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Sample records for leaky buildings isolation

  1. Optimization Criteria In Design Of Seismic Isolated Building

    SciTech Connect

    Clemente, Paolo; Buffarini, Giacomo

    2008-07-08

    Use of new anti-seismic techniques is certainly suitable for buildings of strategic importance and, in general, in the case of very high risk. For ordinary buildings, instead, the cost of base isolation system should be balanced by an equivalent saving in the structure. The comparison criteria have been first defined, then a large numerical investigation has been carried out to analyze the effectiveness and the economic suitability of seismic isolation in concrete buildings.

  2. Circular polarized leaky wave surface

    NASA Astrophysics Data System (ADS)

    Manene, Franklin; Lail, Brian A.; Kinzel, Edward C.

    2014-09-01

    A circular polarized (CP) infrared (IR) leaky wave surface design is presented. The metasurface consists of an array of rectangular patches connected by microstrip and operating over the long-wave infrared (LWIR) spectrum with directional wave emission and absorption. The surface is composed of periodically aligned arrays of sub-wavelength metal patches separated from a ground plane by a dielectric slab. The design combines the features of the conventional patch and leaky wave antenna leading to a metasurface that preferentially emits CP IR radiation by use of axial asymmetrical unit cells. This is a deviation from reported structures that mainly employ a phase shifter to combine linearly polarized waves in order to attain circular polarization. The performance of this leaky wave surface is verified through full-wave simulation using the ANSYS HFSS finite element analysis tool. The leaky wave phenomenon is demonstrated by the frequency and angular dependence of the absorption while circular polarization is characterized via stokes parameters. The main beam of this surface can be steered continuously by varying the frequency while maintaining circular polarization within the main beam direction. A CP leaky wave at 10.6 μm with a scanning angle of 30° is demonstrated. Metasurfaces exhibiting spectral and polarization selectivity in absorption/emission hold the potential for impact in IR applications including detection, imaging, thermal management, energy harvesting and tagging.

  3. Combating isolation: Building mutual mentoring networks

    NASA Astrophysics Data System (ADS)

    Cox, Anne J.

    2015-12-01

    Women physicists can often feel isolated at work. Support from a grant through the ADVANCE program of the National Science Foundation (U.S. government funding) created mutual mentoring networks aimed at combating isolation specifically for women faculty at undergraduate-only institutions. This paper will discuss the organization of one such network, what contributed to its success, some of the outcomes, and how it might be implemented in other contexts.

  4. Diseases associated with leaky hemichannels.

    PubMed

    Retamal, Mauricio A; Reyes, Edison P; Garca, Isaac E; Pinto, Bernardo; Martnez, Agustn D; Gonzlez, Carlos

    2015-01-01

    Hemichannels (HCs) and gap junction channels (GJCs) formed by protein subunits called connexins (Cxs) are major pathways for intercellular communication. While HCs connect the intracellular compartment with the extracellular milieu, GJCs allow the interchange of molecules between cytoplasm of two contacting cells. Under physiological conditions, HCs are mostly closed, but they can open under certain stimuli allowing the release of autocrine and paracrine molecules. Moreover, some pathological conditions, like ischemia or other inflammation conditions, significantly increase HCs activity. In addition, some mutations in Cx genes associated with human diseases, such as deafness or cataracts, lead to the formation of more active HCs or "leaky HCs." In this article we will revise cellular and molecular mechanisms underlying the appearance of leaky HCs, and the consequences of their expression in different cellular systems and animal models, in seeking a common pattern or pathological mechanism of disease. PMID:26283912

  5. Diseases associated with leaky hemichannels

    PubMed Central

    Retamal, Mauricio A.; Reyes, Edison P.; García, Isaac E.; Pinto, Bernardo; Martínez, Agustín D.; González, Carlos

    2015-01-01

    Hemichannels (HCs) and gap junction channels (GJCs) formed by protein subunits called connexins (Cxs) are major pathways for intercellular communication. While HCs connect the intracellular compartment with the extracellular milieu, GJCs allow the interchange of molecules between cytoplasm of two contacting cells. Under physiological conditions, HCs are mostly closed, but they can open under certain stimuli allowing the release of autocrine and paracrine molecules. Moreover, some pathological conditions, like ischemia or other inflammation conditions, significantly increase HCs activity. In addition, some mutations in Cx genes associated with human diseases, such as deafness or cataracts, lead to the formation of more active HCs or “leaky HCs.” In this article we will revise cellular and molecular mechanisms underlying the appearance of leaky HCs, and the consequences of their expression in different cellular systems and animal models, in seeking a common pattern or pathological mechanism of disease. PMID:26283912

  6. Retrofitting Heritage Buildings by Strengthening or Using Seismic Isolation

    NASA Astrophysics Data System (ADS)

    Danieli, Moshe; Bloch, Jacob; Ribakov, Yuri

    2008-07-01

    Many heritage buildings in the Mediterranean area include stone domes as a structural and architectural element. Present stage of these buildings often requires strengthening or retrofitting in order to increase their seismic resistance. Strengthening is possible by casting above existing dome a thin reinforced concrete shell with a support ring. It yields reduction of stresses and strains in the dome. This paper deals with examples of actual restoration and strengthening of three structures in Georgia, two of them damaged by an earthquake in 1991, (a temple in Nikortzminda and a synagogue in Oni, built in 11th and 19r century, respectively) and a mosque in Akhaltzikhe, built in 18th century. Retrofitting of these structures was aimed at preservation of initial geometry and appearance by creating composite (stonereinforced concrete, or stoneshotcrete) structures, which were partially or fully hidden. Further improving of seismic response may be achieved by using hybrid seismic isolation decreasing the seismic forces and adding damping. A brief description of the design procedure for such cases is presented.

  7. Retrofitting Heritage Buildings by Strengthening or Using Seismic Isolation

    SciTech Connect

    Danieli, Moshe; Bloch, Jacob; Ribakov, Yuri

    2008-07-08

    Many heritage buildings in the Mediterranean area include stone domes as a structural and architectural element. Present stage of these buildings often requires strengthening or retrofitting in order to increase their seismic resistance. Strengthening is possible by casting above existing dome a thin reinforced concrete shell with a support ring. It yields reduction of stresses and strains in the dome. This paper deals with examples of actual restoration and strengthening of three structures in Georgia, two of them damaged by an earthquake in 1991, (a temple in Nikortzminda and a synagogue in Oni, built in 11{sup th} and 19{sup r} century, respectively) and a mosque in Akhaltzikhe, built in 18th century. Retrofitting of these structures was aimed at preservation of initial geometry and appearance by creating composite (stone--reinforced concrete, or stone--shotcrete) structures, which were partially or fully hidden. Further improving of seismic response may be achieved by using hybrid seismic isolation decreasing the seismic forces and adding damping. A brief description of the design procedure for such cases is presented.

  8. Analysis of the seismic performance of isolated buildings according to life-cycle cost.

    PubMed

    Dang, Yu; Han, Jian-Ping; Li, Yong-Tao

    2015-01-01

    This paper proposes an indicator of seismic performance based on life-cycle cost of a building. It is expressed as a ratio of lifetime damage loss to life-cycle cost and determines the seismic performance of isolated buildings. Major factors are considered, including uncertainty in hazard demand and structural capacity, initial costs, and expected loss during earthquakes. Thus, a high indicator value indicates poor building seismic performance. Moreover, random vibration analysis is conducted to measure structural reliability and evaluate the expected loss and life-cycle cost of isolated buildings. The expected loss of an actual, seven-story isolated hospital building is only 37% of that of a fixed-base building. Furthermore, the indicator of the structural seismic performance of the isolated building is much lower in value than that of the structural seismic performance of the fixed-base building. Therefore, isolated buildings are safer and less risky than fixed-base buildings. The indicator based on life-cycle cost assists owners and engineers in making investment decisions in consideration of structural design, construction, and expected loss. It also helps optimize the balance between building reliability and building investment. PMID:25653677

  9. Analysis of the Seismic Performance of Isolated Buildings according to Life-Cycle Cost

    PubMed Central

    Dang, Yu; Han, Jian-ping; Li, Yong-tao

    2015-01-01

    This paper proposes an indicator of seismic performance based on life-cycle cost of a building. It is expressed as a ratio of lifetime damage loss to life-cycle cost and determines the seismic performance of isolated buildings. Major factors are considered, including uncertainty in hazard demand and structural capacity, initial costs, and expected loss during earthquakes. Thus, a high indicator value indicates poor building seismic performance. Moreover, random vibration analysis is conducted to measure structural reliability and evaluate the expected loss and life-cycle cost of isolated buildings. The expected loss of an actual, seven-story isolated hospital building is only 37% of that of a fixed-base building. Furthermore, the indicator of the structural seismic performance of the isolated building is much lower in value than that of the structural seismic performance of the fixed-base building. Therefore, isolated buildings are safer and less risky than fixed-base buildings. The indicator based on life-cycle cost assists owners and engineers in making investment decisions in consideration of structural design, construction, and expected loss. It also helps optimize the balance between building reliability and building investment. PMID:25653677

  10. Study on Application of Seismic Isolation System to ABWR-II Building

    SciTech Connect

    Hideaki Saito; Hideo Tanaka; Atsuko Noguchi; Junji Suhara; Yasuaki Fukushima

    2004-07-01

    This paper reports the result of a study that evaluated the applicability of the seismic isolation system to nuclear power plants. The study focuses on possibilities of a standard design with improved seismic safety of building and equipment for ABWR-II. A base isolation system with laminated lead rubber bearing was applied in the study. Based on the structural design of isolated buildings, it was confirmed that the design seismic loads can be largely reduced and that seismic elements of buildings and equipment can be easily designed compared with non-isolated buildings. Improvement in the building construction cost and period was also confirmed. The analytical results of seismic probabilistic safety assessments showed that an isolated building has a much higher degree of the seismic safety than a non-isolated building. The study concludes that the seismic isolation system is well applicable to ABWR-II plants. In addition, with an aim to enhance the earthquake-resistance of future ABWR-II plants, a building concept was developed, in which a lot of important equipment are laid out on a floor directly supported by the base isolation system. On this plant, further improvement of the seismic reliability is expected due to reduction of the seismic responses of important equipment. (authors)

  11. Successful performance of a base-isolated hospital building during the 17 January 1994 northridge earthquake

    USGS Publications Warehouse

    Celebi, M.

    1996-01-01

    The purpose of this paper is to examine the response records and thereby the performance of the base-isolated University of Southern California (USC) hospital building during the Ms = 6-8 Northridge (California) earthquake of 17 January 1994. The data retrieved from the building is the first set of data from any base-isolated building that (a) was tested to acceleration levels at the free-field similar to the zero period acceleration (ZPA) level postulated in the seismic design criteria of the building and (b) exhibits levels of relative displacement excursions which puts the isolators into the nonlinear range. The variation of the fundamental frequency as a function of changing instantaneous stiffness of the isolators is identifiable. During the shaking, the isolators (a) performed well and, having attained up to 10% hysteretic damping, effectively dissipated the incoming energy of motions and (b) reduced the drift ratios of the superstructure of the building to a maximum of 10% of the allowable, which should explain the fact that there was no damage to the structure or its contents. The primary conclusion of this study is that this base-isolated building performed well during the Northridge earthquake of 17 January 1994 when only approximately 10% of the displacement capability of the isolators were utilized. Therefore, there is every reason to believe that the building will perform well during future earthquakes in the region.

  12. Leaky Rayleigh wave investigation on mortar samples.

    PubMed

    Neuenschwander, J; Schmidt, Th; Lthi, Th; Romer, M

    2006-12-01

    Aggressive mineralized ground water may harm the concrete cover of tunnels and other underground constructions. Within a current research project mortar samples are used to study the effects of sulfate interaction in accelerated laboratory experiments. A nondestructive test method based on ultrasonic surface waves was developed to investigate the topmost layer of mortar samples. A pitch and catch arrangement is introduced for the generation and reception of leaky Rayleigh waves in an immersion technique allowing the measurement of their propagation velocity. The technique has been successfully verified for the reference materials aluminium, copper, and stainless steel. First measurements performed on mortar specimens demonstrate the applicability of this new diagnostic tool. PMID:16876218

  13. Effects Of Leaky Sewers On Groundwater Quality

    NASA Astrophysics Data System (ADS)

    Leschik, S.; Musolff, A.; Reinstorf, F.; Strauch, G.; Oswald, S. E.; Schirmer, M.

    2007-12-01

    The impact of urban areas on groundwater quality has become an emerging research field in hydrogeology. Urban subsurface infrastructures like sewer networks are often leaky, so untreated wastewater may enter the urban aquifer. The transport of wastewater into the groundwater is still not well understood under field conditions. In the research platform WASSER Leipzig (Water And Sewershed Study of Environmental Risk in Leipzig- Germany) the effects of leaky sewers on the groundwater quality are investigated. The research is focused on the occurrence and transport of so-called "xenobiotics" such as pharmaceuticals and personal care product additives. Xenobiotics may pose a threat on human health, but can also be considered a marker for an urban impact on water resources. A new test site was established in Leipzig to quantify mass fluxes of xenobiotics into the groundwater from a leaky sewer. Corresponding to the leaks which were detected by closed circuit television inspections, monitoring wells were installed up- and downstream of the sewer. Concentrations of eight xenobiotics (technical-nonylphenol, bisphenol-a, caffeine, galaxolide, tonalide, carbamazepine, phenazone, ethinylestradiol) obtained from first sampling programmes were found to be highly heterogeneous, but a relation between the position of the sampling points and the sewer could not be clearly identified. However, concentrations of sodium, chloride, potassium and nitrate increased significantly downstream of the sewer which may be due to wastewater exfiltration, since no other source is known on the water flowpath from the upstream to the downstream wells. Because of the highly heterogeneous spatial distribution of xenobiotics at the test site, a monitoring concept was developed comprising both high-resolution sampling and an integral approach to obtain representative average concentrations. Direct-push techniques were used to gain insight into the fine-scale spatial distribution of the target compounds. An integral pumping test was performed to determine the total xenobiotic mass fluxes along control planes down- and upstream of the leaky sewer. The new monitoring concept helped to obtain robust estimates of xenobiotic mass fluxes into the groundwater.

  14. Use of a viscoelastic model for the seismic response of base-isolated buildings

    SciTech Connect

    Uras, R.A.

    1994-06-01

    Due to recent developments in elastomer technology, seismic isolation using elastomer bearings is rapidly becoming an acceptable design tool to enhance structural seismic margins and to protect people and equipment from earthquake damage. With proper design of isolators, high-energy seismic input motions are transformed into low-frequency, low energy harmonic motions and the accelerations acting on the isolated building are significantly reduced. Several alternatives exist for the modeling of the isolators. This study is concerned with the use of a viscoelastic model to predict the seismic response of base-isolated buildings. The in-house finite element computer code has been modified to incorporate a viscoelastic spring element, and several simulations are performed. Then, the computed results have been compared with the corresponding observed data recorded at the test facility.

  15. Porphyrin-phospholipid liposomes with tunable leakiness.

    PubMed

    Luo, Dandan; Carter, Kevin A; Razi, Aida; Geng, Jumin; Shao, Shuai; Lin, Cuiyan; Ortega, Joaquin; Lovell, Jonathan F

    2015-12-28

    Drug bioavailability is a key consideration for drug delivery systems. When loaded with doxorubicin, liposomes containing 5 molar % porphyrin-phospholipid (HPPH liposomes) exhibited in vitro and in vivo serum stability that could be fine-tuned by varying the drug-to-lipid ratio. A higher drug loading ratio destabilized the liposomes, in contrast to standard liposomes which displayed an opposite and less pronounced trend. Following systemic administration of HPPH liposomes, near infrared laser irradiation induced vascular photodynamic damage, resulting in enhanced liposomal doxorubicin accumulation in tumors. In laser-irradiated tumors, the use of leaky HPPH liposomes resulted in improved doxorubicin bioavailability compared to stable standard liposomes. Using this approach, a single photo-treatment with 10mg/kg doxorubicin rapidly eradicated tumors in athymic nude mice bearing KB or MIA Paca-2 xenografts. PMID:26578438

  16. Modeling the behavior of an earthquake base-isolated building.

    SciTech Connect

    Coveney, V. A.; Jamil, S.; Johnson, D. E.; Kulak, R. F.; Uras, R. A.

    1997-11-26

    Protecting a structure against earthquake excitation by supporting it on laminated elastomeric bearings has become a widely accepted practice. The ability to perform accurate simulation of the system, including FEA of the bearings, would be desirable--especially for key installations. In this paper attempts to model the behavior of elastomeric earthquake bearings are outlined. Attention is focused on modeling highly-filled, low-modulus, high-damping elastomeric isolator systems; comparisons are made between standard triboelastic solid model predictions and test results.

  17. An optical leaky wave antenna with silicon perturbations for electronic control

    NASA Astrophysics Data System (ADS)

    Campione, Salvatore; Song, Qi; Boyraz, Ozdal; Capolino, Filippo

    2011-10-01

    An optical leaky wave antenna (OLWA) is a device that radiates a light wave into the surrounding space from a leaky wave (LW) guided mode or receives optical power from the surrounding space into a guided optical mode. In this work, we propose and provide a 3D analysis of a novel CMOS compatible OLWA made of a silicon nitride (Si3N4) waveguide comprising periodic silicon perturbations which allow electronic tuning capability. The analysis presented here includes the effect of the number of semiconductor perturbations, the antenna radiation pattern and directivity. We show that the number of the silicon perturbations has to be large to provide a long radiating section required to achieve radiation with high directivity. In other words, the proposed structure allows for a very narrow-beam radiation. Preliminary results are confirmed by exploiting leaky wave and antenna array factor theory, as well as verified by means of two full-wave simulators (HFSS and COMSOL). Our purpose is to ultimately use PIN junctions as building blocks for each silicon implantation for the electronic control of the radiation. In particular, the electronic tunability of the optical parameters of silicon (such as refractive index and absorption coefficient) via current injection renders itself the ideal platform for optical antennas that can facilitate electronic beam control, and boost the efficiency of optoelectronic devices such as light-emitting diodes, lasers and solar cells, and bio-chemical sensors.

  18. Leaky Rayleigh and Scholte waves at the fluid-solid interface subjected to transient point loading

    NASA Astrophysics Data System (ADS)

    Zhu, Jinying; Popovics, John S.; Schubert, Frank

    2004-10-01

    The analysis of acoustic waves generated by a transient normal point load applied on a fluid-solid interface is presented. The closed-form exact solution of the wave motion is obtained by using integral transform techniques. The obtained analytical solution provides necessary theoretical background for optimization of fluid-coupled ultrasonic and acoustic wave detection in experiments. Numerical simulation (elastodynamic finite integration technique) is performed to verify the obtained analytical solution. Detailed descriptions of leaky Rayleigh and Scholte wave solutions are presented. A simplified solution to isolate the contributions of leaky Rayleigh and Scholte waves generated by a transient point load is proposed, and closed-form formulations for displacement and stress components are then presented. The simplified solution is compared to the exact solution for two configurations: water/concrete and air/concrete. The excitation effectiveness of leaky Rayleigh waves for the air/concrete configuration is studied, which has practical significance to air-coupled sensing in civil engineering structures. .

  19. Visualization of Leaky Ultrasonic Lamb Wave Experiments in Multilayer Structures

    NASA Astrophysics Data System (ADS)

    Klieber, C.; Brill, T. M.; Catheline, S.; Vincensini, Y.; Mege, F.

    Leaky ultrasonic Lamb waves propagating in liquid-filled steel pipes are widely used by the oilfield service industry in wellbores to measure the acoustic properties of the material located outside the pipe. Typically, the annular region between the steel pipe and the geological formation is cemented to provide mechanical integrity and to ensure hydraulic isolation between different geological layers in the well. We present results from an experimental study along spatial and temporal dimensions to visualize the propagating waveforms of such measurements for liquid or solid annular materialsbehind the steel pipe. Our measurements focus on the lowest-order flexural waves. These radiate energy into neighboring layers if the flexural phase speed is supersonic with respect to the bulk compressional- or shear-wave phase speeds of the adjacent media. In the case of a compressional phase speed higher than the flexural phase speed, the resulting flexural mode attenuation is then strongly reduced. Several annular materials with compressional velocities higher and lower than the flexural phase speed were investigated to demonstrate this effect. Finally, the propagation of compact flexural-wave packets along the steel pipe was recorded, and the results were compared with computed modal dispersion and attenuation curves.

  20. All-optical excitation and detection of leaky Rayleigh waves.

    PubMed

    Desmet, C; Gusev, V; Lauriks, W; Glorieux, C; Thoen, J

    1997-01-15

    The results of experiments on all-optical monitoring of leaky Rayleigh waves are reported. Leaky Rayleigh waves were excited by pulsed laser action on a liquid-solid interface and were detected by the light-beam-deflection technique. Both the measured velocity of their propagation and the attenuation are in good agreement with theoretical predictions. Possible applications include acoustic spectroscopy of materials, depth profiling of layered structures, and tabletop modeling of seismic phenomena. PMID:18183105

  1. Response of high-rise and base-isolated buildings to a hypothetical mw 7.0 blind thrust earthquake.

    PubMed

    Heaton, T H; Hall, J F; Wald, D J; Halling, M W

    1995-01-13

    High-rise flexible-frame buildings are commonly considered to be resistant to shaking from the largest earthquakes. In addition, base isolation has become increasingly popular for critical buildings that should still function after an earthquake. How will these two types of buildings perform if a large earthquake occurs beneath a metropolitan area? To answer this question, we simulated the near-source ground motions of a M(w) 7.0 thrust earthquake and then mathematically modeled the response of a 20-story steel-frame building and a 3-story base-isolated building. The synthesized ground motions were characterized by large displacement pulses (up to 2 meters) and large ground velocities. These ground motions caused large deformation and possible collapse of the frame building, and they required exceptional measures in the design of the base-isolated building if it was to remain functional. PMID:17791340

  2. Seismic response of base-isolated buildings using a viscoelastic model

    SciTech Connect

    Uras, R.A.

    1993-08-01

    Due to recent developments in elastomer technology,seismic isolation using elastomer bearings is rapidly gaining acceptance as a design tool to enhance structural seismic margins and to protect people and equipment from earthquake damage. With proper design of isolators, the fundamental frequency of the structure can be reduced to a value that is lower than the dominant frequencies of earthquake ground motions. The other feature of an isolation system is that it can provide a mechanism for energy dissipation. In the USA, the use of seismic base-isolation has become an alternate strategy for advanced Liquid Metal-cooled Reactors (LMRs). ANL has been deeply involved in the development and implementation of seismic isolation for use in both nuclear facilities and civil structures for the past decade. Shimizu Corporation of Japan has a test facility at Tohoku University in Sendai, Japan. The test facility has two buildings: one is base isolated and the other is conventionally founded. The buildings are full-size, three-story reinforced concrete structures. The dimensions and construction of the superstructures are identical. They were built side by side in a seismically active area. In 1988, the ANL/Shimizu Joint Program was established to study the differences in behavior of base-isolated and ordinarily founded structures when subjected to earthquake loading. A more comprehensive description of this joint program is presented in a companion paper (Wang et al. 1993). With the increased use of elastomeric polymers in industrial applications such as isolation bearings, the importance of constitutive modeling of viscoelastic materials is more and more pronounced. A realistic representation of material behavior is essential for computer simulations to replicate the response observed in experiments.

  3. Development of a novel multi-layer MRE isolator for suppression of building vibrations under seismic events

    NASA Astrophysics Data System (ADS)

    Yang, Jian; Sun, Shuaishuai; Tian, Tongfei; Li, Weihua; Du, Haiping; Alici, Gursel; Nakano, Masami

    2016-03-01

    Protecting civil engineering structures from uncontrollable events such as earthquakes while maintaining their structural integrity and serviceability is very important; this paper describes the performance of a stiffness softening magnetorheological elastomer (MRE) isolator in a scaled three storey building. In order to construct a closed-loop system, a scaled three storey building was designed and built according to the scaling laws, and then four MRE isolator prototypes were fabricated and utilised to isolate the building from the motion induced by a scaled El Centro earthquake. Fuzzy logic was used to output the current signals to the isolators, based on the real-time responses of the building floors, and then a simulation was used to evaluate the feasibility of this closed loop control system before carrying out an experimental test. The simulation and experimental results showed that the stiffness softening MRE isolator controlled by fuzzy logic could suppress structural vibration well.

  4. Optimal PD/PID control of smart base isolated buildings equipped with piezoelectric friction dampers

    NASA Astrophysics Data System (ADS)

    Etedali, Sadegh; Sohrabi, Mohammad Reza; Tavakoli, Saeed

    2013-03-01

    Long-period pulses in near-field earthquakes lead to large displacements in the base of isolated structures. To dissipate energy in isolated structures using semi-active control, piezoelectric friction dampers (PFD) can be employed. The performance of a PFD is highly dependent on the strategy applied to adjust its contact force. In this paper, the seismic control of a benchmark isolated building equipped with PFD using PD/PID controllers is developed. Using genetic algorithms, these controllers are optimized to create a balance between the performance and robustness of the closed-loop structural system. One advantage of this technique is that the controller forces can easily be estimated. In addition, the structure is equipped with only a single sensor at the base floor to measure the base displacement. Considering seven pairs of earthquakes and nine performance indices, the performance of the closed-loop system is evaluated. Then, the results are compared with those given by two well-known methods: the maximum possive operation of piezoelectric friction dampers and LQG controllers. The simulation results show that the proposed controllers perform better than the others in terms of simultaneous reduction of floor acceleration and maximum displacement of the isolator. Moreover, they are able to reduce the displacement of the isolator systems for different earthquakes without losing the advantages of isolation.

  5. Middle School Girls and the "Leaky Pipeline" to Leadership

    ERIC Educational Resources Information Center

    Shapiro, Mary; Grossman, Diane; Carter, Suzanne; Martin, Karyn; Deyton, Patricia; Hammer, Diane

    2015-01-01

    Why do girls perform so well academically yet lose ground as professional women? This diminishing number of women up the leadership hierarchy is often referred to as the "leaky pipeline," and attributed to many factors: external ones such as work environments not conducive to work/life balance, and internal ones such as women's own…

  6. Leaky coaxial cable signal transmission for remote facilities

    NASA Astrophysics Data System (ADS)

    Smith, S. F.; Crutcher, R. I.

    To develop reliable communications methods to meet the rigorous requirements for nuclear hot cells and similar environments, including control of cranes, transporters, and advanced servomanipulators, the Consolidated Fuel Reprocessing Program (CFRP) at Oak Ridge National Laboratory (ORNL) has conducted extensive tests of numerous technologies to determine their applicability to remote operations. To alleviate the need for large bundles of cables that must accommodate crane/transporter motion relative to the boundaries of the cell, several transmission techniques are available, including slotted-line radio-frequency couplers, infrared beams, fiber-optic cables, free-space microwave, and inductively coupled leaky coaxial cable. This paper discusses the general characteristics, mode of operation, and proposed implementation of leaky coaxial cable technology in a waste-handling facility scheduled to be built in the near future at ORNL. In addition, specific system hardware based around the use of leaky coaxial cable is described in detail. Finally, data from a series of radiation exposure tests conducted by the CFRP on several samples of the basic leaky coaxial cable and associated connectors are presented.

  7. Adaptive control of base-isolated buildings using piezoelectric friction dampers against near-field earthquakes

    NASA Astrophysics Data System (ADS)

    Bitaraf, Maryam; Ozbulut, Osman E.; Hurlebaus, Stefan

    2010-04-01

    This paper investigates the effectiveness of two adaptive control strategies for modulating control force of piezoelectric friction dampers (PFDs) that are employed as semi-active devices in combination with laminated rubber bearings for seismic protection of buildings. The first controller developed in this study is a direct adaptive fuzzy logic controller. It consists of an upper-level and a sub-level direct fuzzy controller. In the hierarchical control scheme, higher-level controller modifies universe of discourse of both premise and consequent variables of the sub-level controller using scaling factors in order to determine command voltage of the damper according to current level of ground motion. The sub-level fuzzy controller employs isolation displacement and velocity as its premise variables and command voltage as its consequent variable. The second controller is based on the simple adaptive control (SAC) method, which is a type of direct adaptive control approach. The objective of the SAC method is to make the plant, the controlled system, track the behavior of the structure with the optimum performance. By using SAC strategy, any change in the characteristics of the structure or uncertainties in the modeling of the structure and in the external excitation would be considered because it continuously monitors its own performance to modify its parameters. Here, SAC methodology is employed to obtain the required force which results in the optimum performance of the structure. Then, the command voltage of the PFD is determined to generate the desired force. For comparison purposes, an optimal controller is also developed and considered in the simulations together with maximum passive operation of the friction damper. Time-history analyses of a base-isolated five-story building are performed to evaluate the performance of the controllers. Results reveal that developed adaptive controllers can successfully improve seismic response of the base-isolated buildings against various types of earthquakes.

  8. Leader neurons in leaky integrate and fire neural network simulations.

    PubMed

    Zbinden, Cyrille

    2011-10-01

    In this paper, we highlight the topological properties of leader neurons whose existence is an experimental fact. Several experimental studies show the existence of leader neurons in population bursts of activity in 2D living neural networks (Eytan and Marom, J Neurosci 26(33):8465-8476, 2006; Eckmann et al., New J Phys 10(015011), 2008). A leader neuron is defined as a neuron which fires at the beginning of a burst (respectively network spike) more often than we expect by chance considering its mean firing rate. This means that leader neurons have some burst triggering power beyond a chance-level statistical effect. In this study, we characterize these leader neuron properties. This naturally leads us to simulate neural 2D networks. To build our simulations, we choose the leaky integrate and fire (lIF) neuron model (Gerstner and Kistler 2002; Cessac, J Math Biol 56(3):311-345, 2008), which allows fast simulations (Izhikevich, IEEE Trans Neural Netw 15(5):1063-1070, 2004; Gerstner and Naud, Science 326:379-380, 2009). The dynamics of our lIF model has got stable leader neurons in the burst population that we simulate. These leader neurons are excitatory neurons and have a low membrane potential firing threshold. Except for these two first properties, the conditions required for a neuron to be a leader neuron are difficult to identify and seem to depend on several parameters involved in the simulations themselves. However, a detailed linear analysis shows a trend of the properties required for a neuron to be a leader neuron. Our main finding is: A leader neuron sends signals to many excitatory neurons as well as to few inhibitory neurons and a leader neuron receives only signals from few other excitatory neurons. Our linear analysis exhibits five essential properties of leader neurons each with different relative importance. This means that considering a given neural network with a fixed mean number of connections per neuron, our analysis gives us a way of predicting which neuron is a good leader neuron and which is not. Our prediction formula correctly assesses leadership for at least ninety percent of neurons. PMID:21234795

  9. Radial flow towards well in leaky unconfined aquifer

    NASA Astrophysics Data System (ADS)

    Mishra, P. K.; Kuhlman, K. L.

    2012-12-01

    An analytical solution is developed for three-dimensional flow towards a partially penetrating large- diameter well in an unconfined aquifer bounded below by a leaky aquitard of finite or semi-infinite extent. The analytical solution is derived using Laplace and Hankel transforms, then inverted numerically. Existing solutions for flow in leaky unconfined aquifers neglect the unsaturated zone following an assumption of instantaneous drainage due to Neuman. We extend the theory of leakage in unconfined aquifers by (1) including water flow and storage in the unsaturated zone above the water table, and (2) allowing the finite-diameter pumping well to partially penetrate the aquifer. The investigation of model-predicted results shows that aquitard leakage leads to significant departure from the unconfined solution without leakage. The investigation of dimensionless time-drawdown relationships shows that the aquitard drawdown also depends on unsaturated zone properties and the pumping-well wellbore storage effects.

  10. Optical leaky waveguide biosensors for the detection of organophosphorus pesticides.

    PubMed

    Zourob, M; Simonian, A; Wild, J; Mohr, S; Fan, Xudong; Abdulhalim, I; Goddard, N J

    2007-02-01

    Organophosphorus (OP) pesticides can be rapidly detected by integrating organophosphorus hydrolase with an optical leaky waveguide biosensor. This enzyme catalyses the hydrolysis of a wide range of organophosphorus compounds causing an increase in the pH. Thus, the direct detection of OP is possible by monitoring of the pH changes associated with the enzyme's activity. This article describes the use of an optical, leaky waveguide clad with absorbing materials for the detection of OP pesticides by measuring changes in refractive index, absorbance and fluorescence. In the most effective configuration, a thick sensing layer was used to increase the amount of immobilized enzyme and to increase the light interaction with the sensing layer, resulting in a greatly enhanced sensitivity. The platforms developed in this work were successfully used to detect paraoxon and parathion down to 4 nM concentrations. PMID:17260070

  11. Direct and indirect effects of UVA on skin vessel leakiness

    SciTech Connect

    Staberg, B.; Worm, A.M.; Brodthagen, H.; Rossing, N.

    1982-12-01

    By using the suction blister technique we have investigated the leakiness of skin vessels in healthy volunteers after whole-body suberythemogenic doses of UVA radiation (a quadrant on one side of the abdominal skin was shielded with lead-rubber). The accumulation of intravenously injected labeled albumin in blister fluid was slightly elevated 1 day after irradiation and increased significantly 2 days later. The blister concentrations of 4 endogenous plasma proteins (albumin, transferrin, IgG, and alpha 2-macroglobulin) were elevated 1 day after radiation exposure and normalized 2 days later. All changes were equal on irradiated and nonirradiated skin. It is concluded that UVA radiation can induce a continued or biphasic increased leakage of plasma proteins in the skin vessels, due to a humoral rather than to a direct physical effect of the radiation on the vessel walls. It is suggested that an increased microvascular leakiness in organs other than the skin might be present.

  12. Holographic leaky-wave metasurfaces for dual-sensor imaging

    PubMed Central

    Li, Yun Bo; Li, Lian Lin; Cai, Ben Geng; Cheng, Qiang; Cui, Tie Jun

    2015-01-01

    Metasurfaces have huge potentials to develop new type imaging systems due to their abilities of controlling electromagnetic waves. Here, we propose a new method for dual-sensor imaging based on cross-like holographic leaky-wave metasurfaces which are composed of hybrid isotropic and anisotropic surface impedance textures. The holographic leaky-wave radiations are generated by special impedance modulations of surface waves excited by the sensor ports. For one independent sensor, the main leaky-wave radiation beam can be scanned by frequency in one-dimensional space, while the frequency scanning in the orthogonal spatial dimension is accomplished by the other sensor. Thus, for a probed object, the imaging plane can be illuminated adequately to obtain the two-dimensional backward scattered fields by the dual-sensor for reconstructing the object. The relativity of beams under different frequencies is very low due to the frequency-scanning beam performance rather than the random beam radiations operated by frequency, and the multi-illuminations with low relativity are very appropriate for multi-mode imaging method with high resolution and anti- noise. Good reconstruction results are given to validate the proposed imaging method. PMID:26658471

  13. Holographic leaky-wave metasurfaces for dual-sensor imaging

    NASA Astrophysics Data System (ADS)

    Li, Yun Bo; Li, Lian Lin; Cai, Ben Geng; Cheng, Qiang; Cui, Tie Jun

    2015-12-01

    Metasurfaces have huge potentials to develop new type imaging systems due to their abilities of controlling electromagnetic waves. Here, we propose a new method for dual-sensor imaging based on cross-like holographic leaky-wave metasurfaces which are composed of hybrid isotropic and anisotropic surface impedance textures. The holographic leaky-wave radiations are generated by special impedance modulations of surface waves excited by the sensor ports. For one independent sensor, the main leaky-wave radiation beam can be scanned by frequency in one-dimensional space, while the frequency scanning in the orthogonal spatial dimension is accomplished by the other sensor. Thus, for a probed object, the imaging plane can be illuminated adequately to obtain the two-dimensional backward scattered fields by the dual-sensor for reconstructing the object. The relativity of beams under different frequencies is very low due to the frequency-scanning beam performance rather than the random beam radiations operated by frequency, and the multi-illuminations with low relativity are very appropriate for multi-mode imaging method with high resolution and anti- noise. Good reconstruction results are given to validate the proposed imaging method.

  14. Holographic leaky-wave metasurfaces for dual-sensor imaging.

    PubMed

    Li, Yun Bo; Li, Lian Lin; Cai, Ben Geng; Cheng, Qiang; Cui, Tie Jun

    2015-01-01

    Metasurfaces have huge potentials to develop new type imaging systems due to their abilities of controlling electromagnetic waves. Here, we propose a new method for dual-sensor imaging based on cross-like holographic leaky-wave metasurfaces which are composed of hybrid isotropic and anisotropic surface impedance textures. The holographic leaky-wave radiations are generated by special impedance modulations of surface waves excited by the sensor ports. For one independent sensor, the main leaky-wave radiation beam can be scanned by frequency in one-dimensional space, while the frequency scanning in the orthogonal spatial dimension is accomplished by the other sensor. Thus, for a probed object, the imaging plane can be illuminated adequately to obtain the two-dimensional backward scattered fields by the dual-sensor for reconstructing the object. The relativity of beams under different frequencies is very low due to the frequency-scanning beam performance rather than the random beam radiations operated by frequency, and the multi-illuminations with low relativity are very appropriate for multi-mode imaging method with high resolution and anti- noise. Good reconstruction results are given to validate the proposed imaging method. PMID:26658471

  15. Design of isolated buildings with S-FBI system subjected to near-fault earthquakes using NSGA-II algorithm

    NASA Astrophysics Data System (ADS)

    Ozbulut, O. E.; Silwal, B.

    2014-04-01

    This study investigates the optimum design parameters of a superelastic friction base isolator (S-FBI) system through a multi-objective genetic algorithm and performance-based evaluation approach. The S-FBI system consists of a flat steel- PTFE sliding bearing and a superelastic NiTi shape memory alloy (SMA) device. Sliding bearing limits the transfer of shear across the isolation interface and provides damping from sliding friction. SMA device provides restoring force capability to the isolation system together with additional damping characteristics. A three-story building is modeled with S-FBI isolation system. Multiple-objective numerical optimization that simultaneously minimizes isolation-level displacements and superstructure response is carried out with a genetic algorithm (GA) in order to optimize S-FBI system. Nonlinear time history analyses of the building with S-FBI system are performed. A set of 20 near-field ground motion records are used in numerical simulations. Results show that S-FBI system successfully control response of the buildings against near-fault earthquakes without sacrificing in isolation efficacy and producing large isolation-level deformations.

  16. Scenario development for the Waste Isolation Pilot Plant: Building confidence in the assessment

    SciTech Connect

    Galson, D.A.; Swift, P.N.

    1994-03-01

    Scenario developments is part of the iterative performance assessment (PA) process for the Waste Isolation Pilot Plant (WIPP). Scenario development for the WIPP has been the subject of intense external review, and is certain to be the subject of continued scrutiny as the project proceeds toward regulatory compliance. The principal means of increasing confidence is this aspect of the PA will be through the use of a systematic and thorough procedure toward developing the scenarios and conceptual models on which the assessment is to be based. Early and ongoing interaction with project reviewers can assist with confidence building. Quality of argument and clarity of presentation in PA will be of key concern. Appropriate tools are required for documenting and tracking assumptions, through a single assessment phase, and between iterative assessment phases. Risks associated with future human actions are of particular concern to the WIPP project, and international consensus on the principles for incorporation of future human actions in assessments would be valuable.

  17. Scenario development for the Waste Isolation Pilot Plant: Building confidence in the assessment

    SciTech Connect

    Galson, D.A.; Swift, P.N.

    1994-07-01

    Scenario development is part of the iterative performance assessment (PA) process for the Waste Isolation Pilot Plant (WIPP). Scenario development for the WIPP has been the subject of intense external review and is certain to be the subject of continued scrutiny as the project proceeds toward regulatory compliance. The principal means of increasing confidence in this aspect of the PA will be through the use of the systematic and thorough procedure toward developing the scenarios and conceptual models on which the assessment is to be based. Early and ongoing interaction with project reviewers can assist with confidence building. Quality of argument and clarity of presentation in PA will be of key concern. Appropriate tools are required for documenting and tracking assumptions, through a single assessment phase, and between iterative assessment phases. Risks associated with future human actions are of particular concern to the WIPP project, and international consensus on the principles for incorporation of future human actions in assessments would be valuable.

  18. Experimental study on flow and gaseous diffusion behind an isolated building.

    PubMed

    Yassin, Mohamed F; Ohba, Masaake; Tanaka, Hideyuki

    2008-12-01

    To assist validation of numerical models of urban pollution dispersion, the effect of obstacles building on the gaseous diffusion in the wake region have been investigated experimentally in the boundary layer wind tunnel under neutral atmospheric conditions using a tracer gas technique from a point source without buoyancy. The flow and diffusion fields in the boundary layer in an urban environment were investigated in the downwind distance of the obstacle building using an isolated high-rise building model. The scale of the model experiment was assumed to be at 1:500. In the experiment, gaseous pollutant was discharged in the simulated boundary layer over the flat terrain. The effluent velocity of the pollutant was set to be negligible. The velocity field and the turbulence characteristics were analyzed and measured using a hot wire anemometer with a split-fibre probe. The experimental technique was involved the continuous release of tracer gas from a ground level source which was located in the downwind distance of the obstacle model and measured using a fast flame ionization detector (FID). Diffusion characteristics were studied and included both the vertical and lateral mean concentrations and concentration fluctuation intensity at various downwind distances. The results of study were demonstrated that the vertical profiles of the longitudinal mean velocity are very thick around the obstacle wake region due to the turbulence mixing and the smoothing of concentration differences was increased with downwind distance from the obstacle model. Furthermore, the experimental results can help to improve the understanding of mechanisms of pollutant dispersion in an urban environment and also use to validate the corresponding computational fluid dynamics (CFD) prediction. PMID:18193336

  19. Earthquake Resilient Tall Reinforced Concrete Buildings at Near-Fault Sites Using Base Isolation and Rocking Core Walls

    NASA Astrophysics Data System (ADS)

    Calugaru, Vladimir

    This dissertation pursues three main objectives: (1) to investigate the seismic response of tall reinforced concrete core wall buildings, designed following current building codes, subjected to pulse type near-fault ground motion, with special focus on the relation between the characteristics of the ground motion and the higher-modes of response; (2) to determine the characteristics of a base isolation system that results in nominally elastic response of the superstructure of a tall reinforced concrete core wall building at the maximum considered earthquake level of shaking; and (3) to demonstrate that the seismic performance, cost, and constructability of a base-isolated tall reinforced concrete core wall building can be significantly improved by incorporating a rocking core-wall in the design. First, this dissertation investigates the seismic response of tall cantilever wall buildings subjected to pulse type ground motion, with special focus on the relation between the characteristics of ground motion and the higher-modes of response. Buildings 10, 20, and 40 stories high were designed such that inelastic deformation was concentrated at a single flexural plastic hinge at their base. Using nonlinear response history analysis, the buildings were subjected to near-fault seismic ground motions as well as simple close-form pulses, which represented distinct pulses within the ground motions. Euler-Bernoulli beam models with lumped mass and lumped plasticity were used to model the buildings. Next, this dissertation investigates numerically the seismic response of six seismically base-isolated (BI) 20-story reinforced concrete buildings and compares their response to that of a fixed-base (FB) building with a similar structural system above ground. Located in Berkeley, California, 2 km from the Hayward fault, the buildings are designed with a core wall that provides most of the lateral force resistance above ground. For the BI buildings, the following are investigated: two isolation systems (both implemented below a three-story basement), isolation periods equal to 4, 5, and 6 s, and two levels of flexural strength of the wall. The first isolation system combines tension-resistant friction pendulum bearings and nonlinear fluid viscous dampers (NFVDs); the second combines low-friction tension-resistant cross-linear bearings, lead-rubber bearings, and NFVDs. Finally, this dissertation investigates the seismic response of four 20-story buildings hypothetically located in the San Francisco Bay Area, 0.5 km from the San Andreas fault. One of the four studied buildings is fixed-base (FB), two are base-isolated (BI), and one uses a combination of base isolation and a rocking core wall (BIRW). Above the ground level, a reinforced concrete core wall provides the majority of the lateral force resistance in all four buildings. The FB and BI buildings satisfy requirements of ASCE 7-10. The BI and BIRW buildings use the same isolation system, which combines tension-resistant friction pendulum bearings and nonlinear fluid viscous dampers. The rocking core-wall includes post-tensioning steel, buckling-restrained devices, and at its base is encased in a steel shell to maximize confinement of the concrete core. The total amount of longitudinal steel in the wall of the BIRW building is 0.71 to 0.87 times that used in the BI buildings. Response history two-dimensional analysis is performed, including the vertical components of excitation, for a set of ground motions scaled to the design earthquake and to the maximum considered earthquake (MCE). While the FB building at MCE level of shaking develops inelastic deformations and shear stresses in the wall that may correspond to irreparable damage, the BI and the BIRW buildings experience nominally elastic response of the wall, with floor accelerations and shear forces which are 0.36 to 0.55 times those experienced by the FB building. The response of the four buildings to two historical and two simulated near-fault ground motions is also studied, demonstrating that the BIRW building has the largest de

  20. Ultrasonic characterization of functionally gradient materials with leaky Rayleigh wave

    NASA Astrophysics Data System (ADS)

    Kawashima, Koichiro; Takenouchi, Naoki; Awaji, Hideo; Nishikawa, Tadahiro

    1999-12-01

    Young's modulus of functionally gradient Al2O3/Ni ceramics, which was formed by centrifugal casting and has gradient of the elastic properties along a particular direction on the surface, is estimated by velocity measurement of the leaky Rayleigh and longitudinal waves. Those velocities were measured every 1mm with a line focused PVDF transducer, of which central frequency, focal length and width are 36MHz, 5mm and 8mm. Thus measured Young's modulus varies from 370GPa (Al2O3 rich side) to 200GPa (Ni rich side).

  1. DISPERSION OF ROOF-TOP EMISSIONS FROM ISOLATED BUILDINGS. A WIND TUNNEL STUDY

    EPA Science Inventory

    A fluid modeling study of the dispersion of roof-top emissions from rectangular buildings was performed in the meteorological wind tunnel of the EPA Fluid Modeling Facility. The basic building shape was a 0.18 meter cube. Variations included a building twice as wide and buildings...

  2. Ultrasonic Lateral Displacement Sensor for Health Monitoring in Seismically Isolated Buildings.

    PubMed

    Matsuya, Iwao; Matsumoto, Fumiya; Ihara, Ikuo

    2015-01-01

    An ultrasonic lateral displacement sensor utilizing air-coupled ultrasound transducers is proposed. The normally-distributed far field of an ultrasound transducer in a lateral direction is taken advantage of for measuring lateral displacement. The measurement system is composed of several air-coupled ultrasound transducers as a receiver and several transmitters. The transmitters are immobilized at a fixed point, whereas the receiver set-up is separately arranged on the opposite side. In order to improve measurement accuracy, a correction method that utilizes polynomial approximation is introduced. The difference between the corrected lateral displacement and the reference displacement is estimated to be 0.2 mm at maximum for the two transmitters system. A good responsiveness is demonstrated by conducting a dynamic response experiment. When five transmitters are arranged, their measurement range is easily extended up to 60 mm with an accuracy of 0.7 mm. In both cases, the fluctuations to the measurement ranges show less than 1%. These results indicate that the developed sensor system is useful for measuring relative lateral displacement of a seismically isolated building in the field of structural health monitoring. PMID:26184220

  3. Ultrasonic Lateral Displacement Sensor for Health Monitoring in Seismically Isolated Buildings

    PubMed Central

    Matsuya, Iwao; Matsumoto, Fumiya; Ihara, Ikuo

    2015-01-01

    An ultrasonic lateral displacement sensor utilizing air-coupled ultrasound transducers is proposed. The normally-distributed far field of an ultrasound transducer in a lateral direction is taken advantage of for measuring lateral displacement. The measurement system is composed of several air-coupled ultrasound transducers as a receiver and several transmitters. The transmitters are immobilized at a fixed point, whereas the receiver set-up is separately arranged on the opposite side. In order to improve measurement accuracy, a correction method that utilizes polynomial approximation is introduced. The difference between the corrected lateral displacement and the reference displacement is estimated to be 0.2 mm at maximum for the two transmitters system. A good responsiveness is demonstrated by conducting a dynamic response experiment. When five transmitters are arranged, their measurement range is easily extended up to ±60 mm with an accuracy of 0.7 mm. In both cases, the fluctuations to the measurement ranges show less than 1%. These results indicate that the developed sensor system is useful for measuring relative lateral displacement of a seismically isolated building in the field of structural health monitoring. PMID:26184220

  4. Metal clad leaky waveguides for chemical and biosensing applications.

    PubMed

    Zourob, Mohammed; Goddard, Nicholas J

    2005-03-15

    Novel metal clad leaky waveguide (MCLW) sensor devices have been developed for sensing applications. These chips are designed to confine the light in a low refractive index waveguide that encompasses the chemically-selective layer, maximising the overlap between the optical mode and the chemistry, thus improving the sensitivity. In this work, a thin metal layer was inserted between the substrate and the thick waveguide layer, increasing the reflectivity of the waveguide/metal interface and decreasing the light lost at each of reflection in the leaky mode, which in turn increases the propagation distance. The device has been used for a range of biosensing applications, including the detection of organophosphoros pesticides. The limit of detection for paraoxon, based on absorbance detection, was calculated to be 6 nM. Refractive index detection was demonstrated by monitoring the change in the out-coupled angle resulting from the binding of protein A to anti-protein A immobilized on agarose. The sensor was also used for detecting the quenching of the fluorescence of an acid-base sensitive ruthenium complex immobilized within the sol-gel and with glucose oxidase enzyme. The limit of detection for glucose was 3 microM. The advantage of using the metal layer in the MCLW was that an electrical potential could be applied to accelerate the diffusion of the analyte to the immobilised antibody, which resulted in a shortened analysis time and a reduction in non-specific binding. PMID:15681186

  5. Response of high-rise and base-isolated buildings to a hypothetical M w 7.0 blind thrust earthquake

    USGS Publications Warehouse

    Heaton, T.H.; Hall, J.F.; Wald, D.J.; Halling, M.W.

    1995-01-01

    High-rise flexible-frame buildings are commonly considered to be resistant to shaking from the largest earthquakes. In addition, base isolation has become increasingly popular for critical buildings that should still function after an earthquake. How will these two types of buildings perform if a large earthquake occurs beneath a metropolitan area? To answer this question, we simulated the near-source ground motions of a Mw 7.0 thrust earthquake and then mathematically modeled the response of a 20-story steel-frame building and a 3-story base-isolated building. The synthesized ground motions were characterized by large displacement pulses (up to 2 meters) and large ground velocities. These ground motions caused large deformation and possible collapse of the frame building, and they required exceptional measures in the design of the base-isolated building if it was to remain functional.

  6. Modestobacter lapidis sp. nov. and Modestobacter muralis sp. nov., isolated from a deteriorated sandstone historic building in Salamanca, Spain.

