Advances in Spacecraft Brine Water Recovery: Development of a Radial Vaned Capillary Drying Tray

NASA Technical Reports Server (NTRS)

Callahan, Michael R.; Sargusingh, Miriam J.; Pickering, Karen D.; Weislogel, Mark M.

2014-01-01

Technology improvements in the recovery of water from brine are critical to establishing closed-loop water recovery systems, enabling long-duration missions, and achieving a sustained human presence in space. A genre of 'in-place drying' brine water recovery concepts, collectively referred to herein as Brine Residual In-Containment, are under development. These brine water recovery concepts aim to increase the overall robustness and reliability of the brine recovery process by performing drying inside the container used for final disposal of the solid residual waste. Implementation of in-place drying techniques have been demonstrated for applications where gravity is present and phase separation occurs naturally by buoyancy-induced effects. In this work, a microgravity-compatible analogue of the gravity-driven phase separation process is considered by exploiting capillarity in the form of surface wetting, surface tension, and container geometry. The proposed design consists of a series of planar radial vanes aligned about a central slotted core. Preliminary testing of the fundamental geometry in a reduced gravity environment has shown the device to spontaneously fill and saturate rapidly, thereby creating a free surface from which evaporation and phase separation can occur similar to a terrestrial-like 'cylindrical pool' of fluid. Mathematical modeling and analysis of the design suggest predictable rates of filling and stability of fluid containment as a function of relevant system dimensions; e.g., number of vanes, vane length, width, and thickness. A description of the proposed capillary design solution is presented along with preliminary results from testing, modeling, and analysis of the system.

Advancements in Spacecraft Brine Water Recovery: Development of a Radial Vaned Capillary Drying Tray

NASA Technical Reports Server (NTRS)

Callahan, Michael R.; Sargusingh, Miriam J.; Pickerin, Karen D.; Weislogel, Mark M.

2013-01-01

Technology improvements in the recovery of water from brine are critical to establishing closedloop water recovery systems, enabling long duration missions, and achieving a sustained human presence in space. A genre of 'in-place drying' brine water recovery concepts, collectively referred to herein as Brine Residual In-Containment (BRIC), are under development which aim to increase the overall robustness and reliability of the brine recovery process by performing drying inside the container used for final disposal of the solid residual waste. Implementation of in-place drying techniques have been demonstrated for applications where gravity is present and phase separation occurs naturally by buoyancy induced effects. In this work, a microgravity compatible analogue of the gravity-driven phase separation process is considered by exploiting capillarity in the form of surface wetting, surface tension, and container geometry. The proposed design consists of a series of planar radial vanes aligned about a central slotted core. Preliminary testing of the fundamental geometry in a reduced gravity environment has shown the device to spontaneously fill and saturate rapidly creating a free surface from which evaporation and phase separation can occur similar to a 1-g like 'cylindrical pool' of fluid. Mathematical modeling and analysis of the design suggest predictable rates of filling and stability of fluid containment as a function of relevant system dimensions, e.g., number of vanes, vane length, width, and thickness. A description of the proposed capillary design solution is presented along with preliminary results from testing, modeling and analysis of the system.

Membrane-less variable focus liquid lens with manual actuation

NASA Astrophysics Data System (ADS)

Patra, Roshan; Agarwal, Shivam; Kondaraju, Sasidhar; Bahga, Supreet Singh

2017-04-01

We present a tunable, membrane-less, mechanical-wetting liquid lens that can be actuated manually using a linear actuator such as screw or piston. The operation of the liquid lens is based on deforming the interface separating two immiscible liquids with different refractive indices, while pinning the three-phase contact line at the sharp edge of lens aperture. Our lens design improves upon the existing designs of mechanical-wetting lenses by eliminating the use of complex actuation mechanisms, without compromising on the optical performance. We demonstrate the operation of the liquid lens by tuning its power back and forth from negative to positive by simple rotation of a screw. We also present an analytical description of the focal length of the lens and validate it with detailed experimental measurements. Our experiments show that the focal length of the liquid lens can be tuned repeatably without any adverse effects of hysteresis and gravity.

Wetting dynamics of a collapsing fluid hole

NASA Astrophysics Data System (ADS)

Bostwick, J. B.; Dijksman, J. A.; Shearer, M.

2017-01-01

The collapse dynamics of an axisymmetric fluid cavity that wets the bottom of a rotating bucket bound by vertical sidewalls are studied. Lubrication theory is applied to the governing field equations for the thin film to yield an evolution equation that captures the effect of capillary, gravitational, and centrifugal forces on this converging flow. The focus is on the quasistatic spreading regime, whereby contact-line motion is governed by a constitutive law relating the contact-angle to the contact-line speed. Surface tension forces dominate the collapse dynamics for small holes with the collapse time appearing as a power law whose exponent compares favorably to experiments in the literature. Gravity accelerates the collapse process. Volume dependence is predicted and compared with experiment. Centrifugal forces slow the collapse process and lead to complex dynamics characterized by stalled spreading behavior that separates the large and small hole asymptotic regimes.

Under-oil superhydrophilic wetted PVDF electrospun modified membrane for continuous gravitational oil/water separation with outstanding flux.

PubMed

Obaid, M; Mohamed, Hend Omar; Yasin, Ahmed S; Yassin, Mohamed A; Fadali, Olfat A; Kim, HakYong; Barakat, Nasser A M

2017-10-15

Water in the world is becoming an increasingly scarce commodity and the membrane technology is a most effective strategy to address this issue. However, the fouling and low flux of the polymeric membrane remains the big challenges. Novel modified Polyvinylidene fluoride (PVDF) membrane was introduced, in this work, using a novel treatment technique for an electrospun polymeric PVDF membrane to be used in oil/water separation systems. The Characterizations of the modified and pristine membranes showed distinct changes in the phase and crystal structure of the membrane material as well as the wettability. The modification process altered the surface morphology and structure of the membrane by forming hydrophilic microspheres on the membrane surface. Therefore, the proposed treatment converts the membrane from highly hydrophobic to be a superhydrophilic under-oil when wetted with water. Accordingly, in the separation of oil/water mixtures, the modified membrane can achieve an outstanding flux of 20664 L/m 2 . hr under gravity, which is higher than the pristine membrane by infinite times. Moreover, in the separation of the emulsion, a high flux of 2727 L/m 2 . h was achieved. The results exhibited that the modified membrane can treat a huge amount of oily water with a minimal energy consumption. The corresponding separation efficiencies of both of oil/water mixtures and emulsion are more than 99%. The achieved characteristics for the modified and pristine membranes could be exploited to design a novel continuous system for oil/water separation with an excellent efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of colostrum on gravity separation of milk somatic cells in skim milk.

PubMed

Geer, S R; Barbano, D M

2014-02-01

Our objective was to determine if immunoglobulins play a role in the gravity separation (rising to the top) of somatic cells (SC) in skim milk. Other researchers have shown that gravity separation of milk fat globules is enhanced by IgM. Our recent research found that bacteria and SC gravity separate in both raw whole and skim milk and that heating milk to >76.9 °C for 25s stopped gravity separation of milk fat, SC, and bacteria. Bovine colostrum is a good natural source of immunoglobulins. An experiment was designed where skim milk was heated at high temperatures (76 °C for 7 min) to stop the gravity separation of SC and then colostrum was added back to try to restore the gravity separation of SC in increments to achieve 0, 0.4, 0.8, 2.0, and 4.0 g/L of added immunoglobulins. The milk was allowed to gravity separate for 22 h at 4 °C. The heat treatment of skim milk was sufficient to stop the gravity separation of SC. The treatment of 4.0 g/L of added immunoglobulins was successful in restoring the gravity separation of SC as compared with raw skim milk. Preliminary spore data on the third replicate suggested that bacterial spores gravity separate the same way as the SC in heated skim milk and heated skim milk with 4.0 g/L of added immunoglobulins. Strong evidence exists that immunoglobulins are at least one of the factors necessary for the gravity separation of SC and bacterial spores. It is uncertain at this time whether SC are a necessary component for gravity separation of fat, bacteria, and spores to occur. Further research is needed to determine separately the role of immunoglobulins and SC in gravity separation of bacteria and spores. Understanding the mechanism of gravity separation may allow the development of a continuous flow technology to remove SC, bacteria, and spores from milk. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Development and Optimization of Gas-Assisted Gravity Drainage (GAGD) Process for Improved Light Oil Recovery

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

Dandina N. Rao; Subhash C. Ayirala; Madhav M. Kulkarni

This is the final report describing the evolution of the project ''Development and Optimization of Gas-Assisted Gravity Drainage (GAGD) Process for Improved Light Oil Recovery'' from its conceptual stage in 2002 to the field implementation of the developed technology in 2006. This comprehensive report includes all the experimental research, models developments, analyses of results, salient conclusions and the technology transfer efforts. As planned in the original proposal, the project has been conducted in three separate and concurrent tasks: Task 1 involved a physical model study of the new GAGD process, Task 2 was aimed at further developing the vanishing interfacialmore » tension (VIT) technique for gas-oil miscibility determination, and Task 3 was directed at determining multiphase gas-oil drainage and displacement characteristics in reservoir rocks at realistic pressures and temperatures. The project started with the task of recruiting well-qualified graduate research assistants. After collecting and reviewing the literature on different aspects of the project such gas injection EOR, gravity drainage, miscibility characterization, and gas-oil displacement characteristics in porous media, research plans were developed for the experimental work to be conducted under each of the three tasks. Based on the literature review and dimensional analysis, preliminary criteria were developed for the design of the partially-scaled physical model. Additionally, the need for a separate transparent model for visual observation and verification of the displacement and drainage behavior under gas-assisted gravity drainage was identified. Various materials and methods (ceramic porous material, Stucco, Portland cement, sintered glass beads) were attempted in order to fabricate a satisfactory visual model. In addition to proving the effectiveness of the GAGD process (through measured oil recoveries in the range of 65 to 87% IOIP), the visual models demonstrated three possible multiphase mechanisms at work, namely, Darcy-type displacement until gas breakthrough, gravity drainage after breakthrough and film-drainage in gas-invaded zones throughout the duration of the process. The partially-scaled physical model was used in a series of experiments to study the effects of wettability, gas-oil miscibility, secondary versus tertiary mode gas injection, and the presence of fractures on GAGD oil recovery. In addition to yielding recoveries of up to 80% IOIP, even in the immiscible gas injection mode, the partially-scaled physical model confirmed the positive influence of fractures and oil-wet characteristics in enhancing oil recoveries over those measured in the homogeneous (unfractured) water-wet models. An interesting observation was that a single logarithmic relationship between the oil recovery and the gravity number was obeyed by the physical model, the high-pressure corefloods and the field data.« less

Capillarity-Driven Bubble Separations

NASA Astrophysics Data System (ADS)

Wollman, Andrew; Weislogel, Mark; Dreyer, Michael

2013-11-01

Techniques for phase separation in the absence of gravity continue to be sought after 5 decades of space flight. This work focuses on the fundamental problem of gas bubble separation in bubbly flows through open wedge-shaped channel in a microgravity environment. The bubbles appear to rise in the channel and coalesce with the free surface. Forces acting on the bubble are the combined effects of surface tension, wetting conditions, and geometry; not buoyancy. A single dimensionless group is identified that characterizes the bubble behavior and supportive experiments are conducted in a terrestrial laboratory, in a 2.1 second drop tower, and aboard the International Space Station as part of the Capillary Channel Flow (CCF) experiments. The data is organized into regime maps that provide insight on passive phase separations for applications ranging from liquid management aboard spacecraft to lab-on-chip technologies. NASA NNX09AP66A, NASA Oregon Space Grant NNX10AK68H, NASA NNX12AO47A, DLR 50WM0535/0845/1145

Bubble Formation at a Submerged Orifice in Reduced Gravity

NASA Technical Reports Server (NTRS)

Buyevich, Yu A.; Webbon, Bruce W.

1994-01-01

The dynamic regime of gas injection through a circular plate orifice into an ideally wetting liquid is considered, when successively detached bubbles may be regarded as separate identities. In normal gravity and at relatively low gas flow rates, a growing bubble is modeled as a spherical segment touching the orifice perimeter during the whole time of its evolution. If the flow rate exceeds a certain threshold value, another stage of the detachment process takes place in which an almost spherical gas envelope is connected with the orifice by a nearly cylindrical stem that lengthens as the bubble rises above the plate. The bubble shape resembles then that of a mushroom and the upper envelope continues to grow until the gas supply through the stem is completely cut off. Such a stage is always present under conditions of sufficiently low gravity, irrespective of the flow rate. Two major reasons make for bubble detachment: the buoyancy force and the force due to the momentum inflow into the bubble with the injected gas. The former force dominates the process at normal gravity whereas the second one plays a key role under negligible gravity conditions. It is precisely this fundamental factor that conditions the drastic influence on bubble growth and detachment that changes in gravity are able to cause. The frequency of bubble formation is proportional to and the volume of detached bubbles is independent of the gas flow rate in sufficiently low gravity, while at normal and moderately reduced gravity conditions the first variable slightly decreases and the second one almost linearly increases as the flow rate grows. Effects of other parameters, such as the orifice radius, gas and liquid densities, and surface tension are discussed.

Gravity separation of fat, somatic cells, and bacteria in raw and pasteurized milks.

PubMed

Caplan, Z; Melilli, C; Barbano, D M

2013-04-01

The objective of experiment 1 was to determine if the extent of gravity separation of milk fat, bacteria, and somatic cells is influenced by the time and temperature of gravity separation or the level of contaminating bacteria present in the raw milk. The objective of experiment 2 was to determine if different temperatures of milk heat treatment affected the gravity separation of milk fat, bacteria, and somatic cells. In raw milk, fat, bacteria, and somatic cells rose to the top of columns during gravity separation. About 50 to 80% of the fat and bacteria were present in the top 8% of the milk after gravity separation of raw milk. Gravity separation for 7h at 12°C or for 22h at 4°C produced equivalent separation of fat, bacteria, and somatic cells. The completeness of gravity separation of fat was influenced by the level of bacteria in the milk before separation. Milk with a high bacterial count had less (about 50 to 55%) gravity separation of fat than milk with low bacteria count (about 80%) in 22h at 4°C. Gravity separation caused fat, bacteria, and somatic cells to rise to the top of columns for raw whole milk and high temperature, short-time pasteurized (72.6°C, 25s) whole milk. Pasteurization at ≥76.9°C for 25s prevented all 3 components from rising, possibly due to denaturation of native bovine immunoglobulins that normally associate with fat, bacteria, and somatic cells during gravity separation. Gravity separation can be used to produce reduced-fat milk with decreased bacterial and somatic cell counts, and may be a critical factor in the history of safe and unique traditional Italian hard cheeses produced from gravity-separated raw milk. A better understanding of the mechanism of this natural process could lead to the development of new nonthermal thermal technology (that does not involve heating the milk to high temperatures) to remove bacteria and spores from milk or other liquids. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Flotability and flotation separation of polymer materials modulated by wetting agents.

PubMed

Wang, Hui; Wang, Chong-qing; Fu, Jian-gang; Gu, Guo-hua

2014-02-01

The surface free energy, surface tension and contact angles were performed to investigate the properties of wetting agents. Adsorption of wetting agents changes wetting behavior of polymer resins. Flotability of polymer materials modulated by wetting agents was studied, and wetting agents change significantly flotability of polymer materials. The flotability decreases with increasing the concentration of wetting agents, and the wetting ability is lignin sulfonate (LS)>tannic acid (TA)>methylcellulose (MC)>triton X-100 (TX-100) (from strong to weak). There is significant difference in the flotability between polymer resins and plastics due to the presence of additives in the plastics. Flotation separation of two-component and multicomponent plastics was conducted based on the flotability modulated by wetting agents. The two-component mixtures can be efficiently separated using proper wetting agent through simple flotation flowsheet. The multicomponent plastic mixtures can be separated efficiently through multi-stage flotation using TA and LS as wetting agents, and the purity of separated component was above 94%, and the recovery was more than 93%. Copyright © 2013 Elsevier Ltd. All rights reserved.

The results of determining the gravity potential difference on the measurement of the relativistic frequency shift of the mobile frequency standard

NASA Astrophysics Data System (ADS)

Gienko, Elena; Kanushin, Vadim; Tolstikov, Alexander; Karpik, Alexander; Kosarev, Nikolay; Ganagina, Irina

2016-04-01

In 2015 in the research on the grant of the Russian science Foundation No. 14-27-00068 was experimentally confirmed the possibility of measuring the gravity potential difference on relativistic frequency shift of the mobile hydrogen standard CH1-1006 (relative frequency instability of the order 10E-14). Hydrogen frequency standard CH1-1006 was calibrated in the system of secondary standard WET 1-19 (SNIIM, Novosibirsk, Russia) and transported to the place of experiment (a distance of 550 km, the Russian Federation, Republic of Altai), where it moved between the measured points at a distance of 35 km with a height difference of 850 meters. To synchronize spatially separated standard CH1-1006 and secondary standard WET 1-19 was applied the method "CommonView", based on the processing results of pseudorange phase GNSS measurements at the point of placement hours. Changing the frequency standard CH1-1006, measured in the system of secondary standard WET 1-19 and associated with his movement between points and the change of gravitational potential, was equal to 7.98•10E-14. Evaluation of root-mean-square two-sample frequency deviation of the standard at the time interval of the experiment was equal to the value of 7.27•10E-15. To control the results of the frequency determination of the gravity potential difference between the points were made high precision gravimetric measurements with an error of 6 MkGal and GNSS measurements for the coordinate determinations in ITRF2008 with an accuracy of 2-5 cm. The difference between the results of the frequency determination of the gravity potential difference with control data from GNSS and gravimetric measurements was estimated 16% of the total value that corresponds to the error of frequency measurement in the experiment. The possibility of using a single moveable frequency standard to determine the gravity potential difference at spaced points using the method of "CommonView", without the use of optical communications between base and mobile frequency standards was shown. Future improvement in engineering the frequency standards and the measurement technique, developed in the course of our experiments, will allow developing one of the most promising areas of relativistic geodesy - autonomous measurement of heights in a common world system which is currently a vitally important problem of geodesy. We got the practical results, which offer further opportunities for more accurate planning of experimental research and the creation of a global relativistic geoid for the formation of a unified global system of heights.

Direct measurement of sub-surface mass change using the variable-baseline gravity gradient method

USGS Publications Warehouse

Kennedy, Jeffrey; Ferré, Ty P.A.; Güntner, Andreas; Abe, Maiko; Creutzfeldt, Benjamin

2014-01-01

Time-lapse gravity data provide a direct, non-destructive method to monitor mass changes at scales from cm to km. But, the effectively infinite spatial sensitivity of gravity measurements can make it difficult to isolate the signal of interest. The variable-baseline gravity gradient method, based on the difference of measurements between two gravimeters, is an alternative to the conventional approach of individually modeling all sources of mass and elevation change. This approach can improve the signal-to-noise ratio for many applications by removing the contributions of Earth tides, loading, and other signals that have the same effect on both gravimeters. At the same time, this approach can focus the support volume within a relatively small user-defined region of the subsurface. The method is demonstrated using paired superconducting gravimeters to make for the first time a large-scale, non-invasive measurement of infiltration wetting front velocity and change in water content above the wetting front.

A visualization study on two-phase gravity drainage in porous media by using magnetic resonance imaging.

PubMed

Teng, Ying; Liu, Yu; Jiang, Lanlan; Song, Yongchen; Zhao, Jiafei; Zhang, Yi; Wang, Dayong

2016-09-01

Gravity drainage characteristics are important to improve our understanding of gas-liquid or liquid-liquid two-phase flow in porous media. Stable or unstable displacement fronts that controlled by the capillary force, viscous force, gravitational force, etc., are relevant features of immiscible two-phase flow. In this paper, three dimensionless parameters, namely, the gravity number, the capillary number and the Bond number, were used to describe the effect of the above mentioned forces on two-phase drainage features, including the displacement front and final displacing-phase saturation. A series of experiments on the downward displacement of a viscous fluid by a less viscous fluid in a vertical vessel that is filled with quartz beads are performed by using magnetic resonance imaging (MRI). The experimental results indicate that the wetting properties at both high and low capillary numbers exert remarkable control on the fluid displacement. When the contact angle is lower than 90°, i.e., the displaced phase is the wetting phase, the average velocity Vf of the interface of the two phases (displacement front velocity) is observably lower than when the displaced phase is the non-wetting phase (contact angle higher than 90°). The results show that a fingering phenomenon occurs when the gravity number G is less than the critical gravity number G'=Δμ/μg. Moreover, the higher Bond number results in higher final displacing-phase saturation, whereas the capillary number has an opposite effect. Copyright © 2016 Elsevier Inc. All rights reserved.

Influence of gravity level and interfacial energies on dispersion-forming tendencies in hypermonotectic Cu-Pb-Al alloys

NASA Technical Reports Server (NTRS)

Andrews, J. B.; Curreri, P. A.; Sandlin, A. C.

1988-01-01

Results on the nondirectional solidification of several hypermonotectic Cu-Pb-Al alloys were obtained aboard NASA's KC-135 zero-gravity aircraft in order to determine the influence of interfacial energies and gravity levels on dispersion-forming tendencies. The Al content was systematially varied in the alloys. The dispersion-forming ability is correlated with gravity level during solidification, the interfacial energy between the immiscible phases, and the tendency for the minority immiscible phase to wet the walls of the crucible.

Rapid deceleration-driven wetting transition during pendant drop deposition on superhydrophobic surfaces.

PubMed

Kwon, Hyuk-Min; Paxson, Adam T; Varanasi, Kripa K; Patankar, Neelesh A

2011-01-21

A hitherto unknown mechanism for wetting transition is reported. When a pendant drop settles upon deposition, there is a virtual "collision" where its center of gravity undergoes rapid deceleration. This induces a high water hammer-type pressure that causes wetting transition. A new phase diagram shows that both large and small droplets can transition to wetted states due to the new deceleration driven and the previously known Laplace mechanisms, respectively. It is explained how the attainment of a nonwetted Cassie-Baxter state is more restrictive than previously known.

Rapid Deceleration-Driven Wetting Transition during Pendant Drop Deposition on Superhydrophobic Surfaces

NASA Astrophysics Data System (ADS)

Kwon, Hyuk-Min; Paxson, Adam T.; Varanasi, Kripa K.; Patankar, Neelesh A.

2011-01-01

A hitherto unknown mechanism for wetting transition is reported. When a pendant drop settles upon deposition, there is a virtual “collision” where its center of gravity undergoes rapid deceleration. This induces a high water hammer-type pressure that causes wetting transition. A new phase diagram shows that both large and small droplets can transition to wetted states due to the new deceleration driven and the previously known Laplace mechanisms, respectively. It is explained how the attainment of a nonwetted Cassie-Baxter state is more restrictive than previously known.

Numerical study of gravity effects on phase separation in a swirl chamber.

PubMed

Hsiao, Chao-Tsung; Ma, Jingsen; Chahine, Georges L

2016-01-01

The effects of gravity on a phase separator are studied numerically using an Eulerian/Lagrangian two-phase flow approach. The separator utilizes high intensity swirl to separate bubbles from the liquid. The two-phase flow enters tangentially a cylindrical swirl chamber and rotate around the cylinder axis. On earth, as the bubbles are captured by the vortex formed inside the swirl chamber due to the centripetal force, they also experience the buoyancy force due to gravity. In a reduced or zero gravity environment buoyancy is reduced or inexistent and capture of the bubbles by the vortex is modified. The present numerical simulations enable study of the relative importance of the acceleration of gravity on the bubble capture by the swirl flow in the separator. In absence of gravity, the bubbles get stratified depending on their sizes, with the larger bubbles entering the core region earlier than the smaller ones. However, in presence of gravity, stratification is more complex as the two acceleration fields - due to gravity and to rotation - compete or combine during the bubble capture.

A mean curvature model for capillary flows in asymmetric containers and conduits

NASA Astrophysics Data System (ADS)

Chen, Yongkang; Tavan, Noël; Weislogel, Mark M.

2012-08-01

Capillarity-driven flows resulting from critical geometric wetting criterion are observed to yield significant shifts of the bulk fluid from one side of the container to the other during "zero gravity" experiments. For wetting fluids, such bulk shift flows consist of advancing and receding menisci sometimes separated by secondary capillary flows such as rivulet-like flows along gaps. Here we study the mean curvature of an advancing meniscus in hopes of approximating a critical boundary condition for fluid dynamics solutions. It is found that the bulk shift flows behave as if the bulk menisci are either "connected" or "disconnected." For the connected case, an analytic method is developed to calculate the mean curvature of the advancing meniscus in an asymptotic sense. In contrast, for the disconnected case the method to calculate the mean curvature of the advancing and receding menisci uses a well-established procedure. Both disconnected and connected bulk shifts can occur as the first tier flow of more complex compound capillary flows. Preliminary comparisons between the analytic method and the results of drop tower experiments are encouraging.

Separating biological cells

NASA Technical Reports Server (NTRS)

Brooks, D. E.

1979-01-01

Technique utilizing electric field to promote biological cell separation from suspending medium in zero gravity increases speed, reduces sedimentation, and improves efficiency of separation in normal gravity.

Separator plate for a fuel cell

DOEpatents

Petri, R.J.; Meek, J.; Bachta, R.P.; Marianowski, L.G.

1996-04-02

A separator plate is described for a fuel cell comprising an anode current collector, a cathode current collector and a main plate, the main plate disposed between the anode current collector and the cathode current collector. The anode current collector forms a flattened peripheral wet seal structure and manifold wet seal structure on the anode side of the separator plate and the cathode current collector forms a flattened peripheral wet seal structure and manifold wet seal structure on the cathode side of the separator plate. In this manner, the number of components required to manufacture and assemble a fuel cell stack is reduced. 9 figs.

Separator plate for a fuel cell

DOEpatents

Petri, Randy J.; Meek, John; Bachta, Robert P.; Marianowski, Leonard G.

1996-01-01

A separator plate for a fuel cell comprising an anode current collector, a cathode current collector and a main plate, the main plate disposed between the anode current collector and the cathode current collector. The anode current collector forms a flattened peripheral wet seal structure and manifold wet seal structure on the anode side of the separator plate and the cathode current collector forms a flattened peripheral wet seal structure and manifold wet seal structure on the cathode side of the separator plate. In this manner, the number of components required to manufacture and assemble a fuel cell stack is reduced.

Methods and apparatus for catalytic hydrothermal gasification of biomass

DOEpatents

Elliott, Douglas C.; Butner, Robert Scott; Neuenschwander, Gary G.; Zacher, Alan H.; Hart, Todd R.

2012-08-14

Continuous processing of wet biomass feedstock by catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent separation of sulfur contaminants, or combinations thereof. Treatment further includes separating the precipitates out of the wet feedstock, removing sulfur contaminants, or both using a solids separation unit and a sulfur separation unit, respectively. Having removed much of the inorganic wastes and the sulfur that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogeneous catalyst for gasification.

Separation of biogenic materials by electrophoresis under zero gravity (L-3)

NASA Technical Reports Server (NTRS)

Kuroda, Masao

1993-01-01

Electrophoresis separates electrically charged materials by imposing a voltage between electrodes. Though free-flow electrophoresis is used without carriers such as colloids to separate and purify biogenic materials including biogenic cells and proteins in blood, its resolving power and separation efficiency is very low on Earth due to sedimentation, flotation, and thermal convection caused by the specific gravity differences between separated materials and buffer solutions. The objective of this experiment is to make a comparative study of various electrophoresis conditions on the ground and in zero-gravity in order to ultimately develop a method for separating various important 'vial' components which are difficult to separate on the ground.

Rapid Separation of Copper Phase and Iron-Rich Phase From Copper Slag at Low Temperature in a Super-Gravity Field

NASA Astrophysics Data System (ADS)

Lan, Xi; Gao, Jintao; Huang, Zili; Guo, Zhancheng

2018-03-01

A novel approach for quickly separating a metal copper phase and iron-rich phase from copper slag at low temperature is proposed based on a super-gravity method. The morphology and mineral evolution of the copper slag with increasing temperature were studied using in situ high-temperature confocal laser scanning microscopy and ex situ scanning electron microscopy and X-ray diffraction methods. Fe3O4 particles dispersed among the copper slag were transformed into FeO by adding an appropriate amount of carbon as a reducing agent, forming the slag melt with SiO2 at low temperature and assisting separation of the copper phase from the slag. Consequently, in a super-gravity field, the metallic copper and copper matte were concentrated as the copper phase along the super-gravity direction, whereas the iron-rich slag migrated in the opposite direction and was quickly separated from the copper phase. Increasing the gravity coefficient (G) significantly enhanced the separation efficiency. After super-gravity separation at G = 1000 and 1473 K (1200 °C) for 3 minutes, the mass fraction of Cu in the separated copper phase reached 86.11 wt pct, while that in the separated iron-rich phase was reduced to 0.105 wt pct. The recovery ratio of Cu in the copper phase was as high as up to 97.47 pct.

Rapid Separation of Copper Phase and Iron-Rich Phase From Copper Slag at Low Temperature in a Super-Gravity Field

NASA Astrophysics Data System (ADS)

Lan, Xi; Gao, Jintao; Huang, Zili; Guo, Zhancheng

2018-06-01

A novel approach for quickly separating a metal copper phase and iron-rich phase from copper slag at low temperature is proposed based on a super-gravity method. The morphology and mineral evolution of the copper slag with increasing temperature were studied using in situ high-temperature confocal laser scanning microscopy and ex situ scanning electron microscopy and X-ray diffraction methods. Fe3O4 particles dispersed among the copper slag were transformed into FeO by adding an appropriate amount of carbon as a reducing agent, forming the slag melt with SiO2 at low temperature and assisting separation of the copper phase from the slag. Consequently, in a super-gravity field, the metallic copper and copper matte were concentrated as the copper phase along the super-gravity direction, whereas the iron-rich slag migrated in the opposite direction and was quickly separated from the copper phase. Increasing the gravity coefficient (G) significantly enhanced the separation efficiency. After super-gravity separation at G = 1000 and 1473 K (1200 °C) for 3 minutes, the mass fraction of Cu in the separated copper phase reached 86.11 wt pct, while that in the separated iron-rich phase was reduced to 0.105 wt pct. The recovery ratio of Cu in the copper phase was as high as up to 97.47 pct.

Study of factors governing oil-water separation process using TiO₂ films prepared by spray deposition of nanoparticle dispersions.

PubMed

Gondal, Mohammed A; Sadullah, Muhammad S; Dastageer, Mohamed A; McKinley, Gareth H; Panchanathan, Divya; Varanasi, Kripa K

2014-08-27

Surfaces which possess extraordinary water attraction or repellency depend on surface energy, surface chemistry, and nano- and microscale surface roughness. Synergistic superhydrophilic-underwater superoleophobic surfaces were fabricated by spray deposition of nanostructured TiO2 on stainless steel mesh substrates. The coated meshes were then used to study gravity driven oil-water separation, where only the water from the oil-water mixture is allowed to permeate through the mesh. Oil-water separation efficiencies of up to 99% could be achieved through the coated mesh of pore sizes 50 and 100 μm, compared to no separation at all, that was observed in the case of uncoated meshes of the same material and pore sizes. An adsorbed water on the TiO2 coated surface, formation of a water-film between the wires that form the mesh and the underwater superoleophobicity of the structured surface are the key factors that contribute to the enhanced efficiency observed in oil-water separation. The nature of the oil-water separation process using this coated mesh (in which the mesh allows water to pass through the porous structure but resists wetting by the oil phase) minimizes the fouling of mesh so that the need for frequent replacement of the separating medium is reduced. The fabrication approach presented here can be applied for coating large surface areas and to develop a large-scale oil-water separation facility for oil-field applications and petroleum industries.

Adaptive mechanical-wetting lens actuated by ferrofluids

NASA Astrophysics Data System (ADS)

Cheng, Hui-Chuan; Xu, Su; Liu, Yifan; Levi, Shoshana; Wu, Shin-Tson

2011-04-01

We report an adaptive mechanical-wetting lens actuated by ferrofluids. The ferrofluids works like a piston to pump liquids in and out from the lens chamber, which in turn reshapes the lens curvature and changes the focal length. Both positive and negative lenses are demonstrated experimentally. The ferrofluid-actuated mechanical-wetting lens exhibits some attractive features, such as high resolution, fast response time, low power consumption, simple structure and electronic control, weak gravity effect, and low cost. Its potential applications in medical imaging, surveillance, and commercial electronics are foreseeable.

Enriching and Separating Primary Copper Impurity from Pb-3 Mass Pct Cu Melt by Super-Gravity Technology

NASA Astrophysics Data System (ADS)

Yang, Yuhou; Song, Bo; Song, Gaoyang; Yang, Zhanbing; Xin, Wenbin

2016-10-01

In this study, super-gravity technology was introduced in the lead bullion-refining process to investigate the enriching and separating laws of copper impurity from Pb-3 mass pct Cu melt. With the gravity coefficient G = 700 at the cooling rate of ν = 5 K min-1, the entire copper phase gathers at the upper area of the sample, and it is hard to find any copper particles at the bottom area of the sample. The floatation movement of copper phase was greatly intensified by super gravity and the mass pct of copper in tailing lead is up to 8.631 pct, while that in the refined lead is only 0.113 pct. The refining rate of lead bullion reached up to 94.27 pct. Copper-phase impurity can be separated effectively from Pb-3 mass pct Cu melt by filtration method in super-gravity field, and the separation efficiency increased with the increasing gravity coefficient in the range of G ≥ 10. After filtration at 613 K (340 °C) with gravity coefficient G = 100 for 10 minutes, the refined lead, with just 0.157 mass pct copper impurity, was separated to the bottom of the crucible, and the copper dross containing only 23.56 mass pct residual lead was intercepted by the carbon fiber felt, leading to the separation efficiency up to 96.18 pct (meaning a great reduction in metal loss).

Dynamics of viscous drops confined in a rough medium

NASA Astrophysics Data System (ADS)

Keiser, Ludovic; Gas, Armelle; Jaafar, Khalil; Bico, Jose; Reyssat, Etienne

2017-11-01

We focus on the dynamics of viscous and non-wetting ``pancake'' droplets of oil conned in a vertical Hele-Shaw cell filled with a less viscous surfactant solution. These dense drops settle at constant velocity driven by gravity. The surfactant solution completely wets the walls, and a thin lubrication film separates the drops from the walls. With smooth walls, two main dynamical regimes are characterized as the gap between the walls is varied. Viscous dissipation is found to dominate either in the droplet or in the lubrication film, depending on the ratio of viscosities and length scales. A sharp transition between both regimes is observed and successfully captured by asymptotic models. With rough walls, that transition is dramatically altered. Drops are generally much slower in a rough Hele-Shaw cell, in comparison with a similar smooth cell. Building up on the seminal works of Seiwert et al. (J.F.M. 2011) on film deposition by dip coating on a rough surface, we shed light on the non-trivial friction processes resulting from the interplay of viscous dissipation at the front of the drop, in the lubrication film and in the bulk of the drop. We acknowledge funding from Total S.A.

Integrated main rail, feed rail, and current collector

DOEpatents

Petri, Randy J.; Meek, John; Bachta, Robert P.; Marianowski, Leonard G.

1994-01-01

A separator plate for a fuel cell comprising an anode current collector, a cathode current collector and a main plate, the main plate disposed between the anode current collector and the cathode current collector. The anode current collector forms a flattened peripheral wet seal structure and manifold wet seal structure on the anode side of the separator plate and the cathode current collector forms a flattened peripheral wet seal structure and manifold wet seal structure on the cathode side of the separator plate. In this manner, the number of components required to manufacture and assemble a fuel cell stack is reduced.

Inorganic Surface Coating with Fast Wetting-Dewetting Transitions for Liquid Manipulations.

PubMed

Yang, Yajie; Zhang, Liaoliao; Wang, Jue; Wang, Xinwei; Duan, Libing; Wang, Nan; Xiao, Fajun; Xie, Yanbo; Zhao, Jianlin

2018-06-06

Liquid manipulation is a fundamental issue for microfluidics and miniaturized sensors. Fast wetting-state transitions by optical methods have proven being efficient for liquid manipulations by organic surface coatings, however rarely been achieved by using inorganic coatings. Here, we report a fast optical-induced wetting-state transition surface achieved by inorganic coating, enabling tens of second transitions for a wetting-dewetting cycle, shortened from an hour, as typically reported. Here, we demonstrate a gravity-driven microfluidic reactor and switch it to a mixer after a second-step exposure in a minimum of within 80 s of UV exposure. The fast wetting-dewetting transition surfaces enable the fast switchable or erasable smart surfaces for water collection, miniature chemical reaction, or sensing systems by using inorganic surface coatings.

Bubble behavior in molten glass in a temperature gradient. [in reduced gravity rocket experiment

NASA Technical Reports Server (NTRS)

Meyyappan, M.; Subramanian, R. S.; Wilcox, W. R.; Smith, H.

1982-01-01

Gas bubble motion in a temperature gradient was observed in a sodium borate melt in a reduced gravity rocket experiment under the NASA SPAR program. Large bubbles tended to move faster than smaller ones, as predicted by theory. When the bubbles contacted a heated platinum strip, motion virtually ceased because the melt only imperfectly wets platinum. In some cases bubble diameter increased noticeably with time.

Hybrid selective surface hydrophilization and froth flotation separation of hazardous chlorinated plastics from E-waste with novel nanoscale metallic calcium composite.

PubMed

Mallampati, Srinivasa Reddy; Heo, Je Haeng; Park, Min Hee

2016-04-05

Treatment by a nanometallic Ca/CaO composite has been found to selectively hydrophilize the surface of polyvinyl chloride (PVC), enhancing its wettability and thereby promoting its separation from E-waste plastics by means of froth flotation. The treatment considerably decreased the water contact angle of PVC, by about 18°. The SEM images of the PVC plastic after treatment displayed significant changes in their surface morphology compared to other plastics. The SEM-EDS results reveal that a markedly decrease of [Cl] concentration simultaneously with dramatic increase of [O] on the surface of the PCV samples. XPS results further confirmed an increase of hydrophilic functional groups on the PVC surface. Froth flotation at 100rpm mixing speed was found to be optimal, separating 100% of the PVC into a settled fraction of 96.4% purity even when the plastics fed into the reactor were of nonuniform size and shape. The total recovery of PVC-free plastics in E-waste reached nearly 100% in the floated fraction, significantly improved from the 20.5wt% of light plastics that can be recovered by means of conventional wet gravity separation. The hybrid method of nanometallic Ca/CaO treatment and froth flotation is effective in the separation of hazardous chlorinated plastics from E-waste plastics. Copyright © 2015 Elsevier B.V. All rights reserved.

On-demand oil-water separation via low-voltage wettability switching of core-shell structures on copper substrates

NASA Astrophysics Data System (ADS)

Kung, Chun Haow; Zahiri, Beniamin; Sow, Pradeep Kumar; Mérida, Walter

2018-06-01

A copper mesh with dendritic copper-oxide core-shell structure is prepared using an additive-free electrochemical deposition strategy for on-demand oil-water separation. Electrochemical manipulation of the oxidation state of the copper oxide shell phase results in opposite affinities towards water and oil. The copper mesh can be tuned to manifest both superhydrophobic and superoleophilic properties to enable oil-removal. Conversely, switching to superhydrophilic and underwater superoleophobic allows water-removal. These changes correspond to the application of small reduction voltages (<1.5 V) and subsequent air drying. In the oil-removal mode, heavy oil selectively passes through the mesh while water is retained; in water-removal mode, the mesh allows water to permeate but blocks light oil. The smart membrane achieved separation efficiencies higher than 98% for a series of oil-water mixtures. The separation efficiency remains high with less than 5% variation after 30 cycles of oil-water separation in both modes. The switchable wetting mechanism is demonstrated with the aid of microstructural and electrochemical analysis and based on the well-known Cassie-Baxter and Wenzel theories. The selective removal of water or oil from the oil-water mixtures is driven solely by gravity and yields high efficiency and recyclability. The potential applications for the relevant technologies include oil spills cleanup, fuel purification, and wastewater treatment.

A Preliminary Assessment of Phase Separator Ground-Based and Reduced-Gravity Testing for ALS Systems

NASA Technical Reports Server (NTRS)

Hall, Nancy Rabel

2006-01-01

A viewgraph presentation of phase separator ground-based and reduced-gravity testing for Advanced Life Support (ALS) systems is shown. The topics include: 1) Multiphase Flow Technology Program; 2) Types of Separators; 3) MOBI Phase Separators; 4) Experiment set-up; and 5) Preliminary comparison/results.

Fluid oscillation in the Drop Tower

NASA Technical Reports Server (NTRS)

Kaukler, William F.

1988-01-01

An interfluid meniscus oscillates within a cylindrical container when suddenly released from earth's gravity and taken into a microgravity environment. Oscillations damp out from energy dissipative mechanisms such as viscosity and interfacial friction. Damping out of the oscillations by the latter mechanism is affected by the nature of the interfacial junction between the fluid-fluid interface and the container wall. Perfluoromethylcyclohexane and isopropanol in glass were the materials used for the experiment. The wetting condition of the fluids against the wall changes at the critical wetting transition temperature. This change in wetting causes a change in the damping characteristics.

Integrated main rail, feed rail, and current collector

DOEpatents

Petri, R.J.; Meek, J.; Bachta, R.P.; Marianowski, L.G.

1994-11-08

A separator plate is described for a fuel cell comprising an anode current collector, a cathode current collector and a main plate, the main plate disposed between the anode current collector and the cathode current collector. The anode current collector forms a flattened peripheral wet seal structure and manifold wet seal structure on the anode side of the separator plate and the cathode current collector forms a flattened peripheral wet seal structure and manifold wet seal structure on the cathode side of the separator plate. In this manner, the number of components required to manufacture and assemble a fuel cell stack is reduced. 9 figs.

Development of the Two Phase Flow Separator Experiment for a Reduced Gravity Aircraft Flight

NASA Technical Reports Server (NTRS)

Golliher, Eric; Gotti, Daniel; Owens, Jay; Gilkey, Kelly; Pham, Nang; Stehno, Philip

2016-01-01

The recent hardware development and testing of a reduced gravity aircraft flight experiment has provided valuable insights for the future design of the Two Phase Flow Separator Experiment (TPFSE). The TPFSE is scheduled to fly within the Fluids Integration Rack (FIR) aboard the International Space Station (ISS) in 2020. The TPFSE studies the operational limits of gas and liquid separation of passive cyclonic separators. A passive cyclonic separator utilizes only the inertia of the incoming flow to accomplish the liquid-gas separation. Efficient phase separation is critical for environmental control and life support systems, such as recovery of clean water from bioreactors, for long duration human spaceflight missions. The final low gravity aircraft flight took place in December 2015 aboard NASA's C9 airplane.

Variable-Speed Instrumented Centrifuges

NASA Technical Reports Server (NTRS)

Chapman, David K.; Brown, Allan H.

1991-01-01

Report describes conceptual pair of centrifuges, speed of which varied to produce range of artificial gravities in zero-gravity environment. Image and data recording and controlled temperature and gravity provided for 12 experiments. Microprocessor-controlled centrifuges include video cameras to record stop-motion images of experiments. Potential applications include studies of effect of gravity on growth and on production of hormones in corn seedlings, experiments with magnetic flotation to separate cells, and electrophoresis to separate large fragments of deoxyribonucleic acid.

Steady Capillary Driven Flow

NASA Technical Reports Server (NTRS)

Weislogel, Mark M.

1996-01-01

A steady capillary driven flow is developed for a liquid index in a circular tube which is partially coated with a surface modifier to produce a discontinuous wetting condition from one side of the tube to the other. The bulk flow is novel in that it is truly steady, and controlled solely by the physics associated with dynamic wetting. The influence of gravity on the flow is minimized through the use of small diameter tubes approximately O(1 mm) tested horizontally in a laboratory and larger tubes approximately O(10 mm) tested in the low gravity environment of a drop tower. Average steady velocities are predicted and compared against a large experimental data set which includes the effects of tube dimensions and fluid properties. The sensitivity of the velocity to surface cleanliness is dramatic and the advantages of experimentation in a microgravity environment are discussed.

Reproductive cell separation: A concept

NASA Technical Reports Server (NTRS)

Cutaia, A. J.

1973-01-01

Attempt has been made to separate mammalian male (Y) bearing sperm from female (X) bearing sperm. Both types of sperm are very dependent on gravity for their direction of movement. Proposed concept suggests electrophoretic force of suitable magnitude and direction may be effective means of separating X and Y sperm under zero gravity.

Separation of Non-metallic Inclusions from a Fe-Al-O Melt Using a Super-Gravity Field

NASA Astrophysics Data System (ADS)

Song, Gaoyang; Song, Bo; Guo, Zhancheng; Yang, Yuhou; Song, Mingming

2018-02-01

An innovative method for separating non-metallic inclusions from a high temperature melt using super gravity was systematically investigated. To explore the separation behavior of inclusion particles with densities less than that of metal liquid under a super-gravity field, a Fe-Al-O melt containing Al2O3 particles was treated with different gravity coefficients. Al2O3 particles migrated rapidly towards the reverse direction of the super gravity and gathered in the upper region of the sample. It was hard to find any inclusion particles with sizes greater than 2 μm in the middle and bottom areas. Additionally, the oxygen content in the middle region of the sample could be reduced to 0.0022 mass pct and the maximum removal rate of the oxygen content reached 61.4 pct. The convection in the melt along the direction of the super gravity was not generated by the super-gravity field, and the fluid velocity in the molten melt consisted only of the rotating tangential velocity. Moreover, the motion behavior of the Al2O3 particles was approximatively determined by Stokes' law along the direction of super gravity.

Film thickness dependence of phase separation and dewetting behaviors in PMMA/SAN blend films.

PubMed

You, Jichun; Liao, Yonggui; Men, Yongfeng; Shi, Tongfei; An, Lijia

2010-09-21

Film thickness dependence of complex behaviors coupled by phase separation and dewetting in blend [poly(methyl methacrylate) (PMMA) and poly(styrene-ran-acrylonitrile) (SAN)] films on silicon oxide substrate at 175 °C was investigated by grazing incidence ultrasmall-angle X-ray scattering (GIUSAX) and in situ atomic force microscopy (AFM). It was found that the dewetting pathway was under the control of the parameter U(q0)/E, which described the initial amplitude of the surface undulation and original thickness of film, respectively. Furthermore, our results showed that interplay between phase separation and dewetting depended crucially on film thickness. Three mechanisms including dewetting-phase separation/wetting, dewetting/wetting-phase separation, and phase separation/wetting-pseudodewetting were discussed in detail. In conclusion, it is relative rates of phase separation and dewetting that dominate the interplay between them.

The Two-Phase Flow Separator Experiment Breadboard Model: Reduced Gravity Aircraft Results

NASA Technical Reports Server (NTRS)

Rame, E; Sharp, L. M.; Chahine, G.; Kamotani, Y.; Gotti, D.; Owens, J.; Gilkey, K.; Pham, N.

2015-01-01

Life support systems in space depend on the ability to effectively separate gas from liquid. Passive cyclonic phase separators use the centripetal acceleration of a rotating gas-liquid mixture to carry out phase separation. The gas migrates to the center, while gas-free liquid may be withdrawn from one of the end plates. We have designed, constructed and tested a breadboard that accommodates the test sections of two independent principal investigators and satisfies their respective requirements, including flow rates, pressure and video diagnostics. The breadboard was flown in the NASA low-gravity airplane in order to test the system performance and design under reduced gravity conditions.

Municipal solid waste processing and separation employing wet torrefaction for alternative fuel production and aluminum reclamation.

PubMed

Mu'min, Gea Fardias; Prawisudha, Pandji; Zaini, Ilman Nuran; Aziz, Muhammad; Pasek, Ari Darmawan

2017-09-01

This study employs wet torrefaction process (also known as hydrothermal) at low temperature. This process simultaneously acts as waste processing and separation of mixed waste, for subsequent utilization as an alternative fuel. The process is also applied for the delamination and separation of non-recyclable laminated aluminum waste into separable aluminum and plastic. A 2.5-L reactor was used to examine the wet torrefaction process at temperatures below 200°C. It was observed that the processed mixed waste was converted into two different products: a mushy organic part and a bulky plastic part. Using mechanical separation, the two products can be separated into a granular organic product and a plastic bulk for further treatment. TGA analysis showed that no changes in the plastic composition and no intrusion from plastic fraction to the organic fraction. It can be proclaimed that both fractions have been completely separated by wet torrefaction. The separated plastic fraction product obtained from the wet torrefaction treatment also contained relatively high calorific value (approximately 44MJ/kg), therefore, justifying its use as an alternative fuel. The non-recyclable plastic fraction of laminated aluminum was observed to be delaminated and separated from its aluminum counterpart at a temperature of 170°C using an additional acetic acid concentration of 3%, leaving less than 25% of the plastic content in the aluminum part. Plastic products from both samples had high calorific values of more than 30MJ/kg, which is sufficient to be converted and used as a fuel. Copyright © 2017 Elsevier Ltd. All rights reserved.

Stratification and segregation features of pulverized electronic waste in flowing film concentration.

PubMed

Vidyadhar, A; Chalavadi, G; Das, A

2013-03-30

Gravity separation of metals from plastics in pulverized e-waste using flowing film concentration in a shaking table was investigated. Over 51% rejection of plastics in a single stage operation was achieved under optimum conditions. The shaking table was shown to be suitable for processing ground PCBs. Pulverized e-waste containing 22% metals was enriched to around 40% metals in a single pass. Statistical models for the mass yield of metal-rich stream and its grade were developed by design of experiments. Optimization was carried out to maximize the mass yield at a target product grade and preferred operating regimes were established. Experiments were designed to prevent metal loss and over 95% recovery values were obtained under all conditions. Settling distances of metals and plastics were computed and shown to be good indicators of separation performance. Particle morphology and stratification in the troughs in between the riffles were shown to influence the separation significantly. Water flow-assisted motion of the plastics was captured and its role in determining the effectiveness of separation was described. The efficacy of tabling was well established for treating ground PCBs. The wet process was shown to be environment friendly and sustainable. It is also relatively cheap and has good potential for industrial application. However, rigorous cost estimates will be required before commercial application. Copyright © 2013 Elsevier Ltd. All rights reserved.

Plane Symmetric Dark Energy Models in the Form of Wet Dark Fluid in f ( R, T) Gravity

NASA Astrophysics Data System (ADS)

Chirde, V. R.; Shekh, S. H.

2016-06-01

In this paper, we have investigated the plane symmetric space-time with wet dark fluid (WDF), which is a candidate for dark energy, in the framework of f ( R, T) gravity Harko et al. 2011, Phys. Rev. D, 84, 024020), where R and T denote the Ricci scalar and the trace of the energy-momentum tensor respectively. We have used the equation of state in the form of WDF for the dark energy component of the Universe. It is modeled on the equation of state p = ω( ρ - ρ ∗). The exact solutions to the corresponding field equations are obtained for power-law and exponential volumetric expansion. The geometrical and physical parameters for both the models are studied. Also, we have discussed the well-known astrophysical phenomena, namely the look-back time, proper distance, the luminosity distance and angular diameter distance with red shift.

Containerless low gravity processing of glass forming and immiscible alloys

NASA Technical Reports Server (NTRS)

Andrews, J. Barry; Briggs, Craig; Robinson, M. B.

1990-01-01

Under normal one-g conditions immiscible alloys segregate extensively during solidification due to sedimentation of the more dense of the immiscible liquid phases. Immiscible (hypermonotectic) gold-rhodium alloys were processed in the 100 meter drop tube under low gravity, containerless conditions to determine the feasibility of producing dispersed structures. Three alloy compositions were utilized. Alloys containing 10 percent by volume of the gold-rich hypermonotectic phase exhibited a tendency for the gold-rich liquid to wet the outer surface of the samples. This wetting tendency led to extensive segregation in several cases. Alloys containing 80 and 90 percent by volume of the gold-rich phase possessed completely different microstructures from the 10 percent samples when processed under low-g, containerless conditions. Several samples exhibited microstructures consisting of well dispersed 2 to 3 microns diameter rhodium-rich spheres in a gold-rich matrix.

Investigation of the free flow electrophoretic process. Volume 2: Technical analysis

NASA Technical Reports Server (NTRS)

Weiss, R. A.; Lanham, J. W.; Richman, D. W.; Walker, C. D.

1979-01-01

The effect of gravity on the free flow electrophoretic process was investigated. The demonstrated effects were then compared with predictions made by mathematical models. Results show that the carrier buffer flow was affected by gravity induced thermal convection and that the movement of the separating particle streams was affected by gravity induced buoyant forces. It was determined that if gravity induced buoyant forces were included in the mathematical models, then effective predictions of electrophoresis chamber separation performance were possible. The results of tests performed using various methods of electrophoresis using supportive media show that the mobility and the ability to separate were essentially independent of concentration, providing promise of being able to perform electrophoresis with higher inlet concentrations in space.

Electrically Driven Liquid Film Boiling Experiment

NASA Technical Reports Server (NTRS)

Didion, Jeffrey R.

2016-01-01

This presentation presents the science background and ground based results that form the basis of the Electrically Driven Liquid Film Boiling Experiment. This is an ISS experiment that is manifested for 2021. Objective: Characterize the effects of gravity on the interaction of electric and flow fields in the presence of phase change specifically pertaining to: a) The effects of microgravity on the electrically generated two-phase flow. b) The effects of microgravity on electrically driven liquid film boiling (includes extreme heat fluxes). Electro-wetting of the boiling section will repel the bubbles away from the heated surface in microgravity environment. Relevance/Impact: Provides phenomenological foundation for the development of electric field based two-phase thermal management systems leveraging EHD, permitting optimization of heat transfer surface area to volume ratios as well as achievement of high heat transfer coefficients thus resulting in system mass and volume savings. EHD replaces buoyancy or flow driven bubble removal from heated surface. Development Approach: Conduct preliminary experiments in low gravity and ground-based facilities to refine technique and obtain preliminary data for model development. ISS environment required to characterize electro-wetting effect on nucleate boiling and CHF in the absence of gravity. Will operate in the FIR - designed for autonomous operation.

Unusual Contact-Line Dynamics of Thick Films and Drops

NASA Technical Reports Server (NTRS)

Veretennikov, Igor; Agarwal, Abhishek; Indeikina, Alexandra; Chang, Hsueh-Chia

1999-01-01

We report several novel phenomena In contact-line and fingering dynamics of macroscopic spinning drops and gravity-driven films with dimensions larger than the capillary length. It is shown through experimental and theoretical analysis that such macroscopic films can exhibit various interfacial shapes, including multi valued ones, near the contact line due to a balance between the external body forces with capillarity. This rich variety of front shapes couples with the usual capillary, viscous, and intermolecular forces at the contact line to produce a rich and unexpected spectrum of contact-line dynamics. A single finger develops when part of the front becomes multivalued on a partially wetting macroscopic spinning drop in contrast to a different mechanism for microscopic drops of completely wetting fluids. Contrary to general expectation, we observe that, at high viscosity and low frequencies of rotation, the speed of a glycerine finger increases with increasing viscosity. Completely wetting Dow Corning 200 Fluid spreads faster over a dry inclined plane than a prewetted one. The presence of a thin prewetted film suppresses fingering both for gravity-driven flow and for spin coating. We analyze some of these unique phenomena in detail and offer qualitative physical explanations for the others.

Dynamic wetting of a liquid film in a vertical hydrophobic tube

NASA Astrophysics Data System (ADS)

Pigeonneau, Franck; Hayoun, Pascaline; Barthel, Etienne; Lequeux, Francois; Verneuil, Emilie; Letailleur, Alban; Teisseire, Jeremie; Saint-Gobain Recherche Collaboration; Espci-Physico-Chimie Des Polymeres Et Milieux Disperses Collaboration; Surface Du Verre Et Interfaces Collaboration

2016-11-01

The drop of a liquid plug through a tube occurs for instance in vending machine. In such a system, the fouling is linked to the creation of the liquid film at the rear of the liquid plug. Consequently, the conditions leading to the film creation are important to know. We study numerically the dynamic wetting transition of a liquid plug undergoing gravity on hydrophobic surface in a vertical tube. Using a lubrication theory, the liquid film thickness obeys the mass conservation equation with a volume flow rate depending on the relative motion of the tube, capillary and gravity forces. An ad hoc friction at the triple line is used to take into account the wetting dynamics. The lubrication equation is solved using a finite difference technique in space and a time integrator for stiff system with an adaptive time step. The numerical results are compared to experimental data. The complex film morphology due to the transients and the critical slowing down at the dynamic transition are reproduced. However, several experimental features are not predicted numerically especially the width of the transition. Our preliminary calculations suggest that the dispersion relation of the liquid film mode can explain the discrepancy.

Numerical analysis of wet separation of particles by density differences

NASA Astrophysics Data System (ADS)

Markauskas, D.; Kruggel-Emden, H.

2017-07-01

Wet particle separation is widely used in mineral processing and plastic recycling to separate mixtures of particulate materials into further usable fractions due to density differences. This work presents efforts aiming to numerically analyze the wet separation of particles with different densities. In the current study the discrete element method (DEM) is used for the solid phase while the smoothed particle hydrodynamics (SPH) is used for modeling of the liquid phase. The two phases are coupled by the use of a volume averaging technique. In the current study, simulations of spherical particle separation were performed. In these simulations, a set of generated particles with two different densities is dropped into a rectangular container filled with liquid. The results of simulations with two different mixtures of particles demonstrated how separation depends on the densities of particles.

Microgravity

NASA Image and Video Library

2004-04-15

Some of the earliest concerns about fluid behavior in microgravity was the management of propellants in spacecraft tanks as they orbited the Earth. On the ground, gravity pulls a fluid to a bottom of a tank (ig, left). In orbit, fluid behavior depends on surface tension, viscosity, wetting effects with the container wall, and other factors. In some cases, a propellant can wet a tank and leave a large gas bubbles in the center (ug, right). Similar probelms can affect much smaller experiments using fluids in small spaces. Photo credit: NASA/Glenn Research Center.

Wet/Dry Vacuum Cleaner

NASA Technical Reports Server (NTRS)

Reimers, Harold; Andampour, Jay; Kunitser, Craig; Thomas, Ike

1995-01-01

Vacuum cleaner collects and retains dust, wet debris, and liquids. Designed for housekeeping on Space Station Freedom, it functions equally well in normal Earth Gravity or in microgravity. Generates acoustic noise at comfortably low levels and includes circuitry that reduces electromagnetic interference to other electronic equipment. Draws materials into bag made of hydrophobic sheet with layers of hydrophilic super-absorbing pads at downstream end material. Hydrophilic material can gel many times its own weight of liquid. Blower also provides secondary airflow to cool its electronic components.

Removal of phosphorus-rich phase from high-phosphorous iron ore by melt separation at 1573 K in a super-gravity field

NASA Astrophysics Data System (ADS)

Gao, Jin-tao; Guo, Lei; Zhong, Yi-wei; Ren, Hong-ru; Guo, Zhan-cheng

2016-07-01

A new approach of removing the phosphorus-rich phase from high-phosphorous iron ore by melt separation at 1573 K in a super- gravity field was investigated. The iron-slag separation by super-gravity resulted in phosphorus being effectively removed from the iron-rich phase and concentrated as a phosphorus-rich phase at a temperature below the melting point of iron. The samples obtained by super-gravity exhibited obvious layered structures. All the iron grains concentrated at the bottom of the sample along the super-gravity direction, whereas the molten slag concentrated in the upper part of the sample along the opposite direction. Meanwhile, fine apatite crystals collided and grew into larger crystals and concentrated at the slag-iron interface. Consequently, in the case of centrifugation with a gravity coefficient of G = 900, the mass fractions of the slag phase and iron-rich phase were similar to their respective theoretical values. The mass fraction of MFe in the iron-rich phase was as high as 97.77wt% and that of P was decreased to 0.092wt%.

A wet/wet differential pressure sensor for measuring vertical hydraulic gradient.

PubMed

Fritz, Brad G; Mackley, Rob D

2010-01-01

Vertical hydraulic gradient is commonly measured in rivers, lakes, and streams for studies of groundwater-surface water interaction. While a number of methods with subtle differences have been applied, these methods can generally be separated into two categories; measuring surface water elevation and pressure in the subsurface separately or making direct measurements of the head difference with a manometer. Making separate head measurements allows for the use of electronic pressure sensors, providing large datasets that are particularly useful when the vertical hydraulic gradient fluctuates over time. On the other hand, using a manometer-based method provides an easier and more rapid measurement with a simpler computation to calculate the vertical hydraulic gradient. In this study, we evaluated a wet/wet differential pressure sensor for use in measuring vertical hydraulic gradient. This approach combines the advantage of high-temporal frequency measurements obtained with instrumented piezometers with the simplicity and reduced potential for human-induced error obtained with a manometer board method. Our results showed that the wet/wet differential pressure sensor provided results comparable to more traditional methods, making it an acceptable method for future use.

On the Motion of an Annular Film in Microgravity Gas-Liquid Flow

NASA Technical Reports Server (NTRS)

McQuillen, John B.

2002-01-01

Three flow regimes have been identified for gas-liquid flow in a microgravity environment: Bubble, Slug, and Annular. For the slug and annular flow regimes, the behavior observed in vertical upflow in normal gravity is similar to microgravity flow with a thin, symmetrical annular film wetting the tube wall. However, the motion and behavior of this film is significantly different between the normal and low gravity cases. Specifically, the liquid film will slow and come to a stop during low frequency wave motion or slugging. In normal gravity vertical upflow, the film has been observed to slow, stop, and actually reverse direction until it meets the next slug or wave.

Low gravity phase separator

NASA Technical Reports Server (NTRS)

Smoot, G. F.; Pope, W. L.; Smith, L. (Inventor)

1977-01-01

An apparatus is described for phase separating a gas-liquid mixture as might exist in a subcritical cryogenic helium vessel for cooling a superconducting magnet at low gravity such as in planetary orbit, permitting conservation of the liquid and extended service life of the superconducting magnet.

Low-gravity fluid dynamics and transport phenomena. Progress in Astronautics and Aeronautics. Vol. 130

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

Koster, J.N.; Sani, R.L.

1990-01-01

Various papers on low-gravity fluid dynamics and transport phenomena are presented. Individual topics addressed include: fluid management in low gravity, nucleate pool boiling in variable gravity, application of energy-stability theory to problems in crystal growth, thermosolutal convection in liquid HgCdTe near the liquidus temperature, capillary surfaces in microgravity, thermohydrodynamic instabilities and capillary flows, interfacial oscillators, effects of gravity jitter on typical fluid science experiments and on natural convection in a vertical cylinder. Also discussed are: double-diffusive convection and its effects under reduced gravity, segregation and convection in dendritic alloys, fluid flow and microstructure development, analysis of convective situations with themore » Soret effect, complex natural convection in low Prandtl number metals, separation physics, phase partitioning in reduced gravity, separation of binary alloys with miscibility gap in the melt, Ostwald ripening in liquids, particle cloud combustion in reduced gravity, opposed-flow flame spread with implications for combustion at microgravity.« less

A daily wetness index from satellite gravity for near-real time global monitoring of hydrological extremes

NASA Astrophysics Data System (ADS)

Gouweleeuw, Ben; Kvas, Andreas; Gruber, Christian; Mayer-Gürr, Torsten; Flechtner, Frank; Hasan, Mehedi; Güntner, Andreas

2017-04-01

Since April 2002, the Gravity Recovery and Climate Experiment (GRACE) satellite mission has been churning out water storage anomaly data, which has been shown to be a unique descriptor of large-scale hydrological extreme events. Nonetheless, efforts to assess the comprehensive information from GRACE on total water storage variations for near-real time flood or drought monitoring have been limited so far, primarily due to its coarse temporal (weekly to monthly) and spatial (> 150.000 km2) resolution and the latency of standard products of about 2 months,. Pending the status of the aging GRACE satellite mission, the Horizon 2020 funded EGSIEM (European Gravity Service for Improved Emergency Management) project is scheduled to launch a 6 month duration near-real time test run of GRACE gravity field data from April 2017 onward, which will provide daily gridded data with a latency of 5 days. This fast availability allows the monitoring of total water storage variations related to hydrological extreme events, as they occur, as opposed to a 'confirmation after occurrence', which is the current situation. This contribution proposes a global GRACE-derived gridded wetness indicator, expressed as a gravity anomaly in dimensionless units of standard deviation. Results of a retrospective evaluation (April 2002-December 2015) of the proposed index against databases of hydrological extremes will be presented. It is shown that signals for large extreme floods related to heavy/monsoonal rainfall are picked up really well in the Southern Hemisphere and lower Northern Hemisphere (Africa, S-America, Australia, S-Asia), while extreme floods in the Northern Hemisphere (Russia) related to snow melt are often not. The latter is possibly related to a lack of mass movement over longer distances, e.g. when melt water is not drained due to river ice blocking.

