Harnessing longitudinal information to identify genetic variation in tolerance of pigs to Porcine Reproductive and Respiratory Syndrome virus infection

USDA-ARS?s Scientific Manuscript database

Background High resistance (the ability of the host to reduce pathogen load) and tolerance (the ability to minimize the impact of infection on performance) are two desirable host traits for maintaining high health and performance levels in animals exposed to infections. For Porcine Reproductive and ...

Design and performance of vacuum system for high heat flux test facility

NASA Astrophysics Data System (ADS)

Swamy Kidambi, Rajamannar; Mokaria, Prakash; Khirwadkar, Samir; Belsare, Sunil; Khan, M. S.; Patel, Tushar; Krishnan, Deepu S.

2017-04-01

High heat flux test facility (HHFTF) at IPR is used for testing thermal performance of plasma facing materials or components. It consists of various subsystems like vacuum system, high power electron beam system, diagnostic and calibration system, data acquisition and control system and high pressure high temperature water circulation system. Vacuum system consists of large D-shaped chamber, target handling system, pumping systems and support structure. The net volume of vacuum chamber is 5 m3 was maintained at the base pressure of the order of 10-6 mbar for operation of electron gun with minimum beam diameter which is achieved with turbo-molecular pump (TMP) and cryo pump. A variable conductance gate valve is used for maintaining required vacuum in the chamber. Initial pumping of the chamber was carried out by using suitable rotary and root pumps. PXI and PLC based faster real time data acquisition and control system is implemented for performing the various operations like remote operation, online vacuum data measurements, display and status indication of all vacuum equipments. This paper describes in detail the design and implementation of various vacuum system for HHFTF.

Antihypoxants, thiasolo[5,4-b]indole derivatives, increase exercise performance in rats and mice.

PubMed

Marysheva, V V; Shabanov, P D

2009-01-01

The actoptrotective activity of 12 new antihypoxants of the thiasolo[5,4-b]indole series was studied on the model of treadmill running until exhaustion 1 and 24 h after intraperitoneal injection. Highly active compounds more effective than the reference drugs bemithyl and phenamine were found. They increased exercise performance 1 or 24 h after injection or maintained high performance throughout 24 h.

Experimental validation of prototype high voltage bushing

NASA Astrophysics Data System (ADS)

Shah, Sejal; Tyagi, H.; Sharma, D.; Parmar, D.; M. N., Vishnudev; Joshi, K.; Patel, K.; Yadav, A.; Patel, R.; Bandyopadhyay, M.; Rotti, C.; Chakraborty, A.

2017-08-01

Prototype High voltage bushing (PHVB) is a scaled down configuration of DNB High Voltage Bushing (HVB) of ITER. It is designed for operation at 50 kV DC to ensure operational performance and thereby confirming the design configuration of DNB HVB. Two concentric insulators viz. Ceramic and Fiber reinforced polymer (FRP) rings are used as double layered vacuum boundary for 50 kV isolation between grounded and high voltage flanges. Stress shields are designed for smooth electric field distribution. During ceramic to Kovar brazing, spilling cannot be controlled which may lead to high localized electrostatic stress. To understand spilling phenomenon and precise stress calculation, quantitative analysis was performed using Scanning Electron Microscopy (SEM) of brazed sample and similar configuration modeled while performing the Finite Element (FE) analysis. FE analysis of PHVB is performed to find out electrical stresses on different areas of PHVB and are maintained similar to DNB HV Bushing. With this configuration, the experiment is performed considering ITER like vacuum and electrical parameters. Initial HV test is performed by temporary vacuum sealing arrangements using gaskets/O-rings at both ends in order to achieve desired vacuum and keep the system maintainable. During validation test, 50 kV voltage withstand is performed for one hour. Voltage withstand test for 60 kV DC (20% higher rated voltage) have also been performed without any breakdown. Successful operation of PHVB confirms the design of DNB HV Bushing. In this paper, configuration of PHVB with experimental validation data is presented.

Large Cargo Containers

DTIC Science & Technology

1974-09-20

shipping and handling; environmental performance tests including high and low temperatures , DO,: FORM(1473 EDITION OF I MOW SS IS OBSO>.ETE I...maintaining Internal temperature . e. Refrigerated Container. An Insulated container that uses either mechanical or other means to lower and...maintain cold internal temperature . Refrigeration equipment may be either fixed or removable. f. Open Top Container. With bottom, side, and end walls, but

Design and Test of Fan/Nacelle Models Quiet High-Speed Fan Design

NASA Technical Reports Server (NTRS)

Miller, Christopher J. (Technical Monitor); Repp, Russ; Gentile, David; Hanson, David; Chunduru, Srinivas

2003-01-01

The primary objective of the Quiet High-Speed Fan (QHSF) program was to develop an advanced high-speed fan design that will achieve a 6 dB reduction in overall fan noise over a baseline configuration while maintaining similar performance. The program applies and validates acoustic, aerodynamic, aeroelastic, and mechanical design tools developed by NASA, US industry, and academia. The successful fan design will be used in an AlliedSignal Engines (AE) advanced regional engine to be marketed in the year 2000 and beyond. This technology is needed to maintain US industry leadership in the regional turbofan engine market.