    PubMed

    Trujillo, Martha E; Goodfellow, Michael; Busarakam, Kanungnid; Riesco, Raul

    2015-08-01

    A polyphasic study was undertaken to establish the taxonomic status of two Modestobacter strains isolated from the surface of deteriorated sandstone of a historic building in Salamanca, Spain. The strains, isolates MDVD1(T) and MON 3.1(T), were found to have chemotaxonomic and morphological properties consistent with their classification in the genus Modestobacter and to form distinct phyletic lines in the Modestobacter 16S rRNA gene tree. Isolate MDVD1(T) was found to be closely related to the type strain of Modestobacter versicolor (98.7 % similarity) and isolate MON 3.1(T) to the type strain of Modestobacter multiseptatus (98.6 % similarity). The isolates were distinguished readily from one another and from the Modestobacter type strains by a broad range of phenotypic properties, by qualitative and quantitative differences in fatty acid profiles and by BOX fingerprint patterns. On the basis of these data, it is proposed that the isolates be classified in the genus Modestobacter as Modestobacter lapidis sp. nov. and Modestobacter muralis sp. nov., with isolates MON 3.1(T) (CECT 8844(T) = DSM 100206(T)) and MDVD1(T) (CECT 8845(T) = DSM 100205(T)) as the respective type strains. PMID:25987397

  7. Bacteria detection using disposable optical leaky waveguide sensors.

    PubMed

    Zourob, Mohammed; Mohr, Stephan; Brown, Bernard J Treves; Fielden, Peter R; McDonnell, Martin B; Goddard, Nicholas J

    2005-08-15

    Novel disposable absorbing material clad leaky waveguide sensor devices (LWD) have been developed for the detection of pathogenic particles such as bacteria. These chips are tailored to give the maximum extension of the evanescent field at the sensor surface in order to place the entire volume of the bacteria captured by immobilized antibodies on the chip surface within this field. This in turn increases the interaction of the light with the bacteria's bulk volume. Disposable LWD chips were fabricated at room temperature and without the use of expensive fabrication equipment. These LWDs have been characterised by detecting refractive index (RI) changes, scattering and fluorescence from bacterial spores at the sensor surface when illuminated at the coupling angle. The detection limit of Bacillus subtilis var. niger (BG) bacterial spores was 10(4) spores/ml and the illumination intensity of the spores was found to be three times greater than the illumination intensity generated using the surface plasmon resonance (SPR). PMID:16023956

  8. In-situ Mechanical Manipulation of Wellbore Cements as a Solution to Leaky Wells

    NASA Astrophysics Data System (ADS)

    Kupresan, D.; Radonjic, M.; Heathman, J.

    2013-12-01

    Wellbore cement provides casing support, zonal isolation, and casing protection from corrosive fluids, which are essential for wellbore integrity. Cements can undergo one or more forms of failure such as debonding at cement/formation and cement/casing interface, fracturing and defects within cement matrix. Failures and defects within cement will ultimately lead to fluids migration, resulting in inter-zonal fluid migration and premature well abandonment. There are over 27,000 abandoned oil and gas wells only in The Gulf of Mexico (some of them dating from the late 1940s) with no gas leakage monitoring. Cement degradation linked with carbon sequestration can potentially lead to contamination of fresh water aquifers with CO2. Gas leaks can particularly be observed in deviated wells used for hydraulic fracking (60% leakage rate as they age) as high pressure fracturing increases the potential for migration pathways. Experimental method utilized in this study enables formation of impermeable seals at interfaces present in a wellbore by mechanically manipulating wellbore cement. Preliminary measurements obtained in bench scale experiments demonstrate that an impermeable cement/formation and cement/casing interface can be obtained. In post-modified cement, nitrogen gas flow-through experiments showed complete zonal isolation and no permeability in samples with pre-engineered microannulus. Material characterization experiments of modified cement revealed altered microstructural properties of cement as well as changes in mineralogical composition. Calcium-silicate-hydrate (CSH), the dominant mineral in hydrated cement which provides low permeability of cement, was modified as a result of cement pore water displacement, resulting in more dense structures. Calcium hydroxide (CH), which is associated with low resistance of cement to acidic fluids and therefore detrimental in most wellbore cements, was almost completely displaced and/or integrated in CSH as a result of mechanical manipulation (shear stress). The main advantage of this methodology is that mechanical manipulation of cement can induce healing of existing fractures, channels and microannulus seal in a wellbore without introducing new materials (e.g. cement squeeze jobs). Furthermore, this methodology is less sensitive to the influence of downhole conditions such as pressure, temperature and formation fluids, since it uses cement pore water as a medium to alter cement sheath. Based on lab experiments observation, it is possible to perceive that once tested at the industrial scale and if successful, the implementation of this method in the field can potentially mitigate leaky wells in CO2 sequestration projects, wellbores completed for hydraulic-fracturing and other conventional oil and gas producing wells. Key words: Wellbore cement integrity; Leaky wells; Cement microstructures; Casing expansion effect on cement mineralogy alterations.

  9. Bringing It to the Teachers: Building a Professional Network among Teachers in Isolated Schools

    ERIC Educational Resources Information Center

    McLean, Fiona M.; Dixon, Roselyn M.; Verenikina, Irina

    2014-01-01

    Teachers in isolated schools are often under-resourced and overwhelmed with additional pressures. Teaching in an isolated community can sometimes challenge teachers' skills and knowledge, particularly when additional pressures such as behavioural issues associated with students with Oppositional Defiant Disorder (ODD) like behaviours are present.…

  10. Bringing It to the Teachers: Building a Professional Network among Teachers in Isolated Schools

    ERIC Educational Resources Information Center

    McLean, Fiona M.; Dixon, Roselyn M.; Verenikina, Irina

    2014-01-01

    Teachers in isolated schools are often under-resourced and overwhelmed with additional pressures. Teaching in an isolated community can sometimes challenge teachers' skills and knowledge, particularly when additional pressures such as behavioural issues associated with students with Oppositional Defiant Disorder (ODD) like behaviours are present.

  11. Mechanical expansion of steel tubing as a solution to leaky wellbores.

    PubMed

    Radonjic, Mileva; Kupresan, Darko

    2014-01-01

    Wellbore cement, a procedural component of wellbore completion operations, primarily provides zonal isolation and mechanical support of the metal pipe (casing), and protects metal components from corrosive fluids. These are essential for uncompromised wellbore integrity. Cements can undergo multiple forms of failure, such as debonding at the cement/rock and cement/metal interfaces, fracturing, and defects within the cement matrix. Failures and defects within the cement will ultimately lead to fluid migration, resulting in inter-zonal fluid migration and premature well abandonment. Currently, there are over 1.8 million operating wells worldwide and over one third of these wells have leak related problems defined as Sustained Casing Pressure (SCP). The focus of this research was to develop an experimental setup at bench-scale to explore the effect of mechanical manipulation of wellbore casing-cement composite samples as a potential technology for the remediation of gas leaks. The experimental methodology utilized in this study enabled formation of an impermeable seal at the pipe/cement interface in a simulated wellbore system. Successful nitrogen gas flow-through measurements demonstrated that an existing microannulus was sealed at laboratory experimental conditions and fluid flow prevented by mechanical manipulation of the metal/cement composite sample. Furthermore, this methodology can be applied not only for the remediation of leaky wellbores, but also in plugging and abandonment procedures as well as wellbore completions technology, and potentially preventing negative impacts of wellbores on subsurface and surface environments. PMID:25490436

  12. Characterization of Defects in Composite Material Using Rapidly Acquired Leaky Lamb Wave Dispersion Data

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Y.; Mal, A.; Chang, Z.

    1998-01-01

    The phenomenon of Leaky Lamb Wave (LLW) in composite materials was first observed in 1982 using a Schlieren system. It has been studied extensively by numerous investigators and successfully shown to be an effective quantitative NDE tool.

  13. Final report on LDRD project :leaky-mode VCSELs for photonic logic circuits.

    SciTech Connect

    Hargett, Terry W.; Hadley, G. Ronald; Serkland, Darwin Keith; Blansett, Ethan L.; Geib, Kent Martin; Sullivan, Charles Thomas; Keeler, Gordon Arthur; Bauer, Thomas; Ongstand, Andrea; Medrano, Melissa R.; Peake, Gregory Merwin; Montano, Victoria A.

    2005-11-01

    This report describes the research accomplishments achieved under the LDRD Project ''Leaky-mode VCSELs for photonic logic circuits''. Leaky-mode vertical-cavity surface-emitting lasers (VCSELs) offer new possibilities for integration of microcavity lasers to create optical microsystems. A leaky-mode VCSEL output-couples light laterally, in the plane of the semiconductor wafer, which allows the light to interact with adjacent lasers, modulators, and detectors on the same wafer. The fabrication of leaky-mode VCSELs based on effective index modification was proposed and demonstrated at Sandia in 1999 but was not adequately developed for use in applications. The aim of this LDRD has been to advance the design and fabrication of leaky-mode VCSELs to the point where initial applications can be attempted. In the first and second years of this LDRD we concentrated on overcoming previous difficulties in the epitaxial growth and fabrication of these advanced VCSELs. In the third year, we focused on applications of leaky-mode VCSELs, such as all-optical processing circuits based on gain quenching.

  14. Dynamics of Networks of Leaky-Integrate-and-Fire Neurons

    NASA Astrophysics Data System (ADS)

    Politi, Antonio; Luccioli, Stefano

    The dynamics of pulse-coupled leaky-integrate-and-fire neurons is discussed in networks with arbitrary structure and in the presence of delayed interactions. The evolution equations are formally recasted as an event-driven map in a general context where the pulses are assumed to have a finite width. The final structure of the mathematical model is simple enough to allow for an easy implementation of standard nonlinear dynamics tools. We also discuss the properties of the transient dynamics in the presence of quenched disorder (and ?-like pulses). We find that the length of the transient depends strongly on the number N of neurons. It can be as long as 106-107 inter-spike intervals for relatively small networks, but it decreases upon increasing N because of the presence of stable clustered states. Finally, we discuss the same problem in the presence of randomly fluctuating synaptic connections (annealed disorder). The stationary state turns out to be strongly affected by finite-size corrections, to the extent that the number of clusters depends on the network size even for N?20,000.

  15. Simulating soil atmosphere above a leaky CCS deposit

    NASA Astrophysics Data System (ADS)

    Schack-Kirchner, Helmer; Maier, Martin

    2015-04-01

    The escape of CO2 at the surface above a leaky geological deposit of carbon dioxide can be a fumarole-like point source or a subsurface plume distributing the gas over a larger area. In the latter case the lost CO2 from the deposit is added to the soil respiration as a quasi one-dimensional non-equimolar gas flux. Whether such an additional flux leads to inhibitory high levels of soil CO2 combined with a rather complete advective displacement of O2 or simply changes the diffusion characteristics in a more or less normal soil atmosphere depends for a given gas diffusivity and permeability on the ratio between the equimolar (respiratory) and the non-equimolar (leak based) flux of CO2. We tested the effecs by parametrization of a conceptual soil model consisting of capillaries filled either with soil air or water joining the soil air and the above-ground atmosphere. Soil atmosphere was simulated by combining a numerical solution of the Dusty-Gas model and a simple gas diffusion model in the water filled capillaries in an iterative process until Argon as noble gas is stagnant. The results show that in soils with high gas permeability even non-equimolar CO2 fluxes more than twice the soil respiration can be transferred to the surface without spectacular changes in soil-air pressure or O2 displacement. However, even low extra CO2 fluxes change significantly the gradient ratio of O2 and CO2 and stress soil aeration which is for many forest ecosystems a limiting factor of root growth.

  16. NF-?B promotes leaky expression of adenovirus genes in a replication-incompetent adenovirus vector.

    PubMed

    Machitani, M; Sakurai, F; Wakabayashi, K; Nakatani, K; Shimizu, K; Tachibana, M; Mizuguchi, H

    2016-01-01

    The replication-incompetent adenovirus (Ad) vector is one of the most promising vectors for gene therapy; however, systemic administration of Ad vectors results in severe hepatotoxicities, partly due to the leaky expression of Ad genes in the liver. Here we show that nuclear factor-kappa B (NF-?B) mediates the leaky expression of Ad genes from the Ad vector genome, and that the inhibition of NF-?B leads to the suppression of Ad gene expression and hepatotoxicities following transduction with Ad vectors. Activation of NF-?B by recombinant tumor necrosis factor (TNF)-? significantly enhanced the leaky expression of Ad genes. More than 50% suppression of the Ad gene expression was found by inhibitors of NF-?B signaling and siRNA-mediated knockdown of NF-?B. Similar results were found when cells were infected with wild-type Ad. Compared with a conventional Ad vector, an Ad vector expressing a dominant-negative I?B? (Adv-CADNI?B?), which is a negative regulator of NF-?B, mediated approximately 70% suppression of the leaky expression of Ad genes in the liver. Adv-CADNI?B? did not induce apparent hepatotoxicities. These results indicate that inhibition of NF-?B leads to suppression of Ad vector-mediated tissue damages via not only suppression of inflammatory responses but also reduction in the leaky expression of Ad genes. PMID:26814140

  17. Isolation and Damping of Shocks, Vibrations and Seismic Movements at Buildings: Equipment and Pipe Networks by SERB-SITON Method

    SciTech Connect

    Panait, A.; Serban, V.

    2006-07-01

    The paper presents SERB -- SITON method to control, limit and damp the shocks, vibration, impact load and seismic movements with applications in buildings, equipment and pipe networks (herein called: 'components'). The elimination or reduction of shocks, vibration, impact load and seismic movements is a difficult problem, still improperly handled theoretically and practically because many times the phenomena are random in character and the behavior of components is non-linear with variations of the properties in time, variations that lead to the increase or decrease of the energy and impulse transfer from the dynamic excitation to the components. Moreover, the existing supports and dampers applied today, are not efficient enough in the reduction of the dynamic movement for all the frequency ranges met with in the technical application field. The stiffness and damping of classic supports do not allow a good isolation of components against shocks and vibrations so to eliminate their propagation to the environment and neither do they provide a satisfactory protection of the components sensitive to shocks and vibrations and seismic movements coming from the environment. In order to reduce the effects of shocks, vibrations impact and seismic movements on the components, this paper presents the results obtained by SITON on the concept, design, construction, experimental testing and application of new types of supports, devices and thin lattice structure, called 'SERB', capable to overtake large static loads, to allow displacements from impact, thermal expansions or yielding of supports and which, in any work position, can elastically overtake large dynamic loads or impact loads which they damp. The new supports and devices and thin lattice structure allow their adjustment without the occurrence of over-stressing in the components due to their non -- linear geometric behavior, and the contact pressure among the elements is limited to pre-set values to avoid blocking phenomena that generates great stresses induced by thermal expansion for example. Due to their characteristics of adjustment to the actual position and level of stress, SERB supports, devices and thin lattice structure show minimal effects on the components stress condition whenever the installation and computation errors. Herein below it is a presentation of the actual results obtained by SITON in the isolation of heavy equipment and pipe networks and others in process of application for buildings. Due to the very good results obtained in the isolation against shocks, vibrations and seismic movements at components in the conventional industry, there is the proposal to implement SERB-SITON method to the increase of the safety level at new or existing Nuclear Power Plants or to protect nuclear building against missiles and airplane crush impact. (authors)

  18. Lateral shift of an optical beam due to leaky surface-plasmon excitations

    NASA Technical Reports Server (NTRS)

    Chuang, S. L.

    1986-01-01

    A leaky-wave theory is applied to the study of the lateral shift of a bounded optical beam reflected from a prism-air-metal (and prism-metal-air) layered configuration with surface-plasmon excitations. The locations of the pole and the zero of the reflection coefficient for the leaky surface-plasmon mode are calculated as one varies the thickness of the center layer. The excited surface-plasmon mode is leaky because of the presence of the prism. Both the real part and the imaginary part of the pole are affected by the energy leakage. The detailed structure of the reflected intensity and the forward and backward shifts of the reflected beam are illustrated.

  19. Analysis and Synthesis of Leaky-Wave Devices in Planar Technology

    NASA Astrophysics Data System (ADS)

    Martinez Ros, Alejandro Javier

    The work developed along this doctoral thesis has been focused on the analysis and synthesis of microwave devices in planar technology. In particular, several types of devices based on the radiation mechanism of leaky waves have been studied. Typically, the radiation properties in leaky-wave devices are determined by the complex propagation constant of the leaky mode, wherein the phase constant is responsible for the pointing angle and the leakage rate for the intensity of the radiated fields. In this manner, by controlling both amplitude and phase of the leaky mode, an effective control over the device's radiation diagram can be obtained. Moreover, with the purpose of efficiently obtaining the leaky mode's radiation properties as function of the main geometrical parameters of the structure, several modal tools based on the transverse resonance analysis of the structure have been performed. In order to demonstrate this simultaneous control over the complex propagation constant in planar technology, several types of leaky-wave devices, including antennas (LWAs), multiplexors and near-field focusing systems, have been designed and manufactured in the technology of substrate integrated waveguide (SIW). This recently proposed technology, allows the design of devices based on classical waveguide technology with standard manufacturing techniques used for printed circuit board (PCB) designs. In this way, most of the parts that form a communication system can be integrated into a single substrate, thus reducing its cost and providing a more robust and compact device, which has less losses compared to other planar technologies such as the microstrip. El trabajo llevado a cabo durante la realizacion de esta tesis doctoral, se ha centrado en el analisis y sintesis de dispositivos de microondas en tecnologia planar. En concreto, se han estudiado diferentes tipos de dispositivos basados en radiacion por ondas de fuga "leaky waves", en los cuales las propiedades de radiacion estan determinadas por la constante de fase del modo "leaky" que es el que determina el angulo de apuntamiento y por la tasa de radiacion que es la que determina la intensidad de los campos radiados. De esta manera, controlando en amplitud y fase el modo "leaky" se puede obtener un control efectivo sobre el diagrama de radiacion del dispositivo. Ademas, con el objetivo de poder obtener de una manera mas eficiente las caracteristicas de propagacion de los modos de fuga "leaky" en funcion de los principales parametros geometricos de la estructura, se han desarrollado diversas herramientas de analisis modal basadas en la tecnica de resonancia transversa de la estructura. La capacidad para obtener un control simultaneo de la constante de propagacion compleja del modo "leaky", ha sido demostrada mediante el diseno y fabricacion de varios tipos de antena "leaky wave" (LWA) y de otros dispositivos como multiplexores y sistemas de enfoque en campo cercano. Para ello, se ha utilizado la tecnologia planar de guia de onda integrada en sustrato (susbstrate integrated waveguide, SIW). Esta recientemente desarrollada tecnologia, permite disenar dispositivos de microondas basados en tecnologia clasica de guia de ondas con sistemas de fabricacion estandar usados en tecnologia de circuitos impresos (printed circuit board, PCB). De esta forma, se pueden integrar en un mismo sustrato muchas de las diferentes partes que forman un sistema de comunicaciones, mejorando asi su robustez y compactibilidad, ademas de reducir el coste y de contar con menores perdidas que otras tecnologias planares como la microstrip.

  20. Coupled Particle Transport and Pattern Formation in a Nonlinear Leaky-Box Model

    NASA Technical Reports Server (NTRS)

    Barghouty, A. F.; El-Nemr, K. W.; Baird, J. K.

    2009-01-01

    Effects of particle-particle coupling on particle characteristics in nonlinear leaky-box type descriptions of the acceleration and transport of energetic particles in space plasmas are examined in the framework of a simple two-particle model based on the Fokker-Planck equation in momentum space. In this model, the two particles are assumed coupled via a common nonlinear source term. In analogy with a prototypical mathematical system of diffusion-driven instability, this work demonstrates that steady-state patterns with strong dependence on the magnetic turbulence but a rather weak one on the coupled particles attributes can emerge in solutions of a nonlinearly coupled leaky-box model. The insight gained from this simple model may be of wider use and significance to nonlinearly coupled leaky-box type descriptions in general.

  1. Vibration analysis and building vibration isolation design for an automated people mover system in airport terminal structures

    NASA Astrophysics Data System (ADS)

    Phillips, James E.

    2002-11-01

    Detailed Finite Element Analysis (FEA) models were developed for a proposed airport terminal expansion project. An Automated People Mover (APM) system is incorporated into the airport structures for shuttling passengers quickly between terminals. The dynamic forces imparted onto the structures by the moving APM vehicles and the analysis approach were based upon established techniques developed for addressing ground-borne and structure-borne vibrations from rail systems. Measurements were conducted at two other major airports with existing rubber tire APM systems on aerial structures. These measurements provided baseline vibration levels for the analysis as well as the forces imparted to the structure by the APM vehicles. The results of the analyses were utilized in the design of a vibration isolation system included in the structural design of a guideway within a terminal building in order to mitigate structure-borne vibration from APM operations.

  2. A biological plausible Generalized Leaky Integrate-and-Fire neuron model.

    PubMed

    Wang, Zhenzhong; Guo, Lilin; Adjouadi, Malek

    2014-01-01

    This study introduces a new Generalized Leaky Integrate-and-Fire (GLIF) neuron model. Unlike Normal Leaky Integrate-and-Fire (NLIF) models, the leaking resistor in the GLIF model equation is assumed to be variable, and an additional term would have the bias current added to the model equation in order to improve the accuracy. Adjusting the parameters defined for the leaking resistor and bias current, a GLIF model could be accurately matched to any Hodgkin-Huxley (HH) model and be able to reproduce plausible biological neuron behaviors. PMID:25571560

  3. Propagation of Leaky Rayleigh Waves across a Fracture along a Fluid-Solid Interface

    NASA Astrophysics Data System (ADS)

    Shao, S.; Pyrak-Nolte, L. J.

    2014-12-01

    Rayleigh waves and leaky Rayleigh waves are sometime used to interpret crustal properties of fault zones or the seafloor. Interpreting these surface wave modes requires an understanding of the effect of mechanical discontinuities such as faults, joints and fractures on leaky Rayleigh wave propagation. In this work, laboratory wavefront imaging experiments were performed to capture the behavior of the leaky Rayleigh waves propagated across fractures at a liquid-solid interface. Cubic samples of aluminum submerged in water were used in this study. The fractured sample was composed of two identical aluminum blocks (dimension: 102 mm x 102 mm x 61 mm), while the intact sample was measured around 102mm on edge. A contact piezoelectric shear-wave transducer (1MHz) was used as the source. A spherically-focused water-coupled compressional-wave transducer (1MHz) was used to receiver the radiated component of the leaky Rayleigh wave. Measurements were made for a range of normal stresses (0 - 6 MPa). For each loading condition, the receiver scanned a 60 mm x 20 mm region in 1 mm increments to map out the arriving wavefront as a function of time. The measured waveforms at different depths from the intact reference sample were the same under different loading conditions. For the fractured sample, the following phenomenon were observed: (1) Prior to crossing the fracture, the velocity of the leaky Rayleigh wave did not change with stress; (2) After crossing the fracture, the velocity was lower than that measured above the fracture and the velocity increased as the stress increased from 0 to 6 MPa; (3) the amplitude of the leaky Rayleigh wave transmitted across the fracture increased with stress; (4) High frequency components experienced more attenuation than the low frequency components; (5) At high stress, the velocity of the leaky-Rayleigh wave approached that observed above the fracture. Correct interpretation of leaky-Rayleigh waves in fractured/faulted regions must account for time delays and attenuation caused by mechanical discontinuities. Acknowledgments: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Geosciences Research Program under Award Number (DE-FG02-09ER16022) and by the Geo-mathematical Imaging Group at Purdue University.

  4. Comparative testing of leaky coaxial cables for communications and guided radar

    NASA Astrophysics Data System (ADS)

    Gale, D. J.; Beal, J. C.

    1980-09-01

    Leaky coaxial cables are finding increasing use in communications systems involving mines, tunnels, railroads, and highways, and in new obstacle detection, or guided radar, schemes for ground transportation and perimeter surveillance. This paper describes the theory and operation of a new laboratory testing technique for these leaky cables based on a novel form of cavity resonator. The technique yields highly consistent and repeatable results that usefully assist in the prediction of the performance of full-size systems, from a simple test on a small sample of cable in a laboratory setting.

  5. Mycobacterium terrae isolated from indoor air of a moisture-damaged building induces sustained biphasic inflammatory response in mouse lungs.

    PubMed Central

    Jussila, Juha; Komulainen, Hannu; Huttunen, Kati; Roponen, Marjut; Iivanainen, Eila; Torkko, Pirjo; Kosma, Veli-Matti; Pelkonen, Jukka; Hirvonen, Maija-Riitta

    2002-01-01

    Occupants in moisture-damaged buildings suffer frequently from respiratory symptoms. This may be partly due to the presence of abnormal microbial growth or the altered microbial flora in the damaged buildings. However, the specific effects of the microbes on respiratory health and the way they provoke clinical manifestations are poorly understood. In the present study, we exposed mice via intratracheal instillation to a single dose of Mycobacterium terrae isolated from the indoor air of a moisture-damaged building (1 X 10(7), 5 X 10(7), or 1 X 10(8) microbes). Inflammation and toxicity in lungs were evaluated 2 hr later. The time course of the effects was assessed with the dose of 1 X 10(8) bacterial cells for up to 28 days. M. terrae caused a sustained biphasic inflammation in mouse lungs. The characteristic features for the first phase, which lasted from 6 hr to 3 days, were elevated proinflammatory cytokine [i.e., tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6)] levels in the bronchoalveolar lavage fluid (BALF). TNF-alpha was produced in the lungs more intensively than was IL-6. Neutrophils were the most abundant cells in the airways during the first phase, although their numbers in BALF remained elevated up to 21 days. The characteristics of the second phase, which lasted from 7 to 28 days, were elevated TNF-alpha levels in BALF, expression of inducible nitric oxide synthase in BAL cells, and recruitment of mononuclear cells such as lymphocytes and macrophages into the airways. Moreover, total protein, albumin, and lactate dehydrogenase concentrations were elevated in both phases in BALF. The bacteria were detected in lungs up to 28 days. In summary, these observations indicate that M. terrae is capable of provoking a sustained, biphasic inflammation in mouse lungs and can cause a moderate degree of cytotoxicity. Thus, M. terrae can be considered a species with potential to adversely affect the health of the occupants of moisture-damaged buildings. PMID:12417483

  6. Seismic Response of a Full-scale 5-story Steel Frame Building Isolated by Triple Pendulum Bearings under Three-Dimensional Excitations

    NASA Astrophysics Data System (ADS)

    Dao, Nhan Dinh

    A full-scale shake table test of a 5-story steel moment frame building was carried out as part of a collaborative NEES/E-Defense research program. The building was tested in three configurations: isolated with triple pendulum bearings (TPB), isolated with lead rubber bearings combined with cross linear sliders (which is not discussed in this dissertation), and fixed base. The test provided full-scale response data of both the isolation system and the isolated structure and demonstrated the efficiency of the isolation system in reducing the demands in the isolated structure. A 3-dimensional TPB element with a general friction model that accounts for the variation of friction coefficients on both velocity and vertical force was developed to predict the response of individual TPB and the overall isolation system. The element accounts for both vertical-horizontal coupling behavior and bidirectional coupling of TPB. The horizontal behavior of the element is based on a series combination of bidirectional elastic-plastic springs and the circular gap elements. The new TPB element was verified by the full scale test data and has been implemented in OpenSees so that it is available for general use. The analytical model of the specimen building was also developed and validated by the test data from both the isolated base and fixed base tests. The following modeling assumption were shown to best present the response characteristics of the tested structure: (1) beam were modeled as nonlinear elements with resultant composite sections, (2) moment connection were modeled using a Krawinkler panel zone model, and (3) energy dissipation was represented by Rayleigh damping calibrated to include higher mode effects observed in the test data, along with additional interstory dampers. The vertical component of the excitation was shown to amplify the horizontal response of both the fixed base and isolated base structures. This coupling effect was small in the tested fixed base configuration relative to the isolated base configuration. The calibrated analytical model was used to identify 3 main sources of this amplification: (1) vertically and horizontally coupled modes of the structure, (2) the rocking of the structure on the isolation system due to vertical flexibility of the isolators and supports and uplift, and (3) the vertical-horizontal coupled response of friction bearings. Only the first source of coupling was applicable to the fixed base building.

  7. How to Say "No" to a Nonword: A Leaky Competing Accumulator Model of Lexical Decision

    ERIC Educational Resources Information Center

    Dufau, Stephane; Grainger, Jonathan; Ziegler, Johannes C.

    2012-01-01

    We describe a leaky competing accumulator (LCA) model of the lexical decision task that can be used as a response/decision module for any computational model of word recognition. The LCA model uses evidence for a word, operationalized as some measure of lexical activity, as input to the "YES" decision node. Input to the "NO" decision node is…

  8. How to Say "No" to a Nonword: A Leaky Competing Accumulator Model of Lexical Decision

    ERIC Educational Resources Information Center

    Dufau, Stephane; Grainger, Jonathan; Ziegler, Johannes C.

    2012-01-01

    We describe a leaky competing accumulator (LCA) model of the lexical decision task that can be used as a response/decision module for any computational model of word recognition. The LCA model uses evidence for a word, operationalized as some measure of lexical activity, as input to the "YES" decision node. Input to the "NO" decision node is

  9. Linking the "Leaky Edges" of the Outside with the Individual Inside

    ERIC Educational Resources Information Center

    Carlson, David Lee

    2007-01-01

    Throughout seven years of teaching in urban schools, the author discovered that the most effective ways to teach difficult literary texts was to refer to students' out-of-school activities. In other words, to connect the "leaky edges of the "social outside"" with the "individual inside" is to create a curriculum of "embodied relationships." This

  10. Construction of leaky strains and extracellular production of exogenous proteins in recombinant Escherichia coli

    PubMed Central

    Chen, Zhao-Yuan; Cao, Jie; Xie, Li; Li, Xiao-Fei; Yu, Zhen-Hai; Tong, Wang-Yu

    2014-01-01

    In this study, a strategy of the construction of leaky strains for the extracellular production of target proteins was exploited, in which the genes mrcA, mrcB, pal and lpp (as a control) from Escherichia coli were knocked out by using single- and/or double-gene deletion methods. Then the recombinant strains for the expression of exogenous target proteins including Trx-hPTH (human parathyroid hormone 184 coupled with thioredoxin as a fusion partner) and reteplase were reconstructed to test the secretory efficiency of the leaky strains. Finally, the fermentation experiments of the target proteins from these recombinant leaky strains were carried out in basic media (Modified R media) and complex media (Terrific Broth media) in flasks or fermenters. The results demonstrated that the resultant leaky strains were genetically stable and had a similar growth profile in the complex media as compared with the original strain, and the secretory levels of target proteins into Modified R media from the strains with double-gene deletion (up to 88.9%/mrcA lpp-pth) are higher than the excretory levels from the strains with single-gene deletion (up to 71.1%/lpp-pth) and the host E. coli?JM109 (DE3) (near zero). The highest level of extracellular production of Trx-hPTH in fermenters is up to 680 mg l?1. PMID:24779863

  11. Real-Time Characterization of Materials Degradation Using Leaky Lamb Wave

    NASA Technical Reports Server (NTRS)

    Shiuh, S.; Bar-Cohen, Y.

    1997-01-01

    Leaky Lamb wave (LLW) propagation in composite materials has been studied extensively since it was first observed in 1982. The wave is induced using a pitch-catch arrangement and the plate wave modes are detected by searching minima in the reflected spectra.

  12. SOLUTIONS APPROXIMATING SOLUTE TRANSPORT IN A LEAKY AQUIFER RECEIVING WASTEWATER INJECTION

    EPA Science Inventory

    A mathematical model amenable to analytical solution techniques is developed for the investigation of contaminant transport from an injection well into a leaky aquifer system, which comprises a pumped and an unpumped aquifer connected to each other by an aquitard. teady state gro...

  13. Construction of leaky strains and extracellular production of exogenous proteins in recombinant Escherichia coli.

    PubMed

    Chen, Zhao-Yuan; Cao, Jie; Xie, Li; Li, Xiao-Fei; Yu, Zhen-Hai; Tong, Wang-Yu

    2014-07-01

    In this study, a strategy of the construction of leaky strains for the extracellular production of target proteins was exploited, in which the genes mrcA, mrcB, pal and lpp (as a control) from Escherichia coli were knocked out by using single- and/or double-gene deletion methods. Then the recombinant strains for the expression of exogenous target proteins including Trx-hPTH (human parathyroid hormone 1-84 coupled with thioredoxin as a fusion partner) and reteplase were reconstructed to test the secretory efficiency of the leaky strains. Finally, the fermentation experiments of the target proteins from these recombinant leaky strains were carried out in basic media (Modified R media) and complex media (Terrific Broth media) in flasks or fermenters. The results demonstrated that the resultant leaky strains were genetically stable and had a similar growth profile in the complex media as compared with the original strain, and the secretory levels of target proteins into Modified R media from the strains with double-gene deletion (up to 88.9%/mrcA lpp-pth) are higher than the excretory levels from the strains with single-gene deletion (up to 71.1%/lpp-pth) and the host E.?coli?JM109 (DE3) (near zero). The highest level of extracellular production of Trx-hPTH in fermenters is up to 680?mg?l(-1). PMID:24779863

  14. SOLUTIONS APPROXIMATING SOLUTE TRANSPORT IN A LEAKY AQUIFER RECEIVING WASTEWATER INJECTION

    EPA Science Inventory

    A mathematical model amenable to analytical solution techniques is developed for the investigation of contaminant transport from an injection well into a leaky aquifer system, which comprises a pumped and an unpumped aquifer connected to each other by an aquitard. A steady state ...

  15. A modeling investigation of the impact of street and building configurations on personal air pollutant exposure in isolated deep urban canyons.

    PubMed

    Ng, Wai-Yin; Chau, Chi-Kwan

    2014-01-15

    This study evaluated the effectiveness of different configurations for two building design elements, namely building permeability and setback, proposed for mitigating air pollutant exposure problems in isolated deep canyons by using an indirect exposure approach. The indirect approach predicted the exposures of three different population subgroups (i.e. pedestrians, shop vendors and residents) by multiplying the pollutant concentrations with the duration of exposure within a specific micro-environment. In this study, the pollutant concentrations for different configurations were predicted using a computational fluid dynamics model. The model was constructed based on the Reynolds-Averaged Navier-Stokes (RANS) equations with the standard k-? turbulence model. Fifty-one canyon configurations with aspect ratios of 2, 4, 6 and different building permeability values (ratio of building spacing to the building faade length) or different types of building setback (recess of a high building from the road) were examined. The findings indicated that personal exposures of shop vendors were extremely high if they were present inside a canyon without any setback or separation between buildings and when the prevailing wind was perpendicular to the canyon axis. Building separation and building setbacks were effective in reducing personal air exposures in canyons with perpendicular wind, although their effectiveness varied with different configurations. Increasing the permeability value from 0 to 10% significantly lowered the personal exposures on the different population subgroups. Likewise, the personal exposures could also be reduced by the introduction of building setbacks despite their effects being strongly influenced by the aspect ratio of a canyon. Equivalent findings were observed if the reduction in the total development floor area (the total floor area permitted to be developed within a particular site area) was also considered. These findings were employed to formulate a hierarchy decision making model to guide the planning of deep canyons in high density urban cities. PMID:24056446

  16. An exact solution to a line-sink in a leaky aquifer

    NASA Astrophysics Data System (ADS)

    Gusyev, M. A.; Haitjema, H. M.

    2007-12-01

    By use of Wirtinger calculus we obtained an exact solution for a line-sink in a leaky aquifer by integrating the potential for a well in a leaky aquifer. The potential for a well in a leaky aquifer is the modified Bessel function of the second kind and zero order K0, which can be represented by an infinite series. Theoretically, this series expansion for the well is exact, although numerical evaluation will only give exact results within some finite distance from the well, depending on machine accuracy. For a double precision machine this distance is about to 18?, whereby ? is the "leakage factor" or "characteristic leakage length" which depends on the aquifer properties. Earlier solutions that were based on an approximation to the function K0 limited the domain of validity even more; from 2? to 8? away from the well. As a result, these earlier (approximate) solutions for a well in a leaky aquifer limited the length of the line-sink along which it could be integrated to approximately ?. It appears that our use of the infinite series (exact representation of K0), makes it possible to formulate a solution for a line-sink of any length, thus avoiding to need to break up line-sinks into smaller sections as has been done to date. Formulating our solution in terms of the complex variable z and its conjugate \\bar{z}, using Wirtinger calculus, also allows us to calculate the exact integrated steady-state flow induced by the line-sink across an arbitrarily placed line element. This feature is often necessary in the context of the analytic element method in order to satisfy boundary conditions in terms of integrated fluxes, such as no-flow boundaries or leaky walls. The capability to accurately calculate such integrated fluxes across line elements is also important in order to obtain the integrated leakage over a domain by applying water balance rather than (numerically) integrating the leakage directly. The new solution is particularly suitable for use in analytic element models of leaky aquifer systems.

  17. An Analytical Solution of Hydraulic Head due to an Oscillatory Pumping Test in a Confined, Unconfined or Leaky Aquifer

    NASA Astrophysics Data System (ADS)

    Huang, C. S.; Yeh, H. D.

    2014-12-01

    This study builds a mathematical model for three-dimensional (3D) transient hydraulic head induced by an oscillatory pumping test in a confined, unconfined or leaky aquifer. The aquifers are of a rectangular shape where the four sides are under the Robin conditions. The 3D flow governing equation with a line sink term representing a vertical well is employed. The sink term has a cosine function for the oscillatory pumping. A general equation describing the head on the top of the three kinds of aquifers is considered. The analytical head solution of the model is derived by the direct Fourier method and the double-integral transform and in terms of a double series with fast convergence. With the aid of the solution, we have found that the vertical component of flow vanishes when Kv d2/(KhD2) > 1 where Kh and Kv are aquifer's hydraulic conductivities, respectively, D is aquifer's thickness, and d is a distance measured from the pumping well. Under the condition, temporal head distributions predicted by the present solution agree with those predicted by solutions developed based on two-dimensional flow by most previous researches.

  18. If you build it will they come? Addressing social isolation within a technology-based HIV intervention for young black men who have sex with men.

    PubMed

    LeGrand, Sara; Muessig, Kathryn E; Pike, Emily C; Baltierra, Nina; Hightow-Weidman, Lisa B

    2014-01-01

    The rate of HIV infections among young black men who have sex with men (YBMSM) continues to rise at an alarming pace. YBMSM are particularly vulnerable to social isolation and a lack of social support due to experiences with racism and homophobia, which may have implications for sexual risk behaviors. The purpose of this study was to explore perceptions of social isolation and sense of community among YBMSM, the need for and receptivity to social networking features designed to reduce social isolation and build community within an Internet- and mobile phone-based primary and secondary HIV prevention intervention for YBMSM and to identify strategies to develop these features. Focus groups were conducted with 22 YBMSM aged 20-30 years at three sites in North Carolina. Data from the focus groups were thematically analyzed using NVivo. Feelings of social isolation and lack of a sense of community were strongly endorsed by participants with homophobia, lack of opportunities for social engagement, and a focus on sex rather than friendship in interpersonal relationships with other YBMSM cited as contributing factors. Participants were receptive to a social networking intervention designed to reduce social isolation and build community. Recommendations offered by participants to increase acceptability and usability of such features included: availability of information about healthy relationships, the ability to connect with other YBMSM and health care providers, and ensuring the site had ongoing facilitation by the study team as well as monitoring for inappropriate content. The development of a social networking feature of an HIV prevention intervention may present an opportunity to reduce social isolation, build community, and reduce risky sexual behaviors among YBMSM. The findings from this study are being used to inform the development of a social networking feature for an existing Internet- and mobile phone-based primary and secondary HIV prevention intervention for YBMSM. PMID:24617609

  19. Saturated-unsaturated flow in a compressible leaky-unconfined aquifer

    NASA Astrophysics Data System (ADS)

    Mishra, Phoolendra K.; Vesselinov, Velimir V.; Kuhlman, Kristopher L.

    2012-06-01

    An analytical solution is developed for three-dimensional flow towards a partially penetrating large-diameter well in an unconfined aquifer bounded below by a leaky aquitard of finite or semi-infinite extent. The analytical solution is derived using Laplace and Hankel transforms, then inverted numerically. Existing solutions for flow in leaky unconfined aquifers neglect the unsaturated zone following an assumption of instantaneous drainage due to Neuman. We extend the theory of leakage in unconfined aquifers by (1) including water flow and storage in the unsaturated zone above the water table, and (2) allowing the finite-diameter pumping well to partially penetrate the aquifer. The investigation of model-predicted results shows that aquitard leakage leads to significant departure from the unconfined solution without leakage. The investigation of dimensionless time-drawdown relationships shows that the aquitard drawdown also depends on unsaturated zone properties and the pumping-well wellbore storage effects.

  20. Integration of Leaky Waveguide Detection with Electrowetting on Dielectric Digital Microfluidic Devices

    NASA Astrophysics Data System (ADS)

    Gupta, Ruchi; Goddard, Nick

    2013-06-01

    Typically, Electrowetting on dielectric (EWOD) digital microfluidic devices consist of an array of metal electrodes covered with a continuous hydrophobic dielectric layer. The monitoring of droplet position and detection in EWOD is usually achieved via microscopy, thereby resulting in increasing the size and complexity of the instrumentation associated with such devices. This work for the first time demonstrates that metal clad leaky waveguide (MCLW) is suitable for detection in EWOD devices. MCLW devices typically consist of a metal layer covered with a dielectric layer in which the leaky waveguide mode propagates. The two structures are fundamentally compatible provided the metal and dielectric layer thicknesses and refractive indices can be optimised to permit both electrowetting and waveguiding. In this work, it has been shown that titanium electrodes covered with a fluoropolymer layer can be used to perform MCLW detection of droplets on EWOD platforms.

  1. Homeotropic polar anchoring energy of a nematic liquid crystal using the fully leaky waveguide technique

    NASA Astrophysics Data System (ADS)

    Yang, Fuzi; Ruan, Lizhen; Sambles, J. R.

    2000-12-01

    Optical excitation of a series of fully leaky guided modes has been used to explore the director distortion of a hybrid-aligned nematic liquid crystal with a negative dielectric anisotropy (Merck-BDH, MLC 6608) under application of an ac electric field. Hybrid alignment is realized by the use of a lecithin film on the top glass plate and rubbed polyimide on the bottom plate, both plates having indium-tin-oxide coatings. Continuum theory is used to model the director profile through the cell. Fitting the fully leaky guided mode data both in transmission and reflection using optical multilayer theory together with continuum modeling gives the director profile both with and without applied fields. From this fitting the changes in the surface tilt angle and its gradient are obtained. Using this information the polar anchoring coefficient of the homeotropic surface W? is deduced. At 23.1 C we find W?=(4.60.2)10-4 J m-2.

  2. Sinusoidally Modulated Graphene Leaky-Wave Antenna for Electronic Beamscanning at THz

    NASA Astrophysics Data System (ADS)

    Esquius-Morote, Marc; Gomez-Diaz, Juan Sebastian; Perruisseau-Carrier, Julien

    2014-01-01

    This paper proposes the concept, analysis and design of a sinusoidally-modulated graphene leaky-wave antenna with beam scanning capabilities at a fixed frequency. The antenna operates at terahertz frequencies and is composed of a graphene sheet transferred onto a back-metallized substrate and a set of polysilicon DC gating pads located beneath it. In order to create a leaky-mode, the graphene surface reactance is sinusoidally-modulated via graphene's field effect by applying adequate DC bias voltages to the different gating pads. The pointing angle and leakage rate can be dynamically controlled by adjusting the applied voltages, providing versatile beamscanning capabilities. The proposed concept and achieved performance, computed using realistic material parameters, are extremely promising for beamscanning at THz frequencies, and could pave the way to graphene-based reconfigurable transceivers and sensors.

  3. {ital V}({ital z}) measurement of multiple leaky wave velocities for elastic constant determination

    SciTech Connect

    Li, W.; Achenbach, J.D.

    1996-09-01

    A multiple leaky acoustic wave method to determine elastic constants from a single {ital V}({ital z}) measurement is presented. The {ital V}({ital z}) curves which include contributions from different leaky acoustic waves, measured using the line-focus acoustic microscope at 225 MHz, have been compared with theoretical results predicted by a {ital V}({ital z}) measurement model. The determination of elastic constants has been achieved numerically by seeking a set of elastic constants that leads to the best fit, in the least square sense, of the theoretical results to the experimental ones. The method has been applied to isotropic materials in bulk, and plate and thin-film configurations. Elastic constants for each of these cases have been determined. The consistency, convergence, sensitivity, and accuracy of the procedure have been investigated. {copyright} {ital 1996 Acoustical Society of America.}

  4. Dirac leaky-wave antennas for continuous beam scanning from photonic crystals.

    PubMed

    Memarian, Mohammad; Eleftheriades, George V

    2015-01-01

    Leaky-Wave Antennas (LWAs) enable directive and scannable radiation patterns, which are highly desirable attributes at terahertz, infrared and optical frequencies. However, a LWA is generally incapable of continuous beam scanning through broadside, due to an open stopband in its dispersion characteristic. This issue is yet to be addressed at frequencies beyond microwaves, mainly as existing microwave solutions (for example, transmission line metamaterials) are unavailable at these higher frequencies. Here we report leaky-wave radiation from the interface of a photonic crystal (PC) with a Dirac-type dispersion and air. The resulting Dirac LWA (DLWA) can radiate at broadside, chiefly owing to the closed Γ-point bandgap of the Dirac PC. Thus, the DLWA can continuously scan a directive beam over a wide range of angles by varying the frequency. These DLWAs can be designed at microwave as well as terahertz to optical frequencies, with feasible dimensions and low losses. PMID:25556705

  5. Effect of perfectly matched layer reflection coefficient on modal analysis of leaky waveguide modes.

    PubMed

    Lai, Chih-Hsien; Chang, Hung-chun

    2011-01-17

    The reflection coefficient is one important parameter of the perfectly matched layer (PML). Here we investigate its effect on the modal analysis of leaky waveguide modes by examining three different leaky waveguide structures, i.e., the holey fiber, the air-core terahertz pipe waveguide, and the gain-guided and index-antiguided slab waveguide. Numerical results reveal that the typical values 10(-8) ~10(-12) are inadequate for obtaining the imaginary part of the complex propagation constant, and the suggested reflection coefficient would be much smaller, for example, 10(-50) or 10(-100). With such a small coefficient, both the computational window size and the PML thickness can be significantly reduced without loss of stability. Moreover, in some cases, the modal field profiles can only be accurately obtained with such a small coefficient. PMID:21263596

  6. A Review of the Ginzburg-Syrovatskii's Galactic Cosmic-Ray Propagation Model and its Leaky-Box Limit

    NASA Technical Reports Server (NTRS)

    Barghouty, A. F.

    2012-01-01

    Phenomenological models of galactic cosmic-ray propagation are based on a diffusion equation known as the Ginzburg-Syrovatskii s equation, or variants (or limits) of this equation. Its one-dimensional limit in a homogeneous volume, known as the leaky-box limit or model, is sketched here. The justification, utility, limitations, and a typical numerical implementation of the leaky-box model are examined in some detail.

  7. Frequency division color characterization apparatus for anisotropic leaky mode light modulators

    NASA Astrophysics Data System (ADS)

    Henrie, A.; Haymore, B.; Smalley, D. E.

    2015-02-01

    This paper presents an optical apparatus for characterizing frequency multiplexing of color in leaky mode, anisotropic waveguide modulators. This type of characterization is particularly useful for informing the design of full color holographic video displays. The primary function of the apparatus is to map the frequency response and angular overlap of red, green, and blue outputs. The apparatus also allows measurements of other parameters such as scan center frequency, optical and RF bandwidth, and scan linearity.

  8. Comparison between leaky and pulsed modes of ion extraction from an electron beam ion trap

    NASA Astrophysics Data System (ADS)

    Hu, Zhimin; Ishiguro, Yusuke; Watanabe, Hirofumi; Ohtani, Shunsuke; Nakamura, Nobuyuki

    2013-03-01

    We present the charge state distributions of highly charged ions extracted from an electron beam ion trap (EBIT). The distributions were obtained in the two different extraction modes, pulsed mode and leaky mode. The number ratio between adjacent charge state ions, which is an important quantity to measure dielectronic recombination cross sections with an EBIT, is compared between the two extraction modes. The results are also compared with recent theoretical predictions by Zhang et al. [17].

  9. Bending loss of leaky modes in optical fibers with arbitrary index profiles.

    PubMed

    Wilczewski, F

    1994-07-15

    Two new bending loss theories for leaky modes in optical fibers with arbitrary refractive-index profiles are presented. The numerical results are compared with the two known theories of Marcuse and Shah and of Vassalo. The two new theories are valid in a larger region of bend radii than the Marcuse-Shah theory. For the first time, to the author's knowledge, it is shown that for even and odd modes the bending loss is different, in general. PMID:19844523

  10. Response of a grounded dielectric slab to an impulse line source using leaky modes

    NASA Technical Reports Server (NTRS)

    Duffy, Dean G.

    1994-01-01

    This paper describes how expansions in leaky (or improper) modes may be used to represent the continuous spectrum in an open radiating waveguide. The technique requires a thorough knowledge of the life history of the improper modes as they migrate from improper to proper Riemann surfaces. The method is illustrated by finding the electric field resulting from an impulsively forced current located in the free space above a grounded dielectric slab.

  11. Shallow boomerang-shaped influenza hemagglutinin G13A mutant structure promotes leaky membrane fusion.

    PubMed

    Lai, Alex L; Tamm, Lukas K

    2010-11-26

    Our previous studies showed that an angled boomerang-shaped structure of the influenza hemagglutinin (HA) fusion domain is critical for virus entry into host cells by membrane fusion. Because the acute angle of ?105 of the wild-type fusion domain promotes efficient non-leaky membrane fusion, we asked whether different angles would still support fusion and thus facilitate virus entry. Here, we show that the G13A fusion domain mutant produces a new leaky fusion phenotype. The mutant fusion domain structure was solved by NMR spectroscopy in a lipid environment at fusion pH. The mutant adopted a boomerang structure similar to that of wild type but with a shallower kink angle of ?150. G13A perturbed the structure of model membranes to a lesser degree than wild type but to a greater degree than non-fusogenic fusion domain mutants. The strength of G13A binding to lipid bilayers was also intermediate between that of wild type and non-fusogenic mutants. These membrane interactions provide a clear link between structure and function of influenza fusion domains: an acute angle is required to promote clean non-leaky fusion suitable for virus entry presumably by interaction of the fusion domain with the transmembrane domain deep in the lipid bilayer. A shallower angle perturbs the bilayer of the target membrane so that it becomes leaky and unable to form a clean fusion pore. Mutants with no fixed boomerang angle interacted with bilayers weakly and did not promote any fusion or membrane perturbation. PMID:20826788

  12. Robust sound onset detection using leaky integrate-and-fire neurons with depressing synapses.

    PubMed

    Smith, Leslie S; Fraser, Dagmar S

    2004-09-01

    A biologically inspired technique for detecting onsets in sound is presented. Outputs from a cochlea-like filter are spike coded, in a way similar to the auditory nerve (AN). These AN-like spikes are presented to a leaky integrate-and-fire neuron through a depressing synapse. Onsets are detected with essentially zero latency relative to these AN spikes. Onset detection results for a tone burst, musical sounds and the DARPA/NIST TIMIT speech corpus are presented. PMID:15484889

  13. Optical phonons in GaN/AlN quantum dots: leaky modes

    NASA Astrophysics Data System (ADS)

    Romanov, Dmitri; Mitin, Vladimir; Stroscio, Michael

    2002-05-01

    Surface polar vibrations of a GaN quantum dot in AlN matrix are analyzed in the framework of the macroscopic dielectric continuum model. The conditions are found for existence of surface modes on a quantum dot of oblate spheroidal form. These conditions determine continuum frequency regions rather than quantized frequencies. The found modes are peculiar leaky states. They can provide effective energy relaxation of the confined electrons.

