2008-03-01

    The NICMOS Cooling System consists of a closed-loop turbo-Brayton cryocooler coupled with a cryogenic circulator that provides refrigeration to the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) on the Hubble Space Telescope (HST). The cryocooler heat is rejected to space through a capillary pumped loop connected to radiators mounted on the side of the telescope. The system was deployed and integrated with NICMOS by astronauts during STS-109 (Space Shuttle Columbia) in March 2002. It has operated nearly continuously without performance degradation since that time, maintaining NICMOS detectors at a constant temperature of 77 K. Miniature, high-speed turbomachines are used in the cryocooler and the circulator loop to provide vibration-free, long-life operation. A small centrifugal compressor and miniature turboalternator are key elements of the closed loop cryocooler. A miniature cryogenic centrifugal circulator in a separate pressurized neon loop transports heat from the NICMOS instrument to the cryocooler interface heat exchanger. This paper describes the development of the system, key operational features, ground and orbital tests prior to its deployment, and operational results during its five-year operational history on orbit.

  16. TRAC-PF1/MOD1 support calculations for the MIST/OTIS program

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fujita, R.K.; Knight, T.D.

    1984-01-01

    We are using the Transient Reactor Analysis Code (TRAC), specifically version TRAC-PF1/MOD1, to perform analyses in support of the MultiLoop Integral-System Test (MIST) and the Once-Through Integral-System (OTIS) experiment program. We have analyzed Geradrohr Dampferzeuger Anlage (GERDA) Test 1605AA to benchmark the TRAC-PF1/MOD1 code against phenomena expected to occur in a raised-loop B and W plant during a small-break loss-of-coolant accident (SBLOCA). These results show that the code can calculate both single- and two-phase natural circulation, flow interruption, boiler-condenser-mode (BCM) heat transfer, and primary-system refill in a B and W-type geometry with low-elevation auxiliary feedwater. 19 figures, 7 tables.

  17. Cycle-averaged dynamics of a periodically driven, closed-loop circulation model

    NASA Technical Reports Server (NTRS)

    Heldt, T.; Chang, J. L.; Chen, J. J. S.; Verghese, G. C.; Mark, R. G.

    2005-01-01

    Time-varying elastance models have been used extensively in the past to simulate the pulsatile nature of cardiovascular waveforms. Frequently, however, one is interested in dynamics that occur over longer time scales, in which case a detailed simulation of each cardiac contraction becomes computationally burdensome. In this paper, we apply circuit-averaging techniques to a periodically driven, closed-loop, three-compartment recirculation model. The resultant cycle-averaged model is linear and time invariant, and greatly reduces the computational burden. It is also amenable to systematic order reduction methods that lead to further efficiencies. Despite its simplicity, the averaged model captures the dynamics relevant to the representation of a range of cardiovascular reflex mechanisms. c2004 Elsevier Ltd. All rights reserved.

  18. Simulation of sodium pumps for nuclear power plants. Technical report 1 Oct 80-1 May 81

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Boadu, H.O.

    1981-05-01

    A single-phase pump model for analysis of transients in sodium cooled fast breeder nuclear power plants has been presented, where homologous characteristic curves are used to predict the behavior of the pump during operating transients. The pump model has been incorporated into BRENDA and FFTF; two system cases to simulate Clinch River Breeder Reactor Plant (CRBRP) and the Fast Flux Test Facility (FFTF) respectively. Two simulation test results for BRENDA which is one loop representation of a three loop plant have been presented. They are: (1) Primary pump coastdown to natural circulation coupled with scram failure, and (2) 10 percentmore » deviation of primary speed with plant controllers incorporated.« less

  19. Benchmark Simulation of Natural Circulation Cooling System with Salt Working Fluid Using SAM

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ahmed, K. K.; Scarlat, R. O.; Hu, R.

    Liquid salt-cooled reactors, such as the Fluoride Salt-Cooled High-Temperature Reactor (FHR), offer passive decay heat removal through natural circulation using Direct Reactor Auxiliary Cooling System (DRACS) loops. The behavior of such systems should be well-understood through performance analysis. The advanced system thermal-hydraulics tool System Analysis Module (SAM) from Argonne National Laboratory has been selected for this purpose. The work presented here is part of a larger study in which SAM modeling capabilities are being enhanced for the system analyses of FHR or Molten Salt Reactors (MSR). Liquid salt thermophysical properties have been implemented in SAM, as well as properties ofmore » Dowtherm A, which is used as a simulant fluid for scaled experiments, for future code validation studies. Additional physics modules to represent phenomena specific to salt-cooled reactors, such as freezing of coolant, are being implemented in SAM. This study presents a useful first benchmark for the applicability of SAM to liquid salt-cooled reactors: it provides steady-state and transient comparisons for a salt reactor system. A RELAP5-3D model of the Mark-1 Pebble-Bed FHR (Mk1 PB-FHR), and in particular its DRACS loop for emergency heat removal, provides steady state and transient results for flow rates and temperatures in the system that are used here for code-to-code comparison with SAM. The transient studied is a loss of forced circulation with SCRAM event. To the knowledge of the authors, this is the first application of SAM to FHR or any other molten salt reactors. While building these models in SAM, any gaps in the code’s capability to simulate such systems are identified and addressed immediately, or listed as future improvements to the code.« less

  20. Integrated design of cryogenic refrigerator and liquid-nitrogen circulation loop for HTS cable

    NASA Astrophysics Data System (ADS)

    Chang, Ho-Myung; Ryu, Ki Nam; Yang, Hyung Suk

    2016-12-01

    A new concept of cryogenic cooling system is proposed and investigated for application to long-length HTS cables. One of major obstacles to the cable length of 1 km or longer is the difficulty in circulating liquid nitrogen (LN) along the cables, since the temperature rise and pressure drop of LN flow could be excessively large. This study attempts a breakthrough by integrating the refrigerator with the LN circulation loop in order to eliminate the cryogenic LN pumps, and generate a large LN flow with the power of compressors at ambient temperature. A variety of thermodynamic structures are investigated on standard and modified Claude cycles, where nitrogen is used as refrigerant and the LN circulation loop is included as part of the closed cycle. Four proposed cycles are fully analyzed and optimized with a process simulator (Aspen HYSYS) to evaluate the FOM (figure of merit) and examine the feasibility. The modified dual-pressure cycle cooled with expander stream is recommended for long HTS cables.

  1. Upward and downward heat and mass transfer with miniature periodically operating loop thermosyphons

    NASA Astrophysics Data System (ADS)

    Fantozzi, Fabio; Filippeschi, Sauro; Latrofa, Enrico Maria

    2004-03-01

    Upward and downward two-phase heat and mass transfer has been considered in the present paper. The heat and mass transfer with the condenser located below the evaporator has been obtained by inserting an accumulator tank in the liquid line of a loop thermosyphon and enforcing a pressure pulsation. In previous papers these heat transfer devices have been called pulsated two phase thermosyphons (PTPT). A mini PTPT has been experimentally investigated. It has shown a stable periodic heat transfer regime weakly influenced by the position of the condenser with respect to the evaporator. In contrast a classical loop mini thermosyphon (diameter of connecting pipes 4 mm) did not achieve a stable functioning for the investigated level differences between evaporator and condenser lower than 0.37 m. The present study shows that the functioning of a PTPT device does not directly depend on the level difference or the presence of noncondensable gas. In order to obtain a natural circulation in mini or micro loops, a periodically operating heat transfer regime should therefore be considered.

  2. Chemical Looping Autothermal Reforming at a 120 kW Pilot Rig

    NASA Astrophysics Data System (ADS)

    Bofhàr-Nordenkampf, Johannes; Pröll, Tobias; Kolbitsch, Philipp; Hofbauer, Hermann

    Chemical looping with selective oxygen transport allows two step combustion or autothermal reforming without mixing of fuel and air. The reactor system consists of two reactors, an air reactor and a fuel reactor with a suitable oxygen carrier that transports the necessary oxygen for operation. In the present study, a highly active nickel based oxygen carrier is tested in a novel dual circulating fluidized bed (DCFB) system at a scale of 120 kW fuel power. The mean particle size of the oxygen carrier is 120 μm and the pilot rig is fueled with natural gas. For the investigated oxygen carrier high CH4 conversion is achieved. Air/fuel ratio is varied at three different fuel reactor temperatures. For chemical looping reforming one can observe synthesis gas composition close to thermodynamic equilibrium. In spite of the fact that no additional steam has been added to the fuel besides the one present through steam fluidization of the loop seals, coke formation does not occur at global stoichiometric air/fuel ratios above 0.46.

  3. Evaluation of Heating Methods for Thermal Structural Testing of Large Structures

    NASA Technical Reports Server (NTRS)

    Daryabeigi, Kamran; Sikora, Joseph G.; Caldwell, Darrell L., Jr.

    1998-01-01

    An experimental study was conducted to evaluate different heating methods for thermal structural testing of large scale structures at temperatures up to 350 F as part of the High Speed Research program. The heating techniques evaluated included: radiative/convective, forced convective, and conductive. The radiative/convective heaters included finned strip heaters, and clear and frosted quartz lamps. The forced convective heating was accomplished by closed loop circulation of heated air. The conductive heater consisted of heating blankets. The tests were conducted on an 1/8 inch thick stainless steel plate in a custom-built oven. The criteria used for comparing the different heating methods included test specimen temperature uniformity, heater response time, and consumed power. The parameters investigated included air circulation in the oven, reflectance of oven walls, and the orientation of the test specimen and heaters (vertical and horizontal). It was found that reflectance of oven walls was not an important parameter. Air circulation was necessary to obtain uniform temperatures only for the vertically oriented specimen. Heating blankets provided unacceptably high temperature non-uniformities. Quartz lamps with internal air circulation had the lowest power consumption levels. Using frosted quartz lamps with closed loop circulation of cool air, and closed loop circulation of heated air provided the fastest response time.

  4. Closed Loop Two-Phase Thermosyphon of Small Dimensions: a Review of the Experimental Results

    NASA Astrophysics Data System (ADS)

    Franco, Alessandro; Filippeschi, Sauro

    2012-06-01

    A bibliographical review on the heat and mass transfer in gravity assisted Closed Loop Two Phase Thermosyphons (CLTPT) with channels having a hydraulic diameter of the order of some millimetres and input power below 1 kW is proposed. The available experimental works in the literature are critically analysed in order to highlight the main results and the correlation between mass flow rate and heat input in natural circulation loops. A comparison of different experimental apparatuses and results is made. It is observed that the results are very different among them and in many cases the experimental data disagree with the conventional theory developed for an imposed flow rate. The paper analyses the main differences among the experimental devices and try to understand these disagreements. From the present analysis it is evident that further systematic studies are required to generate a meaningful body of knowledge of the heat and mass transport mechanism in these devices for practical applications in cooling devices or energy systems.

  5. On the Loop Current Penetration into the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Weisberg, Robert H.; Liu, Yonggang