A Gravity-Driven Microfluidic Particle Sorting Device with Hydrodynamic Separation Amplification

PubMed Central

Huh, Dongeun; Bahng, Joong Hwan; Ling, Yibo; Wei, Hsien-Hung; Kripfgans, Oliver D.; Fowlkes, J. Brian; Grotberg, James B.; Takayama, Shuichi

2008-01-01

This paper describes a simple microfluidic sorting system that can perform size-profiling and continuous mass-dependent separation of particles through combined use of gravity (1g) and hydrodynamic flows capable of rapidly amplifying sedimentation-based separation between particles. Operation of the device relies on two microfluidic transport processes: i) initial hydrodynamic focusing of particles in a microchannel oriented parallel to gravity, ii) subsequent sample separation where positional difference between particles with different mass generated by sedimentation is further amplified by hydrodynamic flows whose streamlines gradually widen out due to the geometry of a widening microchannel oriented perpendicular to gravity. The microfluidic sorting device was fabricated in poly(dimethylsiloxane) (PDMS), and hydrodynamic flows in microchannels were driven by gravity without using external pumps. We conducted theoretical and experimental studies on fluid dynamic characteristics of laminar flows in widening microchannels and hydrodynamic amplification of particle separation. Direct trajectory monitoring, collection, and post-analysis of separated particles were performed using polystyrene microbeads with different sizes to demonstrate rapid (< 1 min) and high-purity (> 99.9 %) separation. Finally, we demonstrated biomedical applications of our system by isolating small-sized (diameter < 6 μm) perfluorocarbon liquid droplets from polydisperse droplet emulsions, which is crucial in preparing contrast agents for safe, reliable ultrasound medical imaging, tracers for magnetic resonance imaging, or transpulmonary droplets used in ultrasound-based occlusion therapy for cancer treatment. Our method enables straightforward, rapid real-time size-monitoring and continuous separation of particles in simple stand-alone microfabricated devices without the need for bulky and complex external power sources. We believe that this system will provide a useful tool o separate colloids and particles for various analytical and preparative applications, and may hold 3 potential for separation of cells or development of diagnostic tools requiring point-of-care sample preparation or testing. PMID:17297936

Separation of Iron Phase and P-Bearing Slag Phase from Gaseous-Reduced, High-Phosphorous Oolitic Iron Ore at 1473 K (1200 °C) by Super Gravity

NASA Astrophysics Data System (ADS)

Gao, Jintao; Zhong, Yiwei; Guo, Lei; Guo, Zhancheng

2016-04-01

In situ observation on the morphology evolution and phosphorous migration of gaseous-reduced, high-phosphorous oolitic iron ore during the melting process was carried out with a high-temperature confocal scanning laser microscope. The results showed that 1473 K (1200 °C) was a critical temperature at which the gangue minerals started to form into the slag phase while the iron grains remained in a solid state; in addition, the phosphorus remained in the slag phase. Since the separation of iron grains and P-bearing slag was not achieved at the low temperature under the conventional conditions, separate experiments of the iron phase and the P-bearing slag phase from gaseous-reduced, high-phosphorous oolitic iron ore at 1473 K (1200 °C) by super gravity were carried out in this study. Based on the iron-slag separation by super gravity, phosphorus was removed effectively from the iron phase at the temperature below the melting point of iron. Iron grains moved along the super-gravity direction, joined, and concentrated as the iron phase on the filter, whereas the slag phase containing apatite crystals broke through the barriers of the iron grains and went through the filter. Consequently, increasing the gravity coefficient was definitely beneficial for the separation of the P-bearing slag phase from the iron phase. With the gravity coefficient of G = 1200, the mass fractions of separated slag and iron phases were close to their respective theoretical values, and the mass fraction of MFe in the separated iron phase was up to 98.09 wt pct and that of P was decreased to 0.083 wt pct. The recovery of MFe in the iron phase and that of P in the slag phase were up to 99.19 and 95.83 pct, respectively.

Implementation of CFD modeling in the performance assessment and optimization of secondary clarifiers: the PVSC case study.

PubMed

Xanthos, S; Ramalingam, K; Lipke, S; McKenna, B; Fillos, J

2013-01-01

The water industry and especially the wastewater treatment sector has come under steadily increasing pressure to optimize their existing and new facilities to meet their discharge limits and reduce overall cost. Gravity separation of solids, producing clarified overflow and thickened solids underflow has long been one of the principal separation processes used in treating secondary effluent. Final settling tanks (FSTs) are a central link in the treatment process and often times act as the limiting step to the maximum solids handling capacity when high throughput requirements need to be met. The Passaic Valley Sewerage Commission (PVSC) is interested in using a computational fluid dynamics (CFD) modeling approach to explore any further FST retrofit alternatives to sustain significantly higher plant influent flows, especially under wet weather conditions. In detail there is an interest in modifying and/or upgrading/optimizing the existing FSTs to handle flows in the range of 280-720 million gallons per day (MGD) (12.25-31.55 m(3)/s) in compliance with the plant's effluent discharge limits for total suspended solids (TSS). The CFD model development for this specific plant will be discussed, 2D and 3D simulation results will be presented and initial results of a sensitivity study between two FST effluent weir structure designs will be reviewed at a flow of 550 MGD (∼24 m(3)/s) and 1,800 mg/L MLSS (mixed liquor suspended solids). The latter will provide useful information in determining whether the existing retrofit of one of the FSTs would enable compliance under wet weather conditions and warrants further consideration for implementing it in the remaining FSTs.

Ultrasonic hydrometer. [Specific gravity of electrolyte

DOEpatents

Swoboda, C.A.

1982-03-09

The disclosed ultrasonic hydrometer determines the specific gravity (density) of the electrolyte of a wet battery, such as a lead-acid battery. The hydrometer utilizes a transducer that when excited emits an ultrasonic impulse that traverses through the electrolyte back and forth between spaced sonic surfaces. The transducer detects the returning impulse, and means measures the time t between the initial and returning impulses. Considering the distance d between the spaced sonic surfaces and the measured time t, the sonic velocity V is calculated with the equation V = 2d/t. The hydrometer also utilizes a thermocouple to measure the electrolyte temperature. A hydrometer database correlates three variable parameters including sonic velocity in and temperature and specific gravity of the electrolyte, for temperature values between 0 and 40/sup 0/C and for specific gravity values between 1.05 and 1.30. Upon knowing two parameters (the calculated sonic velocity and the measured temperature), the third parameter (specific gravity) can be uniquely found in the database. The hydrometer utilizes a microprocessor for data storage and manipulation.

Design and calibration of the carousel wind tunnel

NASA Technical Reports Server (NTRS)

Leach, R. N.; Greeley, R.; Iversen, J.; White, B.; Marshall, J. R.

1986-01-01

In the study of planetary aeolian processes the effect of gravity is not readily modeled. Gravity appears in the equations of particle motion along with interparticle forces but the two terms are not separable. A wind tunnel that would permit variable gravity would allow separation of the forces and aid greatly in understanding planetary aeolian processes. The design Carousel Wind Tunnel (CWT) allows for a long flow distance in a small sized tunnel since the test section is a continuo us circuit and allows for a variable pseudo gravity. A prototype design was built and calibrated to gain some understanding of the characteristics of the design and the results presented.

Design and calibration of the carousel wind tunnel

NASA Technical Reports Server (NTRS)

Leach, R. N.; Greeley, Ronald; Iversen, James D.; White, Bruce R.; Marshall, John R.

1987-01-01

In the study of planetary aeolian processes the effect of gravity is not readily modeled. Gravity appears in the equations of particle motion along with interparticle forces but the two terms are not separable. A wind tunnel that would permit variable gravity would allow separation of the forces and aid greatly in understanding planetary aeolian processes. The design of the Carousel Wind Tunnel (CWT) allows for a long flow distance in a small sized tunnel since the test section is a continuous circuit and allows for a variable pseudo-gravity. A prototype design was built and calibrated to gain some understanding of the characteristics of the design and the results presented.

Satellite observations of ground water changes in New Mexico

USDA-ARS?s Scientific Manuscript database

In 2002 NASA launched the Gravity Recovery and Climate Experiment (GRACE) satellite mission. GRACE consists of two satellites with a separation of about 200 km.  By accurately measuring the separation between the twin satellites, the differences in the gravity field can be determined. Monthly observ...

Disposal of Kitchen Waste from High Rise Apartment

NASA Astrophysics Data System (ADS)

Ori, Kirki; Bharti, Ajay; Kumar, Sunil

2017-09-01

The high rise building has numbers of floor and rooms having variety of users or tenants for residential purposes. The huge quantities of heterogenous mixtures of domestic food waste are generated from every floor of the high rise residential buildings. Disposal of wet and biodegradable domestic kitchen waste from high rise buildings are more expensive in regards of collection and vertical transportation. This work is intended to address the technique to dispose of the wet organic food waste from the high rise buildings or multistory building at generation point with the advantage of gravity and vermicomposting technique. This innovative effort for collection and disposal of wet organic solid waste from high rise apartment is more economical and hygienic in comparison with present system of disposal.

Michigan Magnetic and Gravity Maps and Data: A Website for the Distribution of Data

USGS Publications Warehouse

Daniels, David L.; Kucks, Robert P.; Hill, Patricia L.; Snyder, Stephen L.

2009-01-01

This web site provides the best available, public-domain, aeromagnetic and gravity data in the State of Michigan and merges these data into composite grids that are available for downloading. The magnetic grid is compiled from 25 separate magnetic surveys that have been knit together to form a single composite digital grid and map. The magnetic survey grids have been continued to 305 meters (1,000 feet) above ground and merged together to form the State compilation. A separate map shows the location of the aeromagnetic surveys, color-coded to the survey flight-line spacing. In addition, a complete Bouguer gravity anomaly grid and map were generated from more than 20,000 gravity station measurements from 33 surveys. A table provides the facts about each gravity survey where known.

Preparative liquid column electrophoresis of T and B lymphocytes at gravity = 1

NASA Technical Reports Server (NTRS)

Van Oss, C. J.; Bigazzi, P. E.; Gillman, C. F.; Allen, R. E.

1974-01-01

Vertical liquid columns containing low-molecular-weight dextran density gradients can be used for preparative lymphocyte electrophoresis on earth, in simulation of zero gravity conditions. Another method that has been tested at 1 g, is the electrophoresis of lymphocytes in an upward direction in vertical columns. By both methods up to 100 million lymphocytes can be separated at one time in a 30-cm glass column of 8-mm inside diameter, at 12 V/cm, in two hours. Due to convection and sedimentation problems, the separation at 1 g is less than ideal, but it is expected that at zero gravity electrophoresis will probe to be a uniquely powerful cell separation tool.

Gravity data inversion for 3D topography of the Moho discontinuity by separation of sources in Taiwan region

NASA Astrophysics Data System (ADS)

Lo, Y. T.; Yen, H. Y.

2012-04-01

Taiwan is located at a complex juncture between the Eurasian and Philippine Sea plates. The mountains in Taiwan are very young, formed as a result of the collision between an island arc system and the Asian continental margin. To separate sources of gravity field in depth, a method is suggested, based on upward and downward continuation. Both new methods are applied to isolate the contribution of the Moho interface to the total field and to find its 3D topography. At the first stage, we separate near surface and deeper sources. At the next stage, we isolate the effect of very deep sources. After subtracting this field from the total effect of deeper sources, we obtain the contribution of the Moho interface. We make inversion separately for the area. In this study, we use the detail gravity data around this area to investigate the reliable subsurface density structure. First, we combine with land and marine gravity data to obtain gravity anomaly. Second, considering the geology, tomography and other constrains, we simulate the 3D density structure. The main goal of our study is to understand the Moho topography and sediment-crustal boundary in Taiwan area. We expect that our result can consistent with previous studies.

Processing of electronic waste in a counter current teeter-bed separator.

PubMed

Dey, Sujit Kumar; Ari, Vidyadhar; Das, Avimanyu

2012-09-30

Advanced gravity separation of ground electronic waste (e-waste) in a teeter-bed separator was investigated. It was established that the Floatex Density Seprator (FDS) is a promising device for wet processing of e-waste to recover metal values physically. It was possible to enrich the metal content from 23% in the feed to 37% in the product in a single stage operation using the FDS with over 95% recovery of the metals. A two-stage processing scheme was developed that enriched the metal content further to 48.2%. The influence of the operating variables, namely, teeter water flow rate, bed pressure and feed rate were quantified. Low bed pressures and low teeter water rates produced higher mass yields with poorer product grades. On the contrary, a high bed pressure and high teeter water rate combination led to a lower mass yield but better product quality. A high feed rate introduced en-masse settling leading to higher yield but at a poorer product grade. For an FDS with 230 mm × 230 mm cross section and a height of 530 mm, the process condition with 6.6l pm teeter water rate, 5.27 kPa bed pressure and 82 kg/hr feed rate maximized the yield for a target product grade of 37% metal in a single pass. Copyright © 2012 Elsevier Ltd. All rights reserved.

Facile way in fabricating a cotton fabric membrane for switchable oil/water separation and water purification

NASA Astrophysics Data System (ADS)

Li, Yubin; Feng, Ziliang; He, Yi; Fan, Yi; Ma, Jing; Yin, Xiangying

2018-05-01

With dopamine and NiFe2O4 particles, a novel modified cotton fabric (PDA-NiFe2O4@CF) was prepared by one-pot method. Surface morphology, composition of the PDA-NiFe2O4@CF were investigated with SEM, EDX, XRD and FT-IR, respectively. According to the results, the cotton fiber surface was well coated with NiFe2O4 particles. Subsequently, wetting behavior of the modified cotton fabric was determined. The PDA-NiFe2O4@CF is superamphiphilic in air, and a dual lyophobic behavior was indicated with an oil contact angle (OCA) of 153° under water and a water contact angle (WCA) of 145° under oil. The rough micro-nano scale surface structure and high-surface-energy compositions of the PDA-NiFe2O4@CF makes the surface to be easily covered by one medium and enables it to repel other unmixable medium simultaneously. Therefore, water-oil mixtures can be separated on demand. Besides, with the unusual dual lyophobic surface of PDA-NiFe2O4@CF, both two types of emulsions were separated by gravity driven. On the other hand, it was also found that the as-prepared PDA-NiFe2O4@CF had good adsorption performance for methylene blue.

Interpretations of gravity and magnetic anomalies in the Songliao Basin with Wavelet Multi-scale Decomposition

NASA Astrophysics Data System (ADS)

Li, Changbo; Wang, Liangshu; Sun, Bin; Feng, Runhai; Wu, Yongjing

2015-09-01

In this paper, we introduce the method of Wavelet Multi-scale Decomposition (WMD) combined with Power Spectrum Analysis (PSA) for the separation of regional gravity and magnetic anomalies. The Songliao Basin is situated between the Siberian Plate and the North China Plate, and its main structural trend of gravity and magnetic anomaly fields is NNE. The study area shows a significant feature of deep collage-type construction. According to the feature of gravity field, the region was divided into five sub-regions. The gravity and magnetic fields of the Songliao Basin were separated using WMD with a 4th order separation. The apparent depth of anomalies in each order was determined by Logarithmic PSA. Then, the shallow high-frequency anomalies were removed and the 2nd-4th order wavelet detail anomalies were used to study the basin's major faults. Twenty-six faults within the basement were recognized. The 4th order wavelet approximate anomalies were used for the inversion of the Moho discontinuity and the Curie isothermal surface.

An enhanced trend surface analysis equation for regional-residual separation of gravity data

NASA Astrophysics Data System (ADS)

Obasi, A. I.; Onwuemesi, A. G.; Romanus, O. M.

2016-12-01

Trend surface analysis is a geological term for a mathematical technique which separates a given map set into a regional component and a local component. This work has extended the steps for the derivation of the constants in the trend surface analysis equation from the popularly known matrix and simultaneous form to a more simplified and easily achievable format. To achieve this, matrix inversion was applied to the existing equations and the outcome was tested for suitability using a large volume of gravity data set acquired from the Anambra Basin, south-eastern Nigeria. Tabulation of the field data set was done using the Microsoft Excel spread sheet, while gravity maps were generated from the data set using Oasis Montaj software. A comparison of the residual gravity map produced using the new equations with its software derived counterpart has shown that the former has a higher enhancing capacity than the latter. This equation has shown strong suitability for application in the separation of gravity data sets into their regional and residual components.

Separators for Li-Ion and Li-Metal Battery Including Ionic Liquid Based Electrolytes Based on the TFSI− and FSI− Anions

PubMed Central

Kirchhöfer, Marija; von Zamory, Jan; Paillard, Elie; Passerini, Stefano

2014-01-01

The characterization of separators for Li-ion or Li-metal batteries incorporating hydrophobic ionic liquid electrolytes is reported herein. Ionic liquids made of N-butyl-N-methylpyrrolidinium (PYR14+) or N-methoxyethyl-N-methylpyrrolidinium (PYR12O1+), paired with bis(trifluoromethanesulfonyl)imide (TFSI−) or bis(fluorosulfonyl)imide (FSI−) anions, were tested in combination with separators having different chemistries and morphologies in terms of wetting behavior, Gurley and McMullin number, as well as Li/(Separator + Electrolyte) interfacial properties. It is shown that non-functionalized microporous polyolefin separators are poorly wetted by FSI−-based electrolytes (contrary to TFSI−-based electrolytes), while the ceramic coated separator Separion® allows good wetting with all electrolytes. Furthermore, by comparing the lithium solid electrolyte interphase (SEI) resistance evolution at open circuit and during cycling, depending on separator morphologies and chemistries, it is possible to propose a scale for SEI forming properties in the order: PYR12O1FSI > PYR14FSI > PYR14TFSI > PYR12O1TFSI. Finally, the impact the separator morphology is evidenced by the SEI resistance evolution and by comparing Li electrodes cycled using separators with two different morphologies. PMID:25153637

Upgrading Yellow-Poplar Seeds

Treesearch

F. T. Bonner; G. L. Switzer

1971-01-01

Yellow-poplar seed lots can be upgraded considerably by dewinging in a debearder and then cleaning and separating the seeds into four specific-gravity fractions with a fractionating aspirator or a gravity separator. By this process, lots with an original soundness of 6 to 10 percent were upgraded to between 60 and 65 percent full seeds.

Conversion of a wet waste feedstock to biocrude by hydrothermal processing in a continuous-flow reactor: grape pomace

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

Elliott, Douglas C.; Schmidt, Andrew J.; Hart, Todd R.

Wet waste feedstocks present an apt opportunity for biomass conversion to fuels by hydrothermal processing. In this study, grape pomace slurries from two varieties, Montepulciano and cabernet sauvignon, have been converted into a biocrude by hydrothermal liquefaction (HTL) in a bench-scale, continuous-flow reactor system. Carbon conversion to gravity-separable biocrude product up to 56 % was accomplished at relatively low temperature (350 C) in a pressurized (sub-critical liquid water) environment (20 MPa) when using grape pomace feedstock slurry with a 16.8 wt% concentration of dry solids processed at a liquid hourly space velocity of 2.1 h-1. Direct oil recovery was achievedmore » without the use of a solvent and biomass trace mineral components were removed by processing steps so that they did not cause processing difficulties. In addition, catalytic hydrothermal gasification (CHG) was effectively applied for HTL byproduct water cleanup using a Ru on C catalyst in a fixed bed producing a gas composed of methane and carbon dioxide from water soluble organics. Conversion of 99.8% of the chemical oxygen demand (COD) left in the aqueous phase was demonstrated. As a result, high conversion of grape pomace to liquid and gas fuel products was found with residual organic contamination in byproduct water reduced to <150 mg/kg COD.« less

Capillary Phenomena: Investigations in Compressed Bubble Migration, Geometric Wetting, and Blade-Bound Droplet Stability

NASA Astrophysics Data System (ADS)

Blackmore, William Henry

Capillary flows continue to be important in numerous spacecraft systems where the effective magnitude of the gravity vector is approximately one millionth that of normal Earth gravity. Due to the free fall state of orbiting spacecraft, the effects of capillarity on the fluid systems onboard can dominate the fluid behavior over large length scales. In this research three investigations are pursued where the unique interplay between surface tension forces, wetting characteristics, and system geometry control the fluid behavior, whether in large systems aboard spacecraft, or micro-scale systems on Earth. First, efforts in support of two International Space Station (ISS) experiments are reported. A description of the development of a new NASA ground station at Portland State University is provided along with descriptions of astronaut training activities for the proper operation of four handheld experiments currently in orbit as part of the second iteration of the Capillary Flow Experiments (CFE-2). Concerning the latter, seven more vessels are expected to be launched to the ISS shortly. Analysis of the data alongside numerical simulations shows excellent agreement with theory, and a new intuitive method of viewing critical wetting angles and fluid bulk shift phenomena is offered. Secondly, during the CFE-2 space experiments, unplanned peripheral observations revealed that, on occasion, rapidly compressed air bubbles migrate along paths with vector components common to the residual acceleration onboard the ISS. Unexpectedly however, the migration velocities could be shown to be up to three orders of magnitude greater than the appropriate Stokes flow limit! Likely mechanisms are explored analytically and experimentally while citing prior theoretical works that may have anticipated such phenomena. Once properly understood, compressed bubble migration may be used as an elegant method for phase separation in spacecraft systems or microgravity-based materials manufacturing. Lastly, the stability of drops on surfaces is important in a variety of natural and industrial processes. So called 'wall-edge-vertex bound drops' (a.k.a. drops on blade tips or drops on leaf tips which they resemble) are explored using a numerical approach which applies the Surface Evolver algorithm through implementation of a new file layer and a multi-parameter sweep function. As part of a recently open sourced SE-FIT software, thousands of critical drop configurations are efficiently computed as functions of contact angle, blade edge vertex half-angle, and g-orientation. With the support of other graduate students, simple experiments are performed to benchmark the computations which are then correlated for ease of application. It is shown that sessile, pendant, and wall-edge bound drops are only limiting cases of the more generalized blade-bound drops, and that a ubiquitous 'dry leaf tip' is observed for a range of the critical geometric and wetting parameters.

Antarctic Tectonics: Constraints From an ERS-1 Satellite Marine Gravity Field

PubMed

McAdoo; Laxon

1997-04-25

A high-resolution gravity field of poorly charted and ice-covered ocean near West Antarctica, from the Ross Sea east to the Weddell Sea, has been derived with the use of satellite altimetry, including ERS-1 geodetic phase, wave-form data. This gravity field reveals regional tectonic fabric, such as gravity lineations, which are the expression of fracture zones left by early (65 to 83 million years ago) Pacific-Antarctic sea-floor spreading that separated the Campbell Plateau and New Zealand continent from West Antarctica. These lineations constrain plate motion history and confirm the hypothesis that Antarctica behaved as two distinct plates, separated from each other by an extensional Bellingshausen plate boundary active in the Amundsen Sea before about 61 million years ago.

Liquid phase sintered compacts in space

NASA Technical Reports Server (NTRS)

Mookherji, T. K.; Mcanelly, W. B.

1974-01-01

A model that will explain the effect of gravity on liquid phase sintering was developed. Wetting characteristics and density segregation which are the two important phenomena in liquid phase sintering are considered in the model development. Experiments were conducted on some selected material combinations to study the gravity effects on liquid phase sintering, and to verify the validity of the model. It is concluded that: (1) The surface tension forces acting on solid particles in a one-g environment are not appreciably different from those anticipated in a 0.00001g/g sub 0 (or lower) environment. (2) The capillary forces are dependent on the contact angle, the quantity of the liquid phase, and the distance between solid particles. (3) The pores (i.e., bubbles) do not appear to be driven to the surface by gravity-produced buoyancy forces. (4) The length of time to produce the same degree of settling in a low-gravity environment will be increased significantly. (5) A low gravity environment would appear to offer a unique means of satisfactorily infiltrating a larger and/or complex shaped compact.

Soft collinear effective theory for gravity

NASA Astrophysics Data System (ADS)

Okui, Takemichi; Yunesi, Arash

2018-03-01

We present how to construct a soft collinear effective theory (SCET) for gravity at the leading and next-to-leading powers from the ground up. The soft graviton theorem and decoupling of collinear gravitons at the leading power are manifest from the outset in the effective symmetries of the theory. At the next-to-leading power, certain simple structures of amplitudes, which are completely obscure in Feynman diagrams of the full theory, are also revealed, which greatly simplifies calculations. The effective Lagrangian is highly constrained by effectively multiple copies of diffeomorphism invariance that are inevitably present in gravity SCET due to mode separation, an essential ingredient of any SCET. Further explorations of effective theories of gravity with mode separation may shed light on Lagrangian-level understandings of some of the surprising properties of gravitational scattering amplitudes. A gravity SCET with an appropriate inclusion of Glauber modes may serve as a powerful tool for studying gravitational scattering in the Regge limit.

Compliance Testing of the Eglin AFB Asphalt Concrete Batch Plant, Eglin AFB, Florida

DTIC Science & Technology

1989-06-01

the fan, contactor and separator. A schematic of the scrubber showing these components is presented in Figure 4. Particulate-laden air is blown into...the contactor at high speed by the scrubber fan. In the contactor , the gas stream passes through a fine water mist where particulates are wetted and...and wetted particulates are separated from the gas stream by centrifugal action and drain to the bottom of the separator. Water and sludge are drained

Multiple patterns of polymer gels in microspheres due to the interplay among phase separation, wetting, and gelation.

PubMed

Yanagisawa, Miho; Nigorikawa, Shinpei; Sakaue, Takahiro; Fujiwara, Kei; Tokita, Masayuki

2014-11-11

We report the spontaneous patterning of polymer microgels by confining a polymer blend within microspheres. A poly(ethylene glycol) (PEG) and gelatin solution was confined inside water-in-oil (W/O) microdroplets coated with a layer of zwitterionic lipids: dioleoylphosphatidylethanolamine (PE) and dioleoylphosphatidylcholine (PC). The droplet confinement affected the kinetics of the phase separation, wetting, and gelation after a temperature quench, which determined the final microgel pattern. The gelatin-rich phase completely wetted to the PE membrane and formed a hollow microcapsule as a stable state in the PE droplets. Gelation during phase separation varied the relation between the droplet size and thickness of the capsule wall. In the case of the PC droplets, phase separation was completed only for the smaller droplets, wherein the microgel partially wetted the PC membrane and had a hemisphere shape. In addition, the temperature decrease below the gelation point increased the interfacial tension between the PEG/gelatin phases and triggered a dewetting transition. Interestingly, the accompanying shape deformation to minimize the interfacial area was only observed for the smaller PC droplets. The critical size decreased as the gelatin concentration increased, indicating the role of the gel elasticity as an inhibitor of the deformation. Furthermore, variously patterned microgels with spherically asymmetric shapes, such as discs and stars, were produced as kinetically trapped states by regulating the incubation time, polymer composition, and droplet size. These findings demonstrate a way to regulate the complex shapes of microgels using the interplay among phase separation, wetting, and gelation of confined polymer blends in microdroplets.

Critical point wetting drop tower experiment

NASA Technical Reports Server (NTRS)

Kaukler, William F.

1990-01-01

The 100 m Drop Tower at NASA-Marshall was used to provide the step change in acceleration from 1.0 to 0.0005 g. An inter-fluid meniscus oscillates vertically within a cylindrical container when suddenly released from earth's gravity and taken into a microgravity environment. Oscillations damp out from energy dissipative mechanisms such as viscosity and interfacial friction. Damping of the oscillations by the later mechanism is affected by the nature of the interfacial junction between the fluid-fluid interface and the container wall. In earlier stages of the project, the meniscus shape which developed during microgravity conditions was applied to evaluations of wetting phenomena near the critical temperature. Variations in equilibrium contact angle against the container wall were expected to occur under critical wetting conditions. However, it became apparent that the meaningful phenomenon was the damping of interfacial oscillations. This latter concept makes up the bulk of this report. Perfluoromethyl cyclohexane and isopropanol in glass were the materials used for the experiment. The wetting condition of the fluids against the wall changes at the critical wetting transition temperature. This change in wetting causes a change in the damping characteristics of the interfacial excursions during oscillation and no measurable change in contact angle. The effect of contact line friction measured above and below the wetting transition temperature was to increase the period of vertical oscillation for the vapor-liquid interface when below the wetting transition temperature.

Interfacial instabilities in vibrated fluids

NASA Astrophysics Data System (ADS)

Porter, Jeff; Laverón-Simavilla, Ana; Tinao Perez-Miravete, Ignacio; Fernandez Fraile, Jose Javier

2016-07-01

Vibrations induce a range of different interfacial phenomena in fluid systems depending on the frequency and orientation of the forcing. With gravity, (large) interfaces are approximately flat and there is a qualitative difference between vertical and horizontal forcing. Sufficient vertical forcing produces subharmonic standing waves (Faraday waves) that extend over the whole interface. Horizontal forcing can excite both localized and extended interfacial phenomena. The vibrating solid boundaries act as wavemakers to excite traveling waves (or sloshing modes at low frequencies) but they also drive evanescent bulk modes whose oscillatory pressure gradient can parametrically excite subharmonic surface waves like cross-waves. Depending on the magnitude of the damping and the aspect ratio of the container, these locally generated surfaces waves may interact in the interior resulting in temporal modulation and other complex dynamics. In the case where the interface separates two fluids of different density in, for example, a rectangular container, the mass transfer due to vertical motion near the endwalls requires a counterflow in the interior region that can lead to a Kelvin-Helmholtz type instability and a ``frozen wave" pattern. In microgravity, the dominance of surface forces favors non-flat equilibrium configurations and the distinction between vertical and horizontal applied forcing can be lost. Hysteresis and multiplicity of solutions are more common, especially in non-wetting systems where disconnected (partial) volumes of fluid can be established. Furthermore, the vibrational field contributes a dynamic pressure term that competes with surface tension to select the (time averaged) shape of the surface. These new (quasi-static) surface configurations, known as vibroequilibria, can differ substantially from the hydrostatic state. There is a tendency for the interface to orient perpendicular to the vibrational axis and, in some cases, a bulge or cavity is induced that leads to splitting (fluid separation). We investigate the interaction of these prominent interfacial instabilities in the absence of gravity, concentrating on harmonically vibrated rectangular containers of fluid. We compare vibroequilibria theory with direct numerical simulations and consider the effect of surfaces waves, which can excite sloshing motion of the vibroequilibria. We systematically investigate the saddle-node bifurcation experienced by a symmetric singly connected vibroequilibria solution, for sufficiently deep containers, as forcing is increased. Beyond this instability, the fluid rapidly separates into (at least) two distinct masses. Pronounced hysteresis is associated with this transition, even in the presence of gravity. The interaction of vibroequilibria and frozen waves is investigated in two-fluid systems. Preparations for a parabolic flight experiment on fluids vibrated at high frequencies are discussed.

New polymers for low-gravity purification of cells by phase partitioning

NASA Technical Reports Server (NTRS)

Harris, J. M.

1983-01-01

A potentially powerful technique for separating different biological cell types is based on the partitioning of these cells between the immiscible aqueous phases formed by solution of certain polymers in water. This process is gravity-limited because cells sediment rather than associate with the phase most favored on the basis of cell-phase interactions. In the present contract we have been involved in the synthesis of new polymers both to aid in understanding the partitioning process and to improve the quality of separations. The prime driving force behind the design of these polymers is to produce materials which will aid in space experiments to separate important cell types and to study the partitioning process in the absence of gravity (i.e., in an equilibrium state).

Evaluation of an ATP Assay to Quantify Bacterial Attachment to Surfaces in Reduced Gravity

NASA Technical Reports Server (NTRS)

Birmele, Michele N.; Roberson, Luke B.; Roberts, Michael S.

2010-01-01

Aim: To develop an assay to quantify the biomass of attached cells and biofilm formed on wetted surfaces in variable-gravity environments. Methods and Results: Liquid cultures of Pseudomonas aeruginosa were exposed to 30-35 brief cycles of hypergravity (< 2-g) followed by free fall (i.e., reduced gravity) equivalent to either lunar-g (i.e., 0.17 normal Earth gravity) or micro-g (i.e., < 0.001 normal Earth gravity) in an aircraft flying a series of parabolas. Over the course of two days of parabolic flight testing, 504 polymer or metal coupons were exposed to a stationary-phase population of P. aeruginosa strain ERC1 at a concentration of 1.0 x 10(exp 5) cells per milliliter. After the final parabola on each flight test day, half of the material coupon samples were treated with either 400 micro-g/L ionic silver fluoride (microgravity-exposed cultures) or 1% formalin (lunar-gravity-exposed cultures). The remaining sample coupons from each flight test day were not treated with a fixative. All samples were returned to the laboratory for analysis within 2 hours of landing, and all biochemical assays were completed within 8 hours of exposure to variable gravity. The intracellular ATP luminescent assay accurately reflected cell physiology compared to both cultivation-based and direct-count microscopy analyses. Cells exposed to variable gravity had more than twice as much intracellular ATP as control cells exposed only to normal Earth gravity.

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

Brumbaugh, William D.; Cook, Kenneth L.

During the summers of 1975 and 1976, a gravity survey was conducted in the Cove Fort - Sulphurdale KGRA and north Mineral Mountains area, Millard and Beaver counties, Utah. The survey consisted of 671 gravity stations covering an area of about 1300 km{sup 2}, and included two orthogonal gravity profiles traversing the area. The gravity data are presented as a terrain-corrected Bouguer gravity anomaly map with a contour interval of 1 mgal and as an isometric three-dimensional gravity anomaly surface. Selected anomaly separation techniques were applied to the hand-digitized gravity data (at 1-km intervals on the Universal Transverse Mercator grid)more » in both the frequency and space domains, including Fourier decomposition, second vertical derivative, strike-filter, and polynomial fitting analysis, respectively. Residual gravity gradients of 0.5 to 8.0 mgal/km across north-trending gravity contours observed through the Cove Fort area, the Sulphurdale area, and the areas east of the East Mineral Mountains, along the west flanks of the Tushar Mountains, and on both the east and west flanks of the north Mineral Mountains, were attributed to north-trending Basin and Range high-angle faults. Gravity highs exist over the community of Black Rock area, the north Mineral Mountains, the Paleozoic outcrops in the east Cove Creek-Dog Valley-White Sage Flats areas, the sedimentary thrust zone of the southern Payant Range, and the East Mineral Mountains. The gravity lows over north Milford Valley, southern Black Rock Desert, Cunningham Wash, and northern Beaver Valley are separated from the above gravity highs by steep gravity gradients attributed to a combination of crustal warping and faulting. A gravity low with a closure of 2 mgal corresponds with Sulphur Cove, a circular topographic features containing sulphur deposits.« less

A Physically-based Model for Predicting Soil Moisture Dynamics in Wetlands

NASA Astrophysics Data System (ADS)

Kalin, L.; Rezaeianzadeh, M.; Hantush, M. M.

2017-12-01

Wetlands are promoted as green infrastructures because of their characteristics in retaining and filtering water. In wetlands going through wetting/drying cycles, simulation of nutrient processes and biogeochemical reactions in both ponded and unsaturated wetland zones are needed for an improved understanding of wetland functioning for water quality improvement. The physically-based WetQual model can simulate the hydrology and nutrient and sediment cycles in natural and constructed wetlands. WetQual can be used in continuously flooded environments or in wetlands going through wetting/drying cycles. Currently, WetQual relies on 1-D Richards' Equation (RE) to simulate soil moisture dynamics in unponded parts of the wetlands. This is unnecessarily complex because as a lumped model, WetQual only requires average moisture contents. In this paper, we present a depth-averaged solution to the 1-D RE, called DARE, to simulate the average moisture content of the root zone and the layer below it in unsaturated parts of wetlands. DARE converts the PDE of the RE into ODEs; thus it is computationally more efficient. This method takes into account the plant uptake and groundwater table fluctuations, which are commonly overlooked in hydrologic models dealing with wetlands undergoing wetting and drying cycles. For verification purposes, DARE solutions were compared to Hydrus-1D model, which uses full RE, under gravity drainage only assumption and full-term equations. Model verifications were carried out under various top boundary conditions: no ponding at all, ponding at some point, and no rain. Through hypothetical scenarios and actual atmospheric data, the utility of DARE was demonstrated. Gravity drainage version of DARE worked well in comparison to Hydrus-1D, under all the assigned atmospheric boundary conditions of varying fluxes for all examined soil types (sandy loam, loam, sandy clay loam, and sand). The full-term version of DARE offers reasonable accuracy compared to the full RE solutions from Hydrus-1D, with a significant reduction in computational time. The full-term version of DARE estimated the moisture content with better accuracy for the root zone by considering zero pressure head at a fixed groundwater depth as the bottom boundary condition. The accuracy of this model is lower for the second layer.

Dishwasher For Earth Or Outer Space

NASA Technical Reports Server (NTRS)

Tromble, Jon D.

1991-01-01

Dishwashing machine cleans eating utensils in either Earth gravity or zero gravity of outer space. Cycle consists of three phases: filling, washing, and draining. Rotation of tub creates artificial gravity aiding recirculation of water during washing phase in absence of true gravity. Centrifugal air/water separator helps system function in zero gravity. Self-cleaning filter contains interdigitating blades catching solid debris when water flows between them. Later, blades moved back and forth in scissor-like manner to dislodge debris, removed by backflow of water.

Inorganic separator technology program

NASA Technical Reports Server (NTRS)

Smatko, J. S.; Weaver, R. D.; Kalhammer, F. R.

1973-01-01

Testing and failure analyses of silver zinc cells with largely inorganic separators were performed. The results showed that the wet stand and cycle life objective of the silver-zinc cell development program were essentially accomplished and led to recommendations for cell composition, design, and operation that should yield further improvement in wet and cycle life. A series of advanced inorganic materials was successfully developed and formulated into rigid and semiflexible separator samples. Suitable screening tests for evaluation of largely inorganic separators were selected and modified for application to the separator materials. The results showed that many of these formulations are potentially superior to previously used materials and permitted selection of three promising materials for further evaluation in silver-zinc cells.

Preliminary flight prototype waste collection subsystem. [performance of waste disposal system in weightless environment

NASA Technical Reports Server (NTRS)

Swider, J. E., Jr.

1974-01-01

The zero gravity test program demonstrated the feasibility and practicability of collecting urine from both male and female crew members in a zero gravity environment in an earthlike manner not requiring any manual handling of urine containers. In addition, the testing demonstrated that a seat which is comfortable in both regimes of operation could be designed for use on the ground and in zero-gravity. Further, the tests showed that the vortex liquid/air separator is an effective liquid/air separation method in zero gravity. Visual observations indicate essentially zero liquid carry over. The system also demonstrated its ability to handle post elimination wipes without difficulty. The designs utilized in the WCS were verified as acceptable for usage in the space shuttle or other space vehicles.

Study of Electro-Cyclonic Filtration and Pneumatic Transfer of Lunar Regolith Simulants under 1/6-g and 1-g Gravity Conditions

NASA Technical Reports Server (NTRS)

Mantovani, James G.; Townsend, Ivan I.; Mueller, Robert P.

2009-01-01

NASA has built a prototype oxygen production plant to process the lunar regolith using the hydrogen reduction chemical process. This plant is known as "ROxygen - making oxygen from moon rocks". The ROxygen regolith transfer team has identified the flow and transfer characteristics of lunar regolith simulant to be a concern for lunar oxygen production efforts. It is important to ISRU lunar exploration efforts to develop hardware designs that can demonstrate the ability to flow and transfer a given mass of regolith simulant to a desired vertical height under lunar gravity conditions in order to introduce it into a reactor. We will present results obtained under both 1/6-g and 1-g gravity conditions for a system that can pneumatically convey 16.5 kg of lunar regolith simulant (NU-LHT-2M, Mauna Kea Tephra, and JSC-1A) from a flat-bottom supply hopper to a simulated ISRU reactor (dual-chambered receiving hopper) where the granular material is separated from the convey gas (air) using a series of cyclone separators, one of which is an electrically enhanced cyclone separator (electrocyclone). The results of our study include (1) the mass flow rate as a function of input air pressure for lunar regolith simulants that are conveyed pneumatically as a dusty gas in a vertical direction against gravity under lunar gravity conditions (for NU-LHT-2M and Mauna Kea Tephra), and under earth gravity conditions (for NU-LHT-2M, Mauna Kea Tephra and JSC-1A), and (2) the efficiency of the cyclone/electrocyclone filtration system in separating the convey gas (air) from the granular particulates as a function of particle size.

Fungal microcolonies on indoor surfaces — an explanation for the base-level fungal spore counts in indoor air

NASA Astrophysics Data System (ADS)

Pasanen, A.-L.; Heinonen-Tanski, H.; Kalliokoski, P.; Jantunen, M. J.

In the subarctic winter, fungal spores are found in indoor air even when outdoor spore levels are very low. The results of this study support an explanation that some indoor airborne fungal spores are derived from unnoticeable fungal microcolonies, which may develop on temporarily wet surfaces. Laboratory experiments on Penicillium verrucosum indicated that the fungus germinated on new wallpaper very quickly (about half an hour) under moist conditions. Hyphal growth and sporulation of the fungus on moist wallpaper occured within one day of incubation. In gravity-settling tape samples from occasionally wet surfaces in a suburban home, large spore aggregates, hyphal fragments with some spores and spores in the germination stage were found, indicating fungal growth. These experiments showed that fungal microcolonies can develop within a week on occasionally wet indoor surfaces.

Wetting in a Colloidal Liquid-Gas System

NASA Astrophysics Data System (ADS)

Wijting, W. K.; Besseling, N. A.; Stuart, M. A.

2003-05-01

We present first observations of wetting phenomena in depletion interaction driven, phase separated colloidal dispersions (coated silica cyclohexane-polydimethylsiloxane). The contact angle of the colloidal liquid-gas interface at a solid substrate (coated glass) was determined for a series of compositions. Upon approach to the critical point, a transition occurs from partial to complete wetting.

Wetting in a colloidal liquid-gas system.

PubMed

Wijting, W K; Besseling, N A M; Stuart, M A Cohen

2003-05-16

We present first observations of wetting phenomena in depletion interaction driven, phase separated colloidal dispersions (coated silica-cyclohexane-polydimethylsiloxane). The contact angle of the colloidal liquid-gas interface at a solid substrate (coated glass) was determined for a series of compositions. Upon approach to the critical point, a transition occurs from partial to complete wetting.

Behavior of a particle-laden flow in a spiral channel

NASA Astrophysics Data System (ADS)

Lee, Sungyon; Stokes, Yvonne; Bertozzi, Andrea L.

2014-04-01

Spiral gravity separators are devices used in mineral processing to separate particles based on their specific gravity or size. The spiral geometry allows for the simultaneous application of gravitational and centripetal forces on the particles, which leads to segregation of particles. However, this segregation mechanism is not fundamentally understood, and the spiral separator literature does not tell a cohesive story either experimentally or theoretically. While experimental results vary depending on the specific spiral separator used, present theoretical works neglect the significant coupling between the particle dynamics and the flow field. Using work on gravity-driven monodisperse slurries on an incline that empirically accounts for this coupling, we consider a monodisperse particle slurry of small depth flowing down a rectangular channel that is helically wound around a vertical axis. We use a thin-film approximation to derive an equilibrium profile for the particle concentration and fluid depth and find that, in the steady state limit, the particles concentrate towards the vertical axis of the helix, leaving a region of clear fluid.

Enzymatic corn wet milling: engineering process and cost model

PubMed Central

Ramírez, Edna C; Johnston, David B; McAloon, Andrew J; Singh, Vijay

2009-01-01

Background Enzymatic corn wet milling (E-milling) is a process derived from conventional wet milling for the recovery and purification of starch and co-products using proteases to eliminate the need for sulfites and decrease the steeping time. In 2006, the total starch production in USA by conventional wet milling equaled 23 billion kilograms, including modified starches and starches used for sweeteners and ethanol production [1]. Process engineering and cost models for an E-milling process have been developed for a processing plant with a capacity of 2.54 million kg of corn per day (100,000 bu/day). These models are based on the previously published models for a traditional wet milling plant with the same capacity. The E-milling process includes grain cleaning, pretreatment, enzymatic treatment, germ separation and recovery, fiber separation and recovery, gluten separation and recovery and starch separation. Information for the development of the conventional models was obtained from a variety of technical sources including commercial wet milling companies, industry experts and equipment suppliers. Additional information for the present models was obtained from our own experience with the development of the E-milling process and trials in the laboratory and at the pilot plant scale. The models were developed using process and cost simulation software (SuperPro Designer®) and include processing information such as composition and flow rates of the various process streams, descriptions of the various unit operations and detailed breakdowns of the operating and capital cost of the facility. Results Based on the information from the model, we can estimate the cost of production per kilogram of starch using the input prices for corn, enzyme and other wet milling co-products. The work presented here describes the E-milling process and compares the process, the operation and costs with the conventional process. Conclusion The E-milling process was found to be cost competitive with the conventional process during periods of high corn feedstock costs since the enzymatic process enhances the yields of the products in a corn wet milling process. This model is available upon request from the authors for educational, research and non-commercial uses. PMID:19154623

Parabolic Flight Evaluation of Bacterial Adhesion on Multiple Antimicrobial Surface Treatments

NASA Technical Reports Server (NTRS)

Birmele, Michele

2011-01-01

This report describes the development of a test method and the evaluation of the effectiveness of antimicrobial technologies in reduced gravity based on parabolic flight experiments. Microbial growth is a common occurrence on fully immersed wetted surfaces in spacecraft environmental control and life support systems despite the use of chemical and/or physical \\disinfection. Many materials and surface treatments with antimicrobial properties are commercially available but none have been vetted for spaceflight applications. Herein a test method is explained that included ground and reduced gravity parabolic flight experiments with a standard microorganism recovered from spacecraft, Pseudomonas aeruginosa, added at a concentration of 1 x 10(exp 5) cells per milliliter (mL) onto challenge material coupon surfaces. Several experimental materials were observed to slightly reduce microbial attachment in reduced gravity flight experiments, but none were capable of eliminating all challenge bacteria. Lunar gravity had an increased antimicrobial effect in 28 out of 36 test coupons compared to microgravity when provided otherwise identical conditions for growth, suggesting trace .amounts of gravity may be required for maximum antimicrobial performance. Bacterial cells exposed to variable gravity had more than twice as ,much intracellular adenosine triphosphate (ATP) when compared to control cells exposed only to Earth gravity due to a short duration response to environmental stress. An ATP luminescence assay was the method most amenable to development of an in-flight microbial monitoring assay

Hybrid gravity survey to search for submarine ore deposit

NASA Astrophysics Data System (ADS)

Araya, A.; Kanazawa, T.; Fujimoto, H.; Shinohara, M.; Yamada, T.; Mochizuki, K.; Iizasa, K.; Ishihara, T.; Omika, S.

2011-12-01

Along with seismic surveys, gravity survey is a useful method to profile the underground density structure. We propose a hybrid gravity survey using gravimeters and gravity gradiometers to detect submarine ore deposits as density anomalies by towing the instruments using an AUV (Autonomous Underwater Vehicle) or an ROV (Remotely Operated Vehicle). Gravimeters measure the regional density structure below the seafloor, whereas gravity gradiometers are sensitive to localized mass distribution. A gravity gradiometer comprises two accelerometers arranged with a vertical separation, and a gravity gradient can be obtained from the acceleration difference. Compared to gravimeters, gravity gradiometers are insensitive to common disturbances such as parallel acceleration, thermal drift, and apparent gravity effect (Eötvös effect). We made two accelerometers using astatic pendulums, and obtained common acceleration reduction more than two orders of magnitude. With these pendulums of 500-mm separation, resolution of 7E (=7x10^{-9}(1/s^2)), enough to detect a typical ore deposit buried 50m below the seafloor, was evaluated. During measurements using a submersible mobile object, instrument orientation is required to be controlled to keep verticality and to reduce centrifugal force associated with rotation of the instrument. Using a gyro and a tiltmeter, angular rotation was shown to be controlled within 0.001deg/s which corresponds to 0.3E in effective gravity gradient due to the centrifugal force. In this paper, target of this research, details of the instruments and their performance, and development for the submarine gravity survey using an AUV will be presented.

Normal Gravity Testing of a Microchannel Phase Separator for In Situ Resource Utilization

NASA Technical Reports Server (NTRS)

TeGrotenhuis, Ward E.; Stenkamp, Victoria S.; McQuillen, John (Technical Monitor)

2001-01-01

A microchannel separator, with 2.7 millimeters as the smallest dimension, was tested, and a pore throat structure captured and removed liquid from a gas-liquid stream. The microchannel device was tested over a of gas and liquid flow rates ranging from 0.0005 up to 0. 14 volume fraction of liquid. Four liquids were tested with air. The biggest factor affecting the throughput is the capacity of liquid flow through the pore throat, which is dictated by permeability, liquid viscosity, flow area, pore throat thickness, and pressure difference across the pore throat. Typically, complete separation of gas and liquid fractions was lost when the liquid flow rate reached about 40 to 60% of the pore throat capacity. However, this could occur over a range of 10 to 90% utilization of pore throat capacity. Breakthrough occurs in the microchannel phase separator at conditions similar to the annular to plug flow transition of two-phase microgravity pipe flow implying that operating in the proper flow regime is crucial. Analysis indicates that the Bond number did not affect performance, supporting the premise that hydrodynamic, interfacial, and capillary forces are more important than gravity. However, the relative importance of gravity is better discerned through testing under reduced gravity conditions.

Experimental and numerical studies on the treatment of wet astronaut trash by forced-convection drying

NASA Astrophysics Data System (ADS)

Arquiza, J. M. R. Apollo; Morrow, Robert; Remiker, Ross; Hunter, Jean B.

2017-09-01

During long-term space missions, astronauts generate wet trash, including food containers with uneaten portions, moist hygiene wipes and wet paper towels. This waste produces two problems: the loss of water and the generation of odors and health hazards by microbial growth. These problems are solved by a closed-loop, forced-convection, heat-pump drying system which stops microbial activity by both pasteurization and desiccation, and recovers water in a gravity-independent porous media condensing heat exchanger. A transient, pseudo-homogeneous continuum model for the drying of wet ersatz trash was formulated for this system. The model is based on the conservation equations for energy and moisture applied to the air and solid phases and includes the unique trash characteristic of having both dry and wet solids. Experimentally determined heat and mass transfer coefficients, together with the moisture sorption equilibrium relationship for the wet material are used in the model. The resulting system of differential equations is solved by the finite-volume method as implemented by the commercial software COMSOL. Model simulations agreed well with experimental data under certain conditions. The validated model will be used in the optimization of the entire closed-loop system consisting of fan, air heater, dryer vessel, heat-pump condenser, and heat-recovery modules.

Effect of Residual Noncondensables on Pressurization and Pressure Control of a Zero-Boil-Off Tank in Microgravity

NASA Technical Reports Server (NTRS)

Kassemi, Mohammad; Hylton, Sonya; Kartizova, Olga

2013-01-01

The Zero-Boil-Off Tank (ZBOT) Experiment is a small-scale experiment that uses a transparent ventless Dewar and a transparent simulant phase-change fluid to study sealed tank pressurization and pressure control with applications to on-surface and in-orbit storage of propellant cryogens. The experiment will be carried out under microgravity conditions aboard the International Space Station in the 2014 timeframe. This paper presents preliminary results from ZBOT's ground-based research that focuses on the effects of residual noncondensable gases in the ullage on both pressurization and pressure reduction trends in the sealed Dewar. Tank pressurization is accomplished through heating of the test cell wall in the wetted and un-wetted regions simultaneously or separately. Pressure control is established through mixing and destratification of the bulk liquid using a temperature controlled forced jet flow with different degrees of liquid jet subcooling. A Two-Dimensional axisymmetric two-phase CFD model for tank pressurization and pressure control is also presented. Numerical prediction of the model are compared to experimental 1g results to both validate the model and also indicate the effect of the noncondensable gas on evolution of pressure and temperature distributions in the ullage during pressurization and pressure control. Microgravity simulations case studies are also performed using the validated model to underscore and delineate the profound effect of the noncondensables on condensation rates and interfacial temperature distributions with serious implications for tank pressure control in reduced gravity.

Investigation of Body Force Effects on Flow Boiling Critical Heat Flux

NASA Technical Reports Server (NTRS)

Zhang, Hui; Mudawar, Issam; Hasan, Mohammad M.

2002-01-01

The bubble coalescence and interfacial instabilities that are important to modeling critical heat flux (CHF) in reduced-gravity systems can be sensitive to even minute body forces. Understanding these complex phenomena is vital to the design and safe implementation of two-phase thermal management loops proposed for space and planetary-based thermal systems. While reduced gravity conditions cannot be accurately simulated in 1g ground-based experiments, such experiments can help isolate the effects of the various forces (body force, surface tension force and inertia) which influence flow boiling CHF. In this project, the effects of the component of body force perpendicular to a heated wall were examined by conducting 1g flow boiling experiments at different orientations. FC-72 liquid was boiled along one wall of a transparent rectangular flow channel that permitted photographic study of the vapor-liquid interface at conditions approaching CHF. High-speed video imaging was employed to capture dominant CHF mechanisms. Six different CHF regimes were identified: Wavy Vapor Layer, Pool Boiling, Stratification, Vapor Counterflow, Vapor Stagnation, and Separated Concurrent Vapor Flow. CHF showed great sensitivity to orientation for flow velocities below 0.2 m/s, where very small CHF values where measured, especially with downflow and downward-facing heated wall orientations. High flow velocities dampened the effects of orientation considerably. Figure I shows representative images for the different CHF regimes. The Wavy Vapor Layer regime was dominant for all high velocities and most orientations, while all other regimes were encountered at low velocities, in the downflow and/or downward-facing heated wall orientations. The Interfacial Lift-off model was modified to predict the effects of orientation on CHF for the dominant Wavy Vapor Layer regime. The photographic study captured a fairly continuous wavy vapor layer travelling along the heated wall while permitting liquid contact only in wetting fronts, located in the troughs of the interfacial waves. CHF commenced when wetting fronts near the outlet were lifted off the wall. The Interfacial Lift-off model is shown to be an effective tool for predicting the effects of body force on CHF at high velocities.

Gravity-directed separation of both immiscible and emulsified oil/water mixtures utilizing coconut shell layer.

PubMed

Li, Jian; Xu, Changcheng; Zhang, Yan; Tang, Xiaohua; Qi, Wei; Wang, Qiong

2018-02-01

Pressure-driven and lower flux of superwetting ultrafiltration membranes in various emulsions separation are long-standing issues and major barriers for their large-scale utilization. Even though currently reported membranes have achieved great success in emulsions separeation, they still suffer from low flux and complex fabrication process resulting from their smaller nanoscale pore size. Herein, utilizition of coconut shell as a novel biomaterial for developing into a layer through the simple smashing, cleaning and stacking procedures, which not only could avoid the complexity of film making process, but also could realize efficient gravity-directed separation of both immiscible oil/water mixtures and water-in-oil emulsions with high flux. Specifically, the layer acted as "water-removing" type filtrate material with excellent underwater superoleophobicity, exhibiting high efficiency for various immiscible oil/water mixtures separation and larger oil intrusion pressure. More importantly, the layer could also serve as adsorbent material with underoil superhydrophilicity, achieving gravity-directed kinds of water-in-oil emulsions separation with high separation efficiency (above 99.99%) and higher flux (above 1620L/m 2 h), even when their pore sizes are larger than that of emulsified droplets. We deeply believe that this study would open up a new strategy for both immiscible oil/water mixtures and water-in-oil emulsions separation. Copyright © 2017 Elsevier Inc. All rights reserved.

Ultracapacitor separator

DOEpatents

Wei, Chang; Jerabek, Elihu Calvin; LeBlanc, Jr., Oliver Harris

2001-03-06

An ultracapacitor includes two solid, nonporous current collectors, two porous electrodes separating the collectors, a porous separator between the electrodes and an electrolyte occupying the pores in the electrodes and separator. The electrolyte is a polar aprotic organic solvent and a salt. The porous separator comprises a wet laid cellulosic material.

FAST TRACK COMMUNICATION The Bel-Robinson tensor for topologically massive gravity

NASA Astrophysics Data System (ADS)

Deser, S.; Franklin, J.

2011-02-01

We construct, and establish the (covariant) conservation of, a 4-index 'super stress tensor' for topologically massive gravity. Separately, we discuss its invalidity in quadratic curvature models and suggest a generalization.

Evidence for an east-west regional gravity trend in northern Tunisia: Insight into the structural evolution of northern Tunisian Atlas

NASA Astrophysics Data System (ADS)

Jallouli, Chokri; Mogren, Saad; Mickus, Kevin; Turki, Mohamed Moncef

2013-11-01

The Atlas orogeny in northern Algeria and Tunisia led to the destruction of Tethys oceanic lithosphere and cumulated in a collision of microplates rifted off the European margin with the North African continental margin. The location of the boundary between African plate and Kabylian microplate is expressed in northern Algeria by a crustal wedge with double vergence of thrust sheets, whereas in northern Tunisia the geologic environment is more complex and the location of the plate boundary is ambiguous. In this study, we analyzed gravity data to constrain the crustal structure along the northern margin of Tunisia. The analysis includes a separation of regional and residual gravity anomalies and the application of gradient operators to locate density contrast boundaries. The horizontal gradient magnitude and directional gradient highlight a prominent regional E-W gravity gradient in the northern Tunisian Atlas interpreted as a deep fault (active since at least the Early Mesozoic) having a variable kinematic activity depending on the tectonic regime in the region. The main E-W gravity gradient separates two blocks having different gravitational and seismic responses. The southern block has numerous gravity lineaments trending in different directions implying several density variations within the crust, whereas the northern block shows a long-wavelength negative gravity anomaly with a few lineaments. Taking into account the geologic context of the Western Mediterranean region, we consider the E-W prominent feature as the boundary between African plate and Kabylian microplate in northern Tunisia that rifted off Europe. This hypothesis fits most previous geological and geophysical studies and has an important impact on the petroleum and mineral resource prospection as these two blocks were separated by an ocean and they did not belong to the same margin.

Industrial processes influenced by gravity

NASA Technical Reports Server (NTRS)

Ostrach, Simon

1988-01-01

In considering new directions for low gravity research with particular regard to broadening the number and types of industrial involvements, it is noted that transport phenomena play a vital role in diverse processes in the chemical, pharmaceutical, food, and biotech industries. Relatively little attention has been given to the role of gravity in such processes. Accordingly, numerous industrial processes and phenomena are identified which involve gravity and/or surface tension forces. Phase separations and mixing are examples that will be significantly different in low gravity conditions. A basis is presented for expanding the scope of the low gravity research program and the potential benefits of such research is indicated.

Method of enhancing the wettability of boron nitride for use as an electrochemical cell separator

DOEpatents

McCoy, L.R.

1981-01-23

A felt or other fabric of boron nitride suitable for use as an interelectrode separator within an electrochemical cell is wetted with a solution containing a thermally decomposable organic salt of an alkaline earth metal. An aqueous solution of magnesium acetate is the preferred solution for this purpose. After wetting the boron nitride, the solution is dried by heating at a sufficiently low temperature to prevent rapid boiling and the creation of voids within the separator. The dried material is then calcined at an elevated temperature in excess of 400/sup 0/C to provide a coating of an oxide of magnesium on the surface of the boron nitride fibers. A fabric or felt of boron nitride treated in this manner is easily wetted by molten electrolytic salts, such as the alkali metal halides or alkaline earth metal halides, that are used in high temperature, secondary electrochemical cells.

Method of enhancing the wettability of boron nitride for use as an electrochemical cell separator

DOEpatents

McCoy, Lowell R.

1982-01-01

A felt or other fabric of boron nitride suitable for use as an interelecte separator within an electrochemical cell is wetted with a solution containing a thermally decomposable organic salt of an alkaline earth metal. An aqueous solution of magnesium acetate is the preferred solution for this purpose. After wetting the boron nitride, the solution is dried by heating at a sufficiently low temperature to prevent rapid boiling and the creation of voids within the separator. The dried material is then calcined at an elevated temperature in excess of 400.degree. C. to provide a coating of an oxide of magnesium on the surface of the boron nitride fibers. A fabric or felt of boron nitride treated in this manner is easily wetted by molten electrolytic salts, such as the alkali metal halides or alkaline earth metal halides, that are used in high temperature, secondary electrochemical cells.

Bipolar fuel cell

DOEpatents

McElroy, James F.

1989-01-01

The present invention discloses an improved fuel cell utilizing an ion transporting membrane having a catalytic anode and a catalytic cathode bonded to opposite sides of the membrane, a wet-proofed carbon sheet in contact with the cathode surface opposite that bonded to the membrane and a bipolar separator positioned in electrical contact with the carbon sheet and the anode of the adjacent fuel cell. Said bipolar separator and carbon sheet forming an oxidant flowpath, wherein the improvement comprises an electrically conductive screen between and in contact with the wet-proofed carbon sheet and the bipolar separator improving the product water removal system of the fuel cell.

The effect of immunoglobulins and somatic cells on the gravity separation of fat, bacteria, and spores in pasteurized whole milk.

PubMed

Geer, S R; Barbano, D M

2014-01-01

Our objective was to determine the role that immunoglobulins and somatic cells (SC) play in the gravity separation of milk. The experiment comprised 9 treatments: (1) low-temperature pasteurized (LTP; 72°C for 17.31s) whole milk; (2) LTP (72°C for 17.31s) whole milk with added bacteria and spores; (3) recombined LTP (72°C for 17.31s) whole milk with added bacteria and spores; (4) high-temperature pasteurized (HTP; 76°C for 7min) whole milk with added bacteria and spores; (5) HTP (76°C for 7min) whole milk with added bacteria and spores and added colostrum; (6) HTP (76°C for 7min) centrifugally separated, gravity-separated (CS GS) skim milk with HTP (76°C for 7min) low-SC cream with added bacteria and spores; (7) HTP (76°C for 7min) CS GS skim milk with HTP (76°C for 7min) high-SC cream with added bacteria and spores; (8) HTP (76°C for 7min) CS GS skim milk with HTP (76°C for 7min) low-SC cream with added bacteria and spores and added colostrum; and (9) HTP (76°C for 7min) CS GS skim milk with HTP (76°C for 7min) high-SC cream with added bacteria and spores and added colostrum. The milks in the 9 treatments were gravity separated at 4°C for 23h in glass columns. Five fractions were collected by weight from each of the column treatments, starting from the bottom of the glass column: 0 to 5%, 5 to 90%, 90 to 96%, 96 to 98%, and 98 to 100%. The SC, fat, bacteria, and spores were measured in each of the fractions. The experiment was replicated 3 times in different weeks using a different batch of milk and different colostrum. Portions of the same batch of the frozen bacteria and spore solutions were used for all 3 replicates. The presence of both SC and immunoglobulins were necessary for normal gravity separation (i.e., rising to the top) of fat, bacteria, and spores in whole milk. The presence of immunoglobulins alone without SC was not sufficient to cause bacteria, fat, and spores to rise to the top. The interaction between SC and immunoglobulins was necessary to cause aggregates of fat, SC, bacteria, and spores to rise during gravity separation. The SC may provide the buoyancy required for the aggregates to rise to the top due to gas within the SC. More research is needed to understand the mechanism of the gravity-separation process. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Measurement of absolute gravity acceleration in Firenze

NASA Astrophysics Data System (ADS)

de Angelis, M.; Greco, F.; Pistorio, A.; Poli, N.; Prevedelli, M.; Saccorotti, G.; Sorrentino, F.; Tino, G. M.

2011-01-01

This paper reports the results from the accurate measurement of the acceleration of gravity g taken at two separate premises in the Polo Scientifico of the University of Firenze (Italy). In these laboratories, two separate experiments aiming at measuring the Newtonian constant and testing the Newtonian law at short distances are in progress. Both experiments require an independent knowledge on the local value of g. The only available datum, pertaining to the italian zero-order gravity network, was taken more than 20 years ago at a distance of more than 60 km from the study site. Gravity measurements were conducted using an FG5 absolute gravimeter, and accompanied by seismic recordings for evaluating the noise condition at the site. The absolute accelerations of gravity at the two laboratories are (980 492 160.6 ± 4.0) μGal and (980 492 048.3 ± 3.0) μGal for the European Laboratory for Non-Linear Spectroscopy (LENS) and Dipartimento di Fisica e Astronomia, respectively. Other than for the two referenced experiments, the data here presented will serve as a benchmark for any future study requiring an accurate knowledge of the absolute value of the acceleration of gravity in the study region.

Development and testing of a unique carousel wind tunnel to experimentally determine the effect of gravity and the interparticle force on the physics of wind-blown particles

NASA Technical Reports Server (NTRS)

Leach, R. N.; Greeley, Ronald; White, Bruce R.; Iversen, James D.

1987-01-01

In the study of planetary aeolian processes the effect of gravity is not readily modeled. Gravity appears in the equations of particle motion along with the interparticle forces but the two are not separable. A wind tunnel that perimits multiphase flow experiments with wind blown particles at variable gravity was built and experiments were conducted at reduced gravity. The equations of particle motion initiation (saltation threshold) with variable gravity were experimentally verified and the interparticle force was separated. A uniquely design Carousel Wind Tunnel (CWT) allows for the long flow distance in a small sized tunnel since the test section if a continuous loop and develops the required turbulent boundary layer. A prototype model of the tunnel where only the inner drum rotates was built and tested in the KC-135 Weightless Wonder 4 zero-g aircraft. Future work includes further experiments with walnut shell in the KC-135 which sharply graded particles of widely varying median sizes including very small particles to see how interparticle force varies with particle size, and also experiments with other aeolian material.

GRAIL Twin Spacecraft -- Crust to Core Artist Concept

NASA Image and Video Library

2009-05-18

The Gravity Recovery and Interior Laboratory GRAIL mission utilizes the technique of twin spacecraft flying in formation with a known altitude above the lunar surface and known separation distance to investigate the gravity field of the moon.

Beneficiation of the gold bearing ore by gravity and flotation

NASA Astrophysics Data System (ADS)

Gül, Alim; Kangal, Olgaç; Sirkeci, Ayhan A.; Önal, Güven

2012-02-01

Gold concentration usually consists of gravity separation, flotation, cyanidation, or the combination of these processes. The choice among these processes depends on the mineralogical characterization and gold content of the ore. Recently, the recovery of gold using gravity methods has gained attention because of low cost and environmentally friendly operations. In this study, gold pre-concentrates were produced by the stepwise gravity separation and flotation techniques. The Knelson concentrator and conventional flotation were employed for the recovery of gold. Gold bearing ore samples were taken from Gümüşhane Region, northern east part of Turkey. As a result of stepwise Knelson concentration experiments, a gold concentrate assaying around 620 g/t is produced with 41.4wt% recovery. On the other hand, a gold concentrate about 82 g/t is obtained with 89.9wt% recovery from a gold ore assaying 6 g/t Au by direct flotation.

Fine coal cleaning via the micro-mag process

DOEpatents

Klima, Mark S.; Maronde, Carl P.; Killmeyer, Richard P.

1991-01-01

A method of cleaning particulate coal which is fed with a dense medium slurry as an inlet feed to a cyclone separator. The coal particle size distribution is in the range of from about 37 microns to about 600 microns. The dense medium comprises water and ferromagnetic particles that have a relative density in the range of from about 4.0 to about 7.0. The ferromagnetic particles of the dense medium have particle sizes of less than about 15 microns and at least a majority of the particle sizes are less than about 5 microns. In the cyclone, the particulate coal and dense-medium slurry is separated into a low gravity product stream and a high gravity produce stream wherein the differential in relative density between the two streams is not greater than about 0.2. The low gravity and high gravity streams are treated to recover the ferromagnetic particles therefrom.

Results from the Water Flow Test of the Tank 37 Backflush Valve

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

Fowley, M.D.