  14. A Novel Computational Method to Reduce Leaky Reaction in DNA Strand Displacement.

    PubMed

    Li, Xin; Wang, Xun; Song, Tao; Lu, Wei; Chen, Zhihua; Shi, Xiaolong

    2015-01-01

    DNA strand displacement technique is widely used in DNA programming, DNA biosensors, and gene analysis. In DNA strand displacement, leaky reactions can cause DNA signals decay and detecting DNA signals fails. The mostly used method to avoid leakage is cleaning up after upstream leaky reactions, and it remains a challenge to develop reliable DNA strand displacement technique with low leakage. In this work, we address the challenge by experimentally evaluating the basic factors, including reaction time, ratio of reactants, and ion concentration to the leakage in DNA strand displacement. Specifically, fluorescent probes and a hairpin structure reporting DNA strand are designed to detect the output of DNA strand displacement, and thus can evaluate the leakage of DNA strand displacement reactions with different reaction time, ratios of reactants, and ion concentrations. From the obtained data, mathematical models for evaluating leakage are achieved by curve derivation. As a result, it is obtained that long time incubation, high concentration of fuel strand, and inappropriate amount of ion concentration can weaken leaky reactions. This contributes to a method to set proper reaction conditions to reduce leakage in DNA strand displacement. PMID:26491602

  15. A Novel Computational Method to Reduce Leaky Reaction in DNA Strand Displacement

    PubMed Central

    Li, Xin; Wang, Xun; Song, Tao; Lu, Wei; Chen, Zhihua; Shi, Xiaolong

    2015-01-01

    DNA strand displacement technique is widely used in DNA programming, DNA biosensors, and gene analysis. In DNA strand displacement, leaky reactions can cause DNA signals decay and detecting DNA signals fails. The mostly used method to avoid leakage is cleaning up after upstream leaky reactions, and it remains a challenge to develop reliable DNA strand displacement technique with low leakage. In this work, we address the challenge by experimentally evaluating the basic factors, including reaction time, ratio of reactants, and ion concentration to the leakage in DNA strand displacement. Specifically, fluorescent probes and a hairpin structure reporting DNA strand are designed to detect the output of DNA strand displacement, and thus can evaluate the leakage of DNA strand displacement reactions with different reaction time, ratios of reactants, and ion concentrations. From the obtained data, mathematical models for evaluating leakage are achieved by curve derivation. As a result, it is obtained that long time incubation, high concentration of fuel strand, and inappropriate amount of ion concentration can weaken leaky reactions. This contributes to a method to set proper reaction conditions to reduce leakage in DNA strand displacement. PMID:26491602

  16. Leaky modes and the first arrivals in cased boreholes with poorly bonded conditions

    NASA Astrophysics Data System (ADS)

    Zhang, XiuMei; Wang, XiuMing; Zhang, HaiLan

    2016-02-01

    The generation mechanism of the first arrivals in the cased boreholes for the poorly bonded conditions is investigated. Based on the analyses of the Riemann surface structure of the characteristic function, the dispersion features, excitation spectra and contributions of modes excited in the cased boreholes with different cementing types are studied. The phase velocity dispersion studies of leaky modes show that high-order modes form "plateau" regions with one approximate velocity denoted by v separated by their cutoff frequencies, in which the phase velocity changes little with a considerable frequency range, while the group velocity keeps a relatively constant high value. Usually, the operation frequency range of a specific cementing evaluation acoustic logging tool is covered by such a "plateau" region. Mode excitation and contribution analyses show that the first arrivals in the cased boreholes for the poorly bonded conditions are the contributions from leaky modes, where the traveling velocity of the first arrivals processed by slowness time coherence (STC) method is equal to the approximated velocity v. Analyses on generation of leaky modes in the cased boreholes supplement the understanding of the generation mechanism of the first arrivals.

  17. Properties of Transmission and Leaky Modes in a Plasmonic Waveguide Constructed by Periodic Subwavelength Metallic Hollow Blocks

    NASA Astrophysics Data System (ADS)

    Jei Wu, Jin; Jang Wu, Chien; Qi Shen, Jian; Hou, Da Jun; Chen Lo, Wen

    2015-09-01

    Based on the concept of low-frequency spoof surface plasmon polaritons (spoof SPPs), a kind of leaky mode is proposed in a waveguide made of a subwavelength metal-block array with open slots. Numerical results reveal that a new transmission mode is found in the periodic subwavelength metal open blocks. This modal field is located inside the interior of a hollow block compared with that in a solid metal block array. The dispersion curve shows that such a new SPPs mode has a negative slope, crossing the light line, and then going into a zone of leaky mode at higher frequencies. The leaky mode has a wider frequency bandwidth, and this can lead to a radiation scanning angle of 53 together with high radiation efficiency. Based on the individual characteristics exhibited by a frequency-dependent radiation pattern for the present leaky mode, the waveguide structure can have potential applications such as frequency dividers and demultiplexers. Experimental verification of such a leaky mode at microwave has been performed, and the experimental results are found to be consistent with the theoretical analysis.

  18. Properties of Transmission and Leaky Modes in a Plasmonic Waveguide Constructed by Periodic Subwavelength Metallic Hollow Blocks.

    PubMed

    Wu, Jin Jei; Wu, Chien Jang; Shen, Jian Qi; Hou, Da Jun; Lo, Wen Chen

    2015-01-01

    Based on the concept of low-frequency spoof surface plasmon polaritons (spoof SPPs), a kind of leaky mode is proposed in a waveguide made of a subwavelength metal-block array with open slots. Numerical results reveal that a new transmission mode is found in the periodic subwavelength metal open blocks. This modal field is located inside the interior of a hollow block compared with that in a solid metal block array. The dispersion curve shows that such a new SPPs mode has a negative slope, crossing the light line, and then going into a zone of leaky mode at higher frequencies. The leaky mode has a wider frequency bandwidth, and this can lead to a radiation scanning angle of 53 together with high radiation efficiency. Based on the individual characteristics exhibited by a frequency-dependent radiation pattern for the present leaky mode, the waveguide structure can have potential applications such as frequency dividers and demultiplexers. Experimental verification of such a leaky mode at microwave has been performed, and the experimental results are found to be consistent with the theoretical analysis. PMID:26403387

  19. NF-κB promotes leaky expression of adenovirus genes in a replication-incompetent adenovirus vector

    PubMed Central

    Machitani, M.; Sakurai, F.; Wakabayashi, K.; Nakatani, K.; Shimizu, K.; Tachibana, M.; Mizuguchi, H.

    2016-01-01

    The replication-incompetent adenovirus (Ad) vector is one of the most promising vectors for gene therapy; however, systemic administration of Ad vectors results in severe hepatotoxicities, partly due to the leaky expression of Ad genes in the liver. Here we show that nuclear factor-kappa B (NF-κB) mediates the leaky expression of Ad genes from the Ad vector genome, and that the inhibition of NF-κB leads to the suppression of Ad gene expression and hepatotoxicities following transduction with Ad vectors. Activation of NF-κB by recombinant tumor necrosis factor (TNF)-α significantly enhanced the leaky expression of Ad genes. More than 50% suppression of the Ad gene expression was found by inhibitors of NF-κB signaling and siRNA-mediated knockdown of NF-κB. Similar results were found when cells were infected with wild-type Ad. Compared with a conventional Ad vector, an Ad vector expressing a dominant-negative IκBα (Adv-CADNIκBα), which is a negative regulator of NF-κB, mediated approximately 70% suppression of the leaky expression of Ad genes in the liver. Adv-CADNIκBα did not induce apparent hepatotoxicities. These results indicate that inhibition of NF-κB leads to suppression of Ad vector-mediated tissue damages via not only suppression of inflammatory responses but also reduction in the leaky expression of Ad genes. PMID:26814140

  20. Properties of Transmission and Leaky Modes in a Plasmonic Waveguide Constructed by Periodic Subwavelength Metallic Hollow Blocks

    PubMed Central

    Jei Wu, Jin; Jang Wu, Chien; Qi Shen, Jian; Hou, Da Jun; Chen Lo, Wen

    2015-01-01

    Based on the concept of low-frequency spoof surface plasmon polaritons (spoof SPPs), a kind of leaky mode is proposed in a waveguide made of a subwavelength metal-block array with open slots. Numerical results reveal that a new transmission mode is found in the periodic subwavelength metal open blocks. This modal field is located inside the interior of a hollow block compared with that in a solid metal block array. The dispersion curve shows that such a new SPPs mode has a negative slope, crossing the light line, and then going into a zone of leaky mode at higher frequencies. The leaky mode has a wider frequency bandwidth, and this can lead to a radiation scanning angle of 53 together with high radiation efficiency. Based on the individual characteristics exhibited by a frequency-dependent radiation pattern for the present leaky mode, the waveguide structure can have potential applications such as frequency dividers and demultiplexers. Experimental verification of such a leaky mode at microwave has been performed, and the experimental results are found to be consistent with the theoretical analysis. PMID:26403387

  1. Semi-analytical solution of groundwater flow in a leaky aquifer system subject to bending effect

    NASA Astrophysics Data System (ADS)

    Yu, Chia-Chi; Yang, Shaw-Yang; Yeh, Hund-Der

    2013-04-01

    SummaryThe bending of aquitard like a plate due to aquifer pumping and compression is often encountered in many practical problems of subsurface flow. This reaction will have large influence on the release of the volume of water from the aquifer, which is essential for the planning and management of groundwater resources in aquifers. However, the groundwater flow induced by pumping in a leaky aquifer system is often assumed that the total stress of aquifer maintains constant all the time and the mechanical behavior of the aquitard formation is negligible. Therefore, this paper devotes to the investigation of the effect of aquitard bending on the drawdown distribution in a leaky aquifer system, which is obviously of interest in groundwater hydrology. Based on the work of Wang et al. (2004) this study develops a mathematical model for investigating the impacts of aquitard bending and leakage rate on the drawdown of the confined aquifer due to a constant-rate pumping in the leaky aquifer system. This model contains three equations; two flow equations delineate the transient drawdown distributions in the aquitard and the confined aquifer, while the other describes the vertical displacement in response to the aquitard bending. For the case of no aquitard bending, this new solution can reduce to the Hantush Laplace-domain solution (Hantush, 1960). On the other hand, this solution without the leakage effect can reduce to the time domain solution of Wang et al. (2004). The results show that the aquifer drawdown is influenced by the bending effect at early time and by the leakage effect at late time. The results of sensitivity analysis indicate that the aquifer compaction is sensitive only at early time, causing less amount of water released from the pumped aquifer than that predicted by the traditional groundwater theory. The dimensionless drawdown is rather sensitive to aquitard's hydraulic conductivity at late time. Additionally, both the hydraulic conductivity and thickness of the aquifer are the most sensitive parameters in influencing the predicted dimensionless drawdown.

  2. Leaky ion extraction method for dielectronic recombination strength measurements at electron-beam ion traps

    SciTech Connect

    Zhang, W.; Yao, K.; Yang, Y.; Chen, C.; Hutton, R.; Zou, Y.

    2010-08-15

    There are a number of mechanisms via which ions and electrons interact in a plasma, but by far one of the most important is through dielectronic recombination (DR). This is a resonant process through which an ion can capture a free electron and decrease its charge by one unit. Cross sections or strengths for this process are of vital importance in the modeling of hot plasmas and hence any advance in measurement or calculation procedures for obtaining DR data is of great importance. The work presented here examines the underlying basis of a newly developed method based on leaky mode ion extraction from an electron beam ion trap (EBIT), for relatively quickly obtaining DR strengths. The development attains to use the ratio of the leaked ions in adjacent charge states, i.e., the initial and final charge states of a DR process, to obtain the strengths preassuming that this ratio is the same as that of the ions remaining inside the EBIT trap. This work shows this assumption to be false. Hence DR strengths measured using leaked ions may be subject to error. But this work also reveals that the difference between this ratio and the one for trapped ions is insensitive to most of the experimental conditions, which means reliable DR strengths can still be obtained by leaky mode ion extraction if proper corrections are applied. An example is shown in this paper where after correction of some experimental results for DR strengths, obtained using the leaky mode, excellent agreement with corresponding theoretical calculations is obtained.

  3. Selective detection of hydrocarbon vapors by ATR-leaky mode spectroscopy

    NASA Astrophysics Data System (ADS)

    Podgorsek, R. P.; Franke, Hilmar; Woods, John G.; Lessard, Roger A.

    2000-03-01

    The technique of dynamic ATR-leaky mode spectroscopy is demonstrated for polymer films on 50 nm Ag layers. For the vapor series R OH with R equals H,CH3, C2 H5 and the BTX compounds benzene, toluene and the 3 xylene isomers two different ways of obtaining selective sensor detection are described. The first approach uses the specific sensitivity. Each vapor has a specific molecular polarizability which causes a specific sensitivity. The second approach takes advantage of the dynamic method. The specific diffusion of the particular molecule in the polymer matrix can be evaluated. In this context the characteristic diffusion of the 3 isomers of xylene are investigated.

  4. A generalized Leaky Integrate-and-Fire neuron model with fast implementation method.

    PubMed

    Wang, Zhenzhong; Guo, Lilin; Adjouadi, Malek

    2014-08-01

    This study introduces a new Generalized Leaky Integrate-and-Fire (GLIF) neuron model with variable leaking resistor and bias current in order to reproduce accurately the membrane voltage dynamics of a biological neuron. The accuracy of this model is ensured by adjusting its parameters to the statistical properties of the Hodgkin-Huxley model outputs; while the speed is enhanced by introducing a Generalized Exponential Moving Average method that converts the parameterized kernel functions into pre-calculated lookup tables based on an analytic solution of the dynamic equations of the GLIF model. PMID:24875788

  5. The Morris-Lecar neuron model embeds a leaky integrate-and-fire model.

    PubMed

    Ditlevsen, Susanne; Greenwood, Priscilla

    2013-08-01

    We show that the stochastic Morris-Lecar neuron, in a neighborhood of its stable point, can be approximated by a two-dimensional Ornstein-Uhlenbeck (OU) modulation of a constant circular motion. The associated radial OU process is an example of a leaky integrate-and-fire (LIF) model prior to firing. A new model constructed from a radial OU process together with a simple firing mechanism based on detailed Morris-Lecar firing statistics reproduces the Morris-Lecar Interspike Interval (ISI) distribution, and has the computational advantages of a LIF. The result justifies the large amount of attention paid to the LIF models. PMID:22623224

  6. Resonant absorption in semiconductor nanowires and nanowire arrays: Relating leaky waveguide modes to Bloch photonic crystal modes

    SciTech Connect

    Fountaine, Katherine T.; Whitney, William S.; Atwater, Harry A.

    2014-10-21

    We present a unified framework for resonant absorption in periodic arrays of high index semiconductor nanowires that combines a leaky waveguide theory perspective and that of photonic crystals supporting Bloch modes, as array density transitions from sparse to dense. Full dispersion relations are calculated for each mode at varying illumination angles using the eigenvalue equation for leaky waveguide modes of an infinite dielectric cylinder. The dispersion relations along with symmetry arguments explain the selectivity of mode excitation and spectral red-shifting of absorption for illumination parallel to the nanowire axis in comparison to perpendicular illumination. Analysis of photonic crystal band dispersion for varying array density illustrates that the modes responsible for resonant nanowire absorption emerge from the leaky waveguide modes.

  7. Leaky Landfills.

    ERIC Educational Resources Information Center

    Jones, Linda L. Cronin

    1992-01-01

    Provides background information on landfills and describes an activity where students learn how a modern landfill is constructed and develop an understanding of the reasons for several regulations regarding modern landfill construction. Students design and construct working models of three types of landfills. (PR)

  8. A new method for the interpretation of pumping tests in leaky aquifers.

    PubMed

    Trinchero, Paolo; Sanchez-Vila, Xavier; Copty, Nadim; Findikakis, Angelos

    2008-01-01

    A novel methodology for the interpretation of pumping tests in leaky aquifer systems, referred to as the double inflection point (DIP) method, is presented. The method is based on the analysis of the first and second derivatives of the drawdown with respect to log time for the estimation of the flow parameters. Like commonly used analysis procedures, such as the type-curve approach developed by Walton (1962) and the inflection point method developed by Hantush (1956), the mathematical development of the DIP method is based on the assumption of homogeneity of the leaky aquifer layers. However, contrary to the two methods developed by Hantush and Walton, the new method does not need any fitting process. In homogeneous media, the two classic methods and the one proposed here provide exact results for transmissivity, storativity, and leakage factor when aquifer storage is neglected and the recharging aquifer is unperturbed. The real advantage of the DIP method comes when applying all methods independently to a test in a heterogeneous aquifer, where each method yields parameter values that are weighted differently, and thus each method provides different information about the heterogeneity distribution. Therefore, the methods are complementary and not competitive. In particular, the combination of the DIP method and Hantush method is shown to lead to the identification of contrasts between the local transmissivity in the vicinity of the well and the equivalent transmissivity of the perturbed aquifer volume. PMID:18181872

  9. Theory of Half-Space Light Absorption Enhancement for Leaky Mode Resonant Nanowires.

    PubMed

    Jia, Yiming; Qiu, Min; Wu, Hui; Cui, Yi; Fan, Shanhui; Ruan, Zhichao

    2015-08-12

    Semiconductor nanowires supporting leaky mode resonances have been used to increase light absorption in optoelectronic applications from solar cell to photodetector and sensor. The light conventionally illuminates these devices with a wide range of different incident angles from half space. Currently, most of the investigated nanowires have centrosymmetric geometry cross section, such as circle, hexagon, and rectangle. Here we show that the absorption capability of these symmetrical nanowires has an upper limit under the half-space illumination. Based on the temporal coupled-mode equation, we develop a reciprocity theory for leaky mode resonances in order to connect the angle-dependent absorption cross section and the radiation pattern. We show that in order to exceed such a half-space limit the radiation pattern should be noncentrosymmetric and dominate in the direction reciprocal to the illumination. As an example, we design a metal trough structure to achieve the desired radiation pattern for an embedded nanowire. In comparison to a single nanowire case the trough structure indeed overcomes the half-space limit and leads to 39% and 64% absorption enhancement in TM and TE polarizations, respectively. Also the trough structure enables the enhancement over a broad wavelength range. PMID:26171950

  10. Two Dot1 isoforms in Saccharomyces cerevisiae as a result of leaky scanning by the ribosome

    PubMed Central

    Frederiks, Floor; Heynen, Guus J. J. E.; van Deventer, Sjoerd J.; Janssen, Hans; van Leeuwen, Fred

    2009-01-01

    Dot1 is a conserved histone methyltransferase that methylates histone H3 on lysine 79. We previously observed that in Saccharomyces cerevisiae, a single DOT1 gene encodes two Dot1 protein species. Here, we show that the relative abundance of the two isoforms changed under nutrient-limiting conditions. A mutagenesis approach showed that the two Dot1 isoforms are produced from two alternative translation start sites as a result of leaky scanning by the ribosome. The leaky scanning was not affected by the 5′- or 3′-untranslated regions of DOT1, indicating that translation initiation is determined by the DOT1 coding sequence. Construction of yeast strains expressing either one of the isoforms showed that both were sufficient for Dot1’s role in global H3K79 methylation and telomeric gene silencing. However, the absence of the long isoform of Dot1 altered the resistance of yeast cells to the chitin-binding drug Calcofluor White, suggesting that the two Dot1 isoforms have a differential function in cell wall biogenesis. PMID:19778927

  11. A leaky aquifer below Champlain Sea clay: closed-form solutions for natural seepage.

    PubMed

    Chapuis, Robert P; Saucier, Antoine

    2013-01-01

    Closed-form solutions are proposed for natural seepage in semiconfined (leaky) aquifers such as those existing below the massive Champlain Sea clay layers in the Saint-Lawrence River Valley. The solutions are for an ideal horizontal leaky aquifer below an ideal aquitard that may have either a constant thickness and a constant hydraulic head at its surface, or a variable thickness and a variable hydraulic head at its surface. A few simplifying assumptions were needed to obtain the closed-form solutions. These have been verified using a finite element method, which did not make any of the assumptions but gave an excellent agreement for hydraulic heads and groundwater velocities. For example, the difference between the two solutions was smaller than 1 mm for variations in the 5 to 8 m range for the hydraulic head in the semiconfined aquifer. Note that fitting the hydraulic head data of monitoring wells to the theoretical solutions gives only the ratio of the aquifer and aquitard hydraulic conductivities, a clear case of multiple solutions for an inverse problem. Consequently, field permeability tests in the aquitard and the aquifer, and pumping tests in the aquifer, are still needed to determine the hydraulic conductivity values. PMID:23441962

  12. Analysis of microwave leaky modes propagating through laser plasma filaments column waveguide

    SciTech Connect

    Alshershby, Mostafa; Hao Zuoqiang; Lin Jingquan

    2012-12-15

    A plasma column waveguide formed by a bundle of closely spaced plasma filaments induced by the propagation of ultrafast laser pulses in air and revived by a longer infrared laser pulse is shown to support microwave radiation. We consider values of both the plasma electron density and microwave frequency for which the refractive index of plasma is lower than the refractive index of air; therefore, a leaky plasma waveguide can be realized in extremely high frequency band. The guiding mechanism does not require high conductance of the plasma and can be easily excited by using commercial femtosecond laser sources. A theoretical study of leaky mode characteristics of isotropic and homogeneous plasma column waveguides is investigated with several values of plasma and waveguide structure parameters. The microwave transmission loss was found to be mainly caused by the microwave leakage through the air-plasma interface and is weakly dependent on the plasma absorption. In spite of losses of microwaves caused by leakage and plasma absorption, it is shown to be much lower than both that accompanying to surface waves attaching to single conducting plasma wire and the free space propagation over distances in the order of the filament length, which opens exciting perspectives for short distance point to point wireless transmission of pulsed-modulated microwaves.

  13. Single cell-level detection and quantitation of leaky protein expression from any strongly regulated bacterial system.

    PubMed

    Arora, Kanika; Mangale, Sachin S; Guptasarma, Purnananda

    2015-09-01

    Extremely low levels of "leaky" expression of genes in bacterial protein expression systems can severely curtail cell viability when expressed proteins are toxic. A general method for sensitive detection of such expression is lacking. Here, we present a method based on microscopic visualization of a fluorescent "reporter" protein (RFP-HU-A) constructed by fusing red fluorescent protein (RFP) to the N-terminus of a nucleoid-associated, histone-like DNA-binding protein, HU-A. Localization of RFP-HU-A within nucleoids facilitates detection, quantitation, and characterization of leaky expression at the single-cell level. PMID:26079706

  14. Evaluation of layer thickness in human teeth using higher-order-mode leaky Lamb wave interdigital transducers

    SciTech Connect

    Toda, Shinji; Fujita, Takeshi; Arakawa, Hirohisa; Toda, Kohji

    2005-03-01

    An ultrasonic nondestructive evaluation technique of the layer thickness in human teeth is proposed using a leaky Lamb wave device with two arch-shaped interdigital transducers, operating at a plate/water interface. The use of a higher-order-mode leaky Lamb wave with a phase velocity higher than the longitudinal wave velocity in the human tooth is essential to detect reflected ultrasound beams from the tooth section The layer thickness of dentin, estimated from the measured time interval between two reflected echoes, is in good agreement with the optically measured data.

  15. CFD simulation of pollutant dispersion around isolated buildings: on the role of convective and turbulent mass fluxes in the prediction accuracy.

    PubMed

    Gousseau, P; Blocken, B; van Heijst, G J F

    2011-10-30

    Computational Fluid Dynamics (CFD) is increasingly used to predict wind flow and pollutant dispersion around buildings. The two most frequently used approaches are solving the Reynolds-averaged Navier-Stokes (RANS) equations and Large-Eddy Simulation (LES). In the present study, we compare the convective and turbulent mass fluxes predicted by these two approaches for two configurations of isolated buildings with distinctive features. We use this analysis to clarify the role of these two components of mass transport on the prediction accuracy of RANS and LES in terms of mean concentration. It is shown that the proper simulation of the convective fluxes is essential to predict an accurate concentration field. In addition, appropriate parameterization of the turbulent fluxes is needed with RANS models, while only the subgrid-scale effects are modeled with LES. Therefore, when the source is located outside of recirculation regions (case 1), both RANS and LES can provide accurate results. When the influence of the building is higher (case 2), RANS models predict erroneous convective fluxes and are largely outperformed by LES in terms of prediction accuracy of mean concentration. These conclusions suggest that the choice of the appropriate turbulence model depends on the configuration of the dispersion problem under study. It is also shown that for both cases LES predicts a counter-gradient mechanism of the streamwise turbulent mass transport, which is not reproduced by the gradient-diffusion hypothesis that is generally used with RANS models. PMID:21880420

  16. Leaky Ca2+ release channel/ryanodine receptor 2 causes seizures and sudden cardiac death in mice

    PubMed Central

    Lehnart, Stephan E.; Mongillo, Marco; Bellinger, Andrew; Lindegger, Nicolas; Chen, Bi-Xing; Hsueh, William; Reiken, Steven; Wronska, Anetta; Drew, Liam J.; Ward, Chris W.; Lederer, W.J.; Kass, Robert S.; Morley, Gregory; Marks, Andrew R.

    2008-01-01

    The Ca2+ release channel ryanodine receptor 2 (RyR2) is required for excitation-contraction coupling in the heart and is also present in the brain. Mutations in RyR2 have been linked to exercise-induced sudden cardiac death (catecholaminergic polymorphic ventricular tachycardia [CPVT]). CPVT-associated RyR2 mutations result in leaky RyR2 channels due to the decreased binding of the calstabin2 (FKBP12.6) subunit, which stabilizes the closed state of the channel. We found that mice heterozygous for the R2474S mutation in Ryr2 (Ryr2-R2474S mice) exhibited spontaneous generalized tonic-clonic seizures (which occurred in the absence of cardiac arrhythmias), exercise-induced ventricular arrhythmias, and sudden cardiac death. Treatment with a novel RyR2-specific compound (S107) that enhances the binding of calstabin2 to the mutant Ryr2-R2474S channel inhibited the channel leak and prevented cardiac arrhythmias and raised the seizure threshold. Thus, CPVT-associated mutant leaky Ryr2-R2474S channels in the brain can cause seizures in mice, independent of cardiac arrhythmias. Based on these data, we propose that CPVT is a combined neurocardiac disorder in which leaky RyR2 channels in the brain cause epilepsy, and the same leaky channels in the heart cause exercise-induced sudden cardiac death. PMID:18483626

  17. Large-core tube-leaky waveguide for delivery of high-powered Er:YAG laser

    NASA Astrophysics Data System (ADS)

    Kobayashi, S.; Katagiri, T.; Matsuura, Y.

    2014-02-01

    A tube-leaky fiber that consists of only dielectric thin-film tubing for delivery of Er:YAG laser light is presented. The tube-leaky fiber confines light in the airy core when the film thickness is properly chosen for target wavelength. Transmission properties of the fibers are derived by using a ray optic method and designed the optimum wall thickness for the Er:YAG laser wavelength of 2.94 micron. In fabrication of the tube leaky fiber, we use a microstructural tube made of glass to enhance mechanical strength. The central bore and surrounding glass thin layer that is held by the microstructure function as a tube-leaky fiber. We fabricate a large-core fiber for delivery of high-power medical lasers by stack-and-draw method and we use borosilicate-glass as a fiber material for low cost fabrication. Fabricated fibers have a diameter over 400 ?m and from the loss measurements for Er:YAG laser, and the fibers deliver laser light with a transmission loss of 0.85 dB/m that is comparable to 0.7 dB/m of conventional hollow-optical fibers. The fibers withstand transmission of laser pulses with energy higher than 120 mJ. We confirm that these energies are enough to ablate biological tissues in surgical operations.

  18. Simultaneous confidence intervals for a steady-state leaky aquifer groundwater flow model

    USGS Publications Warehouse

    Christensen, S.; Cooley, R.L.

    1996-01-01

    Using the optimization method of Vecchia & Cooley (1987), nonlinear Scheffe??-type confidence intervals were calculated tor the parameters and the simulated heads of a steady-state groundwater flow model covering 450 km2 of a leaky aquifer. The nonlinear confidence intervals are compared to corresponding linear intervals. As suggested by the significant nonlinearity of the regression model, linear confidence intervals are often not accurate. The commonly made assumption that widths of linear confidence intervals always underestimate the actual (nonlinear widths was not correct for the head intervals. Results show that nonlinear effects can cause the nonlinear intervals to be offset from, and either larger or smaller than, the linear approximations. Prior information on some transmissivities helps reduce and stabilize the confidence intervals, with the most notable effects occurring for the parameters on which there is prior information and for head values in parameter zones for which there is prior information on the parameters.

  19. An integrated optical leaky waveguide sensor with electrically induced concentration system for the detection of bacteria.

    PubMed

    Zourob, Mohammed; Mohr, Stephan; Brown, Bernard J Treves; Fielden, Peter R; McDonnell, Martin B; Goddard, Nicholas J

    2005-12-01

    An integrated, sensitive and rapid system was developed for the detection of bacteria. The system combined an optical metal-clad leaky waveguide (MCLW) sensor with an electric field. The electric field was used to concentrate Bacillus subtilis var. niger(BG) bacteria spores onto the immobilized anti-BG antibody on the MCLW sensor surface. This sensor combination has been characterised by detecting the scattering from bacterial spores, which are concentrated at the sensor surface, when they are illuminated at the coupling angle; and by detection of fluorescence from labelled antibodies added after the spores had been captured on the surface. The light scattering and fluorescence detection methods gave a detection limit of BG bacterial spores of 1 x 10(3) spores ml(-1) when the electric field was applied for 3 minutes. PMID:16286966

  20. An integrated disposable dye clad leaky waveguide sensor for micro-TAS applications.

    PubMed

    Zourob, Mohammed; Mohr, Stephan; Fielden, Peter R; Goddard, Nicholas J

    2005-07-01

    An integrated, disposable, dye clad leaky waveguide (DCLW) device has been fabricated and tested for both refractive index and fluorescence detection in mu-TAS applications. The chip comprises the required flow geometry and optical coupling elements in a robust device that is relatively simple and inexpensive to fabricate. Disposable DCLW chips were fabricated at room temperature by spin-coating both the dye and silica sol-gel waveguiding layers on a polymer substrate which contained injection moulded grating coupler. These devices have been designed to increase the interaction of the evanescent field light at the channel wall and with the sample in the channel. The DCLW device has been used to detect changes in the refractive index of different percentages of glycerol solutions and to detect low concentrations down to 10(-12) M fluorescein using a grating coupler. PMID:15970971

  1. Optical leaky waveguide sensor for detection of bacteria with ultrasound attractor force.

    PubMed

    Zourob, Mohammed; Hawkes, Jeremy J; Coakley, W Terence; Treves Brown, Bernard J; Fielden, Peter R; McDonnell, Martin B; Goddard, Nicholas J

    2005-10-01

    An integrated, sensitive, and rapid system was developed for the detection of bacteria. The system combined an optical metal-clad leaky waveguide (MCLW) sensor with ultrasound standing waves (USW). The performance of a MCLW sensor for the detection of bacteria has been increased (>100 fold) by using USWs to drive bacteria onto the sensor surface. By forming the USW nodes at or within the surface of the MCLW, the diffusion-limited capture rate has been replaced by fast movement. Immobilized anti-BG antibody on the MCLW sensor surface was used to capture Bacillus subtilis var. niger (BG) bacterial spores driven to the surface. This combination of sensor and attractor force combination has been tested by detecting the evanescent scattering from bacterial spores at the sensor surface. Application of ultrasound for 3 min gave a detection limit for BG bacterial spores of 1 x 10(3) spores/mL. PMID:16194074

  2. On the processing of leaky guided waves propagating in immersed plates

    NASA Astrophysics Data System (ADS)

    Bagheri, Abdollah; Rizzo, Piervincenzo; Pistone, Elisabetta

    2014-03-01

    We present a non-destructive inspection method for the structural health monitoring of underwater structures. A laser operating at 532 nm is used to excite leaky guided waves on an aluminum plate immersed in water. The plate has a few artificial defects namely vertical notch, horizontal notch, corrosion, and small hole. An array of five immersion transducers arranged in half-circle is used to detect the propagating waves. A signal processing technique is implemented to assess the presence of damage; the method is based on continuous wavelet transform to extract a few damagesensitive features fed to an artificial neural network for damage classification. The experimental results show that the proposed system can be employed for the inspection of underwater plates.

  3. Radiation-Pressure Acceleration of Ion Beams from Nanofoil Targets: The Leaky Light-Sail Regime

    SciTech Connect

    Qiao, B.; Zepf, M.; Borghesi, M.; Dromey, B.; Geissler, M.; Karmakar, A.; Gibbon, P.

    2010-10-08

    A new ion radiation-pressure acceleration regime, the 'leaky light sail', is proposed which uses sub-skin-depth nanometer foils irradiated by circularly polarized laser pulses. In the regime, the foil is partially transparent, continuously leaking electrons out along with the transmitted laser field. This feature can be exploited by a multispecies nanofoil configuration to stabilize the acceleration of the light ion component, supplementing the latter with an excess of electrons leaked from those associated with the heavy ions to avoid Coulomb explosion. It is shown by 2D particle-in-cell simulations that a monoenergetic proton beam with energy 18 MeV is produced by circularly polarized lasers at intensities of just 10{sup 19} W/cm{sup 2}. 100 MeV proton beams are obtained by increasing the intensities to 2x10{sup 20} W/cm{sup 2}.

  4. Gut-liver axis in liver cirrhosis: How to manage leaky gut and endotoxemia

    PubMed Central

    Fukui, Hiroshi

    2015-01-01

    A “leaky gut” may be the cutting edge for the passage of toxins, antigens or bacteria into the body, and may play a pathogenic role in advanced liver cirrhosis and its complications. Plasma endotoxin levels have been admitted as a surrogate marker of bacterial translocation and close relations of endotoxemia to hyperdynamic circulation, portal hypertension, renal, cardiac, pulmonary and coagulation disturbances have been reported. Bacterial overgrowth, increased intestinal permeability, failure to inactivate endotoxin, activated innate immunity are all likely to play a role in the pathological states of bacterial translocation. Therapeutic approach by management of the gut-liver axis by antibiotics, probiotics, synbiotics, prebiotics and their combinations may improve the clinical course of cirrhotic patients. Special concern should be paid on anti-endotoxin treatment. Adequate management of the gut-liver axis may be effective for prevention of liver cirrhosis itself by inhibiting the progression of fibrosis. PMID:25848468

  5. Efficient calculation of 1-D periodic Green's functions for leaky-wave applications.

    SciTech Connect

    Baccarelli, Paolo; Johnson, William Arthur; Paulotto, Simone; Jackson, David R.; Wilton, Donald R.; Galli, A.; Valero, G.; Celepcikay, F. T.

    2010-08-01

    In this paper an approach is described for the efficient computation of the mixed-potential scalar and dyadic Green's functions for a one-dimensional periodic (periodic along x direction) array of point sources embedded in a planar stratified structure. Suitable asymptotic extractions are performed on the slowly converging spectral series. The extracted terms are summed back through the Ewald method, modified and optimized to efficiently deal with all the different terms. The accelerated Green's functions allow for complex wavenumbers, and are thus suitable for application to leaky-wave antennas analysis. Suitable choices of the spectral integration paths are made in order to account for leakage effects and the proper/improper nature of the various space harmonics that form the 1-D periodic Green's function.

  6. Real-Time Leaky Lamb Wave Spectrum Measurement and Its Application to NDE of Composites

    NASA Technical Reports Server (NTRS)

    Lih, Shyh-Shiuh; Bar-Cohen, Yoseph

    1999-01-01

    Numerous analytical and theoretical studies of the behavior of leaky Lamb waves (LLW) in composite materials were documented in the literature. One of the key issues that are constraining the application of this method as a practical tool is the amount of data that needs to be acquired and the slow process that is involved with such experiments. Recently, a methodology that allows quasi real-time acquisition of LLW dispersion data was developed. At each angle of incidence the reflection spectrum is available in real time from the experimental setup and it can be used for rapid detection of the defects. This technique can be used to rapidly acquire the various plate wave modes along various angles of incidence for the characterization of the material elastic properties. The experimental method and data acquisition technique will be described in this paper. Experimental data was used to examine a series of flaws including porosity and delaminations and demonstrated the efficiency of the developed technique.

  7. A biophysical observation model for field potentials of networks of leaky integrate-and-fire neurons

    PubMed Central

    beim Graben, Peter; Rodrigues, Serafim

    2013-01-01

    We present a biophysical approach for the coupling of neural network activity as resulting from proper dipole currents of cortical pyramidal neurons to the electric field in extracellular fluid. Starting from a reduced three-compartment model of a single pyramidal neuron, we derive an observation model for dendritic dipole currents in extracellular space and thereby for the dendritic field potential (DFP) that contributes to the local field potential (LFP) of a neural population. This work aligns and satisfies the widespread dipole assumption that is motivated by the open-field configuration of the DFP around cortical pyramidal cells. Our reduced three-compartment scheme allows to derive networks of leaky integrate-and-fire (LIF) models, which facilitates comparison with existing neural network and observation models. In particular, by means of numerical simulations we compare our approach with an ad hoc model by Mazzoni et al. (2008), and conclude that our biophysically motivated approach yields substantial improvement. PMID:23316157

  8. Frequency-division multiplexing in the terahertz range using a leaky-wave antenna

    NASA Astrophysics Data System (ADS)

    Karl, Nicholas J.; McKinney, Robert W.; Monnai, Yasuaki; Mendis, Rajind; Mittleman, Daniel M.

    2015-11-01

    The idea of using radiation in the 0.11.0?THz range as carrier waves for free-space wireless communications has attracted growing interest in recent years, due to the promise of the large available bandwidth. Recent research has focused on system demonstrations, as well as the exploration of new components for modulation, beam steering and polarization control. However, the multiplexing and demultiplexing of terahertz signals remains an unaddressed challenge, despite the importance of such capabilities for broadband networks. Using a leaky-wave antenna based on a metal parallel-plate waveguide, we demonstrate frequency-division multiplexing and demultiplexing over more than one octave of bandwidth. We show that this device architecture offers a unique method for controlling the spectrum allocation, by variation of the waveguide plate separation. This strategy, which is distinct from those previously employed in either the microwave or optical regimes, enables independent control of both the centre frequency and bandwidth of multiplexed terahertz channels.

  9. Radiation-pressure acceleration of ion beams from nanofoil targets: the leaky light-sail regime.

    PubMed

    Qiao, B; Zepf, M; Borghesi, M; Dromey, B; Geissler, M; Karmakar, A; Gibbon, P

    2010-10-01

    A new ion radiation-pressure acceleration regime, the "leaky light sail," is proposed which uses sub-skin-depth nanometer foils irradiated by circularly polarized laser pulses. In the regime, the foil is partially transparent, continuously leaking electrons out along with the transmitted laser field. This feature can be exploited by a multispecies nanofoil configuration to stabilize the acceleration of the light ion component, supplementing the latter with an excess of electrons leaked from those associated with the heavy ions to avoid Coulomb explosion. It is shown by 2D particle-in-cell simulations that a monoenergetic proton beam with energy 18 MeV is produced by circularly polarized lasers at intensities of just 10? ?W/cm. 100 MeV proton beams are obtained by increasing the intensities to 2 10? ?W/cm. PMID:21230914

  10. Leaky-wave-induced disks around Be stars: a pulsational analysis on their formation

    NASA Astrophysics Data System (ADS)

    Godart, Melanie; Shibahashi, Hiromoto; Dupret, Marc-Antoine

    2015-01-01

    Be stars are B-type stars near the main sequence which undergo episodic mass loss events detected by emission lines, whose line shape and intensity vary with a timescale of the order of decades. Spectroscopic observations show a large rotation velocity such that one of the prevailing scenarios for the formation of the equatorial disk consists in an increasing equatorial rotation velocity to the break-up limit where gravity is challenged by the centrifugal force. We investigate here a new scenario recently suggested by Ishimatsu & Shibahashi (2013), in which the transport of angular momentum through the photosphere would be achieved by leaky waves, keeping the rotation velocity still below the break-up limit.

  11. Claudin-2 as a mediator of leaky gut barrier during intestinal inflammation

    PubMed Central

    Luettig, J; Rosenthal, R; Barmeyer, C; Schulzke, JD

    2015-01-01

    The epithelial tight junction determines the paracellular water and ion movement in the intestine and also prevents uptake of larger molecules, including antigens, in an uncontrolled manner. Claudin-2, one of the 27 mammalian claudins regulating that barrier function, forms a paracellular channel for small cations and water. It is typically expressed in leaky epithelia like proximal nephron and small intestine and provides a major pathway for the paracellular transport of sodium, potassium, and fluid. In intestinal inflammation (Crohn's disease, ulcerative colitis), immune-mediated diseases (celiac disease), and infections (HIV enteropathy), claudin-2 is upregulated in small and large intestine and contributes to diarrhea via a leak flux mechanism. In parallel to that upregulation, other epithelial and tight junctional features are altered and the luminal uptake of antigenic macromolecules is enhanced, for which claudin-2 may be partially responsible through induction of tight junction strand discontinuities. PMID:25838982

  12. The effects of air gap reflections during air-coupled leaky Lamb wave inspection of thin plates.

    PubMed

    Fan, Zichuan; Jiang, Wentao; Cai, Maolin; Wright, William M D

    2016-02-01

    Air-coupled ultrasonic inspection using leaky Lamb waves offers attractive possibilities for non-contact testing of plate materials and structures. A common method uses an air-coupled pitch-catch configuration, which comprises a transmitter and a receiver positioned at oblique angles to a thin plate. It is well known that the angle of incidence of the ultrasonic bulk wave in the air can be used to preferentially generate specific Lamb wave modes in the plate in a non-contact manner, depending on the plate dimensions and material properties. Multiple reflections of the ultrasonic waves in the air gap between the transmitter and the plate can produce additional delayed waves entering the plate at angles of incidence that are different to those of the original bulk wave source. Similarly, multiple reflections of the leaky Lamb waves in the air gap between the plate and an inclined receiver may then have different angles of incidence and propagation delays when arriving at the receiver and hence the signal analysis may become complex, potentially leading to confusion in the identification of the wave modes. To obtain a better understanding of the generation, propagation and detection of leaky Lamb waves and the effects of reflected waves within the air gaps, a multiphysics model using finite element methods was established. This model facilitated the visualisation of the propagation of the reflected waves between the transducers and the plate, the subsequent generation of additional Lamb wave signals within the plate itself, their leakage into the adjacent air, and the reflections of the leaky waves in the air gap between the plate and receiver. Multiple simulations were performed to evaluate the propagation and reflection of signals produced at different transducer incidence angles. Experimental measurements in air were in good agreement with simulation, which verified that the multiphysics model can provide a convenient and accurate way to interpret the signals in air-coupled ultrasonic inspection using leaky Lamb waves. PMID:26464105

  13. Leaky-mode resonance photonics: technology for biosensors, optical components, MEMS, and plasmonics

    NASA Astrophysics Data System (ADS)

    Magnusson, Robert; Wawro, Debra; Zimmerman, Shelby; Ding, Yiwu; Shokooh-Saremi, Mehrdad; Lee, Kyu Jin; Ussery, Daryl; Kim, Sangin; Song, Seok Ho

    2010-02-01

    Resonant leaky modes can be induced on dielectric, semiconductor, and metallic periodic layers patterned in one or two dimensions. Potential applications include bandpass and bandstop filters, laser mirrors, ultrasensitive biosensors, absorption enhancement in solar cells, security devices, tunable filters, nanoelectromechanical display pixels, dispersion/slow-light elements, and others. As there is now a growing realization worldwide of the utility of these devices, it is of interest to summarize their physical basis and present their applicability in photonic devices and systems. In particular, we have invented and implemented highly accurate, label-free, guided-mode resonance (GMR) biosensors that are being commercialized. The sensor is based on the high parametric sensitivity inherent in the fundamental resonance effect. As an attaching biomolecular layer changes the parameters of the resonance element, the resonance frequency (wavelength) changes. A target analyte interacting with a bio-selective layer on the sensor can thus be identified without additional processing or use of foreign tags. Another promising pursuit in this field is development of optical components including wideband mirrors, filters, and polarizers. We have experimentally realized such devices that exhibit a minimal layer count relative to their classical multilayer thin-film counterparts. Theoretical modeling has shown that wideband tuning of these filters is achievable by perturbing the structural symmetry using nano/microelectromechanical (MEMS) methods. MEMS-tuned resonance elements may be useful as pixels in spatial light modulators, tunable lasers, and multispectral imaging applications. Finally, mixed metallic/dielectric resonance elements exhibit simultaneous plasmonic and leaky-mode resonance effects. Their design and chief characteristics is described.

  14. Neuronal Spike Timing Adaptation Described with a Fractional Leaky Integrate-and-Fire Model

    PubMed Central

    Teka, Wondimu; Marinov, Toma M.; Santamaria, Fidel

    2014-01-01

    The voltage trace of neuronal activities can follow multiple timescale dynamics that arise from correlated membrane conductances. Such processes can result in power-law behavior in which the membrane voltage cannot be characterized with a single time constant. The emergent effect of these membrane correlations is a non-Markovian process that can be modeled with a fractional derivative. A fractional derivative is a non-local process in which the value of the variable is determined by integrating a temporal weighted voltage trace, also called the memory trace. Here we developed and analyzed a fractional leaky integrate-and-fire model in which the exponent of the fractional derivative can vary from 0 to 1, with 1 representing the normal derivative. As the exponent of the fractional derivative decreases, the weights of the voltage trace increase. Thus, the value of the voltage is increasingly correlated with the trajectory of the voltage in the past. By varying only the fractional exponent, our model can reproduce upward and downward spike adaptations found experimentally in neocortical pyramidal cells and tectal neurons in vitro. The model also produces spikes with longer first-spike latency and high inter-spike variability with power-law distribution. We further analyze spike adaptation and the responses to noisy and oscillatory input. The fractional model generates reliable spike patterns in response to noisy input. Overall, the spiking activity of the fractional leaky integrate-and-fire model deviates from the spiking activity of the Markovian model and reflects the temporal accumulated intrinsic membrane dynamics that affect the response of the neuron to external stimulation. PMID:24675903

  15. Neuronal spike timing adaptation described with a fractional leaky integrate-and-fire model.

    PubMed

    Teka, Wondimu; Marinov, Toma M; Santamaria, Fidel

    2014-03-01

    The voltage trace of neuronal activities can follow multiple timescale dynamics that arise from correlated membrane conductances. Such processes can result in power-law behavior in which the membrane voltage cannot be characterized with a single time constant. The emergent effect of these membrane correlations is a non-Markovian process that can be modeled with a fractional derivative. A fractional derivative is a non-local process in which the value of the variable is determined by integrating a temporal weighted voltage trace, also called the memory trace. Here we developed and analyzed a fractional leaky integrate-and-fire model in which the exponent of the fractional derivative can vary from 0 to 1, with 1 representing the normal derivative. As the exponent of the fractional derivative decreases, the weights of the voltage trace increase. Thus, the value of the voltage is increasingly correlated with the trajectory of the voltage in the past. By varying only the fractional exponent, our model can reproduce upward and downward spike adaptations found experimentally in neocortical pyramidal cells and tectal neurons in vitro. The model also produces spikes with longer first-spike latency and high inter-spike variability with power-law distribution. We further analyze spike adaptation and the responses to noisy and oscillatory input. The fractional model generates reliable spike patterns in response to noisy input. Overall, the spiking activity of the fractional leaky integrate-and-fire model deviates from the spiking activity of the Markovian model and reflects the temporal accumulated intrinsic membrane dynamics that affect the response of the neuron to external stimulation. PMID:24675903

  16. Susceptibility to gut leakiness: a possible mechanism for endotoxaemia in non-alcoholic steatohepatitis

    PubMed Central

    Farhadi, Ashkan; Gundlapalli, Sushama; Shaikh, Maliha; Frantzides, Constantine; Harrell, Laura; Kwasny, Mary M.; Keshavarzian, Ali

    2014-01-01

    Introduction One of the proposed second hit mechanisms in the pathophysiology of non-alcoholic steatohepatitis (NASH) is hepatic oxidative stress triggered by elevated levels of endotoxin. We investigated one possible mechanism for the endotoxaemia disruption of intestinal barrier integrity. Methods We enrolled 16 subjects with fatty liver (10 NASH; 6 steatosis) and 12 healthy subjects. Steatosis and NASH were diagnosed by liver biopsy using the Brunt criteria. Gastrointestinal permeability was measured using urinary excretion of 5-h lactulose/mannitol (L/M) ratio and 24-h sucralose. Permeability testing was repeated after aspirin challenge. Results Groups had similar baseline urinary 05 h L/M ratio (small bowel permeability) and 024 h sucralose (whole-gut permeability). Aspirin increased 05 h urinary L/M in most subjects. In contrast, aspirin significantly increased whole-gut permeability only in NASH subjects. In fact, the major increase in the urinary sucralose occurred in the 624 h samples, which points towards the colon as the major site responsible for aspirin-induced leakiness in NASH patients. Serum endotoxin levels were significantly higher in NASH subjects. Discussion Our findings suggest that aspirin acts on the colon to unmask a susceptibility to gut leakiness in patients with NASH. This effect may be the underlying mechanism for increased serum endotoxin, which is the second hit (after altered lipid metabolism) that is required to initiate a necroinflammatory cascade in hepatocytes which are already primed with obesity-induced abnormal lipid homoeostasis. PMID:18397235

  17. Indoor-Outdoor Air Leakage of Apartments and Commercial Buildings

    SciTech Connect

    Price, P.N.; Shehabi, A.; Chan, R.W.; Gadgil, A.J.

    2006-06-01

    We compiled and analyzed available data concerning indoor-outdoor air leakage rates and building leakiness parameters for commercial buildings and apartments. We analyzed the data, and reviewed the related literature, to determine the current state of knowledge of the statistical distribution of air exchange rates and related parameters for California buildings, and to identify significant gaps in the current knowledge and data. Very few data were found from California buildings, so we compiled data from other states and some other countries. Even when data from other developed countries were included, data were sparse and few conclusive statements were possible. Little systematic variation in building leakage with construction type, building activity type, height, size, or location within the u.s. was observed. Commercial buildings and apartments seem to be about twice as leaky as single-family houses, per unit of building envelope area. Although further work collecting and analyzing leakage data might be useful, we suggest that a more important issue may be the transport of pollutants between units in apartments and mixed-use buildings, an under-studied phenomenon that may expose occupants to high levels of pollutants such as tobacco smoke or dry cleaning fumes.

  18. Automated Comparison of Building Energy Simulation Engines (Presentation)

    SciTech Connect

    Polly, B.; Horowitz, S.; Booten, B.; Kruis, N.; Christensen, C.

    2012-08-01

    This presentation describes the BEopt comparative test suite, which is a tool that facilitates the automated comparison of building energy simulation engines. It also demonstrates how the test suite is improving the accuracy of building energy simulation programs. Building energy simulation programs inform energy efficient design for new homes and energy efficient upgrades for existing homes. Stakeholders rely on accurate predictions from simulation programs. Previous research indicates that software tends to over-predict energy usage for poorly-insulated leaky homes. NREL is identifying, investigating, and resolving software inaccuracy issues. Comparative software testing is one method of many that NREL uses to identify potential software issues.

  19. Evaluation of confidence intervals for a steady-state leaky aquifer model

    USGS Publications Warehouse

    Christensen, S.; Cooley, R.L.

    1999-01-01

    The fact that dependent variables of groundwater models are generally nonlinear functions of model parameters is shown to be a potentially significant factor in calculating accurate confidence intervals for both model parameters and functions of the parameters, such as the values of dependent variables calculated by the model. The Lagrangian method of Vecchia and Cooley [Vecchia, A.V. and Cooley, R.L., Water Resources Research, 1987, 23(7), 1237-1250] was used to calculate nonlinear Scheffe-type confidence intervals for the parameters and the simulated heads of a steady-state groundwater flow model covering 450 km2 of a leaky aquifer. The nonlinear confidence intervals are compared to corresponding linear intervals. As suggested by the significant nonlinearity of the regression model, linear confidence intervals are often not accurate. The commonly made assumption that widths of linear confidence intervals always underestimate the actual (nonlinear) widths was not correct. Results show that nonlinear effects can cause the nonlinear intervals to be asymmetric and either larger or smaller than the linear approximations. Prior information on transmissivities helps reduce the size of the confidence intervals, with the most notable effects occurring for the parameters on which there is prior information and for head values in parameter zones for which there is prior information on the parameters.The fact that dependent variables of groundwater models are generally nonlinear functions of model parameters is shown to be a potentially significant factor in calculating accurate confidence intervals for both model parameters and functions of the parameters, such as the values of dependent variables calculated by the model. The Lagrangian method of Vecchia and Cooley was used to calculate nonlinear Scheffe-type confidence intervals for the parameters and the simulated heads of a steady-state groundwater flow model covering 450 km2 of a leaky aquifer. The nonlinear confidence intervals are compared to corresponding linear intervals. As suggested by the significant nonlinearity of the regression model, linear confidence intervals are often not accurate. The commonly made assumption that widths of linear confidence intervals always underestimate the actual (nonlinear) widths was not correct. Results show that nonlinear effects can cause the nonlinear intervals to be asymmetric and either larger or smaller than the linear approximations. Prior information on transmissivities helps reduce the size of the confidence intervals, with the most notable effects occurring for the parameters on which there is prior information and for head values in parameter zones for which there is prior information on the parameters.