    2017-12-01

    The Gulf of Mexico Loop Current generally intrudes some distance into the Gulf of Mexico before shedding an anticyclonic eddy and retreating back to its more direct entry to exit pathway. The control of this aperiodic process remains only partially known. Here we describe the evolution of the Loop Current throughout the era of satellite altimetry, and offer a mechanistic hypothesis on Loop Current intrusion. As a complement to the known effects of Loop Current forcing on the west Florida shelf circulation, we argue that the west Florida shelf, in turn, impacts the Loop Current evolution. A Self-Organizing Map analysis shows that anomalous northward penetrations of the Loop Current into the Gulf of Mexico occur when the eastern side of Loop Current is positioned west from the southwest corner of the west Florida shelf, whereas the more direct inflow to outflow route occurs when the eastern side of the Loop Current comes in contact with the southwest corner of the west Florida shelf. In essence, we argue that the west Florida shelf anchors the Loop Current in its direct path configuration and that farther northward penetration into the Gulf of Mexico occurs when such anchoring is released. To test of this hypothesis heuristically, we estimate that the dissipation and buoyancy work due to known Loop Current forcing of the west Florida shelf circulation (when in contact with the southwest corner) may exceed the pressure work required for the Loop Current to advance against the ambient Gulf of Mexico fluid.Plain Language SummaryThe Gulf of Mexico Loop Current may intrude far into the Gulf of Mexico or take a more direct entry to exit pathway. Such Loop Current behaviors are described using remote observations by satellites, and a heuristic hypothesis on the control of Loop Current intrusion is presented. We argue that energy dissipation and buoyancy work by the west Florida shelf circulation, when the Loop Current contacts the southwest corner of the west Florida shelf, may exceed the work against the ambient fluid that is required to move the Loop Current farther into the Gulf of Mexico. When this occurs the Loop Current may become anchored to the west Florida shelf.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1980EnUK....5..191W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1980EnUK....5..191W"><span>A central solar domestic hot water system - Performance and economic analysis</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wolf, D.; Tamir, A.; Kudish, A. I.</p> <p>1980-02-01</p> <p>A solar-assisted central hot water system was retrofitted onto one of the student dormitory complexes. The system consisted of twenty commercial solar collectors, of the pipe and plate type, and central hot water tank connected to two dormitory buildings. The system has two loops: (1) a solar loop, in which the heated water circulates between the collector panels and the central hot water tank, and (2) a consumer loop, where the solar-heated water circulates between the central hot water tank and the dormitory. The solar-heated water circulates through the individual electric hot water tanks which serve as individual hot water storage and booster units, and the mains water is introduced at the bottom of the central tank to replace consumed water. The description of the system, the design and its performance, together with an economic analysis, are presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1174854','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1174854"><span>Method and device for measuring single-shot transient signals</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Yin, Yan</p> <p>2004-05-18</p> <p>Methods, apparatus, and systems, including computer program products, implementing and using techniques for measuring multi-channel single-shot transient signals. A signal acquisition unit receives one or more single-shot pulses from a multi-channel source. An optical-fiber recirculating loop reproduces the one or more received single-shot optical pulses to form a first multi-channel pulse train for circulation in the recirculating loop, and a second multi-channel pulse train for display on a display device. The optical-fiber recirculating loop also optically amplifies the first circulating pulse train to compensate for signal losses and performs optical multi-channel noise filtration.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/4055932','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/4055932"><span>LMFBR with booster pump in pumping loop</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Rubinstein, H.J.</p> <p>1975-10-14</p> <p>A loop coolant circulation system is described for a liquid metal fast breeder reactor (LMFBR) utilizing a low head, high specific speed booster pump in the hot leg of the coolant loop with the main pump located in the cold leg of the loop, thereby providing the advantages of operating the main pump in the hot leg with the reliability of cold leg pump operation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT.......361S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT.......361S"><span>Investigation of natural circulation instability and transients in passively safe novel modular reactor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, Shanbin</p> <p></p> <p>The Purdue Novel Modular Reactor (NMR) is a new type small modular reactor (SMR) that belongs to the design of boiling water reactor (BWR). Specifically, the NMR is one third the height and area of a conventional BWR reactor pressure vessel (RPV) with an electric output of 50 MWe. The fuel cycle length of the NMR-50 is extended up to 10 years due to optimized neutronics design. The NMR-50 is designed with double passive engineering safety system. However, natural circulation BWRs (NCBWR) could experience certain operational difficulties due to flow instabilities that occur at low pressure and low power conditions. Static instabilities (i.e. flow excursion (Ledinegg) instability and flow pattern transition instability) and dynamic instabilities (i.e. density wave instability and flashing/condensation instability) pose a significant challenge in two-phase natural circulation systems. In order to experimentally study the natural circulation flow instability, a proper scaling methodology is needed to build a reduced-size test facility. The scaling analysis of the NMR uses a three-level scaling method, which was developed and applied for the design of the Purdue Multi-dimensional Integral Test Assembly (PUMA). Scaling criteria is derived from dimensionless field equations and constitutive equations. The scaling process is validated by the RELAP5 analysis for both steady state and startup transients. A new well-scaled natural circulation test facility is designed and constructed based on the scaling analysis of the NMR-50. The experimental facility is installed with different equipment to measure various thermal-hydraulic parameters such as pressure, temperature, mass flow rate and void fraction. Characterization tests are performed before the startup transient tests and quasi-steady tests to determine the loop flow resistance. The controlling system and data acquisition system are programmed with LabVIEW to realize the real-time control and data storage. The thermal-hydraulic and nuclear coupled startup transients are performed to investigate the flow instabilities at low pressure and low power conditions. Two different power ramps are chosen to study the effect of power density on the flow instability. The experimental startup transient tests show the existence of three different flow instability mechanisms during the low pressure startup transients, i.e., flashing instability, condensation induced instability, and density wave oscillations. Flashing instability in the chimney section of the test loop and density wave oscillation are the main flow instabilities observed when the system pressure is below 0.5 MPa. They show completely different type of oscillations, i.e., intermittent oscillation and sinusoidal oscillation, in void fraction profile during the startup transients. In order to perform nuclear-coupled startup transients with void reactivity feedback, the Point Kinetics model is utilized to calculate the transient power during the startup transients. In addition, the differences between the electric resistance heaters and typical fuel element are taken into account. The reactor power calculated shows some oscillations due to flashing instability during the transients. However, the void reactivity feedback does not have significant influence on the flow instability during the startup procedure for the NMR-50. Further investigation of very small power ramp on the startup transients is carried out for the thermal-hydraulic startup transients. It is found that very small power density can eliminate the flashing oscillation in the single phase natural circulation and stabilize the flow oscillations in the phase of net vapor generation. Furthermore, initially pressurized startup procedure is investigated to eliminate the main flow instabilities. The results show that the pressurized startup procedure can suppress the flashing instability at low pressure and low power conditions. In order to have a deep understanding of natural circulation flow instability, the quasi-steady tests are performed using the test facility installed with preheater and subcooler. The effects of system pressure, core inlet subcooling, core power density, inlet flow resistance coefficient, and void reactivity feedback are investigated in the quasi-steady state tests. The stability boundaries are determined between unstable and stable flow conditions in the dimensionless stability plane of inlet subcooling number and Zuber number. In order to predict the stability boundary theoretically, linear stability analysis in the frequency domain is performed at four sections of the loop. The flashing in the chimney is considered as an axially uniform heat source. The dimensionless characteristic equation of the pressure drop perturbation is obtained by considering the void fraction effect and outlet flow resistance in the chimney section. The flashing boundary shows some discrepancies with previous experimental data from the quasi-steady state tests. In the future, thermal non-equilibrium is recommended to improve the accuracy of flashing instability boundary.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1177634-scaling-analysis-direct-reactor-auxiliary-cooling-system-fhrs','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1177634-scaling-analysis-direct-reactor-auxiliary-cooling-system-fhrs"><span>Scaling analysis for the direct reactor auxiliary cooling system for FHRs</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Lv, Q.; Kim, I. H.; Sun, X.</p> <p>2015-04-01</p> <p>The Direct Reactor Auxiliary Cooling System (DRACS) is a passive residual heat removal system proposed for the Fluoride-salt-cooled High-temperature Reactor (FHR) that combines the coated particle fuel and graphite moderator with a liquid fluoride salt as the coolant. The DRACS features three natural circulation/convection loops that rely on buoyancy as the driving force and are coupled via two heat exchangers, namely, the DRACS heat exchanger and the natural draft heat exchanger. A fluidic diode is employed to minimize the parasitic flow into the DRACS primary loop and correspondingly the heat loss to the DRACS during reactor normal operation, and tomore » activate the DRACS in accidents when the reactor is shut down. While the DRACS concept has been proposed, there are no actual prototypic DRACS systems for FHRs built or tested in the literature. In this paper, a detailed scaling analysis for the DRACS is performed, which will provide guidance for the design of scaled-down DRACS test facilities. Based on the Boussinesq assumption and one-dimensional flow formulation, the governing equations are non-dimensionalized by introducing appropriate dimensionless parameters. The key dimensionless numbers that characterize the DRACS system are obtained from the non-dimensional governing equations. Based on the dimensionless numbers and non-dimensional governing equations, similarity laws are proposed. In addition, a scaling methodology has been developed, which consists of a core scaling and a loop scaling. The consistency between the core and loop scaling is examined via the reference volume ratio, which can be obtained from both the core and loop scaling processes. The scaling methodology and similarity laws have been applied to obtain a scientific design of a scaled-down high-temperature DRACS test facility.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28574110','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28574110"><span>Closed-loop helium circulation system for actuation of a continuously operating heart catheter pump.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Karabegovic, Alen; Hinteregger, Markus; Janeczek, Christoph; Mohl, Werner; Gföhler, Margit</p> <p>2017-06-09</p> <p>Currently available, pneumatic-based medical devices are operated using closed-loop pulsatile or open continuous systems. Medical devices utilizing gases with a low atomic number in a continuous closed loop stream have not been documented to date. This work presents the construction of a portable helium circulation addressing the need for actuating a novel, pneumatically operated catheter pump. The design of its control system puts emphasis on the performance, safety and low running cost of the catheter pump. Static and dynamic characteristics of individual elements in the circulation are analyzed to ensure a proper operation of the system. The pneumatic circulation maximizes the working range of the drive unit inside the catheter pump while reducing the total size and noise production.Separate flow and pressure controllers position the turbine's working point into the stable region of the pressure creation element. A subsystem for rapid gas evacuation significantly decreases the duration of helium removal after a leak, reaching subatmospheric pressure in the intracorporeal catheter within several milliseconds. The system presented in the study offers an easy control of helium mass flow while ensuring stable behavior of its internal components.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890000309&hterms=heat+transfer+evaporation+condenser&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dheat%2Btransfer%2Bevaporation%2Bcondenser','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890000309&hterms=heat+transfer+evaporation+condenser&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dheat%2Btransfer%2Bevaporation%2Bcondenser"><span>Capillary-Condenser-Pumped Heat-Transfer Loop</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Silverstein, Calvin C.</p> <p>1989-01-01</p> <p>Heat being transferred supplies operating power. Capillary-condenser-pumped heat-transfer loop similar to heat pipe and to capillary-evaporator-pumped heat-transfer loop in that heat-transfer fluid pumped by evaporation and condensation of fluid at heat source and sink, respectively. Capillary condenser pump combined with capillary evaporator pump to form heat exchanger circulating heat-transfer fluids in both loops. Transport of heat more nearly isothermal. Thermal stress in loop reduced, and less external surface area needed in condenser section for rejection of heat to heat sink.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150011463','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150011463"><span>Pressure Profiles in a Loop Heat Pipe Under Gravity Influence</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ku, Jentung</p> <p>2015-01-01</p> <p>During the operation of a loop heat pipe (LHP), the viscous flow induces pressure drops in various elements of the loop. The total pressure drop is equal to the sum of pressure drops in vapor grooves, vapor line, condenser, liquid line and primary wick, and is sustained by menisci at liquid and vapor interfaces on the outer surface of the primary wick in the evaporator. The menisci will curve naturally so that the resulting capillary pressure matches the total pressure drop. In ground testing, an additional gravitational pressure head may be present and must be included in the total pressure drop when LHP components are placed in a non-planar configuration. Under gravity-neutral and anti-gravity conditions, the fluid circulation in the LHP is driven solely by the capillary force. With gravity assist, however, the flow circulation can be driven by the combination of capillary and gravitational forces, or by the gravitational force alone. For a gravity-assist LHP at a given elevation between the horizontal condenser and evaporator, there exists a threshold heat load below which the LHP operation is gravity driven and above which the LHP operation is capillary force and gravity co-driven. The gravitational pressure head can have profound effects on the LHP operation, and such effects depend on the elevation, evaporator heat load, and condenser sink temperature. This paper presents a theoretical study on LHP operations under gravity neutral, anti-gravity, and gravity-assist modes using pressure diagrams to help understand the underlying physical processes. Effects of the condenser configuration on the gravitational pressure head and LHP operation are also discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150018317','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150018317"><span>Pressure Profiles in a Loop Heat Pipe under Gravity Influence</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ku, Jentung</p> <p>2015-01-01</p> <p>During the operation of a loop heat pipe (LHP), the viscous flow induces pressure drops in various elements of the loop. The total pressure drop is equal to the sum of pressure drops in vapor grooves, vapor line, condenser, liquid line and primary wick, and is sustained by menisci at liquid and vapor interfaces on the outer surface of the primary wick in the evaporator. The menisci will curve naturally so that the resulting capillary pressure matches the total pressure drop. In ground testing, an additional gravitational pressure head may be present and must be included in the total pressure drop when LHP components are placed in a non-planar configuration. Under gravity-neutral and anti-gravity conditions, the fluid circulation in the LHP is driven solely by the capillary force. With gravity assist, however, the flow circulation can be driven by the combination of capillary and gravitational forces, or by the gravitational force alone. For a gravity-assist LHP at a given elevation between the horizontal condenser and evaporator, there exists a threshold heat load below which the LHP operation is gravity driven and above which the LHP operation is capillary force and gravity co-driven. The gravitational pressure head can have profound effects on the LHP operation, and such effects depend on the elevation, evaporator heat load, and condenser sink temperature. This paper presents a theoretical study on LHP operations under gravity-neutral, anti-gravity, and gravity-assist modes using pressure diagrams to help understand the underlying physical processes. Effects of the condenser configuration on the gravitational pressure head and LHP operation are also discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/477301-simulation-small-cold-leg-break-experiment-pmk-test-facility-using-relap5-athlet-codes','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/477301-simulation-small-cold-leg-break-experiment-pmk-test-facility-using-relap5-athlet-codes"><span>Simulation of a small cold-leg-break experiment at the PMK-2 test facility using the RELAP5 and ATHLET codes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ezsoel, G.; Guba, A.; Perneczky, L.</p> <p></p> <p>Results of a small-break loss-of-coolant accident experiment, conducted on the PMK-2 integral-type test facility are presented. The experiment simulated a 1% break in the cold leg of a VVER-440-type reactor. The main phenomena of the experiment are discussed, and in the case of selected events, a more detailed interpretation with the help of measured void fraction, obtained by a special measurement device, is given. Two thermohydraulic computer codes, RELAP5 and ATHLET, are used for posttest calculations. The aim of these calculations is to investigate the code capability for modeling natural circulation phenomena in VVER-440-type reactors. Therefore, the results of themore » experiment and both calculations are compared. Both codes predict most of the transient events well, with the exception that RELAP5 fails to predict the dryout period in the core. In the experiment, the hot- and cold-leg loop-seal clearing is accompanied by natural circulation instabilities, which can be explained by means of the ATHLET calculation.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1369438','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1369438"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Zou, Ling; Zhao, Haihua; Kim, Seung Jun</p> <p></p> <p>In this study, the classical Welander’s oscillatory natural circulation problem is investigated using high-order numerical methods. As originally studied by Welander, the fluid motion in a differentially heated fluid loop can exhibit stable, weakly instable, and strongly instable modes. A theoretical stability map has also been originally derived from the stability analysis. Numerical results obtained in this paper show very good agreement with Welander’s theoretical derivations. For stable cases, numerical results from both the high-order and low-order numerical methods agree well with the non-dimensional flow rate analytically derived. The high-order numerical methods give much less numerical errors compared to themore » low-order methods. For stability analysis, the high-order numerical methods could perfectly predict the stability map, while the low-order numerical methods failed to do so. For all theoretically unstable cases, the low-order methods predicted them to be stable. The result obtained in this paper is a strong evidence to show the benefits of using high-order numerical methods over the low-order ones, when they are applied to simulate natural circulation phenomenon that has already gain increasing interests in many future nuclear reactor designs.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/7168345-core-cooling-under-accident-conditions-high-flux-beam-reactor','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/7168345-core-cooling-under-accident-conditions-high-flux-beam-reactor"><span>Core cooling under accident conditions at the high-flux beam reactor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Tichler, P.; Cheng, L.; Fauske, H.</p> <p></p> <p>The High-Flux Beam Reactor (HFBR) at Brookhaven National Laboratory (BNL) is cooled and moderated by heavy water and contains {sup 235}U in the form of narrow-channel, parallel-plate-type fuel elements. During normal operation, the flow direction is downward through the core. This flow direction is maintained at a reduced flow rate during routine shutdown and on loss of commercial power by means of redundant pumps and power supplies. However, in certain accident scenarios, e.g. loss-of-coolant accidents (LOCAs), all forced-flow cooling is lost. Although there was experimental evidence during the reactor design period (1958-1963) that the heat removal capacity in the fullymore » developed natural circulation cooling mode was relatively high, it was not possible to make a confident prediction of the heat removal capacity during the transition from downflow to natural circulation. Accordingly, a test program was initiated using an electrically heated section to simulate the fuel channel and a cooling loop to simulate the balance of the primary cooling system.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/865078','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/865078"><span>Direct-contact closed-loop heat exchanger</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Berry, Gregory F.; Minkov, Vladimir; Petrick, Michael</p> <p>1984-01-01</p> <p>A high temperature heat exchanger with a closed loop and a heat transfer liquid within the loop, the closed loop having a first horizontal channel with inlet and outlet means for providing direct contact of a first fluid at a first temperature with the heat transfer liquid, a second horizontal channel with inlet and outlet means for providing direct contact of a second fluid at a second temperature with the heat transfer liquid, and means for circulating the heat transfer liquid.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1346153','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1346153"><span>Investigation of Natural Circulation Instability and Transients in Passively Safe Small Modular Reactors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ishii, Mamoru</p> <p></p> <p>The NEUP funded project, NEUP-3496, aims to experimentally investigate two-phase natural circulation flow instability that could occur in Small Modular Reactors (SMRs), especially for natural circulation SMRs. The objective has been achieved by systematically performing tests to study the general natural circulation instability characteristics and the natural circulation behavior under start-up or design basis accident conditions. Experimental data sets highlighting the effect of void reactivity feedback as well as the effect of power ramp-up rate and system pressure have been used to develop a comprehensive stability map. The safety analysis code, RELAP5, has been used to evaluate experimental results andmore » models. Improvements to the constitutive relations for flashing have been made in order to develop a reliable analysis tool. This research has been focusing on two generic SMR designs, i.e. a small modular Simplified Boiling Water Reactor (SBWR) like design and a small integral Pressurized Water Reactor (PWR) like design. A BWR-type natural circulation test facility was firstly built based on the three-level scaling analysis of the Purdue Novel Modular Reactor (NMR) with an electric output of 50 MWe, namely NMR-50, which represents a BWR-type SMR with a significantly reduced reactor pressure vessel (RPV) height. The experimental facility was installed with various equipment to measure thermalhydraulic parameters such as pressure, temperature, mass flow rate and void fraction. Characterization tests were performed before the startup transient tests and quasi-steady tests to determine the loop flow resistance. The control system and data acquisition system were programmed with LabVIEW to realize the realtime control and data storage. The thermal-hydraulic and nuclear coupled startup transients were performed to investigate the flow instabilities at low pressure and low power conditions for NMR-50. Two different power ramps were chosen to study the effect of startup power density on the flow instability. The experimental startup transient results showed the existence of three different flow instability mechanisms, i.e., flashing instability, condensation induced flow instability, and density wave oscillations. In addition, the void-reactivity feedback did not have significant effects on the flow instability during the startup transients for NMR-50. ii Several initial startup procedures with different power ramp rates were experimentally investigated to eliminate the flow instabilities observed from the startup transients. Particularly, the very slow startup transient and pressurized startup transient tests were performed and compared. It was found that the very slow startup transients by applying very small power density can eliminate the flashing oscillations in the single-phase natural circulation and stabilize the flow oscillations in the phase of net vapor generation. The initially pressurized startup procedure was tested to eliminate the flashing instability during the startup transients as well. The pressurized startup procedure included the initial pressurization, heat-up, and venting process. The startup transient tests showed that the pressurized startup procedure could eliminate the flow instability during the transition from single-phase flow to two-phase flow at low pressure conditions. The experimental results indicated that both startup procedures were applicable to the initial startup of NMR. However, the pressurized startup procedures might be preferred due to short operating hours required. In order to have a deeper understanding of natural circulation flow instability, the quasi-steady tests were performed using the test facility installed with preheater and subcooler. The effect of system pressure, core inlet subcooling, core power density, inlet flow resistance coefficient, and void reactivity feedback were investigated in the quasi-steady state tests. The experimental stability boundaries were determined between unstable and stable flow conditions in the dimensionless stability plane of inlet subcooling number and Zuber number. To predict the stability boundary theoretically, linear stability analysis in the frequency domain was performed at four sections of the natural circulation test loop. The flashing phenomena in the chimney section was considered as an axially uniform heat source. And the dimensionless characteristic equation of the pressure drop perturbation was obtained by considering the void fraction effect and outlet flow resistance in the core section. The theoretical flashing boundary showed some discrepancies with previous experimental data from the quasi-steady state tests. In the future, thermal non-equilibrium was recommended to improve the accuracy of flashing instability boundary. As another part of the funded research, flow instabilities of a PWR-type SMR under low pressure and low power conditions were investigated experimentally as well. The NuScale reactor design was selected as the prototype for the PWR-type SMR. In order to experimentally study the natural circulation behavior of NuScale iii reactor during accidental scenarios, detailed scaling analyses are necessary to ensure that the scaled phenomena could be obtained in a laboratory test facility. The three-level scaling method is used as well to obtain the scaling ratios derived from various non-dimensional numbers. The design of the ideally scaled facility (ISF) was initially accomplished based on these scaling ratios. Then the engineering scaled facility (ESF) was designed and constructed based on the ISF by considering engineering limitations including laboratory space, pipe size, and pipe connections etc. PWR-type SMR experiments were performed in this well-scaled test facility to investigate the potential thermal hydraulic flow instability during the blowdown events, which might occur during the loss of coolant accident (LOCA) and loss of heat sink accident (LOHS) of the prototype PWR-type SMR. Two kinds of experiments, normal blowdown event and cold blowdown event, were experimentally investigated and compared with code predictions. The normal blowdown event was experimentally simulated since an initial condition where the pressure was lower than the designed pressure of the experiment facility, while the code prediction of blowdown started from the normal operation condition. Important thermal hydraulic parameters including reactor pressure vessel (RPV) pressure, containment pressure, local void fraction and temperature, pressure drop and natural circulation flow rate were measured and analyzed during the blowdown event. The pressure and water level transients are similar to the experimental results published by NuScale [51], which proves the capability of current loop in simulating the thermal hydraulic transient of real PWR-type SMR. During the 20000s blowdown experiment, water level in the core was always above the active fuel assemble during the experiment and proved the safety of natural circulation cooling and water recycling design of PWR-type SMR. Besides, pressure, temperature, and water level transient can be accurately predicted by RELAP5 code. However, the oscillations of natural circulation flow rate, water level and pressure drops were observed during the blowdown transients. This kind of flow oscillations are related to the water level and the location upper plenum, which is a path for coolant flow from chimney to steam generator and down comer. In order to investigate the transients start from the opening of ADS valve in both experimental and numerical way, the cold blow-down experiment is conducted. For the cold blowdown event, different from setting both reactor iv pressure vessel (RPV) and containment at high temperature and pressure, only RPV was heated close to the highest designed pressure and then open the ADS valve, same process was predicted using RELAP5 code. By doing cold blowdown experiment, the entire transients from the opening of ADS can be investigated by code and benchmarked with experimental data. Similar flow instability observed in the cold blowdown experiment. The comparison between code prediction and experiment data showed that the RELAP5 code can successfully predict the pressure void fraction and temperature transient during the cold blowdown event with limited error, but numerical instability exists in predicting natural circulation flow rate. Besides, the code is lack of capability in predicting the water level related flow instability observed in experiments.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/5076800','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/5076800"><span>Direct-contact closed-loop heat exchanger</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Berry, G.F.; Minkov, V.; Petrick, M.</p> <p>1981-11-02</p> <p>A high temperature heat exchanger is disclosed which has a closed loop and a heat transfer liquid within the loop, the closed loop having a first horizontal channel with inlet and outlet means for providing direct contact of a first fluid at a first temperature with the heat transfer liquid, a second horizontal channel with inlet and outlet means for providing direct contact of a second fluid at a second temperature with the heat transfer liquid, and means for circulating the heat transfer liquid.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_3 --> <div id="page_4" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="61"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.osti.gov/sciencecinema/biblio/1135672','SCIGOVIMAGE-SCICINEMA'); return false;" href="http://www.osti.gov/sciencecinema/biblio/1135672"><span>NETL - Chemical Looping Reactor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/sciencecinema/">ScienceCinema</a></p> <p>None</p> <p>2018-02-14</p> <p>NETL's Chemical Looping Reactor unit is a high-temperature integrated CLC process with extensive instrumentation to improve computational simulations. A non-reacting test unit is also used to study solids flow at ambient temperature. The CLR unit circulates approximately 1,000 pounds per hour at temperatures around 1,800 degrees Fahrenheit.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018EPJWC.17004022S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018EPJWC.17004022S"><span>Measurements Methods for the analysis of Nuclear Reactors Thermal Hydraulic in Water Scaled Facilities</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Spaccapaniccia, C.; Planquart, P.; Buchlin, J. M. AB(; ), AC(; )</p> <p>2018-01-01</p> <p>The Belgian nuclear research institute (SCK•CEN) is developing MYRRHA. MYRRHA is a flexible fast spectrum research reactor, conceived as an accelerator driven system (ADS). The configuration of the primary loop is pool-type: the primary coolant and all the primary system components (core and heat exchangers) are contained within the reactor vessel, while the secondary fluid is circulating in the heat exchangers. The primary coolant is Lead Bismuth Eutectic (LBE). The recent nuclear accident of Fukushima in 2011 changed the requirements for the design of new reactors, which should include the possibility to remove the residual decay heat through passive primary and secondary systems, i.e. natural convection (NC). After the reactor shut down, in the unlucky event of propeller failures, the primary and secondary loops should be able to remove the decay heat in passive way (Natural Convection). The present study analyses the flow and the temperature distribution in the upper plenum by applying laser imaging techniques in a laboratory scaled water model. A parametric study is proposed to study stratification mitigation strategies by varying the geometry of the buffer tank simulating the upper plenum.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1415784','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1415784"><span>Numerical simulation of a full-loop circulating fluidized bed under different operating conditions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Xu, Yupeng; Musser, Jordan M.; Li, Tingwen</p> <p></p> <p>Both experimental and computational studies of the fluidization of high-density polyethylene (HDPE) particles in a small-scale full-loop circulating fluidized bed are conducted. Experimental measurements of pressure drop are taken at different locations along the bed. The solids circulation rate is measured with an advanced Particle Image Velocimetry (PIV) technique. The bed height of the quasi-static region in the standpipe is also measured. Comparative numerical simulations are performed with a Computational Fluid Dynamics solver utilizing a Discrete Element Method (CFD-DEM). This paper reports a detailed and direct comparison between CFD-DEM results and experimental data for realistic gas-solid fluidization in a full-loopmore » circulating fluidized bed system. The comparison reveals good agreement with respect to system component pressure drop and inventory height in the standpipe. In addition, the effect of different drag laws applied within the CFD simulation is examined and compared with experimental results.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/4352109','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/4352109"><span>Neutron activation analysis system</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Taylor, M.C.; Rhodes, J.R.</p> <p>1973-12-25</p> <p>A neutron activation analysis system for monitoring a generally fluid media, such as slurries, solutions, and fluidized powders, including two separate conduit loops for circulating fluid samples within the range of radiation sources and detectors is described. Associated with the first loop is a neutron source that emits s high flux of slow and thermal neutrons. The second loop employs a fast neutron source, the flux from which is substantially free of thermal neutrons. Adjacent to both loops are gamma counters for spectrographic determination of the fluid constituents. Other gsmma sources and detectors are arranged across a portion of each loop for deterMining the fluid density. (Official Gazette)</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22326114','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22326114"><span>Operating and hydrodynamic characteristics of a reversed flow jet loop bioreactor (RFJLB) with ejector.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wagh, Sameer M; Koranne, Kishore V; Sonolikar, Ram L</p> <p>2012-04-01</p> <p>The hydrodynamic characteristics of RFJLB was studied with superficial liquid velocity (Ul), nozzle diameter (Dn) and nozzle height (Hn) in the range of 0.0293-0.094m/s, 17.4-22.0mm and 50-400mm, respectively. For Dn=17.4mm, Hn=50 and 200mm, with ejector mode and regular operating procedure i.e. simultaneous entry of gas with increasing liquid velocity, had limitation of not establishing the circulation loop. To overcome this limitation a modified operating procedure i.e. entry of gas after established liquid circulation loop is proposed. Also the comparison of gas holdups with ejector and injector mode proves the effectiveness of ejector mode and can eliminate the supply of compressed gas. Thus proper choice of Dn, Hn and also the operating procedure becomes necessary. Copyright © 2012 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005ApPhL..87a4102B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005ApPhL..87a4102B"><span>High-temperature self-circulating thermoacoustic heat exchanger</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Backhaus, S.; Swift, G. W.; Reid, R. S.</p> <p>2005-07-01</p> <p>Thermoacoustic and Stirling engines and refrigerators use heat exchangers to transfer heat between the oscillating flow of their thermodynamic working fluids and external heat sources and sinks. An acoustically driven heat-exchange loop uses an engine's own pressure oscillations to steadily circulate its own thermodynamic working fluid through a physically remote high-temperature heat source without using moving parts, allowing for a significant reduction in the cost and complexity of thermoacoustic and Stirling heat exchangers. The simplicity and flexibility of such heat-exchanger loops will allow thermoacoustic and Stirling machines to access diverse heat sources and sinks. Measurements of the temperatures at the interface between such a heat-exchange loop and the hot end of a thermoacoustic-Stirling engine are presented. When the steady flow is too small to flush out the mixing chamber in one acoustic cycle, the heat transfer to the regenerator is excellent, with important implications for practical use.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/866041','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/866041"><span>Sewage sludge dewatering using flowing liquid metals</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Carlson, Larry W.</p> <p>1986-01-01</p> <p>A method and apparatus for reducing the moisture content of a moist sewage sludge having a moisture content of about 50% to 80% and formed of small cellular micro-organism bodies having internally confined water is provided. A hot liquid metal is circulated in a circulation loop and the moist sewage sludge is injected in the circulation loop under conditions of temperature and pressure such that the confined water vaporizes and ruptures the cellular bodies. The vapor produced, the dried sludge, and the liquid metal are then separated. Preferably, the moist sewage sludge is injected into the hot liquid metal adjacent the upstream side of a venturi which serves to thoroughly mix the hot liquid metal and the moist sewage sludge. The venturi and the drying zone after the venturi are preferably vertically oriented. The dried sewage sludge recovered is available as a fuel and is preferably used for heating the hot liquid metal.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910000344&hterms=heat+pumps&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dheat%2Bpumps','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910000344&hterms=heat+pumps&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dheat%2Bpumps"><span>TEM Pump With External Heat Source And Sink</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nesmith, Bill J.</p> <p>1991-01-01</p> <p>Proposed thermoelectric/electromagnetic (TEM) pump driven by external source of heat and by two or more heat pipe radiator heat sink(s). Thermoelectrics generate electrical current to circulate liquid metal in secondary loop of two-fluid-loop system. Intended for use with space and terrestrial dual loop liquid metal nuclear reactors. Applications include spacecraft on long missions or terrestrial beacons or scientific instruments having to operate in remote areas for long times. Design modified to include multiple radiators, converters, and ducts, as dictated by particular application.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720009074','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720009074"><span>Effect of two types of helium circulators on the performance of a subsonic nuclear powered airplane</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Strack, W. C.</p> <p>1971-01-01</p> <p>Two types of helium circulators are analytically compared on the bases of their influence on airplane payload and on propulsion system variables. One type of circulator is driven by the turbofan engines with power takeoff shafting while the other, a turbocirculator, is powered by a turbine placed in the helium loop between the nuclear reactor and the helium-to-air heat exchangers inside the engines. Typical results show that the turbocirculator yields more payload for circulator efficiencies greater than 0.82. Optimum engine and heat exchanger temperatures and pressures are significantly lower in the turbocirculator case compared to the engine-driven circulator scheme.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DFDG30009B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DFDG30009B"><span>Flow Structure and Force Variation with Aspect Ratio for a Two-Degree-of-Freedom Flapping Wing</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burge, Matthew; Favale, James; Ringuette, Matthew</p> <p>2014-11-01</p> <p>We investigate experimentally the effect of aspect ratio (AR) on the flow structure and forces of a two-degree-of-freedom flapping wing. Flapping wings are known to produce complex and unsteady vortex loop structures, and the objective is to characterize their variation with AR and how this influences the lift force. Previous results on rotating wings demonstrated that changes in AR significantly affect the three-dimensional flow structure and lift coefficient. This is primarily due to the relatively greater influence of the tip vortex for lower AR. At Reynolds number of order O(103) we test wings of AR = 2-4, values typically found in nature, with simplified planform shapes. The lift force is measured using a submersible transducer at the base of the wing in a glycerin-water mixture. The qualitative, three-dimensional vortex loop structure for different ARs is obtained using multi-color dye flow visualization. Guided by this, quantitative three-component flow information, namely vorticity, the Q-criterion, and circulation, is acquired from stereoscopic particle image velocimetry in key planes. Of interest is how these parameters and the vortex loop topology vary with AR, and their connection to features in the unsteady force signal. This work is supported by the National Science Foundation, Award Number 1336548, supervised by Dr. Dimitrios Papavassiliou.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930065834&hterms=Water+turbine&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DWater%2Bturbine','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930065834&hterms=Water+turbine&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DWater%2Bturbine"><span>Water cooling system for an air-breathing hypersonic test vehicle</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Petley, Dennis H.; Dziedzic, William M.</p> <p>1993-01-01</p> <p>This study provides concepts for hypersonic experimental scramjet test vehicles which have low cost and low risk. Cryogenic hydrogen is used as the fuel and coolant. Secondary water cooling systems were designed. Three concepts are shown: an all hydrogen cooling system, a secondary open loop water cooled system, and a secondary closed loop water cooled system. The open loop concept uses high pressure helium (15,000 psi) to drive water through the cooling system while maintaining the pressure in the water tank. The water flows through the turbine side of the turbopump to pump hydrogen fuel. The water is then allowed to vent. In the closed loop concept high pressure, room temperature, compressed liquid water is circulated. In flight water pressure is limited to 6000 psi by venting some of the water. Water is circulated through cooling channels via an ejector which uses high pressure gas to drive a water jet. The cooling systems are presented along with finite difference steady-state and transient analysis results. The results from this study indicate that water used as a secondary coolant can be designed to increase experimental test time, produce minimum venting of fluid and reduce overall development cost.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110023292','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110023292"><span>International Space Station Active Thermal Control Sub-System On-Orbit Pump Performance and Reliability Using Liquid Ammonia as a Coolant</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Morton, Richard D.; Jurick, Matthew; Roman, Ruben; Adamson, Gary; Bui, Chinh T.; Laliberte, Yvon J.</p> <p>2011-01-01</p> <p>The International Space Station (ISS) contains two Active Thermal Control Sub-systems (ATCS) that function by using a liquid ammonia cooling system collecting waste heat and rejecting it using radiators. These subsystems consist of a number of heat exchangers, cold plates, radiators, the Pump and Flow Control Subassembly (PFCS), and the Pump Module (PM), all of which are Orbital Replaceable Units (ORU's). The PFCS provides the motive force to circulate the ammonia coolant in the Photovoltaic Thermal Control Subsystem (PVTCS) and has been in operation since December, 2000. The Pump Module (PM) circulates liquid ammonia coolant within the External Active Thermal Control Subsystem (EATCS) cooling the ISS internal coolant (water) loops collecting waste heat and rejecting it through the ISS radiators. These PM loops have been in operation since December, 2006. This paper will discuss the original reliability analysis approach of the PFCS and Pump Module, comparing them against the current operational performance data for the ISS External Thermal Control Loops.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1174426','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1174426"><span>High average power laser using a transverse flowing liquid host</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ault, Earl R.; Comaskey, Brian J.; Kuklo, Thomas C.</p> <p>2003-07-29</p> <p>A laser includes an optical cavity. A diode laser pumping device is located within the optical cavity. An aprotic lasing liquid containing neodymium rare earth ions fills the optical cavity. A circulation system that provides a closed loop for circulating the aprotic lasing liquid into and out of the optical cavity includes a pump and a heat exchanger.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/4092928','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/4092928"><span>IN-PILE CORROSION TEST LOOPS FOR AQUEOUS HOMOGENEOUS REACTOR SOLUTIONS</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Savage, H.C.; Jenks, G.H.; Bohlmann, E.G.</p> <p>1960-12-21</p> <p>An in-pile corrosion test loop is described which is used to study the effect of reactor radiation on the corrosion of materials of construction and the chemical stability of fuel solutions of interest to the Aqueous Homogeneous Reactor Program at ORNL. Aqueous solutions of uranyl sulfate are circulated in the loop by means of a 5-gpm canned-rotor pump, and the pump loop is designed for operation at temperatures to 300 ts C and pressures to 2000 psia while exposed to reactor radiation in beam-hole facilities of the LITR and ORR. Operation of the first loop in-pile was begun in Octobermore » 1954, and since that time 17 other in-pile loop experiments were completed. Design criteria of the pump loop and its associated auxiliary equipment and instrumentation are described. In-pile operating procedures, safety features, and operating experience are presented. A cost summary of the design, fabrication, and installation of the loop and experimental facillties is also included. (auth)« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120016470','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120016470"><span>Efforts to Reduce International Space Station Crew Maintenance Time in the Management of the Extravehicular Mobility Unit Transport Loop Water Quality</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Etter,David; Rector, Tony; Boyle, robert; Zande, Chris Vande</p> <p>2012-01-01</p> <p>The EMU (Extravehicular Mobility Unit) contains a semi-closed-loop re-circulating water circuit (Transport Loop) to absorb heat into a LCVG (Liquid Coolant and Ventilation Garment) worn by the astronaut. A second, single-pass water circuit (Feed-water Loop) provides water to a cooling device (Sublimator) containing porous plates, and that water sublimates through the porous plates to space vacuum. The cooling effect from the sublimation of this water translates to a cooling of the LCVG water that circulates through the Sublimator. The quality of the EMU Transport Loop water is maintained through the use of a water processing kit (ALCLR - Airlock Cooling Loop Remediation) that is used to periodically clean and disinfect the water circuit. Opportunities to reduce crew time associated with ALCLR operations include a detailed review of the historical water quality data for evidence to support an extension to the implementation cycle. Furthermore, an EMU returned after 2-years of use on the ISS (International Space Station) is being used as a test bed to evaluate the results of extended and repeated ALCLR implementation cycles. Finally, design, use and on-orbit location enhancements to the ALCLR kit components are being considered to allow the implementation cycle to occur in parallel with other EMU maintenance and check-out activities, and to extend the life of the ALCLR kit components. These efforts are undertaken to reduce the crew-time and logistics burdens for the EMU, while ensuring the long-term health of the EMU water circuits for a post- Shuttle 6-year service life.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130011190','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130011190"><span>Efforts to Reduce International Space Station Crew Maintenance for the Management of the Extravehicular Mobility Unit Transport Loop Water Quality</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Steele, John W.; Etter, David; Rector, Tony; Boyle, Robert; Vandezande, Christopher</p> <p>2013-01-01</p> <p>The EMU (Extravehicular Mobility Unit) contains a semi-closed-loop re-circulating water circuit (Transport Loop) to absorb heat into a LCVG (Liquid Coolant and Ventilation Garment) worn by the astronaut. A second, single-pass water circuit (Feed-water Loop) provides water to a cooling device (Sublimator) containing porous plates, and that water sublimates through the porous plates to space vacuum. The cooling effect from the sublimation of this water translates to a cooling of the LCVG water that circulates through the Sublimator. The quality of the EMU Transport Loop water is maintained through the use of a water processing kit (ALCLR Airlock Cooling Loop Remediation) that is used to periodically clean and disinfect the water circuit. Opportunities to reduce crew time associated with on-orbit ALCLR operations include a detailed review of the historical water quality data for evidence to support an extension to the implementation cycle. Furthermore, an EMU returned after 2-years of use on the ISS (International Space Station) is being used as a test bed to evaluate the results of extended and repeated ALCLR implementation cycles. Finally, design, use and on-orbit location enhancements to the ALCLR kit components are being considered to allow the implementation cycle to occur in parallel with other EMU maintenance and check-out activities, and to extend the life of the ALCLR kit components. These efforts are undertaken to reduce the crew-time and logistics burdens for the EMU, while ensuring the long-term health of the EMU water circuits for a post-Shuttle 6-year service life.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1011446','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1011446"><span>In situ heat treatment process utilizing a closed loop heating system</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Vinegar, Harold J.; Nguyen, Scott Vinh</p> <p>2010-12-07</p> <p>Systems and methods for an in situ heat treatment process that utilizes a circulation system to heat one or more treatment areas are described herein. The circulation system may use a heated liquid heat transfer fluid that passes through piping in the formation to transfer heat to the formation. In some embodiments, the piping may be positioned in at least two of the wellbores.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26ES..108e2038X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26ES..108e2038X"><span>Research on Parallel Three Phase PWM Converters base on RTDS</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xia, Yan; Zou, Jianxiao; Li, Kai; Liu, Jingbo; Tian, Jun</p> <p>2018-01-01</p> <p>Converters parallel operation can increase capacity of the system, but it may lead to potential zero-sequence circulating current, so the control of circulating current was an important goal in the design of parallel inverters. In this paper, the Real Time Digital Simulator (RTDS) is used to model the converters parallel system in real time and study the circulating current restraining. The equivalent model of two parallel converters and zero-sequence circulating current(ZSCC) were established and analyzed, then a strategy using variable zero vector control was proposed to suppress the circulating current. For two parallel modular converters, hardware-in-the-loop(HIL) study based on RTDS and practical experiment were implemented, results prove that the proposed control strategy is feasible and effective.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920000115&hterms=heat+pumps&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dheat%2Bpumps','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920000115&hterms=heat+pumps&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dheat%2Bpumps"><span>Regenerative Hydride Heat Pump</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jones, Jack A.</p> <p>1992-01-01</p> <p>Hydride heat pump features regenerative heating and single circulation loop. Counterflow heat exchangers accommodate different temperatures of FeTi and LaNi4.7Al0.3 subloops. Heating scheme increases efficiency.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ThEng..61..465R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ThEng..61..465R"><span>A study of natural circulation in the evaporator of a horizontal-tube heat recovery steam generator</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roslyakov, P. V.; Pleshanov, K. A.; Sterkhov, K. V.</p> <p>2014-07-01</p> <p>Results obtained from investigations of stable natural circulation in an intricate circulation circuit with a horizontal layout of the tubes of evaporating surface having a negative useful head are presented. The possibility of making a shift from using multiple forced circulation organized by means of a circulation pump to natural circulation in vertical heat recovery steam generator is estimated. Criteria for characterizing the performance reliability and efficiency of a horizontal evaporator with negative useful head are proposed. The influence of various design solutions on circulation robustness is considered. With due regard of the optimal parameters, the most efficient and least costly methods are proposed for achieving more stable circulation in a vertical heat recovery steam generator when a shift is made from multiple forced to natural circulation. A procedure for calculating the circulation parameters and an algorithm for checking evaporator performance reliability are developed, and recommendations for the design of heat recovery steam generator, nonheated parts of natural circulation circuit, and evaporating surface are suggested.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_4 --> <div id="page_5" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="81"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950016956','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950016956"><span>Quick connect coupling</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lomax, Curtis (Inventor); Webbon, Bruce (Inventor)</p> <p>1995-01-01</p> <p>A cooling apparatus includes a container filled with a quantity of coolant fluid initially cooled to a solid phase, a cooling loop disposed between a heat load and the container, a pump for circulating a quantity of the same type of coolant fluid in a liquid phase through the cooling loop, and a pair of couplings for communicating the liquid phase coolant fluid into the container in a direct interface with the solid phase coolant fluid.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880014574','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880014574"><span>Pumped two-phase heat transfer loop</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Edelstein, Fred</p> <p>1988-01-01</p> <p>A pumped loop two-phase heat transfer system, operating at a nearly constant temperature throughout, includes several independently operating grooved capillary heat exchanger plates supplied with working fluid through independent flow modulation valves connected to a liquid supply line, a vapor line for collecting vapor from the heat exchangers, a condenser between the vapor and the liquid lines, and a fluid circulating pump between the condenser and the heat exchangers.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870013517','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870013517"><span>Pumped two-phase heat transfer loop</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Edelstein, Fred (Inventor)</p> <p>1987-01-01</p> <p>A pumped loop two-phase heat transfer system, operating at a nearly constant temperature throughout, includes a plurality of independently operating grooved capillary heat exchanger plates supplied with working fluid through independent flow modulation valves connected to a liquid supply line, a vapor line for collecting vapor from the heat exchangers, a condenser between the vapor and the liquid lines, and a fluid circulating pump between the condenser and the heat exchangers.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760011170','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760011170"><span>T-111 Rankine system corrosion test loop, volume 1</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Harrison, R. W.; Hoffman, E. E.; Smith, J. P.</p> <p>1975-01-01</p> <p>Results are given of a program whose objective was to determine the performance of refractory metal alloys in a two loop Rankine test system. The test system consisted of a circulating lithium circuit heated to 1230 C maximum transferring heat to a boiling potassium circuit with a 1170 C superheated vapor temperature. The results demonstrate the suitability of the selected refractory alloys to perform from a chemical compatibility standpoint.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MS%26E..278a2108Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MS%26E..278a2108Y"><span>Commissioning of cryogenic system for China Spallation Neutron Source</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ye, Bin; He, Chongchao; Li, Na; Ding, Meiying; Wang, Yaqiong; Yu, Zhang; He, Kun</p> <p>2017-12-01</p> <p>China Spallation Neutron Source(CSNS) cryogenic system provides supercritical cryogenic hydrogen to neutron moderators, including a helium refrigerator, hydrogen loop and hydrogen safety equipment. The helium refrigerator is provided by Linde with cooling capacity of 2200 W at 20 K. Hydrogen loop system mainly includes cryogenic hydrogen pipes, hydrogen circulator cold-box and accumulator cold-box. Cryogenic hydrogen pump, ortho-para convertor, helium-hydrogen heat-exchanger, hydrogen heater and accumulator are integrated in hydrogen circulation cold-box, and accumulator cold-box. Hydrogen safety equipment includes safety valves, rupture disk, hydrogen sensor, flame detector and other equipment to ensure that cryogenic system in dangerous situations will go down, vents, or takes other measures. The cryogenic system commissioning work includes four steps. First, in order to test the refrigerating capacity of refrigerator, when acceptance testing, refrigerator internal heater was used as thermal load. Second, using simulation load as heat load of moderator, hydrogen loop use helium instead of hydrogen, and cooled down to 20 K, then re-warming and test the leak detection of hydrogen loop system. Third, base on the step 2, using hydrogen as working medium, and optimized the control logic. Forth, cryogenic system with the moderators joint commissioning. Now, cryogenic system is connected with the moderators, and the forth step will be carried out in the near future.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NewA...61...30B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NewA...61...30B"><span>On the nature of fast sausage waves in coronal loops</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bahari, Karam</p> <p>2018-05-01</p> <p>The effect of the parameters of coronal loops on the nature of fast sausage waves are investigated. To do this three models of the coronal loop considered, a simple loop model, a current-carrying loop model and a model with radially structured density called "Inner μ" profile. For all the models the Magnetohydrodynamic (MHD) equations solved analytically in the linear approximation and the restoring forces of oscillations obtained. The ratio of the magnetic tension force to the pressure gradient force obtained as a function of the distance from the axis of the loop. In the simple loop model for all values of the loop parameters the fast sausages wave have a mixed nature of Alfvénic and fast MHD waves, in the current-carrying loop model with thick annulus and low density contrast the fast sausage waves can be considered as purely Alfvénic wave in the core region of the loop, and in the "Inner μ" profile for each set of the parameters of the loop the wave can be considered as a purely Alfvénic wave in some regions of the loop.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110023272','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110023272"><span>Management of the Post-Shuttle Extravehicular Mobility Unit (EMU) Water Circuits</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Steele, John W.; Etter, David; Rector, Tony; Hill, Terry; Wells, Kevin</p> <p>2011-01-01</p> <p>The EMU incorporates two separate water circuits for the rejection of metabolic heat from the astronaut and the cooling of electrical components. The first (the Transport Water Loop) circulates in a semi-closed-loop manner and absorbs heat into a Liquid Coolant and Ventilation Garment (LCVG) warn by the astronaut. The second (the Feed Water Loop) provides water to a cooling device (Sublimator) with a porous plate, and that water subsequently sublimates to space vacuum. The cooling effect from the sublimation of this water translates to a cooling of the LCVG water that circulates through the Sublimator. Efforts are underway to streamline the use of a water processing kit (ALCLR) that is being used to periodically clean and disinfect the Transport Loop Water. Those efforts include a fine tuning of the duty cycle based on a review of prior performance data as well as an assessment of a fixed installation of this kit into the EMU backpack or within on-orbit EMU interface hardware. Furthermore, testing is being conducted to ensure compatibility between the International Space Station (ISS) Water Processor Assembly (WPA) effluent and the EMU Sublimator as a prelude to using the WPA effluent as influent to the EMU Feed Water loop. This work is undertaken to reduce the crew-time and logistics burdens for the EMU, while ensuring the long-term health of the EMU water circuits for a post-Shuttle 6-year service life.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120003778','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120003778"><span>Management of the Post-Shuttle Extravehicular Mobility Unit (EMU) Water Circuits</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Steele, John W.; Etter, David; Rector, Tony; Hill, Terry; Wells, Kevin</p> <p>2012-01-01</p> <p>The EMU incorporates two separate water circuits for the rejection of metabolic heat from the astronaut and the cooling of electrical components. The first (the Transport Water Loop) circulates in a semi-closed-loop manner and absorbs heat into a Liquid Coolant and Ventilation Garment (LCVG) worn by the astronaut. The second (the Feed-water Loop) provides water to a cooling device (Sublimator) with a porous plate, and that water subsequently sublimates to space vacuum. The cooling effect from the sublimation of this water translates to a cooling of the LCVG water that circulates through the Sublimator. Efforts are underway to streamline the use of a water processing kit (ALCLR) that is being used to periodically clean and disinfect the Transport Loop Water. Those efforts include a fine tuning of the duty cycle based on a review of prior performance data as well as an assessment of a fixed installation of this kit into the EMU backpack, within on-orbit EMU interface hardware or as a stand-alone unit. Furthermore, testing is being conducted to ensure compatibility between the International Space Station (ISS) Water Processor Assembly (WPA) effluent and the EMU Sublimator as a prelude to using the WPA effluent as influent to the EMU Feed Water loop. This work is undertaken to reduce the crewtime and logistics burdens for the EMU, while ensuring the long-term health of the EMU water circuits for a 6-year service life.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3303483','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3303483"><span>Replication enhancer elements within the open reading frame of tick-borne encephalitis virus and their evolution within the Flavivirus genus</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tuplin, A.; Evans, D. J.; Buckley, A.; Jones, I. M.; Gould, E. A.; Gritsun, T. S.</p> <p>2011-01-01</p> <p>We provide experimental evidence of a replication enhancer element (REE) within the capsid gene of tick-borne encephalitis virus (TBEV, genus Flavivirus). Thermodynamic and phylogenetic analyses predicted that the REE folds as a long stable stem–loop (designated SL6), conserved among all tick-borne flaviviruses (TBFV). Homologous sequences and potential base pairing were found in the corresponding regions of mosquito-borne flaviviruses, but not in more genetically distant flaviviruses. To investigate the role of SL6, nucleotide substitutions were introduced which changed a conserved hexanucleotide motif, the conformation of the terminal loop and the base-paired dsRNA stacking. Substitutions were made within a TBEV reverse genetic system and recovered mutants were compared for plaque morphology, single-step replication kinetics and cytopathic effect. The greatest phenotypic changes were observed in mutants with a destabilized stem. Point mutations in the conserved hexanucleotide motif of the terminal loop caused moderate virus attenuation. However, all mutants eventually reached the titre of wild-type virus late post-infection. Thus, although not essential for growth in tissue culture, the SL6 REE acts to up-regulate virus replication. We hypothesize that this modulatory role may be important for TBEV survival in nature, where the virus circulates by non-viraemic transmission between infected and non-infected ticks, during co-feeding on local rodents. PMID:21622960</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Metro..54.7003W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Metro..54.7003W"><span>Final report on the key comparison, CCM.P-K15 in the pressure range from 1.0 × 10-4 Pa to 1.0 Pa</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wuethrich, Christian; Arai, Kenta; Bergoglio, Mercede; Fedchak, James A.; Jousten, Karl; Hong, Seung Soo; Torres Guzman, Jorge</p> <p>2017-01-01</p> <p>The comparison CCM.P-K15 is a key comparison in pressure involving six laboratories in three regional metrological organizations (RMO). The measurand of the comparison is the accommodation coefficient of two spinning rotating gauge characterized in nitrogen from 0.1 mPa up to 1.0 Pa. The two transfer standards were circulated from November 2009 until March 2011. The circulation consisted of three loops, one for each RMO, and a new calibration by the pilot be-tween each loop. The stability of one of the transfer standards was poor and was worse than expected based on the previous history of the transfer standard while the other transfer standard demonstrated good stability while circulated in Europe and America and a fair stability while circulated in Asia. All the participants demonstrated equivalence to the definition of pressure in their respective primary standards. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017HMT....53.2287F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017HMT....53.2287F"><span>Transient performance and temperature field of a natural convection air dehumidifier loop</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fazilati, Mohammad Ali; Sedaghat, Ahmad; Alemrajabi, Ali-Akbar</p> <p>2017-07-01</p> <p>In this paper, transient performance of the previously introduced natural convection heat and mass transfer loop is investigated for an air dehumidifier system. The performance of the loop is studied in different conditions of heat source/heat sink temperature and different startup desiccant concentrations. Unlike conventional loops, it is observed that natural convection of the fluid originates from the heat sink towards the heat source. The proper operation of the cycle is highly dependent on the heat sink/heat source temperatures. To reduce the time constant of the system, a proper desiccant concentration should be adopted for charge of the loop.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/6219697','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/6219697"><span>Solar-powered turbocompressor heat pump system</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Landerman, A.M.; Biancardi, F.R.; Melikian, G.; Meader, M.D.; Kepler, C.E.; Anderson, T.J.; Sitler, J.W.</p> <p>1982-08-12</p> <p>The turbocompressor comprises a power turbine and a compressor turbine having respective rotors and on a common shaft, rotatably supported by bearings. A first working fluid is supplied by a power loop and is expanded in the turbine. A second working fluid is compressed in the turbine and is circulated in a heat pump loop. A lubricant is mixed with the second working fluid but is excluded from the first working fluid. The bearings are cooled and lubricated by a system which circulates the second working fluid and the intermixed lubricant through the bearings. Such system includes a pump, a thermostatic expansion valve for expanding the working fluid into the space between the bearings, and a return conduit system for withdrawing the expanded working fluid after it passes through the bearings and for returning the working fluid to the evaporator. A shaft seal excludes the lubricant from the power turbine. The power loop includes a float operable by liquid working fluid in the condenser for controlling a recirculation valve so as to maintain a minimum liquid level in the condenser, while causing a feed pump to pump most of the working fluid into the vapor generator. The heat pump compressor loop includes a float in the condenser for operating and expansion valve to maintain a minimum liquid working fluid level in the condenser while causing most of the working fluid to be expanded into the evaporator.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1918375V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1918375V"><span>Contribution of seawater recirculation to submarine groundwater discharge and related nutrient fluxes in two tropical bays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vautier, Camille; Dulaiova, Henrietta</p> <p>2017-04-01</p> <p>Hawaiian coastal waters suffer from excess terrestrial nutrient loading, most of which comes from submarine groundwater discharge (SGD). This study quantifies and distinguishes the role of the fresh terrestrial and tidally pumped salt water components of SGD into the nearshore zone of two reefs on the island of Oahu: Maunalua Bay and Kāneohe Bay. The two components of SGD are characterized using isotopic techniques, and the study mainly focuses on the less understood recirculation component. A two-step approach is implemented: first, a conceptual model of groundwater circulation is established; second, nutrient fluxes associated with seawater recirculation are quantified. Groundwater circulation through the beach berm is quantified and characterized using 222Rn and 224Ra activity measurements. Nutrient fluxes are obtained by coupling nutrient concentration measurements and discharge estimates. The isotopic signatures inform us about the influence of the tidal cycle on groundwater circulation. 222Rn, 224Ra, and δ18O isotopes are used to derive apparent ages of the infiltrated seawater and allow us to quantify recirculation rates. The method is also complemented with the use of silicate concentration as tracers of the recirculation process. The trends in apparent ages observed in pore water in Maunalua match previously published conceptual groundwater circulation models and show a sequentially aging pore water circulation loop. However, the ages obtained in Kāneohe suggest a different tidal pumping dynamic that lacks a circulation loop, perhaps resulting from the absence of freshwater discharge. Derived nutrient fluxes show that the autochthonous production of inorganic nitrogen and phosphorus that occurs during seawater recirculation has a significant impact on nutrient cycles in the nearshore areas of the bays. This result suggests that seawater recirculation should be taken into account in biogeochemical studies of coastal areas.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22105916-experimental-code-simulation-station-blackout-scenario-apr1400-test-facility-atlas-mars-code','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22105916-experimental-code-simulation-station-blackout-scenario-apr1400-test-facility-atlas-mars-code"><span>Experimental and code simulation of a station blackout scenario for APR1400 with test facility ATLAS and MARS code</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Yu, X. G.; Kim, Y. S.; Choi, K. Y.</p> <p>2012-07-01</p> <p>A SBO (station blackout) experiment named SBO-01 was performed at full-pressure IET (Integral Effect Test) facility ATLAS (Advanced Test Loop for Accident Simulation) which is scaled down from the APR1400 (Advanced Power Reactor 1400 MWe). In this study, the transient of SBO-01 is discussed and is subdivided into three phases: the SG fluid loss phase, the RCS fluid loss phase, and the core coolant depletion and core heatup phase. In addition, the typical phenomena in SBO-01 test - SG dryout, natural circulation, core coolant boiling, the PRZ full, core heat-up - are identified. Furthermore, the SBO-01 test is reproduced bymore » the MARS code calculation with the ATLAS model which represents the ATLAS test facility. The experimental and calculated transients are then compared and discussed. The comparison reveals there was malfunction of equipments: the SG leakage through SG MSSV and the measurement error of loop flow meter. As the ATLAS model is validated against the experimental results, it can be further employed to investigate the other possible SBO scenarios and to study the scaling distortions in the ATLAS. (authors)« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4884557','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4884557"><span>On a sparse pressure-flow rate condensation of rigid circulation models</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Schiavazzi, D. E.; Hsia, T. Y.; Marsden, A. L.</p> <p>2015-01-01</p> <p>Cardiovascular simulation has shown potential value in clinical decision-making, providing a framework to assess changes in hemodynamics produced by physiological and surgical alterations. State-of-the-art predictions are provided by deterministic multiscale numerical approaches coupling 3D finite element Navier Stokes simulations to lumped parameter circulation models governed by ODEs. Development of next-generation stochastic multiscale models whose parameters can be learned from available clinical data under uncertainty constitutes a research challenge made more difficult by the high computational cost typically associated with the solution of these models. We present a methodology for constructing reduced representations that condense the behavior of 3D anatomical models using outlet pressure-flow polynomial surrogates, based on multiscale model solutions spanning several heart cycles. Relevance vector machine regression is compared with maximum likelihood estimation, showing that sparse pressure/flow rate approximations offer superior performance in producing working surrogate models to be included in lumped circulation networks. Sensitivities of outlets flow rates are also quantified through a Sobol’ decomposition of their total variance encoded in the orthogonal polynomial expansion. Finally, we show that augmented lumped parameter models including the proposed surrogates accurately reproduce the response of multiscale models they were derived from. In particular, results are presented for models of the coronary circulation with closed loop boundary conditions and the abdominal aorta with open loop boundary conditions. PMID:26671219</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA237577','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA237577"><span>Mesoscale Characteristics and the Role of Deformation on Ocean Dynamics</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1991-06-05</p> <p>34 Thilus, 41 (A), 416-435, 1989. 3. "Ring Evolution in General Circulation Models from Path Analysis ," J. Geo- phys. Res., 95(C10), 18057-18073, 1990...Loop Curren: (up to three in I year [Elliot,. by Vaukovih and Crt, ,tman (19861. Analysis of drifter data 19821). Lewi.a and Kirwan (1983. 19871...seventh drifter. the Lagrangian data sets along with an analysis and anterpre- number 3354. was entrained in the Loop Current at the tim. tation of</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1350960','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1350960"><span>Operation of the NETL Chemical Looping Reactor with Natural Gas and a Novel Copper-Iron Material</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Straub, Douglas; Bayham, Samuel; Weber, Justin</p> <p></p> <p>The proposed Clean Power Plan requires CO 2 emission reductions of 30% by 2030 and further reductions are targeted by 2050. The current strategies to achieve the 30% reduction targets do not include options for coal. However, the 2016 Annual Energy Outlook suggests that coal will continue to provide more electricity than renewable sources for many regions of the country in 2035. Therefore, cost effective options to reduce greenhouse gas emissions from fossil fuel power plants are vital in order to achieve greenhouse gas reduction targets beyond 2030. As part of the U.S. Department of Energy’s Advanced Combustion Program, themore » National Energy Technology Laboratory’s Research and Innovation Center (NETL R&IC) is investigating the feasibility of a novel combustion concept in which the GHG emissions can be significantly reduced. This concept involves burning fuel and air without mixing these two reactants. If this concept is technically feasible, then CO 2 emissions can be significantly reduced at a much lower cost than more conventional approaches. This indirect combustion concept has been called Chemical Looping Combustion (CLC) because an intermediate material (i.e., a metal-oxide) is continuously cycled to oxidize the fuel. This CLC concept is the focus of this research and will be described in more detail in the following sections. The solid material that is used to transport oxygen is called an oxygen carrier material. The cost, durability, and performance of this material is a key issue for the CLC technology. Researchers at the NETL R&IC have developed an oxygen carrier material that consists of copper, iron, and alumina. This material has been tested extensively using lab scale instruments such as thermogravimetric analysis (TGA), scanning electron microscopy (SEM), mechanical attrition (ASTM D5757), and small fluidized bed reactor tests. This report will describe the results from a realistic, circulating, proof-of-concept test that was completed using NETL’s 50kW th circulating Chemical Looping Reactor (CLR) test facility.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930060208&hterms=1047&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2526%25231047','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930060208&hterms=1047&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2526%25231047"><span>Fabricating niobium test loops for the SP-100 space reactor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bryhan, Anthony J.; Chan, Ricky C.</p> <p>1993-01-01</p> <p>This article describes the successful fabrication, operation, and evaluation of a series of niobium-alloy (Nb-1 Zr and PWC-11) thermal convection loops designed to contain and circulate molten lithium at 1,350 K. These loops were used to establish the fabrication variables of significance for a nuclear power supply for space. Approximately 200 weldments were evaluated for their tendency to be attacked by lithium as a function of varying atmospheric contamination. No attack occurred for any weldment free of contamination, with or without heat treatment, and no welds accidentally deviated from purity. The threshold oxygen content for weldment attack was determined to be 170-200 ppm. Attack varied directly with weldment oxygen and nitrogen contents.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/6828357-physical-oceanography-us-atlantic-eastern-gulf-mexico-final-report','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6828357-physical-oceanography-us-atlantic-eastern-gulf-mexico-final-report"><span>Physical oceanography of the US Atlantic and eastern Gulf of Mexico. Final report</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Milliman, J.D.; Imamura, E.</p> <p></p> <p>The report provides a summary of the physical oceanography of the U.S. Atlantic and Eastern Gulf of Mexico and its implication to offshore oil and gas exploration and development. Topics covered in the report include: meteorology and air-sea interactions, circulation on the continental shelf, continental slope and rise circulation, Gulf Stream, Loop Current, deep-western boundary current, surface gravity-wave climatology, offshore engineering implications, implications for resource commercialization, and numerical models of pollutant dispersion.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22263926-experimental-validation-advanced-regulations-superconducting-magnet-cooling-undergoing-periodic-heat-loads','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22263926-experimental-validation-advanced-regulations-superconducting-magnet-cooling-undergoing-periodic-heat-loads"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Lagier, B.; Rousset, B.; Hoa, C.</p> <p></p> <p>Superconducting magnets used in tokamaks undergo periodic heat load caused by cycling plasma operations inducing AC losses, neutrons fluxes and eddy currents in magnet structures. In the cryogenic system of JT60-SA tokamak, the Auxiliary Cold Box (ACB) distributes helium from the refrigerator to the cryogenic users and in particular to the superconducting magnets. ACB comprises a saturated helium bath with immersed heat exchangers, extracting heat from independent cooling loops. The supercritical helium flow in each cooling loop is driven by a cold circulator. In order to safely operate the refrigerator during plasma pulses, the interface between the ACB and themore » refrigerator shall be as stable as possible, with well-balanced bath inlet and outlet mass flows during cycling operation. The solution presented in this paper relies on a combination of regulations to smooth pulsed heat loads and to keep a constant refrigeration power during all the cycle. Two smoothing strategies are presented, both regulating the outlet mass flow of the bath: the first one using the bath as a thermal buffer and the second one storing energy in the loop by varying the cold circulator speed. The bath outlet mass flow is also controlled by an immersed resistive heater which enables a constant evaporation rate in the bath when power coming from the loops is decreasing. The refrigeration power is controlled so that the compensating power remains within an acceptable margin. Experimental validation is achieved using the HELIOS facility. This facility running at CEA Grenoble since 2010 is a scaled down model of the ACB bath and Central Solenoid magnet cooling loop of the JT60-SA tokamak. Test results show performances and robustness of the regulations.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/29032','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/29032"><span>A feasibility study of bridge deck deicing using geothermal energy.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntlsearch.bts.gov/tris/index.do">DOT National Transportation Integrated Search</a></p> <p></p> <p>2015-04-01</p> <p>In this study, we investigated the feasibility of a ground-coupled system that utilizes heat energy harvested from the ground for : deicing of bridge decks. Heat exchange is performed using circulation loops integrated into the deep foundations suppo...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20854195','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20854195"><span>Short communication: evidence of HIV type 1 clade C env clones containing low V3 loop charge obtained from an AIDS patient in India that uses CXCR6 and CCR8 for entry in addition to CCR5.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gharu, Lavina; Ringe, Rajesh; Satyakumar, Anupindi; Patil, Ajit; Bhattacharya, Jayanta</p> <p>2011-02-01</p> <p>Abstract HIV-1 clade C is the major subtype circulating in India and preferentially uses CCR5 during the entire disease course. We have recently shown that env clones from an Indian patient; NARI-VB105 uses multiple coreceptors for entry and was presented with an unusual V3 loop sequence giving rise to high net V3 loop positive charges. Here we show that env clones belonging to subtype C obtained from an AIDS patient, NARI-VB52, use CXCR6 and CCR8 in addition to CCR5 for entry. However, unlike the NARI-105 patient, the env clones contained a low V3 loop net charge of +3 with a conserved GPGQ motif typical of CCR5 using subtype C strains, indicating that residues outside the V3 loop contributed to extended coreceptor use in this particular patient.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1182568','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1182568"><span>Dynamically limiting energy consumed by cooling apparatus</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Chainer, Timothy J.; David, Milnes P.; Iyengar, Madhusudan K.; Parida, Pritish R.; Schmidt, Roger R.; Schultz, Mark D.</p> <p>2015-05-26</p> <p>Cooling apparatuses and methods are provided which include one or more coolant-cooled structures associated with an electronics rack, a coolant loop coupled in fluid communication with one or more passages of the coolant-cooled structure(s), one or more heat exchange units coupled to facilitate heat transfer from coolant within the coolant loop, and N controllable components associated with the coolant loop or the heat exchange unit(s), wherein N.gtoreq.1. The N controllable components facilitate circulation of coolant through the coolant loop or transfer of heat from the coolant via the heat exchange unit(s). A controller is coupled to the N controllable components, and dynamically adjusts operation of the N controllable components, based on Z input parameters and one or more specified constraints, to provide a specified cooling to the coolant-cooled structure(s), while limiting energy consumed by the N controllable components, wherein Z.gtoreq.1.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1183926','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1183926"><span>Dynamically limiting energy consumed by cooling apparatus</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Chainer, Timothy J.; David, Milnes P.; Iyengar, Madhusudan K.; Parida, Pritish R.; Schmidt, Roger R.; Schultz, Mark D.</p> <p>2015-06-09</p> <p>Cooling methods are provided which include providing: one or more coolant-cooled structures associated with an electronics rack, a coolant loop coupled in fluid communication with one or more passages of the coolant-cooled structure(s), one or more heat exchange units coupled to facilitate heat transfer from coolant within the coolant loop, and N controllable components associated with the coolant loop or the heat exchange unit(s), wherein N.gtoreq.1. The N controllable components facilitate circulation of coolant through the coolant loop or transfer of heat from the coolant via the heat exchange unit(s). A controller is also provided to dynamically adjust operation of the N controllable components, based on Z input parameters and one or more specified constraints, and provide a specified cooling to the coolant-cooled structure(s), while limiting energy consumed by the N controllable components, wherein Z.gtoreq.1.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004JNuM..329..213S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004JNuM..329..213S"><span>Assessment of the 3H and 7Be generation in the IFMIF lithium loop</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Simakov, S. P.; Fischer, U.; von Möllendorff, U.</p> <p>2004-08-01</p> <p>A complete evaluation of the 7Be and tritium inventory induced in the IFMIF lithium loop by deuterons and neutrons was performed on the basis of 3D Monte Carlo calculations with the M CDeLicious code and evaluated d-Li and n-Li cross-section data. The associated reaction cross-sections and thick lithium target yields were checked against available experimental data. The IFMIF calculations showed that the deuteron beam will produce 1.5 g of 7Be and 6 g of 3H per full power year in the lithium jet. The tritium generation in the whole lithium loop due to neutron induced reactions is at a rate of 1.5 g/fpy. The radio-active decay results in an equilibrium concentration 0.3 mg of 7Be and 50 mg of 3H per 1 kg of circulating lithium if no radioactive products are removed from the loop.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/6277698','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/6277698"><span>Continuous production of tritium in an isotope-production reactor with a separate circulation system</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Cawley, W.E.; Omberg, R.P.</p> <p>1982-08-19</p> <p>A method is described for producing tritium in a fast breeder reactor cooled with liquid metal. Lithium is allowed to flow through the reactor in separate loops in order to facilitate the production and removal of tritium.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27987352','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27987352"><span>Design of a right ventricular mock circulation loop as a test bench for right ventricular assist devices.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mueller, Indra; Jansen-Park, So-Hyun; Neidlin, Michael; Steinseifer, Ulrich; Abel, Dirk; Autschbach, Rüdiger; Rossaint, Rolf; Schmitz-Rode, Thomas; Sonntag, Simon Johannes</p> <p>2017-04-01</p> <p>Right heart failure (RHF), e.g. due to pulmonary hypertension (PH), is a serious health issue with growing occurrence and high mortality rate. Limited efficacy of medication in advanced stages of the disease constitutes the need for mechanical circulatory support of the right ventricle (RV). An essential contribution to the process of developing right ventricular assist devices (RVADs) is the in vitro test bench, which simulates the hemodynamic behavior of the native circulatory system. To model healthy and diseased arterial-pulmonary hemodynamics in adults (mild and severe PH and RHF), a right heart mock circulation loop (MCL) was developed. Incorporating an anatomically shaped silicone RV and a silicone atrium, it not only enables investigations of hemodynamic values but also suction events or the handling of minimal invasive RVADs in an anatomical test environment. Ventricular pressure-volume loops of all simulated conditions as well as pressure and volume waveforms were recorded and compared to literature data. In an exemplary test, an RVAD was connected to the apex to further test the feasibility of studying such devices with the developed MCL. In conclusion, the hemodynamic behavior of the native system was well reproduced by the developed MCL, which is a useful basis for future RVAD tests.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28703280','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28703280"><span>The OregonHeart Total Artificial Heart: Design and Performance on a Mock Circulatory Loop.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Glynn, Jeremy; Song, Howard; Hull, Bryan; Withers, Stanley; Gelow, Jill; Mudd, James; Starr, Albert; Wampler, Richard</p> <p>2017-10-01</p> <p>Widespread use of heart transplantation is limited by the scarcity of donor organs. Total artificial heart (TAH) development has been pursued to address this shortage, especially to treat patients who require biventricular support. We have developed a novel TAH that utilizes a continuously spinning rotor that shuttles between two positions to provide pulsatile, alternating blood flow to the systemic and pulmonary circulations without artificial valves. Flow rates and pressures generated by the TAH are controlled by adjusting rotor speed, cycle frequency, and the proportion of each cycle spent pumping to either circulation. To validate the design, a TAH prototype was placed in a mock circulatory loop that simulates vascular resistance, pressure, and compliance in normal and pathophysiologic conditions. At a systemic blood pressure of 120/80 mm Hg, nominal TAH output was 7.4 L/min with instantaneous flows reaching 17 L/min. Pulmonary artery, and left and right atrial pressures were all maintained within normal ranges. To simulate implant into a patient with severe pulmonary hypertension, the pulmonary vascular resistance of the mock loop was increased to 7.5 Wood units. By increasing pump speed to the pulmonary circulation, cardiac output could be maintained at 7.4 L/min as mean pulmonary artery pressure increased to 56 mm Hg while systemic blood pressures remained normal. This in vitro testing of a novel, shuttling TAH demonstrated that cardiac output could be maintained across a range of pathophysiologic conditions including pulmonary hypertension. These experiments serve as a proof-of-concept for the design, which has proceeded to in vivo testing. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/21167829-system-analysis-decay-heat-removal-lead-bismuth-cooled-natural-circulated-reactors','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21167829-system-analysis-decay-heat-removal-lead-bismuth-cooled-natural-circulated-reactors"><span>System Analysis for Decay Heat Removal in Lead-Bismuth Cooled Natural Circulated Reactors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Takaaki Sakai; Yasuhiro Enuma; Takashi Iwasaki</p> <p>2002-07-01</p> <p>Decay heat removal analyses for lead-bismuth cooled natural circulation reactors are described in this paper. A combined multi-dimensional plant dynamics code (MSG-COPD) has been developed to conduct the system analysis for the natural circulation reactors. For the preliminary study, transient analysis has been performed for a 100 MWe lead-bismuth-cooled reactor designed by Argonne National Laboratory (ANL). In addition, decay heat removal characteristics of a 400 MWe lead-bismuth-cooled natural circulation reactor designed by Japan Nuclear Cycle Development Institute (JNC) has been evaluated by using MSG-COPD. PRACS (Primary Reactor Auxiliary Cooling System) is prepared for the JNC's concept to get sufficient heatmore » removal capacity. During 2000 sec after the transient, the outlet temperature shows increasing tendency up to the maximum temperature of 430 Centigrade, because the buoyancy force in a primary circulation path is temporary reduced. However, the natural circulation is recovered by the PRACS system and the out let temperature decreases successfully. (authors)« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/20837840-system-analysis-decay-heat-removal-lead-bismuth-cooled-natural-circulation-reactors','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20837840-system-analysis-decay-heat-removal-lead-bismuth-cooled-natural-circulation-reactors"><span>System Analysis for Decay Heat Removal in Lead-Bismuth-Cooled Natural-Circulation Reactors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Sakai, Takaaki; Enuma, Yasuhiro; Iwasaki, Takashi</p> <p>2004-03-15</p> <p>Decay heat removal analyses for lead-bismuth-cooled natural-circulation reactors are described in this paper. A combined multidimensional plant dynamics code (MSG-COPD) has been developed to conduct the system analysis for the natural-circulation reactors. For the preliminary study, transient analysis has been performed for a 300-MW(thermal) lead-bismuth-cooled reactor designed by Argonne National Laboratory. In addition, decay heat removal characteristics of a 400-MW(electric) lead-bismuth-cooled natural-circulation reactor designed by the Japan Nuclear Cycle Development Institute (JNC) has been evaluated by using MSG-COPD. The primary reactor auxiliary cooling system (PRACS) is prepared for the JNC concept to get sufficient heat removal capacity. During 2000 smore » after the transient, the outlet temperature shows increasing tendency up to the maximum temperature of 430 deg. C because the buoyancy force in a primary circulation path is temporarily reduced. However, the natural circulation is recovered by the PRACS system, and the outlet temperature decreases successfully.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28654035','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28654035"><span>Measurement of the Rheology of Crude Oil in Equilibrium with CO2 at Reservoir Conditions.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hu, Ruien; Crawshaw, John</p> <p>2017-06-06</p> <p>A rheometer system to measure the rheology of crude oil in equilibrium with carbon dioxide (CO2) at high temperatures and pressures is described. The system comprises a high-pressure rheometer which is connected to a circulation loop. The rheometer has a rotational flow-through measurement cell with two alternative geometries: coaxial cylinder and double gap. The circulation loop contains a mixer, to bring the crude oil sample into equilibrium with CO2, and a gear pump that transports the mixture from the mixer to the rheometer and recycles it back to the mixer. The CO2 and crude oil are brought to equilibrium by stirring and circulation and the rheology of the saturated mixture is measured by the rheometer. The system is used to measure the rheological properties of Zuata crude oil (and its toluene dilution) in equilibrium with CO2 at elevated pressures up to 220 bar and a temperature of 50 °C. The results show that CO2 addition changes the oil rheology significantly, initially reducing the viscosity as the CO2 pressure is increased and then increasing the viscosity above a threshold pressure. The non-Newtonian response of the crude is also seen to change with the addition of CO2.