2002-11-01

A flow test was conducted in the Thermal Fluids Lab with the Tank 37 Backflush Valve to determine the pressure drop of water flow through the material transfer port. The flow rate was varied from 0 to 100 gpm. The pressure drop through the Backflush Valve for flow rates of 20 and 70 gpm was determined to be 0.18 and 1.77 feet of H2O, respectively. An equivalent length of the Backflush Valve was derived from the flow test data. The equivalent length was used in a head loss calculation for the Tank 37 Gravity Drain Line. The calculation estimated themore » flow rate that would fill the line up to the Separator Tank, and the additional flow rate that would fill the Separator Tank. The viscosity of the fluid used in the calculation was 12 centipoise. Two specific gravities were investigated, 1.4 and 1.8. The Gravity Drain Line was assumed to be clean, unobstructed stainless steel pipe. The flow rate that would fill the line up to the Separator Tank was 73 and 75 gpm for the 1.4 or 1.8 specific gravity fluids, respectively. The flow rate that would fill the Separator Tank was 96 and 100 gpm for the 1.4 or 1.8 specific gravity fluids, respectively. These results indicate that concentrate will not back up into the Separator Tank during evaporator normal operation, 15-25 gpm, or pot liftout, 70 gpm. A noteworthy observation during the flow test was water pouring from the holes in the catheterization tube. Water poured from the holes at 25 gpm and above. Data from the water flow test indicates that at 25 gpm the pressure drop through the Backflush Valve is 0.26 ft of H2O. A concentrate with a specific gravity of 1.8 and a viscosity of 12 cp will produce the same pressure drop at 20 gpm. This implies that concentrate from the evaporator may spill out into the BFV riser during a transfer.« less

Dynamic regimes of buoyancy-affected two-phase flow in unconsolidated porous media.

PubMed

Stöhr, M; Khalili, A

2006-03-01

The invasion and subsequent flow of a nonwetting fluid (NWF) in a three-dimensional, unconsolidated porous medium saturated with a wetting fluid of higher density and viscosity have been studied experimentally using a light-transmission technique. Distinct dynamic regimes have been found for different relative magnitudes of viscous, capillary, and gravity forces. It is shown that the ratio of viscous and hydrostatic pressure gradients can be used as a relevant dimensionless number K for the characterization of the different flow regimes. For low values of K, the invasion is characterized by the migration and fragmentation of isolated clusters of the NWF resulting from the prevalence of gravity and capillary forces. At high values of K, the dominance of viscous and gravity forces leads to an anisotropic fingerlike invasion. When the invasion stops after the breakthrough of the NWF at the open upper boundary, the invasion structure retracts under the influence of gravity and transforms into stable vertical channels. It is shown that the stability of these channels is the result of a balance between hydrostatic and viscous pressure gradients.

Future utilization of space: Silverton Conference on material science and phase transformations in zero-gravity, summary of proceeding

NASA Technical Reports Server (NTRS)

Eisner, M. (Editor)

1975-01-01

The importance of zero gravity environment in the development and production of new and improved materials is considered along with the gravitational effects on phase changes or critical behavior in a variety of materials. Specific experiments discussed include: fine scale phase separation in zero gravity; glass formation in zero gravity; effects of gravitational perturbations on determination of critical exponents; and light scattering from long wave fluctuations in liquids in zero gravity. It is concluded that the space shuttle/spacelab system is applicable to various fields of interest.

A Pseudo-Vertical Equilibrium Model for Slow Gravity Drainage Dynamics

NASA Astrophysics Data System (ADS)

Becker, Beatrix; Guo, Bo; Bandilla, Karl; Celia, Michael A.; Flemisch, Bernd; Helmig, Rainer

2017-12-01

Vertical equilibrium (VE) models are computationally efficient and have been widely used for modeling fluid migration in the subsurface. However, they rely on the assumption of instant gravity segregation of the two fluid phases which may not be valid especially for systems that have very slow drainage at low wetting phase saturations. In these cases, the time scale for the wetting phase to reach vertical equilibrium can be several orders of magnitude larger than the time scale of interest, rendering conventional VE models unsuitable. Here we present a pseudo-VE model that relaxes the assumption of instant segregation of the two fluid phases by applying a pseudo-residual saturation inside the plume of the injected fluid that declines over time due to slow vertical drainage. This pseudo-VE model is cast in a multiscale framework for vertically integrated models with the vertical drainage solved as a fine-scale problem. Two types of fine-scale models are developed for the vertical drainage, which lead to two pseudo-VE models. Comparisons with a conventional VE model and a full multidimensional model show that the pseudo-VE models have much wider applicability than the conventional VE model while maintaining the computational benefit of the conventional VE model.

Closed-loop system for growth of aquatic biomass and gasification thereof

DOEpatents

Oyler, James R.

2017-09-19

Processes, systems, and methods for producing combustible gas from wet biomass are provided. In one aspect, for example, a process for generating a combustible gas from a wet biomass in a closed system is provided. Such a process may include growing a wet biomass in a growth chamber, moving at least a portion of the wet biomass to a reactor, heating the portion of the wet biomass under high pressure in the reactor to gasify the wet biomass into a total gas component, separating the gasified component into a liquid component, a non-combustible gas component, and a combustible gas component, and introducing the liquid component and non-combustible gas component containing carbon dioxide into the growth chamber to stimulate new wet biomass growth.

Environmentally-friendly oxygen-free roasting/wet magnetic separation technology for in situ recycling cobalt, lithium carbonate and graphite from spent LiCoO2/graphite lithium batteries.

PubMed

Li, Jia; Wang, Guangxu; Xu, Zhenming

2016-01-25

The definite aim of the present paper is to present some novel methods that use oxygen-free roasting and wet magnetic separation to in situ recycle of cobalt, Lithium Carbonate and Graphite from mixed electrode materials. The in situ recycling means to change waste into resources by its own components, which is an idea of "waste+waste→resources." After mechanical scraping the mixed electrode materials enrich powders of LiCoO2 and graphite. The possible reaction between LiCoO2 and graphite was obtained by thermodynamic analysis. The feasibility of the reaction at high temperature was studied with the simultaneous thermogravimetry analysis under standard atmospheric pressure. Then the oxygen-free roasting/wet magnetic separation method was used to transfer the low added value mixed electrode materials to high added value products. The results indicated that, through the serious technologies of oxygen-free roasting and wet magnetic separation, mixture materials consist with LiCoO2 and graphite powders are transferred to the individual products of cobalt, Lithium Carbonate and Graphite. Because there is not any chemical solution added in the process, the cost of treating secondary pollution can be saved. This study provides a theoretical basis for industrial-scale recycling resources from spent LIBs. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparison of separation performance of laser-ablated and wet-etched microfluidic devices

PubMed Central

Baker, Christopher A.; Bulloch, Rayford; Roper, Michael G.

2010-01-01

Laser ablation of glass allows for production of microfluidic devices without the need of hydrofluoric acid and photolithography. The goal of this study was to compare the separation performance of microfluidic devices produced using a low-cost laser ablation system and conventional wet etching. During laser ablation, cracking of the glass substrate was prevented by heating the glass to 300°C. A range of laser energy densities was found to produce channel depths ranging from 4 – 35 μm and channel widths from 118 – 162 μm. The electroosmotic flow velocity was lower in laser-ablated devices, 0.110 ± 0.005 cm s−1, as compared to wet-etched microfluidic chips, 0.126 ± 0.003 cm s−1. Separations of both small and large molecules performed on both wet- and laser-ablated devices were compared by examining limits of detection, theoretical plate count, and peak asymmetry. Laser-induced fluorescence detection limits were 10 pM fluorescein for both types of devices. Laser-ablated and wet-etched microfluidic chips had reproducible migration times with ≤ 2.8% RSD and peak asymmetries ranging from 1.0 – 1.8. Numbers of theoretical plates were between 2.8- and 6.2-fold higher on the wet-etched devices compared to laser-ablated devices. Nevertheless, resolution between small and large analytes was accomplished, which indicates that laser ablation may find an application in pedagogical studies of electrophoresis or microfluidic devices, or in settings where hydrofluoric acid cannot be used. PMID:20827468

A facile approach for the fabrication of 3D flower-like Cu2S nanostructures on brass mesh with temperature-induced wetting transition for efficient oil-water separation

NASA Astrophysics Data System (ADS)

Niu, Lei; Kang, Zhixin

2017-11-01

3D flower-like Cu2S nanostructures on brass meshes have been fabricated for the first time, with a reversible wetting transition and excellent durability. In the present work, we demonstrated a simple and environmentally-benign method to fabricate the nanostructures utilizing an electrolyte containing CuSO4·5H2O, EDTA-2Na and CH3CSNH2. The superhydrophobicity was achieved by drying thoroughly at 200 °C, instead of using low surface energy materials. After annealing at 300 °C for 6 min, the superhydrophobic surface was oxidized and became superhydrophilic. However, the superhydrophobicity can be restored by heating at 200 °C for several hours. In simpler terms, the reversible wetting transition is responded to the temperature. Scanning electron microscopy, X-ray diffractometer, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy were employed to characterize the surfaces and analyze the wetting transition mechanism. Furthermore, different kinds of oily sewages were separated by as-prepared mesh with high separation efficiency. It is believed that this method should have a promising future in expanding the applications of copper alloys.

Emerging Contaminants in Wet-Weather Flow: Characterization and Treatability

EPA Science Inventory

An extensive literature review was conducted on the presence and magnitude of emerging contaminants (ECs) in wet-weather flow (WWF) including separate stormwater, combined sewer overflow (CSO), and sanitary sewer overflow (SSO). Although little information exists for stormwater ...

Estimation of alluvial-fill thickness in the Mimbres ground-water basin, New Mexico, from interpretation of isostatic residual gravity anomalies

USGS Publications Warehouse

Heywood, Charles E.

2002-01-01

The geologic structure of the Mimbres ground-water basin in southwest New Mexico is characterized by north- and northwest-trending structural subbasins. Sedimentation of Miocene and Pliocene age has filled and obscured the boundaries of these subbasins and formed poten- tially productive aquifers of varied thickness. The location and depth of the subbasins can be esti- mated from analysis of isostatic residual gravity anomalies. Density contrasts of various basement lithologies generate complex regional gravity trends, which are convolved with the gravity signal from the Miocene and Pliocene alluvial fill. An iterative scheme was used to separate these regional gravity trends from the alluvial-fill grav- ity signal, which was inverted with estimated depth-density relations to compute the thickness of the alluvial fill at 1-kilometer spacing. The thickness estimates were constrained by explor- atory drill-hole information, interpreted seismic- refraction profiles, and location of bedrock lithol- ogy from surficial geologic mapping. The result- ing map of alluvial-fill thickness suggests large areas of thin alluvium that separate deep structural subbasins.

Photometric Separation of Stellar Properties Using SDSS Filters

NASA Astrophysics Data System (ADS)

Lenz, Dawn D.; Newberg, Jo; Rosner, Robert; Richards, Gordon T.; Stoughton, Chris

1998-12-01

Using synthetic photometry of Kurucz model spectra, we explore the colors of stars as a function of temperature, metallicity, and surface gravity with Sloan Digital Sky Survey (SDSS) filters, u'g'r'i'z'. The synthetic colors show qualitative agreement with the few published observations in these filters. We find that the locus of synthetic stars is basically two-dimensional for 4500 < T < 8000 K, which precludes simultaneous color separation of the three basic stellar characteristics we consider. Colors including u' contain the most information about normal stellar properties; measurements in this filter are also important for selecting white dwarfs. We identify two different subsets of the locus in which the loci separate by either metallicity or surface gravity. For 0.5 < g' - r' < 0.8 (corresponding roughly to G stars), the locus separates by metallicity; for photometric error of a few percent, we estimate metallicity to within ~0.5 dex in this range. In the range -0.15 < g' - r' < 0.00 (corresponding roughly to A stars), the locus shows separation by surface gravity. In both cases, we show that it is advantageous to use more than two colors when determining stellar properties by color. Strategic observations in SDSS filters are required to resolve the source of a ~5% discrepancy between synthetic colors of Gunn-Stryker stars, Kurucz models, and external determinations of the metallicities and surface gravities. The synthetic star colors can be used to investigate the properties of any normal star and to construct analytic expressions for the photometric prediction of stellar properties in special cases.

Selective Template Wetting Routes to Hierarchical Polymer Films: Polymer Nanotubes from Phase-Separated Films via Solvent Annealing.

PubMed

Ko, Hao-Wen; Cheng, Ming-Hsiang; Chi, Mu-Huan; Chang, Chun-Wei; Chen, Jiun-Tai

2016-03-01

We demonstrate a novel wetting method to prepare hierarchical polymer films with polymer nanotubes on selective regions. This strategy is based on the selective wetting abilities of polymer chains, annealed in different solvent vapors, into the nanopores of porous templates. Phase-separated films of polystyrene (PS) and poly(methyl methacrylate) (PMMA), two commonly used polymers, are prepared as a model system. After anodic aluminum oxide (AAO) templates are placed on the films, the samples are annealed in vapors of acetic acid, in which the PMMA chains are swollen and wet the nanopores of the AAO templates selectively. As a result, hierarchical polymer films containing PMMA nanotubes can be obtained after the AAO templates are removed. The distribution of the PMMA nanotubes of the hierarchical polymer films can also be controlled by changing the compositions of the polymer blends. This work not only presents a novel method to fabricate hierarchical polymer films with polymer nanotubes on selective regions, but also gives a deeper understanding in the selective wetting ability of polymer chains in solvent vapors.

A Model of Gravity Vector Measurement Noise for Estimating Accelerometer Bias in Gravity Disturbance Compensation.

PubMed

Tie, Junbo; Cao, Juliang; Chang, Lubing; Cai, Shaokun; Wu, Meiping; Lian, Junxiang

2018-03-16

Compensation of gravity disturbance can improve the precision of inertial navigation, but the effect of compensation will decrease due to the accelerometer bias, and estimation of the accelerometer bias is a crucial issue in gravity disturbance compensation. This paper first investigates the effect of accelerometer bias on gravity disturbance compensation, and the situation in which the accelerometer bias should be estimated is established. The accelerometer bias is estimated from the gravity vector measurement, and a model of measurement noise in gravity vector measurement is built. Based on this model, accelerometer bias is separated from the gravity vector measurement error by the method of least squares. Horizontal gravity disturbances are calculated through EGM2008 spherical harmonic model to build the simulation scene, and the simulation results indicate that precise estimations of the accelerometer bias can be obtained with the proposed method.

A Model of Gravity Vector Measurement Noise for Estimating Accelerometer Bias in Gravity Disturbance Compensation

PubMed Central

Cao, Juliang; Cai, Shaokun; Wu, Meiping; Lian, Junxiang

2018-01-01

Compensation of gravity disturbance can improve the precision of inertial navigation, but the effect of compensation will decrease due to the accelerometer bias, and estimation of the accelerometer bias is a crucial issue in gravity disturbance compensation. This paper first investigates the effect of accelerometer bias on gravity disturbance compensation, and the situation in which the accelerometer bias should be estimated is established. The accelerometer bias is estimated from the gravity vector measurement, and a model of measurement noise in gravity vector measurement is built. Based on this model, accelerometer bias is separated from the gravity vector measurement error by the method of least squares. Horizontal gravity disturbances are calculated through EGM2008 spherical harmonic model to build the simulation scene, and the simulation results indicate that precise estimations of the accelerometer bias can be obtained with the proposed method. PMID:29547552

Gas-Liquid Flows and Phase Separation

NASA Technical Reports Server (NTRS)

McQuillen, John

2004-01-01

Common issues for space system designers include:Ability to Verify Performance in Normal Gravity prior to Deployment; System Stability; Phase Accumulation & Shedding; Phase Separation; Flow Distribution through Tees & Manifolds Boiling Crisis; Heat Transfer Coefficient; and Pressure Drop.The report concludes:Guidance similar to "A design that operates in a single phase is less complex than a design that has two-phase flow" is not always true considering the amount of effort spent on pressurizing, subcooling and phase separators to ensure single phase operation. While there is still much to learn about two-phase flow in reduced gravity, we have a good start. Focus now needs to be directed more towards system level problems .

Application of electrohydrodynamic phenomena to space processing

NASA Technical Reports Server (NTRS)

Jones, T. B.

1975-01-01

The capabilities of electrohydrodynamic (EHD) unit separation, liquid handling/control, and mixing are introduced to industrial chemists and metallurgists, working on specific zero-gravity processes. Previously proposed zero-gravity applications of EHD are presented along with the prominent electrohydrodynamical force effects.

GRAIL Twin Spacecraft fly in Tandem Around the Moon Artist Concept

NASA Image and Video Library

2009-05-18

The Gravity Recovery and Interior Laboratory GRAIL mission utilizes the technique of twin spacecraft flying in formation with a known altitude above the lunar surface and known separation distance to investigate the gravity field of the moon.

Peak Stress Testing Protocol Framework

EPA Science Inventory

Treatment of peak flows during wet weather is a common challenge across the country for municipal wastewater utilities with separate and/or combined sewer systems. Increases in wastewater flow resulting from infiltration and inflow (I/I) during wet weather events can result in op...

Feasibility study on the use of soil washing to remediate the As-Hg contamination at an ancient mining and metallurgy area.

PubMed

Sierra, C; Menéndez-Aguado, J M; Afif, E; Carrero, M; Gallego, J R

2011-11-30

Soils in abandoned mining sites generally present high concentrations of trace elements, such as As and Hg. Here we assessed the feasibility of washing procedures to physically separate these toxic elements from soils affected by a considerable amount of mining and metallurgical waste ("La Soterraña", Asturias, NW Spain). After exhaustive soil sampling and subsequent particle-size separation via wet sieving, chemical and mineralogical analysis revealed that the finer fractions held very high concentrations of As (up to 32,500 ppm) and Hg (up to 1600 ppm). These elements were both associated mainly with Fe/Mn oxides and hydroxides. Textural and geochemical data were correlated with the geological substrate by means of a multivariate statistical analysis. In addition, the Hg liberation size (below 200 μm) was determined to be main factor conditioning the selection of suitable soil washing strategies. These studies were finally complemented with a specific-gravity study performed with a C800 Mozley separator together with a grindability test, both novel approaches in soil washing feasibility studies. The results highlighted the difficulties in treating "La Soterraña" soils. These difficulties are attributed to the presence of contaminants embedded in the soil and spoil heap aggregates, caused by the meteorization of gangue and ore minerals. As a result of these two characteristics, high concentrations of the contaminants accumulate in all grain-size fractions. Therefore, the soil washing approach proposed here includes the grinding of particles above 125 μm. Copyright © 2011 Elsevier B.V. All rights reserved.

VERIFICATION OF HIGH-RATE SEPARATION DEVICES UNDER THE WET-WEATHER FLOW TECHNOLOGIES PILOT - ETV PROGRAM

EPA Science Inventory

This paper presents performance verification data on two types of high-rate separation devices utilized for solids removal: Vortex separation devices (a class of physical treatment technologies that use cylindrical chambers to create centrifugal forces that separate settleable so...

A fine coal circuitry study using column flotation and gravity separation. Quarterly report, 1 March 1995--31 May 1995

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

Honaker, R.Q.; Reed, S.

1995-12-31

Column flotation provides excellent recovery of ultrafine coal while producing low ash content concentrates. However, column flotation is not efficient for treating fine coal containing significant amounts of mixed-phase particles. Fortunately, enhanced gravity separation has proved to have the ability to treat the mixed-phased particles more effectively. A disadvantage of gravity separation is that ultrafine clay particles are not easily rejected. Thus, a combination of these two technologies may provide a circuit that maximizes both the ash and sulfur rejection that can be achieved by physical coal cleaning while maintaining a high energy recovery. This project is studying the potentialmore » of using different combinations of gravity separators, i.e., a Floatex hydrosizer and a Falcon Concentrator, and a proven flotation column, which will be selected based on previous studies by the principle investigator. During this reporting period, an extensive separation performance comparison between a pilot-scale Floatex Density Separator (18{times}18-inch) and an existing spiral circuit has been conducted at Kerf-McGee Coal Preparation plan for the treatment of nominally {minus}16 mesh coal. The results indicate that the Floatex is a more efficient separation device (E{sub p}=0.12) than a conventional coal spiral (E{sub p}=0.18) for Illinois seam coals. In addition, the treatment of {minus}100 mesh Illinois No. 5 fine coal from the same plant using Falcon concentrator, column flotation (Packed-Column) and their different combinations was also evaluated. For a single operation, both Falcon concentrator and column flotation can produce a clean coal product with 90% combustible recovery and 5% ash content. In the case of the combined circuit, column flotation followed by the Falcon achieved a higher combustible recovery value (about 75%) than that obtained by the individual units while maintaining an ash content less than 3%.« less

Hydrodynamic effects on phase separation morphologies in evaporating thin films of polymer solutions

NASA Astrophysics Data System (ADS)

Zoumpouli, Garyfalia A.; Yiantsios, Stergios G.

2016-08-01

We examine effects of hydrodynamics on phase separation morphologies developed during drying of thin films containing a volatile solvent and two dissolved polymers. Cahn-Hilliard and Flory-Huggins theories are used to describe the free energy of the phase separating systems. The thin films, considered as Newtonian fluids, flow in response to Korteweg stresses arising due to concentration non-uniformities that develop during solvent evaporation. Numerical simulations are employed to investigate the effects of a Peclet number, defined in terms of system physical properties, as well as the effects of parameters characterizing the speed of evaporation and preferential wetting of the solutes at the gas interface. For systems exhibiting preferential wetting, diffusion alone is known to favor lamellar configurations for the separated phases in the dried film. However, a mechanism of hydrodynamic instability of a short length scale is revealed, which beyond a threshold Peclet number may deform and break the lamellae. The critical Peclet number tends to decrease as the evaporation rate increases and to increase with the tendency of the polymers to selectively wet the gas interface. As the Peclet number increases, the instability moves closer to the gas interface and induces the formation of a lateral segregation template that guides the subsequent evolution of the phase separation process. On the other hand, for systems with no preferential wetting or any other property asymmetries between the two polymers, diffusion alone favors the formation of laterally separated configurations. In this case, concentration perturbation modes that lead to enhanced Korteweg stresses may be favored for sufficiently large Peclet numbers. For such modes, a second mechanism is revealed, which is similar to the solutocapillary Marangoni instability observed in evaporating solutions when interfacial tension increases with the concentration of the non-volatile component. This mechanism may lead to multiple length scales in the laterally phase separated configurations.

REMOVAL OF HUMICSUBSTANCES AND ALGAE BY DISSOLVED AIR FLOTATION

EPA Science Inventory

Dissolved air flotation (DAF) is used in place of conventional gravity settling as a means to separate low density floc particles from water. The following objectives were: (1) to compare DAF to conventional water treatment of coagulation-flocculation followed by gravity settling...

Mechanical and physical properties of wood fiber-reinforced, sulfur-based wood composites

Treesearch

Chung-Yun Hse; Ben S. Bryant

1993-01-01

Sulfur-based composite was made from sulfur impregnated, oven dried, wet-formed fiber mats. The fiber mats consisted of a 50/50 mixture of recycled newsprint pulp and mechanical hardwood pulp from several species made from chips in a laboratory refiner. The thickness of the composites was 0.125 inch and the specific gravity of the unimpregnated fiber mat was 0.2. The...

Proteome Analysis of Thyroid Cancer Cells After Long-Term Exposure to a Random Positioning Machine

NASA Astrophysics Data System (ADS)

Pietsch, Jessica; Bauer, Johann; Weber, Gerhard; Nissum, Mikkel; Westphal, Kriss; Egli, Marcel; Grosse, Jirka; Schönberger, Johann; Eilles, Christoph; Infanger, Manfred; Grimm, Daniela

2011-11-01

Annulling gravity during cell culturing triggers various types of cells to change their protein expression in a time dependent manner. We therefore decided to determine gravity sensitive proteins and their period of sensitivity to the effects of gravity. In this study, thyroid cancer cells of the ML-1 cell line were cultured under normal gravity (1 g) or in a random positioning machine (RPM), which simulated near weightlessness for 7 and 11 days. Cells were then sonicated and proteins released into the supernatant were separated from those that remained attached to the cell fragments. Subsequently, both types of proteins were fractionated by free-flow isoelectric focussing (FF-IEF). The fractions obtained were further separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to which comparable FF-IEF fractions derived from cells cultured either under 1 g or on the RPM had been applied side by side. The separation resulted in pairs of lanes, on which a number of identical bands were observed. Selected gel pieces were excised and their proteins determined by mass spectrometry. Equal proteins from cells cultured under normal gravity and the RPM, respectively, were detected in comparable gel pieces. However, many of these proteins had received different Mascot scores. Quantifying heat shock cognate 71 kDa protein, glutathione S-transferase P, nucleoside diphosphate kinase A and annexin-2 by Western blotting using whole cell lysates indicated usefulness of Mascot scores for selecting the most efficient antibodies.

Harmonic analysis of the DTU10 global gravity anomalies

NASA Astrophysics Data System (ADS)

Abrykosov, O.; Förste, Ch.; Gruber, Ch.; Shako, R.; Barthelmes, F.

2012-04-01

We have computed the Earth's gravity models to degree/order 5400 and 10800 (in terms of the ellipsoidal and spherical harmonics) from a rigorous integration of the 2'x2' and 1'x1' global grids of gravity anomalies provided by the Danish Technical University (DTU). The gravity signal recovered from the DTU10 data shows 1) a strong dependency on the truncation of the EGM2008 gravity model which were used to fill-in land areas in the DTU10 grids and 2) an irregular behaviour at frequencies behind the resolution of the EGM2008. We discuss the gravity signal and its accuracy estimation computed from the complete DTU10 grids as well as separately from the data over land and ocean areas.

Optimization of gold ore Sumbawa separation using gravity method: Shaking table

NASA Astrophysics Data System (ADS)

Ferdana, Achmad Dhaefi; Petrus, Himawan Tri Bayu Murti; Bendiyasa, I. Made; Prijambada, Irfan Dwidya; Hamada, Fumio; Sachiko, Takahi

2018-04-01

Most of artisanal small gold mining in Indonesia has been using amalgamation method, which caused negative impact to the environment around ore processing area due to the usage of mercury. One of the more environmental-friendly method for gold processing is gravity method. Shaking table is one of separation equipment of gravity method used to increase concentrate based on difference of specific gravity. The optimum concentration result is influenced by several variables, such as rotational speed shaking, particle size and deck slope. In this research, the range of rotational speed shaking was between 100 rpm and 200 rpm, the particle size was between -100 + 200 mesh and -200 + 300 mesh and deck slope was between 3° and 7°. Gold concentration in concentrate was measured by EDX. The result shows that the optimum condition is obtained at a shaking speed of 200 rpm, with a slope of 7° and particle size of -100 + 200 mesh.

Development of a gravity-independent wastewater bioprocessor for advanced life support in space

NASA Technical Reports Server (NTRS)

Nashashibi-Rabah, Majda; Christodoulatos, Christos; Korfiatis, George P.; Janes, H. W. (Principal Investigator)

2005-01-01

Operation of aerobic biological reactors in space is controlled by a number of challenging constraints, mainly stemming from mass transfer limitations and phase separation. Immobilized-cell packed-bed bioreactors, specially designed to function in the absence of gravity, offer a viable solution for the treatment of gray water generated in space stations and spacecrafts. A novel gravity-independent wastewater biological processor, capable of carbon oxidation and nitrification of high-strength aqueous waste streams, is presented. The system, consisting of a fully saturated pressurized packed bed and a membrane oxygenation module attached to an external recirculation loop, operated continuously for over one year. The system attained high carbon oxidation efficiencies often exceeding 90% and ammonia oxidation reaching approximately 60%. The oxygen supply module relies on hydrophobic, nonporous, oxygen selective membranes, in a shell and tube configuration, for transferring oxygen to the packed bed, while keeping the gaseous and liquid phases separated. This reactor configuration and operating mode render the system gravity-independent and suitable for space applications.

On the Resolvability of Steam Assisted Gravity Drainage Reservoirs Using Time-Lapse Gravity Gradiometry

NASA Astrophysics Data System (ADS)

Elliott, E. Judith; Braun, Alexander

2017-11-01

Unconventional heavy oil resource plays are important contributors to oil and gas production, as well as controversial for posing environmental hazards. Monitoring those reservoirs before, during, and after operations would assist both the optimization of economic benefits and the mitigation of potential environmental hazards. This study investigates how gravity gradiometry using superconducting gravimeters could resolve depletion areas in steam assisted gravity drainage (SAGD) reservoirs. This is achieved through modelling of a SAGD reservoir at 1.25 and 5 years of operation. Specifically, the density change structure identified from geological, petrological, and seismic observations is forward modelled for gravity and gradients. Three main parameters have an impact on the resolvability of bitumen depletion volumes and are varied through a suitable parameter space: well pair separation, depth to the well pairs, and survey grid sampling. The results include a resolvability matrix, which identifies reservoirs that could benefit from time-lapse gravity gradiometry monitoring. After 1.25 years of operation, during the rising phase, the resolvable maximum reservoir depth ranges between the surface and 230 m, considering a well pair separation between 80 and 200 m. After 5 years of production, during the spreading phase, the resolvability of depletion volumes around single well pairs is greatly compromised as the depletion volume is closer to the surface, which translates to a larger portion of the gravity signal. The modelled resolvability matrices were derived from visual inspection and spectral analysis of the gravity gradient signatures and can be used to assess the applicability of time-lapse gradiometry to monitor reservoir density changes.

Microgravity Fluid Separation Physics: Experimental and Analytical Results

NASA Technical Reports Server (NTRS)

Shoemaker, J. Michael; Schrage, Dean S.

1997-01-01

Effective, low power, two-phase separation systems are vital for the cost-effective study and utilization of two-phase flow systems and flow physics of two-phase flows. The study of microgravity flows have the potential to reveal significant insight into the controlling mechanisms for the behavior of flows in both normal and reduced gravity environments. The microgravity environment results in a reduction in gravity induced buoyancy forces acting on the discrete phases. Thus, surface tension, viscous, and inertial forces exert an increased influence on the behavior of the flow as demonstrated by the axisymmetric flow patterns. Several space technology and operations groups have studied the flow behavior in reduced gravity since gas-liquid flows are encountered in several systems such as cabin humidity control, wastewater treatment, thermal management, and Rankine power systems.

Near-critical fluid boiling: overheating and wetting films.

PubMed

Hegseth, J; Oprisan, A; Garrabos, Y; Lecoutre-Chabot, C; Nikolayev, V S; Beysens, D

2008-08-01

The heating of coexisting gas and liquid phases of pure fluid through its critical point makes the fluid extremely compressible, expandable, slows the diffusive transport, and decreases the contact angle to zero (perfect wetting by the liquid phase). We have performed experiments on near-critical fluids in a variable volume cell in the weightlessness of an orbiting space vehicle, to suppress buoyancy-driven flows and gravitational constraints on the liquid-gas interface. The high compressibility, high thermal expansion, and low thermal diffusivity lead to a pronounced adiabatic heating called the piston effect. We have directly visualized the near-critical fluid's boundary layer response to a volume quench when the external temperature is held constant. We have found that when the system's temperature T is increased at a constant rate past the critical temperature T(c), the interior of the fluid gains a higher temperature than the hot wall (overheating). This extends previous results in temperature quenching experiments in a similarly prepared system when the gas is clearly isolated from the wall. Large elliptical wetting film distortions are also seen during these ramps. By ray tracing through the elliptically shaped wetting film, we find very thick wetting film on the walls. This wetting film is at least one order of magnitude thicker than films that form in the Earth's gravity. The thick wetting film isolates the gas bubble from the wall allowing gas overheating to occur due to the difference in the piston effect response between gas and liquid. Remarkably, this overheating continues and actually increases when the fluid is ramped into the single-phase supercritical phase.

Containment of a silicone fluid free surface in reduced gravity using barrier coatings

NASA Technical Reports Server (NTRS)

Pline, Alexander D.; Jacobson, Thomas P.

1988-01-01

In support of the Surface Tension Driven Convection Experiment planned for flight aboard the Space Shuttle, tests were conducted under reduced gravity in the 2.2-sec Drop Tower and the 5.0-sec Zero-G facility at the NASA Lewis Research Center. The dynamics of controlling the test fluid, a 10-cSt viscosity silicone fluid in a low gravity environment were investigated using different container designs and barrier coatings. Three container edge designs were tested without a barrier coating; a square edge, a sharp edge with a 45-deg slope, and a sawtooth edge. All three edge designs were successful in containing the fluid below the edge. G-jitter experiments were made in scaled down containers subjected to horizontal accelerations. The data showed that a barrier coating is effective in containing silicone fluid under g-levels up to 10 sup -1 sub g sub 0. In addition, a second barrier coating was found which has similar anti-wetting characteristics and is also more durable.

Analysis of ammonia separation from purge gases in microporous hollow fiber membrane contactors.

PubMed

Karami, M R; Keshavarz, P; Khorram, M; Mehdipour, M

2013-09-15

In this study, a mathematical model was developed to analyze the separation of ammonia from the purge gas of ammonia plants using microporous hollow fiber membrane contactors. A numerical procedure was proposed to solve the simultaneous linear and non linear partial differential equations in the liquid, membrane and gas phases for non-wetted or partially wetted conditions. An equation of state was applied in the model instead of Henry's law because of high solubility of ammonia in water. The experimental data of CO₂-water system in the literature was used to validate the model due to the lack of data for ammonia-water system. The model showed that the membrane contactor can separate ammonia very effectively and with recoveries higher than 99%. SEM images demonstrated that ammonia caused some micro-cracks on the surfaces of polypropylene fibers, which could be an indication of partial wetting of membrane in long term applications. However, the model results revealed that the membrane wetting did not have significant effect on the absorption of ammonia because of very high solubility of ammonia in water. It was also found that the effect of gas velocity on the absorption flux was much more than the effect of liquid velocity. Copyright © 2013 Elsevier B.V. All rights reserved.

Liquid-absorption preconcentrator sampling instrument

DOEpatents

Zaromb, Solomon

1990-01-01

A system for detecting trace concentrations of an analyte in air and includes a preconcentrator for the analyte and an analyte detector. The preconcentrator includes an elongated tubular container in which is disposed a wettable material extending substantially the entire length of the container. One end of the wettable material is continuously wetted with an analyte-sorbing liquid, which flows to the other end of the container. Sample air is flowed through the container in contact with the wetted material for trapping and preconcentrating the traces of analyte in the sorbing liquid, which is then collected at the other end of the container and discharged to the detector. The wetted material may be a wick comprising a bundle of fibers, one end of which is immersed in a reservoir of the analyte-sorbing liquid, or may be a liner disposed on the inner surface of the container, with the sorbing liquid being centrifugally dispersed onto the liner at one end thereof. The container is preferably vertically oriented so that gravity effects the liquid flow.

Liquid-absorption preconcentrator sampling instrument

DOEpatents

Zaromb, S.

1990-12-11

A system is described for detecting trace concentrations of an analyte in air and includes a preconcentrator for the analyte and an analyte detector. The preconcentrator includes an elongated tubular container in which is disposed a wettable material extending substantially the entire length of the container. One end of the wettable material is continuously wetted with an analyte-sorbing liquid, which flows to the other end of the container. Sample air is flowed through the container in contact with the wetted material for trapping and preconcentrating the traces of analyte in the sorbing liquid, which is then collected at the other end of the container and discharged to the detector. The wetted material may be a wick comprising a bundle of fibers, one end of which is immersed in a reservoir of the analyte-sorbing liquid, or may be a liner disposed on the inner surface of the container, with the sorbing liquid being centrifugally dispersed onto the liner at one end thereof. The container is preferably vertically oriented so that gravity effects the liquid flow. 4 figs.

Wetting Transitions in ^4He/^3He Mixtures on Cesium

NASA Astrophysics Data System (ADS)

Ross, David

1997-03-01

Over the last several years, helium on cesium has proven to be an ideal model system for the study of wetting and wetting transitions(E. Cheng, M.W. Cole, W.F. Saam, and J. Treiner, Phys. Rev. Lett. 67), 1007 (1991).^,(J.E. Rutledge and P. Taborek, Phys. Rev. Lett. 69), 937 (1992).^,(D. Ross, J.E. Rutledge, and P. Taborek, Phys. Rev. Lett. 76), 2350 (1996).. This presentation will focus on the adsorption of binary liquid mixtures of the helium isotopes, ^3He and ^4He, on cesium substrates over a range of temperatures extending from 0.2 K to 1.0 K. The results, spanning ^3He concentrations from 0 to 1, constitute the first experimentally constructed complete wetting phase diagram for a two component liquid at a weakly binding substrate. The wetting behavior is particularly interesting in the vicinity of bulk liquid phase separation. A wetting transition of the ^4He rich liquid between the ^3He rich liquid and the cesium substrate has been found with Tw = 0.53 K. The surface phase transition line associated with this wetting transition is found to extend to both sides of the bulk phase separation line. On the ^3He rich side it is a prewetting line, and on the ^4He rich side it becomes a line of triple point induced dewetting transitions. General arguments indicate that this behavior should be typical of a large class of binary liquid mixtures at weakly binding substrates.

Migration And Entrapment Of Mercury In The Subsurface

NASA Astrophysics Data System (ADS)

M, D.; Nambi, I. M.

2009-12-01

Elemental mercury is an immiscible liquid with high density and high surface tension. The movement of mercury in the saturated subsurface region is therefore considered a case of two phase flow involving mercury and water and is expected to be governed by gravity, viscous and capillary forces. Fundamental investigation into the migration and capillary entrapment of mercury in the subsurface was done by controlled laboratory capillary pressure saturation experiments using mercury and water as non wetting and wetting fluid respectively. Residual mercury saturation and van Genuchten’s capillary entrapment parameters were determined independently for different sizes of porous media. Based on the experimental data, theoretical investigations were done on the role of the three predominant forces and their influence on mercury migration and entrapment. The effects of fluid density and interfacial tension and the influence of Capillary and Bond number on mercury entrapment were analyzed with the help of similar capillary pressure - saturation experiments using Tetrachloroethylene (PCE)-water fluid pair. Mercury-water systems exhibited a low residual saturation of 0.02 and 0.07 as compared to 0.16 and 0.27 for PCE-water systems. Less residual mercury saturation, lack of apparent hysteresis in capillary pressure saturation curves and large variation in van Genuchten’s parameters 'α'(inverse of displacement pressure) and ‘n’ (pore size distribution index) for mercury-water systems compared to PCE-water systems were observed. These anomalies between the two systems elucidate that the capillary trapping is equally dependent on the fluid characteristics especially for high density immiscible fluids. Gravity force nevertheless a predominant controlling factor in the migration of highly dense mercury, is counteracted by not less trivial capillary force which was 1.22x104 times higher than gravity force. The capillary forces thus surmount the gravity forces and cause entrapment of mercury in the soil pores even in homogeneous porous medium system. Bond number (Bond number relates gravity and capillary forces) for mercury-water system was found to 2.5 times higher than PCE-water systems. Large density differences between mercury and water lead to high Bond number and thus less residual saturation. Capillary number (Capillary number relates viscous and capillary forces) was found to be less for mercury-water systems. Literature review unveils that low Capillary number does not influence non wetting residual saturation. But for high density mercury with natural infiltration, even low Capillary number influences residual saturation. With the alarming increase in number of mercury spill sites, results of this study showed a better understanding of the capillary entrapment phenomena and the extent of influence of each predominant force during displacement of highly dense mercury. The fundamental inputs to NAPL entrapment models were generated in this study for mercury for the first time. This data will be used to assess the distribution of mercury in contaminated sites and design suitable remedial alternatives.

Wetting-layer formation mechanisms of surface-directed phase separation under different quench depths with off-critical compositions in polymer binary mixture

NASA Astrophysics Data System (ADS)

Yan, Li-Tang; Xie, Xu-Ming

2007-02-01

Focusing on the off-critical condition, the quench depth dependence of surface-directed phase separation in the polymer binary mixture is numerically investigated by combination of the Cahn-Hilliard-Cook theory and the Flory-Huggins-de Gennes theory. Two distinct situations, i.e., for the wetting, the minority component is preferred by the surface and the majority component is preferred by the surface, are discussed in detail. The simulated results show that the formation mechanism of the wetting layer is affected by both the quench depth and the off-critical extent. Moreover, a diagram, illustrating the formation mechanisms of the wetting layer with various quench depths and compositions, is obtained on the basis of the simulated results. It is found that, when the minority component is preferred by the surface, the growth of the wetting layer can exhibit pure diffusion limited growth law, logarithmic growth law, and Lifshitz-Slyozov growth law. However, when the majority component is preferred by the surface, the wetting layer always grows logarithmically, regardless of the quench depth and the off-critical extent. It is interesting that the surface-induced nucleation can be observed in this case. The simulated results demonstrate that the surface-induced nucleation only occurs below a certain value of the quench depth, and a detailed range about it is calculated and indicated. Furthermore, the formation mechanisms of the wetting layer are theoretically analyzed in depth by the chemical potential gradient.

Molten carbonate fuel cell separator

DOEpatents

Nickols, Richard C.

1986-09-02

In a stacked array of molten carbonate fuel cells, a fuel cell separator is positioned between adjacent fuel cells to provide isolation as well as a conductive path therebetween. The center portion of the fuel cell separator includes a generally rectangular, flat, electrical conductor. Around the periphery of the flat portion of the separator are positioned a plurality of elongated resilient flanges which form a gas-tight seal around the edges of the fuel cell. With one elongated flange resiliently engaging a respective edge of the center portion of the separator, the sealing flanges, which are preferably comprised of a noncorrosive material such as an alloy of yttrium, iron, aluminum or chromium, form a tight-fitting wet seal for confining the corrosive elements of the fuel cell therein. This arrangement permits a good conductive material which may be highly subject to corrosion and dissolution to be used in combination with a corrosion-resistant material in the fuel cell separator of a molten carbonate fuel cell for improved fuel cell conductivity and a gas-tight wet seal.

Molten carbonate fuel cell separator

DOEpatents

Nickols, R.C.

1984-10-17

In a stacked array of molten carbonate fuel cells, a fuel cell separator is positioned between adjacent fuel cells to provide isolation as well as a conductive path therebetween. The center portion of the fuel cell separator includes a generally rectangular, flat, electrical conductor. Around the periphery of the flat portion of the separator are positioned a plurality of elongated resilient flanges which form a gas-tight seal around the edges of the fuel cell. With one elongated flange resiliently engaging a respective edge of the center portion of the separator, the sealing flanges, which are preferably comprised of a noncorrosive material such as an alloy of yttrium, iron, aluminum or chromium, form a tight-fitting wet seal for confining the corrosive elements of the fuel cell therein. This arrangement permits a good conductive material which may be highly subject to corrosion and dissolution to be used in combination with a corrosion-resistant material in the fuel cell separator of a molten carbonate fuel cell for improved fuel cell conductivity and a gas-tight wet seal.

Drying southern pine at 240°F. -- effects of air velocity and humidity, board thickness and density

Treesearch

Peter Koch

1972-01-01

Kiln time to each 10 percent moisture content was shortened by circulating air at high velocity, but was little affected by board specific gravity. A wet-bulb depression of 80oF. provided faster drying than depressions of 40 or 115oF. At 80 depression and with air circulated at 930 f.p.m., kiln time was directly...

Effectiveness of combined sewer overflow treatment for dissolved oxygen improvement in the Chicago waterways.

PubMed

Alp, E; Melching, C S; Zhang, H; Lanyon, R

2007-01-01

An Use Attainability Analysis (UAA) has been initiated to evaluate what water-quality standards can be achieved in the Chicago Waterway System (CWS). There are nearly 200 combined sewer overflow (CSO) locations discharging to the CWS by gravity. Three CSO pumping stations also drain approximately 140 km2. Because of the dynamic nature of the CWS the DUFLOW model that is capable of simulating hydraulics and water-quality processes under unsteady-flow conditions was used to evaluate the effectiveness of water-quality improvement techniques identified by the UAA including CSO treatment. Several CSO treatment levels were applied at gravity flow CSOs to evaluate improvement in dissolved oxygen (DO). The results show that pollutant removal at CSOs improves DO to a certain degree, but it still was not sufficient to bring DO concentrations to 5 mg/L or higher for 90% of the time during wet weather at most locations on the CWS. Flow from the pumping stations results in substantial stress on DO since a huge amount of un-treated water with a high pollution load is discharged into the CWS in a short period of time at a certain location. The simulation results indicate that CSO treatment does not effectively improve DO during wet-weather periods on the CWS.

Thermocapillary flow with evaporation and condensation at low gravity. Part 2: Deformable surface

NASA Technical Reports Server (NTRS)

Schmidt, G. R.; Chung, T. J.; Nadarajah, A.

1995-01-01

The free surface behavior of a volatile wetting liquid at low gravity is studied using scaling and numerical techniques. An open cavity model, which was applied in part 1 to investigate fluid flow and heat transfer in non-deforming pores, is used to evaluate the influence of convection on surface morphology with length scales and subcooling/superheating limits of 1 less than or equal to D less than or equal to 10(exp 2) microns and approximately 1 K, respectively. Results show that the menisci shapes of highly wetting fluids are sensitive to thermocapillary flow and to a lesser extent the recoil force associated with evaporation and condensation. With subcooling, thermocapillarity produces a suction about the pore centerline that promotes loss of mechanical equilibrium, while condensation exerts an opposing force that under some conditions offsets this destabilizing influence. With superheating, thermocapillarity and evaporation act in the same direction and mutually foster surface stability. All of these trends are magnified by high capillary and Biot numbers, and the stronger circulation intensities associated with small contact angles. These phenomena strongly depend on the thermal and interfacial equilibrium between the liquid and vapor, and have important ramifications for systems designed to maintain a pressure differential across a porous surface.

Student Understanding of Gravity in Introductory College Astronomy

ERIC Educational Resources Information Center

Williamson, Kathryn E.; Willoughby, Shannon

2012-01-01

Twenty-four free-response questions were developed to explore introductory college astronomy students' understanding of gravity in a variety of contexts, including in and around Earth, throughout the solar system, and in hypothetical situations. Questions were separated into three questionnaires, each of which was given to a section of…

Monitoring gravity and water storage changes in northern Benin

NASA Astrophysics Data System (ADS)

Hector, B.; Hinderer, J.; Boy, J.; Calvo, M.; Séguis, L.; Descloitres, M.; Cohard, J.; Rosat, S.; Riccardi, U.; Galle, S.

2013-12-01

The humid sudanian zone of West-Africa undergoes a monsoon climate, implying a strong seasonality in water storage changes (WSC). The GHYRAF (Gravity and Hydrology in Africa) project aims at monitoring both these local and non-local hydrological contributions with the main gravity sensors available today (FG5 absolute gravimeter, superconducting gravimeter -SG- and CG5 micro-gravimeter). The study area is located in hard-rock basement context in Djougou, northern Benin, and is also part of the long-term observing system AMMA-Catch, and thus under intense hydro-meteorological monitoring (rainfall, soil moisture, water table, evapotranspiration, ...). Gravity-derived WSC are compared to hydrological data and to physically-based or conceptual hydrological models calibrated on these data. This presentation shows the results and limitations of each gravimeter in the context of WSC retrieval. This site was first measured with a FG5 absolute gravimeter four times a year from 2008 to 2013. This can be considered as a high sampling rate, given the remote location and the complexity of FG5 carriage and installation. It allowed to derive an average specific yield for the local aquifer, and preliminary estimates of seasonal WSC (up to 120 nm/s2 - 270mm). Yet the lack of continuity in the data avoids further investigations. The SG-060 superconducting gravimeter has been installed in 2010 in order to monitor gravity response to WSC in a continuous way. A strong drift is present (230nm/s2/yr), and FG5 data together with a-priori information on WSC are needed for estimating its effect. Also, frequent power-failures lead to some significant gaps and offsets during which fast WSC may occur (e.g. rain), yielding to a challenging correction for these events. The retrieval of inter-annual WSC suffers from these strong and limiting instrumental effects. At higher frequencies, up to a few days, continuous gravity monitoring may help to quantify evapotranspiration (ET), a poorly-known variable of the hydrological cycle. In Djougou, favorable -flat- topographic conditions and significant ET (up to 5 mm/day) are present. However, the shelter size together with the low altitude of the SG sensor with respect to the ground yield to diminish the expected effect of ET. Also, atmospheric contribution at such frequencies in the equatorial band is governed by S1 and S2 pressure waves of planetary extension, with rather complicated behavior. Therefore, the retrieval of ET is limited by the SG environment (shelter and instrument height) and our ability to fully correct for atmospheric effects. The spatial variations of gravity changes on the local catchment are also investigated by CG5 micro-gravity surveys since July 2011 with weekly measurements in the wet season and monthly in the dry season, resulting in more than two years and 3 wet seasons coverage. This survey helped to identify preferential recharge areas and some specific water-redistribution processes at the catchment scale, driven by subsurface heterogeneities.

[Counteracting effects of intermittent head-up tilt on simulated-weightlessness induced atrophy of anti-gravity muscles].

PubMed

Liu, C; Zhang, L F; Zhang, L N; Ni, H Y; Zhang, Y Q; Sun, L

2000-12-01

Objective. To study the efficacy of intermittent + Gz (45 degrees head-up tilt, HUT) exposures in preventing or alleviating atrophic changes in hind limb muscles induced by simulated weightlessness. Method. Male Sprague-Dawley (SD) rats were assigned randomly to one of three groups: simultaneous control (CON), simulated weightlessness (SUS), and SUS plus 6 h/d HUT (SUS + HUT). Muscles examined included soleus (SOL), medial gastrocnemius (correction from grastrocnemius) (MG), lateral gastrocnemius (LG) and extensor digitorum longus (EDL). Sections were treated with an adenosinetriphosphatase (ATPase) stain or alkaline phosphatase stain. The cross-sectional areas (CSA) of fibers, the relative proportion of type I fiber and the ratio of capillaries/fibers (C/F) were measured using Leica image analysis system. Result. Compared with CON, the wet weight of hind limb muscles in SUS were significantly reduced. The changes of wet weight in different groups were various. The C/F ratios of all muscles were significantly reduced. SUS + HUT rats showed significant increases in SOL and MG wet weight, and the relative counter-effects of intermittent HUT were 93.4% and 34.8%, respectively. In SUS + HUT group, the CSA of both type I and II fibers and relative proportion of type I fibers were completely recovered in SOL, and partially recovered in MG, while the counter-effects were much less obvious in the fibers of LG and EDL. However, HUT resulted in a significant recovery of the C/F ratios in all muscles. Conclusion. The present study demonstrated that intermittent HUT is effective in counteracting the atrophy induced by simulated weightlessness. The result that reactivity to HUT varied among different muscles suggests that the intermittent artificial gravity should be complemented with other countermeasures.

Assessment of radar altimetry correction slopes for marine gravity recovery: A case study of Jason-1 GM data

NASA Astrophysics Data System (ADS)

Zhang, Shengjun; Li, Jiancheng; Jin, Taoyong; Che, Defu

2018-04-01

Marine gravity anomaly derived from satellite altimetry can be computed using either sea surface height or sea surface slope measurements. Here we consider the slope method and evaluate the errors in the slope of the corrections supplied with the Jason-1 geodetic mission data. The slope corrections are divided into three groups based on whether they are small, comparable, or large with respect to the 1 microradian error in the current sea surface slope models. (1) The small and thus negligible corrections include dry tropospheric correction, inverted barometer correction, solid earth tide and geocentric pole tide. (2) The moderately important corrections include wet tropospheric correction, dual-frequency ionospheric correction and sea state bias. The radiometer measurements are more preferred than model values in the geophysical data records for constraining wet tropospheric effect owing to the highly variable water-vapor structure in atmosphere. The items of dual-frequency ionospheric correction and sea state bias should better not be directly added to range observations for obtaining sea surface slopes since their inherent errors may cause abnormal sea surface slopes and along-track smoothing with uniform distribution weight in certain width is an effective strategy for avoiding introducing extra noises. The slopes calculated from radiometer wet tropospheric corrections, and along-track smoothed dual-frequency ionospheric corrections, sea state bias are generally within ±0.5 microradians and no larger than 1 microradians. (3) Ocean tide has the largest influence on obtaining sea surface slopes while most of ocean tide slopes distribute within ±3 microradians. Larger ocean tide slopes mostly occur over marginal and island-surrounding seas, and extra tidal models with better precision or with extending process (e.g. Got-e) are strongly recommended for updating corrections in geophysical data records.

Thermosyphon Flooding Limits in Reduced Gravity Environments

NASA Technical Reports Server (NTRS)

Gibson, Marc A.; Jaworske, Donald A.; Sanzi, James L.; Ljubanovic, Damir

2012-01-01

Fission Power Systems have long been recognized as potential multi-kilowatt power solutions for lunar, Martian, and extended planetary surface missions. Current heat rejection technology associated with fission surface power systems has focused on titanium water thermosyphons embedded in carbon composite radiator panels. The thermosyphons, or wickless heat pipes, are used as a redundant and efficient way to spread the waste heat from the power conversion unit(s) over the radiator surface area where it can be rejected to space. It is well known that thermosyphon performance is reliant on gravitational forces to keep the evaporator wetted with the working fluid. One of the performance limits that can be encountered, if not understood, is the phenomenon of condenser flooding, otherwise known as evaporator dry out. This occurs when the gravity forces acting on the condensed fluid cannot overcome the shear forces created by the vapor escaping the evaporator throat. When this occurs, the heat transfer process is stalled and may not re-stabilize to effective levels without corrective control actions. The flooding limit in earth's gravity environment is well understood as experimentation is readily accessible, but when the environment and gravity change relative to other planetary bodies, experimentation becomes difficult. An innovative experiment was designed and flown on a parabolic flight campaign to achieve the Reduced Gravity Environments (RGE) needed to obtain empirical data for analysis. The test data is compared to current correlation models for validation and accuracy.

Advances in electrophoretic separations

NASA Technical Reports Server (NTRS)

Snyder, R. S.; Rhodes, P. H.

1984-01-01

Free fluid electrophoresis is described using laboratory and space experiments combined with extensive mathematical modeling. Buoyancy driven convective flows due to thermal and concentration gradients are absent in the reduced gravity environment of space. The elimination of convection in weightlessness offers possible improvements in electrophoresis and other separation methods which occur in fluid media. The mathematical modeling suggests new ways of doing electrophoresis in space and explains various phenomena observed during past experiments. The extent to which ground based separation techniques are limited by gravity induced convection is investigated and space experiments are designed to evaluate specific characteristics of the fluid/particle environment. A series of experiments are proposed that require weightlessness and apparatus is developed that can be used to carry out these experiments in the near future.

A Sea Floor Gravity Survey of the Sleipner Field to Monitor CO2 Migration

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

Mark Zumberge

Carbon dioxide gas (CO{sub 2}) is a byproduct of many wells that produce natural gas. Frequently the CO{sub 2} separated from the valuable fossil fuel gas is released into the atmosphere. This adds to the growing problem of the climatic consequences of greenhouse gas contamination. In the Sleipner North Sea natural gas production facility, the separated CO{sub 2} is injected into an underground saline aquifer to be forever sequestered. Monitoring the fate of such sequestered material is important - and difficult. Local change in Earth's gravity field over the injected gas is one way to detect the CO{sub 2} andmore » track its migration within the reservoir over time. The density of the injected gas is less than that of the brine that becomes displaced from the pore space of the formation, leading to slight but detectable decrease in gravity observed on the seafloor above the reservoir. Using equipment developed at Scripps Institution of Oceanography, we have been monitoring gravity over the Sleipner CO{sub 2} sequestration reservoir since 2002. We surveyed the field in 2009 in a project jointly funded by a consortium of European oil and gas companies and the US Department of Energy. The value of gravity at some 30 benchmarks on the seafloor, emplaced at the beginning of the monitoring project, was observed in a week-long survey with a remotely operated vehicle. Three gravity meters were deployed on the benchmarks multiple times in a campaign-style survey, and the measured gravity values compared to those collected in earlier surveys. A clear signature in the map of gravity differences is well correlated with repeated seismic surveys.« less

Evaluation of a 6-wire thermocouple psychrometer for determination of in-situ water potentials

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

Loskot, C.L.; Rousseau, J.P.; Kurzmack, M.A.

1994-12-31

A 6-wire, Peltier-type thermocouple psychrometer was designed and evaluated by the U.S. Geological Survey for monitoring in-situ water potentials in dry-drilled boreholes in the unsaturated zone at Yucca Mountain, Nye County, Nevada. The psychrometer consists of a wet-bulb, chromel-constantan, sensing junction and a separate dry-bulb, copper-constantan, reference junction. Two additional reference junctions are formed where the chromel and constantan wires of the wet-bulb sensing junction are soldered to separate, paired, copper, lead wires. In contrast, in the standard 3-wire thermocouple psychrometer, both the wet bulb and dry bulb share a common wire. The new design has resulted in a psychrometermore » that has an expanded range and greater reliability, sensitivity, and accuracy compared to the standard model.« less

Theoretical model of droplet wettability on a low-surface-energy solid under the influence of gravity.

PubMed

Yonemoto, Yukihiro; Kunugi, Tomoaki

2014-01-01

The wettability of droplets on a low surface energy solid is evaluated experimentally and theoretically. Water-ethanol binary mixture drops of several volumes are used. In the experiment, the droplet radius, height, and contact angle are measured. Analytical equations are derived that incorporate the effect of gravity for the relationships between the droplet radius and height, radius and contact angle, and radius and liquid surface energy. All the analytical equations display good agreement with the experimental data. It is found that the fundamental wetting behavior of the droplet on the low surface energy solid can be predicted by our model which gives geometrical information of the droplet such as the contact angle, droplet radius, and height from physical values of liquid and solid.

Higher curvature gravities, unlike GR, cannot be bootstrapped from their (usual) linearizations

NASA Astrophysics Data System (ADS)

Deser, S.

2017-12-01

We show that higher curvature order gravities, in particular the propagating quadratic curvature models, cannot be derived by self-coupling from their linear, flat space, forms, except through an unphysical version of linearization; only GR can. Separately, we comment on an early version of the self-coupling bootstrap.

Gravity settling

DOEpatents

Davis, Hyman R.; Long, R. H.; Simone, A. A.

1979-01-01

Solids are separated from a liquid in a gravity settler provided with inclined solid intercepting surfaces to intercept the solid settling path to coalesce the solids and increase the settling rate. The intercepting surfaces are inverted V-shaped plates, each formed from first and second downwardly inclined upwardly curved intersecting conical sections having their apices at the vessel wall.

Wetting Behavior in Colloid-Polymer Mixtures at Different Substrates.

PubMed

Wijting, Willem K; Besseling, Nicolaas A M; Cohen Stuart, Martien A

2003-09-25

We present experimental observations on wetting phenomena in depletion interaction driven, phase separated colloidal dispersions. The contact angle of the colloidal liquid-gas interface at a solid substrate was determined for a series of compositions. Upon approach to the critical point, a transition occurs from partial to complete wetting. The interaction with the substrate was manipulated by modifying the substrate with a polymer. In that case, a transition from partial to complete drying is observed upon approach to the critical point.

Continuous flow electrophoretic separation of proteins and cells from mammalian tissues

NASA Technical Reports Server (NTRS)

Hymer, W. C.; Barlow, Grant H.; Blaisdell, Steven J.; Cleveland, Carolyn; Farrington, Mary Ann; Feldmeier, Mary; Hatfield, J. Michael; Lanham, J. Wayne; Grindeland, Richard; Snyder, Robert S.

1987-01-01

This paper describes an apparatus for continuous flow electrophoresis (CFE), designed to separate macromolecules and cells at conditions of microgravity. In this CFE, buffer flows upward in a 120-cm long flow chamber, which is 16-cm wide x 3.0-mm thick in the microgravity version (and 6-cm wide x 1.5-mm thick in the unit-gravity laboratory version). Ovalbumin and rat serum albumin were separated in space (flight STS-4) with the same resolution of the two proteins achieved at 25 percent total w/v concentration that was obtained in the laboratory at 0.2 percent w/v concentration. Rat anterior pituitary cells, cultured human embryonic kidney cells, and canine Langerhans cells were separated into subpopulations (flight STS-8) more effectively than in unit gravity, with comparable resolution having been achieved at 100 times the concentration possible on earth.

Flight prototype regenerative particulate filter system development

NASA Technical Reports Server (NTRS)

Green, D. C.; Garber, P. J.

1974-01-01

The effort to design, fabricate, and test a flight prototype Filter Regeneration Unit used to regenerate (clean) fluid particulate filter elements is reported. The design of the filter regeneration unit and the results of tests performed in both one-gravity and zero-gravity are discussed. The filter regeneration unit uses a backflush/jet impingement method of regenerating fluid filter elements that is highly efficient. A vortex particle separator and particle trap were designed for zero-gravity use, and the zero-gravity test results are discussed. The filter regeneration unit was designed for both inflight maintenance and ground refurbishment use on space shuttle and future space missions.

TESTING SOLIDS SETTING APPARATUSES FOR DESIGN AND OPERATION OF WET-WEATHER FLOW SOLIDS-LIQUID SEPARATION PROCESSES

EPA Science Inventory

This study was a side-by-side comparison of two settling evaluation methods: one traditional and one new. The project investigated whether these column tests were capable of capturing or representing the rapidly settling particles present in wet-weather flows (WWF). The report r...

Recovery of hydrogen iodide

DOEpatents

Norman, John H.

1983-01-01

A method of extraction of HI from an aqueous solution of HI and I.sub.2. HBr is added to create a two-phase liquid mixture wherein a dry phase consists essentially of HBr, I and HI and is in equilibrium with a wet phase having a far greater HBr:HI ratio. Using a countercurrent extractor, two solutions can be obtained: a dry HBr--HI--I.sub.2 solution and a wet essentially HBr solution. The dry and wet phases are easily separable, and HI is recovered from the dry phase, after first separating I.sub.2, as by distillation. Alternatively, the HI-HBr liquid mixture is treated to catalytically decompose the HI. HBr is recovered from the wet phase by suitable treatment, including high-pressure distillation, to produce an H.sub.2 O--HBr azeotrope that is not more than 25 mole percent HBr. The azeotrope may be returned for use in an earlier step in the overall process which results in the production of the aqueous solution of HI and I.sub.2 without major detriment because of the presence of HBr.

Recovery of hydrogen iodide

DOEpatents

Norman, J.H.

1983-08-02

A method is described for extraction of HI from an aqueous solution of HI and I[sub 2]. HBr is added to create a two-phase liquid mixture wherein a dry phase consists essentially of HBr, I and HI and is in equilibrium with a wet phase having a far greater HBr:HI ratio. Using a countercurrent extractor, two solutions can be obtained: a dry HBr--HI--I[sub 2] solution and a wet essentially HBr solution. The dry and wet phases are easily separable, and HI is recovered from the dry phase, after first separating I[sub 2], as by distillation. Alternatively, the HI-HBr liquid mixture is treated to catalytically decompose the HI. HBr is recovered from the wet phase by suitable treatment, including high-pressure distillation, to produce an H[sub 2]O--HBr azeotrope that is not more than 25 mole percent HBr. The azeotrope may be returned for use in an earlier step in the overall process which results in the production of the aqueous solution of HI and I[sub 2] without major detriment because of the presence of HBr. 1 fig.

The Origin and Evolution of the White Dwarf Stars

NASA Astrophysics Data System (ADS)

Clemens, J. C.

1994-05-01

The secret of how white dwarf stars form and evolve is hidden in their interiors. There, gravity separates the constituent elements into layers; the lighter elements float to the top and the heavier ones sink. Consequently, a white dwarf's structure depends on the quantity of the elements present. Measuring that structure can tell us about the processes which formed white dwarfs and allow us to calculate how fast they cool. The latter is indispensable for measuring the age of our galaxy using the oldest white dwarfs as chronometers. Because some white dwarfs pulsate, we can exploit the resulting luminosity variations to measure their internal structure using asteroseismology. Exploring white dwarf structure via asteroseismology poses a difficult observational task: acquiring essentially uninterrupted time series measurements of the brightness changes of pulsating white dwarf stars. We have accomplished this task using an instrument we call the Whole Earth Telescope (WET). By combining data from the WET with published measurements, we have detected a common pattern in the pulsation spectra of all the variable, hydrogen spectra white dwarfs (DAVs), implying that they have similar surface hydrogen layer masses. Because we have identified the degree (l) and the radial overtone (k) of the modes in the pattern detected, we have been able to compare their periods to published pulsation models to find the mass of the hydrogen layer; it is about 10(-4) times the total stellar mass. This result will require adjustments to published estimates of the age of the galaxy which use theoretical cooling times of the oldest white dwarfs as a time standard; the theoretical models typically assume much thinner hydrogen layers. We have also investigated the two classes of pulsating helium spectra white dwarfs (DOVs and DBVs). From their pulsation properties, and the mass of the hydrogen layer measured for the DAVs, we have concluded that the helium surface white dwarfs do not form via the same process as the hydrogen surface stars. There must be at least two separate channels for white dwarf formation.

Dual Superlyophobic Copper Foam with Good Durability and Recyclability for High Flux, High Efficiency, and Continuous Oil-Water Separation.

PubMed

Zhou, Wenting; Li, Song; Liu, Yan; Xu, Zhengzheng; Wei, Sufeng; Wang, Guoyong; Lian, Jianshe; Jiang, Qing

2018-03-21

Traditional oil-water separation materials have to own ultrahigh or ultralow surface energy. Thus, they can only be wetted by one of the two, oil or water. Our experiment here demonstrates that the wettability in oil-water mixtures can be tuned by oil and water initially. Hierarchical voids are built on commercial copper foams with the help of hydrothermally synthesized titanium dioxide nanorods. The foams can be easily wetted by both oil and water. The water prewetted foams are superhydrophilic and superoleophobic under oil-water mixtures, meanwhile the oil prewetted foams are superoleophilic and superhydrophobic. In this paper, many kinds of water-oil mixtures were separated by two foams, prewetted by corresponding oil or water, respectively, combining a straight tee in a high flux, high efficiency, and continuous mode. This research indicates that oil-water mixtures can be separated more eco-friendly and at lower cost.

External-Field-Induced Gradient Wetting for Controllable Liquid Transport: From Movement on the Surface to Penetration into the Surface.