  20. CYP2E1 potentiates binge alcohol-induced gut leakiness, steatohepatitis, and apoptosis.

    PubMed

    Abdelmegeed, Mohamed A; Banerjee, Atrayee; Jang, Sehwan; Yoo, Seong-Ho; Yun, Jun-Won; Gonzalez, Frank J; Keshavarzian, Ali; Song, Byoung-Joon

    2013-12-01

    Ethanol-inducible cytochrome P450 2E1 (CYP2E1) contributes to increased oxidative stress and steatosis in chronic alcohol-exposure models. However, its role in binge ethanol-induced gut leakiness and hepatic injury is unclear. This study was aimed at investigating the role of CYP2E1 in binge alcohol-induced gut leakiness and the mechanisms of steatohepatitis. Female wild-type (WT) and Cyp2e1-null mice were treated with three doses of binge ethanol (WT-EtOH or Cyp2e1-null-EtOH) (6g/kg oral gavage at 12-h intervals) or dextrose (negative control). Intestinal histology of only WT-EtOH exhibited epithelial alteration and blebbing of lamina propria, and liver histology obtained at 6h after the last ethanol dose showed elevated steatosis with scattered inflammatory foci. These were accompanied by increased levels of serum endotoxin, hepatic enterobacteria, and triglycerides. All these changes, including the intestinal histology and hepatic apoptosis, determined by TUNEL assay, were significantly reversed when WT-EtOH mice were treated with the specific inhibitor of CYP2E1 chlormethiazole and the antioxidant N-acetylcysteine, both of which suppressed oxidative markers including intestinal CYP2E1. WT-EtOH also exhibited elevated amounts of serum TNF-?, hepatic cytokines, CYP2E1, and lipid peroxidation, with decreased levels of mitochondrial superoxide dismutase and suppressed aldehyde dehydrogenase 2 activity. Increased hepatocyte apoptosis with elevated levels of proapoptotic proteins and decreased levels of active (phosphorylated) p-AKT, p-AMPK, and peroxisome proliferator-activated receptor-?, all of which are involved in fat metabolism and inflammation, were observed in WT-EtOH. These changes were significantly attenuated in the corresponding Cyp2e1-null-EtOH mice. These data indicate that both intestinal and hepatic CYP2E1 induced by binge alcohol seems critical in binge alcohol-mediated increased nitroxidative stress, gut leakage, and endotoxemia; altered fat metabolism; and inflammation contributing to hepatic apoptosis and steatohepatitis. PMID:24064383

  1. Acoustoelectric effects in reflection of leaky-wave-radiated bulk acoustic waves from piezoelectric crystal-conductive liquid interface.

    PubMed

    Rimeika, Romualdas; Čiplys, Daumantas; Jonkus, Vytautas; Shur, Michael

    2016-01-01

    The leaky surface acoustic wave (SAW) propagating along X-axis of Y-cut lithium tantalate crystal strongly radiates energy in the form of an obliquely propagating narrow bulk acoustic wave (BAW) beam. The reflection of this beam from the crystal-liquid interface has been investigated. The test liquids were solutions of potassium nitrate in distilled water and of lithium chloride in isopropyl alcohol with the conductivity varied by changing the solution concentration. The strong dependences of the reflected wave amplitude and phase on the liquid conductivity were observed and explained by the acoustoelectric interaction in the wave reflection region. The novel configuration of an acoustic sensor for liquid media featuring important advantages of separate measuring and sensing surfaces and rigid structure has been proposed. The application of leaky-SAW radiated bulk waves for identification of different brands of mineral water has been demonstrated. PMID:26391353

  2. Fully leaky guided wave determination of the polar anchoring energy of a homogeneously aligned nematic liquid crystal

    NASA Astrophysics Data System (ADS)

    Yang, Fuzi; Sambles, J. R.; Dong, Youmei; Gao, Hongjin

    2000-03-01

    Optical excitation of a series of fully leaky guided modes has been used to explore the director distortion of a homogeneously aligned nematic liquid crystal (Merck-BDH E7) under application of an ac electric field (1 kHz) normal to the cell wall. Homogeneous alignment is realized by rubbed polyimide films on glass plates with indium-tin-oxide coatings. By using continuum theory to model the director profile through the cell to fit the fully leaky guided mode reflectivity and transmissivity data, both with and without applied fields, the changes of surface tilt angle and its gradient can be obtained from which the polar anchoring coefficient, W?, is derived. At 26.8 C we find that W?=1.210-4 Jm-2.

  3. Hybrid method for the precise calculation of the general dyadic Greens functions for SAW and leaky wave substrates.

    SciTech Connect

    Branch, Darren W.

    2008-05-01

    Recently, the generalized method for calculation of the 16-element Green's function for analysis of surface acoustic waves has proven crucial to develop more sophisticated transducers. The generalized Green's function provides a precise relationship between the acoustic stresses and electric displacement on the three mechanical displacements and electric potential. This generalized method is able to account for mass loading effects which is absent in the effective permittivity approach. However, the calculation is numerically intensive and may lead to numerical instabilities when solving for both the eigenvalues and eigenvectors simultaneously. In this work, the general eigenvalue problem was modified to eliminate the numerical instabilities in the solving procedure. An algorithm is also presented to select the proper eigenvalues rapidly to facilitate analysis for all types of acoustic propagation. The 4 x 4 Green's functions and effective permittivities were calculated for materials supporting Rayleigh, leaky, and leaky longitudinal waves as demonstration of the method.

  4. An integrated metal clad leaky waveguide sensor for detection of bacteria.

    PubMed

    Zourob, Mohammed; Mohr, Stephan; Treves Brown, Bernard J; Fielden, Peter R; McDonnell, Martin B; Goddard, Nicholas J

    2005-01-01

    An integrated optical metal clad leaky waveguide (MCLW) sensor device has been developed for the detection of bacteria. This is more sensitive than waveguide sensors currently in use. The MCLW device has been fabricated to extend the evanescent field to provide significant light intensity over the entire volume of the bacteria bound on the chip surface within this field. This in turn increases the interaction of the light with the entire volume of the bacteria. MCLW devices have been used for detecting refractive index changes, scattering, and fluorescence from bacterial spores captured on an immobilized antibody. The detection limit of Bacillus subtilis var. niger bacterial spores using refractive index detection was 8 x10(4) spores/mL. The scattering intensity of the BG spores was found to be three times greater than the scattering intensity generated using surface plasmon resonance. The extended light propagation along the direction of flow for a few millimeters provides an effective interrogation approach to increase the area of detection to detect low concentrations down to 1 x 10(4) spores/mL. The sensor was then optimized by studying the key factors affecting sensor performance including changing the pH of the medium, type of antibody immobilization matrix, sensor surface regeneration approaches, and longevity of the sensor. PMID:15623301

  5. Concentration history during pumping from a leaky aquifer with stratified initial concentration

    USGS Publications Warehouse

    Goode, Daniel J.; Hsieh, Paul A.; Shapiro, Allen M.; Wood, Warren W.; Kraemer, Thomas F.

    1993-01-01

    Analytical and numerical solutions are employed to examine the concentration history of a dissolved substance in water pumped from a leaky aquifer. Many aquifer systems are characterized by stratification, for example, a sandy layer overlain by a clay layer. To obtain information about separate hydrogeologic units, aquifer pumping tests are often conducted with a well penetrating only one of the layers. When the initial concentration distribution is also stratified (the concentration varies with elevation only), the concentration breakthrough in the pumped well may be interpreted to provide information on aquifer hydraulic and transport properties. To facilitate this interpretation, we present some simple analytical and numerical solutions for limiting cases and illustrate their application to a fractured bedrock/glacial drift aquifer system where the solute of interest is dissolved radon gas. In addition to qualitative information on water source, this method may yield estimates of effective porosity and saturated thickness (or fracture transport aperture) from a single-hole test. Little information about dispersivity is obtained because the measured concentration is not significantly affected by dispersion in the aquifer.

  6. Influence of inhomogeneous porosity on silicon nanowire Raman enhancement and leaky mode modulated photoluminescence.

    PubMed

    Ratchford, Daniel; Yeom, Junghoon; Long, James P; Pehrsson, Pehr E

    2015-03-01

    Metal-assisted chemical etching (MACE) offers an inexpensive, massively parallel fabrication process for producing silicon nanowires (SiNWs). These nanowires can possess a degree of porosity depending on etch conditions. Because the porosity is often spatially inhomogeneous, there is a need to better understand its nature if applications exploiting the porosity are to be pursued. Here, the resolution afforded by micro-Raman and micro-photoluminescence (PL) is used to elucidate the effects of porosity heterogeneity on the optical properties of individual SiNWs produced in large arrays with MACE, while also determining the spatial character of the heterogeneity. For highly porous SiNWs, there is a dramatic reduction in Raman signal and an increase in PL near the SiNW tips. PL spectra collected along the SiNW length exhibit peaks due to leaky mode resonances. Analysis of the PL resonance peaks, Raman spectrum line shape, SEM images, and EDS spectra indicate that the SiNWs possess both radial and axial heterogeneity wherein, from base to SiNW tip, the SiNWs comprise a shell of increasingly thick porous Si surrounding a tapering core of bulk Si. This work describes how structural porosity variation shapes SiNW optical properties, which will influence the design of new SiNW-based photonic devices and chemical/biological sensors. PMID:25666765

  7. Leaky-guided channeled substrate planar (LCSP) laser with reduced substrate radiation and heating

    NASA Astrophysics Data System (ADS)

    Lee, Song Jae; Ramaswamy, Ramu V.; Figueroa, Luis

    1989-07-01

    A semiconductor laser design, the leaky-guided channeled substrate planar (LCSP) structure, is presented. The structure with a buffer layer in the region outside the channel provides a built-in negative effective index step. The transverse mode is well damped in the buffer layer, and the substrate radiation in the region outside the channel is virtually eliminated. As a result, the significant heating and facet degradation in the region outside the channel that is related to the substrate radiation in conventional CSP lasers is minimized. The calculated local temperature rise in the region outside the channel of the CSP laser is about 45 C for an output power level of 100 mW and is in reasonably good agreement with previous experimental results. Analysis using the complex domain effective index method shows that the LCSP structure provides better lateral mode discrimination than either gain-guided or positive index step structures. The LCSP structure with reduced heating and strong lateral coupling effect may be useful for high-power linear array lasers.

  8. Role of leaky neuronal ryanodine receptors in stress-induced cognitive dysfunction.

    PubMed

    Liu, Xiaoping; Betzenhauser, Matthew J; Reiken, Steve; Meli, Albano C; Xie, Wenjun; Chen, Bi-Xing; Arancio, Ottavio; Marks, Andrew R

    2012-08-31

    The type 2 ryanodine receptor/calcium release channel (RyR2), required for excitation-contraction coupling in the heart, is abundant in the brain. Chronic stress induces catecholamine biosynthesis and release, stimulating ?-adrenergic receptors and activating cAMP signaling pathways in neurons. In a murine chronic restraint stress model, neuronal RyR2 were phosphorylated by protein kinase A (PKA), oxidized, and nitrosylated, resulting in depletion of the stabilizing subunit calstabin2 (FKBP12.6) from the channel complex and intracellular calcium leak. Stress-induced cognitive dysfunction, including deficits in learning and memory, and reduced long-term potentiation (LTP) at the hippocampal CA3-CA1 connection were rescued by oral administration of S107, a compound developed in our laboratory that stabilizes RyR2-calstabin2 interaction, or by genetic ablation of the RyR2 PKA phosphorylation site at serine 2808. Thus, neuronal RyR2 remodeling contributes to stress-induced cognitive dysfunction. Leaky RyR2 could be a therapeutic target for treatment of stress-induced cognitive dysfunction. PMID:22939628

  9. Intrinsic Noise Induces Critical Behavior in Leaky Markovian Networks Leading to Avalanching

    PubMed Central

    Jenkinson, Garrett; Goutsias, John

    2014-01-01

    The role intrinsic statistical fluctuations play in creating avalanches patterns of complex bursting activity with scale-free properties is examined in leaky Markovian networks. Using this broad class of models, we develop a probabilistic approach that employs a potential energy landscape perspective coupled with a macroscopic description based on statistical thermodynamics. We identify six important thermodynamic quantities essential for characterizing system behavior as a function of network size: the internal potential energy, entropy, free potential energy, internal pressure, pressure, and bulk modulus. In agreement with classical phase transitions, these quantities evolve smoothly as a function of the network size until a critical value is reached. At that value, a discontinuity in pressure is observed that leads to a spike in the bulk modulus demarcating loss of thermodynamic robustness. We attribute this novel result to a reallocation of the ground states (global minima) of the system's stationary potential energy landscape caused by a noise-induced deformation of its topographic surface. Further analysis demonstrates that appreciable levels of intrinsic noise can cause avalanching, a complex mode of operation that dominates system dynamics at near-critical or subcritical network sizes. Illustrative examples are provided using an epidemiological model of bacterial infection, where avalanching has not been characterized before, and a previously studied model of computational neuroscience, where avalanching was erroneously attributed to specific neural architectures. The general methods developed here can be used to study the emergence of avalanching (and other complex phenomena) in many biological, physical and man-made interaction networks. PMID:24415927

  10. Acclimation to low light by C4 maize: implications for bundle sheath leakiness.

    PubMed

    Bellasio, Chandra; Griffiths, Howard

    2014-05-01

    C4 plants have a biochemical carbon concentrating mechanism (CCM) that increases CO2 concentration around ribulose bisphosphate carboxylase oxygenase (Rubisco) in the bundle sheath (BS). Under limiting light, the activity of the CCM generally decreases, causing an increase in leakiness, (?), the ratio of CO2 retrodiffusing from the BS relative to C4 carboxylation processes. Maize plants were grown under high and low light regimes (respectively HL, 600 versus LL, 100??E?m(-2) ?s(-1) ). Short-term acclimation of ? was compared from isotopic discrimination (?), gas exchange and photochemistry. Direct measurement of respiration in the light, and ATP production rate (JATP ), allowed us use a novel approach to derive ?, compared with the conventional fitting of measured and predicted ?. HL grown plants responded to decreasing light intensities with the well-documented increase in ?. Conversely, LL plants showed a constant ?, which has not been observed previously. We explain the pattern by two contrasting acclimation strategies: HL plants maintained a high CCM activity at LL, resulting in high CO2 overcycling and increased ?; LL plants acclimated by down-regulating the CCM, effectively optimizing scarce ATP supply. This surprising plasticity may limit the impact of ?-dependent carbon losses in leaves becoming shaded within developing canopies. PMID:24004447

  11. Associative memory of phase-coded spatiotemporal patterns in leaky Integrate and Fire networks.

    PubMed

    Scarpetta, Silvia; Giacco, Ferdinando

    2013-04-01

    We study the collective dynamics of a Leaky Integrate and Fire network in which precise relative phase relationship of spikes among neurons are stored, as attractors of the dynamics, and selectively replayed at different time scales. Using an STDP-based learning process, we store in the connectivity several phase-coded spike patterns, and we find that, depending on the excitability of the network, different working regimes are possible, with transient or persistent replay activity induced by a brief signal. We introduce an order parameter to evaluate the similarity between stored and recalled phase-coded pattern, and measure the storage capacity. Modulation of spiking thresholds during replay changes the frequency of the collective oscillation or the number of spikes per cycle, keeping preserved the phases relationship. This allows a coding scheme in which phase, rate and frequency are dissociable. Robustness with respect to noise and heterogeneity of neurons parameters is studied, showing that, since dynamics is a retrieval process, neurons preserve stable precise phase relationship among units, keeping a unique frequency of oscillation, even in noisy conditions and with heterogeneity of internal parameters of the units. PMID:23053861

  12. Interflow Moving over Leaky Impeding Layers: How Far Can We Expect It to Go?

    NASA Astrophysics Data System (ADS)

    Jackson, C. R.; Hopp, L.; McDonnell, J.; Bitew, M. M.; Du, E.; Klaus, J.; Griffiths, N.

    2014-12-01

    Interflow can occur in any slope where higher conductivity topsoils are underlain by a low conductivity impeding layer which could include B horizons, till layers, hardpans, C horizons and bedrock of various permeabilities. Impeding layers of essentially impermeable bedrock seem to be a rarity, as studies that have evaluated interflow on slopes underlain by apparently solid crystalline rock have still found leakage into the rock. Hewlett's concrete soil trough studies thus comprise an endpoint of interflow boundary conditions. In many hillslope environments, downslope interflow necessarily includes a normal flow component into the leaky impeding layer. By making a simplifying assumption of zero pressure at the base of the impeding layer (for perched conditions), the downslope travel distance as interflow of a parcel of water can be estimated from the ratio of the hydraulic conductivities, the ratio of the downslope and normal hydraulic gradients, and the thickness of the saturated zone above the impeding layer. For many hillslopes, downslope travel distances imply that only the slope segments adjacent to the riparian valley can be expected to deliver interflow to the valley during a storm. Over most of the hillslope, interflow acts only to redistribute recharge downslope from the point of infiltration. Therefore, continuous perching of water moving as interflow from the ridge to the valley does not imply continuous connectivity. In terms of stormflow contributions, only the lower slopes within the range of the downslope travel distance may be connected to stream valleys.

  13. Input-output relationship of the Leaky-integrator neuron model.

    PubMed

    Scharstein, H

    1979-12-01

    This paper presents a method of calculating the spike sequence at the output of the Leaky-Integrator Neuron Model (LIM) in response to an arbitrary input stimulus. The calculations have revealed new properties of the initial transient behavior of the LIM, as well as new constraints upon necessary and sufficient conditions for the appearance of spikes with a fixed phase relation to a periodic input. It is also possible to infer what knowledge about the input stimulus can be obtained from a temporal sequence of spikes at the output of the LIM. In the Discussion, neuronal examples are considered which do not encode the transmitted information as a spike rate, but rather monitor the time of occurence of individual spikes by comparison with a reference signal. This relatively common case is not adequately treated by previous descriptions based on system theory; ways are suggested by which the formalism developed here can be used to describe completely, and understand more fully, the performance of such systems. PMID:541580

  14. Composite Materials NDE Using Enhanced Leaky Lamb Wave Dispersion Data Acquisition Method

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Mal, Ajit; Lih, Shyh-Shiuh; Chang, Zensheu

    1999-01-01

    The leaky Lamb wave (LLW) technique is approaching a maturity level that is making it an attractive quantitative NDE tool for composites and bonded joints. Since it was first observed in 1982, the phenomenon has been studied extensively, particularly in composite materials. The wave is induced by oblique insonification using a pitch-catch arrangement and the plate wave modes are detected by identifying minima in the reflected spectra to obtain the dispersion data. The wave behavior in multi-orientation laminates has been well documented and corroborated experimentally with high accuracy. The sensitivity of the wave to the elastic constants of the material and to the boundary conditions led to the capability to measure the elastic properties of bonded joints. Recently, the authors significantly enhanced the LLW method's capability by increasing the speed of the data acquisition, the number of modes that can be identified and the accuracy of the data inversion. In spite of the theoretical and experimental progress, methods that employ oblique insonification of composites are still not being applied as standard industrial NDE methods. The authors investigated the issues that are hampering the transition of the LLW to industrial applications and identified 4 key issues. The current capability of the method and the nature of these issues are described in this paper.

  15. Reconstructing Stimuli from the Spike Times of Leaky Integrate and Fire Neurons

    PubMed Central

    Gerwinn, Sebastian; Macke, Jakob H.; Bethge, Matthias

    2010-01-01

    Reconstructing stimuli from the spike trains of neurons is an important approach for understanding the neural code. One of the difficulties associated with this task is that signals which are varying continuously in time are encoded into sequences of discrete events or spikes. An important problem is to determine how much information about the continuously varying stimulus can be extracted from the time-points at which spikes were observed, especially if these time-points are subject to some sort of randomness. For the special case of spike trains generated by leaky integrate and fire neurons, noise can be introduced by allowing variations in the threshold every time a spike is released. A simple decoding algorithm previously derived for the noiseless case can be extended to the stochastic case, but turns out to be biased. Here, we review a solution to this problem, by presenting a simple yet efficient algorithm which greatly reduces the bias, and therefore leads to better decoding performance in the stochastic case. PMID:21390287

  16. Influence of inhomogeneous porosity on silicon nanowire Raman enhancement and leaky mode modulated photoluminescence

    NASA Astrophysics Data System (ADS)

    Ratchford, Daniel; Yeom, Junghoon; Long, James P.; Pehrsson, Pehr. E.

    2015-02-01

    Metal-assisted chemical etching (MACE) offers an inexpensive, massively parallel fabrication process for producing silicon nanowires (SiNWs). These nanowires can possess a degree of porosity depending on etch conditions. Because the porosity is often spatially inhomogeneous, there is a need to better understand its nature if applications exploiting the porosity are to be pursued. Here, the resolution afforded by micro-Raman and micro-photoluminescence (PL) is used to elucidate the effects of porosity heterogeneity on the optical properties of individual SiNWs produced in large arrays with MACE, while also determining the spatial character of the heterogeneity. For highly porous SiNWs, there is a dramatic reduction in Raman signal and an increase in PL near the SiNW tips. PL spectra collected along the SiNW length exhibit peaks due to leaky mode resonances. Analysis of the PL resonance peaks, Raman spectrum line shape, SEM images, and EDS spectra indicate that the SiNWs possess both radial and axial heterogeneity wherein, from base to SiNW tip, the SiNWs comprise a shell of increasingly thick porous Si surrounding a tapering core of bulk Si. This work describes how structural porosity variation shapes SiNW optical properties, which will influence the design of new SiNW-based photonic devices and chemical/biological sensors.Metal-assisted chemical etching (MACE) offers an inexpensive, massively parallel fabrication process for producing silicon nanowires (SiNWs). These nanowires can possess a degree of porosity depending on etch conditions. Because the porosity is often spatially inhomogeneous, there is a need to better understand its nature if applications exploiting the porosity are to be pursued. Here, the resolution afforded by micro-Raman and micro-photoluminescence (PL) is used to elucidate the effects of porosity heterogeneity on the optical properties of individual SiNWs produced in large arrays with MACE, while also determining the spatial character of the heterogeneity. For highly porous SiNWs, there is a dramatic reduction in Raman signal and an increase in PL near the SiNW tips. PL spectra collected along the SiNW length exhibit peaks due to leaky mode resonances. Analysis of the PL resonance peaks, Raman spectrum line shape, SEM images, and EDS spectra indicate that the SiNWs possess both radial and axial heterogeneity wherein, from base to SiNW tip, the SiNWs comprise a shell of increasingly thick porous Si surrounding a tapering core of bulk Si. This work describes how structural porosity variation shapes SiNW optical properties, which will influence the design of new SiNW-based photonic devices and chemical/biological sensors. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr06329e

  17. Temporal changes in microvessel leakiness during wound healing discriminated by in vivo fluorescence recovery after photobleaching

    PubMed Central

    Machado, Maria J C; Mitchell, Christopher A

    2011-01-01

    Abstract Regeneration of injured tissue is a dynamic process, critically dependent on the formation of new blood vessels and restructuring of the nascent plexus. Endothelial barrier function, a functional correlate of vascular restructuring and maturation, was quantified via intravital microscopic analysis of 150 kDa FITC-dextran-perfused blood vessels within discrete wounds created in the panniculus carnosus (PC) muscle of dorsal skinfold chamber (DSC) preparations in mice. Time to recovery of half-peak fluorescence intensity (t1/2) within individual vessel segments in three functional regions of the wound (pre-existing vessels, angiogenic plexus and blind-ended vessels (BEVs)) was quantified using in vivo fluorescence recovery after photobleaching (FRAP) and linear regression analysis of recovery profiles. Plasma flux across the walls of new vessel segments, particularly BEVs, was greater than that of pre-existing vessels at days 5–7 after injury (P < 0.05). TNP-470 reduced the permeability of BEVs at the leading edge of the advancing vascular plexus as measured by the decrease in luminal t1/2 (P < 0.05), confirming the utility of FRAP as a quantitative measure of endothelial barrier function. Furthermore, these data are suggestive of a role for TNP-470 in selection for less leaky vascular segments within healing wounds. Increased FITC-dextran leakage was observed from pre-existing vessels after treatment with TNP-470 (P < 0.05), consistent with induction of transient vascular damage, although the significance of this finding is unclear. Using in vivo FRAP this study demonstrates the relationship between temporal changes in microvascular macromolecular flux and the morphology of maturing vascular segments. This combination of techniques may be useful to assess the therapeutic potential of angiogenic agents in restoring pre-injury levels of endothelial barrier function, following the establishment of a functional vascular plexus such as in models of wounding or tumour development. PMID:21768268

  18. En echelon knolls in the Nosappu Fracture Zone, NW Pacific: A possible leaky transform fault zone

    NASA Astrophysics Data System (ADS)

    Ogawa, Y.; Hirano, N.; Shipboard Scientific Party Kr03-07, .

    2003-12-01

    During JAMSTEC R/V KAIREI cruise KR03-07, we mapped significant en echelon arrays of knolls and ridges on the NNW-trending Nosappu Fracture Zone between Hokkaido and Shatsky Rise, NW Pacific. This fracture zone has been known to be irregular, including a deep-sea channel, the Nakwe Channel, enigmatic for inside the wide oceanic plate. Considering the previously recognized magnetic lineament dislocation, the fracture zone has long (more than 150 km) left-lateral strike-slip component as a ridge-ridge transform fault zone between the Izanagi and Pacific plates during Early Cretaceous. Detail multi-narrowbeam mapping around 37 N latitude, 150 E longitude (covering 78 km x 137 km), indicated many small knolls and ridges that form en echelon arrangement. Some are boomerang, sock or E-letter in shape. The two dominant directions of ridges are recognized, one is parallel to the fracture zone and the other is in left-handed en echelon fashion. Besides these ridges, there are other types of ridges or conical knolls lower than 500 m in relief; one is a group of rather large knolls extending to NE, roughly perpendicular to the fracture zone direction, and the other is independent small knolls, summing up to five or six in number. Another expression of a depression zone was recognized with a moderate angle to the fracture zone in a crank fashion. This may correspond to the so-called _gNakwe Channel_h which has been wrongly mistaken. Such en echelon arrays are involved in a 50 km wide NNW-SSE zone, which is sharply demarcated by fault scarps. These characteristics in the fracture zone area and associated knolls suggest that this part of the Nosappu Fracture Zone might have developed in a fault interaction area which has a left-lateral component of leaky transform faulting close to the spreading ridge.

  19. Understanding the leaky engineering pipeline: Motivation and job adaptability of female engineers

    NASA Astrophysics Data System (ADS)

    Saraswathiamma, Manjusha Thekkedathu

    This dissertation is a mixed-method study conducted using qualitative grounded theory and quantitative survey and correlation approaches. This study aims to explore the motivation and adaptability of females in the engineering profession and to develop a theoretical framework for both motivation and adaptability issues. As a result, this study endeavors to design solutions for the low enrollment and attenuation of female engineers in the engineering profession, often referred to as the "leaky female engineering pipeline." Profiles of 123 female engineers were studied for the qualitative approach, and 98 completed survey responses were analyzed for the quantitative approach. The qualitative, grounded-theory approach applied the constant comparison method; open, axial, and selective coding was used to classify the information in categories, sub-categories, and themes for both motivation and adaptability. The emergent themes for decisions motivating female enrollment include cognitive, emotional, and environmental factors. The themes identified for adaptability include the seven job adaptability factors: job satisfaction, risk- taking attitude, career/skill development, family, gender stereotyping, interpersonal skills, and personal benefit, as well as the self-perceived job adaptability factor. Illeris' Three-dimensional Learning Theory was modified as a model for decisions motivating female enrollment. This study suggests a firsthand conceptual parallelism of McClusky's Theory of Margin for the adaptability of female engineers in the profession. Also, this study attempted to design a survey instrument to measure job adaptability of female engineers. The study identifies two factors that are significantly related to job adaptability: interpersonal skills (< p = 0.01) and family (< p = 0.05); gender stereotyping and personal benefit are other factors that are also significantly (< p = 0.1) related.

  20. The imbalance of new and export production in the western Antarctic Peninsula, a potentially "leaky" ecosystem

    NASA Astrophysics Data System (ADS)

    Stukel, Michael R.; Asher, Elizabeth; Couto, Nicole; Schofield, Oscar; Strebel, Stefanie; Tortell, Philippe; Ducklow, Hugh W.

    2015-09-01

    To quantify the balance between new production and vertical nitrogen export of sinking particles, we measured nitrate uptake, net nitrate drawdown, ΔO2/Ar-based net community production, sediment trap flux, and 234Th export at a coastal site near Palmer Station, Antarctica, during the phytoplankton growing season from October 2012 to March 2013. We also measured nitrate uptake and 234Th export throughout the northern western Antarctic Peninsula (WAP) region on a cruise in January 2013. We used a nonsteady state 234Th equation with temporally varying upwelling rates and an irradiance-based phytoplankton production model to correct our export and new production estimates in the complex coastal site near Palmer Station. Results unequivocally showed that nitrate uptake and net community production were significantly greater than the sinking particle export on region-wide spatial scales and season-long temporal scales. At our coastal site, new production (105 ± 17.4 mg N m-2 d-1, mean ± standard error) was 5.3 times greater than vertical nitrogen export (20.4 ± 2.4 mg N m-2 d-1). On the January cruise in the northern WAP, new production (47.9 ± 14.4 mg N m-2 d-1) was 2.4 times greater than export (19.9 ± 1.4 mg N m-2 d-1). Much of this imbalance can be attributed to diffusive losses of particulate nitrogen from the surface ocean due to diapycnal mixing, indicative of a "leaky" WAP ecosystem. If these diffusive losses are common in other systems where new production exceeds export, it may be necessary to revise current estimates of the ocean's biological pump.

  1. Leaky RAG Deficiency in Adult Patients with Impaired Antibody Production against Bacterial Polysaccharide Antigens

    PubMed Central

    Geier, Christoph B.; Piller, Alexander; Linder, Angela; Sauerwein, Kai M. T.; Eibl, Martha M.; Wolf, Hermann M.

    2015-01-01

    Loss of function mutations in the recombination activating genes RAG1 and RAG2 have been reported to cause a T-B-NK+ type of severe combined immunodeficiency. In addition identification of hypomorphic mutations in RAG1 and RAG2 has led to an expansion of the spectrum of disease to include Omenn syndrome, early onset autoimmunity, granuloma, chronic cytomegalovirus- or EBV-infection with expansion of gamma/delta T-cells, idiophatic CD4 lymphopenia and a phenotype resembling common variable immunodeficiency. Herein we describe a novel presentation of leaky RAG1 and RAG2 deficiency in two unrelated adult patients with impaired antibody production against bacterial polysaccharide antigens. Clinical manifestation included recurrent pneumonia, sinusitis, otitis media and in one patient recurrent cutaneous vasculitis. Both patients harbored a combination of a null mutation on one allele with a novel hypomorphic RAG1/2 mutation on the other allele. One of these novel mutations affected the start codon of RAG1 and resulted in an aberrant gene and protein expression. The second novel RAG2 mutation leads to a truncated RAG2 protein, lacking the C-terminus with intact core RAG2 and reduced VDJ recombination capacity as previously described in a mouse model. Both patients presented with severely decreased numbers of naïve CD4+ T cells and defective T independent IgG responses to bacterial polysaccharide antigens, while T cell-dependent IgG antibody formation e.g. after tetanus or TBEV vaccination was intact. In conclusion, hypomorphic mutations in genes responsible for SCID should be considered in adults with predominantly antibody deficiency. PMID:26186701

  2. Analytical solutions for two-phase subsurface flow to a leaky fault considering vertical flow effects and fault properties

    NASA Astrophysics Data System (ADS)

    Kang, Mary; Nordbotten, Jan M.; Doster, Florian; Celia, Michael A.

    2014-04-01

    Conductive faults in geologic formations can serve as leakage pathways for fluids such as CO2 and methane, which would otherwise remain trapped beneath low-permeability layers. To estimate leakage rates and the associated pressure effects on adjacent aquifers, modeling of the flow in the vicinity of leaky faults must be performed. The flow from an aquifer to a leaky fault is controlled by aquifer properties as well as fault properties, including the fault permeability, fault width, and anisotropy in the fault permeability. Depending on aquifer properties and leakage rates, vertical flow equilibrium may not be reached in the aquifer in the vicinity of the leaky fault. Therefore, analytical solutions for leakage through faults that allow for vertical flow need to be developed. To do this, the vertically integrated form of the two-phase flow formulation based on vertical equilibrium is expanded by assuming a linearly structured vertical flow field, and steady state analytical solutions for single-phase and two-phase leakage are derived. In the case of two-phase leakage, anisotropic aquifer permeabilities are shown to produce stronger vertical flow effects than in the case of single-phase leakage. Using numerical simulations, a model representing fault properties that is compatible with the analytical solutions is developed. The combination of the fault model and the analytical solutions captures the effects of leakage through faults with different properties and vertical flow effects. The incorporation of this fault model/analytical solution in larger basin-wide multiscale models can enable subgrid-scale effects due to leakage through faults to be captured with improved efficiency.

  3. Transmission enhancement through square coaxial aperture arrays in metallic film: when leaky modes filter infrared light for multispectral imaging.

    PubMed

    Vial, Benjamin; Commandr, Mireille; Demsy, Guillaume; Nicolet, Andr; Zolla, Frdric; Bedu, Frdric; Dallaporta, Herv; Tisserand, Stphane; Roux, Laurent

    2014-08-15

    The diffractive behavior of arrays of square coaxial apertures in a gold layer is studied. These structures exhibit a resonant transmission enhancement that is used to design tunable bandpass filters for multispectral imaging in the 7-13 ?m wavelength range. A modal analysis is used for this design and the study of their spectral features. Thus we show that the resonance peak is due to the excitation of leaky modes of the open photonic structure. Fourier transform infrared (FTIR) spectrophotometry transmission measurements of samples deposited on Si substrate show good agreement with numerical results and demonstrate angular tolerance of up to 30 degrees of the fabricated filters. PMID:25121858

  4. The Andes Hantavirus NSs Protein Is Expressed from the Viral Small mRNA by a Leaky Scanning Mechanism

    PubMed Central

    Vera-Otarola, Jorge; Solis, Loretto; Soto-Rifo, Ricardo; Ricci, Emiliano P.; Pino, Karla; Tischler, Nicole D.; Ohlmann, Théophile; Darlix, Jean-Luc

    2012-01-01

    The small mRNA (SmRNA) of all Bunyaviridae encodes the nucleocapsid (N) protein. In 4 out of 5 genera in the Bunyaviridae, the smRNA encodes an additional nonstructural protein denominated NSs. In this study, we show that Andes hantavirus (ANDV) SmRNA encodes an NSs protein. Data show that the NSs protein is expressed in the context of an ANDV infection. Additionally, our results suggest that translation initiation from the NSs initiation codon is mediated by ribosomal subunits that have bypassed the upstream N protein initiation codon through a leaky scanning mechanism. PMID:22156529

  5. Leaky rivers: Implications of the loss of longitudinal fluvial disconnectivity in headwater streams

    NASA Astrophysics Data System (ADS)

    Wohl, Ellen; Beckman, Natalie D.

    2014-01-01

    Naturally induced longitudinal disconnectivity in the form of channel-spanning logjams creates backwaters along headwater streams that reduce velocity and transport capacity, create at least temporary storage sites for finer sediment and organic matter, and enhance biological processing and uptake of nutrients. Land uses that reduce wood recruitment and instream storage result in reduced stream complexity and increased longitudinal connectivity in headwater rivers. We examine three scales of naturally occurring longitudinal disconnectivity in headwater streams of the Colorado Front Range and the implications for channel process and form of historical alterations in disconnectivity. Basin-scale disconnectivity at channel lengths of 102-103 m results from downstream alternations between steep, narrowly confined valley segments with single-thread channels, and lower gradient, wider, valley segments with multi-thread channels. This variation in valley geometry likely reflects differences in average spacing between joints in bedrock outcrops, which influences bedrock weathering and erosion. Greater volumes of wood stored in the wide valley segments correlate with more closely spaced channel-spanning logjams and greater storage of fine sediments and organic matter. Reach-scale disconnectivity at channel lengths of 101-102 m results from the presence of numerous, closely spaced channel-spanning logjams, which cumulatively store substantial amounts of fine sediment and organic matter. The backwater effects associated with an individual jam can result in the accumulation of up to ~ 11 m3 of fine sediment upstream from the jam, of which as much as 21% is organic matter. Unit-scale disconnectivity at channel lengths of 100-101 m results from the presence of an individual channel-spanning logjam, which locally alters bed gradient, substrate composition, bedform dimensions, and the transport of sediment and organic matter. The transport and storage of instream wood is a critical component of disconnectivity at all spatial scales examined. Land uses such as timber harvest, flow regulation, and placer mining that result in reduced wood recruitment or removal of instream wood appear to create an alternative stable state in which channels are unable to retain wood because of reduced debris roughness. The net effect of reduced longitudinal disconnectivity is increased transport of fine sediment and organic matter and reduced biological uptake of nutrients. The altered headwater streams become leaky with respect to fine sediments and nutrients.

  6. Dc to ac field conversion due to leaky-wave excitation in a plasma slab behind an ionization front

    NASA Astrophysics Data System (ADS)

    Kostin, V. A.; Vvedenskii, N. V.

    2015-03-01

    We present a way for generating coherent tunable electromagnetic radiation through dc to ac field conversion by an ionization front. The conversion is caused by the excitation of leaky waves behind the transversely limited ionization front propagating in a uniform electrostatic field. This differs significantly from the well-known dc-to-ac-radiation-converter models which consider Doppler-like frequency conversion by a transversely unlimited ionization front propagating in a spatially periodic electric field. We explore the dispersion properties and excitation of these leaky waves radiated through the transverse plasma boundary at the Cherenkov angle to the direction of propagation of a superluminal ionization front as dependent on the parameters of the plasma produced and on the speed of the ionization front. It is shown that not only the center frequency but also the duration and waveform of the generated pulse may significantly depend on the speed of the ionization front. The results indicate the possibility of using such converters based on planar photoconductive antennas to create sources of microwave and terahertz radiation with controllable waveforms that are transformed from video to radio pulse when the angle of incident ionizing radiation is tuned.

  7. Theory of a Directive Optical Leaky Wave Antenna Integrated into a Resonator and Enhancement of Radiation Control

    NASA Astrophysics Data System (ADS)

    Guclu, Caner; Campione, Salvatore; Boyraz, Ozdal; Capolino, Filippo

    2014-05-01

    We provide for the first time the detailed study of the radiation performance of an optical leaky wave antenna (OLWA) integrated into a Fabry-P\\'erot resonator. We show that the radiation pattern can be expressed as the one generated by the interference of two leaky waves counter-propagating in the resonator leading to a design procedure for achieving optimized broadside radiation, i.e., normal to the waveguide axis. We thus report a realizable implementation of the OLWA made of semiconductor and dielectric regions. The theoretical modeling is supported by full-wave simulation results, which are found to be in good agreement. We aim to control the radiation intensity in the broadside direction via excess carrier generation in the semiconductor regions. We show that the presence of the resonator can provide an effective way of enhancing the radiation level modulation, which reaches values as high as 13.5 dB, paving the way for novel promising control capabilities that might allow the generation of very fast optical switches, as an example.

  8. Transportation of single cell and microbubbles by phase-shift introduced to standing leaky surface acoustic waves.

    PubMed

    Meng, Long; Cai, Feiyan; Zhang, Zidong; Niu, Lili; Jin, Qiaofeng; Yan, Fei; Wu, Junru; Wang, Zhanhui; Zheng, Hairong

    2011-12-01

    A microfluidic device was developed to precisely transport a single cell or multiple microbubbles by introducing phase-shifts to a standing leaky surface acoustic wave (SLSAW). The device consists of a polydimethyl-siloxane (PDMS) microchannel and two phase-tunable interdigital transducers (IDTs) for the generation of the relative phase for the pair of surface acoustic waves (SAW) propagating along the opposite directions forming a standing wave. When the SAW contacts the fluid medium inside the microchannel, some of SAW energy is coupled to the fluid and the SAW becomes the leaky surface wave. By modulating the relative phase between two IDTs, the positions of pressure nodes of the SLSAW in the microchannel change linearly resulting in the transportation of a single cell or microbubbles. The results also reveal that there is a good linear relationship between the relative phase and the displacement of a single cell or microbubbles. Furthermore, the single cell and the microbubbles can be transported over a predetermined distance continuously until they reach the targeted locations. This technique has its distinct advantages, such as precise position-manipulation, simple to implement, miniature size, and noninvasive character, which may provide an effective method for the position-manipulation of a single cell and microbubbles in many biological and biomedical applications. PMID:22662056

  9. Creativity and sensory gating indexed by the P50: selective versus leaky sensory gating in divergent thinkers and creative achievers.

    PubMed

    Zabelina, Darya L; O'Leary, Daniel; Pornpattananangkul, Narun; Nusslock, Robin; Beeman, Mark

    2015-03-01

    Creativity has previously been linked with atypical attention, but it is not clear what aspects of attention, or what types of creativity are associated. Here we investigated specific neural markers of a very early form of attention, namely sensory gating, indexed by the P50 ERP, and how it relates to two measures of creativity: divergent thinking and real-world creative achievement. Data from 84 participants revealed that divergent thinking (assessed with the Torrance Test of Creative Thinking) was associated with selective sensory gating, whereas real-world creative achievement was associated with "leaky" sensory gating, both in zero-order correlations and when controlling for academic test scores in a regression. Thus both creativity measures related to sensory gating, but in opposite directions. Additionally, divergent thinking and real-world creative achievement did not interact in predicting P50 sensory gating, suggesting that these two creativity measures orthogonally relate to P50 sensory gating. Finally, the ERP effect was specific to the P50 - neither divergent thinking nor creative achievement were related to later components, such as the N100 and P200. Overall results suggest that leaky sensory gating may help people integrate ideas that are outside of focus of attention, leading to creativity in the real world; whereas divergent thinking, measured by divergent thinking tests which emphasize numerous responses within a limited time, may require selective sensory processing more than previously thought. PMID:25623426

  10. EXTERIOR GENERAL VIEW, A view from B Building looking southwest ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXTERIOR GENERAL VIEW, A view from B Building looking southwest toward the roof of I Building - Department of Energy, Mound Facility, Isolated Building (I Building), One Mound Road, Miamisburg, Montgomery County, OH

  11. Vibro-acoustic 3D FE simulations to validate a SAFE-BEM formulation for leaky waves computation

    NASA Astrophysics Data System (ADS)

    Mazzotti, M.; Bartoli, I.; Castellazzi, G.; Marzani, A.; Mao, Q.

    2014-03-01

    Vibroacoustic three-dimensional finite element simulations are performed to validate a novel formulation that model leaky guided waves properties for waveguides surrounded by fluids. The above formulation couples a mesh of semi-analytical finite elements (SAFE), to discretize the waveguide cross-section, with a mesh of boundary elements (BEM) to model the unbounded outer fluid domain. The resulting dispersion curves are validated through dedicated finite element simulations where the extracted time-transient waveforms are analyzed via a modified Matrix Pencil Method in time and space. Wave simulations are achieved using ABAQUS/Explicit for an elastic steel bar of square cross section immersed in water and the results obtained are compared with those given by the SAFE-BEM method.

  12. Reliability of neuronal information conveyed by unreliable neuristor-based leaky integrate-and-fire neurons: a model study

    PubMed Central

    Lim, Hyungkwang; Kornijcuk, Vladimir; Seok, Jun Yeong; Kim, Seong Keun; Kim, Inho; Hwang, Cheol Seong; Jeong, Doo Seok

    2015-01-01

    We conducted simulations on the neuronal behavior of neuristor-based leaky integrate-and-fire (NLIF) neurons. The phase-plane analysis on the NLIF neuron highlights its spiking dynamics determined by two nullclines conditional on the variables on the plane. Particular emphasis was placed on the operational noise arising from the variability of the threshold switching behavior in the neuron on each switching event. As a consequence, we found that the NLIF neuron exhibits a Poisson-like noise in spiking, delimiting the reliability of the information conveyed by individual NLIF neurons. To highlight neuronal information coding at a higher level, a population of noisy NLIF neurons was analyzed in regard to probability of successful information decoding given the Poisson-like noise of each neuron. The result demonstrates highly probable success in decoding in spite of large variability due to the variability of the threshold switching behavior of individual neurons. PMID:25966658

  13. Ultrasonic leaky guided waves in fluid-coupled generic waveguides: hybrid finite-boundary element dispersion analysis and experimental validation

    NASA Astrophysics Data System (ADS)

    Mazzotti, M.; Bartoli, I.; Marzani, A.

    2014-04-01

    A numerical procedure is presented for the computation of dispersive parameters in elastic mechanical waveguides of generic cross-section immersed in non-viscous fluids. The method uses a semi-analytical finite element formulation to describe the solid waveguide, while a two-and-a-half dimensional boundary element method is used to represent the unbounded surrounding fluid. Leaky and trapped guided wave modes are found on the appropriate Riemann sheets by enforcing the generalized Snell-Descartes law along the fluid-structure interface and solving a nonlinear eigenvalue problem. The method is validated experimentally by extracting the frequency-real wavenumber dispersion curves of a rectangular bar and a thin angle aluminum bar via a two-dimensional Fast Fourier Transform. In both cases, a very good agreement is observed between the numerical and the experimental solutions.

  14. Acousto-optic interaction with leaky surface acoustic waves in Y-cut LiTaO3 crystals.

    PubMed

    Belovickis, Jaroslavas; Rimeika, Romualdas; Ciplys, Daumantas

    2012-07-01

    The acousto-optic interaction with leaky surface acoustic wave radiation into the bulk of YX-cut LiTaO(3) crystals has been investigated. The light incidence and diffraction angles corresponding to the strongest acousto-optic interaction were calculated and measured as functions of the acoustic wave frequency. The dependencies of the diffracted light intensity on the amplitude of radio-frequency voltage applied to the interdigital transducer (IDT) were studied. Our acousto-optic measurements revealed generation, by the IDTs, of slow shear bulk acoustic waves propagating at different angles depending on their frequency. A secondary acousto-optic interaction from the bulk waves radiated by the receiving IDT has been studied. PMID:22222180

  15. Reliability of neuronal information conveyed by unreliable neuristor-based leaky integrate-and-fire neurons: a model study

    NASA Astrophysics Data System (ADS)

    Lim, Hyungkwang; Kornijcuk, Vladimir; Seok, Jun Yeong; Kim, Seong Keun; Kim, Inho; Hwang, Cheol Seong; Jeong, Doo Seok

    2015-05-01

    We conducted simulations on the neuronal behavior of neuristor-based leaky integrate-and-fire (NLIF) neurons. The phase-plane analysis on the NLIF neuron highlights its spiking dynamics - determined by two nullclines conditional on the variables on the plane. Particular emphasis was placed on the operational noise arising from the variability of the threshold switching behavior in the neuron on each switching event. As a consequence, we found that the NLIF neuron exhibits a Poisson-like noise in spiking, delimiting the reliability of the information conveyed by individual NLIF neurons. To highlight neuronal information coding at a higher level, a population of noisy NLIF neurons was analyzed in regard to probability of successful information decoding given the Poisson-like noise of each neuron. The result demonstrates highly probable success in decoding in spite of large variability - due to the variability of the threshold switching behavior - of individual neurons.

  16. Reliability of neuronal information conveyed by unreliable neuristor-based leaky integrate-and-fire neurons: a model study.

    PubMed

    Lim, Hyungkwang; Kornijcuk, Vladimir; Seok, Jun Yeong; Kim, Seong Keun; Kim, Inho; Hwang, Cheol Seong; Jeong, Doo Seok

    2015-01-01

    We conducted simulations on the neuronal behavior of neuristor-based leaky integrate-and-fire (NLIF) neurons. The phase-plane analysis on the NLIF neuron highlights its spiking dynamics--determined by two nullclines conditional on the variables on the plane. Particular emphasis was placed on the operational noise arising from the variability of the threshold switching behavior in the neuron on each switching event. As a consequence, we found that the NLIF neuron exhibits a Poisson-like noise in spiking, delimiting the reliability of the information conveyed by individual NLIF neurons. To highlight neuronal information coding at a higher level, a population of noisy NLIF neurons was analyzed in regard to probability of successful information decoding given the Poisson-like noise of each neuron. The result demonstrates highly probable success in decoding in spite of large variability--due to the variability of the threshold switching behavior--of individual neurons. PMID:25966658

  17. Non-leaky vesiculation of large unilamellar vesicles (LUV) induced by plasma high density lipoproteins (HDL): Detection by HPLC

    SciTech Connect

    Tischler, U.; Rueckert, D.S.; Schubert, R.; Jaroni, H.W.; Schmidt, K.H.

    1989-05-15

    Interaction of large unilamellar phosphatidylcholine vesicles (LUV, 75nm) and plasma high density lipoproteins (HDL) resulted in a non-leaky vesiculation of LUV. This vesiculation was detected by a HPLC-system consisting of a combination of three TSK-gel columns (6000PW, 5000PW, 3000SW). With increasing incubation time liposomal (/sup 14/C)PC, entrapped (/sup 3/H)inulin, and apoprotein of HDL origin decreased. The decrease was accompanied by a formation of new particles, consisting of liposomal PC and apoprotein. These particles also enclosed (3H)inulin, reflecting a hydrophilic inner space. The formation of the particles reached a maximum after one day of incubation. Retention time was 21 minutes for LUV, 28 minutes for the new particles, and 36 minutes for HDL. In vesicles with membranes consisting of phosphatidylcholine and 30% cholesterol no interactions were observed.

  18. Different types of noise in leaky integrate-and-fire model of neuronal dynamics with discrete periodical input.

    PubMed

    Di Maio, V; Lnsk, P; Rodriguez, R

    2004-03-01

    Different variants of stochastic leaky integrate-and-fire model for the membrane depolarisation of neurons are investigated. The model is driven by a constant input and equidistant pulses of fixed amplitude. These two types of signal are considered under the influence of three types of noise: white noise, jitter on interpulse distance, and noise in the amplitude of pulses. The results of computational experiments demonstrate the enhancement of the signal by noise in subthreshold regime and deterioration of the signal if it is sufficiently strong to carry the information in absence of noise. Our study holds mainly to central neurons that process discrete pulses although an application in sensory system is also available. PMID:15270127

  19. A high-accuracy pseudospectral full-vectorial leaky optical waveguide mode solver with carefully implemented UPML absorbing boundary conditions.

    PubMed

    Chiang, Po-jui; Chang, Hung-chun

    2011-01-17

    The previously developed full-vectorial optical waveguide eigenmode solvers using pseudospectral frequency-domain (PSFD) formulations for optical waveguides with arbitrary step-index profile is further implemented with the uniaxial perfectly matched layer (UPML) absorption boundary conditions for treating leaky waveguides and calculating their complex modal effective indices. The role of the UPML reflection coefficient in achieving high-accuracy mode solution results is particularly investigated. A six-air-hole microstructured fiber is analyzed as an example to compare with published high-accuracy multipole method results for both the real and imaginary parts of the effective indices. It is shown that by setting the UPML reflection coefficient values as small as on the order of 10(-40) ∼ 10(-70), relative errors in the calculated complex effective indices can be as small as on the order of 10(-12). PMID:21263699

  20. A leaky splicing mutation in NFU1 is associated with a particular biochemical phenotype. Consequences for the diagnosis.