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120003157','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120003157"><span>Development and Analysis of Cold Trap for Use in Fission Surface Power-Primary Test Circuit</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wolfe, T. M.; Dervan, C. A.; Pearson, J. B.; Godfroy, T. J.</p> <p>2012-01-01</p> <p>The design and analysis of a cold trap proposed for use in the purification of circulated eutectic sodium potassium (NaK-78) loops is presented. The cold trap is designed to be incorporated into the Fission Surface Power-Primary Test Circuit (FSP-PTC), which incorporates a pumped NaK loop to simulate in-space nuclear reactor-based technology using non-nuclear test methodology as developed by the Early Flight Fission-Test Facility. The FSP-PTC provides a test circuit for the development of fission surface power technology. This system operates at temperatures that would be similar to those found in a reactor (500-800 K). By dropping the operating temperature of a specified percentage of NaK flow through a bypass containing a forced circulation cold trap, the NaK purity level can be increased by precipitating oxides from the NaK and capturing them within the cold trap. This would prevent recirculation of these oxides back through the system, which may help prevent corrosion.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28375841','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28375841"><span>A mock heart engineered with helical aramid fibers for in vitro cardiovascular device testing.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jansen-Park, So-Hyun; Hsu, Po-Lin; Müller, Indra; Steinseifer, Ulrich; Abel, Dirk; Autschbach, Rüdiger; Rossaint, Rolf; Schmitz-Rode, Thomas</p> <p>2017-04-01</p> <p>Mock heart circulation loops (MHCLs) serve as in-vitro platforms to investigate the physiological interaction between circulatory systems and cardiovascular devices. A mock heart (MH) engineered with silicone walls and helical aramid fibers, to mimic the complex contraction of a natural heart, has been developed to advance the MHCL previously developed in our group. A mock aorta with an anatomical shape enables the evaluation of a cannulation method for ventricular assist devices (VADs) and investigation of the usage of clinical measurement systems like pressure-volume catheters. Ventricle and aorta molds were produced based on MRI data and cast with silicone. Aramid fibers were layered in the silicone ventricle to reproduce ventricle torsion. A rotating hollow shaft was connected to the apex enabling the rotation of the MH and the connection of a VAD. Silicone wall thickness, aramid fiber angle and fiber pitch were varied to generate different MH models. All MH models were placed in a tank filled with variable amounts of water and air simulating the compliance. In this work, physiological ventricular torsion angles (15°-26°) and physiological pressure-volume loops were achieved. This MHCL can serve as a comprehensive testing platform for cardiovascular devices, such as artificial heart valves and cannulation of VADs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010pot..book..664S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010pot..book..664S"><span>A Hydrodynamic Characteristic of a Dual Fluidized Bed Gasification</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sung, Yeon Kyung; Song, Jae Hun; Bang, Byung Ryeul; Yu, Tae U.; Lee, Uen Do</p> <p></p> <p>A cold model dual fluidized bed (DFB) reactor, consisting of two parallel interconnected bubbling and fast fluidized beds, was designed for developing an auto-thermal biomass gasifier. The combustor of this system burns the rest char of the gasification process and provides heat to the gasifier by circulating solids inventory. To find an optimal mixing and circulation of heavy solid inventory and light biomass and char materials, we investigate two types of DFB reactors which have different configuration of distributor and way-out location of the solid inventory and char materials in the gasifier. To determine appropriate operating conditions, we measured minimum fluidization velocity, solid circulation rate, axial solid holdup and gas bypassing between the lower loop seal and the gasifier.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1013656','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1013656"><span>In situ conversion process utilizing a closed loop heating system</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Sandberg, Chester Ledlie [Palo Alto, CA; Fowler, Thomas David [Houston, TX; Vinegar, Harold J [Bellaire, TX; Schoeber, Willen Jan Antoon Henri</p> <p>2009-08-18</p> <p>An in situ conversion system for producing hydrocarbons from a subsurface formation is described. The system includes a plurality of u-shaped wellbores in the formation. Piping is positioned in at least two of the u-shaped wellbores. A fluid circulation system is coupled to the piping. The fluid circulation system is configured to circulate hot heat transfer fluid through at least a portion of the piping to form at least one heated portion of the formation. An electrical power supply is configured to provide electrical current to at least a portion of the piping located below an overburden in the formation to resistively heat at least a portion of the piping. Heat transfers from the piping to the formation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16341923','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16341923"><span>A LabVIEW model incorporating an open-loop arterial impedance and a closed-loop circulatory system.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cole, R T; Lucas, C L; Cascio, W E; Johnson, T A</p> <p>2005-11-01</p> <p>While numerous computer models exist for the circulatory system, many are limited in scope, contain unwanted features or incorporate complex components specific to unique experimental situations. Our purpose was to develop a basic, yet multifaceted, computer model of the left heart and systemic circulation in LabVIEW having universal appeal without sacrificing crucial physiologic features. The program we developed employs Windkessel-type impedance models in several open-loop configurations and a closed-loop model coupling a lumped impedance and ventricular pressure source. The open-loop impedance models demonstrate afterload effects on arbitrary aortic pressure/flow inputs. The closed-loop model catalogs the major circulatory waveforms with changes in afterload, preload, and left heart properties. Our model provides an avenue for expanding the use of the ventricular equations through closed-loop coupling that includes a basic coronary circuit. Tested values used for the afterload components and the effects of afterload parameter changes on various waveforms are consistent with published data. We conclude that this model offers the ability to alter several circulatory factors and digitally catalog the most salient features of the pressure/flow waveforms employing a user-friendly platform. These features make the model a useful instructional tool for students as well as a simple experimental tool for cardiovascular research.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21071448','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21071448"><span>Deciphering the roles of outer membrane protein A extracellular loops in the pathogenesis of Escherichia coli K1 meningitis.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mittal, Rahul; Krishnan, Subramanian; Gonzalez-Gomez, Ignacio; Prasadarao, Nemani V</p> <p>2011-01-21</p> <p>Outer membrane protein A (OmpA) has been implicated as an important virulence factor in several gram-negative bacterial infections such as Escherichia coli K1, a leading cause of neonatal meningitis associated with significant mortality and morbidity. In this study, we generated E. coli K1 mutants that express OmpA in which three or four amino acids from various extracellular loops were changed to alanines, and we examined their ability to survive in several immune cells. We observed that loop regions 1 and 2 play an important role in the survival of E. coli K1 inside neutrophils and dendritic cells, and loop regions 1 and 3 are needed for survival in macrophages. Concomitantly, E. coli K1 mutants expressing loop 1 and 2 mutations were unable to cause meningitis in a newborn mouse model. Of note, mutations in loop 4 of OmpA enhance the severity of the pathogenesis by allowing the pathogen to survive better in circulation and to produce high bacteremia levels. These results demonstrate, for the first time, the roles played by different regions of extracellular loops of OmpA of E. coli K1 in the pathogenesis of meningitis and may help in designing effective preventive strategies against this deadly disease.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910028212&hterms=knowledge+power&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dknowledge%2Bpower','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910028212&hterms=knowledge+power&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dknowledge%2Bpower"><span>Startup thaw concept for the SP-100 space reactor power system</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kirpich, A.; Das, A.; Choe, H.; Mcnamara, E.; Switick, D.; Bhandari, P.</p> <p>1990-01-01</p> <p>A thaw concept for a space reactor power system which employs lithium as a circulant for both the heat-transport and the heat-rejection fluid loops is presented. An exemplary thermal analysis for a 100-kWe (i.e., SP-100) system is performed. It is shown that the design of the thaw system requires a thorough knowledge of the various physical states of the circulant throughout the system, both spatially and temporally, and that the design has to provide adequate margins for the system to avoid a structural or thermally induced damage.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24431098','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24431098"><span>A global multiscale mathematical model for the human circulation with emphasis on the venous system.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Müller, Lucas O; Toro, Eleuterio F</p> <p>2014-07-01</p> <p>We present a global, closed-loop, multiscale mathematical model for the human circulation including the arterial system, the venous system, the heart, the pulmonary circulation and the microcirculation. A distinctive feature of our model is the detailed description of the venous system, particularly for intracranial and extracranial veins. Medium to large vessels are described by one-dimensional hyperbolic systems while the rest of the components are described by zero-dimensional models represented by differential-algebraic equations. Robust, high-order accurate numerical methodology is implemented for solving the hyperbolic equations, which are adopted from a recent reformulation that includes variable material properties. Because of the large intersubject variability of the venous system, we perform a patient-specific characterization of major veins of the head and neck using MRI data. Computational results are carefully validated using published data for the arterial system and most regions of the venous system. For head and neck veins, validation is carried out through a detailed comparison of simulation results against patient-specific phase-contrast MRI flow quantification data. A merit of our model is its global, closed-loop character; the imposition of highly artificial boundary conditions is avoided. Applications in mind include a vast range of medical conditions. Of particular interest is the study of some neurodegenerative diseases, whose venous haemodynamic connection has recently been identified by medical researchers. Copyright © 2014 John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70023399','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70023399"><span>Measurement of 224Ra and 226Ra activities in natural waters using a radon-in-air monitor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kim, G.; Burnett, W.C.; Dulaiova, H.; Swarzenski, P.W.; Moore, W.S.</p> <p>2001-01-01</p> <p>We report a simple new technique for measuring low-level radium isotopes (224Ra and 226Ra) in natural waters. The radium present in natural waters is first preconcentrated onto MnO2-coated acrylic fiber (Mn fiber) in a column mode. The radon produced from the adsorbed radium is then circulated through a closed air-loop connected to a commercial radon-in-air monitor. The monitor counts alpha decays of radon daughters (polonium isotopes) which are electrostatically collected onto a silicon semiconductor detector. Count data are collected in energy-specific windows, which eliminate interference and maintain very low backgrounds. Radium-224 is measured immediately after sampling via 220Rn (216Po), and 226Ra is measured via 222Rn (218Po) after a few days of ingrowth of 222Rn. This technique is rapid, simple, and accurate for measurements of low-level 224Ra and 226Ra activities without requiring any wet chemistry. Rapid measurements of short-lived 222Rn and 224Ra, along with long-lived 226Ra, may thus be made in natural waters using a single portable system for environmental monitoring of radioactivity as well as tracing of various geochemical and geophysical processes. The technique could be especially useful for the on-site rapid determination of 224Ra which has recently been found to occur at elevated activities in some groundwater wells.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1136601-dynamics-coupled-human-climate-system-resulting-from-closed-loop-control-solar-geoengineering','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1136601-dynamics-coupled-human-climate-system-resulting-from-closed-loop-control-solar-geoengineering"><span>Dynamics of the Coupled Human-climate System Resulting from Closed-loop Control of Solar Geoengineering</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>MacMartin, Douglas; Kravitz, Benjamin S.; Keith, David</p> <p>2014-07-08</p> <p>If solar radiation management (SRM) were ever implemented, feedback of the observed climate state might be used to adjust the radiative forcing of SRM, in order to compensate for uncertainty in either the forcing or the climate response; this would also compensate for unexpected changes in the system, e.g. a nonlinear change in climate sensitivity. This feedback creates an emergent coupled human-climate system, with entirely new dynamics. In addition to the intended response to greenhouse-gas induced changes, the use of feedback would also result in a geoengineering response to natural climate variability. We use a simple box-diffusion dynamic model tomore » understand how changing feedback-control parameters and time delay affect the behavior of this coupled natural-human system, and verify these predictions using the HadCM3L general circulation model. In particular, some amplification of natural variability is unavoidable; any time delay (e.g., to average out natural variability, or due to decision-making) exacerbates this amplification, with oscillatory behavior possible if there is a desire for rapid correction (high feedback gain), but a delayed response needed for decision making. Conversely, the need for feedback to compensate for uncertainty, combined with a desire to avoid excessive amplification, results in a limit on how rapidly SRM could respond to uncertain changes.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=recycling+AND+landfill&pg=2&id=ED476803','ERIC'); return false;" href="https://eric.ed.gov/?q=recycling+AND+landfill&pg=2&id=ED476803"><span>Closing the Loop Sampler.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>California Integrated Waste Management Board, Sacramento.</p> <p></p> <p>Closing the Loop (CTL) is a science curriculum designed to introduce students to integrated waste management through awareness. This document presents five lesson plans focusing on developing an understanding of natural resources, solid wastes, conservation, and the life of landfills. Contents include: (1) "What Are Natural Resources?"; (2)…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740003898','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740003898"><span>A Computer Model of a Phase Lock Loop</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shelton, Ralph Paul</p> <p>1973-01-01</p> <p>A computer model is reported of a PLL (phase-lock loop), preceded by a bandpass filter, which is valid when the bandwidth of the bandpass filter is of the same order of magnitude as the natural frequency of the PLL. New results for the PLL natural frequency equal to the bandpass filter bandwidth are presented for a second order PLL operating with carrier plus noise as the input. However, it is shown that extensions to higher order loops, and to the case of a modulated carrier are straightforward. The new results presented give the cycle skipping rate of the PLL as a function of the input carrier to noise ratio when the PLL natural frequency is equal to the bandpass filter bandwidth. Preliminary results showing the variation of the output noise power and cycle skipping rates of the PLL as a function of the loop damping ratio for the PLL natural frequency equal to the bandpass filter bandwidth are also included.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JNuM..398..104K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JNuM..398..104K"><span>Ni-rich precipitates in a lead bismuth eutectic loop</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kikuchi, K.; Saito, S.; Hamaguchi, D.; Tezuka, M.</p> <p>2010-03-01</p> <p>Solidified LBE was sampled from the specimens, electro-magnetic pump, filter, drain valve and oxygen sensor at the JAEA Lead Bismuth Loop-1 (JLBL-1) where the structural material was made of SS316. The concentration of Ni, Fe and Cr in LBE were analyzed by the Inductive Coupled Plasma atomic emission spectrometer. It was concluded that the solution of Ni into LBE was not saturated although the concentration of Fe and Cr almost achieved to the values in the literature. A needle-type structure appeared on the surface of solidified LBE inside the tube specimens. It was found to be Ni-rich precipitates by X-ray analyses (Field Emission Scanning Electron Microscope, FE-SEM). LBE samples collected from a circulating loop after discharging did not show the amount of impurities equivalent to the LBE bulk property.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25958141','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25958141"><span>Aeration and mass transfer optimization in a rectangular airlift loop photobioreactor for the production of microalgae.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guo, Xin; Yao, Lishan; Huang, Qingshan</p> <p>2015-08-01</p> <p>Effects of superficial gas velocity and top clearance on gas holdup, liquid circulation velocity, mixing time, and mass transfer coefficient are investigated in a new airlift loop photobioreactor (PBR), and empirical models for its rational control and scale-up are proposed. In addition, the impact of top clearance on hydrodynamics, especially on the gas holdup in the internal airlift loop reactor, is clarified; a novel volume expansion technique is developed to determine the low gas holdup in the PBR. Moreover, a model strain of Chlorella vulgaris is cultivated in the PBR and the volumetric power is analyzed with a classic model, and then the aeration is optimized. It shows that the designed PBR, a cost-effective reactor, is promising for the mass cultivation of microalgae. Copyright © 2015 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26401602','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26401602"><span>Adding the 'heart' to hanging drop networks for microphysiological multi-tissue experiments.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rismani Yazdi, Saeed; Shadmani, Amir; Bürgel, Sebastian C; Misun, Patrick M; Hierlemann, Andreas; Frey, Olivier</p> <p>2015-11-07</p> <p>Microfluidic hanging-drop networks enable culturing and analysis of 3D microtissue spheroids derived from different cell types under controlled perfusion and investigating inter-tissue communication in multi-tissue formats. In this paper we introduce a compact on-chip pumping approach for flow control in hanging-drop networks. The pump includes one pneumatic chamber located directly above one of the hanging drops and uses the surface tension at the liquid-air-interface for flow actuation. Control of the pneumatic protocol provides a wide range of unidirectional pulsatile and continuous flow profiles. With the proposed concept several independent hanging-drop networks can be operated in parallel with only one single pneumatic actuation line at high fidelity. Closed-loop medium circulation between different organ models for multi-tissue formats and multiple simultaneous assays in parallel are possible. Finally, we implemented a real-time feedback control-loop of the pump actuation based on the beating of a human iPS-derived cardiac microtissue cultured in the same system. This configuration allows for simulating physiological effects on the heart and their impact on flow circulation between the organ models on chip.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP41A1824R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP41A1824R"><span>Characteristics of Helical Flow through Neck Cutoffs</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Richards, D.; Konsoer, K. M.; Turnipseed, C.; Willson, C. S.</p> <p>2017-12-01</p> <p>Meander cutoffs and oxbows lakes are a ubiquitous feature of riverine landscapes yet there is a paucity of detailed investigations concentrated on the three-dimensional flow structure through evolving neck cutoffs. The purpose of this research is to investigate and characterize helical flow through neck cutoffs with two different planform configurations: elongate meander loops and serpentine loops. Three-dimensional velocity measurements was collected with an acoustic Doppler current profiler for five cutoffs on the White River, Arkansas. Pronounced helical flow was found through all elongate loop cutoff sites, formed from the balance between centrifugal force resulting from the curving of flow through the cutoff channel and pressure gradient force resulting from water surface super-elevation between primary flow and flow at the entrance and exit of the abandoned loop. The sense of motion of the helical flow caused near-surface fluid to travel outward toward the abandoned loop while near-bed fluid was redirected toward the downstream channel. Another characteristic of the helical flow structure for elongate loop cutoffs was the reversal of helical flow over a relatively short distance, causing patterns of secondary circulation that differed from typical patterns observed through curved channels with point bars. Lastly, helical flow was revealed within zones of strong flow recirculation, enhanced by an exchange of streamwise momentum between shear layers.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990063809&hterms=McCormick&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DMcCormick','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990063809&hterms=McCormick&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DMcCormick"><span>Developments in TurboBrayton Technology for Low Temperature Applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Swift, W. L.; Zagarola, M. V.; Nellis, G. F.; McCormick, J. A.; Gibbon, Judy</p> <p>1999-01-01</p> <p>A single stage reverse Brayton cryocooler using miniature high-speed turbomachines recently completed a successful space shuttle test flight demonstrating its capabilities for use in cooling the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) on the Hubble Space Telescope (HST). The NICMOS CryoCooler (NCC) is designed for a cooling load of about 8 W at 65 K, and comprises a closed loop cryocooler coupled to an independent cryogenic circulating loop. Future space applications involve instruments that will require 5 mW to 200 mW of cooling at temperatures between 4 K and 10 K. This paper discusses the extension of Turbo-Brayton technology to meet these requirements.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1333020-pathways-naturally-small-dirac-neutrino-masses','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1333020-pathways-naturally-small-dirac-neutrino-masses"><span>Pathways to naturally small Dirac neutrino masses</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Ma, Ernest; Popov, Oleg</p> <p>2016-11-18</p> <p>If neutrinos are truly Dirac fermions, the smallness of their masses may still be natural if certain symmetries exist beyond those of the standard model of quarks and leptons. We perform a systematic study of how this may occur at tree level and in one loop. As a result, we also propose a scotogenic version of the left-right gauge model with naturally small Dirac neutrino masses in one loop.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24684686','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24684686"><span>Pro-tumorigenic effects of transforming growth factor beta 1 in canine osteosarcoma.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Portela, R F; Fadl-Alla, B A; Pondenis, H C; Byrum, M L; Garrett, L D; Wycislo, K L; Borst, L B; Fan, T M</p> <p>2014-01-01</p> <p>Transforming growth factor beta 1 (TGFβ1) is a pleiotropic cytokine that contributes to reparative skeletal remodeling by inducing osteoblast proliferation, migration, and angiogenesis. Organic bone matrix is the largest bodily reservoir for latent TGFβ1, and active osteoblasts express cognate receptors for TGFβ1 (TGFβRI and TGFβRII). During malignant osteolysis, TGFβ1 is liberated from eroded bone matrix and promotes local progression of osteotropic solid tumors by its mitogenic and prosurvival activities. Canine osteosarcoma (OS) cells will possess TGFβ1 signaling machinery. Blockade of TGFβ1 signaling will attenuate pro-tumorigenic activities in OS cells. Naturally occurring primary OS samples will express cognate TGFβ1 receptors; and in dogs with OS, focal malignant osteolysis will contribute to circulating TGFβ1 concentrations. Thirty-three dogs with appendicular OS. Expression of TGFβ1 and its cognate receptors, as well as the biologic effects of TGFβ1 blockade, was characterized in OS cells. Ten spontaneous OS samples were characterized for TGFβRI/II expressions by immunohistochemistry. In 33 dogs with OS, plasma TGFβ1 concentrations were quantified and correlated with bone resorption. Canine OS cells secrete TGFβ1, express cognate receptors, and TGFβ1 signaling blockade decreases proliferation, migration, and vascular endothelial growth factor secretion. Naturally occurring OS samples abundantly and uniformly express TGFβRI/II, and in OS-bearing dogs, circulating TGFβ1 concentrations correlate with urine N-telopeptide excretion. Canine OS cells possess TGFβ1 signaling machinery, potentially allowing for the establishment of an autocrine and paracrine pro-tumorigenic signaling loop. As such, TGFβ1 inhibitors might impede localized OS progression in dogs. Copyright © 2014 by the American College of Veterinary Internal Medicine.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.nrel.gov/esif/labs-system-performance.html','SCIGOVWS'); return false;" href="https://www.nrel.gov/esif/labs-system-performance.html"><span>Systems Performance Laboratory | Energy Systems Integration Facility | NREL</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.science.gov/aboutsearch.html">Science.gov Websites</a></p> <p></p> <p></p> <p>array access Small Commercial Power Hardware in the <em>Loop</em> The small commercial power-hardware-in-the-<em>loop</em> (PHIL) test bay is dedicated to small-scale power hardware-in-the-<em>loop</em> studies of inverters and other , natural gas supply Multi-Inverter Power Hardware in the <em>Loop</em> The multi-inverter test bay is dedicated to</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29568152','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29568152"><span>Comparative PIV and LDA studies of Newtonian and non-Newtonian flows in an agitated tank.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Story, Anna; Jaworski, Zdzisław; Simmons, Mark J; Nowak, Emilia</p> <p>2018-01-01</p> <p>The paper presents results of an experimental study of the fluid velocity field in a stirred tank equipped with a Prochem Maxflo T (PMT) type impeller which was rotating at a constant frequency of N  = 4.1 or 8.2 s -1 inducing transitional ( Re  = 499 or 1307) or turbulent ( Re  = 2.43 × 10 4 ) flow of the fluid. The experiments were performed for a Newtonian fluid (water) and a non-Newtonian fluid (0.2 wt% aqueous solution of carboxymethyl cellulose, CMC) exhibiting mild viscoelastic properties. Measurements were carried out using laser light scattering on tracer particles which follow the flow (2-D PIV). For both the water and the CMC solution one primary and two secondary circulation loops were observed within the fluid volume; however, the secondary loops were characterized by much lower intensity. The applied PMT-type impeller produced in the Newtonian fluid an axial primary flow, whilst in the non-Newtonian fluid the flow was more radial. The results obtained in the form of the local mean velocity components were in satisfactory agreement with the literature data from LDA. Distribution of the shear rate in the studied system was also analyzed. For the non-Newtonian fluid an area was computed where the elastic force dominates over the viscous one. The area was nearly matching the region occupied by the primary circulation loop.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26142111','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26142111"><span>Closed-loop controller for chest compressions based on coronary perfusion pressure: a computer simulation study.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Chunfei; Zhang, Guang; Wu, Taihu; Zhan, Ningbo; Wang, Yaling</p> <p>2016-03-01</p> <p>High-quality cardiopulmonary resuscitation contributes to cardiac arrest survival. The traditional chest compression (CC) standard, which neglects individual differences, uses unified standards for compression depth and compression rate in practice. In this study, an effective and personalized CC method for automatic mechanical compression devices is provided. We rebuild Charles F. Babbs' human circulation model with a coronary perfusion pressure (CPP) simulation module and propose a closed-loop controller based on a fuzzy control algorithm for CCs, which adjusts the CC depth according to the CPP. Compared with a traditional proportion-integration-differentiation (PID) controller, the performance of the fuzzy controller is evaluated in computer simulation studies. The simulation results demonstrate that the fuzzy closed-loop controller results in shorter regulation time, fewer oscillations and smaller overshoot than traditional PID controllers and outperforms the traditional PID controller for CPP regulation and maintenance.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170010141','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170010141"><span>Development Specification for the FN-323/324, Oxygen Ventilation Loop Fan Assembly</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ralston, Russell; Campbell, Colin</p> <p>2017-01-01</p> <p>This specification establishes the requirements for design, performance, safety, and manufacture of the FN-323/324, Oxygen Ventilation Loop Fan Assembly as part of the Advanced EMU (AEMU) Portable Life Support System (PLSS). Fan development for the advanced Portable Life Support System (PLSS) began in 2009 with the development of Fan 1.0. This fan was used in PLSS 2.0 for circulation of the ventilation loop gas. Fan 2.0 was delivered in 2015 and will be used in the PLSS 2.5 Live Loads test series. This fan used the same motor as Fan 1.0, but had a larger volute and impeller in hopes of achieving lower speeds. The next iteration of the advanced PLSS fan is the subject of the requirements contained within this document, and will be used with the PLSS 2.5 -302 configuration.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/875095','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/875095"><span>Control method for mixed refrigerant based natural gas liquefier</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kountz, Kenneth J.; Bishop, Patrick M.</p> <p>2003-01-01</p> <p>In a natural gas liquefaction system having a refrigerant storage circuit, a refrigerant circulation circuit in fluid communication with the refrigerant storage circuit, and a natural gas liquefaction circuit in thermal communication with the refrigerant circulation circuit, a method for liquefaction of natural gas in which pressure in the refrigerant circulation circuit is adjusted to below about 175 psig by exchange of refrigerant with the refrigerant storage circuit. A variable speed motor is started whereby operation of a compressor is initiated. The compressor is operated at full discharge capacity. Operation of an expansion valve is initiated whereby suction pressure at the suction pressure port of the compressor is maintained below about 30 psig and discharge pressure at the discharge pressure port of the compressor is maintained below about 350 psig. Refrigerant vapor is introduced from the refrigerant holding tank into the refrigerant circulation circuit until the suction pressure is reduced to below about 15 psig, after which flow of the refrigerant vapor from the refrigerant holding tank is terminated. Natural gas is then introduced into a natural gas liquefier, resulting in liquefaction of the natural gas.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/4293136-armour-dust-fueled-reactor-adfr-quarterly-progress-report-period-may-august','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/4293136-armour-dust-fueled-reactor-adfr-quarterly-progress-report-period-may-august"><span>THE ARMOUR DUST FUELED REACTOR (ADFR). Quarterly Progress Report No. 2 For the Period May 21, 1958 to August 21, 1958</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Loewe, W.E.; Krucoff, D.</p> <p>1958-10-31</p> <p>Study of the ADFR concept included experimental work on fuel dust suspension stability and redispersibility, erosion, and dust deposition using the fuel dust circulation loop. Some theoretical work was done in the areas of reactor safety and breeding. (For preceding period -see AECU-3827.) (auth)</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998JCli...11..831G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998JCli...11..831G"><span>A Decadal Climate Cycle in the North Atlantic Ocean as Simulated by the ECHO Coupled GCM.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grötzner, A.; Latif, M.; Barnett, T. P.</p> <p>1998-05-01</p> <p>In this paper a decadal climate cycle in the North Atlantic that was derived from an extended-range integration with a coupled ocean-atmosphere general circulation model is described. The decadal mode shares many features with the observed decadal variability in the North Atlantic. The period of the simulated oscillation, however, is somewhat longer than that estimated from observations. While the observations indicate a period of about 12 yr, the coupled model simulation yields a period of about 17 yr. The cyclic nature of the decadal variability implies some inherent predictability at these timescales.The decadal mode is based on unstable air-sea interactions and must be therefore regarded as an inherently coupled mode. It involves the subtropical gyre and the North Atlantic oscillation. The memory of the coupled system, however, resides in the ocean and is related to horizontal advection and to the oceanic adjustment to low-frequency wind stress curl variations. In particular, it is found that variations in the intensity of the Gulf Stream and its extension are crucial to the oscillation. Although differing in details, the North Atlantic decadal mode and the North Pacific mode described by M. Latif and T. P. Barnett are based on the same fundamental mechanism: a feedback loop between the wind driven subtropical gyre and the extratropical atmospheric circulation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010pot..book..206L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010pot..book..206L"><span>Design and Application of Novel Horizontal Circulating Fluidized Bed Boiler</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lit, Q. H.; Zhang, Y. G.; Meng, A. H.</p> <p></p> <p>The vertical circulating fluidized bed (CFB) boiler has been found wide application in power generation and tends to be enlarged in capacity. Because CFB is one of environment friendly and high efficiency combustion technologies, the CFB boiler has also been expected to be used in the industrial area, such as textile mill, region heating, brewery, seed drying and so on. However, the necessary height of furnace is hard to be implemented for CFB with especially small capacity. Thereby, a novel horizontal circulating fluidized bed boiler has been proposed and developed. The horizontal CFB is composed of primary combustion chamber, secondary combustion chamber, burnout chamber, cyclone, loop seal, heat recovery area. The primary combustion chamber is a riser like as that in vertical CFB, and the secondary combustion chamber is a downward passage that is a natural extension of the primary riser, which can reduce the overall height of the boiler. In some extent, the burnout chamber is also the extension of primary riser. The capacity of horizontal CFB is about 4.2-24.5MWth (6-35t/h) steam output or equivalent hot water supply. The hot water boiler of 7MWth and steam boilers of 4.2MWth (6t/h) and 10.5MWth (15t/h) are all designed and working well now. The three units of hot water horizontal CFB boiler were erected in the Neimenggu Autonomous Region, Huhehaote city for region heating. The three units of steam horizontal CFB has been installed in Yunnan, Jiang Xi and Guangdong provinces, respectively. The basic principle for horizontal CFB and experiences for designing and operating are presented in this paper. Some discussions are also given to demonstrate the promising future of horizontal CFB.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvF...3d4603H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvF...3d4603H"><span>Impact of a small ellipticity on the sustainability condition of developed turbulence in a precessing spheroid</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Horimoto, Yasufumi; Simonet-Davin, Gabriel; Katayama, Atsushi; Goto, Susumu</p> <p>2018-04-01</p> <p>We experimentally investigate the flow transition to developed turbulence in a precessing spheroid with a small ellipticity. Fully developed turbulence appears through a subcritical transition when we fix the Reynolds number (the spin rate) and gradually increase the Poincaré number (the precession rate). In the transitional range of the Poincaré number, two qualitatively different turbulent states (i.e., fully developed turbulence and quiescent turbulence with a spin-driven global circulation) are stable and they are connected by a hysteresis loop. This discontinuous transition is in contrast to the continuous transition in a precessing sphere, for which neither bistable turbulent states nor hysteresis loops are observed. The small ellipticity of the container makes the global circulation of the confined fluid more stable, and it requires much stronger precession of the spheroid, than a sphere, for fully developed turbulence to be sustained. Nevertheless, once fully developed turbulence is sustained, its flow structures are almost identical in the spheroid and sphere. The argument [Lorenzani and Tilgner, J. Fluid Mech. 492, 363 (2003), 10.1017/S002211200300572X; Noir et al., Geophys. J. Int. 154, 407 (2003), 10.1046/j.1365-246X.2003.01934.x] on the basis of the analytical solution [Busse, J. Fluid Mech. 33, 739 (1968), 10.1017/S0022112068001655] of the steady global circulation in a weak precession range well describes the onset of the fully developed turbulence in the spheroid.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1370577','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1370577"><span>Folding of the natural hammerhead ribozyme is enhanced by interaction of auxiliary elements</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>PENEDO, J. CARLOS; WILSON, TIMOTHY J.; JAYASENA, SUMEDHA D.; KHVOROVA, ANASTASIA; LILLEY, DAVID M.J.</p> <p>2004-01-01</p> <p>It has been shown that the activity of the hammerhead ribozyme at μM magnesium ion concentrations is markedly increased by the inclusion of loops in helices I and II. We have studied the effect of such loops on the magnesium ion-induced folding of the ribozyme, using fluorescence resonance energy transfer. We find that with the loops in place, folding into the active conformation occurs in a single step, in the μM range of magnesium ion concentration. Disruption of the loop–loop interaction leads to a reversion to two-step folding, with the second stage requiring mM concentrations of magnesium ion. Sodium ions also promote the folding of the natural form of the ribozyme at high concentrations, but the folding occurs as a two-stage process. The loops clearly act as important auxiliary elements in the function of the ribozyme, permitting folding to occur efficiently under physiological conditions. PMID:15100442</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AIPC.1145..325T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AIPC.1145..325T"><span>Hyperstaticity and loops in frictional granular packings</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tordesillas, Antoinette; Lam, Edward; Metzger, Philip T.</p> <p>2009-06-01</p> <p>The hyperstatic nature of granular packings of perfectly rigid disks is analyzed algebraically and through numerical simulation. The elementary loops of grains emerge as a fundamental element in addressing hyperstaticity. Loops consisting of an odd number of grains behave differently than those with an even number. For odd loops, the latent stresses are exterior and are characterized by the sum of frictional forces around each loop. For even loops, the latent stresses are interior and are characterized by the alternating sum of frictional forces around each loop. The statistics of these two types of loop sums are found to be Gibbsian with a "temperature" that is linear with the friction coefficient μ when μ<1.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AIPC.1931b0005A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AIPC.1931b0005A"><span>Carbon-free hydrogen production from low rank coal</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aziz, Muhammad; Oda, Takuya; Kashiwagi, Takao</p> <p>2018-02-01</p> <p>Novel carbon-free integrated system of hydrogen production and storage from low rank coal is proposed and evaluated. To measure the optimum energy efficiency, two different systems employing different chemical looping technologies are modeled. The first integrated system consists of coal drying, gasification, syngas chemical looping, and hydrogenation. On the other hand, the second system combines coal drying, coal direct chemical looping, and hydrogenation. In addition, in order to cover the consumed electricity and recover the energy, combined cycle is adopted as addition module for power generation. The objective of the study is to find the best system having the highest performance in terms of total energy efficiency, including hydrogen production efficiency and power generation efficiency. To achieve a thorough energy/heat circulation throughout each module and the whole integrated system, enhanced process integration technology is employed. It basically incorporates two core basic technologies: exergy recovery and process integration. Several operating parameters including target moisture content in drying module, operating pressure in chemical looping module, are observed in terms of their influence to energy efficiency. From process modeling and calculation, two integrated systems can realize high total energy efficiency, higher than 60%. However, the system employing coal direct chemical looping represents higher energy efficiency, including hydrogen production and power generation, which is about 83%. In addition, optimum target moisture content in drying and operating pressure in chemical looping also have been defined.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/111431','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/111431"><span>The low-power low-pressure flow resonance in a natural circulation cooled boiling water reactor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Hagen, T.H.J.J. van der; Stekelenburg, A.J.C.</p> <p>1995-09-01</p> <p>The last few years the possibility of flow resonances during the start-up phase of natural circulation cooled BWRs has been put forward by several authors. The present paper reports on actual oscillations observed at the Dodewaard reactor, the world`s only operating BWR cooled by natural circulation. In addition, results of a parameter study performed by means of a simple theoretical model are presented. The influence of relevant parameters on the resonance characteristics, being the decay ratio and the resonance frequency, is investigated and explained.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21738438','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21738438"><span>Biomolecular and structural analyses of cauliflower-like DNAs by ultraviolet, circular dichroism, and fluorescence spectroscopies in comparison with natural DNA.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gill, Pooria; Ranjbar, Bijan; Saber, Reza; Khajeh, Khosro; Mohammadian, Mehdi</p> <p>2011-07-01</p> <p>Cauliflower-like DNAs are stem-loop DNAs that are fabricated periodically in inverted repetitions from deoxyribonucleic acid phosphates (dNTPs) by loop-mediated isothermal amplification (LAMP). Cauliflower-like DNAs have ladder-shape behaviors on gel electrophoresis, and increasing the time of LAMP leads to multiplying the repetitions, stem-loops, and electrophoretic bands. Cauliflower-like DNAs were fabricated via LAMP using two loop primers, two bumper primers, dNTPs, a λ-phage DNA template, and a Bst DNA polymerase in 75- and 90-min periods. These times led to manufacturing two types of cauliflower-like DNAs with different contents of inverted repetitions and stem-loops, which were clearly indicated by two comparable electrophoresis patterns in agarose gel. LAMP-fabricated DNAs and natural dsB-DNA (salmon genomic DNA) were dialyzed in Gomori phosphate buffer (10 mM, pH 7.4) to be isolated from salts, nucleotides, and primers. Dialyzed DNAs were studied using UV spectroscopy, circular dichroism spectropolarimetry, and fluorescence spectrophotometry. Structural analyses indicated reduction of the molecular ellipticity and extinction coefficients in comparison with B-DNA. Also, cauliflower-like DNAs demonstrated less intrinsic and more extrinsic fluorescence in comparison with natural DNA. The overwinding and lengthening of the cauliflower-like configurations of LAMP DNAs led to changes in physical parameters of this type of DNA in comparison with natural DNA. The results obtained introduced new biomolecular characteristics of DNA macromolecules fabricated within a LAMP process and show the effects of more inverted repeats and stem-loops, which are manufactured by lengthening the process.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920041224&hterms=Magnet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DMagnet','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920041224&hterms=Magnet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DMagnet"><span>Self-driven cooling loop for a large superconducting magnet in space</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mord, A. J.; Snyder, H. A.</p> <p>1992-01-01</p> <p>Pressurized cooling loops in which superfluid helium circulation is driven by the heat being removed have been previously demonstrated in laboratory tests. A simpler and lighter version which eliminates a heat exchanger by mixing the returning fluid directly with the superfluid helium bath was analyzed. A carefully designed flow restriction must be used to prevent boiling in this low-pressure system. A candidate design for Astromag is shown that can keep the magnet below 2.0 K during magnet charging. This gives a greater margin against accidental quench than approaches that allow the coolant to warm above the lambda point. A detailed analysis of one candidate design is presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990028505','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990028505"><span>Design and Testing of a Cryogenic Capillary Pumped Loop Flight Experiment</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bugby, David C.; Kroliczek, Edward J.; Ku, Jentung; Swanson, Ted; Tomlinson, B. J.; Davis, Thomas M.; Baumann, Jane; Cullimore, Brent</p> <p>1998-01-01</p> <p>This paper details the flight configuration and pre-flight performance test results of the fifth generation cryogenic capillary pumped loop (CCPL-5). This device will fly on STS-95 in October 1998 as part of the CRYOTSU Flight Experiment. This flight represents the first in-space demonstration of a CCPL; a miniaturized two-phase fluid circulator for thermally linking cryogenic components. CCPL-5 utilizes N2 as the working fluid and has a practical operating range of 75-110 K. Test results indicate that CCPL-5, which weighs about 200 grams, can transport over 10 W of cooling a distance of 0.25 m (or more) with less than a 5 K temperature drop.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1038654','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1038654"><span>The Investigation of Pointing Behaviors in Web Browsing</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2016-09-26</p> <p>fast movements have a different error model from slow movements and study the impact induced by the open-loop nature of fast 1. REPORT DATE (DD-MM-YYYY...whether or not fast movements have a different error model from slow movements and study the impact induced by the open-loop nature of fast movements. (3...PI will comparison of Fitts’ law results for natural browsing using two different pointing devices: physical mouse and laptop touchpad in order to</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70194929','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70194929"><span>Seeding hydrate formation in water-saturated sand with dissolved-phase methane obtained from hydrate dissolution: A progress report</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Waite, William F.; Osegovic, J.P.; Winters, William J.; Max, M.D.; Mason, David H.</p> <p>2008-01-01</p> <p>An isobaric flow loop added to the Gas Hydrate And Sediment Test Laboratory Instrument (GHASTLI) is being investigated as a means of rapidly forming methane hydrate in watersaturated sand from methane dissolved in water. Water circulates through a relatively warm source chamber, dissolving granular methane hydrate that was pre-made from seed ice, then enters a colder hydrate growth chamber where hydrate can precipitate in a water-saturated sand pack. Hydrate dissolution in the source chamber imparts a known methane concentration to the circulating water, and hydrate particles from the source chamber entrained in the circulating water can become nucleation sites to hasten the onset of hydrate formation in the growth chamber. Initial results suggest hydrate grows rapidly near the growth chamber inlet. Techniques for establishing homogeneous hydrate formation throughout the sand pack are being developed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020015710','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020015710"><span>Structural Damage Detection Using Virtual Passive Controllers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lew, Jiann-Shiun; Juang, Jer-Nan</p> <p>2001-01-01</p> <p>This paper presents novel approaches for structural damage detection which uses the virtual passive controllers attached to structures, where passive controllers are energy dissipative devices and thus guarantee the closed-loop stability. The use of the identified parameters of various closed-loop systems can solve the problem that reliable identified parameters, such as natural frequencies of the open-loop system may not provide enough information for damage detection. Only a small number of sensors are required for the proposed approaches. The identified natural frequencies, which are generally much less sensitive to noise and more reliable than the identified natural frequencies, are used for damage detection. Two damage detection techniques are presented. One technique is based on the structures with direct output feedback controllers while the other technique uses the second-order dynamic feedback controllers. A least-squares technique, which is based on the sensitivity of natural frequencies to damage variables, is used for accurately identifying the damage variables.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSEC33A..08L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSEC33A..08L"><span>Gulf of Mexico Loop Current Interactions with the West Florida Shelf and its Influence on Harmful Algae Blooms</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Y.; Weisberg, R. H.</p> <p>2016-02-01</p> <p>Interactions of the Loop Current (LC) system with the West Florida Shelf (WFS) are examined using 20+ years (1993 - 2015) of Ssalto/Duacs multi-mission altimetry data in the eastern Gulf of Mexico. Characteristic patterns of LC system sea surface height and surface geostrophic currents are extracted by an unsupervised neural network, Self-Organizing Map, along with their frequencies of occurrence. These current patterns suggest linkages with harmful algae bloom occurrences as recorded by in situ K. brevis cell counts. It is argued that LC system interactions with the shelf slope play an important role in WFS ecology through the upwelling of new inorganic nutrients across the shelf break. This is particularly important when the LC impinges on the southwest corner of the WFS slope, thereby impacting shallow water isobaths and setting the entire shelf circulation into motion. If such conditions persist, then deeper ocean waters with elevated nutrient content may broach the shelf and be transported landward. Resetting the nutrient state of the shelf by the coastal ocean circulation in response to deep-ocean forcing demonstrates the importance of physical oceanography in shelf ecology.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5424877','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5424877"><span>Adding the ‘heart’ to hanging drop networks for microphysiological multi-tissue experiments†</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yazdi, Saeed Rismani; Shadmani, Amir; Bürgel, Sebastian C.; Misun, Patrick M.; Hierlemann, Andreas; Frey, Olivier</p> <p>2017-01-01</p> <p>Microfluidic hanging-drop networks enable culturing and analysis of 3D microtissue spheroids derived from different cell types under controlled perfusion and investigating inter-tissue communication in multi-tissue formats. In this paper we introduce a compact on-chip pumping approach for flow control in hanging-drop networks. The pump includes one pneumatic chamber located directly above one of the hanging drops and uses the surface tension at the liquid–air-interface for flow actuation. Control of the pneumatic protocol provides a wide range of unidirectional pulsatile and continuous flow profiles. With the proposed concept several independent hanging-drop networks can be operated in parallel with only one single pneumatic actuation line at high fidelity. Closed-loop medium circulation between different organ models for multi-tissue formats and multiple simultaneous assays in parallel are possible. Finally, we implemented a real-time feedback control-loop of the pump actuation based on the beating of a human iPS-derived cardiac microtissue cultured in the same system. This configuration allows for simulating physiological effects on the heart and their impact on flow circulation between the organ models on chip. PMID:26401602</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/880046','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/880046"><span>High Average Power Laser Gain Medium With Low Optical Distortion Using A Transverse Flowing Liquid Host</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Comaskey, Brian J.; Ault, Earl R.; Kuklo, Thomas C.</p> <p>2005-07-05</p> <p>A high average power, low optical distortion laser gain media is based on a flowing liquid media. A diode laser pumping device with tailored irradiance excites the laser active atom, ion or molecule within the liquid media. A laser active component of the liquid media exhibits energy storage times longer than or comparable to the thermal optical response time of the liquid. A circulation system that provides a closed loop for mixing and circulating the lasing liquid into and out of the optical cavity includes a pump, a diffuser, and a heat exchanger. A liquid flow gain cell includes flow straighteners and flow channel compression.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24884467','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24884467"><span>Distinguishing West Nile virus infection using a recombinant envelope protein with mutations in the conserved fusion-loop.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chabierski, Stefan; Barzon, Luisa; Papa, Anna; Niedrig, Matthias; Bramson, Jonathan L; Richner, Justin M; Palù, Giorgio; Diamond, Michael S; Ulbert, Sebastian</p> <p>2014-05-09</p> <p>West Nile Virus (WNV) is an emerging mosquito-transmitted flavivirus that continues to spread and cause disease throughout several parts of the world, including Europe and the Americas. Specific diagnosis of WNV infections using current serological testing is complicated by the high degree of cross-reactivity between antibodies against other clinically relevant flaviviruses, including dengue, tick-borne encephalitis (TBEV), Japanese encephalitis (JEV), and yellow fever (YFV) viruses. Cross-reactivity is particularly problematic in areas where different flaviviruses co-circulate or in populations that have been immunized with vaccines against TBEV, JEV, or YFV. The majority of cross-reactive antibodies against the immunodominant flavivirus envelope (E) protein target a conserved epitope in the fusion loop at the distal end of domain II. We tested a loss-of-function bacterially expressed recombinant WNV E protein containing mutations in the fusion loop and an adjacent loop domain as a possible diagnostic reagent. By comparing the binding of sera from humans infected with WNV or other flaviviruses to the wild type and the mutant E proteins, we analyzed the potential of this technology to specifically detect WNV antibodies. Using this system, we could reliably determine WNV infections. Antibodies from WNV-infected individuals bound equally well to the wild type and the mutant protein. In contrast, sera from persons infected with other flaviviruses showed significantly decreased binding to the mutant protein. By calculating the mean differences between antibody signals detected using the wild type and the mutant proteins, a value could be assigned for each of the flaviviruses, which distinguished their pattern of reactivity. Recombinant mutant E proteins can be used to discriminate infections with WNV from those with other flaviviruses. The data have important implications for the development of improved, specific serological assays for the detection of WNV antibodies in regions where other flaviviruses co-circulate or in populations that are immunized with other flavivirus vaccines.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19790009309','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790009309"><span>A dual-loop model of the human controller</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hess, R. A.</p> <p>1977-01-01</p> <p>A representative model of the human controller in single-axis compensatory tracking tasks that exhibits an internal feedback loop which is not evident in single-loop models now in common use is presented. This hypothetical inner-loop involves a neuromuscular command signal derived from the time rate of change of controlled element output which is due to control activity. It is not contended that the single-loop human controller models now in use are incorrect, but that they contain an implicit but important internal loop closure, which, if explicitly considered, can account for a good deal of the adaptive nature of the human controller in a systematic manner.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28252141','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28252141"><span>Limestone calcination under calcium-looping conditions for CO2 capture and thermochemical energy storage in the presence of H2O: an in situ XRD analysis.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Valverde, Jose Manuel; Medina, Santiago</p> <p>2017-03-15</p> <p>This work reports an in situ XRD analysis of whether the calcination/carbonation behavior of natural limestone (CaCO 3 ) is affected by the addition of H 2 O to the calciner at a very low concentration under relevant Calcium-Looping (CaL) conditions for CO 2 capture in coal fired power plants (CFPP) and Thermochemical Energy Storage (TCES) in Concentrated Solar Power plants (CSP). Previous studies have demonstrated that the presence of steam in the calciner at a high concentration yields a significant increase in the reaction rate. However, a further undesired consequence is the serious deterioration of the CaO mechanical strength, which would lead to particle attrition and mass loss in any CaL process based on the use of circulating fluidized beds. The results presented in this manuscript on the time evolution of the wt% and crystallite size of the phases involved in the calcination/carbonation reactions indicate that the calcination rate is still notably increased by the presence of H 2 O at very low concentrations whereas the reactivity toward carbonation and crystal structure of the formed CaO are not essentially affected, which suggests that the CaO mechanical strength is not impaired. Thus, the benefit of using steam for calcination in the CaL process could be still retained while at the same time particle attrition would not be promoted.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoRL..42.5508T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoRL..42.5508T"><span>Southern Hemisphere extratropical circulation: Recent trends and natural variability</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thomas, Jordan L.; Waugh, Darryn W.; Gnanadesikan, Anand</p> <p>2015-07-01</p> <p>Changes in the Southern Annular Mode (SAM), Southern Hemisphere (SH) westerly jet location, and magnitude are linked with changes in ocean circulation along with ocean heat and carbon uptake. Recent trends have been observed in these fields but not much is known about the natural variability. Here we aim to quantify the natural variability of the SH extratropical circulation by using Coupled Model Intercomparison Project Phase 5 (CMIP5) preindustrial control model runs and compare with the observed trends in SAM, jet magnitude, and jet location. We show that trends in SAM are due partly to external forcing but are not outside the natural variability as described by these models. Trends in jet location and magnitude, however, lie outside the unforced natural variability but can be explained by a combination of natural variability and the ensemble mean forced trend. These results indicate that trends in these three diagnostics cannot be used interchangeably.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AcMSn..33..595Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AcMSn..33..595Z"><span>Gravitational effects on global hemodynamics in different postures: A closed-loop multiscale mathematical analysis</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Xiancheng; Noda, Shigeho; Himeno, Ryutaro; Liu, Hao</p> <p>2017-06-01</p> <p>We present a novel methodology and strategy to predict pressures and flow rates in the global cardiovascular network in different postures varying from supine to upright. A closed-loop, multiscale mathematical model of the entire cardiovascular system (CVS) is developed through an integration of one-dimensional (1D) modeling of the large systemic arteries and veins, and zero-dimensional (0D) lumped-parameter modeling of the heart, the cardiac-pulmonary circulation, the cardiac and venous valves, as well as the microcirculation. A versatile junction model is proposed and incorporated into the 1D model to cope with splitting and/or merging flows across a multibranched junction, which is validated to be capable of estimating both subcritical and supercritical flows while ensuring the mass conservation and total pressure continuity. To model gravitational effects on global hemodynamics during postural change, a robust venous valve model is further established for the 1D venous flows and distributed throughout the entire venous network with consideration of its anatomically realistic numbers and locations. The present integrated model is proven to enable reasonable prediction of pressure and flow rate waveforms associated with cardiopulmonary circulation, systemic circulation in arteries and veins, as well as microcirculation within normal physiological ranges, particularly in mean venous pressures, which well match the in vivo measurements. Applications of the cardiovascular model at different postures demonstrate that gravity exerts remarkable influence on arterial and venous pressures, venous returns and cardiac outputs whereas venous pressures below the heart level show a specific correlation between central venous and hydrostatic pressures in right atrium and veins.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JSP...162.1425K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JSP...162.1425K"><span>Feedback Regulation and Its Efficiency in Biochemical Networks</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kobayashi, Tetsuya J.; Yokota, Ryo; Aihara, Kazuyuki</p> <p>2016-03-01</p> <p>Intracellular biochemical networks fluctuate dynamically due to various internal and external sources of fluctuation. Dissecting the fluctuation into biologically relevant components is important for understanding how a cell controls and harnesses noise and how information is transferred over apparently noisy intracellular networks. While substantial theoretical and experimental advancement on the decomposition of fluctuation was achieved for feedforward networks without any loop, we still lack a theoretical basis that can consistently extend such advancement to feedback networks. The main obstacle that hampers is the circulative propagation of fluctuation by feedback loops. In order to define the relevant quantity for the impact of feedback loops for fluctuation, disentanglement of the causally interlocked influences between the components is required. In addition, we also lack an approach that enables us to infer non-perturbatively the influence of the feedback to fluctuation in the same way as the dual reporter system does in the feedforward networks. In this work, we address these problems by extending the work on the fluctuation decomposition and the dual reporter system. For a single-loop feedback network with two components, we define feedback loop gain as the feedback efficiency that is consistent with the fluctuation decomposition for feedforward networks. Then, we clarify the relation of the feedback efficiency with the fluctuation propagation in an open-looped FF network. Finally, by extending the dual reporter system, we propose a conjugate feedback and feedforward system for estimating the feedback efficiency non-perturbatively only from the statistics of the system.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002iaf..confE.902J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002iaf..confE.902J"><span>Study of Fluid Cooling Loop System in Chinese Manned Spacecraft</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiang, Jun; Xu, Jiwan; Fan, Hanlin; Huang, Jiarong</p> <p>2002-01-01</p> <p>change. To solve the questions, a fluid cooling loop system must be applied to Chinese manned spacecraft besides other conventional thermal control methods, such as thermal control coatings, multiplayer insulation blankets, heat pipes, electro-heating adjustment temperature devices, and so on. The paper will introduce the thermal design of inner and outer fluid loop including their constitution and fundamental, etc. The capability of heat transportation and the accuracy of control temperature for the fluid loop will be evaluated and analyzed. To insure the air temperature of sealed cabins within 21+/-4, the inlet liquid temperature of condensing heat exchanger needs to be controlled within 9+/-2. To insure this, the inlet liquid temperature of middle heat exchanger needs to be controlled within 8+/-1.8. The inlet temperature point is controlled by a subsidiary loop adjusting: when the computer receives feedbacks of the deviation and the variety rate of deviation from the controlled temperature point. It drives the temperature control valve to adjust the flow flux distribution between the main loop through radiator and the subsidiary loop which isn't through radiator to control the temperature of the mixed fluid within 8+/-1.8. The paper will also introduce thermal designs of key parts in the cooling loop, such as space radiators, heat exchangers and cooling plates. Thermal simulated tests on the ground and flight tests have been performed to verify correctness of thermal designs. rational and the loop system works order. It realizes the circulation of absorbing heat dissipation to the loop and transferring it to radiator then radiating it to space. (2) loop control system controls inlet temperature of middle heat exchanger within 8+/-1.8 under various thermal cases. Thermal design of the middle heat exchanger insures inlet temperature of condensing heat within 9+/-2. Thereby, the air temperature of sealed cabins is controlled within about 21+/-4 accurately. (3) The thermal designs of the key heat exchanging parts (such as radiator, heat exchangers and cooling plates) in the cooling loop are rational and effective, they meet the requirements of heat exchanging and assure the entire system work order.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910000109&hterms=deming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Ddeming','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910000109&hterms=deming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Ddeming"><span>Nonazeotropic Heat Pump</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ealker, David H.; Deming, Glenn</p> <p>1991-01-01</p> <p>Heat pump collects heat from water circulating in heat-rejection loop, raises temperature of collected heat, and transfers collected heat to water in separate pipe. Includes sealed motor/compressor with cooling coils, evaporator, and condenser, all mounted in outer housing. Gradients of temperature in evaporator and condenser increase heat-transfer efficiency of vapor-compression cycle. Intended to recover relatively-low-temperature waste heat and use it to make hot water.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090035900','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090035900"><span>Constructing LDPC Codes from Loop-Free Encoding Modules</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Divsalar, Dariush; Dolinar, Samuel; Jones, Christopher; Thorpe, Jeremy; Andrews, Kenneth</p> <p>2009-01-01</p> <p>A method of constructing certain low-density parity-check (LDPC) codes by use of relatively simple loop-free coding modules has been developed. The subclasses of LDPC codes to which the method applies includes accumulate-repeat-accumulate (ARA) codes, accumulate-repeat-check-accumulate codes, and the codes described in Accumulate-Repeat-Accumulate-Accumulate Codes (NPO-41305), NASA Tech Briefs, Vol. 31, No. 9 (September 2007), page 90. All of the affected codes can be characterized as serial/parallel (hybrid) concatenations of such relatively simple modules as accumulators, repetition codes, differentiators, and punctured single-parity check codes. These are error-correcting codes suitable for use in a variety of wireless data-communication systems that include noisy channels. These codes can also be characterized as hybrid turbolike codes that have projected graph or protograph representations (for example see figure); these characteristics make it possible to design high-speed iterative decoders that utilize belief-propagation algorithms. The present method comprises two related submethods for constructing LDPC codes from simple loop-free modules with circulant permutations. The first submethod is an iterative encoding method based on the erasure-decoding algorithm. The computations required by this method are well organized because they involve a parity-check matrix having a block-circulant structure. The second submethod involves the use of block-circulant generator matrices. The encoders of this method are very similar to those of recursive convolutional codes. Some encoders according to this second submethod have been implemented in a small field-programmable gate array that operates at a speed of 100 megasymbols per second. By use of density evolution (a computational- simulation technique for analyzing performances of LDPC codes), it has been shown through some examples that as the block size goes to infinity, low iterative decoding thresholds close to channel capacity limits can be achieved for the codes of the type in question having low maximum variable node degrees. The decoding thresholds in these examples are lower than those of the best-known unstructured irregular LDPC codes constrained to have the same maximum node degrees. Furthermore, the present method enables the construction of codes of any desired rate with thresholds that stay uniformly close to their respective channel capacity thresholds.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26827363','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26827363"><span>Note: A dual temperature closed loop batch reactor for determining the partitioning of trace gases within CO2-water systems.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Warr, Oliver; Rochelle, Christopher A; Masters, Andrew J; Ballentine, Christopher J</p> <p>2016-01-01</p> <p>An experimental approach is presented which can be used to determine partitioning of trace gases within CO2-water systems. The key advantages of this system are (1) The system can be isolated with no external exchange, making it ideal for experiments with conservative tracers. (2) Both phases can be sampled concurrently to give an accurate composition at each phase at any given time. (3) Use of a lower temperature flow loop outside of the reactor removes contamination and facilitates sampling. (4) Rapid equilibration at given pressure/temperature conditions is significantly aided by stirring and circulating the water phase using a magnetic stirrer and high-pressure liquid chromatography pump, respectively.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29706399','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29706399"><span>High performance liquid chromatography column efficiency enhancement by zero dead volume recycling and practical approach using park and recycle arrangement.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Minarik, Marek; Franc, Martin; Minarik, Milan</p> <p>2018-06-15</p> <p>A new instrumental approach to recycling HPLC is described. The concept is based on fast reintroduction of incremental peak sections back onto the separation column. The re-circulation is performed within a closed loop containing only the column and two synchronized switching valves. By having HPLC pump out of the cycle, the method minimizes peak broadening due to dead volume. As a result the efficiency is dramatically increased allowing for the most demanding analytical applications. In addition, a parking loop is employed for temporary storage of analytes from the middle section of the separated mixture prior to their recycling. Copyright © 2018 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990025391','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990025391"><span>Design and Testing of a Cryogenic Capillary Pumped Loop Flight Experiment</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bugby, David C.; Kroliczek, Edward J.; Ku, Jentung; Swanson, Ted; Tomlinson, B. J.; Davis, Thomas M.; Baumann, Jane; Cullimore, Brent</p> <p>1998-01-01</p> <p>This paper details the flight configuration and pre-flight performance test results of the fifth generation cryogenic capillary pumped loop (CCPL-5). This device will fly on STS-95 in October 1998 as part of the CRYOTSU Flight Experiment. This flight represents the first in-space demonstration of a CCPL, a miniaturized two-phase fluid circulator for thermally linking cryogenic cooling sources to remote cryogenic components. CCPL-5 utilizes N2 as the working fluid and has a practical operating range of 75-110 K. Test results indicate that CCPL-5, which weighs about 200 grams, can transport over 10 W of cooling a distance of 0.25 m (or more) with less than a 5 K temperature drop.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800021345','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800021345"><span>Solar heating and hot water system installed at office building, One Solar Place, Dallas, Texas</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1980-01-01</p> <p>A solar heating on cooling system is described which is designed to provide 87 percent of the space heating needs, 100 percent of the potable hot water needs and is sized for future absorption cooling. The collection subsystem consists of 28 solargenics, series 76, flat plate collectors with a total area of 1,596 square feet. The solar loop circulates an ethylene glyco water solution through the collectors into a hot water system exchanger. The water storage subsystem consists of a heat exchanger, two 2,300 gallon concrete hot water storage tanks with built in heat exchangers and a back-up electric boiler. The domestic hot water subsystem sends hot water to the 10,200 square feet floor area office building hot water water fixtures. The building cold water system provides make up to the solar loop, the heating loop, and the hot water concrete storage tanks. The design, construction, cost analysis, operation and maintenance of the solar system are described.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JPhCS.390a2008N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JPhCS.390a2008N"><span>Open loop, auto reversing liquid nitrogen circulation thermal system for thermo vacuum chamber</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Naidu, M. C. A.; Nolakha, Dinesh; Saharkar, B. S.; Kavani, K. M.; Patel, D. R.</p> <p>2012-11-01</p> <p>In a thermo vacuum chamber, attaining and controlling low and high temperatures (-100 Deg. C to +120 Deg. C) is a very important task. This paper describes the development of "Open loop, auto reversing liquid nitrogen based thermal system". System specifications, features, open loop auto reversing system, liquid nitrogen flow paths etc. are discussed in this paper. This thermal system consists of solenoid operated cryogenic valves, double embossed thermal plate (shroud), heating elements, temperature sensors and PLC. Bulky items like blowers, heating chambers, liquid nitrogen injection chambers, huge pipe lines and valves were not used. This entire thermal system is very simple to operate and PLC based, fully auto system with auto tuned to given set temperatures. This system requires a very nominal amount of liquid nitrogen (approx. 80 liters / hour) while conducting thermo vacuum tests. This system was integrated to 1.2m dia thermo vacuum chamber, as a part of its augmentation, to conduct extreme temperature cycling tests on passive antenna reflectors of satellites.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24959622','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24959622"><span>Heat removal from bipolar transistor by loop heat pipe with nickel and copper porous structures.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nemec, Patrik; Smitka, Martin; Malcho, Milan</p> <p>2014-01-01</p> <p>Loop heat pipes (LHPs) are used in many branches of industry, mainly for cooling of electrical elements and systems. The loop heat pipe is a vapour-liquid phase-change device that transfers heat from evaporator to condenser. One of the most important parts of the LHP is the porous wick structure. The wick structure provides capillary force to circulate the working fluid. To achieve good thermal performance of LHP, capillary wicks with high permeability and porosity and fine pore radius are expected. The aim of this work was to develop porous structures from copper and nickel powder with different grain sizes. For experiment copper powder with grain size of 50 and 100 μm and nickel powder with grain size of 10 and 25 μm were used. Analysis of these porous structures and LHP design are described in the paper. And the measurements' influences of porous structures in LHP on heat removal from the insulated gate bipolar transistor (IGBT) have been made.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880020479','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880020479"><span>Study of toluene stability for an Organic Rankine Cycle (ORC) space-based power system</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Havens, Vance; Ragaller, Dana</p> <p>1988-01-01</p> <p>The design, fabrication, assembly, and endurance operation of a dynamic test loop, built to evaluate the thermal stability of a proposed Organic Rankine Cycle (ORC) working fluid, is discussed. The test fluid, toluene, was circulated through a heater, simulated turbine, regenerator, condenser and pump to duplicate an actual ORC system. The maximum nominal fluid temperature, 750 F, was at the turbine simulator inlet. Samples of noncondensible gases and liquid toluene were taken periodically during the test. The samples were analyzed to identify the degradation products formed and the quantity of these products. From these data it was possible to determine the degradation rate of the working fluid and the generation rate of noncondensible gases. A further goal of this work was to relate the degradation observed in the dynamic operating loop to degradation obtained in isothermal capsule tests. This relationship was the basis for estimating the power loop degradation in the Space Station Organic Rankine Cycle system.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4052570','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4052570"><span>Heat Removal from Bipolar Transistor by Loop Heat Pipe with Nickel and Copper Porous Structures</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Smitka, Martin; Malcho, Milan</p> <p>2014-01-01</p> <p>Loop heat pipes (LHPs) are used in many branches of industry, mainly for cooling of electrical elements and systems. The loop heat pipe is a vapour-liquid phase-change device that transfers heat from evaporator to condenser. One of the most important parts of the LHP is the porous wick structure. The wick structure provides capillary force to circulate the working fluid. To achieve good thermal performance of LHP, capillary wicks with high permeability and porosity and fine pore radius are expected. The aim of this work was to develop porous structures from copper and nickel powder with different grain sizes. For experiment copper powder with grain size of 50 and 100 μm and nickel powder with grain size of 10 and 25 μm were used. Analysis of these porous structures and LHP design are described in the paper. And the measurements' influences of porous structures in LHP on heat removal from the insulated gate bipolar transistor (IGBT) have been made. PMID:24959622</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EPJAP..5820502S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EPJAP..5820502S"><span>Characteristics of tuneable optical filters using optical ring resonator with PCF resonance loop</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shalmashi, K.; Seraji, F. E.; Mersagh, M. R.</p> <p>2012-05-01</p> <p>A theoretical analysis of a tuneable optical filter is presented by proposing an optical ring resonator (ORR) using photonic crystal fiber (PCF) as the resonance loop. The influences of the characteristic parameters of the PCF on the filter response have been analyzed under steady-state condition of the ORR. It is shown that the tuneability of the filter is mainly achieved by changing the modulation frequency of the light signal applied to the resonator. The analyses have shown that the sharpness and the depth of the filter response are controlled by parameters such as amplitude modulation index of applied field, the coupling coefficient of the ORR, and hole-spacing and air-filling ratio of the PCF, respectively. When transmission coefficient of the loop approaches the coupling coefficient, the filter response enhances sharply with PCF parameters. The depth and the full-width at half-maximum (FWHM) of the response strongly depend on the number of field circulations in the resonator loop. With the proposed tuneability scheme for optical filter, we achieved an FWHM of ~1.55 nm. The obtained results may be utilized in designing optical add/drop filters used in WDM communication systems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23669927','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23669927"><span>Self-stabilizing optical clock pulse-train generator using SOA and saturable absorber for asynchronous optical packet processing.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nakahara, Tatsushi; Takahashi, Ryo</p> <p>2013-05-06</p> <p>We propose a novel, self-stabilizing optical clock pulse-train generator for processing preamble-free, asynchronous optical packets with variable lengths. The generator is based on an optical loop that includes a semiconductor optical amplifier (SOA) and a high-extinction spin-polarized saturable absorber (SA), with the loop being self-stabilized by balancing out the gain and absorption provided by the SOA and SA, respectively. The optical pulse train is generated by tapping out a small portion of a circulating seed pulse. The convergence of the generated pulse energy is enabled by the loop round-trip gain function that has a negative slope due to gain saturation in the SOA. The amplified spontaneous emission (ASE) of the SOA is effectively suppressed by the SA, and a backward optical pulse launched into the SOA enables overcoming the carrier-recovery speed mismatch between the SOA and SA. Without external control for the loop gain, a stable optical pulse train consisting of more than 50 pulses with low jitter is generated from a single 10-ps seed optical pulse even with a variation of 10 dB in the seed pulse intensity.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22654388-first-imaging-observation-standing-slow-wave-coronal-fan-loops','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22654388-first-imaging-observation-standing-slow-wave-coronal-fan-loops"><span>First Imaging Observation of Standing Slow Wave in Coronal Fan Loops</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Pant, V.; Tiwari, A.; Banerjee, D.</p> <p>2017-09-20</p> <p>We observe intensity oscillations along coronal fan loops associated with the active region AR 11428. The intensity oscillations were triggered by blast waves that were generated due to X-class flares in the distant active region AR 11429. To characterize the nature of oscillations, we created time–distance maps along the fan loops and noted that the intensity oscillations at two ends of the loops were out of phase. As we move along the fan loop, the amplitude of the oscillations first decreased and then increased. The out-of-phase nature together with the amplitude variation along the loop implies that these oscillations aremore » very likely to be standing waves. The period of the oscillations is estimated to be ∼27 minutes, damping time to be ∼45 minutes, and phase velocity projected in the plane of sky to be ∼65–83 km s{sup −1}. The projected phase speeds were in the range of the acoustic speed of coronal plasma at about 0.6 MK, which further indicates that these are slow waves. To the best of our knowledge, this is the first report on the existence of the standing slow waves in non-flaring fan loops.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MS%26E..307a2022I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MS%26E..307a2022I"><span>Performance of Control System Using Microcontroller for Sea Water Circulation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Indriani, A.; Witanto, Y.; Pratama, A. S.; Supriyadi; Hendra; Tanjung, A.</p> <p>2018-02-01</p> <p>Now a day control system is very important rule for any process. Control system have been used in the automatic system. Automatic system can be seen in the industrial filed, mechanical field, electrical field and etc. In industrial and mechanical field, control system are used for control of motion component such as motor, conveyor, machine, control of process made of product, control of system and soon. In electrical field, control system can met for control of electrical system as equipment or part electrical like fan, rice cooker, refrigerator, air conditioner and etc. Control system are used for control of temperature and circulation gas, air and water. Control system of temperature and circulation of water also can be used for fisher community. Control system can be create by using microcontroller, PLC and other automatic program [1][2]. In this paper we will focus on the close loop system by using microcontroller Arduino Mega to control of temperature and circulation of sea water for fisher community. Performance control system is influenced by control equipment, sensor sensitivity, test condition, environment and others. The temperature sensor is measured using the DS18S20 and the sea water clarity sensor for circulation indicator with turbidity sensor. From the test results indicated that this control system can circulate sea water and maintain the temperature and clarity of seawater in a short time.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003Cryo...43..693C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003Cryo...43..693C"><span>Experimental study on natural circulation precooling of cryogenic pump system with gas phase inlet reflux configuration</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, G. B.; Zhong, Y. K.; Zheng, X. L.; Li, Q. F.; Xie, X. M.; Gan, Z. H.; Huang, Y. H.; Tang, K.; Kong, B.; Qiu, L. M.</p> <p>2003-12-01</p> <p>A novel gas-phase inlet configuration in the natural circulation system instead of the liquid-phase inlet is introduced to cool down a cryogenic pump system from room temperature to cryogenic temperatures, effectively. The experimental apparatus is illustrated and test process is described. Heat transfer and pressure drop data during the cool-down process are recorded and portrayed. By contrast with liquid-phase inlet configuration, experimental results demonstrate that the natural circulation with the gas-phase inlet configuration is an easier and more controllable way to cool down the pump system and maintain it at cryogenic temperatures.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JCAP...04..030S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JCAP...04..030S"><span>Cosmological perturbation theory using the FFTLog: formalism and connection to QFT loop integrals</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Simonović, Marko; Baldauf, Tobias; Zaldarriaga, Matias; Carrasco, John Joseph; Kollmeier, Juna A.</p> <p>2018-04-01</p> <p>We present a new method for calculating loops in cosmological perturbation theory. This method is based on approximating a ΛCDM-like cosmology as a finite sum of complex power-law universes. The decomposition is naturally achieved using an FFTLog algorithm. For power-law cosmologies, all loop integrals are formally equivalent to loop integrals of massless quantum field theory. These integrals have analytic solutions in terms of generalized hypergeometric functions. We provide explicit formulae for the one-loop and the two-loop power spectrum and the one-loop bispectrum. A chief advantage of our approach is that the difficult part of the calculation is cosmology independent, need be done only once, and can be recycled for any relevant predictions. Evaluation of standard loop diagrams then boils down to a simple matrix multiplication. We demonstrate the promise of this method for applications to higher multiplicity/loop correlation functions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19173611','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19173611"><span>Selectivity in ligand recognition of G-quadruplex loops.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Campbell, Nancy H; Patel, Manisha; Tofa, Amina B; Ghosh, Ragina; Parkinson, Gary N; Neidle, Stephen</p> <p>2009-03-03</p> <p>A series of disubstituted acridine ligands have been cocrystallized with a bimolecular DNA G-quadruplex. The ligands have a range of cyclic amino end groups of varying size. The crystal structures show that the diagonal loop in this quadruplex results in a large cavity for these groups, in contrast to the steric constraints imposed by propeller loops in human telomeric quadruplexes. We conclude that the nature of the loop has a significant influence on ligand selectivity for particular quadruplex folds.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16268350','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16268350"><span>[Cardiovascular circulation feedback control treatment instrument].</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ge, Yu-zhi; Zhu, Xing-huan; Sheng, Guo-tai; Cao, Ping-liang; Liu, Dong-sheng; Wu, Zhi-ting</p> <p>2005-07-01</p> <p>The cardiovascular circulation feedback control treatment instrument (CFCTI) is an automatic feedback control treatment system, which has the function of monitoring, alarming, trouble self-diagnosis and testing on the line in the closed loop. The instrument is designed based on the successful clinical experiences and the data are inputted into the computer in real-time through a pressure sensor and A/D card. User interface window is set up for the doctor's choosing different medicine. The orders are outputted to control the dose of medicine through the transfusion system. The response to medicine is updated continually. CFCTI can avoid the man-made errors and the long interval of sampling. Its reliability and accuracy in rescuing the critical patients are much higher than the traditional methods.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1035094','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1035094"><span>Analytic Result for the Two-loop Six-point NMHV Amplitude in N = 4 Super Yang-Mills Theory</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Dixon, Lance J.; /SLAC; Drummond, James M.</p> <p>2012-02-15</p> <p>We provide a simple analytic formula for the two-loop six-point ratio function of planar N = 4 super Yang-Mills theory. This result extends the analytic knowledge of multi-loop six-point amplitudes beyond those with maximal helicity violation. We make a natural ansatz for the symbols of the relevant functions appearing in the two-loop amplitude, and impose various consistency conditions, including symmetry, the absence of spurious poles, the correct collinear behavior, and agreement with the operator product expansion for light-like (super) Wilson loops. This information reduces the ansatz to a small number of relatively simple functions. In order to fix these parametersmore » uniquely, we utilize an explicit representation of the amplitude in terms of loop integrals that can be evaluated analytically in various kinematic limits. The final compact analytic result is expressed in terms of classical polylogarithms, whose arguments are rational functions of the dual conformal cross-ratios, plus precisely two functions that are not of this type. One of the functions, the loop integral {Omega}{sup (2)}, also plays a key role in a new representation of the remainder function R{sub 6}{sup (2)} in the maximally helicity violating sector. Another interesting feature at two loops is the appearance of a new (parity odd) x (parity odd) sector of the amplitude, which is absent at one loop, and which is uniquely determined in a natural way in terms of the more familiar (parity even) x (parity even) part. The second non-polylogarithmic function, the loop integral {tilde {Omega}}{sup (2)}, characterizes this sector. Both {Omega}{sup (2)} and {tilde {Omega}}{sup (2)} can be expressed as one-dimensional integrals over classical polylogarithms with rational arguments.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JMMM..431..229Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JMMM..431..229Y"><span>Energy transport in cooling device by magnetic fluid</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yamaguchi, Hiroshi; Iwamoto, Yuhiro</p> <p>2017-06-01</p> <p>Temperature sensitive magnetic fluid has a great potential with high performance heat transport ability as well as long distance energy (heat) transporting. In the present study experimental set-up was newly designed and constructed in order to measure basic heat transport characteristics under various magnetic field conditions. Angular dependence for the device (heat transfer section) was also taken into consideration for a sake of practical applications. The energy transfer characteristic (heat transport capability) in the magnetically-driven heat transport (cooling) device using the binary TSMF was fully investigated with the set-up. The obtained results indicate that boiling of the organic mixture (before the magnetic fluid itself reaching boiling point) effectively enhances the heat transfer as well as boosting the flow to circulate in the closed loop by itself. A long-distance heat transport of 5 m is experimentally confirmed, transferring the thermal energy of 35.8 W, even when the device (circulation loop) is horizontally placed. The highlighted results reveal that the proposed cooling device is innovative in a sense of transporting substantial amount of thermal energy (heat) as well as a long distance heat transport. The development of the magnetically-driven heat transport device has a great potential to be replaced for the conventional heat pipe in application of thermal engineering.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/6533940','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/6533940"><span>COBRA-WC pretest predictions and post-test analysis of the FOTA temperature distribution during FFTF natural-circulation transients</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Khan, E.U.; George, T.L.; Rector, D.R.</p> <p></p> <p>The natural circulation tests of the Fast Flux Test Facility (FFTF) demonstrated a safe and stable transition from forced convection to natural convection and showed that natural convection may adequately remove decay heat from the reactor core. The COBRA-WC computer code was developed by the Pacific Northwest laboratory (PNL) to account for buoyancy-induced coolant flow redistribution and interassembly heat transfer, effects that become important in mitigating temperature gradients and reducing reactor core temperatures when coolant flow rate in the core is low. This report presents work sponsored by the US Department of Energy (DOE) with the objective of checking themore » validity of COBRA-WC during the first 220 seconds (sec) of the FFTF natural-circulation (plant-startup) tests using recorded data from two instrumented Fuel Open Test Assemblies (FOTAs). Comparison of COBRA-WC predictions of the FOTA data is a part of the final confirmation of the COBRA-WC methodology for core natural-convection analysis.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010pot..book.1095L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010pot..book.1095L"><span>Characterization of Combustion and Emission of Several Kinds of Herbaceous Biomass Pellets in a Circulating Fluidized Bed Combustor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, S. Y.; Teng, H. P.; Jiao, W. H.; Shang, L. L.; Lu, Q. G.</p> <p></p> <p>Characterizations of combustion and emission of four kinds of herbaceous biomass pellets were investigated in a 0.15 MWt circulating fluidized bed. Corn stalk, wheat stalk, cotton stalk and king grass, which are typical herbaceous biomass in China, were chosen for this study. Temperature profile, emission in flue gas and agglomeration were studied by changing the combustion temperature between 750°C and 880°C. The combustion efficiencies are in the range from 97.4% to 99.4%, which are relatively high due to the homogeneous temperature profiles and good circulating fluidization of bed material. Suitable combustion temperatures for the different herbaceous biomass are mainly depended on the emission and bed agglomeration. SO2 and HCl concentrations in flue gas are in direct proportion to the sulfur and chlorine contents of the herbaceous biomass. Agglomeration at the cyclone leg and the loop seal is the main reason for defluidization in the CFB combustor.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMOS43C1296N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMOS43C1296N"><span>Upwelling and downwelling induced by mesoscale circulation in the DeSoto Canyon region</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nguyen, T. T.; Chassignet, E.; Morey, S. L.; Dukhovskoy, D. S.