PubMed

Li, Yan; He, Linlin; Zhang, Xiaofang; Zhang, Na; Tian, Dongliang

2017-12-01

External-field-responsive liquid transport has received extensive research interest owing to its important applications in microfluidic devices, biological medical, liquid printing, separation, and so forth. To realize different levels of liquid transport on surfaces, the balance of the dynamic competing processes of gradient wetting and dewetting should be controlled to achieve good directionality, confined range, and selectivity of liquid wetting. Here, the recent progress in external-field-induced gradient wetting is summarized for controllable liquid transport from movement on the surface to penetration into the surface, particularly for liquid motion on, patterned wetting into, and permeation through films on superwetting surfaces with external field cooperation (e.g., light, electric fields, magnetic fields, temperature, pH, gas, solvent, and their combinations). The selected topics of external-field-induced liquid transport on the different levels of surfaces include directional liquid motion on the surface based on the wettability gradient under an external field, partial entry of a liquid into the surface to achieve patterned surface wettability for printing, and liquid-selective permeation of the film for separation. The future prospects of external-field-responsive liquid transport are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Geologic structure of the Yucaipa area inferred from gravity data, San Bernardino and Riverside Counties, California

USGS Publications Warehouse

Mendez, Gregory O.; Langenheim, V.E.; Morita, Andrew; Danskin, Wesley R.

2016-09-30

In the spring of 2009, the U.S. Geological Survey, in cooperation with the San Bernardino Valley Municipal Water District, began working on a gravity survey in the Yucaipa area to explore the three-dimensional shape of the sedimentary fill (alluvial deposits) and the surface of the underlying crystalline basement rocks. As water use has increased in pace with rapid urbanization, water managers have need for better information about the subsurface geometry and the boundaries of groundwater subbasins in the Yucaipa area. The large density contrast between alluvial deposits and the crystalline basement complex permits using modeling of gravity data to estimate the thickness of alluvial deposits. The bottom of the alluvial deposits is considered to be the top of crystalline basement rocks. The gravity data, integrated with geologic information from surface outcrops and 51 subsurface borings (15 of which penetrated basement rock), indicated a complex basin configuration where steep slopes coincide with mapped faults―such as the Crafton Hills Fault and the eastern section of the Banning Fault―and concealed ridges separate hydrologically defined subbasins.Gravity measurements and well logs were the primary data sets used to define the thickness and structure of the groundwater basin. Gravity measurements were collected at 256 new locations along profiles that totaled approximately 104.6 km (65 mi) in length; these data supplemented previously collected gravity measurements. Gravity data were reduced to isostatic anomalies and separated into an anomaly field representing the valley fill. The ‘valley-fill-deposits gravity anomaly’ was converted to thickness by using an assumed, depth-varying density contrast between the alluvial deposits and the underlying bedrock.To help visualize the basin geometry, an animation of the elevation of the top of the basement-rocks was prepared. The animation “flies over” the Yucaipa groundwater basin, viewing the land surface, geology, faults, and ridges and valleys of the shaded-relief elevation of the top of the basement complex.

Whole body cleaning agent containing N-acyltaurate

NASA Technical Reports Server (NTRS)

Lentsch, Steven E. (Inventor)

1992-01-01

The subject invention relates to a human cleansing agent particularly suitable for use in long duration spaceflight and to a method of bathing with the agent. The agent of the subject invention is in the form of a paste having a pH of 5.0 to 7.9 which comprises an acyltaurate, a skin conditioner, a hair conditioner, and a preservative. More specifically, it includes sodium N-coconut acid-N-methyl taurate, in combination with soybean lecithin, polyquaternium 16, and formalin. This particular combination satisfies the following objectives: (1) that it be usable with a minimum amount of water per shower (approximately 1 gallon); (2) that it be easily separated from the water for purposes of water reclamation; (3) that it be pH compatible with skin and hair; (4) that it rinse well in deionized water; (5) that it be mild to skin and eyes; (6) that it effectively clean both skin and hair; (7) that it be suitable for use in zero gravity; and (8) that it provide ease of combing of wet and dry hair. The method of the invention includes the steps of wetting the skin and hair with a small quantity of water, lathering the skin with the paste, rinsing the lather from the skin and hair with a small quantity of water to produce a rinse water containing the cleansing agent, defoaming the rinse water, and supplying the defoamed rinse water to a water reclamation unit for recycling the water. The novelty of the invention appears to lie in the particular formulation of the cleansing agent and its method of use which provide optimal results under the given constraints and objectives.

Interpretation of gravity anomalies in the northwest Adirondack lowlands, northern New York

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

Revetta, F.A.; O'Brian, B.

1993-03-01

Twelve hundred gravity measurements were made in the Adirondack Highlands and northwest Adirondack Lowlands, New York between 44[degree]15 minutes and 44[degree]30 minutes N. Latitude and 75[degree]00 minutes W. Longitude. A Bouguer gravity map constructed from the gravity measurements includes the Carthage-Colton Mylonite Zone, a major structural boundary between the highlands and lowlands. The gravity map indicates the gravity contours trend parallel to the CCMZ along most of its length however in some areas the contours cross the boundary. No clear-cut relationships exists between the CCMZ and gravity contours. The Bouguer gravity map shows several prominent gravity anomalies which correlate withmore » the geology seismicity and mineral deposits in the area. Gravity lows of 20 to 30 g.u. are centered over the Gouverneur, Hyde and Payne Lake Alaskite gneiss bodies. A gravity high of 20 g.u. occurs over the Pleasant Lake gabbro pluton. Gravity highs of 35 and 100 g.u. occur over the Sylvia Lake Zinc District and marble just north of the district. A gravity high at Russell, N.Y. coincides with a cluster of nine earthquake epicenters. Finally a steep gravity gradient separates high density rocks from lower density rocks along the Black Lake fault. Two-dimensional computer modeling of the geologic features is underway and quantitative models of the structures will be presented.« less

Quantifying the resolution level where the GRACE satellites can separate Greenland's glacial mass balance from surface mass balance

NASA Astrophysics Data System (ADS)

Bonin, J. A.; Chambers, D. P.

2015-09-01

Mass change over Greenland can be caused by either changes in the glacial dynamic mass balance (DMB) or the surface mass balance (SMB). The GRACE satellite gravity mission cannot directly separate the two physical causes because it measures the sum of the entire mass column with limited spatial resolution. We demonstrate one theoretical way to indirectly separate cumulative SMB from DMB with GRACE, using a least squares inversion technique with knowledge of the location of the glaciers. However, we find that the limited 60 × 60 spherical harmonic representation of current GRACE data does not provide sufficient resolution to adequately accomplish the task. We determine that at a maximum degree/order of 90 × 90 or above, a noise-free gravity measurement could theoretically separate the SMB from DMB signals. However, current GRACE satellite errors are too large at present to separate the signals. A noise reduction of a factor of 10 at a resolution of 90 × 90 would provide the accuracy needed for the interannual cumulative SMB and DMB to be accurately separated.

Quantifying the resolution level where the GRACE satellites can separate Greenland's glacial mass balance from surface mass balance

NASA Astrophysics Data System (ADS)

Bonin, J. A.; Chambers, D. P.

2015-02-01

Mass change over Greenland can be caused by either changes in the glacial mass balance (GMB) or the precipitation-based surface mass balance (SMB). The GRACE satellite gravity mission cannot directly separate the two physical causes because it measures the sum of the entire mass column with limited spatial resolution. We demonstrate one theoretical way to indirectly separate SMB from GMB with GRACE, using a least squares inversion technique with knowledge of the location of the glacier. However, we find that the limited 60 × 60 spherical harmonic representation of current GRACE data does not provide sufficient resolution to adequately accomplish the task. We determine that at a maximum degree/order of 90 × 90 or above, a noise-free gravity measurement could theoretically separate the SMB from GMB signals. However, current GRACE satellite errors are too large at present to separate the signals. A noise reduction of a factor of 9 at a resolution of 90 × 90 would provide the accuracy needed for the interannual SMB and GMB to be accurately separated.

Influence of World and Gravity Model Selection on Surface Interacting Vehicle Simulations

NASA Technical Reports Server (NTRS)

Madden, Michael M.

2007-01-01

A vehicle simulation is surface-interacting if the state of the vehicle (position, velocity, and acceleration) relative to the surface is important. Surface-interacting simulations perform ascent, entry, descent, landing, surface travel, or atmospheric flight. Modeling of gravity is an influential environmental factor for surface-interacting simulations. Gravity is the free-fall acceleration observed from a world-fixed frame that rotates with the world. Thus, gravity is the sum of gravitation and the centrifugal acceleration due to the world s rotation. In surface-interacting simulations, the fidelity of gravity at heights above the surface is more significant than gravity fidelity at locations in inertial space. A surface-interacting simulation cannot treat the gravity model separately from the world model, which simulates the motion and shape of the world. The world model's simulation of the world's rotation, or lack thereof, produces the centrifugal acceleration component of gravity. The world model s reproduction of the world's shape will produce different positions relative to the world center for a given height above the surface. These differences produce variations in the gravitation component of gravity. This paper examines the actual performance of world and gravity/gravitation pairs in a simulation using the Earth.

Morphology-Patterned Anisotropic Wetting Surface for Fluid Control and Gas-Liquid Separation in Microfluidics.

PubMed

Wang, Shuli; Yu, Nianzuo; Wang, Tieqiang; Ge, Peng; Ye, Shunsheng; Xue, Peihong; Liu, Wendong; Shen, Huaizhong; Zhang, Junhu; Yang, Bai

2016-05-25

This article shows morphology-patterned stripes as a new platform for directing flow guidance of the fluid in microfluidic devices. Anisotropic (even unidirectional) spreading behavior due to anisotropic wetting of the underlying surface is observed after integrating morphology-patterned stripes with a Y-shaped microchannel. The anisotropic wetting flow of the fluid is influenced by the applied pressure, dimensions of the patterns, including the period and depth of the structure, and size of the channels. Fluids with different surface tensions show different flowing anisotropy in our microdevice. Moreover, the morphology-patterned surfaces could be used as a microvalve, and gas-water separation in the microchannel was realized using the unidirectional flow of water. Therefore, benefiting from their good performance and simple fabrication process, morphology-patterned surfaces are good candidates to be applied in controlling the fluid behavior in microfluidics.

Condensing Heat Exchanger Concept Developed for Space Systems

NASA Technical Reports Server (NTRS)

Hasan, Mohammad M.; Nayagam, Vedha

2005-01-01

The current system for moisture removal and humidity control for the space shuttles and the International Space Station uses a two-stage process. Water first condenses onto fins and is pulled through "slurper bars." These bars take in a two-phase mixture of air and water that is then separated by the rotary separator. A more efficient design would remove the water directly from the air without the need of an additional water separator downstream. For the Condensing Heat Exchanger for Space Systems (CHESS) project, researchers at the NASA Glenn Research Center in collaboration with NASA Johnson Space Center are designing a condensing heat exchanger that utilizes capillary forces to collect and remove water and that can operate in varying gravitational conditions including microgravity, lunar gravity, and Martian gravity.

Preparative electrophoresis of living lymphocytes

NASA Technical Reports Server (NTRS)

Vanoss, C. J.; Bigazzi, P. E.; Gillman, C. F.; Allen, R. E.

1974-01-01

Vertical liquid columns containing low molecular weight dextran density gradients can be used for preparative lymphocyte electrophoresis on earth, in simulation of 0 gravity conditions. Another method that has been tested at 1 G, is the electrophoresis of lymphocytes in a upward direction in vertical columns. By both methods up to 10 to the 7th power lymphocytes can be separated at one time in a 30 cm glass column of 8 mm inside diameter, at 12 v/cm, in 2 hours. Due to convection and sedimentation problems, the separation at 1 G is less than ideal, but it is expected that at 0 gravity electrophoresis will prove to be a uniquely powerful cell separation tool. The technical feasibility of electrophoresing inert particles at 0 G has been proven earlier, during the flight of Apollo 16.

Cell Partition in Two Polymer Aqueous Phases

NASA Technical Reports Server (NTRS)

Harris, J. M.

1985-01-01

Partition of biological cells in two phase aqueous polymer systems is recognized as a powerful separation technique which is limited by gravity. The synthesis of new, selective polymer ligand conjugates to be used in affinity partition separations is of interest. The two most commonly used polymers in two phase partitioning are dextran and polyethylene glycol. A thorough review of the chemistry of these polymers was begun, particularly in the area of protein attachment. Preliminary studies indicate the importance in affinity partitioning of minimizing gravity induced randomizing forces in the phase separation process. The PEG-protein conjugates that were prepared appear to be ideally suited for achieving high quality purifications in a microgravity environment. An interesting spin-off of this synthetic work was the observation of catalytic activity for certain of our polymer derivatives.

An electric current associated with gravity sensing in maize roots

NASA Technical Reports Server (NTRS)

Bjorkman, T.; Leopold, A. C.

1987-01-01

The study of gravisensing would be greatly enhanced if physiological events associated with gravity sensing could be detected separately from subsequent growth processes. This report presents a means to discriminate sensing from the growth processes. By using a vibrating probe, we have found an electric current generated by the gravity sensing region of the root cap of maize (Zea mays cv Merit) in response to gravistimulation. On the upper surface of the root cap, the change from the endogenous current has a density of 0.55 microampere per square centimeter away from gravity. The onset of the current shift has a characteristic of lag of three to four minutes after gravistimulation, which corresponds to the presentation time for gravity sensing in this tissue. A description of the current provides some information about the sensing mechanism, as well as being a valuable means to detect gravity sensing independently of differential growth.

A procedure for partitioning bulk sediments into distinct grain-size fractions for geochemical analysis

USGS Publications Warehouse

Barbanti, A.; Bothner, Michael H.

1993-01-01

A method to separate sediments into discrete size fractions for geochemical analysis has been tested. The procedures were chosen to minimize the destruction or formation of aggregates and involved gentle sieving and settling of wet samples. Freeze-drying and sonication pretreatments, known to influence aggregates, were used for comparison. Freeze-drying was found to increase the silt/clay ratio by an average of 180 percent compared to analysis of a wet sample that had been wet sieved only. Sonication of a wet sample decreased the silt/clay ratio by 51 percent. The concentrations of metals and organic carbon in the separated fractions changed depending on the pretreatment procedures in a manner consistent with the hypothesis that aggregates consist of fine-grained organic- and metal-rich particles. The coarse silt fraction of a freeze-dried sample contained 20–44 percent higher concentrations of Zn, Cu, and organic carbon than the coarse silt fraction of the wet sample. Sonication resulted in concentrations of these analytes that were 18–33 percent lower in the coarse silt fraction than found in the wet sample. Sonication increased the concentration of lead in the clay fraction by an average of 40 percent compared to an unsonicated sample. Understanding the magnitude of change caused by different analysis protocols is an aid in designing future studies that seek to interpret the spatial distribution of contaminated sediments and their transport mechanisms.

Investigations of Physical Processes in Microgravity Relevant to Space Electrochemical Power Systems

NASA Technical Reports Server (NTRS)

Lvovich, Vadim F.; Green, Robert; Jakupca, Ian

2015-01-01

NASA has performed physical science microgravity flight experiments in the areas of combustion science, fluid physics, material science and fundamental physics research on the International Space Station (ISS) since 2001. The orbital conditions on the ISS provide an environment where gravity driven phenomena, such as buoyant convection, are nearly negligible. Gravity strongly affects fluid behavior by creating forces that drive motion, shape phase boundaries and compress gases. The need for a better understanding of fluid physics has created a vigorous, multidisciplinary research community whose ongoing vitality is marked by the continuous emergence of new fields in both basic and applied science. In particular, the low-gravity environment offers a unique opportunity for the study of fluid physics and transport phenomena that are very relevant to management of fluid - gas separations in fuel cell and electrolysis systems. Experiments conducted in space have yielded rich results. These results provided valuable insights into fundamental fluid and gas phase behavior that apply to space environments and could not be observed in Earth-based labs. As an example, recent capillary flow results have discovered both an unexpected sensitivity to symmetric geometries associated with fluid container shape, and identified key regime maps for design of corner or wedge-shaped passive gas-liquid phase separators. In this presentation we will also briefly review some of physical science related to flight experiments, such as boiling, that have applicability to electrochemical systems, along with ground-based (drop tower, low gravity aircraft) microgravity electrochemical research. These same buoyancy and interfacial phenomena effects will apply to electrochemical power and energy storage systems that perform two-phase separation, such as water-oxygen separation in life support electrolysis, and primary space power generation devices such as passive primary fuel cell.

Gravity packaging final waste recovery based on gravity separation and chemical imaging control.

PubMed

Bonifazi, Giuseppe; Serranti, Silvia; Potenza, Fabio; Luciani, Valentina; Di Maio, Francesco

2017-02-01

Plastic polymers are characterized by a high calorific value. Post-consumer plastic waste can be thus considered, in many cases, as a typical secondary solid fuels according to the European Commission directive on End of Waste (EoW). In Europe the practice of incineration is considered one of the solutions for waste disposal waste, for energy recovery and, as a consequence, for the reduction of waste sent to landfill. A full characterization of these products represents the first step to profitably and correctly utilize them. Several techniques have been investigated in this paper in order to separate and characterize post-consumer plastic packaging waste fulfilling the previous goals, that is: gravity separation (i.e. Reflux Classifier), FT-IR spectroscopy, NIR HyperSpectralImaging (HSI) based techniques and calorimetric test. The study demonstrated as the proposed separation technique and the HyperSpectral NIR Imaging approach allow to separate and recognize the different polymers (i.e. PolyVinyl Chloride (PVC), PolyStyrene (PS), PolyEthylene (PE), PoliEtilene Tereftalato (PET), PolyPropylene (PP)) in order to maximize the removal of the PVC fraction from plastic waste and to perform the full quality control of the resulting products, can be profitably utilized to set up analytical/control strategies finalized to obtain a low content of PVC in the final Solid Recovered Fuel (SRF), thus enhancing SRF quality, increasing its value and reducing the "final waste". Copyright © 2016 Elsevier Ltd. All rights reserved.

Development of a Device to Deploy Fluid Droplets in Microgravity

NASA Technical Reports Server (NTRS)

Robinson, David W.; Chai, An-Ti

1997-01-01

A free-floating droplet in microgravity is ideal for scientific observation since it is free of confounding factors such as wetting and nonsymmetrical heat transfer introduced by contact with surfaces. However, the technology to reliably deploy in microgravity has not yet been developed. In some recent fluid deployment experiments, droplets are either shaken off the dispenser or the dispenser is quickly retracted from the droplet. These solutions impart random residual motion to deployed droplet, which can be undesirable for certain investigations. In the present study, two new types of droplet injectors were built and tested. Testing of the droplet injectors consisted of neutral buoyancy tank tests, 5-sec drop tower tests at the NASA Lewis Zero Gravity Facility, and DC-9 tests. One type, the concentric injector, worked well in the neutral buoyancy tank but did not do well in low-gravity. However, it appeared that it makes a fine apparatus for constructing bubbles in low-gravity conditions. The other type, the T-injector, showed the most promise for future development. In both neutral buoyancy and DC-9 tests, water droplets were formed and deployed with some control and repeatability, although in low-gravity the residual velocities were higher than desirable. Based on our observations, further refinements are suggested for future development work.

NOTE: Circular symmetry in topologically massive gravity

NASA Astrophysics Data System (ADS)

Deser, S.; Franklin, J.

2010-05-01

We re-derive, compactly, a topologically massive gravity (TMG) decoupling theorem: source-free TMG separates into its Einstein and Cotton sectors for spaces with a hypersurface-orthogonal Killing vector, here concretely for circular symmetry. We then generalize the theorem to include matter; surprisingly, the single Killing symmetry also forces conformal invariance, requiring the sources to be null.

Modeling the wet bulb globe temperature using standard meteorological measurements.

PubMed

Liljegren, James C; Carhart, Richard A; Lawday, Philip; Tschopp, Stephen; Sharp, Robert

2008-10-01

The U.S. Army has a need for continuous, accurate estimates of the wet bulb globe temperature to protect soldiers and civilian workers from heat-related injuries, including those involved in the storage and destruction of aging chemical munitions at depots across the United States. At these depots, workers must don protective clothing that increases their risk of heat-related injury. Because of the difficulty in making continuous, accurate measurements of wet bulb globe temperature outdoors, the authors have developed a model of the wet bulb globe temperature that relies only on standard meteorological data available at each storage depot for input. The model is composed of separate submodels of the natural wet bulb and globe temperatures that are based on fundamental principles of heat and mass transfer, has no site-dependent parameters, and achieves an accuracy of better than 1 degree C based on comparisons with wet bulb globe temperature measurements at all depots.

Droplet evaporation on a horizontal substrate under gravity field by mesoscopic modeling.

PubMed

Xie, Chiyu; Zhang, Jianying; Bertola, Volfango; Wang, Moran

2016-02-01

The evaporation of water drop deposited on a horizontal substrate is investigated using a lattice Boltzmann method (LBM) for multiphase flows with a large-density ratio. To account for the variation of evaporation flux distribution along the drop interface, a novel evaporation scheme is introduced into the LBM framework, and validated by comparison with experimental data. We aim at discovering the effect of gravity on the evaporating drop in detail, and various evaporation conditions are considered as well as different wetting properties of the substrates. An effective diameter is introduced as an indicator of the critical drop size under which gravity is negligible. Our results show that such critical diameter is much smaller than the capillary length, which has been widely accepted as the critical size in previous and current works. The critical diameter is found to be almost independent of the evaporation conditions and the surface wettability. A correlation between this critical diameter and the capillary length is also proposed for easy use in applications. Copyright © 2015 Elsevier Inc. All rights reserved.

Wetting and drying of soil in response to precipitation: Data analysis, modeling, and forecasting

USGS Publications Warehouse

Basak, Aniruddha; Kulkarni, Chinmay; Schmidt, Kevin M.; Mengshoel, Ole

2016-01-01

This paper investigates methods to analyze and forecast soil moisture time series. We extend an existing Antecedent Water Index (AWI) model, which expresses soil moisture as a function of time and rainfall. Unfortunately, the existing AWI model does not forecast effectively for time periods beyond a few hours. To overcome this limitation, we develop a novel AWI-based model. Our model accumulates rainfall over a time interval and can fit a diverse range of wetting and drying curves. In addition, parameters in our model reflect hydrologic redistribution processes of gravity and suction.We validate our models using experimental soil moisture and rainfall time series data collected from steep gradient post-wildfire sites in Southern California, where rapid landscape change was observed in response to small to moderate rain storms. We found that our novel model fits the data for three distinct soil textures, occurring at different depths below the ground surface (5, 15, and 30 cm). Our model also successfully forecasts soil moisture trends, such as drying and wetting rate.

Drying southern pine at 240°F-- effects of air velocity and humidity, board thickness and density

Treesearch

P. Koch

1972-01-01

Kiln time to reach 10 percent moisture content was shortened by circulating air at high velocity, but was little affected by board specific gravity. A wet-bulb depression of 80°F. provided faster drying than depressions of 40 or 115°F. At 80° depression and with air circulated at 930 f.p.m.. kiln time was directly proportional to board thickness. Under these optimum...

Hydrologic implications of GRACE satellite data in the Colorado River Basin

USGS Publications Warehouse

Scanlon, Bridget R.; Zhang, Zizhan; Reedy, Robert C.; Pool, Donald R.; Save, Himanshu; Long, Di; Chen, Jianli; Wolock, David M.; Conway, Brian D.; Winester, Daniel

2015-01-01

Use of GRACE (Gravity Recovery and Climate Experiment) satellites for assessing global water resources is rapidly expanding. Here we advance application of GRACE satellites by reconstructing long-term total water storage (TWS) changes from ground-based monitoring and modeling data. We applied the approach to the Colorado River Basin which has experienced multiyear intense droughts at decadal intervals. Estimated TWS declined by 94 km3 during 1986–1990 and by 102 km3 during 1998–2004, similar to the TWS depletion recorded by GRACE (47 km3) during 2010–2013. Our analysis indicates that TWS depletion is dominated by reductions in surface reservoir and soil moisture storage in the upper Colorado basin with additional reductions in groundwater storage in the lower basin. Groundwater storage changes are controlled mostly by natural responses to wet and dry cycles and irrigation pumping outside of Colorado River delivery zones based on ground-based water level and gravity data. Water storage changes are controlled primarily by variable water inputs in response to wet and dry cycles rather than increasing water use. Surface reservoir storage buffers supply variability with current reservoir storage representing ∼2.5 years of available water use. This study can be used as a template showing how to extend short-term GRACE TWS records and using all available data on storage components of TWS to interpret GRACE data, especially within the context of droughts.

Development of a Contingency Capillary Wastewater Management Device

NASA Technical Reports Server (NTRS)

Thomas, Evan A.

2010-01-01

The Personal Body .Attached Liquid Liquidator (PBALL) is conceived as a passive, capillary driven contingency wastewater disposal device. In this contingency scenario, the airflow system on the NASA Crew Exploration Vehicle (CEV) is assumed to have failed, leaving only passive hardware and vacuum vent to dispose of the wastewater. To meet these needs, the PBALL was conceived to rely on capillary action and urine wetting design considerations. The PBALL is designed to accommodate a range of wetting conditions, from 0deg < (theta)adv approx. 90deg, be adaptable for both male and female use, collect and retain up to a liter of urine, minimize splash-back, and allow continuous drain of the wastewater to vacuum while minimizing cabin air loss. A sub-scale PBALL test article was demonstrated on NASA's reduced gravity aircraft in April, 2010.

The electrical properties of zero-gravity processed immiscibles

NASA Technical Reports Server (NTRS)

Lacy, L. L.; Otto, G. H.

1974-01-01

When dispersed or mixed immiscibles are solidified on earth, a large amount of separation of the constituents takes place due to differences in densities. However, when the immiscibles are dispersed and solidified in zero-gravity, density separation does not occur, and unique composite solids can be formed with many new and promising electrical properties. By measuring the electrical resistivity and superconducting critical temperature, Tc, of zero-g processed Ga-Bi samples, it has been found that the electrical properties of such materials are entirely different from the basic constituents and the ground control samples. Our results indicate that space processed immiscible materials may form an entirely new class of electronic materials.

Feasibility Studies for Production of Pellet Grade Concentrate from Sub Grade Iron Ore Using Multi Gravity Separator

NASA Astrophysics Data System (ADS)

Rao, Gottumukkala Venkateswara; Markandeya, R.; Kumar, Rajan

2018-04-01

An attempt has been made to utilise Sub Grade Iron Ore by producing pellet grade concentrate from Deposit 5, Bacheli Complex, Bailadila, Chhattisgarh, India. The `as received' Run of Mine (ROM) sample assayed 40.80% Fe, 40.90% SiO2. Mineralogical studies indicated that the main ore mineral is Hematite and lone gangue mineral is Quartz. Mineral liberation studies indicated that, the ore mineral Hematite and gangue mineral Quartz are getting liberated below 100 microns. The stage crushed and ground sample was subjected to concentration by using a Multi Gravity Separator (MGS). Rougher Multi Gravity Separation (MGS) experimental results were optimised to recover highest possible iron values. A concentrate of 55.80% Fe with a yield of 61.73% by weight with a recovery of 84.42% Iron values was obtained in rougher MGS concentrate. Further experiments were carried out with rougher MGS concentrate to produce a concentrate suitable for commercial grade pellet concentrate. It was proved that a concentrate assaying 66.67% Fe, 3.12% SiO2 with an yield of 45.08% by weight and with a recovery of 73.67% iron values in the concentrate.

Dynamic wetting and spreading and the role of topography.

PubMed

McHale, Glen; Newton, Michael I; Shirtcliffe, Neil J

2009-11-18

The spreading of a droplet of a liquid on a smooth solid surface is often described by the Hoffman-de Gennes law, which relates the edge speed, v(e), to the dynamic and equilibrium contact angles θ and θ(e) through [Formula: see text]. When the liquid wets the surface completely and the equilibrium contact angle vanishes, the edge speed is proportional to the cube of the dynamic contact angle. When the droplets are non-volatile this law gives rise to simple power laws with time for the contact angle and other parameters in both the capillary and gravity dominated regimes. On a textured surface, the equilibrium state of a droplet is strongly modified due to the amplification of the surface chemistry induced tendencies by the topography. The most common example is the conversion of hydrophobicity into superhydrophobicity. However, when the surface chemistry favors partial wetting, topography can result in a droplet spreading completely. A further, frequently overlooked consequence of topography is that the rate at which an out-of-equilibrium droplet spreads should also be modified. In this report, we review ideas related to the idea of topography induced wetting and consider how this may relate to dynamic wetting and the rate of droplet spreading. We consider the effect of the Wenzel and Cassie-Baxter equations on the driving forces and discuss how these may modify power laws for spreading. We relate the ideas to both the hydrodynamic viscous dissipation model and the molecular-kinetic theory of spreading. This suggests roughness and solid surface fraction modified Hoffman-de Gennes laws relating the edge speed to the dynamic and equilibrium contact angle. We also consider the spreading of small droplets and stripes of non-volatile liquids in the capillary regime and large droplets in the gravity regime. In the case of small non-volatile droplets spreading completely, a roughness modified Tanner's law giving the dependence of dynamic contact angle on time is presented. We review existing data for the spreading of small droplets of polydimethylsiloxane oil on surfaces decorated with micro-posts. On these surfaces, the initial droplet spreads with an approximately constant volume and the edge speed-dynamic contact angle relationship follows a power law [Formula: see text]. As the surface texture becomes stronger the exponent goes from p = 3 towards p = 1 in agreement with a Wenzel roughness driven spreading and a roughness modified Hoffman-de Gennes power law. Finally, we suggest that when a droplet spreads to a final partial wetting state on a rough surface, it approaches its Wenzel equilibrium contact angle in an exponential manner with a time constant dependent on roughness.

In situ polymerized superhydrophobic and superoleophilic nanofibrous membranes for gravity driven oil-water separation

NASA Astrophysics Data System (ADS)

Tang, Xiaomin; Si, Yang; Ge, Jianlong; Ding, Bin; Liu, Lifang; Zheng, Gang; Luo, Wenjing; Yu, Jianyong

2013-11-01

Creating an efficient, cost-effective method that can provide simple, practical and high-throughput separation of oil-water mixtures has proved extremely challenging. This work responds to these challenges by designing, fabricating and evaluating a novel fluorinated polybenzoxazine (F-PBZ) modified nanofibrous membrane optimized to achieve gravity driven oil-water separation. The membrane design is then realized by a facile combination of electrospun poly(m-phenylene isophthalamide) (PMIA) nanofibers and an in situ polymerized F-PBZ functional layer incorporating SiO2 nanoparticles (SiO2 NPs). By employing the F-PBZ/SiO2 NP modification, the pristine hydrophilic PMIA nanofibrous membranes are endowed with promising superhydrophobicity with a water contact angle of 161° and superoleophilicity with an oil contact angle of 0°. This new membrane shows high thermal stability (350 °C) and good repellency to hot water (80 °C), and achieves an excellent mechanical strength of 40.8 MPa. Furthermore, the as-prepared membranes exhibited fast and efficient separation of oil-water mixtures by a solely gravity driven process, which makes them good candidates for industrial oil-polluted water treatments and oil spill cleanup, and also provided new insights into the design and development of functional nanofibrous membranes through F-PBZ modification.Creating an efficient, cost-effective method that can provide simple, practical and high-throughput separation of oil-water mixtures has proved extremely challenging. This work responds to these challenges by designing, fabricating and evaluating a novel fluorinated polybenzoxazine (F-PBZ) modified nanofibrous membrane optimized to achieve gravity driven oil-water separation. The membrane design is then realized by a facile combination of electrospun poly(m-phenylene isophthalamide) (PMIA) nanofibers and an in situ polymerized F-PBZ functional layer incorporating SiO2 nanoparticles (SiO2 NPs). By employing the F-PBZ/SiO2 NP modification, the pristine hydrophilic PMIA nanofibrous membranes are endowed with promising superhydrophobicity with a water contact angle of 161° and superoleophilicity with an oil contact angle of 0°. This new membrane shows high thermal stability (350 °C) and good repellency to hot water (80 °C), and achieves an excellent mechanical strength of 40.8 MPa. Furthermore, the as-prepared membranes exhibited fast and efficient separation of oil-water mixtures by a solely gravity driven process, which makes them good candidates for industrial oil-polluted water treatments and oil spill cleanup, and also provided new insights into the design and development of functional nanofibrous membranes through F-PBZ modification. Electronic supplementary information (ESI) available: Detailed synthesis and structural confirmation of BAF-oda, OCA results, Raman spectrum and Movies S1 and S2. See DOI: 10.1039/c3nr03937d

Liquid/Gas Separator Handles Varying Loads

NASA Technical Reports Server (NTRS)

Mann, John

1992-01-01

Liquid/gas separator includes two independent motors, one for pumping mixture and other for drawing off extracted gas. Two materials moved at speeds best suited for them. Liquid expelled radially outward from separator rotor. Entrained gas released, flows axially through rotor, and leaves through fan at downstream end. Unit developed to separate air from urine in spacecraft wastewater-treatment system, also functions in normal gravity. Made largely of titanium to resist corrosion.

Development of a New Membrane Casting Apparatus for Studying Macrovoid Defects in Low-G

NASA Technical Reports Server (NTRS)

Lee, Hanyong; Hwang, Sun-Tak; Krantz, William B.; Greenberg, Alan R.; Khare, Vivek; Zartman, Jeremiah; Todd, Paul W.

2002-01-01

A new membrane-casting apparatus is developed for studying macrovoid defects in polymeric membranes made by the wet- and dry-casting process in low-gravity. Macrovoids are large (10-50 micron), open cavities interspersed among the smaller pores in the substructure under the gelled skin surface layer of the cast membrane. Although their occurrence is considered endemic to the wet- and dry-casting process since they can lead to compaction or skin rupture in the membrane process, recent studies suggest several useful applications such as transdermal and osmotic drug delivery systems, miniature bioreactors, etc. However, lack of knowledge about the macrovoid formation mechanism is an obstacle to further development of applications using them. An on-going debate is the role of the surface-tension-driven solutocapillary convection during macrovoid formation. The rapid growth of macrovoids within 1-5 seconds and the high polymer concentration in and near macrovoids make it difficult to explain the mechanism of macrovoid growth by diffusion alone, which is the widely accepted hypothesis proposed by Reuvers et al. The hypothesis advanced by our research group can explain this rapid growth via a mechanism that involves diffusion from the casting solution in the meta-stable region to the macrovoid enhanced by solutocapillary convection induced by the steep nonsolvent concentration gradient in the vicinity of the macrovoid. Since macrovoid growth is hypothesized to be the interplay of a solutocapillary-induced driving force counteracted by viscous drag and buoyancy, eliminate the latter provides a means for testing this hypothesis. Moreover, free convection mass transfer in the nonsolvent immersion bath used to cause phase-separation in membrane casting complicates developing a model for both the wet-casting process and macrovoid growth. The low-g environment minimizes gravitationally induced free convection thereby permitting a tractable solution to the ternary diffusion equations that characterize membrane formation. NASA's Parabolic Flight Research Aircraft provides a small window of low-g (approximately 25 s) that can be used to study macrovoid development in both wet- and dry-cast membranes if an appropriate casting apparatus is used. This casting apparatus should be able to cast the membrane in both low- and high-g in a manner so that essential one-dimensional mass transfer conditions are achieved to insure lateral uniformity in the membrane. The apparatus used in previous research on membrane casting in low-gravity was operated with the plunger driven mechanism. The spring-loaded plunger pushes the bottom block containing the polymer casting solution well directly under the absorbent chamber located in the upper stationary block. However, membranes made via this casting apparatus often displayed lateral nonuniformities that precluded obtaining quantitative information on the macrovoid growth process. Thus, it was necessary to determine the reason for these structural irregularities observed in the low-g casting apparatus. Both experimental as well as computer simulation studies of the low-g casting apparatus established that the impulsive action of the plunger caused the undesired structural nonuniformities. The simulation results showed that the width-to-depth aspect ratio of the shallow well that contains the casting solution in this apparatus was not an important factor in minimizing this problem. Even for a 40:1 (width : depth) aspect ratio, any convection induced by the horizontal motion of the interface of the casting solution will be damped out within 6.25x10(exp 4) seconds. However, the experimental studies revealed that the impulsive motion of the plunger caused a 'sloshing' of the casting solution that had to be eliminated. Therefore, the plungerdriven mechanism was changed to a cam-driven mechanism that did not cause any impulsive motion of the casting solution. Other refinements to this new membrane-casting apparatus include provision for removing the membranes from the casting wells in a less destructive manner. This was accomplished by using a slit geometry for the casting well that permitted disassembly for removal of the cast membrane. The materials used in the construction of this casting apparatus were chosen to insure wetting at the side walls and to maintain precise control of the thickness of the polymer solution in the casting well. An additional provision in this new casting apparatus is the ability to carry out both wet- as well as dry-casting. As such, this apparatus permitted the first studies of the wet-casting of polymeric membranes in low-g. Both wet- and dry-casting experiments on NASA's KC-135 research aircraft employing this new membrane-casting apparatus are scheduled in July 2002. The morphology of the resulting membranes will be characterized using an environmental scanning electron microscope (ESEM). The results of these low-g studies will be reported later.

The prediction of zenith range refraction from surface measurements of meteorological parameters. [mathematical models of atmospheric refraction used to improve spacecraft tracking space navigation

NASA Technical Reports Server (NTRS)

Berman, A. L.

1976-01-01

In the last two decades, increasingly sophisticated deep space missions have placed correspondingly stringent requirements on navigational accuracy. As part of the effort to increase navigational accuracy, and hence the quality of radiometric data, much effort has been expended in an attempt to understand and compute the tropospheric effect on range (and hence range rate) data. The general approach adopted has been that of computing a zenith range refraction, and then mapping this refraction to any arbitrary elevation angle via an empirically derived function of elevation. The prediction of zenith range refraction derived from surface measurements of meteorological parameters is presented. Refractivity is separated into wet (water vapor pressure) and dry (atmospheric pressure) components. The integration of dry refractivity is shown to be exact. Attempts to integrate wet refractivity directly prove ineffective; however, several empirical models developed by the author and other researchers at JPL are discussed. The best current wet refraction model is here considered to be a separate day/night model, which is proportional to surface water vapor pressure and inversely proportional to surface temperature. Methods are suggested that might improve the accuracy of the wet range refraction model.

Methods for sulfate removal in liquid-phase catalytic hydrothermal gasification of biomass

DOEpatents

Elliott, Douglas C; Oyler, James R

2014-11-04

Processing of wet biomass feedstock by liquid-phase catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a pre-treatment temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent removal of soluble sulfate contaminants, or combinations thereof. Processing further includes reacting the soluble sulfate contaminants with cations present in the feedstock material to yield a sulfate-containing precipitate and separating the inorganic precipitates and/or the sulfate-containing precipitates out of the wet feedstock. Having removed much of the inorganic wastes and the sulfate contaminants that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogeneous catalyst for gasification.

Methods for sulfate removal in liquid-phase catalytic hydrothermal gasification of biomass

DOEpatents

Elliott, Douglas C; Oyler, James

2013-12-17

Processing of wet biomass feedstock by liquid-phase catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a pre-treatment temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent removal of soluble sulfate contaminants, or combinations thereof. Processing further includes reacting the soluble sulfate contaminants with cations present in the feedstock material to yield a sulfate-containing precipitate and separating the inorganic precipitates and/or the sulfate-containing precipitates out of the wet feedstock. Having removed much of the inorganic wastes and the sulfate contaminants that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogenous catalyst for gasification.

Landfill Mining - Wet mechanical treatment of fine MSW with a wet jigger.

PubMed

Wanka, Sebastian; Münnich, Kai; Fricke, Klaus

2017-01-01

The motives for landfill mining are various. In the last couple of years Enhanced Landfill Mining (ELFM) has become increasingly important in academic discourse and practical implementation. The main goal of ELFM is to recover as much material as possible from deposited municipal solid waste (MSW). In most of the projects carried out so far, the main focus has been set on coarse materials such as plastics, woods, papers and metals. These fractions can be separated easily by sieving in combination with magnetic separation. In these projects most of the fine materials, which might represent as much as 60-70% of the total mass of the landfill body, had to be deposited again. A further treatment aiming at reducing the masses of these fine materials, which are still a conglomerate of soil, calorific fractions, metals, minerals and residues, usually did not take place. One topic in the framework of the landfill mining project TÖNSLM, in addition to the separation of the calorific fraction and metals has been the treatment of fine materials with the goal to re-use these e.g. for construction purposes. This paper shows the results obtained after the wet mechanical treatment of fine MSW 10-60mm with a wet jigger. The physical principle of this process is the separation of the mass flux due to the different densities of the waste constituents. As a result, three main waste fluxes are obtained: Dense inert and dense fine fraction with a high content of minerals and a lightweight fraction with a high calorific value between 16 and 20MJ/kg. An additional positive effect of wet mechanical treatment is the removal of the finest particles from the surface of the waste material, thus increasing the quality of the generated waste fluxes. The mass fluxes of the different fractions and their qualities as well as possible recovery paths are described below. An economical and ecological consideration of the treatment of the fine materials does not take place within the framework of this feasibility study. Copyright © 2016 Elsevier Ltd. All rights reserved.

Investigations on gel forming media use in low gravity bioseparations research

NASA Technical Reports Server (NTRS)

Todd, Paul; Szlag, David C.; Plank, Lindsay D.; Delcourt, Scott G.; Kunze, M. Elaine

1989-01-01

Research on gelling media and conditions suitable for the preservation of the spatial configuration of cell suspensions and macromolecular solutions after separation in free fluid during low gravity experiments is presented. The examples studied included free electrophoresis of cells in a cylindrical column and two-phase aqueous polymer separation. Microgravity electrophoresis experiments were simulated by separating model cell types (animal or human) in a vertical density gradient containing low-conductivity buffer, 1.7-6.5 percent Ficoll, 6.8-5.0 percent sucrose, and 1 percent SeaPrep low-melting temperature agarose. Upon cooling, a gel formed in the column and cells could be captured at the forming locations. Two-phase extraction experiments were simulated using two-polymer solutions in which phase separation occurs in normal saline at temperatures compatible with cell viability and in which one or both phases form a gel upon cooling. Suitable polymers included commercial agaroses (1-2 percent), maltodextrin (5-7 percent), and gelatin (5-20 percent).

Separating liquid and solid products of liquefaction of coal or like carbonaceous materials

DOEpatents

Malek, John M.

1979-06-26

Slurryform products of coal liquefaction are treated with caustic soda in presence of H.sub.2 O in an inline static mixer and then the treated product is separated into a solids fraction and liquid fractions, including liquid hydrocarbons, by gravity settling preferably effected in a multiplate settling separator with a plurality of settling spacings.

Massachusetts Institute of Technology Lincoln Laboratory Facilities Replacement on Hanscom Air Force Base Phase 1 Final Environmental Assessment

DTIC Science & Technology

2014-07-24

Service UST Underground Storage Tank VC Vitrified Clay VOCs Volatile Organic Compounds W Watts 1 1.0 PURPOSE AND NEED FOR ACTION 1.1 INTRODUCTION The...discharged to sanitary drain and the solids slurry is hauled off site for disposal Fluoride drain: welded stainless steel drain piping from wet...diameter vitrified clay (VC) gravity sewer collection pipe, flowing north/northeast to the upper pumping station at Building 1306, is located within the

Motion of a drop driven by substrate vibrations

NASA Astrophysics Data System (ADS)

Brunet, P.; Eggers, J.; Deegan, R. D.

2009-01-01

We report an experimental study of liquid drops moving against gravity, when placed on a vertically vibrating inclined plate, which is partially wet by the drop. Frequency of vibrations ranges from 30 to 200 Hz, and above a threshold in vibration acceleration, drops experience an upward motion. We attribute this surprising motion to the deformations of the drop, as a consequence of an up/down symmetry-breaking induced by the presence of the substrate. We relate the direction of motion to contact angle measurements.

Forced flow evaporator for unusual gravity conditions

NASA Technical Reports Server (NTRS)

Niggemann, Richard E. (Inventor); Ellis, Wilbert E. (Inventor)

1987-01-01

Low efficiency heat transfer in evaporators subject to unusual gravitational conditions is avoided through the use of a spiral evaporator conduit 12 receiving at an inlet 14 a vaporizable coolant at least partly in the liquid phase. Flow of the coolant through the conduit 12 demists the coolant by centrifuging the liquid phase against a pressurre wall 44 of the conduit 12. Vapor flow 40 induces counterrotating vortices 46, 48 which circulate the liquid phase coolant around the interior of the conduit 12 to wet all surfaces thereof.

Dynamical phase separation using a microfluidic device: experiments and modeling

NASA Astrophysics Data System (ADS)

Aymard, Benjamin; Vaes, Urbain; Radhakrishnan, Anand; Pradas, Marc; Gavriilidis, Asterios; Kalliadasis, Serafim; Complex Multiscale Systems Team

2017-11-01

We study the dynamical phase separation of a binary fluid by a microfluidic device both from the experimental and from the modeling points of view. The experimental device consists of a main channel (600 μm wide) leading into an array of 276 trapezoidal capillaries of 5 μm width arranged on both sides and separating the lateral channels from the main channel. Due to geometrical effects as well as wetting properties of the substrate, and under well chosen pressure boundary conditions, a multiphase flow introduced into the main channel gets separated at the capillaries. Understanding this dynamics via modeling and numerical simulation is a crucial step in designing future efficient micro-separators. We propose a diffuse-interface model, based on the classical Cahn-Hilliard-Navier-Stokes system, with a new nonlinear mobility and new wetting boundary conditions. We also propose a novel numerical method using a finite-element approach, together with an adaptive mesh refinement strategy. The complex geometry is captured using the same computer-aided design files as the ones adopted in the fabrication of the actual device. Numerical simulations reveal a very good qualitative agreement between model and experiments, demonstrating also a clear separation of phases.

Satellite Gravity Drilling the Earth

NASA Technical Reports Server (NTRS)

vonFrese, R. R. B.; Potts, L. V.; Leftwich, T. E.; Kim, H. R.; Han, S.-H.; Taylor, P. T.; Ashgharzadeh, M. F.

2005-01-01

Analysis of satellite-measured gravity and topography can provide crust-to-core mass variation models for new insi@t on the geologic evolution of the Earth. The internal structure of the Earth is mostly constrained by seismic observations and geochemical considerations. We suggest that these constraints may be augmented by gravity drilling that interprets satellite altitude free-air gravity observations for boundary undulations of the internal density layers related to mass flow. The approach involves separating the free-air anomalies into terrain-correlated and -decorrelated components based on the correlation spectrum between the anomalies and the gravity effects of the terrain. The terrain-decorrelated gravity anomalies are largely devoid of the long wavelength interfering effects of the terrain gravity and thus provide enhanced constraints for modeling mass variations of the mantle and core. For the Earth, subcrustal interpretations of the terrain-decorrelated anomalies are constrained by radially stratified densities inferred from seismic observations. These anomalies, with frequencies that clearly decrease as the density contrasts deepen, facilitate mapping mass flow patterns related to the thermodynamic state and evolution of the Earth's interior.

A test of Hořava gravity: the dark energy

NASA Astrophysics Data System (ADS)

Park, Mu-In

2010-01-01

Recently Hořava proposed a renormalizable gravity theory with higher spatial derivatives in four dimensions which reduces to Einstein gravity with a non-vanishing cosmological constant in IR but with improved UV behaviors. Here, I consider a non-trivial test of the new gravity theory in FRW universe by considering an IR modification which breaks ``softly'' the detailed balance condition in the original Hořava model. I separate the dark energy parts from the usual Einstein gravity parts in the Friedman equations and obtain the formula of the equations of state parameter. The IR modified Hořava gravity seems to be consistent with the current observational data but we need some more refined data sets to see whether the theory is really consistent with our universe. From the consistency of our theory, I obtain some constraints on the allowed values of w0 and wa in the Chevallier, Polarski, and Linder's parametrization and this may be tested in the near future, by sharpening the data sets.

The effect of substrate composition and storage time on urine specific gravity in dogs.

PubMed

Steinberg, E; Drobatz, K; Aronson, L

2009-10-01

The purpose of this study is to evaluate the effects of substrate composition and storage time on urine specific gravity in dogs. A descriptive cohort study of 15 dogs. The urine specific gravity of free catch urine samples was analysed during a 5-hour time period using three separate storage methods; a closed syringe, a diaper pad and non-absorbable cat litter. The urine specific gravity increased over time in all three substrates. The syringe sample had the least change from baseline and the diaper sample had the greatest change from baseline. The urine specific gravity for the litter and diaper samples had a statistically significant increase from the 1-hour to the 5-hour time point. The urine specific gravity from canine urine stored either on a diaper or in a non-absorbable litter increased over time. Although the change was found to be statistically significant over the 5-hour study period it is unlikely to be clinically significant.

A terracing operator for physical property mapping with potential field data

USGS Publications Warehouse

Cordell, L.; McCafferty, A.E.

1989-01-01

The terracing operator works iteratively on gravity or magnetic data, using the sense of the measured field's local curvature, to produce a field comprised of uniform domains separated by abrupt domain boundaries. The result is crudely proportional to a physical-property function defined in one (profile case) or two (map case) horizontal dimensions. This result can be extended to a physical-property model if its behavior in the third (vertical) dimension is defined, either arbitrarily or on the basis of the local geologic situation. The terracing algorithm is computationally fast and appropriate to use with very large digital data sets. The terracing operator was applied separately to aeromagnetic and gravity data from a 136km x 123km area in eastern Kansas. Results provide a reasonable good physical representation of both the gravity and the aeromagnetic data. Superposition of the results from the two data sets shows many areas of agreement that can be referenced to geologic features within the buried Precambrian crystalline basement. -from Authors

Silverton Conference on Applications of the Zero Gravity Space Shuttle Environment to Problems in Fluid Dynamics

NASA Technical Reports Server (NTRS)

Eisner, M. (Editor)

1974-01-01

The possible utilization of the zero gravity resource for studies in a variety of fluid dynamics and fluid-dynamic related problems was investigated. A group of experiments are discussed and described in detail; these include experiments in the areas of geophysical fluid models, fluid dynamics, mass transfer processes, electrokinetic separation of large particles, and biophysical and physiological areas.

Investigation of Ionospheric Turbulence and Whistler Wave Interactions with Space Plasmas

DTIC Science & Technology

2012-11-21

an oscillating LOS velocity with the same periodicity as the heating modulation pattern. A set of Fourier periodogram from the MUIR LOS velocity...scale ionospheric turbulence are discussed separately, viz., (a) anomalous heat source-induced acoustic gravity waves (AGW), and (b) HF radio wave...ionospheric ducts, acoustic gravity waves (AGWs), anomalous heat sources, inner and outer radiation belts, L parameter, whistler wave interactions

Interactions between gravitropism and phototropism in plants

NASA Technical Reports Server (NTRS)

Correll, Melanie J.; Kiss, John Z.

2002-01-01

To receive adequate light and nutrients for survival, plants orient stems and stem-like organs toward light and away from the gravity vector and, conversely, orient roots into the soil, away from light toward the direction of gravity. Therefore, both gravity and light can influence the differential growth of plant organs. To add to the complexity of the interactions between gravity and light, each stimulus can enhance or reduce the effectiveness of the other. On earth, the constant presence of gravity makes it difficult to determine whether plant growth and development is influenced by gravity or light alone or the combination of the two stimuli. In the past decade, our understanding of the gravity and light transduction pathways has advanced through the use of mutants in either gravitropic or phototropic responses and the use of innovative techniques that reduce the effects of one stimulus on the other. Thus, both unique and common elements in the transduction pathways of the gravitropic and phototropic responses have been isolated. This article is focused on the interactions between the light- and gravity-transduction pathways and describes methods used to separate the influences of these two environmental stimuli.

Interactions between gravitropism and phototropism in plants.

PubMed

Correll, Melanie J; Kiss, John Z

2002-06-01

To receive adequate light and nutrients for survival, plants orient stems and stem-like organs toward light and away from the gravity vector and, conversely, orient roots into the soil, away from light toward the direction of gravity. Therefore, both gravity and light can influence the differential growth of plant organs. To add to the complexity of the interactions between gravity and light, each stimulus can enhance or reduce the effectiveness of the other. On earth, the constant presence of gravity makes it difficult to determine whether plant growth and development is influenced by gravity or light alone or the combination of the two stimuli. In the past decade, our understanding of the gravity and light transduction pathways has advanced through the use of mutants in either gravitropic or phototropic responses and the use of innovative techniques that reduce the effects of one stimulus on the other. Thus, both unique and common elements in the transduction pathways of the gravitropic and phototropic responses have been isolated. This article is focused on the interactions between the light- and gravity-transduction pathways and describes methods used to separate the influences of these two environmental stimuli.

Effect of Substrate Wetting on the Morphology and Dynamics of Phase Separating Multi-Component Mixture

NASA Astrophysics Data System (ADS)

Goyal, Abheeti; Toschi, Federico; van der Schoot, Paul

2017-11-01

We study the morphological evolution and dynamics of phase separation of multi-component mixture in thin film constrained by a substrate. Specifically, we have explored the surface-directed spinodal decomposition of multicomponent mixture numerically by Free Energy Lattice Boltzmann (LB) simulations. The distinguishing feature of this model over the Shan-Chen (SC) model is that we have explicit and independent control over the free energy functional and EoS of the system. This vastly expands the ambit of physical systems that can be realistically simulated by LB simulations. We investigate the effect of composition, film thickness and substrate wetting on the phase morphology and the mechanism of growth in the vicinity of the substrate. The phase morphology and averaged size in the vicinity of the substrate fluctuate greatly due to the wetting of the substrate in both the parallel and perpendicular directions. Additionally, we also describe how the model presented here can be extended to include an arbitrary number of fluid components.

Management of Herbaceous Seeps and Wet Savannas for Threatened and Endangered Species.

DTIC Science & Technology

1998-04-01

This document covers the ecology of, impacts to, and management for imbedded (or " inclusional ") wetland communities within the matrix. These wetland...Figure 3. Costal Plain depression pond in Georgia. These inclusional communities usually are not treated separately in literature syntheses regarding...Associated Plant Communities Herbaceous hillside seeps, wet savannas, and small depression ponds exist as inclusional communities within more extensive

Ultrasonic hydrometer

DOEpatents

Swoboda, Carl A.

1984-01-01

The disclosed ultrasonic hydrometer determines the specific gravity (density) of the electrolyte of a wet battery, such as a lead-acid battery. The hydrometer utilizes a transducer that when excited emits an ultrasonic impulse that traverses through the electrolyte back and forth between spaced sonic surfaces. The transducer detects the returning impulse, and means measures the time "t" between the initial and returning impulses. Considering the distance "d" between the spaced sonic surfaces and the measured time "t", the sonic velocity "V" is calculated with the equation "V=2d/t". The hydrometer also utilizes a thermocouple to measure the electrolyte temperature. A hydrometer database correlates three variable parameters including sonic velocity in and temperature and specific gravity of the electrolyte, for temperature values between 0.degree. and 40.degree. C. and for specific gravity values between 1.05 and 1.30. Upon knowing two parameters (the calculated sonic velocity and the measured temperature), the third parameter (specific gravity) can be uniquely found in the database. The hydrometer utilizes a microprocessor for data storage and manipulation. The disclosed modified battery has a hollow spacer nub on the battery side wall, the sonic surfaces being on the inside of the nub and the electrolyte filling between the surfaces to the exclusion of intervening structure. An accessible pad exposed on the nub wall opposite one sonic surface allows the reliable placement thereagainst of the transducer.

Reconstruction of a phreatic eruption on 27 September 2014 at Ontake volcano, central Japan, based on proximal pyroclastic density current and fallout deposits

NASA Astrophysics Data System (ADS)

Maeno, Fukashi; Nakada, Setsuya; Oikawa, Teruki; Yoshimoto, Mitsuhiro; Komori, Jiro; Ishizuka, Yoshihiro; Takeshita, Yoshihiro; Shimano, Taketo; Kaneko, Takayuki; Nagai, Masashi

2016-05-01

The phreatic eruption at Ontake volcano on 27 September 2014, which caused the worst volcanic disaster in the past half-century in Japan, was reconstructed based on observations of the proximal pyroclastic density current (PDC) and fallout deposits. Witness observations were also used to clarify the eruption process. The deposits are divided into three major depositional units (Units A, B, and C) which are characterized by massive, extremely poorly sorted, and multimodal grain-size distribution with 30-50 wt% of fine ash (silt-clay component). The depositional condition was initially dry but eventually changed to wet. Unit A originated from gravity-driven turbulent PDCs in the relatively dry, vent-opening phase. Unit B was then produced mainly by fallout from a vigorous moist plume during vent development. Unit C was derived from wet ash fall in the declining stage. Ballistic ejecta continuously occurred during vent opening and development. As observed in the finest population of the grain-size distribution, aggregate particles were formed throughout the eruption, and the effect of water in the plume on the aggregation increased with time and distance. Based on the deposit thickness, duration, and grain-size data, and by applying a scaling analysis using a depth-averaged model of turbulent gravity currents, the particle concentration and initial flow speed of the PDC at the summit area were estimated as 2 × 10-4-2 × 10-3 and 24-28 m/s, respectively. The tephra thinning trend in the proximal area shows a steeper slope than in similar-sized magmatic eruptions, indicating a large tephra volume deposited over a short distance owing to the wet dispersal conditions. The Ontake eruption provided an opportunity to examine the deposits from a phreatic eruption with a complex eruption sequence that reflects the effect of external water on the eruption dynamics.

Enhanced Wettability and Thermal Stability of a Novel Polyethylene Terephthalate-Based Poly(Vinylidene Fluoride) Nanofiber Hybrid Membrane for the Separator of Lithium-Ion Batteries.

PubMed

Zhu, Chunhong; Nagaishi, Tomoki; Shi, Jian; Lee, Hoik; Wong, Pok Yin; Sui, Jianhua; Hyodo, Kenji; Kim, Ick Soo

2017-08-09

In this study, a novel membrane for the separator in a lithium-ion (Li-ion) battery was proposed via a mechanically pressed process with a poly(vinylidene fluoride) (PVDF) nanofiber subject and polyethylene terephthalate (PET) microfiber support. Important physical properties, such as surface morphology, wettability, and heat stability were considered for the PET-reinforced PVDF nanofiber (PRPN) hybrid separator. Images of scanning electron microscopy (SEM) showed that the PRPN hybrid separator had a homogeneous pore size and high porosity. It can wet out in battery electrolytes completely and quickly, satisfying wettability requirements. Moreover, the electrolyte uptake was higher than that of dry-laid and wet-laid nonwovens. For heat stability, no shrink occurred even when the heating temperature reached 135 °C, demonstrating thermal and dimensional stability. Moreover, differential scanning calorimetry (DSC) showed that the PRPN hybrid separator possessed a shutdown temperature of 131 °C, which is the same as conventional separators. Also, the meltdown temperature reached 252 °C, which is higher than the shutdown temperature, and thus can protect against internal cell shorts. The proposed PRPN hybrid separator is a strong candidate material for utilization in Li-ion batteries.

Low gravity containerless processing of immiscible gold rhodium alloys

NASA Technical Reports Server (NTRS)

Andrews, J. Barry

1986-01-01

Under normal one-g conditions immiscible alloys segregate extensively during solidification due to sedementation of the more dense of the immiscible liquid phases. However, under low-g conditions it should be possible to form a dispersion of the two immiscible liquids and maintain this dispersed structure during solidification. Immiscible (hypermonotectic) gold-rhodium alloys were processed in the Marshall Space Flight Center 105 meter drop tube in order to investigate the influence of low gravity, containerless solidification on their microstructure. Hypermonotectic alloys composed of 65 atomic % rhodium exhibited a tendency for the gold rich liquid to wet the outer surface of the containerless processed samples. This tendency led to extensive segregation in several cases. However, well dispersed microstructures consisting of 2 to 3 micron diameter rhodium-rich spheres in a gold-rich matrix were produced in 23.4 atomic % rhodium alloys. This is one of the best dispersions obtained in research on immiscible alloy-systems to data.

Airflow in Gravity Sewers - Determination of Wastewater Drag Coefficient.

PubMed

Bentzen, Thomas Ruby; Østertoft, Kristian Kilsgaard; Vollertsen, Jes; Fuglsang, Emil Dietz; Nielsen, Asbjørn Haaning

2016-03-01

Several experiments have been conducted in order to improve the understanding of the wastewater drag and the wall frictional force acting on the headspace air in gravity sewers. The aim of the study is to improve the data basis for a numerical model of natural sewer ventilation. The results of the study shows that by integrating the top/side wall shear stresses the log-law models for the air velocity distribution along the unwetted perimeter resulted in a good agreement with the friction forces calculated by use of the Colebrook-White formula for hydraulic smooth pipes. Secondly, the water surface drags were found by log-law models of the velocity distribution in turbulent flows to fit velocity profiles measured from the water surface and by integrating the water surface drags along the wetted perimeter, mean water surface drags were found and a measure of the water surface drag coefficient was found.

The Effect of Dynamic Wetting on the Stability of a Gas-Liquid Interface Subjected to Vertical Oscillations

NASA Astrophysics Data System (ADS)

Kraynik, Andrew M.; Romero, Louis; Torczynski, John R.; Brooks, Carlton F.; O'Hern, Timothy J.; Jepson, Richard A.; Benavides, Gilbert L.

2009-11-01

The stability of an interface in a container partially filled with silicone oil and subjected to gravity and vertical oscillations has been examined theoretically and computationally. An exact theory for the onset of a parametric instability producing Faraday-like waves was developed for arbitrary liquid viscosity, stress-free walls, and deep two-dimensional or axisymmetric containers. Finite-element simulations for stress-free walls are in excellent agreement with the theory, which predicts instability in discrete frequency bands. These simpler calculations are a departure point for examining the more realistic problem, which involves no-slip at the walls and dynamic wetting modeled with a Blake condition. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Thin liquid film in polymer tubing : dynamics and dewetting in partial wetting condition

NASA Astrophysics Data System (ADS)

Hayoun, Pascaline; Letailleur, Alban; Teisseire, Jérémie; Verneuil, Emilie; Lequeux, François; Barthel, Etienne

2015-11-01

Polymers such as PVC and Silicone are low cost materials widely used in industry to produce tubing for fluid transport. Most of these applications involve repeated, intermittent flow of liquids which can lead to unwanted contamination. This study aims at better understanding contamination mechanisms during intermittent flow in polymer tubing, and at elucidating the relation between flow, wetting and contamination. We experimentally and theoretically investigate, flow regimes as well as dewetting process at the triple line induced by gravity flow of a vertical liquid slug in a cylindrical geometry. Our results for Newtonian fluids evidence a succession of thick film formation, hydraulic jump creation in the thickness profile, oscillatory regime and destabilization leading to substrate contamination. In order to understand theoretically the flow, one crucial quantity to assess is the film thickness in the inside of the tube. Based on an absorption measurement method, we provide explanations for behaviors and flow regimes observed experimentally.

Imbibition with swelling: Capillary rise in thin deformable porous media

NASA Astrophysics Data System (ADS)

Kvick, Mathias; Martinez, D. Mark; Hewitt, Duncan R.; Balmforth, Neil J.

2017-07-01

The imbibition of a liquid into a thin deformable porous substrate driven by capillary suction is considered. The substrate is initially dry and has uniform porosity and thickness. Two-phase flow theory is used to describe how the liquid flows through the pore space behind the wetting front when out-of-plane deformation of the solid matrix is considered. Neglecting gravity and evaporation, standard shallow-layer scalings are used to construct a reduced model of the dynamics. The model predicts convergence to a self-similar behavior in all regions except near the wetting front, where a boundary layer arises whose structure narrows with the advance of the front. Over time, the rise height approaches the similarity scaling of t1 /2, as in the classical Washburn or BCLW law. The results are compared with a series of laboratory experiments using cellulose paper sheets, which provide qualitative agreement.

Electrophoresis demonstration on Apollo 16

NASA Technical Reports Server (NTRS)

Snyder, R. S.

1972-01-01

Free fluid electrophoresis, a process used to separate particulate species according to surface charge, size, or shape was suggested as a promising technique to utilize the near zero gravity condition of space. Fluid electrophoresis on earth is disturbed by gravity-induced thermal convection and sedimentation. An apparatus was developed to demonstrate the principle and possible problems of electrophoresis on Apollo 14 and the separation boundary between red and blue dye was photographed in space. The basic operating elements of the Apollo 14 unit were used for a second flight demonstration on Apollo 16. Polystyrene latex particles of two different sizes were used to simulate the electrophoresis of large biological particles. The particle bands in space were extremely stable compared to ground operation because convection in the fluid was negligible. Electrophoresis of the polystyrene latex particle groups according to size was accomplished although electro-osmosis in the flight apparatus prevented the clear separation of two particle bands.

Analytical study on the thermal performance of a partially wet constructal T-shaped fin

NASA Astrophysics Data System (ADS)

Hazarika, Saheera Azmi; Zeeshan, Mohd; Bhanja, Dipankar; Nath, Sujit

2017-07-01

The present paper addresses the thermal analysis of a T-shaped fin under partially wet condition by adopting a cubic variation of the humidity ratio of saturated air with the corresponding fin surface temperature. The point separating the dry and wet parts may lie either in the flange or stem part of the fin and so, two different cases having different governing equations and boundary conditions are analyzed in this paper. Since the governing equations are highly non-linear, they are solved by using an analytical technique called the Differential Transform Method and subsequently, the dry fin length, temperature distribution and fin performances are evaluated and analyzed for a wide range of the various psychometric, geometric and thermo-physical parameters. Finally, it can be highlighted that relative humidity has a pronounced effect on the performance parameters when the fin surface is partially wet whereas this effect is marginally small for fully wet surface.

Frequencies of gravity-capillary waves on highly curved interfaces with edge constraints

NASA Astrophysics Data System (ADS)

Shankar, P. N.