    PubMed

    Ferrer-Cortès, Xènia; Narbona, Juan; Bujan, Núria; Matalonga, Leslie; Del Toro, Mireia; Arranz, José Antonio; Riudor, Encarnació; Garcia-Cazorla, Angels; Jou, Cristina; O'Callaghan, Mar; Pineda, Mercé; Montero, Raquel; Arias, Angela; García-Villoria, Judit; Alston, Charlotte L; Taylor, Robert W; Briones, Paz; Ribes, Antonia; Tort, Frederic

    2016-01-01

    Mutations in NFU1 were recently identified in patients with fatal encephalopathy. NFU1 is an iron-sulfur cluster protein necessary for the activity of the mitochondrial respiratory chain complexes I-II and the synthesis of lipoic acid. We report two NFU1 compound heterozygous individuals with normal complex I and lipoic acid-dependent enzymatic activities and low, but detectable, levels of lipoylated proteins. We demonstrated a leaky splicing regulation due to a splice site mutation (c.545+5G>A) that produces small amounts of wild type NFU1 mRNA that might result in enough protein to partially lipoylate and restore the activity of lipoic acid-dependent enzymes and the assembly and activity of complex I. These results allowed us to gain insights into the molecular basis underlying this disease and should be considered for the diagnosis of NFU1 patients. PMID:26688339

  1. Auto- and Crosscorrelograms for the Spike Response of Leaky Integrate-and-Fire Neurons with Slow Synapses

    SciTech Connect

    Moreno-Bote, Ruben; Parga, Nestor

    2006-01-20

    An analytical description of the response properties of simple but realistic neuron models in the presence of noise is still lacking. We determine completely up to the second order the firing statistics of a single and a pair of leaky integrate-and-fire neurons receiving some common slowly filtered white noise. In particular, the auto- and cross-correlation functions of the output spike trains of pairs of cells are obtained from an improvement of the adiabatic approximation introduced previously by Moreno-Bote and Parga [Phys. Rev. Lett. 92, 028102 (2004)]. These two functions define the firing variability and firing synchronization between neurons, and are of much importance for understanding neuron communication.

  2. Increased Sensitivity to Binge Alcohol-Induced Gut Leakiness and Inflammatory Liver Disease in HIV Transgenic Rats.

    PubMed

    Banerjee, Atrayee; Abdelmegeed, Mohamed A; Jang, Sehwan; Song, Byoung-Joon

    2015-01-01

    The mechanisms of alcohol-mediated advanced liver injury in HIV-infected individuals are poorly understood. Thus, this study was aimed to investigate the effect of binge alcohol on the inflammatory liver disease in HIV transgenic rats as a model for simulating human conditions. Female wild-type (WT) or HIV transgenic rats were treated with three consecutive doses of binge ethanol (EtOH) (3.5 g/kg/dose oral gavages at 12-h intervals) or dextrose (Control). Blood and liver tissues were collected at 1 or 6-h following the last dose of ethanol or dextrose for the measurements of serum endotoxin and liver pathology, respectively. Compared to the WT, the HIV rats showed increased sensitivity to alcohol-mediated gut leakiness, hepatic steatosis and inflammation, as evidenced with the significantly elevated levels of serum endotoxin, hepatic triglycerides, histological fat accumulation and F4/80 staining. Real-time PCR analysis revealed that hepatic levels of toll-like receptor-4 (TLR4), leptin and the downstream target monocyte chemoattractant protein-1 (MCP-1) were significantly up-regulated in the HIV-EtOH rats, compared to all other groups. Subsequent experiments with primary cultured cells showed that both hepatocytes and hepatic Kupffer cells were the sources of the elevated MCP-1 in HIV-EtOH rats. Further, TLR4 and MCP-1 were found to be upregulated by leptin. Collectively, these results show that HIV rats, similar to HIV-infected people being treated with the highly active anti-retroviral therapy (HAART), are more susceptible to binge alcohol-induced gut leakiness and inflammatory liver disease than the corresponding WT, possibly due to additive or synergistic interaction between binge alcohol exposure and HIV infection. Based on these results, HIV transgenic rats can be used as a surrogate model to study the molecular mechanisms of many disease states caused by heavy alcohol intake in HIV-infected people on HAART. PMID:26484872

  3. Increased Sensitivity to Binge Alcohol-Induced Gut Leakiness and Inflammatory Liver Disease in HIV Transgenic Rats

    PubMed Central

    Banerjee, Atrayee; Abdelmegeed, Mohamed A.; Jang, Sehwan; Song, Byoung-Joon

    2015-01-01

    The mechanisms of alcohol-mediated advanced liver injury in HIV-infected individuals are poorly understood. Thus, this study was aimed to investigate the effect of binge alcohol on the inflammatory liver disease in HIV transgenic rats as a model for simulating human conditions. Female wild-type (WT) or HIV transgenic rats were treated with three consecutive doses of binge ethanol (EtOH) (3.5 g/kg/dose oral gavages at 12-h intervals) or dextrose (Control). Blood and liver tissues were collected at 1 or 6-h following the last dose of ethanol or dextrose for the measurements of serum endotoxin and liver pathology, respectively. Compared to the WT, the HIV rats showed increased sensitivity to alcohol-mediated gut leakiness, hepatic steatosis and inflammation, as evidenced with the significantly elevated levels of serum endotoxin, hepatic triglycerides, histological fat accumulation and F4/80 staining. Real-time PCR analysis revealed that hepatic levels of toll-like receptor-4 (TLR4), leptin and the downstream target monocyte chemoattractant protein-1 (MCP-1) were significantly up-regulated in the HIV-EtOH rats, compared to all other groups. Subsequent experiments with primary cultured cells showed that both hepatocytes and hepatic Kupffer cells were the sources of the elevated MCP-1 in HIV-EtOH rats. Further, TLR4 and MCP-1 were found to be upregulated by leptin. Collectively, these results show that HIV rats, similar to HIV-infected people being treated with the highly active anti-retroviral therapy (HAART), are more susceptible to binge alcohol-induced gut leakiness and inflammatory liver disease than the corresponding WT, possibly due to additive or synergistic interaction between binge alcohol exposure and HIV infection. Based on these results, HIV transgenic rats can be used as a surrogate model to study the molecular mechanisms of many disease states caused by heavy alcohol intake in HIV-infected people on HAART. PMID:26484872

  4. Analysis on the Radiation Property of the Bounded Modes of Periodic Leaky-Wave Structure with Finite-Length Using a Hybrid Method

    PubMed Central

    Li, Zheng; Wang, Junhong; Duan, Jianjie; Zhang, Zhan; Chen, Meie

    2016-01-01

    In this paper the radiation property of the one-dimensional periodic leaky-wave structure is analysed using a new hybrid method, which involves the mode expansion method for expanding the periodic aperture field in terms of spatial harmonics and the method of effective radiation sections for transforming the expanded fields into far fields. Using this method, the radiation of each spatial harmonic can be achieved, and the contributions of the harmonics (especially the bounded modes) to the total radiation of the periodic leaky-wave structure can be calculated. The main findings in this paper demonstrate that the bounded modes in a finite length structure have obvious contribution to the far-field radiation, which was considered to be non-radiative and always ignored in the conventional researches. PMID:26987698

  5. Component Leakage Testing in Residential Buildings

    SciTech Connect

    Dickerhoff, D.J.; Grimsrud, D.T.; Lipschutz, R.D.

    1982-07-01

    The common approach to leakage area measurements in residential housing through pressurization of an entire structure with a blower door. However, this technique does not provide quantitative measurements of the leakiness of individual building components. By pressurizing individual components, it is possible to determine the distribution of leakage within a structure. The studies described in this paper involved measurement of the leakage areas of fireplaces, bathroom and kitchen exhaust vents, electrical outlets and leakage in the ducts of forced air distribution systems. Component leakage measurements were made in a total of thirty-four houses in Atlanta, Georgia, Reno, Nevada and the San Francisco Bay area. Damperless fireplaces and ductwork were found to be the most significant sources of leakage in the western houses. In the Atlanta houses, where cooling loads dominate, the significant leakage area was in the ductwork of the distribution system for central air conditioning that passes through the unconditioned space in the attic and crawlspace.

  6. Low velocity non-Darcian flow to a well fully penetrating a confined aquifer in the first kind of leaky aquifer system

    NASA Astrophysics Data System (ADS)

    Meng, Xianmeng; Shao, Junyu; Yin, Maosheng; Liu, Dengfeng; Xue, Xianwu

    2015-11-01

    In this study, we use a finite difference method to solve low velocity non-Darcian flow to a well in the first kind of leaky aquifer system. Flow in the confined aquifer is assumed to be Darcian and horizontal, whereas flow in the aquitard is assumed to be non-Darcian and vertical. The threshold hydraulic gradient existence of non-Darcian flow in low permeability porous media is employed to describe the non-Darcian flow in the aquitard. A numerical solution has been obtained by using a finite difference method. This solution is compared with the previous solution for Darcian flow case in leaky aquifer system. The error has been analyzed. The comparison of this study and Darcian flow case (Hantush and Jacob, 1955) in leaky aquifer system indicates that the error is very small and can be neglected. However, the hydrogeological parameter calculation of leaky aquifer system is remarkably influenced by low velocity non-Darcian flow in aquitard. For the inflection point method (Hantush, 1956), the absolute values of estimated errors for coefficient of transmissibility of confined aquifer and vertical hydraulic conductivity of aquitard show negative relationship with the pumping rate. For the type curve-fitting method (Walton, 1962), the estimated errors for coefficient of transmissibility and elastic drainable porosity of confined aquifer are very small under small pumping rate. In general, the estimated errors for coefficient of transmissibility and elastic drainable porosity of confined aquifer can be controlled under certain level through adjusting pumping rate. The estimated error of vertical hydraulic conductivity of aquitard is quite large no matter which method is used, even up to nearly 300%.

  7. Suppression of leaky expression of adenovirus genes by insertion of microRNA-targeted sequences in the replication-incompetent adenovirus vector genome

    PubMed Central

    Shimizu, Kahori; Sakurai, Fuminori; Tomita, Kyoko; Nagamoto, Yasuhito; Nakamura, Shin-ichiro; Katayama, Kazufumi; Tachibana, Masashi; Kawabata, Kenji; Mizuguchi, Hiroyuki

    2014-01-01

    Leaky expression of adenovirus (Ad) genes occurs following transduction with a conventional replication-incompetent Ad vector, leading to an induction of cellular immunity against Ad proteins and Ad protein-induced toxicity, especially in the late phase following administration. To suppress the leaky expression of Ad genes, we developed novel Ad vectors by incorporating four tandem copies of sequences with perfect complementarity to miR-122a or miR-142-3p into the 3?-untranslated region (UTR) of the E2A, E4, or pIX gene, which were mainly expressed from the Ad vector genome after transduction. These Ad vectors easily grew to high titers comparable to those of a conventional Ad vector in conventional 293 cells. The leaky expression of these Ad genes in mouse organs was significantly suppressed by 2- to 100-fold, compared with a conventional Ad vector, by insertion of the miRNA-targeted sequences. Notably, the Ad vector carrying the miR-122atargeted sequences into the 3?-UTR of the E4 gene expressed higher and longer-term transgene expression and more than 20-fold lower levels of all the Ad early and late genes examined in the liver than a conventional Ad vector. miR-122amediated suppression of the E4 gene expression in the liver significantly reduced the hepatotoxicity which an Ad vector causes via both adaptive and non-adaptive immune responses. PMID:26015975

  8. Visual attractiveness is leaky: the asymmetrical relationship between face and hair

    PubMed Central

    Saegusa, Chihiro; Intoy, Janis; Shimojo, Shinsuke

    2015-01-01

    Predicting personality is crucial when communicating with people. It has been revealed that the perceived attractiveness or beauty of the face is a cue. As shown in the well-known “what is beautiful is good” stereotype, perceived attractiveness is often associated with desirable personality. Although such research on attractiveness used mainly the face isolated from other body parts, the face is not always seen in isolation in the real world. Rather, it is surrounded by one’s hairstyle, and is perceived as a part of total presence. In human vision, perceptual organization/integration occurs mostly in a bottom up, task-irrelevant fashion. This raises an intriguing possibility that task-irrelevant stimulus that is perceptually integrated with a target may influence our affective evaluation. In such a case, there should be a mutual influence between attractiveness perception of the face and surrounding hair, since they are assumed to share strong and unique perceptual organization. In the current study, we examined the influence of a task-irrelevant stimulus on our attractiveness evaluation, using face and hair as stimuli. The results revealed asymmetrical influences in the evaluation of one while ignoring the other. When hair was task-irrelevant, it still affected attractiveness of the face, but only if the hair itself had never been evaluated by the same evaluator. On the other hand, the face affected the hair regardless of whether the face itself was evaluated before. This has intriguing implications on the asymmetry between face and hair, and perceptual integration between them in general. Together with data from a post hoc questionnaire, it is suggested that both implicit non-selective and explicit selective processes contribute to attractiveness evaluation. The findings provide an understanding of attractiveness perception in real-life situations, as well as a new paradigm to reveal unknown implicit aspects of information integration for emotional judgment. PMID:25914656

  9. Visual attractiveness is leaky: the asymmetrical relationship between face and hair.

    PubMed

    Saegusa, Chihiro; Intoy, Janis; Shimojo, Shinsuke

    2015-01-01

    Predicting personality is crucial when communicating with people. It has been revealed that the perceived attractiveness or beauty of the face is a cue. As shown in the well-known "what is beautiful is good" stereotype, perceived attractiveness is often associated with desirable personality. Although such research on attractiveness used mainly the face isolated from other body parts, the face is not always seen in isolation in the real world. Rather, it is surrounded by one's hairstyle, and is perceived as a part of total presence. In human vision, perceptual organization/integration occurs mostly in a bottom up, task-irrelevant fashion. This raises an intriguing possibility that task-irrelevant stimulus that is perceptually integrated with a target may influence our affective evaluation. In such a case, there should be a mutual influence between attractiveness perception of the face and surrounding hair, since they are assumed to share strong and unique perceptual organization. In the current study, we examined the influence of a task-irrelevant stimulus on our attractiveness evaluation, using face and hair as stimuli. The results revealed asymmetrical influences in the evaluation of one while ignoring the other. When hair was task-irrelevant, it still affected attractiveness of the face, but only if the hair itself had never been evaluated by the same evaluator. On the other hand, the face affected the hair regardless of whether the face itself was evaluated before. This has intriguing implications on the asymmetry between face and hair, and perceptual integration between them in general. Together with data from a post hoc questionnaire, it is suggested that both implicit non-selective and explicit selective processes contribute to attractiveness evaluation. The findings provide an understanding of attractiveness perception in real-life situations, as well as a new paradigm to reveal unknown implicit aspects of information integration for emotional judgment. PMID:25914656

  10. Reconstruction of the input signal of the leaky integrate-and-fire neuronal model from its interspike intervals.

    PubMed

    Seydnejad, Saeid R

    2016-02-01

    Extracting the input signal of a neuron by analyzing its spike output is an important step toward understanding how external information is coded into discrete events of action potentials and how this information is exchanged between different neurons in the nervous system. Most of the existing methods analyze this decoding problem in a stochastic framework and use probabilistic metrics such as maximum-likelihood method to determine the parameters of the input signal assuming a leaky and integrate-and-fire (LIF) model. In this article, the input signal of the LIF model is considered as a combination of orthogonal basis functions. The coefficients of the basis functions are found by minimizing the norm of the observed spikes and those generated by the estimated signal. This approach gives rise to the deterministic reconstruction of the input signal and results in a simple matrix identity through which the coefficients of the basis functions and therefore the neuronal stimulus can be identified. The inherent noise of the neuron is considered as an additional factor in the membrane potential and is treated as the disturbance in the reconstruction algorithm. The performance of the proposed scheme is evaluated by numerical simulations, and it is shown that input signals with different characteristics can be well recovered by this algorithm. PMID:26658736

  11. Study on highly sensitive asymmetric waveguide optical sensor for detection of sucrose concentration based on leaky quasi-modes

    NASA Astrophysics Data System (ADS)

    Dutta, Aradhana; Deka, Bidyut; Sahu, Partha Pratim

    2013-11-01

    The development of a highly sensitive asymmetric planar waveguide optical sensor based on a mathematical model using leaky quasi-modes in an endeavor to measure slight changes of aqueous sucrose concentration is presented in this paper. The planar waveguide sensor has been fabricated using Silicon Oxynitride (SiON) based material with standard fabrication process such as Plasma Enhanced Chemical Vapor Deposition (PECVD) and Reactive Ion Etching (RIE) techniques. The propagation constant of fundamental modes for TE mode of the waveguide geometry have been estimated using Simple Effective Index Method (SEIM) based on sinusoidal modes. The technique is based on Evanescent Wave Sensing (EWS) scheme, inducing an effective refractive index change. The merits of this sensor are simplicity, highly sensitivity, screening the potential that it can be used for online monitoring of blood glucose levels in the near future. The sensitivity of the waveguide is ~10 times more than that of the previously reported work on planar waveguide sensors and the results obtained experimentally matches well with the obtained theoretical result.

  12. Linear MHD Wave Propagation in Time-Dependent Flux Tube - III. Leaky Waves in Zero-Beta Plasma

    NASA Astrophysics Data System (ADS)

    Williamson, A.; Erdlyi, R.

    2015-11-01

    In this article, we evaluate the time-dependent wave properties and the damping rate of propagating fast magneto-hydrodynamic (MHD) waves when energy leakage into a magnetised atmosphere is considered. By considering a cold plasma, initial investigations into the evolution of MHD wave damping through this energy leakage will take place. The time-dependent governing equations have been derived previously in Williamson and Erdlyi (2014a, Solar Phys. 289, 899 - 909) and are now solved when the assumption of evanescent wave propagation in the outside of the waveguide is relaxed. The dispersion relation for leaky waves applicable to a straight magnetic field is determined in both an arbitrary tube and a thin-tube approximation. By analytically solving the dispersion relation in the thin-tube approximation, the explicit expressions for the temporal evolution of the dynamic frequency and wavenumber are determined. The damping rate is, then, obtained from the dispersion relation and is shown to decrease as the density ratio increases. By comparing the decrease in damping rate to the increase in damping for a stationary system, as shown, we aim to point out that energy leakage may not be as efficient a damping mechanism as previously thought.

  13. Effects of passive dendritic tree properties on the firing dynamics of a leaky-integrate-and-fire neuron.

    PubMed

    Saparov, Abulhair; Schwemmer, Michael A

    2015-11-01

    We study the effects of dendritic tree topology and biophysical properties on the firing dynamics of a leaky-integrate-and-fire (LIF) neuron that explicitly includes spiking dynamics. We model the dendrites as a multi-compartment tree with passive dynamics. Owing to the simplicity of the system, we obtain the full analytical solution for the model which we use to derive a lower dimensional return map that captures the complete dynamics of the system. Using the map, we explore how biophysical properties and dendritic tree architecture affect firing dynamics. As was first reported in earlier work by one of the authors, we also find that the addition of the dendritic tree can induce bistability between periodic firing and quiescence. However, we go beyond their results by systematically examining how dendritic tree topology affects the appearance of this bistable behavior. We find that the structure of the dendritic tree can have significant quantitative effects on the bifurcation structure of the system, with branchier topologies tending to promote bistable behavior over unbranched chain topologies. We also show that this effect occurs even when the input conductance at the soma is held fixed, indicating that the topology of the dendritic tree is mainly responsible for this quantitative change in the bifurcation structure. Lastly, we demonstrate how our framework can be used to explore the effect of biophysical properties on the firing dynamics of a neuron with a more complex dendritic tree topology. PMID:26334675

  14. Leaky guided waves in generic bars: Numerical prediction and experimental validation by means of ultrasonic underwater testing

    SciTech Connect

    Mazzotti, Matteo; Bartoli, Ivan; Marzani, Alessandro

    2014-02-18

    Guided Ultrasonic Waves (GUWs) are used in several industrial and civil applications for the non-destructive tests and inspection of mechanical waveguides immersed in fluids. As well known, the impedance mismatch at the fluid-structure interface causes the bulk waves traveling inside the waveguide to be partially refracted in the surrounding fluid. The leakage of bulk waves involves continuous energy radiation along the propagation direction, resulting in high attenuation rates and, consequently, reduced inspection ranges. In this work, the dispersion behaviour of leaky guided waves that propagate in immersed waveguides of general cross-section is investigated. To this end, a Semi-Analytical Finite Element (SAFE) method coupled with a 2.5D Boundary Element method (BEM) is used to extract the wave dispersion equation. The proposed formulation avoids the well known limitations of analytical methods in treating complex geometries as well as those of Finite Element-based methods in representing propagation processes in unbounded domains. Numerical and experimental results are presented, in which the dispersion curves are extracted for different bars of arbitrary shape immersed in water. The results obtained in this paper can be useful for the design of testing conditions in practical applications and to tune experimental set up.

  15. Linear MHD Wave Propagation in Time-Dependent Flux Tube. III. Leaky Waves in Zero-Beta Plasma

    NASA Astrophysics Data System (ADS)

    Williamson, A.; Erdélyi, R.

    2016-01-01

    In this article, we evaluate the time-dependent wave properties and the damping rate of propagating fast magneto-hydrodynamic (MHD) waves when energy leakage into a magnetised atmosphere is considered. By considering a cold plasma, initial investigations into the evolution of MHD wave damping through this energy leakage will take place. The time-dependent governing equations have been derived previously in Williamson and Erdélyi (2014a, Solar Phys. 289, 899 - 909) and are now solved when the assumption of evanescent wave propagation in the outside of the waveguide is relaxed. The dispersion relation for leaky waves applicable to a straight magnetic field is determined in both an arbitrary tube and a thin-tube approximation. By analytically solving the dispersion relation in the thin-tube approximation, the explicit expressions for the temporal evolution of the dynamic frequency and wavenumber are determined. The damping rate is, then, obtained from the dispersion relation and is shown to decrease as the density ratio increases. By comparing the decrease in damping rate to the increase in damping for a stationary system, as shown, we aim to point out that energy leakage may not be as efficient a damping mechanism as previously thought.

  16. Translation of the shallot virus X TGB3 gene depends on non-AUG initiation and leaky scanning.

    PubMed

    Lezzhov, Alexander A; Gushchin, Vladimir A; Lazareva, Ekaterina A; Vishnichenko, Valery K; Morozov, Sergey Y; Solovyev, Andrey G

    2015-10-01

    Triple gene block (TGB), a conserved gene module found in the genomes of many filamentous and rod-shaped plant viruses, encodes three proteins, TGB1, TGB2 and TGB3, required for viral cell-to-cell movement through plasmodesmata and systemic transport via the phloem. The genome of Shallot virus X, the type species of the genus Allexivirus, includes TGB1 and TGB2 genes, but contains no canonical ORF for TGB3 protein. However, a TGB3-like protein-encoding sequence lacking an AUG initiator codon has been found in the shallot virus X (ShVX) genome in a position typical for TGB3 genes. This putative TGB3 gene is conserved in all allexiviruses. Here, we carried out sequence analysis to predict possible non-AUG initiator codons in the ShVX TGB3-encoding sequence. We further used an agroinfiltration assay in Nicotiana benthamiana to confirm this prediction. Site-directed mutagenesis was used to demonstrate that the ShVX TGB3 could be translated on a bicistronic mRNA template via a leaky scanning mechanism. PMID:26296665

  17. Constitutive production and efficient secretion of soluble full-length streptavidin by an Escherichia coli 'leaky mutant'.

    PubMed

    Mller, Jakob Michael; Wetzel, David; Flaschel, Erwin; Friehs, Karl; Risse, Joe Max

    2016-03-10

    Due to its various applications the protein streptavidin is a highly interesting target for heterologous production. This study focuses on different Escherichia coli-based constructs targeting a high-level expression and secretion of streptavidin to the medium. The effect of various promoters, variants of the target gene, leader sequences and host strains on expression and secretion into the culture broth was analyzed. Constitutive production of full-length streptavidin fused with the leader sequence of the bglA gene from Bacillus amyloliquefaciens by the periplasmic 'leaky mutant' E. coli JW1667-5 (?lpp-752:kan) at 30C generated the highest yield of the conditions tested, surpassing the extracellular concentration of a conventional T7-based expression system. Supplementation of the medium by the non-ionic surfactants Triton() X-100 and X-45 led to an improved secretion of the protein to the culture supernatant. Tetrameric concentrations of streptavidin of 2790166nM were reached in shake flasks at a productivity of 49.6nMh(-1). Optimization of conditions led to a successful transfer to the bioreactor, yielding a maximal concentration of 2608169nM and a productivity of 65.2nMh(-1) in fed-batch operation. The proportion of biotin-blocked binding sites of 8.34.3% indicated a highly bioactive product. PMID:26820322

  18. Planarized process for resonant leaky-wave coupled phase-locked arrays of mid-IR quantum cascade lasers

    NASA Astrophysics Data System (ADS)

    Chang, C.-C.; Kirch, J. D.; Boyle, C.; Sigler, C.; Mawst, L. J.; Botez, D.; Zutter, B.; Buelow, P.; Schulte, K.; Kuech, T.; Earles, T.

    2015-03-01

    On-chip resonant leaky-wave coupling of quantum cascade lasers (QCLs) emitting at 8.36 μm has been realized by selective regrowth of interelement layers in curved trenches, defined by dry and wet etching. The fabricated structure provides large index steps (Δn = 0.10) between antiguided-array element and interelement regions. In-phase-mode operation to 5.5 W front-facet emitted power in a near-diffraction-limited far-field beam pattern, with 4.5 W in the main lobe, is demonstrated. A refined fabrication process has been developed to produce phased-locked antiguided arrays of QCLs with planar geometry. The main fabrication steps in this process include non-selective regrowth of Fe:InP in interelement trenches, defined by inductive-coupled plasma (ICP) etching, a chemical polishing (CP) step to planarize the surface, non-selective regrowth of interelement layers, ICP selective etching of interelement layers, and non-selective regrowth of InP cladding layer followed by another CP step to form the element regions. This new process results in planar InGaAs/InP interelement regions, which allows for significantly improved control over the array geometry and the dimensions of element and interelement regions. Such a planar process is highly desirable to realize shorter emitting wavelength (4.6 μm) arrays, where fabrication tolerance for single-mode operation are tighter compared to 8 μm-emitting devices.

  19. Leaky guided waves in generic bars: Numerical prediction and experimental validation by means of ultrasonic underwater testing

    NASA Astrophysics Data System (ADS)

    Mazzotti, Matteo; Bartoli, Ivan; Marzani, Alessandro

    2014-02-01

    Guided Ultrasonic Waves (GUWs) are used in several industrial and civil applications for the non-destructive tests and inspection of mechanical waveguides immersed in fluids. As well known, the impedance mismatch at the fluid-structure interface causes the bulk waves traveling inside the waveguide to be partially refracted in the surrounding fluid. The leakage of bulk waves involves continuous energy radiation along the propagation direction, resulting in high attenuation rates and, consequently, reduced inspection ranges. In this work, the dispersion behaviour of leaky guided waves that propagate in immersed waveguides of general cross-section is investigated. To this end, a Semi-Analytical Finite Element (SAFE) method coupled with a 2.5D Boundary Element method (BEM) is used to extract the wave dispersion equation. The proposed formulation avoids the well known limitations of analytical methods in treating complex geometries as well as those of Finite Element-based methods in representing propagation processes in unbounded domains. Numerical and experimental results are presented, in which the dispersion curves are extracted for different bars of arbitrary shape immersed in water. The results obtained in this paper can be useful for the design of testing conditions in practical applications and to tune experimental set up.

  20. Evolution of mammalian endothermic metabolism: leaky membranes as a source of heat

    SciTech Connect

    Else, P.L.; Hulbert, A.J.

    1987-07-01

    O/sub 2/ consumption was measured at 37/degrees/C in tissue slices of liver, kidney, and brain from Amphilbolurus vitticeps and Rattus norvegicus (a reptile and mammal with same weight and body temperature) both in the presence and absence of ouabain. O/sub 2/ consumption of the mammalian tissues was two to four times that of the reptilian tissues and the mammalian tissues used three to six times the energy for Na/sup +/-K/sup +/ transport than the reptilian tissues. Passive permeability to /sup 42/K/sup +/ was measured at 37/degrees/C in liver and kidney slices, and passive permeability to /sup 22/Na/sup +/ was measured at 37/degrees/C in isolated and cultured liver cells from each species. The mammalian cell membrane was severalfold leakier to both these ions than was the reptilian cell membrane, and thus the membrane pumps must use more energy to maintain the transmembrane ion gradients. It is postulated that this is a general difference between the cells of ectotherms and endotherms and thus partly explains the much higher levels of metabolism found in endothermic mammals.

  1. Are isolated wetlands isolated?

    USGS Publications Warehouse

    Smith, Loren M.; Euliss, Ned H.; Haukos, David A.

    2011-01-01

    While federal regulations during the past 10 years have treated isolated wetlands as unconnected to aquatic resources protected by the Clean Water Act, they provide critical ecosystem services to society that extend well beyond their wetland boundaries. The authors offer well-documented examples from the scientific literature on some of the ecosystem services provided by isolated wetlands to society and other ecosystems.

  2. Building Awareness.

    ERIC Educational Resources Information Center

    Meilach, Dona Z.

    2001-01-01

    Discusses the importance of developing students' building awareness by exploring logos, or buildings that symbolize a country, to learn about architecture and the cultures in different countries. Explores categories of buildings. Includes examples of logos from around the world. (CMK)

  3. Bundle Sheath Leakiness and Light Limitation during C4 Leaf and Canopy CO2 Uptake1[W][OA

    PubMed Central

    Kromdijk, Johannes; Schepers, Hans E.; Albanito, Fabrizio; Fitton, Nuala; Carroll, Faye; Jones, Michael B.; Finnan, John; Lanigan, Gary J.; Griffiths, Howard

    2008-01-01

    Perennial species with the C4 pathway hold promise for biomass-based energy sources. We have explored the extent that CO2 uptake of such species may be limited by light in a temperate climate. One energetic cost of the C4 pathway is the leakiness (φ) of bundle sheath tissues, whereby a variable proportion of the CO2, concentrated in bundle sheath cells, retrodiffuses back to the mesophyll. In this study, we scale φ from leaf to canopy level of a Miscanthus crop (Miscanthus × giganteus hybrid) under field conditions and model the likely limitations to CO2 fixation. At the leaf level, measurements of photosynthesis coupled to online carbon isotope discrimination showed that leaves within a 3.3-m canopy (leaf area index = 8.3) show a progressive increase in both carbon isotope discrimination and φ as light decreases. A similar increase was observed at the ecosystem scale when we used eddy covariance net ecosystem CO2 fluxes, together with isotopic profiles, to partition photosynthetic and respiratory isotopic flux densities (isofluxes) and derive canopy carbon isotope discrimination as an integrated proxy for φ at the canopy level. Modeled values of canopy CO2 fixation using leaf-level measurements of φ suggest that around 32% of potential photosynthetic carbon gain is lost due to light limitation, whereas using φ determined independently from isofluxes at the canopy level the reduction in canopy CO2 uptake is estimated at 14%. Based on these results, we identify φ as an important limitation to CO2 uptake of crops with the C4 pathway. PMID:18971428

  4. Evidences for a Leaky Scanning Mechanism for the Synthesis of the Shorter M23 Protein Isoform of Aquaporin-4

    PubMed Central

    Rossi, Andrea; Pisani, Francesco; Nicchia, Grazia Paola; Svelto, Maria; Frigeri, Antonio

    2010-01-01

    Aquaporin-4 (AQP4) exists as two major isoforms that differ in the length of the N terminus, the shorter AQP4-M23 and the longer AQP4-M1. Both isoforms form tetramers, which can further aggregate in the plasma membrane to form typical orthogonal arrays of particles (OAPs) whose dimension depends on the ratio of the M1 and M23. In this study, we tested the hypothesis that the M23 isoform can be produced directly by the M1 mRNA. In cells transiently transfected with AQP4-M1 coding sequence we observed besides AQP4-M1 the additional presence of the AQP4-M23 isoform associated with the formation of typical OAPs observable by two-dimensional blue native/SDS-PAGE and total internal reflection microscopy. The mutation of the second in-frame methionine M23 in AQP4-M1 (AQP4-M1M23I) prevented the expression of the M23 isoform and the formation of OAPs. We propose leaky scanning as a translational mechanism for the expression of AQP4-M23 protein isoform and that the formation of OAPs may occur even in the absence of AQP4-M23 mRNA. This mechanism can have important pathophysiological implications for the cell regulation of the M1/M23 ratio and thus OAP size. In this study we also provide evidence that AQP4-M1 is mobile in the plasma membrane, that it is inserted and not excluded into immobile OAPs, and that it is an important determinant of OAP structure and size. PMID:20007705

  5. ESTABLISHING DIAGNOSTIC CRITERIA FOR SCID, LEAKY SCID, AND OMENN SYNDROME: THE PRIMARY IMMUNE DEFICIENCY TREATMENT CONSORTIUM EXPERIENCE

    PubMed Central

    Shearer, William T.; Dunn, Elizabeth; Notarangelo, Luigi D.; Dvorak, Christopher C.; Puck, Jennifer M.; Logan, Brent R.; Griffith, Linda M.; Kohn, Donald B.; OReilly, Richard J.; Fleisher, Thomas A.; Pai, Sung-Yun; Martinez, Caridad A.; Buckley, Rebecca H.; Cowan, Morton J.

    2014-01-01

    Background The approach to the diagnosis of Severe Combined Immunodeficiency Disease (SCID) and related disorders varies among institutions and countries. Objectives The Primary Immune Deficiency Treatment Consortium (PIDTC) attempted to develop a uniform set of criteria for diagnosing SCID and related disorders, and has evaluated the results as part of a retrospective study of SCID in North America. Methods Clinical records from 2000 through 2009 at 27 centers in North America were collected on 332 children treated with hematopoietic cell transplant (HCT), enzyme replacement therapy (ERT) or gene therapy (GT) for SCID and related disorders. Eligibility for inclusion in the study and classification into disease groups were established by set criteria and applied by an expert review group. Result Two hundred eighty-five (86%) of the patients were determined to be eligible and 47 (14%) were not eligible. Of the 285 eligible patients, 84% were classified as typical SCID; 13% were classified as leaky SCID, Omenn syndrome, or reticular dysgenesis; and 3% had a history of enzyme replacement or gene therapy. Detection of a genotype predicting a SCID phenotype was accepted for eligibility. Reasons for non-eligibility were failure to demonstrate either impaired lymphocyte proliferation or maternal T cell engraftment. Overall (n = 332) rates of testing were: proliferation to PHA 77%, maternal engraftment 35%, and genotype 79% (mutation identified in 62%). Conclusion Lack of complete laboratory evaluation of patients prior to HCT presents a significant barrier to definitive diagnosis of SCID and related disorders and prevented inclusion of individuals in our observational HCT study. This lesson is critical for patient care as well as the design of future, prospective treatment studies for such children, since a well-defined and consistent study population is important for precision in outcomes analysis. PMID:24290292

  6. Experimental demonstration of directive Si3N4 optical leaky wave antennas with semiconductor perturbations at near infrared frequencies

    NASA Astrophysics Data System (ADS)

    Zhao, Qiancheng; Guclu, Caner; Huang, Yuwang; Campione, Salvatore; Capolino, Filippo; Boyraz, Ozdal

    2015-02-01

    Directive optical leaky wave antennas (OLWAs) with tunable radiation pattern are promising integrated optical modulation and scanning devices. OLWAs fabricated using CMOS-compatible semiconductor planar waveguide technology have the potential of providing high directivity with electrical tunability for modulation and switching capabilities. We experimentally demonstrate directive radiation from a silicon nitride (Si3N4) waveguide-based OLWA. The OLWA design comprises 50 crystalline Si perturbations buried inside the waveguide, with a period of 1 μm, each with a length of 260 nm and a height of 150 nm, leading to a directive radiation pattern at telecom wavelengths. The measured far-field radiation pattern at the wavelength of 1540 nm is very directive, with the maximum intensity at the angle of 84.4° relative to the waveguide axis and a half-power beam width around 6.2°, which is consistent with our theoretical predictions. The use of semiconductor perturbations facilitates electronic radiation control thanks to the refractive index variation induced by a carrier density change in the perturbations. To assess the electrical modulation capability, we study carrier injection and depletion in Si perturbations, and investigate the Franz-Keldysh effect in germanium as an alternative way. We theoretically show that the silicon wire modulator has a -3 dB modulation bandwidth of 75 GHz with refractive index change of 3×10-4 in depletion mode, and 350 MHz bandwidth with refractive index change of 1.5×10-2 in injection mode. The Franz-Keldysh effect has the potential to generate very fast modulation in radiation control at telecom wavelengths.

  7. Lactobacillus GG Treatment Ameliorates Alcohol-induced Intestinal Oxidative Stress, Gut Leakiness, and Liver Injury in a Rat Model of Alcoholic Steatohepatitis

    PubMed Central

    Forsyth, Christopher B.; Farhadi, Ashkan; Jakate, Shriram M.; Tang, Yueming; Shaikh, Maliha; Keshavarzian, Ali

    2009-01-01

    Since only 30% of alcoholics develop alcoholic liver disease (ALD), a factor other than heavy alcohol consumption must be involved in development of alcohol-induced liver injury. Animal and human studies suggest that bacterial products such as endotoxin are the second key co-factor and oxidant-mediated gut leakiness is one of the sources of endotoxemia. Probiotics have been used to prevent and treat diseases associated with gut-derived bacterial products and disorders associated with gut leakiness. Indeed, “probiotic” Lactobacillus has been successfully used to treat alcohol-induced liver injury in rats. But, the mechanism of action of the potential beneficial effects of Lactobacillus in alcohol liver injury is not known. We hypothesized that probiotics could preserve normal barrier function in an animal model of ALD by preventing alcohol-induced oxidative stress and thus prevent development of hyperpermeability and subsequent alcoholic steatohepatitis. Male Sprague-Dawley rats were gavaged with alcohol twice daily (8gm/kg) for 10 weeks. In addition, alcoholic rats were also treated with once daily gavage of either 2.5 107 live Lactobacillus GG (LGG) or vehicle. Intestinal permeability (baseline and 10wk) was determined using a sugar bolus and GC analysis of urinary sugars. Intestinal and liver tissues were analyzed for markers of oxidative stress and inflammation. In addition livers were assessed histologically for severity of alcoholic steatohepatitis (ASH) and total fat (steatosis). Alcohol-LGG fed rats had significantly (p≤ .05) less severe ASH than alcohol-vehicle fed rats. LGG also improved alcohol-induced gut leakiness and significantly blunted alcohol-induced oxidative stress and inflammation in both intestine and the liver. LGG probiotic gavage significantly ameliorated alcoholic steatohepatitis in rats. This improvement was associated with reduced markers of intestinal and liver oxidative stress and inflammation and preserved gut barrier function. Our study provides a scientific rationale to test probiotics for treatment and/or prevention of alcoholic liver disease in man. PMID:19251117

  8. Conceptual design study of JSFR reactor building

    SciTech Connect

    Yamamoto, T.; Katoh, A.; Chikazawa, Y.; Ohya, T.; Iwasaki, M.; Hara, H.; Akiyama, Y.

    2012-07-01

    Japan Sodium-cooled Fast Reactor (JSFR) is planning to adopt the new concepts of reactor building. One is that the steel plate reinforced concrete is adopted for containment vessel and reactor building. The other is the advanced seismic isolation system. This paper describes the detail of new concepts for JSFR reactor building and engineering evaluation of the new concepts. (authors)

  9. Building America

    SciTech Connect

    Brad Oberg

    2010-12-31

    IBACOS researched the constructability and viability issues of using high performance windows as one component of a larger approach to building houses that achieve the Building America 70% energy savings target.

  10. Essay: leaky pipes.

    PubMed

    McCoy, Melissa

    2015-03-01

    In the face of great tragedy, the desire to pinpoint blame can be instinctual as a remedy for alleviating one's conscience in a system that causes great suffering. However, to remedy the system that causes such suffering requires a critical analysis of the factors that perpetuate inequitable power structures. This is the story of a journey that broadened my lens of analysis with which to critically evaluate the harmful structural and social determinants magnified in resource-limited settings. PMID:25648124

  11. Collapsed Building

    USGS Multimedia Gallery

    This masonry office building in the downtown area of Concepcion, Chile collapsed as a result of the M 8.8 earthquake on Feb. 27, 2010. The construction of this building predates the establishment of strict building codes in Chile, put in place following the devastating earthquake of 1960. ...

  12. Healthy Buildings?

    ERIC Educational Resources Information Center

    Grubb, Deborah

    Health problems related to school buildings can be categorized in five major areas: sick-building syndrome; health-threatening building materials; environmental hazards such as radon gas and asbestos; lead poisoning; and poor indoor air quality due to smoke, chemicals, and other pollutants. This paper provides an overview of these areas,…

  13. Consensus Building.

    ERIC Educational Resources Information Center

    Vanderwood, Michael L.; Erickson, Ron

    1994-01-01

    Discusses the use of a Multi-Attribute Consensus Building (MACB) technique to build consensus on a national model of educational outcomes and indicators. Describes the stages of consensus building and the tasks mandated in each stage, including the generation of input, the consensus conference, and the synthesis of consensus. (RJM)

  14. Field investigation of duct system performance in California light commercial buildings

    SciTech Connect

    Delp, W.W.; Matson, N.E.; Tschudy, E.

    1997-12-09

    This paper discusses field measurements of duct system performance in fifteen systems located in eight northern California buildings. Light commercial buildings, one- and two-story with package roof-top HVAC units, make up approximately 50% of the non-residential building stock in the U.S. Despite this fact little is known about the performance of these package roof-top units and their associated ductwork. These simple systems use similar duct materials and construction techniques as residential systems (which are known to be quite leaky). This paper discusses a study to characterize the buildings, quantify the duct leakage, and analyze the performance of the ductwork in these types of buildings. The study tested fifteen systems in eight different buildings located in northern California. All of these buildings had the ducts located in the cavity between the drop ceiling and the roof deck. In 50% of these buildings, this cavity was functionally outside the building`s air and thermal barriers. The effective leakage area of the ducts in this study was approximately 2.6 times that in residential buildings. This paper looks at the thermal analysis of the ducts, from the viewpoint of efficiency and thermal comfort. This includes the length of a cycle, and whether the fan is always on or if it cycles with the cooling equipment. 66% of the systems had frequent on cycles of less than 10 minutes, resulting in non-steady-state operation.

  15. Building digests: cooling of buildings

    SciTech Connect

    Verma, V.V.; Agarwal, K.N.; Chadra, P.; Jain, S.P.; Sharma, M.R.

    1981-01-01

    Nine bulletins are compiled covering: Control of Solar Heat Gain through Glass Windows; Simple and Effective Roof Spraying System of Cooling Buildings in Hot Dry Climates; Shading Devices for Glass Openings in Air-conditioned Buildings; Cooling of Buildings by Roof Surface Evaporation; Roof-surface Evaporative Cooling of Buildings by Water Soaked Gunny Bags; Loose Fill Materials for Cold Storage Insulation; Cooling Load and Indoor Air Temperature of Office Buildings under Tropical Climate; Thermal Design of Potato Cold Storage; and Suitability of Rice-husk and Saw-dust as a Cold Storage Insulation. These bulletins provide comprehensive, step-by-step instructions on how to use the materials and techniques covered.

  16. Building cavities used as ducts: Air leakage characteristics and impacts in light commercial buildings

    SciTech Connect

    Cummings, J.B.; Withers, C.R. Jr.

    1998-12-31

    Field testing in 70 small commercial buildings in central Florida identified that building cavities were used as part of the air distribution system in 33 buildings. The various building cavity types (number of buildings in parentheses) are: enclosed air-handler support platforms (10)mechanical closets (8), mechanical rooms (6), ceiling spaces (7), wall cavities (6), chases (1), and other building cavities (2). Testing found that these building cavities are considerably more leaky than standard ducts and plenums because they are generally not built to the same airtightness standard as ducts. Actual air leakage is a function not only of duct hole size but also pressure differential across the leak sites. Pressure differentials generally range from {minus}0.080 in. WC ({minus}20 Pa) to {minus}0.401 in. WC ({minus}100 Pa) in support platforms, mechanical closets and rooms, wall cavities, and chases. By contrast, ceiling plenums often operate at less than 0.004 in. WC (1 Pa) difference from the occupied space and sometimes at positive pressure with respect to outdoors. The energy, infiltration, and relative humidity impacts of building cavity duct leakage depend upon the leak airflow rate and the temperature and humidity conditions of the air entering the leaks. Therefore, the location of the building cavity ducts is very important. If the return leak air is drawn from the occupied space, that leakage will have little or no impact on energy, infiltration, or relative humidity. At the other extreme, if the leaking air comes from a hot and humid attic space, the impacts will be large. The interaction of various building cavity duct leaks with eight different building configurations--based on the location of the primary air and thermal boundaries in the ceiling space--is discussed here. The paper concludes that building cavities should not, as a general rule, be used as a part of the air-distribution system. The exception is use of ceiling space return plenums. Ceiling plenums can be designed to operate at near neutral pressure with respect to outdoors and, therefore, can experience little or no duct leakage.

  17. Intelligent buildings

    SciTech Connect

    McClelland, S.

    1989-01-01

    The use and development of integrated sensor based systems in building design could turn the concept of an intelligent building from dream to reality over the next few years. To the user, an intelligent building offers economic and efficient environmental systems - heating, lighting and air conditioning; increased safety - with fire and security monitoring; improved business potential - with integrated data communication systems. To the manufacturer, intelligent buildings offer a lucrative market, particularly if they are able to exploit both the commercial and consumer markets. This book provides architects, building developers, system suppliers, engineers and academic researchers with an overview of the intelligent building market. The book brings together previously published papers as well as new material and examines the economics of sensor based systems. It explores the latest technological development and discusses the problems and the pitfalls. Emphasis is placed on practical case study material, covering a broad range of end users.

  18. Laboratory Building.

    SciTech Connect

    Herrera, Joshua M.

    2015-03-01

    This report is an analysis of the means of egress and life safety requirements for the laboratory building. The building is located at Sandia National Laboratories (SNL) in Albuquerque, NM. The report includes a prescriptive-based analysis as well as a performance-based analysis. Following the analysis are appendices which contain maps of the laboratory building used throughout the analysis. The top of all the maps is assumed to be north.

  19. Estimation of bar p/p Flux Ratio from Leaky Box and Closed Galaxy Models Using CERN Accelerator Results on bar p Production

    NASA Astrophysics Data System (ADS)

    Saha, R. K.; Majumdar, R.; Pal, P.; Bhattacharyya, D. P.

    Using steady state leaky box and closed galaxy models and the latest primary proton spectrum based on the directly measured data along with the accelerator data on bar p production, the bar p/p flux ratio in the interstellar medium has been estimated in the spectral range from 6 to 100 GeV/n. The derived result is in approximate agreement with the balloon borne calorimeter data of Golden et al. We have closed galaxy model for the estimation of the old component and young component of primary proton spectrum from the composite primary proton spectrum obtained from the recent experiments performed by Menn et al., Webber et al., Seo et al., JACEE and others. The derived results differ slightly from the results of Protheroe, Pal and Bhattacharyya.

  20. Determination of the flexoelectric coefficient (e1-e3) in nematic liquid crystal by using fully leaky optical-guided mode

    NASA Astrophysics Data System (ADS)

    Zheng, Guili; Zhang, Hui; Ye, Wenjiang; Zhang, Zhidong; Song, Hong-wei; Xuan, Li

    2016-02-01

    Fully leaky optical-guided mode was employed to determine the difference in the splay and bend flexoelectric coefficient (e1-e3) in negative nematic liquid crystal MS-N01300-000. The experimental curves of reflectivity versus internal angle (angle of incident light to the liquid crystal) were obtained when a laser beam passed through the hybrid-aligned nematic in-plane switching liquid crystal cell; the cell was embedded in pyramid-coupled waveguide with different alternating current (AC) and direct current (DC) voltages. The curves of the applied DC with voltage similar to that of AC shift to the left or the right. Experimental results were then compared with theoretical results derived from elastic continuum theory and multi-layer optical theory of liquid crystals. The approximate value of the flexoelectric coefficient (e1-e3) of MS-N01300-000 is 9.0 × 10-11 C/m.

  1. Effectiveness of duct sealing and duct insulation in multi-family buildings. Final report

    SciTech Connect

    Karins, N.H.; Tuluca, A.; Modera, M.

    1997-07-01

    This research investigated the cost-effectiveness of sealing and insulating the accessible portions of duct systems exposed to unconditioned areas in multifamily housing. Airflow and temperature measurements were performed in 25 apartments served by 10 systems a 9 multi-family properties. The measurements were performed before and after each retrofit, and included apartment airflow (supply and return), duct system temperatures, system fan flow and duct leakage area. The costs for each retrofit were recorded. The data were analyzed and used to develop a prototypical multifamily house. This prototype was used in energy simulations (DOE-2.1E) and air infiltration simulations (COMIS 2.1). The simulations were performed for two climates: New York City and Albany. In each climate, one simulation was performed assuming the basement was tight, and another assuming the basement was leaky. Simulation results and average retrofit costs were used to calculate cost-effectiveness. The results of the analysis indicate that sealing leaks of the accessible ductwork is cost-effective under all conditions simulated (simple payback was between 3 and 4 years). Insulating the accessible ductwork, however, is only cost-effective for buildings with leaky basement, in both climates (simple paybacks were less than 5 years). The simple payback period for insulating the ducts in buildings with tight basements was greater than 10 years, the threshold of cost-effectiveness for this research. 13 refs., 5 figs., 27 tabs.

  2. ROOF, A view looking north/northeast on roof of building toward ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ROOF, A view looking north/northeast on roof of building toward penthouses, with various air handling systems in the foreground - Department of Energy, Mound Facility, Isolated Building (I Building), One Mound Road, Miamisburg, Montgomery County, OH

  3. To build capacity, build confidence

    NASA Astrophysics Data System (ADS)

    Hewitson, Bruce

    2015-07-01

    The history of attempts to spread scientific know-how beyond western centres of excellence is littered with failures. Capacity building needs long-term commitment, a critical mass of trainees, and a supportive home environment.

  4. EKG isolator

    NASA Technical Reports Server (NTRS)

    Palmer, E.; Rasquin, J. R.; Smith, H. E.

    1971-01-01

    Light beam transmits heartbeat signal from electrodes on patient to electrocardiograph without exposing patient to possible severe electrical shock. System provides complete isolation between patient and EKG instrumentation.

  5. Toward Plugging the Leaky Pipeline: Biological and Agricultural Engineering Female Faculty in the United States and Canada

    NASA Astrophysics Data System (ADS)

    Cauble, Stephanie M.; Christy, Ann D.; Lima, Marybeth

    Correspondence concerning this article should be addressed to Marybeth Lima, Louisiana State University, Department of Biological and Agricultural Engineering, Room 149, E. B. Doran Building, Baton Rouge, LA 70803-4505. The authors acknowledge all the women BAE faculty who took the time, effort, and energy to complete this survey. The LSU Division of Instructional Support and Development (Measurement and Evaluation Resource Center) provided assistance with survey development. Drs. Evangelyn Alocilja, Karen Mancl, Bobby Matthews, and Kelly Rusch assisted with survey validity efforts. N. Rao Lakkakula provided computer assistance and helped with figure preparation. Undergraduate student workers Claire Burleigh, Tessa Byrne, Dawn Farver, Garbriela Gonzales, and Jared Powell assisted with data collection, and Andrea Albright and Gail Smith proofread the manuscript. Support for this research was provided in part by the Louisiana Agricultural Experimental Station, the Louisiana State University Agricultural and Mechanical College, The Ohio State University, and the Ohio Agricultural Research and Development Center.

  6. Building Sinusoids

    ERIC Educational Resources Information Center

    Landers, Mara G.

    2013-01-01

    In this article, the author describes the development and implementation of a measurement-based group activity designed to support students in understanding the connection between angle magnitude and the shape of the sine function. She explains that the benefit of this activity is that it allows students to build their trigonometric knowledge

  7. Team building

    SciTech Connect

    Kane, C.

    1993-04-01

    Power plants are particularly complicated projects with abundant opportunities for disputes. Efforts are beginning in the power industry to change the way the industry does business. Key elements of a comprehensive team-building approach include partnering, constructability, use of incentives, and the disputes review board.