</p> <p>2014-12-01</p> <p>Ocean dynamics are complex over irregular topography areas, and the northeastern Gulf of Mexico, specifically the DeSoto Canyon region, is a challenge for modelers and oceanographers. Vertical movement of waters, especially upwelling, is observed to take place over the canyon's head and along the coast; however, it is not well understood. We focus on upwelling/downwelling processes induced by the Loop Current and its associated eddy field using multi-decadal Hybrid Coordinate Ocean Model simulations. The Loop Current, part of the Gulf Stream, can develop northward into the Gulf through the Yucatan Channel and exit through the Florida Straits. It can reach the continental slope of the study domain and directly depress the isopycnals. Cyclonic eddies in front of the Loop Current also induce upwelling underneath. On the other hand, the Loop Current sometimes impinges on the West Florida Shelf and generates a high pressure disturbance, which travels northward along the shelf into the study region. Consequently, large-scale downwelling occurs across the continental slopes. Our analysis of sea surface height shows that the Loop Current pressure disturbance tends to propagate along the shallow isobaths of 100 to 300 m in the topographic wave direction from south of the West Florida Shelf to the Mississippi Delta. In addition, after shedding a large anticyclonic eddy, the Loop Current retracts southward and can touch the southeastern corner of the West Florida Shelf. This can result in a higher pressure disturbance, and therefore stronger large-scale downwelling in the DeSoto Canyon region.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22482843-note-dual-temperature-closed-loop-batch-reactor-determining-partitioning-trace-gases-within-co-sub-water-systems','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22482843-note-dual-temperature-closed-loop-batch-reactor-determining-partitioning-trace-gases-within-co-sub-water-systems"><span>Note: A dual temperature closed loop batch reactor for determining the partitioning of trace gases within CO{sub 2}-water systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Warr, Oliver, E-mail: oliver.warr@earth.ox.ac.uk; Ballentine, Christopher J.; Rochelle, Christopher A.</p> <p></p> <p>An experimental approach is presented which can be used to determine partitioning of trace gases within CO{sub 2}-water systems. The key advantages of this system are (1) The system can be isolated with no external exchange, making it ideal for experiments with conservative tracers. (2) Both phases can be sampled concurrently to give an accurate composition at each phase at any given time. (3) Use of a lower temperature flow loop outside of the reactor removes contamination and facilitates sampling. (4) Rapid equilibration at given pressure/temperature conditions is significantly aided by stirring and circulating the water phase using a magneticmore » stirrer and high-pressure liquid chromatography pump, respectively.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1129744-phase-shift-method-estimate-solids-circulation-rate-circulating-fluidized-beds','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1129744-phase-shift-method-estimate-solids-circulation-rate-circulating-fluidized-beds"><span>Phase shift method to estimate solids circulation rate in circulating fluidized beds</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ludlow, James Christopher; Panday, Rupen; Shadle, Lawrence J.</p> <p>2013-01-01</p> <p>While solids circulation rate is a critical design and control parameter in circulating fluidized bed (CFB) reactor systems, there are no available techniques to measure it directly at conditions of industrial interest. Cold flow tests have been conducted at NETL in an industrial scale CFB unit where the solids flow has been the topic of research in order to develop an independent method which could be applied to CFBs operating under the erosive and corrosive high temperatures and pressures of a coal fired boiler or gasifier. The dynamic responses of the CFB loop to modest modulated aeration flows in themore » return leg or standpipe were imposed to establish a periodic response in the unit without causing upset in the process performance. The resulting periodic behavior could then be analyzed with a dynamic model and the average solids circulation rate could be established. This method was applied to the CFB unit operated under a wide range of operating conditions including fast fluidization, core annular flow, dilute and dense transport, and dense suspension upflow. In addition, the system was operated in both low and high total solids inventories to explore the influence of inventory limiting cases on the estimated results. The technique was able to estimate the solids circulation rate for all transport circulating fluidized beds when operating above upper transport velocity, U{sub tr2}. For CFB operating in the fast fluidized bed regime (i.e., U{sub g}< U{sub tr2}), the phase shift technique was not successful. The riser pressure drop becomes independent of the solids circulation rate and the mass flow rate out of the riser does not show modulated behavior even when the riser pressure drop does.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4686674','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4686674"><span>Groundwater Isolation Governs Chemistry and Microbial Community Structure along Hydrologic Flowpaths</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ben Maamar, Sarah; Aquilina, Luc; Quaiser, Achim; Pauwels, Hélène; Michon-Coudouel, Sophie; Vergnaud-Ayraud, Virginie; Labasque, Thierry; Roques, Clément; Abbott, Benjamin W.; Dufresne, Alexis</p> <p>2015-01-01</p> <p>This study deals with the effects of hydrodynamic functioning of hard-rock aquifers on microbial communities. In hard-rock aquifers, the heterogeneous hydrologic circulation strongly constrains groundwater residence time, hydrochemistry, and nutrient supply. Here, residence time and a wide range of environmental factors were used to test the influence of groundwater circulation on active microbial community composition, assessed by high throughput sequencing of 16S rRNA. Groundwater of different ages was sampled along hydrogeologic paths or loops, in three contrasting hard-rock aquifers in Brittany (France). Microbial community composition was driven by groundwater residence time and hydrogeologic loop position. In recent groundwater, in the upper section of the aquifers or in their recharge zone, surface water inputs caused high nitrate concentration and the predominance of putative denitrifiers. Although denitrification does not seem to fully decrease nitrate concentrations due to low dissolved organic carbon concentrations, nitrate input has a major effect on microbial communities. The occurrence of taxa possibly associated with the application of organic fertilizers was also noticed. In ancient isolated groundwater, an ecosystem based on Fe(II)/Fe(III) and S/SO4 redox cycling was observed down to several 100 of meters below the surface. In this depth section, microbial communities were dominated by iron oxidizing bacteria belonging to Gallionellaceae. The latter were associated to old groundwater with high Fe concentrations mixed to a small but not null percentage of recent groundwater inducing oxygen concentrations below 2.5 mg/L. These two types of microbial community were observed in the three sites, independently of site geology and aquifer geometry, indicating hydrogeologic circulation exercises a major control on microbial communities. PMID:26733990</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/5076283-influence-fentanyl-morphine-intestinal-circulation','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5076283-influence-fentanyl-morphine-intestinal-circulation"><span>Influence of fentanyl and morphine on intestinal circulation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Tverskoy, M.; Gelman, S.; Fowler, K.C.</p> <p></p> <p>The influence of fentanyl and morphine on the intestinal circulation was evaluated in an isolated loop preparation in 37 dogs anesthetized with pentobarbital intravenously. Selected intestinal segments were pumped with aortic blood at a constant pressure of 100 mm Hg. A mixture of /sup 86/Rb and 9-micron spheres labeled with /sup 141/Ce was injected into the arterial cannula supplying the intestinal loop, while mesenteric venous blood was collected for activity counting. A strong correlation was found between the clearances of rubidium and microspheres (r = 0.97, P less than 0.0001), suggesting that the shunting of 9-micron spheres through the intestinesmore » reflects the shunting of blood through nonnutritive vessels. Intravenous fentanyl decreased oxygen uptake (O/sub 2/up), and vascular resistance (VR), and increased blood flow (BF), rubidium and microsphere clearances (Cl-Rb, Cl-Sph, respectively), and permeability--surface area product (PS) in a dose-related fashion. Intravenous morphine in a dose of 1 mg X kg-1 increased Cl-Rb (nutritive BF) without changes in total (nutritive and nonnutritive) BF. This increase in nutritive BF is probably related to morphine-induced histamine release. Morphine in a dose of 5 mg X kg-1 was accompanied by vasoconstriction that was completely abolished by alpha-adrenoceptor blockade. The data suggest that morphine-induced intestinal vasoconstriction is mediated via a release of epinephrine, apparently from the adrenal medulla. It is concluded that changes in the intestinal circulation during anesthesia with narcotics might play a certain role in the cardiovascular homeostasis during anesthesia and surgery. An increase in oxygen content in portal venous blood, resulting from a decrease in intestinal oxygen uptake, should facilitate hepatic oxygenation.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvL.115l1603G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvL.115l1603G"><span>Loop Integrands for Scattering Amplitudes from the Riemann Sphere</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geyer, Yvonne; Mason, Lionel; Monteiro, Ricardo; Tourkine, Piotr</p> <p>2015-09-01</p> <p>The scattering equations on the Riemann sphere give rise to remarkable formulas for tree-level gauge theory and gravity amplitudes. Adamo, Casali, and Skinner conjectured a one-loop formula for supergravity amplitudes based on scattering equations on a torus. We use a residue theorem to transform this into a formula on the Riemann sphere. What emerges is a framework for loop integrands on the Riemann sphere that promises to have a wide application, based on off-shell scattering equations that depend on the loop momentum. We present new formulas, checked explicitly at low points, for supergravity and super-Yang-Mills amplitudes and for n -gon integrands at one loop. Finally, we show that the off-shell scattering equations naturally extend to arbitrary loop order, and we give a proposal for the all-loop integrands for supergravity and planar super-Yang-Mills theory.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3203546','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3203546"><span>Efficient Ligation of the Schistosoma Hammerhead Ribozyme †</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Canny, Marella D.; Jucker, Fiona M.; Pardi, Arthur</p> <p>2011-01-01</p> <p>The hammerhead ribozyme from Schistosoma mansoni is the best characterized of the natural hammerhead ribozymes. Biophysical, biochemical, and structural studies have shown that the formation of the loop-loop tertiary interaction between stems I and II alters the global folding, cleavage kinetics, and conformation of the catalytic core of this hammerhead, leading to a ribozyme that is readily cleaved under physiological conditions. This study investigates the ligation kinetics and the internal equilibrium between cleavage and ligation for the Schistosoma hammerhead. Single turnover kinetic studies on a construct where the ribozyme cleaves and ligates substrate(s) in trans showed up to 23% ligation when starting from fully cleaved products. This was achieved by a ~2,000-fold increase in the rate of ligation compared to a minimal hammerhead without the loop-loop tertiary interaction, yielding an internal equilibrium that ranges from 2–3 at physiological Mg2+ ion concentrations (0.1 –1 mM). Thus, the natural Schistosoma hammerhead ribozyme is almost as efficient at ligation as it is at cleavage. The results here are consistent with a model where formation of the loop-loop tertiary interaction leads to a higher population of catalytically active molecules, and where formation of this tertiary interaction has a much larger effect on the ligation than the cleavage activity of the Schistosoma hammerhead ribozyme. PMID:17319693</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1265312-high-temperature-annealing-ion-irradiated-tungsten','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1265312-high-temperature-annealing-ion-irradiated-tungsten"><span>High temperature annealing of ion irradiated tungsten</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Ferroni, Francesco; Yi, Xiaoou; Arakawa, Kazuto; ...</p> <p>2015-03-21</p> <p>In this study, transmission electron microscopy of high temperature annealing of pure tungsten irradiated by self-ions was conducted to elucidate microstructural and defect evolution in temperature ranges relevant to fusion reactor applications (500–1200°C). Bulk isochronal and isothermal annealing of ion irradiated pure tungsten (2 MeV W + ions, 500°C, 1014 W +/cm 2) with temperatures of 800, 950, 1100 and 1400°C, from 0.5 to 8 h, was followed by ex situ characterization of defect size, number density, Burgers vector and nature. Loops with diameters larger than 2–3 nm were considered for detailed analysis, among which all loops had View themore » MathML source and were predominantly of interstitial nature. In situ annealing experiments from 300 up to 1200°C were also carried out, including dynamic temperature ramp-ups. These confirmed an acceleration of loop loss above 900°C. At different temperatures within this range, dislocations exhibited behaviour such as initial isolated loop hopping followed by large-scale rearrangements into loop chains, coalescence and finally line–loop interactions and widespread absorption by free-surfaces at increasing temperatures. An activation energy for the annealing of dislocation length was obtained, finding E a=1.34±0.2 eV for the 700–1100°C range.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JHEP...03..068G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JHEP...03..068G"><span>Gluons and gravitons at one loop from ambitwistor strings</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geyer, Yvonne; Monteiro, Ricardo</p> <p>2018-03-01</p> <p>We present new and explicit formulae for the one-loop integrands of scattering amplitudes in non-supersymmetric gauge theory and gravity, valid for any number of particles. The results exhibit the colour-kinematics duality in gauge theory and the double-copy relation to gravity, in a form that was recently observed in supersymmetric theories. The new formulae are expressed in a particular representation of the loop integrand, with only one quadratic propagator, which arises naturally from the framework of the loop-level scattering equations. The starting point in our work are the expressions based on the scattering equations that were recently derived from ambitwistor string theory. We turn these expressions into explicit formulae depending only on the loop momentum, the external momenta and the external polarisations. These formulae are valid in any number of spacetime dimensions for pure Yang-Mills theory (gluon) and its natural double copy, NS-NS gravity (graviton, dilaton, B-field), and we also present formulae in four spacetime dimensions for pure gravity (graviton). We perform several tests of our results, such as checking gauge invariance and directly matching our four-particle formulae to previously known expressions. While these tests would be elaborate in a Feynman-type representation of the loop integrand, they become straightforward in the representation we use.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JHEP...08..031N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JHEP...08..031N"><span>Electric dipole moments in natural supersymmetry</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakai, Yuichiro; Reece, Matthew</p> <p>2017-08-01</p> <p>We discuss electric dipole moments (EDMs) in the framework of CP-violating natural supersymmetry (SUSY). Recent experimental results have significantly tightened constraints on the EDMs of electrons and of mercury, and substantial further progress is expected in the near future. We assess how these results constrain the parameter space of natural SUSY. In addition to our discussion of SUSY, we provide a set of general formulas for two-loop fermion EDMs, which can be applied to a wide range of models of new physics. In the SUSY context, the two-loop effects of stops and charginos respectively constrain the phases of A t μ and M 2 μ to be small in the natural part of parameter space. If the Higgs mass is lifted to 125 GeV by a new tree-level superpotential interaction and soft term with CP-violating phases, significant EDMs can arise from the two-loop effects of W bosons and tops. We compare the bounds arising from EDMs to those from other probes of new physics including colliders, b → sγ, and dark matter searches. Importantly, improvements in reach not only constrain higher masses, but require the phases to be significantly smaller in the natural parameter space at low mass. The required smallness of phases sharpens the CP problem of natural SUSY model building.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006CQGra..23R..63L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006CQGra..23R..63L"><span>TOPICAL REVIEW: Knot theory and a physical state of quantum gravity</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liko, Tomás; Kauffman, Louis H.</p> <p>2006-02-01</p> <p>We discuss the theory of knots, and describe how knot invariants arise naturally in gravitational physics. The focus of this review is to delineate the relationship between knot theory and the loop representation of non-perturbative canonical quantum general relativity (loop quantum gravity). This leads naturally to a discussion of the Kodama wavefunction, a state which is conjectured to be the ground state of the gravitational field with positive cosmological constant. This review can serve as a self-contained introduction to loop quantum gravity and related areas. Our intent is to make the paper accessible to a wider audience that may include topologists, knot theorists, and other persons innocent of the physical background to this approach to quantum gravity.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/930654-mechanism-which-influenza-virus-nucleoprotein-forms-oligomers-binds-rna','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/930654-mechanism-which-influenza-virus-nucleoprotein-forms-oligomers-binds-rna"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ye, Qiaozhen; Krug, Robert M.; Tao, Yizhi Jane</p> <p></p> <p>Influenza A viruses pose a serious threat to world public health, particularly the currently circulating avian H5N1 viruses. The influenza viral nucleoprotein forms the protein scaffold of the helical genomic ribonucleoprotein complexes, and has a critical role in viral RNA replication. Here we report a 3.2 Angstrom crystal structure of this nucleoprotein, the overall shape of which resembles a crescent with a head and a body domain, with a protein fold different compared with that of the rhabdovirus nucleoprotein. Oligomerization of the influenza virus nucleoprotein is mediated by a flexible tail loop that is inserted inside a neighboring molecule. Thismore » flexibility in the tail loop enables the nucleoprotein to form loose polymers as well as rigid helices, both of which are important for nucleoprotein functions. Single residue mutations in the tail loop result in the complete loss of nucleoprotein oligomerization. An RNA-binding groove, which is found between the head and body domains at the exterior of the nucleoprotein oligomer, is lined with highly conserved basic residues widely distributed in the primary sequence. The nucleoprotein structure shows that only one of two proposed nuclear localization signals are accessible, and suggests that the body domain of nucleoprotein contains the binding site for the viral polymerase. Our results identify the tail loop binding pocket as a potential target for antiviral development.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/6123086','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/6123086"><span>SASSYS pretest analysis of the THORS-SHRS experiments. [LMFBR</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bordner, G.L.; Dunn, F.E.</p> <p></p> <p>The THORS Facility at ORNL was recently modified to allow the testing of two parallel 19-pin simulated fueled subassemblies under natural circulation conditions similar to those that might occur during a partial failure of the shutdown heat removal system (SHRS) of a liquid-metal fast breeder reactor. The planned experimental program included a series of tests at various inlet plenum temperatures to determine boiling threshold power levels and the power range for stable boiling during natural circulation operation. Pretest calculations were performed at ANL, which supplement those carried out at ORNL for the purposes of validating the SASSYS model in themore » natural circulation regime and of providing data which would be useful in planning the experiments.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004EOSTr..85..333P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004EOSTr..85..333P"><span>Global Change and the Earth System</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pollack, Henry N.</p> <p>2004-08-01</p> <p>The Earth system in recent years has come to mean the complex interactions of the atmosphere, biosphere, lithosphere and hydrosphere, through an intricate network of feedback loops. This system has operated over geologic time, driven principally by processes with long time scales. Over the lifetime of the solar system, the Sun has slowly become more radiant, and the geography of continents and oceans basins has evolved via plate tectonics. This geography has placed a first-order constraint on the circulation of ocean waters, and thus has strongly influenced regional and global climate. At shorter time scales, the Earth system has been influenced by Milankovitch orbital factors and occasional exogenous events such as bolide impacts. Under these influences the system chugged along for eons, until some few hundred thousand years ago, when one remarkable species evolved: Homo sapiens. As individuals, humans are of course insignificant in shaping the Earth system, but collectively the six billion human occupants of the planet now rival ``natural'' processes in modifying the Earth system. This profound human influence underlies the dubbing of the present epoch of geologic history as the ``Anthropocene.''</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/874783','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/874783"><span>Photon generator</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Srinivasan-Rao, Triveni</p> <p>2002-01-01</p> <p>A photon generator includes an electron gun for emitting an electron beam, a laser for emitting a laser beam, and an interaction ring wherein the laser beam repetitively collides with the electron beam for emitting a high energy photon beam therefrom in the exemplary form of x-rays. The interaction ring is a closed loop, sized and configured for circulating the electron beam with a period substantially equal to the period of the laser beam pulses for effecting repetitive collisions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22470089-prediction-technological-failures-nuclear-power-plant-operation','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22470089-prediction-technological-failures-nuclear-power-plant-operation"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Salnykov, A. A., E-mail: admin@rasnpp.org.ru</p> <p></p> <p>A method for predicting operating technological failures in nuclear power plants which makes it possible to reduce the unloading of the generator unit during the onset and development of an anomalous engineering state of the equipment by detecting a change in state earlier and taking suitable measures. With the circulating water supply loop of a nuclear power plant as an example, scenarios and algorithms for predicting technological failures in the operation of equipment long before their actual occurrence are discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4770242','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4770242"><span>DNA–DNA kissing complexes as a new tool for the assembly of DNA nanostructures</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Barth, Anna; Kobbe, Daniela; Focke, Manfred</p> <p>2016-01-01</p> <p>Kissing-loop annealing of nucleic acids occurs in nature in several viruses and in prokaryotic replication, among other circumstances. Nucleobases of two nucleic acid strands (loops) interact with each other, although the two strands cannot wrap around each other completely because of the adjacent double-stranded regions (stems). In this study, we exploited DNA kissing-loop interaction for nanotechnological application. We functionalized the vertices of DNA tetrahedrons with DNA stem-loop sequences. The complementary loop sequence design allowed the hybridization of different tetrahedrons via kissing-loop interaction, which might be further exploited for nanotechnology applications like cargo transport and logical elements. Importantly, we were able to manipulate the stability of those kissing-loop complexes based on the choice and concentration of cations, the temperature and the number of complementary loops per tetrahedron either at the same or at different vertices. Moreover, variations in loop sequences allowed the characterization of necessary sequences within the loop as well as additional stability control of the kissing complexes. Therefore, the properties of the presented nanostructures make them an important tool for DNA nanotechnology. PMID:26773051</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/20837906-experimental-investigation-natural-circulation-flow-behavior-under-low-power-low-pressure-conditions-large-scale-panda-facility','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20837906-experimental-investigation-natural-circulation-flow-behavior-under-low-power-low-pressure-conditions-large-scale-panda-facility"><span>Experimental Investigation of Natural-Circulation Flow Behavior Under Low-Power/Low-Pressure Conditions in the Large-Scale PANDA Facility</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Auban, Olivier; Paladino, Domenico; Zboray, Robert</p> <p>2004-12-15</p> <p>Twenty-five tests have been carried out in the large-scale thermal-hydraulic facility PANDA to investigate natural-circulation and stability behavior under low-pressure/low-power conditions, when void flashing might play an important role. This work, which extends the current experimental database to a large geometric scale, is of interest notably with regard to the start-up procedures in natural-circulation-cooled boiling water reactors. It should help the understanding of the physical phenomena that may cause flow instability in such conditions and can be used for validation of thermal-hydraulics system codes. The tests were performed at a constant power, balanced by a specific condenser heat removal capacity.more » The test matrix allowed the reactor pressure vessel power and pressure to be varied, as well as other parameters influencing the natural-circulation flow. The power spectra of flow oscillations showed in a few tests a major and unique resonance peak, and decay ratios between 0.5 and 0.9 have been found. The remainder of the tests showed an even more pronounced stable behavior. A classification of the tests is presented according to the circulation modes (from single-phase to two-phase flow) that could be assumed and particularly to the importance and the localization of the flashing phenomenon.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19778256','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19778256"><span>Loop system for creating jet fuel vapor standards used in the calibration of infrared spectrophotometers and gas chromatographs.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reboulet, James; Cunningham, Robert; Gunasekar, Palur G; Chapman, Gail D; Stevens, Sean C</p> <p>2009-02-01</p> <p>A whole body inhalation study of mixed jet fuel vapor and its aerosol necessitated the development of a method for preparing vapor only standards from the neat fuel. Jet fuel is a complex mixture of components which partitions between aerosol and vapor when aspirated based on relative volatility of the individual compounds. A method was desired which could separate the vapor portion from the aerosol component to prepare standards for the calibration of infrared spectrophotometers and a head space gas chromatography system. A re-circulating loop system was developed which provided vapor only standards whose composition matched those seen in an exposure system. Comparisons of nominal concentrations in the exposure system to those determined by infrared spectrophotometry were in 92-95% agreement. Comparison of jet fuel vapor concentrations determined by infrared spectrophotometry compared to head space gas chromatography yielded a 93% overall agreement in trial runs. These levels of agreement show the loop system to be a viable method for creating jet fuel vapor standards for calibrating instruments.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/886876','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/886876"><span>Silica Precipitation and Scaling in Dynamic Geothermal Systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bohlmann, E.G.; Shor, A.J.; Berlinski, P.</p> <p>1976-01-01</p> <p>The authors are modifying an existing 100 gpm titanium loop to provide a facility for studying the formation of silica precipitates, their properties and fates, principally as a function of brine composition, temperature, and flow conditions. This loop demonstrated excellent serviceability over a period of years in saline water corrosion studies (to 275 C and 2 M NaCl), with and without pollutant additives such as H{sub 2}S, NH{sub 3}, and SO{sub 2}, and should be equally useful in this application. Simulated silica saturated geothermal waters are prepared by circulating part of the loop flow ({approx} 1 gpm) through a bypassmore » column filled with amorphous silica powder. Exploratory studies in a Once-Through Development System indicated that porous Vycor (Cornin-Glass Code No.7930, 97% SiO{sub 2}, 3% B{sub 2}O{sub 3}) was a suitable material for loading the column. A recent run at {approx} 220 C confirmed this: the system approached equilibrium in agreement with calculation and with the anticipated 15 psi pressure drop through an 18 in. deep bed of 140-200 mesh Vycor powder.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28005494','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28005494"><span>Glomerular Lesions in Proteinuric Miniature Schnauzer Dogs.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Furrow, E; Lees, G E; Brown, C A; Cianciolo, R E</p> <p>2017-05-01</p> <p>Miniature Schnauzer dogs are predisposed to idiopathic hypertriglyerceridemia, which increases risk for diseases such as pancreatitis and gallbladder mucocele. Recently, elevated triglyceride concentrations have been associated with proteinuria in this breed, although it is difficult to determine which abnormality is primary. Retrospective review of renal tissue from 27 proteinuric Miniature Schnauzers revealed that 20 dogs had ultrastructural evidence of osmophilic globules consistent with lipid in glomerular tufts. Seven of these dogs had lipid thromboemboli in glomerular capillary loops that distorted their shape and compressed circulating erythrocytes. Triglyceride concentrations were reported in 6 of these 7 dogs, and all were hypertriglyceridemic. In addition, glomerular lipidosis (defined as accumulation of foam cells within peripheral capillary loops) was identified in a single dog. The remaining 12 dogs had smaller amounts of lipid that could only be identified ultrastructurally. Neither signalment data nor clinicopathologic parameters (serum albumin, serum creatinine, urine protein-to-creatinine ratio, and blood pressure) differed among the various types of lipid lesions. During the time course of this study, all dogs diagnosed with glomerular lipid thromboemboli were Miniature Schnauzers, underscoring the importance of recognizing these clear spaces within capillary loops as lipid.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..96u4504C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..96u4504C"><span>No evidence for orbital loop currents in charge-ordered YBa2Cu3O6 +x from polarized neutron diffraction</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Croft, T. P.; Blackburn, E.; Kulda, J.; Liang, Ruixing; Bonn, D. A.; Hardy, W. N.; Hayden, S. M.</p> <p>2017-12-01</p> <p>It has been proposed that the pseudogap state of underdoped cuprate superconductors may be due to a transition to a phase which has circulating currents within each unit cell. Here, we use polarized neutron diffraction to search for the corresponding orbital moments in two samples of underdoped YBa2Cu3O6 +x with doping levels p =0.104 and 0.123. In contrast to some other reports using polarized neutrons, but in agreement with nuclear magnetic resonance and muon spin rotation measurements, we find no evidence for the appearance of magnetic order below 300 K. Thus, our experiment suggests that such order is not an intrinsic property of high-quality cuprate superconductor single crystals. Our results provide an upper bound for a possible orbital loop moment which depends on the pattern of currents within the unit cell. For example, for the CC-θI I pattern proposed by Varma, we find that the ordered moment per current loop is less than 0.013 μB for p =0.104 .</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080004793','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080004793"><span>Staged regenerative sorption heat pump</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jones, Jack A. (Inventor)</p> <p>1995-01-01</p> <p>A regenerative adsorbent heat pump process and system for cooling and heating a space. A sorbent is confined in a plurality of compressors of which at least four are first stage and at least four are second stage. The first stage operates over a first pressure region and the second stage over a second pressure region which is higher than the first. Sorbate from the first stage enters the second stage. The sorbate loop includes a condenser, expansion valve, evaporator and the compressors. A single sorbate loop can be employed for single-temperature-control such as air conditioning and heating. Two sorbate loops can be used for two-temperature-control as in a refrigerator and freezer. The evaporator temperatures control the freezer and refrigerator temperatures. Alternatively the refrigerator temperature can be cooled by the freezer with one sorbate loop. A heat transfer fluid is circulated in a closed loop which includes a radiator and the compressors. Low temperature heat is exhausted by the radiator. High temperature heat is added to the heat transfer fluid entering the compressors which are desorbing vapor. Heat is transferred from compressors which are sorbing vapor to the heat transfer fluid, and from the heat transfer fluid to the compressors which are desorbing vapor. Each compressor is subjected to the following phases, heating to its highest temperature, cooling down from its highest temperature, cooling to its lowest temperature, and warming up from its lowest temperature. The phases are repeated to complete a cycle and regenerate heat.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18959664','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18959664"><span>Physiological control of a rotary blood pump with selectable therapeutic options: control of pulsatility gradient.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Arndt, Andreas; Nüsser, Peter; Graichen, Kurt; Müller, Johannes; Lampe, Bernhard</p> <p>2008-10-01</p> <p>A control strategy for rotary blood pumps meeting different user-selectable control objectives is proposed: maximum support with the highest feasible flow rate versus medium support with maximum ventricular washout and controlled opening of the aortic valve (AoV). A pulsatility index (PI) is calculated from the pressure difference, which is deduced from the axial thrust measured by the magnetic bearing of the pump. The gradient of PI with respect to pump speed (GPI) is estimated via online system identification. The outer loop of a cascaded controller regulates GPI to a reference value satisfying the selected control objective. The inner loop controls the PI to a reference value set by the outer loop. Adverse pumping states such as suction and regurgitation can be detected on the basis of the GPI estimates and corrected by the controller. A lumped-parameter computer model of the assisted circulation was used to simulate variations of ventricular contractility, pulmonary venous pressure, and aortic pressure. The performance of the outer control loop was demonstrated by transitions between the two control modes. Fast reaction of the inner loop was tested by stepwise reduction of venous return. For maximum support, a low PI was maintained without inducing ventricular collapse. For maximum washout, the pump worked at a high PI in the transition region between the opening and the permanently closed AoV. The cascaded control of GPI and PI is able to meet different control objectives and is worth testing in vitro and in vivo.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MS%26E..278a2116B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MS%26E..278a2116B"><span>Model-based minimization algorithm of a supercritical helium loop consumption subject to operational constraints</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bonne, F.; Bonnay, P.; Girard, A.; Hoa, C.; Lacroix, B.; Le Coz, Q.; Nicollet, S.; Poncet, J.-M.; Zani, L.</p> <p>2017-12-01</p> <p>Supercritical helium loops at 4.2 K are the baseline cooling strategy of tokamaks superconducting magnets (JT-60SA, ITER, DEMO, etc.). This loops work with cryogenic circulators that force a supercritical helium flow through the superconducting magnets in order that the temperature stay below the working range all along their length. This paper shows that a supercritical helium loop associated with a saturated liquid helium bath can satisfy temperature constraints in different ways (playing on bath temperature and on the supercritical flow), but that only one is optimal from an energy point of view (every Watt consumed at 4.2 K consumes at least 220 W of electrical power). To find the optimal operational conditions, an algorithm capable of minimizing an objective function (energy consumption at 5 bar, 5 K) subject to constraints has been written. This algorithm works with a supercritical loop model realized with the Simcryogenics [2] library. This article describes the model used and the results of constrained optimization. It will be possible to see that the changes in operating point on the temperature of the magnet (e.g. in case of a change in the plasma configuration) involves large changes on the cryodistribution optimal operating point. Recommendations will be made to ensure that the energetic consumption is kept as low as possible despite the changing operating point. This work is partially supported by EUROfusion Consortium through the Euratom Research and Training Program 20142018 under Grant 633053.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22663986-unravelling-components-multi-thermal-coronal-loop-using-magnetohydrodynamic-seismology','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22663986-unravelling-components-multi-thermal-coronal-loop-using-magnetohydrodynamic-seismology"><span>UNRAVELLING THE COMPONENTS OF A MULTI-THERMAL CORONAL LOOP USING MAGNETOHYDRODYNAMIC SEISMOLOGY</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Prasad, S. Krishna; Jess, D. B.; Klimchuk, J. A.</p> <p></p> <p>Coronal loops, constituting the basic building blocks of the active Sun, serve as primary targets to help understand the mechanisms responsible for maintaining multi-million Kelvin temperatures in the solar and stellar coronae. Despite significant advances in observations and theory, our knowledge on the fundamental properties of these structures is limited. Here, we present unprecedented observations of accelerating slow magnetoacoustic waves along a coronal loop that show differential propagation speeds in two distinct temperature channels, revealing the multi-stranded and multithermal nature of the loop. Utilizing the observed speeds and employing nonlinear force-free magnetic field extrapolations, we derive the actual temperature variationmore » along the loop in both channels, and thus are able to resolve two individual components of the multithermal loop for the first time. The obtained positive temperature gradients indicate uniform heating along the loop, rather than isolated footpoint heating.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22953716','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22953716"><span>Structural variations of single and tandem mismatches in RNA duplexes: a joint MD simulation and crystal structure database analysis.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Halder, Sukanya; Bhattacharyya, Dhananjay</p> <p>2012-10-04</p> <p>Internal loops within RNA duplex regions are formed by single or tandem basepairing mismatches with flanking canonical Watson-Crick basepairs on both sides. They are the most common motif observed in RNA secondary structures and play integral functional and structural roles. In this report, we have studied the structural features of 1 × 1, 2 × 2, and 3 × 3 internal loops using all-atom molecular dynamics (MD) simulation technique with explicit solvent model. As MD simulation is intricately dependent on the choice of force-field and these are often rather approximate, we have used both the most popular force-fields for nucleic acids-CHARMM27 and AMBER94-for a comparative analysis. We find that tandem noncanonical basepairs forming 2 × 2 and 3 × 3 internal loops are considerably more stable than the single mismatches forming 1 × 1 internal loops, irrespective of the force field. We have also analyzed crystal structure database to study the conservation of these helical fragments in the corresponding sets of RNA structures. We observe that the nature of stability in MD simulations mimic their fluctuating natures in crystal data sets also, probably indicating reliable natures of both the force fields to reproduce experimental results. We also notice significant structural changes in the wobble G:U basepairs present in these double helical stretches, leading to a biphasic stability for these wobble pairs to release the deformational strains introduced by internal loops within duplex regions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JCAP...01..026L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JCAP...01..026L"><span>Non-topological cycloops</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lake, Matthew; Thomas, Steven; Ward, John</p> <p>2010-01-01</p> <p>We propose a mechanism for the creation of cosmic string loops with dynamically stabilised windings in the internal space. Assuming a velocity correlations regime in the post-inflationary epoch, such windings are seen to arise naturally in string networks prior to loop formation. The angular momentum of the string in the compact space may then be sufficient to ensure that the windings remain stable after the loop chops off from the network, even if the internal manifold is simply connected. For concreteness we embed our model in the Klebanov-Strassler geometry, which provides a natural mechanism for brane inflation, as well a being one of the best understood compactification schemes in type IIB string theory. We see that the interaction of angular momentum with the string tension causes the loop to oscillate between phases of expansion and contraction. This, in principle, should give rise to a distinct gravitational wave signature, the future detection of which could provide indirect evidence for the existence of extra dimensions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090032143','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090032143"><span>Dynamic Self-Locking of an OEO Containing a VCSEL</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Strekalov, Dmitry; Matsko, Andrey; Yu, Nan; Savchenkov, Anatoliy; Maleki, Lute</p> <p>2009-01-01</p> <p>A method of dynamic self-locking has been demonstrated to be effective as a means of stabilizing the wavelength of light emitted by a vertical-cavity surface-emitting laser (VCSEL) that is an active element in the frequency-control loop of an optoelectronic oscillator (OEO) designed to implement an atomic clock based on an electromagnetically- induced-transparency (EIT) resonance. This scheme can be considered an alternative to the one described in Optical Injection Locking of a VCSEL in an OEO (NPO-43454), NASA Tech Briefs, Vol. 33, No. 7 (July 2009), page 33. Both schemes are expected to enable the development of small, low-power, high-stability atomic clocks that would be suitable for use in applications involving precise navigation and/or communication. To recapitulate from the cited prior article: In one essential aspect of operation of an OEO of the type described above, a microwave modulation signal is coupled into the VCSEL. Heretofore, it has been well known that the wavelength of light emitted by a VCSEL depends on its temperature and drive current, necessitating thorough stabilization of these operational parameters. Recently, it was discovered that the wavelength also depends on the microwave power coupled into the VCSEL. This concludes the background information. From the perspective that led to the conception of the optical injection-locking scheme described in the cited prior article, the variation of the VCSEL wavelength with the microwave power circulating in the frequency-control loop is regarded as a disadvantage and optical injection locking is a solution of the problem of stabilizing the wavelength in the presence of uncontrolled fluctuations in the microwave power. The present scheme for dynamic self-locking emerges from a different perspective, in which the dependence of VCSEL wavelength on microwave power is regarded as an advantageous phenomenon that can be exploited as a means of controlling the wavelength. The figure schematically depicts an atomic-clock OEO of the type in question, wherein (1) the light from the VCSEL is used to excite an EIT resonance in selected atoms in a gas cell (e.g., 87Rb atoms in a low-pressure mixture of Ar and Ne) and (2) the power supplied to the VCSEL is modulated by a microwave signal that includes components at beat frequencies among the VCSEL wavelength and modulation sidebands. As the VCSEL wavelength changes, it moves closer to or farther from a nearby absorption spectral line, and the optical power transmitted through the cell (and thus the loop gain) changes accordingly. A change in the loop gain causes a change in the microwave power and, thus, in the VCSEL wavelength. It is possible to choose a set of design and operational parameters (most importantly, the electronic part of the loop gain) such that the OEO stabilizes itself in the sense that an increase in circulating microwave power causes the VCSEL wavelength to change in a direction that results in an increase in optical absorption and thus a decrease in circulating microwave power. Typically, such an appropriate choice of operational parameters involves setting the nominal VCSEL wavelength to a point on the shorter-wavelength wing of an absorption spectral line.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28228590','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28228590"><span>A Polymorphism within the Internal Fusion Loop of the Ebola Virus Glycoprotein Modulates Host Cell Entry.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hoffmann, Markus; Crone, Lisa; Dietzel, Erik; Paijo, Jennifer; González-Hernández, Mariana; Nehlmeier, Inga; Kalinke, Ulrich; Becker, Stephan; Pöhlmann, Stefan</p> <p>2017-05-01</p> <p>The large scale of the Ebola virus disease (EVD) outbreak in West Africa in 2013-2016 raised the question whether the host cell interactions of the responsible Ebola virus (EBOV) strain differed from those of other ebolaviruses. We previously reported that the glycoprotein (GP) of the virus circulating in West Africa in 2014 (EBOV2014) exhibited reduced ability to mediate entry into two nonhuman primate (NHP)-derived cell lines relative to the GP of EBOV1976. Here, we investigated the molecular determinants underlying the differential entry efficiency. We found that EBOV2014-GP-driven entry into diverse NHP-derived cell lines, as well as human monocyte-derived macrophages and dendritic cells, was reduced compared to EBOV1976-GP, although entry into most human- and all bat-derived cell lines tested was comparable. Moreover, EBOV2014 replication in NHP but not human cells was diminished relative to EBOV1976, suggesting that reduced cell entry translated into reduced viral spread. Mutagenic analysis of EBOV2014-GP and EBOV1976-GP revealed that an amino acid polymorphism in the receptor-binding domain, A82V, modulated entry efficiency in a cell line-independent manner and did not account for the reduced EBOV2014-GP-driven entry into NHP cells. In contrast, polymorphism T544I, located in the internal fusion loop in the GP2 subunit, was found to be responsible for the entry phenotype. These results suggest that position 544 is an important determinant of EBOV infectivity for both NHP and certain human target cells. IMPORTANCE The Ebola virus disease outbreak in West Africa in 2013 entailed more than 10,000 deaths. The scale of the outbreak and its dramatic impact on human health raised the question whether the responsible virus was particularly adept at infecting human cells. Our study shows that an amino acid exchange, A82V, that was acquired during the epidemic and that was not observed in previously circulating viruses, increases viral entry into diverse target cells. In contrast, the epidemic virus showed a reduced ability to enter cells of nonhuman primates compared to the virus circulating in 1976, and a single amino acid exchange in the internal fusion loop of the viral glycoprotein was found to account for this phenotype. Copyright © 2017 American Society for Microbiology.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19959885','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19959885"><span>Intestinal volvulus with coagulative hepatic necrosis in a chicken.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Haridy, Mohie; Goryo, Masanobu; Sasaki, Jun; Okada, Kosuke</p> <p>2010-04-01</p> <p>A 7-week-old SPF chicken inoculated at 4 weeks of age with chicken anemia virus was puffed up depressed and had ruffled feathers and a good body condition. Intestinal volvulus involving the jejunum and part of the duodenum forming two loops with one knob was observed. Microscopically, venous infarction of the obstructed loops, periportal and sublobular multifocal coagulative hepatic necrosis and granulomatous inflammation of the cecal tonsils were observed. Gram staining revealed no bacteria in hepatic tissue; however, gram-positive bacilli were detected in the necrotic debris in the intestinal lumen. Immunosuppression might have predisposed the chicken to intestinal and cecal tonsil infection that then progressed to volvulus. Loss of the mucosal barrier in infarction might allow bacterial toxins and vasoactive factors to escape into the systemic circulation (toxemia) and be responsible for the hepatic necrosis.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SMaS...26j5035G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SMaS...26j5035G"><span>Looped energy harvester for human motion</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geisler, M.; Boisseau, S.; Gasnier, P.; Willemin, J.; Gobbo, C.; Despesse, G.; Ait-Ali, I.; Perraud, S.</p> <p>2017-10-01</p> <p>The development of energy harvesters for smart wearables is a challenging topic, with a difficult combination of ergonomics constraints, lifetime and electrical requirements. In this work, we focus on an inertial inductive structure, composed of a magnetic ball circulating inside a closed-loop guide and converting the kinetic energy of the user’s limbs into electricity during the run. A specific induction issue related to the free self-rotation of the ball is underlined and addressed using a ferromagnetic ‘rail’ component. From a 2 g moving ball, a 5 cm-diameter 21 cm3 prototype generated up to 4.8 mW of average power when worn by someone running at 8 km h-1. This device is demonstrated to charge a 2.4 V NiMH battery and supply an acceleration and temperature Wireless Sensor Node at 20 Hz.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhyC..549..126J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhyC..549..126J"><span>Impurity bound states in mesoscopic topological superconducting loops</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jin, Yan-Yan; Zha, Guo-Qiao; Zhou, Shi-Ping</p> <p>2018-06-01</p> <p>We study numerically the effect induced by magnetic impurities in topological s-wave superconducting loops with spin-orbit interaction based on spin-generalized Bogoliubov-de Gennes equations. In the case of a single magnetic impurity, it is found that the midgap bound states can cross the Fermi level at an appropriate impurity strength and the circulating spin current jumps at the crossing point. The evolution of the zero-energy mode can be effectively tuned by the located site of a single magnetic impurity. For the effect of many magnetic impurities, two independent midway or edge impurities cannot lead to the overlap of zero modes. The multiple zero-energy modes can be effectively realized by embedding a single Josephson junction with impurity scattering into the system, and the spin current displays oscillatory feature with increasing the layer thickness.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990eec..rept...26B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990eec..rept...26B"><span>Hot dry rock geothermal energy: A renewable energy resource that is ready for development now</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brown, D. W.; Potter, R. M.; Myers, C. W.</p> <p></p> <p>Hot dry rock (HDR) geothermal energy, which utilizes the natural heat contained in the earth's crust, is a very large and well-distributed resource of nonpolluting, and essentially renewable, energy that is available globally. Its use could help mitigate climatic change and reduce acid rain, two of the major environmental consequences of our ever-increasing use of fossil fuels for heating and power generation. In addition, HDR, as a readily available source of indigenous energy, can reduce our nations's dependence on imported oil, enhancing national security and reducing our trade deficit. On a national scale we can begin to develop this new source, using it directly for power generation or for direct-heat applications, or indirectly in hybrid geothermal/fossil-fuel power plants. In the HDR concept, which has been demonstrated in the field in two different applications and flow-tested for periods up to one year, heat is recovered from the earth by pressurized water in a closed-loop circulation system. As a consequence, minimal effluents are released to the atmosphere, and no wastes are produced. This paper describes the nature of the HDR resource and the technology required to implement the heat-mining concept. An assessment of the requirements for establishing HDR feasibility is presented in the context of providing a commercially competitive energy source.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4878617','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4878617"><span>Using in-cell SHAPE-Seq and simulations to probe structure–function design principles of RNA transcriptional regulators</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Takahashi, Melissa K.; Watters, Kyle E.; Gasper, Paul M.; Abbott, Timothy R.; Carlson, Paul D.; Chen, Alan A.</p> <p>2016-01-01</p> <p>Antisense RNA-mediated transcriptional regulators are powerful tools for controlling gene expression and creating synthetic gene networks. RNA transcriptional repressors derived from natural mechanisms called attenuators are particularly versatile, though their mechanistic complexity has made them difficult to engineer. Here we identify a new structure–function design principle for attenuators that enables the forward engineering of new RNA transcriptional repressors. Using in-cell SHAPE-Seq to characterize the structures of attenuator variants within Escherichia coli, we show that attenuator hairpins that facilitate interaction with antisense RNAs require interior loops for proper function. Molecular dynamics simulations of these attenuator variants suggest these interior loops impart structural flexibility. We further observe hairpin flexibility in the cellular structures of natural RNA mechanisms that use antisense RNA interactions to repress translation, confirming earlier results from in vitro studies. Finally, we design new transcriptional attenuators in silico using an interior loop as a structural requirement and show that they function as desired in vivo. This work establishes interior loops as an important structural element for designing synthetic RNA gene regulators. We anticipate that the coupling of experimental measurement of cellular RNA structure and function with computational modeling will enable rapid discovery of structure–function design principles for a diverse array of natural and synthetic RNA regulators. PMID:27103533</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=protocol+AND+sip&id=EJ784844','ERIC'); return false;" href="https://eric.ed.gov/?q=protocol+AND+sip&id=EJ784844"><span>Dispensing with the DVD Circulation Dilemma</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Ellis, Mark</p> <p>2008-01-01</p> <p>Richmond Public Library (RPL) is a four-branch suburban library with the highest per capita circulation of any comparable library in Canada. While DVDs naturally fit into RPL's emphasis on popular material, circulating them using the standard model proved problematic: Long hold queues built up, DVDs idled on the hold shelves, and the circulation…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870000147&hterms=photovoltaic+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dphotovoltaic%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870000147&hterms=photovoltaic+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dphotovoltaic%2Benergy"><span>Residential Photovoltaic/Thermal Energy System</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Selcuk, M. K.</p> <p>1987-01-01</p> <p>Proposed system supplies house with both heat and electricity. Pair of reports describes concept for self-sufficient heating, cooling, and power-generating system for house. Panels on walls of house provide hot water, space heating, and heat to charge heat-storage system, and generate electricity for circulation pumps and fans. Roof panels generate electricity for household, operate heat pump for summer cooling, and provide supplementary winter heating via heat pump, using solar-cell cooling-fluid loop. Wall and roof panels used independently.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/5046706-operation-maintenance-sol-dance-building-solar-system-final-report','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5046706-operation-maintenance-sol-dance-building-solar-system-final-report"><span>Operation and maintenance of the SOL-DANCE building solar system. Final report</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Not Available</p> <p>1980-07-29</p> <p>The Sol-Dance building solar heating system consists of 136 flat plate solar collectors divided evenly into two separate building systems, each providing its total output to a common thermal storage tank. An aromatic base transformer oil is circulated through a closed loop consisting of the collectors and a heat exchanger. Water from the thermal storage tank is passed through the same heat exchanger where heat from the oil is given up to the thermal storage. Back-up heat is provided by air source heat pumps. Heat is transferred from the thermal storage to the living space by liquid-to-air coils in themore » distribution ducts. Separate domestic hot water systems are provided for each building. The system consists of 2 flat plate collectors with a single 66 gallon storage tank with oil circulated in a closed loop through an external tube and shell heat exchanger. Some problems encountered and lessons learned during the project construction are listed as well as beneficial aspects and a project description. As-built drawings are provided as well as system photographs. An acceptance test plan is provided that checks the collection, thermal storage, and space and water heating subsystems and the total system installation. Predicted performance data are tabulated. Details are discussed regarding operation, maintenance, and repair, and manufacturers data are provided. (LEW)« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A43I2584Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A43I2584Z"><span>Recent intensification of the Walker Circulation and the role of natural sea surface temperature variability</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, X.; Allen, R.</p> <p>2017-12-01</p> <p>In a warming world, the tropical atmospheric overturning circulation-including the Walker Circulation-is expected to weaken due to thermodynamic constraints. Tropical precipitation increases at a slower rate than water vapor-which increases according to Clausius Clapeyron scaling, assuming constant relative humidity-so the tropical overturning circulation slows down. This is supported by both observations and model simulations, which show a slowdown of the Walker Circulation over the 20th century. Model projections suggest a further weakening of the Walker Circulation in the 21st century. However, over the last several decades (1979-2014), multiple observations reveal a robust strengthening of the Walker Circulation. Although coupled CMIP5 simulations are unable to reproduce this strengthening, AMIP simulations-which feature the observed evolution of SSTs-are generally able to reproduce it. Assuming the ensemble mean sea surface temperatures (SSTs) from historical CMIP5 simulations accurately represent the externally forced SST response, the observed SSTs can be decomposed into a forced and an unforced component. CAM5 AMIP-type simulations driven by the unforced component of observed SSTs reproduce the observed strengthening of the Walker Circulation. Corresponding simulations driven by the forced component of observed SSTs yield a weaker Walker Circulation. These results are consistent with the zonal tropical SST gradient and the Bjerknes feedback. The unforced component of SSTs yield an increased SST gradient over tropical Pacific (a La Nina like pattern) and strengthening of the tropical trade winds, which constitute the lower branch of the Walker Circulation. The forced component of SSTs yields a zonally uniform tropical Pacific SST warming and a marginal weakening of the Walker Circulation. Our results suggest significant modulation of the tropical Walker Circulation by natural SST variability over the last several decades.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23482694','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23482694"><span>NK cell-released exosomes: Natural nanobullets against tumors.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fais, Stefano</p> <p>2013-01-01</p> <p>We have recently reported that human natural killer (NK) cells release exosomes that express both NK-cell markers and cytotoxic molecules. Similar results were obtained with circulating exosomes from human healthy donors. Both NK-cell derived and circulating exosomes exerted a full functional activity and killed both tumor and activated immune cells. These findings indicate that NK-cell derived exosomes might constitute a new promising therapeutic tool.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.8925M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.8925M"><span>Renewed circulation scheme of the Baltic Sea - based on the 40-year simulation with GETM.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maljutenko, Ilja; Raudsepp, Urmas</p> <p>2015-04-01</p> <p>The general circulation of the Baltic Sea has been characterized as cyclonic in all sub-basins based on numerous measurements and model simulations. From the long-term hydrodynamical simulation our model results have verified the general cyclonic circulation in the Baltic Proper and in the Gulf of Bothnia, but the Gulf of Finland and the Gulf of Riga have shown tendency to anticyclonic circulation. We have applied the General Estuarine Transport Model ( GETM ) for the period of 1966 - 2006 with a 1 nautical mile horizontal resolution and density adaptive bottom following vertical coordinates to make it possible to simulate horizontal and vertical density gradients with better precision. The atmospheric forcing from dynamically downscaled ERA40-HIRLAM and parametrized lateral boundary conditions are applied. Model simulation show close agreement with measurements conducted in the main monitoring stations in the BS during the simulation period. The geostrophic adjustment of density driven currents along with the upward salinity flux due to entrainment could explain the anticyclonic circulation and strong coastal current. Mean vertical velocities show that upward and downward movements are forming closed vertical circulation loops along the bottom slope of the Baltic Proper and the Gulf of Bothnia. The model has also reproduced patchy vertical movement across the BS with some distinctive areas of upward advective fluxes in the GoF along the thalweg. The distinctive areas of deepwater upwelling are also evident in the Gdansk Basin, western Gotland Basin, northern Gotland Basin and in the northen part of the Bothnia Sea.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3855832','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3855832"><span>Mapping the Structural and Dynamical Features of Multiple p53 DNA Binding Domains: Insights into Loop 1 Intrinsic Dynamics</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lukman, Suryani; Lane, David P.; Verma, Chandra S.</p> <p>2013-01-01</p> <p>The transcription factor p53 regulates cellular integrity in response to stress. p53 is mutated in more than half of cancerous cells, with a majority of the mutations localized to the DNA binding domain (DBD). In order to map the structural and dynamical features of the DBD, we carried out multiple copy molecular dynamics simulations (totaling 0.8 μs). Simulations show the loop 1 to be the most dynamic element among the DNA-contacting loops (loops 1-3). Loop 1 occupies two major conformational states: extended and recessed; the former but not the latter displays correlations in atomic fluctuations with those of loop 2 (~24 Å apart). Since loop 1 binds to the major groove whereas loop 2 binds to the minor groove of DNA, our results begin to provide some insight into the possible mechanism underpinning the cooperative nature of DBD binding to DNA. We propose (1) a novel mechanism underlying the dynamics of loop 1 and the possible tread-milling of p53 on DNA and (2) possible mutations on loop 1 residues to restore the transcriptional activity of an oncogenic mutation at a distant site. PMID:24324553</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850044932&hterms=GMT&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DGMT','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850044932&hterms=GMT&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DGMT"><span>Transverse ageostrophic circulations associated with elevated mixed layers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Keyser, D.; Carlson, T. N.</p> <p>1984-01-01</p> <p>The nature of the frontogenetically forced transverse ageostrophic circulations connected with elevated mixed layer structure is investigated as a first step toward diagnosing the complex vertical circulation patterns occurring in the vicinity of elevated mixed layers within a severe storm environment. The Sawyer-Eliassen ageostrophic circulation equation is reviewed and applied to the elevated mixed layer detected in the SESAME IV data set at 2100 GMT of May 9, 1979. The results of the ageostrophic circulation diagnosis are confirmed and refined by considering an analytic specification for the elevated mixed layer structure.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4370825','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4370825"><span>Pituitary Androgen Receptor Signalling Regulates Prolactin but Not Gonadotrophins in the Male Mouse</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>O’Hara, Laura; Curley, Michael; Tedim Ferreira, Maria; Cruickshanks, Lyndsey; Milne, Laura; Smith, Lee B.</p> <p>2015-01-01</p> <p>Production of the androgen testosterone is controlled by a negative feedback loop within the hypothalamic-pituitary-gonadal (HPG) axis. Stimulation of testicular Leydig cells by pituitary luteinising hormone (LH) is under the control of hypothalamic gonadotrophin releasing hormone (GnRH), while suppression of LH secretion by the pituitary is controlled by circulating testosterone. Exactly how androgens exert their feedback control of gonadotrophin secretion (and whether this is at the level of the pituitary), as well as the role of AR in other pituitary cell types remains unclear. To investigate these questions, we exploited a transgenic mouse line (Foxg1Cre/+; ARfl/y) which lacks androgen receptor in the pituitary gland. Both circulating testosterone and gonadotrophins are unchanged in adulthood, demonstrating that AR signalling is dispensable in the male mouse pituitary for testosterone-dependent regulation of LH secretion. In contrast, Foxg1Cre/+; ARfl/y males have a significant increase in circulating prolactin, suggesting that, rather than controlling gonadotrophins, AR-signalling in the pituitary acts to suppress aberrant prolactin production in males. PMID:25799562</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19260857','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19260857"><span>Changes in endometrial natural killer cell expression of CD94, CD158a and CD158b are associated with infertility.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McGrath, Emma; Ryan, Elizabeth J; Lynch, Lydia; Golden-Mason, Lucy; Mooney, Eoghan; Eogan, Maeve; O'Herlihy, Colm; O'Farrelly, Cliona</p> <p>2009-04-01</p> <p>Cycle-dependent fluctuations in natural killer (NK) cell populations in endometrium and circulation may differ, contributing to unexplained infertility. NK cell phenotypes were determined by flow cytometry in endometrial biopsies and matched blood samples. While circulating and endometrial T cell populations remained constant throughout the menstrual cycle in fertile and infertile women, circulating NK cells in infertile women increased during the secretory phase. However, increased expression of CD94, CD158b (secretory phase), and CD158a (proliferative phase) by endometrial NK cells from infertile women was observed. These changes were not reflected in the circulation. In infertile women, changes in circulating NK cell percentages are found exclusively during the secretory phase and not in endometrium; cycle-related changes in NK receptor expression are observed only in infertile endometrium. While having exciting implications for understanding NK cell function in fertility, our data emphasize the difficulty in attaching diagnostic or prognostic significance to NK cell analyses in individual patients.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5766102','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5766102"><span>Impact of lipopolysaccharide-induced acute inflammation on baroreflex-controlled sympathetic arterial pressure regulation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tohyama, Takeshi; Kawada, Toru; Kishi, Takuya; Yoshida, Keimei; Nishikawa, Takuya; Mannoji, Hiroshi; Kamada, Kazuhiro; Sunagawa, Kenji; Tsutsui, Hiroyuki</p> <p>2018-01-01</p> <p>Background Lipopolysaccharide (LPS) induces acute inflammation, activates sympathetic nerve activity (SNA) and alters hemodynamics. Since the arterial baroreflex is a negative feedback system to stabilize arterial pressure (AP), examining the arterial baroreflex function is a prerequisite to understanding complex hemodynamics under LPS challenge. We investigated the impact of LPS-induced acute inflammation on SNA and AP regulation by performing baroreflex open-loop analysis. Methods Ten anesthetized Sprague-Dawley rats were used. Acute inflammation was induced by an intravenous injection of LPS (60 μg/kg). We isolated the carotid sinuses from the systemic circulation and controlled carotid sinus pressure (CSP) by a servo-controlled piston pump. We matched CSP to AP to establish the baroreflex closed-loop condition, whereas we decoupled CSP from AP to establish the baroreflex open-loop condition and changed CSP stepwise to evaluate the baroreflex open-loop function. We recorded splanchnic SNA and hemodynamic parameters under baroreflex open- and closed-loop conditions at baseline and at 60 and 120 min after LPS injection. Results In the baroreflex closed-loop condition, SNA continued to increase after LPS injection, reaching three-fold the baseline value at 120 min (baseline: 94.7 ± 3.6 vs. 120 min: 283.9 ± 31.9 a.u.). In contrast, AP increased initially (until 75 min), then declined to the baseline level. In the baroreflex open-loop condition, LPS reset the neural arc (CSP-SNA relationship) upward to higher SNA, while shifted the peripheral arc (SNA-AP relationship) downward at 120 min after the injection. As a result, the operating point determined by the intersection between function curves of neural arc and peripheral arc showed marked sympatho-excitation without substantial changes in AP. Conclusions LPS-induced acute inflammation markedly increased SNA via resetting of the baroreflex neural arc, and suppressed the peripheral arc. The balance between the augmented neural arc and suppressed peripheral arc determines SNA and hemodynamics in LPS-induced acute inflammation. PMID:29329321</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29329321','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29329321"><span>Impact of lipopolysaccharide-induced acute inflammation on baroreflex-controlled sympathetic arterial pressure regulation.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tohyama, Takeshi; Saku, Keita; Kawada, Toru; Kishi, Takuya; Yoshida, Keimei; Nishikawa, Takuya; Mannoji, Hiroshi; Kamada, Kazuhiro; Sunagawa, Kenji; Tsutsui, Hiroyuki</p> <p>2018-01-01</p> <p>Lipopolysaccharide (LPS) induces acute inflammation, activates sympathetic nerve activity (SNA) and alters hemodynamics. Since the arterial baroreflex is a negative feedback system to stabilize arterial pressure (AP), examining the arterial baroreflex function is a prerequisite to understanding complex hemodynamics under LPS challenge. We investigated the impact of LPS-induced acute inflammation on SNA and AP regulation by performing baroreflex open-loop analysis. Ten anesthetized Sprague-Dawley rats were used. Acute inflammation was induced by an intravenous injection of LPS (60 μg/kg). We isolated the carotid sinuses from the systemic circulation and controlled carotid sinus pressure (CSP) by a servo-controlled piston pump. We matched CSP to AP to establish the baroreflex closed-loop condition, whereas we decoupled CSP from AP to establish the baroreflex open-loop condition and changed CSP stepwise to evaluate the baroreflex open-loop function. We recorded splanchnic SNA and hemodynamic parameters under baroreflex open- and closed-loop conditions at baseline and at 60 and 120 min after LPS injection. In the baroreflex closed-loop condition, SNA continued to increase after LPS injection, reaching three-fold the baseline value at 120 min (baseline: 94.7 ± 3.6 vs. 120 min: 283.9 ± 31.9 a.u.). In contrast, AP increased initially (until 75 min), then declined to the baseline level. In the baroreflex open-loop condition, LPS reset the neural arc (CSP-SNA relationship) upward to higher SNA, while shifted the peripheral arc (SNA-AP relationship) downward at 120 min after the injection. As a result, the operating point determined by the intersection between function curves of neural arc and peripheral arc showed marked sympatho-excitation without substantial changes in AP. LPS-induced acute inflammation markedly increased SNA via resetting of the baroreflex neural arc, and suppressed the peripheral arc. The balance between the augmented neural arc and suppressed peripheral arc determines SNA and hemodynamics in LPS-induced acute inflammation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22971666','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22971666"><span>Modified loop technique in three dogs with mitral regurgitation.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Aoki, Takuma; Fujii, Yoko; Sunahara, Hiroshi; Takano, Hiroshi; Wakao, Yoshito</p> <p>2013-01-31</p> <p>Mitral valvuloplasty (MVP) is used in dogs with refractory mitral regurgitation (MR); however, it is difficult to tie the artificial chord, i.e., the expanded polytetrafluoroethylene suture, at the planned height of the mitral valve, because of the slippery nature of the knot. The loop technique has resolved these difficulties in humans. Premanufactured loops (length, 8.0-15.0 mm with 1.0-mm increments) were used in the new modified loop technique. In the current study, cardiac murmurs disappeared, and the MR markedly improved or completely disappeared approximately 3 months after surgery in 3 dogs. Therefore, this new technique might be effective in dogs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ApJ...759...33S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ApJ...759...33S"><span>Multiple Plasma Ejections and Intermittent Nature of Magnetic Reconnection in Solar Chromospheric Anemone Jets</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, K. A. P.; Isobe, H.; Nishizuka, N.; Nishida, K.; Shibata, K.</p> <p>2012-11-01</p> <p>The recent discovery of chromospheric anemone jets with the Solar Optical Telescope (SOT) on board Hinode has shown an indirect evidence of magnetic reconnection in the solar chromosphere. However, the basic nature of magnetic reconnection in chromosphere is still unclear. We studied nine chromospheric anemone jets from SOT/Hinode using Ca II H filtergrams, and we found multiple bright, plasma ejections along the jets. In most cases, the major intensity enhancements (larger than 30% relative to the background intensity) of the loop correspond to the timing of the plasma ejections. The typical lifetime and size of the plasma ejecta are about 20-60 s and 0.3-1.5 Mm, respectively. The height-time plot of jet shows many sub-structures (or individual jets) and the typical lifetime of the individual jet is about one to five minutes. Before the onset of the jet activity, a loop appears in Ca II H and gradually increases in size, and after few minutes several jets are launched from the loop. Once the jet activity starts and several individual jets are launched, the loop starts shrinking with a speed of ~4 km s-1. In some events, a downward moving blob with a speed of ~35 km s-1 was observed, associated with the upward moving plasma along one of the legs of the loop hosting the jets. The upward moving plasma gradually developed into jets. Multiple plasma ejections in chromospheric anemone jet show the strongly time-dependent as well as intermittent nature of magnetic reconnection in the solar chromosphere.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28941584','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28941584"><span>High-Throughput Microfluidic Labyrinth for the Label-free Isolation of Circulating Tumor Cells.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Eric; Rivera-Báez, Lianette; Fouladdel, Shamileh; Yoon, Hyeun Joong; Guthrie, Stephanie; Wieger, Jacob; Deol, Yadwinder; Keller, Evan; Sahai, Vaibhav; Simeone, Diane M; Burness, Monika L; Azizi, Ebrahim; Wicha, Max S; Nagrath, Sunitha</p> <p>2017-09-27</p> <p>We present "Labyrinth," a label-free microfluidic device to isolate circulating tumor cells (CTCs) using the combination of long loops and sharp corners to focus both CTCs and white blood cells (WBCs) at a high throughput of 2.5 mL/min. The high yield (>90%) and purity (600 WBCs/mL) of Labyrinth enabled us to profile gene expression in CTCs. As proof of principle, we used previously established cancer stem cell gene signatures to profile single cells isolated from the blood of breast cancer patients. We observed heterogeneous subpopulations of CTCs expressing genes for stem cells, epithelial cells, mesenchymal cells, and cells transitioning between epithelial and mesenchymal. Labyrinth offers a cell-surface marker-independent single-cell isolation platform to study heterogeneous CTC subpopulations. Copyright © 2017 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25977189','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25977189"><span>Liquid biopsy in liver cancer.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Labgaa, Ismail; Villanueva, Augusto</p> <p>2015-04-01</p> <p>Liver cancer has become the second cause of cancer-related death worldwide. Most patients are still diagnosed at intermediate or advanced stage, where potentially curative treatment options are not recommended. Unlike other solid tumors, there are no validated oncogenic addiction loops and the only systemic agent to improve survival in advanced disease is sorafenib. All phase 3 clinical trials testing molecular therapies after sorafenib have been negative, none of which selected patients based on predictive biomarkers of response. Theoretically, analysis of circulating cancer byproducts (e.g., circulating tumor cells, cell-free nucleic acids), namely "liquid biopsy," could provide easy access to molecular tumor information, improve patients' stratification and allow to assess tumor dynamics over time. Recent technical developments and preliminary data from other malignancies indicate that liquid biopsy might have a role in the future management of cancer patients.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUSMOS34A..01M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUSMOS34A..01M"><span>Mesoscale Numerical Simulations of the IAS Circulation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mooers, C. N.; Ko, D.</p> <p>2008-05-01</p> <p>Real-time nowcasts and forecasts of the IAS circulation have been made for several years with mesoscale resolution using the Navy Coastal Ocean Model (NCOM) implemented for the IAS. It is commonly called IASNFS and is driven by the lower resolution Global NCOM on the open boundaries, synoptic atmospheric forcing obtained from the Navy Global Atmospheric Prediction System (NOGAPS), and assimilated satellite-derived sea surface height anomalies and sea surface temperature. Here, examples of the model output are demonstrated; e.g., Gulf of Mexico Loop Current eddy shedding events and the meandering Caribbean Current jet and associated eddies. Overall, IASNFS is ready for further analysis, application to a variety of studies, and downscaling to even higher resolution shelf models. Its output fields are available online through NOAA's National Coastal Data Development Center (NCDDC), located at the Stennis Space Center.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1096005','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1096005"><span>Mechanically-reattachable liquid-cooled cooling apparatus</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Arney, Susanne; Cheng, Jen-Hau; Kolodner, Paul R; Kota-Venkata, Krishna-Murty; Scofield, William; Salamon, Todd R; Simon, Maria E</p> <p>2013-09-24</p> <p>An apparatus comprising a rack having a row of shelves, each shelf supporting an electronics circuit board, each one of the circuit boards being manually removable from the shelve supporting the one of the circuit boards and having a local heat source thereon. The apparatus also comprises a cooler attached to the rack and being able to circulate a cooling fluid around a channel forming a closed loop. The apparatus further comprises a plurality of heat conduits, each heat conduit being located over a corresponding one of the circuit boards and forming a path to transport heat from the local heat source of the corresponding one of the circuit boards to the cooler. Each heat conduit is configured to be manually detachable from the cooler or the circuit board, without breaking a circulation pathway of the fluid through the cooler.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJWC.11402082N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJWC.11402082N"><span>Experimental study of high-performance cooling system pipeline diameter and working fluid amount</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nemec, Patrik; Malcho, Milan; Hrabovsky, Peter; Papučík, Štefan</p> <p>2016-03-01</p> <p>This work deals with heat transfer resulting from the operation of power electronic components. Heat is removed from the mounting plate, which is the evaporator of the loop thermosyphon to the condenser and by natural convection is transferred to ambient. This work includes proposal of cooling device - loop thermosyphon, with its construct and follow optimization of cooling effect. Optimization proceeds by selecting the quantity of working fluid and selection of diameters vapour line and liquid line of loop thermosyphon.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23889536','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23889536"><span>Analysis of pressure head-flow loops of pulsatile rotodynamic blood pumps.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jahren, Silje E; Ochsner, Gregor; Shu, Fangjun; Amacher, Raffael; Antaki, James F; Vandenberghe, Stijn</p> <p>2014-04-01</p> <p>The clinical importance of pulsatility is a recurring topic of debate in mechanical circulatory support. Lack of pulsatility has been identified as a possible factor responsible for adverse events and has also demonstrated a role in myocardial perfusion and cardiac recovery. A commonly used method for restoring pulsatility with rotodynamic blood pumps (RBPs) is to modulate the speed profile, synchronized to the cardiac cycle. This introduces additional parameters that influence the (un)loading of the heart, including the timing (phase shift) between the native cardiac cycle and the pump pulses, and the amplitude of speed modulation. In this study, the impact of these parameters upon the heart-RBP interaction was examined in terms of the pressure head-flow (HQ) diagram. The measurements were conducted using a rotodynamic Deltastream DP2 pump in a validated hybrid mock circulation with baroreflex function. The pump was operated with a sinusoidal speed profile, synchronized to the native cardiac cycle. The simulated ventriculo-aortic cannulation showed that the level of (un)loading and the shape of the HQ loops strongly depend on the phase shift. The HQ loops displayed characteristic shapes depending on the phase shift. Increased contribution of native contraction (increased ventricular stroke work [WS ]) resulted in a broadening of the loops. It was found that the previously described linear relationship between WS and the area of the HQ loop for constant pump speeds becomes a family of linear relationships, whose slope depends on the phase shift. © 2013 Wiley Periodicals, Inc. and International Center for Artificial Organs and Transplantation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930062335&hterms=litwin&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dlitwin','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930062335&hterms=litwin&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dlitwin"><span>On the structure of solar and stellar coronae - Loops and loop heat transport</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Litwin, Christof; Rosner, Robert</p> <p>1993-01-01</p> <p>We discuss the principal constraints on mechanisms for structuring and heating the outer atmospheres - the coronae - of stars. We argue that the essential cause of highly localized heating in the coronae of stars like the sun is the spatially intermittent nature of stellar surface magnetic fields, and that the spatial scale of the resulting coronal structures is related to the spatial structure of the photospheric fields. We show that significant constraints on coronal heating mechanisms derive from the observed variations in coronal emission, and, in addition, show that the observed structuring perpendicular to coronal magnetic fields imposes severe constraints on mechanisms for heat dispersal in the low-beta atmosphere. In particular, we find that most of commonly considered mechanisms for heat dispersal, such as anomalous diffusion due to plasma turbulence or magnetic field line stochasticity, are much too slow to account for the observed rapid heating of coronal loops. The most plausible mechanism appears to be reconnection at the interface between two adjacent coronal flux bundles. Based on a model invoking hyperresistivity, we show that such a mechanism naturally leads to dominance of isolated single bright coronal loops and to bright coronal plasma structures whose spatial scale transverse to the local magnetic field is comparable to observed dimensions of coronal X-ray loops.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JNEng..10b6020B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JNEng..10b6020B"><span>Real-time control of hind limb functional electrical stimulation using feedback from dorsal root ganglia recordings</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bruns, Tim M.; Wagenaar, Joost B.; Bauman, Matthew J.; Gaunt, Robert A.; Weber, Douglas J.</p> <p>2013-04-01</p> <p>Objective. Functional electrical stimulation (FES) approaches often utilize an open-loop controller to drive state transitions. The addition of sensory feedback may allow for closed-loop control that can respond effectively to perturbations and muscle fatigue. Approach. We evaluated the use of natural sensory nerve signals obtained with penetrating microelectrode arrays in lumbar dorsal root ganglia (DRG) as real-time feedback for closed-loop control of FES-generated hind limb stepping in anesthetized cats. Main results. Leg position feedback was obtained in near real-time at 50 ms intervals by decoding the firing rates of more than 120 DRG neurons recorded simultaneously. Over 5 m of effective linear distance was traversed during closed-loop stepping trials in each of two cats. The controller compensated effectively for perturbations in the stepping path when DRG sensory feedback was provided. The presence of stimulation artifacts and the quality of DRG unit sorting did not significantly affect the accuracy of leg position feedback obtained from the linear decoding model as long as at least 20 DRG units were included in the model. Significance. This work demonstrates the feasibility and utility of closed-loop FES control based on natural neural sensors. Further work is needed to improve the controller and electrode technologies and to evaluate long-term viability.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3640462','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3640462"><span>Real-time control of hind limb functional electrical stimulation using feedback from dorsal root ganglia recordings</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bruns, Tim M; Wagenaar, Joost B; Bauman, Matthew J; Gaunt, Robert A; Weber, Douglas J</p> <p>2013-01-01</p> <p>Objective Functional electrical stimulation (FES) approaches often utilize an open-loop controller to drive state transitions. The addition of sensory feedback may allow for closed-loop control that can respond effectively to perturbations and muscle fatigue. Approach We evaluated the use of natural sensory nerve signals obtained with penetrating microelectrode arrays in lumbar dorsal root ganglia (DRG) as real-time feedback for closed-loop control of FES-generated hind limb stepping in anesthetized cats. Main results Leg position feedback was obtained in near real-time at 50 ms intervals by decoding the firing rates of more than 120 DRG neurons recorded simultaneously. Over 5 m of effective linear distance was traversed during closed-loop stepping trials in each of two cats. The controller compensated effectively for perturbations in the stepping path when DRG sensory feedback was provided. The presence of stimulation artifacts and the quality of DRG unit sorting did not significantly affect the accuracy of leg position feedback obtained from the linear decoding model as long as at least 20 DRG units were included in the model. Significance This work demonstrates the feasibility and utility of closed-loop FES control based on natural neural sensors. Further work is needed to improve the controller and electrode technologies and to evaluate long-term viability. PMID:23503062</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995QuEle..25..984P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995QuEle..25..984P"><span>SPECIAL ISSUE ON OPTICAL PROCESSING OF INFORMATION: Circulatory fibre-optic memory loop with a built-in service channel</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pilipovich, V. A.; Esman, A. K.; Goncharenko, I. A.; Posed'ko, V. S.; Solonovich, I. F.</p> <p>1995-10-01</p> <p>A method for increasing the information capacity and enhancing the reliability of information storage in a dynamic fibre-optic memory is proposed. An additional built-in channel with counterpropagating circulation of signals is provided for this purpose. This additional channel can be used to transmit both information and service signals, such as address words, clock signals, correcting sequences, etc. The possibility of compensating the attenuation of an information signal by stimulated Raman scattering is considered.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA239805','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA239805"><span>Nonflammable Hydraulic Power System for Tactical Aircraft. Volume 2. Equipment and Systems Test and Evaluation.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1991-04-01</p> <p>hold large quantities of air in solution at high pressures and at 8000 psi CTFE holds 500 times its volume of standard atmospheric air. Since air...cart bleeding can be expected to reduce dissolved air to about 1.5 times the amount held at atmospheric pressure. This is more than adequate for...aircraft hydraulic systems while circulating fluid through the cart reservoir which is vented to atmosphere . After open loop air bleeding, the aircraft</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA508448','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA508448"><span>Production and Field Planting of Vegetative Propagules for Restoration of Redhead Grass and Sago Pondweed in Chesapeake Bay</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2009-08-01</p> <p>submerged aquatic vegetation (SAV) have been lost from shallow waters of Chesapeake Bay (Orth and Moore 1983) and other coastal ecosystems worldwide...a mixture of ambient estuarine water from the Choptank River (a tributary of Chesapeake Bay) and freshwater (tap) needed to maintain a salinity of 7...with a mixture of freshwater and ambient estuarine water (to maintain a salinity of 10) that was circulated through a closed- loop recirculation system</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA433973','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA433973"><span>Multifunctional Carbon Nanotube Fiber Composites</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2004-12-26</p> <p>Opt. Eng. 4234 (Smart Materials), 223-23 1, (2001). 9. " Microfabricated Electroactive Carbon Nanotube Actuators", A. Ahluwalia, R.H. Baughman, D. De...peristaltic pumped circulating flow of PVA operating in an open loop consisting of a 1.5 m long, 0.40 cm diameter glass pipe , flex-tubing, and a polymer reserve...forming a gel-like ribbon that flows down the length of the pipe before being released into a rotating water bath where it is collected on a mandrel. Our</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26523257','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26523257"><span>Double Stent Assist Coiling of Ruptured Large Saccular Aneurysm in Proximal Basilar Artery Fenestration.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Park, Woong Bae; Sung, Jae Hoon; Huh, Joon; Cho, Chul Bum; Yang, Seung Ho; Kim, Il Sup; Hong, Jae Taek; Lee, Sang Won</p> <p>2015-09-01</p> <p>Basilar artery fenestration is infrequent and even rarer in association with a large aneurysm. With proximity to brain stem and vital perforators, endovascular coiling can be considered first. If the large ruptured aneurysm with a wide neck originated from fenestra of the proximal basilar artery and the fenestration loop has branches of posterior circulation, therapeutic consideration should be thorough and fractionized. We report endovascular therapeutic details for a case of a ruptured large saccular aneurysm in proximal basilar artery fenestration.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19690000042','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19690000042"><span>Instabilities encountered during heat transfer to a supercritical fluid</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cornelius, A. J.</p> <p>1969-01-01</p> <p>Investigation was made of the unstable behavior of a heat-transfer loop operating at a supercritical pressure. Natural convection operation of the loop, with observations on acoustic and slow oscillatory behavior, was emphasized during testing. The basic cause of both types of behavior appeared to originate in the heated boundary layer.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/5166963','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/5166963"><span>TRAC-PF1 code verification with data from the OTIS test facility. [Once-Through Intergral System</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Childerson, M.T.; Fujita, R.K.</p> <p>1985-01-01</p> <p>A computer code (TRAC-PF1/MOD1) developed for predicting transient thermal and hydraulic integral nuclear steam supply system (NSSS) response was benchmarked. Post-small break loss-of-coolant accident (LOCA) data from a scaled, experimental facility, designated the One-Through Integral System (OTIS), were obtained for the Babcock and Wilcox NSSS and compared to TRAC predictions. The OTIS tests provided a challenging small break LOCA data set for TRAC verification. The major phases of a small break LOCA observed in the OTIS tests included pressurizer draining and loop saturation, intermittent reactor coolant system circulation, boiler-condenser mode, and the initial stages of refill. The TRAC code wasmore » successful in predicting OTIS loop conditions (system pressures and temperatures) after modification of the steam generator model. In particular, the code predicted both pool and auxiliary-feedwater initiated boiler-condenser mode heat transfer.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1207275','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1207275"><span>System and method for conditioning intake air to an internal combustion engine</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Sellnau, Mark C.</p> <p></p> <p>A system for conditioning the intake air to an internal combustion engine includes a means to boost the pressure of the intake air to the engine and a liquid cooled charge air cooler disposed between the output of the boost means and the charge air intake of the engine. Valves in the coolant system can be actuated so as to define a first configuration in which engine cooling is performed by coolant circulating in a first coolant loop at one temperature, and charge air cooling is performed by coolant flowing in a second coolant loop at a lower temperature. Themore » valves can be actuated so as to define a second configuration in which coolant that has flowed through the engine can be routed through the charge air cooler. The temperature of intake air to the engine can be controlled over a wide range of engine operation.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27087363','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27087363"><span>A Reusable, Compliant, Small Volume Blood Reservoir for In Vitro Hemolysis Testing.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Olia, Salim E; Herbertson, Luke H; Malinauskas, Richard A; Kameneva, Marina V</p> <p>2017-02-01</p> <p>Bench-top in vitro hemolysis testing is a fundamental tool during the design and regulatory safety evaluation of blood-contacting medical devices. While multiple published experimental protocols exist, descriptions of the test loop reservoir remain ambiguous. A critical fixture within the circuit, there is no readily available blood reservoir that ensures thorough mixing and complete air evacuation: two major factors which can affect results. As part of the Food and Drug Administration (FDA) Critical Path Initiative, we developed a three-piece reservoir consisting of a 3D-printed base, a plastic clamp set, and a medical-grade blood bag. This simple, reusable, and cost-effective design was used successfully in the hemolysis assessment of FDA benchmark nozzles and prototype rotary blood pumps, and may be useful as an integral component to any in vitro blood circulation loop. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800018279','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800018279"><span>Solar energy system performance evaluation: Seasonal report for Elcam Tempe Arizona State University, Tempe, Arizona</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1980-01-01</p> <p>The solar system, Elcam-Tempe, was designed by Elcam Incorporated, Santa Barbara, California, to supply commercial domestic hot water heating systems to the Agriculture Department residence at Arizona State University. The building is a single story residence located at the agriculture experiment farm of the Arizona State University. The energy system's four modes of operation are described. Electrical energy savings at the site was a net of 5.54 million Btu after the 0.17 million Btu of operating energy required to operate collector loop circulating pump were subtracted. The energy savings due to solar was less than the system's potential. On an average, twice as much hot water could have been used with significant solar energy contribution. The system corrosion and deposits caused by using dissimilar metals in the collector loop was the only problem noted with the Elcam-Tempe system.