2007-06-01

A recently developed technique to calculate the natural frequencies of gravity-capillary waves in a confined liquid mass with a possibly highly curved free surface is extended to the case where the contact line is pinned. The general technique is worked out in detail for the cases of rectangular and cylindrical containers of circular section, the cases for which experimental data are available. The results of the present method are in excellent agreement with all earlier experimental and theoretical data for the flat static interface case [Benjamin and Scott, 1979. Gravity-capillary waves with edge constraints. J. Fluid Mech. 92, 241-267; Graham-Eagle, 1983. A new method for calculating eigenvalues with applications to gravity-capillary waves with edge constraints. Math. Proc. Camb. Phil. Soc. 94, 553-564; Henderson and Miles, 1994. Surface-wave damping in a circular cylinder with a fixed contact line. J. Fluid Mech. 275, 285-299]. However, the present method is applicable even when the contact angle is not π/2 and the static interface is curved. As a consequence we are able to work out the effects of a curved meniscus on the results of Cocciaro et al. [1993. Experimental investigation of capillary effects on surface gravity waves: non-wetting boundary conditions. J. Fluid Mech. 246, 43-66] where the measured contact angle was 62∘. We find that the meniscus does indeed account, as suggested by Cocciaro et al., for the earlier discrepancy between theory and experiment of about 20 mHz and there is now excellent agreement between the two.

The Influence of Topography on Subaqueous Sediment Gravity Flows and the Resultant Deposits: Examples from Deep-water Systems in Offshore Morocco and Offshore Trinidad

NASA Astrophysics Data System (ADS)

Deng, H.; Wood, L.; Overeem, I.; Hutton, E.

2016-12-01

Submarine topography has a fundamental control on the movement of sediment gravity flows as well as the distribution, morphology, and internal heterogeneity of resultant overlying, healing-phase, deep-water reservoirs. Some of the most complex deep-water topography is generated through both destructive and constructive mass transport processes. A series of numerical models using Sedflux software have been constructed over high resolution mass transport complexes (MTCs) top paleobathymetric surfaces mapped from 3D seismic data in offshore Morocco and offshore eastern Trinidad. Morocco's margin is characterized by large, extant rafted blocks and a flow perpendicular fabric. Trinidad's margin is characterized by muddier, plastic flows and isolated extrusive diapiric buttresses. In addition, Morocco's margin is a dry, northern latitude margin that lacks major river inputs, while Trinidad's margin is an equatorial, wet climate that is fed by the Orinoco River and delta. These models quantitatively delineate the interaction of healing-phase gravity flows on the tops of two very different topographies and provide insights into healing-phase reservoir distribution and stratigraphic trap development. Slopes roughness, curvatures, and surface shapes are measured and quantified relative to input points to quantify depositional surface character. A variety of sediment gravity flow types have been input and the resultant interval assessed for thickness and distribution relative to key topography parameters. Mathematical relationships are to be analyzed and compared with seismic data interpretation of healing-phase interval character, toward an improved model of gravity sedimentation and topography interactions.

CHARACTERIZATION OF HUMIC ACID SIZE FRACTIONS BY SEC AND MALS (R822832)

EPA Science Inventory

Latahco silt-loam humic acid was separated on a preparatory scale by size exclusion chromatography (SEC) on a gravity-fed Sepharose column. Four fractions from this separation were collected and further analyzed, along with whole humic acid, by high-performance SEC coupled with a...

Microgravity Segregation in Binary Mixtures of Inelastic Spheres Driven by Velocity Fluctuation Gradients

NASA Technical Reports Server (NTRS)

Jenkins, James T.; Louge, Michel Y.

1996-01-01

We are interested in collisional granular flows of dry materials in reduced gravity. Because the particles interact through collisions, the energy of the particle velocity fluctuations plays an important role in the physics. Here we focus on the separation of grains by properties - size, for example - that is driven by spatial gradients in the fluctuation energy of the grains. The segregation of grains by size is commonly observed in geophysical flows and industrial processes. Segregation of flowing grains can also take place based on other properties, e.g. shape, mass, friction, and coefficient of restitution. Many mechanisms may be responsible for segregation; most of these are strongly influenced by gravity. Here, we outline a mechanism that is independent of gravity. This mechanism may be important but is often obscured in terrestrial grain flows. It is driven by gradients in fluctuation energy. In microgravity, the separation of grains by property will proceed slowly enough to permit flight observations to provide an unambiguous measurement of the transport coefficients associated with the segregation. In this context, we are planning a microgravity shear cell experiment that contains a mixture of two types of spherical grains. The grains will be driven to interact with two different types of boundaries on either sides of the cell. The resulting separation will be observed visually.

Separate and combined sewer systems: a long-term modelling approach.

PubMed

Mannina, Giorgio; Viviani, Gaspare

2009-01-01

Sewer systems convey mostly dry weather flow, coming from domestic and industrial sanitary sewage as well as infiltration flow, and stormwater due to meteoric precipitations. Traditionally, in urban drainage two types of sewer systems are adopted: separate and combined sewers. The former convey dry and wet weather flow separately into two different networks, while the latter convey dry and wet weather flow together. Which is the best solution in terms of cost-benefit analysis still remains a controversial subject. The present study was aimed at comparing the pollution loads discharged to receiving bodies by Wastewater Treatment Plant (WWTP) and Combined Sewer Overflow (CSO) for different kinds of sewer systems (combined and separate). To accomplish this objective, a comparison between the two systems was carried out using results from simulations of catchments characterised by different dimensions, population densities and water supply rate. The analysis was based on a parsimonious mathematical model able to simulate the sewer system as well as the WWTP during both dry and wet weather. The rain series employed for the simulations was six years long. Several pollutants, both dissolved and particulate, were modelled. The results confirmed the uncertainties in the choice of one system versus the other, emphasising the concept that case-by-case solutions have to be undertaken. Further, the compared systems showed different responses in terms of effectiveness in reducing the discharged mass to the RWB in relation to the particular pollutant taken into account.

Separation of mouse testis cells on a Celsep (TM) apparatus and their usefulness as a source of high molecular weight DNA or RNA

NASA Technical Reports Server (NTRS)

Wolgemuth, D. J.; Gizang-Ginsberg, E.; Engelmyer, E.; Gavin, B. J.; Ponzetto, C.

1985-01-01

The use of a self-contained unit-gravity cell separation apparatus for separation of populations of mouse testicular cells is described. The apparatus, a Celsep (TM), maximizes the unit area over which sedimentation occurs, reduces the amount of separation medium employed, and is quite reproducible. Cells thus isolated have been good sources for isolation of DNA, and notably, high molecular weight RNA.

The Underlying Physics in Wetted Particle Collisions

NASA Astrophysics Data System (ADS)

Donahue, Carly; Hrenya, Christine; Davis, Robert

2008-11-01

Wetted granular particles are relevant in many industries including the pharmaceutical and chemical industries and has applications to granulation, filtration, coagulation, spray coating, drying and pneumatic transport. In our current focus, we investigate the dynamics of a three-body normal wetted particle collision. In order to conduct collisions we use an apparatus called a ``Stokes Cradle,'' similar to the Newton's Cradle (desktop toy) except that the target particles are covered with oil. Here, we are able to vary the oil thickness, oil viscosity, and material properties. With a three particle collision there are four possible outcomes: fully agglomerated (FA); Newton's Cradle (NC), the striker and the first target ball are agglomerated and the last target ball is separated; Reverse Newton's Cradle (RNC), the striker is separated and the two targets are agglomerated; and fully separated (FS). Varying the properties of the collisions, we have observed all four outcomes. We use elastohydrodynamics as a theoretical basis for modeling the system. We also have considered the glass transition of the oil as the pressure increases upon impact and the cavitation of the oil as the pressure drops below the vapor pressure upon rebound. A toy model has been developed where the collision is modeled as a series of two-body collisions. A qualitative agreement between the toy model and experiments gives insight into the underlying physics.

Wetting in a phase separating polymer blend film: quench depth dependence

PubMed

Geoghegan; Ermer; Jungst; Krausch; Brenn

2000-07-01

We have used 3He nuclear reaction analysis to measure the growth of the wetting layer as a function of immiscibility (quench depth) in blends of deuterated polystyrene and poly(alpha-methylstyrene) undergoing surface-directed spinodal decomposition. We are able to identify three different laws for the surface layer growth with time t. For the deepest quenches, the forces driving phase separation dominate (high thermal noise) and the surface layer grows with a t(1/3) coarsening behavior. For shallower quenches, a logarithmic behavior is observed, indicative of a low noise system. The crossover from logarithmic growth to t(1/3) behavior is close to where a wetting transition should occur. We also discuss the possibility of a "plating transition" extending complete wetting to deeper quenches by comparing the surface field with thermal noise. For the shallowest quench, a critical blend exhibits a t(1/2) behavior. We believe this surface layer growth is driven by the curvature of domains at the surface and shows how the wetting layer forms in the absence of thermal noise. This suggestion is reinforced by a slower growth at later times, indicating that the surface domains have coalesced. Atomic force microscopy measurements in each of the different regimes further support the above. The surface in the region of t(1/3) growth is initially somewhat rougher than that in the regime of logarithmic growth, indicating the existence of droplets at the surface.

Hydrologic implications of GRACE satellite data in the Colorado River Basin

NASA Astrophysics Data System (ADS)

Scanlon, Bridget R.; Zhang, Zizhan; Reedy, Robert C.; Pool, Donald R.; Save, Himanshu; Long, Di; Chen, Jianli; Wolock, David M.; Conway, Brian D.; Winester, Daniel

2015-12-01

Use of GRACE (Gravity Recovery and Climate Experiment) satellites for assessing global water resources is rapidly expanding. Here we advance application of GRACE satellites by reconstructing long-term total water storage (TWS) changes from ground-based monitoring and modeling data. We applied the approach to the Colorado River Basin which has experienced multiyear intense droughts at decadal intervals. Estimated TWS declined by 94 km3 during 1986-1990 and by 102 km3 during 1998-2004, similar to the TWS depletion recorded by GRACE (47 km3) during 2010-2013. Our analysis indicates that TWS depletion is dominated by reductions in surface reservoir and soil moisture storage in the upper Colorado basin with additional reductions in groundwater storage in the lower basin. Groundwater storage changes are controlled mostly by natural responses to wet and dry cycles and irrigation pumping outside of Colorado River delivery zones based on ground-based water level and gravity data. Water storage changes are controlled primarily by variable water inputs in response to wet and dry cycles rather than increasing water use. Surface reservoir storage buffers supply variability with current reservoir storage representing ˜2.5 years of available water use. This study can be used as a template showing how to extend short-term GRACE TWS records and using all available data on storage components of TWS to interpret GRACE data, especially within the context of droughts. This article was corrected on 12 JAN 2016. See the end of the full text for details.

Fabrication and test of inorganic/organic separators. [for silver zinc batteries

NASA Technical Reports Server (NTRS)

Smatko, J. S.

1974-01-01

Completion of testing and failure analysis of MDC 40 Ahr silver zinc cells containing largely inorganic separators was accomplished. The results showed that the wet stand and cycle life objectives of the silver zinc cell development program were accomplished. Building, testing and failure analysis of two plate cells employing three optimum separators selected on the basis of extensive screening tests, was performed. The best separator material as a result of these tests was doped calcium zirconate.

Piercing the water surface with a blade: Singularities of the contact line

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

Alimov, Mars M.; Kornev, Konstantin G.

An external meniscus on a narrow blade with a slit-like cross section is studied using the hodograph formulation of the Laplace nonlinear equation of capillarity. On narrow blades, the menisci are mostly shaped by the wetting and capillary forces; gravity plays a secondary role. To describe a meniscus in this asymptotic case, the model of Alimov and Kornev [“Meniscus on a shaped fibre: Singularities and hodograph formulation,” Proc. R. Soc. A 470, 20140113 (2014)] has been employed. It is shown that at the sharp edges of the blade, the contact line makes a jump. In the wetting case, the contactmore » line sitting at each side of the blade is lifted above the points where the meniscus first meets the blade edges. In the non-wetting case, the contact line is lowered below these points. The contours of the constant height emanating from the blade edges generate unusual singularities with infinite curvatures at some points at the blade edges. The meniscus forms a unique surface made of two mirror-symmetric sheets fused together. Each sheet is supported by the contact line sitting at each side of the blade.« less

Contact Angle Influence on Geysering Jets in Microgravity Investigated

NASA Technical Reports Server (NTRS)

Chato, David J.

2004-01-01

Microgravity poses many challenges to the designer of spacecraft tanks. Chief among these are the lack of phase separation and the need to supply vapor-free liquid or liquid-free vapor to the spacecraft processes that require fluid. One of the principal problems of phase separation is the creation of liquid jets. A jet can be created by liquid filling, settling of the fluid to one end of the tank, or even closing a valve to stop the liquid flow. Anyone who has seen a fountain knows that jets occur in normal gravity also. However, in normal gravity, the gravity controls and restricts the jet flow. In microgravity, with gravity largely absent, surface tension forces must be used to contain jets. To model this phenomenon, a numerical method that tracks the fluid motion and the surface tension forces is required. Jacqmin has developed a phase model that converts the discrete surface tension force into a barrier function that peaks at the free surface and decays rapidly away. Previous attempts at this formulation were criticized for smearing the interface. This can be overcome by sharpening the phase function, double gridding the fluid function, and using a higher-order solution for the fluid function. The solution of this equation can be rewritten as two coupled Poisson equations that also include the velocity.

Experiment plans to study preignition processes of a pool fire in low gravity. M.S. Thesis - 1988 Final Report

NASA Technical Reports Server (NTRS)

Schiller, David N.

1989-01-01

Science requirements are specified to guide experimental studies of transient heat transfer and fluid flow in an enclosure containing a two-layer gas-and-liquid system heated unevenly from above. Specifications are provided for experiments in three separate settings: (1) a normal gravity laboratory, (2) the NASA-LeRC Drop towers, and (3) a space-based laboratory (e.g., Shuttle, Space Station). A rationale is developed for both minimum and desired requirement levels. The principal objective of the experimental effort is to validate a computational model of the enclosed liquid fuel pool during the preignition phase and to determine via measurement the role of gravity on the behavior of the system. Preliminary results of single-phase normal gravity experiments and simulations are also presented.

Chesapeake Bay Protection and Restoration: Improvements and Lessons Learned at Craney Island and Southgate Annex, Norfolk, Virginia

DTIC Science & Technology

2011-05-01

Annex Case Study Bay Impairment  Low Dissolved Oxygen  Poor Water Clarity  Too Much Bad Algae 3 Impaired Water Note: Representation of 303(d...Bioretention Regional pond Grass Channels Dry swale Level spreader Soils compost amendments Wet swale Underground detention Vegetated Roofs Filtering...practice Oil/grit separator Rainwater harvesting Constructed wetlands Tree box filter Permeable pavement Wet ponds Other: ________________ Existing

Foam flow and liquid films motion: role of the surfactants properties

NASA Astrophysics Data System (ADS)

Cantat, Isabelle

2011-11-01

Liquid foams absorb energy in a much more efficient way than each of its constituents, taken separately. However, the local process at the origin of the energy dissipation is not entirely elucidated yet, and several models may apply, thus making worth local studies on simpler systems. We investigate the motion through a wet tube of transverse soap films, or lamellae, combining local thickness and velocity measurements in the wetting film. For foaming solution with a high dilatational surface modulus, we reveal a zone of several centimeters in length, the dynamic wetting film, which is significantly influenced by a moving lamella. The dependence of this influence length on lamella velocity and wetting film thickness provides an accurate discrimination among several possible surfactants models. In collaboration with B. Dollet.

Process Development for Hydrothermal Liquefaction of Algae Feedstocks in a Continuous-Flow Reactor

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

Elliott, Douglas C.; Hart, Todd R.; Schmidt, Andrew J.

Wet algae slurries can be converted into an upgradeable biocrude by hydrothermal liquefaction (HTL). High levels of carbon conversion to gravity-separable biocrude product were accomplished at relatively low temperature (350 °C) in a continuous-flow, pressurized (sub-critical liquid water) environment (20 MPa). As opposed to earlier work in batch reactors reported by others, direct oil recovery was achieved without the use of a solvent and biomass trace components were removed by processing steps so that they did not cause process difficulties. High conversions were obtained even with high slurry concentrations of up to 35 wt% of dry solids. Catalytic hydrotreating wasmore » effectively applied for hydrodeoxygenation, hydrodenitrogenation, and hydrodesulfurization of the biocrude to form liquid hydrocarbon fuel. Catalytic hydrothermal gasification was effectively applied for HTL byproduct water cleanup and fuel gas production from water soluble organics, allowing the water to be considered for recycle of nutrients to the algae growth ponds. As a result, high conversion of algae to liquid hydrocarbon and gas products was found with low levels of organic contamination in the byproduct water. All three process steps were accomplished in bench-scale, continuous-flow reactor systems such that design data for process scale-up was generated.« less

Improved low-cost, non-hazardous, all-iron cell for the developing world

NASA Astrophysics Data System (ADS)

Tucker, Michael C.; Lambelet, David; Oueslati, Mohamed; Williams, Benjamin; Wang, Wu-Chieh Jerry; Weber, Adam Z.

2016-11-01

A low-cost, non-hazardous personal-power system based on an aqueous all-iron electrochemical cell is demonstrated. The system is intended to be assembled and operated by developing-world households that lack sufficient access to electricity, thereby enabling LED lighting or mobile phone charging on demand. Lab-scale hardware is used to assess the performance of individual cell components. It is found that coffee filter paper is an effective low-cost separator. Carbon felt is a low-cost electrode material, and its performance and wetting by the electrolyte solution is greatly improved by pre-treatment with sulfuric acid. The carbon felt does not degrade after a week of daily use. By using these components, performance of the system is significantly improved over the previous baseline, with power density more than doubling to 40 mW cm-2, and iron utilization improving from 78% to 88%. The operating cost is estimated to be less than US0.03 per mobile phone charge. Based on the lab-scale results, a stand-alone prototype consumer product is designed, fabricated, and tested. It successfully provides 2.5 h of LED illumination while consuming 200 mL of electrolyte solution via gravity feed. We anticipate these results will enable deployment of this innovative system to energy-impoverished individuals in the developing world.

Marangoni Effects in the Boiling of Binary Fluid Mixtures

NASA Technical Reports Server (NTRS)

Ahmed, Sayeed; Carey, Van P.; Motil, Brian

1996-01-01

Results of very recent experimental studies indicate that during nucleate boiling in some binary mixture, Marangoni effects augment the gravity driven flow of liquid towards the heated surface. With gravity present, it is impossible to separate the two effects. The reduced gravity environment gives an unique opportunity to explore th role of Marangoni effects on the boiling mechanisms free of gravitational body forces that obscure the role of such effects. However, recent experimental results suggest that under reduced gravity conditions, Marangoni effects is the dominant mechanism of vapor-liquid exchange at the surface for some binary mixture. To further explore such effects, experiments have been conducted with water/2-propanol mixtures at three different concentrations under normal gravity with different orientations of the heater surface and under reduce gravity aboard the DC-9 aircraft at NASA Lewis Research Center. The system pressure was sub atmospheric (approx. 8 kP at 1g(n)) and the bulk liquid temperature varied from low subcooling to near saturation. The molar concentrations of 2-propanol tested were 0.015, 0.025, and 0.1. Boiling curves were obtained both for high gravity (approx. 2g(n)) and reduce gravity (approx. 0.01g(n)). For each concentration of 2-propanol, the critical heat flux has been determined in the flight experiments only for reduced gravity conditions. Comparison of boiling curves and CHF obtained under l-g(n) an reduced gravity indicates that boiling mechanism in this mixtures is nearly independent of gravity. The results also indicate that the Marangoni mechanism is strong enough in these mixtures to sustain the boiling under reduced gravity conditions.

Towing Asteroids with Gravity Tractors Enhanced by Tethers and Solar Sails

NASA Technical Reports Server (NTRS)

Shen, Haijun; Roithmayr, Carlos M.

2015-01-01

Material collected from an asteroid's surface can be used to increase gravitational attraction between the asteroid and a Gravity Tractor (GT); the spacecraft therefore operates more effectively and is referred to as an Enhanced Gravity Tractor (EGT). The use of tethers and solar sails to further improve effectiveness and simplify operations is investigated. By employing a tether, the asteroidal material can be placed close to the asteroid while the spacecraft is stationed farther away, resulting in a better safety margin and improved thruster efficiency. A solar sail on a spacecraft can naturally provide radial offset and inter-spacecraft separation required for multiple EGTs.

Nucleate pool boiling in subcooled liquid under microgravity: Results of TEXUS experimental investigations

NASA Astrophysics Data System (ADS)

Zell, M.; Straub, J.; Weinzierl, A.

1984-12-01

Experiments on subcooled nucleate pool boiling in microgravity were carried out to separate gravity driven effects on heat transfer within the boiling process. A ballistic trajectory by sounding rocket flight (TEXUS 5 and 10) achieved a gravity level of a/g = 0.0001 for 360 sec. For determination of geometrical effects on heat transport two different experimental configurations (platinum wire and flat plate) were employed. Boiling curves and bubble dynamics recorded by cinematography lead to gravity independent modelling of the boiling phenomena. The results ensure the applicability and high efficiency of nucleate pool boiling for heat exchangers in space laboratories.

Near Critical/Supercritical Carbon Dioxide Extraction for Treating Contaminated Bilgewater

DTIC Science & Technology

2000-02-24

SUMMARY i TABLE OF CONTENTS ii LIST OF FIGURES iii LIST OF TABLES iii 1. INTRODUCTION 1 1.1 Current Treatment Processes 1 2. SUPERCRITICAL...Treatment Processes Historically, the Navy has relied on gravimetric separation to remove oily contaminants from bilgewater. Most ships contain one...continuously changes the orientation of the separator with respect to gravity, lowering the effectiveness of a separation process that relies on subtle

7 CFR 201.47 - Separation.

Code of Federal Regulations, 2012 CFR

2012-01-01

... light (diaphanoscope), or specific gravity (seed blowers). Specific instructions for classification of... of bahiagrass, orchardgrass, side-oats grama, and blue grama. (f) Procedures for purity analysis for...

7 CFR 201.47 - Separation.

Code of Federal Regulations, 2014 CFR

2014-01-01

... light (diaphanoscope), or specific gravity (seed blowers). Specific instructions for classification of... of bahiagrass, orchardgrass, side-oats grama, and blue grama. (f) Procedures for purity analysis for...

7 CFR 201.47 - Separation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... light (diaphanoscope), or specific gravity (seed blowers). Specific instructions for classification of... of bahiagrass, orchardgrass, side-oats grama, and blue grama. (f) Procedures for purity analysis for...

7 CFR 201.47 - Separation.

Code of Federal Regulations, 2011 CFR

2011-01-01

... light (diaphanoscope), or specific gravity (seed blowers). Specific instructions for classification of... of bahiagrass, orchardgrass, side-oats grama, and blue grama. (f) Procedures for purity analysis for...

7 CFR 201.47 - Separation.

Code of Federal Regulations, 2013 CFR

2013-01-01

... light (diaphanoscope), or specific gravity (seed blowers). Specific instructions for classification of... of bahiagrass, orchardgrass, side-oats grama, and blue grama. (f) Procedures for purity analysis for...

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

Aydin, M.E.; Yildirim, I.; Dogan, M.Z.

The Istanbul Region coals are characterized by high moisture contents (avg. 35%), high volatile matter values (avg. 45%), and more importantly high levels of sulfur in the range of 1 to 5%. These lignitic coals generally have relatively low ash (10%), and higher levels of calorific values over 5,000 Kcal/kg. The Multi-Gravity Separator (MGS), a new fine size gravity separation equipment, was tested to evaluate its potential for the desulfurization of these low-rank coals. Systematic tests conducted on two different samples of minus 1 mm size indicate that despite the finely distributed nature of coal and relatively small difference betweenmore » coal and its associated gangue minerals, the degree of pyritic sulfur removal is 65.7% and 85.9% for the respective coals.« less

Surface Wetting-Driven Separation of Surfactant-Stabilized Water-Oil Emulsions.

PubMed

Zhang, Qian; Li, Lei; Li, Yanxiang; Cao, Lixia; Yang, Chuanfang

2018-05-15

Four fluorocarbon polymers including polytetrafluoroethylene and polyvinylidene fluoride were coated on a stainless steel felt to separate emulsified water droplets from ultralow sulfur diesel (ULSD) fuels. The original fuel treated with clay to remove additives was additized again with four known surfactants including pentaerythrityoleate, (octadecadienoic acid) dipolymer, (octadecadienoic acid) tripolymer, and monoolein individually. The different surfactants adsorbed on the fuel-water interface reduce the interfacial intension with different intensities. The separation efficiency at various surfactant concentrations was used to evaluate the coalescence effect exerted by these coatings. It was found the separation was both surfactant- and coating-dependent. A fluoro-polyurethane coating (FC1) stood out to counteract the adverse effect of all the surfactants. Solid free energy was then measured using acid-base and Kaelble-Uy adhesion theories for all the coatings, but its correlation with coalescence was not found at all. Coating aging in surfactant-additized fuel on the coating's water wettability was also examined to better understand how historical wetting affects separation. A tumbled model for fluorocarbons was identified that well-explained the continuous decline of the water contact angle on the FC1 coating in fuel. Subject to the challenge of the foreign environment, the fluoroalkyl chains of the polymer tilt to expose the carbonyl groups underneath, resulting in favored coalescence separation in the presence of surfactants.

Water outlet control mechanism for fuel cell system operation in variable gravity environments

NASA Technical Reports Server (NTRS)

Vasquez, Arturo (Inventor); McCurdy, Kerri L. (Inventor); Bradley, Karla F. (Inventor)

2007-01-01

A self-regulated water separator provides centrifugal separation of fuel cell product water from oxidant gas. The system uses the flow energy of the fuel cell's two-phase water and oxidant flow stream and a regulated ejector or other reactant circulation pump providing the two-phase fluid flow. The system further uses a means of controlling the water outlet flow rate away from the water separator that uses both the ejector's or reactant pump's supply pressure and a compressibility sensor to provide overall control of separated water flow either back to the separator or away from the separator.

Ultrathin graphene oxide-based hollow fiber membranes with brush-like CO2-philic agent for highly efficient CO2 capture.

PubMed

Zhou, Fanglei; Tien, Huynh Ngoc; Xu, Weiwei L; Chen, Jung-Tsai; Liu, Qiuli; Hicks, Ethan; Fathizadeh, Mahdi; Li, Shiguang; Yu, Miao

2017-12-13

Among the current CO 2 capture technologies, membrane gas separation has many inherent advantages over other conventional techniques. However, fabricating gas separation membranes with both high CO 2 permeance and high CO 2 /N 2 selectivity, especially under wet conditions, is a challenge. In this study, sub-20-nm thick, layered graphene oxide (GO)-based hollow fiber membranes with grafted, brush-like CO 2 -philic agent alternating between GO layers are prepared by a facile coating process for highly efficient CO 2 /N 2 separation under wet conditions. Piperazine, as an effective CO 2 -philic agent, is introduced as a carrier-brush into the GO nanochannels with chemical bonding. The membrane exhibits excellent separation performance under simulated flue gas conditions with CO 2 permeance of 1,020 GPU and CO 2 /N 2 selectivity as high as 680, demonstrating its potential for CO 2 capture from flue gas. We expect this GO-based membrane structure combined with the facile coating process to facilitate the development of ultrathin GO-based membranes for CO 2 capture.

Evaluation of an enhanced gravity-based fine-coal circuit for high-sulfur coal

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

Mohanty, M.K.; Samal, A.R.; Palit, A.

One of the main objectives of this study was to evaluate a fine-coal cleaning circuit using an enhanced gravity separator specifically for a high sulfur coal application. The evaluation not only included testing of individual unit operations used for fine-coal classification, cleaning and dewatering, but also included testing of the complete circuit simultaneously. At a scale of nearly 2 t/h, two alternative circuits were evaluated to clean a minus 0.6-mm coal stream utilizing a 150-mm-diameter classifying cyclone, a linear screen having a projected surface area of 0.5 m{sup 2}, an enhanced gravity separator having a bowl diameter of 250 mmmore » and a screen-bowl centrifuge having a bowl diameter of 500 mm. The cleaning and dewatering components of both circuits were the same; however, one circuit used a classifying cyclone whereas the other used a linear screen as the classification device. An industrial size coal spiral was used to clean the 2- x 0.6-mm coal size fraction for each circuit to estimate the performance of a complete fine-coal circuit cleaning a minus 2-mm particle size coal stream. The 'linear screen + enhanced gravity separator + screen-bowl circuit' provided superior sulfur and ash-cleaning performance to the alternative circuit that used a classifying cyclone in place of the linear screen. Based on these test data, it was estimated that the use of the recommended circuit to treat 50 t/h of minus 2-mm size coal having feed ash and sulfur contents of 33.9% and 3.28%, respectively, may produce nearly 28.3 t/h of clean coal with product ash and sulfur contents of 9.15% and 1.61 %, respectively.« less

A System Approach to Navy Medical Education and Training. Appendix 9. Laboratory Technician.

DTIC Science & Technology

1974-08-31

USING CARBONDIOXIDE IC021 46 ICHECK /ADJUST PH OF BUFFERS/REAGENTS 47 IPREPARE STANDARD CURVE 48 ISTANDARDIZE REAGENTS 49 IPREPARE CULTURE MEDIA FROM...CELL MORPHOLOGY 6 ISTAIN SMEARS TO DEMONSTRATE PARASITE 7 ICENTRIFUGE URINE 8 ICENTRIFUGE BLOOD AND SEPARATE SERUM OR PLASMA 9 ICHECK SPECIFIC GRAVITY...OF URINE 10 ICHECK SPECIFIC GRAVITY OF CHEMICAL SOLUTIONS 11 IDETERMINE SPERM COUNTS 12 1EXAMINE SEMINAL FLUID FOR SPERM MORPHOLOGY 13 I EXAMINE

Phase partitioning in space and on earth

NASA Technical Reports Server (NTRS)

Van Alstine, James M.; Karr, Laurel J.; Snyder, Robert S.; Matsos, Helen C.; Curreri, Peter A.; Harris, J. Milton; Bamberger, Stephan B.; Boyce, John; Brooks, Donald E.

1987-01-01

The influence of gravity on the efficiency and quality of the impressive separations achievable by bioparticle partitioning is investigated by demixing polymer phase systems in microgravity. The study involves the neutral polymers dextran and polyethylene glycol, which form a two-phase system in aqueous solution at low concentrations. It is found that demixing in low-gravity occurs primarily by coalescence, whereas on earth the demixing occurs because of density differences between the phases.

A Capillary-Based Static Phase Separator for Highly Variable Wetting Conditions

NASA Technical Reports Server (NTRS)

Thomas, Evan A.; Graf, John C.; Weislogel, Mark M.

2010-01-01

The invention, a static phase separator (SPS), uses airflow and capillary wetting characteristics to passively separate a two-phase (liquid and air) flow. The device accommodates highly variable liquid wetting characteristics. The resultant design allows for a range of wetting properties from about 0 to over 90 advancing contact angle, with frequent complete separation of liquid from gas observed when using appropriately scaled test conditions. Additionally, the design accommodates a range of air-to-liquid flow-rate ratios from only liquid flow to over 200:1 air-to-liquid flow rate. The SPS uses a helix input section with an ice-cream-cone-shaped constant area cross section (see figure). The wedge portion of the cross section is on the outer edge of the helix, and collects the liquid via centripetal acceleration. The helix then passes into an increasing cross-sectional area vane region. The liquid in the helix wedge is directed into the top of capillary wedges in the liquid containment section. The transition from diffuser to containment section includes a 90 change in capillary pumping direction, while maintaining inertial direction. This serves to impinge the liquid into the two off-center symmetrical vanes by the airflow. Rather than the airflow serving to shear liquid away from the capillary vanes, the design allows for further penetration of the liquid into the vanes by the air shear. This is also assisted by locating the air exit ports downstream of the liquid drain port. Additionally, any droplets not contained in the capillary vanes are re-entrained downstream by a third opposing capillary vane, which directs liquid back toward the liquid drain port. Finally, the dual air exit ports serve to slow the airflow down, and to reduce the likelihood of shear. The ports are stove-piped into the cavity to form an unfriendly capillary surface for a wetting fluid to carryover. The liquid drain port is located at the start of the containment region, allowing for draining the bulk fluid in a continuous circuit. The functional operation of the SPS involves introducing liquid flow (from a human body, a syringe, or other source) to the two-phase inlet while an air fan pulls on the air exit lines. The fan is operated until the liquid is fully introduced. The system is drained by negative pressure on the liquid drain lines when the SPS containment system is full.

Supergravity separation of Pb and Sn from waste printed circuit boards at different temperatures

NASA Astrophysics Data System (ADS)

Meng, Long; Wang, Zhe; Zhong, Yi-wei; Chen, Kui-yuan; Guo, Zhan-cheng

2018-02-01

Printed circuit boards (PCBs) contain many toxic substances as well as valuable metals, e.g., lead (Pb) and tin (Sn). In this study, a novel technology, named supergravity, was used to separate different mass ratios of Pb and Sn from Pb-Sn alloys in PCBs. In a supergravity field, the liquid metal phase can permeate from solid particles. Hence, temperatures of 200, 280, and 400°C were chosen to separate Pb and Sn from PCBs. The results depicted that gravity coefficient only affected the recovery rates of Pb and Sn, whereas it had little effect on the mass ratios of Pb and Sn in the obtained alloys. With an increase in gravity coefficient, the recovery values of Pb and Sn in each step of the separation process increased. In the single-step separation process, the mass ratios of Pb and Sn in Pb-Sn alloys were 0.55, 0.40, and 0.64 at 200, 280, and 400°C, respectively. In the two-step separation process, the mass ratios were 0.12 and 0.55 at 280 and 400°C, respectively. Further, the mass ratio was observed to be 0.76 at 400°C in the three-step separation process. This process provides an innovative approach to the recycling mechanism of Pb and Sn from PCBs.

Effects of high-pressure extruding pretreatment on MSW upgrading and hydrolysis enhancement.

PubMed

Xu, Shuang; Kong, Xin; Liu, Jianguo; Zhao, Ke; Zhao, Guangqi; Bahdolla, Amanjol

2016-12-01

High-pressure extruding (HPE) is an efficient technology used to separate municipal solid waste (MSW) into wet (biodegradable) and dry (combustible) fractions. Effects of pressure, 10, 20, 30, and 40MPa on quality upgrading of the MSW and hydrolysis of the wet fraction were examined. TS of the dry fraction increased from 48.5% to 59.4% when the extruding pressure increased from 10 to 40MPa, meanwhile the biochemical methane potential (BMP) of the wet fraction extruded under 40MPa was 674mL CH 4 /g·VS, 33% higher than that of the organic fraction of the MSW (OFMSW) control. Furthermore, in the initial stage of hydrolysis experiment, the extruded wet fractions had lower pH and higher COD, volatile fatty acids (VFAs) and COD/VFA than those of the OFMSW control. The results confirmed that HPE upgraded the MSW and enhanced hydrolysis of the wet fractions. However, high extruding pressure as 40MPa aggravated the excessive acidification of the wet fractions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Prevalence of wet litter and the associated risk factors in broiler flocks in the United Kingdom.

PubMed

Hermans, P G; Fradkin, D; Muchnik, I B; Organ, K L

2006-05-06

A postal questionnaire was sent to the managers of 857 broiler farms in the UK to determine the prevalence and risk factors for wet litter. The response rate was 75 per cent. Wet litter was reported by 75 per cent (95 per cent confidence interval [CI] 71.3 to 78.3) of the respondents in at least one flock during the year 2001 and 56.1 per cent (95 per cent CI 52.0 to 60.0) of them reported that they had an outbreak of wet litter in their most recently reared flock. Wet litter occurred more often during the winter months and farms using side ventilation systems were at an increased risk (odds ratio 1.74; 95 per cent CI 1.09 to 2.76). A multivariable analysis was carried out using two different definitions of wet litter as outcome variables - all cases of wet litter, and cases of wet litter associated with disease. Consistent risk factors for both outcomes were coccidiosis, feed equipment failures and the availability of separate farm clothing for each house. Cases of wet litter associated with disease were reported by 33.7 per cent (95 per cent CI 28.8 to 39.1) of the managers in their last flock and were associated with the use of hand sanitisers and broiler houses with walls made of concrete.

Apollo-Soyuz pamphlet no. 8: Zero-g technology. [experimental designispace processing and aerospace engineering

NASA Technical Reports Server (NTRS)

Page, L. W.; From, T. P.

1977-01-01

The behavior of liquids in zero gravity environments is discussed with emphasis on foams, wetting, and wicks. A multipurpose electric furnace (MA-010) for the high temperature processing of metals and salts in zero-g is described. Experiments discussed include: monolectic and synthetic alloys (MA-041); multiple material melting point (MA-150); zero-g processing of metals (MA-070); surface tension induced convection (MA-041); halide eutectic growth; interface markings in crystals (MA-060); crystal growth from the vapor phase (MA-085); and photography of crystal growth (MA-028).

Chemical Clarification Methods for Confined Dredged Material Disposal.

DTIC Science & Technology

1983-07-01

foot second per metre cubic yards 0.7645549 cubic metres Farenheit degrees 5/9 Celsius degrees or Kelvins* feet 0.3048 metres feet per minute 0.3048...unknown in freshwater environments, use zero S.G. = specific gravity of solids; use 2.67 if unknown Wt. H20 [(weight of wet sample and dish, g...62.4 lb/ft v = average velocity, ft/sec Ps= absolute viscosity, 2.36 x 10-5 at 60F The duration t of the mixing is determined by t =L (6) v The net

Root niche separation can explain avoidance of seasonal drought stress and vulnerability of overstory trees to extended drought in a mature Amazonian forest

NASA Astrophysics Data System (ADS)

Ivanov, Valeriy Y.; Hutyra, Lucy R.; Wofsy, Steven C.; Munger, J. William; Saleska, Scott R.; de Oliveira, Raimundo C., Jr.; de Camargo, Plínio B.

2012-12-01

Large areas of Amazonian evergreen forest experience seasonal droughts extending for three or more months, yet show maximum rates of photosynthesis and evapotranspiration during dry intervals. This apparent resilience is belied by disproportionate mortality of the large trees in manipulations that reduce wet season rainfall, occurring after 2-3 years of treatment. The goal of this study is to characterize the mechanisms that produce these contrasting ecosystem responses. A mechanistic model is developed based on the ecohydrological framework of TIN (Triangulated Irregular Network)-based Real Time Integrated Basin Simulator + Vegetation Generator for Interactive Evolution (tRIBS+VEGGIE). The model is used to test the roles of deep roots and soil capillary flux to provide water to the forest during the dry season. Also examined is the importance of "root niche separation," in which roots of overstory trees extend to depth, where during the dry season they use water stored from wet season precipitation, while roots of understory trees are concentrated in shallow layers that access dry season precipitation directly. Observational data from the Tapajós National Forest, Brazil, were used as meteorological forcing and provided comprehensive observational constraints on the model. Results strongly suggest that deep roots with root niche separation adaptations explain both the observed resilience during seasonal drought and the vulnerability of canopy-dominant trees to extended deficits of wet season rainfall. These mechanisms appear to provide an adaptive strategy that enhances productivity of the largest trees in the face of their disproportionate heat loads and water demand in the dry season. A sensitivity analysis exploring how wet season rainfall affects the stability of the rainforest system is presented.

Gravity Effects in Diffusive Coarsening of Bubble Lattices: von Neumann's Law

NASA Technical Reports Server (NTRS)

Noever, David A.

2000-01-01

von Neumann modelled the evolution of two-dimensional soap froths as a purely diffusive phenomenon; the area growth of a given cell was found to depend only on the geometry of the bubble lattice. In the model, hexagons are stable, pentagons shrink and heptagons grow. The simplest equivalent to the area growth law is / approximately t(sub beta). The result depends on assuming (1) an incompressible gas; (2) bubble walls which meet at 120 deg and (3) constant wall thickness and curvature. Each assumption is borne out in experiments except the last one: bubble wall thickness between connecting cells varies in unit gravity because of gravity drainage. The bottom part of the soap membrane is thickened, the top part is thinned, such that gas diffusion across the membrane shows a complex dependence on gravity. As a result, experimental tests of von Neumann's law have been influenced by effects of gravity; fluid behavior along cell borders can give non-uniform wall thicknesses and thus alter the effective area and gas diffusion rates between adjacent bubbles. For area plotted as a function of time, Glazier (J.A. Glazier, S.P. Gross, and I. Stavans, Phys. Rev. A. 36, 306 (1987); J. Stavans, J.A, Glazier, Phys. Rev. Lett. 62, 1318 (1989).) suggest that in some cases their failure to observe von Neumann's predicted growth exponent ((sup beta)theor(sup =1; beta)exp(sup =0.70 + 0.10)) may have been the result of such "fluid drainage onto the lower glass plate". Additional experiments which varied plate spacing gave different beta exponents in a fashion consistent with this suggestion. During preliminary long duration experiments (approximately 100 h) aboard Spacelab-J, a low-gravity test of froth coarsening has examined (1) power law scaling of von Neumann's law (beta values) in the appropriate diffusive limits; (2) new bubble lattice dynamics such as greater fluid wetting behavior on froth membranes in low gravity; and (3) explicit relations for the gravity dependence of the second moment (or disorder parameter) governing the geometric spread in cell-sidedness around the mean of perfect hexagonal filling. By reducing the gravity-induced distortion in lattice wall thickness, the diffusion-limited regime of bubble coarsening becomes available for performing critical tests of network dynamics.

Causal properties of nonlinear gravitational waves in modified gravity

NASA Astrophysics Data System (ADS)

Suvorov, Arthur George; Melatos, Andrew

2017-09-01

Some exact, nonlinear, vacuum gravitational wave solutions are derived for certain polynomial f (R ) gravities. We show that the boundaries of the gravitational domain of dependence, associated with events in polynomial f (R ) gravity, are not null as they are in general relativity. The implication is that electromagnetic and gravitational causality separate into distinct notions in modified gravity, which may have observable astrophysical consequences. The linear theory predicts that tachyonic instabilities occur, when the quadratic coefficient a2 of the Taylor expansion of f (R ) is negative, while the exact, nonlinear, cylindrical wave solutions presented here can be superluminal for all values of a2. Anisotropic solutions are found, whose wave fronts trace out time- or spacelike hypersurfaces with complicated geometric properties. We show that the solutions exist in f (R ) theories that are consistent with Solar System and pulsar timing experiments.

Probing gravity at cosmological scales by measurements which test the relationship between gravitational lensing and matter overdensity.

PubMed

Zhang, Pengjie; Liguori, Michele; Bean, Rachel; Dodelson, Scott

2007-10-05

The standard cosmology is based on general relativity (GR) and includes dark matter and dark energy and predicts a fixed relationship between the gravitational potentials responsible for gravitational lensing and the matter overdensity. Alternative theories of gravity often make different predictions. We propose a set of measurements which can test this relationship, thereby distinguishing between dark energy or matter models and models in which gravity differs from GR. Planned surveys will be able to measure E(G), an observational quantity whose expectation value is equal to the ratio of the Laplacian of the Newtonian potentials to the peculiar velocity divergence, to percent accuracy. This will easily separate alternatives such as the cold dark matter model with a cosmological constant, Dvali-Gabadadze-Porrati, TeVeS, and f(R) gravity.

Field Testing of a Wet FGD Additive for Enhanced Mercury Control - Pilot-Scale Test Results

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

Gary M. Blythe

2006-03-01

This Topical Report summarizes progress on Cooperative Agreement DE-FC26-04NT42309, ''Field Testing of a Wet FGD Additive.'' The objective of the project is to demonstrate the use of a flue gas desulfurization (FGD) additive, Degussa Corporation's TMT-15, to prevent the reemissions of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project intends to demonstrate that the additive can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine TMT salt that can be separated from the FGD liquor and bulk solid byproducts for separate disposal.more » The project will conduct pilot and full-scale tests of the TMT-15 additive in wet FGD absorbers. The tests are intended to determine required additive dosage requirements to prevent Hg{sup 0} reemissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Power River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, TXU Generation Company LP, Southern Company, and Degussa Corporation. TXU Generation has provided the Texas lignite/PRB co-fired test site for pilot FGD tests, Monticello Steam Electric Station Unit 3. Southern Company is providing the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, as well as the pilot and full-scale jet bubbling reactor (JBR) FGD systems to be tested. A third utility, to be named later, will provide the high-sulfur Eastern bituminous coal full-scale FGD test site. Degussa Corporation is providing the TMT-15 additive and technical support to the test program. The project is being conducted in six tasks. Of the six project tasks, Task 1 involves project planning and Task 6 involves management and reporting. The other four tasks involve field testing on FGD systems, either at pilot or full scale. The four tasks include: Task 2 - Pilot Additive Testing in Texas Lignite Flue Gas; Task 3 - Full-scale FGD Additive Testing in High Sulfur Eastern Bituminous Flue Gas; Task 4 - Pilot Wet Scrubber Additive Tests at Yates; and Task 5 - Full-scale Additive Tests at Plant Yates. This topical report presents the results from the Task 2 and Task 4 pilot-scale additive tests. The Task 3 and Task 5 full-scale additive tests will be conducted later in calendar year 2006.« less

Further Investigations of Gravity Modeling on Surface-Interacting Vehicle Simulations

NASA Technical Reports Server (NTRS)

Madden, Michael M.

2009-01-01

A vehicle simulation is "surface-interacting" if the state of the vehicle (position, velocity, and acceleration) relative to the surface is important. Surface-interacting simulations perform ascent, entry, descent, landing, surface travel, or atmospheric flight. The dynamics of surface-interacting simulations are influenced by the modeling of gravity. Gravity is the sum of gravitation and the centrifugal acceleration due to the world s rotation. Both components are functions of position relative to the world s center and that position for a given set of geodetic coordinates (latitude, longitude, and altitude) depends on the world model (world shape and dynamics). Thus, gravity fidelity depends on the fidelities of the gravitation model and the world model and on the interaction of the gravitation and world model. A surface-interacting simulation cannot treat the gravitation separately from the world model. This paper examines the actual performance of different pairs of world and gravitation models (or direct gravity models) on the travel of a subsonic civil transport in level flight under various starting conditions.

Gravity Modeling Effects on Surface-Interacting Vehicles in Supersonic Flight

NASA Technical Reports Server (NTRS)

Madden, Michael M.

2010-01-01

A vehicle simulation is "surface-interacting" if the state of the vehicle (position, velocity, and acceleration) relative to the surface is important. Surface-interacting simulations per-form ascent, entry, descent, landing, surface travel, or atmospheric flight. The dynamics of surface-interacting simulations are influenced by the modeling of gravity. Gravity is the sum of gravitation and the centrifugal acceleration due to the world s rotation. Both components are functions of position relative to the world s center and that position for a given set of geodetic coordinates (latitude, longitude, and altitude) depends on the world model (world shape and dynamics). Thus, gravity fidelity depends on the fidelities of the gravitation model and the world model and on the interaction of these two models. A surface-interacting simulation cannot treat gravitation separately from the world model. This paper examines the actual performance of different pairs of world and gravitation models (or direct gravity models) on the travel of a supersonic aircraft in level flight under various start-ing conditions.

Removal of dissolved and colloidal silica

DOEpatents

Midkiff, William S.

2002-01-01

Small amorphous silica particles are used to provide a relatively large surface area upon which silica will preferentially adsorb, thereby preventing or substantially reducing scaling caused by deposition of silica on evaporative cooling tower components, especially heat exchange surfaces. The silica spheres are contacted by the cooling tower water in a sidestream reactor, then separated using gravity separation, microfiltration, vacuum filtration, or other suitable separation technology. Cooling tower modifications for implementing the invention process have been designed.

Wetting properties of hybrid structure with hydrophilic ridges and hydrophobic channels

NASA Astrophysics Data System (ADS)

Lee, Dong-Ki; Choi, Su Young; Park, Min Soo; Cho, Young Hak

2018-02-01

In the present study, we fabricated a hybrid structure where the upper surface of the ridge is hydrophilic and the inner surface of the channel is hydrophobic. Laser-induced backside wet etching (LIBWE) process was performed to machine the hybrid structure on a Pyrex glass substrate. Wetting properties were evaluated from static contact angles (CAs) measurement in parallel and orthogonal directions. The water droplet on the hybrid structure was in the Cassie-Baxter state and showed anisotropic wetting property along groove lines. Moisture condensation studies under humid condition indicated that water droplets grew and coalesced on the ridge with hydrophilicity. Furthermore, water-oil separation was tested using a microfluidic chip with the developed hybrid structure. In case of hybrid microfluidic chip, the water could not flow into channel but the hexadecane could flow due to the capillary pressure difference.

An effective medium approach to predict the apparent contact angle of drops on super-hydrophobic randomly rough surfaces.

PubMed

Bottiglione, F; Carbone, G

2015-01-14

The apparent contact angle of large 2D drops with randomly rough self-affine profiles is numerically investigated. The numerical approach is based upon the assumption of large separation of length scales, i.e. it is assumed that the roughness length scales are much smaller than the drop size, thus making it possible to treat the problem through a mean-field like approach relying on the large-separation of scales. The apparent contact angle at equilibrium is calculated in all wetting regimes from full wetting (Wenzel state) to partial wetting (Cassie state). It was found that for very large values of the roughness Wenzel parameter (r(W) > -1/ cos θ(Y), where θ(Y) is the Young's contact angle), the interface approaches the perfect non-wetting condition and the apparent contact angle is almost equal to 180°. The results are compared with the case of roughness on one single scale (sinusoidal surface) and it is found that, given the same value of the Wenzel roughness parameter rW, the apparent contact angle is much larger for the case of a randomly rough surface, proving that the multi-scale character of randomly rough surfaces is a key factor to enhance superhydrophobicity. Moreover, it is shown that for millimetre-sized drops, the actual drop pressure at static equilibrium weakly affects the wetting regime, which instead seems to be dominated by the roughness parameter. For this reason a methodology to estimate the apparent contact angle is proposed, which relies only upon the micro-scale properties of the rough surface.

Using dry and wet year hydroclimatic extremes to guide future hydrologic projections

NASA Astrophysics Data System (ADS)

Oni, Stephen; Futter, Martyn; Ledesma, Jose; Teutschbein, Claudia; Buttle, Jim; Laudon, Hjalmar

2016-07-01

There are growing numbers of studies on climate change impacts on forest hydrology, but limited attempts have been made to use current hydroclimatic variabilities to constrain projections of future climatic conditions. Here we used historical wet and dry years as a proxy for expected future extreme conditions in a boreal catchment. We showed that runoff could be underestimated by at least 35 % when dry year parameterizations were used for wet year conditions. Uncertainty analysis showed that behavioural parameter sets from wet and dry years separated mainly on precipitation-related parameters and to a lesser extent on parameters related to landscape processes, while uncertainties inherent in climate models (as opposed to differences in calibration or performance metrics) appeared to drive the overall uncertainty in runoff projections under dry and wet hydroclimatic conditions. Hydrologic model calibration for climate impact studies could be based on years that closely approximate anticipated conditions to better constrain uncertainty in projecting extreme conditions in boreal and temperate regions.

Interpretation of gravity and magnetic data with geological constraints for 3D structure of the Thuringian Basin, Germany

NASA Astrophysics Data System (ADS)

Prutkin, Ilya; Vajda, Peter; Jahr, Thomas; Bleibinhaus, Florian; Novák, Pavel; Tenzer, Robert

2017-01-01

We apply a novel method for the separation of potential field sources and their 3D inversion at the regional study area of Thuringian Basin in central Germany. The gravity and magnetic data are separated into long, medium and short wavelengths and then inverted separately. The main goal is to study uniqueness of the solution and its stability in all numerical steps of the interpretation process and to demonstrate, how geological constraints can diminish the degree of non-uniqueness by the interpretation of the gravity and magnetic anomalies. Our numerical experiments with medium wavelengths reveal that if we explain negative anomalies with the topography of near-surface layers, the obtained solution is not supported by borehole data. These negative anomalies are thus explained by restricted bodies (granitic intrusions) at the depths from 4 down to 10 km. These bodies are located above a density interface with topography at the depth of approximately 10 km. The 3D inversion of magnetic data (at short wavelengths) allows investigating a detailed structure of the upper boundary of the crystalline basement: two uplifts in the depths between 2.0 and 0.7 km are found. By using the residual negative anomalies we further study the salt tectonics, showing that the geometry of a salt pillow with a thickness of approximately 200 m closely agrees with borehole data.

Candidate space processing techniques for biomaterials other than preparative electrophoresis

NASA Technical Reports Server (NTRS)

Brooks, D. E.

1976-01-01

The advantages of performing the partition and countercurrent distribution (CCD) of cells in phase separated aqueous polymer systems under reduced gravity were assessed. Other possible applications considered for the space processing program include the freezing front separation of cells, adsorption of cells at the air-water interface, and the macrophage electrophoretic mobility test for cancer.

The Marshall Space Flight Center KC-135 zero gravity test program for FY 1982

NASA Technical Reports Server (NTRS)

Shurney, R. E. (Editor)

1983-01-01

During FY-82, researchers and experimenters from Marshall Space Flight Center (MSFC) conducted 11 separate investigations during 26.3 hr of testing aboard the KC-135 zero-gravity aircraft, based at Ellington Air force Base, Texas. Although this represented fewer hours than initially projected, all experiment and test objectives were met or exceeded. This Technical Memorandum compiles all results achieved by MSFC users during FY-82, a year considered to be highly productive.

Novel Methodology for the Highly-Efficient Separation of Oil and Water (Briefing Charts)

DTIC Science & Technology

2014-03-16

2DISTRIBUTION A. Approved for public release; distribution unlimited. Non-wetting surfaces Superhydrophilic Hydrophilic Hydrophobic Superhydrophobic ...concentrations many surfaces are both superhydrophobic and superoleophilic (*alkane ≈ 0°). Thus, these porous surfaces form ideal membranes for separating...Fluorodecyl POSS Advancing - Water Receding - Water Advancing - Octane Receding - Octane Superhydrophobic Superoleophilic Superhydrophobic

Recycled fiber quality from a laboratory-scale blade separator/blend

Treesearch

Bei-Hong Liang; Stephen M. Shaler; Laurence Mott; Leslie Groom

1994-01-01

A simple and inexpensive fiber separator/blender was developed to generate useful secondary fibers from hydropulped waste paper. Processing wet hydropulped fiber resulted in a furnish with no change in average fiber length in three out of four types of recycled fibers tested. In all cases, the Canadian Standard freeness increased after processing compared to...

Recycled fiber quality from a laboratory-scale blade separator/blender

Treesearch

Bei-Hong Liang; Stephen M. Shaler; Laurence Mott; Leslie Groom

1994-01-01

A simple and inexpensive fiber separator/blender was developed to generate useful secondary fibers from hydropulped waste paper. Processing wet hydropulped fiber resulted in a furnish with no change in average fiber length in three out of four types of recycled fibers tested. In all cases, the canadian standard freeness increased after processing compared to...

Gravity evidence for a shallow intrusion under Medicine Lake volcano, California.

USGS Publications Warehouse

Finn, C.; Williams, D.L.

1982-01-01

A positive gravity anomaly is associated with Medicine Lake volcano, California. Trials with different Bouguer reduction densities indicate that this positive anomaly cannot be explained by an inappropriate choice of Bouguer reduction density but must be caused by a subvolcanic body. After separating the Medicine Lake gravity high from the regional field, we were able to fit the 27mgal positive residual anomaly with a large, shallow body of high density contrast (+0.41g/cm3) and a thickness of 2.5km. We interpret this body to be an intrusion of dense material emplaced within the several-kilometres-thick older volcanic layer that probably underlies Medicine Lake volcano.-Authors

High Water Tolerance of a Core-Shell-Structured Zeolite for CO2 Adsorptive Separation under Wet Conditions.

PubMed

Miyamoto, Manabu; Ono, Shumpei; Kusukami, Kodai; Oumi, Yasunori; Uemiya, Shigeyuki

2018-06-11

Dehumidification in CO 2 adsorptive separation processes is an important issue, owing to its high energy consumption. However, available adsorbents such as low-silica zeolites show a significant decrease in CO 2 adsorption capacity when water vapor is present. A core-shell-structured MFI-type zeolite with a hydrophilic ZSM-5 coated with a hydrophobic silicalite-1 shell layer was applied in CO 2 adsorptive separation under wet conditions. This hybrid material demonstrated remarkably high water tolerance with stable CO 2 adsorption performance without additional thermal treatment for regeneration, whereas a significant decrease in the CO 2 adsorption amount because of water vapor was observed on the parent ZSM-5. The core-shell structure of zeolites with high pore volumes, such as LTA or CHA, could also be suitable candidates for high CO 2 adsorption capacity and high water tolerance for practical applications. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Capillary Flow Experiment in Node 2

NASA Image and Video Library

2013-06-15

Astronaut Karen Nyberg,Expedition 36 flight engineer,works on the Capillary Flow Experiment (CFE) Vane Gap-1 (VG-1) setup in the Node 2/Harmony. The CFE-2 vessel is used to observe fluid interface and critical wetting behavior in a cylindrical chamber with elliptic cross-section and an adjustable central perforated vane. The primary objective of the Vane Gap experiments is to determine equilibrium interface configurations and critical wetting conditions for interfaces between interior corners separated by a gap.

Data reduction and tying in regional gravity surveys—results from a new gravity base station network and the Bouguer gravity anomaly map for northeastern Mexico

NASA Astrophysics Data System (ADS)

Hurtado-Cardador, Manuel; Urrutia-Fucugauchi, Jaime

2006-12-01

Since 1947 Petroleos Mexicanos (Pemex) has conducted oil exploration projects using potential field methods. Geophysical exploration companies under contracts with Pemex carried out gravity anomaly surveys that were referred to different floating data. Each survey comprises observations of gravity stations along highways, roads and trails at intervals of about 500 m. At present, 265 separate gravimeter surveys that cover 60% of the Mexican territory (mainly in the oil producing regions of Mexico) are available. This gravity database represents the largest, highest spatial resolution information, and consequently has been used in the geophysical data compilations for the Mexico and North America gravity anomaly maps. Regional integration of gravimeter surveys generates gradients and spurious anomalies in the Bouguer anomaly maps at the boundaries of the connected surveys due to the different gravity base stations utilized. The main objective of this study is to refer all gravimeter surveys from Pemex to a single new first-order gravity base station network, in order to eliminate problems of gradients and spurious anomalies. A second objective is to establish a network of permanent gravity base stations (BGP), referred to a single base from the World Gravity System. Four regional loops of BGP covering eight States of Mexico were established to support the tie of local gravity base stations from each of the gravimeter surveys located in the vicinity of these loops. The third objective is to add the gravity constants, measured and calculated, for each of the 265 gravimeter surveys to their corresponding files in the Pemex and Instituto Mexicano del Petroleo database. The gravity base used as the common datum is the station SILAG 9135-49 (Latin American System of Gravity) located in the National Observatory of Tacubaya in Mexico City. We present the results of the installation of a new gravity base network in northeastern Mexico, reference of the 43 gravimeter surveys to the new network, the regional compilation of Bouguer gravity data and a new updated Bouguer gravity anomaly map for northeastern Mexico.

Superhydrophobic meshes that can repel hot water and strong corrosive liquids used for efficient gravity-driven oil/water separation.

PubMed

Li, Jian; Kang, Ruimei; Tang, Xiaohua; She, Houde; Yang, Yaoxia; Zha, Fei

2016-04-14

Oil-polluted water has become a worldwide problem due to increasing industrial oily wastewater as well as frequent oil-spill pollution. Compared with underwater superoleophobic (water-removing) filtration membranes, superhydrophobic/superoleophilic (oil-removing) materials have advantages as they can be used for the filtration of heavy oil or the absorption of floating oil from water/oil mixtures. However, most of the superhydrophobic materials used for oil/water separation lose their superhydrophobicity when exposed to hot (e.g. >50 °C) water and strong corrosive liquids. Herein, we demonstrate superhydrophobic overlapped candle soot (CS) and silica coated meshes that can repel hot water (about 92 °C) and strong corrosive liquids, and were used for the gravity driven separation of oil-water mixtures in hot water and strong acidic, alkaline, and salty environments. To the best of our knowledge, we are unaware of any previously reported studies on the use of superhydrophobic materials for the separation of oil from hot water and corrosive aqueous media. In addition, the as-prepared robust superhydrophobic CS and silica coated meshes can separate a series of oils and organic solvents like kerosene, toluene, petroleum ether, heptane and chloroform from water with a separation efficiency larger than 99.0%. Moreover, the as-prepared coated mesh still maintained a separation efficiency above 98.5% and stable recyclability after 55 cycles of separation. The robust superhydrophobic meshes developed in this work can therefore be practically used as a highly efficient filtration membrane for the separation of oil from harsh water conditions, benefiting the environment and human health.

Enhancement of the recycling of waste Ni-Cd and Ni-MH batteries by mechanical treatment.

PubMed

Huang, Kui; Li, Jia; Xu, Zhenming

2011-06-01

A serious environmental problem was presented by waste batteries resulting from lack of relevant regulations and effective recycling technologies in China. The present work considered the enhancement of waste Ni-Cd and Ni-MH batteries recycling by mechanical treatment. In the process of characterization, two types of waste batteries (Ni-Cd and Ni-MH batteries) were selected and their components were characterized in relation to their elemental chemical compositions. In the process of mechanical separation and recycling, waste Ni-Cd and Ni-MH batteries were processed by a recycling technology without a negative impact on the environment. The technology contained mechanical crushing, size classification, gravity separation, and magnetic separation. The results obtained demonstrated that: (1) Mechanical crushing was an effective process to strip the metallic parts from separators and pastes. High liberation efficiency of the metallic parts from separators and pastes was attained in the crushing process until the fractions reached particle sizes smaller than 2mm. (2) The classified materials mainly consisted of the fractions with the size of particles between 0.5 and 2mm after size classification. (3) The metallic concentrates of the samples were improved from around 75% to 90% by gravity separation. More than 90% of the metallic materials were separated into heavy fractions when the particle sizes were larger than 0.5mm. (4) The size of particles between 0.5 and 2mm and the rotational speed of the separator between 30 and 60 rpm were suitable for magnetic separation during industrial application, with the recycling efficiency exceeding 95%. Copyright © 2011 Elsevier Ltd. All rights reserved.

Scaling and design of landslide and debris-flow experiments

USGS Publications Warehouse

Iverson, Richard M.

2015-01-01

Scaling plays a crucial role in designing experiments aimed at understanding the behavior of landslides, debris flows, and other geomorphic phenomena involving grain-fluid mixtures. Scaling can be addressed by using dimensional analysis or – more rigorously – by normalizing differential equations that describe the evolving dynamics of the system. Both of these approaches show that, relative to full-scale natural events, miniaturized landslides and debris flows exhibit disproportionately large effects of viscous shear resistance and cohesion as well as disproportionately small effects of excess pore-fluid pressure that is generated by debris dilation or contraction. This behavioral divergence grows in proportion to H3, where H is the thickness of a moving mass. Therefore, to maximize geomorphological relevance, experiments with wet landslides and debris flows must be conducted at the largest feasible scales. Another important consideration is that, unlike stream flows, landslides and debris flows accelerate from statically balanced initial states. Thus, no characteristic macroscopic velocity exists to guide experiment scaling and design. On the other hand, macroscopic gravity-driven motion of landslides and debris flows evolves over a characteristic time scale (L/g)1/2, where g is the magnitude of gravitational acceleration and L is the characteristic length of the moving mass. Grain-scale stress generation within the mass occurs on a shorter time scale, H/(gL)1/2, which is inversely proportional to the depth-averaged material shear rate. A separation of these two time scales exists if the criterion H/L < < 1 is satisfied, as is commonly the case. This time scale separation indicates that steady-state experiments can be used to study some details of landslide and debris-flow behavior but cannot be used to study macroscopic landslide or debris-flow dynamics.

Membrane of Functionalized Reduced Graphene Oxide Nanoplates with Angstrom-Level Channels

PubMed Central

Lee, Byeongho; Li, Kunzhou; Yoon, Hong Sik; Yoon, Jeyong; Mok, Yeongbong; Lee, Yan; Lee, Hong H.; Kim, Yong Hyup

2016-01-01

Membranes with atomic level pores or constrictions are valuable for separation and catalysis. We report a graphene-based membrane with an interlayer spacing of 3.7 angstrom (Å). When graphene oxide nanoplates are functionalized and then reduced, the laminated reduced graphene oxide (rGO) nanoplates or functionalized rGO membrane is little affected by an intercalated fluid, and the interlayer spacing of 3.7 Å increases only to 4.4 Å in wetted state, in contrast to the graphene oxide (GO) membrane whose interlayer spacing increases from 9 Å to 13 Å in wetted state. When applied to ion separation, this membrane reduced the permeation rate of small ions such as K+ and Na+ by three orders of magnitude compared to the GO membrane. PMID:27306853

Identification of Baribis fault - West Java using second vertical derivative method of gravity

NASA Astrophysics Data System (ADS)

Sari, Endah Puspita; Subakti, Hendri

2015-04-01

Baribis fault is one of West Java fault zones which is an active fault. In modern era, the existence of fault zone can be observed by gravity anomaly. Baribis fault zone has not yet been measured by gravity directly. Based on this reason, satellite data supported this research. Data used on this research are GPS satellite data downloaded from TOPEX. The purpose of this research is to determine the type and strike of Baribis fault. The scope of this research is Baribis fault zone which lies on 6.50o - 7.50o S and 107.50o - 108.80o E. It consists of 5146 points which one point to another is separated by 1 minute meridian. The method used in this research is the Second Vertical Derivative (SVD) of gravity anomaly. The Second Vertical Derivative of gravity anomaly show as the amplitude of gravity anomaly caused by fault structure which appears as residual anomaly. The zero value of residual gravity anomaly indicates that the contact boundary of fault plane. Second Vertical Derivative method of gravity was applied for identifying Baribis fault. The result of this research shows that Baribis fault has a thrust mechanism. It has a lineament strike varies from 107o to 127o. This result agrees with focal mechanism data of earthquakes occurring on this region based on Global CMT catalogue.

Compact cyclone filter train for radiological and hazardous environments

DOEpatents

Bench, Thomas R.

1998-01-01

A compact cyclone filter train for the removal of hazardous and radiologi particles from a gaseous fluid medium which permits a small cyclone separator to be used in a very small space envelope due to the arrangement of the filter housing adjacent to the separator with the cyclone separator and the filters mounted on a plate. The entire unit will have a hoist connection at the center of gravity so that the entire unit including the separator, the filters, and the base can be lifted and repositioned as desired.

Separation Of Liquid And Gas In Zero Gravity

NASA Technical Reports Server (NTRS)

Howard, Frank S.; Fraser, Wilson S.