  8. Building Trades.

    ERIC Educational Resources Information Center

    Gudzak, Raymond

    This curriculum guide provides materials for a competency-based course in building trades at the secondary level. The curriculum design uses the curriculum infused model for the teaching of basic skills as part of vocational education and demonstrates the relationship of vocationally related skills to communication, mathematics, and science

  9. 9. Building No. 5, Main Building; Building NO. 9, Guard ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Building No. 5, Main Building; Building NO. 9, Guard House (left). Viewed from across corner Lakeside Avenue and Main Street - Thomas A. Edison Laboratories, Main Street & Lakeside Avenue, West Orange, Essex County, NJ

  10. 2. PRINTING AND ADVERTISING BUILDING, ADMINISTRATION BUILDING, MERCHANDISE BUILDING, AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. PRINTING AND ADVERTISING BUILDING, ADMINISTRATION BUILDING, MERCHANDISE BUILDING, AND GARDEN, VIEW TO SOUTHWEST - Sears Roebuck & Company Mail Order Plant, Bounded by Lexington & Grenshaw Streets, Kedzie Avenue & Independence Boulevard, Chicago, Cook County, IL

  11. 5.5 W near-diffraction-limited power from resonant leaky-wave coupled phase-locked arrays of quantum cascade lasers

    SciTech Connect

    Kirch, J. D.; Chang, C.-C.; Boyle, C.; Mawst, L. J.; Botez, D.; Lindberg, D.; Earles, T.

    2015-02-09

    Five, 8.36 μm-emitting quantum-cascade lasers (QCLs) have been monolithically phase-locked in the in-phase array mode via resonant leaky-wave coupling. The structure is fabricated by etch and regrowth which provides large index steps (Δn = 0.10) between antiguided-array elements and interelement regions. Such high index contrast photonic-crystal (PC) lasers have more than an order of magnitude higher index contrast than PC-distributed feedback lasers previously used for coherent beam combining in QCLs. Absorption loss to metal layers inserted in the interelement regions provides a wide (∼1.0 μm) range in interelement width over which the resonant in-phase mode is strongly favored to lase. Room-temperature, in-phase-mode operation with ∼2.2 kA/cm{sup 2} threshold-current density is obtained from 105 μm-wide aperture devices. The far-field beam pattern has lobewidths 1.65× diffraction limit (D.L.) and 82% of the light in the main lobe, up to 1.8× threshold. Peak pulsed near-D.L. power of 5.5 W is obtained, with 4.5 W emitted in the main lobe. Means of how to increase the device internal efficiency are discussed.

  12. Large negative dispersion in dual-concentric-core photonic crystal fiber with hybrid cladding structure based on complete leaky mode coupling

    NASA Astrophysics Data System (ADS)

    Yuan, Jinhui; Sang, Xinzhu; Yu, Chongxiu; Jin, Cang; Shen, Xiangwei; Zhou, Guiyao; Li, Shuguang; Hou, Lantian

    2011-12-01

    Considering the optical stability of solution, the sugar-solution is infused into the outer core ring of dual-concentric-core photonic crystal fiber (DCCPCF). The influences of structure parameters and solution concentration on the phase and loss matching are comprehensively analyzed. By choosing the appropriate outer core mode to completely couple with the inner core fundamental mode, the large negative dispersion PCF around 1.55 ?m is designed, which has the dispersion value of - 39,500 ps/km/nm as well as bandwidth of 7.4 nm and effective mode area of 28.3 ?m 2. The designed PCF with hybrid cladding structure can effectively compensate the positive dispersion of conventional single mode fiber, and suppress the system perturbation caused by a series of nonlinear effects. Considering the mode field mismatching between the DCCPCF and the tapered fiber, the calculated connection loss around 1.55 ?m is below 3 dB. In addition, the equivalent propagation constants of two leaky modes are deduced from the coupled-mode theory, and the complete mode coupling case can be well predicted by comparing the real and imaginary parts of propagation constants.

  13. Building Specifications

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The building in the top photo is the new home of the National Permanent Savings Bank in Washington, D.C., designed by Hartman-Cox Architects. Its construction was based on a money-saving method of preparing building specifications which derived from NASA technology developed to obtain quality construction while holding down cost of launch facilities, test centers and other structures. Written technical specifications spell out materials and components to be used on construction projects and identify the quality tests each item must pass. Specifications can have major impact on construction costs. Poorly formulated specifications can lead to unacceptable construction which must be replaced, unnecessarily high materials costs, safety hazards, disputes and often additional costs due to delays and litigation. NASA's Langley Research Center developed a novel approach to providing accurate, uniform, cost-effective specifications which can be readily updated to incorporate new building technologies. Called SPECSINTACT, it is a computerized - system accessible to all NASA centers involved in construction programs. The system contains a comprehensive catalog of master specifications applicable to many types of construction. It enables designers of any structure to call out relevant sections from computer storage and modify them to fit the needs of the project at hand. Architects and engineers can save time by concentrating their efforts on needed modifications rather than developing all specifications from scratch. Successful use of SPECSINTACT has led to a number of spinoff systems. One of the first was MASTERSPEC, developed from NASA's experience by Production Systems for Architects and Engineers, Inc., an organization established by the American Institute of Architects. MASTERSPEC, used in construction of the bank building pictured, follows the same basic format as SPECSINTACT and can be used in either automated or manual modes. The striking appearance of the bank building shows that, while MASTERSPEC saves time and money, its use involves no sacrfice in architectural design freedom. The Naval Engineering Facilities Command employs an automated specifications system based on SPECSINTACT. The Public Buildings Service of the General Services Administration used SPECSINTACT as a starting point in a plan to make its guideline specifications available to architects and engineers on a nationwide computer network. Public Technology, Inc., a NASA Technology Application Team, is working with Production Systems for Architects and Engineers, Inc., to promote widespread use of the system by state and local governments for cost benefits to taxpayers.

  14. Reactor building assembly and method of operation

    SciTech Connect

    Fennern, L.E.; Caraway, H.A.; Hsu, Li C.

    1993-06-01

    A reactor building assembly is described comprising: a reactor pressure vessel containing a reactor core for generating heat in the form of steam; a containment vessel enclosing said pressure vessel; a first enclosure surrounding said containment vessel and spaced laterally therefrom to define a first chamber there between, and having a top and a bottom; a second enclosure surrounding said first enclosure and spaced laterally therefrom to define a second chamber there between, and having a top and a bottom; a building inlet for receiving into said second chamber fresh air from outside said second enclosure; a building outlet for discharging stale air from said first chamber; a transfer duct disposed through said first enclosure selectively joining in flow communication said first and second chambers; said building inlet being disposed at said second enclosure top, said building outlet being disposed at said first enclosure top, and said transfer duct being disposed adjacent said first enclosure bottom for allowing said fresh air to flow downwardly by gravity through said second chamber and through said transfer duct into said first chamber for cooling said first chamber, said stale air flowing upwardly by natural buoyancy for discharger from said first chamber through said building outlet; an exhaust stack disposed above said building outlet and in flow communication therewith for channeling upwardly said stale air from said first chamber for discharge into the surrounding environs; and a passive first driving means for increasing flow of said stale air from said building outlet comprising: an isolation pool containing isolation water; an isolation condenser disposed in said isolation pool, and joined in flow communication with said reactor pressure vessel for receiving primary steam therefrom, said primary steam being cooled in said isolation condenser for heating said isolation water to generate secondary steam.

  15. Building Buildings with Triangular Numbers

    ERIC Educational Resources Information Center

    Pagni, David L.

    2006-01-01

    Triangular numbers are used to unravel a new sequence of natural numbers here-to-fore not appearing on the Encyclopedia of Integer Sequences website. Insight is provided on the construction of the sequence using "buildings" as a viewable model of the sequence entries. A step-by-step analysis of the sequence pattern reveals a method for generating

  16. In vivo mutational analysis of the mupirocin gene cluster reveals labile points in the biosynthetic pathway: the "leaky hosepipe" mechanism.

    PubMed

    Wu, Ji'en; Hothersall, Joanne; Mazzetti, Carlo; O'Connell, Yvonne; Shields, Jennifer A; Rahman, Ayesha S; Cox, Russell J; Crosby, John; Simpson, Thomas J; Thomas, Christopher M; Willis, Christine L

    2008-06-16

    A common feature of the mupirocin and other gene clusters of the AT-less polyketide synthase (PKS) family of metabolites is the introduction of carbon branches by a gene cassette that contains a beta-hydroxy-beta-methylglutaryl CoA synthase (HMC) homologue and acyl carrier protein (ACP), ketosynthase (KS) and two crotonase superfamily homologues. In vivo studies of Pseudomonas fluorescens strains in which any of these components have been mutated reveal a common phenotype in which the two major isolable metabolites are the truncated hexaketide mupirocin H and the tetraketide mupiric acid. The structure of the latter has been confirmed by stereoselective synthesis. Mupiric acid is also the major metabolite arising from inactivation of the ketoreductase (KR) domain of module 4 of the modular PKS. A number of other mutations in the tailoring region of the mupirocin gene cluster also result in production of both mupirocin H and mupiric acid. To explain this common phenotype we propose a mechanistic rationale in which both mupirocin H and mupiric acid represent the products of selective and spontaneous release from labile points in the pathway that occur at significant levels when mutations block the pathway either close to or distant from the labile points. PMID:18465759

  17. Tumour exosomes display differential mechanical and complement activation properties dependent on malignant state: implications in endothelial leakiness

    PubMed Central

    Whitehead, Bradley; Wu, LinPing; Hvam, Michael Lykke; Aslan, Husnu; Dong, Mingdong; Dyrskjøt, Lars; Ostenfeld, Marie Stampe; Moghimi, Seyed Moein; Howard, Kenneth Alan

    2015-01-01

    Background Exosomes have been implicated in tumour progression and metastatic spread. Little is known of the effect of mechanical and innate immune interactions of malignant cell-derived exosomes on endothelial integrity, which may relate to increased extravasation of circulating tumour cells and, therefore, increased metastatic spread. Methods Exosomes isolated from non-malignant immortalized HCV-29 and isogenic malignant non-metastatic T24 and malignant metastatic FL3 bladder cells were characterized by nanoparticle tracking analysis and quantitative nanomechanical mapping atomic force microscopy (QNM AFM) to determine size and nanomechanical properties. Effect of HCV-29, T24 and FL3 exosomes on human umbilical vein endothelial cell (HUVEC) monolayer integrity was determined by transendothelial electrical resistance (TEER) measurements and transport was determined by flow cytometry. Complement activation studies in human serum of malignant and non-malignant cell-derived exosomes were performed. Results FL3, T24 and HCV-29 cells produced exosomes at similar concentration per cell (6.64, 6.61 and 6.46×104 exosomes per cell for FL3, T24 and HCV-29 cells, respectively) and of similar size (120.2 nm for FL3, 127.6 nm for T24 and 117.9 nm for HCV-29, respectively). T24 and FL3 cell-derived exosomes exhibited a markedly reduced stiffness, 95 MPa and 280 MPa, respectively, compared with 1,527 MPa with non-malignant HCV-29 cell-derived exosomes determined by QNM AFM. FL3 and T24 exosomes induced endothelial disruption as measured by a decrease in TEER in HUVEC monolayers, whereas no effect was observed for HCV-29 derived exosomes. FL3 and T24 exosomes traffic more readily (11.6 and 21.4% of applied exosomes, respectively) across HUVEC monolayers than HCV-29 derived exosomes (7.2% of applied exosomes). Malignant cell-derived exosomes activated complement through calcium-sensitive pathways in a concentration-dependent manner. Conclusions Malignant (metastatic and non-metastatic) cell line exosomes display a markedly reduced stiffness and adhesion but an increased complement activation compared to non-malignant cell line exosomes, which may explain the observed increased endothelial monolayer disruption and transendothelial transport of these vesicles. PMID:26714455

  18. Response of an emulsion of leaky dielectric drops immersed in a simple shear flow: Drops more conductive than the suspending fluid

    NASA Astrophysics Data System (ADS)

    Fernández, Arturo

    2008-04-01

    Direct numerical simulation is used to examine the rheological properties of an emulsion of leaky dielectric fluids when an electric field is applied to the system. The emulsion consisting of neutrally buoyant drops is immersed in a simple shear flow where an electric potential difference is applied between the plates. It is assumed that drops are more conductive than the suspending fluid and that the electrical conductivity ratio between the drops and the suspending fluid, R =σi/σo, is larger than the dielectric permittivity ratio, S =ɛo/ɛi. If a single leaky dielectric drop is immersed in an electric field, this combination of properties leads to a viscous fluid motion from the equator to the poles. The response of an emulsion depends on the competition between the electrical forces and the fluid shear. This relation is quantified by the Mason number, Mn =(3λ+2)μγ˙/6(λ+1)ɛ0β2E∞2. The significance of drop deformability is measured through the electric capillary number, Ce=ɛ0β2E∞2a/γ. The microstructure and properties of an emulsion depend mainly on Mn, Ce, and R. An emulsion immersed in an electric field exhibits three different regimes for increasing Mn. When the electrical forces are substantially larger than the fluid shear, Mn <0.02, the drops aggregate in structures oriented parallel to the electric field that dictate the response of the system. At intermediate shear rates, 0.020.2, the aggregated structures are broken up, and the effect of the electrical interaction weakens. The application of an electric field leads electrorheological emulsions to exhibit an increase in their effective viscosity for the range of properties examined here, 0.001

  19. A coupled SAFE-2.5D BEM approach for the dispersion analysis of damped leaky guided waves in embedded waveguides of arbitrary cross-section.

    PubMed

    Mazzotti, M; Bartoli, I; Marzani, A; Viola, E

    2013-09-01

    The paper presents a Semi-Analytical Finite Element (SAFE) formulation coupled with a 2.5D Boundary Element Method (BEM) for the computation of the dispersion properties of viscoelastic waveguides with arbitrary cross-section and embedded in unbounded isotropic viscoelastic media. Attenuation of guided modes is described through the imaginary component of the axial wavenumber, which accounts for material damping, introduced via linear viscoelastic constitutive relations, as well as energy loss due to radiation of bulk waves in the surrounding media. Energy radiation is accounted in the SAFE model by introducing an equivalent dynamic stiffness matrix for the surrounding medium, which is derived from a regularized 2.5D boundary element formulation. The resulting dispersive wave equation is configured as a nonlinear eigenvalue problem in the complex axial wavenumber. The eigenvalue problem is reduced to a linear one inside a chosen contour in the complex plane of the axial wavenumber by using a contour integral method. Poles of leaky and evanescent modes are obtained by choosing appropriately the phase of the wavenumbers normal to the interface in compliance with the nature of the waves in the surrounding medium. Finally, the obtained eigensolutions are post-processed to compute the energy velocity and the radiated wavefield in the surrounding domain. The reliability of the method is first validated on existing results for waveguides of circular cross sections embedded in elastic and viscoelastic media. Next, the potential of the proposed numerical framework is shown by computing the dispersion properties for a square steel bar embedded in grout and for an H-shaped steel pile embedded in soil. PMID:23642317

  20. Spectroscopy of semiconductor meta-device building blocks (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Butakov, Nikita A.; Schuller, Jon A.

    2015-09-01

    Inspired by the potential of designing highly efficient nanophotonic optical elements, numerous researchers are currently exploring the use of dielectric resonators in constructing meta-devices. A wide range of optical components have been demonstrated, including metasurfaces that act as two-dimensional lenses, gratings, and axicons. At the core of these devices is a dielectric building block, typically a Silicon nano-disk or nano-rod, that supports Mie-like leaky mode excitations with a geometrically tunable amplitude and phase response. Here we present a comprehensive experimental characterization of these building blocks. We elucidate their multipolar mode structure, and explain the dependence on the underlying substrate. We find that fundamentally new buried magnetic modes emerge in high-index substrates, and that Fabry-Perot effects in silicon-on-insulator platforms can be utilized to enhance or suppress specific modes. When individual resonators are arranged into arrays with sub-wavelength periodicities, inter-particle coupling leads to a shift in the resonant response. When the periodicities are on the same order as the operating wavelength, the localized resonances may couple with the global diffraction modes, leading to the possible formation of distinct high-quality-factor surface-lattice-resonant modes, similar to those encountered in plasmonic gratings. We conclude by exploring the behavior of resonators constructed out of active materials, such as polar materials that support phonon-polariton excitations, and phase-change materials with tunable dielectric constants.

  1. 2. View northwest of main hospital building complex, hospital building ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. View northwest of main hospital building complex, hospital building (Building 90), administration and clinical hospital building (Building 88), and hospital building (Building 91) - National Home for Disabled Volunteer Soldiers Western Branch, 4101 South Fourth Street, Leavenworth, Leavenworth County, KS

  2. Commercial Buildings Energy Consumption Survey - Office Buildings

    EIA Publications

    2010-01-01

    Provides an in-depth look at this building type as reported in the 2003 Commercial Buildings Energy Consumption Survey. Office buildings are the most common type of commercial building and they consumed more than 17% of all energy in the commercial buildings sector in 2003. This special report provides characteristics and energy consumption data by type of office building (e.g. administrative office, government office, medical office) and information on some of the types of equipment found in office buildings: heating and cooling equipment, computers, servers, printers, and photocopiers.

  3. PHYSICAL MODELING OF CONCENTRATION DISTRIBUTIONS AROUND TWIN HIGH-RISE BUILDINGS WITH A DISTRICT HEATING PLANT

    EPA Science Inventory

    A wind tunnel experiment was conducted to investigate the effects of three high-rise building configurations on the diffusion of emissions released near the downstream base of the buildings. he building configurations included an isolated high-rise building, two high-rise buildin...

  4. PHYSICAL MODELING OF THE FLOW FIELD AROUND TWIN HIGH-RISE BUILDINGS

    EPA Science Inventory

    A wind tunnel study was conducted to investigate the flow characteristics near three configurations of high-rise buildings - an isolated high-rise building, two high-rise buildings separated in the streamwise direction, and two high-rise buildings separated in the streamwise dire...

  5. Building America

    SciTech Connect

    Brad Oberg

    2010-12-31

    Builders generally use a 'spec and purchase' business management system (BMS) when implementing energy efficiency. A BMS is the overall operational and organizational systems and strategies that a builder uses to set up and run its company. This type of BMS treats building performance as a simple technology swap (e.g. a tank water heater to a tankless water heater) and typically compartmentalizes energy efficiency within one or two groups in the organization (e.g. purchasing and construction). While certain tools, such as details, checklists, and scopes of work, can assist builders in managing the quality of the construction of higher performance homes, they do nothing to address the underlying operational strategies and issues related to change management that builders face when they make high performance homes a core part of their mission. To achieve the systems integration necessary for attaining 40% + levels of energy efficiency, while capturing the cost tradeoffs, builders must use a 'systems approach' BMS, rather than a 'spec and purchase' BMS. The following attributes are inherent in a systems approach BMS; they are also generally seen in quality management systems (QMS), such as the National Housing Quality Certification program: Cultural and corporate alignment, Clear intent for quality and performance, Increased collaboration across internal and external teams, Better communication practices and systems, Disciplined approach to quality control, Measurement and verification of performance, Continuous feedback and improvement, and Whole house integrated design and specification.

  6. A Markov Chain Monte Carlo technique to sample transport and source parameters of Galactic cosmic rays. I. Method and results for the Leaky-Box model

    NASA Astrophysics Data System (ADS)

    Putze, A.; Derome, L.; Maurin, D.; Perotto, L.; Taillet, R.

    2009-04-01

    Context: Propagation of charged cosmic-rays in the Galaxy depends on the transport parameters, whose number can be large depending on the propagation model under scrutiny. A standard approach for determining these parameters is a manual scan, leading to an inefficient and incomplete coverage of the parameter space. Aims: In analyzing the data from forthcoming experiments, a more sophisticated strategy is required. An automated statistical tool is used, which enables a full coverage of the parameter space and provides a sound determination of the transport and source parameters. The uncertainties in these parameters are also derived. Methods: We implement a Markov Chain Monte Carlo (MCMC), which is well suited to multi-parameter determination. Its specificities (burn-in length, acceptance, and correlation length) are discussed in the context of cosmic-ray physics. Its capabilities and performances are explored in the phenomenologically well-understood Leaky-Box Model. Results: From a technical point of view, a trial function based on binary-space partitioning is found to be extremely efficient, allowing a simultaneous determination of up to nine parameters, including transport and source parameters, such as slope and abundances. Our best-fit model includes both a low energy cut-off and reacceleration, whose values are consistent with those found in diffusion models. A Kolmogorov spectrum for the diffusion slope (δ = 1/3) is excluded. The marginalised probability-density function for δ and α (the slope of the source spectra) are δ ≈ 0.55-0.60 and α ≈ 2.14-2.17, depending on the dataset used and the number of free parameters in the fit. All source-spectrum parameters (slope and abundances) are positively correlated among themselves and with the reacceleration strength, but are negatively correlated with the other propagation parameters. Conclusions: The MCMC is a practical and powerful tool for cosmic-ray physic analyses. It can be used to confirm hypotheses concerning source spectra (e.g., whether α_i≠ α_j) and/or determine whether different datasets are compatible. A forthcoming study will extend our analysis to more physical diffusion models.

  7. Response of an emulsion of leaky dielectric drops immersed in a simple shear flow: Drops less conductive than the suspending fluid

    NASA Astrophysics Data System (ADS)

    Fernández, Arturo

    2008-04-01

    Direct numerical simulations of the effects of an electric field on an emulsion of drops are presented. A simple shear flow configuration is adopted where the electric field is applied perpendicular to the sliding plates. Both the drops and the suspending fluid are assumed to behave as leaky dielectric fluids. Here, drops less conductive than the suspending fluid with an electrical conductivity ratio smaller than the dielectric permittivity ratio are considered. This combination of electrical properties leads to a viscous fluid motion from the poles to the equator. The response of an emulsion is governed by the competition between the electrical forces, the fluid shear, and the capillary forces. The Mason number [Mn=(3λ+2)μγ˙/6(λ+1)ɛ0β2E∞2] and the electric capillary number [Ce=ɛ0β2E∞2a/γ] are used to describe the response of the systems. As previously observed in experiments at low shear rates, Mn <0.2, the drops aggregate in chains that tilt under a shear. The competition between the electrical forces and the fluid shear results in shorter chains at intermediate shear rates, 0.22.0, the chains of drops break up. The rheological properties mainly depend on the emulsion microstructure. The effective viscosity exhibits a strong shear-thinning response because the chains of drops, which appear at low shear rates, increase the resistance of the system to shear. As the chains shorten and break up, the effective viscosity decreases. The elastic properties of the emulsion are also affected by the presence of the electric field. Normal stress differences arise as a consequence of the deformation of the drops and the surface tension acting on the interface between the fluids. The shape of the drops is determined by the deformation caused by the viscous forces and the deformation due to the electric stresses. At low shear rates, the electric effects are predominant and the application of an electric field leads the drops to deform into oblate shapes. The oblate deformation results in higher stresses in the direction parallel to the shearing motion than perpendicular to it, which results in a significant increase in the first normal stress difference. As the shear rate is increased, the oblate deformation is supplemented by the deformation due to the fluid shear. The deformation caused by the electric field is also responsible for the negative magnitude of the second normal stress difference in three-dimensional emulsions.

  8. East side. Building 517 is to the right. Building 511 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    East side. Building 517 is to the right. Building 511 is to the left. - Fitzsimons General Hospital, Central Service Building, North of Building No. 511, East of corridor connecting Building 511 to Building 515, Aurora, Adams County, CO

  9. Wind interference effect on an octagonal plan shaped tall building due to square plan shaped tall buildings

    NASA Astrophysics Data System (ADS)

    Kar, Rony; Dalui, Sujit Kumar

    2016-02-01

    The variation of pressure at the faces of the octagonal plan shaped tall building due to interference of three square plan shaped tall building of same height is analysed by computational fluid dynamics module, namely ANSYS CFX for 0° wind incidence angle only. All the buildings are closely spaced (distance between two buildings varies from 0.4h to 2h, where h is the height of the building). Different cases depending upon the various positions of the square plan shaped buildings are analysed and compared with the octagonal plan shaped building in isolated condition. The comparison is presented in the form of interference factors (IF) and IF contours. Abnormal pressure distribution is observed in some cases. Shielding and channelling effect on the octagonal plan shaped building due to the presence of the interfering buildings are also noted. In the interfering condition the pressure distribution at the faces of the octagonal plan shaped building is not predictable. As the distance between the principal octagonal plan shaped building and the third square plan shaped interfering building increases the behaviour of faces becomes more systematic. The coefficient of pressure (C p) for each face of the octagonal plan shaped building in each interfering case can be easily found if we multiply the IF with the C p in the isolated case.

  10. Petrologic implications of leaky rocks

    SciTech Connect

    Spear, F.S.

    1985-01-01

    P-T paths computed from zoned garnets in pelitic schist, New Hampshire indicate that prograde metamorphic devolatilization reactions proceeded during cooling, suggesting a decrease in P (H20) relative to P(rock). It is proposed that the mechanisms for lowering P(H20) relative to P(rock) is for the rocks to leak. Fluids leave rocks at a rate that is determined by the local pressure gradient and permeability. Fluids are generated in rocks at a rate that is dictated by the P-T path, the heating rate and the reactions that are encountered. Calculations show that for (1) reasonable permeabilities, (2) a heating cycle along a model P-T path typical for crustal thickening and (3) a pressure gradient determined by the difference in lithostatic and hydrostatic pressure. At this point, the rocks begin to dry out with the following consequences: 1) P(H20) decreases relative to P(rock) eventually reaching a value that is near hydrostatic. 2) Devolatilization reactions will continue even after the rocks begin to cool. 3) Metamorphic isograds will progress through the crust in a steady state thermal environment. 4) Fluid inclusions that trap late fluids will record P(fluid) < P(rock), which will result in an underestimation of the depth of burial at the time of entrapment if the pressure is assumed to be lithostatic.

  11. Leaky cavities with unwanted noise

    SciTech Connect

    Semenov, A. A.; Vasylyev, D. Yu.; Vogel, W.; Khanbekyan, M.; Welsch, D.-G.

    2006-09-15

    A phenomenological approach is developed that allows one to completely describe the effects of unwanted noise, such as the noise associated with absorption and scattering, in high-Q cavities. This noise is modeled by a block of beam splitters and an additional input-output port. The replacement schemes enable us to formulate appropriate quantum Langevin equations and input-output relations. It is demonstrated that unwanted noise renders it possible to combine a cavity input mode and the intracavity mode in a nonmonochromatic output mode. Possible applications to unbalanced and cascaded homodyning of the intracavity mode are discussed and the advantages of the latter method are shown.

  12. Building 1100--NASA

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Building 1100 is the NASA administrative building. Services located in this building include two banks, a post office, barber shop, cafeteria, snack bar, travel agency, dry cleaners, the NASA Exchange retail store and medical facilities for employees.

  13. Solar buildings. Overview: The Solar Buildings Program

    SciTech Connect

    Not Available

    1998-04-01

    Buildings account for more than one third of the energy used in the United States each year, consuming vast amounts of electricity, natural gas, and fuel oil. Given this level of consumption, the buildings sector is rife with opportunity for alternative energy technologies. The US Department of Energy`s Solar Buildings Program was established to take advantage of this opportunity. The Solar Buildings Program is engaged in research, development, and deployment on solar thermal technologies, which use solar energy to produce heat. The Program focuses on technologies that have the potential to produce economically competitive energy for the buildings sector.

  14. Green buildings: Implications for acousticians

    NASA Astrophysics Data System (ADS)

    Noble, Michael R.

    2005-04-01

    This presentation will deal with the practical implications of green design protocols of the US Green Building Council on interior acoustics of buildings. Three areas of particular consequence to acousticians will be discussed. Ventilation Systems: reduced energy consumption goals dictate reliance on natural cooling and ventilation using ambient air when possible. The consequent large openings in the building envelope to bring fresh air into rooms, and similar sized openings to transfer the mixed air out, can severely compromise the noise isolation of the rooms concerned. Radiant Cooling: the heavy concrete floors of buildings can be used as a thermal flywheel to lessen the cooling load, which forces the concrete ceilings to be exposed to the occupied rooms for heat transfer, and strictly limits the application of acoustical absorption on the ceilings. This challenges the room acoustics design. Green Materials: the LEED protocols require the elimination of potentially harmful finishes, including fibrous materials which may impact air quality or contribute to health problems. Since the backbone of sound absorption is glass and mineral fibres, this further challenges provision of superior room acoustics. Examples and commentary will be provided based on current and recent projects.

  15. 16. Perimeter acquisition radar building room #102, electrical equipment room; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Perimeter acquisition radar building room #102, electrical equipment room; the prime power distribution system. Excellent example of endulum-types shock isolation. The grey cabinet and barrel assemble is part of the polychlorinated biphenyl (PCB) retrofill project - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

  16. The Building Commissioning Handbook.

    ERIC Educational Resources Information Center

    Heinz, John A.; Casault, Rick

    This book discusses building commissioning, which is the process of certifying that a new facility meets the required specifications. As buildings have become more complex, the traditional methods for building start-up and final acceptance have been proven inadequate, and building commissioning has been developed, which often necessitates the use

  17. The Building Commissioning Handbook.

    ERIC Educational Resources Information Center

    Heinz, John A.; Casault, Rick

    This book discusses building commissioning, which is the process of certifying that a new facility meets the required specifications. As buildings have become more complex, the traditional methods for building start-up and final acceptance have been proven inadequate, and building commissioning has been developed, which often necessitates the use…

  18. Modular Buildings Buying Guide.

    ERIC Educational Resources Information Center

    Morris, Susan

    1991-01-01

    Suggests that child care program directors who are expanding their programs or opening new child care centers investigate the possibility of renting, leasing, or purchasing a modular building. Discusses the advantages of modular buildings over conventional building construction or rented space in an occupied building. Provides information about

  19. Concepts in Building Firesafety.

    ERIC Educational Resources Information Center

    Egan, M. David

    The goal of this book is to present in a graphical format the principles of design for building firesafety. The book's more than 270 illustrations represent the core of its coverage of factors affecting fire ignition and spread in buildings, building site planning for fire suppression and occupant rescue operations, protection by building

  20. Friendly protection of houses by affordable isolation

    SciTech Connect

    Mazzolani, Federico M.; Mandara, Alberto; Froncillo, Salvatore

    2008-07-08

    The paper deals with a case of seismic isolation carried out in Campania (Italy), referring to the construction of a house building. The concerned case is a three-storey reinforced concrete frame building, in which the isolation system has been applied between the basement top and the first floor deck. The paper reports the main steps of this work, starting from the design, carried out according to the latest Italian seismic code, going throughout the construction stage, up to the extensive on-site testing program performed to evaluate the dynamic response of the building. Relevant technological solutions are illustrated and discussed. Both theoretical calculation and experimental measurements demonstrate the effectiveness of the solution adopted, not only from the technical point of view, but also in an economic perspective.

  1. Building a Brighter Tomorrow: Library Buildings 1992.

    ERIC Educational Resources Information Center

    Fox, Bette-Lee; And Others

    1992-01-01

    Presents statistics on public and academic library construction for new buildings, as well as for additions and renovations. Information is provided on funding sources, costs, size, book capacity, and seating capacity. A directory of architects, numerous photographs, and a list of buildings in progress are also included. (LRW)

  2. Isolated sleep paralysis

    MedlinePLUS

    Sleep paralysis - isolated; Parasomnia - isolated sleep paralysis ... Episodes of isolated sleep paralysis last from a few seconds to 1 or 2 minutes. During these episodes the person is unable to move ...

  3. Building Design & Construction - Sustainability

    SciTech Connect

    2003-11-01

    Offers a brief history of green building; presents the results of a specially commissioned survey; and analyzes the chief trends, issues, and published research, based on interviews with dozens of experts and participants in green building.

  4. Buildings interoperability landscape - Draft

    SciTech Connect

    Hardin, Dave B.; Stephan, Eric G.; Wang, Weimin; Corbin, Charles D.; Widergren, Steven E.

    2015-02-01

    Buildings are an integral part of our nation’s energy economy. The advancement in information and communications technology (ICT) has revolutionized energy management in industrial facilities and large commercial buildings. As ICT costs decrease and capabilities increase, buildings automation and energy management features are transforming the small-medium commercial and residential buildings sectors. A vision of a connected world in which equipment and systems within buildings coordinate with each other to efficiently meet their owners’ and occupants’ needs, and where buildings regularly transact business with other buildings and service providers (such as gas and electric service providers) is emerging. However, while the technology to support this collaboration has been demonstrated at various degrees of maturity, the integration frameworks and ecosystems of products that support the ability to easily install, maintain, and evolve building systems and their equipment components are struggling to nurture the fledging business propositions of their proponents.

  5. Building Materials Property Table

    SciTech Connect

    2010-04-16

    This information sheet describes a table of some of the key technical properties of many of the most common building materials taken from ASHRAE Fundamentals - 2001, Moisture Control in Buildings, CMHC, NRC/IRC, IEA Annex 24, and manufacturer data.

  6. Better Buildings Challenge Overview

    SciTech Connect

    2011-06-01

    The Better Buildings Challenge is a national leadership initiative calling on corporate chief executive officers, university presidents, and state and local leaders to make a significant commitment to building energy efficiency.

  7. Building Blueprints: Making Music.

    ERIC Educational Resources Information Center

    College Planning & Management, 2002

    2002-01-01

    Depicts how Cornell University renovated its civil engineering and architecture building to include space for musical performances, teaching, and rehearsals. The article highlights the facility's contemporary design, which also compliments the form and massing of the original building. (GR)

  8. 1. BUILDING NO. 804, ARMAMENT INSPECTION & ADJUSTMENT BUILDING, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. BUILDING NO. 804, ARMAMENT INSPECTION & ADJUSTMENT BUILDING, LOOKING NORTHWEST - Wendover Air Force Base, Armament Inspection & Adjustment Building, South of Interstate 80, Wendover, Tooele County, UT

  9. Old Buildings, New Life.

    ERIC Educational Resources Information Center

    Smith, Charles R.

    2001-01-01

    Explains how schools can cost-effectively upgrade their existing science facilities and offer technologies normally found only in new buildings. Explores the decision-making process leading to a decision to build or renovate. Includes a case study on meeting the challenges poised by a building's infrastructure. (GR)

  10. Cryogenic Faraday isolator

    SciTech Connect

    Zheleznov, D S; Zelenogorskii, V V; Katin, E V; Mukhin, I B; Palashov, O V; Khazanov, Efim A

    2010-05-26

    A Faraday isolator is described in which thermal effects are suppressed by cooling down to liquid nitrogen temperatures. The principal scheme, main characteristics and modifications of the isolator are presented. The isolation degree is studied experimentally for the subkilowatt average laser radiation power. It is shown that the isolator can be used at radiation powers up to tens of kilowatts. (quantum electronic devices)

  11. Improved RF Isolation Amplifier

    NASA Technical Reports Server (NTRS)

    Stevens, G. L.; Macconnell, J.

    1985-01-01

    Circuit has high reverse isolation and wide bandwidth. Wideband isolation amplifier has low intermodulation distortion and high reverse isolation. Circuit does not require selected or matched components or directional coupling device. Circuit used in applications requiring high reverse isolation such as receiver intermediate-frequency (IF) strips and frequency distribution systems. Also applicable in RF and video signaling.

  12. Building L west elevation oblique from cartway (between Buildings L ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Building L west elevation oblique from cartway (between Buildings L and M), also showing west elevation of Building J - Daniel F. Waters Germantown Dye Works, Building L, 37-55 East Wister Street, Philadelphia, Philadelphia County, PA

  13. 10. Building 105, Facilities Engineering Building, 1830, interior, air condition ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Building 105, Facilities Engineering Building, 1830, interior, air condition repair shop, S end of building, looking N. - Watervliet Arsenal, Building 105, South Broadway, on Hudson River, Watervliet, Albany County, NY

  14. 2. Building No. 1, left; Building No. 9, Guard House, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Building No. 1, left; Building No. 9, Guard House, center; Building No. 5, Main Building, right. View from across Main Street - Thomas A. Edison Laboratories, Main Street & Lakeside Avenue, West Orange, Essex County, NJ

  15. Green Buildings and Health.

    PubMed

    Allen, Joseph G; MacNaughton, Piers; Laurent, Jose Guillermo Cedeno; Flanigan, Skye S; Eitland, Erika Sita; Spengler, John D

    2015-09-01

    Green building design is becoming broadly adopted, with one green building standard reporting over 3.5 billion square feet certified to date. By definition, green buildings focus on minimizing impacts to the environment through reductions in energy usage, water usage, and minimizing environmental disturbances from the building site. Also by definition, but perhaps less widely recognized, green buildings aim to improve human health through design of healthy indoor environments. The benefits related to reduced energy and water consumption are well-documented, but the potential human health benefits of green buildings are only recently being investigated. The objective of our review was to examine the state of evidence on green building design as it specifically relates to indoor environmental quality and human health. Overall, the initial scientific evidence indicates better indoor environmental quality in green buildings versus non-green buildings, with direct benefits to human health for occupants of those buildings. A limitation of much of the research to date is the reliance on indirect, lagging and subjective measures of health. To address this, we propose a framework for identifying direct, objective and leading "Health Performance Indicators" for use in future studies of buildings and health. PMID:26231502

  16. EMCS for building management

    SciTech Connect

    Vaculik, F.

    1983-06-01

    This article contends that to be a useful building management tool, the Energy Monitoring and Control System (EMCS) must control the HVAC systems and monitor both the building environmental quality and the building energy performance. Suggested environmental quality and building energy performance indicators are expected to keep the building manager and operator informed in a real-time sense about the overall HVAC systems performance. The Building Energy Performance Profile (BEPP) is presented graphically. The article discusses environmental quality indicators, energy performance indicators, applying the indicators, and resolving problems. It is concluded that the proposed method, which is based on providing the manager (and the building operator) with a set of meaningful performance indicators, is simple to follow and economical to implement because a minimum of instrumentation is required.

  17. Commercial Buildings Characteristics, 1992

    SciTech Connect

    Not Available

    1994-04-29

    Commercial Buildings Characteristics 1992 presents statistics about the number, type, and size of commercial buildings in the United States as well as their energy-related characteristics. These data are collected in the Commercial Buildings Energy Consumption Survey (CBECS), a national survey of buildings in the commercial sector. The 1992 CBECS is the fifth in a series conducted since 1979 by the Energy Information Administration. Approximately 6,600 commercial buildings were surveyed, representing the characteristics and energy consumption of 4.8 million commercial buildings and 67.9 billion square feet of commercial floorspace nationwide. Overall, the amount of commercial floorspace in the United States increased an average of 2.4 percent annually between 1989 and 1992, while the number of commercial buildings increased an average of 2.0 percent annually.

  18. 23. SOUTH PLANT MUSTARD FILLING BUILDING (BUILDING 728) AND WAREHOUSE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. SOUTH PLANT MUSTARD FILLING BUILDING (BUILDING 728) AND WAREHOUSE (BUILDING 729) FROM ROOF OF TON CONTAINER RECONDITIONING BUILDING, SHOWING FACILITIES MAINTENANCE BUILDING AT FOREGROUND AND BUILDING 741, 742 AND 743 AT CENTER BACKGROUND. VIEW TO SOUTHEAST. - Rocky Mountain Arsenal, Bounded by Ninety-sixth Avenue & Fifty-sixth Avenue, Buckley Road, Quebec Street & Colorado Highway 2, Commerce City, Adams County, CO

  19. South side. Building 520 is to the right. Building 516 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    South side. Building 520 is to the right. Building 516 is to the left. - Fitzsimons General Hospital, Physiotherapy & Electrocardiograph Department Building, North of Building No. 516, East of corridor connecting Building No. 511 to Building No. 515, Aurora, Adams County, CO

  20. A Seismic Isolation Application Using Rubber Bearings; Hangar Project in Turkey

    SciTech Connect

    Sesigur, Haluk; Cili, Feridun

    2008-07-08

    Seismic isolation is an effective design strategy to mitigate the seismic hazard wherein the structure and its contents are protected from the damaging effects of an earthquake. This paper presents the Hangar Project in Sabiha Goekcen Airport which is located in Istanbul, Turkey. Seismic isolation system where the isolation layer arranged at the top of the columns is selected. The seismic hazard analysis, superstructure design, isolator design and testing were based on the Uniform Building Code (1997) and met all requirements of the Turkish Earthquake Code (2007). The substructure which has the steel vertical trusses on facades and RC H shaped columns in the middle axis of the building was designed with an R factor limited to 2.0 in accordance with Turkish Earthquake Code. In order to verify the effectiveness of the isolation system, nonlinear static and dynamic analyses are performed. The analysis revealed that isolated building has lower base shear (approximately 1/4) against the non-isolated structure.

  1. Thinking Ahead: Autonomic Buildings

    SciTech Connect

    Brambley, Michael R. )

    2002-08-31

    The time has come for the commercial buildings industries to reconsider the very nature of the systems installed in facilities today and to establish a vision for future buildings that differs from anything in the history of human shelter. Drivers for this examination include reductions in building operation staffs; uncertain costs and reliability of electric power; growing interest in energy-efficient and resource-conserving?green? and?high-performance? commercial buildings; and a dramatic increase in security concerns since the tragic events of September 11. This paper introduces a new paradigm? autonomic buildings? which parallels the concept of autonomic computing, introduced by IBM as a fundamental change in the way computer networks work. Modeled after the human nervous system,?autonomic systems? themselves take responsibility for a large portion of their own operation and even maintenance. For commercial buildings, autonomic systems could provide environments that afford occupants greater opportunity to focus on the things we do in buildings rather than on operation of the building itself, while achieving higher performance levels, increased security, and better use of energy and other natural resources. The author uses the human body and computer networking to introduce and illustrate this new paradigm for high-performance commercial buildings. He provides a vision for the future of commercial buildings based on autonomicity, identifies current research that could contribute to this future, and highlights research and technological gaps. The paper concludes with a set of issues and needs that are key to converting this idealized future into reality.

  2. Seismic isolation systems with distinct multiple frequencies

    DOEpatents

    Wu, Ting-shu (Downers Grove, IL); Seidensticker, Ralph W. (Wheaton, IL)

    1990-01-01

    A method and apparatus for isolating a building or other structure from smic vibratory motion which provides increased assurance that large horizontal motion of the structure will not occur than is provided by other isolation systems. Increased assurance that large horizontal motion will not occur is achieved by providing for change of the natural frequency of the support and structure system in response to displacement of the structure beyond a predetermined value. The natural frequency of the support and structure system may be achieved by providing for engaging and disengaging of the structure and some supporting members in response to motion of the supported structure.

  3. Seismic Behaviour of Vertical Mass Isolated Structures

    SciTech Connect

    Nekooei, M.; Ziyaeifar, M.

    2008-07-08

    In this paper, the seismic behaviour of vertical mass isolated structures against the earthquake is studied. These structures are assumed to be consisted of two subsystems. Mass subsystem possesses low lateral stiffness but carries the major part of mass of the system. Stiffness subsystem, however, controls the deformation of the mass subsystem and attributes with much higher stiffness. The isolator layer is, therefore, located in between the mass and the stiffness subsystems and assumed to be a viscous damper layer. The analytical model used for this investigation is a dual mass-spring model which is an extended form of the three element Maxwell model. In this study, the ability of mass isolation techniques in reducing earthquake effects on buildings with two approaches, parametric and numerical approaches, is shown. In the parametric approach, by definition an isolation factor for structure and determination the dynamic characteristics of system, the relative optimum value of the isolator damping coefficient is obtained. The results provide an insight on role of relative stiffness and mass ratio of the two subsystems. Finally, in the numerical approach, the spectral responses of these structures due to the earthquake are investigated. The results show a noticeable decrease in earthquake input force to vertical mass isolated structures in comparison with non-isolated structures.

  4. Atrium building study

    SciTech Connect

    Not Available

    1990-01-01

    The CIGNA design team was faced with creating a new 500,000 square foot office building on a pastoral 610 acre corporate campus in Bloomfield, Connecticut, just outside of Hartford. Challenges abounded during the design process, from the selection of a specific building site on the sprawling campus to the evolution of a building form incorporating an atrium, to the selection of building systems and materials, to the design to the office interiors and atrium landscape. This document summarizes the original design problem, focusing on design criteria and performance standards that led to the decision to design an atrium building as well as decision concerning its function, its form, its building systems and materials, and its passive energy strategies.

  5. The Building Design Advisor

    SciTech Connect

    Papamichael, K.; LaPorta, J.; Chauvet, H.; Collins, D.; Trzcinski, T.; Thorpe, J.; Selkowitz, S.

    1996-03-01

    The Building Design Advisor (BDA) is a software environment that supports the integrated use of multiple analysis and visualization tools throughout the building design process, from the initial, schematic design phases to the detailed specification of building components and systems. Based on a comprehensive design theory, the BDA uses an object-oriented representation of the building and its context, and acts as a data manager and process controller to allow building designers to quickly navigate through the multitude of descriptive and performance parameters addressed by the analysis and visualization tools linked to the BDA. Through the Browser the user can edit the values of input parameters and select any number of input and/or output parameters for display in the Decision Desktop. The Desktop allows building designers to compare multiple design alternatives with respect to any number of parameters addressed by the tools linked to the BDA.

  6. Short-Coupled Polymorphic Ventricular Tachycardia At Rest Linked to a Novel Ryanodine Receptor (RyR2) Mutation: Leaky RyR2 Channels Under Non-Stress Conditions

    PubMed Central

    Cheung, Jim W.; Meli, Albano C.; Xie, Wenjun; Mittal, Suneet; Reiken, Steven; Wronska, Anetta; Xu, Linna; Steinberg, Jonathan S.; Markowitz, Steven M.; Iwai, Sei; Lacampagne, Alain; Lerman, Bruce B.; Marks, Andrew R.

    2014-01-01

    Background Ryanodine receptor (RyR2) mutations have largely been associated with catecholaminergic polymorphic ventricular tachycardia (PMVT). The role of RyR2 mutations in the pathogenesis of arrhythmias and syncope at rest is unknown. We sought to characterize the clinical and functional characteristics associated with a novel RyR2 mutation found in a mother and daughter with PMVT at rest. Methods and Results A 31-year-old female with syncope at rest and recurrent short-coupled premature ventricular contractions (PVCs) initiating PMVT was found to be heterozygous for a novel RyR2-H29D mutation. Her mother, who also had syncope at rest and short-coupled PMVT, was found to harbor the same mutation. Human RyR2-H29D mutant channels were generated using site-directed mutagenesis and heterologously expressed in HEK293 cells together with the stabilizing protein calstabin2 (FKPB12.6). Single channel measurements of RyR2-H29D mutant channels and wild type (WT) RyR2 channels were compared at varying concentrations of cytosolic Ca2+. Binding affinities of the RyR2-H29D channels and RyR2-WT channels to calstabin2 were compared. Functional characterization of the RyR2-H29D mutant channel revealed significantly higher open probability and opening frequency at diastolic levels of cytosolic Ca2+ under non-stress conditions without protein kinase A treatment. This was associated with a modest depletion of calstabin2 binding under resting conditions. Conclusions The RyR2-H29D mutation is associated with a clinical phenotype of short-coupled PMVT at rest. In contrast to catecholaminergic PMVT-associated RyR2 mutations, RyR2-H29D causes a leaky channel at diastolic levels of Ca2+ under non-stress conditions. Leaky RyR2 may be an under-recognized mechanism for idiopathic PMVT at rest. PMID:25463374

  7. Electricity and buildings

    SciTech Connect

    Hughes, G.J.

    1984-01-01

    This book describes modern design procedures for the installation of electrical services in buildings. It is a guide rather than a textbook, aimed at professionals and specifiers engaged in the design, construction and maintenance of buildings. It is not written primarily for electrical engineers but for those of other disciplines, and students, to enable them to appreciate the part played by electricity in buildings and the need to make correct provision for electrical services.

  8. Mycotoxins in Crude Building Materials from Water-Damaged Buildings

    PubMed Central

    Tuomi, Tapani; Reijula, Kari; Johnsson, Tom; Hemminki, Kaisa; Hintikka, Eeva-Liisa; Lindroos, Outi; Kalso, Seija; Koukila-Khkl, Pirkko; Mussalo-Rauhamaa, Helena; Haahtela, Tari

    2000-01-01

    We analyzed 79 bulk samples of moldy interior finishes from Finnish buildings with moisture problems for 17 mycotoxins, as well as for fungi that could be isolated using one medium and one set of growth conditions. We found the aflatoxin precursor, sterigmatocystin, in 24% of the samples and trichothecenes in 19% of the samples. Trichothecenes found included satratoxin G or H in five samples; diacetoxyscirpenol in five samples; and 3-acetyl-deoxynivalenol, deoxynivalenol, verrucarol, or T-2-tetraol in an additional five samples. Citrinine was found in three samples. Aspergillus versicolor was present in most sterigmatocystin-containing samples, and Stachybotrys spp. were present in the samples where satratoxins were found. In many cases, however, the presence of fungi thought to produce the mycotoxins was not correlated with the presence of the expected compounds. However, when mycotoxins were found, some toxigenic fungi usually were present, even if the species originally responsible for producing the mycotoxin was not isolated. We conclude that the identification and enumeration of fungal species present in bulk materials are important to verify the severity of mold damage but that chemical analyses are necessary if the goal is to establish the presence of mycotoxins in moldy materials. PMID:10788357

  9. Building Energy Consumption Analysis

    SciTech Connect

    2005-03-02

    DOE2.1E-121SUNOS is a set of modules for energy analysis in buildings. Modules are included to calculate the heating and cooling loads for each space in a building for each hour of a year (LOADS), to simulate the operation and response of the equipment and systems that control temperature and humidity and distribute heating, cooling and ventilation to the building (SYSTEMS), to model energy conversion equipment that uses fuel or electricity to provide the required heating, cooling and electricity (PLANT), and to compute the cost of energy and building operation based on utility rate schedule and economic parameters (ECONOMICS).

  10. Building Energy Consumption Analysis

    Energy Science and Technology Software Center (ESTSC)

    2005-03-02

    DOE2.1E-121SUNOS is a set of modules for energy analysis in buildings. Modules are included to calculate the heating and cooling loads for each space in a building for each hour of a year (LOADS), to simulate the operation and response of the equipment and systems that control temperature and humidity and distribute heating, cooling and ventilation to the building (SYSTEMS), to model energy conversion equipment that uses fuel or electricity to provide the required heating,more » cooling and electricity (PLANT), and to compute the cost of energy and building operation based on utility rate schedule and economic parameters (ECONOMICS).« less

  11. Analog signal isolation techniques

    SciTech Connect

    Beadle, E.R.

    1992-01-01

    This paper discusses several techniques for isolating analog signals in an accelerator environment. The techniques presented here encompass isolation amplifiers, voltage-to-frequency converters (VIFCs), transformers, optocouplers, discrete fiber optics, and commercial fiber optic links. Included within the presentation of each method are the design issues that must be considered when selecting the isolation method for a specific application.

  12. Analog signal isolation techniques

    SciTech Connect

    Beadle, E.R.

    1992-12-31

    This paper discusses several techniques for isolating analog signals in an accelerator environment. The techniques presented here encompass isolation amplifiers, voltage-to-frequency converters (VIFCs), transformers, optocouplers, discrete fiber optics, and commercial fiber optic links. Included within the presentation of each method are the design issues that must be considered when selecting the isolation method for a specific application.

  13. Isolated rat hepatocyte couplets: a primary secretory unit for electrophysiologic studies of bile secretory function.

    PubMed Central

    Graf, J; Gautam, A; Boyer, J L

    1984-01-01

    Hepatocyte couplets were isolated by collagenase perfusion from rat liver. Between adjacent cells, the bile canaliculus forms a closed space into which secretion occurs. As in intact liver, Mg2+-ATPase is localized at the canalicular lumen, the organic anion fluorescein is excreted, and secretion is modified by osmotic gradients. By passing a microelectrode through one cell into the canalicular vacuole, a transepithelial potential profile was obtained. In 27 cell couplets the steady-state intracellular (-26.3 +/- 5.3 mV) and intracanalicular (-5.9 +/- 3.3 mV) potentials were recorded at 37 degrees C with reference to the external medium. Input resistances were determined within the cell (86 +/- 23 M omega) and in the bile canalicular lumen (32 +/- 17 M omega) by passing current pulses through the microelectrode. These data define electrical driving forces for ion transport across the sinusoidal, canalicular, and paracellular barriers and indicate ion permeation across a leaky paracellular junctional pathway. These findings indicate that the isolated hepatocyte couplet is an effective model for electrophysiologic studies of bile secretory function. Images PMID:6149546

  14. Isolated Rat Hepatocyte Couplets: A Primary Secretory Unit for Electrophysiologic Studies of Bile Secretory Function

    NASA Astrophysics Data System (ADS)

    Graf, J.; Gautam, A.; Boyer, J. L.