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5217952','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5217952"><span>Proportional Insulin Infusion in Closed-Loop Control of Blood Glucose</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Grasman, Johan</p> <p>2017-01-01</p> <p>A differential equation model is formulated that describes the dynamics of glucose concentration in blood circulation. The model accounts for the intake of food, expenditure of calories and the control of glucose levels by insulin and glucagon. These and other hormones affect the blood glucose level in various ways. In this study only main effects are taken into consideration. Moreover, by making a quasi-steady state approximation the model is reduced to a single nonlinear differential equation of which parameters are fit to data from healthy subjects. Feedback provided by insulin plays a key role in the control of the blood glucose level. Reduced β-cell function and insulin resistance may hamper this process. With the present model it is shown how by closed-loop control these defects, in an organic way, can be compensated with continuous infusion of exogenous insulin. PMID:28060898</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/5038580','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/5038580"><span>Open-cycle magnetohydrodynamic power plant based upon direct-contact closed-loop high-temperature heat exchanger</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Berry, G.F.; Minkov, V.; Petrick, M.</p> <p>1981-11-02</p> <p>A magnetohydrodynamic (MHD) power generating system is described in which ionized combustion gases with slag and seed are discharged from an MHD combustor and pressurized high temperature inlet air is introduced into the combustor for supporting fuel combustion at high temperatures necessary to ionize the combustion gases, and including a heat exchanger in the form of a continuous loop with a circulating heat transfer liquid such as copper oxide. The heat exchanger has an upper horizontal channel for providing direct contact between the heat transfer liquid and the combustion gases to cool the gases and condense the slag which thereupon floats on the heat transfer liquid and can be removed from the channel, and a lower horizontal channel for providing direct contact between the heat transfer liquid and pressurized air for preheating the inlet air. The system further includes a seed separator downstream of the heat exchanger.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1176576','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1176576"><span>Open-cycle magnetohydrodynamic power plant based upon direct-contact closed-loop high-temperature heat exchanger</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Berry, Gregory F.; Minkov, Vladimir; Petrick, Michael</p> <p>1988-01-05</p> <p>A magnetohydrodynamic (MHD) power generating system in which ionized combustion gases with slag and seed are discharged from an MHD combustor and pressurized high temperature inlet air is introduced into the combustor for supporting fuel combustion at high temperatures necessary to ionize the combustion gases, and including a heat exchanger in the form of a continuous loop with a circulating heat transfer liquid such as copper oxide. The heat exchanger has an upper horizontal channel for providing direct contact between the heat transfer liquid and the combustion gases to cool the gases and condense the slag which thereupon floats on the heat transfer liquid and can be removed from the channel, and a lower horizontal channel for providing direct contact between the heat transfer liquid and pressurized air for preheating the inlet air. The system further includes a seed separator downstream of the heat exchanger.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/875206','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/875206"><span>Open-cycle magnetohydrodynamic power plant based upon direct-contact closed-loop high-temperature heat exchanger</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Berry, Gregory F.; Minkov, Vladimir; Petrick, Michael</p> <p>1988-01-01</p> <p>A magnetohydrodynamic (MHD) power generating system in which ionized combustion gases with slag and seed are discharged from an MHD combustor and pressurized high temperature inlet air is introduced into the combustor for supporting fuel combustion at high temperatures necessary to ionize the combustion gases, and including a heat exchanger in the form of a continuous loop with a circulating heat transfer liquid such as copper oxide. The heat exchanger has an upper horizontal channel for providing direct contact between the heat transfer liquid and the combustion gases to cool the gases and condense the slag which thereupon floats on the heat transfer liquid and can be removed from the channel, and a lower horizontal channel for providing direct contact between the heat transfer liquid and pressurized air for preheating the inlet air. The system further includes a seed separator downstream of the heat exchanger.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1212892','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1212892"><span>Education & Collection Facility GSHP Demonstration Project</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Joplin, Jeff</p> <p></p> <p>The Denver Museum of Nature & Science (DMNS) designed and implemented an innovative ground source heat pump (GSHP) system for heating and cooling its new Education and Collection Facility (ECF) building addition. The project goal was to successfully design and install an open-loop GSHP system that utilized water circulating within an underground municipal recycled (non-potable) water system as the heat sink/source as a demonstration project. The expected results were to significantly reduce traditional GSHP installation costs while increasing system efficiency, reduce building energy consumption, require significantly less area and capital to install, and be economically implemented wherever access to amore » recycled water system is available. The project added to the understanding of GSHP technology by implementing the first GSHP system in the United States utilizing a municipal recycled water system as a heat sink/source. The use of this fluid through a GSHP system has not been previously documented. This use application presents a new opportunity for local municipalities to develop and expand the use of underground municipal recycled (non-potable) water systems. The installation costs for this type of technology in the building structure would be a cost savings over traditional GSHP costs, provided the local municipal infrastructure was developed. Additionally, the GSHP system functions as a viable method of heat sink/source as the thermal characteristics of the fluid are generally consistent throughout the year and are efficiently exchanged through the GSHP system and its components. The use of the recycled water system reduces the area required for bore or loop fields; therefore, presenting an application for building structures that have little to no available land use or access. This GSHP application demonstrates the viability of underground municipal recycled (non-potable) water systems as technically achievable, environmentally supportive, and an efficient system.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740026659','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740026659"><span>Application of remote sensing to study nearshore circulation. [and the continental shelf</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zeigler, J.; Lobecker, R.; Stauble, D.; Welch, C.; Haas, L.; Fang, C. S.</p> <p>1974-01-01</p> <p>The research to use remote sensing techniques for studying the continental shelf is reported. The studies reported include: (1) nearshore circulation in the vincinity of a natural tidal inlet; (2) identification of indicators of biological activity; (3) remote navigation system for tracking free drifting buoys; (4) experimental design of an estuaring tidal circulation; and (5) Skylab support work.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040086485','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040086485"><span>A Selected Operational History of the Internal Thermal Control System (ITCS) for International Space Station (ISS)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Patel, Vipul P.; Winton, Dale; Ibarra, Thomas H.</p> <p>2004-01-01</p> <p>The Internal Thermal Control System (ITCS) has been developed jointly by Boeing Corporation, Huntsville, Alabama and Honeywell Engines & Systems, Torrance, California to meet the internal thermal control needs for the International Space Station (ISS). The ITCS provides heat removal for the critical life support systems and thermal conditioning for numerous experiment racks. The ITCS will be fitted on a number of modules on the ISS. The first US Element containing the ITCS, Node 1, was launched in December 1998. Since Node 1 does not contain a pump to circulate the fluid it was not filled with ITCS fluid until after the US Laboratory Module was installed. The second US Element module, US Laboratory Module, which contains the pumps and all the major ITCS control hardware, was launched in February 2001. The third US Element containing the ITCS, the US Airlock, was launched in July 2001. The dual loop system of the ITCS is comprised of a lowtemperature loop (LTL) and a moderate-temperature loop (MTL). Each loop has a pump package assembly (PPA), a system flow control assembly (SFCA), a threeway mixing valve (TWMV), several rack flow control assemblies (RFCA), cold plates, pressure sensors, temperature sensors, pump bypass assembly (PBA) and a heat exchanger. In addition, the MTL has an additional TWMV, a payload regeneration heat exchanger (P/RHE) and a manual flow control valve (MFCV). The LTL has a service performance and checkout unit (SPCU) heat exchanger. The two loops are linked via one loop crossover assembly (LCA) providing cross loop capabilities and a single PPA, two-loop functionality. One important parameter monitored by the ground stations and on-orbit is the amount of fluid leakage from the ITCS. ISS fluid leakage is of importance since ITCS fluid is costly to re-supply, may be difficult to clean up in zero-g, and if uncontained could lead to equipment failures and potential hazards. This paper examines the nominal leakage observed over period of a year of on-orbit operation and compares this with analysis predictions. This paper also addresses the off-nominal leakage and a fluid transfer event causing significant changes in accumulator quantity.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27754775','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27754775"><span>Whole glove permeation of cyclohexanol through disposable nitrile gloves on a dextrous robot hand and comparison with the modified closed-loop ASTM F739 method 1. No fist clenching.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mathews, Airek R; Que Hee, Shane S</p> <p>2017-04-01</p> <p>The aim was to develop a whole glove permeation method for cyclohexanol to generate permeation parameter data for a non-moving dextrous robot hand (normalized breakthrough time t b , standardized breakthrough time t s , steady state permeation rate P s , and diffusion coefficient D). Four types of disposable powderless, unsupported, and unlined nitrile gloves from the same producer were investigated: Safeskin Blue and Kimtech Science Blue, Purple, and Sterling. The whole glove method developed involved a peristaltic pump for water circulation through chemically resistant Viton tubing to continually wash the inner surface of the test glove via holes in the tubing, a dextrous robot hand operated by a microprocessor, a chemically protective nitrile glove to protect the robot hand, an incubator to maintain 35°C temperature, and a hot plate to maintain 35°C at the sampling point of the circulating water. Aliquots of 1.0 mL were sampled at regular time intervals for the first 60 min followed by removal of 0.5 mL aliquots every hour to 8 hr. Quantification was by the internal standard method after gas chromatography-selective ion electron impact mass spectrometry using a non-polar capillary column. The individual glove values of t b and t s differed for the ASTM closed loop method except for Safeskin Blue, but did not for the whole glove method. Most of the kinetic parameters agreed within an order of magnitude for the two techniques. The order of most protective to least protective glove was Blue and Safeskin, then Purple followed by Sterling for the whole gloves. The analogous order for the modified F739 ASTM closed loop method was: Safeskin, Blue, Purple, and Sterling, almost the same as for the whole glove. The Sterling glove was "not recommended" from the modified ASTM data, and was "poor" from the whole glove data.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhFl...28i5103B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhFl...28i5103B"><span>Investigation of the viscous reconnection phenomenon of two vortex tubes through spectral simulations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beardsell, Guillaume; Dufresne, Louis; Dumas, Guy</p> <p>2016-09-01</p> <p>This paper aims to shed further light on the viscous reconnection phenomenon. To this end, we propose a robust and efficient method in order to quantify the degree of reconnection of two vortex tubes. This method is used to compare the evolutions of two simple initial vortex configurations: orthogonal and antiparallel. For the antiparallel configuration, the proposed method is compared with alternative estimators and it is found to improve accuracy since it can account properly for the formation of looping structures inside the domain. This observation being new, the physical mechanism for the formation of those looping structures is discussed. For the orthogonal configuration, we report results from simulations that were performed at a much higher vortex Reynolds number (ReΓ ≡ circulation/viscosity = 104) and finer resolution (N3 = 10243) than previously presented in the literature. The incompressible Navier-stokes equations are solved directly (Direct Numerical Simulation or DNS) using a Fourier pseudospectral algorithm with triply periodic boundary conditions. The associated zero-circulation constraint is circumvented by solving the governing equations in a proper rotating frame of reference. Using ideas similar to those behind our method to compute the degree of reconnection, we split the vorticity field into its reconnected and non-reconnected parts, which allows to create insightful visualizations of the evolving vortex topology. It also allows to detect regions in the vorticity field that are neither reconnected nor non-reconnected and thus must be associated to internal looping structures. Finally, the Reynolds number dependence of the reconnection time scale Trec is investigated in the range 500 ≤ ReΓ ≤ 10 000. For both initial configurations, the scaling is generally found to vary continuously as ReΓ is increased from T rec ˜ R eΓ - 1 to T rec ˜ R eΓ - 1 / 2 , thus providing quantitative support for previous claims that the reconnection physics of two vortices should be similar regardless of their spatial arrangement.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27103533','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27103533"><span>Using in-cell SHAPE-Seq and simulations to probe structure-function design principles of RNA transcriptional regulators.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Takahashi, Melissa K; Watters, Kyle E; Gasper, Paul M; Abbott, Timothy R; Carlson, Paul D; Chen, Alan A; Lucks, Julius B</p> <p>2016-06-01</p> <p>Antisense RNA-mediated transcriptional regulators are powerful tools for controlling gene expression and creating synthetic gene networks. RNA transcriptional repressors derived from natural mechanisms called attenuators are particularly versatile, though their mechanistic complexity has made them difficult to engineer. Here we identify a new structure-function design principle for attenuators that enables the forward engineering of new RNA transcriptional repressors. Using in-cell SHAPE-Seq to characterize the structures of attenuator variants within Escherichia coli, we show that attenuator hairpins that facilitate interaction with antisense RNAs require interior loops for proper function. Molecular dynamics simulations of these attenuator variants suggest these interior loops impart structural flexibility. We further observe hairpin flexibility in the cellular structures of natural RNA mechanisms that use antisense RNA interactions to repress translation, confirming earlier results from in vitro studies. Finally, we design new transcriptional attenuators in silico using an interior loop as a structural requirement and show that they function as desired in vivo. This work establishes interior loops as an important structural element for designing synthetic RNA gene regulators. We anticipate that the coupling of experimental measurement of cellular RNA structure and function with computational modeling will enable rapid discovery of structure-function design principles for a diverse array of natural and synthetic RNA regulators. © 2016 Takahashi et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJBC...2650076P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJBC...2650076P"><span>Spatiotemporal Dynamics of a Network of Coupled Time-Delay Digital Tanlock Loops</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paul, Bishwajit; Banerjee, Tanmoy; Sarkar, B. C.</p> <p></p> <p>The time-delay digital tanlock loop (TDTLs) is an important class of phase-locked loop that is widely used in electronic communication systems. Although nonlinear dynamics of an isolated TDTL has been studied in the past but the collective behavior of TDTLs in a network is an important topic of research and deserves special attention as in practical communication systems separate entities are rarely isolated. In this paper, we carry out the detailed analysis and numerical simulations to explore the spatiotemporal dynamics of a network of a one-dimensional ring of coupled TDTLs with nearest neighbor coupling. The equation representing the network is derived and we carry out analytical calculations using the circulant matrix formalism to obtain the stability criteria. An extensive numerical simulation reveals that with the variation of gain parameter and coupling strength the network shows a variety of spatiotemporal dynamics such as frozen random pattern, pattern selection, spatiotemporal intermittency and fully developed spatiotemporal chaos. We map the distinct dynamical regions of the system in two-parameter space. Finally, we quantify the spatiotemporal dynamics by using quantitative measures like Lyapunov exponent and the average quadratic deviation of the full network.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23498830','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23498830"><span>"Passing loop" technique: a new modification of the piggyback technique tailored to voluminous liver grafts--case report.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Eldeen, F Z; Lee, C-F; Lee, C-S; Chan, K-M; Lee, W-C</p> <p>2013-03-01</p> <p>The modified piggyback technique with side-to-side cavocavostomy decreases the risk of outflow obstruction compared with the standard piggyback method. However, this modification is not ideal for recipients who receive a graft that is voluminous or bears an enlarged caudate lobe. We modified the inferior vena cava (IVC) preservation technique against deleterious complications of compression by using a passing loop. A 49-year-old woman, who underwent orthotopic liver transplantation for hepatic failure, was allocated a large-size liver. In anticipation of serious caval compression due to the voluminous grafts, we kept the suprahepatic or infrahepatic donor caval cuffs open for an anastomosis. The first anastomosis was performed between suprahepatic donor IVC cuff and recipient middle-left hepatic vein common channel; the second anastomosis was a terminolateral cavocavostomy between infrahepatic donor IVC cuff and the anterior wall of the recipient's IVC. When the liver circulation was restored, the donor retrohepatic vena cava served as a passing loop for both hepatic venous outflow and infra-diaphragmatic venous return to bypass possible IVC compression. Our technique may solve a dilemna for patients receiving voluminous liver grafts. Copyright © 2013 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5266673','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5266673"><span>Glomerular Lesions in Proteinuric Miniature Schnauzer Dogs</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Furrow, E.; Lees, G. E.; Brown, C. A.; Cianciolo, R. E.</p> <p>2017-01-01</p> <p>Miniature Schnauzer dogs are predisposed to idiopathic hypertriglyerceridemia, which increases risk for diseases such as pancreatitis and gallbladder mucocele. Recently, elevated triglyceride concentrations have been associated with proteinuria in this breed, although it is difficult to determine which abnormality is primary. Retrospective review of renal tissue from 27 proteinuric Miniature Schnauzers revealed that 20 dogs had ultrastructural evidence of osmophilic globules consistent with lipid in glomerular tufts. Seven of these dogs had lipid thromboemboli in glomerular capillary loops that distorted their shape and compressed circulating erythrocytes. Triglyceride concentrations were reported in 6 of these 7 dogs, and all were hypertriglyceridemic. In addition, glomerular lipidosis (defined as accumulation of foam cells within peripheral capillary loops) was identified in a single dog. The remaining 12 dogs had smaller amounts of lipid that could only be identified ultrastructurally. Neither signalment data nor clinicopathologic parameters (serum albumin, serum creatinine, urine protein-to-creatinine ratio, and blood pressure) differed among the various types of lipid lesions. During the time course of this study, all dogs diagnosed with glomerular lipid thromboemboli were Miniature Schnauzers, underscoring the importance of recognizing these clear spaces within capillary loops as lipid. PMID:28005494</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010pot..book..659T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010pot..book..659T"><span>First Experiences with the New Chalmers Gasifier</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thunman, H.; Seemann, M. C.</p> <p></p> <p>During summer 2007 a 2-6 MWth indirect gasification section was integrated into the loop of the existing 82➀2 MWth circulating fluidized bed boiler at Chalmers University. With help of a particle distributor the gasification unit is connected to the loop after the cyclone. Hot bed material entrained from the boiler is so transferred to the gasifier providing the heat for the production of a nearly nitrogen free product gas. Non-gasified char is returned together with the bed material into the boiler and converted. Biomass can be fed into both sections; the boiler and the gasifier. The gasification is separated from the boiler via two loop seals and a particle distributer, directing particles either back to the boiler or into the gasification section. For that reason the CFB boiler can be operated even after the retrofit independently, just like before, or in combined combustion/gasification mode. This possibility keeps the risk for a retrofit low. As, furthermore, the investment costs for the integration are considerably lower than standalone gasification units of that size, the retrofit is an easy way to extend the potential of a CFB Boiler towards bi- and tri-generation (heat, power, fuel) and enter new markets.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/863860','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/863860"><span>System for thermal energy storage, space heating and cooling and power conversion</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Gruen, Dieter M.; Fields, Paul R.</p> <p>1981-04-21</p> <p>An integrated system for storing thermal energy, for space heating and cong and for power conversion is described which utilizes the reversible thermal decomposition characteristics of two hydrides having different decomposition pressures at the same temperature for energy storage and space conditioning and the expansion of high-pressure hydrogen for power conversion. The system consists of a plurality of reaction vessels, at least one containing each of the different hydrides, three loops of circulating heat transfer fluid which can be selectively coupled to the vessels for supplying the heat of decomposition from any appropriate source of thermal energy from the outside ambient environment or from the spaces to be cooled and for removing the heat of reaction to the outside ambient environment or to the spaces to be heated, and a hydrogen loop for directing the flow of hydrogen gas between the vessels. When used for power conversion, at least two vessels contain the same hydride and the hydrogen loop contains an expansion engine. The system is particularly suitable for the utilization of thermal energy supplied by solar collectors and concentrators, but may be used with any source of heat, including a source of low-grade heat.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/353009','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/353009"><span>Power generation costs and ultimate thermal hydraulic power limits in hypothetical advanced designs with natural circulation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Duffey, R.B.; Rohatgi, U.S.</p> <p></p> <p>Maximum power limits for hypothetical designs of natural circulation plants can be described analytically. The thermal hydraulic design parameters are those which limit the flow, being the elevations, flow areas, and loss coefficients. WE have found some simple ``design`` equations for natural circulation flow to power ratio, and for the stability limit. The analysis of historical and available data for maximum capacity factor estimation shows 80% to be reasonable and achievable. The least cost is obtained by optimizing both hypothetical plant performance for a given output,a nd the plant layout and design. There is also scope to increase output andmore » reduce cost by considering design variations of primary and secondary pressure, and by optimizing component elevations and loss coefficients. The design limits for each are set by stability and maximum flow considerations, which deserve close and careful evaluation.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1129349-responses-east-asian-summer-monsoon-natural-anthropogenic-forcings-latest-cmip5-models','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1129349-responses-east-asian-summer-monsoon-natural-anthropogenic-forcings-latest-cmip5-models"><span>Responses of East Asian Summer Monsoon to Natural and Anthropogenic Forcings in the 17 Latest CMIP5 Models</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Song, Fengfei; Zhou, Tianjun; Qian, Yun</p> <p>2014-01-31</p> <p>In this study, we examined the responses of East Asian Summer Monsoon (EASM) to natural (solar variability and volcanic aerosols) and anthropogenic (greenhouse gasses and aerosols) forcings simulated in the 17 latest Coupled Model Intercomparison Program phase 5 (CMIP5) models with 105 realizations. The observed weakening trend of low-level EASM circulation during 1958-2001 is partly reproduced under all-forcing runs. A comparison of separate forcing experiments reveals that the aerosol-forcing plays a primary role in driving the weakened low-level monsoon circulation. The preferential cooling over continental East Asia caused by aerosol affects the monsoon circulation through reducing the land-sea thermal contrastmore » and results in higher sea level pressure over northern China. In the upper-level, both natural-forcing and aerosol-forcing contribute to the observed southward shift of East Asian subtropical jet through changing the meridional temperature gradient.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25910166','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25910166"><span>Uncertainty loops in travel-time tomography from nonlinear wave physics.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Galetti, Erica; Curtis, Andrew; Meles, Giovanni Angelo; Baptie, Brian</p> <p>2015-04-10</p> <p>Estimating image uncertainty is fundamental to guiding the interpretation of geoscientific tomographic maps. We reveal novel uncertainty topologies (loops) which indicate that while the speeds of both low- and high-velocity anomalies may be well constrained, their locations tend to remain uncertain. The effect is widespread: loops dominate around a third of United Kingdom Love wave tomographic uncertainties, changing the nature of interpretation of the observed anomalies. Loops exist due to 2nd and higher order aspects of wave physics; hence, although such structures must exist in many tomographic studies in the physical sciences and medicine, they are unobservable using standard linearized methods. Higher order methods might fruitfully be adopted.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27055927','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27055927"><span>Prevalence of mutations within major hydrophilic region of hepatitis B virus and their correlation with genotypes among chronically infected patients in Egypt.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Abu Zeid, Walaa M; Ramadan, Dalia I; Shemis, Mohamed A</p> <p>2016-03-01</p> <p>Mutations within the major hydrophilic region (MHR) of the hepatitis B surface antigen (HBsAg) have been reported in relation to viral persistence by evasion from vaccine and immunotherapy, severity of liver disease and lack of detection by commercial kits. The aim of this study was to elucidate the circulation of hepatitis B virus (HBV) genotypes, subgenotypes and serotypes in Egypt, with recognition of the pattern and prevalence of MHR mutations possibly occurring during the course of the disease. Eighty-eight samples from patients with chronic HBV infection were included in the study. The surface protein-encoding gene (S gene) in the HBV genome was subjected to amplification and partial sequencing. Based on phylogenetic analysis, only genotype D was found circulating among patients. The majority of isolates belonged to subgenotype D3 (86.3%), followed by D7 (8%), then D5 (3.4%) and lastly D1 (2.3%). Two subtypes were identified: ayw2 (97%) and ayw3 (2%). The 'w' sub-determinant was not defined in one isolate (1%). A significant proportion of patients (13/88, 14.8%) exhibited mutations in the MHR, 10 of whom harboured mutations in the 'a' determinant region and three outside. The first loop comprised four patients with three mutations (P127S, P127T and Y134F). The second loop contained six patients, all with one mutation, S143L, which was most frequently encountered in this study (6.8%). We conclude that genotype D, subgenotype D3 and HBsAg subtype ayw2 are the most common types circulating in Egypt, which account for 100%, 86.3% and 97% of the population, respectively, with a moderate degree of MHR mutations. Copyright © 2016 Arab Journal of Gastroenterology. Published by Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110022488','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110022488"><span>Geoscience Laser Altimetry System (GLAS) Loop Heat Pipe Anomaly and On Orbit Testing</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Baker, Charles; Butler, Dan; Grob, Eric; Jester, Peggy</p> <p>2011-01-01</p> <p>The Geoscience Laser Altimetry System (GLAS) is the sole instrument on the ICESat Satellite. On day 230 of 2003, the GLAS Component Loop Heat Pipe (CLHP) entered a slow circulation mode that resulted in the main electronics box reaching its hot safing temperature, after which the entire instrument was turned off. The CLHP had a propylene working fluid and was actively temperature controlled via a heater on the compensation chamber. The slow circulation mode happened right after a planned propulsive yaw maneuver with the spacecraft. It took several days to recover the CLHP and ensure that it was still operational. The recovery occurred after the entire instrument was cooled to survival temperatures and the CLHP compensation chamber cycled on a survival heater. There are several theories as to why this slow circulation mode exhibited itself, including: accumulation of Non-Condensible Gas (NCG), the secondary wick being under designed or improperly implemented, or an expanded (post-launch) leak across the primary wick. Each of these is discussed in turn, and the secondary wick performance is identified as the most likely source of the anomalous behavior. After the anomaly, the CLHP was controlled to colder temperatures to improve its performance (as the surface tension increases with lower temperature, as does the volume of liquid in the compensation chamber) and only precursor pulses occurred later in the mission. After GLAS s last laser failed, in late 2009, a decision was made to conduct engineering tests of both LHPs to try and duplicate this flight anomaly. The engineering tests consisted of control setpoint changes, sink changes, and one similar propulsive Yaw maneuver. The only test that showed any similar anomaly precursors on the CLHP was the propulsive maneuver followed by a setpoint increase. The ICESat Satellite was placed in a decaying orbit and ended its mission on August 30, 2010 in Barents Sea.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12664145','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12664145"><span>A novel circulating loop bioreactor with cells immobilized in loofa ( Luffa cylindrica) sponge for the bioconversion of raw cassava starch to ethanol.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Roble, N D; Ogbonna, J C; Tanaka, H</p> <p>2003-02-01</p> <p>A circulating loop bioreactor (CLB) with cells immobilized in loofa sponge was constructed for simultaneous aerobic and anaerobic processes. The CLB consists of an aerated riser and a non-aerated downcomer column connected at the top and bottom by cylindrical pipes. Ethanol production from raw cassava starch was investigated in the CLB. Aspergillus awamori IAM 2389 and Saccharomyces cerevisiae IR2 immobilized on loofa sponge were placed, respectively, in the aerated riser column and non-aerated downcomer column. Both alpha-amylase and glucoamylase activities increased as the aeration rate was increased. Ethanol yield and productivity increased with an increase in the aeration rate up to 0.5 vvm, but decreased at higher aeration rates. The CLB was operated at an aeration rate of 0.5 vvm for more than 600 h, resulting in an average ethanol productivity and yield from raw cassava starch of 0.5 g-ethanol l(-1) x h(-1) and 0.45 g ethanol/g starch, respectively. In order to increase ethanol productivity, it was necessary to increase the dissolved oxygen (DO) concentration in the riser column and decrease the DO concentration in the downcomer column. However, increasing the aeration rate resulted in increases in the DO concentration in both the riser and the downcomer columns. At high aeration rate, there was no significant difference in the DO concentration in the riser and downcomer columns. The aeration rate was therefore uncoupled from the liquid circulation by attaching a time-controlled valve in the upper connecting pipe. By optimizing the time and frequency of valve opening, and operation at high aeration rate, it was possible to maintain a very high DO concentration in the riser column and a low DO concentration in the downcomer column. Under these conditions, ethanol productivity increased by more than 100%, to 1.17 g l(-1) x h(-1).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24091801','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24091801"><span>Maternal plasma DNA testing for aneuploidy in pregnancies achieved by assisted reproductive technologies.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lambert-Messerlian, Geralyn; Kloza, Edward M; Williams, John; Loucky, Jaroslav; O'Brien, Barbara; Wilkins-Haug, Louise; Mahoney, Maurice J; De Biasio, Pierangela; Borrell, Antoni; Ehrich, Mathias; van den Boom, Dirk; Bombard, Allan T; Deciu, Cosmin; Palomaki, Glenn E</p> <p>2014-05-01</p> <p>We sought to compare measurements of circulating cell-free DNA as well as Down syndrome test results in women with naturally conceived pregnancies with those conceived using assisted reproductive technologies. Data regarding assisted reproductive technologies were readily available from seven enrollment sites participating in an external clinical validation trial of nested case/control design. Measurements of circulating cell-free fetal and total DNA, fetal fraction (ratio of fetal to total DNA), chromosome-specific z-scores, and karyotype results were available for analysis. Analyses were restricted to 632 euploid (5.2% assisted reproductive technologies) and 73 Down syndrome (13.7% assisted reproductive technologies), including 16 twin pregnancies. No differences were found for fetal or total circulating cell-free DNA, or for the fetal fraction in euploid (P = 0.70) or Down syndrome (P = 0.58) pregnancies by method of conception. There appeared to be systematic z-score reductions for chromosomes 21, 18, and 13 in assisted reproductive technologies versus natural euploid pregnancies (P = 0.048, 0.0032, and 0.36, respectively). Assisted reproductive technologies and naturally conceived pregnancies contribute similar levels of circulating cell-free DNA into maternal circulation. Small differences in the z-scores of pregnancies achieved by assisted reproductive technologies were observed and do not appear to be test-related artifacts. However, the findings need confirmation before any consideration of changes to testing and reporting protocols.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PMag...90.4623Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PMag...90.4623Y"><span>The temperature dependence of heavy-ion damage in iron: A microstructural transition at elevated temperatures</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yao, Z.; Jenkins, M. L.; Hernández-Mayoral, M.; Kirk, M. A.</p> <p>2010-12-01</p> <p>A transition is reported in the dislocation microstructure of pure Fe produced by heavy-ion irradiation of thin foils, which took place between irradiation temperatures (T irr) of 300°C and 500°C. At T irr ≤ 400°C, the microstructure was dominated by round or irregular non-edge dislocation loops of interstitial nature and with Burgers vectors b = ½ ⟨111⟩, although interstitial ⟨100⟩ loops were also present; at 500°C only rectilinear pure-edge ⟨100⟩ loops occurred. At intermediate temperatures there was a gradual transition between the two types of microstructure. At temperatures just below 500°C, mobile ½⟨111⟩ loops were seen to be subsumed by sessile ⟨100⟩ loops. A possible explanation of these observations is given.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22181447','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22181447"><span>Looped star polymers show conformational transition from spherical to flat toroidal shapes.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reiss, Pascal; Fritsche, Miriam; Heermann, Dieter W</p> <p>2011-11-01</p> <p>Inspired by the topological organization of the circular Escherichia coli chromosome, which is compacted by separate domains, we study a polymer architecture consisting of a central ring to which either looped or linear side chains are grafted. A shape change from a spherical to a toroidal organization takes place as soon as the inner ring becomes large enough for the attached arms to fit within its circumference. Building up a torus, the system flattens, depending on the effective bending rigidity of the chain induced by entropic repulsion of the attached loops and, to a lesser extent, linear arms. Our results suggest that the natural formation of a toroidal structure with a decreased amount of writhe induced by a specific underlying topology could be one driving force, among others, that nature exploits to ensure proper packaging of the genetic material within a rod-shaped, bacterial envelope.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012MsT..........4B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012MsT..........4B"><span>Design of Test Loops for Forced Convection Heat Transfer Studies at Supercritical State</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Balouch, Masih N.</p> <p></p> <p>Worldwide research is being conducted to improve the efficiency of nuclear power plants by using supercritical water (SCW) as the working fluid. One such SCW reactor considered for future development is the CANDU-Supercritical Water Reactor (CANDU-SCWR). For safe and accurate design of the CANDU-SCWR, a detailed knowledge of forced-convection heat transfer in SCW is required. For this purpose, two supercritical fluid loops, i.e. a SCW loop and an R-134a loop are developed at Carleton University. The SCW loop is designed to operate at pressures as high as 28 MPa, temperatures up to 600 °C and mass fluxes of up to 3000 kg/m2s. The R-134a loop is designed to operate at pressures as high as 6 MPa, temperatures up to 140 °C and mass fluxes in the range of 500-6000 kg/m2s. The test loops designs allow for up to 300 kW of heating power to be imparted to the fluid. Both test loops are of the closed-loop design, where flow circulation is achieved by a centrifugal pump in the SCW loop and three parallel-connected gear pumps in the R-134a loop, respectively. The test loops are pressurized using a high-pressure nitrogen cylinder and accumulator assembly, which allows independent control of the pressure, while simultaneously dampening pump induced pressure fluctuations. Heat exchangers located upstream of the pumps control the fluid temperature in the test loops. Strategically located measuring instrumentation provides information on the flow rate, pressure and temperature in the test loops. The test loops have been designed to accommodate a variety of test-section geometries, ranging from a straight circular tube to a seven-rod bundle, achieving heat fluxes up to 2.5 MW/m2 depending on the test-section geometry. The design of both test loops allows for easy reconfiguration of the test-section orientation relative to the gravitational direction. All the test sections are of the directly-heated design, where electric current passing through the pressure retaining walls of the test sections provides the Joule heating required to heat up the fluid to supercritical conditions. A high-temperature dielectric gasket isolates the current carrying parts of the test section from the rest of the assembly. Temperature and pressure drop data are collected at the inlet and outlet, and along the heated length of the test section. The test loops and test sections are designed according to American Society of Mechanical Engineers (ASME) Pressure Piping B31.1, and Boiler and Pressure Vessel Code, Section VIII-Division 1 rules. The final test loops and test sections assemblies are certified by Technical Standards and Safety Authority (TSSA). Every attempt is made to use off-the-shelf components where possible in order to streamline the design process and reduce costs. Following a rigorous selection process, stainless steel Types 316 and 316H are selected as the construction materials for the test loops, and Inconel 625 is selected as the construction material for the test sections. This thesis describes the design of the SCW and R-134a loops along with the three test-section geometries (i.e., tubular, annular and bundle designs).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JNR....20...39V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JNR....20...39V"><span>The Ca-looping process for CO2 capture and energy storage: role of nanoparticle technology</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Valverde, Jose Manuel</p> <p>2018-02-01</p> <p>The calcium looping (CaL) process, based on the cyclic carbonation/calcination of CaO, has come into scene in the last years with a high potential to be used in large-scale technologies aimed at mitigating global warming. In the CaL process for CO2 capture, the CO2-loaded flue gas is used to fluidize a bed of CaO particles at temperatures around 650 °C. The carbonated particles are then circulated into a calciner reactor wherein the CaO solids are regenerated at temperatures near 950 °C under high CO2 concentration. Calcination at such harsh conditions causes a marked sintering and loss of reactivity of the regenerated CaO. This main drawback could be however compensated from the very low cost of natural CaO precursors such as limestone or dolomite. Another emerging application of the CaL process is thermochemical energy storage (TCES) in concentrated solar power (CSP) plants. Importantly, carbonation/calcination conditions to maximize the global CaL-CSP plant efficiency could differ radically from those used for CO2 capture. Thus, carbonation could be carried out at high temperatures under high CO2 partial pressure for maximum efficiency, whereas the solids could be calcined at relatively low temperatures in the absence of CO2 to promote calcination. Our work highlights the critical role of carbonation/calcination conditions on the performance of CaO derived from natural precursors. While conditions in the CaL process for CO2 capture lead to a severe CaO deactivation with the number of cycles, the same material may exhibit a high and stable conversion at optimum CaL-CSP conditions. Moreover, the type of CaL conditions influences critically the reaction kinetics, which plays a main role on the optimization of relevant operation parameters such as the residence time in the reactors. This paper is devoted to a brief review on the latest research activity in our group concerning these issues as well as the possible role of nanoparticle technology to enhance the activity of Ca-based materials at CaL conditions for CO2 capture and energy storage.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15172290','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15172290"><span>Clinical experience with the mini-extracorporeal circulation system: an evolution or a revolution?</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Remadi, Jean-Paul; Marticho, Paul; Butoi, Irina; Rakotoarivelo, Zava; Trojette, Faouzi; Benamar, Amar; Beloucif, Sadek; Foure, Dominique; Poulain, Henri J</p> <p>2004-06-01</p> <p>We studied a cohort of 150 patients operated on with a new cardiopulmonary bypass (CPB) system. This is the mini-extracorporeal circulation (MECC) system. The MECC is a fully heparin coated closed-loop CPB system that includes a centrifugal pump and has a priming volume of 450 mL. Between March 2001 and September 2002, 150 consecutive patients were operated on using the mini-CPB (MECC) method. This includes 105 coronary artery bypass graft and 45 aortic valve replacement patients. The median age was 66.7 +/- 10.7 years with a gender ratio of 3.27 males to 1 female. The 30-day operative mortality was 1.3%. The hemoglobin concentration was stable and perioperative transfusion was needed in only 6% of all patients. The renal and neuropsychiatric complications were less than 1%. In our experience, the MECC system is a reliable new concept for CPB with good clinical results.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28772696','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28772696"><span>Effect of Immobilized Antithrombin III on the Thromboresistance of Polycarbonate Urethane.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lukas, Karin; Stadtherr, Karin; Gessner, Andre; Wehner, Daniel; Schmid, Thomas; Wendel, Hans Peter; Schmid, Christof; Lehle, Karla</p> <p>2017-03-24</p> <p>The surface of foils and vascular grafts made from a thermoplastic polycarbonate urethanes (PCU) (Chronoflex AR) were chemically modified using gas plasma treatment, binding of hydrogels-(1) polyethylene glycol bisdiamine and carboxymethyl dextran (PEG-DEX) and (2) polyethyleneimine (PEI)-and immobilization of human antithrombin III (AT). Their biological impact was tested in vitro under static and dynamic conditions. Static test methods showed a significantly reduced adhesion of endothelial cells, platelets, and bacteria, compared to untreated PCU. Modified PCU grafts were circulated in a Chandler-Loop model for 90 min at 37 °C with human blood. Before and after circulation, parameters of the hemostatic system (coagulation, platelets, complement, and leukocyte activation) were analyzed. PEI-AT significantly inhibited the activation of both coagulation and platelets and prevented the activation of leukocytes and complement. In conclusion, both modifications significantly reduce coagulation activation, but only PEI-AT creates anti-bacterial and anti-thrombogenic functionality.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMPP43B1677M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMPP43B1677M"><span>Stable isotope records of convection variability in the West Pacific Warm Pool from fast-growing stalagmites</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maupin, C. R.; Partin, J. W.; Quinn, T. M.; Shen, C.; Lin, K.; Taylor, F. W.; Sinclair, D. J.; Banner, J. L.</p> <p>2010-12-01</p> <p>The potential response of the tropical Pacific to ongoing anthropogenic global warming conditions is informed by instrumental data, model predictions and climate proxy evidence. However, these distinct lines of evidence lead to opposing predictions in terms of the nature of interannual (ENSO) variability in a warming world. Interpreted in an ENSO framework, warming in the tropical Pacific may elicit a zonally asymmetrical response and lead to an intensified Walker Circulation (more ‘La Niña - like’). Alternatively, discrepancies in the increasing rates of latent heat flux and rainfall due to warming conditions may in fact reduce Walker Circulation (more ‘El Niño - like’). However, in order for such a framework to be useful in the context of future climate change, some knowledge of the natural variability in the strength of Walker Circulation components is required. The extant instrumental data are not of sufficient temporal length to fully assess the spectrum of natural variability in such climate components. Oxygen isotope records from tropical speleothems have been successfully used to document the nature of precessional forcing on precipitation and atmospheric circulation patterns throughout the tropics. Typical stalagmite growth rates of 10-100 μm yr-1 allow decadally resolved records of δ18O variability on time scales of centuries to millennia and beyond. Here we present the initial results from calcite stalagmites of heretofore unprecedented growth rates (~1-4 mm yr-1) in a cave in northwest Guadalcanal, Solomon Islands (~9°S, 160°E). These stalagmites have been absolutely dated by U-Th techniques and indicate stalagmite growth spanning ~1650 to 2010 CE. The δ18O records from stalagmites provide evidence for changes in convection in the equatorial WPWP region of the SPCZ: the rising limb of the Pacific Walker Circulation, and therefore provide critical insight into changes in zonal atmospheric circulation across the Pacific.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/10164145-assessment-relap5-mod2-against-pressurizer-spray-valve-inadverted-fully-opening-transient-recovery-natural-circulation-jose-cabrera-nuclear-station','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/10164145-assessment-relap5-mod2-against-pressurizer-spray-valve-inadverted-fully-opening-transient-recovery-natural-circulation-jose-cabrera-nuclear-station"><span>Assessment of RELAP5/MOD2 against a pressurizer spray valve inadverted fully opening transient and recovery by natural circulation in Jose Cabrera Nuclear Station</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Arroyo, R.; Rebollo, L.</p> <p>1993-06-01</p> <p>This document presents the comparison between the simulation results and the plant measurements of a real event that took place in JOSE CABRERA nuclear power plant in August 30th, 1984. The event was originated by the total, continuous and inadverted opening of the pressurizer spray valve PCV-400A. JOSE CABRERA power plant is a single loop Westinghouse PWR belonging to UNION ELECTRICA FENOSA, S.A. (UNION FENOSA), an Spanish utility which participates in the International Code Assessment and Applications Program (ICAP) as a member of UNIDAD ELECTRICA, S.A. (UNESA). This is the second of its two contributions to the Program: the firstmore » one was an application case and this is an assessment one. The simulation has been performed using the RELAP5/MOD2 cycle 36.04 code, running on a CDC CYBER 180/830 computer under NOS 2.5 operating system. The main phenomena have been calculated correctly and some conclusions about the 3D characteristics of the condensation due to the spray and its simulation with a 1D tool have been got.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3962102','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3962102"><span>Thumb-loops up for catalysis: a structure/function investigation of a functional loop movement in a GH11 xylanase</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Paës, Gabriel; Cortés, Juan; Siméon, Thierry; O'Donohue, Michael J.; Tran, Vinh</p> <p>2012-01-01</p> <p>Dynamics is a key feature of enzyme catalysis. Unfortunately, current experimental and computational techniques do not yet provide a comprehensive understanding and description of functional macromolecular motions. In this work, we have extended a novel computational technique, which combines molecular modeling methods and robotics algorithms, to investigate functional motions of protein loops. This new approach has been applied to study the functional importance of the so-called thumb-loop in the glycoside hydrolase family 11 xylanase from Thermobacillus xylanilyticus (Tx-xyl). The results obtained provide new insight into the role of the loop in the glycosylation/deglycosylation catalytic cycle, and underline the key importance of the nature of the residue located at the tip of the thumb-loop. The effect of mutations predicted in silico has been validated by in vitro site-directed mutagenesis experiments. Overall, we propose a comprehensive model of Tx-xyl catalysis in terms of substrate and product dynamics by identifying the action of the thumb-loop motion during catalysis. PMID:24688637</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013IJMPC..2450015H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013IJMPC..2450015H"><span>Simple and Flexible Self-Reproducing Structures in Asynchronous Cellular Automata and Their Dynamics</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Xin; Lee, Jia; Yang, Rui-Long; Zhu, Qing-Sheng</p> <p>2013-03-01</p> <p>Self-reproduction on asynchronous cellular automata (ACAs) has attracted wide attention due to the evident artifacts induced by synchronous updating. Asynchronous updating, which allows cells to undergo transitions independently at random times, might be more compatible with the natural processes occurring at micro-scale, but the dark side of the coin is the increment in the complexity of an ACA in order to accomplish stable self-reproduction. This paper proposes a novel model of self-timed cellular automata (STCAs), a special type of ACAs, where unsheathed loops are able to duplicate themselves reliably in parallel. The removal of sheath cannot only allow various loops with more flexible and compact structures to replicate themselves, but also reduce the number of cell states of the STCA as compared to the previous model adopting sheathed loops [Y. Takada, T. Isokawa, F. Peper and N. Matsui, Physica D227, 26 (2007)]. The lack of sheath, on the other hand, often tends to cause much more complicated interactions among loops, when all of them struggle independently to stretch out their constructing arms at the same time. In particular, such intense collisions may even cause the emergence of a mess of twisted constructing arms in the cellular space. By using a simple and natural method, our self-reproducing loops (SRLs) are able to retract their arms successively, thereby disentangling from the mess successfully.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AIPC.1659c0004P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AIPC.1659c0004P"><span>Parametric study of natural circulation flow in molten salt fuel in molten salt reactor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pauzi, Anas Muhamad; Cioncolini, Andrea; Iacovides, Hector</p> <p>2015-04-01</p> <p>The Molten Salt Reactor (MSR) is one of the most promising system proposed by Generation IV Forum (GIF) for future nuclear reactor systems. Advantages of the MSR are significantly larger compared to other reactor system, and is mainly achieved from its liquid nature of fuel and coolant. Further improvement to this system, which is a natural circulating molten fuel salt inside its tube in the reactor core is proposed, to achieve advantages of reducing and simplifying the MSR design proposed by GIF. Thermal hydraulic analysis on the proposed system was completed using a commercial computation fluid dynamics (CFD) software called FLUENT by ANSYS Inc. An understanding on theory behind this unique natural circulation flow inside the tube caused by fission heat generated in molten fuel salt and tube cooling was briefly introduced. Currently, no commercial CFD software could perfectly simulate natural circulation flow, hence, modeling this flow problem in FLUENT is introduced and analyzed to obtain best simulation results. Results obtained demonstrate the existence of periodical transient nature of flow problem, hence improvements in tube design is proposed based on the analysis on temperature and velocity profile. Results show that the proposed system could operate at up to 750MW core power, given that turbulence are enhanced throughout flow region, and precise molten fuel salt physical properties could be defined. At the request of the authors and the Proceedings Editor the name of the co-author Andrea Cioncolini was corrected from Andrea Coincolini. The same name correction was made in the Acknowledgement section on page 030004-10 and in reference number 4. The updated article was published on 11 May 2015.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1036321-yeast-mitochondrial-threonyl-trna-synthetase-recognizes-trna-isoacceptors-distinct-mechanisms-promotes-cun-codon-reassignment','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1036321-yeast-mitochondrial-threonyl-trna-synthetase-recognizes-trna-isoacceptors-distinct-mechanisms-promotes-cun-codon-reassignment"><span>Yeast mitochondrial threonyl-tRNA synthetase recognizes tRNA isoacceptors by distinct mechanisms and promotes CUN codon reassignment</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ling, Jiqiang; Peterson, Kaitlyn M.; Simonovic, Ivana</p> <p>2014-03-12</p> <p>Aminoacyl-tRNA synthetases (aaRSs) ensure faithful translation of mRNA into protein by coupling an amino acid to a set of tRNAs with conserved anticodon sequences. Here, we show that in mitochondria of Saccharomyces cerevisiae, a single aaRS (MST1) recognizes and aminoacylates two natural tRNAs that contain anticodon loops of different size and sequence. Besides a regular ?? with a threonine (Thr) anticodon, MST1 also recognizes an unusual ??, which contains an enlarged anticodon loop and an anticodon triplet that reassigns the CUN codons from leucine to threonine. Our data show that MST1 recognizes the anticodon loop in both tRNAs, but employsmore » distinct recognition mechanisms. The size but not the sequence of the anticodon loop is critical for ?? recognition, whereas the anticodon sequence is essential for aminoacylation of ??. The crystal structure of MST1 reveals that, while lacking the N-terminal editing domain, the enzyme closely resembles the bacterial threonyl-tRNA synthetase (ThrRS). A detailed structural comparison with Escherichia coli ThrRS, which is unable to aminoacylate ??, reveals differences in the anticodon-binding domain that probably allow recognition of the distinct anticodon loops. Finally, our mutational and modeling analyses identify the structural elements in MST1 (e.g., helix {alpha}11) that define tRNA selectivity. Thus, MTS1 exemplifies that a single aaRS can recognize completely divergent anticodon loops of natural isoacceptor tRNAs and that in doing so it facilitates the reassignment of the genetic code in yeast mitochondria.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=146618','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=146618"><span>Structural features of the DNA hairpin d(ATCCTA-GTTA-TAGGAT): formation of a G-A base pair in the loop.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>van Dongen, M J; Mooren, M M; Willems, E F; van der Marel, G A; van Boom, J H; Wijmenga, S S; Hilbers, C W</p> <p>1997-01-01</p> <p>The three-dimensional structure of the hairpin formed by d(ATCCTA-GTTA-TAGGAT) has been determined by means of two-dimensional NMR studies, distance geometry and molecular dynamics calculations. The first and the last residues of the tetraloop of this hairpin form a sheared G-A base pair on top of the six Watson-Crick base pairs in the stem. The glycosidic torsion angles of the guanine and adenine residues in the G-A base pair reside in the anti and high- anti domain ( approximately -60 degrees ) respectively. Several dihedral angles in the loop adopt non-standard values to accommodate this base pair. The first and second residue in the loop are stacked in a more or less normal helical fashion; the fourth loop residue also stacks upon the stem, while the third residue is directed away from the loop region. The loop structure can be classified as a so-called type-I loop, in which the bases at the 5'-end of the loop stack in a continuous fashion. In this situation, loop stability is unlikely to depend heavily on the nature of the unpaired bases in the loop. Moreover, the present study indicates that the influence of the polarity of a closing A.T pair is much less significant than that of a closing C.G base pair. PMID:9092659</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA511958','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA511958"><span>Relating Agulhas Leakage to the Agulhas Current Retroflection Location</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2009-11-03</p> <p>branch return flow of the Atlantic meridional overturning circulation (Gordon, 1986; Weijer et al., 1999; Peeters et al., 2004; Biastoch et al., 2008a...demonstrated that the mesoscale dynamics reflected in the decadal variability of the Atlantic meridional overturning circulation (Biastoch et al...Lutjeharms, J. R. E.: Agulhas leakage dynamics affects decadal variability in Atlantic overturn - ing circulation , Nature, 456, 489–492, 2008a. Biastoch, A</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28317434','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28317434"><span>Dynamics of the active site loops in catalyzing aminoacylation reaction in seryl and histidyl tRNA synthetases.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dutta, Saheb; Kundu, Soumya; Saha, Amrita; Nandi, Nilashis</p> <p>2018-03-01</p> <p>Aminoacylation reaction is the first step of protein biosynthesis. The catalytic reorganization at the active site of aminoacyl tRNA synthetases (aaRSs) is driven by the loop motions. There remain lacunae of understanding concerning the catalytic loop dynamics in aaRSs. We analyzed the functional loop dynamics in seryl tRNA synthetase from Methanopyrus kandleri ( mk SerRS) and histidyl tRNA synthetases from Thermus thermophilus ( tt HisRS), respectively, using molecular dynamics. Results confirm that the motif 2 loop and other active site loops are flexible spots within the catalytic domain. Catalytic residues of the loops form a network of interaction with the substrates to form a reactive state. The loops undergo transitions between closed state and open state and the relaxation of the constituent residues occurs in femtosecond to nanosecond time scale. Order parameters are higher for constituent catalytic residues which form a specific network of interaction with the substrates to form a reactive state compared to the Gly residues within the loop. The development of interaction is supported from mutation studies where the catalytic domain with mutated loop exhibits unfavorable binding energy with the substrates. During the open-close motion of the loops, the catalytic residues make relaxation by ultrafast librational motion as well as fast diffusive motion and subsequently relax rather slowly via slower diffusive motion. The Gly residues act as a hinge to facilitate the loop closing and opening by their faster relaxation behavior. The role of bound water is analyzed by comparing implicit solvent-based and explicit solvent-based simulations. Loops fail to form catalytically competent geometry in absence of water. The present result, for the first time reveals the nature of the active site loop dynamics in aaRS and their influence on catalysis.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5244330','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5244330"><span>Identification of New World Quails Susceptible to Infection with Avian Leukosis Virus Subgroup J</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Plachý, Jiří; Reinišová, Markéta; Kučerová, Dana; Šenigl, Filip; Stepanets, Volodymyr; Hron, Tomáš; Trejbalová, Kateřina; Elleder, Daniel</p> <p>2016-01-01</p> <p>ABSTRACT The J subgroup of avian leukosis virus (ALV-J) infects domestic chickens, jungle fowl, and turkeys. This virus enters the host cell through a receptor encoded by the tvj locus and identified as Na+/H+ exchanger 1. The resistance to avian leukosis virus subgroup J in a great majority of galliform species has been explained by deletions or substitutions of the critical tryptophan 38 in the first extracellular loop of Na+/H+ exchanger 1. Because there are concerns of transspecies virus transmission, we studied natural polymorphisms and susceptibility/resistance in wild galliforms and found the presence of tryptophan 38 in four species of New World quails. The embryo fibroblasts of New World quails are susceptible to infection with avian leukosis virus subgroup J, and the cloned Na+/H+ exchanger 1 confers susceptibility on the otherwise resistant host. New World quails are also susceptible to new avian leukosis virus subgroup J variants but resistant to subgroups A and B and weakly susceptible to subgroups C and D of avian sarcoma/leukosis virus due to obvious defects of the respective receptors. Our results suggest that the avian leukosis virus subgroup J could be transmitted to New World quails and establish a natural reservoir of circulating virus with a potential for further evolution. IMPORTANCE Since its spread in broiler chickens in China and Southeast Asia in 2000, ALV-J remains a major enzootic challenge for the poultry industry. Although the virus diversifies rapidly in the poultry, its spillover and circulation in wild bird species has been prevented by the resistance of most species to ALV-J. It is, nevertheless, important to understand the evolution of the virus and its potential host range in wild birds. Because resistance to avian retroviruses is due particularly to receptor incompatibility, we studied Na+/H+ exchanger 1, the receptor for ALV-J. In New World quails, we found a receptor compatible with virus entry, and we confirmed the susceptibilities of four New World quail species in vitro. We propose that a prospective molecular epidemiology study be conducted to identify species with the potential to become reservoirs for ALV-J. PMID:27881654</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27881654','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27881654"><span>Identification of New World Quails Susceptible to Infection with Avian Leukosis Virus Subgroup J.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Plachý, Jiří; Reinišová, Markéta; Kučerová, Dana; Šenigl, Filip; Stepanets, Volodymyr; Hron, Tomáš; Trejbalová, Kateřina; Elleder, Daniel; Hejnar, Jiří</p> <p>2017-02-01</p> <p>The J subgroup of avian leukosis virus (ALV-J) infects domestic chickens, jungle fowl, and turkeys. This virus enters the host cell through a receptor encoded by the tvj locus and identified as Na + /H + exchanger 1. The resistance to avian leukosis virus subgroup J in a great majority of galliform species has been explained by deletions or substitutions of the critical tryptophan 38 in the first extracellular loop of Na + /H + exchanger 1. Because there are concerns of transspecies virus transmission, we studied natural polymorphisms and susceptibility/resistance in wild galliforms and found the presence of tryptophan 38 in four species of New World quails. The embryo fibroblasts of New World quails are susceptible to infection with avian leukosis virus subgroup J, and the cloned Na + /H + exchanger 1 confers susceptibility on the otherwise resistant host. New World quails are also susceptible to new avian leukosis virus subgroup J variants but resistant to subgroups A and B and weakly susceptible to subgroups C and D of avian sarcoma/leukosis virus due to obvious defects of the respective receptors. Our results suggest that the avian leukosis virus subgroup J could be transmitted to New World quails and establish a natural reservoir of circulating virus with a potential for further evolution. Since its spread in broiler chickens in China and Southeast Asia in 2000, ALV-J remains a major enzootic challenge for the poultry industry. Although the virus diversifies rapidly in the poultry, its spillover and circulation in wild bird species has been prevented by the resistance of most species to ALV-J. It is, nevertheless, important to understand the evolution of the virus and its potential host range in wild birds. Because resistance to avian retroviruses is due particularly to receptor incompatibility, we studied Na + /H + exchanger 1, the receptor for ALV-J. In New World quails, we found a receptor compatible with virus entry, and we confirmed the susceptibilities of four New World quail species in vitro We propose that a prospective molecular epidemiology study be conducted to identify species with the potential to become reservoirs for ALV-J. Copyright © 2017 American Society for Microbiology.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070008450','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070008450"><span>Gravity Effect on Capillary Limit in a Miniature Loop Heat Pipe with Multiple Evaporators and Multiple Condensers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nagano, Hosei; Ku, Jentung</p> <p>2007-01-01</p> <p>This paper describes the gravity effect on heat transport characteristics in a minia6re loop heat pipe with multiple evaporators and multiple condensers. Tests were conducted in three different orientations: horizontal, 45deg tilt, and vertical. The gravity affected the loop's natural operating temperature, the maximum heat transport capability, and the thermal conductance. In the case that temperatures of compensation chambers were actively controlled, the required control heater power was also dependent on the test configuration. In the vertical configuration, the secondary wick was not able to pump the liquid from the CC to the evaporator against the gravity. Thus the loop could operate stably or display some peculiar behaviors depending on the initial liquid distribution between the evaporator and the CC. Because such an initial condition was not known prior to the test, the subsequent loop performance was unpredictable.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24940739','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24940739"><span>An electrical analogy relating the Atlantic multidecadal oscillation to the Atlantic meridional overturning circulation.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kurtz, Bruce E</p> <p>2014-01-01</p> <p>The Atlantic meridional overturning circulation (AMOC) is the northward flow of surface water to subpolar latitudes where deepwater is formed, balanced by southward abyssal flow and upwelling in the vicinity of the Southern Ocean. It is generally accepted that AMOC flow oscillates with a period of 60-80 years, creating a regular variation in North Atlantic sea surface temperature known as the Atlantic multidecadal oscillation (AMO). This article attempts to answer two questions: how is the AMOC driven and why does it oscillate? Using methods commonly employed by chemical engineers for analyzing processes involving flowing liquids, apparently not previously applied to trying to understand the AMOC, an equation is developed for AMOC flow as a function of the meridional density gradient or the corresponding temperature gradient. The equation is based on the similarity between the AMOC and an industrial thermosyphon loop cooler, which circulates a heat transfer liquid without using a mechanical pump. Extending this equation with an analogy between the flow of heat and electricity explains why the AMOC flow oscillates and what determines its period. Calculated values for AMOC flow and AMO oscillation period are in good agreement with measured values.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4062526','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4062526"><span>An Electrical Analogy Relating the Atlantic Multidecadal Oscillation to the Atlantic Meridional Overturning Circulation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kurtz, Bruce E.</p> <p>2014-01-01</p> <p>The Atlantic meridional overturning circulation (AMOC) is the northward flow of surface water to subpolar latitudes where deepwater is formed, balanced by southward abyssal flow and upwelling in the vicinity of the Southern Ocean. It is generally accepted that AMOC flow oscillates with a period of 60–80 years, creating a regular variation in North Atlantic sea surface temperature known as the Atlantic multidecadal oscillation (AMO). This article attempts to answer two questions: how is the AMOC driven and why does it oscillate? Using methods commonly employed by chemical engineers for analyzing processes involving flowing liquids, apparently not previously applied to trying to understand the AMOC, an equation is developed for AMOC flow as a function of the meridional density gradient or the corresponding temperature gradient. The equation is based on the similarity between the AMOC and an industrial thermosyphon loop cooler, which circulates a heat transfer liquid without using a mechanical pump. Extending this equation with an analogy between the flow of heat and electricity explains why the AMOC flow oscillates and what determines its period. Calculated values for AMOC flow and AMO oscillation period are in good agreement with measured values. PMID:24940739</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MS%26E..278a2023S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MS%26E..278a2023S"><span>Coupled Cryogenic Thermal and Electrical Models for Transient Analysis of Superconducting Power Devices with Integrated Cryogenic Systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Satyanarayana, S.; Indrakanti, S.; Kim, J.; Kim, C.; Pamidi, S.</p> <p>2017-12-01</p> <p>Benefits of an integrated high temperature superconducting (HTS) power system and the associated cryogenic systems on board an electric ship or aircraft are discussed. A versatile modelling methodology developed to assess the cryogenic thermal behavior of the integrated system with multiple HTS devices and the various potential configurations are introduced. The utility and effectiveness of the developed modelling methodology is demonstrated using a case study involving a hypothetical system including an HTS propulsion motor, an HTS generator and an HTS power cable cooled by an integrated cryogenic helium circulation system. Using the methodology, multiple configurations are studied. The required total cooling power and the ability to maintain each HTS device at the required operating temperatures are considered for each configuration and the trade-offs are discussed for each configuration. Transient analysis of temperature evolution in the cryogenic helium circulation loop in case of a system failure is carried out to arrive at the required critical response time. The analysis was also performed for a similar liquid nitrogen circulation for an isobaric condition and the cooling capacity ratio is used to compare the relative merits of the two cryogens.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/862348','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/862348"><span>NORTH PORTAL-HOT WATER CIRCULATION PUMP CALCULATION-SHOP BUILDING #5006</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>R. Blackstone</p> <p>1996-01-25</p> <p>The purpose of this design analysis and calculation is to size a circulating pump for the service hot water system in the Shop Building 5006, in accordance with the Uniform Plumbing Code (Section 4.4.1) and U.S. Department of Energy Order 6430.1A-1540 (Section 4.4.2). The method used for the calculation is based on Reference 5.2. This consists of determining the total heat transfer from the service hot water system piping to the surrounding environment. The heat transfer is then used to define the total pumping capacity based on a given temperature change in the circulating hot water as it flows throughmore » the closed loop piping system. The total pumping capacity is used to select a pump model from manufacturer's literature. This established the head generation for that capacity and particular pump model. The total length of all hot water supply and return piping including fittings is then estimated from the plumbing drawings which defines the pipe friction losses that must fit within the available pump head. Several iterations may be required before a pump can be selected that satisfies the head-capacity requirements.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750002386','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750002386"><span>Preliminary design of a Primary Loop Pump Assembly (PLPA), using electromagnetic pumps</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moss, T. A.; Matlin, G.; Donelan, L.; Johnson, J. L.; Rowe, I.</p> <p>1972-01-01</p> <p>A preliminary design study of flight-type dc conduction-permanent magnetic, ac helical induction, and ac linear induction pumps for circulating 883 K (1130 F) NaK at 9.1 kg/sec (20 lb/sec) is described. Various electromagnetic pump geometrics are evaluated against hydraulic performance, and the effects of multiple windings and numbers of pumps per assembly on overall reliability were determined. The methods used in the electrical-hydraulic, stress, and thermal analysis are discussed, and the high temperature electrical materials selected for the application are listed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/20854165-apparatus-calibration-certification-direct-reading-tritium-air-monitors','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20854165-apparatus-calibration-certification-direct-reading-tritium-air-monitors"><span>Apparatus for the Calibration/Certification of Direct Reading Tritium in Air Monitors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Otlet, R.L.; Mather, I.D.; Pottinger, M</p> <p>2005-07-15</p> <p>Direct reading tritium-in-air-monitors are widely used for immediate observation of discharges or working area levels where significant sources of tritium are held. These monitors require initial and periodic calibration certification at the levels likely to be encountered. We describe a purpose built gas handling apparatus which enables various activity levels of tritiated gas ({sup 3}H + N{sub 2}) to be precisely metered and circulated in a closed loop through the monitor under calibration at a wide range of activity levels.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA216024','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA216024"><span>Summer Study Program in Geophysical Fluid Dynamics - The Influence of Convection on Large-Scale Circulations - 1988</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1989-07-01</p> <p>the vector of the body force." lo., ,P /’P l> 16 __ __ _ __ ___P . 19 U In the first lecture we define the buoyancy force, develop a simplified...force and l’is a unit vector along the motion vector . Integrating Bernoulli’s law over a closed loop one gets: I also [ C by integrating along the...convection. It is conveiient to write these equations as evolution equations for a atate vector U(x, z, t) where x is the horizontal coordinate vector</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/4293137-armour-dust-fueled-reactor-adfr-quarterly-progress-report-period-february-may','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/4293137-armour-dust-fueled-reactor-adfr-quarterly-progress-report-period-february-may"><span>THE ARMOUR DUST FUELED REACTOR (ADFR). Quarterly Progress Report No. 1 for the Period February 21, 1958 to May 21, 1958</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Loewe, W.E.; Krucoff, D.</p> <p>1958-10-31</p> <p>Work has begun on the ADFR, a reactor using a new fuel form -- fissionable dust carried in an inent gas. Temperatures in the range 2,000 to 3,000 deg F appear feasible in an all-ceramic system. Experimental study of the fuel form was initiated, and a loop to circulate the fuel dust was constructed. Initial operation is encouraging. Theoretical studies were carried on in the areas of reactor physics, heat transfer, and safety. (auth)</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1419976','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1419976"><span>The principle of maximal transcendentality and the four-loop collinear anomalous dimension</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Dixon, Lance J.</p> <p></p> <p>Here, we use the principle of maximal transcendentality and the universal nature of subleading infrared poles to extract the analytic value of the four-loop collinear anomalous dimension in planar N = 4 super-Yang-Mills theory from recent QCD results, obtainingmore » $$\\hat{g}$$$(4)\\atop{0}$$ =$-$300ζ 7$-$256ζ 2ζ 5$-$384ζ 3ζ 4. This value agrees with a previous numerical result to within 0.2%. It also provides the Regge trajectory, threshold soft anomalous dimension and rapidity anomalous dimension through four loops.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1419976-principle-maximal-transcendentality-four-loop-collinear-anomalous-dimension','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1419976-principle-maximal-transcendentality-four-loop-collinear-anomalous-dimension"><span>The principle of maximal transcendentality and the four-loop collinear anomalous dimension</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Dixon, Lance J.</p> <p>2018-01-16</p> <p>Here, we use the principle of maximal transcendentality and the universal nature of subleading infrared poles to extract the analytic value of the four-loop collinear anomalous dimension in planar N = 4 super-Yang-Mills theory from recent QCD results, obtainingmore » $$\\hat{g}$$$(4)\\atop{0}$$ =$-$300ζ 7$-$256ζ 2ζ 5$-$384ζ 3ζ 4. This value agrees with a previous numerical result to within 0.2%. It also provides the Regge trajectory, threshold soft anomalous dimension and rapidity anomalous dimension through four loops.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930013387','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930013387"><span>Intelligent flight control systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stengel, Robert F.</p> <p>1993-01-01</p> <p>The capabilities of flight control systems can be enhanced by designing them to emulate functions of natural intelligence. Intelligent control functions fall in three categories. Declarative actions involve decision-making, providing models for system monitoring, goal planning, and system/scenario identification. Procedural actions concern skilled behavior and have parallels in guidance, navigation, and adaptation. Reflexive actions are spontaneous, inner-loop responses for control and estimation. Intelligent flight control systems learn knowledge of the aircraft and its mission and adapt to changes in the flight environment. Cognitive models form an efficient basis for integrating 'outer-loop/inner-loop' control functions and for developing robust parallel-processing algorithms.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AIPC.1953l0029K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AIPC.1953l0029K"><span>Multiferroic properties in NdFeO3-PbTiO3 solid solutions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kumar, Sunil; Pal, Jaswinder; Kaur, Shubhpreet; Agrawal, P.; Singh, Mandeep; Singh, Anupinder</p> <p>2018-05-01</p> <p>The x(NdFeO3) - 1-x(PbTiO3) where x = 0.2 solid solution was prepared using solid state reaction route. The X-ray diffraction (XRD) data reveals the single phase formation. The microstructure shows grain growth with lesser porosity. The energy dispersive analysis confirms the presence of elements in stochiometric proportion. The polarization vs. Electric field loop estabilished a ferroelectric type behavior but lossy in nature. This lossy nature may be due to the presence of large leakage current in solid solution. The Magnetization vs. Magnetic field plot exhibits a unsaturated hysteriss loop indicates that the sample is not purely ferromagnetic.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5642698','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5642698"><span>Principles for computational design of binding antibodies</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pszolla, M. Gabriele; Lapidoth, Gideon D.; Norn, Christoffer; Dym, Orly; Unger, Tamar; Albeck, Shira; Tyka, Michael D.; Fleishman, Sarel J.</p> <p>2017-01-01</p> <p>Natural proteins must both fold into a stable conformation and exert their molecular function. To date, computational design has successfully produced stable and atomically accurate proteins by using so-called “ideal” folds rich in regular secondary structures and almost devoid of loops and destabilizing elements, such as cavities. Molecular function, such as binding and catalysis, however, often demands nonideal features, including large and irregular loops and buried polar interaction networks, which have remained challenging for fold design. Through five design/experiment cycles, we learned principles for designing stable and functional antibody variable fragments (Fvs). Specifically, we (i) used sequence-design constraints derived from antibody multiple-sequence alignments, and (ii) during backbone design, maintained stabilizing interactions observed in natural antibodies between the framework and loops of complementarity-determining regions (CDRs) 1 and 2. Designed Fvs bound their ligands with midnanomolar affinities and were as stable as natural antibodies, despite having >30 mutations from mammalian antibody germlines. Furthermore, crystallographic analysis demonstrated atomic accuracy throughout the framework and in four of six CDRs in one design and atomic accuracy in the entire Fv in another. The principles we learned are general, and can be implemented to design other nonideal folds, generating stable, specific, and precise antibodies and enzymes. PMID:28973872</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA523188','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA523188"><span>The Seasonal and Interannual Variability of the West Greenland Current System in the Labrador Sea</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2010-06-01</p> <p>Atlantic meridional overturning circulation ”, Nature, 459 [6] P. Brandt, F. Schott, A. Funk, and C. Sena Martins (2004). “Seasonal to inter- annual...variations in the Atlantic meridional overturning circulation and its relationship with the net northward heat transport in the South Atlantic ”, Geophys...water formation, plays an important role in the Meridional Overturning Circulation . While the interior of the Labrador Sea, where the deepest convection</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JNuM..498..430B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JNuM..498..430B"><span>Atomistic study of the hardening of ferritic iron by Ni-Cr decorated dislocation loops</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bonny, G.; Bakaev, A.; Terentyev, D.; Zhurkin, E.; Posselt, M.</p> <p>2018-01-01</p> <p>The exact nature of the radiation defects causing hardening in reactor structural steels consists of several components that are not yet clearly determined. While generally, the hardening is attributed to dislocation loops, voids and secondary phases (radiation-induced precipitates), recent advanced experimental and computational studies point to the importance of solute-rich clusters (SRCs). Depending on the exact composition of the steel, SRCs may contain Mn, Ni and Cu (e.g. in reactor pressure vessel steels) or Ni, Cr, Si, Mn (e.g. in high-chromium steels for generation IV and fusion applications). One of the hypotheses currently implied to explain their formation is the process of radiation-induced diffusion and segregation of these elements to small dislocation loops (heterogeneous nucleation), so that the distinction between SRCs and loops becomes somewhat blurred. In this work, we perform an atomistic study to investigate the enrichment of loops by Ni and Cr solutes and their interaction with an edge dislocation. The dislocation loops decorated with Ni and Cr solutes are obtained by Monte Carlo simulations, while the effect of solute segregation on the loop's strength and interaction mechanism is then addressed by large scale molecular dynamics simulations. The synergy of the Cr-Ni interaction and their competition to occupy positions in the dislocation loop core are specifically clarified.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/5410091','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/5410091"><span>Core cooling under accident conditions at the high flux beam reactor (HFBR)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Tichler, P.; Cheng, L.; Fauske, H.</p> <p></p> <p>In certain accident scenarios, e.g. loss of coolant accidents (LOCA) all forced flow cooling is lost. Decay heating causes a temperature increase in the core coolant and the resulting thermal buoyancy causes a reversal of the flow direction to a natural circulation mode. Although there was experimental evidence during the reactor design period (1958--1963) that the heat removal capacity in the fully developed natural circulation cooling mode was relatively high, it was not possible to make a confident prediction of the heat removal capacity during the transition from downflow to natural circulation. In a LOCA scenario where even limited fuelmore » damage occurs and natural circulation is established, fission product gases could be carried from the damaged fuel by steam into areas where operator access is required to maintain the core in a coolable configuration. This would force evacuation of the building and lead to extensive core damage. As a result the HFBR was shut down by the Department of Energy (DOE) and an extensive review of the HFBR was initiated. In an effort to address this issue BNL developed a model designed to predict the heat removal limit during flow reversal that was found to be in good agreement with the test results. Currently a thermal-hydraulic test program is being developed to provide a more realistic and defensible estimate of the flow reversal heat removal limit so that the reactor power level can be increased.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MNRAS.476.3328M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MNRAS.476.3328M"><span>Thermal responses in a coronal loop maintained by wave heating mechanisms</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matsumoto, Takuma</p> <p>2018-05-01</p> <p>A full 3-dimensional compressible magnetohydrodynamic (MHD) simulation is conducted to investigate the thermal responses of a coronal loop to the dynamic dissipation processes of MHD waves. When the foot points of the loop are randomly and continuously forced, the MHD waves become excited and propagate upward. Then, 1-MK temperature corona is produced naturally as the wave energy dissipates. The excited wave packets become non-linear just above the magnetic canopy, and the wave energy cascades into smaller spatial scales. Moreover, collisions between counter-propagating Alfvén wave packets increase the heating rate, resulting in impulsive temperature increases. Our model demonstrates that the heating events in the wave-heated loops can be nanoflare-like in the sense that they are spatially localized and temporally intermittent.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=317266','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=317266"><span>Characterization of circulating transfer RNA-Derived RNA fragments in cattle</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>The objective was to characterize naturally occurring circulating transfer RNA-derived RNA Fragments (tRFs) in cattle. Serum from eight clinically normal adult dairy cows was collected, and small non-coding RNAs were extracted immediately after collection and sequenced by Illumina MiSeq. Sequences a...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27132978','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27132978"><span>Automated Droplet Manipulation Using Closed-Loop Axisymmetric Drop Shape Analysis.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yu, Kyle; Yang, Jinlong; Zuo, Yi Y</p> <p>2016-05-17</p> <p>Droplet manipulation plays an important role in a wide range of scientific and industrial applications, such as synthesis of thin-film materials, control of interfacial reactions, and operation of digital microfluidics. Compared to micron-sized droplets, which are commonly considered as spherical beads, millimeter-sized droplets are generally deformable by gravity, thus introducing nonlinearity into control of droplet properties. Such a nonlinear drop shape effect is especially crucial for droplet manipulation, even for small droplets, at the presence of surfactants. In this paper, we have developed a novel closed-loop axisymmetric drop shape analysis (ADSA), integrated into a constrained drop surfactometer (CDS), for manipulating millimeter-sized droplets. The closed-loop ADSA generalizes applications of the traditional drop shape analysis from a surface tension measurement methodology to a sophisticated tool for manipulating droplets in real time. We have demonstrated the feasibility and advantages of the closed-loop ADSA in three applications, including control of drop volume by automatically compensating natural evaporation, precise control of surface area variations for high-fidelity biophysical simulations of natural pulmonary surfactant, and steady control of surface pressure for in situ Langmuir-Blodgett transfer from droplets. All these applications have demonstrated the accuracy, versatility, applicability, and automation of this new ADSA-based droplet manipulation technique. Combining with CDS, the closed-loop ADSA holds great promise for advancing droplet manipulation in a variety of material and surface science applications, such as thin-film fabrication, self-assembly, and biophysical study of pulmonary surfactant.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22842011','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22842011"><span>Natural selection for costly nutrient recycling in simulated microbial metacommunities.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Boyle, Richard A; Williams, Hywel T P; Lenton, Timothy M</p> <p>2012-11-07</p> <p>Recycling of essential nutrients occurs at scales from microbial communities to global biogeochemical cycles, often in association with ecological interactions in which two or more species utilise each others' metabolic by-products. However, recycling loops may be unstable; sequences of reactions leading to net recycling may be parasitised by side-reactions causing nutrient loss, while some reactions in any closed recycling loop are likely to be costly to participants. Here we examine the stability of nutrient recycling loops in an individual-based ecosystem model based on microbial functional types that differ in their metabolism. A supplied nutrient is utilised by a "source" functional type, generating a secondary nutrient that is subsequently used by two other types-a "mutualist" that regenerates the initial nutrient at a growth rate cost, and a "parasite" that produces a refractory waste product but does not incur any additional cost. The three functional types are distributed across a metacommunity in which separate patches are linked by a stochastic diffusive migration process. Regions of high mutualist abundance feature high levels of nutrient recycling and increased local population density leading to greater export of individuals, allowing the source-mutualist recycling loop to spread across the system. Individual-level selection favouring parasites is balanced by patch-level selection for high productivity, indirectly favouring mutualists due to the synergistic productivity benefits of the recycling loop they support. This suggests that multi-level selection may promote nutrient cycling and thereby help to explain the apparent ubiquity and stability of nutrient recycling in nature.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPA....7e6653K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPA....7e6653K"><span>Vortex spin-torque oscillator stabilized by phase locked loop using integrated circuits</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kreissig, Martin; Lebrun, R.; Protze, F.; Merazzo-Jaimes, K.; Hem, J.; Vila, L.; Ferreira, R.; Cyrille, M.-C.; Ellinger, F.; Cros, V.; Ebels, U.; Bortolotti, P.</p> <p>2017-05-01</p> <p>Spin-torque nano-oscillators (STO) are candidates for the next technological implementation of spintronic devices in commercial electronic systems. For use in microwave applications, improving the noise figures by efficient control of their phase dynamics is a mandatory requirement. In order to achieve this, we developed a compact phase locked loop (PLL) based on custom integrated circuits (ICs) and demonstrate that it represents an efficient way to reduce the phase noise level of a vortex based STO. The advantage of our approach to phase stabilize STOs is that our compact system is highly reconfigurable e.g. in terms of the frequency divider ratio N, RF gain and loop gain. This makes it robust against device to device variations and at the same time compatible with a large range of STOs. Moreover, by taking advantage of the natural highly non-isochronous nature of the STO, the STO frequency can be easily controlled by e.g. changing the divider ratio N.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22370040-unresolved-fine-scale-structure-solar-coronal-loop-tops','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22370040-unresolved-fine-scale-structure-solar-coronal-loop-tops"><span>Unresolved fine-scale structure in solar coronal loop-tops</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Scullion, E.; Van der Voort, L. Rouppe; Wedemeyer, S.</p> <p>2014-12-10</p> <p>New and advanced space-based observing facilities continue to lower the resolution limit and detect solar coronal loops in greater detail. We continue to discover even finer substructures within coronal loop cross-sections, in order to understand the nature of the solar corona. Here, we push this lower limit further to search for the finest coronal loop substructures, through taking advantage of the resolving power of the Swedish 1 m Solar Telescope/CRisp Imaging Spectro-Polarimeter (CRISP), together with co-observations from the Solar Dynamics Observatory/Atmospheric Image Assembly (AIA). High-resolution imaging of the chromospheric Hα 656.28 nm spectral line core and wings can, under certainmore » circumstances, allow one to deduce the topology of the local magnetic environment of the solar atmosphere where its observed. Here, we study post-flare coronal loops, which become filled with evaporated chromosphere that rapidly condenses into chromospheric clumps of plasma (detectable in Hα) known as a coronal rain, to investigate their fine-scale structure. We identify, through analysis of three data sets, large-scale catastrophic cooling in coronal loop-tops and the existence of multi-thermal, multi-stranded substructures. Many cool strands even extend fully intact from loop-top to footpoint. We discover that coronal loop fine-scale strands can appear bunched with as many as eight parallel strands within an AIA coronal loop cross-section. The strand number density versus cross-sectional width distribution, as detected by CRISP within AIA-defined coronal loops, most likely peaks at well below 100 km, and currently, 69% of the substructure strands are statistically unresolved in AIA coronal loops.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18078684','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18078684"><span>Sensory motor systems of artificial and natural hands.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chappell, Paul H; Cranny, Andy; Cotton, Darryl P J; White, Neil M; Beeby, Steve P</p> <p>2007-12-01</p> <p>The surgeon Ambroise Paré designed an anthropomorphic hand for wounded soldiers in the 16th century. Since that time, there have been advances in technology through the use of computer-aided design, modern materials, electronic controllers and sensors to realise artificial hands which have good functionality and reliability. Data from touch, object slip, finger position and temperature sensors, mounted in the fingers and on the palm, can be used in feedback loops to automatically hold objects. A study of the natural neuromuscular systems reveals a complexity which can only in part be realised today with technology. Highlights of the parallels and differences between natural and artificial hands are discussed with reference to the Southampton Hand. The anatomical structure of parts of the natural systems can be made artificially such as the antagonist muscles using tendons. Theses solutions look promising as they are based on the natural form but in practice lack the desired physical specification. However, concepts of the lower spinal loops can be mimicked in principle. Some future devices will require greater skills from the surgeon to create the interface between the natural system and an artificial device. Such developments may offer a more natural control with ease of use for the limb deficient person.