1991-01-01

Pair of reports describe scheme for separating liquid from gas so liquid could be pumped. Designed to operate in absence of gravitation. Jet of liquid, gas, or liquid/gas mixture fed circumferentially into cylindrical tank filled with liquid/gas mixture. Jet starts liquid swirling. Swirling motion centrifugally separates liquid from gas. Liquid then pumped from tank at point approximately diametrically opposite point of injection of jet. Vortex phase separator replaces such devices as bladders and screens. Requires no components inside tank. Pumps for gas and liquid outside tank and easily accessible for maintenance and repairs.

Preparation and stability of milk somatic cell reference materials.

PubMed

Di Marzo, Larissa; Wojciechowski, Karen L; Barbano, David M

2016-09-01

Our objectives were to develop a method to produce milk somatic cell count (SCC) reference materials for calibration of electronic somatic cell count (ESCC) using gravity separation and to determine the effect of refrigerated storage (4°C) and freeze-thaw stability of the skim and whole milk SCC reference materials. Whole raw milk was high-temperature short-time pasteurized and split into 2 portions. One portion was gravity separated at 4°C for 22 h and the second portion was centrifugally separated to produce skim milk that was also gravity separated with somatic cells rising to the surface. After 22 h, stock solutions (low SCC skim milk, high SCC skim milk, high SCC whole milk) were prepared and preserved (bronopol). Two experiments were conducted, one to compare the shelf-life of skim and whole milk SCC standards at 4°C and one to determine the effect of freezing and thawing on SCC standards. Both experiments were replicated 3 times. Gravity separation was an effective approach to isolate and concentrate somatic cells from bovine milk and redistribute them in a skim or whole milk matrix to create a set of reference materials with a wider and more uniformly distributed range of SCC than current calibration sets. The liquid SCC reference materials stored using the common industry practice at 4°C were stable (i.e., fit for purpose, no large decrease in SCC) for a 2-wk period, whereas frozen and thawed reference materials may have a much longer useful life. A gradual decrease occurred in residual difference in ESCC (SCC × 1,000/mL) versus original assigned reference SCC over duration of refrigerated storage for both skim and whole milk SCC samples, indicating that milk ESCC of the preserved milks was gradually decreasing during 28 d of storage at 4°C by about 15,000 SCC/mL. No difference in the ESCC for skim milk was detected between refrigerated and frozen storage, whereas for whole milk the ESCC for frozen was lower than refrigerated samples. Future work is needed to determine the time and temperature of longer term frozen storage over which the SCC results are stable. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Tethered orbital refueling study

NASA Technical Reports Server (NTRS)

Fester, Dale A.; Rudolph, L. Kevin; Kiefel, Erlinda R.; Abbott, Peter W.; Grossrode, Pat

1986-01-01

One of the major applications of the space station will be to act as a refueling depot for cryogenic-fueled space-based orbital transfer vehicles (OTV), Earth-storable fueled orbit maneuvering vehicles, and refurbishable satellite spacecraft using hydrazine. One alternative for fuel storage at the space station is a tethered orbital refueling facility (TORF), separated from the space station by a sufficient distance to induce a gravity gradient force that settles the stored fuels. The technical feasibility was examined with the primary focus on the refueling of LO2/LH2 orbital transfer vehicles. Also examined was the tethered facility on the space station. It was compared to a zero-gravity facility. A tethered refueling facility should be considered as a viable alternative to a zero-gravity facility if the zero-gravity fluid transfer technology, such as the propellant management device and no vent fill, proves to be difficult to develop with the required performance.

A Simple Theory of Capillary-Gravity Wave Turbulence

NASA Technical Reports Server (NTRS)

Glazman, Roman E.

1995-01-01

Employing a recently proposed 'multi-wave interaction' theory, inertial spectra of capillary gravity waves are derived. This case is characterized by a rather high degree of nonlinearity and a complicated dispersion law. The absence of scale invariance makes this and some other problems of wave turbulence (e.g., nonlinear inertia gravity waves) intractable by small-perturbation techniques, even in the weak-turbulence limit. The analytical solution obtained in the present work for an arbitrary degree of nonlinearity is shown to be in reasonable agreement with experimental data. The theory explains the dependence of the wave spectrum on wind input and describes the accelerated roll-off of the spectral density function in the narrow sub-range separating scale-invariant regimes of purely gravity and capillary waves, while the appropriate (long- and short-wave) limits yield power laws corresponding to the Zakharov-Filonenko and Phillips spectra.

Mechanics of a gaseous film barrier to lubricant wetting of elastohydrodynamically lubricated conjunctions

NASA Technical Reports Server (NTRS)

Prahl, J. M.; Hamrock, B. J.

1985-01-01

Two analytical models, one based on simple hydrodynamic lubrication and the other on soft elastohydrodynamic lubrication, are presented and compared to delineate the dominant physical parameters that govern the mechanics of a gaseous film between a small droplet of lubricant and the outer race of a ball bearing. Both models are based on the balance of gravity forces, air drag forces, and air film lubrication forces and incorporate a drag coefficient C sub D and a lubrication coefficient C sub L to be determined from experiment. The soft elastohydrodynamic lubrication (EHL) model considers the effects of droplet deformation and solid-surface geometry; the simpler hydrodynamic lubrication (HL) model assumes that the droplet remains essentially spherical. The droplet's angular position depended primarily on the ratio of gas inertia to droplet gravity forces and on the gas Reynolds number and weakly on the ratio of droplet gravity forces to surface tension forces (Bond number) and geometric ratios for the soft EHL. An experimental configuration in which an oil droplet is supported by an air film on the rotating outer race of a ball bearing within a pressure-controlled chamber produced measurements of droplet angular position as a function of outer-race velocity droplet size and type, and chamber pressure.

Low-gravity sensing of liquid/vapor interface and transient liquid flow

NASA Astrophysics Data System (ADS)

Jacobson, Saul A.; Korba, James M.; Lynnworth, Lawrence C.; Nguyen, Toan H.; Orton, George F.

1987-03-01

The work reported here deals mainly with tests on internally vaned cylindrical shell acrylic containers capped by hemispherical acrylic or aluminum end domes. Three different ultrasonic sensor techniques and one nucleonic technique presently are evaluated as possible solutions to the low-gravity liquid gauging problem. The ultrasonic techniques are as follows: use of a torsional wave sensor in which transit time is proportional to the integral of wetted distance x liquid density; integration of the flow rate output signal of a fast-response ultrasonic flowmeter; and use of multiplexed externally mounted 'point-sensor' transducers that sense transit times to liquid-gas interfaces. Using two commercial flowmeters and a thickness gauge modified for this particular project, bench tests were conducted at 1 g on liquids such as water, freon, and solvent 140, including both steady flow and pulsating flow with 40, 80, and 120 ms flow pulses. Subsequently, flight tests were conducted in the NASA KC-135 aircraft in which nearly 0-g conditions are obtainable for up to about 5 s in each of a number of repetitive parabolic flight trajectories. In some of these brief low-gravity flight tests freon was replaced with a higher-viscosity fuel to reduce sloshing and thereby obtain settled surfaces more quickly.

High intensity magnetic separation for the clean-up of a site polluted by lead metallurgy.

PubMed

Sierra, C; Martínez, J; Menéndez-Aguado, J M; Afif, E; Gallego, J R

2013-03-15

The industrial history in the district of Linares (Spain) has had a severe impact on soil quality. Here we examined soil contaminated by lead and other heavy metals in "La Cruz" site, a brownfield affected by metallurgical residues. Initially, the presence of contaminants mainly associated with the presence of lead slag fragments mixed with the soil was evaluated. The subsequent analysis showed a quasi-uniform distribution of the pollution irrespective of the grain-size fractions. This study was accompanied by a characterization of the lead slag behavior under the presence of a magnetic field. Two main magnetic components were detected: first a ferromagnetic and/or ferrimagnetic contribution, second a paramagnetic and/or antiferromagnetic one. It was also established that the slag was composed mainly of lead spherules and iron oxides embedded in a silicate matrix. Under these conditions, the capacity of magnetic separation to remove pollutants was examined. Therefore, two high intensity magnetic separators (dry and wet devices, respectively) were used. Dry separation proved to be successful at decontaminating soil in the first stages of a soil washing plant. In contrast, wet separation was found effective as a post-process for the finer fractions. Copyright © 2013 Elsevier B.V. All rights reserved.

Microfluidic Droplet Dehydration for Concentrating Processes in Biomolecules

NASA Astrophysics Data System (ADS)

Anna, Shelley

2014-03-01

Droplets in microfluidic devices have proven useful as picoliter reactors for biochemical processing operations such as polymerase chain reaction, protein crystallization, and the study of enzyme kinetics. Although droplets are typically considered to be self-contained, constant volume reactors, there can be significant transport between the dispersed and continuous phases depending on solubility and other factors. In the present talk, we show that water droplets trapped within a microfluidic device for tens of hours slowly dehydrate, concentrating the contents encapsulated within. We use this slow dehydration along with control of the initial droplet composition to influence gellation, crystallization, and phase separation processes. By examining these concentrating processes in many trapped drops at once we gain insight into the stochastic nature of the events. In one example, we show that dehydration rate impacts the probability of forming a specific crystal habit in a crystallizing amino acid. In another example, we phase separate a common aqueous two-phase system within droplets and use the ensuing two phases to separate DNA from an initial mixture. We further influence wetting conditions between the two aqueous polymer phases and the continuous oil, promoting complete de-wetting and physical separation of the polymer phases. Thus, controlled dehydration of droplets allows for concentration, separation, and purification of important biomolecules on a chip.

Thin Film Mediated Phase Change Phenomena: Crystallization, Evaporation and Wetting

NASA Technical Reports Server (NTRS)

Wettlaufer, John S.

1998-01-01

We focus on two distinct materials science problems that arise in two distinct microgravity environments: In space and within the space of a polymeric network. In the former environment, we consider a near eutectic alloy film in contact with its vapor which, when evaporating on earth, will experience compositionally induced buoyancy driven convection. The latter will significantly influence the morphology of the crystallized end member. In the absence of gravity, the morphology will be dominated by molecular diffusion and Marangoni driven viscous flow, and we study these phenomena theoretically and experimentally. The second microgravity environment exists in liquids, gels, and other soft materials where the small mass of individual molecules makes the effect of gravity negligible next to the relatively strong forces of intermolecular collisions. In such materials, an essential question concerns how to relate the molecular dynamics to the bulk rheological behavior. Here, we observe experimentally the diffusive motion of a single molecule in a single polymer filament, embedded within a polymer network and find anomalous diffusive behavior.

Brownian motion of non-wetting droplets held on a flat solid by gravity

NASA Astrophysics Data System (ADS)

Pomeau, Yves

2013-12-01

At equilibrium a small liquid droplet standing on a solid (dry) horizontal surface it does not wet rests on this surface on a small disc. As predicted and observed if such a droplet is in a low-viscosity vapor the main source of drag for a motion along the surface is the viscous dissipation in the liquid near the disc of contact. This dissipation is minimized by a Huygens-like motion coupling rolling and translation in such a way that the fluid near the disc of contact is almost motionless with respect to the solid. Because of this reduced drag and the associated large mobility the coefficient of Brownian diffusion is much larger than its standard Stokes-Enstein value. This is correct if the weight of the droplet is sufficient to keep it on the solid, instead of being lifted by thermal noise. The coupling between translation along the surface and rotation could be measured by correlated random angular deviations and horizontal displacement in this Brownian motion.

Effects of mechanostimulation on gravitropism and signal persistence in flax roots.

PubMed

John, Susan P; Hasenstein, Karl H

2011-09-01

Gravitropism describes curvature of plants in response to gravity or differential acceleration and clinorotation is commonly used to compensate unilateral effect of gravity. We report on experiments that examine the persistence of the gravity signal and separate mechanostimulation from gravistimulation. Flax roots were reoriented (placed horizontally for 5, 10 or 15 min) and clinorotated at a rate of 0.5 to 5 rpm either vertically (parallel to the gravity vector and root axis) or horizontally (perpendicular to the gravity vector and parallel to the root axis). Image sequences showed that horizontal clinorotation did not affect root growth rate (0.81 ± 0.03 mm h-1) but vertical clinorotation reduced root growth by about 7%. The angular velocity (speed of clinorotation) did not affect growth for either direction. However, maximal curvature for vertical clinorotation decreased with increasing rate of rotation and produced straight roots at 5 rpm. In contrast, horizontal clinorotation increased curvature with increasing angular velocity. The point of maximal curvature was used to determine the longevity (memory) of the gravity signal, which lasted about 120 min. The data indicate that mechanostimulation modifies the magnitude of the graviresponse but does not affect memory persistence.

Gravity and decoherence: the double slit experiment revisited

NASA Astrophysics Data System (ADS)

Samuel, Joseph

2018-02-01

The double slit experiment is iconic and widely used in classrooms to demonstrate the fundamental mystery of quantum physics. The puzzling feature is that the probability of an electron arriving at the detector when both slits are open is not the sum of the probabilities when the slits are open separately. The superposition principle of quantum mechanics tells us to add amplitudes rather than probabilities and this results in interference. This experiment defies our classical intuition that the probabilities of exclusive events add. In understanding the emergence of the classical world from the quantum one, there have been suggestions by Feynman, Diosi and Penrose that gravity is responsible for suppressing interference. This idea has been pursued in many different forms ever since, predominantly within Newtonian approaches to gravity. In this paper, we propose and theoretically analyse two ‘gedanken’ or thought experiments which lend strong support to the idea that gravity is responsible for decoherence. The first makes the point that thermal radiation can suppress interference. The second shows that in an accelerating frame, Unruh radiation does the same. Invoking the Einstein equivalence principle to relate acceleration to gravity, we support the view that gravity is responsible for decoherence.

Convectionless electrophoretic separation of biological preparations

NASA Technical Reports Server (NTRS)

Griffin, R. N.; Mccreight, L. R.

1972-01-01

Free electrophoresis in a zero gravity environment was investigated on the Apollo 14, and 16 flights. The Apollo 16 electrophoresis equipment and experiment are described along with the required ground-based testing.

Modeling of Vapor Bubble Growth Under Nucleate Boiling Conditions in Reduced Gravity

NASA Technical Reports Server (NTRS)

Buyevich, Yu A.; Webbon, Bruce W.

1995-01-01

A dynamic model is developed to describe the evolution of a vapor bubble growing at a nucleation site on a superheated surface under arbitrary gravity. The bubble is separated from the surface by a thin microlayer and grows due to the evaporation from the microlayer interface. The average thickness of the microlayer increases as the bubble expands along the surface if the evaporation rate is lower than some critical value. The corresponding threshold value of the surface temperature has to be associated with the burn-out crisis. Two main reasons make for bubble separation, which are the buoyancy force and a force caused by the vapor momentum that comes to the bubble with vapor molecules. The latter force is somewhat diminished if condensation takes place at the upper bubble surface in subcooled liquids. The action of the said forces is opposed by inertia of the additional mass of liquid as the bubble center rises above the surface and by inertia of liquid being expelled by the growing bubble in radial directions. An extra pressure force arises due to the liquid inflow into the microlayer with a finite velocity. The last force helps in holding the bubble close to the surface during an initial stage of bubble evolution. Two limiting regimes with distinctly different properties can be singled out, depending on which of the forces that favor bubble detachment dominates. Under conditions of moderately reduced gravity, the situation is much the same as in normal gravity, although the bubble detachment volume increases as gravity diminishes. In microgravity, the buoyancy force is negligible. Then the bubble is capable of staying near the surface for a long time, with intensive evaporation from the microlayer. It suggests a drastic change in the physical mechanism of heat removal as gravity falls below a certain sufficiently low level. Inferences of the model and conclusions pertaining to effects caused on heat transfer processes by changes in bubble hydrodynamics induced by gravity are discussed in connection with experimental evidence, both available in current and in as yet unpublished literature.

CRDM with separate SCRAM latch engagement and locking

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

Dodd, Christopher D.; DeSantis, Paul K.; Stambaugh, Kevin J.

A control rod drive mechanism (CRDM) configured to latch onto the lifting rod of a control rod assembly and including separate latch engagement and latch holding mechanisms. A CRDM configured to latch onto the lifting rod of a control rod assembly and including a four-bar linkage closing the latch, wherein the four-bar linkage biases the latch closed under force of gravity.

Liquid surface skimmer apparatus for molten lithium and method

DOEpatents

Robinson, Samuel C.; Pollard, Roy E.; Thompson, William F.; Stark, Marshall W.; Currin, Jr., Robert T.

1995-01-01

This invention relates to an apparatus for separating two fluids having different specific gravities. The invention also relates to a method for using the separating apparatus of the present invention. This invention particularly relates to the skimming of molten lithium metal from the surface of a fused salt electrolyte in the electrolytic production of lithium metal from a mixed fused salt.

Characterization of shredded television scrap and implications for materials recovery.

PubMed

Cui, Jirang; Forssberg, Eric

2007-01-01

Characterization of TV scrap was carried out by using a variety of methods, such as chemical analysis, particle size and shape analysis, liberation degree analysis, thermogravimetric analysis, sink-float test, and IR spectrometry. A comparison of TV scrap, personal computer scrap, and printed circuit board scrap shows that the content of non-ferrous metals and precious metals in TV scrap is much lower than that in personal computer scrap or printed circuit board scrap. It is expected that recycling of TV scrap will not be cost-effective by utilizing conventional manual disassembly. The result of particle shape analysis indicates that the non-ferrous metal particles in TV scrap formed as a variety of shapes; it is much more heterogeneous than that of plastics and printed circuit boards. Furthermore, the separability of TV scrap using density-based techniques was evaluated by the sink-float test. The result demonstrates that a high recovery of copper could be obtained by using an effective gravity separation process. Identification of plastics shows that the major plastic in TV scrap is high impact polystyrene. Gravity separation of plastics may encounter some challenges in separation of plastics from TV scrap because of specific density variations.

Testing Modified Gravity Theories via Wide Binaries and GAIA

NASA Astrophysics Data System (ADS)

Pittordis, Charalambos; Sutherland, Will

2018-06-01

The standard ΛCDM model based on General Relativity (GR) including cold dark matter (CDM) is very successful at fitting cosmological observations, but recent non-detections of candidate dark matter (DM) particles mean that various modified-gravity theories remain of significant interest. The latter generally involve modifications to GR below a critical acceleration scale ˜10-10 m s-2. Wide-binary (WB) star systems with separations ≳ 5 kAU provide an interesting test for modified gravity, due to being in or near the low-acceleration regime and presumably containing negligible DM. Here, we explore the prospects for new observations pending from the GAIA spacecraft to provide tests of GR against MOND or TeVes-like theories in a regime only partially explored to date. In particular, we find that a histogram of (3D) binary relative velocities, relative to equilibrium circular velocity predicted from the (2D) projected separation predicts a rather sharp feature in this distribution for standard gravity, with an 80th (90th) percentile value close to 1.025 (1.14) with rather weak dependence on the eccentricity distribution. However, MOND/TeVeS theories produce a shifted distribution, with a significant increase in these upper percentiles. In MOND-like theories without an external field effect, there are large shifts of order unity. With the external field effect included, the shifts are considerably reduced to ˜0.04 - 0.08, but are still potentially detectable statistically given reasonably large samples and good control of contaminants. In principle, followup of GAIA-selected wide binaries with ground-based radial velocities accurate to ≲ 0.03 { km s^{-1}} should be able to produce an interesting new constraint on modified-gravity theories.

Gravity investigation of the Manson impact structure, Iowa

NASA Technical Reports Server (NTRS)

Plescia, J. B.

1993-01-01

The Manson crater, of probable Cretaceous/Tertiary age, is located in northwestern Iowa (center at 42 deg. 34.44 min N; 94 deg. 33.60 min W). A seismic reflection profile along an east west line across the crater and drill hole data indicate a crater about 35 km in diameter having the classic form for an impact crater, an uplifted central peak composed of uplifted Proterozoic crystalline bedrock, surrounded by a 'moat' filled with impact produced breccia and a ring graben zone composed of tilted fault blocks of the Proterozoic and Paleozoic country rocks. The structure has been significantly eroded. This geologic structure would be expected to produce a significant gravity signature and study of that signature would shed additional light on the details of the crater structure. A gravity study was undertaken to better resolve the crustal structure. The regional Bouguer gravity field is characterized by a southeastward decreasing field. To first order, the Bouguer gravity field can be understood in the context of the geology of the Precambrian basement. The high gravity at the southeast corner is associated with the mid-continent gravity high; the adjacent low to the northwest results from a basin containing low-density clastic sediments shed from the basement high. Modeling of a simple basin and adjacent high predicts much of the observed Bouguer gravity signature. A gravity signature due to structure associated with the Manson impact is not apparent in the Bouguer data. To resolve the gravity signature of the impact, a series of polynomial surfaces were fit to the Bouguer gravity field to isolate the small wavelength residual anomalies. The residual gravity obtained after subtracting a 5th- or 6th-order polynomial seems to remove most of the regional effects and isolate local anomalies. The pattern resolved in the residual gravity is one of a gravity high surrounded by gravity lows and in turn surrounded by isolated gravity highs. The central portion of the crater is characterized by two positive anomalies having amplitudes of about plus 4 mGal separated by a gentle saddle located approximately at the crater center.

Gravity model for the North Atlantic ocean mantle: results, uncertainties and links to regional geodynamics

NASA Astrophysics Data System (ADS)

Barantsrva, O.; Artemieva, I. M.; Thybo, H.

2015-12-01

We present the results of gravity modeling for the North Atlantic region based on interpretation of GOCE gravity satellite data. First, to separate the gravity signal caused by density anomalies within the crust and the upper mantle, we subtract the lower harmonics in the gravity field, which are presumably caused by deep density structure of the Earth (the core and the lower mantle). Next, the gravity effect of the upper mantle is calculated by subtracting the gravity effect of the crustal model. Our "basic model" is constrained by a recent regional seismic model EUNAseis for the crustal structure (Artemieva and Thybo, 2013); for bathymetry and topography we use a global ETOPO1 model by NOAA. We test sensitivity of the results to different input parameters, such as bathymetry, crustal structure, and gravity field. For bathymetry, we additionally use GEBCO data; for crustal correction - a global model CRUST 1.0 (Laske, 2013); for gravity - EGM2008 (Pavlis, 2012). Sensitivity analysis shows that uncertainty in the crustal structure produces the largest deviation from "the basic model". Use of different bathymetry data has little effect on the final results, comparable to the interpolation error. The difference in mantle residual gravity models based on GOCE and EMG2008 gravity data is 5-10 mGal. The results based on two crustal models have a similar pattern, but differ significantly in amplitude (ca. 250 mGal) for the Greenland-Faroe Ridge. The results demonstrate the presence of a strong gravity and density heterogeneity in the upper mantle in the North Atlantic region. A number of mantle residual gravity anomalies are robust features, independent of the choice of model parameters. This include (i) a sharp contrast at the continent-ocean transition, (ii) positive mantle gravity anomalies associated with continental fragments (microcontinents) in the North Atlantic ocean; (iii) negative mantle gravity anomalies which mark regions with anomalous oceanic mantle and the Mid-Atlantic Ridge. To understand better a complex geodynamics mosaic in the region, we compare our results with regional geochemical data (Korenaga and Klemen, 2000), and find that residual mantle gravity anomalies are well correlated with anomalies in epsilon-Nd and iron-depletion.

POPULATION PROPERTIES OF BROWN DWARF ANALOGS TO EXOPLANETS

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

Faherty, Jacqueline K.; Gagne, Jonathan; Weinberger, Alycia

2016-07-01

We present a kinematic analysis of 152 low surface gravity M7-L8 dwarfs by adding 18 new parallaxes (including 10 for comparative field objects), 38 new radial velocities, and 19 new proper motions. We also add low- or moderate-resolution near-infrared spectra for 43 sources confirming their low surface gravity features. Among the full sample, we find 39 objects to be high-likelihood or new bona fide members of nearby moving groups, 92 objects to be ambiguous members and 21 objects that are non-members. Using this age-calibrated sample, we investigate trends in gravity classification, photometric color, absolute magnitude, color–magnitude, luminosity, and effective temperature.more » We find that gravity classification and photometric color clearly separate 5–130 Myr sources from >3 Gyr field objects, but they do not correlate one to one with the narrower 5–130 Myr age range. Sources with the same spectral subtype in the same group have systematically redder colors, but they are distributed between 1 and 4 σ from the field sequences and the most extreme outlier switches between intermediate- and low-gravity sources either confirmed in a group or not. The absolute magnitudes of low-gravity sources from the J band through W 3 show a flux redistribution when compared to equivalently typed field brown dwarfs that is correlated with spectral subtype. Low-gravity, late-type L dwarfs are fainter at J than the field sequence but brighter by W 3. Low-gravity M dwarfs are >1 mag brighter than field dwarfs in all bands from J through W 3. Clouds, which are a far more dominant opacity source for L dwarfs, are the likely cause. On color–magnitude diagrams, the latest-type, low-gravity L dwarfs drive the elbow of the L/T transition up to 1 mag redder and 1 mag fainter than field dwarfs at M{sub J} but are consistent with or brighter than the elbow at M{sub W1} and M{sub W2}. We conclude that low-gravity dwarfs carry an extreme version of the cloud conditions of field objects to lower temperatures, which logically extends into the lowest-mass, directly imaged exoplanets. Furthermore, there is an indication on color-magnitude diagrams (CMDs; such as M{sub J} versus (J – W 2)) of increasingly redder sequences separated by gravity classification, although it is not consistent across all CMD combinations. Examining bolometric luminosities for planets and low-gravity objects, we confirm that (in general) young M dwarfs are overluminous while young L dwarfs are normal compared to the field. Using model extracted radii, this translates into normal to slightly warmer M dwarf temperatures compared to the field sequence and lower temperatures for L dwarfs with no obvious correlation with the assigned moving group.« less

Centrifugal Sieve for Gravity-Level-Independent Size Segregation of Granular Materials

NASA Technical Reports Server (NTRS)

Walton, Otis R.; Dreyer, Christopher; Riedel, Edward

2013-01-01

Conventional size segregation or screening in batch mode, using stacked vibrated screens, is often a time-consuming process. Utilization of centrifugal force instead of gravity as the primary body force can significantly shorten the time to segregate feedstock into a set of different-sized fractions. Likewise, under reduced gravity or microgravity, a centrifugal sieve system would function as well as it does terrestrially. When vibratory and mechanical blade sieving screens designed for terrestrial conditions were tested under lunar gravity conditions, they did not function well. The centrifugal sieving design of this technology overcomes the issues that prevented sieves designed for terrestrial conditions from functioning under reduced gravity. These sieves feature a rotating outer (cylindrical or conical) screen wall, rotating fast enough for the centrifugal forces near the wall to hold granular material against the rotating screen. Conventional centrifugal sieves have a stationary screen and rapidly rotating blades that shear the granular solid near the stationary screen, and effect the sieving process assisted by the airflow inside the unit. The centrifugal sieves of this new design may (or may not) have an inner blade or blades, moving relative to the rotating wall screen. Some continuous flow embodiments would have no inner auger or blades, but achieve axial motion through vibration. In all cases, the shearing action is gentler than conventional centrifugal sieves, which have very high velocity differences between the stationary outer screen and the rapidly rotating blades. The new design does not depend on airflow in the sieving unit, so it will function just as well in vacuum as in air. One advantage of the innovation for batch sieving is that a batch-mode centrifugal sieve may accomplish the same sieving operation in much less time than a conventional stacked set of vibrated screens (which utilize gravity as the primary driving force for size separation). In continuous mode, the centrifugal sieves can provide steady streams of fine and coarse material separated from a mixed feedstock flow stream. The centrifugal sieves can be scaled to any desired size and/or mass flow rate. Thus, they could be made in sizes suitable for small robotic exploratory missions, or for semi-permanent processing of regolith for extraction of volatiles of minerals. An advantage of the continuous-mode system is that it can be made with absolutely no gravity flow components for feeding material into, or for extracting the separated size streams from, the centrifugal sieve. Thus, the system is capable of functioning in a true microgravity environment. Another advantage of the continuous-mode system is that some embodiments of the innovation have no internal blades or vanes, and thus, can be designed to handle a very wide range of feedstock sizes, including occasional very large oversized pieces, without jamming or seizing up.

Fluid Physics and Transport Phenomena in a Simulated Reduced Gravity Environment

NASA Technical Reports Server (NTRS)

Lipa, J.

2004-01-01

We describe a ground-based apparatus that allows the cancellation of gravity on a fluid using magnetic forces. The present system was designed for liquid oxygen studies over the range 0.001 - 5 g s. This fluid is an essential component of any flight mission using substantial amounts of liquid propellant, especially manned missions. The apparatus has been used to reduce the hydrostatic compression near the oxygen critical point and to demonstrate inverted phase separation. It could also be used to study pool boiling and two-phase heat transfer in Martian, Lunar or near-zero gravity, as well as phenomena such as Marangoni flow and convective instabilities. These studies would contribute directly to the reliability and optimization of the Moon and Mars flight programs.

A model of the general ocean circulation determined from a joint solution for the Earth's gravity field

NASA Technical Reports Server (NTRS)

Nerem, R. S.; Tapley, B. D.; Shum, C. K.; Yuan, D. N.

1989-01-01

If the geoid and the satellite position are known accurately, satellite altimetry can be used to determine the geostrophic velocity of the surface ocean currents. The purpose of this investigation is to simultaneously estimate the sea surface topography, zeta, the model for the gravity field, and the satellite orbit. Satellite tracking data from fourteen satellites were used; along with Seasat and Geosat altimeter data as well as surface gravity data for the solution. The estimated model of zeta compares well at long wavelengths with the hydrographic model of zeta. Covariance studies show that the geoid is separable from zeta up to degree 9, at which point geoid error becomes comparable to the signal of zeta.

Coupled Heat Transfer and Fluid Dynamics Modeling of InSb Solidification

NASA Astrophysics Data System (ADS)

Barvinschi, Paul; Barvinschi, Floricica

2011-10-01

A method for the directional solidification of melted InSb in a silica ampoule is presented and solved with COMSOL Multiphysics. The configuration and initial boundary settings of the model resemble those used in a de-wetting vertical Bridgman configuration [1]. A slightly modified version of the method presented by Voller and Prakash [2] is used to account for solidification of the liquid phase, including convection and conduction heat transfer with mushy region phase change. Axial-symmetric numerical simulations of temperature and velocity fields, under normal gravity, are carried out using different thermal conditions.

Martian rampart crater ejecta - Experiments and analysis of melt-water interaction

NASA Technical Reports Server (NTRS)

Wohletz, K. H.; Sheridan, M. F.

1983-01-01

The possible effects of explosive water vaporization on ejecta emplacement after impact into a wet target are described. A general model is formulated from analysis of Viking imagery of Mars and experimental vapor explosions as well as consideration of fluidized particulate transport and lobate volcanic deposits. The discussed model contends that as target water content increases, the effects of vapor expansion due to impact increasingly modify the ballistic flow field during crater excavation. This modification results in transport by gravity-driven surface flowage, and is similar to that of atmospheric drag effects on ejecta modelled by Schultz and Gault (1979).

Weddell-Scotia sea marginal ice zone observations from space, October 1984

NASA Technical Reports Server (NTRS)

Carsey, F. D.; Holt, B.; Martin, S.; Rothrock, D. A.; Mcnutt, L.

1986-01-01

Imagery from the Shuttle imaging radar-B experiment as well as other satellite and meteorological data are examined to learn more about the open sea ice margin of the Weddell-Scotia Seas region. At the ice edge, the ice forms into bandlike aggregates of small ice floes similar to those observed in the Bering Sea. The radar backscatter characteristics of these bands suggest that their upper surface is wet. Further into the pack, the radar imagery shows a transition to large floes. In the open sea, large icebergs and long surface gravity waves are discernable in the radar images.

Geophysical granular and particle-laden flows: review of the field.

PubMed

Hutter, Kolumban

2005-07-15

An introduction is given to the title theme, in general, and the specific topics treated in detail in the articles of this theme issue of the Philosophical Transactions. They fit into the following broader subjects: (i) dense, dry and wet granular flows as avalanche and debris flow events, (ii) air-borne particle-laden turbulent flows in air over a granular base as exemplified in gravity currents, aeolian transport of sand, dust and snow and (iii) transport of a granular mass on a two-dimensional surface in ripple formations of estuaries and rivers and the motion of sea ice.

Nucleate pool boiling: High gravity to reduced gravity; liquid metals to cryogens

NASA Technical Reports Server (NTRS)

Merte, Herman, Jr.

1988-01-01

Requirements for the proper functioning of equipment and personnel in reduced gravity associated with space platforms and future space station modules introduce unique problems in temperature control; power generation; energy dissipation; the storage, transfer, control and conditioning of fluids; and liquid-vapor separation. The phase change of boiling is significant in all of these. Although both pool and flow boiling would be involved, research results to date include only pool boiling because buoyancy effects are maximized for this case. The effective application of forced convection boiling heat transfer in the microgravity of space will require a well grounded and cogent understanding of the mechanisms involved. Experimental results are presented for pool boiling from a single geometrical configuration, a flat surface, covering a wide range of body forces from a/g = 20 to 1 to a/g = 0 to -1 for a cryogenic liquid, and from a/g = 20 to 1 for water and a liquid metal. Similarities in behavior are noted for these three fluids at the higher gravity levels, and may reasonably be expected to continue at reduced gravity levels.

Separating Dark Physics from Physical Darkness: Minimalist Modified Gravity vs. Dark Energy

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

Huterer, Dragan; Linder, Eric V.

The acceleration of the cosmic expansion may be due to a new component of physical energy density or a modification of physics itself. Mapping the expansion of cosmic scales and the growth of large scale structure in tandem can provide insights to distinguish between the two origins. Using Minimal Modified Gravity (MMG) - a single parameter gravitational growth index formalism to parameterize modified gravity theories - we examine the constraints that cosmological data can place on the nature of the new physics. For next generation measurements combining weak lensing, supernovae distances, and the cosmic microwave background we can extend themore » reach of physics to allow for fitting gravity simultaneously with the expansion equation of state, diluting the equation of state estimation by less than 25percent relative to when general relativity is assumed, and determining the growth index to 8percent. For weak lensing we examine the level of understanding needed of quasi- and nonlinear structure formation in modified gravity theories, and the trade off between stronger precision but greater susceptibility to bias as progressively more nonlinear information is used.« less

Separating dark physics from physical darkness: Minimalist modified gravity versus dark energy

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

Huterer, Dragan; Linder, Eric V.

The acceleration of the cosmic expansion may be due to a new component of physical energy density or a modification of physics itself. Mapping the expansion of cosmic scales and the growth of large scale structure in tandem can provide insights to distinguish between the two origins. Using Minimal Modified Gravity (MMG) - a single parameter gravitational growth index formalism to parametrize modified gravity theories - we examine the constraints that cosmological data can place on the nature of the new physics. For next generation measurements combining weak lensing, supernovae distances, and the cosmic microwave background we can extend themore » reach of physics to allow for fitting gravity simultaneously with the expansion equation of state, diluting the equation of state estimation by less than 25% relative to when general relativity is assumed, and determining the growth index to 8%. For weak lensing we examine the level of understanding needed of quasi- and nonlinear structure formation in modified gravity theories, and the trade off between stronger precision but greater susceptibility to bias as progressively more nonlinear information is used.« less

Evaluation of prototype air/fluid separator for Space Station Freedom Health Maintenance Facility

NASA Technical Reports Server (NTRS)

Billica, Roger; Smith, Maureen; Murphy, Linda; Kizzee, Victor D.

1991-01-01

A prototype air/fluid separator suction apparatus proposed as a possible design for use with the Health Maintenance Facility aboard Space Station Freedom (SSF) was evaluated. A KC-135 parabolic flight test was performed for this purpose. The flights followed the standard 40 parabola profile with 20 to 25 seconds of near-zero gravity in each parabola. A protocol was prepared to evaluate the prototype device in several regulator modes (or suction force), using three fluids of varying viscosity, and using either continuous or intermittent suction. It was felt that a matrixed approach would best approximate the range of utilization anticipated for medical suction on SSF. The protocols were performed in one-gravity in a lab setting to familiarize the team with procedures and techniques. Identical steps were performed aboard the KC-135 during parabolic flight.

Study on Sumbawa gold recovery using centrifuge

NASA Astrophysics Data System (ADS)

Ferdana, A. D.; Petrus, H. T. B. M.; Bendiyasa, I. M.; Prijambada, I. D.; Hamada, F.; Sachiko, T.

2018-01-01

The Artisanal Small Gold Mining in Sumbawa has been processing gold with mercury (Hg), which poses a serious threat to the mining and global environment. One method of gold processing that does not use mercury is by gravity method. Before processing the ore first performed an analysis of Mineragraphy and analysis of compound with XRD. Mineragraphy results show that gold is associated with chalcopyrite and covelite and is a single particle (native) on size 58.8 μm, 117 μm up to 294 μm. characterization with XRD shows that the Sumbawa Gold Ore is composed of quartz, pyrite, pyroxene, and sericite compounds. Sentrifugation is one of separation equipment of gravity method to increase concentrate based on difference of specific gravity. The optimum concentration result is influenced by several variables, such as water flow rate and particle size. In this present research, the range of flow rate is 5 lpm and 10 lpm, the particle size - 100 + 200 mesh and -200 +300 mesh. Gold concentration in concentrate is measured by EDX. The result shows that the optimum condition is obtained at a separation with flow rate 5 lpm and a particle size of -100 + 200 mesh.

Field Testing of a Wet FGD Additive for Enhanced Mercury Control - Task 5 Full-Scale Test Results

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

Gary Blythe; MariJon Owens

2007-12-01

This Topical Report summarizes progress on Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project is to demonstrate the use of two flue gas desulfurization (FGD) additives, Evonik Degussa Corporation's TMT-15 and Nalco Company's Nalco 8034, to prevent the re-emission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project intends to demonstrate whether the additive can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine salt that can be separated from the FGD liquor and bulkmore » solid byproducts for separate disposal. The project is conducting pilot- and full-scale tests of the additives in wet FGD absorbers. The tests are intended to determine required additive dosages to prevent Hg{sup 0} re-emissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Powder River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, Luminant Power (was TXU Generation Company LP), Southern Company, IPL (an AES company), Evonik Degussa Corporation and the Nalco Company. Luminant Power has provided the Texas lignite/PRB co-fired test site for pilot FGD tests and cost sharing. Southern Company has provided the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, as well as the pilot- and full-scale jet bubbling reactor (JBR) FGD systems tested. IPL provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Evonik Degussa Corporation is providing the TMT-15 additive, and the Nalco Company is providing the Nalco 8034 additive. Both companies are also supplying technical support to the test program as in-kind cost sharing. The project is being conducted in six tasks. Of the six project tasks, Task 1 involves project planning and Task 6 involves management and reporting. The other four tasks involve field testing on FGD systems, either at pilot or full scale. The four tasks include: Task 2 - Pilot Additive Testing in Texas Lignite Flue Gas; Task 3 - Full-scale FGD Additive Testing in High-sulfur Eastern Bituminous Flue Gas; Task 4 - Pilot Wet Scrubber Additive Tests at Plant Yates; and Task 5 - Full-scale Additive Tests at Plant Yates. The pilot-scale tests and the full-scale test using high-sulfur coal were completed in 2005 and 2006 and have been previously reported. This topical report presents the results from the Task 5 full-scale additive tests, conducted at Southern Company's Plant Yates Unit 1. Both additives were tested there.« less

Field Testing of a Wet FGD Additive for Enhanced Mercury Control - Task 3 Full-scale Test Results

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

Gary Blythe

2007-05-01

This Topical Report summarizes progress on Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project is to demonstrate the use of a flue gas desulfurization (FGD) additive, Degussa Corporation's TMT-15, to prevent the reemission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project intends to demonstrate whether the additive can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine TMT salt that can be separated from the FGD liquor and bulk solid byproducts for separate disposal.more » The project is conducting pilot- and full-scale tests of the TMT-15 additive in wet FGD absorbers. The tests are intended to determine required additive dosages to prevent Hg{sup 0} reemissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Power River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, TXU Generation Company LP, Southern Company, and Degussa Corporation. TXU Generation has provided the Texas lignite/PRB cofired test site for pilot FGD tests, Monticello Steam Electric Station Unit 3. Southern Company is providing the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, as well as the pilot- and full-scale jet bubbling reactor (JBR) FGD systems to be tested. IPL, an AES company, provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Degussa Corporation is providing the TMT-15 additive and technical support to the test program as cost sharing. The project is being conducted in six tasks. Of the six project tasks, Task 1 involves project planning and Task 6 involves management and reporting. The other four tasks involve field testing on FGD systems, either at pilot or full scale. The four tasks include: Task 2 - Pilot Additive Testing in Texas Lignite Flue Gas; Task 3 - Full-scale FGD Additive Testing in High-sulfur Eastern Bituminous Flue Gas; Task 4 - Pilot Wet Scrubber Additive Tests at Plant Yates; and Task 5 - Full-scale Additive Tests at Plant Yates. The pilot-scale tests were completed in 2005 and have been previously reported. This topical report presents the results from the Task 3 full-scale additive tests, conducted at IPL's Petersburg Station Unit 2. The Task 5 full-scale additive tests will be conducted later in calendar year 2007.« less

NASA In-step: Permeable Membrane Experiment

NASA Technical Reports Server (NTRS)

1992-01-01

Viewgraphs on the Permeable Membrane Experiment are presented. An experiment overview is given. The Membrane Phase Separation Experiment, Membrane Diffusion Interference Experiment, and Membrane Wetting Experiment are described. Finally, summary and conclusions are discussed.

Treatment of electrochemical cell components with lithium tetrachloroaluminate (LiAlCl.sub.4) to promote electrolyte wetting

DOEpatents

Eberhart, James G.; Battles, James E.

1980-01-01

Electrochemical cell components such as interelectrode separators, retaining screens and current collectors are contacted with lithium tetrachloroaluminate prior to contact with molten electrolytic salt to improve electrolyte wetting. The LiAlCl.sub.4 can be applied in powdered, molten or solution form but, since this material has a lower melting point than the electrolytic salt used in high-temperature cells, the powdered LiAlCl.sub.4 forms a molten flux prior to contact by the molten electrolyte when both materials are initially provided in solid form. Components of materials such as boron nitride and other materials which are difficult to wet with molten salts are advantageously treated by this process.

Dewetting and spreading transitions for active matter on random pinning substrates.

PubMed

Sándor, Cs; Libál, A; Reichhardt, C; Olson Reichhardt, C J

2017-05-28

We show that sterically interacting self-propelled disks in the presence of random pinning substrates exhibit transitions among a variety of different states. In particular, from a phase separated cluster state, the disks can spread out and homogeneously cover the substrate in what can be viewed as an example of an active matter wetting transition. We map the location of this transition as a function of activity, disk density, and substrate strength, and we also identify other phases including a cluster state, coexistence between a cluster and a labyrinth wetted phase, and a pinned liquid. Convenient measures of these phases include the cluster size, which dips at the wetting-dewetting transition, and the fraction of sixfold coordinated particles, which drops when dewetting occurs.

Positivity-preserving well-balanced discontinuous Galerkin methods for the shallow water flows in open channels

NASA Astrophysics Data System (ADS)

Qian, Shouguo; Li, Gang; Shao, Fengjing; Xing, Yulong

2018-05-01

We construct and study efficient high order discontinuous Galerkin methods for the shallow water flows in open channels with irregular geometry and a non-flat bottom topography in this paper. The proposed methods are well-balanced for the still water steady state solution, and can preserve the non-negativity of wet cross section numerically. The well-balanced property is obtained via a novel source term separation and discretization. A simple positivity-preserving limiter is employed to provide efficient and robust simulations near the wetting and drying fronts. Numerical examples are performed to verify the well-balanced property, the non-negativity of the wet cross section, and good performance for both continuous and discontinuous solutions.

Wetting phenomenon in the liquid-vapor phase coexistence of a partially miscible Lennard-Jones binary mixture

NASA Astrophysics Data System (ADS)

Ramírez-Santiago, Guillermo; Díaz-Herrera, Enrique; Moreno Razo, José A.

2004-03-01

We have carried out extensive equilibrium MD simulations to study wetting phenomena in the liquid-vapor phase coexistence of a partially miscible binary LJ mixture. We find that in the temperature range 0.60 ≤ T^* < 0.80, the system separates forming a liquid A-liquid B interface in coexistence with the vapor phase. At higher temperatures, 0.80 ≤ T^* < 1.25 the liquid phases are wet by the vapor phase. By studying the behavior of the surface tension as a function of temperature we estimate the wetting transition temperature (WTT) to be T^*_w≃ 0.80. The adsorption of molecules at the liquid-liquid interface shows a discontinuity at about T^*≃ 0.79 suggesting that the wetting transition is a first order phase transition. These results are in agreement with some experiments carried out in fluid binary mixtures. In addition, we estimated the consolute temperature to be T^* _cons≃ 1.25. The calculated phase diagram of the mixture suggest the existence of a tricritical point.

Numerical study of the effects of surface topography and chemistry on the wetting transition using the string method.

PubMed

Zhang, Yanan; Ren, Weiqing

2014-12-28

Droplets on a solid surface patterned with microstructures can exhibit the composite Cassie-Baxter (CB) state or the wetted Wenzel state. The stability of the CB state is determined by the energy barrier separating it from the wetted state. In this work, we study the CB to Wenzel transition using the string method [E et al., J. Chem. Phys. 126, 164103 (2007); W. Ren and E. Vanden-Eijnden, J. Chem. Phys. 138, 134105 (2013)]. We compute the transition states and energy barriers for a three-dimensional droplet on patterned surfaces. The liquid-vapor coexistence is modeled using the mean field theory. Numerical results are obtained for surfaces patterned with straight pillars and nails, respectively. It is found that on both type of surfaces, wetting occurs via infiltration of the liquid in a single groove. The reentrant geometry of nails creates large energy barrier for the wetting of the solid surface compared to straight pillars. We also study the effect of surface chemistry, pillar height, and inter-pillar spacing on the energy barrier and compare it with nails.

Individual contributions of climate and vegetation change to soil moisture trends across multiple spatial scales.

PubMed

Feng, Huihui

2016-09-07

Climate and vegetation change are two dominating factors for soil moisture trend. However, their individual contributions remain unknown due to their complex interaction. Here, I separated their contributions through a trajectory-based method across the global, regional and local scales. Our results demonstrated that climate change accounted for 98.78% and 114.64% of the global drying and wetting trend. Vegetation change exhibited a relatively weak influence (contributing 1.22% and -14.64% of the global drying and wetting) because it occurred in a limited area on land. Regionally, the impact of vegetation change cannot be neglected, which contributed -40.21% of the soil moisture change in the wetting zone. Locally, the contributions strongly correlated to the local environmental characteristics. Vegetation negatively affected soil moisture trends in the dry and sparsely vegetated regions and positively in the wet and densely vegetated regions. I conclude that individual contributions of climate and vegetation change vary at the global, regional and local scales. Climate change dominates the soil moisture trends, while vegetation change acts as a regulator to drying or wetting the soil under the changing climate.

Numerical study of the effects of surface topography and chemistry on the wetting transition using the string method

NASA Astrophysics Data System (ADS)

Zhang, Yanan; Ren, Weiqing

2014-12-01

Droplets on a solid surface patterned with microstructures can exhibit the composite Cassie-Baxter (CB) state or the wetted Wenzel state. The stability of the CB state is determined by the energy barrier separating it from the wetted state. In this work, we study the CB to Wenzel transition using the string method [E et al., J. Chem. Phys. 126, 164103 (2007); W. Ren and E. Vanden-Eijnden, J. Chem. Phys. 138, 134105 (2013)]. We compute the transition states and energy barriers for a three-dimensional droplet on patterned surfaces. The liquid-vapor coexistence is modeled using the mean field theory. Numerical results are obtained for surfaces patterned with straight pillars and nails, respectively. It is found that on both type of surfaces, wetting occurs via infiltration of the liquid in a single groove. The reentrant geometry of nails creates large energy barrier for the wetting of the solid surface compared to straight pillars. We also study the effect of surface chemistry, pillar height, and inter-pillar spacing on the energy barrier and compare it with nails.

Landscape-scale water balance monitoring with an iGrav superconducting gravimeter in a field enclosure

NASA Astrophysics Data System (ADS)

Güntner, Andreas; Reich, Marvin; Mikolaj, Michal; Creutzfeldt, Benjamin; Schroeder, Stephan; Wziontek, Hartmut

2017-04-01

In spite of the fundamental role of the landscape water balance for the Earth's water and energy cycles, monitoring the water balance and its components beyond the point scale is notoriously difficult due to the multitude of flow and storage processes and their spatial heterogeneity. Here, we present the first deployment of an iGrav superconducting gravimeter (SG) in a minimized field enclosure on a grassland site for integrative monitoring of water storage changes. Results of the field SG were compared to data provided by a nearby SG located in the controlled environment of an observatory building. For wet-temperate climate conditions, the system proves to provide gravity time series that are similarly precise as those of the observatory SG. At the same time, the field SG is more sensitive to hydrological variations than the observatory SG. We demonstrate that the gravity variations observed by the field setup are almost independent of the depth below the terrain surface where water storage changes occur (contrary to SGs in buildings), and thus the field SG system directly observes the total water storage change, i.e., the water balance, in its surroundings in an integrative way. We provide a framework to single out the water balance components actual evapotranspiration and lateral subsurface discharge from the gravity time series on annual to daily time scales. With about 99% and 85% of the gravity signal originating within a radius of 4000 and 200 meter around the instrument, respectively, this setup paves the road towards gravimetry as a continuous hydrological field monitoring technique at the landscape scale.

Root gravitropism: an experimental tool to investigate basic cellular and molecular processes underlying mechanosensing and signal transmission in plants

NASA Technical Reports Server (NTRS)

Boonsirichai, K.; Guan, C.; Chen, R.; Masson, P. H.

2002-01-01

The ability of plant organs to use gravity as a guide for growth, named gravitropism, has been recognized for over two centuries. This growth response to the environment contributes significantly to the upward growth of shoots and the downward growth of roots commonly observed throughout the plant kingdom. Root gravitropism has received a great deal of attention because there is a physical separation between the primary site for gravity sensing, located in the root cap, and the site of differential growth response, located in the elongation zones (EZs). Hence, this system allows identification and characterization of different phases of gravitropism, including gravity perception, signal transduction, signal transmission, and curvature response. Recent studies support some aspects of an old model for gravity sensing, which postulates that root-cap columellar amyloplasts constitute the susceptors for gravity perception. Such studies have also allowed the identification of several molecules that appear to function as second messengers in gravity signal transduction and of potential signal transducers. Auxin has been implicated as a probable component of the signal that carries the gravitropic information between the gravity-sensing cap and the gravity-responding EZs. This has allowed the identification and characterization of important molecular processes underlying auxin transport and response in plants. New molecular models can be elaborated to explain how the gravity signal transduction pathway might regulate the polarity of auxin transport in roots. Further studies are required to test these models, as well as to study the molecular mechanisms underlying a poorly characterized phase of gravitropism that is independent of an auxin gradient.

Magnetic basement and crustal structure in the Arabia-Eurasia collision zone from a combined gravity and magnetic model

NASA Astrophysics Data System (ADS)

Mousavi, Naeim; Ebbing, Jörg

2017-04-01

In this study, we investigate the magnetic basement and crustal structure in the region of Iran by inverse and forward modeling of aeromagnetic data and gravity data. The main focus is on the definition of the magnetic top basement. The combination of multiple shallow magnetic sources and an assumed shallow Curie isotherm depth beneath the Iranian Plateau creates a complex magnetic architecture over the area. Qualitative analysis, including pseudo gravity, wavelength filtering and upward continuation allowed a first separation of probable deep and shallow features, like the Sanandaj Sirjan zone, Urumieh Dokhtar Magmatic Assemblage, Kopet Dagh structural unit and Central Iran domain. In the second step, we apply inverse modeling to generate an estimate of the top basement geometry. The initial model was established from top basement to (a) constant depth of 25 km and (b) Moho depth. The inversion result was used as starting model for more detailed modelling in 3D to evaluate the effect of susceptibility heterogeneities in the crust. Subsequently, the model was modified with respect to tectonic and geological characterization of the region. Further modification of model in regards more details of susceptibility distribution was led to separating upper crust to different magnetic domains. In addition, we refined the top basement geometry by using terrestrial gravity observation as well. The best fitting model is consistent with the Curie isotherm depth as the base of magnetization. The Curie isotherm was derived from independent geophysical-petrological model.

Mechanotransduction as an Adaptation to Gravity

PubMed Central

Najrana, Tanbir; Sanchez-Esteban, Juan

2016-01-01

Gravity has played a critical role in the development of terrestrial life. A key event in evolution has been the development of mechanisms to sense and transduce gravitational force into biological signals. The objective of this manuscript is to review how living organisms on Earth use mechanotransduction as an adaptation to gravity. Certain cells have evolved specialized structures, such as otoliths in hair cells of the inner ear and statoliths in plants, to respond directly to the force of gravity. By conducting studies in the reduced gravity of spaceflight (microgravity) or simulating microgravity in the laboratory, we have gained insights into how gravity might have changed life on Earth. We review how microgravity affects prokaryotic and eukaryotic cells at the cellular and molecular levels. Genomic studies in yeast have identified changes in genes involved in budding, cell polarity, and cell separation regulated by Ras, PI3K, and TOR signaling pathways. Moreover, transcriptomic analysis of late pregnant rats have revealed that microgravity affects genes that regulate circadian clocks, activate mechanotransduction pathways, and induce changes in immune response, metabolism, and cells proliferation. Importantly, these studies identified genes that modify chromatin structure and methylation, suggesting that long-term adaptation to gravity may be mediated by epigenetic modifications. Given that gravity represents a modification in mechanical stresses encounter by the cells, the tensegrity model of cytoskeletal architecture provides an excellent paradigm to explain how changes in the balance of forces, which are transmitted across transmembrane receptors and cytoskeleton, can influence intracellular signaling pathways and gene expression. PMID:28083527

Mechanotransduction as an Adaptation to Gravity.

PubMed

Najrana, Tanbir; Sanchez-Esteban, Juan

2016-01-01

Gravity has played a critical role in the development of terrestrial life. A key event in evolution has been the development of mechanisms to sense and transduce gravitational force into biological signals. The objective of this manuscript is to review how living organisms on Earth use mechanotransduction as an adaptation to gravity. Certain cells have evolved specialized structures, such as otoliths in hair cells of the inner ear and statoliths in plants, to respond directly to the force of gravity. By conducting studies in the reduced gravity of spaceflight (microgravity) or simulating microgravity in the laboratory, we have gained insights into how gravity might have changed life on Earth. We review how microgravity affects prokaryotic and eukaryotic cells at the cellular and molecular levels. Genomic studies in yeast have identified changes in genes involved in budding, cell polarity, and cell separation regulated by Ras, PI3K, and TOR signaling pathways. Moreover, transcriptomic analysis of late pregnant rats have revealed that microgravity affects genes that regulate circadian clocks, activate mechanotransduction pathways, and induce changes in immune response, metabolism, and cells proliferation. Importantly, these studies identified genes that modify chromatin structure and methylation, suggesting that long-term adaptation to gravity may be mediated by epigenetic modifications. Given that gravity represents a modification in mechanical stresses encounter by the cells, the tensegrity model of cytoskeletal architecture provides an excellent paradigm to explain how changes in the balance of forces, which are transmitted across transmembrane receptors and cytoskeleton, can influence intracellular signaling pathways and gene expression.

Improved low-cost, non-hazardous, all-iron cell for the developing world

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

Tucker, Michael C.; Lambelet, David; Oueslati, Mohamed

A low-cost, non-hazardous personal-power system based on an aqueous all-iron electrochemical cell is demonstrated in this paper. The system is intended to be assembled and operated by developing-world households that lack sufficient access to electricity, thereby enabling LED lighting or mobile phone charging on demand. Lab-scale hardware is used to assess the performance of individual cell components. It is found that coffee filter paper is an effective low-cost separator. Carbon felt is a low-cost electrode material, and its performance and wetting by the electrolyte solution is greatly improved by pre-treatment with sulfuric acid. The carbon felt does not degrade aftermore » a week of daily use. By using these components, performance of the system is significantly improved over the previous baseline, with power density more than doubling to 40 mW cm -2, and iron utilization improving from 78% to 88%. The operating cost is estimated to be less than US$0.03 per mobile phone charge. Based on the lab-scale results, a stand-alone prototype consumer product is designed, fabricated, and tested. It successfully provides 2.5 h of LED illumination while consuming 200 mL of electrolyte solution via gravity feed. Finally, we anticipate these results will enable deployment of this innovative system to energy-impoverished individuals in the developing world.« less

Effect of extrusion rate on morphology of Kaolin/PolyEtherSulfone (PESf) membrane precursor

NASA Astrophysics Data System (ADS)

Misaran, M. S.; Sarbatly, R.; Bono, A.; Rahman, M. M.

2016-11-01

This study aims to investigate the influence of apparent viscosity induced by spinneret geometry and extrusion rate on morphology of Kaolin/PESf hollow fiber membranes. Different extrusion rates at two different rheology properties were introduced on a straight and conical spinneret resulting in various shear rates. The hollow fiber membrane precursors were spun using the wet spinning method to decouple the effect of shear and elongation stress due to gravity stretched drawing. The morphology of the spun hollow fiber was observed under Scanning Electron Microscope (SEM) and the overall porosity were measured using mercury intrusion porosimeter. Shear rate and apparent viscosity at the tip of the spinneret annulus were simulated using a computational fluid dynamics package; solidworks floworks. Simulation data shows that extrusion rate increment increases the shear rate at the spinneret wall which in turn reduce the apparent viscosity; consistent with a non Newtonian shear thinning fluid behavior. Thus, the outer finger-like region grows as the shear rate increases. Also, overall porosity of hollow fiber membrane decreases with extrusion rate increment which is caused by better molecular orientation; resulting in denser hollow fiber membrane. Thin outer finger-like region is achieved at low shear experience of 109.55 s-1 via a straight spinneret. Increasing the extrusion rate; thus shear rate will cause outer finger-like region growth which is not desirable in a separation process.

Improved low-cost, non-hazardous, all-iron cell for the developing world

DOE PAGES

Tucker, Michael C.; Lambelet, David; Oueslati, Mohamed; ...

2016-09-28

A low-cost, non-hazardous personal-power system based on an aqueous all-iron electrochemical cell is demonstrated in this paper. The system is intended to be assembled and operated by developing-world households that lack sufficient access to electricity, thereby enabling LED lighting or mobile phone charging on demand. Lab-scale hardware is used to assess the performance of individual cell components. It is found that coffee filter paper is an effective low-cost separator. Carbon felt is a low-cost electrode material, and its performance and wetting by the electrolyte solution is greatly improved by pre-treatment with sulfuric acid. The carbon felt does not degrade aftermore » a week of daily use. By using these components, performance of the system is significantly improved over the previous baseline, with power density more than doubling to 40 mW cm -2, and iron utilization improving from 78% to 88%. The operating cost is estimated to be less than US$0.03 per mobile phone charge. Based on the lab-scale results, a stand-alone prototype consumer product is designed, fabricated, and tested. It successfully provides 2.5 h of LED illumination while consuming 200 mL of electrolyte solution via gravity feed. Finally, we anticipate these results will enable deployment of this innovative system to energy-impoverished individuals in the developing world.« less

Optimizing and developing a continuous separation system for the wet process separation of aluminum and polyethylene in aseptic composite packaging waste.

PubMed

Yan, Dahai; Peng, Zheng; Liu, Yuqiang; Li, Li; Huang, Qifei; Xie, Minghui; Wang, Qi

2015-01-01

The consumption of milk in China is increasing as living standards rapidly improve, and huge amounts of aseptic composite milk packaging waste are being generated. Aseptic composite packaging is composed of paper, polyethylene, and aluminum. It is difficult to separate the polyethylene and aluminum, so most of the waste is currently sent to landfill or incinerated with other municipal solid waste, meaning that enormous amounts of resources are wasted. A wet process technique for separating the aluminum and polyethylene from the composite materials after the paper had been removed from the original packaging waste was studied. The separation efficiency achieved using different separation reagents was compared, different separation mechanisms were explored, and the impacts of a range of parameters, such as the reagent concentration, temperature, and liquid-solid ratio, on the separation time and aluminum loss ratio were studied. Methanoic acid was found to be the optimal separation reagent, and the suitable conditions were a reagent concentration of 2-4 mol/L, a temperature of 60-80°C, and a liquid-solid ratio of 30 L/kg. These conditions allowed aluminum and polyethylene to be separated in less than 30 min, with an aluminum loss ratio of less than 3%. A mass balance was produced for the aluminum-polyethylene separation system, and control technique was developed to keep the ion concentrations in the reaction system stable. This allowed a continuous industrial-scale process for separating aluminum and polyethylene to be developed, and a demonstration facility with a capacity of 50t/d was built. The demonstration facility gave polyethylene and aluminum recovery rates of more than 98% and more than 72%, respectively. Separating 1t of aluminum-polyethylene composite packaging material gave a profit of 1769 Yuan, meaning that an effective method for recycling aseptic composite packaging waste was achieved. Copyright © 2014 Elsevier Ltd. All rights reserved.

Purification of Giardia muris cysts by velocity sedimentation.

PubMed Central

Sauch, J F

1984-01-01

Giardia muris cysts were separated from fecal contaminants in primary isolates by unit gravity velocity sedimentation. Crude isolates obtained by centrifugation over 1.0 M sucrose were overlaid onto a Percoll density gradient, 1.01 to 1.03 g/ml. G. muris cysts were well separated from faster-sedimenting fecal debris and slower-sedimenting Spironucleus muris and bacteria in 1.5 h. PMID:6486790

Compact cyclone filter train for radiological and hazardous environments

DOEpatents

Bench, T.R.

1998-04-28

A compact cyclone filter train is disclosed for the removal of hazardous and radiological particles from a gaseous fluid medium. This filter train permits a small cyclone separator to be used in a very small space envelope due to the arrangement of the filter housing adjacent to the separator with the cyclone separator and the filters mounted on a plate. The entire unit will have a hoist connection at the center of gravity so that the entire unit including the separator, the filters, and the base can be lifted and repositioned as desired. 3 figs.

Separation of cells from the rat anterior pituitary gland

NASA Technical Reports Server (NTRS)

Hymer, W. C.; Hatfield, J. Michael

1984-01-01

Data concerned with analyzing the cellular organization of the rat anterior pituitary gland are examined. The preparation of the cell suspensions and the methods used to separate pituitary cell types are described. Particular emphasis is given to velocity sedimentation at unit gravity, density gradient centrifugation, affinity methods, fluorescence activated cell sorting, and density gradient and continuous-flow electrophoresis. The difficulties encountered when attempting to compare data from different pituitary cell separation studies are discussed, and results from various experiments are presented. The functional capabilities of the separated cell populations can be tested in various culture systems.

Development of a passive phase separator for space and earth applications

PubMed Central

Wu, Xiongjun; Loraine, Greg; Hsiao, Chao-Tsung; Chahine, Georges L.

2018-01-01

The limited amount of liquids and gases that can be carried to space makes it imperative to recycle and reuse these fluids for extended human operations. During recycling processes gas and liquid phases are often intermixed. In the absence of gravity, separating gases from liquids is challenging due to the absence of buoyancy. This paper describes development of a passive phase separator that is capable of efficiently and reliably separating gas–liquid mixtures of both high and low void fractions in a wide range of flow rates that is applicable to for both space and earth applications. PMID:29628785

Ultrasonically enhanced fractionation of milk fat in a litre-scale prototype vessel.

PubMed

Leong, Thomas; Johansson, Linda; Mawson, Raymond; McArthur, Sally L; Manasseh, Richard; Juliano, Pablo

2016-01-01

The ultrasonic fractionation of milk fat in whole milk to fractions with distinct particle size distributions was demonstrated using a stage-based ultrasound-enhanced gravity separation protocol. Firstly, a single stage ultrasound gravity separation was characterised after various sonication durations (5-20 min) with a mass balance, where defined volume partitions were removed across the height of the separation vessel to determine the fat content and size distribution of fat droplets. Subsequent trials using ultrasound-enhanced gravity separation were carried out in three consecutive stages. Each stage consisted of 5 min sonication, with single and dual transducer configurations at 1 MHz and 2 MHz, followed by aliquot collection for particle size characterisation of the formed layers located at the bottom and top of the vessel. After each sonication stage, gentle removal of the separated fat layer located at the top was performed. Results indicated that ultrasound promoted the formation of a gradient of vertically increasing fat concentration and particle size across the height of the separation vessel, which became more pronounced with extended sonication time. Ultrasound-enhanced fractionation provided fat enriched fractions located at the top of the vessel of up to 13 ± 1% (w/v) with larger globules present in the particle size distributions. In contrast, semi-skim milk fractions located at the bottom of the vessel as low as 1.2 ± 0.01% (w/v) could be produced, containing proportionally smaller sized fat globules. Particle size differentiation was enhanced at higher ultrasound energy input (up to 347 W/L). In particular, dual transducer after three-stage operation at maximum energy input provided highest mean particle size differentiation with up to 0.9 μm reduction in the semi-skim fractions. Higher frequency ultrasound at 2 MHz was more effective in manipulating smaller sized fat globules retained in the later stages of skimming than 1 MHz. While 2 MHz ultrasound removed 59 ± 2% of the fat contained in the initial sample, only 47 ± 2% was removed with 1 MHz after 3 ultrasound-assisted fractionation stages. Copyright © 2015 Elsevier B.V. All rights reserved.

Long-term Global Morphology of Gravity Wave Activity Using UARS Data

NASA Technical Reports Server (NTRS)

Eckermann, Stephen D.; Jackman, C. (Technical Monitor)

2000-01-01

An extensive body of research this quarter is documented. Further methodical analysis of temperature residuals in Cryogenic Limb Array Etalon Spectrometer (CLAES) Version 8 level 3AT data show signatures during December 1992 at middle and high northern latitudes that, when compared to Naval Research Laboratory/Mountain Wave Forecast Model (NRL)/(MWFM) mountain wave hindcasts, reveal evidence of long mountain waves in these data over Eurasia, Greenland, Scandinavia and North America. The explicit detection of gravity waves in limb-scanned Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) temperatures is modeled at length, to derive visibility functions. These insights are used to convert CRISTA gravity wave temperature residuals into data that more closely resemble gravity wave fluctuations detected in data from other satellite instruments, such as Microwave Limb Sounder (MLS), Limb Infrared Monitor of the Stratosphere (LIMS) and Global Positioning System/Meteorology (GPS)/(MET). Finally, newly issued mesospheric temperatures from inversion of CRISTA 15gin emissions are analyzed using a new method that uses separate Kalman fits to the ascending and descending node data. This allows us to study global gravity wave amplitudes at two local times, 12 hours apart. In the equatorial mesosphere, where a large diurnal tidal temperature signal exists, we see modulations of gravity wave activity that are consistent with gravity wave-tidal interactions produced by tidal temperature variability.