    1984-10-01

    Hepatocyte couplets were isolated by collagenase perfusion from rat liver. Between adjacent cells, the bile canaliculus forma a closed space into which secretion occurs. As in intact liver, Mg2+-ATPase is localized at the canalicular lumen, the organic anion fluorescein is excreted, and secretion is modified by osmotic gradients. By passing a microelectrode through one cell into the canalicular vacuole, a transepithelial potential profile was obtained. In 27 cell couplets the steady-state intracellular (-26.3 5.3 mV) and intracanalicular (-5.9 3.3 mV) potentials were recorded at 37 degrees C with reference to the external medium. Input resistances were determined within the cell (86 23 M? ) and in the bile canalicular lumen (32 17 M? ) by passing current pulses through the microelectrode. These data define electrical driving forces for ion transport across the sinusoidal, canalicular, and paracellular barriers and indicate ion permeation across a leaky paracellular junctional pathway. These findings indicate that the isolated hepatocyte couplet is an effective model for electrophysiologic studies of bile secretory function.

  15. Building Maintenance Syllabus.

    ERIC Educational Resources Information Center

    Fischer, Joseph; Messier, Joseph

    Building maintenance is a basic two-year trade education course requiring 2 1/2 hours of study on each of 160 teaching days per year. Student abilities should range from those capable of the simplest custodial work to those who may eventually be superintendents of building complexes. The syllabus is organized in sections by traditional skills…

  16. Reusing Old Manufacturing Buildings

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2014-01-01

    This article presents an interesting design challenge for students, one that will certainly let them integrate subject matter and get a sense of pride for doing something useful in their own community. The author would be willing to bet that the average town or city has some old red brick manufacturing building(s) that have seen much better days.…

  17. Classification of Building Areas.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC. Building Research Advisory Board.

    A study was undertaken to evaluate existing methods of categorizing areas in buildings for pertinency to the requirements of federal agencies. The concern was primarily with defining classes of area within buildings, rather than allowances per individual, per machine, or other unit. Recommendations include--(1) adoption of a standard set of

  18. New Medical Library Buildings

    PubMed Central

    Robinow, Beatrix H.

    1972-01-01

    The library occupies parts of two floors of the new Health Sciences Centre building and includes the Multimedia Learning Resources. Design and description of the library and of the teaching system as it affects the library are given and also some description of the building as a whole. Images PMID:5084347

  19. Survey of Solar Buildings.

    ERIC Educational Resources Information Center

    Gray, Robert; Baker, Steven

    This survey brings together information concerning the growing number of buildings utilizing solar energy and is designed to facilitate the comparison of specific characteristics of the buildings. The 66 U.S. entries are divided into five regions, arranged by state, and roughly by date within each state. Seven entries are from other countries. A

  20. Community Capacity Building.

    ERIC Educational Resources Information Center

    McGinty, Sue

    As community assets, schools are central to community development and are best suited to provide a learning community that can build the whole community's capacity to address educational disadvantage. Community capacity building means strengthening a community's ability to become self-reliant by increasing social cohesion and social capital. In

  1. Building Global Learning Communities

    ERIC Educational Resources Information Center

    Cochrane, Thomas; Buchem, Ilona; Camacho, Mar; Cronin, Catherine; Gordon, Averill; Keegan, Helen

    2013-01-01

    Within the background where education is increasingly driven by the economies of scale and research funding, we propose an alternative online open and connected framework (OOC) for building global learning communities using mobile social media. We critique a three year action research case study involving building collaborative global learning…

  2. LARGE BUILDING RADON MANUAL

    EPA Science Inventory

    The report summarizes information on how bilding systems -- especially the heating, ventilating, and air-conditioning (HVAC) system -- inclurence radon entry into large buildings and can be used to mitigate radon problems. It addresses the fundamentals of large building HVAC syst...

  3. Facility Focus: Science Buildings.

    ERIC Educational Resources Information Center

    College Planning & Management, 1998

    1998-01-01

    Provides an overview of five custom designs used in university science buildings. Descriptions include renovation to a mechanical engineering lab, construction of a new building for molecular biology, the reconstruction of chemistry labs, the renovation of a vision lab, and a new research and education facility. Includes photos. (RJM)

  4. Building a Better Robot

    ERIC Educational Resources Information Center

    Navah, Jan

    2012-01-01

    Kids love to build robots, letting their imaginations run wild with thoughts of what they might look like and what they could be programmed to do. Yet when students use cereal boxes and found objects to make robots, often the projects look too similar and tend to fall apart. This alternative allows students to "build" robots in a different way,…

  5. Building a Better Robot

    ERIC Educational Resources Information Center

    Navah, Jan

    2012-01-01

    Kids love to build robots, letting their imaginations run wild with thoughts of what they might look like and what they could be programmed to do. Yet when students use cereal boxes and found objects to make robots, often the projects look too similar and tend to fall apart. This alternative allows students to "build" robots in a different way,

  6. Building a Data Warehouse.

    ERIC Educational Resources Information Center

    Levine, Elliott

    2002-01-01

    Describes how to build a data warehouse, using the Schools Interoperability Framework (www.sifinfo.org), that supports data-driven decision making and complies with the Freedom of Information Act. Provides several suggestions for building and maintaining a data warehouse. (PKP)

  7. Reusing Old Manufacturing Buildings

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2014-01-01

    This article presents an interesting design challenge for students, one that will certainly let them integrate subject matter and get a sense of pride for doing something useful in their own community. The author would be willing to bet that the average town or city has some old red brick manufacturing building(s) that have seen much better days.

  8. Building Global Learning Communities

    ERIC Educational Resources Information Center

    Cochrane, Thomas; Buchem, Ilona; Camacho, Mar; Cronin, Catherine; Gordon, Averill; Keegan, Helen

    2013-01-01

    Within the background where education is increasingly driven by the economies of scale and research funding, we propose an alternative online open and connected framework (OOC) for building global learning communities using mobile social media. We critique a three year action research case study involving building collaborative global learning

  9. Building Numbers from Primes

    ERIC Educational Resources Information Center

    Burkhart, Jerry

    2009-01-01

    Prime numbers are often described as the "building blocks" of natural numbers. This article shows how the author and his students took this idea literally by using prime factorizations to build numbers with blocks. In this activity, students explore many concepts of number theory, including the relationship between greatest common factors and

  10. Build a Solar Greenhouse.

    ERIC Educational Resources Information Center

    Conservation and Renewable Energy Inquiry and Referral Service (DOE), Silver Spring, MD.

    Attached solar greenhouses are relatively inexpensive and easy to build; they can provide additional heat to homes all winter as well as fresh vegetables and flowers. This bulletin: (1) describes the characteristics of a solar greenhouse; (2) provides a checklist of five items to consider before building a solar greenhouse; (3) describes the four…

  11. The sick building syndrome

    PubMed Central

    Joshi, Sumedha M.

    2008-01-01

    The sick building syndrome comprises of various nonspecific symptoms that occur in the occupants of a building. This feeling of ill health increases sickness absenteeism and causes a decrease in productivity of the workers. As this syndrome is increasingly becoming a major occupational hazard, the cause, management and prevention of this condition have been discussed in this article. PMID:20040980

  12. Building Numbers from Primes

    ERIC Educational Resources Information Center

    Burkhart, Jerry

    2009-01-01

    Prime numbers are often described as the "building blocks" of natural numbers. This article shows how the author and his students took this idea literally by using prime factorizations to build numbers with blocks. In this activity, students explore many concepts of number theory, including the relationship between greatest common factors and…

  13. Survey of Solar Buildings.

    ERIC Educational Resources Information Center

    Gray, Robert; Baker, Steven

    This survey brings together information concerning the growing number of buildings utilizing solar energy and is designed to facilitate the comparison of specific characteristics of the buildings. The 66 U.S. entries are divided into five regions, arranged by state, and roughly by date within each state. Seven entries are from other countries. A…

  14. Improvement of Velocity Measurement Accuracy of Leaky Surface Acoustic Waves for Materials with Highly Attenuated Waveform of the V(z) curve by the Line-Focus-Beam Ultrasonic Material Characterization System

    NASA Astrophysics Data System (ADS)

    Ohashi, Yuji; Arakawa, Mototaka; Kushibiki, Jun?ichi

    2006-05-01

    Measurement accuracies of leaky surface acoustic wave (LSAW) velocities for materials with highly attenuated waveforms of V(z) curves obtained by the line-focus-beam ultrasonic material characterization (LFB-UMC) system are investigated. Theoretical investigations were carried out and experiments were performed for TiO2-SiO2 glass (C-7972), Li2O-Al2O3-SiO2 glass ceramic (Zerodur\\textregistered), and (111) gadolinium gallium garnet (GGG) single crystal as specimens. Waveform attenuations of V(z) curves for C-7972 and Zerodur\\textregistered are greater than those for the (111) GGG single crystal. Frequency dependences of the waveform attenuations were calculated for each specimen by considering the propagation attenuation of LSAWs. The theoretical results revealed that the waveform attenuation dominantly depends upon the acoustic energy loss due to the water loading effect on the specimen surface, and that the waveform attenuation becomes smaller with decreasing frequency. Significant improvement of the measurement precision of LSAW velocities was demonstrated for each specimen using three LFB ultrasonic devices with different curvature radii R of the cylindrical acoustic lenses: R=2.0 mm at 75 MHz, R=1.5 mm at 110 MHz, and R=1.0 mm at 225 MHz; for C-7972, the precisions were improved from 0.0053% at 225 MHz to 0.0020% at 75 MHz.

  15. Leaky mode suppression in planar optical waveguides written in Er:TeO2-WO3 glass and CaF2 crystal via double energy implantation with MeV N+ ions

    NASA Astrophysics Data System (ADS)

    Bnysz, I.; Zolnai, Z.; Fried, M.; Berneschi, S.; Pelli, S.; Nunzi-Conti, G.

    2014-05-01

    Ion implantation proved to be an universal technique for producing waveguides in most optical materials. Tellurite glasses are good hosts of rare-earth elements for the development of fibre and integrated optical amplifiers and lasers covering all the main telecommunication bands. Er3+-doped tellurite glasses are good candidates for the fabrication of broadband amplifiers in wavelength division multiplexing around 1.55 ?m, as they exhibit large stimulated cross sections and broad emission bandwidth. Calcium fluoride is an excellent optical material, due to its perfect optical characteristics from UV wavelengths up to near IR. It has become a promising laser host material (doped with rare earth elements). Ion implantation was also applied to optical waveguide fabrication in CaF2 and other halide crystals. In the present work first single-energy implantations at 3.5 MeV at various fluences were applied. Waveguide operation up to 1.5 ?m was observed in Er:Te glass, and up to 980 nm in CaF2. Then double-energy implantations at a fixed upper energy of 3.5 MeV and lower energies between 2.5 and 3.2 MeV were performed to suppress leaky modes by increasing barrier width.

  16. VIEW LOOKING SOUTHWEST AT BUILDING 121, THE PLANT SECURITY BUILDING. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW LOOKING SOUTHWEST AT BUILDING 121, THE PLANT SECURITY BUILDING. BUILDING 121 WAS ONE OF THE ORIGINAL STRUCTURES AT THE ROCKY FLATS PLANT. IT SHARES A COMMON WALL WITH BUILDING 122, THE EMERGENCY MEDICAL BUILDING. (7/29/52) - Rocky Flats Plant, Security & Armory, West of Third Street, south of Central Avenue, Golden, Jefferson County, CO

  17. GENERAL VIEW OF FLIGHT LINE SUPPORT BUILDINGS (ELECTRICAL SUBSTATION, BUILDING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GENERAL VIEW OF FLIGHT LINE SUPPORT BUILDINGS (ELECTRICAL SUBSTATION, BUILDING 2775; SURVIVAL EQUIPMENT SHOP (PARACHUTE AND DINGY SHOP), BUILDING 2784; MAINTENANCE DOCK (BUILDING 2785) AND BUILDING 2783 WAR). VIEW TO SOUTHWEST - Plattsburgh Air Force Base, U.S. Route 9, Plattsburgh, Clinton County, NY

  18. NREL Buildings Research Video

    SciTech Connect

    2009-01-01

    Through research, the National Renewable Energy Laboratory (NREL) has developed many strategies and design techniques to ensure both commercial and residential buildings use as little energy as possible and also work well with the surroundings. Here you will find a video that introduces the work of NREL Buildings Research, highlights some of the facilities on the NREL campus, and demonstrates these efficient building strategies. Watch this video to see design highlights of the Science and Technology Facility on the NREL campusthe first Federal building to be LEED Platinum certified. Additionally, the video demonstrates the energy-saving features of NRELs Thermal Test Facility. For a text version of this video visit http://www.nrel.gov/buildings/about_research_text_version.html

  19. NREL Buildings Research Video

    ScienceCinema

    None

    2013-05-29

    Through research, the National Renewable Energy Laboratory (NREL) has developed many strategies and design techniques to ensure both commercial and residential buildings use as little energy as possible and also work well with the surroundings. Here you will find a video that introduces the work of NREL Buildings Research, highlights some of the facilities on the NREL campus, and demonstrates these efficient building strategies. Watch this video to see design highlights of the Science and Technology Facility on the NREL campus?the first Federal building to be LEED® Platinum certified. Additionally, the video demonstrates the energy-saving features of NRELs Thermal Test Facility. For a text version of this video visit http://www.nrel.gov/buildings/about_research_text_version.html

  20. [The sick building syndrome].

    PubMed

    Seifert, B

    1991-01-01

    The term "sick building syndrome" (SBS) has been used for several years to describe a number of mostly unspecific complaints of some occupants of air-conditioned buildings. Based on the literature, a definition of the SBS is given and some results of larger SBS studies carried out in Germany, Denmark and the United Kingdom are described. These studies show that SBS is a multifactorial event which may include physical, chemical, biological as well as psychological factors. In many cases, the occurrence of SBS in a building is due to insufficient maintenance of the HVAC system. SBS-induced investigations in a building should be carried out stepwise, the measurement of indoor air pollutants not being the first step. Strategies to avoid SBS must take into account factors specific to the building, the HVAC system and the equipment as well as psychological factors. PMID:1837855

  1. Comparison of seismic response of ordinary and base-isolated structures

    SciTech Connect

    Kuroda, T.; Kobatake, M.; Seidensticker, R.W.; Chang, Y.W.

    1992-04-01

    Seismic isolation is growing rapidly worldwide as a cost-effective and reliable design strategy for a wide range of critical and important facilities (e.g., hospitals, computer centers, etc.) Shimizu Corporation of Japan has a test facility at Tohoku University in Sendai, Japan. The test facility was constructed in 1986 and has two buildings: one is base isolated and the other is conventionally founded. The buildings are full-size, three-story reinforced concrete structures. The dimensions and construction of the superstructures are identical. For the past several years, Shimizu Corporation has installed a number of different isolation systems in the isolated building at the test facility to study the response of base isolation systems to actual earthquake motions. Argonne National Laboratory (ANL) has been deeply involved in the development of seismic isolation for use in nuclear facilities for the past decade. Using the funding and direction of the US Department of Energy (USDOE), ANL has been developing methodology needed to evaluate the usefulness and effectiveness of seismic isolation for advanced liquid metal-cooled reactors (LMRs). This paper compares the seismic responses of ordinary and base-isolated buildings. Earthquake records of significant importance from April 1989 to September 1991, after the installation of bearings have been analyzed. Numerical simulations of the building responses have been performed and correlated with earthquake observation data. It is hoped that the results of this study will provide guidelines for the future use of isolator bearings for mitigation of earthquake damages.

  2. Comparison of seismic response of ordinary and base-isolated structures

    SciTech Connect

    Kuroda, T.; Kobatake, M. ); Seidensticker, R.W.; Chang, Y.W. )

    1992-01-01

    Seismic isolation is growing rapidly worldwide as a cost-effective and reliable design strategy for a wide range of critical and important facilities (e.g., hospitals, computer centers, etc.) Shimizu Corporation of Japan has a test facility at Tohoku University in Sendai, Japan. The test facility was constructed in 1986 and has two buildings: one is base isolated and the other is conventionally founded. The buildings are full-size, three-story reinforced concrete structures. The dimensions and construction of the superstructures are identical. For the past several years, Shimizu Corporation has installed a number of different isolation systems in the isolated building at the test facility to study the response of base isolation systems to actual earthquake motions. Argonne National Laboratory (ANL) has been deeply involved in the development of seismic isolation for use in nuclear facilities for the past decade. Using the funding and direction of the US Department of Energy (USDOE), ANL has been developing methodology needed to evaluate the usefulness and effectiveness of seismic isolation for advanced liquid metal-cooled reactors (LMRs). This paper compares the seismic responses of ordinary and base-isolated buildings. Earthquake records of significant importance from April 1989 to September 1991, after the installation of bearings have been analyzed. Numerical simulations of the building responses have been performed and correlated with earthquake observation data. It is hoped that the results of this study will provide guidelines for the future use of isolator bearings for mitigation of earthquake damages.

  3. 31. SITE BUILDING 002 SCANNER BUILDING AT INTERIOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. SITE BUILDING 002 - SCANNER BUILDING AT INTERIOR - BACK OF POWER SUPPLY UNITS 3045-17 AND 3046-29. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  4. Building 909, oblique view to southeast, 135 mm lens. Building ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Building 909, oblique view to southeast, 135 mm lens. Building 908 at extreme right for context. - Travis Air Force Base, Handling Crew Building, North of W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

  5. 24. SITE BUILDING 002 SCANNER BUILDING OPERATIONS CENTER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. SITE BUILDING 002 - SCANNER BUILDING - OPERATIONS CENTER -- MWOC IN OPEARATION AT 1924 ZULU TIME. 26 OCTOBER, 1999. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  6. Interior building details of Building A, dungeon cell adjacent to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior building details of Building A, dungeon cell adjacent to northwest cell: granite and brick threshold, poured concrete floors, plastered finished walls, vaulted veiling; northwesterly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA

  7. 7. Building 7 interior, west end of building showing tier ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Building 7 interior, west end of building showing tier of skylight windows and modern equipment. View looking west. - John & James Dobson Carpet Mill (West Parcel), Building No. 7, 4041-4055 Ridge Avenue, Philadelphia, Philadelphia County, PA

  8. 23. SITE BUILDING 002 SCANNER BUILDING RADAR CONTROL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. SITE BUILDING 002 - SCANNER BUILDING - RADAR CONTROL INTERFACE "RCL NO. 2" WITH COMPUTER CONTROL DISC DRIVE UNITS IN FOREGROUND. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  9. Exterior building details of Building B, east faade: ca. 1914 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Exterior building details of Building B, east faade: ca. 1914 covered porch with an asphalt singled low-hipped roof; southwesterly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA

  10. 6. BUILDING 1006 NORTH SIDE (LEFT) AND BUILDING 1049 EAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. BUILDING 1006 NORTH SIDE (LEFT) AND BUILDING 1049 EAST SIDE (RIGHT). - Presidio of San Francisco, Letterman General Hospital, Building No. 27, Letterman Hospital Complex, Edie Road, San Francisco, San Francisco County, CA

  11. 4. NORTHWEST SIDE LOOKING EAST, ADMINISTRATION BUILDING AND HEADQUARTERS BUILDING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. NORTHWEST SIDE LOOKING EAST, ADMINISTRATION BUILDING AND HEADQUARTERS BUILDING TO LEFT - Santa Fe Land Improvement Company, Office Building, 16915 Avenida de Acacias, Rancho Santa Fe, San Diego County, CA

  12. 11. SITE BUILDING 002 SCANNER BUILDING EVAPORATIVE COOLING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. SITE BUILDING 002 - SCANNER BUILDING - EVAPORATIVE COOLING TOWER SYSTEM IN FOREGROUND. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  13. Elevation of pier building and main house looking south. Building ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Elevation of pier building and main house looking south. Building at far right was fish smokehouse. Roof of building at right was used for drying fish. - Beacon Marine Basin, 211 East Main Street, Gloucester, Essex County, MA

  14. Interior building details of Building A, dungeon central hallway: poured ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior building details of Building A, dungeon central hallway: poured concrete floors, plaster-finished brick walls, vaulted ceiling, arch entryway to cells; southerly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA

  15. Interior building details of Building A, dungeon northwest cell: poured ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior building details of Building A, dungeon northwest cell: poured concrete floors, plastered finished walls, exposed brick wall, vaulted veiling; westerly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA

  16. 19. BUILDINGS 243247. PRIMER DRYHOUSES. BUILDING LAYOUT. February 16, 1917 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. BUILDINGS 243-247. PRIMER DRYHOUSES. BUILDING LAYOUT. February 16, 1917 - Frankford Arsenal, Building Nos. 242-246A, South side Craig Road between Eakin & Walbach Streets, Philadelphia, Philadelphia County, PA

  17. VIEW ALONG SERVICE AREA, WITH SQUADRON OPERATIONS BUILDING (BUILDING 2841) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW ALONG SERVICE AREA, WITH SQUADRON OPERATIONS BUILDING (BUILDING 2841) IN RIGHT FOREGROUND AND AIRCRAFT MAINTENANCE DOCK (BUILDING 2837) IN BACKGROUND. VIEW TO NORTHWEST - Plattsburgh Air Force Base, U.S. Route 9, Plattsburgh, Clinton County, NY

  18. 8. BUILDING No. 5 SOUTH SIDE (LEFT); BUILDING No. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. BUILDING No. 5 - SOUTH SIDE (LEFT); BUILDING No. 13 - WEST AND SOUTH SIDES (CENTER); BUILDING No. 6 - WEST SIDE (RIGHT), VIEW TO THE EAST - Whiting-Plover Paper Mill, 3243 Whiting Road, Whiting, Portage County, WI

  19. Smokestack with incinerator building (building 616) to right and unnumbered ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Smokestack with incinerator building (building 616) to right and unnumbered building to right - Fitzsimons General Hospital, Incinerator Smokestack, 560 feet east-northeast of intersection of East Bushnell Avenue, & South Van Valzah Street, Aurora, Adams County, CO

  20. 3. East side of Building 1001 (administration building), looking west ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. East side of Building 1001 (administration building), looking west - Naval Air Station Chase Field, Building 1001, Independence Street, .45 mile south of intersection of Texas State Highway & Independence Street, Beeville, Bee County, TX

  1. 9. Interior of Building 1001 (administration building), Room 204, vault, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Interior of Building 1001 (administration building), Room 204, vault, looking east - Naval Air Station Chase Field, Building 1001, Independence Street, .45 mile south of intersection of Texas State Highway & Independence Street, Beeville, Bee County, TX

  2. 6. West side of Building 1001 (administration building), looking southeast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. West side of Building 1001 (administration building), looking southeast - Naval Air Station Chase Field, Building 1001, Independence Street, .45 mile south of intersection of Texas State Highway & Independence Street, Beeville, Bee County, TX

  3. 4. South side of Building 1001 (administration building), looking north ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. South side of Building 1001 (administration building), looking north - Naval Air Station Chase Field, Building 1001, Independence Street, .45 mile south of intersection of Texas State Highway & Independence Street, Beeville, Bee County, TX

  4. 5. North side of Building 1001 (administration building), looking southeast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. North side of Building 1001 (administration building), looking southeast - Naval Air Station Chase Field, Building 1001, Independence Street, .45 mile south of intersection of Texas State Highway & Independence Street, Beeville, Bee County, TX

  5. Exterior building details of Building A; east faade: fixed fiveoverfive ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Exterior building details of Building A; east faade: fixed five-over-five wood windows with five-light hoppers with concrete sills; westerly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA

  6. Exterior building details of Building A; north faade: iron latticed ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Exterior building details of Building A; north faade: iron latticed gate dungeon entrance, granite base; southerly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA

  7. Exterior building details of Building A; north faade: fouroverfour doublehung ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Exterior building details of Building A; north faade: four-over-four double-hung wood sash window with concrete sill; southerly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA

  8. 8. VIEW NORTHWEST OF BUILDING 12 AND BUILDING 13 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW NORTHWEST OF BUILDING 12 AND BUILDING 13 - Naval Surface Warfare Center, Transonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

  9. 47. Overall view of building 156, Warhead Building on far ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    47. Overall view of building 156, Warhead Building on far right, and building 160, acid fueling station on far left, looking northeast - Nike Missile Battery MS-40, County Road No. 260, Farmington, Dakota County, MN

  10. 48. Overall view of building 156, Warhead Building on far ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    48. Overall view of building 156, Warhead Building on far right, and building 160, acid fueling station on far left, looking east - Nike Missile Battery MS-40, County Road No. 260, Farmington, Dakota County, MN

  11. 51. Overall view of building 156, Warhead Building on far ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    51. Overall view of building 156, Warhead Building on far left, acid fueling station and standby generator building on far right, looking northwest - Nike Missile Battery MS-40, County Road No. 260, Farmington, Dakota County, MN

  12. 49. Overall view of building 156, Warhead Building on far ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    49. Overall view of building 156, Warhead Building on far left, and building 160, acid fueling station on far right, looking west - Nike Missile Battery MS-40, County Road No. 260, Farmington, Dakota County, MN

  13. 9. FERTILIZER PLANT AND STORAGE BUILDINGS, LOOKING EAST FROM BUILDING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. FERTILIZER PLANT AND STORAGE BUILDINGS, LOOKING EAST FROM BUILDING 149; LIVESTOCK HOLDING BUILDINGS (HOG AND SHEEP HOTELS) OCCUPIED OPEN AREA IN FOREGROUND - Rath Packing Company, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

  14. Buildings Interoperability Landscape

    SciTech Connect

    Hardin, Dave; Stephan, Eric G.; Wang, Weimin; Corbin, Charles D.; Widergren, Steven E.

    2015-12-31

    Through its Building Technologies Office (BTO), the United States Department of Energy’s Office of Energy Efficiency and Renewable Energy (DOE-EERE) is sponsoring an effort to advance interoperability for the integration of intelligent buildings equipment and automation systems, understanding the importance of integration frameworks and product ecosystems to this cause. This is important to BTO’s mission to enhance energy efficiency and save energy for economic and environmental purposes. For connected buildings ecosystems of products and services from various manufacturers to flourish, the ICT aspects of the equipment need to integrate and operate simply and reliably. Within the concepts of interoperability lie the specification, development, and certification of equipment with standards-based interfaces that connect and work. Beyond this, a healthy community of stakeholders that contribute to and use interoperability work products must be developed. On May 1, 2014, the DOE convened a technical meeting to take stock of the current state of interoperability of connected equipment and systems in buildings. Several insights from that meeting helped facilitate a draft description of the landscape of interoperability for connected buildings, which focuses mainly on small and medium commercial buildings. This document revises the February 2015 landscape document to address reviewer comments, incorporate important insights from the Buildings Interoperability Vision technical meeting, and capture thoughts from that meeting about the topics to be addressed in a buildings interoperability vision. In particular, greater attention is paid to the state of information modeling in buildings and the great potential for near-term benefits in this area from progress and community alignment.

  15. Strontium, barium, and manganese metabolism in isolated presynaptic nerve terminals

    SciTech Connect

    Rasgado-Flores, H.; Sanchez-Armass, S.; Blaustein, M.P.; Nachshen, D.A.

    1987-06-01

    To gain insight into the mechanisms by which the divalent cations Sr, Ba, and Mn affect neurotransmitter release from presynaptic nerve terminals, the authors examined the sequestration of these cations, ion comparison to Ca, by mitochondrial and nonmitochondrial organelles and the extrusion of these cations from isolated nerve terminals. Sequestration was studied in synaptosomes made leaky to small ions by treatment with saponin; efflux was examined in intact synaptosomes that were preloaded with the divalent cations by incubation in depolarizing (K rich) media. The selectivity sequence for ATP-dependent mitochondrial uptake that they observed was Mn>>Ca>Sr>>Ba, whereas that for the SER was Ca greater than or equal to Mn>Sr>>Ba. When synaptosomes that were preloaded with divalent cations were incubated in Na- and Ca-free media, there was little efflux of /sup 45/Ca, /sup 133/Ba, /sup 85/Sr, or /sup 54/Mn. When the incubation was carried out in media containing Na without Ca, there was substantial stimulation of Ca and Sr efflux, but only slight stimulation of Ba or Mn efflux. In Na-free media, the addition of 1 mM Ca promoted the efflux of all four divalent cations, probably via Ca-divalent cation exchange. In summary, the sequestration and extrusion data suggest that, with equal loads, Mn will be buffered to the greatest extent, whereas Ba will be least well buffered. These results may help to explain why Mn has a very long-lasting effect on transmitter release, while the effect of Sr is much briefer.

  16. Building Informatics Environment

    SciTech Connect

    2008-06-02

    The Building Informatics Environment is a modeling environment based on the Modelica language. The environment allows users to create a computer model of a building and its energy systems with various time scales and physical resolutions. The environment can be used for rapid development of, e.g., demand controls algorithms, new HVAC system solutions and new operational strategies (controls, fault detection and diagnostics). Models for building energy and control systems are made available in the environment. The models can be used as provided, or they can be changed and/or linked with each other in order to model the effects that a particular user is interested in.

  17. INL Green Building Strategy

    SciTech Connect

    Jennifer Dalton

    2005-05-01

    Green buildings, also known as sustainable buildings, resource efficient buildings, and high performance buildings, are structures that minimize the impact on the environment by using less energy and water, reducing solid waste and pollutants, and limiting the depletion of natural resources. As Idaho National Laboratory (INL) becomes the nation’s premier nuclear energy research laboratory, the physical infrastructure will be established to help accomplish the mission. This infrastructure, particularly the buildings, should incorporate green design features in order to be environmentally responsible and reflect an image of progressiveness and innovation to the public and prospective employees. With this in mind, the recommendations described in this strategy are intended to form the INL foundation for green building standards. The recommendations in this strategy are broken down into three levels: Baseline Minimum, Leadership in Energy and Environmental Design (LEED)Certification, and Innovative. Baseline Minimum features should be included in all new occupied buildings no matter what the purpose or size. These features do not require significant research, design, or capital costs and yet they can reduce Operation and Maintenance (O&M) costs and produce more environmentally friendly buildings. LEED Certification features are more aggressive than the Baseline Minimums in that they require documentation, studies, and/or additional funding. Combined with the Baseline Minimums, many of the features in this level will need to be implemented to achieve the goal of LEED certification. LEED Silver certification should be the minimum goal for all new buildings (including office buildings, laboratories, cafeterias, and visitor centers) greater than 25,000 square feet or a total cost of $10 million. Innovative features can also contribute to LEED certification, but are less mainstream than those listed in the previous two levels. These features are identified as areas where INL can demonstrate leadership but they could require significant upfront cost, additional studies, and/or development. Appendix A includes a checklist summary of the INL Green Building Strategy that can be used as a tool during the design process when considering which green building features to include. It provides a quick reference for determining which strategies have lower or no increased capital cost, yield lower O&M costs, increase employee productivity, and contribute to LEED certification.

  18. Reduced aerobic capacity causes leaky ryanodine receptors that trigger arrhythmia in a rat strain artificially selected and bred for low aerobic running capacity

    PubMed Central

    Hydal, MA; Stlen, TO; Johnsen, AB; Alvez, M; Catalucci, D; Condorelli, G; Koch, LG; Britton, SL; Smith, GL; Wislff, U

    2014-01-01

    Aim Rats selectively bred for inborn Low Capacity of Running (LCR) display a series of poor health indices where as rats selected for High Capacity of Running (HCR) display a healthy profile. We hypothesized that selection of low aerobic capacity over generations leads to a phenotype with increased diastolic Ca2+ leak that trigger arrhythmia. Methods We used rats selected for HCR (N=10) or LCR (N=10) to determine the effect of inborn aerobic capacity on Ca2+ leak and susceptibility of ventricular arrhythmia. We studied isolated FURA2/AM loaded cardiomyocytes to detect Ca2+-handling and function on an inverted epi-fluorescence microscope. To determine arrhythmogenicity we did a final experiment with electrical burst pacing in Langendorff perfused hearts. Results Ca2+-handling was impaired by reduced Ca2+ amplitude, prolonged time to 50% Ca2+ decay, and reduced sarcoplasmic reticulum (SR) Ca2+-content. Impaired Ca2+ removal was influenced by reduced SR Ca2+ ATP-ase 2a (SERCA2a) function and increased sodium/Ca2+-exchanger (NCX) in LCR rats. Diastolic Ca2 leak was 87% higher in LCR rats. The leak was reduced by CaMKII inhibition. Expression levels of phosphorylated theorine-286 CaMKII levels and increased RyR2 phosphorylation at the Serine-2814 site mechanistically support our findings of increased leak in LCR. LCR rats had significantly higher incidence of ventricular fibrillation. Conclusion Selection of inborn low aerobic capacity over generations leads to a phenotype with increased risk of ventricular fibrillation. Increased phosphorylation of CaMKII at serine-2814 at the cardiac ryanodine receptor appears as an important mechanism of impaired Ca2+ handling and diastolic Ca2+ leak that results in increased susceptibility to ventricular fibrillation. PMID:24444142

  19. Building Technologies Program Key Activities

    SciTech Connect

    2011-12-15

    The Building Technologies Program (BTP) employs a balanced approach to making buildings more energy efficient. The three pillars of our program, research and development (R&D), market stimulation, and building and equipment standards, help meet our strategic vision.

  20. The Building Blocks of Geology.

    ERIC Educational Resources Information Center

    Gibson, Betty O.

    2001-01-01

    Discusses teaching techniques for teaching about rocks, minerals, and the differences between them. Presents a model-building activity that uses plastic building blocks to build crystal and rock models. (YDS)

  1. Overview of Commercial Buildings, 2003

    EIA Publications

    2008-01-01

    The Energy Information Administration conducts the Commercial Buildings Energy Consumption Survey (CBECS) to collect information on energy-related building characteristics and types and amounts of energy consumed in commercial buildings in the United States.

  2. Buildings Sector Analysis

    SciTech Connect

    Hostick, Donna J.; Nicholls, Andrew K.; McDonald, Sean C.; Hollomon, Jonathan B.

    2005-08-01

    A joint NREL, ORNL, and PNNL team conducted market analysis to help inform DOE/EERE's Weatherization and Intergovernmental Program planning and management decisions. This chapter presents the results of the market analysis for the Buildings sector.

  3. Building Energy Consumption Analysis

    Energy Science and Technology Software Center (ESTSC)

    2005-01-24

    DOE2.1E-121 is a set of modules for energy analysis in buildings. Modules are included to calculate the heating and cooling loads for each space in a building for each hour of a year (LOADS), to simulate the operation and response of the equipment and systems that control temperature and humidity and distribute heating, cooling and ventilation to the building (SYSTEMS), to model energy conversion equipment that uses fuel or electricity to provide the required heating,more » cooling and electricity (PLANT), and to compute the cost of energy and building operation based on utility rate schedule and economic parameters (ECONOMICS). DOE2.1E-121 contains modifications to DOE2.1E which allows 1000 zones to be modeled.« less

  4. Building for the future

    PubMed Central

    2013-01-01

    As the staff of the MRC Laboratory of Molecular Biology settle into their new building in Cambridge, its director Hugh Pelham explains the challenges of living up to its prestigious past. PMID:23741620

  5. Car Crushed Under Building

    USGS Multimedia Gallery

    An automobile lies crushed under the third story of this apartment building in the Marina District. The ground levels are no longer visible because of structural failure and sinking due to liquefaction....

  6. Building a Planetarium.

    ERIC Educational Resources Information Center

    Page, Scott M.

    1999-01-01

    School budgets dictate what can and cannot be done in science. Article offers an inexpensive, modified design to build a planetarium. The planetarium provides hands-on experience in plotting and mapping constellations. (CCM)

  7. Building Energy Consumption Analysis

    SciTech Connect

    2005-01-24

    DOE2.1E-121 is a set of modules for energy analysis in buildings. Modules are included to calculate the heating and cooling loads for each space in a building for each hour of a year (LOADS), to simulate the operation and response of the equipment and systems that control temperature and humidity and distribute heating, cooling and ventilation to the building (SYSTEMS), to model energy conversion equipment that uses fuel or electricity to provide the required heating, cooling and electricity (PLANT), and to compute the cost of energy and building operation based on utility rate schedule and economic parameters (ECONOMICS). DOE2.1E-121 contains modifications to DOE2.1E which allows 1000 zones to be modeled.

  8. Building technology roadmaps

    SciTech Connect

    1999-01-27

    DOE's Office of Building Technology, State and Community Programs (BTS) is facilitating an industry-led initiative to develop a series of technology roadmaps that identify key goals and strategies for different areas of the building and equipment industry. This roadmapping initiative is a fundamental component of the BTS strategic plan and will help to align government resources with the high-priority needs identified by industry.

  9. Mutation and premating isolation

    NASA Technical Reports Server (NTRS)

    Woodruff, R. C.; Thompson, J. N. Jr

    2002-01-01

    While premating isolation might be traceable to different genetic mechanisms in different species, evidence supports the idea that as few as one or two genes may often be sufficient to initiate isolation. Thus, new mutation can theoretically play a key role in the process. But it has long been thought that a new isolation mutation would fail, because there would be no other individuals for the isolation-mutation-carrier to mate with. We now realize that premeiotic mutations are very common and will yield a cluster of progeny carrying the same new mutant allele. In this paper, we discuss the evidence for genetically simple premating isolation barriers and the role that clusters of an isolation mutation may play in initiating allopatric, and even sympatric, species divisions.

  10. Module isolation devices

    SciTech Connect

    Carolan, Michael Francis; Cooke, John Albert; Buzinski, Michael David

    2010-04-27

    A gas flow isolation device includes a gas flow isolation valve movable from an opened condition to a closed condition. The module isolation valve in one embodiment includes a rupture disk in flow communication with a flow of gas when the module isolation valve is in an opened condition. The rupture disk ruptures when a predetermined pressure differential occurs across it causing the isolation valve to close. In one embodiment the valve is mechanically linked to the rupture disk to maintain the valve in an opened condition when the rupture disk is intact, and which permits the valve to move into a closed condition when the rupture disk ruptures. In another embodiment a crushable member maintains the valve in an open condition, and the flow of gas passed the valve upon rupturing of the rupture disk compresses the crushable member to close the isolation valve.

  11. Vibration isolation technology experiment

    NASA Technical Reports Server (NTRS)

    Keckler, C. R.

    1984-01-01

    The objectives of the vibration isolation technology experiment are to demonstrate the viability of the magnetic suspension technology in providing the isolation of large structures elements from the external environment and to quantify the degree of isolation provided by this system. The approach proposed for this experiment is to mount a six-degrees-of-freedom magnetic bearing suspension system at the free end of a shuttle-attached flexible structure such as MAST. The disturbance generator, located on top of the isolation system, will be energized at selected and broadband frequencies to simulate a typical spacecraft vibration environment. Sensors located on the isolation system and the flexible structures element will be used to quantify the degree of isolation provided by this system.

  12. High Performance Buildings Database

    DOE Data Explorer

    The High Performance Buildings Database is a shared resource for the building industry, a unique central repository of in-depth information and data on high-performance, green building projects across the United States and abroad. The database includes information on the energy use, environmental performance, design process, finances, and other aspects of each project. Members of the design and construction teams are listed, as are sources for additional information. In total, up to twelve screens of detailed information are provided for each project profile. Projects range in size from small single-family homes or tenant fit-outs within buildings to large commercial and institutional buildings and even entire campuses. The database is a data repository as well. A series of Web-based data-entry templates allows anyone to enter information about a building project into the database. Once a project has been submitted, each of the partner organizations can review the entry and choose whether or not to publish that particular project on its own Web site.

  13. Building Better Buildings: Sustainable Building Activities in California Higher Education Systems.

    ERIC Educational Resources Information Center

    Sowell, Arnold; Eichel, Amanda; Alevantis, Leon; Lovegreen, Maureen

    2003-01-01

    This article outlines the activities and recommendations of California's sustainable building task force, discusses sustainable building activities in California's higher education systems, and highlights key issues that California is grappling with in its implementation of sustainable building practices. (EV)

  14. Modeling Best Practice through Online Learning: Building Relationships

    ERIC Educational Resources Information Center

    Cerniglia, Ellen G.

    2011-01-01

    Students may fear that they will feel unsupported and isolated when engaged in online learning. They don't know how they will be able to build relationships with their teacher and classmates solely based on written words, without facial expressions, tone of voice, and other nonverbal communication cues. Traditionally, online learning required

  15. Aquaporin-4 antibody testing: direct comparison of M1-AQP4-DNA-transfected cells with leaky scanning versus M23-AQP4-DNA-transfected cells as antigenic substrate

    PubMed Central

    2014-01-01

    Background Neuromyelitis optica (NMO, Devic syndrome) is associated with antibodies to aquaporin-4 (NMO-IgG/AQP4-Ab) in the majority of cases. NMO-IgG/AQP4-Ab seropositivity in patients with NMO and its spectrum disorders has important differential diagnostic, prognostic and therapeutic implications. So-called cell-based assays (CBA) are thought to provide the best AQP4-Ab detection rates. Objective To compare directly the AQP4-IgG detection rates of the currently most widely used commercial CBA, which employs cells transfected with a full-length (M1)-human AQP4 DNA in a fashion that allows leaky scanning (LS) and thus expression of M23-AQP4 in addition to M1-AQP, to that of a newly developed CBA from the same manufacturer employing cells transfected with human M23-AQP4-DNA. Methods Results from 368 serum samples that had been referred for routine AQP4-IgG determination and had been tested in parallel in the two assays were compared. Results Seventy-seven out of 368 samples (20.9%) were positive for NMO-IgG/AQP4-Ab in at least one assay. Of these, 73 (94.8%) were positive in both assays. A single sample (1.3%) was exclusively positive in the novel assay; three samples (3.9%) were unequivocally positive only in the classic assay due to high background intensity in the novel assay. Both median fluorescence intensity and background intensity were higher in the new assay. Conclusions This large study did not reveal significant differences in AQP4-IgG detection rates between the classic CBA and a new M23-DNA-based CBA. Importantly, our results largely re-affirm the validity of previous studies that had used the classic AQP4-CBA to establish NMO-IgG/AQP4-Ab seropositivity rates in NMO and in a variety of NMO spectrum disorders. PMID:25074611

  16. Passive base isolation with superelastic nitinol SMA helical springs

    NASA Astrophysics Data System (ADS)

    Huang, Bin; Zhang, Haiyang; Wang, Han; Song, Gangbing

    2014-06-01

    Seismic isolation of structures such as multi-story buildings, nuclear reactors, bridges, and liquid storage tanks should be designed to preserve structural integrity. By implementing seismic isolation technology, the deformation of superstructures can be dramatically reduced, consequently helping to protect their safety as well. In this paper, an innovative type of passive base isolation system, which is mainly composed of superelastic nitinol SMA helical springs, is developed. In order to verify the effectiveness of the proposed system, a two-story experimental steel frame model is constructed, and two superelastic SMA helical springs are thermo-mechanically built in the laboratory. To describe the nonlinear mechanical properties of the superelastic SMA helical springs under reciprocating load, a phenomenological model is presented in terms of a series of tensile tests. Afterwards, a numerical model of the two-story frame with the suggested isolation system is set up to simulate the response of the isolated frame subjected to an earthquake. Both the experimental and the numerical simulation results indicate that the proposed base isolation system can remarkably suppress structural vibrations and has improved isolation effects when compared with a steel spring isolation system. Due to the capabilities of energy dissipation as well as fully re-centering, it is very applicable to utilize the suggested isolation system in base isolated structures to resist earthquakes.

  17. 2. Building 3 north elevation showing stack, Building 4 on ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Building 3 north elevation showing stack, Building 4 on right, Building 15 with steel water tower and hopper behind. View looking SSW. - John & James Dobson Carpet Mill (West Parcel), Building No. 3, 4041-4055 Ridge Avenue, Philadelphia, Philadelphia County, PA

  18. 1. Building 3 east elevation, Building 15 and steel water ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Building 3 east elevation, Building 15 and steel water tank (elevated) to left, stack associated with Building 3 Boiler room, center. View looking west. - John & James Dobson Carpet Mill (West Parcel), Building No. 3, 4041-4055 Ridge Avenue, Philadelphia, Philadelphia County, PA

  19. 31. SOUTH PLANT NORTHERN EDGE, SHOWING CELL BUILDING (BUILDING 242) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. SOUTH PLANT NORTHERN EDGE, SHOWING CELL BUILDING (BUILDING 242) AT LEFT, LABORATORY (BUILDING 241) AT CENTER AND CAUSTIC FUSION PLANT (BUILDING 254) AT RIGHT. VIEW TO SOUTHWEST. - Rocky Mountain Arsenal, Bounded by Ninety-sixth Avenue & Fifty-sixth Avenue, Buckley Road, Quebec Street & Colorado Highway 2, Commerce City, Adams County, CO

  20. 62. BUILDING NO. 1301, ORDNANCE FACILITY (MORTAR POWDER BUILDING), LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    62. BUILDING NO. 1301, ORDNANCE FACILITY (MORTAR POWDER BUILDING), LOOKING AT NORTHWEST FACADE. ACCESS TO ROOF ALLOWS MAINTENANCE OF VENTILATION EQUIPMENT WHICH IS PLACED OUTSIDE BUILDING TO MINIMIZE EXPLOSION HAZARD. NO. 2 VISIBLE ON WALL OF BUILDING STANDS FOR EXPLOSION HAZARD WITH FRAGMENTATION. - Picatinny Arsenal, State Route 15 near I-80, Dover, Morris County, NJ

  1. 19. VIEW OF THE INTERIOR OF BUILDING 374. BUILDING 374, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. VIEW OF THE INTERIOR OF BUILDING 374. BUILDING 374, ATTACHED TO BUILDING 371, BECAME OPERATIONAL IN 1978 AS THE NEW RADIOACTIVE WASTE TREATMENT FACILITY, REPLACING BUILDING 774. (6/26/79) - Rocky Flats Plant, Plutonium Recovery Facility, Northwest portion of Rocky Flats Plant, Golden, Jefferson County, CO

  2. 13. General view of buildings: Building No. 6 with smokestack ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. General view of buildings: Building No. 6 with smokestack (left foreground); Building No. 5 (left background); Base of Water Tower (right foreground); Buildings 4, 3, 2, 1 (center foreground to background) - Thomas A. Edison Laboratories, Main Street & Lakeside Avenue, West Orange, Essex County, NJ

  3. 1. VIEW LOOKING SOUTH AT BUILDING 771 UNDER CONSTRUCTION. BUILDING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW LOOKING SOUTH AT BUILDING 771 UNDER CONSTRUCTION. BUILDING 771 WAS ONE OF THE FIRST FOUR MAJOR BUILDINGS AT THE ROCKY FLATS PLANT, BUILDING 771 WAS ORIGINALLY THE PRIMARY FACILITY FOR PLUTONIUM OPERATIONS. (5/29/52) - Rocky Flats Plant, Plutonium Recovery & Fabrication Facility, North-central section of plant, Golden, Jefferson County, CO

  4. 1. VIEW LOOKING NORTHWEST AT BUILDING 701. BUILDING 701 WAS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW LOOKING NORTHWEST AT BUILDING 701. BUILDING 701 WAS USED TO DESIGN, BUILD, AND EVALUATE BENCH-SCALE TECHNOLOGIES USED IN ROCKY FLATS WASTE TREATMENT PROCESSES. (1/98) - Rocky Flats Plant, Design Laboratory, Northwest quadrant of Plant, between buildings 776-777 & 771, Golden, Jefferson County, CO

  5. Detailed description and performance of a passive perfluorocarbon tracer system for building ventilation and air exchange measurements

    SciTech Connect

    Dietz, R.N.; Goodrich, R.W.; Cote, E.A.; Wieser, R.F.

    1985-02-01

    The manufacturing procedures and performance of a building air infiltration kit consisting of miniature passive perfluorocarbon tracer (PFT) permeation sources and passive adsorption tube samplers are described. Having four PFT-types available, homes and buildings with up to four separate zones can be fully evaluated under steady state conditions for the air infiltration and exfiltration rates from each zone as well as the air exchange rates between zones using this inexpensive and non-obtrusive field kit. Complete details on deployment in homes and on gas chromatographic analysis of the passive samplers are presented. Examples of total air changes per hour (ACH) results in several studies showed average values between 0.25 to 0.64 h/sup -1/. A generalized correlation was used to characterize the leakiness of eleven homes in the US and Canada, showing ACH dependency only on inside-outside temperature difference, wind speed to the 1.5 power, and a subjective terrain factor; the approach has application in evaluating weatherization performance. Details of multizone measurements in four homes provided insight into the role of attics, crawl-spaces, and basements on the indoor air quality and weatherization needs for the living zone. 26 refs., 15 figs., 23 tabs.

  6. THE IMPACT OF BUILDING TOPOGRAPHY ON AEROSOL DISPERSION IN AN URBAN STREET CANYON

    EPA Science Inventory

    This extended abstract describes numerical simulations of the flow through a building array which includes an isolated tall tower. The work seeks to explore the impact of a single tall building on the circulation and channeling of aerosolized traffic emissions within a series of...

  7. SYSTEMATIC STUDY ON THE CONTROL OF LEAD IN A NEW BUILDING

    EPA Science Inventory

    A new building was identified as having high lead levels in its drinking water. hrough a detailed sampling protocol, the sources of lead were identified as brass plumbing fittings and fixtures, and Pb:Sn solder. tudy was performed in two isolated sections of the building plumbing...

  8. Cell isolation and culture.

    PubMed Central

    Zhang, Sihui; Kuhn, Jeffrey R

    2013-01-01

    Cell isolation and culture are essential tools for the study of cell function. Isolated cells grown under controlled conditions can be manipulated and imaged at a level of resolution that is not possible in whole animals or even tissue explants. Recent advances have allowed for large-scale isolation and culture of primary C. elegans cells from both embryos and all four larval stages. Isolated cells can be used for single-cell profiling, electrophysiology, and high-resolution microscopy to assay cell autonomous development and behavior. This chapter describes protocols for the isolation and culture of C. elegans embryonic and larval stage cells. Our protocols describe isolation of embryonic and L1 stage cells from nematodes grown on high-density NA22 bacterial plates and isolation of L2 through L4 stage cells from nematodes grown in axenic liquid culture. Both embryonic and larval cells can be isolated from nematode populations within 3 hours and can be cultured for several days. A primer on sterile cell culture techniques is given in the appendices. PMID:23430760

  9. Wrentit Genetic Isolation Map

    USGS Multimedia Gallery

    This map of the Thousand Oaks, Calif. area visualizes the degree of genetic isolation being experienced by the wrentit (Chamaea fasciata), a small songbird. USGS and National Park Service biologists discovered that as urban development fragmented the Santa Monica Mountains scrubland into isolated

  10. Energy Simulator Residential Buildings

    Energy Science and Technology Software Center (ESTSC)

    1992-02-24

    SERI-RES performs thermal energy analysis of residential or small commercial buildings and has the capability of modeling passive solar equipment such as rock beds, trombe walls, and phase change material. The analysis is accomplished by simulation. A thermal model of the building is created by the user and translated into mathematical form by the program. The mathematical equations are solved repeatedly at time intervals of one hour or less for the period of simulation. Themore » mathematical representation of the building is a thermal network with nonlinear, temperature-dependent controls. A combination of forward finite differences, Jacobian iteration, and constrained optimization techniques is used to obtain a solution. An auxiliary interactive editing program, EDITOR, is included for creating building descriptions. EDITOR checks the validity of the input data and also provides facilities for storing and referencing several types of building description files. Some of the data files used by SERI-RES need to be implemented as direct-access files. Programs are included to convert sequential files to direct-access files and vice versa.« less

  11. Positive isolation disconnect

    NASA Technical Reports Server (NTRS)

    Rosener, A. A.; Jonkoniec, T. G.