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1005331','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1005331"><span>Indomethacin Inhibits Circulating PGE2 and Reverses Postexercise Suppression of Natural Killer Cell Activity</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1999-01-01</p> <p>after the oral administration of a placebo, the PG inhibitor indomethacin (75 mg/day for 5 days), or naltrexone (reported elsewhere). Circulating...which blocks PGE2 biosynthe- sis via inhibition of cyclooxygenase activity (57). Maxi- mal suppression of PG production occurs with doses between 50...and 150 mg (1). In addition to the indepen- dent effects of PGE2 on NKCA, low circulating levels of PGE2 can synergize with endogenous glucocorticoids</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5379057','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5379057"><span>A microfluidic culture model of the human reproductive tract and 28-day menstrual cycle</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xiao, Shuo; Coppeta, Jonathan R.; Rogers, Hunter B.; Isenberg, Brett C.; Zhu, Jie; Olalekan, Susan A.; McKinnon, Kelly E.; Dokic, Danijela; Rashedi, Alexandra S.; Haisenleder, Daniel J.; Malpani, Saurabh S.; Arnold-Murray, Chanel A.; Chen, Kuanwei; Jiang, Mingyang; Bai, Lu; Nguyen, Catherine T.; Zhang, Jiyang; Laronda, Monica M.; Hope, Thomas J.; Maniar, Kruti P.; Pavone, Mary Ellen; Avram, Michael J.; Sefton, Elizabeth C.; Getsios, Spiro; Burdette, Joanna E.; Kim, J. Julie; Borenstein, Jeffrey T.; Woodruff, Teresa K.</p> <p>2017-01-01</p> <p>The endocrine system dynamically controls tissue differentiation and homeostasis, but has not been studied using dynamic tissue culture paradigms. Here we show that a microfluidic system supports murine ovarian follicles to produce the human 28-day menstrual cycle hormone profile, which controls human female reproductive tract and peripheral tissue dynamics in single, dual and multiple unit microfluidic platforms (Solo-MFP, Duet-MFP and Quintet-MPF, respectively). These systems simulate the in vivo female reproductive tract and the endocrine loops between organ modules for the ovary, fallopian tube, uterus, cervix and liver, with a sustained circulating flow between all tissues. The reproductive tract tissues and peripheral organs integrated into a microfluidic platform, termed EVATAR, represents a powerful new in vitro tool that allows organ–organ integration of hormonal signalling as a phenocopy of menstrual cycle and pregnancy-like endocrine loops and has great potential to be used in drug discovery and toxicology studies. PMID:28350383</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/7335086','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/7335086"><span>System design description of forced-convection molten-salt corrosion loops MSR-FCL-3 and MSR-FCL-4</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Huntley, W.R.; Silverman, M.D.</p> <p>1976-11-01</p> <p>Molten-salt corrosion loops MSR-FCL-3 and MSR-FCL-4 are high-temperature test facilities designed to evaluate corrosion and mass transfer of modified Hastelloy N alloys for future use in Molten-Salt Breeder Reactors. Salt is circulated by a centrifugal sump pump to evaluate material compatibility with LiF-BeF/sub 2/-ThF/sub 4/-UF/sub 4/ fuel salt at velocities up to 6 m/s (20 fps) and at salt temperatures from 566 to 705/sup 0/C (1050 to 1300/sup 0/F). The report presents the design description of the various components and systems that make up each corrosion facility, such as the salt pump, corrosion specimens, salt piping, main heaters, salt coolers,more » salt sampling equipment, and helium cover-gas system, etc. The electrical systems and instrumentation and controls are described, and operational procedures, system limitations, and maintenance philosophy are discussed.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1987snps.conf..169C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987snps.conf..169C"><span>A liquid-metal filling system for pumped primary loop space reactors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crandall, D. L.; Reed, W. C.</p> <p></p> <p>Some concepts for the SP-100 space nuclear power reactor use liquid metal as the primary coolant in a pumped loop. Prior to filling ground engineering test articles or reactor systems, the liquid metal must be purified and circulated through the reactor primary system to remove contaminants. If not removed, these contaminants enhance corrosion and reduce reliability. A facility was designed and built to support Department of Energy Liquid Metal Fast Breeder Reactor tests conducted at the Idaho National Engineering Laboratory. This test program used liquid sodium to cool nuclear fuel in in-pile experiments; thus, a system was needed to store and purify sodium inventories and fill the experiment assemblies. This same system, with modifications and potential changeover to lithium or sodium-potassium (NaK), can be used in the Space Nuclear Power Reactor Program. This paper addresses the requirements, description, modifications, operation, and appropriateness of using this liquid-metal system to support the SP-100 space reactor program.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/872123','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/872123"><span>Hot spot detection system for vanes or blades of a combustion turbine</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Twerdochlib, Michael</p> <p>1999-01-01</p> <p>This invention includes a detection system that can determine if a turbine component, such as a turbine vane or blade, has exceeded a critical temperature, such as a melting point, along any point along the entire surface of the vane or blade. This system can be employed in a conventional combustion turbine having a compressor, a combustor and a turbine section. Included within this system is a chemical coating disposed along the entire interior surface of a vane or blade and a closed loop cooling system that circulates a coolant through the interior of the vane or blade. If the temperature of the vane or blade exceeds a critical temperature, the chemical coating will be expelled from the vane or blade into the coolant. Since while traversing the closed loop cooling system the coolant passes through a detector, the presence of the chemical coating in the coolant will be sensed by the system. If the chemical coating is detected, this indicates that the vane or blade has exceeded a critical temperature.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AIPC.1573.1453C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AIPC.1573.1453C"><span>Performance of the dark energy camera liquid nitrogen cooling system</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cease, H.; Alvarez, M.; Alvarez, R.; Bonati, M.; Derylo, G.; Estrada, J.; Flaugher, B.; Flores, R.; Lathrop, A.; Munoz, F.; Schmidt, R.; Schmitt, R. L.; Schultz, K.; Kuhlmann, S.; Zhao, A.</p> <p>2014-01-01</p> <p>The Dark Energy Camera, the Imager and its cooling system was installed onto the Blanco 4m telescope at the Cerro Tololo Inter-American Observatory in Chile in September 2012. The imager cooling system is a LN2 two-phase closed loop cryogenic cooling system. The cryogenic circulation processing is located off the telescope. Liquid nitrogen vacuum jacketed transfer lines are run up the outside of the telescope truss tubes to the imager inside the prime focus cage. The design of the cooling system along with commissioning experiences and initial cooling system performance is described. The LN2 cooling system with the DES imager was initially operated at Fermilab for testing, then shipped and tested in the Blanco Coudé room. Now the imager is operating inside the prime focus cage. It is shown that the cooling performance sufficiently cools the imager in a closed loop mode, which can operate for extended time periods without maintenance or LN2 fills.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JNuM..495..516G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JNuM..495..516G"><span>Microstructure evolution of recrystallized Zircaloy-4 under charged particles irradiation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gaumé, M.; Onimus, F.; Dupuy, L.; Tissot, O.; Bachelet, C.; Mompiou, F.</p> <p>2017-11-01</p> <p>Recrystallized zirconium alloys are used as nuclear fuel cladding tubes of Pressurized Water Reactors. During operation, these alloys are submitted to fast neutron irradiation which leads to their in-reactor deformation and to a change of their mechanical properties. These phenomena are directly related to the microstructure evolution under irradiation and especially to the formation of <a>-type dislocation loops. In the present work, the radiation damage evolution in recrystallized Zircaloy-4 has been studied using charged particles irradiation. The <a> loop nucleation and growth kinetics, and also the helical climb of <a> linear dislocations, were observed in-situ using a High Voltage Electron Microscope (HVEM) under 1 MeV electron irradiation at 673 and 723 K. In addition, 600 keV Zr+ ion irradiations were conducted at the same temperature. Transmission Electron Microscopy (TEM) characterizations have been performed after both types of irradiations, and show dislocation loops with a <a> Burgers vector belonging to planes close to { 10 1 bar 0 } first order prismatic planes. The nature of the loops has been characterized. Only interstitial <a> dislocation loops have been observed after ion irradiation at 723 K. However, after electron irradiation conducted at 673 and 723 K, both interstitial and vacancy loops were observed, the proportion of interstitial loops increasing as the temperature is increased. The loop growth kinetics analysis shows that as the temperature increases, the loop number density decreases and the loop growth rate tends to increase. An increase of the flux leads to an increase of the loop number density and a decrease of the loop growth rate. The results are compared to previous works and discussed in the light of point defects diffusion.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150005718&hterms=hydrothermal+plumes&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dhydrothermal%2Bplumes','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150005718&hterms=hydrothermal+plumes&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dhydrothermal%2Bplumes"><span>Enceladus and Europa: How Does Hydrothermal Activity Begin at the Surface?</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Matson, D. L.; Castillo-Rogez, J. C.; Johnson, T. V.; Lunine, J. I.; Davies, A. G.</p> <p>2011-01-01</p> <p>The question of how the surface hydrothermal activity (e.g., eruptive plumes and heat flow) is initiated can be addressed within the frame-work of our "Perrier Ocean" model. This model delivers the necessary heat and chemicals to support the heat flow and plumes observed by Cassini in Enceladus' South Polar Region. The model employs closed-loop circulation of water from a sub-surface ocean. The ocean is the main reservoir of heat and chemicals, including dissolved gases. As ocean water moves up toward the surface, pressure is re-duced and gases exsolve forming bubbles. This bub-bly mixture is less dense than the icy crust and the buoyant ocean-water mixture rises toward the surface. Near the surface, heat and chemicals, including some volatiles, are delivered to the chambers in which plumes form and also to shallow reservoirs that keep the surface ice "warm". (Plume operations, per se, are as described by Schmidt et al. and Postberg et al. and are adopted by us.) After transferring heat, the water cools, bubbles contract and dissolve, and the mixture is now relatively dense. It descends through cracks in the crust and returns to the ocean. Once the closed-loop circulation has started it is self-sustaining. Loss of water via the erupting plumes is relatively negligible compared to the amount needed to maintain the heat flow.We note that the activity described herein for the the "Perrier-Ocean" model could, a priori, apply to all small icy bodies that sheltered an interior ocean at some point in their history.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28658430','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28658430"><span>Evidences of the circulation of natural philosophical knowledge about Brazil in a 1763 manuscript by António Nunes Ribeiro Sanches.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Conceição, Gisele C</p> <p>2017-01-01</p> <p>António Nunes Ribeiro Sanches was a Portuguese physician and the author of several works about education and science in Portugal and its Empire. Many of these texts circulated and were made public through letters written by him and sent to other intellectuals. This article sheds light on an unpublished manuscript written by Sanches in 1763, in which he argued for the recognition of Brazilian natural resources and their exploitation for trade and medicine.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/863190','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/863190"><span>Apparatus for controlling nuclear core debris</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Jones, Robert D.</p> <p>1978-01-01</p> <p>Nuclear reactor apparatus for containing, cooling, and dispersing reactor debris assumed to flow from the core area in the unlikely event of an accident causing core meltdown. The apparatus includes a plurality of horizontally disposed vertically spaced plates, having depressions to contain debris in controlled amounts, and a plurality of holes therein which provide natural circulation cooling and a path for debris to continue flowing downward to the plate beneath. The uppermost plates may also include generally vertical sections which form annular-like flow areas which assist the natural circulation cooling.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/4792565','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/4792565"><span>IN-PILE LOOP IRRADIATION OF AQUEOUS THORIA-URANIA SLURRY AT ELEVATED TEMPERATURE. DESIGN AND IN-PILE OPERATION OF LOOP L-2-27S</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Savage, H.C.; Compere, E.L.; Baker, J.M.</p> <p>1962-02-14</p> <p>An in-pile pump loop, designed to fit within horizontal beam hole HB-2 of the Low-Intensity Test Reactor (LlTR), was used to circulate an aqueous thoria- urania slurry while exposed to reactor irradiation. The total loop volume was about 1600 ml, including pump and pressurizer, but the slurry was confined to the 900-ml volume of the main loop stream by means of a sintered stainless steel filter. The filter was an important feature of the loop design in that it provided a thoria-free filtrate as a purge stream to the pressurizer and pump bearings to prevent entry and accumulation of thoriamore » in these two regions. Corrosion-test specimens of Zircaloy-2, titanium, and type 347 stainless steel were placed in the loop at three different locations for exposure to three different levels of irradiation. Duplicate sets of specimens in each position were exposed to flow velocities of 8 and 22 fps, respectively. For the in-pile irradiation, thorium oxide containing 0.43 wt of enriched U, based on Th, was used. This thoria-urania was produced by air calcination at l225 deg C of coprecipit.ited oxalates and had a me.in particle size of l.7 mu . A Pd catalyst w-as dispersed in the slurry for liquid-phase recombination of the radiolytic gas. The loop was operated in beam-holc HB-2 of the LlTR from July 19 to October l9, l960. During this period slurry was continuously eireulated at 280 deg C for 2220 hr without incident; 1839 hr were at full reactor power (3 Mwt), at which the estimated average thermal flux over the 300volume core section was 5 x l0/sup 12/ neutrons/cm/sup 2/- see. At the start of in-pile operation the loop was charged to a concei tration of 979 g of Th and 3.83 g of fully enriched U per li (at 280 deg C) which was reduced by sampling to 748 g of Th idnd 2.74 g of U per liter at the end of the irradiiition period bascd on the assunmption that no losses had occurrcd. Siinmples of slurry were withdrawn at intervals for analyses to determine the effects of radiation on the thoria-urania slurry. (auth)« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15373950','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15373950"><span>Prenatal programming of postnatal obesity: fetal nutrition and the regulation of leptin synthesis and secretion before birth.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McMillen, I C; Muhlhausler, B S; Duffield, J A; Yuen, B S J</p> <p>2004-08-01</p> <p>Exposure to either an increased or decreased level of intrauterine nutrition can result in an increase in adiposity and in circulating leptin concentrations in later life. In animals such as the sheep and pig in which fat is deposited before birth, leptin is synthesised in fetal adipose tissue and is present in the fetal circulation throughout late gestation. In the sheep a moderate increase or decrease in the level of maternal nutrition does not alter fetal plasma leptin concentrations, but there is evidence that chronic fetal hyperglycaemia and hyperinsulinaemia increase fetal fat mass and leptin synthesis within fetal fat depots. Importantly, there is a positive relationship between the relative mass of the 'unilocular' component of fetal perirenal and interscapular adipose tissue and circulating fetal leptin concentrations in the sheep. Thus, as in the neonate and adult, circulating leptin concentrations may be a signal of fat mass in fetal life. There is also evidence that leptin can act to regulate the lipid storage, leptin synthetic capacity and potential thermogenic functions of fat before birth. Thus, leptin may act as a signal of energy supply and have a 'lipostatic' role before birth. Future studies are clearly required to determine whether the intrauterine and early postnatal nutrient environment programme the endocrine feedback loop between adipose tissue and the central and peripheral neuroendocrine systems that regulate energy balance, resulting in an enhanced risk of obesity in adult life.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003CSR....23..777H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003CSR....23..777H"><span>West Florida shelf circulation and temperature budget for the 1998 fall transition</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>He, Ruoying; Weisberg, Robert H.</p> <p>2003-05-01</p> <p>Mid-latitude continental shelves undergo a fall transition as the net heat flux changes from warming to cooling. Using in situ data and a numerical model we investigate the circulation on the west Florida shelf (WFS) for the fall transition of 1998. The model is a regional adaptation of the primitive equation, Princeton Ocean Model forced by NCEP reanalysis wind, air pressure, and heat flux fields, plus river inflows. After comparison with observations the model is used to draw inferences on the seasonal and synoptic scale features of the shelf circulation. By running twin experiments, one without and the other with an idealized Loop Current (LC), we explore the relative importance of local versus deep-ocean forcing. We find that local forcing largely controls the inner-shelf circulation, including changes from the Florida Panhandle in the north to regions farther south. The effects of the LC in fall 1998 are to reinforce the mid-shelf currents and to increase the across-shelf transports in the bottom Ekman layer, thereby accentuating the shoreward transport of cold, nutrient rich water of deep-ocean origin. A three-dimensional analysis of the temperature budget reveals that surface heat flux largely controls both the seasonal and synoptic scale temperature variations. Surface cooling leads to convective mixing that rapidly alters temperature gradients. One interesting consequence is that upwelling can result in near-shore warming as warmer offshore waters are advected landward. The temperature balances on the shelf are complex and fully three-dimensional.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22386655','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22386655"><span>Extracorporeal bypass model of blood circulation for the study of microvascular hemodynamics.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nam, Kweon-Ho; Yeom, Eunseop; Lee, Sang Joon</p> <p>2012-05-01</p> <p>Many studies have been performed to better understand the hemodynamics in microvessels, such as arterioles and venules. However, due to the heterogeneous features of size, shape, blood-flow velocity, and pulsatility of microvessels, conducting a systematic study on these factors has been almost impossible. Although in vitro studies have been performed for this purpose, the usefulness of in vitro data is limited by the fact that the rheological properties of blood are changed as blood is exposed to in vitro environments. The purpose of the present study is to investigate the feasibility of a rat extracorporeal bypass model that combines in vivo and in vitro models. An arteriovenous shunt loop with a sub-bypass loop of fluorinated ethylene propylene (FEP) microtube was constructed between the jugular vein and femoral artery of a rat. Three pinch valves were installed in the main loop. Microscopic images of the blood flow in the FEP tube were sequentially captured with a high-speed camera, and the whole velocity field information was obtained using a micro-particle image velocimetry technique. Experimental results reveal that the velocity fields of the blood flow inside the microtube are well measured because the FEP tube is transparent and has nearly the same refractive index as water. The flow velocity and the pulsatility index of the blood flow in the microtube can be controlled by adjusting the three pinch valves installed upstream, midstream, and downstream of the bypass loop. This hybrid model that combines in vivo and in vitro models can be useful in studying microvascular hemodynamics. Copyright © 2012 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26278094','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26278094"><span>Insights from Placing Photosynthetic Light Harvesting into Context.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Demmig-Adams, Barbara; Stewart, Jared J; Burch, Tyson A; Adams, William W</p> <p>2014-08-21</p> <p>Solar-energy conversion through natural photosynthesis forms the base of virtually all food chains on Earth and provides fiber, materials, and fuels, as well as inspiration for the design of biomimetic energy-conversion systems. We summarize well-known as well as recently discovered feedback loops between natural light-harvesting systems and whole-organism function in natural settings. We propose that the low effective quantum yield of natural light-harvesting systems in high light is caused by downstream limitations rather than unavoidable intrinsic vulnerabilities. We evaluate potential avenues, and their costs and benefits, for increasing the maximal rate and photon yield of photosynthesis in high light in plants and photosynthetic microbes. By summarizing mechanisms observable only in complex systems (whole plants, algae, or, in some cases, intact leaves), we aim to stimulate future research efforts on reciprocal feedback loops between light harvesting and downstream processes in whole organisms and to provide additional arguments for the significance of research on photosynthetic light harvesting.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991PNAS...88.3204K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991PNAS...88.3204K"><span>The Activation Domain of the Bovine Papillomavirus E2 Protein Mediates Association of DNA-Bound Dimers to form DNA Loops</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Knight, Jonathan D.; Li, Rong; Botchan, Michael</p> <p>1991-04-01</p> <p>The E2 transactivator protein of bovine papillomavirus binds its specific DNA target sequence as a dimer. We have found that E2 dimers, performed in solution independent of DNA, exhibit substantial cooperativity of DNA binding as detected by both nitrocellulose filter retention and footprint analysis techniques. If the binding sites are widely spaced, E2 forms stable DNA loops visible by electron microscopy. When three widely separated binding sites reside on te DNA, E2 condenses the molecule into a bow-tie structure. This implies that each E2 dimer has at least two independent surfaces for multimerization. Two naturally occurring shorter forms of the protein, E2C and D8/E2, which function in vivo as repressors of transcription, do not form such loops. Thus, the looping function of E2 maps to the 161-amino acid activation domain. These results support the looping model of transcription activation by enhancers.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19790061327&hterms=natural+law&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dnatural%2Blaw','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19790061327&hterms=natural+law&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dnatural%2Blaw"><span>Gust alleviation - Criteria and control laws</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rynaski, E. G.</p> <p>1979-01-01</p> <p>The relationships between criteria specified for aircraft gust alleviation and the form of the control laws that result from the criteria are considered. Open-loop gust alleviation based on the linearized, small perturbation equations of aircraft motion is discussed, and an approximate solution of the open-loop control law is presented for the case in which the number of degrees of freedom of the aircraft exceeds the rank of the control effectiveness matrix. Excessive actuator lag is compensated for by taking into account actuator dynamics in the equations of motion, resulting in the specification of a general load network. Criteria for gust alleviation when output motions are gust alleviated and the closed-loop control law derived from them are examined and linear optimal control law is derived. Comparisons of the control laws reveal that the effectiveness of an open-loop control law is greatest at low aircraft frequencies but deteriorates as the natural frequency of the actuators is approached, while closed-loop methods are found to be more effective at higher frequencies.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatCh...8..419D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatCh...8..419D"><span>Discovery of a regioselectivity switch in nitrating P450s guided by molecular dynamics simulations and Markov models</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dodani, Sheel C.; Kiss, Gert; Cahn, Jackson K. B.; Su, Ye; Pande, Vijay S.; Arnold, Frances H.</p> <p>2016-05-01</p> <p>The dynamic motions of protein structural elements, particularly flexible loops, are intimately linked with diverse aspects of enzyme catalysis. Engineering of these loop regions can alter protein stability, substrate binding and even dramatically impact enzyme function. When these flexible regions are unresolvable structurally, computational reconstruction in combination with large-scale molecular dynamics simulations can be used to guide the engineering strategy. Here we present a collaborative approach that consists of both experiment and computation and led to the discovery of a single mutation in the F/G loop of the nitrating cytochrome P450 TxtE that simultaneously controls loop dynamics and completely shifts the enzyme's regioselectivity from the C4 to the C5 position of L-tryptophan. Furthermore, we find that this loop mutation is naturally present in a subset of homologous nitrating P450s and confirm that these uncharacterized enzymes exclusively produce 5-nitro-L-tryptophan, a previously unknown biosynthetic intermediate.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040139305','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040139305"><span>Closed Loop System Identification with Genetic Algorithms</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Whorton, Mark S.</p> <p>2004-01-01</p> <p>High performance control design for a flexible space structure is challenging since high fidelity plant models are di.cult to obtain a priori. Uncertainty in the control design models typically require a very robust, low performance control design which must be tuned on-orbit to achieve the required performance. Closed loop system identi.cation is often required to obtain a multivariable open loop plant model based on closed-loop response data. In order to provide an accurate initial plant model to guarantee convergence for standard local optimization methods, this paper presents a global parameter optimization method using genetic algorithms. A minimal representation of the state space dynamics is employed to mitigate the non-uniqueness and over-parameterization of general state space realizations. This control-relevant system identi.cation procedure stresses the joint nature of the system identi.cation and control design problem by seeking to obtain a model that minimizes the di.erence between the predicted and actual closed-loop performance.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930044662&hterms=Bipolar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DBipolar','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930044662&hterms=Bipolar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DBipolar"><span>The origin of morphological asymmetries in bipolar active regions. [magnetic field in solar convective envelope</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fan, Y.; Fisher, G. H.; Deluca, E. E.</p> <p>1993-01-01</p> <p>A series of 3D numerical simulations was carried out to examine the dynamical evolution of emerging flux loops in the solar convective envelope. The innermost portions of the loops are anchored beneath the base of the convective zone by the subadiabatic temperature gradient of the underlying overshoot region. It is found that, as the emerging loops approach the photosphere, the magnetic field strength of the leading side of each rising loop is about twice as large as that of the following side at the same depth. The evacuation of plasma out of the leading side of the rising loop results in an enhanced magnetic field strength there compared with the following side. It is argued that this result provides a natural explanation for the fact that the preceding (leading) polarity tends to have a less organized and more fragmented appearance, and that the preceding spots tend to be larger in area and fewer in number, and have a longer lifetime than the following spots.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012CQGra..29x9001D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012CQGra..29x9001D"><span>BOOK REVIEW: A First Course in Loop Quantum Gravity A First Course in Loop Quantum Gravity</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dittrich, Bianca</p> <p>2012-12-01</p> <p>Students who are interested in quantum gravity usually face the difficulty of working through a large amount of prerequisite material before being able to deal with actual quantum gravity. A First Course in Loop Quantum Gravity by Rodolfo Gambini and Jorge Pullin, aimed at undergraduate students, marvellously succeeds in starting from the basics of special relativity and covering basic topics in Hamiltonian dynamics, Yang Mills theory, general relativity and quantum field theory, ending with a tour on current (loop) quantum gravity research. This is all done in a short 173 pages! As such the authors cannot cover any of the subjects in depth and indeed this book should be seen more as a motivation and orientation guide so that students can go on to follow the hints for further reading. Also, as there are many subjects to cover beforehand, slightly more than half of the book is concerned with more general subjects (special and general relativity, Hamiltonian dynamics, constrained systems, quantization) before the starting point for loop quantum gravity, the Ashtekar variables, are introduced. The approach taken by the authors is heuristic and uses simplifying examples in many places. However they take care in motivating all the main steps and succeed in presenting the material pedagogically. Problem sets are provided throughout and references for further reading are given. Despite the shortness of space, alternative viewpoints are mentioned and the reader is also referred to experimental results and bounds. In the second half of the book the reader gets a ride through loop quantum gravity; the material covers geometric operators and their spectra, the Hamiltonian constraints, loop quantum cosmology and, more broadly, black hole thermodynamics. A glimpse of recent developments and open problems is given, for instance a discussion on experimental predictions, where the authors carefully point out the very preliminary nature of the results. The authors close with an 'open issues and controversies' section, addressing some of the criticism of loop quantum gravity and pointing to weak points of the theory. Again, readers aiming at starting research in loop quantum gravity should take this as a guide and motivation for further study, as many technicalities are naturally left out. In summary this book fully reaches the aim set by the authors - to introduce the topic in a way that is widely accessible to undergraduates - and as such is highly recommended.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/20845744-experimental-examination-loss-flow-accident-phenomenon-prototypical-iter-divertor-channels','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20845744-experimental-examination-loss-flow-accident-phenomenon-prototypical-iter-divertor-channels"><span>An Experimental Examination of the Loss-of-Flow Accident Phenomenon for Prototypical ITER Divertor Channels of Y = 0 and Y = 2</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Marshall, Theron D.; McDonald, Jimmie M.; Cadwallader, Lee C.</p> <p>2000-01-15</p> <p>This paper discusses the thermal response of two prototypical International Thermonuclear Experimental Reactor (ITER) divertor channels during simulated loss-of-flow-accident (LOFA) experiments. The thermal response was characterized by the time-to-burnout (TBO), which is a figure of merit on the mockups' survivability. Data from the LOFA experiments illustrate that (a) the pre-LOFA inlet velocity does not significantly influence the TBO, (b) the incident heat flux (IHF) does influence the TBO, and (c) a swirl tape insert significantly improves the TBO and promotes the initiation of natural circulation. This natural circulation enabled the mockup to absorb steady-state IHFs after the coolant circulation pumpmore » was disabled. Several methodologies for thermal-hydraulic modeling of the LOFA were attempted.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/20005657-experimental-examination-loss-flow-accident-phenomenon-prototypical-iter-divertor-channels','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20005657-experimental-examination-loss-flow-accident-phenomenon-prototypical-iter-divertor-channels"><span>An experimental examination of the loss-of-flow accident phenomenon for prototypical ITER divertor channels of Y=0 and Y=2</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Marshall, T.D.; McDonald, J.M.; Cadwallader, L.C.</p> <p>2000-01-01</p> <p>This paper discusses the thermal response of two prototypical International Thermonuclear Experimental Reactor (ITER) divertor channels during simulated loss-of-flow-accident (LOFA) experiments. The thermal response was characterized by the time-to-burnout (TBO), which is a figure of merit on the mockups' survivability. Data from the LOFA experiments illustrate that (a) the pre-LOFA inlet velocity does not significantly influence the TBO, (b) the incident heat flux (IHF) does influence the TBO, and (c) a swirl tape insert significantly improves the TBO and promotes the initiation of natural circulation. This natural circulation enabled the mockup to absorb steady-state IHFs after the coolant circulation pumpmore » was disabled. Several methodologies for thermal-hydraulic modeling of the LOFA were attempted.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/21010974-neutrino-mass-implications-muon-decay-parameters','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21010974-neutrino-mass-implications-muon-decay-parameters"><span>Neutrino mass implications for muon decay parameters</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Erwin, Rebecca J.; Kile, Jennifer; Ramsey-Musolf, Michael J.</p> <p>2007-02-01</p> <p>We use the scale of neutrino mass and naturalness considerations to obtain model-independent expectations for the magnitude of possible contributions to muon decay Michel parameters from new physics above the electroweak symmetry-breaking scale. Focusing on Dirac neutrinos, we obtain a complete basis of dimension four and dimension six effective operators that are invariant under the gauge symmetry of the standard model and that contribute to both muon decay and neutrino mass. We show that - in the absence of fine tuning - the most stringent neutrino-mass naturalness bounds on chirality-changing vector operators relevant to muon decay arise from one-loop operatormore » mixing. The bounds we obtain on their contributions to the Michel parameters are 2 orders of magnitude stronger than bounds previously obtained in the literature. In addition, we analyze the implications of one-loop matching considerations and find that the expectations for the size of various scalar and tensor contributions to the Michel parameters are considerably smaller than derived from previous estimates of two-loop operator mixing. We also show, however, that there exist gauge-invariant operators that generate scalar and tensor contributions to muon decay but whose flavor structure allows them to evade neutrino-mass naturalness bounds. We discuss the implications of our analysis for the interpretation of muon-decay experiments.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22140234-detecting-nanoflare-heating-events-subarcsecond-inter-moss-loops-using-hi','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22140234-detecting-nanoflare-heating-events-subarcsecond-inter-moss-loops-using-hi"><span>DETECTING NANOFLARE HEATING EVENTS IN SUBARCSECOND INTER-MOSS LOOPS USING Hi-C</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Winebarger, Amy R.; Moore, Ronald; Cirtain, Jonathan</p> <p>2013-07-01</p> <p>The High-resolution Coronal Imager (Hi-C) flew aboard a NASA sounding rocket on 2012 July 11 and captured roughly 345 s of high-spatial and temporal resolution images of the solar corona in a narrowband 193 A channel. In this paper, we analyze a set of rapidly evolving loops that appear in an inter-moss region. We select six loops that both appear in and fade out of the Hi-C images during the short flight. From the Hi-C data, we determine the size and lifetimes of the loops and characterize whether these loops appear simultaneously along their length or first appear at onemore » footpoint before appearing at the other. Using co-aligned, co-temporal data from multiple channels of the Atmospheric Imaging Assembly on the Solar Dynamics Observatory, we determine the temperature and density of the loops. We find the loops consist of cool ({approx}10{sup 5} K), dense ({approx}10{sup 10} cm{sup -3}) plasma. Their required thermal energy and their observed evolution suggest they result from impulsive heating similar in magnitude to nanoflares. Comparisons with advanced numerical simulations indicate that such dense, cold and short-lived loops are a natural consequence of impulsive magnetic energy release by reconnection of braided magnetic field at low heights in the solar atmosphere.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.3758H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.3758H"><span>Unmixing Magnetic Hysteresis Loops</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heslop, D.; Roberts, A. P.</p> <p>2012-04-01</p> <p>Magnetic hysteresis loops provide important information in rock and environmental magnetic studies. Natural samples often contain an assemblage of magnetic particles composed of components with different origins. Each component potentially carries important environmental information. Hysteresis loops, however, provide information concerning the bulk magnetic assemblage, which makes it difficult to isolate the specific contributions from different sources. For complex mineral assemblages an unmixing strategy with which to separate hysteresis loops into their component parts is therefore essential. Previous methods to unmix hysteresis data have aimed at separating individual loops into their constituent parts using libraries of type-curves thought to correspond to specific mineral types. We demonstrate an alternative approach, which rather than decomposing a single loop into monomineralic contributions, examines a collection of loops to determine their constituent source materials. These source materials may themselves be mineral mixtures, but they provide a genetically meaningful decomposition of a magnetic assemblage in terms of the processes that controlled its formation. We show how an empirically derived hysteresis mixing space can be created, without resorting to type-curves, based on the co-variation within a collection of measured loops. Physically realistic end-members, which respect the expected behaviour and symmetries of hysteresis loops, can then be extracted from the mixing space. These end-members allow the measured loops to be described as a combination of invariant parts that are assumed to represent the different sources in the mixing model. Particular attention is paid to model selection and estimating the complexity of the mixing model, specifically, how many end-members should be included. We demonstrate application of this approach using lake sediments from Butte Valley, northern California. Our method successfully separates the hysteresis loops into sources with a variety of terrigenous and authigenic origins.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/9713726','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/9713726"><span>A second-generation blood substitute (perfluorodichlorooctane emulsion) does not activate complement during an ex vivo circulation model of bypass.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rosoff, J D; Soltow, L O; Vocelka, C R; Schmer, G; Chandler, W L; Cochran, R P; Kunzelman, K S; Spiess, B D</p> <p>1998-08-01</p> <p>To examine whether a second-generation perfluorocarbon (PFC) blood substitute added to the cardiopulmonary bypass (CPB) prime influences complement production. A prospective, randomized, single-blinded, ex vivo model. A university hospital, laboratory, and clinics. Ten healthy adult consented volunteer blood donors (five men, five women). Ex vivo closed-loop extracorporeal circuit including membrane oxygenator, tubing, and filter primed with crystalloid or crystalloid plus PFC was circulated for 1 hour with the addition of 500 mL of heparinized fresh human whole blood. Laboratory specimens were drawn from the circuit at 10-minute intervals for 1 hour and measured for complement (C3a, Bb fragment) concentrations, blood gases, fibrinogen concentration, platelet count, and hematocrit. In the PFC group, C3a and Bb fragments were equal to or less than those in the group that received crystalloid alone. The second-generation PFC added to the prime of a CPB circuit does not independently increase complement production.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1015455','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1015455"><span>RF power recovery feedback circulator</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Sharamentov, Sergey I [Bolingbrook, IL</p> <p>2011-03-29</p> <p>A device and method for improving the efficiency of RF systems having a Reflective Load. In the preferred embodiment, Reflected Energy from a superconducting resonator of a particle accelerator is reintroduced to the resonator after the phase of the Reflected Energy is aligned with the phase of the Supply Energy from a RF Energy Source. In one embodiment, a Circulator is used to transfer Reflected Energy from the Reflective Load into a Phase Adjuster which aligns the phase of the Reflected Energy with that of the Supply Energy. The phase-aligned energy is then combined with the Supply Energy, and reintroduced into the Reflective Load. In systems having a constant phase shift, the Phase Adjuster may be designed to shift the phase of the Reflected Energy by a constant amount using a Phase Shifter. In systems having a variety (variable) phase shifts, a Phase Shifter controlled by a phase feedback loop comprising a Phase Detector and a Feedback Controller to account for the various phase shifts is preferable.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/EJ1052320.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ1052320.pdf"><span>Causality: Physics and Philosophy</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Chatterjee, Atanu</p> <p>2013-01-01</p> <p>Nature is a complex causal network exhibiting diverse forms and species. These forms or rather systems are physically open, structurally complex and naturally adaptive. They interact with the surrounding media by operating a positive-feedback loop through which, they adapt, organize and self-organize themselves in response to the ever-changing…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/908526','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/908526"><span>High efficiency Brayton cycles using LNG</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Morrow, Charles W [Albuquerque, NM</p> <p>2006-04-18</p> <p>A modified, closed-loop Brayton cycle power conversion system that uses liquefied natural gas as the cold heat sink media. When combined with a helium gas cooled nuclear reactor, achievable efficiency can approach 68 76% (as compared to 35% for conventional steam cycle power cooled by air or water). A superheater heat exchanger can be used to exchange heat from a side-stream of hot helium gas split-off from the primary helium coolant loop to post-heat vaporized natural gas exiting from low and high-pressure coolers. The superheater raises the exit temperature of the natural gas to close to room temperature, which makes the gas more attractive to sell on the open market. An additional benefit is significantly reduced costs of a LNG revaporization plant, since the nuclear reactor provides the heat for vaporization instead of burning a portion of the LNG to provide the heat.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22663359-expanding-contracting-coronal-loops-evidence-vortex-flows-induced-solar-eruptions','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22663359-expanding-contracting-coronal-loops-evidence-vortex-flows-induced-solar-eruptions"><span>Expanding and Contracting Coronal Loops as Evidence of Vortex Flows Induced by Solar Eruptions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Dudík, J.; Zuccarello, F. P.; Aulanier, G.</p> <p></p> <p>Eruptive solar flares were predicted to generate large-scale vortex flows at both sides of the erupting magnetic flux rope. This process is analogous to a well-known hydrodynamic process creating vortex rings. The vortices lead to advection of closed coronal loops located at the peripheries of the flaring active region. Outward flows are expected in the upper part and returning flows in the lower part of the vortex. Here, we examine two eruptive solar flares, the X1.1-class flare SOL2012-03-05T03:20 and the C3.5-class SOL2013-06-19T07:29. In both flares, we find that the coronal loops observed by the Atmospheric Imaging Assembly in its 171more » Å, 193 Å, or 211 Å passbands show coexistence of expanding and contracting motions, in accordance with the model prediction. In the X-class flare, multiple expanding and contracting loops coexist for more than 35 minutes, while in the C-class flare, an expanding loop in 193 Å appears to be close by and cotemporal with an apparently imploding loop arcade seen in 171 Å. Later, the 193 Å loop also switches to contraction. These observations are naturally explained by vortex flows present in a model of eruptive solar flares.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26375709','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26375709"><span>Changes in Microbial Plankton Assemblages Induced by Mesoscale Oceanographic Features in the Northern Gulf of Mexico.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Williams, Alicia K; McInnes, Allison S; Rooker, Jay R; Quigg, Antonietta</p> <p>2015-01-01</p> <p>Mesoscale circulation generated by the Loop Current in the Northern Gulf of Mexico (NGOM) delivers growth-limiting nutrients to the microbial plankton of the euphotic zone. Consequences of physicochemically driven community shifts on higher order consumers and subsequent impacts on the biological carbon pump remain poorly understood. This study evaluates microbial plankton <10 μm abundance and community structure across both cyclonic and anti-cyclonic circulation features in the NGOM using flow cytometry (SYBR Green I and autofluorescence parameters). Non-parametric multivariate hierarchical cluster analyses indicated that significant spatial variability in community structure exists such that stations that clustered together were defined as having a specific 'microbial signature' (i.e. statistically homogeneous community structure profiles based on relative abundance of microbial groups). Salinity and a combination of sea surface height anomaly and sea surface temperature were determined by distance based linear modeling to be abiotic predictor variables significantly correlated to changes in microbial signatures. Correlations between increased microbial abundance and availability of nitrogen suggest nitrogen-limitation of microbial plankton in this open ocean area. Regions of combined coastal water entrainment and mesoscale convergence corresponded to increased heterotrophic prokaryote abundance relative to autotrophic plankton. The results provide an initial assessment of how mesoscale circulation potentially influences microbial plankton abundance and community structure in the NGOM.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MS%26E..278a2090C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MS%26E..278a2090C"><span>Impact of large beam-induced heat loads on the transient operation of the beam screens and the cryogenic plants of the Future Circular Collider (FCC)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Correia Rodrigues, H.; Tavian, L.</p> <p>2017-12-01</p> <p>The Future Circular Collider (FCC) under study at CERN will produce 50-TeV high-energy proton beams. The high-energy particle beams are bent by 16-T superconducting dipole magnets operating at 1.9 K and distributed over a circumference of 80 km. The circulating beams induce 5 MW of dynamic heat loads by several processes such as synchrotron radiation, resistive dissipation of beam image currents and electron clouds. These beam-induced heat loads will be intercepted by beam screens operating between 40 and 60 K and induce transients during beam injection. Energy ramp-up and beam dumping on the distributed beam-screen cooling loops, the sector cryogenic plants and the dedicated circulators. Based on the current baseline parameters, numerical simulations of the fluid flow in the cryogenic distribution system during a beam operation cycle were performed. The effects of the thermal inertia of the headers on the helium flow temperature at the cryogenic plant inlet as well as the temperature gradient experienced by the beam screen has been assessed. Additionally, this work enabled a thorough exergetic analysis of different cryogenic plant configurations and laid the building-block for establishing design specification of cold and warm circulators.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000DPS....32.3508Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000DPS....32.3508Y"><span>Circulation of Plasma in the Jovian Magnetosphere as Inferred from the Galileo Magnetometer Observations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Z. J.; Russell, C. T.; Kivelson, M. G.; Khurana, K. K.</p> <p>2000-10-01</p> <p>Massloading of the jovian magnetosphere by the addition of ions at the moon Io is the ultimate engine of the circulation of the magnetospheric plasma. In steady state the radial density profile enables the radial outflow velocity to be calculated from the mass addition rate. Some of these ions are lost from the field lines through pitch angle diffusion. Expected loss rates can be calculated from the fluctuation level in the magnetic field. Radial velocities can be calculated from observations of the Europa wake and force balance in the magnetodisk. The resulting transport times are shorter than the pitch angle scattering loss times so that most of the plasma is transported to the tail and lost by magnetic island formation. In turn the island formation process (reconnection) depletes magnetic field lines making them buoyant and allowing them to "float" back to the inner magnetosphere. In the torus these depleted flux tubes can be seen as thin tubes with stronger than the ambient field strength, implying plasma pressures about 2% of the magnetic field and ion temperatures principally in the range 30-150 eV. When the depleted flux tubes reach the orbit of Io where the energy density of the plasma drops these depleted flux tubes become indistinguishable from the ambient plasma, completing the circulation loop.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4951322','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4951322"><span>A short-term increase of the postoperative naturally circulating dendritic cells subsets in flurbiprofen-treated patients with esophageal carcinoma undergoing thoracic surgery</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chai, Xiao-qing; Shu, Shu-hua; Zhang, Xiao-lin; Xie, Yan-hu; Wei, Xin; Wu, Yu-jing; Wei, Wei</p> <p>2016-01-01</p> <p>The present study evaluated whether flurbiprofen increased the naturally circulating dendritic cells (DCs) subsets in patients with esophageal squamous cell carcinoma (ESCC) undergoing esophageal resection. Compared to healthy donors (n=20), the significantly depressed percentages of plasmacytoid DCs (pDCs), CD1c+ myeloid DCs (mDCs), and CD141+ mDCs among ESCC patients (n=60) were confirmed. Flurbiprofen was administered before skin incision and at the end of operation in group F (n=30), as well as placebo in group C (n=30). The postoperative suppressed percentages of pDCs, CD1c+ mDCs, and CD141+ mDCs increased significantly following the perioperative treatment with flurbiprofen. Flurbiprofen also significantly stimulated the postoperative IFN-f and IL-17 production, but inhibited the immunosuppressive IL-10 and TGF-β levels. Furthermore, flurbiprofen exerted a similar analgesic effect and brought a significantly less sufentanil consumption compared to group C. Taken together, flurbiprofen provided a short-term increase of postoperative naturally circulating DCs in ESCC patients. PMID:26959879</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26959879','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26959879"><span>A short-term increase of the postoperative naturally circulating dendritic cells subsets in flurbiprofen-treated patients with esophageal carcinoma undergoing thoracic surgery.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Di; Yang, Xin-lu; Chai, Xiao-qing; Shu, Shu-hua; Zhang, Xiao-lin; Xie, Yan-hu; Wei, Xin; Wu, Yu-jing; Wei, Wei</p> <p>2016-04-05</p> <p>The present study evaluated whether flurbiprofen increased the naturally circulating dendritic cells (DCs) subsets in patients with esophageal squamous cell carcinoma (ESCC) undergoing esophageal resection. Compared to healthy donors (n=20), the significantly depressed percentages of plasmacytoid DCs (pDCs), CD1c+ myeloid DCs (mDCs), and CD141+ mDCs among ESCC patients (n=60) were confirmed. Flurbiprofen was administered before skin incision and at the end of operation in group F (n=30), as well as placebo in group C (n=30). The postoperative suppressed percentages of pDCs, CD1c+ mDCs, and CD141+ mDCs increased significantly following the perioperative treatment with flurbiprofen. Flurbiprofen also significantly stimulated the postoperative IFN-f and IL-17 production, but inhibited the immunosuppressive IL-10 and TGF-β levels. Furthermore, flurbiprofen exerted a similar analgesic effect and brought a significantly less sufentanil consumption compared to group C. Taken together, flurbiprofen provided a short-term increase of postoperative naturally circulating DCs in ESCC patients.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAP...122k4902H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAP...122k4902H"><span>A looped-tube traveling-wave engine with liquid pistons</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hyodo, H.; Tamura, S.; Biwa, T.</p> <p>2017-09-01</p> <p>This report describes the operation of a liquid piston engine that uses thermoacoustic spontaneous oscillations of liquid and gas columns connected in series to form a loop. Analysis of the analogous mass-spring model and the numerical calculation based on hydrodynamic equations shows that the natural mode oscillations of the system allow the working gas to execute a Stirling thermodynamic cycle. Numerical results of the operating temperature difference were confirmed from experimentally obtained results.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSH12B..07S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSH12B..07S"><span>Steady State Model for Solar Coronal Loops</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sugiyama, L.; Asgari-Targhi, M.</p> <p>2017-12-01</p> <p>Solar coronal loops on the surface of the sun provide background magnetic and plasma structures for the release of a significant amount of the sun's energy, through energetic solar flares and coronal mass ejections and more gradual processes. Understanding their steady states is the first step in understanding loop dynamics. A consistent MHD steady state model, for a curved magnetic flux rope that contains plasma, has been developed[1] for simple coronal loops with both ends anchored in the photosphere. Plasma pressure or current makes the loop unstable to expansion in major radius and must be balanced by external forces, such as the solar gravity. The MHD momentum equation has a well defined small parameter ordering in the loop inverse aspect ratio ɛ=a/Ro (minor/major radius). Different types of common coronal loops fall in different parameter regimes, determined by the relative values of the plasma beta β=po/(Bo2/2μo), the MHD gravity parameter Ĝ≡ga/vA2 (the gravitational acceleration g normalized to the minor radius a and shear Alfvén velocity vA), and ɛ. The largest possible gravity, Ĝ ɛ1β, corresponds to the largest loops because it reduces the plasma density at the top of the loop exponentially compared to its lower ends, reducing the downward gravitational force -ρĜ there. The thin loops that are ubiquitous in solar active regions have ``high'' beta, β ɛ1, for ɛ≃0.02, and fit the predicted model scalings. The thicker loops that can give rise to flares and CMEs have ``low'' beta, β ɛ2. Cool loops, such as solar filaments outside active regions, that have a central pressure lower than that of the surrounding corona would have the strongest stability against radial expansion. The model raises a number of questions about the connection of loops to the photosphere and the force-free nature of the magnetic field there. [1] L. Sugiyama, M. Asgari-Targhi, Phys. Plasmas 24, 022904 (2017).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1000500','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1000500"><span>LOOP CALCULUS AND BELIEF PROPAGATION FOR Q-ARY ALPHABET: LOOP TOWER</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>CHERTKOV, MICHAEL; CHERNYAK, VLADIMIR</p> <p></p> <p>Loop calculus introduced in [1], [2] constitutes a new theoretical tool that explicitly expresses symbol Maximum-A-Posteriori (MAP) solution of a general statistical inference problem via a solution of the Belief Propagation (BP) equations. This finding brought a new significance to the BP concept, which in the past was thought of as just a loop-free approximation. In this paper they continue a discussion of the Loop Calculus, partitioning the results into three Sections. In Section 1 they introduce a new formulation of the Loop Calculus in terms of a set of transformations (gauges) that keeping the partition function of the problemmore » invariant. The full expression contains two terms referred to as the 'ground state' and 'excited states' contributions. The BP equations are interpreted as a special (BP) gauge fixing condition that emerges as a special orthogonality constraint between the ground state and excited states, which also selects loop contributions as the only surviving ones among the excited states. In Section 2 they demonstrate how the invariant interpretation of the Loop Calculus, introduced in Section 1, allows a natural extension to the case of a general q-ary alphabet, this is achieved via a loop tower sequential construction. The ground level in the tower is exactly equivalent to assigning one color (out of q available) to the 'ground state' and considering all 'excited' states colored in the remaining (q-1) colors, according to the loop calculus rule. Sequentially, the second level in the tower corresponds to selecting a loop from the previous step, colored in (q-1) colors, and repeating the same ground vs excited states splitting procedure into one and (q-2) colors respectively. The construction proceeds till the full (q-1)-levels deep loop tower (and the corresponding contributions to the partition function) are established. In Section 3 they discuss an ultimate relation between the loop calculus and the Bethe-Free energy variational approach of [3].« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24388926','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24388926"><span>The Sustainability Cycle and Loop: models for a more unified understanding of sustainability.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hay, Laura; Duffy, Alex; Whitfield, R I</p> <p>2014-01-15</p> <p>In spite of the considerable research on sustainability, reports suggest that we are barely any closer to a more sustainable society. As such, there is an urgent need to improve the effectiveness of human efforts towards sustainability. A clearer and more unified understanding of sustainability among different people and sectors could help to facilitate this. This paper presents the results of an inductive literature investigation, aiming to develop models to explain the nature of sustainability in the Earth system, and how humans can effectively strive for it. The major contributions are two general and complementary models, that may be applied in any context to provide a common basis for understanding sustainability: the Sustainability Cycle (S-Cycle), and the Sustainability Loop (S-Loop). Literature spanning multiple sectors is examined from the perspective of three concepts, emerging as significant in relation to our aim. Systems are shown to provide the context for human action towards sustainability, and the nature of the Earth system and its sub-systems is explored. Activities are outlined as a fundamental target that humans need to sustain, since they produce the entities both needed and desired by society. The basic behaviour of activities operating in the Earth system is outlined. Finally, knowledge is positioned as the driver of human action towards sustainability, and the key components of knowledge involved are examined. The S-Cycle and S-Loop models are developed via a process of induction from the reviewed literature. The S-Cycle describes the operation of activities in a system from the perspective of sustainability. The sustainability of activities in a system depends upon the availability of resources, and the availability of resources depends upon the rate that activities consume and produce them. Humans may intervene in these dynamics via an iterative process of interpretation and action, described in the S-Loop model. The models are briefly applied to a system described in the literature. It is shown that the S-Loop may be used to guide efforts towards sustainability in a particular system of interest, by prescribing the basic activities involved. The S-Cycle may be applied complementary to the S-Loop, to support the interpretation of activity behaviour described in the latter. Given their general nature, the models provide the basis for a more unified understanding of sustainability. It is hoped that their use may go some way towards improving the effectiveness of human action towards sustainability. Copyright © 2013 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110016225','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110016225"><span>An Active Broad Area Cooling Model of a Cryogenic Propellant Tank with a Single Stage Reverse Turbo-Brayton Cycle Cryocooler</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Guzik, Monica C.; Tomsik, Thomas M.</p> <p>2011-01-01</p> <p>As focus shifts towards long-duration space exploration missions, an increased interest in active thermal control of cryogenic propellants to achieve zero boil-off of cryogens has emerged. An active thermal control concept of considerable merit is the integration of a broad area cooling system for a cryogenic propellant tank with a combined cryocooler and circulator system that can be used to reduce or even eliminate liquid cryogen boil-off. One prospective cryocooler and circulator combination is the reverse turbo-Brayton cycle cryocooler. This system is unique in that it has the ability to both cool and circulate the coolant gas efficiently in the same loop as the broad area cooling lines, allowing for a single cooling gas loop, with the primary heat rejection occurring by way of a radiator and/or aftercooler. Currently few modeling tools exist that can size and characterize an integrated reverse turbo-Brayton cycle cryocooler in combination with a broad area cooling design. This paper addresses efforts to create such a tool to assist in gaining a broader understanding of these systems, and investigate their performance in potential space missions. The model uses conventional engineering and thermodynamic relationships to predict the preliminary design parameters, including input power requirements, pressure drops, flow rate, cycle performance, cooling lift, broad area cooler line sizing, and component operating temperatures and pressures given the cooling load operating temperature, heat rejection temperature, compressor inlet pressure, compressor rotational speed, and cryogenic tank geometry. In addition, the model allows for the preliminary design analysis of the broad area cooling tubing, to determine the effect of tube sizing on the reverse turbo-Brayton cycle system performance. At the time this paper was written, the model was verified to match existing theoretical documentation within a reasonable margin. While further experimental data is needed for full validation, this tool has already made significant steps towards giving a clearer understanding of the performance of a reverse turbo-Brayton cycle cryocooler integrated with broad area cooling technology for zero boil-off active thermal control.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1511515K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1511515K"><span>Transport and fate of river waters under flood conditions and rim current influence: the Mississippi River test case</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kourafalou, Villy; Androulidakis, Yannis</p> <p>2013-04-01</p> <p>Large river plumes are a major supplier of freshwater, sediments and nutrients in coastal and shelf seas. Novel processes controlling the transport and fate of riverine waters (and associated materials) will be presented, under flood conditions and in the presence of complex topography, ambient shelf circulation and slope processes, controlled by the interaction with rim currents. The Mississippi River (MR) freshwater outflow is chosen as a test case, as a major circulation forcing mechanism for the Northern Gulf of Mexico and a unique river plume for the intense interactions with a large scale ocean current, namely the Loop Current branch of the Gulf Stream, and associated eddy field. The largest MR outflow in history (45,000 m3/sec in 2011) is compared with the second largest outflow in the last 8 years (41,000 m3/sec in 2008). Realistically forced simulations, based on the Hybrid Coordinate Ocean Model (HYCOM) with careful treatment of river plume dynamics and nested to a data assimilated, basin-wide model, reveal the synergistic effect of enhanced discharge, winds, stratification of ambient shelf waters and offshore circulation over the transport of plume waters. The investigation targets a broader understanding of the dynamics of large scale river plumes in general, and of the MR plume in particular. In addition, in situ observations from ship surveys and satellite chl-a data showed that the mathematical simulations with high temporal resolution river outflow input may reproduce adequately the buoyant waters spreading over the Northern Gulf of Mexico shelf and offshore areas. The fate of the river plume is strongly determined and affected by deep basin processes. The strong impacts of the Loop Current system (and its frontal eddies) on river plume evolution are of particular importance under conditions of increased offshore spreading, which is presumed under large discharge rates and can cause loss of riverine materials to the basin interior. Flood conditions can increase both downstream (westward) and upstream (eastward) spreading. The high outflow rates enhance the anticyclonic bulge, strengthen the downstream coastal current toward the western Louisiana-Texas shelf. The substantial eastward spreading over the eastern Mississippi-Alabama-Florida shelf was highly correlated with the Loop Current northward extension. On the contrary, cyclonic eddies east of the Delta effectively block the offshore eastward spreading of the plume and may keep the river waters away from the eastern shelf. We show that the proximity of eddies to the shelf break is a sufficient condition for shelf-to-offshore interaction, which is facilitated by the steep bottom topography near the Delta.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22341931-hot-spine-loops-nature-late-phase-solar-flare','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22341931-hot-spine-loops-nature-late-phase-solar-flare"><span>Hot spine loops and the nature of a late-phase solar flare</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Sun, Xudong; Todd Hoeksema, J.; Liu, Yang</p> <p>2013-12-01</p> <p>The fan-spine magnetic topology is believed to be responsible for many curious features in solar explosive events. A spine field line links distinct flux domains, but direct observation of such a feature has been rare. Here we report a unique event observed by the Solar Dynamic Observatory where a set of hot coronal loops (over 10 MK) connected to a quasi-circular chromospheric ribbon at one end and a remote brightening at the other. Magnetic field extrapolation suggests that these loops are partly tracers of the evolving spine field line. Continuous slipping- and null-point-type reconnections were likely at work, energizing themore » loop plasma and transferring magnetic flux within and across the fan quasi-separatrix layer. We argue that the initial reconnection is of the 'breakout' type, which then transitioned to a more violent flare reconnection with an eruption from the fan dome. Significant magnetic field changes are expected and indeed ensued. This event also features an extreme-ultraviolet (EUV) late phase, i.e., a delayed secondary emission peak in warm EUV lines (about 2-7 MK). We show that this peak comes from the cooling of large post-reconnection loops beside and above the compact fan, a direct product of eruption in such topological settings. The long cooling time of the large arcades contributes to the long delay; additional heating may also be required. Our result demonstrates the critical nature of cross-scale magnetic coupling—topological change in a sub-system may lead to explosions on a much larger scale.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PhDT........28P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PhDT........28P"><span>A theoretical study in extracting the essential features and dynamics of molecular motions: Intrinsic geometry methods for PF(5) pseudorotations and statistical methods for argon clusters</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panahi, Nima S.</p> <p></p> <p>We studied the problem of understanding and computing the essential features and dynamics of molecular motions through the development of two theories for two different systems. First, we studied the process of the Berry Pseudorotation of PF5 and the rotations it induces in the molecule through its natural and intrinsic geometric nature by setting it in the language of fiber bundles and graph theory. With these tools, we successfully extracted the essentials of the process' loops and induced rotations. The infinite number of pseudorotation loops were broken down into a small set of essential loops called "super loops", with their intrinsic properties and link to the physical movements of the molecule extensively studied. In addition, only the three "self-edge loops" generated any induced rotations, and then only a finite number of classes of them. Second, we studied applying the statistical methods of Principal Components Analysis (PCA) and Principal Coordinate Analysis (PCO) to capture only the most important changes in Argon clusters so as to reduce computational costs and graph the potential energy surface (PES) in three dimensions respectively. Both methods proved successful, but PCA was only partially successful since one will only see advantages for PES database systems much larger than those both currently being studied and those that can be computationally studied in the next few decades to come. In addition, PCA is only needed for the very rare case of a PES database that does not already include Hessian eigenvalues.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22086476-multiple-plasma-ejections-intermittent-nature-magnetic-reconnection-solar-chromospheric-anemone-jets','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22086476-multiple-plasma-ejections-intermittent-nature-magnetic-reconnection-solar-chromospheric-anemone-jets"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Singh, K. A. P.; Nishida, K.; Shibata, K.</p> <p></p> <p>The recent discovery of chromospheric anemone jets with the Solar Optical Telescope (SOT) on board Hinode has shown an indirect evidence of magnetic reconnection in the solar chromosphere. However, the basic nature of magnetic reconnection in chromosphere is still unclear. We studied nine chromospheric anemone jets from SOT/Hinode using Ca II H filtergrams, and we found multiple bright, plasma ejections along the jets. In most cases, the major intensity enhancements (larger than 30% relative to the background intensity) of the loop correspond to the timing of the plasma ejections. The typical lifetime and size of the plasma ejecta are aboutmore » 20-60 s and 0.3-1.5 Mm, respectively. The height-time plot of jet shows many sub-structures (or individual jets) and the typical lifetime of the individual jet is about one to five minutes. Before the onset of the jet activity, a loop appears in Ca II H and gradually increases in size, and after few minutes several jets are launched from the loop. Once the jet activity starts and several individual jets are launched, the loop starts shrinking with a speed of {approx}4 km s{sup -1}. In some events, a downward moving blob with a speed of {approx}35 km s{sup -1} was observed, associated with the upward moving plasma along one of the legs of the loop hosting the jets. The upward moving plasma gradually developed into jets. Multiple plasma ejections in chromospheric anemone jet show the strongly time-dependent as well as intermittent nature of magnetic reconnection in the solar chromosphere.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvD..96h4011V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvD..96h4011V"><span>Immirzi parameter without Immirzi ambiguity: Conformal loop quantization of scalar-tensor gravity</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Veraguth, Olivier J.; Wang, Charles H.-T.</p> <p>2017-10-01</p> <p>Conformal loop quantum gravity provides an approach to loop quantization through an underlying conformal structure i.e. conformally equivalent class of metrics. The property that general relativity itself has no conformal invariance is reinstated with a constrained scalar field setting the physical scale. Conformally equivalent metrics have recently been shown to be amenable to loop quantization including matter coupling. It has been suggested that conformal geometry may provide an extended symmetry to allow a reformulated Immirzi parameter necessary for loop quantization to behave like an arbitrary group parameter that requires no further fixing as its present standard form does. Here, we find that this can be naturally realized via conformal frame transformations in scalar-tensor gravity. Such a theory generally incorporates a dynamical scalar gravitational field and reduces to general relativity when the scalar field becomes a pure gauge. In particular, we introduce a conformal Einstein frame in which loop quantization is implemented. We then discuss how different Immirzi parameters under this description may be related by conformal frame transformations and yet share the same quantization having, for example, the same area gaps, modulated by the scalar gravitational field.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=closed+AND+loop&pg=4&id=EJ163553','ERIC'); return false;" href="https://eric.ed.gov/?q=closed+AND+loop&pg=4&id=EJ163553"><span>Verification Processes in Recognition Memory: The Role of Natural Language Mediators</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Marshall, Philip H.; Smith, Randolph A. S.</p> <p>1977-01-01</p> <p>The existence of verification processes in recognition memory was confirmed in the context of Adams' (Adams & Bray, 1970) closed-loop theory. Subjects' recognition was tested following a learning session. The expectation was that data would reveal consistent internal relationships supporting the position that natural language mediation plays…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/20708923-free-energy-phase-transition-matrix-model-plane-wave','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20708923-free-energy-phase-transition-matrix-model-plane-wave"><span>Free energy and phase transition of the matrix model on a plane wave</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Hadizadeh, Shirin; Ramadanovic, Bojan; Semenoff, Gordon W.</p> <p>2005-03-15</p> <p>It has recently been observed that the weakly coupled plane-wave matrix model has a density of states which grows exponentially at high energy. This implies that the model has a phase transition. The transition appears to be of first order. However, its exact nature is sensitive to interactions. In this paper, we analyze the effect of interactions by computing the relevant parts of the effective potential for the Polyakov loop operator in the finite temperature plane-wave matrix model to three-loop order. We show that the phase transition is indeed of first order. We also compute the correction to the Hagedornmore » temperature to order two loops.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28574723','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28574723"><span>Closed-Loop Insulin Delivery for Adults with Type 1 Diabetes Undertaking High-Intensity Interval Exercise Versus Moderate-Intensity Exercise: A Randomized, Crossover Study.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jayawardene, Dilshani C; McAuley, Sybil A; Horsburgh, Jodie C; Gerche, André La; Jenkins, Alicia J; Ward, Glenn M; MacIsaac, Richard J; Roberts, Timothy J; Grosman, Benyamin; Kurtz, Natalie; Roy, Anirban; O'Neal, David N</p> <p>2017-06-01</p> <p>We aimed to compare closed-loop glucose control for people with type 1 diabetes undertaking high-intensity interval exercise (HIIE) versus moderate-intensity exercise (MIE). Adults with type 1 diabetes established on insulin pumps undertook HIIE and MIE stages in random order during automated insulin delivery via a closed-loop system (Medtronic). Frequent venous sampling for glucose, lactate, ketones, insulin, catecholamines, cortisol, growth hormone, and glucagon levels was performed. The primary outcome was plasma glucose <4.0 mmol/L for ≥15 min, from exercise commencement to 120 min postexercise. Secondary outcomes included continuous glucose monitoring and biochemical parameters. Twelve adults (age mean ± standard deviation 40 ± 13 years) were recruited; all completed the study. Plasma glucose of one participant fell to 3.4 mmol/L following MIE completion; no glucose levels were <4.0 mmol/L for HIIE (primary outcome). There were no glucose excursions >15.0 mmol/L for either stage. Mean (±standard error) plasma glucose did not differ between stages pre-exercise; was higher during exercise in HIIE than MIE (11.3 ± 0.5 mmol/L vs. 9.7 ± 0.6 mmol/L, respectively; P < 0.001); and remained higher until 60 min postexercise. There were no differences in circulating free insulin before, during, or postexercise. During HIIE compared with MIE, there were greater increases in lactate (P < 0.001), catecholamines (all P < 0.05), and cortisol (P < 0.001). Ketones increased more with HIIE than MIE postexercise (P = 0.031). Preliminary findings suggest that closed-loop glucose control is safe for people undertaking HIIE and MIE. However, the management of the postexercise rise in ketones secondary to counter-regulatory hormone-induced insulin resistance observed with HIIE may represent a challenge for closed-loop systems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1814123M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1814123M"><span>Flood events across the North Atlantic region - past development and future perspectives</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matti, Bettina; Dieppois, Bastien; Lawler, Damian; Dahlke, Helen E.; Lyon, Steve W.</p> <p>2016-04-01</p> <p>Flood events have a large impact on humans, both socially and economically. An increase in winter and spring flooding across much of northern Europe in recent years opened up the question of changing underlying hydro-climatic drivers of flood events. Predicting the manifestation of such changes is difficult due to the natural variability and fluctuations in northern hydrological systems caused by large-scale atmospheric circulations, especially under altered climate conditions. Improving knowledge on the complexity of these hydrological systems and their interactions with climate is essential to be able to determine drivers of flood events and to predict changes in these drivers under altered climate conditions. This is particularly true for the North Atlantic region where both physical catchment properties and large-scale atmospheric circulations have a profound influence on floods. This study explores changes in streamflow across North Atlantic region catchments. An emphasis is placed on high-flow events, namely the timing and magnitude of past flood events, and selected flood percentiles were tested for stationarity by applying a flood frequency analysis. The issue of non-stationarity of flood return periods is important when linking streamflow to large-scale atmospheric circulations. Natural fluctuations in these circulations are found to have a strong influence on the outcome causing natural variability in streamflow records. Long time series and a multi-temporal approach allows for determining drivers of floods and linking streamflow to large-scale atmospheric circulations. Exploring changes in selected hydrological signatures consistency was found across much of the North Atlantic region suggesting a shift in flow regime. The lack of an overall regional pattern suggests that how catchments respond to changes in climatic drivers is strongly influenced by their physical characteristics. A better understanding of hydrological response to climate drivers is essential for example for forecasting purposes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20090019141&hterms=corona&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcorona','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20090019141&hterms=corona&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcorona"><span>Heating of the Solar Corona and its Loops</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Klimchuk, James A.</p> <p>2009-01-01</p> <p>At several million degrees, the solar corona is more than two orders of magnitude hotter than the underlying solar surface. The reason for these extreme conditions has been a puzzle for decades and is considered one of the fundamental problems in astrophysics. Much of the coronal plasma is organized by the magnetic field into arch-like structures called loops. Recent observational and theoretical advances have led to great progress in understanding the nature of these loops. In particular, we now believe they are bundles of unresolved magnetic strands that are heated by storms of impulsive energy bursts called nanoflares. Turbulent convection at the solar surface shuffles the footpoints of the strands and causes them to become tangled. A nanoflare occurs when the magnetic stresses reach a critical threshold, probably by way of a mechanism called the secondary instability. I will describe our current state of knowledge concerning the corona, its loops, and how they are heated.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950040883&hterms=Omega&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DOmega%2B3','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950040883&hterms=Omega&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DOmega%2B3"><span>Theoretical properties of Omega-loops in the convective zone of the Sun. 1: Emerging bipolar magnetic regions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Parker, E. N.</p> <p>1994-01-01</p> <p>It is proposed that the observed 500 G intensity of the magnetic fields emerging through the surface of the Sun can be understood from the Bernoulli effect in the upwelling Omega-loops of magnetic field. It is also proposed that the inferred 10(exp 5) G azimuthal flux bundles below the base of the convective zone can be understood as a consequence of the large-scale buoyancy associated with the upwelling fluid in and around the rising Omega-loop. The process fits in naturally with the Babcock-Leighton form of the solar alpha-omega-dynamo. The emerging Omega-loop implies the coherence of the upwelling all the way from the bottom of the convective zone, enhancing the convective heat transport to account for the observed variation of the solar irradiance by about two parts in 10(exp 3).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RMxAA..53...37B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RMxAA..53...37B"><span>SNR radio spectral index distribution and its correlation with polarization. a case study: the Lupus Loop</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Borka Jovanović, V.; Jovanović, P.; Borka, D.</p> <p>2017-04-01</p> <p>We use radio-continuum all-sky surveys at 1420 and 408 MHz with the aim to investigate properties of the Galactic radio source Lupus Loop. The survey data at 1435 MHz, with the linear polarization of the southern sky, are also used. We calculate properties of this supernova remnant: the brightness temperature, surface brightness and radio spectral index. To determine its borders and to calculate its properties, we use the method we have developed. The non-thermal nature of its radiation is confirmed. The distribution of spectral index over its area is also given. A significant correlation between the radio spectral index distribution and the corresponding polarized intensity distribution inside the loop borders is found, indicating that the polarization maps could provide us information about the distribution of the interstellar medium, and thus could represent one additional way to search for new Galactic loops.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19790050507&hterms=human+behavior&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dhuman%2Bbehavior','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19790050507&hterms=human+behavior&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dhuman%2Bbehavior"><span>A rationale for human operator pulsive control behavior</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hess, R. A.</p> <p>1979-01-01</p> <p>When performing tracking tasks which involve demanding controlled elements such as those with K/s-squared dynamics, the human operator often develops discrete or pulsive control outputs. A dual-loop model of the human operator is discussed, the dominant adaptive feature of which is the explicit appearance of an internal model of the manipulator-controlled element dynamics in an inner feedback loop. Using this model, a rationale for pulsive control behavior is offered which is based upon the assumption that the human attempts to reduce the computational burden associated with time integration of sensory inputs. It is shown that such time integration is a natural consequence of having an internal representation of the K/s-squared-controlled element dynamics in the dual-loop model. A digital simulation is discussed in which a modified form of the dual-loop model is shown to be capable of producing pulsive control behavior qualitively comparable to that obtained in experiment.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3560238','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3560238"><span>A proof for loop-law constraints in stoichiometric metabolic networks</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2012-01-01</p> <p>Background Constraint-based modeling is increasingly employed for metabolic network analysis. Its underlying assumption is that natural metabolic phenotypes can be predicted by adding physicochemical constraints to remove unrealistic metabolic flux solutions. The loopless-COBRA approach provides an additional constraint that eliminates thermodynamically infeasible internal cycles (or loops) from the space of solutions. This allows the prediction of flux solutions that are more consistent with experimental data. However, it is not clear if this approach over-constrains the models by removing non-loop solutions as well. Results Here we apply Gordan’s theorem from linear algebra to prove for the first time that the constraints added in loopless-COBRA do not over-constrain the problem beyond the elimination of the loops themselves. Conclusions The loopless-COBRA constraints can be reliably applied. Furthermore, this proof may be adapted to evaluate the theoretical soundness for other methods in constraint-based modeling. PMID:23146116</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018EPJC...78..231D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018EPJC...78..231D"><span>Universal dual amplitudes and asymptotic expansions for gg→ H and H→ γ γ in four dimensions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Driencourt-Mangin, Félix; Rodrigo, Germán; Sborlini, Germán F. R.</p> <p>2018-03-01</p> <p>Though the one-loop amplitudes of the Higgs boson to massless gauge bosons are finite because there is no direct interaction at tree level in the Standard Model, a well-defined regularization scheme is still required for their correct evaluation. We reanalyze these amplitudes in the framework of the four-dimensional unsubtraction and the loop-tree duality (FDU/LTD), and show how a local renormalization solves potential regularization ambiguities. The Higgs boson interactions are also used to illustrate new additional advantages of this formalism. We show that LTD naturally leads to very compact integrand expressions in four space-time dimensions of the one-loop amplitude with virtual electroweak gauge bosons. They exhibit the same functional form as the amplitudes with top quarks and charged scalars, thus opening further possibilities for simplifications in higher-order computations. Another outstanding application is the straightforward implementation of asymptotic expansions by using dual amplitudes. One of the main benefits of the LTD representation is that it is supported in a Euclidean space. This characteristic feature naturally leads to simpler asymptotic expansions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920016491','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920016491"><span>A preliminary look at an optimal multivariable design for propulsion-only flight control of jet-transport aircraft</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Azzano, Christopher P.</p> <p>1992-01-01</p> <p>Control of a large jet transport aircraft without the use of conventional control surfaces was studied. Engine commands were used to attempt to recreate the forces and moments typically provided by the elevator, ailerons, and rudder. Necessary conditions for aircraft controllability were developed pertaining to aircraft configuration such as the number of engines and engine placement. An optimal linear quadratic regulator controller was developed for the Boeing 707-720, in particular, for regulation of its natural dynamic modes. The design used a method of assigning relative weights to the natural modes, i.e., phugoid and dutch roll, for a more intuitive selection of the cost function. A prototype pilot command interface was then integrated into the loop based on pseudorate command of both pitch and roll. Closed loop dynamics were evaluated first with a batch linear simulation and then with a real time high fidelity piloted simulation. The NASA research pilots assisted in evaluation of closed loop handling qualities for typical cruise and landing tasks. Recommendations for improvement on this preliminary study of optimal propulsion only flight control are provided.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27517530','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27517530"><span>The Prevalence and Use of Walking Loops in Neighborhood Parks: A National Study.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cohen, Deborah A; Han, Bing; Evenson, Kelly R; Nagel, Catherine; McKenzie, Thomas L; Marsh, Terry; Williamson, Stephanie; Harnik, Peter</p> <p>2017-02-01</p> <p>Previous studies indicate that the design of streets and sidewalks can influence physical activity among residents. Park features also influence park use and park-based physical activity. Although individuals can walk on streets and sidewalks, walking loops in parks offer a setting to walk in nature and to avoid interruptions from traffic. Here we describe the use of walking loops in parks and compare the number of park users and their physical activity in urban neighborhood parks with and without walking loops. We analyzed data from the National Study of Neighborhood Parks in which a representative sample of neighborhood parks (n = 174) from 25 U.S. cities with > 100,000 population were observed systematically to document facilities and park users by age group and sex. We compared the number of people and their physical activity in parks with and without walking loops, controlling for multiple factors, including park size, facilities, and population density. Overall, compared with parks without walking loops, on average during an hourly observation, parks with walking loops had 80% more users (95% CI: 42, 139%), and levels of moderate-to-vigorous physical activity were 90% higher (95% CI: 49, 145%). The additional park use and park-based physical activity occurred not only on the walking loops but throughout the park. Walking loops may be a promising means of increasing population level physical activity. Further studies are needed to confirm a causal relationship. Citation: Cohen DA, Han B, Evenson KR, Nagel C, McKenzie TL, Marsh T, Williamson S, Harnik P. 2017. The prevalence and use of walking loops in neighborhood parks: a national study. Environ Health Perspect 125:170-174; http://dx.doi.org/10.1289/EHP293.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5289910','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5289910"><span>The Prevalence and Use of Walking Loops in Neighborhood Parks: A National Study</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cohen, Deborah A.; Han, Bing; Evenson, Kelly R.; Nagel, Catherine; McKenzie, Thomas L.; Marsh, Terry; Williamson, Stephanie; Harnik, Peter</p> <p>2016-01-01</p> <p>Background: Previous studies indicate that the design of streets and sidewalks can influence physical activity among residents. Park features also influence park use and park-based physical activity. Although individuals can walk on streets and sidewalks, walking loops in parks offer a setting to walk in nature and to avoid interruptions from traffic. Objectives: Here we describe the use of walking loops in parks and compare the number of park users and their physical activity in urban neighborhood parks with and without walking loops. Methods: We analyzed data from the National Study of Neighborhood Parks in which a representative sample of neighborhood parks (n = 174) from 25 U.S. cities with > 100,000 population were observed systematically to document facilities and park users by age group and sex. We compared the number of people and their physical activity in parks with and without walking loops, controlling for multiple factors, including park size, facilities, and population density. Results: Overall, compared with parks without walking loops, on average during an hourly observation, parks with walking loops had 80% more users (95% CI: 42, 139%), and levels of moderate-to-vigorous physical activity were 90% higher (95% CI: 49, 145%). The additional park use and park-based physical activity occurred not only on the walking loops but throughout the park. Conclusions: Walking loops may be a promising means of increasing population level physical activity. Further studies are needed to confirm a causal relationship. Citation: Cohen DA, Han B, Evenson KR, Nagel C, McKenzie TL, Marsh T, Williamson S, Harnik P. 2017. The prevalence and use of walking loops in neighborhood parks: a national study. Environ Health Perspect 125:170–174; http://dx.doi.org/10.1289/EHP293 PMID:27517530</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SSRv..149..199R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SSRv..149..199R"><span>Transverse Oscillations of Coronal Loops</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ruderman, Michael S.; Erdélyi, Robert</p> <p>2009-12-01</p> <p>On 14 July 1998 TRACE observed transverse oscillations of a coronal loop generated by an external disturbance most probably caused by a solar flare. These oscillations were interpreted as standing fast kink waves in a magnetic flux tube. Firstly, in this review we embark on the discussion of the theory of waves and oscillations in a homogeneous straight magnetic cylinder with the particular emphasis on fast kink waves. Next, we consider the effects of stratification, loop expansion, loop curvature, non-circular cross-section, loop shape and magnetic twist. An important property of observed transverse coronal loop oscillations is their fast damping. We briefly review the different mechanisms suggested for explaining the rapid damping phenomenon. After that we concentrate on damping due to resonant absorption. We describe the latest analytical results obtained with the use of thin transition layer approximation, and then compare these results with numerical findings obtained for arbitrary density variation inside the flux tube. Very often collective oscillations of an array of coronal magnetic loops are observed. It is natural to start studying this phenomenon from the system of two coronal loops. We describe very recent analytical and numerical results of studying collective oscillations of two parallel homogeneous coronal loops. The implication of the theoretical results for coronal seismology is briefly discussed. We describe the estimates of magnetic field magnitude obtained from the observed fundamental frequency of oscillations, and the estimates of the coronal scale height obtained using the simultaneous observations of the fundamental frequency and the frequency of the first overtone of kink oscillations. In the last part of the review we summarise the most outstanding and acute problems in the theory of the coronal loop transverse oscillations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150003027','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150003027"><span>Failure Analysis Results and Corrective Actions Implemented for the Extravehicular Mobility Unit 3011 Water in the Helmet Mishap</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Steele, John; Metselaar, Carol; Peyton, Barbara; Rector, Tony; Rossato, Robert; Macias, Brian; Weigel, Dana; Holder, Don</p> <p>2015-01-01</p> <p>Water entered the Extravehicular Mobility Unit (EMU) helmet during extravehicular activity (EVA) no. 23 aboard the International Space Station on July 16, 2013, resulting in the termination of the EVA approximately 1 hour after it began. It was estimated that 1.5 liters of water had migrated up the ventilation loop into the helmet, adversely impacting the astronaut's hearing, vision, and verbal communication. Subsequent on-board testing and ground-based test, tear-down, and evaluation of the affected EMU hardware components determined that the proximate cause of the mishap was blockage of all water separator drum holes with a mixture of silica and silicates. The blockages caused a failure of the water separator degassing function, which resulted in EMU cooling water spilling into the ventilation loop, migrating around the circulating fan, and ultimately pushing into the helmet. The root cause of the failure was determined to be ground-processing shortcomings of the Airlock Cooling Loop Recovery (ALCLR) Ion Filter Beds, which led to various levels of contaminants being introduced into the filters before they left the ground. Those contaminants were thereafter introduced into the EMU hardware on-orbit during ALCLR scrubbing operations. This paper summarizes the failure analysis results along with identified process, hardware, and operational corrective actions that were implemented as a result of findings from this investigation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11315804','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11315804"><span>Scale up of fuel ethanol production from sugar beet juice using loofa sponge immobilized bioreactor.