Study Of Phase Separation In Glass

NASA Technical Reports Server (NTRS)

Neilson, George F.; Weinberg, Michael C.; Smith, Gary L.

1989-01-01

Report describes an experimental study of effect of hydroxide content on phase separation in soda/silica glasses. Ordinary and gel glasses melted at 1,565 degree C, and melts stirred periodically. "Wet" glasses produced by passing bubbles of N2 saturated with water through melts; "dry" glasses prepared in similar manner, except N2 dried before passage through melts. Analyses of compositions of glasses performed by atomic-absorption and index-of-refraction measurements. Authors conclude hydroxide speeds up phase separation, regardless of method (gel or ordinary) by which glass prepared. Eventually helps material scientists to find ways to control morphology of phase separation.

Gravity separation of pericardial fat in cardiotomy suction blood: an in vitro model.

PubMed

Kinard, M Rhett; Shackelford, Anthony G; Sistino, Joseph J

2009-06-01

Fat emboli generated during cardiac surgery have been shown to cause neurologic complications in patients postoperatively. Cardiotomy suction has been known to be a large generator of emboli. This study will examine the efficacy of a separation technique in which the cardiotomy suction blood is stored in a cardiotomy reservoir for various time intervals to allow spontaneous separation of fat from blood by density. Soybean oil was added to heparinized porcine blood to simulate the blood of a patient with hypertriglyceridemia (> 150 mg/dL). Roller pump suction was used to transfer the room temperature blood into the cardiotomy reservoir. Blood was removed from the reservoir in 200-mL aliquots at 0, 15, 30 45, and 60 minutes. Samples were taken at each interval and centrifuged to facilitate further separation of liquid fat. Fat content in each sample was determined by a point-of-care triglyceride analyzer. Three trials were conducted for a total of 30 samples. The 0-minute group was considered a baseline and was compared to the other four times. Fat concentration was reduced significantly in the 45- and 60-minute groups compared to the 0-, 15-, and 30-minute groups (p < .05). Gravity separation of cardiotomy suction blood is effective; however, it may require retention of blood for more time than is clinically acceptable during a routing coronary artery bypass graft surgery.

P-wave tomography of Northeast Asia: Constraints on the western Pacific plate subduction and mantle dynamics

NASA Astrophysics Data System (ADS)

Ma, Jincheng; Tian, You; Liu, Cai; Zhao, Dapeng; Feng, Xuan; Zhu, Hongxiang

2018-01-01

A high-resolution model of 3-D P-wave velocity structure beneath Northeast Asia and adjacent regions is determined by using 244,180 arrival times of 14,163 local and regional earthquakes and 319,857 relative travel-time residuals of 9988 teleseismic events recorded at ∼2100 seismic stations in the study region. Our tomographic results reveal the subducting Pacific slab clearly as a prominent high-velocity anomaly from the Japan Trench to the North-South Gravity lineament (NSGL) in East China. The NSGL is roughly coincident with the western edge of the stagnant Pacific slab in the mantle transition zone (MTZ). The subducting Pacific slab has partly sunk into the lower mantle beneath Northeast China, but under the Sino-Korean Craton the slab lies horizontally in the MTZ. The NSGL, as an important tectonic line in Mainland China, is marked by sharp differences in the surface topography, gravity anomaly, crustal and lithospheric thickness and mantle seismic velocity from the east to the west. These features of the NSGL and large-scale hot and wet upwelling in the big mantle wedge (BMW) in the east of the NSGL are all related to the subduction processes of the Western Pacific plate. The Changbai intraplate volcanic group is underlain by a striking low-velocity anomaly from the upper MTZ and the BMW up to the surface, and deep earthquakes (410-650 km depths) occur actively in the subducting Pacific slab to the east of the Changbai volcano. We propose that the Changbai volcanic group is caused by upwelling of hot and wet asthenospheric materials and active convection in the BMW. The formation of other volcanic groups in the east of the NSGL is also associated with the subduction-driven corner flow in the BMW.

Solid surface wetting and the deployment of drops in microgravity

NASA Technical Reports Server (NTRS)

Trinh, E. H.; Depew, J.

1994-01-01

The complete or partial deployment of liquid samples in low gravity is primarily influenced by the interfacial properties of the specific liquid and solid materials used because the overwhelming bias of the Earth gravitational acceleration is removed. This study addresses the engineering aspects of injecting and deploying drops of prescribed volume into an acoustic positioning chamber in microgravity. The specific problems of interest are the design, testing, and implementation of injector tips to be used in a simultaneously retracting dual-injector system in the Drop Physics Module microgravity experiment facility. Prior to release, the liquid to be deployed must be retained within a restricted area at the very end of the injectors under dynamic stimuli from the continuous injection flow as well as from the stepped motion of the injectors. The final released drop must have a well determined volume and negligible residual linear or angular momentum. The outcome of Earth-based short-duration low gravity experiments had been the selection of two types of injector tips which were flown as back-up parts. They were successfully utilized during the USML-1 Spacelab mission as the primary tips. The combination of a larger contact surface, liquid pinning with a sharp edge, and selective coating of strategic tip surfaces with a non-wetting compound has allowed a significant increase in the success rate of deployment of simple and compound drops of aqueous solutions of glycerol and silicone oil. The diameter of the samples studied in the Drop Physics Module range between 0.3 and 2.7 cm. The tests conducted on-orbit with a manually operated small device have allowed the calibration of the volume deployed for a few drop sizes. The design for improved tips to be used during the next USML flight is based on these results.

Solid Surface Wetting and the Deployment of Drops in Microgravity

NASA Technical Reports Server (NTRS)

Trinh, E. H.; Depew, J.

1994-01-01

The complete or partial deployment of liquid samples in low gravity is primarily influenced by the interfacial properties of the specific liquid and solid materials used because the overwhelming bias of the Earth gravitational acceleration is removed. This study addresses the engineering aspects of injecting and deploying drops of prescribed volume into an acoustic positioning chamber in microgravity. The specific problems of interest are the design, testing, and implementation of injector tips to be used in a simuttaneously retracting dual-injector system used in the Drop Physics Module microgravity experiment facility. Prior to release, the liquid to be deployed must be retained within a restricted area at the very end of the injectors even under dynamic stimuli due to continuous injection flow as well as to the stepped motion of the injectors, and the final released drop must have a well determined volume as well as negligible residual linear or angular momentum from the deployment process. The outcome of Earthbased short-duration low gravity experiments had been the selection of two types of injector tips which were flown as back-up parts and were successfully utilized during the USML-1 Spacelab mission. The combination of a larger contact surface, liquid pinning with a sharp edge, and selective coating of strategic tip surfaces with a non-wetting compound has allowed a significant increase in the success rate of deployment of simple and compound drops of aqueous solutions of glycerol and silicone oil. The diameter of the samples studied in the Drop Physics Module ranged between 0.3 and 2.7 cm. The tests conducted onsrbit with a manually operated small device have allowed the calibration of the volume deployed for a few drop sizes. The design for improved tips to be used during the next USML flight is based on these results.

The Gravity of the Situation. Chapter 1

NASA Technical Reports Server (NTRS)

Paloski, William; Clement, Gilles; Bukley, Angie; Paloski, William

2006-01-01

Prolonged exposure in humans to a microgravity environment can lead to significant loss of bone and muscle mass, cardiovascular and sensory-motor deconditioning, and hormonal changes. These adaptive changes to weightlessness present a formidable obstacle to human exploration of space, particularly for missions requiring travel times of several months or more, such as on a trip to Mars. Countermeasures that address each of these body systems separately show only limited success. One possible remedy for this situation is artificial gravity, because it tackles all these systems across the board.

Development of Uniform Microstructures in Immiscible Alloys by Processing in a Low-Gravity Environment

NASA Technical Reports Server (NTRS)

Grugel, R. N.; Brush, L. N.

1996-01-01

Highly segregated macrostructures tend to develop during processing of hypermonotectic alloys because of the density difference existing between the two liquid phases. The approximately 4.6 seconds of low-gravity provided by Marshall Space Flight Center's 105 meter drop tube was utilized to minimize density-driven separation and promote uniform microstructures in hypermonotectic Ag-Ni and Ag-Mn alloys. For the Ag-Ni alloys a numerical model was developed to track heat flow and solidification of the bi-metal drop configuration. Results, potential applications, and future work are presented.

Apollo-Soyuz pamphlet no. 4: Gravitational field. [experimental design

NASA Technical Reports Server (NTRS)

Page, L. W.; From, T. P.

1977-01-01

Two Apollo Soyuz experiments designed to detect gravity anomalies from spacecraft motion are described. The geodynamics experiment (MA-128) measured large-scale gravity anomalies by detecting small accelerations of Apollo in the 222 km orbit, using Doppler tracking from the ATS-6 satellite. Experiment MA-089 measured 300 km anomalies on the earth's surface by detecting minute changes in the separation between Apollo and the docking module. Topics discussed in relation to these experiments include the Doppler effect, gravimeters, and the discovery of mascons on the moon.

A Fast Estimation Algorithm for Two-Dimensional Gravity Data (GEOFAST),

DTIC Science & Technology

1979-11-15

to a wide class of problems (Refs. 9 and 17). The major inhibitor to the widespread appli- ( cation of optimal gravity data processing is the severe...extends directly to two dimensions. Define the nln 2xn1 n2 diagonal window matrix W as the Kronecker product of two one-dimensional windows W = W1 0 W2 (B...Inversion of Separable Matrices Consider the linear system y = T x (B.3-1) where T is block Toeplitz of dimension nln 2xnIn 2 . Its fre- quency domain

Microgravity methods for characterization of groundwater-storage changes and aquifer properties in the karstic Madison aquifer in the Black Hills of South Dakota, 2009-12

USGS Publications Warehouse

Koth, Karl R.; Long, Andrew J.

2012-01-01

A study of groundwater storage in the karstic Madison aquifer in the Black Hills of South Dakota using microgravity methods was conducted by the U.S. Geological Survey in cooperation with West Dakota Water Development District, South Dakota Department of Environment and Natural Resources, and Lawrence County. Microgravity measurements from 2009 to 2012 were used to investigate groundwater-storage changes and effective porosity in unconfined areas of the Madison aquifer. Time-lapse microgravity surveys that use portable high-sensitivity absolute and relative gravimeters indicated temporal-gravity changes as a result of changing groundwater mass. These extremely precise measurements of gravity required characterization and removal of internal instrumental and external environmental effects on gravity from the raw data. The corrected data allowed groundwater-storage volume to be quantified with an accuracy of about plus or minus 0.5 foot of water per unit area of aquifer. Quantification of groundwater-storage change, coupled with water-level data from observation wells located near the focus areas, also was used to calculate the effective porosity at specific altitudes directly beneath gravity stations. Gravity stations were established on bedrock outcrops in three separate focus areas for this study. The first area, the Spring Canyon focus area, is located to the south of Rapid City with one gravity station on the rim of Spring Canyon near the area where Spring Creek sinks into the Madison aquifer. The second area, the Doty focus area, is located on outcrops of the Madison Limestone and Minnelusa Formation to the northwest of Rapid City, and consists of nine gravity stations. The third area, the Limestone Plateau focus area, consists of a single gravity station in the northwestern Black Hills located on an outcrop of the Madison Limestone. An absolute-gravity station, used to tie relative-gravity survey data together, was established on a relatively impermeable bedrock outcrop to minimize groundwater-storage change at the reference location. Data from the three focus areas allow for interpretation of groundwater-storage characteristics using microgravity measurements. Gravity measurements, together with water-level data from an observation well located 2 miles from the Spring Canyon focus area and measured streamflow in Spring Creek, provided evidence that rapid groundwater-storage change, responding to changes in sinking streamflow over the recharge area of the aquifer, occurred in the Madison aquifer directly beneath the gravity station at Spring Canyon. This phenomenon likely was a result of groundwater movement through caverns, conduits, and fractures, which are common in karst aquifers. Spatially and temporally separated microgravity data for the Doty focus area indicated horizontal and vertical heterogeneity of effective porosity for the Madison aquifer. One such example of this was indicated by water-level measurements at an observation well and gravity measurements at four gravity stations in the southeastern part of the Doty area, which were used to estimate effective porosity values ranging from greater than 0 to 0.18. A decrease in groundwater storage determined by microgravity measurements during the spring recharge period for five upgradient stations in the Doty focus area indicated the possibility of rapid release and downgradient cascading of perched groundwater. Evidence for similar phenomena was documented for Wind Cave and Brooks Cave in the Black Hills. Absolute-gravity measurements at the Limestone Plateau focus area confirmed the relation between water levels in an observation well and changes in groundwater storage. Comparison of these gravity measurements with water levels in a nearby observation well resulted in an effective porosity estimate of 0.02 for the Madison aquifer beneath the gravity station.

EMG analysis of human postural responses during parabolic flight microgravity episodes

NASA Technical Reports Server (NTRS)

Layne, Charles S.; Spooner, Brian S.

1990-01-01

Anticipatory postural activity in the trunk and legs precedes rapid shoulder flexion in unit gravity. The hypothesis that anticipatory activity is a component of a single neural command for arm movement was tested by monitoring the surface electromyographic activity of the biceps femoris, paraspinals, and deltoid muscles of three subjects during the microgravity phase of parabolic flight. If part of a single command, anticipatory postural activity would be expected to remain intact despite the absence of the body's center of gravity in a reduced gravity environment. However, in at least 75 percent of the microgravity trials anticipatory biceps femoris activity was absent, indicating a separation of postural and agonist muscle activity. Such a finding suggests that anticipatory postural biceps femoris activity may be initiated independently of agonist (deltoid) activity.

The response of single human cells to zero gravity

NASA Technical Reports Server (NTRS)

Montgomery, P. O., Jr.; Cook, J. E.; Reynolds, R. C.; Paul, J. S.; Hayflick, L.; Schulz, W. W.; Stock, D.; Kinzey, S.; Rogers, T.; Campbell, D.

1975-01-01

Twenty separate cultures of Wistar-38 human embryonic lung cells were exposed to a zero-gravity environment on Skylab for periods of time ranging from one to 59 days. Duplicate cultures were run concurrently as ground controls. Ten cultures were fixed on board the satellite during the first 12 days of flight. Growth curves, DNA microspectrophotometry, phase microscopy, and ultrastructural studies of the fixed cells revealed no effects of a zero-gravity environment on the ten cultures. Two cultures were photographed with phase time lapse cinematography during the first 27 days of flight. No differences were found in mitotic index, cell cycle, and migration between the flight and control cells. Eight cultures were returned to earth in an incubated state. Karyotyping and chromosome banding tests show no differences between the flight and control cells.

Quantum gravity: yesterday and today

NASA Astrophysics Data System (ADS)

Dewitt, Bryce

2009-02-01

Bryce DeWitt was one of the great pioneers of quantum gravity. This unpublished lecture gives his recent views on the topic, which we believe will be of great interest not only to researchers involved in modern attempts to quantize Einstein’s theory, but also to a much wider audience. It is the first installment of a book “The Pursuit of Quantum Gravity 1946-2004; Memoirs of Bryce DeWitt” that Cecile DeWitt is preparing. We would like to thank her for the permission to publish this lecture separately in General Relativity and Gravitation. Readers who have unpublished material such as letters from Bryce, and would be willing to send copies to Cecile, are hereby invited to do so. She would be very grateful. G.F.R. Ellis, H. Nicolai (Editors-in-chief).

Strange stars in f( R) theories of gravity in the Palatini formalism

NASA Astrophysics Data System (ADS)

Panotopoulos, Grigoris

2017-05-01

In the present work we study strange stars in f( R) theories of gravity in the Palatini formalism. We consider two concrete well-known cases, namely the R+R^2/(6 M^2) model as well as the R-μ ^4/R model for two different values of the mass parameter M or μ . We integrate the modified Tolman-Oppenheimer-Volkoff equations numerically, and we show the mass-radius diagram for each model separately. The standard case corresponding to the General Relativity is also shown in the same figure for comparison. Our numerical results show that the interior solution can be vastly different depending on the model and/or the value of the parameter of each model. In addition, our findings imply that (i) for the cosmologically interesting values of the mass scales M,μ the effect of modified gravity on strange stars is negligible, while (ii) for the values predicting an observable effect, the modified gravity models discussed here would be ruled out by their cosmological effects.

Development of an Atom Interferometer Gravity Gradiometer for Earth Sciences

NASA Technical Reports Server (NTRS)

Rakholia, A.; Sugarbaker, A.; Black, A.; Kasecivh, M.; Saif, B.; Luthcke, S.; Callahan, L.; Seery, B.; Feinberg, L.; Mather, J.;

A contribution of gravity and seismic data in understanding the geometry of the Zouaraa - Ouchtata dune (NW Tunisia): Hydrogeological implications

NASA Astrophysics Data System (ADS)

Djebbi, M.; Gabtni, H.

2018-01-01

As it is located in a very particular and complex domain within the Tellian fold and thrust belt zone in northwestern Tunisia, the Nefza area has always been challenging. Geological, hydrogeological and geophysical studies were conducted in the region. A multidisciplinary study was performed by combining geological and geophysical techniques. Gravity data processing revealed the continuity of the outcropping series of Argoub Er Romane and Jebel Hamra underneath the dune deposits building a high zone separating the dune of Zouaraa and Ouchtata into two asymmetric basins. It forms a threshold zone that controls the geometry of the dune reservoir in the area. The distribution of the gravity anomaly along the dune of Zouaraa proved the heterogeneity of this dune reservoir. Gravity data modeling for this area confirmed these results and showed a preferential tendency of subsidence to the northwest and thus the thickening of Zouaraa dune sequence as compared to that of Ouchtata.

Hormone purification by isoelectric focusing in space

NASA Technical Reports Server (NTRS)

Bier, M.

1988-01-01

The objective of the program was the definition and development of optimal methods for electrophoretic separations in microgravity. The approach is based on a triad consisting of ground based experiments, mathematical modeling and experiments in microgravity. Zone electrophoresis is a rate process, where separation is achieved in uniform buffers on the basis of differences in electrophoretic mobilities. Optimization and modeling of continuous flow electrophoresis mainly concern the hydrodynamics of the flow process, including gravity dependent fluid convection due to density gradients and gravity independent electroosmosis. Optimization of focusing requires a more complex model describing the molecular transport processes involved in electrophoresis of interacting systems. Three different focusing instruments were designed, embodying novel principles of fluid stabilization. Fluid stability was achieved by: (1) flow streamlining by means of membrane elements in combination with rapid fluid recycling; (2) apparatus rotation in combination with said membrane elements; and (3) shear stress induced by rapid recycling through a narrow gap channel.

Forced-flow once-through boilers. [structural design criteria/aerospace environments

NASA Technical Reports Server (NTRS)

Stone, J. R.; Gray, V. H.; Gutierrez, O. A.

1975-01-01

A compilation and review of NASA-sponsored research on boilers for use in spacecraft electrical power generation systems is presented. Emphasis is on the heat-transfer and fluid-flow problems. In addition to space applications, much of the boiler technology is applicable to terrestrial and marine uses such as vehicular power, electrical power generation, vapor generation, and heating and cooling. Related research areas are discussed such as condensation, cavitation, line and boiler dynamics, the SNAP-8 project (Mercury-Rankine cycle), and conventional terrestrial boilers (either supercritical or gravity-assisted liquid-vapor separation types). The research effort was directed at developing the technology for once-through compact boilers with high heat fluxes to generate dry vapor stably, without utilizing gravity for phase separations. A background section that discusses, tutorially, the complex aspects of the boiling process is presented. Discussions of tests on alkali metals are interspersed with those on water and other fluids on a phenomenological basis.

Inertial waste separation system for zero G WMS

NASA Technical Reports Server (NTRS)

1971-01-01

The design, operation, and flight test are presented for an inertial waste separation system. Training personnel to use this system under simulated conditions is also discussed. Conclusions indicate that before the system is usable in zero gravity environments, a mirror for the user's guidance should be installed, the bounce cycle and bag changing system should be redesigned, and flange clips should be added to improve the user's balance.

Discussion of Priorities

NASA Technical Reports Server (NTRS)

2003-01-01

The Microgravity Science Division identifies four priority ratings for microgravity research and technology issues: 1) Critical; 2) Severely Limiting; 3) Enhancements; 4) Communication. Reduced gravity instabilities are critical, while severely limiting issues include phase separation, phase change, and flow through components. Enhancements are listed for passive phase separation and phase change. This viewgraph presentation also classifies microgravity issues as spaceflight, ground-based, or other for the time periods 2003-2008, 2009-2015, and beyond.

Separation of lymphocytes by electrophoresis under terrestrial conditions and at zero gravity, phase 3

NASA Technical Reports Server (NTRS)

Rubin, A. L.; Stenzel, K. H.; Cheigh, J. S.; Seaman, G. V. F.; Novogrodsky, A.

1977-01-01

Electrophoretic mobilities (EPM) of peripheral lymphocytes were studied from normal subjects, chronic hemodialysis patients and kidney transplant recipients. A technique to separate B lymphocytes and null cells from non-T lymphocyte preparation was developed. The experiments were designed to determine which subpopulation of the non-T lymphocytes is primarily affected and shows a decreased EPM in chronic hemodialysis patients and kidney transplant recipients.

Biomimetic Multilayer Nanofibrous Membranes with Elaborated Superwettability for Effective Purification of Emulsified Oily Wastewater.

PubMed

Ge, Jianlong; Jin, Qing; Zong, Dingding; Yu, Jianyong; Ding, Bin

2018-05-09

Creating a porous membrane to effectively separate the emulsified oil-in-water emulsions with energy-saving property is highly desired but remains a challenge. Herein, a multilayer nanofibrous membrane was developed with the inspiration of the natural architectures of earth for gravity-driven water purification. As a result, the obtained biomimetic multilayer nanofibrous membranes exhibited three individual layers with designed functions; they were the inorganic nanofibrous layer to block the serious intrusion of oil to prevent the destructive fouling of the polymeric matrix; the submicron porous layer with designed honeycomb-like cavities to catch the smaller oil droplets and ensures a satisfactory water permeability; and the high porous fibrous substrate with larger pore size provided a template support and allows water to pass through quickly. Consequently, with the cooperation of these three functional layers, the resultant composite membrane possessed superior anti-oil-fouling property and robust oil-in-water emulsion separation performance with good separation efficiency and competitive permeation flux solely under the drive of gravity. The permeation flux of the membrane for the emulsion was up to 5163 L m -2 h -1 with a separation efficiency of 99.5%. We anticipate that our strategy could provide a facile route for developing a new generation of specific membranes for oily wastewater remediation.

46 CFR 153.1600 - Equipment required for conducting the stripping quantity test.

Code of Federal Regulations, 2012 CFR

2012-10-01

...) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS... container: (1) A wet vacuum. (2) A positive displacement pump. (3) An eductor with an air/water separator in...

46 CFR 153.1600 - Equipment required for conducting the stripping quantity test.

Code of Federal Regulations, 2014 CFR

2014-10-01

...) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS... container: (1) A wet vacuum. (2) A positive displacement pump. (3) An eductor with an air/water separator in...

46 CFR 153.1600 - Equipment required for conducting the stripping quantity test.

Code of Federal Regulations, 2013 CFR

2013-10-01

...) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS... container: (1) A wet vacuum. (2) A positive displacement pump. (3) An eductor with an air/water separator in...

46 CFR 153.1600 - Equipment required for conducting the stripping quantity test.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS... container: (1) A wet vacuum. (2) A positive displacement pump. (3) An eductor with an air/water separator in...

Comparison of digestion methods for total elemental analysis of peat and separation of its organic and inorganic components

USGS Publications Warehouse

Papp, C.S.E.; Harms, T.F.

1985-01-01

In order to find the most efficient digestion method for the total elemental recovery in peat, ten samples were subjected to different techniques and analysed for Ca, Mg, Fe, AI, Na, K, Mn, P, Zn, Cu, Li, Cd, Co, Ni, Pb and Si using atomic-absorption spectrophotometry. The most satisfactory procedures were dry ashing followed by hydrofluoric acid treatment and wet digestion using a mixture of hot nitric, perchloric and hydrofluoric acids. The wet digestion offers the advantage of a single decomposition method for the determination of Ca, Mg, Fe, AI, K, Na, Mn, Cu, Li, Zn and P. An alkaline fusion technique was required for the determination of Si. Hydrogen peroxide was used to separate the peat into its organic and inorganic components, leading to the total recovery of the elements for both fractions.

Spatial patterns and temporal trends in mercury concentrations, precipitation depths, and mercury wet deposition in the North American Great Lakes region, 2002-2008

USGS Publications Warehouse

Risch, Martin R.; Gay, David A.; Fowler, Kathleen K.; Keeler, Gerard J.; Backus, Sean M.; Blanchard, Pierrette; Barres, James A.; Dvonch, J. Timothy

2012-01-01

Annual and weekly mercury (Hg) concentrations, precipitation depths, and Hg wet deposition in the Great Lakes region were analyzed by using data from 5 monitoring networks in the USA and Canada for a 2002-2008 study period. High-resolution maps of calculated annual data, 7-year mean data, and net interannual change for the study period were prepared to assess spatial patterns. Areas with 7-year mean annual Hg concentrations higher than the 12 ng per liter water-quality criterion were mapped in 4 states. Temporal trends in measured weekly data were determined statistically. Monitoring sites with significant 7-year trends in weekly Hg wet deposition were spatially separated and were not sites with trends in weekly Hg concentration. During 2002-2008, Hg wet deposition was found to be unchanged in the Great Lakes region and its subregions. Any small decreases in Hg concentration apparently were offset by increases in precipitation.

Biodiesel production from wet municipal sludge: evaluation of in situ transesterification using xylene as a cosolvent.

PubMed

Choi, O K; Song, J S; Cha, D K; Lee, J W

2014-08-01

This study proposes a method to produce biodiesel from wet wastewater sludge. Xylene was used as an alternative cosolvent to hexane for transesterification in order to enhance the biodiesel yield from wet wastewater sludge. The water present in the sludge could be separated during transesterification by employing xylene, which has a higher boiling point than water. Xylene enhanced the biodiesel yield up to 8.12%, which was 2.5 times higher than hexane. It was comparable to the maximum biodiesel yield of 9.68% obtained from dried sludge. Xylene could reduce either the reaction time or methanol consumption, when compared to hexane for a similar yield. The fatty acid methyl esters (FAMEs) content of the biodiesel increased approximately two fold by changing the cosolvent from hexane to xylene. The transesterification method using xylene as a cosolvent can be applied effectively and economically for biodiesel recovery from wet wastewater sludge without drying process. Copyright © 2014 Elsevier Ltd. All rights reserved.

Direction of unsaturated flow in a homogeneous and isotropic hillslope

USGS Publications Warehouse

Lu, Ning; Kaya, Basak Sener; Godt, Jonathan W.

2011-01-01

The distribution of soil moisture in a homogeneous and isotropic hillslope is a transient, variably saturated physical process controlled by rainfall characteristics, hillslope geometry, and the hydrological properties of the hillslope materials. The major driving mechanisms for moisture movement are gravity and gradients in matric potential. The latter is solely controlled by gradients of moisture content. In a homogeneous and isotropic saturated hillslope, absent a gradient in moisture content and under the driving force of gravity with a constant pressure boundary at the slope surface, flow is always in the lateral downslope direction, under either transient or steady state conditions. However, under variably saturated conditions, both gravity and moisture content gradients drive fluid motion, leading to complex flow patterns. In general, the flow field near the ground surface is variably saturated and transient, and the direction of flow could be laterally downslope, laterally upslope, or vertically downward. Previous work has suggested that prevailing rainfall conditions are sufficient to completely control these flow regimes. This work, however, shows that under time-varying rainfall conditions, vertical, downslope, and upslope lateral flow can concurrently occur at different depths and locations within the hillslope. More importantly, we show that the state of wetting or drying in a hillslope defines the temporal and spatial regimes of flow and when and where laterally downslope and/or laterally upslope flow occurs.

Integrative monitoring of water storage variations at the landscape-scale with an iGrav superconducting gravimeter in a field enclosure

NASA Astrophysics Data System (ADS)

Guntner, A.; Reich, M.; Mikolaj, M.; Creutzfeldt, B.; Schroeder, S.; Wziontek, H.

2017-12-01

In spite of the fundamental role of the landscape water balance for the Earth's water and energy cycles, monitoring the water balance and related storage dynamics beyond the point scale is notoriously difficult due to the multitude of flow and storage processes and their spatial heterogeneity. We present the first outdoor deployment of an iGrav superconducting gravimeter (SG) in a minimized field enclosure on a wet-temperate grassland site for integrative monitoring of water storage changes. It is shown that the system performs similarly precise as SGs that have hitherto been deployed in observatory buildings, but with higher sensitivity to hydrological variations in the surroundings of the instrument. Gravity variations observed by the field setup are almost independent of the depth below the terrain surface where water storage changes occur, and thus the field SG system directly observes the total water storage change in an integrative way. We provide a framework to single out the water balance components actual evapotranspiration and lateral subsurface discharge from the gravity time series on annual to daily time scales. With about 99% and 85% of the gravity signal originating within a radius of 4000 and 200 meter around the instrument, respectively, the setup paves the road towards gravimetry as a continuous hydrological field monitoring technique for water storage dynamics at the landscape scale.

A train of kink folds in the surficial salt of Qom Kuh, Central Iran

NASA Astrophysics Data System (ADS)

Cosgrove, John W.; Talbot, Christopher J.; Aftabi, Pedram

2009-11-01

The many subaerial extrusions of salt current in Iran are smaller and faster versions of steady state extrusions of metamorphic rocks from crustal channels in mountain chains. The extruded salt develops a variety of internal folds as the salt accumulates ductile displacements that can reach metres a year. Weather-induced elastic strains de-stress the outer layers of salt extrusions to a brittle carapace of broken dilated salt. Qom Kuh, situated in Central Iran, is a comparatively small and slow example of a viscous salt fountain and, as a result, its brittle elastic carapace may be thicker than most. This may account for Qom Kuh being the only salt fountain known to have a train of 10 m scale kink folds in its surficial salt. We attribute these folds to lateral shortening and back-shear of a surface-parallel planar mechanical anisotropy in the surficial salt induced by gravitationally driven ductile flow of the underlying salt. When it is dry, the elastic carapace is relatively strong and acts as a stiff corset impeding gravity spreading of the underlying confined salt. However, the carapace weakens and kinks on wetting, allowing the underlying salt to gravity spread. These folds illustrate how the weather can affect gravity spreading of surficial salt masses and how complex the interplay of tectonic and climatic signals can be in "steady state" mountains.

Direction of unsaturated flow in a homogeneous and isotropic hillslope

USGS Publications Warehouse

Lu, N.; Kaya, B.S.; Godt, J.W.

2011-01-01

The distribution of soil moisture in a homogeneous and isotropic hillslope is a transient, variably saturated physical process controlled by rainfall characteristics, hillslope geometry, and the hydrological properties of the hillslope materials. The major driving mechanisms for moisture movement are gravity and gradients in matric potential. The latter is solely controlled by gradients of moisture content. In a homogeneous and isotropic saturated hillslope, absent a gradient in moisture content and under the driving force of gravity with a constant pressure boundary at the slope surface, flow is always in the lateral downslope direction, under either transient or steady state conditions. However, under variably saturated conditions, both gravity and moisture content gradients drive fluid motion, leading to complex flow patterns. In general, the flow field near the ground surface is variably saturated and transient, and the direction of flow could be laterally downslope, laterally upslope, or vertically downward. Previous work has suggested that prevailing rainfall conditions are sufficient to completely control these flow regimes. This work, however, shows that under time-varying rainfall conditions, vertical, downslope, and upslope lateral flow can concurrently occur at different depths and locations within the hillslope. More importantly, we show that the state of wetting or drying in a hillslope defines the temporal and spatial regimes of flow and when and where laterally downslope and/or laterally upslope flow occurs. Copyright 2011 by the American Geophysical Union.

Radiochemical Separation and Quantification of Tritium in Metallic Radwastes Generated from CANDU Type NPP - 13279

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

Ahn, H.J.; Choi, K.C.; Choi, K.S.

2013-07-01

As a destructive quantification method of {sup 3}H in low and intermediate level radwastes, bomb oxidation, sample oxidation, and wet oxidation methods have been introduced. These methods have some merits and demerits in the radiochemical separation of {sup 3}H radionuclides. That is, since the bomb oxidation and sample oxidation methods are techniques using heating at high temperature, the separation methods of the radionuclides are relatively simple. However, since {sup 3}H radionuclide has a property of being diffused deeply into the inside of metals, {sup 3}H which is distributed on the surface of the metals can only be extracted if themore » methods are applied. As an another separation method, the wet oxidation method makes {sup 3}H oxidized with an acidic solution, and extracted completely to an oxidized HTO compound. However, incomplete oxidized {sup 3}H compounds, which are produced by reactions of acidic solutions and metallic radwastes, can be released into the air. Thus, in this study, a wet oxidation method to extract and quantify the {sup 3}H radionuclide from metallic radwastes was established. In particular, a complete extraction method and complete oxidation method of incomplete chemical compounds of {sup 3}H using a Pt catalyst were studied. The radioactivity of {sup 3}H in metallic radwastes is extracted and measured using a wet oxidation method and liquid scintillation counter. Considering the surface dose rate of the sample, the appropriate size of the sample was determined and weighed, and a mixture of oxidants was added to a 200 ml round flask with 3 tubes. The flask was quickly connected to the distilling apparatus. 20 mL of 16 wt% H{sub 2}SO{sub 4} was given into the 200-ml round flask through a dropping funnel while under stirring and refluxing. After dropping, the temperature of the mixture was raised to 96 deg. C and the sample was leached and oxidized by refluxing for 3 hours. At that time, the incomplete oxidized {sup 3}H compounds were completely oxidized using the Pt catalysts and produced a stable HTO compound. After that, about a 20 ml solution was distilled in the separation apparatus, and the distillate was mixed with an ultimagold LLT as a cocktail solution. The solution in the vial was left standing for at least 24 hours. The radioactivity of {sup 3}H was counted directly using a liquid scintillation analyzer (Packard, 2500 TR/AB, Alpha and Beta Liquid Scintillation Analyzer). (authors)« less

Thermophoretic separation of aerosol particles from a sampled gas stream

DOEpatents

Postma, Arlin K.

1986-01-01

A method for separating gaseous samples from a contained atmosphere that includes aerosol particles uses the step of repelling particles from a gas permeable surface or membrane by heating the surface to a temperature greater than that of the surrounding atmosphere. The resulting thermophoretic forces maintain the gas permeable surface clear of aerosol particles. The disclosed apparatus utilizes a downwardly facing heated plate of gas permeable material to combine thermophoretic repulsion and gravity forces to prevent particles of any size from contacting the separating plate surfaces.

UV Grafting Modification of Polyethylene Separator for Liion Battery

NASA Astrophysics Data System (ADS)

Lv, Xiaoyuan; Li, Hua; Zhang, Zhiqiang; Chang, Hiunam; Jiang, Li; Liu, Hezhou

Polyethylene (PE) separator was modified by UV grafting methyl acrylate (MA) and nano-SiO2 composite layer. The structure of functional group and morphology of the separator were analyzed by Fourier transform infrared spectrum (FT-IR) and scanning electron microscope (SEM). The wetting behavior and the heat resistance of the separator were also investigated by contact angle test and thermal shrinkage test respectively. The results show that MA/nano-SiO2 composite layer is successfully grafted onto the PE separator, and the addition of the DI water and butanol can make the nano-SiO2 dispersed better and lead to a microporous structure of the grafting layer. The grafted separator has a better wettability and heat resistance than the pristine one.

Effects of feeder design and changing source of water to a location separate from the wet-dry feeder at 4 or 8 weeks before harvest on growth, feeding behavior, and carcass characteristics of finishing pigs.

PubMed

Bergstrom, J R; Nelssen, J L; Edwards, L N; Tokach, M D; Dritz, S S; Goodband, R D; DeRouchey, J M

2012-12-01

Our objectives were to compare a conventional dry (5-space, 152.4-cm-wide) and a wet-dry (double-sided, each side = 38.1-cm-wide single space) feeder and to determine if changing the source of water to a location separate from a wet-dry feeder would result in improved G:F and carcass characteristics. Water supply to the wet-dry feeder was shut off and the cup waterer was turned on in 8 pens at 8 (d 69) or 4 (d 97) wk prior to harvest. For the remaining 8 wet-dry feeder pens, the feeder provided the sole water source for the entire experiment. A total of 1,296 pigs (PIC, 337 × 1050; initially 19.4 kg BW) were used, with 27 pigs/pen (14 barrows and 13 gilts) and 24 pens/feeder design. From d 0 to 69, pigs fed with the wet-dry feeder had increased (P < 0.05) ADG, ADFI, G:F, and d 69 BW compared with those using the conventional dry feeder. Overall (d 0 to 124), pigs using fed with the water source in the wet-dry feeder the entire time had greater (P < 0.05) ADG, ADFI, final BW, and HCW the other treatments. The overall G:F was not different (P > 0.05) among pigs fed with the different feeder treatments. Pigs fed with the wet-dry feeder where water source was changed at 4 wk before harvest had greater (P < 0.05) ADG than pigs that used a conventional dry feeder. Pigs where the water source was changed at 4 wk had greater (P < 0.05) ADFI than those were the water source was changed 8 wk prior to harvest, and for pigs fed with the conventional dry feeder ADFI was intermediate. Back fat depth of pigs where the water source was changed at 8 wk before harvest was reduced (P < 0.05) compared with all other treatments and LM depth was greater (P < 0.05) than that of pigs using a conventional dry feeder and where the water source was changed at 4 week before harvest. Pigs fed using the wet-dry feeder visited the feeder less frequently (P < 0.05) and spent less total time at the feeder (P < 0.05) than those fed with the conventional dry feeder. The differences in feeding patterns remained even after the access to water was removed from the wet-dry feeder, with no change in the amount of aggressive behavior observed at the feeder. Pigs fed with a wet-dry feeder had an increased growth rate compared with those fed with a conventional dry feeder. Although measures of carcass leanness were improved by changing the location of the water, removing the water from the feeder also eliminated any net improvement in BW from using a wet-dry feeder.

WET FLUORIDE SEPARATION METHOD

DOEpatents

Seaborg, G.T.; Gofman, J.W.; Stoughton, R.W.

1958-11-25

The separation of U/sup 233/ from thorium, protactinium, and fission products present in neutron-irradiated thorium is accomplished by dissolving the irradiated materials in aqueous nitric acid, adding either a soluble fluoride, iodate, phosphate, or oxalate to precipltate the thorium, separating the precipltate from the solution, and then precipitating uranlum and protactinium by alkalizing the solution. The uranium and protactinium precipitate is removcd from the solution and dissolved in nitric acid. The uranyl nitrate may then be extracted from the acid solution by means of ether, and the protactinium recovered from the aqueous phase.

Effect of microstructure and surface features on wetting angle of a Fe-3.2 wt%C.E. cast iron with water

NASA Astrophysics Data System (ADS)

Riahi, Samira; Niroumand, Behzad; Dorri Moghadam, Afsaneh; Rohatgi, Pradeep K.

2018-05-01

In the present study, variation in surface wetting behavior of a hypoeutectic cast iron with its microstructural features and surface roughness was investigated. Samples with an identical composition, i.e. Fe-3.2 wt%C.E., and different microstructures (a gray cast iron with A-type flake graphite and a white cast iron) were fabricated by gravity casting of molten cast iron in a chill mold at different cooling rates. A variation of surface roughness was also developed by polishing, a four-stage electroetching and a four-stage mechanical abrading on the samples. Roughness and water contact angles of all surfaces were then measured. The surface roughness factor and the solid fraction in contact with water by the Wenzel and Cassie-Baxter contact models were also calculated and compared with the corresponding measured contact angles to find out which regime was active. Results indicated that the surface microstructure and the type of constituents present at the surface influenced the cast iron surface wettability and that it was possible to change the surface contact angle by modification of the surface microstructure. The mechanically abraded gray cast iron followed the Wenzel-type regime while the electroetched surfaces of gray cast iron exhibited a transition from Wenzel to Cassie-Baxter type regime. In white cast iron, the results indicated Wenzel type behavior in the electroetched samples while for the mechanically abraded samples, none of these two models could predict the wetting behavior. Furthermore, the wetting angles of both gray and white cast irons were measured after 1, 2, 3 and 4 weeks of air exposure. The results showed that the wetting angles of both samples increased to above 90° after one week of air exposure which was likely due to adsorption of low surface energy hydrocarbons on the surfaces.

Fabrication of Biomimetic Fog-Collecting Superhydrophilic-Superhydrophobic Surface Micropatterns Using Femtosecond Lasers.

PubMed

Kostal, Elisabeth; Stroj, Sandra; Kasemann, Stephan; Matylitsky, Victor; Domke, Matthias

2018-03-06

The exciting functionalities of natural superhydrophilic and superhydrophobic surfaces served as inspiration for a variety of biomimetic designs. In particular, the combination of both extreme wetting states to micropatterns opens up interesting applications, as the example of the fog-collecting Namib Desert beetle shows. In this paper, the beetle's elytra were mimicked by a novel three-step fabrication method to increase the fog-collection efficiency of glasses. In the first step, a double-hierarchical surface structure was generated on Pyrex wafers using femtosecond laser structuring, which amplified the intrinsic wetting property of the surface and made it superhydrophilic (water contact angle < 10°). In the second step, a Teflon-like polymer (CF 2 ) n was deposited by a plasma process that turned the laser-structured surface superhydrophobic (water contact angle > 150°). In the last step, the Teflon-like coating was selectively removed by fs-laser ablation to uncover superhydrophilic spots below the superhydrophobic surface, following the example of the Namib Desert beetle's fog-collecting elytra. To investigate the influence on the fog-collection behavior, (super)hydrophilic, (super)hydrophobic, and low and high contrast wetting patterns were fabricated on glass wafers using selected combinations of these three processing steps and were exposed to fog in an artificial nebulizer setup. This experiment revealed that high-contrast wetting patterns collected the highest amount of fog and enhanced the fog-collection efficiency by nearly 60% compared to pristine Pyrex glass. The comparison of the fog-collection behavior of the six samples showed that the superior fog-collection efficiency of surface patterns with extreme wetting contrast is due to the combination of water attraction and water repellency: the superhydrophilic spots act as drop accumulation areas, whereas the surrounding superhydrophobic areas allow a fast water transportation caused by gravity. The presented method enables a fast and flexible surface functionalization of a broad range of materials including transparent substrates, which offers exciting possibilities for the design of biomedical and microfluidic devices.

Description and cost analysis of a deluge dry/wet cooling system.

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

Wiles, L.E.; Bamberger, J.A.; Braun, D.J.

1978-06-01

The use of combined dry/wet cooling systems for large base-load power plants offers the potential for significant water savings as compared to evaporatively cooled power plants and significant cost savings in comparison to dry cooled power plants. The results of a detailed engineering and cost study of one type of dry/wet cooling system are described. In the ''deluge'' dry/wet cooling method, a finned-tube heat exchanger is designed to operate in the dry mode up to a given ambient temperature. To avoid the degradation of performance for higher ambient temperatures, water (the delugeate) is distributed over a portion of the heatmore » exchanger surface to enhance the cooling process by evaporation. The deluge system used in this study is termed the HOETERV system. The HOETERV deluge system uses a horizontal-tube, vertical-plate-finned heat exchanger. The delugeate is distributed at the top of the heat exchanger and is allowed to fall by gravity in a thin film on the face of the plate fin. Ammonia is used as the indirect heat transfer medium between the turbine exhaust steam and the ambient air. Steam is condensed by boiling ammonia in a condenser/reboiler. The ammonia is condensed in the heat exchanger by inducing airflow over the plate fins. Various design parameters of the cooling system have been studied to evaluate their impact on the optimum cooling system design and the power-plant/utility-system interface. Annual water availability was the most significant design parameter. Others included site meteorology, heat exchanger configuration and air flow, number and size of towers, fan system design, and turbine operation. It was concluded from this study that the HOETERV deluge system of dry/wet cooling, using ammonia as an intermediate heat transfer medium, offers the potential for significant cost savings compared with all-dry cooling, while achieving substantially reduced water consumption as compared to an evaporatively cooled power plant. (LCL)« less

Non-evaporative effects of a wet mid layer on heat transfer through protective clothing.

PubMed

Bröde, Peter; Havenith, George; Wang, Xiaoxin; Candas, Victor; den Hartog, Emiel A; Griefahn, Barbara; Holmér, Ingvar; Kuklane, Kalev; Meinander, Harriet; Nocker, Wolfgang; Richards, Mark

2008-09-01

In order to assess the non-evaporative components of the reduced thermal insulation of wet clothing, experiments were performed with a manikin and with human subjects in which two layers of underwear separated by an impermeable barrier were worn under an impermeable overgarment at 20 degrees C, 80% RH and 0.5 ms(-1) air velocity. By comparing manikin measurements with dry and wetted mid underwear layer, the increase in heat loss caused by a wet layer kept away from the skin was determined, which turned out to be small (5-6 W m(-2)), irrespective of the inner underwear layer being dry or wetted, and was only one third of the evaporative heat loss calculated from weight change, i.e. evaporative cooling efficiency was far below unity. In the experiments with eight males, each subject participated in two sessions with the mid underwear layer either dry or wetted, where they stood still for the first 30 min and then performed treadmill work for 60 min. Reduced heat strain due to lower insulation with the wetted mid layer was observed with decreased microclimate and skin temperatures, lowered sweat loss and cardiac strain. Accordingly, total clothing insulation calculated over the walking period from heat balance equations was reduced by 0.02 m(2) degrees C W(-1) (16%), while for the standing period the same decrease in insulation, representing 9% reduction only showed up after allowing for the lower evaporative cooling efficiency in the calculations. As evaporation to the environment and inside the clothing was restricted, the observed small alterations may be attributed to the wet mid layer's increased conductivity, which, however, appears to be of minor importance compared to the evaporative effects in the assessment of the thermal properties of wet clothing.

Root productivity of deciduous and evergreen species identified using a molecular approach

NASA Astrophysics Data System (ADS)

Ellsworth, P.; Sternberg, L. O.

2012-12-01

The linkage between leaf traits and root structure may explain how plants integrate above and belowground traits into whole plant adaptations to environmental stresses. In dry seasonal forests, the lack of dry season precipitation dries out the relatively nutrient-rich shallow soil, leaving shallow soil water and nutrients inaccessible to uptake until the wet season. In tropical or subtropical seasonal dry forests, deciduousness may allow for the survival of shallow fine roots during the dry season. Losing leaves during the dry season reduces aboveground plant water demand, and a greater proportion of water extracted from deep soil can be used to maintain shallow roots until the wet season. Higher shallow root survival through the dry season than evergreen species means that deciduous species can take advantage of the nutrient pulse associated with the onset of the wet season. To test the above hypothesis, fine roots were collected from soil cores in a seasonally dry forest during the dry season, onset of the wet season, and the wet season and were identified to selected evergreen and deciduous study species. The fine roots of two of the selected species (Lyonia ferruginea and Carya floridana) could be identified from visual characteristics. The other three study species, which were all from the genus Quercus (Q. geminata, Q. myrtifolia, and Q. laevis), were impossible to separate visually. We developed a PCR-based restriction fragment length polymorphism (PCR-RFLP) technique, which provided a quick, simple, low-cost way to identify the species of all fine roots of our study species. We extracted DNA from all roots that were not visually identified, amplified the internal transcribed spacer region (ITS), digested the ITS region with the restriction enzyme TaqαI, and used gel electrophoresis to separate DNA fragments. Using a PCR-RFLP based root identification key that we developed for the species at Archbold Biological Station, all species that could not be identified visually were separated based on each species ' unique banding pattern of restriction fragments. Approximately 2,500 roots were identified using PCR-RFLP and approximately 1,500 more roots were identified visually. Identifying fine roots to species allows for species-level analysis of root productivity in this in situ study.

Visual wetness perception based on image color statistics.

PubMed

Sawayama, Masataka; Adelson, Edward H; Nishida, Shin'ya

2017-05-01

Color vision provides humans and animals with the abilities to discriminate colors based on the wavelength composition of light and to determine the location and identity of objects of interest in cluttered scenes (e.g., ripe fruit among foliage). However, we argue that color vision can inform us about much more than color alone. Since a trichromatic image carries more information about the optical properties of a scene than a monochromatic image does, color can help us recognize complex material qualities. Here we show that human vision uses color statistics of an image for the perception of an ecologically important surface condition (i.e., wetness). Psychophysical experiments showed that overall enhancement of chromatic saturation, combined with a luminance tone change that increases the darkness and glossiness of the image, tended to make dry scenes look wetter. Theoretical analysis along with image analysis of real objects indicated that our image transformation, which we call the wetness enhancing transformation, is consistent with actual optical changes produced by surface wetting. Furthermore, we found that the wetness enhancing transformation operator was more effective for the images with many colors (large hue entropy) than for those with few colors (small hue entropy). The hue entropy may be used to separate surface wetness from other surface states having similar optical properties. While surface wetness and surface color might seem to be independent, there are higher order color statistics that can influence wetness judgments, in accord with the ecological statistics. The present findings indicate that the visual system uses color image statistics in an elegant way to help estimate the complex physical status of a scene.

Geophysical setting of western Utah and eastern Nevada between latitudes 37°45′ and 40°N

USGS Publications Warehouse

Mankinen, Edward A.; McKee, Edwin H.; Tripp, Bryce; Krahulec, Ken; Jordan, Lucy

2009-01-01

Gravity and aeromagnetic data refine the structural setting for the region of western Utah and eastern Nevada between Snake and Hamlin Valleys on the west and Tule Valley on the east. These data are used here as part of a regional analysis. An isostatic gravity map shows large areas underlain by gravity lows, the most prominent of which is a large semi-circular low associated with the Indian Peak caldera complex in the southwestern part of the study area. Another low underlies the Thomas caldera in the northeast, and linear lows elsewhere indicate low-density basin-fill in all major north-trending graben valleys. Gravity highs reflect pre-Cenozoic rocks mostly exposed in the mountain ranges. In the Confusion Range, however, the gravity high extends about 15 km east of the range front to Coyote Knolls, indicating a broad pediment cut on upper Paleozoic rocks and covered by a thin veneer of alluvium. Aeromagnetic highs sharply delineate Oligocene and Miocene volcanic rocks and intracaldera plutons associated with the Indian Peak caldera complex and the Pioche–Marysvale igneous belt. Jurassic to Eocene plutons and volcanic rocks elsewhere in the study area, however, have much more modest magnetic signatures. Some relatively small magnetic highs in the region are associated with outcrops of volcanic rock, and the continuation of those anomalies indicates that the rocks are probably extensive in the subsurface. A gravity inversion method separating the isostatic gravity anomaly into fields representing pre-Cenozoic basement rocks and Cenozoic basin deposits was used to calculate depth to basement and estimate maximum amounts of alluvial and volcanic fill within the valleys. Maximum depths within the Indian Peak caldera complex average about 2.5 km, locally reaching 3 km. North of the caldera complex, thickness of valley fill in most graben valleys ranges from 1.5 to 3 km thick, with Hamlin and Pine Valleys averaging ~3 km. The main basin beneath Tule Valley is relatively shallow (~0.6 km), reaching a maximum depth of ~1 km over a small area northeast of Coyote Knolls. Maximum horizontal gradients were calculated for both long-wavelength gravity and magnetic-potential data, and these were used to constrain major density and magnetic lineaments. These lineaments help delineate deep-seated crustal structures that separate major tectonic domains, potentially localizing Cenozoic tectonic features that may control regional ground-water flow.

Worlds and Anti-worlds Revisted

NASA Astrophysics Data System (ADS)

Wolff, Milo

1996-05-01

In =D2Worlds and Anti-worlds=D3 (1960) Hannes Alfven=20 described a universe symmetric in matter and anti-matter. Today we cannot decide if galaxies and anti-galaxies exist because radiation from both=20 is alike. If matter attracts anti-matter by gravity, intense annihilation= =20 radiation is expected. Since this is not observed, cosmologists concluded the universe is un-symmetrical and tailored the big-bang accordingly. But there is another possibility. The anti-symmetry of particles and anti-particles, suggests repulsive gravity. The rarity of anti-matter and the weakness of gravity makes tesing difficult. But indeed if it is repulsive, galaxies and anti-galaxies would separate and the annihilation radiation would be small as observed. A first guess is 50-50 that anti-gravity exists but there is other evidence: Gamma-ray bursts observed by NASA satellites, solar anti-neutrino flux, and a proposed wave-structure of the electron: =D2Exploring the Physics of the Unknown Universe=D3(1991), ISBN 0-9627787-0-2, suggest that anti-gravity may exist. If true, expect a rush back to the drawing board to revise the expansion and structure of the universe.

Effects of Humidity and Temperature on Orange Dye-Based Organic Field Effect Transistors Fabricated at Different Gravity

NASA Astrophysics Data System (ADS)

Fatima, N.; Ahmed, M. M.; Karimov, Kh. S.

2017-11-01

This study reports the fabrication of organic field effect transistors (OFETs) using 3-[ethyl[4-[(4-nitrophenyl)azo]phenyl]amino]propanenitrile, usually known as Orange-Dye 25 (OD) and its composite with sugar. The study investigated the heat- and humidity-dependent electrical characteristics of the fabricated devices. Fabrication was carried out from the aqueous solution of the materials using different gravity conditions, i.e., at positive (normal) gravity (+1 g) and at negative gravity (-1 g). A thin layer (10-15 μm) of OD or OD:sugar was deposited by drop-casting on pre-fabricated drain and source silver (Ag) electrodes having 30 μm separation and 2 mm length followed by aluminum (Al) thermal evaporation to achieve a Schottky barrier. Devices fabricated using OD at -1 g were more sensitive in capacitance-temperature and impedance-humidity relationships than those fabricated at +1 g. Moreover, OFETs fabricated at -1 g using OD:sugar offered capacitance-temperature sensitivity much higher than the devices fabricated at +1 g. It has been observed that, in the drop-casting method, the properties of OFETs are dependent upon gravity as well as the solution composition employed for channel definition.

A New Global Regression Analysis Method for the Prediction of Wind Tunnel Model Weight Corrections

NASA Technical Reports Server (NTRS)

Ulbrich, Norbert Manfred; Bridge, Thomas M.; Amaya, Max A.

2014-01-01

A new global regression analysis method is discussed that predicts wind tunnel model weight corrections for strain-gage balance loads during a wind tunnel test. The method determines corrections by combining "wind-on" model attitude measurements with least squares estimates of the model weight and center of gravity coordinates that are obtained from "wind-off" data points. The method treats the least squares fit of the model weight separate from the fit of the center of gravity coordinates. Therefore, it performs two fits of "wind- off" data points and uses the least squares estimator of the model weight as an input for the fit of the center of gravity coordinates. Explicit equations for the least squares estimators of the weight and center of gravity coordinates are derived that simplify the implementation of the method in the data system software of a wind tunnel. In addition, recommendations for sets of "wind-off" data points are made that take typical model support system constraints into account. Explicit equations of the confidence intervals on the model weight and center of gravity coordinates and two different error analyses of the model weight prediction are also discussed in the appendices of the paper.

Upgrading the SPP-500-1 moisture separators-steam reheaters used in the Leningrad NPP turbine units

NASA Astrophysics Data System (ADS)

Legkostupova, V. V.; Sudakov, A. V.

2015-03-01

The specific features of existing designs of moisture separators-steam reheaters (MSRs) and experience gained with using them at nuclear power plants are considered. Main factors causing damage to and failures of MSRs are described: nonuniform distribution of wet steam flow among the separation modules, breakthrough of moisture through the separator (and sometimes also through the steam reheater), which may lead to the occurrence of additional thermal stresses and, hence, to thermal-fatigue damage to or stress corrosion cracking of metal. MSR failure results in a less efficient operation of the turbine unit as a whole and have an adverse effect on the reliability of the low-pressure cylinder's last-stage blades. By the time the design service life of the SPP-500-1 MSRs had been exhausted in power units equipped with RBMK-1000 reactors, the number of damages inflicted to both the separation part and to the pipework and heating surface tubes was so large, that a considerable drop of MSR effectiveness and turbine unit efficiency as a whole occurred. The design of the upgraded separation part used in the SPP-500-1 MSR at the Leningrad NPP is described and its effectiveness is shown, which was confirmed by tests. First, efforts taken to achieve more uniform distribution of moisture content over the perimeter and height of steam space downstream of the separation modules and to bring it to values close to the design ones were met with success. Second, no noticeable effect of the individual specific features of separation modules on the moisture content was revealed. Recommendations on elaborating advanced designs of moisture separators-steam reheaters are given: an MSR arrangement in which the separator is placed under or on the side from the steam reheater; axial admission of wet steam for ensuring its uniform distribution among the separation modules; inlet chambers with an extended preliminary separation system and devices for uniformly distributing steam flows in the separator; separated layout of the of the separator and steam reheater; and use of transversely finned tube bundles for organizing cross flow of steam over the tubes.

Integrating gravity and magnetic field data to delineate structurally controlled gold mineralization in the Sefwi Belt of Ghana

NASA Astrophysics Data System (ADS)

Konadu Amoah, Bernard; Dadzie, Isaac; Takyi-Kyeremeh, Kwaku

2018-08-01

Gravity and magnetic surveys were used to delineate potential gold mineralization zones in the Sefwi belt of Ghana. The study area is an intrusive dominated area that hosts pockets of small scale mining operations locally referred to as Galamsey. These Galamsey operations are not guided by a scientific approach to back the trend of gold mineralization which is conventionally mined. The study aimed at mapping lithological units, structural setting and relating Galamsey sites to delineate potential zones of gold mineralization. A Scintrex CG5 gravimeter and GEM’s Overhauser magnetometer were used for gravity and magnetic data acquisition respectively. The magnetic data were corrected and enhancing filters such as reduction to the pole (RTP), analytical signal and first vertical derivative were applied using Oasis montaj 7.1. Gravity data were also reduced to the geoid using the Oasis montaj software to produce a complete Bouguer anomaly map. The regional/residual separation technique produced a residual gravity map. The RTP and analytical signal filters from the magnetic data and residual gravity anomaly map from the gravity data helped in mapping belt type (Dixcove) Birimian granitoids and mafic intrusive unit, interpreted as gabbro. The first vertical derivative filter was useful in mapping NE/SW minor faults and crosscutting dykes largely concentrated in the belt type Birimian granitoids. All the three mapped Galamsey sites fell on a minor fault and are associated with the belt type granitoids which were used in delineating four potential zones of gold mineralization.

Results of pre-drilling potential field measurements at the Bosumtwi crater

NASA Astrophysics Data System (ADS)

Danuor, S. K.; Menyeh, A.

Gravity and magnetic measurements were carried out at the Bosumtwi crater to determine the geophysical signature of the crater. Land gravity data was acquired at 163 locations around the structure and on the shore of the lake. The separation between the gravity stations was 500 m for radial profiles, but 700-1000 m along roads and footpaths that ran parallel to the lake's shore. Additionally, a marine gravity survey was carried out along 14 north-south and 15 east-west profiles on the lake. Magnetic data was also acquired along 14 north-south profiles on the lake. In all marine surveys, the line spacing was 800 m, and navigation was provided by a Garmin 235 Echo Sounder/GPS. The gravity signature of the crater is characterized by a negative Bouguer anomaly with an amplitude of about -18 mgal. Using the seismic results as constraints, the gravity model obtained indicates the central uplift at a depth of 250 m. The negative anomaly is the contribution of the gravity deficiencies due to fractured and brecciated rocks in the rim area and below the crater floor, the impact breccias within the crater, and the sedimentary and water infilling of the lake. Magnetic modeling yielded a model for the causative body, which is located north of the central uplift: the model has a magnetic susceptibility of 0.03 S.I. and extends from a depth of 250 to 610 m. The causative bodies have been interpreted as impactites.

Calculation of metamorphic two-dimensional quantum energy system: Application to wetting layer states in InAs/InGaAs metamorphic quantum dot nanostructures

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

Seravalli, L.; Trevisi, G.; Frigeri, P.

In this work, we calculate the two-dimensional quantum energy system of the In(Ga)As wetting layer that arises in InAs/InGaAs/GaAs metamorphic quantum dot structures. Model calculations were carried on the basis of realistic material parameters taking in consideration their dependence on the strain relaxation of the metamorphic buffer; results of the calculations were validated against available literature data. Model results confirmed previous hypothesis on the extrinsic nature of the disappearance of wetting layer emission in metamorphic structures with high In composition. We also show how, by adjusting InGaAs metamorphic buffer parameters, it could be possible: (i) to spatially separate carriers confinedmore » in quantum dots from wetting layer carriers, (ii) to create an hybrid 0D-2D system, by tuning quantum dot and wetting layer levels. These results are interesting not only for the engineering of quantum dot structures but also for other applications of metamorphic structures, as the two design parameters of the metamorphic InGaAs buffer (thickness and composition) provide additional degrees of freedom to control properties of interest.« less

Capillary Contact Angle in a Completely Wet Groove

NASA Astrophysics Data System (ADS)

Parry, A. O.; Malijevský, A.; Rascón, C.

2014-10-01

We consider the phase equilibria of a fluid confined in a deep capillary groove of width L with identical side walls and a bottom made of a different material. All walls are completely wet by the liquid. Using density functional theory and interfacial models, we show that the meniscus separating liquid and gas phases at two phase capillary coexistence meets the bottom capped end of the groove at a capillary contact angle θcap(L) which depends on the difference between the Hamaker constants. If the bottom wall has a weaker wall-fluid attraction than the side walls, then θcap>0 even though all the isolated walls are themselves completely wet. This alters the capillary condensation transition which is now first order; this would be continuous in a capped capillary made wholly of either type of material. We show that the capillary contact angle θcap(L) vanishes in two limits, corresponding to different capillary wetting transitions. These occur as the width (i) becomes macroscopically large, and (ii) is reduced to a microscopic value determined by the difference in Hamaker constants. This second wetting transition is characterized by large scale fluctuations and essential critical singularities arising from marginal interfacial interactions.

Numerical study of the effects of surface topography and chemistry on the wetting transition using the string method

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

Zhang, Yanan, E-mail: ynzhang@suda.edu.cn; Ren, Weiqing, E-mail: matrw@nus.edu.sg; Institute of High Performance Computing, Singapore 138632

2014-12-28

Droplets on a solid surface patterned with microstructures can exhibit the composite Cassie-Baxter (CB) state or the wetted Wenzel state. The stability of the CB state is determined by the energy barrier separating it from the wetted state. In this work, we study the CB to Wenzel transition using the string method [E et al., J. Chem. Phys. 126, 164103 (2007); W. Ren and E. Vanden-Eijnden, J. Chem. Phys. 138, 134105 (2013)]. We compute the transition states and energy barriers for a three-dimensional droplet on patterned surfaces. The liquid-vapor coexistence is modeled using the mean field theory. Numerical results aremore » obtained for surfaces patterned with straight pillars and nails, respectively. It is found that on both type of surfaces, wetting occurs via infiltration of the liquid in a single groove. The reentrant geometry of nails creates large energy barrier for the wetting of the solid surface compared to straight pillars. We also study the effect of surface chemistry, pillar height, and inter-pillar spacing on the energy barrier and compare it with nails.« less

A Robust, Gravity-Insensitive, High-Temperature Condenser for Water Recovery

NASA Technical Reports Server (NTRS)

Chen, Weibo; Conboy, Thomas; Ewert, Michael

2016-01-01

Regenerative life support systems are vital for NASA's future long-duration human space exploration missions. A Heat Melt Compactor (HMC) system is being developed by NASA to dry and compress trash generated during space missions. The resulting water vapor is recovered and separated from the process gas flow by a gravity-insensitive condenser. Creare is developing a high-temperature condenser for this application. The entire condenser is constructed from metals that have excellent resistance to chemical attack from contaminants and is suitable for high-temperature operation. The metal construction and design configuration also offer greatest flexibility for potential coating and regeneration processes to reduce biofilm growth and thus enhancing the reliability of the condenser. The proposed condenser builds on the gravity-insensitive phase separator technology Creare developed for aircraft and spacecraft applications. This paper will first discuss the design requirements for the condenser in an HMC system that will be demonstrated on the International Space Station (ISS). Then, it will present the overall design of the condenser and the preliminary thermal test results of a subscale condenser. Finally, this paper will discuss the predicted performance of the full-size condenser and the development plan to mature the technology and enhance its long-term reliability for a flight system.

A simple preparative free-flow electrophoresis joined with gratis gravity: I. Gas cushion injector and self-balance collector instead of multiple channel pump.

PubMed

Chen, Su; Palmer, James F; Zhang, Wei; Shao, Jing; Li, Si; Fan, Liu-Yin; Sun, Ren; Dong, Yu-Chao; Cao, Cheng-Xi

2009-06-01

This paper describes a novel free-flow electrophoresis (FFE), which is joined with gratis gravity, gas cushion injector (GCI) and self-balance collector instead of multiple channel pump, for the purpose of preparative purification. The FFE was evaluated by systemic experiments. The results manifest that (i) even though one-channel peristaltic pump is used for the driving of background buffer, there is still stable flow in the FFE chamber; (ii) the stable flow is induced by the gravity-induced pressure due to the difference of buffer surfaces in the GCI and self-balance collector; (iii) the pulse flow of background buffer induced by the peristaltic pump is greatly reduced by the GCI with good compressibility of included air; (iv) the FFE can be well used for zone electrophoretic separation of amino acids; (v) up to 20 inlets simultaneous sample injection and up to five to tenfold condensation of amino acid can be achieved by combining the FFE device with the method of moving reaction boundary. To the best of authors' knowledge, FFE has not been used for such separation and condensation of amino acids. The relevant results achieved in the paper have evident significance for the development of preparative FFE.