    1975-01-01

    A positive isolation disconnect was developed for component replacement in serviced liquid and gaseous spacecraft systems. Initially a survey of feasible concepts was made to determine the optimum method for fluid isolation, sealing techniques, coupling concepts, and foolproofing techniques. The top concepts were then further evaluated, including the fabrication of a semifunctional model. After all tradeoff analyses were made, a final configuration was designed and fabricated for development testing. This resulted in a 6.35 mm (1/4 inch) line and 12.7 mm (1/2 inch) line positive isolation disconnect, each unit consisting of two coupled disconnect halves, each capable of fluid isolation with essentially zero clearance between them for zero leakage upon disconnect half disengagement. An interlocking foolproofing technique was incorporated that prevents uncoupling of disconnect halves prior to fluid isolation.

  12. Building Trades. Block II. Foundations.

    ERIC Educational Resources Information Center

    Texas A and M Univ., College Station. Vocational Instructional Services.

    Twelve informational lessons and eleven manipulative lessons are provided on foundations as applied to the building trades. Informational lessons cover land measurements; blueprint reading; level instruments; building and site planning; building site preparation; laying out building lines; soil preparation and special evacuation; concrete forms;

  13. SOLAR EFFECTS ON BUILDING DESIGN.

    ERIC Educational Resources Information Center

    Building Research Inst., Inc., Washington, DC.

    A REPORT OF A PROGRAM HELD AS PART OF THE BUILDING RESEARCH INSTITUTE 1962 SPRING CONFERENCE ON THE SOLAR EFFECTS ON BUILDING DESIGN. TOPICS DISCUSSED ARE--(1) SOLAR ENERGY DATA APPLICABLE TO BUILDING DESIGN, (2) THERMAL EFFECTS OF SOLAR RADIATION ON MAN, (3) SOLAR EFFECTS ON ARCHITECTURE, (4) SOLAR EFFECTS ON BUILDING COSTS, (5) SELECTION OF…

  14. Energy conservation in swine buildings

    SciTech Connect

    Jones, D.D.; Friday, W.H.

    1980-05-01

    Saving energy in confinement swine buildings can be achieved by conserving existing animal heat through both proper building construction and control of the environment. Environmental management practices considered include building insulation and modifications, heating and cooling system selection, ventilation system adjustments, and proper building temperature. (MCW)

  15. Building Air Quality. Action Plan.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Washington, DC. Indoor Air Div.

    Building managers and owners often confront competing demands to reduce operating costs and increase revenues that can siphon funds and resources from other building management concerns such as indoor air quality (IAQ). This resource booklet, designed for use with the "Building Air Quality Guide," provides building owners and managers with an…

  16. Building Informatics Environment

    Energy Science and Technology Software Center (ESTSC)

    2008-06-02

    The Building Informatics Environment is a modeling environment based on the Modelica language. The environment allows users to create a computer model of a building and its energy systems with various time scales and physical resolutions. The environment can be used for rapid development of, e.g., demand controls algorithms, new HVAC system solutions and new operational strategies (controls, fault detection and diagnostics). Models for building energy and control systems are made available in the environment.more » The models can be used as provided, or they can be changed and/or linked with each other in order to model the effects that a particular user is interested in.« less

  17. BODY BUILD IN INFANTS

    PubMed Central

    Bakwin, Harry; Bakwin, Ruth Morris

    1931-01-01

    In these three papers the body build of infants during health and disease is described quantitatively. This is done by comparison of ratios of various external dimensions to the total body length. In the first paper the technique for measuring the external dimensions of the body in infants is described and various sources of error discussed. In the second paper general empirical formulae for the relationship between various external dimensions and total body length in healthy infants are developed. By comparing two groups of infants from different social environments, it is shown that environment may influence body build. In the third paper the results obtained in the second paper for healthy infants are used for comparison with sick infants. Various differences in the body build of infants with acute intestinal intoxication, tetany and eczema are described. PMID:16693985

  18. Building brains for bodies

    NASA Technical Reports Server (NTRS)

    Brooks, Rodney Allen; Stein, Lynn Andrea

    1994-01-01

    We describe a project to capitalize on newly available levels of computational resources in order to understand human cognition. We will build an integrated physical system including vision, sound input and output, and dextrous manipulation, all controlled by a continuously operating large scale parallel MIMD computer. The resulting system will learn to 'think' by building on its bodily experiences to accomplish progressively more abstract tasks. Past experience suggests that in attempting to build such an integrated system we will have to fundamentally change the way artificial intelligence, cognitive science, linguistics, and philosophy think about the organization of intelligence. We expect to be able to better reconcile the theories that will be developed with current work in neuroscience.

  19. Solar building construction

    SciTech Connect

    McCue, J.H.

    1983-12-20

    A vertically inclined solar collector on the south side of a building not only provides a source of high velocity solar heated air from which energy is extracted by an air turbine generator, but it also serves to enhance the downward flow of relatively cool, dense air entering the north side of the building at an elevated location. The relatively cool air cools the interior of the building as the air descends and eventually flows into the bottom end of the collector. Interposed in the path of the cooling air is one or more air turbine generators which serve to extract energy from the cool air flow. Electrical storage batteries connected to the turbine generators provide a reservoir of electrical energy; and air washers, coolers and humidifiers increase the downward velocity and cooling effect of the cooling air.

  20. RESRAD-BUILD verification.

    SciTech Connect

    Kamboj, S.; Yu, C.; Biwer, B. M.; Klett, T.

    2002-01-31

    The results generated by the RESRAD-BUILD code (version 3.0) were verified with hand or spreadsheet calculations using equations given in the RESRAD-BUILD manual for different pathways. For verification purposes, different radionuclides--H-3, C-14, Na-22, Al-26, Cl-36, Mn-54, Co-60, Au-195, Ra-226, Ra-228, Th-228, and U-238--were chosen to test all pathways and models. Tritium, Ra-226, and Th-228 were chosen because of the special tritium and radon models in the RESRAD-BUILD code. Other radionuclides were selected to represent a spectrum of radiation types and energies. Verification of the RESRAD-BUILD code was conducted with an initial check of all the input parameters for correctness against their original source documents. Verification of the calculations was performed external to the RESRAD-BUILD code with Microsoft{reg_sign} Excel to verify all the major portions of the code. In some cases, RESRAD-BUILD results were compared with those of external codes, such as MCNP (Monte Carlo N-particle) and RESRAD. The verification was conducted on a step-by-step basis and used different test cases as templates. The following types of calculations were investigated: (1) source injection rate, (2) air concentration in the room, (3) air particulate deposition, (4) radon pathway model, (5) tritium model for volume source, (6) external exposure model, (7) different pathway doses, and (8) time dependence of dose. Some minor errors were identified in version 3.0; these errors have been corrected in later versions of the code. Some possible improvements in the code were also identified.

  1. Marine Science Building Dedicated

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Officials cut the ribbon during dedication ceremonies of the George A. Knauer Marine Science Building on Oct. 17 at NASA Stennis Space Center (SSC). The $2.75 million facility, the first building at the test site funded by the state of Mississippi, houses six science labs, classrooms and office space for 40 faculty and staff. Pictured are, from left, Rear Adm. Thomas Donaldson, commander of the Naval Meteorology and Oceanography Command; SSC Assistant Director David Throckmorton; Dr. George A. Knauer, founder of the Center of Marine Science at the University of Southern Mississippi (USM); Lt. Gov. Amy Tuck; and USM President Dr. Shelby Thames.

  2. Re-Building Greensburg

    ScienceCinema

    Hewitt, Steven; Wallach, Daniel; Peterson, Stephanie;

    2013-05-29

    Greensburg, KS - A town that was devastated by a tornado in 2007, yet came back to be one of the Nation's most energy-efficient, sustainable communities. Civic leaders and entrepreneurs helped rally residents behind the idea of "greening" Greensburg, inspiring the construction of numerous energy-efficient buildings, some of which generate their own renewable power with solar panels and wind turbines. Many of the town's government buildings use cutting edge energy-saving technologies, saving the local taxpayers' money. Greensburg has demonstrated to the world that any city can reach its energy efficiency and renewable energy goals today using widely available technologies.

  3. Building insulation technology: Kuwait

    SciTech Connect

    Ezz Al Din, M.A.

    1986-01-01

    Recommendations are reached through the use of a value analysis approach to adapt building insulation technology to Kuwait environment. The economical and technical aspects of using insulation influencing architectural and engineering decisions are presented. Research has confirmed that savings of 25% to 40% of electrical energy required in cooling and heating the building can be achieved by the proper use of insulating materials. Though the ideas of this study are tailored for Kuwait, yet it may be appropriate and applicable to many countries with hot climate.

  4. Re-Building Greensburg

    SciTech Connect

    Hewitt, Steven; Wallach, Daniel; Peterson, Stephanie

    2010-01-01

    Greensburg, KS - A town that was devastated by a tornado in 2007, yet came back to be one of the Nation's most energy-efficient, sustainable communities. Civic leaders and entrepreneurs helped rally residents behind the idea of "greening" Greensburg, inspiring the construction of numerous energy-efficient buildings, some of which generate their own renewable power with solar panels and wind turbines. Many of the town's government buildings use cutting edge energy-saving technologies, saving the local taxpayers' money. Greensburg has demonstrated to the world that any city can reach its energy efficiency and renewable energy goals today using widely available technologies.

  5. Performance Metrics for Commercial Buildings

    SciTech Connect

    Fowler, Kimberly M.; Wang, Na; Romero, Rachel L.; Deru, Michael P.

    2010-09-30

    Commercial building owners and operators have requested a standard set of key performance metrics to provide a systematic way to evaluate the performance of their buildings. The performance metrics included in this document provide standard metrics for the energy, water, operations and maintenance, indoor environmental quality, purchasing, waste and recycling and transportation impact of their building. The metrics can be used for comparative performance analysis between existing buildings and industry standards to clarify the impact of sustainably designed and operated buildings.

  6. The COSPAR Capacity Building Initiative

    NASA Astrophysics Data System (ADS)

    Gabriel, C.; Willmore, P.; Mndez, M.; Mathieu, P.-P.; Santolik, O.; Smith, R.

    2011-07-01

    The COSPAR Capacity Building Workshops have been conceived to meet the following objectives: (1) To increase knowledge and use of public archives of space data in order both to broaden the scope of research programs in developing countries and to ensure that scientists in those countries are aware of the full range of facilities that are available to them; (2) To provide highly-practical instruction in the use of these archives and the associated publicly-available software; and (3) To foster personal links between participants and experienced scientists attending the workshops to contribute to reducing the isolation often experienced by scientists in developing countries. Since 2001 a total of twelve workshops have been successfully held in different scientific areas (X-ray, Gamma-ray, Space Optical and UV Astronomy, Magnetospheric Physics, Space Oceanography and Planetary Science) in nine developing countries (Brazil, India, China, South Africa, Morocco, Romania, Uruguay, Egypt and Malaysia). In this contribution we discuss the modalities of the workshops, the experience so-far gained, and the future including collaborations with other institutions sharing the aim of increasing the scientific activities in developing countries.

  7. Transport of arginine and ornithine into isolated mitochondria of Saccharomyces cerevisiae.

    PubMed

    Soetens, O; Crabeel, M; El Moualij, B; Duyckaerts, C; Sluse, F

    1998-12-01

    In this work we have characterised the transport of L-arginine and L-ornithine into mitochondria isolated from a wild-type Saccharomyces cerevisiae strain and an isogenic arg11 knock-out mutant. The Arg11 protein (Arg11p) is a mitochondrial carrier required for arginine biosynthesis [Crabeel, M., Soetens, O., De Rijcke, M., Pratiwi, R. & Pankiewicz, R. (1996) J. Biol. Chem. 271, 25011-25019]. Reconstitution experiments have confirmed that it is an L-ornithine carrier also transporting L-arginine and L-lysine by order of decreasing affinity, but not L-histidine [Palmieri, L., De Marco, V., Iacobazzi, V., Palmieri, F., Runswick, M. & Walker, J. (1997) FEBS Lett. 410, 447-451]. Evidence is presented here that the mitochondrial inner membrane contains an L-arginine and L-ornithine transporting system distinct from Arg11p, in keeping with the arginine leaky phenotype of arg11 knock-out mutants. The newly characterised carrier, which we propose to name Bac1p (basic amino acid carrier), behaves as an antiporter catalysing the electroneutral exchange of the basic amino acids L-arginine, L-lysine, L-ornithine and L-histidine and displays the highest affinity for L-arginine (Km of 30 microM). L-Arginine uptake has a pH optimum in the range of 7.5-9 and is inhibited by several sulphydryl reagents, by pyridoxal 5'-phosphate and by cations. PMID:9874237

  8. MOX Fabrication Isolation Considerations

    SciTech Connect

    Eric L. Shaber; Bradley J Schrader

    2005-08-01

    This document provides a technical position on the preferred level of isolation to fabricate demonstration quantities of mixed oxide transmutation fuels. The Advanced Fuel Cycle Initiative should design and construct automated glovebox fabrication lines for this purpose. This level of isolation adequately protects the health and safety of workers and the general public for all mixed oxide (and other transmutation fuel) manufacturing efforts while retaining flexibility, allowing parallel development and setup, and minimizing capital expense. The basis regulations, issues, and advantages/disadvantages of five potential forms of isolation are summarized here as justification for selection of the preferred technical position.

  9. Fault detection and isolation

    NASA Technical Reports Server (NTRS)

    Bernath, Greg

    1994-01-01

    In order for a current satellite-based navigation system (such as the Global Positioning System, GPS) to meet integrity requirements, there must be a way of detecting erroneous measurements, without help from outside the system. This process is called Fault Detection and Isolation (FDI). Fault detection requires at least one redundant measurement, and can be done with a parity space algorithm. The best way around the fault isolation problem is not necessarily isolating the bad measurement, but finding a new combination of measurements which excludes it.

  10. Isolation of Chlamydomonas Flagella

    PubMed Central

    Craige, Branch; Brown, Jason M.; Witman, George B.

    2014-01-01

    A simple, scalable, and fast procedure for the isolation of Chlamydomonas flagella is described. Chlamydomonas can be synchronously deflagellated by treatment with chemicals, pH shock, or mechanical shear. The Basic Protocol describes the procedure for flagellar isolation using dibucaine to induce flagellar abscission; we also describe the pH shock method as an Alternate Protocol when flagellar regeneration is desirable. Sub-fractionation of the isolated flagella into axonemes and the membrane + matrix fraction is described in a Support Protocol. PMID:23728744

  11. Building a Learning Community.

    ERIC Educational Resources Information Center

    Cosner, Shelby; Peterson, Kent

    2003-01-01

    Instructional leadership is a thoughtful journey that builds and sustains learning cultures. School leaders must confront negative norms and values head-on and recognize and celebrate a learning environment. Offers ideas for shaping and reinforcing a positive learning culture and lists brief case studies. (MLF)

  12. Building a Twig Phylogeny

    ERIC Educational Resources Information Center

    Flinn, Kathryn M.

    2015-01-01

    In this classroom activity, students build a phylogeny for woody plant species based on the morphology of their twigs. Using any available twigs, students can practice the process of cladistics to test evolutionary hypotheses for real organisms. They identify homologous characters, determine polarity through outgroup comparison, and construct a

  13. Building safer structures

    USGS Publications Warehouse

    Celebi, Mehmet; Page, Robert A.; Seekins, Linda

    1995-01-01

    In this century, major earthquakes in the United States have damaged or destroyed numerous buildings, bridges, and other structures. By monitoring how structures respond to earthquakes and applying the knowledge gained, scientists and engineers are improving the ability of structures to survive major earthquakes. Many lives and millions of dollars have already been saved by this ongoing research.

  14. Building Background Knowledge

    ERIC Educational Resources Information Center

    Neuman, Susan B.; Kaefer, Tanya; Pinkham, Ashley

    2014-01-01

    This article make a case for the importance of background knowledge in children's comprehension. It suggests that differences in background knowledge may account for differences in understanding text for low- and middle-income children. It then describes strategies for building background knowledge in the age of common core standards.

  15. Building a Twig Phylogeny

    ERIC Educational Resources Information Center

    Flinn, Kathryn M.

    2015-01-01

    In this classroom activity, students build a phylogeny for woody plant species based on the morphology of their twigs. Using any available twigs, students can practice the process of cladistics to test evolutionary hypotheses for real organisms. They identify homologous characters, determine polarity through outgroup comparison, and construct a…

  16. Building a Brainier Mouse.

    ERIC Educational Resources Information Center

    Tsien, Joe Z.

    2000-01-01

    Describes a genetic engineering project to build an intelligent mouse. Cites understanding the molecular basis of learning and memory as a very important step. Concludes that while science will never create a genius mouse that plays the stock market, it can turn a mouse into a quick learner with a better memory. (YDS)

  17. Building Community in Schools.

    ERIC Educational Resources Information Center

    Sergiovanni, Thomas J.

    This book provides a view of community that educators can use to define and build community in their schools. Chapter 1 critiques the traditional view of schools as formal organizations and offers a theory of community as an alternative. Chapter 2 describes a pattern of relationships characteristic of communities, which can be applied to

  18. Building a Better CTO

    ERIC Educational Resources Information Center

    Fletcher, Geoffrey H.

    2010-01-01

    This article features the new Framework of Essential Skills of the K-12 CTO of the Consortium for School Networking (CoSN). This latest, version 2.0 iteration of the skills framework builds upon work the organization did earlier this decade. This time CoSN, a professional association for district technology leaders, reached out to a variety of

  19. Building Alliances Series: Education

    ERIC Educational Resources Information Center

    Brady, Cecilia

    2009-01-01

    Public-private partnerships done right are a powerful tool for development, providing enduring solutions to some of the greatest challenges. To help familiarize readers with the art of alliance building, the Global Development Alliance (GDA) office has created a series of practical guides that highlight proven practices in partnerships,…

  20. Looking into sick buildings

    SciTech Connect

    Scarry, R.L. )

    1994-07-01

    This article examines the effect of geographic location (humid vs dry climate) and indoor relative humidity on the potential for IAQ problems. Poor indoor air quality (IAQ) has been a problem for centuries. The more current interest surrounds the Legionella pneumophila epidemic of 1976. The Legionnaire's disease outbreak was the first recognized instance of a building related illness (BRI). Sick building syndrome (SBS) is a less well defined condition than BRI. In SBS, occupants of a building suffer ill health due to some obscure condition or conditions in the building. Additionally, the health condition appears to be self-resolving when the person leaves the premises. A complete listing of SBS variables has not been determined, but the general conditions have been identified. The primary groupings include irritants, allergens, and toxins. It should be noted that infectious agents were intentionally omitted as their involvement more specifically indicated a BRI. Additionally, some contaminants may be classified as more than a single type; e.g., Aspergillus sp. may be labeled both allergenic and toxigenic.

  1. Building the Best Auditorium

    ERIC Educational Resources Information Center

    Sturgeon, Julie

    2008-01-01

    Building a quality auditorium has never come at a cheap price. In today's economy, a $750,000 minimum price tag just for sound, lighting, stage rigging and seats can be exorbitant. However, schools that have built new auditoriums or upgraded existing ones in the past decade say the investment is worth every penny. This article discusses the…

  2. Bridge-Building 101.

    ERIC Educational Resources Information Center

    Wilson, E. B.

    2001-01-01

    Discusses how a college board of trustees can get beyond academe's famed turf battles to build a governance culture that embraces all constituencies and improves its own work. Addresses the best practices of strategic vision, presidential leadership, cohesive teamwork, continuing trustee education, faculty as partners, and effective board

  3. LARGE BUILDING HVAC SIMULATION

    EPA Science Inventory

    The report discusses the monitoring and collection of data relating to indoor pressures and radon concentrations under several test conditions in a large school building in Bartow, Florida. The Florida Solar Energy Center (FSEC) used an integrated computational software, FSEC 3.0...

  4. String Model Building

    SciTech Connect

    Raby, Stuart

    2010-02-10

    In this talk I review some recent progress in heterotic and F theory model building. I then consider work in progress attempting to find the F theory dual to a class of heterotic orbifold models which come quite close to the MSSM.

  5. Building Industries Occupations: Syllabus.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    The Building Industries Occupations course is a two-year program of approximately 160 three-period teaching days per year. The required course content is designed to be effectively taught in 80 percent of the total course time, thus allowing 20 percent of the time for instruction adapted to such local conditions as employment prospects, student

  6. Building Camaraderie from Competition

    ERIC Educational Resources Information Center

    Marino, Gordon

    2007-01-01

    Educational institutions have adopted athletics programs to promote character building. Sports help people feel comfortable in their skins and provide unique opportunities to develop qualities such as cooperation, perseverance, and the ability to cope with fear. But the arena can be a hothouse for more primal feelings that emerge in competition.

  7. Wayside Teaching: Building Autonomy

    ERIC Educational Resources Information Center

    Powell, Sara Davis

    2011-01-01

    Educators can implement strategies to build positive relationships with students that will help them become more autonomous and less anonymous in school. These strategies allow young adolescents to become more self aware, to take greater responsibility for their actions, to reflect on their own lives and actions, and to have choices regarding

  8. Building Automation Systems.

    ERIC Educational Resources Information Center

    Honeywell, Inc., Minneapolis, Minn.

    A number of different automation systems for use in monitoring and controlling building equipment are described in this brochure. The system functions include--(1) collection of information, (2) processing and display of data at a central panel, and (3) taking corrective action by sounding alarms, making adjustments, or automatically starting and…

  9. Special Section: Library Buildings.

    ERIC Educational Resources Information Center

    Cooper, Walter; And Others

    1994-01-01

    This special section includes eight articles that address issues concerning library buildings. Highlights include information technologies; industry standards; design; management issues, including organizational climate; long-range, or strategic, planning, including models and political issues; friends of library groups; technology in reference

  10. Building the Best Auditorium

    ERIC Educational Resources Information Center

    Sturgeon, Julie

    2008-01-01

    Building a quality auditorium has never come at a cheap price. In today's economy, a $750,000 minimum price tag just for sound, lighting, stage rigging and seats can be exorbitant. However, schools that have built new auditoriums or upgraded existing ones in the past decade say the investment is worth every penny. This article discusses the

  11. Financing medical office buildings.

    PubMed

    Blake, J W

    1995-01-01

    This article discusses financing medical office buildings. In particular, financing and ownership options from a not-for-profit health care system perspective are reviewed, including use of tax-exempt debt, taxable debt, limited partnerships, sale, and real estate investment trusts (REITs). PMID:8528824

  12. Library Building and Design.

    ERIC Educational Resources Information Center

    Jones, David J.; Gordon, Heather; Caddy, Julie; Kahlert, Maureen; Johnson, Carolyn; Holdstock, Fiona

    1997-01-01

    More frequently, community connections are being expressed in library design briefs and reflected in the completed buildings. This collection of brief articles discusses community involvement in library design and services and describes library construction projects in Australia and Malaysia. Also, discusses community art programs, integrating

  13. To Build a Boat.

    ERIC Educational Resources Information Center

    Bonniwell, Tom; Coburn, Doug; McCarter, William S.

    1998-01-01

    A Virginia high school's Legacy program began six years ago when the Nature Conservancy, the Eastern Shore Historical Society, and Northampton County Schools joined forces to create an educational program to expose students to the area's ecological and historical richness. A boat-building project helped revitalize the hands-on learning project,

  14. Building Migratory Bridges

    ERIC Educational Resources Information Center

    Roy, Michael; Doss, Laurie K.

    2007-01-01

    The Building Migratory Bridges (BOMB) program--a collaboration between the Marvel wood School and Audubon Sharon in Connecticut and Conservation Research Education Action (CR EA), a U.S. not-for-profit in Panama--uses nontropical migratory bird research in the United States and Panama to demonstrate how negative environmental impacts in one

  15. Building Successful Cleaning Processes.

    ERIC Educational Resources Information Center

    Walker, John P.

    2002-01-01

    Discusses how to build a successful cleaning process in order to most effectively maintain school facilities, explaining that the cleaning processes used plays a critical role in productivity. Focuses on: developing a standardized system; making sure that employees have the right tools for the work they perform; training employees; tracking and…

  16. Fire Protection for Buildings

    ERIC Educational Resources Information Center

    Edmunds, Jane

    1972-01-01

    Reviews attack on fire safety in high rise buildings made by a group of experts representing the iron and steel industry at a recent conference. According to one expert, fire problems are people oriented, which calls for emphasis on fire prevention rather than reliance on fire suppression and for fire pretection to be built into a structure.…

  17. Building Migratory Bridges

    ERIC Educational Resources Information Center

    Roy, Michael; Doss, Laurie K.

    2007-01-01

    The Building Migratory Bridges (BOMB) program--a collaboration between the Marvel wood School and Audubon Sharon in Connecticut and Conservation Research Education Action (CR EA), a U.S. not-for-profit in Panama--uses nontropical migratory bird research in the United States and Panama to demonstrate how negative environmental impacts in one…

  18. Building with Sand

    ERIC Educational Resources Information Center

    Ashbrook, Peggy

    2010-01-01

    Children playing in damp sand invariably try to make a tower or a tunnel. By providing experiences with a variety of materials, alone and together, teachers set up the conditions for children to learn through their senses and ensure that a class approaches a topic with a common set of experiences to build on. Learning about the properties of

  19. Building Model Motorcars.

    ERIC Educational Resources Information Center

    Altshuler, Ken

    1995-01-01

    Describes a project where students build a motorized car that can perform well in two distinctly different competitions: traveling 20 meters in the shortest time and pulling a 500-gram mass the farthest distance in 20 seconds. Enables students to apply physics principles to a real problem and to discover the importance of teamwork on large

  20. Plastics in Building.

    ERIC Educational Resources Information Center

    Skeist, Irving, Ed.

    The evaluation and use of plastics in the construction industry are explained. The contributors offer extensive, timely, and thoroughly researched data on the chemistry, properties, functions, engineering behavior, and specific applications of plastics to building requirements. The major subjects discussed in depth are--(1) the role of plastics in…

  1. Library Buildings Section. Papers.

    ERIC Educational Resources Information Center

    International Federation of Library Associations, The Hague (Netherlands).

    Papers on library architecture, which were presented at the 1982 International Federation of Library Associations (IFLA) conference focus on the effect of library networks on library design. Topics include: (1) "Some Problems in Designing of the University Library Buildings in China: A Developing Country University Librarian's View Based on His

  2. Flattened Apartment Buildings

    USGS Multimedia Gallery

    This is where 6 large apartments buildings all were completely flattened. Luckily they were uninhabitated. Residents were supposed to have moved in during June, but were delayed. The fault is seen in the foreground. Aykut Barka has a photo taken of this area from a helicopter....

  3. Building Relationships with Reporters

    ERIC Educational Resources Information Center

    Kidwai, Sabrina

    2008-01-01

    Each story that is written about career and technical education (CTE) increases knowledge and support with local government, school officials and the community. The first step in improving publicity for one's program is to build a relationship with local reporters covering education. In this article, the author discusses how important it is to

  4. Team Building Concepts.

    ERIC Educational Resources Information Center

    Massachusetts Career Development Inst., Springfield.

    This booklet is one of six texts from a workplace literacy curriculum designed to assist learners in facing the increased demands of the workplace. It briefly explains how team building concepts affect businesses in new ways and how they help create an environment that provides job satisfaction for everyone and high-quality products for the

  5. Fire Protection for Buildings

    ERIC Educational Resources Information Center

    Edmunds, Jane

    1972-01-01

    Reviews attack on fire safety in high rise buildings made by a group of experts representing the iron and steel industry at a recent conference. According to one expert, fire problems are people oriented, which calls for emphasis on fire prevention rather than reliance on fire suppression and for fire pretection to be built into a structure.

  6. Building Camaraderie from Competition

    ERIC Educational Resources Information Center

    Marino, Gordon

    2007-01-01

    Educational institutions have adopted athletics programs to promote character building. Sports help people feel comfortable in their skins and provide unique opportunities to develop qualities such as cooperation, perseverance, and the ability to cope with fear. But the arena can be a hothouse for more primal feelings that emerge in competition.…

  7. Building Satellites is Easier

    NASA Technical Reports Server (NTRS)

    Marsh, Phyllis Nimmo

    1996-01-01

    'Building Satellites' is a story about Jim Marsh's recovery from a severe head injury told by his wife Phyllis from the moment she learned of its happening, through the ups and downs of a lengthy rehabilitation, until his return to work and daily living. It continues on, however, and narrates his battle with the more insidious Grave's disease. Told in the first person, 'Building Satellites' vividly portrays Phyllis's thoughts and feelings throughout this experience with scrupulous honestly. This is a story worth reading for many reasons. First of all, Jim was an accomplished scientist, respected by his colleagues both in this country and abroad. Secondly, it narrates the many stages of his recovery from head injury with detailed readable accuracy; it informs us as well as inspires. Finally, 'Building Satellites" also tells us the story of Phyllis Marsh's remarkable creative response to this crisis. It narrates her personal experiences as she progresses through the strange and somewhat bizarre world of medicine and rehabilitation, guided by a few basic beliefs, which she learned as a child in Iowa, that provided her with the strength to endure. 'Building Satellites' seems to reaffirm our unconscious, but settled conviction, that when confornted overnight with adversity, we are somehow given the means for coping, supported by our basic beliefs, strengthened by family and friends, and eventually learning to accept any outcome.

  8. Plastics in Building.

    ERIC Educational Resources Information Center

    Skeist, Irving, Ed.

    The evaluation and use of plastics in the construction industry are explained. The contributors offer extensive, timely, and thoroughly researched data on the chemistry, properties, functions, engineering behavior, and specific applications of plastics to building requirements. The major subjects discussed in depth are--(1) the role of plastics in

  9. Checklist for Physics Buildings.

    ERIC Educational Resources Information Center

    American Inst. of Physics, New York, NY.

    This booklet was written to encourage close communication between architect and client and to assist planners of physics facilities in providing important features of building design. Some 300 items considered important are listed Also included is a list of 17 references related to facility construction (many available free of charge. A companion

  10. Facility Focus: Science Buildings.

    ERIC Educational Resources Information Center

    College Planning & Management, 2000

    2000-01-01

    Describes three college science buildings that support student- centered learning in their science programs. How the schools created facility spaces that were interactive but quiet, merged multi- disciplinary sciences into the facility design, and encouraged departmental collaboration in the planning stage are addressed. (GR)

  11. Energy efficient building design

    SciTech Connect

    Not Available

    1992-03-01

    The fundamental concepts of the building design process, energy codes and standards, and energy budgets are introduced. These tools were combined into Energy Design Guidelines and design contract requirements. The Guidelines were repackaged for a national audience and a videotape for selling the concept to government executives. An effort to test transfer of the Guidelines to outside agencies is described.

  12. Building Relationships with Reporters

    ERIC Educational Resources Information Center

    Kidwai, Sabrina

    2008-01-01

    Each story that is written about career and technical education (CTE) increases knowledge and support with local government, school officials and the community. The first step in improving publicity for one's program is to build a relationship with local reporters covering education. In this article, the author discusses how important it is to…

  13. Building Automation Systems.

    ERIC Educational Resources Information Center

    Honeywell, Inc., Minneapolis, Minn.

    A number of different automation systems for use in monitoring and controlling building equipment are described in this brochure. The system functions include--(1) collection of information, (2) processing and display of data at a central panel, and (3) taking corrective action by sounding alarms, making adjustments, or automatically starting and

  14. Building with Sand

    ERIC Educational Resources Information Center

    Ashbrook, Peggy

    2010-01-01

    Children playing in damp sand invariably try to make a tower or a tunnel. By providing experiences with a variety of materials, alone and together, teachers set up the conditions for children to learn through their senses and ensure that a class approaches a topic with a common set of experiences to build on. Learning about the properties of…

  15. Building Successful Cleaning Processes.

    ERIC Educational Resources Information Center

    Walker, John P.

    2002-01-01

    Discusses how to build a successful cleaning process in order to most effectively maintain school facilities, explaining that the cleaning processes used plays a critical role in productivity. Focuses on: developing a standardized system; making sure that employees have the right tools for the work they perform; training employees; tracking and

  16. The barnacle and the building: a modern morality tale.

    PubMed

    Buckeridge, John S

    2008-06-01

    A rare and almost complete barnacle fossil, previously described on the basis of two isolated shell fragments, was recently exposed in a limestone block on the outer wall of Melbourne's Old Magistrates' Courts in Victoria, Australia. These courts comprise one of the oldest and grandest buildings in Melbourne and because of this they have a heritage listing. As heritage-listed buildings are protected from alteration by law, and as removal of the fossil would be deemed "alteration", official permission had to be obtained to extract the specimen. This paper discusses the processes involved with extraction of a unique specimen from a protected building and provides an overview of the palaeontological significance of the fossil. Consideration is given to the likely fate of a fossil of this nature, situated a little below eye level on a busy city street, if it was left in situ; finally, the implications of designating a holotype from material removed from a building are assessed. PMID:21396054

  17. Deactivation of Building 7602

    SciTech Connect

    Yook, H.R.; Barnett, J.R.; Collins, T.L.

    1995-10-01

    The Department of Energy (DOE) has sponsored research and development programs in Building 7602 at Oak Ridge National Laboratory (ORNL) since 1984. This work focused on development of advanced technology for processing nuclear fuels. Building 7602 was used for engineering-scale tests using depleted and natural uranium to simulate the nuclear fuel. In April 1994 the DOE Office of Nuclear Energy (NE) sent supplemental FY 1994 guidance to ORNL stating that in FY 1995 and beyond, Building 7602 is considered surplus to NE programs and missions and shall be shut down (deactivated) and maintained in a radiologically and industrially safe condition with minimal surveillance and maintenance (S&M). DOE-NE subsequently provided FY 1995 funding to support the deactivation activities. Deactivation of Building 7602 was initiated on October 1, 1994. The principal activity during the first quarter of FY 1995 was removal of process materials (chemicals and uranium) from the systems. The process systems were operated to achieve chemical solution concentrations needed for reuse or disposal of the solutions prior to removal of the materials from the systems. During this phase of deactivation the process materials processed and removed were: (1) Uranyl nitrate solution 30,178 L containing 4490 kg of uranium; (2) Nitric acid (neutralized) 9850 L containing less than 0.013 kg of uranium; (3) Organic solution 3346 L containing 265 kg of uranium; (4) Uranium oxide powder 95 kg; and (5) Miscellaneous chemicals. At the end of December 1994, the process systems and control systems were shut down and deactivated. Disposition of the process materials removed from the process systems in Building 7602 proved to be the most difficult part of the deactivation. An operational stand down and funding reductions at Y-12 prevented planned conversion of the uranyl nitrate solution to depleted uranium oxide powder. This led to disposal of the uranyl nitrate solution as waste.

  18. Asbestos exposure in buildings

    SciTech Connect

    Gaensler, E.A. )

    1992-06-01

    Asbestos-related diseases are dose-related. Among these, asbestosis has occurred only with the heavy exposures of the past, is a disappearing disease, and is of no concern with the very small exposures from building occupancy. A possibly increased incidence of lung cancer has been included in risk analysis, but probably is also related to high exposure in that both epidemiologic and experimental data suggest a link between the process of alveolar inflammation and fibrogenesis and carcinogenesis. The major concern has been mesothelioma in that it has occurred with much lower household and neighborhood exposure. Additionally, anxiety concerning buildings with ACM has been heightened by finding of friable asbestos in about 20% of public buildings, discovery of environmental asbestos fibers and asbestos bodies in autopsies, and demonstration of a linear relationship between exposure and lung cancer risk in occupational groups, inviting extrapolation to a much lower dose. Legislative and regulatory mandates, promotional activities of abatement companies, adverse court decisions placing the onus of repairs on asbestos manufacturers, and a pandemic of mediagenic disease' all have contributed to panic among building owners, school boards, insurers, and others. In that there is neither clinical nor epidemiologic support for asbestos-related disease from building occupancy, risk estimates have been based on extrapolation from past experience with generally high-dose occupational exposure. However, only a few epidemiologic studies have contained quantitative estimates of exposure, and these have been measured in terms of all particles, with conversion to asbestos fibers uncertain and the fiber type and dimension largely unknown.

  19. Flexible building primitives for 3D building modeling

    NASA Astrophysics Data System (ADS)

    Xiong, B.; Jancosek, M.; Oude Elberink, S.; Vosselman, G.

    2015-03-01

    3D building models, being the main part of a digital city scene, are essential to all applications related to human activities in urban environments. The development of range sensors and Multi-View Stereo (MVS) technology facilitates our ability to automatically reconstruct level of details 2 (LoD2) models of buildings. However, because of the high complexity of building structures, no fully automatic system is currently available for producing building models. In order to simplify the problem, a lot of research focuses only on particular buildings shapes, and relatively simple ones. In this paper, we analyze the property of topology graphs of object surfaces, and find that roof topology graphs have three basic elements: loose nodes, loose edges, and minimum cycles. These elements have interesting physical meanings: a loose node is a building with one roof face; a loose edge is a ridge line between two roof faces whose end points are not defined by a third roof face; and a minimum cycle represents a roof corner of a building. Building primitives, which introduce building shape knowledge, are defined according to these three basic elements. Then all buildings can be represented by combining such building primitives. The building parts are searched according to the predefined building primitives, reconstructed independently, and grouped into a complete building model in a CSG-style. The shape knowledge is inferred via the building primitives and used as constraints to improve the building models, in which all roof parameters are simultaneously adjusted. Experiments show the flexibility of building primitives in both lidar point cloud and stereo point cloud.

  20. Base isolation: Fresh insight

    SciTech Connect

    Shustov, V.

    1993-07-15

    The objective of the research is a further development of the engineering concept of seismic isolation. Neglecting the transient stage of seismic loading results in a widespread misjudgement: The force of resistance associated with velocity is mostly conceived as a source of damping vibrations, though it is an active force at the same time, during an earthquake type excitation. For very pliant systems such as base isolated structures with relatively low bearing stiffness and with artificially added heavy damping mechanism, the so called `damping`` force may occur even the main pushing force at an earthquake. Thus, one of the two basic pillars of the common seismic isolation philosophy, namely, the doctrine of usefulness and necessity of a strong damping mechanism, is turning out to be a self-deception, sometimes even jeopardizing the safety of structures and discrediting the very idea of seismic isolation. There is a way out: breaking with damping dependancy.

  1. Isolated Vascular Vertigo

    PubMed Central

    2014-01-01

    Strokes in the distribution of the posterior circulation may present with vertigo, imbalance, and nystagmus. Although the vertigo due to a posterior circulation stroke is usually associated with other neurologic symptoms or signs, small infarcts involving the cerebellum or brainstem can develop vertigo without other localizing symptoms. Approximately 11% of the patients with an isolated cerebellar infarction present with isolated vertigo, nystagmus, and postural unsteadiness mimicking acute peripheral vestibular disorders. The head impulse test can differentiate acute isolated vertigo associated with cerebellar strokes (particularly within the territory of the posterior inferior cerebellar artery) from more benign disorders involving the inner ear. Acute audiovestibular loss may herald impending infarction in the territory of anterior inferior cerebellar artery. Appropriate bedside evaluation is superior to MRIs for detecting central vascular vertigo syndromes. This article reviews the keys to diagnosis of acute isolated vertigo syndrome due to posterior circulation strokes involving the brainstem and cerebellum. PMID:25328871

  2. [Isolated gluteal hydatid cyst].

    PubMed

    Gürbüz, Bülent; Baysal, Hakan; Baysal, Begümhan; Yalman, Haydar; Yiğitbaşı, Mehmet Rafet

    2014-01-01

    Hydatid cyst disease is a parasitic infection caused by Echinococcus granulosus and poses a serious health problem in endemic areas, including our country. Hydatid disease mostly affects the liver and lung, although involvements in many parts of the body have been reported in the literature. Isolated soft tissue involvement is very rare. We present an isolated hydatid disease case which affected the gluteal region of the body. PMID:24659703

  3. Reproductive isolation during domestication.

    PubMed

    Dempewolf, Hannes; Hodgins, Kathryn A; Rummell, Sonja E; Ellstrand, Norman C; Rieseberg, Loren H

    2012-07-01

    It has been hypothesized that reproductive isolation should facilitate evolution under domestication. However, a systematic comparison of reproductive barrier strength between crops and their progenitors has not been conducted to test this hypothesis. Here, we present a systematic survey of reproductive barriers between 32 economically important crop species and their progenitors to better understand the role of reproductive isolation during the domestication process. We took a conservative approach, avoiding those types of reproductive isolation that are poorly known for these taxa (e.g., differences in flowering time). We show that the majority of crops surveyed are isolated from their progenitors by one or more reproductive barriers, despite the fact that the most important reproductive barrier in natural systems, geographical isolation, was absent, at least in the initial stages of domestication for most species. Thus, barriers to reproduction between crops and wild relatives are closely associated with domestication and may facilitate it, thereby raising the question whether reproductive isolation could be viewed as a long-overlooked "domestication trait." Some of the reproductive barriers observed (e.g., polyploidy and uniparental reproduction), however, may have been favored for reasons other than, or in addition to, their effects on gene flow. PMID:22773750

  4. 6. BUILDING 123 INTERIOR, FROM APPROXIMATE CENTER OF BUILDING, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. BUILDING 123 INTERIOR, FROM APPROXIMATE CENTER OF BUILDING, LOOKING WEST, WITH OFFICE MEZZANINE AT WESTERN END. - Oakland Naval Supply Center, Pier Transit Sheds, North Marginal Wharf, between First & Third Streets, Oakland, Alameda County, CA

  5. 17. NORTHEAST CORNER OF BUILDING 345 (ENTRY CONTROL BUILDING) IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. NORTHEAST CORNER OF BUILDING 345 (ENTRY CONTROL BUILDING) IN STORAGE AREA. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  6. 23. SOUTHWEST CORNER OF BUILDING 220 (ENTRY CONTROL BUILDING) IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. SOUTHWEST CORNER OF BUILDING 220 (ENTRY CONTROL BUILDING) IN ASSEMBLY AREA. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  7. 24. CONTEXT VIEW OF BUILDING 220 (ENTRY CONTROL BUILDING) LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. CONTEXT VIEW OF BUILDING 220 (ENTRY CONTROL BUILDING) LOOKING NORTH THROUGH SECURITY GATES. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  8. 22. NORTH ELEVATION OF BUILDING 220 (ENTRY CONTROL BUILDING) IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. NORTH ELEVATION OF BUILDING 220 (ENTRY CONTROL BUILDING) IN ASSEMBLY AREA. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  9. 16. EAST FRONT ELEVATION OF BUILDING 345 (ENTRY CONTROL BUILDING) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. EAST FRONT ELEVATION OF BUILDING 345 (ENTRY CONTROL BUILDING) IN STORAGE AREA. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  10. Building 932, oblique view to northwest, 90 mm lens. Building ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Building 932, oblique view to northwest, 90 mm lens. Building 933-935 at extreme left. - Travis Air Force Base, Nuclear Weapons Assembly Plant 5, W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

  11. 56. Photocopy of Photograph, BUILDING NO. 534, SOLVENT RECOVERY BUILDING, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    56. Photocopy of Photograph, BUILDING NO. 534, SOLVENT RECOVERY BUILDING, DETAIL VIEW OF SPARK PROOF EXTERIOR ELECTRICAL SWITCHES IN SOUTHEAST ELEVATION. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  12. 50. BUILDING NO. 533, SOLVENT RECOVERY BUILDING, LOOKING SOUTHWEST AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    50. BUILDING NO. 533, SOLVENT RECOVERY BUILDING, LOOKING SOUTHWEST AT NORTHWEST ELEVATION. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  13. 7. BUILDING NO. 816, ASSEMBLY BUILDING, DETAIL OF WEST FACADE, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. BUILDING NO. 816, ASSEMBLY BUILDING, DETAIL OF WEST FACADE, SHOWING EXTERIOR ELECTRICAL SWITCHGEAR AND ALARMS. - Picatinny Arsenal, 800 Area, Complete Rounds-Melt Loading District, State Route 15 near I-80, Dover, Morris County, NJ

  14. 18. Walkway between maintenance building and office building along south ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. Walkway between maintenance building and office building along south side of main plant looking east - Skinner Meat Packing Plant, Main Plant, 6006 South Twenty-seventh Street, Omaha, Douglas County, NE

  15. 11. BEACH TOILET BUILDING, OFFICE AND FIRST AID BUILDING, PLANS, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. BEACH TOILET BUILDING, OFFICE AND FIRST AID BUILDING, PLANS, ELEVATIONS AND SECTIONS Drawing No. 103-07 - Glen Echo Park, Crystal Swimming Pool, 7300 McArthur Boulevard, Glen Echo, Montgomery County, MD

  16. Interior view showing interface between building 271 and with building ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view showing interface between building 271 and with building 87 in background; camera facing west. - Mare Island Naval Shipyard, Mechanics Shop, Waterfront Avenue, west side between A Street & Third Street, Vallejo, Solano County, CA

  17. Contextual view of building showing relation to building 91 at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Contextual view of building showing relation to building 91 at right; camera facing southwest. - Mare Island Naval Shipyard, Mechanics Shop, Waterfront Avenue, west side between A Street & Third Street, Vallejo, Solano County, CA

  18. 18. Historic American Buildings Survey BUILDING OF THE HOTEL, FEBRUARY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. Historic American Buildings Survey BUILDING OF THE HOTEL, FEBRUARY 1, 1907 From the Collection of the Dorothea B. Hoover Historical Museum, Joplin, Missouri, Photocopy by Charles Snow - The Connor Hotel, 324 Main Street, Joplin, Jasper County, MO

  19. 17. Historic American Buildings Survey BUILDING OF THE HOTEL, OCTOBER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. Historic American Buildings Survey BUILDING OF THE HOTEL, OCTOBER 1, 1906 From the Collection of the Dorothea B. Hoover Historical Museum, Joplin, Missouri, Photocopy by Charles Snow - The Connor Hotel, 324 Main Street, Joplin, Jasper County, MO

  20. 19. Historic American Buildings Survey BUILDING OF THE HOTEL, MARCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. Historic American Buildings Survey BUILDING OF THE HOTEL, MARCH 1, 1907 From the Collection of the Dorothea B. Hoover Historical Museum, Joplin, Missouri, Photocopy by Charles Snow - The Connor Hotel, 324 Main Street, Joplin, Jasper County, MO

  1. 21. Historic American Buildings Survey BUILDING OF THE HOTEL, JULY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. Historic American Buildings Survey BUILDING OF THE HOTEL, JULY 1, 1907 From the Collection of the Dorothea B. Hoover Historical Museum, Joplin, Missouri, Photocopy by Charles Snow - The Connor Hotel, 324 Main Street, Joplin, Jasper County, MO

  2. 20. Historic American Buildings Survey BUILDING OF THE HOTEL, APRIL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Historic American Buildings Survey BUILDING OF THE HOTEL, APRIL 1, 1907 From the Collection of the Dorothea B. Hoover Historical Museum, Joplin, Missouri, Photocopy by Charles Snow - The Connor Hotel, 324 Main Street, Joplin, Jasper County, MO

  3. Detail view of base of Building 70021, showing Building 70022 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail view of base of Building 70021, showing Building 70022 (background), facing southeast - Naval Ordnance Test Station Inyokern, Randsburg Wash Facility Target Test Towers, Tower Road, China Lake, Kern County, CA

  4. View of hoist southeast of Building 70022. facing northwest. Building ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of hoist southeast of Building 70022. facing northwest. Building 70022 is in background - Naval Ordnance Test Station Inyokern, Randsburg Wash Facility Target Test Towers, Tower Road, China Lake, Kern County, CA

  5. View showing base of Building 70021 with Building 70022 in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View showing base of Building 70021 with Building 70022 in background, facing southeast - Naval Ordnance Test Station Inyokern, Randsburg Wash Facility Target Test Towers, Tower Road, China Lake, Kern County, CA

  6. View of building 11050. With view of building 11070 (See ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of building 11050. With view of building 11070 (See HABS No. CA 2774-B) in background. Looking southwest. - Naval Ordnance Test Station Inyokern, China Lake Pilot Plant, Machine Shop, C Street, China Lake, Kern County, CA

  7. View of building 11070, with building 11050 in the background ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of building 11070, with building 11050 in the background (left side). Looking northeast. - Naval Ordnance Test Station Inyokern, China Lake Pilot Plant, Maintenance Shop, C Street, China Lake, Kern County, CA

  8. 3. VIEW OF ADMINISTRATION BUILDING AND SIDE ELEVATION OF BUILDING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW OF ADMINISTRATION BUILDING AND SIDE ELEVATION OF BUILDING 2, FACING SOUTHEAST. - New Orleans City Railroad Company, Canal Station, Square 365, bounded by Canal, North Dupre, Iberville, & North White Streets, New Orleans, Orleans Parish, LA

  9. 54. SOUTHWEST SIDE ELEVATION OF BUILDING 367 (ADMINISTRATIVE OFFICE BUILDING) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    54. SOUTHWEST SIDE ELEVATION OF BUILDING 367 (ADMINISTRATIVE OFFICE BUILDING) IN BASE SPARES AREA. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  10. 58. NORTHEAST SIDE ELEVATION OF BUILDING 370 (ADMINISTRATIVE OFFICE BUILDING) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    58. NORTHEAST SIDE ELEVATION OF BUILDING 370 (ADMINISTRATIVE OFFICE BUILDING) IN BASE SPARES AREA. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  11. 49. NORTHEAST FRONT ELEVATION OF BUILDING 365 (ARMAMENT TESTING BUILDING) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    49. NORTHEAST FRONT ELEVATION OF BUILDING 365 (ARMAMENT TESTING BUILDING) IN BASE SPARES AREA. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  12. 41. CONTEXT VIEW LOOKING EAST OF BUILDING 269 (PAINT BUILDING) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. CONTEXT VIEW LOOKING EAST OF BUILDING 269 (PAINT BUILDING) IN ASSEMBLY AREA SHOWING ROW OF IGLOOS IN BACKGROUND. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  13. 70. INTERIOR, BUILDING 272 (PLUTONIUM STORAGE BUILDING) LOOKING WEST INTO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    70. INTERIOR, BUILDING 272 (PLUTONIUM STORAGE BUILDING) LOOKING WEST INTO STORAGE AREA SHOWING THE FOUR STORAGE ROOM ENTRANCES. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  14. 50. EAST CORNER OF BUILDING 365 (ARMAMENT TESTING BUILDING) IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    50. EAST CORNER OF BUILDING 365 (ARMAMENT TESTING BUILDING) IN BASE SPARES AREA. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  15. 53. WEST CORNER OF BUILDING 367 (ADMINISTRATIVE OFFICE BUILDING) IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    53. WEST CORNER OF BUILDING 367 (ADMINISTRATIVE OFFICE BUILDING) IN BASE SPARES AREA. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  16. 60. SOUTH CORNER OF BUILDING 370 (ADMINISTRATIVE OFFICE BUILDING) IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    60. SOUTH CORNER OF BUILDING 370 (ADMINISTRATIVE OFFICE BUILDING) IN BASE SPARES AREA. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  17. 52. NORTHWEST FRONT ELEVATION OF BUILDING 367 (ADMINISTRATION OFFICE BUILDING) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    52. NORTHWEST FRONT ELEVATION OF BUILDING 367 (ADMINISTRATION OFFICE BUILDING) IN BASE SPARES AREA. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  18. 59. EAST CORNER OF BUILDING 370 (ADMINISTRATIVE OFFICE BUILDING) IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    59. EAST CORNER OF BUILDING 370 (ADMINISTRATIVE OFFICE BUILDING) IN BASE SPARES AREA. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  19. 40. NORTHWEST FRONT ELEVATION OF BUILDING 269 (PAINT BUILDING) IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. NORTHWEST FRONT ELEVATION OF BUILDING 269 (PAINT BUILDING) IN ASSEMBLY AREA. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  20. 20. BUILDING I, BAYS 3, 2 AND 1, AND BUILDING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. BUILDING I, BAYS 3, 2 AND 1, AND BUILDING K, VIEW SOUTHEAST, NORTHWEST ELEVATIONS - Public Service Railway Company, Newton Avenue Car Shops, Bounded by Tenth, Mount Ephraim, Border & Newton Avenue, Camden, Camden County, NJ