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ogbonna, J C; Mashima, H; Tanaka, H</p> <p>2001-01-01</p> <p>Production of fuel ethanol from sugar beet juice, using cells immobilized on loofa sponge was investigated. Based on ethanol productivity and ease of cell immobilization, a flocculating yeast strain, Saccharomyces cerevisiae IR2 was selected for ethanol production from sugar beet juice. It was found that raw sugar beet juice was an optimal substrate for ethanol production, requiring neither pH adjustment nor nitrogen source supplement. When compared with a 2 l bubble column bioreactor, mixing was not sufficient in an 8 l bioreactor containing a bed of sliced loofa sponges and consequently, the immobilized cells were not uniformly distributed within the bed. Most of the cells were immobilized in the lower part of the bed and this resulted in decreased ethanol productivity. By using an external loop bioreactor, constructing the fixed bed with cylindrical loofa sponges, dividing the bed into upper, middle and lower sections with approximately 1 cm spaces between them and circulating the broth through the loop during the immobilization, uniform cell distribution within the bed was achieved. Using this method, the system was scaled up to 50 l and when compared with the 2 l bubble column bioreactor, there were no significant differences (P > 0.05) in ethanol productivity and yield. By using external loop bioreactor to immobilize the cells uniformly on the loofa sponge beds, efficient large scale ethanol production systems can be constructed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140016950','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140016950"><span>Failure Analysis Results and Corrective Actions Implemented for the EMU 3011 Water in the Helmet Mishap</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Steele, John; Metselaar, Carol; Peyton, Barbara; Rector, Tony; Rossato, Robert; Macias, Brian; Weigel, Dana; Holder, Don</p> <p>2015-01-01</p> <p>During EVA (Extravehicular Activity) No. 23 aboard the ISS (International Space Station) on 07/16/2013 water entered the EMU (Extravehicular Mobility Unit) helmet resulting in the termination of the EVA (Extravehicular Activity) approximately 1-hour after it began. It was estimated that 1.5-L of water had migrated up the ventilation loop into the helmet, adversely impacting the astronauts hearing, vision and verbal communication. Subsequent on-board testing and ground-based TT and E (Test, Tear-down and Evaluation) of the affected EMU hardware components led to the determination that the proximate cause of the mishap was blockage of all water separator drum holes with a mixture of silica and silicates. The blockages caused a failure of the water separator function which resulted in EMU cooling water spilling into the ventilation loop, around the circulating fan, and ultimately pushing into the helmet. The root cause of the failure was determined to be ground-processing short-comings of the ALCLR (Airlock Cooling Loop Recovery) Ion Filter Beds which led to various levels of contaminants being introduced into the Filters before they left the ground. Those contaminants were thereafter introduced into the EMU hardware on-orbit during ALCLR scrubbing operations. This paper summarizes the failure analysis results along with identified process, hardware and operational corrective actions that were implemented as a result of findings from this investigation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28698113','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28698113"><span>Patient-specific biomechanical model of hypoplastic left heart to predict post-operative cardio-circulatory behaviour.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cutrì, Elena; Meoli, Alessio; Dubini, Gabriele; Migliavacca, Francesco; Hsia, Tain-Yen; Pennati, Giancarlo</p> <p>2017-09-01</p> <p>Hypoplastic left heart syndrome is a complex congenital heart disease characterised by the underdevelopment of the left ventricle normally treated with a three-stage surgical repair. In this study, a multiscale closed-loop cardio-circulatory model is created to reproduce the pre-operative condition of a patient suffering from such pathology and virtual surgery is performed. Firstly, cardio-circulatory parameters are estimated using a fully closed-loop cardio-circulatory lumped parameter model. Secondly, a 3D standalone FEA model is build up to obtain active and passive ventricular characteristics and unloaded reference state. Lastly, the 3D model of the single ventricle is coupled to the lumped parameter model of the circulation obtaining a multiscale closed-loop pre-operative model. Lacking any information on the fibre orientation, two cases were simulated: (i) fibre distributed as in the physiological right ventricle and (ii) fibre as in the physiological left ventricle. Once the pre-operative condition is satisfactorily simulated for the two cases, virtual surgery is performed. The post-operative results in the two cases highlighted similar hemodynamic behaviour but different local mechanics. This finding suggests that the knowledge of the patient-specific fibre arrangement is important to correctly estimate the single ventricle's working condition and consequently can be valuable to support clinical decision. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24380462','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24380462"><span>Childcare outdoor renovation as a built environment health promotion strategy: evaluating the preventing obesity by design intervention.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cosco, Nilda G; Moore, Robin C; Smith, William R</p> <p>2014-01-01</p> <p>To evaluate the effectiveness of Preventing Obesity by Design (POD), a childcare center outdoor renovation intervention. Pre-post intervention evaluation. North Carolina licensed childcare centers (N = 27). Preschool children. Outdoor renovation, teacher training. Behavior mapping, Preschool Outdoor Environment Measurement Scale (POEMS), center director interview. Descriptive statistics, ordinary least squares and logistic regressions calculated to assess levels of association between environmental change, children's physical activity (PA), social behaviors, and environmental quality. Qualitative interview data analyzed to help understand intervention impact. Behavior mapping showed that site layout attributes, such as the form (i.e., "single loop" and "double loop") of pathways (functioning as circulation routes and wheeled toy settings), are associated with higher levels of PA. Teacher interaction was associated with decreased children's PA. Absence of teacher or lack of child/child interaction was associated with increased PA. POEMS assessment of environmental quality was higher after renovation. POEMS domains (Physical Space and Teacher/Caregiver Roles) were positively associated with PA. After renovation, 68% of center directors reported positive changes in children's behavior and 40% mentioned edible plant installations as greatest success. Built environment renovation of childcare center outdoors, including looped pathways installation, coupled with teacher training, may support increased PA. Renovation, including food gardens, may be a key to success for preschool health promotion and support change in childcare policy.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...591L...5N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...591L...5N"><span>Undamped transverse oscillations of coronal loops as a self-oscillatory process</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakariakov, V. M.; Anfinogentov, S. A.; Nisticò, G.; Lee, D.-H.</p> <p>2016-06-01</p> <p>Context. Standing transverse oscillations of coronal loops are observed to operate in two regimes: rapidly decaying, large amplitude oscillations and undamped small amplitude oscillations. In the latter regime the damping should be compensated by energy supply, which allows the loop to perform almost monochromatic oscillations with almost constant amplitude and phase. Different loops oscillate with different periods. The oscillation amplitude does not show dependence on the loop length or the oscillation period. Aims: We aim to develop a low-dimensional model explaining the undamped kink oscillations as a self-oscillatory process caused by the effect of negative friction. The source of energy is an external quasi-steady flow, for example, supergranulation motions near the loop footpoints or external flows in the corona. Methods: We demonstrate that the interaction of a quasi-steady flow with a loop can be described by a Rayleigh oscillator equation that is a non-linear ordinary differential equation, with the damping and resonant terms determined empirically. Results: Small-amplitude self-oscillatory solutions to the Rayleigh oscillator equation are harmonic signals of constant amplitude, which is consistent with the observed properties of undamped kink oscillations. The period of self-oscillations is determined by the frequency of the kink mode. The damping by dissipation and mode conversion is compensated by the continuous energy deposition at the frequency of the natural oscillation. Conclusions: We propose that undamped kink oscillations of coronal loops may be caused by the interaction of the loops with quasi-steady flows, and hence are self-oscillations, which is analogous to producing a tune by moving a bow across a violin string.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA543419','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA543419"><span>The Implementation of IS on the Knowledge Management and Mental Models at the Decision-Making Process</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2011-03-01</p> <p>Management entities can also poll end stations to check the values of certain variables. Polling can be automatic or user initiated, but agents in the...the environment in which knowledge artifacts are created and managed , but the flow of knowledge itself remains almost indirect. For example... interaction of these loops with one another. Thus, the cognitive nature of feedback loops correlates the entity with the environment that the decision was</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/381061','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/381061"><span>LM-research opportunities and activities at Beer-Sheva</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Lesin, S.</p> <p>1996-06-01</p> <p>Energy conversion concepts based on liquid metal (LM) magnetohydrodynamic (MHD) technology was intensively investigated at the Center for MHD Studies (CMHDS), in the Ben-Gurion University of the Negev in Israel. LMMHD energy conversion systems operate in a closed cycle as follows: heat intended for conversion into electricity is added to a liquid metal contained in a closed loop of pipes. The liquid metal is mixed with vapor or gas introduced from outside so that a two-phase mixture is formed. The gaseous phase performs a thermodynamic cycle, converting a certain amount of heat into mechanical energy of the liquid metal. Thismore » energy is converted into electrical power as the metal flows across a magnetic field in the MHD channel. Those systems where the expanding thermodynamic fluid performs work against gravitational forces (natural circulation loops) and using heavy liquid metals are named ETGAR systems. A number of different heavy-metal facilities have been specially constructed and tested with fluid combinations of mercury and steam, mercury and nitrogen, mercury and freon, lead-bismuth and steam, and lead and steam. Since the experimental investigation of such flows is a very difficult task and all the known measurment methods are incomplete and not fully reliable, a variety of experimental approaches have been developed. In most experiments, instantaneous pressure distribution along the height of the upcomer were measured and the average void fraction was calculated numerically using the one-dimensional equation for the two-phase flow. The research carried out at the CMHDS led to significant improvements in the characterization of the two-phase phenomena expected in the riser of ETGAR systems. One of the most important outcomes is the development of a new empirical correlation which enables the reliable prediction of the velocity ratio between the LM and the steam (slip), the friction factor, as well as of the steam void fraction distribution along the riser.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28412545','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28412545"><span>DNA Topoisomerase 1 Prevents R-loop Accumulation to Modulate Auxin-Regulated Root Development in Rice.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shafiq, Sarfraz; Chen, Chunli; Yang, Jing; Cheng, Lingling; Ma, Fei; Widemann, Emilie; Sun, Qianwen</p> <p>2017-06-05</p> <p>R-loop structures (RNA:DNA hybrids) have important functions in many biological processes, including transcriptional regulation and genome instability among diverse organisms. DNA topoisomerase 1 (TOP1), an essential manipulator of DNA topology during RNA transcription and DNA replication processes, can prevent R-loop accumulation by removing the positive and negative DNA supercoiling that is made by RNA polymerases during transcription. TOP1 is required for plant development, but little is known about its function in preventing co-transcriptional R-loop accumulation in various biological processes in plants. Here we show that knockdown of OsTOP1 strongly affects rice development, causing defects in root architecture and gravitropism, which are the consequences of misregulation of auxin signaling and transporter genes. We found that R-loops are naturally formed at rice auxin-related gene loci, and overaccumulate when OsTOP1 is knocked down or OsTOP1 protein activity is inhibited. OsTOP1 therefore sets the accurate expression levels of auxin-related genes by preventing the overaccumulation of inherent R-loops. Our data reveal R-loops as important factors in polar auxin transport and plant root development, and highlight that OsTOP1 functions as a key to link transcriptional R-loops with plant hormone signaling, provide new insights into transcriptional regulation of hormone signaling in plants. Copyright © 2017 The Author. Published by Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017A%26A...603A..42X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017A%26A...603A..42X"><span>Coronal rain in magnetic bipolar weak fields</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xia, C.; Keppens, R.; Fang, X.</p> <p>2017-07-01</p> <p>Aims: We intend to investigate the underlying physics for the coronal rain phenomenon in a representative bipolar magnetic field, including the formation and the dynamics of coronal rain blobs. Methods: With the MPI-AMRVAC code, we performed three dimensional radiative magnetohydrodynamic (MHD) simulation with strong heating localized on footpoints of magnetic loops after a relaxation to quiet solar atmosphere. Results: Progressive cooling and in-situ condensation starts at the loop top due to radiative thermal instability. The first large-scale condensation on the loop top suffers Rayleigh-Taylor instability and becomes fragmented into smaller blobs. The blobs fall vertically dragging magnetic loops until they reach low-β regions and start to fall along the loops from loop top to loop footpoints. A statistic study of the coronal rain blobs finds that small blobs with masses of less than 1010 g dominate the population. When blobs fall to lower regions along the magnetic loops, they are stretched and develop a non-uniform velocity pattern with an anti-parallel shearing pattern seen to develop along the central axis of the blobs. Synthetic images of simulated coronal rain with Solar Dynamics Observatory Atmospheric Imaging Assembly well resemble real observations presenting dark falling clumps in hot channels and bright rain blobs in a cool channel. We also find density inhomogeneities during a coronal rain "shower", which reflects the observed multi-stranded nature of coronal rain. Movies associated to Figs. 3 and 7 are available at http://www.aanda.org</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1376391-dislocation-loop-evolution-during-situ-ion-irradiation-model-fecral-alloys','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1376391-dislocation-loop-evolution-during-situ-ion-irradiation-model-fecral-alloys"><span>Dislocation loop evolution during in-situ ion irradiation of model FeCrAl alloys</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Haley, Jack C.; Briggs, Samuel A.; Edmondson, Philip D.</p> <p></p> <p>Model FeCrAl alloys of Fe-10%Cr-5%Al, Fe-12%Cr-4.5%Al, Fe-15%Cr-4%Al, and Fe-18%Cr-3%Al (in wt %) were irradiated with 1 MeV Kr++ ions in-situ with transmission electron microscopy to a dose of 2.5 displacements per atom (dpa) at 320 °C. In all cases, the microstructural damage consisted of dislocation loops with ½< 111 > and <100 > Burgers vectors. The proportion of ½< 111 > dislocation loops varied from ~50% in the Fe-10%Cr-5%Al model alloy and the Fe-18Cr%-3%Al model alloy to a peak of ~80% in the model Fe-15%Cr-4.5%Al alloy. The dislocation loop volume density increased with dose for all alloys and showed signsmore » of approaching an upper limit. The total loop populations at 2.5 dpa had a slight (and possibly insignificant) decline as the chromium content was increased from 10 to 15 wt %, but the Fe-18%Cr-3%Al alloy had a dislocation loop population ~50% smaller than the other model alloys. As a result, the largest dislocation loops in each alloy had image sizes of close to 20 nm in the micrographs, and the median diameters for all alloys ranged from 6 to 8 nm. Nature analysis by the inside-outside method indicated most dislocation loops were interstitial type.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1376391-dislocation-loop-evolution-during-situ-ion-irradiation-model-fecral-alloys','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1376391-dislocation-loop-evolution-during-situ-ion-irradiation-model-fecral-alloys"><span>Dislocation loop evolution during in-situ ion irradiation of model FeCrAl alloys</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Haley, Jack C.; Briggs, Samuel A.; Edmondson, Philip D.; ...</p> <p>2017-07-06</p> <p>Model FeCrAl alloys of Fe-10%Cr-5%Al, Fe-12%Cr-4.5%Al, Fe-15%Cr-4%Al, and Fe-18%Cr-3%Al (in wt %) were irradiated with 1 MeV Kr++ ions in-situ with transmission electron microscopy to a dose of 2.5 displacements per atom (dpa) at 320 °C. In all cases, the microstructural damage consisted of dislocation loops with ½< 111 > and <100 > Burgers vectors. The proportion of ½< 111 > dislocation loops varied from ~50% in the Fe-10%Cr-5%Al model alloy and the Fe-18Cr%-3%Al model alloy to a peak of ~80% in the model Fe-15%Cr-4.5%Al alloy. The dislocation loop volume density increased with dose for all alloys and showed signsmore » of approaching an upper limit. The total loop populations at 2.5 dpa had a slight (and possibly insignificant) decline as the chromium content was increased from 10 to 15 wt %, but the Fe-18%Cr-3%Al alloy had a dislocation loop population ~50% smaller than the other model alloys. As a result, the largest dislocation loops in each alloy had image sizes of close to 20 nm in the micrographs, and the median diameters for all alloys ranged from 6 to 8 nm. Nature analysis by the inside-outside method indicated most dislocation loops were interstitial type.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23392585','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23392585"><span>Microembolism and catheter ablation I: a comparison of irrigated radiofrequency and multielectrode-phased radiofrequency catheter ablation of pulmonary vein ostia.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Haines, David E; Stewart, Mark T; Dahlberg, Sarah; Barka, Noah D; Condie, Cathy; Fiedler, Gary R; Kirchhof, Nicole A; Halimi, Franck; Deneke, Thomas</p> <p>2013-02-01</p> <p>Cerebral diffusion-weighted MRI lesions have been observed after catheter ablation of atrial fibrillation. We hypothesized that conditions predisposing to microembolization could be identified using a porcine model of pulmonary vein ablation and an extracorporeal circulation loop. Ablations of the pulmonary veins were performed in 18 swine with echo monitoring. The femoral artery and vein were cannulated and an extracorporeal circulation loop with 2 ultrasonic bubble detectors and a 73-μm filter were placed in series. Microemboli and microbubbles were compared between ablation with an irrigated radiofrequency system (Biosense-Webster) and a phased radiofrequency multielectrode system (pulmonary vein ablation catheter [PVAC], Medtronic, Inc, Carlsbad, CA) in unipolar and 3 blended unipolar/bipolar modes. Animal pathology was examined. The size and number of microbubbles observed during ablation ranged from 30 to 180 μm and 0 to 3253 bubbles per ablation. Microbubble volumes with PVAC (29.1 nL) were greater than with irrigated radiofrequency (0.4 nL; P=0.045), and greatest with type II or III microbubbles on transesophageal echocardiography. Ablation with the PVAC showed fewest microbubbles in the unipolar mode (P=0.012 versus bipolar). The most occurred during bipolar energy delivery with overlap of proximal and distal electrodes (median microbubble volume, 1744 nL; interquartile range, 737-4082 nL; maximum, 19 516 nL). No cerebral MRI lesions were seen, but 2 animals had renal embolization. Left atrial ablation with irrigated radiofrequency and PVAC catheters in swine is associated with microbubble and microembolus production. Avoiding overlap of electrodes 1 and 10 on PVAC should reduce the microembolic burden associated with this procedure.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26616139','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26616139"><span>Molecular detection and characterization of noroviruses in river water in Thailand.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Inoue, K; Motomura, K; Boonchan, M; Takeda, N; Ruchusatsawa, K; Guntapong, R; Tacharoenmuang, R; Sangkitporn, S; Chantaroj, S</p> <p>2016-03-01</p> <p>Norovirus (NoV) generally exists as a mixture of multiple genotype variants in nature. However, there has been no published report monitoring NoV in natural settings in Thailand. To obtain information on mixed presence of the NoV RNA genome, we conducted viral genome analysis of 15 water specimens collected from five sites in a river near Bangkok between August 2013 and August 2014. The number of viral RNA copies per specimen declined progressively from the most upstream to the most downstream site. Following direct nucleotide sequencing of the PCR products, we obtained three partial genome sequences of the NoV GI strain and 13 partial genome sequences of the NoV GII strains. Phylogenetic analysis indicated the presence of four GII.4 variant groups pro-circulated after the Den Haag_2006b, New Orleans_2009 and Sydney_2012 outbreaks. On the other hand, only GI.4 was observed from the specimens collected on April, 2014. These results indicated that multiple genogroups and genotypes of noroviruses are present and are circulating in the natural environment in Thailand as in other countries. Our study provides comprehensive information on the occurrence of new variants. Our study is the first paper that multiple genogroups and genotypes of norovirus exist, and are circulating in the river water near Bangkok, Thailand. Phylogenetic analysis indicated the presence of four GII.4 variant groups pro-circulated after the Den Haag_2006b, New Orleans_2009 and Sydney_2012 that caused outbreaks in the world. Continued research will be essential for understanding the natural history of NoV and the control of future outbreaks. © 2015 The Society for Applied Microbiology.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26414901','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26414901"><span>Invariant Natural Killer T Cell Deficiency and Functional Impairment in Sleep Apnea: Links to Cancer Comorbidity.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gaoatswe, Gadintshware; Kent, Brian D; Corrigan, Michelle A; Nolan, Geraldine; Hogan, Andrew E; McNicholas, Walter T; O'Shea, Donal</p> <p>2015-10-01</p> <p>Emerging evidence links obstructive sleep apnea (OSA) with increased cancer incidence and mortality. Invariant natural killer T (iNKT) cells play an important role in cancer immunity. We hypothesized that patients with OSA have low number of circulating invariant natural killer T (iNKT) cells, which may also be functionally impaired. This study aims to evaluate the frequency of circulating iNKT cells in OSA. We evaluated the frequency of circulating iNKT cells by flow cytometry in 33 snorers being assessed for possible OSA. Using iNKT cell lines, we also evaluated the effect of exposure to hypoxia over 24 hours on apoptosis, cytotoxicity, and cytokine production. Teaching hospital based sleep unit and research laboratory. Thirty-three snorers were evaluated: 9 with no OSA (apnea-hypopnea frequency [AHI] < 5/h), 12 with mild-moderate OSA (AHI 5-30) and 12 with severe OSA (AHI > 30). Patients with severe OSA had considerably fewer iNKT cells (0.18%) compared to patients with mild-moderate (0.24%) or no OSA (0.35%), P = 0.0026. The frequency of iNKT cells correlated negatively with apnea-hypopnea index (r = -0.58, P = 0.001), oxygen desaturation index (r = -0.58, P = 0.0003), and SpO2% < 90% (r = -0.5407, P = 0.005). The frequency of iNKT cells increased following 12 months of nCPAP therapy (P = 0.015). Hypoxia resulted in increased apoptosis (P = 0.016) and impaired cytotoxicity (P = 0.035). Patients with obstructive sleep apnea (OSA) have significantly reduced levels of circulating invariant natural killer T (iNKT) cells and hypoxia leads to impaired iNKT cell function. These observations may partly explain the increased cancer risk reported in patients with OSA. © 2015 Associated Professional Sleep Societies, LLC.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003ARep...47..873Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003ARep...47..873Z"><span>Spectral-Temporal Evolution of Low-Frequency Pulsations in the Microwave Radiation of Solar Flares</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zaitsev, V. V.; Kislyakov, A. G.; Urpo, S.; Stepanov, A. V.; Shkelev, E. I.</p> <p>2003-10-01</p> <p>Low-frequency pulsations of 22 and 37 GHz microwave radiation detected during solar flares are analyzed. Several microwave bursts observed at the Metsähovi Radio Observatory are studied with time resolutions of 100 and 50 ms. A fast Fourier transformation with a sliding window and the Wigner-Ville method are used to obtain frequency-time diagrams for the low-frequency pulsations, which are interpreted as natural oscillations of coronal magnetic loops; the dynamical spectra of the pulsations are synthesized for the first time. Three types of low-frequency fluctuations modulating the flare microwave radiation can be distinguished in the observations. First, there are fast and slow magneto-acoustic oscillations with periods of 0.5 0.8 s and 200 280 s, respectively. The fast magneto-acoustic oscillations appear as trains of narrow-band signals with durations of 100 200 s, a positive frequency drift dν/dt=0.25 MHz/min, and frequency splitting δν=0.01 0.05 Hz. Second, there are natural oscillations of the coronal magnetic loops as equivalent electrical circuits. These oscillations have periods of 0.5 10 s and positive or negative frequency drift rates dν/dt=8×10-3 Hz/min or dν/dt=-1.3×10-2 Hz/min, depending on the phase of the radio outburst. Third, there are modulations of the microwave radiation by short periodic pulses with a period of 20 s. The dynamical spectra of the low-frequency pulsations supply important information about the parameters of the magnetic loops: the ratio of the loop radius to its length r/L≈0.1, the plasma parameter β≈10-3, the ratio of the plasma densities outside and inside the loop ρe/ρi≈10-2, and the electrical current flowing along the loop I≈1012 A.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70185160','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70185160"><span>West Florida shelf circulation and temperature budget for the 1999 spring transition</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>He, Ruoying; Weisberg, Robert H.</p> <p>2002-01-01</p> <p>Mid-latitude continental shelves undergo a spring transition as the net surface heat flux changes from cooling to warming. Using in situ data and a numerical circulation model we investigate the circulation and temperature budget on the West Florida Continental Shelf (WFS) for the spring transition of 1999. The model is a regional adaptation of the primitive equation, Princeton Ocean Model forced by NCEP reanalysis wind and heat flux fields and by river inflows. Based on agreements between the modeled and observed fields we use the model to draw inferences on how the surface momentum and heat fluxes affect the seasonal and synoptic scale variability. We account for a strong southeastward current at mid-shelf by the baroclinic response to combined wind and buoyancy forcing, and we show how this local forcing leads to annually occurring cold and low salinity tongues. Through term-by-term analyses of the temperature budget we describe the WFS temperature evolution in spring. Heat flux largely controls the seasonal transition, whereas ocean circulation largely controls the synoptic scale variability. These two processes, however, are closely linked. Bottom topography and coastline geometry are important in generating regions of convergence and divergence. Rivers contribute to the local hydrography and are important ecologically. Along with upwelling, river inflows facilitate frontal aggregation of nutrients and the spring formation of a high concentration chlorophyll plume near the shelf break (the so-called ‘Green River’) coinciding with the cold, low salinity tongues. These features originate by local, shelf-wide forcing; the Loop Current is not an essential ingredient.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3426563','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3426563"><span>Defining the Nature of Thermal Intermediate in 3 State Folding Proteins: Apoflavodoxin, a Study Case</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>García-Fandiño, Rebeca; Bernadó, Pau; Ayuso-Tejedor, Sara; Sancho, Javier; Orozco, Modesto</p> <p>2012-01-01</p> <p>The early stages of the thermal unfolding of apoflavodoxin have been determined by using atomistic multi microsecond-scale molecular dynamics (MD) simulations complemented with a variety of experimental techniques. Results strongly suggest that the intermediate is reached very early in the thermal unfolding process and that it has the properties of an “activated” form of the native state, where thermal fluctuations in the loops break loop-loop contacts. The unrestrained loops gain then kinetic energy corrupting short secondary structure elements without corrupting the core of the protein. The MD-derived ensembles agree with experimental observables and draw a picture of the intermediate state inconsistent with a well-defined structure and characteristic of a typical partially disordered protein. Our results allow us to speculate that proteins with a well packed core connected by long loops might behave as partially disordered proteins under native conditions, or alternatively behave as three state folders. Small details in the sequence, easily tunable by evolution, can yield to one or the other type of proteins. PMID:22927805</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1334238-multi-loop-positivity-planar-mathcal-sym-six-point-amplitude','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1334238-multi-loop-positivity-planar-mathcal-sym-six-point-amplitude"><span>Multi-loop positivity of the planar $$ \\mathcal{N} $$ = 4 SYM six-point amplitude</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Dixon, Lance J.; von Hippel, Matt; McLeod, Andrew J.; ...</p> <p>2017-02-22</p> <p>We study the six-point NMHV ratio function in planarmore » $$ \\mathcal{N} $$ = 4 SYM theory in the context of positive geometry. The Amplituhedron construction of the integrand for the amplitudes provides a kinematical region in which the integrand was observed to be positive. It is natural to conjecture that this property survives integration, i.e. that the final result for the ratio function is also positive in this region. Establishing such a result would imply that preserving positivity is a surprising property of the Minkowski contour of integration and it might indicate some deeper underlying structure. We find that the ratio function is positive everywhere we have tested it, including analytic results for special kinematical regions at one and two loops, as well as robust numerical evidence through five loops. There is also evidence for not just positivity, but monotonicity in a “radial” direction. We also investigate positivity of the MHV six-gluon amplitude. While the remainder function ceases to be positive at four loops, the BDS-like normalized MHV amplitude appears to be positive through five loops.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JNuM..494..252O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JNuM..494..252O"><span>Full characterization of dislocations in ion-irradiated polycrystalline UO2</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Onofri, C.; Legros, M.; Léchelle, J.; Palancher, H.; Baumier, C.; Bachelet, C.; Sabathier, C.</p> <p>2017-10-01</p> <p>In order to fully characterize the dislocation loops and lines features (Burgers vectors, habit/slip planes, interstitial or vacancy type) induced by irradiation in UO2, polycrystalline thin foils were irradiated with 4 MeV Au or 390 keV Xe ions at different temperatures (25, 600 and 800 °C) and fluences (0.5 and 1 × 1015 ions/cm2), and further analyzed using TEM. In all the cases, this study, performed on a large number of dislocation loops (diameter ranging from 10 to 80 nm) and for the first time on several dislocation lines, reveals unfaulted prismatic dislocation loops with an interstitial nature and Burgers vectors only along the <110>-type directions. Almost 60% of the studied loops are purely prismatic type and lie on {110} habit planes perpendicular to the Burgers vector directions. The others lie on the {110} or {111} planes, which are neither perpendicular to the Burgers vectors, nor contain them. About 87% of the dislocation lines, formed by loop overlapping as fluence increases, are edge or mixed type in the <100>{100} slip systems, as those induced under mechanical load.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Metro..54.3001A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Metro..54.3001A"><span>Final report on APMP supplementary comparison of industrial platinum resistance thermometer for range -50 °C to 400 °C. (APMP.T-S6)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ali, Nurulaini Md; Othman, Hafidzah; Ho, Mong-Kim; Yang, Inseok; Gabi, Victor; Zhang, Zhe; Sheng, Ying; Hu, Jing; Zhang, Jintao; Tsai, Shu-Fei; Liao, Su-Chuion; Shafiqul Alam, Md; Norranim, Uthai; Yaokulbodee, Charuayrat; Liedberg, Hans; Gamal Ahmed, Mohamed; Harba, Naser; Fuad Flaifel, Mustafa; Suherlan; Achmadi, Aditya; Haoyuan, Kho; Yan, Fan; Boon Kwee, Neoh; Thanh Binh, Pham; Ragay, Monalisa</p> <p>2017-01-01</p> <p>The National Metrology Laboratory, Malaysia (NML-SIRIM) had coordinated the Supplementary Comparison of Industrial Platinum Resistance Thermometer (IPRT) started from July 2009 until April 2011 together with the National Measurement Institute of Australia (NMIA) and Korea Research Institute of Standards and Science (KRISS). This comparison was opened to all APMP members and 16 participants had taken part in order to consolidate or improve their calibration and measurement capabilities (CMCs). Three units of artefacts 100-ohm IPRT belonging to NML-SIRIM, NMIA and KRISS were used and three loops of measurement were run in parallel to shorten the circulation time. The stability of artefacts was monitored with initial and final ice point measurement by each laboratory. The participants need to perform measurement at temperature points (0,-50,-30, 0, 100, 200, 300, 400,0) °C. All submitted data were compiled and adjusted at nominal temperature and by using the linkage from NMIA and KRISS as reference value for all three loops , the temperature deviation from participants from different loops can be compared. The approach of Birge Ratio for final exclusion comprised all the excluded results from the analysis of each loop and the measurement performance for each participant were summarized by the En number value. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26564191','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26564191"><span>Thermodynamic analysis of in situ gasification-chemical looping combustion (iG-CLC) of Indian coal.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Suresh, P V; Menon, Kavitha G; Prakash, K S; Prudhvi, S; Anudeep, A</p> <p>2016-10-01</p> <p>Chemical looping combustion (CLC) is an inherent CO 2 capture technology. It is gaining much interest in recent years mainly because of its potential in addressing climate change problems associated with CO 2 emissions from power plants. A typical chemical looping combustion unit consists of two reactors-fuel reactor, where oxidation of fuel occurs with the help of oxygen available in the form of metal oxides and, air reactor, where the reduced metal oxides are regenerated by the inflow of air. These oxides are then sent back to the fuel reactor and the cycle continues. The product gas from the fuel reactor contains a concentrated stream of CO 2 which can be readily stored in various forms or used for any other applications. This unique feature of inherent CO 2 capture makes the technology more promising to combat the global climate changes. Various types of CLC units have been discussed in literature depending on the type of fuel burnt. For solid fuel combustion three main varieties of CLC units exist namely: syngas CLC, in situ gasification-CLC (iG-CLC) and chemical looping with oxygen uncoupling (CLOU). In this paper, theoretical studies on the iG-CLC unit burning Indian coal are presented. Gibbs free energy minimization technique is employed to determine the composition of flue gas and oxygen carrier of an iG-CLC unit using Fe 2 O 3 , CuO, and mixed carrier-Fe 2 O 3 and CuO as oxygen carriers. The effect of temperature, suitability of oxygen carriers, and oxygen carrier circulation rate on the performance of a CLC unit for Indian coal are studied and presented. These results are analyzed in order to foresee the operating conditions at which economic and smooth operation of the unit is expected.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=false+AND+information&pg=6&id=EJ986152','ERIC'); return false;" href="https://eric.ed.gov/?q=false+AND+information&pg=6&id=EJ986152"><span>Children's Natural Conversations Following Exposure to a Rumor: Linkages to Later False Reports</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Principe, Gabrielle F.; Cherson, Mollie; DiPuppo, Julie; Schindewolf, Erica</p> <p>2012-01-01</p> <p>Previous research has shown that children naturally propagate overheard false rumors and that the circulation of such information can induce children and their peers to wrongly recall actually experiencing rumored-but-nonexperienced events. The current study extends this work by recording 3- to 6-year-olds' naturally occurring conversations…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ChPhB..25c7501C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ChPhB..25c7501C"><span>Effect of exchange coupling on magnetic property in Sm-Co/α-Fe layered system</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>C, X. Sang; G, P. Zhao; W, X. Xia; X, L. Wan; F, J. Morvan; X, C. Zhang; L, H. Xie; J, Zhang; J, Du; A, R. Yan; P, Liu</p> <p>2016-03-01</p> <p>The hysteresis loops as well as the spin distributions of Sm-Co/α-Fe bilayers have been investigated by both three-dimensional (3D) and one-dimensional (1D) micromagnetic calculations, focusing on the effect of the interface exchange coupling under various soft layer thicknesses ts. The exchange coupling coefficient Ahs between the hard and soft layers varies from 1.8 × 10-6 erg/cm to 0.45 × 10-6 erg/cm, while the soft layer thickness increases from 2 nm to 10 nm. As the exchange coupling decreases, the squareness of the loop gradually deteriorates, both pinning and coercive fields rise up monotonically, and the nucleation field goes down. On the other hand, an increment of the soft layer thickness leads to a significant drop of the nucleation field, the deterioration of the hysteresis loop squareness, and an increase of the remanence. The simulated loops based on the 3D and 1D methods are consistent with each other and in good agreement with the measured loops for Sm-Co/α-Fe multilayers. Project supported by the National Natural Science Foundation of China (Grant Nos. 11074179 and 10747007), the National Basic Research Program of China (Grant No. 2014CB643702), the Zhejiang Provincial Natural Science Foundation of China (Grant No. LY14E010006), the Construction Plan for Scientific Research Innovation Teams of Universities in Sichuan Province, China (Grant No. 12TD008), the Scientific Research Foundation for the Returned Overseas Chinese Scholars of the Education Ministry, China, and the Program for Key Science and Technology Innovation Team of Zhejiang Province, China (Grant No. 2013TD08).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140017287','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140017287"><span>Proteins with Novel Structure, Function and Dynamics</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pohorille, Andrew</p> <p>2014-01-01</p> <p>Recently, a small enzyme that ligates two RNA fragments with the rate of 10(exp 6) above background was evolved in vitro (Seelig and Szostak, Nature 448:828-831, 2007). This enzyme does not resemble any contemporary protein (Chao et al., Nature Chem. Biol. 9:81-83, 2013). It consists of a dynamic, catalytic loop, a small, rigid core containing two zinc ions coordinated by neighboring amino acids, and two highly flexible tails that might be unimportant for protein function. In contrast to other proteins, this enzyme does not contain ordered secondary structure elements, such as alpha-helix or beta-sheet. The loop is kept together by just two interactions of a charged residue and a histidine with a zinc ion, which they coordinate on the opposite side of the loop. Such structure appears to be very fragile. Surprisingly, computer simulations indicate otherwise. As the coordinating, charged residue is mutated to alanine, another, nearby charged residue takes its place, thus keeping the structure nearly intact. If this residue is also substituted by alanine a salt bridge involving two other, charged residues on the opposite sides of the loop keeps the loop in place. These adjustments are facilitated by high flexibility of the protein. Computational predictions have been confirmed experimentally, as both mutants retain full activity and overall structure. These results challenge our notions about what is required for protein activity and about the relationship between protein dynamics, stability and robustness. We hypothesize that small, highly dynamic proteins could be both active and fault tolerant in ways that many other proteins are not, i.e. they can adjust to retain their structure and activity even if subjected to mutations in structurally critical regions. This opens the doors for designing proteins with novel functions, structures and dynamics that have not been yet considered.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1421487','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1421487"><span>FY 2017-Progress Report on the Design and Construction of the Sodium Loop SMT-3</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Natesan, K.; Momozaki, Y.</p> <p></p> <p>This report provides an update on the design of a forced-convection sodium loop to be used for the evaluation of sodium compatibility of advanced Alloy 709 with emphasis on long term exposures of tensile, creep, fatigue, creep fatigue, and fracture toughness ASTM-size specimens in support of ASME Code qualification and NRC licensing. The report is a deliverable (Level 4) in FY17 (M4AT-17AN1602094), under the Work Package AT-17AN160209, “Sodium Compatibility” performed by Argonne National Laboratory (ANL), as part of the Advanced Materials Program for the Advanced Reactor Technology. This work package enables the development of advanced structural materials by providing corrosion,more » microstructure, and mechanical property data from the standpoint of sodium compatibility of advanced structural alloys. The first sodium loop (SMT-1) with a single tank was constructed in 2011 at ANL and has been in operation for exposure of subsize sheet specimens of advanced alloys at a single temperature. The second sodium loop with dual tanks (SMT-2) was constructed in 2013 and has been in operation for the exposure of subsize sheet specimens of advanced alloys at two different temperatures. The current loop (SMT-3) has been designed to incorporate sufficient chamber capacity to expose a large number of ASTM-size specimens to evaluate the sodium effects on tensile, creep, fatigue, creep-fatigue, and fracture toughness properties, in support of ASME Code Qualification and USNRC Licensing. The design of individual components for the third sodium loop SMT-3 is almost complete. The design also has been sent to an outside vendor for piping analysis to be in compliance with ASME Code. A purchase order has been placed with an outside vendor for the fabrication of major components such as the specimen exposure tanks. However, we have contracted with another vendor to establish the piping design in compliance with ASME design codes. The piping design was completed in FY2017 and the information is being transmitted to the tank fabricator. The SMT-3 loop will be located in Building 206 adjacent to the currently operating SMT-2 loop. In addition, we have demolished the aged power supply system in Building 206 and installed a new transformer, wiring, and power panels for the new loop. Procurement of some of the long lead items such as valves, EM pumps, EM flowmeters, etc. is in progress and will continue in FY 2018. The construction of components such as cold trap, economizers, piping arrangement etc. will be performed in the central shops at ANL. About 150 liters of sodium for the loop will be procured in early FY2018. The loop system is designed to circulate sodium through the sample tanks and the associated loop without an operator for an extended period of time. With the three sodium loops (with single-tank, dual-tank and four–tanks), materials can be tested at different sodium temperatures, and large tensile, creep, fatigue, creep-fatigue, and fracture toughness specimens can be exposed to sodium for extended periods of time and generate data on mechanical properties in support of ASME Code Qualification and USNRC Licensing of advanced Alloy 709 for use as a structural material in SFRs.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=305604','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=305604"><span>Surveillance for influenza virus subtypes H1, H2 and H3 among wild birds in Ukraine in 2006-2012</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Background: Influenza is one of the most important and unpredictable diseases of humans, other mammals and birds. Influenza virus of H1, H2, and H3 subtypes circulate in humans and cause seasonal influenza. Similar subtypes are also circulating in the natural reservoir, wild aquatic birds, and und...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA574451','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA574451"><span>New Approaches to the Parameterization of Gravity-Wave and Flow-Blocking Drag due to Unresolved Mesoscale Orography Guided by Mesoscale Model Predictability Research</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2012-09-30</p> <p>oscillation (SAO) and quasi-biennial oscillation ( QBO ) of stratospheric equatorial winds in long-term (10-year) nature runs. The ability of these new schemes...to generate and maintain tropical SAO and QBO circulations in Navy models for the first time is an important breakthrough, since these circulations</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/21503573-infrared-propagators-yang-mills-theory-from-perturbation-theory','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21503573-infrared-propagators-yang-mills-theory-from-perturbation-theory"><span>Infrared propagators of Yang-Mills theory from perturbation theory</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Tissier, Matthieu; Wschebor, Nicolas</p> <p>2010-11-15</p> <p>We show that the correlation functions of ghosts and gluons for the pure Yang-Mills theory in Landau gauge can be accurately reproduced for all momenta by a one-loop calculation. The key point is to use a massive extension of the Faddeev-Popov action. The agreement with lattice simulation is excellent in d=4. The one-loop calculation also reproduces all the characteristic features of the lattice simulations in d=3 and naturally explains the peculiarities of the propagators in d=2.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/321246','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/321246"><span>Hot spot detection system for vanes or blades of a combustion turbine</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Twerdochlib, M.</p> <p>1999-02-02</p> <p>This invention includes a detection system that can determine if a turbine component, such as a turbine vane or blade, has exceeded a critical temperature, such as a melting point, along any point along the entire surface of the vane or blade. This system can be employed in a conventional combustion turbine having a compressor, a combustor and a turbine section. Included within this system is a chemical coating disposed along the entire interior surface of a vane or blade and a closed loop cooling system that circulates a coolant through the interior of the vane or blade. If the temperature of the vane or blade exceeds a critical temperature, the chemical coating will be expelled from the vane or blade into the coolant. Since while traversing the closed loop cooling system the coolant passes through a detector, the presence of the chemical coating in the coolant will be sensed by the system. If the chemical coating is detected, this indicates that the vane or blade has exceeded a critical temperature. 5 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/873850','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/873850"><span>Circulating current battery heater</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ashtiani, Cyrus N.; Stuart, Thomas A.</p> <p>2001-01-01</p> <p>A circuit for heating energy storage devices such as batteries is provided. The circuit includes a pair of switches connected in a half-bridge configuration. Unidirectional current conduction devices are connected in parallel with each switch. A series resonant element for storing energy is connected from the energy storage device to the pair of switches. An energy storage device for intermediate storage of energy is connected in a loop with the series resonant element and one of the switches. The energy storage device which is being heated is connected in a loop with the series resonant element and the other switch. Energy from the heated energy storage device is transferred to the switched network and then recirculated back to the battery. The flow of energy through the battery causes internal power dissipation due to electrical to chemical conversion inefficiencies. The dissipated power causes the internal temperature of the battery to increase. Higher internal temperatures expand the cold temperature operating range and energy capacity utilization of the battery. As disclosed, either fixed frequency or variable frequency modulation schemes may be used to control the network.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29544508','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29544508"><span>Effects of HIV infection and ART on phenotype and function of circulating monocytes, natural killer, and innate lymphoid cells.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nabatanzi, Rose; Cose, Stephen; Joloba, Moses; Jones, Sarah Rowland; Nakanjako, Damalie</p> <p>2018-03-15</p> <p>HIV infection causes upregulation of markers of inflammation, immune activation and apoptosis of host adaptive, and innate immune cells particularly monocytes, natural killer (NK) and innate lymphoid cells (ILCs). Although antiretroviral therapy (ART) restores CD4 T-cell counts, the persistent aberrant activation of monocytes, NK and ILCs observed likely contributes to the incomplete recovery of T-cell effector functions. A better understanding of the effects of HIV infection and ART on the phenotype and function of circulating monocytes, NK, and ILCs is required to guide development of novel therapeutic interventions to optimize immune recovery.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MsT..........9B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MsT..........9B"><span>Design of an Experimental Facility for Passive Heat Removal in Advanced Nuclear Reactors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bersano, Andrea</p> <p></p> <p>With reference to innovative heat exchangers to be used in passive safety system of Gen- eration IV nuclear reactors and Small Modular Reactors it is necessary to study the natural circulation and the efficiency of heat removal systems. Especially in safety systems, as the decay heat removal system of many reactors, it is increasing the use of passive components in order to improve their availability and reliability during possible accidental scenarios, reducing the need of human intervention. Many of these systems are based on natural circulation, so they require an intense analysis due to the possible instability of the related phenomena. The aim of this thesis work is to build a scaled facility which can reproduce, in a simplified way, the decay heat removal system (DHR2) of the lead-cooled fast reactor ALFRED and, in particular, the bayonet heat exchanger, which transfers heat from lead to water. Given the thermal power to be removed, the natural circulation flow rate and the pressure drops will be studied both experimentally and numerically using the code RELAP5 3D. The first phase of preliminary analysis and project includes: the calculations to design the heat source and heat sink, the choice of materials and components and CAD drawings of the facility. After that, the numerical study is performed using the thermal-hydraulic code RELAP5 3D in order to simulate the behavior of the system. The purpose is to run pretest simulations of the facility to optimize the dimensioning setting the operative parameters (temperature, pressure, etc.) and to chose the most adequate measurement devices. The model of the system is continually developed to better simulate the system studied. High attention is dedicated to the control logic of the system to obtain acceptable results. The initial experimental tests phase consists in cold zero power tests of the facility in order to characterize and to calibrate the pressure drops. In future works the experimental results will be compared to the values predicted by the system code and differences will be discussed with the ultimate goal to qualify RELAP5-3D for the analysis of decay heat removal systems in natural circulation. The numerical data will be also used to understand the key parameters related to the heat transfer in natural circulation and to optimize the operation of the system.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUSMOS34A..06J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUSMOS34A..06J"><span>Connectivity of the South Florida Coral Reef Ecosystem to Upstream Waters of the Western Caribbean and Gulf of Mexico</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johns, E. M.; Smith, R. H.; Lamkin, J. T.; Birbriezca, L. C.; Vasquez-Yeomans, L.; Cordero, E. S.</p> <p>2008-05-01</p> <p>The coastal waters of south Florida, including the coral reefs of NOAA's Florida Keys National Marine Sanctuary (FKNMS), are directly connected by means of strong ocean currents with upstream waters of the western Caribbean Sea and the Gulf of Mexico. The Caribbean Current and the Loop Current provide a rapid conduit for transport from Mexican and Belizean coral reefs, located off the eastern shore of the Yucatan Peninsula, to nearshore regions of northern Cuba, Florida, and the Bahamas. Interdisciplinary cruise data collected in August 2002, March 2006 and January 2007 aboard the NOAA Ship Gordon Gunter, in combination with satellite-tracked surface drifter trajectories and remote sensing imagery, clearly show the highly variable and dynamic nature of the regional current regimes and provide a means of quantifying the potential pathways and transport rates of the coastal waters and their biological and chemical constituents from one region to another. Results from these cruises and ancillary data show that the study areas are connected with rapid transport time scales, and that frontal eddies and gyres play an important role in establishing the time and length scales of this connectivity. Such direct physical connectivity between the coral reef biota of these geographically separated spawning grounds via ocean currents may have an important influence on the degree of biological connectivity between regional larval populations. Initial analyses of ichthyoplankton surveys and inshore collections along the Yucatan mesoamerican reef suggest large scale variability in both local recruitment and large scale spatial distribution. Despite strong northward flowing currents, inshore collections indicate that local recruitment in some areas is strongly influenced by small scale circulation patterns. However, the distribution of spawning aggregations along the Yucatan coast suggests a larger role for the Caribbean Current. Determining the interactions between the larger scale circulation patterns and the smaller scale biological processes is a key research objective for understanding the observed regional population connections.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhRvB..85e4425J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhRvB..85e4425J"><span>Itinerant electrons in the Coulomb phase</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jaubert, L. D. C.; Piatecki, Swann; Haque, Masudul; Moessner, R.</p> <p>2012-02-01</p> <p>We study the interplay between magnetic frustration and itinerant electrons. For example, how does the coupling to mobile charges modify the properties of a spin liquid, and does the underlying frustration favor insulating or conducting states? Supported by Monte Carlo simulations, our goal is in particular to provide an analytical picture of the mechanisms involved. The models under consideration exhibit Coulomb phases in two and three dimensions, where the itinerant electrons are coupled to the localized spins via double exchange interactions. Because of the Hund coupling, magnetic loops naturally emerge from the Coulomb phase and serve as conducting channels for the mobile electrons, leading to doping-dependent rearrangements of the loop ensemble in order to minimize the electronic kinetic energy. At low electron density ρ, the double exchange coupling mainly tends to segment the very long loops winding around the system into smaller ones while it gradually lifts the extensive degeneracy of the Coulomb phase with increasing ρ. For higher doping, the results are strongly lattice dependent, displaying loop crystals with a given loop length for some specific values of ρ. By varying ρ, they can melt into different mixtures of these loop crystals, recovering extensive degeneracy in the process. Finally, we contrast this to the qualitatively different behavior of analogous models on kagome or triangular lattices.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22661301-observable-signatures-energy-release-braided-coronal-loops','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22661301-observable-signatures-energy-release-braided-coronal-loops"><span>Observable Signatures of Energy Release in Braided Coronal Loops</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Pontin, D. I.; Janvier, M.; Tiwari, S. K.</p> <p></p> <p>We examine the turbulent relaxation of solar coronal loops containing non-trivial field line braiding. Such field line tangling in the corona has long been postulated in the context of coronal heating models. We focus on the observational signatures of energy release in such braided magnetic structures using MHD simulations and forward modeling tools. The aim is to answer the following question: if energy release occurs in a coronal loop containing braided magnetic flux, should we expect a clearly observable signature in emissions? We demonstrate that the presence of braided magnetic field lines does not guarantee a braided appearance to themore » observed intensities. Observed intensities may—but need not necessarily—reveal the underlying braided nature of the magnetic field, depending on the degree and pattern of the field line tangling within the loop. However, in all cases considered, the evolution of the braided loop is accompanied by localized heating regions as the loop relaxes. Factors that may influence the observational signatures are discussed. Recent high-resolution observations from Hi-C have claimed the first direct evidence of braided magnetic fields in the corona. Here we show that both the Hi-C data and some of our simulations give the appearance of braiding at a range of scales.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18761102','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18761102"><span>A dihydropyridine receptor alpha1s loop region critical for skeletal muscle contraction is intrinsically unstructured and binds to a SPRY domain of the type 1 ryanodine receptor.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cui, Yanfang; Tae, Han-Shen; Norris, Nicole C; Karunasekara, Yamuna; Pouliquin, Pierre; Board, Philip G; Dulhunty, Angela F; Casarotto, Marco G</p> <p>2009-03-01</p> <p>The II-III loop of the dihydropyridine receptor (DHPR) alpha(1s) subunit is a modulator of the ryanodine receptor (RyR1) Ca(2+) release channel in vitro and is essential for skeletal muscle contraction in vivo. Despite its importance, the structure of this loop has not been reported. We have investigated its structure using a suite of NMR techniques which revealed that the DHPR II-III loop is an intrinsically unstructured protein (IUP) and as such belongs to a burgeoning structural class of functionally important proteins. The loop does not possess a stable tertiary fold: it is highly flexible, with a strong N-terminal helix followed by nascent helical/turn elements and unstructured segments. Its residual structure is loosely globular with the N and C termini in close proximity. The unstructured nature of the II-III loop may allow it to easily modify its interaction with RyR1 following a surface action potential and thus initiate rapid Ca(2+) release and contraction. The in vitro binding partner for the II-III was investigated. The II-III loop interacts with the second of three structurally distinct SPRY domains in RyR1, whose function is unknown. This interaction occurs through two preformed N-terminal alpha-helical regions and a C-terminal hydrophobic element. The A peptide corresponding to the helical N-terminal region is a common probe of RyR function and binds to the same SPRY domain as the full II-III loop. Thus the second SPRY domain is an in vitro binding site for the II-III loop. The possible in vivo role of this region is discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1179513-tropical-meteorology-climate-hadley-circulation','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1179513-tropical-meteorology-climate-hadley-circulation"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Lu, Jian; Vecchi, Gabriel A.</p> <p></p> <p>The Hadley circulation, a prominent circulation feature characterized by rising air near the Equator and sinking air in the subtropics, defines the position of dry subtropical areas and is a fundamental regulator of the earth’s energy and momentum budgets. The character of the Hadley circulation, and its related precipitation regimes, exhibits variation and change in response to both climate variability and radiative forcing changes. The strength and position of the Hadley circulation change from year to year paced by El Niño and La Niña events. Over the last few decades of the twentieth century, the Hadley cell has expanded polewardmore » in both hemispheres, with changes in atmospheric composition (including stratospheric ozone depletion and greenhouse gas increases) thought to have contributed to its expansion. This article introduces the basic phenomenology and driving mechanism of the Hadley circulation and discusses its variations under both natural and anthropogenic climate forcings.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20000057039&hterms=methanol+fuel+cells&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmethanol%2Bfuel%2Bcells','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20000057039&hterms=methanol+fuel+cells&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmethanol%2Bfuel%2Bcells"><span>Design and Operation of an Electrochemical Methanol Concentration Sensor for Direct Methanol Fuel Cell Systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Narayanan, S. R.; Valdez, T. I.; Chun, W.</p> <p>2000-01-01</p> <p>The development of a 150-Watt packaged power source based on liquid feed direct methanol fuel cells is being pursued currently at the Jet propulsion Laboratory for defense applications. In our studies we find that the concentration of methanol in the fuel circulation loop affects the electrical performance and efficiency the direct methanol fuel cell systems significantly. The practical operation of direct methanol fuel cell systems, therefore, requires accurate monitoring and control of methanol concentration. The present paper reports on the principle and demonstration of an in-house developed electrochemical sensor suitable for direct methanol fuel cell systems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012APS..MARA54014K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012APS..MARA54014K"><span>Loops in hierarchical channel networks</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Katifori, Eleni; Magnasco, Marcelo</p> <p>2012-02-01</p> <p>Nature provides us with many examples of planar distribution and structural networks having dense sets of closed loops. An archetype of this form of network organization is the vasculature of dicotyledonous leaves, which showcases a hierarchically-nested architecture. Although a number of methods have been proposed to measure aspects of the structure of such networks, a robust metric to quantify their hierarchical organization is still lacking. We present an algorithmic framework that allows mapping loopy networks to binary trees, preserving in the connectivity of the trees the architecture of the original graph. We apply this framework to investigate computer generated and natural graphs extracted from digitized images of dicotyledonous leaves and animal vasculature. We calculate various metrics on the corresponding trees and discuss the relationship of these quantities to the architectural organization of the original graphs. This algorithmic framework decouples the geometric information from the metric topology (connectivity and edge weight) and it ultimately allows us to perform a quantitative statistical comparison between predictions of theoretical models and naturally occurring loopy graphs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4574113','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4574113"><span>Changes in Microbial Plankton Assemblages Induced by Mesoscale Oceanographic Features in the Northern Gulf of Mexico</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Williams, Alicia K.; McInnes, Allison S.; Rooker, Jay R.; Quigg, Antonietta</p> <p>2015-01-01</p> <p>Mesoscale circulation generated by the Loop Current in the Northern Gulf of Mexico (NGOM) delivers growth-limiting nutrients to the microbial plankton of the euphotic zone. Consequences of physicochemically driven community shifts on higher order consumers and subsequent impacts on the biological carbon pump remain poorly understood. This study evaluates microbial plankton <10 μm abundance and community structure across both cyclonic and anti-cyclonic circulation features in the NGOM using flow cytometry (SYBR Green I and autofluorescence parameters). Non-parametric multivariate hierarchical cluster analyses indicated that significant spatial variability in community structure exists such that stations that clustered together were defined as having a specific ‘microbial signature’ (i.e. statistically homogeneous community structure profiles based on relative abundance of microbial groups). Salinity and a combination of sea surface height anomaly and sea surface temperature were determined by distance based linear modeling to be abiotic predictor variables significantly correlated to changes in microbial signatures. Correlations between increased microbial abundance and availability of nitrogen suggest nitrogen-limitation of microbial plankton in this open ocean area. Regions of combined coastal water entrainment and mesoscale convergence corresponded to increased heterotrophic prokaryote abundance relative to autotrophic plankton. The results provide an initial assessment of how mesoscale circulation potentially influences microbial plankton abundance and community structure in the NGOM. PMID:26375709</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSH41E..03X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSH41E..03X"><span>Formation and plasma circulation of solar prominences and coronal rains</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xia, C.</p> <p>2016-12-01</p> <p>Solar prominences are long-lived cool and dense plasma curtains in the hot and rarefied corona. The physical mechanism responsible for their formation and especially for their internal plasma circulation has been uncertain for decades. The observed ubiquitous down flows in quiescent prominences are difficult to interpret as plasma with high conductivity seems to move across horizontal magnetic field lines. Here we present three-dimensional (3D) numerical simulations of prominence formation and evolution in an elongated magnetic flux rope as a result of in-situ plasma condensations fueled by continuous plasma evaporation from the solar chromosphere. The prominence is born and maintained in a fragmented, highly dynamic state with continuous reappearance of multiple blobs and thread structures that move mainly downward dragging along mass-loaded field lines. The prominence plasma circulation is characterized by the dynamic balance between the drainage of prominence plasma back to the chromosphere and the formation of prominence plasma via continuous condensation. Plasma evaporates from the chromosphere, condenses into the prominence in the corona, and drains back to the chromosphere, establishing a stable chromosphere-corona plasma cycle. Another form of cool and dense plasma in the corona is coronal rain, which forms in-situ and drain down arched pathways along loops near active regions. We present 3D simulations of coronal rain in a bipolar arcade and compare it with observational results.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12897410','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12897410"><span>Influence of the direct NO-donor SIN-1 on the interaction between platelets and stainless steel stents under dynamic conditions.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jung, F; Mrowietz, C; Seyfert, U T; Grewe, R; Franke, R P</p> <p>2003-01-01</p> <p>It was investigated whether the NO-donor SIN-1, the active metabolite of molsidomine, influenced the activation of platelets, the formation of circulating platelet aggregates, the spontaneous aggregation of platelets and the activation of the clotting system triggered by a body foreign surface in an in vitro closed-loop perfusion model. With human platelet-rich plasma at micromolar concentrations SIN-1 exerted pronounced effects on the interaction between platelets and an exogenous surface. In the absence of SIN-1, the number of circulating single platelets decreased significantly, which could be due either to the formation of circulating platelet aggregates or to the adhesion of platelets to the stent. Both these processes were blocked by the addition of SIN-1. Moreover, the platelets exhibited hyperaggregability in the absence of SIN-1 whereas the NO-donor was able to completely inhibit spontaneous platelet aggregation. Similar results were obtained in flow cytometry experiments. Without SIN-1, high platelet surface densities of both the GPIb/IX and GPIIb/IIIa receptors were observed. In addition, the density of the fibrinogen receptor increased significantly with the number of perfusion cycles. SIN-1 was able to suppress the augmented GPIIb/IIIa receptor expression significantly. Molsidomine seemed to have the potential to reduce the incidence of thrombotic processes triggered by the exogenous surface of the stent.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23343002','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23343002"><span>An integrated approach to patient-specific predictive modeling for single ventricle heart palliation.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Corsini, Chiara; Baker, Catriona; Kung, Ethan; Schievano, Silvia; Arbia, Gregory; Baretta, Alessia; Biglino, Giovanni; Migliavacca, Francesco; Dubini, Gabriele; Pennati, Giancarlo; Marsden, Alison; Vignon-Clementel, Irene; Taylor, Andrew; Hsia, Tain-Yen; Dorfman, Adam</p> <p>2014-01-01</p> <p>In patients with congenital heart disease and a single ventricle (SV), ventricular support of the circulation is inadequate, and staged palliative surgery (usually 3 stages) is needed for treatment. In the various palliative surgical stages individual differences in the circulation are important and patient-specific surgical planning is ideal. In this study, an integrated approach between clinicians and engineers has been developed, based on patient-specific multi-scale models, and is here applied to predict stage 2 surgical outcomes. This approach involves four distinct steps: (1) collection of pre-operative clinical data from a patient presenting for SV palliation, (2) construction of the pre-operative model, (3) creation of feasible virtual surgical options which couple a three-dimensional model of the surgical anatomy with a lumped parameter model (LPM) of the remainder of the circulation and (4) performance of post-operative simulations to aid clinical decision making. The pre-operative model is described, agreeing well with clinical flow tracings and mean pressures. Two surgical options (bi-directional Glenn and hemi-Fontan operations) are virtually performed and coupled to the pre-operative LPM, with the hemodynamics of both options reported. Results are validated against postoperative clinical data. Ultimately, this work represents the first patient-specific predictive modeling of stage 2 palliation using virtual surgery and closed-loop multi-scale modeling.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1195800','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1195800"><span>Displacement Fields and Self-Energies of Circular and Polygonal Dislocation Loops in Homogeneous and Layered Anisotropic Solids</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gao, Yanfei; Larson, Ben C.</p> <p></p> <p>There are large classes of materials problems that involve the solutions of stress, displacement, and strain energy of dislocation loops in elastically anisotropic solids, including increasingly detailed investigations of the generation and evolution of irradiation induced defect clusters ranging in sizes from the micro- to meso-scopic length scales. Based on a two-dimensional Fourier transform and Stroh formalism that are ideal for homogeneous and layered anisotropic solids, we have developed robust and computationally efficient methods to calculate the displacement fields for circular and polygonal dislocation loops. Using the homogeneous nature of the Green tensor of order -1, we have shown thatmore » the displacement and stress fields of dislocation loops can be obtained by numerical quadrature of a line integral. In addition, it is shown that the sextuple integrals associated with the strain energy of loops can be represented by the product of a pre-factor containing elastic anisotropy effects and a universal term that is singular and equal to that for elastic isotropic case. Furthermore, we have found that the self-energy pre-factor of prismatic loops is identical to the effective modulus of normal contact, and the pre-factor of shear loops differs from the effective indentation modulus in shear by only a few percent. These results provide a convenient method for examining dislocation reaction energetic and efficient procedures for numerical computation of local displacements and stresses of dislocation loops, both of which play integral roles in quantitative defect analyses within combined experimental–theoretical investigations.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1195800-displacement-fields-self-energies-circular-polygonal-dislocation-loops-homogeneous-layered-anisotropic-solids','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1195800-displacement-fields-self-energies-circular-polygonal-dislocation-loops-homogeneous-layered-anisotropic-solids"><span>Displacement Fields and Self-Energies of Circular and Polygonal Dislocation Loops in Homogeneous and Layered Anisotropic Solids</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Gao, Yanfei; Larson, Ben C.</p> <p>2015-06-19</p> <p>There are large classes of materials problems that involve the solutions of stress, displacement, and strain energy of dislocation loops in elastically anisotropic solids, including increasingly detailed investigations of the generation and evolution of irradiation induced defect clusters ranging in sizes from the micro- to meso-scopic length scales. Based on a two-dimensional Fourier transform and Stroh formalism that are ideal for homogeneous and layered anisotropic solids, we have developed robust and computationally efficient methods to calculate the displacement fields for circular and polygonal dislocation loops. Using the homogeneous nature of the Green tensor of order -1, we have shown thatmore » the displacement and stress fields of dislocation loops can be obtained by numerical quadrature of a line integral. In addition, it is shown that the sextuple integrals associated with the strain energy of loops can be represented by the product of a pre-factor containing elastic anisotropy effects and a universal term that is singular and equal to that for elastic isotropic case. Furthermore, we have found that the self-energy pre-factor of prismatic loops is identical to the effective modulus of normal contact, and the pre-factor of shear loops differs from the effective indentation modulus in shear by only a few percent. These results provide a convenient method for examining dislocation reaction energetic and efficient procedures for numerical computation of local displacements and stresses of dislocation loops, both of which play integral roles in quantitative defect analyses within combined experimental–theoretical investigations.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title36-vol1/pdf/CFR-2012-title36-vol1-sec9-36.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title36-vol1/pdf/CFR-2012-title36-vol1-sec9-36.pdf"><span>36 CFR 9.36 - Plan of operations.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... and characteristics of the proposed circulating medium or mediums to be employed for rotary drilling... regulations; (16) Background information, including: (i) A description of the natural, cultural, social and... indirect effects of the operations on the unit's natural, cultural, social, and economic environment; (iii...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title36-vol1/pdf/CFR-2011-title36-vol1-sec9-36.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title36-vol1/pdf/CFR-2011-title36-vol1-sec9-36.pdf"><span>36 CFR 9.36 - Plan of operations.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... and characteristics of the proposed circulating medium or mediums to be employed for rotary drilling... regulations; (16) Background information, including: (i) A description of the natural, cultural, social and... indirect effects of the operations on the unit's natural, cultural, social, and economic environment; (iii...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title36-vol1/pdf/CFR-2014-title36-vol1-sec9-36.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title36-vol1/pdf/CFR-2014-title36-vol1-sec9-36.pdf"><span>36 CFR 9.36 - Plan of operations.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... and characteristics of the proposed circulating medium or mediums to be employed for rotary drilling... regulations; (16) Background information, including: (i) A description of the natural, cultural, social and... indirect effects of the operations on the unit's natural, cultural, social, and economic environment; (iii...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title36-vol1/pdf/CFR-2013-title36-vol1-sec9-36.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title36-vol1/pdf/CFR-2013-title36-vol1-sec9-36.pdf"><span>36 CFR 9.36 - Plan of operations.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... and characteristics of the proposed circulating medium or mediums to be employed for rotary drilling... regulations; (16) Background information, including: (i) A description of the natural, cultural, social and... indirect effects of the operations on the unit's natural, cultural, social, and economic environment; (iii...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title36-vol1/pdf/CFR-2010-title36-vol1-sec9-36.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title36-vol1/pdf/CFR-2010-title36-vol1-sec9-36.pdf"><span>36 CFR 9.36 - Plan of operations.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... and characteristics of the proposed circulating medium or mediums to be employed for rotary drilling... regulations; (16) Background information, including: (i) A description of the natural, cultural, social and... indirect effects of the operations on the unit's natural, cultural, social, and economic environment; (iii...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3583913','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3583913"><span>NK cell-released exosomes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fais, Stefano</p> <p>2013-01-01</p> <p>We have recently reported that human natural killer (NK) cells release exosomes that express both NK-cell markers and cytotoxic molecules. Similar results were obtained with circulating exosomes from human healthy donors. Both NK-cell derived and circulating exosomes exerted a full functional activity and killed both tumor and activated immune cells. These findings indicate that NK-cell derived exosomes might constitute a new promising therapeutic tool. PMID:23482694</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17662044','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17662044"><span>Characterization of human invariant natural killer T subsets in health and disease using a novel invariant natural killer T cell-clonotypic monoclonal antibody, 6B11.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Montoya, Carlos J; Pollard, David; Martinson, Jeffrey; Kumari, Kumud; Wasserfall, Clive; Mulder, Candice B; Rugeles, Maria T; Atkinson, Mark A; Landay, Alan L; Wilson, S Brian</p> <p>2007-09-01</p> <p>Identification of human CD1d-restricted T-cell receptor (TCR)-invariant natural killer T (iNKT) cells has been dependent on utilizing combinations of monoclonal antibodies or CD1d tetramers, which do not allow for the most specific analysis of this T-cell subpopulation. A novel monoclonal antibody (clone 6B11), specific for the invariant CDR3 loop of human canonical Valpha24Jalpha18 TCR alpha chain, was developed and used to specifically characterize iNKT cells. In healthy individuals studied for up to 1 year, a wide but stable frequency of circulating iNKT cells (range: 0.01-0.92%) was observed, with no differences in frequency by gender. Four stable iNKT cell subsets were characterized in peripheral blood based on the expression of CD4 and CD8, with CD8(+) iNKT cells being a phenotypic and functionally different subset from CD4(+) and double negative iNKT cells; in particular, LAG-3 was preferentially expressed on CD8(+) iNKT cells. In addition, a strong negative linear correlation between the frequency of total iNKT cells and percentage of the CD4(+) subset was observed. In terms of their potential association with disease, patients at risk for type 1 diabetes had significantly expanded frequencies of double negative iNKT cells when compared to matched controls and first-degree relatives. Moreover, peripheral blood CD4(+) iNKT cells were the highest producers of interleukin-4, while the production of interferon-gamma and tumour necrosis factor-alpha was similar amongst all iNKT cell subsets. These differences in iNKT cell subsets suggest that in humans the relative ratio of iNKT cell subsets may influence susceptibility vs. resistance to immune-mediated diseases.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2265989','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2265989"><span>Characterization of human invariant natural killer T subsets in health and disease using a novel invariant natural killer T cell-clonotypic monoclonal antibody, 6B11</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Montoya, Carlos J; Pollard, David; Martinson, Jeffrey; Kumari, Kumud; Wasserfall, Clive; Mulder, Candice B; Rugeles, Maria T; Atkinson, Mark A; Landay, Alan L; Wilson, S Brian</p> <p>2007-01-01</p> <p>Identification of human CD1d-restricted T-cell receptor (TCR)-invariant natural killer T (iNKT) cells has been dependent on utilizing combinations of monoclonal antibodies or CD1d tetramers, which do not allow for the most specific analysis of this T-cell subpopulation. A novel monoclonal antibody (clone 6B11), specific for the invariant CDR3 loop of human canonical Vα24Jα18 TCR α chain, was developed and used to specifically characterize iNKT cells. In healthy individuals studied for up to 1 year, a wide but stable frequency of circulating iNKT cells (range: 0·01–0·92%) was observed, with no differences in frequency by gender. Four stable iNKT cell subsets were characterized in peripheral blood based on the expression of CD4 and CD8, with CD8+ iNKT cells being a phenotypic and functionally different subset from CD4+ and double negative iNKT cells; in particular, LAG-3 was preferentially expressed on CD8+ iNKT cells. In addition, a strong negative linear correlation between the frequency of total iNKT cells and percentage of the CD4+ subset was observed. In terms of their potential association with disease, patients at risk for type 1 diabetes had significantly expanded frequencies of double negative iNKT cells when compared to matched controls and first-degree relatives. Moreover, peripheral blood CD4+ iNKT cells were the highest producers of interleukin-4, while the production of interferon-γ and tumour necrosis factor-α was similar amongst all iNKT cell subsets. These differences in iNKT cell subsets suggest that in humans the relative ratio of iNKT cell subsets may influence susceptibility vs. resistance to immune-mediated diseases. PMID:17662044</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...630680S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...630680S"><span>Antiferroelectric Nature of CH3NH3PbI3-xClx Perovskite and Its Implication for Charge Separation in Perovskite Solar Cells</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sewvandi, Galhenage A.; Kodera, Kei; Ma, Hao; Nakanishi, Shunsuke; Feng, Qi</p> <p>2016-07-01</p> <p>Perovskite solar cells (PSCs) have been attracted scientific interest due to high performance. Some researchers have suggested anomalous behavior of PSCs to the polarizations due to the ion migration or ferroelectric behavior. Experimental results and theoretical calculations have suggested the possibility of ferroelectricity in organic-inorganic perovskite. However, still no studies have been concretely discarded the ferroelectric nature of perovskite absorbers in PSCs. Hysteresis of P-E (polarization-electric field) loops is an important evidence to confirm the ferroelectricity. In this study, P-E loop measurements, in-depth structural study, analyses of dielectric behavior and the phase transitions of CH3NH3PbI3-xClx perovskite were carried out and investigated. The results suggest that CH3NH3PbI3-xClx perovskite is in an antiferroelectric phase at room temperature. The antiferroelectric phase can be switched to ferroelectric phase by the poling treatment and exhibits ferroelectric-like hysteresis P-E loops and dielectric behavior around room temperature; namely, the perovskite can generate a ferroelectric polarization under PSCs operating conditions. Furthermore, we also discuss the implications of ferroelectric polarization on PSCs charge separation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27468802','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27468802"><span>Antiferroelectric Nature of CH3NH3PbI3-xClx Perovskite and Its Implication for Charge Separation in Perovskite Solar Cells.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sewvandi, Galhenage A; Kodera, Kei; Ma, Hao; Nakanishi, Shunsuke; Feng, Qi</p> <p>2016-07-29</p> <p>Perovskite solar cells (PSCs) have been attracted scientific interest due to high performance. Some researchers have suggested anomalous behavior of PSCs to the polarizations due to the ion migration or ferroelectric behavior. Experimental results and theoretical calculations have suggested the possibility of ferroelectricity in organic-inorganic perovskite. However, still no studies have been concretely discarded the ferroelectric nature of perovskite absorbers in PSCs. Hysteresis of P-E (polarization-electric field) loops is an important evidence to confirm the ferroelectricity. In this study, P-E loop measurements, in-depth structural study, analyses of dielectric behavior and the phase transitions of CH3NH3PbI3-xClx perovskite were carried out and investigated. The results suggest that CH3NH3PbI3-xClx perovskite is in an antiferroelectric phase at room temperature. The antiferroelectric phase can be switched to ferroelectric phase by the poling treatment and exhibits ferroelectric-like hysteresis P-E loops and dielectric behavior around room temperature; namely, the perovskite can generate a ferroelectric polarization under PSCs operating conditions. Furthermore, we also discuss the implications of ferroelectric polarization on PSCs charge separation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..DFDD21006G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..DFDD21006G"><span>Open-loop control of quasiperiodic thermoacoustic oscillations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guan, Yu; Gupta, Vikrant; Kashinath, Karthik; Li, Larry K. B.</p> <p>2017-11-01</p> <p>The open-loop application of periodic acoustic forcing has been shown to be a potentially effective strategy for controlling periodic thermoacoustic oscillations, but its effectiveness on aperiodic thermoacoustic oscillations is less clear. In this experimental study, we apply periodic acoustic forcing to a ducted premixed flame oscillating quasiperiodically at two incommensurate natural frequencies, f1 and f2. We find that (i) above a critical forcing amplitude, the system locks into the forcing by oscillating only at the forcing frequency ff, producing a closed periodic orbit in phase space with no evidence of the original T2 torus attractor; (ii) the critical forcing amplitude required for lock-in decreases as ff approaches either f1 or f2, resulting in characteristic ∨-shaped lock-in boundaries around the two natural modes; and (iii) for a wide range of forcing frequencies, the system's oscillation amplitude can be reduced to less than 20% of that of the unforced system. These findings show that the open-loop application of periodic acoustic forcing can be an effective strategy for controlling aperiodic thermoacoustic oscillations. This work was supported by the Research Grants Council of Hong Kong (Project No. 16235716 and 26202815).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1039058-lysophospholipid-presentation-cd1d-recognition-human-natural-killer-cell-receptor','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1039058-lysophospholipid-presentation-cd1d-recognition-human-natural-killer-cell-receptor"><span>Lysophospholipid presentation by CD1d and recognition by a human Natural Killer T-cell receptor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>López-Sagaseta, Jacinto; Sibener, Leah V.; Kung, Jennifer E.</p> <p>2014-10-02</p> <p>Invariant Natural Killer T (iNKT) cells use highly restricted {alpha}{beta} T cell receptors (TCRs) to probe the repertoire of lipids presented by CD1d molecules. Here, we describe our studies of lysophosphatidylcholine (LPC) presentation by human CD1d and its recognition by a native, LPC-specific iNKT TCR. Human CD1d presenting LPC adopts an altered conformation from that of CD1d presenting glycolipid antigens, with a shifted {alpha}1 helix resulting in an open A pocket. Binding of the iNKT TCR requires a 7-{angstrom} displacement of the LPC headgroup but stabilizes the CD1d-LPC complex in a closed conformation. The iNKT TCR CDR loop footprint onmore » CD1d-LPC is anchored by the conserved positioning of the CDR3{alpha} loop, whereas the remaining CDR loops are shifted, due in part to amino-acid differences in the CDR3{beta} and J{beta} segment used by this iNKT TCR. These findings provide insight into how lysophospholipids are presented by human CD1d molecules and how this complex is recognized by some, but not all, human iNKT cells.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JSemi..39d5003W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JSemi..39d5003W"><span>A 5 Gb/s CMOS adaptive equalizer for serial link</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Hongbing; Wang, Jingyu; Liu, Hongxia</p> <p>2018-04-01</p> <p>A 5 Gb/s adaptive equalizer with a new adaptation scheme is presented here by using 0.13 μm CMOS process. The circuit consists of the combination of equalizer amplifier, limiter amplifier and adaptation loop. The adaptive algorithm exploits both the low frequency gain loop and the equalizer loop to minimize the inter-symbol interference (ISI) for a variety of cable characteristics. In addition, an offset cancellation loop is used to alleviate the offset influence of the signal path. The adaptive equalizer core occupies an area of 0.3567 mm2 and consumes a power consumption of 81.7 mW with 1.8 V power supply. Experiment results demonstrate that the equalizer could compensate for a designed cable loss with 0.23 UI peak-to-peak jitter. Project supported by the National Natural Science Foundation of China (No. 61376099), the Foundation for Fundamental Research of China (No. JSZL2016110B003), and the Major Fundamental Research Program of Shaanxi (No. 2017ZDJC-26).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810002580','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810002580"><span>Spacecraft momentum management procedures. [large space telescope</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chen, L. C.; Davenport, P. B.; Sturch, C. R.</p> <p>1980-01-01</p> <p>Techniques appropriate for implementation onboard the space telescope and other spacecraft to manage the accumulation of momentum in reaction wheel control systems using magnetic torquing coils are described. Generalized analytical equations are derived for momentum control laws that command the magnetic torquers. These control laws naturally fall into two main categories according to the methods used for updating the magnetic dipole command: closed loop, in which the update is based on current measurements to achieve a desired torque instantaneously, and open-loop, in which the update is based on predicted information to achieve a desired momentum at the end of a period of time. Physical interpretations of control laws in general and of the Space Telescope cross product and minimum energy control laws in particular are presented, and their merits and drawbacks are discussed. A technique for retaining the advantages of both the open-loop and the closed-loop control laws is introduced. Simulation results are presented to compare the performance of these control laws in the Space Telescope environment.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvL.120o7202C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvL.120o7202C"><span>Designing Hysteresis with Dipolar Chains</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Concha, Andrés; Aguayo, David; Mellado, Paula</p> <p>2018-04-01</p> <p>Materials that have hysteretic response to an external field are essential in modern information storage and processing technologies. A myriad of magnetization curves of several natural and artificial materials have previously been measured and each has found a particular mechanism that accounts for it. However, a phenomenological model that captures all the hysteresis loops and at the same time provides a simple way to design the magnetic response of a material while remaining minimal is missing. Here, we propose and experimentally demonstrate an elementary method to engineer hysteresis loops in metamaterials built out of dipolar chains. We show that by tuning the interactions of the system and its geometry we can shape the hysteresis loop which allows for the design of the softness of a magnetic material at will. Additionally, this mechanism allows for the control of the number of loops aimed to realize multiple-valued logic technologies. Our findings pave the way for the rational design of hysteretical responses in a variety of physical systems such as dipolar cold atoms, ferroelectrics, or artificial magnetic lattices, among others.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29756885','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29756885"><span>Designing Hysteresis with Dipolar Chains.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Concha, Andrés; Aguayo, David; Mellado, Paula</p> <p>2018-04-13</p> <p>Materials that have hysteretic response to an external field are essential in modern information storage and processing technologies. A myriad of magnetization curves of several natural and artificial materials have previously been measured and each has found a particular mechanism that accounts for it. However, a phenomenological model that captures all the hysteresis loops and at the same time provides a simple way to design the magnetic response of a material while remaining minimal is missing. Here, we propose and experimentally demonstrate an elementary method to engineer hysteresis loops in metamaterials built out of dipolar chains. We show that by tuning the interactions of the system and its geometry we can shape the hysteresis loop which allows for the design of the softness of a magnetic material at will. Additionally, this mechanism allows for the control of the number of loops aimed to realize multiple-valued logic technologies. Our findings pave the way for the rational design of hysteretical responses in a variety of physical systems such as dipolar cold atoms, ferroelectrics, or artificial magnetic lattices, among others.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990070924&hterms=McCormick&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DMcCormick','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990070924&hterms=McCormick&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DMcCormick"><span>Flight Test Results for the NICMOS Cryocooler</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dolan, F. X.; McCormick, J. A.; Nellis, G. F.; Sixsmith, H.; Swift, W. L.</p> <p>1999-01-01</p> <p>In October 1998 a mechanical cryocooler and cryogenic circulator loop were flown on NASA's STS-95 as part of the Hubble Orbital System Test (HOST). The system will be installed on the Hubble Space Telescope (HST) during Service Mission #3 in 2000 and will provide cooling to the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). It will extend the useful life of that instrument by 5 to 10 years. This was the first successful space demonstration of a turbobrayton cryocooler. The cooler is a single stage reverse Brayton type, using low-vibration high-speed miniature turbomachines for the compression and expansion functions. A miniature centrifugal cryogenic circulator is used to deliver refrigerated neon to the instrument. During the mission, the cooler operated without anomalies for approximately 185 hours over a range of conditions to verify its mechanical, thermodynamic and control functions. The cryocooler satisfied all mission objectives including maximum cooldown to near-design operating conditions, warm and cold starts and stops, operation at near-design temperatures, and demonstration of long-term temperature stability. This paper presents a description of the cooler and its operation during the HOST flight.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24972365','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24972365"><span>Development of an improved RT-LAMP assay for detection of currently circulating rubella viruses.