Prediction and modeling of the two-dimensional separation characteristic of a steam generator at a nuclear power station with VVER-1000 reactors

NASA Astrophysics Data System (ADS)

Parchevsky, V. M.; Guryanova, V. V.

2017-01-01

A computational and experimental procedure for construction of the two-dimensional separation curve (TDSC) for a horizontal steam generator (SG) at a nuclear power station (NPS) with VVER-reactors. In contrast to the conventional one-dimensional curve describing the wetness of saturated steam generated in SG as a function of the boiler water level at one, usually rated, load, TDSC is a function of two variables, which are the level and the load of SGB that enables TDSC to be used for wetness control in a wide load range. The procedure is based on two types of experimental data obtained during rated load operation: the nonuniformity factor of the steam load at the outlet from the submerged perforated sheet (SPS) and the dependence of the mass water level in the vicinity of the "hot" header on the water level the "cold" end of SG. The TDSC prediction procedure is presented in the form of an algorithm using SG characteristics, such as steam load and water level as the input and giving the calculated steam wetness at the output. The zoneby-zone calculation method is used. The result is presented in an analytical form (as an empirical correlation) suitable for uploading into controllers or other controls. The predicted TDSC can be used during real-time operation for implementation of different wetness control scenarios (for example, if the effectiveness is a priority, then the minimum water level, minimum wetness, and maximum turbine efficiency should be maintained; if safety is a priority, then the maximum level at the allowable wetness and the maximum water inventory should be kept), for operation of NPS in controlling the frequency and power in a power system, at the design phase (as a part of the simulation complex for verification of design solutions), during construction and erection (in developing software for personnel training simulators), during commissioning tests (to reduce the duration and labor-intensity of experimental activities), and for training.

Observations on infiltration of silicon carbide compacts with an aluminium alloy

NASA Technical Reports Server (NTRS)

Asthana, R.; Rohatgi, P. K.

1992-01-01

The melt infiltration of ceramic particulates permits an opportunity to observe such fundamental materials phenomena as nucleation, dynamic wetting and growth in constrained environments. Experimental observations are presented on the infiltration behavior and matrix microstructures that form when porous compacts of platelet-shaped single crystals of alpha- (hexagonal) silicon carbide are infiltrated with a liquid 2014 Al alloy. The infiltration process involved counter gravity infiltration of suitably tamped and preheated compacts of silicon carbide platelets under an external pressure in a special pressure chamber for a set period, then by solidification of the infiltrant metal in the interstices of the bed at atmospheric pressure.

Vibration-Induced Climbing of Drops

NASA Astrophysics Data System (ADS)

Brunet, P.; Eggers, J.; Deegan, R. D.

2007-10-01

We report an experimental study of liquid drops moving against gravity, when placed on a vertically vibrating inclined plate, which is partially wetted by the drop. The frequency of vibrations ranges from 30 to 200 Hz, and, above a threshold in vibration acceleration, drops experience an upward motion. We attribute this surprising motion to the deformations of the drop, as a consequence of an up or down symmetry breaking induced by the presence of the substrate. We relate the direction of motion to contact angle measurements. This phenomenon can be used to move a drop along an arbitrary path in a plane, without special surface treatments or localized forcing.

Distal alluvial fan sediments in early Proterozoic red beds of the Wilgerivier formation, Waterberg Group, South Africa

NASA Astrophysics Data System (ADS)

Van Der Neut, M.; Eriksson, P. G.; Callaghan, C. C.

The 1900 - 1700 M.a. Waterberg Group belongs to a series of southern African cratonic cover sequences of roughly equivalent age. Red beds of the Wilgerivier Formation comprise sandstones, interbedded with subordinate conglomerates and minor mudrocks. These immature sedimentary rocks exhibit lenticular bedding, radial palaeocurrent patterns and features indicative of both streamflow and gravity-flow deposition. A distal wet alluvial fan palaeoenvironmental setting is envisaged, with fan-deltas forming where alluvial lobes prograded into a lacustrine basin. Intrastratal, diagenetic alteration of ferromagnesian detrital grains and ferruginous grain coatings led to the red colouration of the Wilgerivier sediments.

Landscape-scale water balance monitoring with an iGrav superconducting gravimeter in a field enclosure

NASA Astrophysics Data System (ADS)

Güntner, Andreas; Reich, Marvin; Mikolaj, Michal; Creutzfeldt, Benjamin; Schroeder, Stephan; Wziontek, Hartmut

2017-06-01

In spite of the fundamental role of the landscape water balance for the Earth's water and energy cycles, monitoring the water balance and its components beyond the point scale is notoriously difficult due to the multitude of flow and storage processes and their spatial heterogeneity. Here, we present the first field deployment of an iGrav superconducting gravimeter (SG) in a minimized enclosure for long-term integrative monitoring of water storage changes. Results of the field SG on a grassland site under wet-temperate climate conditions were compared to data provided by a nearby SG located in the controlled environment of an observatory building. The field system proves to provide gravity time series that are similarly precise as those of the observatory SG. At the same time, the field SG is more sensitive to hydrological variations than the observatory SG. We demonstrate that the gravity variations observed by the field setup are almost independent of the depth below the terrain surface where water storage changes occur (contrary to SGs in buildings), and thus the field SG system directly observes the total water storage change, i.e., the water balance, in its surroundings in an integrative way. We provide a framework to single out the water balance components actual evapotranspiration and lateral subsurface discharge from the gravity time series on annual to daily timescales. With about 99 and 85 % of the gravity signal due to local water storage changes originating within a radius of 4000 and 200 m around the instrument, respectively, this setup paves the road towards gravimetry as a continuous hydrological field-monitoring technique at the landscape scale.

The Determination of Titan Gravity Field from Doppler Tracking of the Cassini Spacecraft

NASA Technical Reports Server (NTRS)

Iess, L.; Armstrong, J. W.; Aamar, S. W.; DiBenedetto, M.; Graziani, A.; Mackenzie, R.; Racioppa, P.; Rappaport, N.; Tortora, P.

2007-01-01

In its tour of the Saturnian system, the spacecraft Cassini is carrying out measurements of the gravity field of Titan, whose knowledge is crucial for constraining the internal structure of the satellite. In the five flybys devoted to gravity science, the spacecraft is tracked in X (8.4 GHz) and Ka band (32.5 GHz) from the antennas of NASA's Deep Space Network. The use of a dual frequency downlink is used to mitigate the effects of interplanetary plasma, the largest noise source affecting Doppler measurements. Variations in the wet path delay are effectively compensated by means of advanced water vapor radiometers placed close to the ground antennas. The first three flybys occurred on February 27, 2006, December 28, 2006, and June 29, 2007. Two additional flybys are planned in July 2008 and May 2010. This paper presents the estimation of the mass and quadrupole field of Titan from the first two flybys, carried out by the Cassini Radio Science Team using a short arc orbit determination. The data from the two flybys are first independently fit using a dynamical model of the spacecraft and the bodies of the Saturnian system, and then combined in a multi-arc solution. Under the assumption that the higher degree harmonics are negligible, the estimated values of the gravity parameters from the combined, multi-arc solution are GM = 8978.1337 +/- 0.0025 km(exp 3) / s(exp 2), J (sub 2) = (2.7221 +/- 0.0185) 10 (exp -5) and C (sub 22) = (1.1159 +/- 0.0040) 10 (exp -5) The excellent agreement (within 1.7 sigma) of the results from the two flybys further increases the confidence in the solution and provides an a posteriori validation of the dynamical model.

Field Testing of a Wet FGD Additive for Enhanced Mercury Control

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

Gary Blythe; MariJon Owens

2007-12-31

This document is the final report for DOE-NETL Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project has been to demonstrate the use of two flue gas desulfurization (FGD) additives, Evonik Degussa Corporation's TMT-15 and Nalco Company's Nalco 8034, to prevent the re-emission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project was intended to demonstrate whether such additives can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine salt that can be separated from themore » FGD liquor and bulk solid byproducts for separate disposal. The project involved pilot- and full-scale tests of the additives in wet FGD absorbers. The tests were intended to determine required additive dosages to prevent Hg{sup 0} re-emissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Powder River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, Luminant Power (was TXU Generation Company LP), Southern Company, IPL (an AES company), Evonik Degussa Corporation and the Nalco Company. Luminant Power provided the Texas lignite/PRB co-fired test site for pilot FGD tests and project cost sharing. Southern Company provided the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, the pilot- and full-scale jet bubbling reactor (JBR) FGD systems tested, and project cost sharing. IPL provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Evonik Degussa Corporation provided the TMT-15 additive, and the Nalco Company provided the Nalco 8034 additive. Both companies also supplied technical support to the test program as in-kind cost sharing. The project was conducted in six tasks. Of the six tasks, Task 1 involved project planning and Task 6 involved management and reporting. The other four tasks involved field testing on FGD systems, either at pilot or full scale. These four tasks included: Task 2 - Pilot Additive Testing in Texas Lignite Flue Gas; Task 3 - Full-scale FGD Additive Testing in High-sulfur Eastern Bituminous Flue Gas; Task 4 - Pilot Wet Scrubber Additive Tests at Plant Yates; and Task 5 - Full-scale Additive Tests at Plant Yates. The pilot-scale tests were completed in 2005 and the full-scale test using high-sulfur coal was completed in 2006; only the TMT-15 additive was tested in these efforts. The Task 5 full-scale additive tests conducted at Southern Company's Plant Yates Unit 1 were completed in 2007, and both the TMT-15 and Nalco 8034 additives were tested.« less

Existence, stability, and nonlinear dynamics of detached Bridgman growth states under zero gravity

NASA Astrophysics Data System (ADS)

Yeckel, Andrew; Derby, Jeffrey J.

2011-01-01

A thermocapillary model is used to study the existence, stability, and nonlinear dynamics of detached melt crystal growth in a vertical Bridgman system under zero gravity conditions. The model incorporates time-dependent heat, mass, and momentum transport, and accounts for temperature-dependent surface tension effects at the menisci bounding the melt. The positions of the menisci and phase-change boundary are computed to satisfy the conservation laws rigorously. A rich bifurcation structure in gap width versus pressure difference is uncovered, demarcating conditions under which growth with a stable gap is feasible. Thermal effects shift the bifurcation diagram to a slightly different pressure range, but do not alter its general structure. Necking and freeze-off are shown to be two different manifestations of the same instability mechanism. Supercooling of melt at the meniscus and low thermal gradients in the melt ahead of the crystal-melt-gas triple phase line, either of which may be destabilizing, are both observed under some conditions. The role of wetting and growth angles in dynamic shape stability is clarified.

Scaling law on formation and rupture of a dynamical liquid bridge

NASA Astrophysics Data System (ADS)

Zhang, Huang; Zhang, Zehao; Liu, Qianfeng; Li, Shuiqing; Department of Thermal Engineering, Tsinghua University Collaboration; Institute of Nuclear Energy; Technology, Tsinghua University Collaboration

2017-11-01

The formation and breakup of a pendular liquid bridge in dynamic state is investigated experimentally. The experimental setup arises from a system to measure the coefficient of restitution (COR) of a glass sphere impacting and bouncing on a wetted surface. We compare the effect of surface tension and gravity on the liquid bridge rupture by the capillary length κ-1. For water and liquid 1 (50% water mixed with 50% glycerol), the gravity is dominant on the liquid bridge breakup. And we find that the rupture distance is in good linear trend with the non-dimensional number G by the scaling law analysis. Further, for liquid 2 (25% water mixed with 75% glycerol) that is relatively high viscous, the linear changing of the rupture distance with the capillary number Ca is found. The relation of the rupture distance with G and Ca would be helpful in understanding the complex behavior of the dynamical liquid bridge. This work was funded by the Major State Basic Research Development Program of China (Grant No. 2016YFC0203705) and the China Postdoctoral Science Foundation (Grant No. 2016M601024).

Zero-gravity Mean Free Surface Curvature of a Confined Liquid in a Radially-Vaned Container

NASA Technical Reports Server (NTRS)

Chen, Yongkang; Callahan, Michael; Weislogel, Mark

2013-01-01

A variety of increasingly intricate container geometries are under consideration for the passive manipulation of liquids aboard spacecraft where the impact of gravity may be neglected. In this study we examine the mean curvature of a liquid volume confined within a radial array of disconnected vanes of infinite extent. This particular geometry possesses a number of desirable characteristics relevant to waste water treatment aboard spacecraft for life support. It is observed that under certain conditions the slender shape of the free surface approaches an asymptote, which can be predicted analytically using new hybrid boundary conditions proposed herein. This contribution represents possibly the final extension of what has been referred to as the method of de Lazzer et al. (1996). The method enables the integration of the Young-Laplace equation over a domain with its boundaries, including the wetted portion of the solid boundaries, symmetry planes, and circular arcs representing free surfaces at the center plane of the liquid body. Asymptotic solutions at several limits are obtained and the analysis is confirmed with numerical computations.

The In-Space Soldering Investigation: Research Conducted on the International Space Station in Support of NASA's Exploration Initiative

NASA Technical Reports Server (NTRS)

Grugel, R. N.; Fincke, M.; Sergre, P. N.; Ogle, J. A.; Funkhouser, G.; Parris, F.; Murphy, L.; Gillies, D.; Hua, F.

2004-01-01

Soldering is a well established joining and repair process that is of particular importance in the electronics industry. Still. internal solder joint defects such as porosity are prevalent and compromise desired properties such as electrical/thermal conductivity and fatigue strength. Soldering equipment resides aboard the International Space Station (ISS) and will likely accompany Exploration Missions during transit to, as well as on, the moon and Mars. Unfortunately, detrimental porosity appears to be enhanced in lower gravity environments. To this end, the In-Space Soldering Investigation (ISSI) is being conducted in the Microgravity Workbench Area (MWA) aboard the ISS as "Saturday Science" with the goal of promoting our understanding of joining techniques, shape equilibrium, wetting phenomena, and microstructural development in a microgravity environment. The work presented here will focus on direct observation of melting dynamics and shape determination in comparison to ground-based samples, with implications made to processing in other low-gravity environments. Unexpected convection effects, masked on Earth, will also be shown as well as the value of the ISS as a research platform in support of Exploration Missions.

The In-Space Soldering Investigation: To Date Analysis of Experiments Conducted on the International Space Station

NASA Technical Reports Server (NTRS)

Grugel, Richard N.; Gillies, D. C.; Hua, F.; Anilkumar, A.

2006-01-01

Soldering is a well established joining and repair process that is of particular importance in the electronics industry. Still, internal solder joint defects such as porosity are prevalent and compromise desired properties such as electrical/thermal conductivity and fatigue strength. Soldering equipment resides aboard the International Space Station (ISS) and will likely accompany Exploration Missions during transit to, as well as on, the moon and Mars. Unfortunately, detrimental porosity appears to be enhanced in lower gravity environments. To this end, the In-Space Soldering Investigation (ISSI) is being conducted in the Microgravity Workbench Area (MWA) aboard the ISS as "Saturday Science" with the goal of promoting our understanding of joining techniques, shape equilibrium, wetting phenomena, and microstructural development in a microgravity environment. The work presented here will focus on direct observation of melting dynamics and shape determination in comparison to ground-based samples, with implications made to processing in other low-gravity environments. Unexpected convection effects, masked on Earth, will also be shown as well as the value of the ISS as a research platform in support of Exploration Missions.

Free-Surface and Contact Line Motion of Liquid in Microgravity

NASA Technical Reports Server (NTRS)

Schwartz, Leonard W.

1996-01-01

This project involves fundamental studies of the role of nonlinearity in determining the motion of liquid masses under the principal influences of surface tension, viscosity and inertia. Issues to be explored are relevant to aspects of terrestrial processes, as well as being immediately applicable to fluid management in a low-gravity environment. Specific issues include: (1) the mechanic's of liquid masses in large-amplitude motions, (2) the influence of bounding surfaces on the motion, and (3) the ability of such surfaces to control liquid motion by wetting forces, especially when they are augmented by various surface treatments. Mathematical techniques include asymptotic analysis of the governing equations, for problem simplification, and numerical simulation, using both boundary-element and finite-difference methods. The flow problem is divided into an 'outer' or inviscid potential-flow region and one or more inner, or viscous dominated, regions. Relevant to one inner region, the vicinity of the contact line, we discuss time-dependent simulation of slow droplet motion, on a surface of variable wettability, using the lubrication approximation. The simulation uses a disjoining pressure model and reproduces realistic wetting-dewetting behavior.

Positive feedback and momentum growth during debris-flow entrainment of wet bed sediment

USGS Publications Warehouse

Iverson, R.M.; Reid, M.E.; Logan, M.; LaHusen, R.G.; Godt, J.W.; Griswold, J.P.

2011-01-01

Debris flows typically occur when intense rainfall or snowmelt triggers landslides or extensive erosion on steep, debris-mantled slopes. The flows can then grow dramatically in size and speed as they entrain material from their beds and banks, but the mechanism of this growth is unclear. Indeed, momentum conservation implies that entrainment of static material should retard the motion of the flows if friction remains unchanged. Here we use data from large-scale experiments to assess the entrainment of bed material by debris flows. We find that entrainment is accompanied by increased flow momentum and speed only if large positive pore pressures develop in wet bed sediments as the sediments are overridden by debris flows. The increased pore pressure facilitates progressive scour of the bed, reduces basal friction and instigates positive feedback that causes flow speed, mass and momentum to increase. If dryer bed sediment is entrained, however, the feedback becomes negative and flow momentum declines. We infer that analogous feedbacks could operate in other types of gravity-driven mass flow that interact with erodible beds. ?? 2011 Macmillan Publishers Limited. All rights reserved.

Growth and characterization of binary and pseudo-binary 3-5 compounds exhibiting non-linear optical behavior. Undergraduate research opportunities in microgravity science and technology

NASA Technical Reports Server (NTRS)

Witt, August F.

1992-01-01

In line with the specified objectives, a Bridgman-type growth configuration in which unavoidable end effects - conventionally leading to growth interface relocation - are compensated by commensurate input-power changes is developed; the growth rate on a microscale is predictable and unaffected by changes in heat transfer conditions. To permit quantitative characterization of the growth furnace cavity (hot-zone), a 3-D thermal field mapping technique, based on the thermal image, is being tested for temperatures up to 1100 C. Computational NIR absorption analysis was modified to now permit characterization of semi-insulating single crystals. Work on growth and characterization of bismuth-silicate was initiated. Growth of BSO (B12SiO20) for seed material by the Czochralski technique is currently in progress. Undergraduate research currently in progress includes: ground based measurements of the wetting behavior (contact angles) of semiconductor melts on substrates consisting of potential confinement materials for solidification experiments in a reduced gravity environment. Hardware modifications required for execution of the wetting experiments in a KC-135 facility are developed.

Microgravity electrophoresis: A study of the factors that affect free-fluid separation

NASA Technical Reports Server (NTRS)

1985-01-01

Electrophoresis experiments have been performed in the microgravity environment of the Space Shuttle. Test particles (fixed human and rabbit erythrocytes) migrated as expected in a static column and test macromolecules (human serum albumin, ovalbumin, hemoglobin A, and Pneumococcus polysaccharide 6B) migrated as expected in a continuous flow apparatus. The concentrations studied exceeded those that can be used in free-fluid separation and purification processes at unit gravity.

Analysis of the fluid flow and heat transfer in a thin liquid film in the presence and absence of gravity

NASA Technical Reports Server (NTRS)

Rahman, M. M.; Hankey, W. L.; Faghri, A.

1991-01-01

The hydrodynamic and thermal behavior of a thin liquid film flowing over a solid horizontal surface is analyzed for both plane and radially spreading flows. The situations where the gravitational force is completely absent and where it is significant are analyzed separately and their practical relevance to a micro-gravity environment is discussed. In the presence of gravity, in addition to Reynolds number, the Froude number of the film is found to be an important parameter that determines the supercritical and subcritical flow regimes and any associated hydraulic jump. A closed-form solution is possible under some flow situations, whereas others require numerical integration of ordinary differential equations. The approximate analytical results are found to compare well with the available two-dimensional numerical solutions.

GOCE, Satellite Gravimetry and Antarctic Mass Transports

NASA Astrophysics Data System (ADS)

Rummel, Reiner; Horwath, Martin; Yi, Weiyong; Albertella, Alberta; Bosch, Wolfgang; Haagmans, Roger

2011-09-01

In 2009 the European Space Agency satellite mission GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) was launched. Its objectives are the precise and detailed determination of the Earth's gravity field and geoid. Its core instrument, a three axis gravitational gradiometer, measures the gravity gradient components V xx , V yy , V zz and V xz (second-order derivatives of the gravity potential V) with high precision and V xy , V yz with low precision, all in the instrument reference frame. The long wavelength gravity field is recovered from the orbit, measured by GPS (Global Positioning System). Characteristic elements of the mission are precise star tracking, a Sun-synchronous and very low (260 km) orbit, angular control by magnetic torquing and an extremely stiff and thermally stable instrument environment. GOCE is complementary to GRACE (Gravity Recovery and Climate Experiment), another satellite gravity mission, launched in 2002. While GRACE is designed to measure temporal gravity variations, albeit with limited spatial resolution, GOCE is aiming at maximum spatial resolution, at the expense of accuracy at large spatial scales. Thus, GOCE will not provide temporal variations but is tailored to the recovery of the fine scales of the stationary field. GRACE is very successful in delivering time series of large-scale mass changes of the Antarctic ice sheet, among other things. Currently, emphasis of respective GRACE analyses is on regional refinement and on changes of temporal trends. One of the challenges is the separation of ice mass changes from glacial isostatic adjustment. Already from a few months of GOCE data, detailed gravity gradients can be recovered. They are presented here for the area of Antarctica. As one application, GOCE gravity gradients are an important addition to the sparse gravity data of Antarctica. They will help studies of the crustal and lithospheric field. A second area of application is ocean circulation. The geoid surface from the gravity field model GOCO01S allows us now to generate rather detailed maps of the mean dynamic ocean topography and of geostrophic flow velocities in the region of the Antarctic Circumpolar Current.

Crustal analysis of the Ulleung Basin in the East Sea (Japan Sea) from enhanced gravity mapping

NASA Astrophysics Data System (ADS)

Park, Chan Hong; Kim, Jeong Woo; Isezaki, Nobuhiro; Roman, Daniel R.; von Frese, Ralph R. B.

2006-12-01

To facilitate geological analyses of the Ulleung Basin in the East Sea (Japan Sea) between Korea and Japan, shipborne and satellite altimetry-derived gravity data are combined to derive a regionally coherent anomaly field. The 2-min gridded satellite altimetry-based gravity predicted by Sandwell and Smith [Sandwell DT, Smith WHF (1997) J Geophys Res 102(B5):10,039-10,054] are used for making cross-over adjustments that reduce the errors between track segments and at the cross-over points of shipborne gravity profiles. Relative to the regionally more homogeneous satellite gravity anomalies, the longer wavelength components of the shipborne anomalies are significantly improved with minimal distortion of their shorter wavelength components. The resulting free-air gravity anomaly map yields a more coherent integration of short and long wavelength anomalies compared to that obtained from either the shipborne or satellite data sets separately. The derived free-air anomalies range over about 140 mGals or more in amplitude and regionally correspond with bathymetric undulations in the Ulleung Basin. The gravity lows and highs along the basin’s margin indicate the transition from continental to oceanic crust. However, in the northeastern and central Ulleung Basin, the negative regional correlation between the central gravity high and bathymetric low suggests the presence of shallow denser mantle beneath thinned oceanic crust. A series of gravity highs mark seamounts or volcanic terranes from the Korean Plateau to Oki Island. Gravity modeling suggests underplating by mafic igneous rocks of the northwestern margin of the Ulleung Basin and the transition between continental and oceanic crust. The crust of the central Ulleung Basin is about a 14-15 km thick with a 4-5 km thick sediment cover. It may also include a relatively weakly developed buried fossil spreading ridge with approximately 2 km of relief.

Thermal infrared sounding observations of lower atmospheric variances at Mars and their implications for gravity wave activity: a preliminary examination

NASA Astrophysics Data System (ADS)

Heavens, N. G.

2017-12-01

It has been recognized for over two decades that the mesoscale statistical variance observed by Earth-observing satellites at temperature-sensitive frequencies above the instrumental noise floor is a measure of gravity wave activity. These types of observation have been made by a variety of satellite instruments have been an important validation tool for gravity wave parameterizations in global and mesoscale models. At Mars, the importance of topographic and non-topographic sources of gravity waves for the general circulation is now widely recognized and the target of recent modeling efforts. However, despite several ingenious studies, gravity wave activity near hypothetical lower atmospheric sources has been poorly and unsystematically characterized, partly because of the difficulty of separating the gravity wave activity from baroclinic wave activity and the thermal tides. Here will be presented a preliminary analysis of calibrated radiance variance at 15.4 microns (635-665 cm-1) from nadir, off-nadir, and limb observations by the Mars Climate Sounder on board Mars Reconnaissance Orbiter. The overarching methodology follows Wu and Waters (1996, 1997). Nadir, off-nadir, and lowest detector limb observations should sample variability with vertical weighting functions centered high in the lower atmosphere (20-30 km altitude) and full width half maximum (FWHM) 20 km but be sensitive to gravity waves with different horizontal wavelengths and slightly different vertical wavelengths. This work is supported by NASA's Mars Data Analysis Program (NNX14AM32G). References Wu, D.L. and J.W. Waters, 1996, Satellite observations of atmospheric variances: A possible indication of gravity waves, GRL, 23, 3631-3634. Wu D.L. and J.W. Waters, 1997, Observations of Gravity Waves with the UARS Microwave Limb Sounder. In: Hamilton K. (eds) Gravity Wave Processes. NATO ASI Series (Series I: Environmental Change), vol 50. Springer, Berlin, Heidelberg.

Goce and Its Role in Combined Global High Resolution Gravity Field Determination

NASA Astrophysics Data System (ADS)

Fecher, T.; Pail, R.; Gruber, T.

2013-12-01

Combined high-resolution gravity field models serve as a mandatory basis to describe static and dynamic processes in system Earth. Ocean dynamics can be modeled referring to a high-accurate geoid as reference surface, solid earth processes are initiated by the gravity field. Also geodetic disciplines such as height system determination depend on high-precise gravity field information. To fulfill the various requirements concerning resolution and accuracy, any kind of gravity field information, that means satellite as well as terrestrial and altimetric gravity field observations have to be included in one combination process. A key role is here reserved for GOCE observations, which contribute with its optimal signal content in the long to medium wavelength part and enable a more accurate gravity field determination than ever before especially in areas, where no high-accurate terrestrial gravity field observations are available, such as South America, Asia or Africa. For our contribution we prepare a combined high-resolution gravity field model up to d/o 720 based on full normal equation including recent GOCE, GRACE and terrestrial / altimetric data. For all data sets, normal equations are set up separately, relative weighted to each other in the combination step and solved. This procedure is computationally challenging and can only be performed using super computers. We put special emphasis on the combination process, for which we modified especially our procedure to include GOCE data optimally in the combination. Furthermore we modified our terrestrial/altimetric data sets, what should result in an improved outcome. With our model, in which we included the newest GOCE TIM4 gradiometry results, we can show how GOCE contributes to a combined gravity field solution especially in areas of poor terrestrial data coverage. The model is validated by independent GPS leveling data in selected regions as well as computation of the mean dynamic topography over the oceans. Further, we analyze the statistical error estimates derived from full covariance propagation and compare them with the absolute validation with independent data sets.

Characterization of structural stability of palm oil esters-based nanocosmeceuticals loaded with tocotrienol

PubMed Central

2013-01-01

Background Palm oil esters (POEs) are esters derived from palm oil and oleyl alcohol have great potential in the cosmetic and pharmaceutical industries due to the excellent wetting behavior of the esters without the oily feel. The role of oil-in-water nanoemulsions loaded with tocotrienol sedimentation behavior was studied. LUMiFuge® 116 particle separation analyzer was used to investigate the sedimentation behavior of POEs/tocotrienol/xanthan gum nanoemulsion system during centrifugation. Analyzing the sedimentation kinetics of dispersions in a centrifugal field also yields information about the rheological behavior and structural stability. Methods Experiments were performed in an analytical centrifuge at 11×g to 1140×g (LUMiFuge® 116 particle separation analyzer). The samples in the LUMiFuge® 116 particle separation analyzer were centrifuged at 3000 rpm for 15 h at 32°C. Sample volume of 2 cm3 was used. The rheological property of nanoemulsions was investigated using oscillatory measurements test. A rotational/oscillatory viscometer, Kinexus Rheometer (Malvern Instrument, UK) was used. All measurements were performed with a stainless steel cone-plate sensor at 25.0 ± 0.1°C with 4°/40 mm. Results The stable nanoemulsions showed sedimentation rates at earth gravity of 5.2, 3.0 and 2.6 mm/month for 10%, 20% and 30% (w/w) oil phase, respectively. Rheological behavior is an important target during the design of palm oil esters-based nanocosmeceuticals. The presence of a network structure was indicated by measurements which showed G’ to be greater than G”. This result implied the predominant elastic response and high storage stability of the nanoemulsion. It was also observed that the increase in oil phase concentration led to the profile which strongly indicated that the solid like elastic property; where the values of phase angle, δ of these nanoemulsions was lower than 45°. Conclusions The nanoemulsions with higher oil phase concentration (30% (w/w)) showed greater elasticity which implied strong dynamic rigidity of the nanoemulsion. It was the most stable with longest shelf-life. PMID:24059593

Familiar trajectories facilitate the interpretation of physical forces when intercepting a moving target.

PubMed

Mijatović, Antonija; La Scaleia, Barbara; Mercuri, Nicola; Lacquaniti, Francesco; Zago, Myrka

2014-12-01

Familiarity with the visual environment affects our expectations about the objects in a scene, aiding in recognition and interaction. Here we tested whether the familiarity with the specific trajectory followed by a moving target facilitates the interpretation of the effects of underlying physical forces. Participants intercepted a target sliding down either an inclined plane or a tautochrone. Gravity accelerated the target by the same amount in both cases, but the inclined plane represented a familiar trajectory whereas the tautochrone was unfamiliar to the participants. In separate sessions, the gravity field was consistent with either natural gravity or artificial reversed gravity. Target motion was occluded from view over the last segment. We found that the responses in the session with unnatural forces were systematically delayed relative to those with natural forces, but only for the inclined plane. The time shift is consistent with a bias for natural gravity, in so far as it reflects an a priori expectation that a target not affected by natural forces will arrive later than one accelerated downwards by gravity. Instead, we did not find any significant time shift with unnatural forces in the case of the tautochrone. We argue that interception of a moving target relies on the integration of the high-level cue of trajectory familiarity with low-level cues related to target kinematics.

Combining nutation and surface gravity observations to estimate the Earth's core and inner core resonant frequencies

NASA Astrophysics Data System (ADS)

Ziegler, Yann; Lambert, Sébastien; Rosat, Séverine; Nurul Huda, Ibnu; Bizouard, Christian

2017-04-01

Nutation time series derived from very long baseline interferometry (VLBI) and time varying surface gravity data recorded by superconducting gravimeters (SG) have long been used separately to assess the Earth's interior via the estimation of the free core and inner core resonance effects on nutation or tidal gravity. The results obtained from these two techniques have been shown recently to be consistent, making relevant the combination of VLBI and SG observables and the estimation of Earth's interior parameters in a single inversion. We present here the intermediate results of the ongoing project of combining nutation and surface gravity time series to improve estimates of the Earth's core and inner core resonant frequencies. We use VLBI nutation time series spanning 1984-2016 derived by the International VLBI Service for geodesy and astrometry (IVS) as the result of a combination of inputs from various IVS analysis centers, and surface gravity data from about 15 SG stations. We address here the resonance model used for describing the Earth's interior response to tidal excitation, the data preparation consisting of the error recalibration and amplitude fitting for nutation data, and processing of SG time-varying gravity to remove any gaps, spikes, steps and other disturbances, followed by the tidal analysis with the ETERNA 3.4 software package, the preliminary estimates of the resonant periods, and the correlations between parameters.

Crustal Movements and Gravity Variations in the Southeastern Po Plain, Italy

NASA Astrophysics Data System (ADS)

Zerbini, S.; Bruni, S.; Errico, M.; Santi, E.; Wilmes, H.; Wziontek, H.

2014-12-01

At the Medicina observatory, in the southeastern Po Plain, in Italy, we have started a project of continuous GPS and gravity observations in mid 1996. The experiment, focused on a comparison between height and gravity variations, is still ongoing; these uninterrupted time series certainly constitute a most important data base to observe and estimate reliably long-period behaviors but also to derive deeper insights on the nature of the crustal deformation. Almost two decades of continuous GPS observations from two closely located receivers have shown that the coordinate time series are characterized by linear and non-linear variations as well as by sudden jumps. Both over long- and short-period time scales, the GPS height series show signals induced by different phenomena, for example, those related to mass transport in the Earth system. Seasonal effects are clearly recognizable and are mainly associated with the water table seasonal behavior. To understand and separate the contribution of different forcings is not an easy task; to this end, the information provided by the superconducting gravimeter observations and also by absolute gravity measurements offers a most important means to detect and understand mass contributions. In addition to GPS and gravity data, at Medicina, a number of environmental parameters time series are also regularly acquired, among them water table levels. We present the results of study investigating correlations between height, gravity and environmental parameters time series.

Need for improvements in physical pretreatment of source-separated household food waste.

PubMed

Bernstad, A; Malmquist, L; Truedsson, C; la Cour Jansen, J

2013-03-01

The aim of the present study was to investigate the efficiency in physical pretreatment processes of source-separated solid organic household waste. The investigation of seventeen Swedish full-scale pretreatment facilities, currently receiving separately collected food waste from household for subsequent anaerobic digestion, shows that problems with the quality of produced biomass and high maintenance costs are common. Four full-scale physical pretreatment plants, three using screwpress technology and one using dispergation technology, were compared in relation to resource efficiency, losses of nitrogen and potential methane production from biodegradable matter as well as the ratio of unwanted materials in produced biomass intended for wet anaerobic digestion. Refuse generated in the processes represent 13-39% of TS in incoming wet waste. The methane yield from these fractions corresponds to 14-36Nm(3)/ton separately collected solid organic household waste. Also, 13-32% of N-tot in incoming food waste is found in refuse. Losses of both biodegradable material and nutrients were larger in the three facilities using screwpress technology compared to the facility using dispersion technology.(1) Thus, there are large potentials for increase of both the methane yield and nutrient recovery from separately collected solid organic household waste through increased efficiency in facilities for physical pretreatment. Improved pretreatment processes could thereby increase the overall environmental benefits from anaerobic digestion as a treatment alternative for solid organic household waste. Copyright © 2012 Elsevier Ltd. All rights reserved.

Interpretation of Local Gravity Anomalies in Northern New York

NASA Astrophysics Data System (ADS)

Revetta, F. A.

2004-05-01

About 10,000 new gravity measurements at a station spacing of 1 to 2 Km were made in the Adirondack Mountains, Lake Champlain Valley, St. Lawrence River Valley and Tug Hill Plateau. These closely spaced gravity measurements were compiled to construct computer contoured gravity maps of the survey areas. The gravity measurements reveal local anomalies related to seismicity, faults, mineral resources and gas fields that are not seen in the regional gravity mapping. In northern New York gravity and seismicity maps indicate epicenters are concentrated in areas of the most pronounced gravity anomalies along steep gravity gradients. Zones of weakness along the contacts of these lithologies of different density could possibly account for the earthquakes in this high stress area. Also, a computer contoured gravity map of the 5.3 magnitude Au Sable Forks earthquake of April 20, 2002 indicates the epicenter lies along a north-south trending gravity gradient produced by a high angle fault structure separating a gravity low in the west from high gravity in the east. In the St. Lawrence Valley, the Carthage-Colton Mylonite Zone, a major northeast trending structural boundary between the Adirondack Highlands and Northwest Lowlands, is represented as a steep gravity gradient extending into the eastern shore of Lake Ontario. At Russell, New York near the CCMZ, a small circular shaped gravity high coincides with a cluster of earthquakes. The coincidence of the epicenters over the high may indicate stress amplification at the boundary of a gabbro pluton. The Morristown fault located in the Morristown Quadrangle in St. Lawrence County produces both gravity and magnetic anomalies due to Precambrian Basement faulting. This faulting indicates control of the Morristown fault in the overlying Paleozoics by the Precambrian faults. Gravity and magnetic anomalies also occur over proposed extensions of the Gloucester and Winchester Springs faults into northern New York. Gravity and magnetic surveys were conducted at the closed Benson Mines magnetite mine and the Zinc Mines at Balmat, New York. The gravity and magnetic anomalies at Benson Mines indicate that significant amounts of magnetite remain in the subsurface and the steep gradients indicate a shallow depth. A gravity high of 35 gravity units in the Sylvia Lake Zinc District at Balmat, New York occurs over the upper marble and a 100 gu anomaly occurs just northeast of the zinc district. Abandoned natural gas fields exist along the southern and southwestern boundary of the Tug Hill Plateau. Gravity surveys were conducted in the vicinity of three of these gas fields in the Tug Hill Plateau (Camden, Sandy Creek and Pulaski). The Tug Hill Plateau is thought to be an uplifted-fault-bounded block which, if correct, might account for the existence of those gas fields. The trends of the gravity contours on the gravity maps lends credence to the fault interpretation. Also gravity and magnetic traverses were conducted across faults in the Trenton-Black River. These traverses show gravity anomalies across the faults which indicate control by faulting in the Precambrian.

Gravitropism in leafy dicot stems

NASA Technical Reports Server (NTRS)

Salisbury, F. B.

1984-01-01

In an attempt to separate plant responses to mechanical stresses from responses to gravity compensation, six treatments were automated: (1) upright stationary controls; (2) horizontal clinostat; (3) intermittent clinostat (plants upright 3.3 minutes out of every 4 minutes, horizontal and rotated once in the remaining time); (4) inversion every ten minutes (plants upside down half the time); (5) inversion and immediate return to the vertical; and (6) vertical rotation. Epinasty appeared only on clinostated and on inverted plants, both subjected to gravity compensation. The mechanics of gravitropic stem bending and the effects of a unilateral application of ethephon of gravitropic bending were also investigated.

Coarsening and pattern formation during true morphological phase separation in unstable thin films under gravity

NASA Astrophysics Data System (ADS)

Kumar, Avanish; Narayanam, Chaitanya; Khanna, Rajesh; Puri, Sanjay

2017-12-01

We address in detail the problem of true morphological phase separation (MPS) in three-dimensional or (2 +1 )-dimensional unstable thin liquid films (>100 nm) under the influence of gravity. The free-energy functionals of these films are asymmetric and show two points of common tangency, which facilitates the formation of two equilibrium phases. Three distinct patterns formed by relative preponderance of these phases are clearly identified in "true MPS". Asymmetricity induces two different pathways of pattern formation, viz., defect and direct pathway for true MPS. The pattern formation and phase-ordering dynamics have been studied using statistical measures such as structure factor, correlation function, and growth laws. In the late stage of coarsening, the system reaches into a scaling regime for both pathways, and the characteristic domain size follows the Lifshitz-Slyozov growth law [L (t ) ˜t1 /3] . However, for the defect pathway, there is a crossover of domain growth behavior from L (t ) ˜t1 /4→t1 /3 in the dynamical scaling regime. We also underline the analogies and differences behind the mechanisms of MPS and true MPS in thin liquid films and generic spinodal phase separation in binary mixtures.

NWEI Azura December 2016 Data

DOE Data Explorer

Terry Lettenmaier

2016-12-29

Data files for the NWEI Azura grid-connected deployment at the 30-meter berth of the US Navys Wave Energy Test Site (WETS 30m Site) at the Kaneohe Marine Corps Base Hawaii (MCBH) on the windward (northeast) coast of the island of Oahu, HI. See general documentation describing specifics of the data files and formats in a separate submission. This month's data only covers the period Dec 1-6, 2016. On Dec 7, the Azura was shut down and disconnected in preparation for its Dec 8 removal from the WETS 30 m site. The Azura will be modified and re-deployed in 2017.

Method for recovering catalytic elements from fuel cell membrane electrode assemblies

DOEpatents

Shore, Lawrence [Edison, NJ; Matlin, Ramail [Berkeley Heights, NJ; Heinz, Robert [Ludwigshafen, DE

2012-06-26

A method for recovering catalytic elements from a fuel cell membrane electrode assembly is provided. The method includes converting the membrane electrode assembly into a particulate material, wetting the particulate material, forming a slurry comprising the wetted particulate material and an acid leachate adapted to dissolve at least one of the catalytic elements into a soluble catalytic element salt, separating the slurry into a depleted particulate material and a supernatant containing the catalytic element salt, and washing the depleted particulate material to remove any catalytic element salt retained within pores in the depleted particulate material.

Galaxy-galaxy weak gravitational lensing in f(R) gravity

NASA Astrophysics Data System (ADS)

Li, Baojiu; Shirasaki, Masato

2018-03-01

We present an analysis of galaxy-galaxy weak gravitational lensing (GGL) in chameleon f(R) gravity - a leading candidate of non-standard gravity models. For the analysis, we have created mock galaxy catalogues based on dark matter haloes from two sets of numerical simulations, using a halo occupation distribution (HOD) prescription which allows a redshift dependence of galaxy number density. To make a fairer comparison between the f(R) and Λ cold dark matter (ΛCDM) models, their HOD parameters are tuned so that the galaxy two-point correlation functions in real space (and therefore the projected two-point correlation functions) match. While the f(R) model predicts an enhancement of the convergence power spectrum by up to ˜ 30 per cent compared to the standard ΛCDM model with the same parameters, the maximum enhancement of GGL is only half as large and less than 5 per cent on separations above ˜1-2 h-1 Mpc, because the latter is a cross-correlation of shear (or matter, which is more strongly affected by modified gravity) and galaxy (which is weakly affected given the good match between galaxy autocorrelations in the two models) fields. We also study the possibility of reconstructing the matter power spectrum by combination of GGL and galaxy clustering in f(R) gravity. We find that the galaxy-matter cross-correlation coefficient remains at unity down to ˜2-3 h-1 Mpc at relevant redshifts even in f(R) gravity, indicating joint analysis of GGL and galaxy clustering can be a powerful probe of matter density fluctuations in chameleon gravity. The scale dependence of the model differences in their predictions of GGL can potentially allows us to break the degeneracy between f(R) gravity and other cosmological parameters such as Ωm and σ8.

Thermophoretic motion behavior of submicron particles in boundary-layer-separation flow around a droplet.

PubMed

Wang, Ao; Song, Qiang; Ji, Bingqiang; Yao, Qiang

2015-12-01

As a key mechanism of submicron particle capture in wet deposition and wet scrubbing processes, thermophoresis is influenced by the flow and temperature fields. Three-dimensional direct numerical simulations were conducted to quantify the characteristics of the flow and temperature fields around a droplet at three droplet Reynolds numbers (Re) that correspond to three typical boundary-layer-separation flows (steady axisymmetric, steady plane-symmetric, and unsteady plane-symmetric flows). The thermophoretic motion of submicron particles was simulated in these cases. Numerical results show that the motion of submicron particles around the droplet and the deposition distribution exhibit different characteristics under three typical flow forms. The motion patterns of particles are dependent on their initial positions in the upstream and flow forms. The patterns of particle motion and deposition are diversified as Re increases. The particle motion pattern, initial position of captured particles, and capture efficiency change periodically, especially during periodic vortex shedding. The key effects of flow forms on particle motion are the shape and stability of the wake behind the droplet. The drag force of fluid and the thermophoretic force in the wake contribute jointly to the deposition of submicron particles after the boundary-layer separation around a droplet.

Wetting and phase separation in soft adhesion

PubMed Central

Jensen, Katharine E.; Sarfati, Raphael; Style, Robert W.; Boltyanskiy, Rostislav; Chakrabarti, Aditi; Chaudhury, Manoj K.; Dufresne, Eric R.

2015-01-01

In the classic theory of solid adhesion, surface energy drives deformation to increase contact area whereas bulk elasticity opposes it. Recently, solid surface stress has been shown also to play an important role in opposing deformation of soft materials. This suggests that the contact line in soft adhesion should mimic that of a liquid droplet, with a contact angle determined by surface tensions. Consistent with this hypothesis, we observe a contact angle of a soft silicone substrate on rigid silica spheres that depends on the surface functionalization but not the sphere size. However, to satisfy this wetting condition without a divergent elastic stress, the gel phase separates from its solvent near the contact line. This creates a four-phase contact zone with two additional contact lines hidden below the surface of the substrate. Whereas the geometries of these contact lines are independent of the size of the sphere, the volume of the phase-separated region is not, but rather depends on the indentation volume. These results indicate that theories of adhesion of soft gels need to account for both the compressibility of the gel network and a nonzero surface stress between the gel and its solvent. PMID:26553989

ISOTOPE SEPARATORS

DOEpatents

Bacon, C.G.

1958-08-26

An improvement is presented in the structure of an isotope separation apparatus and, in particular, is concerned with a magnetically operated shutter associated with a window which is provided for the purpose of enabling the operator to view the processes going on within the interior of the apparatus. The shutier is mounted to close under the force of gravity in the absence of any other force. By closing an electrical circuit to a coil mouated on the shutter the magnetic field of the isotope separating apparatus coacts with the magnetic field of the coil to force the shutter to the open position.

Recovery of nonferrous metals from scrap automobiles by magnetic fluid levitation.

NASA Technical Reports Server (NTRS)

Mir, L.; Simard, C.; Grana, D.

1973-01-01

Ferrofluids are colloidal dispersions of subdomain magnetic solids in carrier liquids. In the presence of a non-homogeneous magnetic field, ferrofluids exert a pressure on immersed nonmagnetic objects in the opposite sense of the field gradient. This pressure force can, when opposite to gravity, levitate objects of higher density than the ferrofluid. This levitation technique can be used to separate solids according to density. Its application to the separation of nonferrous metals from shredded automobiles has been demonstrated on a prototype of a full-scale separator. Its use to recover nonferrous metals from municipal solid wastes also seems practical.

Cell separation and electrofusion in space

NASA Technical Reports Server (NTRS)

Morrison, D. R.; Hofmann, G. A.

1990-01-01

In microgravity, free-fluid electrophoretic methods for separating living cells and proteins are improved significantly by the absence of gravity-driven phenomena. Cell fusion, culture, and other bioprocessing steps are being investigated to understand the limits of earth-based processing. A multistep space bioprocess is described that includes electrophoretic separation of human target cells, single-cell manipulations using receptor-specific antibodies, electrofusion to produce immortal hybridomas, gentle suspension culture, and monoclonal antibody recovery using continuous-flow electrophoresis or recirculating isoelectric focusing. Improvements in several key steps already have been demonstrated by space experiments, and others will be studied on Space Station Freedom.

Experimental investigations of stability of static liquid fillets and liquid-gas interface in capillary passages for gas-free liquid acquisition in zero gravity

NASA Astrophysics Data System (ADS)

Purohit, Ghanshyam Purshottamdas

Experimental investigations of static liquid fillets formed between small gaps of a cylindrical surface and a flat surface are carried out. The minimum volume of liquid required to form a stable fillet and the maximum liquid content the fillet can hold before becoming unstable are studied. Fillet shapes are captured in photographs obtained by a high speed image system. Experiments were conducted using water, UPA and PF 5060 on two surfaces-stand-blasted titanium and polished copper for different surface inclinations. Experimental data are generalized using appropriate non-dimensional groups. Analytical model are developed to describe the fillet curvature. Fillet curvature data are compared against model predictions and are found to be in close agreement. Bubble point experiments were carried out to measure the capillary pressure difference across the liquid-gas interface in the channels of photo-chemically etched disk stacks. Experiments were conducted using titanium stacks of five different geometrical configurations. Both well wetting liquids (IPA and PF5060) and partially wetting liquid (water) were used during experiments. Test results are found to be in close agreement with analytical predictions. Experiments were carried out to measure the frictional pressure drop across the stack as a function of liquid flow rate using two different liquids (water and IPA) and five stacks of different geometrical configurations. A channel pressure drop model is developed by treating the flow within stack channels as fully developed laminar flow between parallel plates and solving the one-dimensional Navier Stokes equation. An alternate model is developed by treating the flow in channels as flow within porous media. Expressions are developed for effective porosity and permeability for the stacks and the pressure drop is related to these parameters. Pressure drop test results are found to be in close agreement with model predictions. As a specific application of this work, a surface tension propellant management device (PMD) that uses photo-chemically etched disk stacks as capillary elements is examined. These PMDs are used in gas pressurized liquid propellant tanks to supply gas-free propellant to rocket engines in near zero-gravity environment. The experimentally validated models are integrated to perform key analyses for predicting PMD performance in zero gravity.

40 CFR 63.681 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... drain system, a gravity-operated conveyor (such as a chute), and a mechanically-powered conveyor (such... features permanently integrated into the design of the unit. Emission point means an individual tank, surface impoundment, container, oil-water or organic-water separator, transfer system, process vent, or...

Electrophoretic separation of human kidney cells at zero gravity

NASA Technical Reports Server (NTRS)

Barlow, G. H.; Lazer, S. L.; Rueter, A.; Allen, R. E.

1977-01-01

Electrophoretic isolation of cells results in a loss of resolution power caused by the sedimentation of the cells in the media. The results of an experiment to extract urokinase from human embryos during the Apollo Soyuz mission are presented and discussed.

40 CFR 63.681 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... drain system, a gravity-operated conveyor (such as a chute), and a mechanically-powered conveyor (such... features permanently integrated into the design of the unit. Emission point means an individual tank, surface impoundment, container, oil-water or organic-water separator, transfer system, process vent, or...

40 CFR 63.681 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... drain system, a gravity-operated conveyor (such as a chute), and a mechanically-powered conveyor (such... features permanently integrated into the design of the unit. Emission point means an individual tank, surface impoundment, container, oil-water or organic-water separator, transfer system, process vent, or...

BIOLOGICAL TREATMENT, EFFLUENT REUSE, AND SLUDGE HANDLING FOR THE SIDE LEATHER TANNING INDUSTRY

EPA Science Inventory

An evaluation of the treatability of unsegregated, unequalized, and unneutralized wastewaters from a side-leather tanning industry utilizing the hair pulping process by primary and secondary biological and gravity separation in clarifier-thickeners, whereas the secondary treatmen...

Shear shedding of drops and the use of superhydrophobic surfaces in microgravity: PFC and ground based results

NASA Astrophysics Data System (ADS)

Milne, Andrew; Amirfazli, Alidad

In free fall, the absence of gravity poses many challenges for fluid handling systems. One such example of this is condensers. On earth, the condensed liquid is removed from the tilted condenser plate by gravity forced shedding. In microgravity, proposed solutions include the use of surfaces with gradients in wettability [1], the use of electrowetting [2], and shearing airflow [3]. In this talk, shear shedding results for a variety of surface (hydrophilic to superhydrophobic (extremely water repelling)) will be presented. Surface science and aerodynamics are used to reveal fundamental parameters controlling incipient motion for drops exposed to shearing airflow. It is found that wetting parameters such as contact angle and surface tension are very influential in determining the minimum required air velocity for drop shedding. Based on experimental results for drops of water and hexadecane (0.5-100 l) on PMMA, Teflon, and a superhydrophobic aluminum surface, an exponential function is proposed that relates the critical air velocity for shedding to the ratio of drop base length to projected area. The results for the water systems can be collapsed to a self similar curve by normalization, which also explains results from other researchers. Since shedding from superhydrophobic surfaces (SHS) is seen to be easier compared to other surfaces, the behaviour of SHS is also probed in this talk. SHS have space-based applications to shedding, self cleaning, anti-icing (spacecraft launch/re-entry), anti-fouling, fluid actuation, and decreased fluid friction. The mechanism for SHS is understood to be the existence of an air layer between large portions of the drop and solid. The first concrete visual evidence of this was gained performing a parabolic flight experiment with the ESA. Results of this experi-ment will be discussed, showing the extreme water repelling potential of SHS in microgravity, and demonstrating how the wetting behaviours seen (partial penetration, transition of wetting states, unpredicted contact angle behaviour) affect models of superhydrophobicity and the use of SHS to both space and Earth based applications. 1) Darhuber, A. A.; Troian, S. M. Annual Review of Fluid Mechanics 2005, 425-455. 2) Berthier, J.; Dubois, P.; Clementz, P.; Claustre, P.; Peponnet, C.; Fouillet, Y. Sensors and Actuators A: Physical 2007, 134, 471-479. 3) Milne, A. J. B.; Amirfazli, A. Langmuir 2009, 25, 14155-14164.

Ferromagnetic nickel silicide nanowires for isolating primary CD4+ T lymphocytes

NASA Astrophysics Data System (ADS)

Kim, Dong-Joo; Seol, Jin-Kyeong; Lee, Mi-Ri; Hyung, Jung-Hwan; Kim, Gil-Sung; Ohgai, Takeshi; Lee, Sang-Kwon

2012-04-01

Direct CD4+ T lymphocytes were separated from whole mouse splenocytes using 1-dimensional ferromagnetic nickel silicide nanowires (NiSi NWs). NiSi NWs were prepared by silver-assisted wet chemical etching of silicon and subsequent deposition and annealing of Ni. This method exhibits a separation efficiency of ˜93.5%, which is comparable to that of the state-of-the-art superparamagnetic bead-based cell capture (˜96.8%). Furthermore, this research shows potential for separation of other lymphocytes, B, natural killer and natural killer T cells, and even rare tumor cells simply by changing the biotin-conjugated antibodies.

Phase segregation due to simultaneous migration and coalescence

NASA Technical Reports Server (NTRS)

Davis, Robert H.; Wang, Hua; Hawker, Debra

1994-01-01

Ground-based modeling and experiments have been performed on the interaction and coalescence of drops leading to macroscopic phase separation. The focus has been on gravity-induced motion, with research also initiated on thermocapillary motion of drops. The drop size distribution initially shifts toward larger drops with time due to coalescence, and then a back towards smaller drops due to the larger preferentially settling out. As a consequence, the phase separation rate initially increases with time and then decreases.

SEWER SEDIMENT AND CONTROL: A MANAGEMENT PRACTICES REFERENCES GUIDE

EPA Science Inventory

Sewer-solids sediment is one of major sources of pollutants in urban wet-weather flow (WWF) discharges that include combined-sewer overflow (CSO), separate sanitary-sewer overflow (SSO), and stormwater runoff. During low-flow, dry-weather periods, sanitary wastewater solids depo...

Superhydrophilic graphene oxide@electrospun cellulose nanofiber hybrid membrane for high-efficiency oil/water separation.

PubMed

Ao, Chenghong; Yuan, Wei; Zhao, Jiangqi; He, Xu; Zhang, Xiaofang; Li, Qingye; Xia, Tian; Zhang, Wei; Lu, Canhui

2017-11-01

Inspired from fishscales, membranes with special surface wettability have been applied widely for the treatment of oily waste water. Herein, a novel superhydrophilic graphene oxide (GO)@electrospun cellulose nanofiber (CNF) membrane was successfully fabricated. This membrane exhibited a high separation efficiency, excellent antifouling properties, as well as a high flux for the gravity-driven oil/water separation. Moreover, the GO@CNF membrane was capable to effectively separate oil/water mixtures in a broad pH range or with a high concentration of salt, suggesting that this membrane was quite promising for future real-world practice in oil spill cleanup and oily wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Selected contribution: redistribution of pulmonary perfusion during weightlessness and increased gravity

NASA Technical Reports Server (NTRS)

Glenny, R. W.; Lamm, W. J.; Bernard, S. L.; An, D.; Chornuk, M.; Pool, S. L.; Wagner, W. W. Jr; Hlastala, M. P.; Robertson, H. T.

2000-01-01

To compare the relative contributions of gravity and vascular structure to the distribution of pulmonary blood flow, we flew with pigs on the National Aeronautics and Space Administration KC-135 aircraft. A series of parabolas created alternating weightlessness and 1.8-G conditions. Fluorescent microspheres of varying colors were injected into the pulmonary circulation to mark regional blood flow during different postural and gravitational conditions. The lungs were subsequently removed, air dried, and sectioned into approximately 2 cm(3) pieces. Flow to each piece was determined for the different conditions. Perfusion heterogeneity did not change significantly during weightlessness compared with normal and increased gravitational forces. Regional blood flow to each lung piece changed little despite alterations in posture and gravitational forces. With the use of multiple stepwise linear regression, the contributions of gravity and vascular structure to regional perfusion were separated. We conclude that both gravity and the geometry of the pulmonary vascular tree influence regional pulmonary blood flow. However, the structure of the vascular tree is the primary determinant of regional perfusion in these animals.

Casual Set Approach to a Minimal Invariant Length

NASA Astrophysics Data System (ADS)

Raut, Usha

2007-04-01

Any attempt to quantize gravity would necessarily introduce a minimal observable length scale of the order of the Planck length. This conclusion is based on several different studies and thought experiments and appears to be an inescapable feature of all quantum gravity theories, irrespective of the method used to quantize gravity. Over the last few years there has been growing concern that such a minimal length might lead to a contradiction with the basic postulates of special relativity, in particular the Lorentz-Fitzgerald contraction. A few years ago, Rovelli et.al, attempted to reconcile an invariant minimal length with Special Relativity, using the framework of loop quantum gravity. However, the inherently canonical formalism of the loop quantum approach is plagued by a variety of problems, many brought on by separation of space and time co-ordinates. In this paper we use a completely different approach. Using the framework of the causal set paradigm, along with a statistical measure of closeness between Lorentzian manifolds, we re-examine the issue of introducing a minimal observable length that is not at odds with Special Relativity postulates.

High resolution Slovak Bouguer gravity anomaly map and its enhanced derivative transformations: new possibilities for interpretation of anomalous gravity fields

NASA Astrophysics Data System (ADS)

Pašteka, Roman; Zahorec, Pavol; Kušnirák, David; Bošanský, Marián; Papčo, Juraj; Szalaiová, Viktória; Krajňák, Martin; Ivan, Marušiak; Mikuška, Ján; Bielik, Miroslav

2017-06-01

The paper deals with the revision and enrichment of the present gravimetric database of the Slovak Republic. The output of this process is a new version of the complete Bouguer anomaly (CBA) field on our territory. Thanks to the taking into account of more accurate terrain corrections, this field has significantly higher quality and higher resolution capabilities. The excellent features of this map will allow us to re-evaluate and improve the qualitative interpretation of the gravity field when researching the structural and tectonic geology of the Western Carpathian lithosphere. In the contribution we also analyse the field of the new CBA based on the properties of various transformed fields - in particular the horizontal gradient, which by its local maximums defines important density boundaries in the lateral direction. All original and new transformed maps make a significant contribution to improving the geological interpretation of the CBA field. Except for the horizontal gradient field, we are also interested in a new special transformation of TDXAS, which excellently separates various detected anomalies of gravity field and improves their lateral delimitation.

Transition from geostrophic turbulence to inertia-gravity waves in the atmospheric energy spectrum.

PubMed

Callies, Jörn; Ferrari, Raffaele; Bühler, Oliver

2014-12-02

Midlatitude fluctuations of the atmospheric winds on scales of thousands of kilometers, the most energetic of such fluctuations, are strongly constrained by the Earth's rotation and the atmosphere's stratification. As a result of these constraints, the flow is quasi-2D and energy is trapped at large scales—nonlinear turbulent interactions transfer energy to larger scales, but not to smaller scales. Aircraft observations of wind and temperature near the tropopause indicate that fluctuations at horizontal scales smaller than about 500 km are more energetic than expected from these quasi-2D dynamics. We present an analysis of the observations that indicates that these smaller-scale motions are due to approximately linear inertia-gravity waves, contrary to recent claims that these scales are strongly turbulent. Specifically, the aircraft velocity and temperature measurements are separated into two components: one due to the quasi-2D dynamics and one due to linear inertia-gravity waves. Quasi-2D dynamics dominate at scales larger than 500 km; inertia-gravity waves dominate at scales smaller than 500 km.

Transition from geostrophic turbulence to inertia–gravity waves in the atmospheric energy spectrum

PubMed Central

Callies, Jörn; Ferrari, Raffaele; Bühler, Oliver

2014-01-01

Midlatitude fluctuations of the atmospheric winds on scales of thousands of kilometers, the most energetic of such fluctuations, are strongly constrained by the Earth’s rotation and the atmosphere’s stratification. As a result of these constraints, the flow is quasi-2D and energy is trapped at large scales—nonlinear turbulent interactions transfer energy to larger scales, but not to smaller scales. Aircraft observations of wind and temperature near the tropopause indicate that fluctuations at horizontal scales smaller than about 500 km are more energetic than expected from these quasi-2D dynamics. We present an analysis of the observations that indicates that these smaller-scale motions are due to approximately linear inertia–gravity waves, contrary to recent claims that these scales are strongly turbulent. Specifically, the aircraft velocity and temperature measurements are separated into two components: one due to the quasi-2D dynamics and one due to linear inertia–gravity waves. Quasi-2D dynamics dominate at scales larger than 500 km; inertia–gravity waves dominate at scales smaller than 500 km. PMID:25404349

Large scale DNA microsequencing device

DOEpatents

Foote, Robert S.

1997-01-01

A microminiature sequencing apparatus and method provide means for simultaneously obtaining sequences of plural polynucleotide strands. The apparatus comprises a microchip into which plural channels have been etched using standard lithographic procedures and chemical wet etching. The channels include a reaction well and a separating section. Enclosing the channels is accomplished by bonding a transparent cover plate over the apparatus. A first oligonucleotide strand is chemically affixed to the apparatus through an alkyl chain. Subsequent nucleotides are selected by complementary base pair bonding. A target nucleotide strand is used to produce a family of labelled sequencing strands in each channel which are separated in the separating section. During or following separation the sequences are determined using appropriate detection means.

Large scale DNA microsequencing device

DOEpatents

Foote, Robert S.

1999-01-01

A microminiature sequencing apparatus and method provide means for simultaneously obtaining sequences of plural polynucleotide strands. The apparatus comprises a microchip into which plural channels have been etched using standard lithographic procedures and chemical wet etching. The channels include a reaction well and a separating section. Enclosing the channels is accomplished by bonding a transparent cover plate over the apparatus. A first oligonucleotide strand is chemically affixed to the apparatus through an alkyl chain. Subsequent nucleotides are selected by complementary base pair bonding. A target nucleotide strand is used to produce a family of labelled sequencing strands in each channel which are separated in the separating section. During or following separation the sequences are determined using appropriate detection means.

Large scale DNA microsequencing device

DOEpatents

Foote, R.S.

1999-08-31

A microminiature sequencing apparatus and method provide means for simultaneously obtaining sequences of plural polynucleotide strands. The apparatus comprises a microchip into which plural channels have been etched using standard lithographic procedures and chemical wet etching. The channels include a reaction well and a separating section. Enclosing the channels is accomplished by bonding a transparent cover plate over the apparatus. A first oligonucleotide strand is chemically affixed to the apparatus through an alkyl chain. Subsequent nucleotides are selected by complementary base pair bonding. A target nucleotide strand is used to produce a family of labelled sequencing strands in each channel which are separated in the separating section. During or following separation the sequences are determined using appropriate detection means. 11 figs.

Characterization and mechanical separation of metals from computer Printed Circuit Boards (PCBs) based on mineral processing methods.

PubMed

Sarvar, Mojtaba; Salarirad, Mohammad Mehdi; Shabani, Mohammad Amin

2015-11-01

In this paper, a novel mechanical process is proposed for enriching metal content of computer Printed Circuit Boards (PCBs). The PCBs are crushed and divided into three different size fractions namely: -0.59, +0.59 to 1.68 and +1.68 mm. Wet jigging and froth flotation methods are selected for metal enrichment. The coarse size fraction (+1.68 mm) is processed by jigging. The plastic free product is grinded and screened. The oversized product is separated as the first concentrate. It was rich of metal because the grinding process was selective. The undersized product is processed by froth flotation. Based on the obtained results, the middle size fraction (+0.59 to 1.68 mm) and the small size fraction (-0.59 mm) are processed by wet jigging and froth flotation respectively. The wet jigging process is optimized by investigating the effect of pulsation frequency and water flow rate. The results of examining the effect of particle size, solid to liquid ratio, conditioning time and using apolar collector showed that collectorless flotation is a promising method for separating nonmetals of PCBs. 95.6%, 97.5% and 85% of metal content of coarse size, middle size and small size fraction are recovered. The grades of obtained concentrates were 63.3%, 92.5% and 75% respectively. The total recovery is calculated as 95.64% and the grade of the final concentrate was 71.26%. Determining the grade of copper and gold in the final product reveals that 4.95% of copper and 24.46% of gold are lost during the concentration. The major part of the lost gold is accumulated in froth flotation tail. Copyright © 2015 Elsevier Ltd. All rights reserved.

Provision of food and water in rodent whole body plethysmography safety pharmacology respiratory studies - Impact on animal welfare and data quality.

PubMed

Grant, Claire; Marks, Louise; Prior, Helen

2017-11-01

We evaluated the feasibility of providing food and water to rodents during whole body plethysmography (WBP) studies as a welfare improvement to standard conditions. Male Han Wistar rats or CD1 mice (n=8) were placed in WBP chambers and respiratory parameters recorded for approximately 6h on four separate occasions. On each occasion the animals were exposed to a different plethysmography chamber environment using a randomised design: no food/water (the standard conditions), water bottle, hydrating gel and wet food. In a further session, rats (n=8) were administered theophylline, or vehicle and respiratory parameters measured in the plethysmography chamber containing wet food. Respiratory parameters of rats were not significantly altered by the provision of water or food. Providing wet food resulted in reduced body weight loss. Administration of theophylline caused the expected increase in respiratory rate. When mice were given access to hydrating gel or wet food the respiratory parameters were significantly affected; respiratory rate and tidal volume were increased. Providing wet food resulted in reduced bodyweight loss. The provision of food and water did not impact on respiratory parameters in rats placed in WBP chambers. When provided with wet food, rats lost less bodyweight. Therefore, to improve welfare conditions for rats during WBP respiratory studies wet food should be provided when appropriate to the study design. In mice, provision of food and water led to changes in respiratory parameters, therefore these improvements in welfare conditions are not suitable for mice. Copyright © 2017. Published by Elsevier Inc.