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Abo, H; Okamoto, K; Anraku, M; Otsuki, N; Sakata, M; Icenogle, J; Zheng, Q; Kurata, T; Kase, T; Komase, K; Takeda, M; Mori, Y</p> <p>2014-10-01</p> <p>Rubella virus is the causative agent of rubella. The symptoms are usually mild, and characterized by a maculopapular rash and fever. However, rubella infection in pregnant women sometimes can result in the birth of infants with congenital rubella syndrome (CRS). Global efforts have been made to reduce and eliminate CRS. Although a reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay for detection of rubella virus has been reported, the primers contained several mismatched nucleotides with the genomes of currently circulating rubella virus strains. In the present study, a new RT-LAMP assay was established. The detection limit of this assay was 100-1000PFU/reaction of viruses for all rubella genotypes, except for genotype 2C, which is not commonly found in the current era. Therefore, the new RT-LAMP assay can successfully detect all current rubella virus genotypes, and does not require sophisticated devices like TaqMan real-time PCR systems. This assay should be a useful assay for laboratory diagnosis of rubella and CRS. Copyright © 2014 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27693728','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27693728"><span>Simulation of biomass-steam gasification in fluidized bed reactors: Model setup, comparisons and preliminary predictions.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yan, Linbo; Lim, C Jim; Yue, Guangxi; He, Boshu; Grace, John R</p> <p>2016-12-01</p> <p>A user-defined solver integrating the solid-gas surface reactions and the multi-phase particle-in-cell (MP-PIC) approach is built based on the OpenFOAM software. The solver is tested against experiments. Then, biomass-steam gasification in a dual fluidized bed (DFB) gasifier is preliminarily predicted. It is found that the predictions agree well with the experimental results. The bed material circulation loop in the DFB can form automatically and the bed height is about 1m. The voidage gradually increases along the height of the bed zone in the bubbling fluidized bed (BFB) of the DFB. The U-bend and cyclone can separate the syngas in the BFB and the flue gas in the circulating fluidized bed. The concentration of the gasification products is relatively higher in the conical transition section, and the dry and nitrogen-free syngas at the BFB outlet is predicted to be composed of 55% H 2 , 20% CO, 20% CO 2 and 5% CH 4 . Copyright © 2016 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/870997','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/870997"><span>Plasma wake field XUV radiation source</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Prono, Daniel S.; Jones, Michael E.</p> <p>1997-01-01</p> <p>A XUV radiation source uses an interaction of electron beam pulses with a gas to create a plasma radiator. A flowing gas system (10) defines a circulation loop (12) with a device (14), such as a high pressure pump or the like, for circulating the gas. A nozzle or jet (16) produces a sonic atmospheric pressure flow and increases the density of the gas for interacting with an electron beam. An electron beam is formed by a conventional radio frequency (rf) accelerator (26) and electron pulses are conventionally formed by a beam buncher (28). The rf energy is thus converted to electron beam energy, the beam energy is used to create and then thermalize an atmospheric density flowing gas to a fully ionized plasma by interaction of beam pulses with the plasma wake field, and the energetic plasma then loses energy by line radiation at XUV wavelengths Collection and focusing optics (18) are used to collect XUV radiation emitted as line radiation when the high energy density plasma loses energy that was transferred from the electron beam pulses to the plasma.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1177051','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1177051"><span>Closed Brayton cycle power conversion systems for nuclear reactors :</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wright, Steven A.; Lipinski, Ronald J.; Vernon, Milton E.</p> <p>2006-04-01</p> <p>This report describes the results of a Sandia National Laboratories internally funded research program to study the coupling of nuclear reactors to gas dynamic Brayton power conversion systems. The research focused on developing integrated dynamic system models, fabricating a 10-30 kWe closed loop Brayton cycle, and validating these models by operating the Brayton test-loop. The work tasks were performed in three major areas. First, the system equations and dynamic models for reactors and Closed Brayton Cycle (CBC) systems were developed and implemented in SIMULINKTM. Within this effort, both steady state and dynamic system models for all the components (turbines, compressors,more » reactors, ducting, alternators, heat exchangers, and space based radiators) were developed and assembled into complete systems for gas cooled reactors, liquid metal reactors, and electrically heated simulators. Various control modules that use proportional-integral-differential (PID) feedback loops for the reactor and the power-conversion shaft speed were also developed and implemented. The simulation code is called RPCSIM (Reactor Power and Control Simulator). In the second task an open cycle commercially available Capstone C30 micro-turbine power generator was modified to provide a small inexpensive closed Brayton cycle test loop called the Sandia Brayton test-Loop (SBL-30). The Capstone gas-turbine unit housing was modified to permit the attachment of an electrical heater and a water cooled chiller to form a closed loop. The Capstone turbine, compressor, and alternator were used without modification. The Capstone systems nominal operating point is 1150 K turbine inlet temperature at 96,000 rpm. The annular recuperator and portions of the Capstone control system (inverter) and starter system also were reused. The rotational speed of the turbo-machinery is controlled by adjusting the alternator load by using the electrical grid as the load bank. The SBL-30 test loop was operated at the manufacturers site (Barber-Nichols Inc.) and installed and operated at Sandia. A sufficiently detailed description of the loop is provided in this report along with the design characteristics of the turbo-alternator-compressor set to allow other researchers to compare their results with those measured in the Sandia test-loop. The third task consisted of a validation effort. In this task the test loop was operated and compared with the modeled results to develop a more complete understanding of this electrically heated closed power generation system and to validate the model. The measured and predicted system temperatures and pressures are in good agreement, indicating that the model is a reasonable representation of the test loop. Typical deviations between the model and the hardware results are less than 10%. Additional tests were performed to assess the capability of the Brayton engine to continue to remove decay heat after the reactor/heater is shutdown, to develop safe and effective control strategies, and to access the effectiveness of gas inventory control as an alternative means to provide load following. In one test the heater power was turned off to simulate a rapid reactor shutdown, and the turbomachinery was driven solely by the sensible heat stored in the heater for over 71 minutes without external power input. This is an important safety feature for CBC systems as it means that the closed Brayton loop will keep cooling the reactor without the need for auxiliary power (other than that needed to circulate the waste heat rejection coolant) provided the heat sink is available.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22391620-parametric-study-natural-circulation-flow-molten-salt-fuel-molten-salt-reactor','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22391620-parametric-study-natural-circulation-flow-molten-salt-fuel-molten-salt-reactor"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Pauzi, Anas Muhamad, E-mail: Anas@uniten.edu.my; Cioncolini, Andrea; Iacovides, Hector</p> <p></p> <p>The Molten Salt Reactor (MSR) is one of the most promising system proposed by Generation IV Forum (GIF) for future nuclear reactor systems. Advantages of the MSR are significantly larger compared to other reactor system, and is mainly achieved from its liquid nature of fuel and coolant. Further improvement to this system, which is a natural circulating molten fuel salt inside its tube in the reactor core is proposed, to achieve advantages of reducing and simplifying the MSR design proposed by GIF. Thermal hydraulic analysis on the proposed system was completed using a commercial computation fluid dynamics (CFD) software calledmore » FLUENT by ANSYS Inc. An understanding on theory behind this unique natural circulation flow inside the tube caused by fission heat generated in molten fuel salt and tube cooling was briefly introduced. Currently, no commercial CFD software could perfectly simulate natural circulation flow, hence, modeling this flow problem in FLUENT is introduced and analyzed to obtain best simulation results. Results obtained demonstrate the existence of periodical transient nature of flow problem, hence improvements in tube design is proposed based on the analysis on temperature and velocity profile. Results show that the proposed system could operate at up to 750MW core power, given that turbulence are enhanced throughout flow region, and precise molten fuel salt physical properties could be defined. At the request of the authors and the Proceedings Editor the name of the co-author Andrea Cioncolini was corrected from Andrea Coincolini. The same name correction was made in the Acknowledgement section on page 030004-10 and in reference number 4. The updated article was published on 11 May 2015.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=materialistic&pg=3&id=EJ944083','ERIC'); return false;" href="https://eric.ed.gov/?q=materialistic&pg=3&id=EJ944083"><span>"Romantic", "Classic" and "Baroque" Views of Nature: An Analysis of Pictures about the Environment in Greek Primary School Textbooks--Diachronic Considerations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Lemoni, Rea; Stamou, Anastasia G.; Stamou, George P.</p> <p>2011-01-01</p> <p>Taking the view that pictures are not a transparent but rather a deforming mirror of reality, shaping representations of the world bound up with the interests of the social institutions within which pictures are circulated and read, our aim is to explore what view of nature and of the human-nature relationship is built in Greek natural science…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160011194','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160011194"><span>Supra Arcade Downflows with XRT Informed by Dipolarization Fronts with THEMIS</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kobelski, Adam; Savage, Sabrina Leah; Malaspina, David</p> <p>2016-01-01</p> <p>Magnetic reconnection can rapidly reconfigure the magnetic field of the corona, accelerating plasma through the site of reconnection. Ambiguities due to the nature of remote sensing have complicated the interpretation of observations of the inflowing and outflowing plasma in reconnecting regions. In particular, the interpretation of sunward moving density depletions above flare arcades (known as Supra Arcade Downflows - SADs) is still debated. Hinode/XRT has provided a wealth of observations for SADs and helped inform our current understanding of these structures. SADs have been interpreted as wakes behind newly reconnected and outflowing loops (Supra Arcade Downflowing Loops - SADLs). Models have shown the plausibility of this interpretation, though this interpretation has not yet been fully accepted. We present here observations of newly reconnected outflowing loops observed via in situ instruments in the magnetosphere. These observations, provided by five THEMIS spacecraft, show that around retracting loops (dipolarization fronts in this context) similar dynamic temperature and density structures are found as seen in SADs. We compare data from multiple SADs and dipolarization fronts to show that the observational signatures implied in the corona can be directly observed in similar plasma regimes in the magnetosphere, strongly favoring the interpretation of SADs as wakes behind retracting loops.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhCS.655a2043C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhCS.655a2043C"><span>Effect of the application of an electric field on the performance of a two-phase loop device: preliminary results</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Creatini, F.; Di Marco, P.; Filippeschi, S.; Fioriti, D.; Mameli, M.</p> <p>2015-11-01</p> <p>In the last decade, the continuous development of electronics has pointed out the need for a change in mind with regard to thermal management. In the present scenario, Pulsating Heat Pipes (PHPs) are novel promising two-phase passive heat transport devices that seem to meet all present and future thermal requirements. Nevertheless, PHPs governing phenomena are quite unique and not completely understood. In particular, single closed loop PHPs manifest several drawbacks, mostly related to the reduction of device thermal performance and reliability, i.e. the occurrence of multiple operational quasi-steady states. The present research work proposes the application of an electric field as a technique to promote the circulation of the working fluid in a preferential direction and stabilize the device operation. The tested single closed loop PHP is made of a copper tube with an inner tube diameter equal to 2.00 mm and filled with pure ethanol (60% filling ratio). The electric field is generated by a couple of wire-shaped electrodes powered with DC voltage up to 20 kV and laid parallel to the longitudinal axis of the glass tube constituting the adiabatic section. Although the electric field intensity in the working fluid region is weakened both by the polarization phenomenon of the working fluid and by the interposition of the glass tube, the experimental results highlight the influence of the electric field on the device thermal performance and encourage the continuation of the research in this direction.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9448E..04G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9448E..04G"><span>Digital capillaroscopy as important tool for early diagnostics of arterial hypertension</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gurfinkel, Yu. I.; Sasonko, M. L.; Priezzhev, A. V.</p> <p>2015-03-01</p> <p>The study is aimed to determine the digital capillaroscopy possibilities in early diagnostics of an arterial hypertension. A total of 123 adult persons were examined in the study. The first group consisted of 40 patients with prehypertension (BP 130-139/85-89 mm Hg). The second group included 36 patients with 1-2 stage of hypertension (mean systolic BP 152.7±12 mm Hg). Patients in both groups did not receive regular drug therapy. The group of volunteers (n=47) included healthy adults without signs of cardiovascular pathology. The capillary circulation was examined on the nailbed using the optical digital capillaroscope developed by the company "AET", Russia. Diameters of the arterial and venous segments, perivascular zone size, capillary blood velocity, the degree of arterial loops narrowing and the density of the capillary network were estimated. In patients with arterial hypertension and even in patients with prehypertension remodeling and rarefaction of capillaries and the expressed narrowing their arterial loops were manifested. The results of the study revealed the presence of abnormalities of microcirculation parameters in patients of both groups. The capillaries density in both groups of patients was significantly lower than in healthy persons. The significant narrowing of arterial loops was revealed in patients with both arterial hypertension and prehypertension, in comparison with healthy volunteers. Capillary blood velocity did not differ significantly between healthy volunteers group and the group of prehypertensive patients. However in patients with hypertension this parameter was significantly lower in comparison with control group.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018CQGra..35d5009F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018CQGra..35d5009F"><span>Entanglement entropy and correlations in loop quantum gravity</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Feller, Alexandre; Livine, Etera R.</p> <p>2018-02-01</p> <p>Black hole entropy is one of the few windows into the quantum aspects of gravitation, and its study over the years has highlighted the holographic nature of gravity. At the non-perturbative level in quantum gravity, promising explanations are being explored in terms of the entanglement entropy between regions of space. In the context of loop quantum gravity, this translates into an analysis of the correlations between the regions of the spin network states defining the quantum state of the geometry of space. In this paper, we explore a class of states, motivated by results in condensed matter physics, satisfying an area law for entanglement entropy and having non-trivial correlations. We highlight that entanglement comes from holonomy operators acting on loops crossing the boundary of the region.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24359968','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24359968"><span>Real-time measurement of free thrombin: evaluation of the usability of a new thrombin assay for coagulation monitoring during extracorporeal circulation.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Krajewski, Stefanie; Krauss, Sabrina; Kurz, Julia; Neumann, Bernd; Schlensak, Christian; Wendel, Hans P</p> <p>2014-03-01</p> <p>In patients undergoing cardiac surgery with heart-lung machine support, adequate anticoagulation to mitigate blood clotting caused by the artificial surfaces of the extracorporeal circulation (ECC) system is essential. These patients routinely receive heparin, whose effectiveness is monitored by measurements of the activated clotting time (ACT). However, ACT values only poorly correlate with the actual hemostatic status. The aim of our study was to evaluate the detection of free thrombin in heparinized human blood as a monitor of anticoagulation during ECC. Human whole blood was anticoagulated with different concentrations of heparin (0.75, 1, 2 or 3 IU/ml) and circulated in the Chandler-loop model for up to 240 min at 37 °C. Next to ACT, ECC-mediated changes in free active thrombin, prothrombin fragment 1+2 (F1+2) and thrombin-antithrombin-III (TAT) levels were measured before and during circulation. Platelet activation and cell count parameters were further investigated. Our study shows that detection of ECC-mediated changes in free thrombin is possible in blood anticoagulated with 0.75 or 1 IU/ml heparin, whereas no thrombin was detectable at higher heparin concentrations. Thrombin generation during 240 min of ECC is comparable to F 1+2 and TAT plasma levels during ECC. Thrombin is the key enzyme in the coagulation cascade and hence represents a promising marker for monitoring the coagulation status of patients. Although detection of free thrombin was not feasible at high heparin concentrations, the employed test represents an additional test to current laboratory methods investigating blood coagulation at low heparin concentrations. Copyright © 2013 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999JGR...10420523V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999JGR...10420523V"><span>Ring-slope interactions and the formation of the western boundary current in the Gulf of Mexico</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vidal, VíCtor M. V.; Vidal, Francisco V.; Meza, Eustorgio; Portilla, Josué; Zambrano, Lorenzo; Jaimes, BenjamíN.</p> <p>1999-09-01</p> <p>Hydrographic data from the Gulf of Mexico (gulf) provide evidence that a western boundary current was set up by the interaction of an anticyclonic Loop Current (LC) ring with the continental margin of the western gulf during March-August 1985. The March 1985 geostrophic circulation reveals a remnant anticyclonic ring colliding with the slope. During this collision, two cyclonic rings were shed as the anticyclone transferred vorticity to the surrounding slope water. During July-August 1985, the ring triad weakened and evolved into a ˜900-km-long, north flowing, along-slope, western boundary current and cyclonic-anticyclonic ring pairs distributed throughout the central and western gulf. This western boundary current attained maximum northward flow speeds of 25 cm s-1 and an 8.3-Sv mass transport between 94°-96°W at 25°N. Our March-August 1985 observations reveal that the residence time and decay period of LC anticyclones in the western gulf may exceed 150 days. Within this time period the western gulf's cyclonic-anticyclonic vorticity field decayed ˜50%. Thus the western boundary current's evolutionary period, from its gestation to its absolute decay, is estimated to be of the order of 300 days. Although the presence of a western boundary current in the gulf has been attributed to the annual wind stress curl cycle [Sturges, 1993], our analyses of the western gulf March and July-August 1985 ring-driven geostrophic circulation and corresponding (January, February and May, June 1985) monthly mean synoptic wind stress curl distributions reveal that these constitute competing forcing mechanisms for the gulf's regional circulation. However, when very strong local forcing such as large eddies are present, the wind-driven background circulation is overwhelmed by such eddy forcing.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170002450','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170002450"><span>Impacts of Local Soil Moisture Anomalies on the Atmospheric Circulation and on Remote Surface Meteorological Fields During Boreal Summer: A Comprehensive Analysis over North America</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Koster, Randal D.; Chang, Yehui; Wang, Hailan; Schubert, Siegfried D.</p> <p>2016-01-01</p> <p>We perform a series of stationary wave model (SWM) experiments in which the boreal summer atmosphere is forced, over a number of locations in the continental U.S., with an idealized diabatic heating anomaly that mimics the atmospheric heating associated with a dry land surface. For localized heating within a large portion of the continental interior, regardless of the specific location of this heating, the spatial pattern of the forced atmospheric circulation anomaly (in terms of 250-mb eddy streamfunction) is largely the same: a high anomaly forms over west central North America and a low anomaly forms to the east. In supplemental atmospheric general circulation model (AGCM) experiments, we find similar results; imposing soil moisture dryness in the AGCM in different locations within the US interior tends to produce the aforementioned pattern, along with an associated near-surface warming and precipitation deficit in the center of the continent. The SWM-based and AGCM-based patterns generally agree with composites generated using reanalysis and precipitation gauge data. The AGCM experiments also suggest that dry anomalies imposed in the lower Mississippi Valley have remote surface impacts of particularly large spatial extent, and a region along the eastern half of the US-Canada border is particularly sensitive to dry anomalies in a number of remote areas. Overall, the SWM and AGCM experiments support the idea of a positive feedback loop operating over the continent: dry surface conditions in many interior locations lead to changes in atmospheric circulation that act to enhance further the overall dryness of the continental interior.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017CQGra..34j7001C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017CQGra..34j7001C"><span>A note on the Poisson bracket of 2d smeared fluxes in loop quantum gravity</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cattaneo, Alberto S.; Perez, Alejandro</p> <p>2017-05-01</p> <p>We show that the non-Abelian nature of geometric fluxes—the corner-stone in the definition of quantum geometry in the framework of loop quantum gravity (LQG)—follows directly form the continuum canonical commutations relations of gravity in connection variables and the validity of the Gauss law. The present treatment simplifies previous formulations and thus identifies more clearly the root of the discreteness of geometric operators in LQG. Our statement generalizes to arbitrary gauge theories and relies only on the validity of the Gauss law.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ClDy...46.3387Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ClDy...46.3387Y"><span>Wind effect on the Atlantic meridional overturning circulation via sea ice and vertical diffusion</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Haijun; Wang, Kun; Dai, Haijin; Wang, Yuxing; Li, Qing</p> <p>2016-06-01</p> <p>Effects of wind and fresh water on the Atlantic meridional overturning circulation (AMOC) are investigated using a fully coupled climate model. The AMOC can change significantly when perturbed by either wind stress or freshwater flux in the North Atlantic. This study focuses on wind stress effect. Our model results show that the wind forcing is crucial in maintaining the AMOC. Reducing wind forcing over the ocean can cause immediately weakening of the vertical salinity diffusion and convection in the mid-high latitudes Atlantic, resulting in an enhancement of vertical salinity stratification that restrains the deep water formation there, triggering a slowdown of the thermohaline circulation. As the thermohaline circulation weakens, the sea ice expands southward and melts, providing the upper ocean with fresh water that weakens the thermohaline circulation further. The wind perturbation experiments suggest a positive feedback between sea-ice and thermohaline circulation strength, which can eventually result in a complete shutdown of the AMOC. This study also suggests that sea-ice variability may be also important to the natural AMOC variability on decadal and longer timescales.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.9630O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.9630O"><span>Greenland meltwater experiments</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Olsen, S. M.; Schmith, T.</p> <p>2012-04-01</p> <p>We explore the climatic response to additional Greenland Ice Sheet melting in the EC-EARTH coupled climate model. As reference runs, we use an ensemble of two simulations from 1850 to present with historic forcing. For each of these we pick the years 1935,1950 and 1965, respectively as initial conditions for perturbed experiments with an additional freshwater forcing of 0.1 Sv distributed uniformly around Greenland , a plausible value in the upper end of future Greenland ice sheet melt estimates. We find give no evidence for abrupt transitions associated with tipping points in the Atlantic overturning circulation and mid-latitude heat transport. In fact, modelled decline in overturning in response to the additional forcing does not project onto a comparable reduction in the mid latitude (36N) ocean heat transport. This result points to an ongoing watermass transformation in the subpolar region and Arctic Mediterranean as a whole and a continued thermal mode of operation of the overturning. At the northern boundary of the subpolar region (60N) the response in overturning shows a contrasting increase in intensity along with an increase in heat transport. Whereas the latter may be expected as a result of freshwater capping and subsurface warming in the subpolar region, the increased overturning at 60N is more difficult to explain. In order to assess this in more detail we have quantified the individual thermohaline exchange components of light and dense water masses across the Greenland-Scotland Ridge. We find that the intensified overturning at 60N is reflected in increased transports of light Atlantic Water to the Nordic Seas. However, the vertical, thermohalinie overturning loop is not equally strengthened. On the contrary, we model a decline in the denser parts of the outflow, the overflows in the Denmark Strait and Faroe Bank Channel and a strong increase in the polar outflow in the Denmark Strait. We observe a gradual transition from a vertical mode of operation with 70% of the Atlantic Inflow being transformed to dense overflow towards a state approaching an equal contribution of the vertical and horizontal thermohaline circulation loops after 20-30 years. Along with this transition we find an overall decline in the intensity of the barotropic gyre circulation of the Nordic Seas reflecting in part a reduced winter deepening of the mixed layer. Thus, we may seek to explain this transition as a result of more efficient lateral mixing of the Atlantic Inflow during its cyclonic circulation around the basin margins. Finally, we show that the associated atmospheric response is a standing Rossby wave train reflected in the mean tropospheric thickness anomaly field with a through over Labrador Sea, a ridge over Barents Sea and a minor through over eastern Europe. Corresponding anomalies are found in the surface temperature field.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApJ...855...52F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApJ...855...52F"><span>On the Occurrence of Thermal Nonequilibrium in Coronal Loops</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Froment, C.; Auchère, F.; Mikić, Z.; Aulanier, G.; Bocchialini, K.; Buchlin, E.; Solomon, J.; Soubrié, E.</p> <p>2018-03-01</p> <p>Long-period EUV pulsations, recently discovered to be common in active regions, are understood to be the coronal manifestation of thermal nonequilibrium (TNE). The active regions previously studied with EIT/Solar and Heliospheric Observatory and AIA/SDO indicated that long-period intensity pulsations are localized in only one or two loop bundles. The basic idea of this study is to understand why. For this purpose, we tested the response of different loop systems, using different magnetic configurations, to different stratifications and strengths of the heating. We present an extensive parameter-space study using 1D hydrodynamic simulations (1020 in total) and conclude that the occurrence of TNE requires specific combinations of parameters. Our study shows that the TNE cycles are confined to specific ranges in parameter space. This naturally explains why only some loops undergo constant periodic pulsations over several days: since the loop geometry and the heating properties generally vary from one loop to another in an active region, only the ones in which these parameters are compatible exhibit TNE cycles. Furthermore, these parameters (heating and geometry) are likely to vary significantly over the duration of a cycle, which potentially limits the possibilities of periodic behavior. This study also confirms that long-period intensity pulsations and coronal rain are two aspects of the same phenomenon: both phenomena can occur for similar heating conditions and can appear simultaneously in the simulations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JHEP...06..023A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JHEP...06..023A"><span>All-loop Mondrian diagrammatics and 4-particle amplituhedron</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>An, Yang; Li, Yi; Li, Zhinan; Rao, Junjie</p> <p>2018-06-01</p> <p>Based on 1712.09990 which handles the 4-particle amplituhedron at 3-loop, we have found an extremely simple pattern, yet far more non-trivial than one might naturally expect: the all-loop Mondrian diagrammatics. By further simplifying and rephrasing the key relation of positivity in the amplituhedron setting, remarkably, we find a completeness relation unifying all diagrams of the Mondrian types for the 4-particle integrand of planar N = 4 SYM to all loop orders, each of which can be mapped to a simple product following a few plain rules designed for this relation. The explicit examples we investigate span from 3-loop to 7-loop order, and based on them, we classify the basic patterns of Mondrian diagrams into four types: the ladder, cross, brick-wall and spiral patterns. Interestingly, for some special combinations of ordered subspaces (a concept defined in the previous work), we find failed exceptions of the completeness relation which are called "anomalies", nevertheless, they substantially give hints on the all-loop recursive proof of this relation. These investigations are closely related to the combinatoric knowledge of separable permutations and Schröder numbers, and go even further from a diagrammatic perspective. For physical relevance, we need to further consider dual conformal invariance for two basic diagrammatic patterns to correct the numerator for a local integrand involving one or both of such patterns, while the denominator encoding its pole structure and also the sign factor, are already fixed by rules of the completeness relation. With this extra treatment to ensure the integrals are dual conformally invariant, each Mondrian diagram can be exactly translated to its corresponding physical loop integrand after being summed over all ordered subspaces that admit it.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/6422715','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/6422715"><span>Thermal-hydraulic simulation of natural convection decay heat removal in the High Flux Isotope Reactor (HFIR) using RELAP5 and TEMPEST: Part 2, Interpretation and validation of results</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ruggles, A.E.; Morris, D.G.</p> <p></p> <p>The RELAP5/MOD2 code was used to predict the thermal-hydraulic behavior of the HFIR core during decay heat removal through boiling natural circulation. The low system pressure and low mass flux values associated with boiling natural circulation are far from conditions for which RELAP5 is well exercised. Therefore, some simple hand calculations are used herein to establish the physics of the results. The interpretation and validation effort is divided between the time average flow conditions and the time varying flow conditions. The time average flow conditions are evaluated using a lumped parameter model and heat balance. The Martinelli-Nelson correlations are usedmore » to model the two-phase pressure drop and void fraction vs flow quality relationship within the core region. Systems of parallel channels are susceptible to both density wave oscillations and pressure drop oscillations. Periodic variations in the mass flux and exit flow quality of individual core channels are predicted by RELAP5. These oscillations are consistent with those observed experimentally and are of the density wave type. The impact of the time varying flow properties on local wall superheat is bounded herein. The conditions necessary for Ledinegg flow excursions are identified. These conditions do not fall within the envelope of decay heat levels relevant to HFIR in boiling natural circulation. 14 refs., 5 figs., 1 tab.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2136198','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2136198"><span>ON THE NATURE OF BACTEREMIA IN EXPERIMENTAL PNEUMOCOCCAL PNEUMONIA IN THE DOG</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Robertson, O. H.; Hamburger, Morton; Gregg, Lucien A.</p> <p>1953-01-01</p> <p>In a study of the relationship of natural antipneumococcal immune substances to the incidence and course of bacteremia in dogs with experimental pneumococcus pneumonia the following findings came to light: (1) In non-bacteremic animals, natural immune substances, as measured by the pneumococcidal-promoting action of the serum, continue to be present in relatively undiminished concentration throughout the course of the infection. (2) With the advent of bacteremia these immune properties of the blood tend to decrease or disappear, depending on the degree of bacteremia and the length of the disease course, but in certain instances they persist despite the presence of large numbers of circulating pneumococci. (3) Disappearance of natural immune substances from the blood during bacteremia is followed by their reappearance upon cessation of the bacteremia. (4) Bacteremic blood containing antipneumococcal immune substances and a sufficient quantity of leucocytes is capable of destroying in vitro relatively large numbers of pneumococci and will often sterilize itself. (5) The sequence of bacteremia first, then diminution and disappearance of humoral immunity excludes this antipneumococcal action of the blood as being the principal inhibitor of blood invasion. These observations have been interpreted as indicating that the bacteremic state consists of a constant escape of pneumococci from the pulmonary lesion and an attempt on the part of the body to compensate for the depletion of circulating immune substances resulting from their progressive immobilization by the pneumococci and their products. Thus, the loss or retention of humoral immune substances in the presence of bacteremia would appear to depend on the rate at which the body can provide new supplies of antibodies and on the number of pneumococci being discharged into the circulation. While the pneumococcidal action of the blood may not be sufficient to prevent the occurrence of bacteremia our study provides ample evidence that it exerts a potent restraining effect on the increase in numbers of pneumococci in the circulation. PMID:13022879</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22809311','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22809311"><span>Reconstructing a missing link in the evolution of a recently diverged phosphotriesterase by active-site loop remodeling.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Afriat-Jurnou, Livnat; Jackson, Colin J; Tawfik, Dan S</p> <p>2012-08-07</p> <p>Only decades after the introduction of organophosphate pesticides, bacterial phosphotriesterases (PTEs) have evolved to catalyze their degradation with remarkable efficiency. Their closest known relatives, lactonases, with promiscuous phosphotriasterase activity, dubbed PTE-like lactonases (PLLs), share only 30% sequence identity and also differ in the configuration of their active-site loops. PTE was therefore presumed to have evolved from a yet unknown PLL whose primary activity was the hydrolysis of quorum sensing homoserine lactones (HSLs) (Afriat et al. (2006) Biochemistry 45, 13677-13686). However, how PTEs diverged from this presumed PLL remains a mystery. In this study we investigated loop remodeling as a means of reconstructing a homoserine lactonase ancestor that relates to PTE by few mutational steps. Although, in nature, loop remodeling is a common mechanism of divergence of enzymatic functions, reproducing this process in the laboratory is a challenge. Structural and phylogenetic analyses enabled us to remodel one of PTE's active-site loops into a PLL-like configuration. A deletion in loop 7, combined with an adjacent, highly epistatic, point mutation led to the emergence of an HSLase activity that is undetectable in PTE (k(cat)/K(M) values of up to 2 × 10(4)). The appearance of the HSLase activity was accompanied by only a minor decrease in PTE's paraoxonase activity. This specificity change demonstrates the potential role of bifunctional intermediates in the divergence of new enzymatic functions and highlights the critical contribution of loop remodeling to the rapid divergence of new enzyme functions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22521933-how-gas-dynamic-flare-models-powered-petschek-reconnection-differ-from-those-ad-hoc-energy-sources','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22521933-how-gas-dynamic-flare-models-powered-petschek-reconnection-differ-from-those-ad-hoc-energy-sources"><span>HOW GAS-DYNAMIC FLARE MODELS POWERED BY PETSCHEK RECONNECTION DIFFER FROM THOSE WITH AD HOC ENERGY SOURCES</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Longcope, D. W.; Klimchuk, J. A.</p> <p></p> <p>Aspects of solar flare dynamics, such as chromospheric evaporation and flare light curves, have long been studied using one-dimensional models of plasma dynamics inside a static flare loop, subjected to some energy input. While extremely successful at explaining the observed characteristics of flares, all such models so far have specified energy input ad hoc, rather than deriving it self-consistently. There is broad consensus that flares are powered by magnetic energy released through reconnection. Recent work has generalized Petschek’s basic reconnection scenario, topological change followed by field line retraction and shock heating, to permit its inclusion in a one-dimensional flare loop model. Heremore » we compare the gas dynamics driven by retraction and shocking to those from more conventional static loop models energized by ad hoc source terms. We find significant differences during the first minute, when retraction leads to larger kinetic energies and produces higher densities at the loop top, while ad hoc heating tends to rarify the loop top. The loop-top density concentration is related to the slow magnetosonic shock, characteristic of Petschek’s model, but persists beyond the retraction phase occurring in the outflow jet. This offers an explanation for observed loop-top sources of X-ray and EUV emission, with advantages over that provided by ad hoc heating scenarios. The cooling phases of the two models are, however, notably similar to one another, suggesting that observations at that stage will yield little information on the nature of energy input.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22039106-self-organization-reconnecting-plasmas-marginal-collisionality-solar-corona','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22039106-self-organization-reconnecting-plasmas-marginal-collisionality-solar-corona"><span>SELF-ORGANIZATION OF RECONNECTING PLASMAS TO MARGINAL COLLISIONALITY IN THE SOLAR CORONA</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Imada, S.; Zweibel, E. G.</p> <p></p> <p>We explore the suggestions by Uzdensky and Cassak et al. that coronal loops heated by magnetic reconnection should self-organize to a state of marginal collisionality. We discuss their model of coronal loop dynamics with a one-dimensional hydrodynamic calculation. We assume that many current sheets are present, with a distribution of thicknesses, but that only current sheets thinner than the ion skin depth can rapidly reconnect. This assumption naturally causes a density-dependent heating rate which is actively regulated by the plasma. We report nine numerical simulation results of coronal loop hydrodynamics in which the absolute values of the heating rates aremore » different but their density dependences are the same. We find two regimes of behavior, depending on the amplitude of the heating rate. In the case that the amplitude of heating is below a threshold value, the loop is in stable equilibrium. Typically, the upper and less dense part of a coronal loop is collisionlessly heated and conductively cooled. When the amplitude of heating is above the threshold, the conductive flux to the lower atmosphere required to balance collisionless heating drives an evaporative flow which quenches fast reconnection, ultimately cooling and draining the loop until the cycle begins again. The key elements of this cycle are gravity and the density dependence of the heating function. Some additional factors are present, including pressure-driven flows from the loop top, which carry a large enthalpy flux and play an important role in reducing the density. We find that on average the density of the system is close to the marginally collisionless value.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22370312-heating-mechanisms-intermittent-loops-active-region-cores-from-aia-sdo-euv-observations','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22370312-heating-mechanisms-intermittent-loops-active-region-cores-from-aia-sdo-euv-observations"><span>Heating mechanisms for intermittent loops in active region cores from AIA/SDO EUV observations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Cadavid, A. C.; Lawrence, J. K.; Christian, D. J.</p> <p>2014-11-01</p> <p>We investigate intensity variations and energy deposition in five coronal loops in active region cores. These were selected for their strong variability in the AIA/SDO 94 Å intensity channel. We isolate the hot Fe XVIII and Fe XXI components of the 94 Å and 131 Å by modeling and subtracting the 'warm' contributions to the emission. HMI/SDO data allow us to focus on 'inter-moss' regions in the loops. The detailed evolution of the inter-moss intensity time series reveals loops that are impulsively heated in a mode compatible with a nanoflare storm, with a spike in the hot 131 Å signalsmore » leading and the other five EUV emission channels following in progressive cooling order. A sharp increase in electron temperature tends to follow closely after the hot 131 Å signal confirming the impulsive nature of the process. A cooler process of growing emission measure follows more slowly. The Fourier power spectra of the hot 131 Å signals, when averaged over the five loops, present three scaling regimes with break frequencies near 0.1 min{sup –1} and 0.7 min{sup –1}. The low frequency regime corresponds to 1/f noise; the intermediate indicates a persistent scaling process and the high frequencies show white noise. Very similar results are found for the energy dissipation in a 2D 'hybrid' shell model of loop magneto-turbulence, based on reduced magnetohydrodynamics, that is compatible with nanoflare statistics. We suggest that such turbulent dissipation is the energy source for our loops.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900036745&hterms=Water+turbine&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DWater%2Bturbine','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900036745&hterms=Water+turbine&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DWater%2Bturbine"><span>Comparison of steady and unsteady secondary flows in a turbine stator cascade</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hebert, Gregory J.; Tiederman, William G.</p> <p>1989-01-01</p> <p>The effect of periodic rotor wakes on the secondary flow structure in a turbine stator cascade was investigated. A mechanism simulated the wakes shed from rotor blades by passing cylindrical rods across the inlet to a linear cascade installed in a recirculating water flow loop. Velocity measurements showed a passage vortex, similar to that seen in steady flow, during the time associated with undisturbed fluid. However, as the rotor wake passed through the blade row, a large crossflow toward the suction surface was observed in the midspan region. This caused the development of two large areas of circulation between the midspan and endwall regions, significantly distorting and weakening the passage vortices.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/1445312','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/1445312"><span>A peptide sequence on carcinoembryonic antigen binds to a 80kD protein on Kupffer cells.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Thomas, P; Petrick, A T; Toth, C A; Fox, E S; Elting, J J; Steele, G</p> <p>1992-10-30</p> <p>Clearance of carcinoembryonic antigen (CEA) from the circulation is by binding to Kupffer cells in the liver. We have shown that CEA binding to Kupffer cells occurs via a peptide sequence YPELPK representing amino acids 107-112 of the CEA sequence. This peptide sequence is located in the region between the N-terminal and the first immunoglobulin like loop domain. Using native CEA and peptides containing this sequence complexed with a heterobifunctional crosslinking agent and ligand blotting with biotinylated CEA and NCA we have shown binding to an 80kD protein on the Kupffer cell surface. This binding protein may be important in the development of hepatic metastases.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1176135','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1176135"><span>Power converter having improved fluid cooling</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Meyer, Andreas A.; Radosevich, Lawrence D.; Beihoff, Bruce C.; Kehl, Dennis L.; Kannenberg, Daniel G.</p> <p>2007-03-06</p> <p>A thermal support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support, which may be controlled in a closed-loop manner. Interfacing between circuits, circuit mounting structure, and the support provide for greatly enhanced cooling. The support may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/4807984-role-disturbances-vegetative-nervous-regulation-ionizing-radiation-induced-changes-cardio-vascular-system','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/4807984-role-disturbances-vegetative-nervous-regulation-ionizing-radiation-induced-changes-cardio-vascular-system"><span>ON THE ROLE OF DISTURBANCES IN VEGETATIVE NERVOUS REGULATION IN IONIZING RADIATION INDUCED CHANGES IN CARDIO-VASCULAR SYSTEM (in Russian)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Smirnova, N.P.</p> <p></p> <p>A total exposure to x radiation induced disturbances of the central blood circulation apparatus. The disturbances were evaluated by the response of the hypothalamic region to irritation. An increased or changed reaction without variability in the excitation threshold are characteristic of hypothalamic effects of a neurohumoral nature (blood circulation and cutaneous vessel reaction). Considerable changes in irritation thresholds were found. (R.V.J.)</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/21143276-preemptive-vortex-loop-proliferation-multicomponent-interacting-bose-einstein-condensates','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21143276-preemptive-vortex-loop-proliferation-multicomponent-interacting-bose-einstein-condensates"><span>Preemptive vortex-loop proliferation in multicomponent interacting Bose-Einstein condensates</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Dahl, E. K.; Kragset, S.; Sudboe, A.</p> <p>2008-04-01</p> <p>We use analytical arguments and large-scale Monte Carlo calculations to investigate the nature of the phase transitions between distinct complex superfluid phases in a two-component Bose-Einstein condensate when a nondissipative drag between the two components is being varied. We focus on understanding the role of topological defects in various phase transitions and develop vortex-matter arguments, allowing an analytical description of the phase diagram. We find the behavior of fluctuation induced vortex matter to be much more complex and substantially different from that of single-component superfluids. We propose and numerically investigate a drag-induced ''preemptive vortex loop proliferation'' scenario. Such a transitionmore » may be a quite generic feature in many multicomponent systems where symmetry is restored by a gas of several kinds of competing vortex loops.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JCAP...05..009W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JCAP...05..009W"><span>Loop corrections to primordial fluctuations from inflationary phase transitions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Yi-Peng; Yokoyama, Jun'ichi</p> <p>2018-05-01</p> <p>We investigate loop corrections to the primordial fluctuations in the single-field inflationary paradigm from spectator fields that experience a smooth transition of their vacuum expectation values. We show that when the phase transition involves a classical evolution effectively driven by a negative mass term from the potential, important corrections to the curvature perturbation can be generated by field perturbations that are frozen outside the horizon by the time of the phase transition, yet the correction to tensor perturbation is naturally suppressed by the spatial derivative couplings between spectator fields and graviton. At one-loop level, the dominant channel for the production of primordial fluctuations comes from a pair-scattering of free spectator fields that decay into the curvature perturbations, and this decay process is only sensitive to field masses comparable to the Hubble scale of inflation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003JHEP...07..011G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003JHEP...07..011G"><span>Traces on orbifolds: anomalies and one-loop amplitudes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Groot Nibbelink, Stefan</p> <p>2003-07-01</p> <p>In the recent literature one can find calculations of various one-loop amplitudes, like anomalies, tadpoles and vacuum energies, on specific types of orbifolds, like S1/Bbb Z2. This work aims to give a general description of such one-loop computations for a large class of orbifold models. In order to achieve a high degree of generality, we formulate these calculations as evaluations of traces of operators over orbifold Hilbert spaces. We find that in general the result is expressed as a sum of traces over hyper surfaces with local projections, and the derivatives perpendicular to these hyper surfaces are rescaled. These local projectors naturally takes into account possible non-periodic boundary conditions. As the examples T6/Bbb Z4 and T4/D4 illustrate, the methods can be applied to non-prime as well as non-abelian orbifolds.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060022175','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060022175"><span>Adaptive Inner-Loop Rover Control</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kulkarni, Nilesh; Ippolito, Corey; Krishnakumar, Kalmanje; Al-Ali, Khalid M.</p> <p>2006-01-01</p> <p>Adaptive control technology is developed for the inner-loop speed and steering control of the MAX Rover. MAX, a CMU developed rover, is a compact low-cost 4-wheel drive, 4-wheel steer (double Ackerman), high-clearance agile durable chassis, outfitted with sensors and electronics that make it ideally suited for supporting research relevant to intelligent teleoperation and as a low-cost autonomous robotic test bed and appliance. The design consists of a feedback linearization based controller with a proportional - integral (PI) feedback that is augmented by an online adaptive neural network. The adaptation law has guaranteed stability properties for safe operation. The control design is retrofit in nature so that it fits inside the outer-loop path planning algorithms. Successful hardware implementation of the controller is illustrated for several scenarios consisting of actuator failures and modeling errors in the nominal design.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EPJWC..6604021M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EPJWC..6604021M"><span>Constituent Quarks and Gluons, Polyakov loop and the Hadron Resonance Gas Model *</xref>**</xref></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Megías, E.; Ruiz Arriola, E.; Salcedo, L. L.</p> <p>2014-03-01</p> <p>Based on first principle QCD arguments, it has been argued in [1] that the vacuum expectation value of the Polyakov loop can be represented in the hadron resonance gas model. We study this within the Polyakov-constituent quark model by implementing the quantum and local nature of the Polyakov loop [2, 3]. The existence of exotic states in the spectrum is discussed. Presented by E. Megías at the International Nuclear Physics Conference INPC 2013, 2-7 June 2013, Firenze, Italy.Supported by Plan Nacional de Altas Energías (FPA2011-25948), DGI (FIS2011-24149), Junta de Andalucía grant FQM-225, Spanish Consolider-Ingenio 2010 Programme CPAN (CSD2007-00042), Spanish MINECO's Centro de Excelencia Severo Ochoa Program grant SEV-2012-0234, and the Juan de la Cierva Program.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18449841','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18449841"><span>Linear versus non-linear measures of temporal variability in finger tapping and their relation to performance on open- versus closed-loop motor tasks: comparing standard deviations to Lyapunov exponents.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Christman, Stephen D; Weaver, Ryan</p> <p>2008-05-01</p> <p>The nature of temporal variability during speeded finger tapping was examined using linear (standard deviation) and non-linear (Lyapunov exponent) measures. Experiment 1 found that right hand tapping was characterised by lower amounts of both linear and non-linear measures of variability than left hand tapping, and that linear and non-linear measures of variability were often negatively correlated with one another. Experiment 2 found that increased non-linear variability was associated with relatively enhanced performance on a closed-loop motor task (mirror tracing) and relatively impaired performance on an open-loop motor task (pointing in a dark room), especially for left hand performance. The potential uses and significance of measures of non-linear variability are discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4485566','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4485566"><span>The Response of Ω-Loop D Dynamics to Truncation of Trimethyllysine 72 of Yeast Iso-1-cytochrome c Depends on the Nature of Loop Deformation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>McClelland, Levi J.; Seagraves, Sean M.; Khan, Khurshid Alam; Cherney, Melisa M.; Bandi, Swati; Culbertson, Justin E.; Bowler, Bruce E.</p> <p>2015-01-01</p> <p>Trimethyllysine 72 (tmK72) has been suggested to play a role in sterically constraining the heme crevice dynamics of yeast iso-1-cytochrome c mediated by the Ω-loop D cooperative substructure (residues 70 to 85). A tmK72A mutation causes a gain in peroxidase activity, a function of cytochrome c that is important early in apoptosis. More than one higher energy state is accessible for the Ω-loop D substructure via tier 0 dynamics. Two of these are alkaline conformers mediated by Lys73 and Lys79. In the current work, the effect of the tmK72A mutation on the thermodynamic and kinetic properties of wild type iso-1-cytochrome c (yWT versus WT*) and on variants carrying a K73H mutation (yWT/K73H versus WT*/K73H) is studied. Whereas the tmK72A mutation confers increased peroxidase activity in wild type yeast iso-1-cytochrome c and increased dynamics for formation of a previously studied His79-heme alkaline conformer, the tmK72A mutation speeds return of the His73-heme alkaline conformer to the native state through destabilization of the His73-heme alkaline conformer relative to the native conformer. These opposing behaviors demonstrate that the response of the dynamics of a protein substructure to mutation depends on the nature of the perturbation to the substructure. For a protein substructure which mediates more than one function of a protein through multiple non-native structures, a mutation could change the partitioning between these functions. The current results suggest that the tier 0 dynamics of Ω-loop D that mediates peroxidase activity has similarities to the tier 0 dynamics required to form the His79-heme alkaline conformer. PMID:25948392</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28378547','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28378547"><span>Deficiencies of Circulating Mucosal-associated Invariant T Cells and Natural Killer T Cells in Patients with Multiple Trauma.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jo, Young Goun; Choi, Hyun Jung; Kim, Jung Chul; Cho, Young Nan; Kang, Jeong Hwa; Jin, Hye Mi; Kee, Seung Jung; Park, Yong Wook</p> <p>2017-05-01</p> <p>Mucosal-associated invariant T (MAIT) cells and natural killer T (NKT) cells are known to play important roles in autoimmunity, infectious diseases and cancers. However, little is known about the roles of these invariant T cells in multiple trauma. The purposes of this study were to examine MAIT and NKT cell levels in patients with multiple trauma and to investigate potential relationships between these cell levels and clinical parameters. The study cohort was composed of 14 patients with multiple trauma and 22 non-injured healthy controls (HCs). Circulating MAIT and NKT cell levels in the peripheral blood were measured by flow cytometry. The severity of injury was categorised according to the scoring systems, such as Acute Physiology and Chronic Health Evaluation (APACHE) II score, Simplified Acute Physiology Score (SAPS) II, and Injury Severity Score (ISS). Circulating MAIT and NKT cell numbers were significantly lower in multiple trauma patients than in HCs. Linear regression analysis showed that circulating MAIT cell numbers were significantly correlated with age, APACHE II, SAPS II, ISS category, hemoglobin, and platelet count. NKT cell numbers in the peripheral blood were found to be significantly correlated with APACHE II, SAPS II, and ISS category. This study shows numerical deficiencies of circulating MAIT cells and NKT cells in multiple trauma. In addition, these invariant T cell deficiencies were found to be associated with disease severity. These findings provide important information for predicting the prognosis of multiple trauma. © 2017 The Korean Academy of Medical Sciences.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AIPC.1608..281Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AIPC.1608..281Z"><span>Cooling molten salt reactors using "gas-lift"</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zitek, Pavel; Valenta, Vaclav; Klimko, Marek</p> <p>2014-08-01</p> <p>This study briefly describes the selection of a type of two-phase flow, suitable for intensifying the natural flow of nuclear reactors with liquid fuel - cooling mixture molten salts and the description of a "Two-phase flow demonstrator" (TFD) used for experimental study of the "gas-lift" system and its influence on the support of natural convection. The measuring device and the application of the TDF device is described. The work serves as a model system for "gas-lift" (replacing the classic pump in the primary circuit) for high temperature MSR planned for hydrogen production. An experimental facility was proposed on the basis of which is currently being built an experimental loop containing the generator, separator bubbles and necessary accessories. This loop will model the removal of gaseous fission products and tritium. The cleaning of the fuel mixture of fluoride salts eliminates problems from Xenon poisoning in classical reactors.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29670941','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29670941"><span>Organization of feed-forward loop motifs reveals architectural principles in natural and engineered networks.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gorochowski, Thomas E; Grierson, Claire S; di Bernardo, Mario</p> <p>2018-03-01</p> <p>Network motifs are significantly overrepresented subgraphs that have been proposed as building blocks for natural and engineered networks. Detailed functional analysis has been performed for many types of motif in isolation, but less is known about how motifs work together to perform complex tasks. To address this issue, we measure the aggregation of network motifs via methods that extract precisely how these structures are connected. Applying this approach to a broad spectrum of networked systems and focusing on the widespread feed-forward loop motif, we uncover striking differences in motif organization. The types of connection are often highly constrained, differ between domains, and clearly capture architectural principles. We show how this information can be used to effectively predict functionally important nodes in the metabolic network of Escherichia coli . Our findings have implications for understanding how networked systems are constructed from motif parts and elucidate constraints that guide their evolution.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22442752','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22442752"><span>A fast and flexible panoramic virtual reality system for behavioural and electrophysiological experiments.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Takalo, Jouni; Piironen, Arto; Honkanen, Anna; Lempeä, Mikko; Aikio, Mika; Tuukkanen, Tuomas; Vähäsöyrinki, Mikko</p> <p>2012-01-01</p> <p>Ideally, neuronal functions would be studied by performing experiments with unconstrained animals whilst they behave in their natural environment. Although this is not feasible currently for most animal models, one can mimic the natural environment in the laboratory by using a virtual reality (VR) environment. Here we present a novel VR system based upon a spherical projection of computer generated images using a modified commercial data projector with an add-on fish-eye lens. This system provides equidistant visual stimulation with extensive coverage of the visual field, high spatio-temporal resolution and flexible stimulus generation using a standard computer. It also includes a track-ball system for closed-loop behavioural experiments with walking animals. We present a detailed description of the system and characterize it thoroughly. Finally, we demonstrate the VR system's performance whilst operating in closed-loop conditions by showing the movement trajectories of the cockroaches during exploratory behaviour in a VR forest.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5903899','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5903899"><span>Organization of feed-forward loop motifs reveals architectural principles in natural and engineered networks</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Grierson, Claire S.</p> <p>2018-01-01</p> <p>Network motifs are significantly overrepresented subgraphs that have been proposed as building blocks for natural and engineered networks. Detailed functional analysis has been performed for many types of motif in isolation, but less is known about how motifs work together to perform complex tasks. To address this issue, we measure the aggregation of network motifs via methods that extract precisely how these structures are connected. Applying this approach to a broad spectrum of networked systems and focusing on the widespread feed-forward loop motif, we uncover striking differences in motif organization. The types of connection are often highly constrained, differ between domains, and clearly capture architectural principles. We show how this information can be used to effectively predict functionally important nodes in the metabolic network of Escherichia coli. Our findings have implications for understanding how networked systems are constructed from motif parts and elucidate constraints that guide their evolution. PMID:29670941</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27148933','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27148933"><span>The Value of Circulating Biomarkers in Bicuspid Aortic Valve-Associated Aortopathy.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Naito, Shiho; Hillebrand, Mathias; Bernhardt, Alexander Martin Justus; Jagodzinski, Annika; Conradi, Lenard; Detter, Christian; Sydow, Karsten; Reichenspurner, Hermann; Kodolitsch, Yskert von; Girdauskas, Evaldas</p> <p>2018-06-01</p> <p>Traditional risk stratification model of bicuspid aortic valve (BAV) aortopathy is based on measurement of maximal cross-sectional aortic diameter, definition of proximal aortic shape, and aortic stiffness/elasticity parameters. However, conventional imaging-based criteria are unable to provide reliable information regarding the risk stratification in BAV aortopathy, especially considering the heterogeneous nature of BAV disease. Given those limitations of conventional imaging, there is a growing clinical interest to use circulating biomarkers in the screening process for thoracic aortic aneurysms as well as in the risk-assessment algorithms. We aimed to systematically review currently available biomarkers, which may be of value to predict the natural evolution of aortopathy in individuals with BAV. Georg Thieme Verlag KG Stuttgart · New York.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/6463747-utsg-theoretical-model-describing-transient-behavior-pressurized-water-reactor-natural-circulation-tube-steam-generator','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6463747-utsg-theoretical-model-describing-transient-behavior-pressurized-water-reactor-natural-circulation-tube-steam-generator"><span>UTSG-2; A theoretical model describing the transient behavior of a pressurized water reactor natural circulation U-tube steam generator</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Hold, A.</p> <p></p> <p>An advanced nonlinear transient model for calculating steady-state and dynamic behaviors of characteristic parameters of a Kraftwerk Union-type vertical natural-circulation U-tube steam generator and its main steam system is presented. This model has been expanded due to the increasing need for safety-related accident research studies. It now takes into consideration the possibilities of dryout and superheating along the secondary side of the steam generator. The resulting theoretical model is the basis of the digital code UTSG-2, which can be used both by itself and in combination with other pressurized water reactor transient codes, such as ALMOD-3.4, AMOD-4, and ATHLET.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16049909','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16049909"><span>Development of a hybrid (numerical-hydraulic) circulatory model: prototype testing and its response to IABP assistance.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ferrari, G; Kozarski, M; De Lazzari, C; Górczyńska, K; Tosti, G; Darowski, M</p> <p>2005-07-01</p> <p>Merging numerical and physical models of the circulation makes it possible to develop a new class of circulatory models defined as hybrid. This solution reduces the costs, enhances the flexibility and opens the way to many applications ranging from research to education and heart assist devices testing. In the prototype described in this paper, a hydraulic model of systemic arterial tree is connected to a lumped parameters numerical model including pulmonary circulation and the remaining parts of systemic circulation. The hydraulic model consists of a characteristic resistance, of a silicon rubber tube to allow the insertion of an Intra-Aortic Balloon Pump (IABP) and of a lumped parameters compliance. Two electro-hydraulic interfaces, realized by means of gear pumps driven by DC motors, connect the numerical section with both terminals of the hydraulic section. The lumped parameters numerical model and the control system (including analog to digital and digital to analog converters)are developed in LabVIEW environment. The behavior of the model is analyzed by means of the ventricular pressure-volume loops and the time courses of arterial and ventricular pressures and flows in different circulatory conditions. A simulated pathological condition was set to test the IABP and verify the response of the system to this type of mechanical circulatory assistance. The results show that the model can represent hemodynamic relationships in different ventricular and circulatory conditions and is able to react to the IABP assistance.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/4166301','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/4166301"><span>The effect of adrenaline and noradrenaline on hormone secretion and blood flow from the thyroid vein in sheep with exteriorized thyroids.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Falconer, I R</p> <p>1967-02-01</p> <p>1. Emotional stimulus to the sheep has previously been shown to cause increased thyroid hormone secretion; the influence of adrenaline and noradrenaline in this process has been investigated.2. Sheep bearing exteriorized thyroid glands on carotid artery-jugular vein loops were used. Thyroid vein blood was collected through a cannula in the jugular vein within the loop, and blood flow was measured by a plethysmographic technique.3. (131)I (50 muc) was injected intramuscularly (I.M.) into the sheep, and 4-7 days later the concentration of total and protein bound (131)I in thyroid vein blood was measured in samples taken every 10 min for 4 hr. Intracarotid injections of 1 mug, I.V. injections of 5 mug, or I.V. infusions at 10 mug/min for 10 min, of adrenaline or noradrenaline were administered 1.5 hr after commencement of sampling. Blood flow from the thyroid was measured in similar experiments.4. No significant changes in thyroid hormone secretion could be attributed to adrenaline or noradrenaline, and it was concluded that circulating catecholamines do not influence the release of thyroid hormone observed after brief emotional stimulus in the sheep.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15137614','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15137614"><span>Association between an aplastic basilar artery, unaccompanied by a primitive carotid-vertebrobasilar anastomosis, and multiple aneurysms on the dominant posterior communicating artery.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Behari, Sanjay; Krishna, Himanshu; Kumar, Marakani V Kiran; Sawlani, Vijay; Phadke, Rajendra V; Jain, Vijendra K</p> <p>2004-05-01</p> <p>Basilar artery (BA) aplasia when unaccompanied by a primitive carotid-vertebrobasilar anastomosis is exceedingly rare. The association of BA aplasia with two aneurysms on the dominant posterior communicating artery (PCoA) has not been previously reported. This 40-year-old man presented in a state of drowsiness and responded to simple commands only after being coaxed. He had complete left cranial third nerve palsy, right hemiparesis, and persisting signs of meningeal irritation. A computerized tomography (CT) scan revealed subarachnoid and intraventricular hemorrhage. An angiogram revealed BA aplasia. The right PCoA followed a sinuous course with multiple loops and provided the dominant supply to the posterior circulation. This vessel harbored two aneurysms, one at the origin of the PCoA from the internal carotid artery and the other at the looping segment just proximal to the brainstem. The left PCoA was extremely thin. The pterional transsylvian approach was used to clip the two aneurysms on the PCoA. The hemodynamic changes produced by the BA aplasia may have produced alterations in the cerebral vasculature leading to aneurysm formation and consequent subarachnoid hemorrhage.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11687932','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11687932"><span>Hydrodynamic characteristics and mixing behaviour of Sclerotium glucanicum culture fluids in an airlift reactor with an internal loop used for scleroglucan production.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kang, X; Wang, H; Wang, Y; Harvey, L M; McNeil, B</p> <p>2001-10-01</p> <p>The filamentous fungus, Sclerotium glucanicum NRRL 3006, was cultivated in a 0.008 m(3) airlift bioreactor with internal recirculation loop (ARL-IL) for production of the biopolymer, scleroglucan. The rheological behaviour of the culture fluid was characterised by measurement of the fluid consistency coefficient (K) and the flow behaviour index (n). Based on these measurements, the culture fluid changed from a low viscosity Newtonian system early in the process, to a viscous non-Newtonian (pseudoplastic) system. In addition, reactor hydrodynamics and mixing behaviour were characterised by measurement of whole mean gas hold-up (epsilon(g)), liquid re-circulation velocity (U(ld)) and mixing time (t(m)). Under identical process conditions, the effects of the viscosity of the culture fluid and air flow rate on epsilon(g), U(ld) and t(m) were examined and empirical correlations for epsilon(g), U(ld) and t(m) with both superficial velocity U(g) and consistency coefficient K were obtained and expressed separately. The correlations obtained are likely to describe the behaviour of real fungal culture fluids more accurately than previous correlations based on Newtonian or simulated non-Newtonian systems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880017005','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880017005"><span>Design and testing of a high power spacecraft thermal management system</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mccabe, Michael E., Jr.; Ku, Jentung; Benner, Steve</p> <p>1988-01-01</p> <p>The design and test results are presented of an ammonia hybrid capillary pumped loop thermal control system which could be used for heat acquisition and transport on future large space platforms and attached payloads, such as those associated with the NASA Space Station. The High Power Spacecraft Thermal Management System (HPSTM) can operate as either a passive, capillary pumped two phase thermal control system, or, when additional pressure head is required, as a mechanically pumped loop. Testing has shown that in the capillary mode, the HPSTM evaporators can acquire a total heat load of between 600 W and 24 kW, transported over 10 meters, at a maximum heat flux density of 4.3 W/sq cm. With the mechanical pump circulating the ammonia, a heat acquisition potential of 52 kW was demonstrated for 15 minutes without an evaporator failure. These results represent a significant improvement over the maximum transport capability previously displayed in other capillary systems. The HPSTM system still retains the proven capillary capabilities of heat load sharing and flow control between evaporator plates, rapid power cycling, and nonuniform heating in both the capillary and hybrid operating modes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060013344','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060013344"><span>Multiphase Flow Technology Impacts on Thermal Control Systems for Exploration</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>McQuillen, John; Sankovic, John; Lekan, Jack</p> <p>2006-01-01</p> <p>The Two-Phase Flow Facility (TPHIFFy) Project focused on bridging the critical knowledge gap by developing and demonstrating critical multiphase fluid products for advanced life support, thermal management and power conversion systems that are required to enable the Vision for Space Exploration. Safety and reliability of future systems will be enhanced by addressing critical microgravity fluid physics issues associated with flow boiling, condensation, phase separation, and system stability. The project included concept development, normal gravity testing, and reduced gravity aircraft flight campaigns, in preparation for the development of a space flight experiment implementation. Data will be utilized to develop predictive models that could be used for system design and operation. A single fluid, two-phase closed thermodynamic loop test bed was designed, assembled and tested. The major components in this test bed include: a boiler, a condenser, a phase separator and a circulating pump. The test loop was instrumented with flow meters, thermocouples, pressure transducers and both high speed and normal speed video cameras. A low boiling point surrogate fluid, FC-72, was selected based on scaling analyses using preliminary designs for operational systems. Preliminary results are presented which include flow regime transitions and some observations regarding system stability.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70020551','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70020551"><span>Numerical analysis of seawater circulation in carbonate platforms: I. Geothermal convection</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Sanford, W.E.; Whitaker, F.F.; Smart, P.L.; Jones, G.</p> <p>1998-01-01</p> <p>Differences in fluid density between cold ocean water and warm ground water can drive the circulation of seawater through carbonate platforms. The circulating water can be the major source of dissolved constituents for diagenetic reactions such as dolomitization. This study was undertaken to investigate the conditions under which such circulation can occur and to determine which factors control both the flux and the patterns of fluid circulation and temperature distribution, given the expected ranges of those factors in nature. Results indicate that the magnitude and distribution of permeability within a carbonate platform are the most important parameters. Depending on the values of horizontal and vertical permeability, heat transport within a platform can occur by one of three mechanisms: conduction, forced convection, or free convection. Depth-dependent relations for porosity and permeability in carbonate platforms suggest circulation may decrease rapidly with depth. The fluid properties of density and viscosity are controlled primarily by their dependency on temperature. The bulk thermal conductivity of the rocks within the platform affects the conductive regime to some extent, especially if evaporite minerals are present within the section. Platform geometry has only a second-order effect on circulation. The relative position of sealevel can create surface conditions that range from exposed (with a fresh-water lens present) to shallow water (with hypersaline conditions created by evaporation in constricted flow conditions) to submerged or drowned (with free surface water circulation), but these boundary conditions and associated ocean temperature profiles have only a second-order effect on fluid circulation. Deep, convective circulation can be caused by horizon tal temperature gradients and can occur even at depths below the ocean bottom. Temperature data from deep holes in the Florida and Bahama platforms suggest that geothermal circulation is actively occurring today to depths as great as several kilometers.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4965787','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4965787"><span>Antiferroelectric Nature of CH3NH3PbI3−xClx Perovskite and Its Implication for Charge Separation in Perovskite Solar Cells</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sewvandi, Galhenage A.; Kodera, Kei; Ma, Hao; Nakanishi, Shunsuke; Feng, Qi</p> <p>2016-01-01</p> <p>Perovskite solar cells (PSCs) have been attracted scientific interest due to high performance. Some researchers have suggested anomalous behavior of PSCs to the polarizations due to the ion migration or ferroelectric behavior. Experimental results and theoretical calculations have suggested the possibility of ferroelectricity in organic-inorganic perovskite. However, still no studies have been concretely discarded the ferroelectric nature of perovskite absorbers in PSCs. Hysteresis of P-E (polarization-electric field) loops is an important evidence to confirm the ferroelectricity. In this study, P-E loop measurements, in-depth structural study, analyses of dielectric behavior and the phase transitions of CH3NH3PbI3−xClx perovskite were carried out and investigated. The results suggest that CH3NH3PbI3−xClx perovskite is in an antiferroelectric phase at room temperature. The antiferroelectric phase can be switched to ferroelectric phase by the poling treatment and exhibits ferroelectric-like hysteresis P-E loops and dielectric behavior around room temperature; namely, the perovskite can generate a ferroelectric polarization under PSCs operating conditions. Furthermore, we also discuss the implications of ferroelectric polarization on PSCs charge separation. PMID:27468802</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22701593','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22701593"><span>Quantifying loopy network architectures.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Katifori, Eleni; Magnasco, Marcelo O</p> <p>2012-01-01</p> <p>Biology presents many examples of planar distribution and structural networks having dense sets of closed loops. An archetype of this form of network organization is the vasculature of dicotyledonous leaves, which showcases a hierarchically-nested architecture containing closed loops at many different levels. Although a number of approaches have been proposed to measure aspects of the structure of such networks, a robust metric to quantify their hierarchical organization is still lacking. We present an algorithmic framework, the hierarchical loop decomposition, that allows mapping loopy networks to binary trees, preserving in the connectivity of the trees the architecture of the original graph. We apply this framework to investigate computer generated graphs, such as artificial models and optimal distribution networks, as well as natural graphs extracted from digitized images of dicotyledonous leaves and vasculature of rat cerebral neocortex. We calculate various metrics based on the asymmetry, the cumulative size distribution and the Strahler bifurcation ratios of the corresponding trees and discuss the relationship of these quantities to the architectural organization of the original graphs. This algorithmic framework decouples the geometric information (exact location of edges and nodes) from the metric topology (connectivity and edge weight) and it ultimately allows us to perform a quantitative statistical comparison between predictions of theoretical models and naturally occurring loopy graphs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4491732','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4491732"><span>Cooperative folding of a polytopic α-helical membrane protein involves a compact N-terminal nucleus and nonnative loops</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Paslawski, Wojciech; Lillelund, Ove K.; Kristensen, Julie Veje; Schafer, Nicholas P.; Baker, Rosanna P.; Urban, Sinisa; Otzen, Daniel E.</p> <p>2015-01-01</p> <p>Despite the ubiquity of helical membrane proteins in nature and their pharmacological importance, the mechanisms guiding their folding remain unclear. We performed kinetic folding and unfolding experiments on 69 mutants (engineered every 2–3 residues throughout the 178-residue transmembrane domain) of GlpG, a membrane-embedded rhomboid protease from Escherichia coli. The only clustering of significantly positive ϕ-values occurs at the cytosolic termini of transmembrane helices 1 and 2, which we identify as a compact nucleus. The three loops flanking these helices show a preponderance of negative ϕ-values, which are sometimes taken to be indicative of nonnative interactions in the transition state. Mutations in transmembrane helices 3–6 yielded predominantly ϕ-values near zero, indicating that this part of the protein has denatured-state–level structure in the transition state. We propose that loops 1–3 undergo conformational rearrangements to position the folding nucleus correctly, which then drives folding of the rest of the domain. A compact N-terminal nucleus is consistent with the vectorial nature of cotranslational membrane insertion found in vivo. The origin of the interactions in the transition state that lead to a large number of negative ϕ-values remains to be elucidated. PMID:26056273</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/1341070','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/1341070"><span>Pathobiology and management of hypergastrinemia and the Zollinger-Ellison syndrome.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hirschowitz, B I</p> <p>1992-01-01</p> <p>Gastrin is both stimulatory and trophic to the cells of the gastric fundus--parietal and peptic cells, and enterochromaffin-like (ECL) cells which are major intermediaries of the gastrin effect. Gastrin (from the antrum) and acid (from the fundus) represent the interactive positive and negative limbs of a feedback loop. The nature and extent of sub-loops, perhaps involving the vagus, acetylcholine, histamine, and other peptides and cell products are at present unclear or unknown. Loss of either gastrin or acid has predictable consequences. Absent acid, as in pernicious anemia or as a result of omeprazole, leads to hypergastrinemia. In rats, such hypergastrinemia (gastrin > 1,000 pg/ml) causes fundic ECL hyperplasia and, eventually, carcinoids; in humans with pernicious anemia, hypergastrinemia causes ECL-cell hyperplasia, which may progress to carcinoids that are reversible upon withdrawal of gastrin, illustrated by three cases described here. Loss of gastrin by antrectomy for duodenal ulcer leads to fundic involution and marked reduction in basal acid output, maximal acid output, and fundic histamine. An uncontrolled excess of gastrin, as from a gastrinoma outside the negative feedback loop, causes acid and pepsin hypersecretion with upper GI mucosal damage, the Zollinger-Ellison syndrome. This paper summarizes the abnormal regulation of gastrin and the biology, natural history, diagnosis, and management of ZE syndrome by medical and surgical means.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/959667-small-molecule-inhibition-activation-loop-trans-phosphorylation-igf1-receptor','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/959667-small-molecule-inhibition-activation-loop-trans-phosphorylation-igf1-receptor"><span>Small-Molecule Inhibition and Activation-Loop Trans-Phosphorylation of the IGF1 Receptor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wu,J.; Li, W.; Craddock, B.</p> <p>2008-01-01</p> <p>The insulin-like growth factor-1 receptor (IGF1R) is a receptor tyrosine kinase (RTK) that has a critical role in mitogenic signalling during embryogenesis and an antiapoptotic role in the survival and progression of many human tumours. Here, we present the crystal structure of the tyrosine kinase domain of IGF1R (IGF1RK), in its unphosphorylated state, in complex with a novel compound, cis-3-[3-(4-methyl-piperazin-l-yl)-cyclobutyl]-1-(2-phenyl-quinolin-7-yl)-imidazo[1, 5-a]pyrazin-8-ylamine (PQIP), which we show is a potent inhibitor of both the unphosphorylated (basal) and phosphorylated (activated) states of the kinase. PQIP interacts with residues in the ATP-binding pocket and in the activation loop, which confers specificity for IGF1RK andmore » the highly related insulin receptor (IR) kinase. In this crystal structure, the IGF1RK active site is occupied by Tyr1135 from the activation loop of an symmetry (two-fold)-related molecule. This dimeric arrangement affords, for the first time, a visualization of the initial trans-phosphorylation event in the activation loop of an RTK, and provides a molecular rationale for a naturally occurring mutation in the activation loop of the IR that causes type II diabetes mellitus.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760003454','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760003454"><span>Monitoring estuarine circulation and ocean waste dispersion using an integrated satellite-aircraft-drogue approach. [Delaware coast and Delaware Bay</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Klemas, V. (Principal Investigator); Davis, G.; Wang, H.</p> <p>1975-01-01</p> <p>The author has identified the following significant results. An inexpensive, integrated drogue-aircraft-satellite approach was developed which is based on the Lagrangian technique and employs remotely tracked drogues and dyes together with satellite observation of natural tracers, such as suspended sediment. Results include current circulation studies in Delaware Bay in support of an oil slick movement model; investigations of the dispersion and movement of acid wastes dumped 40 miles off the Delaware coast; and coastal current circulation. In each case, the integrated drogue-aircraft-satellite approach compares favorably with other techniques on the basis of accuracy, cost effectiveness, and performance under severe weather conditions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720014635&hterms=emotional&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Demotional','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720014635&hterms=emotional&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Demotional"><span>Advantages of cryopumping with liquid hydrogen instead of helium refrigerators</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Anderson, J. W.; Tueller, J. E.</p> <p>1972-01-01</p> <p>Open loop hydrogen vaporizers and helium refrigerators are compared for operational complexity, installation and operating cost, and safety requirements. Data from two vacuum chambers using helium refrigerators are used to provide comparative data. In general, the use of hydrogen is attractive in the larger systems, even when extra safety precautions are taken. Emotional resistance to the use of hydrogen because of safety requirements is considered great. However, the experience gained in the handling of large quantities of cryogenics, particularly hydrogen and liquefied natural gases, should be considered in the design of open loop hydrogen cooling systems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1439460','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1439460"><span>Leading-Color Fully Differential Two-Loop Soft Corrections to QCD Dipole Showers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Dulat, Falko; Höche, Stefan; Prestel, Stefan</p> <p></p> <p>We compute the next-to-leading order corrections to soft-gluon radiation differentially in the one-emission phase space. We show that their contribution to the evolution of color dipoles can be obtained in a modified subtraction scheme, such that both one- and two-emission terms are amenable to Monte-Carlo integration. The two-loop cusp anomalous dimension is recovered naturally upon integration over the full phase space. We present two independent implementations of the new algorithm in the two event generators Pythia and Sherpa, and we compare the resulting fully differential simulation to the CMW scheme.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1982STIN...8330942E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1982STIN...8330942E"><span>Wide-beam sensors for controlling dual-delay systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Edwards, J. B.; Twemlow, J. K.</p> <p>1982-09-01</p> <p>A class of dual delay feedback systems of open loop transfer function G(s) = k exp(-Xs)/l - exp(-Ws) is shown to be unstable if ratio X/W is noninteger. By means of z-transform techniques it is shown that, by using a feedback transducer that senses over a substantial distance either side of its central axis, closed-loop stability may be restored. Such transducers, termed widebeam sensors, include transmission, backscatter and natural radiation types as well as electromechanical conveyor belt weighers. Designing transducers for very narrow beams may not be desirable from the overall system viewpoint.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JPCM...21g8001G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JPCM...21g8001G"><span>COMMENT: Comment on 'Particle size dependent exchange bias and cluster-glass states in LaMn0.7Fe0.3O3 '</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geshev, J.</p> <p>2009-02-01</p> <p>Thakur et al (2008 J. Phys.: Condens. Matter 20 195215) have recently reported magnetization hysteresis loops shifted along the field axis of the cluster-glass compound LaMn0.7Fe0.3O3, attributed there to exchange bias induced at ferromagnetic/spin-glass-like interfaces. The present comment affirms that their results are insufficient for assigning the phenomenon solely to exchange bias since the corresponding field shift, if any, cannot be separated from that of a minor hysteresis loop of a ferromagnet, naturally displaced from the origin.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED111631.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED111631.pdf"><span>Human Requirements of Flight. Aviation and Spaceflight. Aerospace Education III.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Coard, E. A.</p> <p></p> <p>This book, one in the series on Aerospace Education III, deals with the general nature of human physiology during space flights. Chapter 1 begins with a brief discussion of the nature of the atmosphere. Other topics examined in this chapter include respiration and circulation, principles and problems of vision, noise and vibration, and…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT.......124A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT.......124A"><span>Spatially-protected Topology and Group Cohomology in Band Insulators</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alexandradinata, A.</p> <p></p> <p>This thesis investigates band topologies which rely fundamentally on spatial symmetries. A basic geometric property that distinguishes spatial symmetry regards their transformation of the spatial origin. Point groups consist of spatial transformations that preserve the spatial origin, while un-split extensions of the point groups by spatial translations are referred to as nonsymmorphic space groups. The first part of the thesis addresses topological phases with discretely-robust surface properties: we introduce theories for the Cnv point groups, as well as certain nonsymmorphic groups that involve glide reflections. These band insulators admit a powerful characterization through the geometry of quasimomentum space; parallel transport in this space is represented by the Wilson loop. The non-symmorphic topology we study is naturally described by a further extension of the nonsymmorphic space group by quasimomentum translations (the Wilson loop), thus placing real and quasimomentum space on equal footing -- here, we introduce the language of group cohomology into the theory of band insulators. The second part of the thesis addresses topological phases without surface properties -- their only known physical consequences are discrete signatures in parallel transport. We provide two such case studies with spatial-inversion and discrete-rotational symmetries respectively. One lesson learned here regards the choice of parameter loops in which we carry out transport -- the loop must be chosen to exploit the symmetry that protects the topology. While straight loops are popular for their connection with the geometric theory of polarization, we show that bent loops also have utility in topological band theory.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730017657','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730017657"><span>Wave-mean flow interactions in the upper atmosphere</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lindzen, R. S.</p> <p>1973-01-01</p> <p>The nature of internal gravity waves is described with special emphasis on their ability to transport energy and momentum. The conditions under which these fluxes interact with the mean state of the atmosphere are described and the results are applied to various problems of the upper atmosphere, including the quasi-biennial oscillation, the heat budget of the thermosphere, the general circulation of the mesosphere, turbulence in the mesosphere, and the 4-day circulation of the Venusian atmosphere.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1010658','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1010658"><span>Relationship between Gastrointestinal Peptides, Intestinal Wall Compliance, and Vascular Resistance</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1983-01-20</p> <p>the motility of the small intestine with special reference to the dumping syndrome. Acta Chir , Scand, 128: 530-540, 1964, 173. Piper, P,J., S.I...cholecystokinin on splanchnic circulation in the dog. Acta Chir . Scand. 139: 687- 690, 1973. 220. Thulin, L., and P. Olsson, Effects of pure natural...cholecystokinin on splanchnic circulation in the dog. Acta Chir . Scand. 139: 681- 686, 1973. 221. Thulin, L., and P. Olsson. Effects of intestinal peptide</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15641638','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15641638"><span>Circulating natural killer T cells in patients with asthma.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ikegami, Yasuhiko; Yokoyama, Akihito; Haruta, Yoshinori; Hiyama, Keiko; Kohno, Nobuoki</p> <p>2004-01-01</p> <p>Recent studies suggest that therapies targeted at depletion or limiting of natural killer (NK) T cells may be a possible strategy for the treatment of asthma. In the present study, we measured the number of circulating V alpha24+ NKT cells in 32 asthmatic patients and compared these patients with 29 nonatopic healthy controls. We investigated the relationships between NKT cell number and clinical variables such as the number of eosinophils, the circulating level of IgE, and the severity of asthma. In addition, we also investigated the ability of NKT cells to proliferate in response to alpha-galactosyl ceramide (alpha-GalCer) in vitro. The V alpha24+ NKT cell counts of asthmatic patients were significantly lower than those of healthy controls. There were no significant differences observed in asthmatic patients among the subgroups in terms of atopic status and severity. There was no significant correlation between the number of NKT cells and clinical variables. The proliferative response to alpha-GalCer of the patients and controls was not significantly different, indicating no intrinsic proliferative defect of NKT cells in asthma. These results suggest that the number of circulating NKT cells was already decreased in patients with asthma. Further study, such as the evaluation of lung NKT cells, will be needed to determine the role of NKT cells in patients with asthma.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...621531G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...621531G"><span>In vivo acoustic and photoacoustic focusing of circulating cells</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Galanzha, Ekaterina I.; Viegas, Mark G.; Malinsky, Taras I.; Melerzanov, Alexander V.; Juratli, Mazen A.; Sarimollaoglu, Mustafa; Nedosekin, Dmitry A.; Zharov, Vladimir P.</p> <p>2016-03-01</p> <p>In vivo flow cytometry using vessels as natural tubes with native cell flows has revolutionized the study of rare circulating tumor cells in a complex blood background. However, the presence of many blood cells in the detection volume makes it difficult to count each cell in this volume. We introduce method for manipulation of circulating cells in vivo with the use of gradient acoustic forces induced by ultrasound and photoacoustic waves. In a murine model, we demonstrated cell trapping, redirecting and focusing in blood and lymph flow into a tight stream, noninvasive wall-free transportation of blood, and the potential for photoacoustic detection of sickle cells without labeling and of leukocytes targeted by functionalized nanoparticles. Integration of cell focusing with intravital imaging methods may provide a versatile biological tool for single-cell analysis in circulation, with a focus on in vivo needleless blood tests, and preclinical studies of human diseases in animal models.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. 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