High voltage systems (tube-type microwave)/low voltage system (solid-state microwave) power distribution

NASA Technical Reports Server (NTRS)

Nussberger, A. A.; Woodcock, G. R.

1980-01-01

SPS satellite power distribution systems are described. The reference Satellite Power System (SPS) concept utilizes high-voltage klystrons to convert the onboard satellite power from dc to RF for transmission to the ground receiving station. The solar array generates this required high voltage and the power is delivered to the klystrons through a power distribution subsystem. An array switching of solar cell submodules is used to maintain bus voltage regulation. Individual klystron dc voltage conversion is performed by centralized converters. The on-board data processing system performs the necessary switching of submodules to maintain voltage regulation. Electrical power output from the solar panels is fed via switch gears into feeder buses and then into main distribution buses to the antenna. Power also is distributed to batteries so that critical functions can be provided through solar eclipses.

Electrochemical activity of Fe-MIL-100 as a positive electrode for Na-ion batteries

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

Sava Gallis, Dorina F.; Pratt III, Harry D.; Anderson, Travis M.

2016-01-01

Here we investigate the electrochemical activity of metal-organic frameworks (MOFs) as positive electrodes for Na-ion batteries in coin cell configurations. The performance of Fe-MIL-100 material is highly dependent on the choice of sodium salt source, and electrolyte system. The overall capacity fades over many cycles, however the high Coulombic efficiency is maintained. This can be correlated with inaccessibility of active sites for Na intercalation, due to the increase of extra carbonaceous material inside the pores. High resolution synchrotron powder X-ray and pair distribution function analyses of the as-made and cycled electrodes reveal the structure maintains the long-range order with progressivemore » cycling. This finding suggests that careful consideration of all variables in battery components, and especially electrolyte selection can lead to greatly improved performances.« less

Development of low-cost high-performance multispectral camera system at Banpil

NASA Astrophysics Data System (ADS)

Oduor, Patrick; Mizuno, Genki; Olah, Robert; Dutta, Achyut K.

2014-05-01

Banpil Photonics (Banpil) has developed a low-cost high-performance multispectral camera system for Visible to Short- Wave Infrared (VIS-SWIR) imaging for the most demanding high-sensitivity and high-speed military, commercial and industrial applications. The 640x512 pixel InGaAs uncooled camera system is designed to provide a compact, smallform factor to within a cubic inch, high sensitivity needing less than 100 electrons, high dynamic range exceeding 190 dB, high-frame rates greater than 1000 frames per second (FPS) at full resolution, and low power consumption below 1W. This is practically all the feature benefits highly desirable in military imaging applications to expand deployment to every warfighter, while also maintaining a low-cost structure demanded for scaling into commercial markets. This paper describes Banpil's development of the camera system including the features of the image sensor with an innovation integrating advanced digital electronics functionality, which has made the confluence of high-performance capabilities on the same imaging platform practical at low cost. It discusses the strategies employed including innovations of the key components (e.g. focal plane array (FPA) and Read-Out Integrated Circuitry (ROIC)) within our control while maintaining a fabless model, and strategic collaboration with partners to attain additional cost reductions on optics, electronics, and packaging. We highlight the challenges and potential opportunities for further cost reductions to achieve a goal of a sub-$1000 uncooled high-performance camera system. Finally, a brief overview of emerging military, commercial and industrial applications that will benefit from this high performance imaging system and their forecast cost structure is presented.

Doubling immunochemistry laboratory testing efficiency with the cobas e 801 module while maintaining consistency in analytical performance.

PubMed

Findeisen, P; Zahn, I; Fiedler, G M; Leichtle, A B; Wang, S; Soria, G; Johnson, P; Henzell, J; Hegel, J K; Bendavid, C; Collet, N; McGovern, M; Klopprogge, K

2018-06-04

The new immunochemistry cobas e 801 module (Roche Diagnostics) was developed to meet increasing demands on routine laboratories to further improve testing efficiency, while maintaining high quality and reliable data. During a non-interventional multicenter evaluation study, the overall performance, functionality and reliability of the new module was investigated under routine-like conditions. It was tested as a dedicated immunochemistry system at four sites and as a consolidator combined with clinical chemistry at three sites. We report on testing efficiency and analytical performance of the new module. Evaluation of sample workloads with site-specific routine request patterns demonstrated increased speed and almost doubled throughput (maximal 300 tests per h), thus revealing that one cobas e 801 module can replace two cobas e 602 modules while saving up to 44% floor space. Result stability was demonstrated by QC analysis per assay throughout the study. Precision testing over 21 days yielded excellent results within and between labs, and, method comparison performed versus the cobas e 602 module routine results showed high consistency of results for all assays under study. In a practicability assessment related to performance and handling, 99% of graded features met (44%) or even exceeded (55%) laboratory expectations, with enhanced reagent management and loading during operation being highlighted. By nearly doubling immunochemistry testing efficiency on the same footprint as a cobas e 602 module, the new module has a great potential to further consolidate and enhance laboratory testing while maintaining high quality analytical performance with Roche platforms. Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Monitoring and Managing Fatigue in Basketball

PubMed Central

Edwards, Toby; Spiteri, Tania; Piggott, Benjamin; Bonhotal, Joshua; Joyce, Christopher

2018-01-01

The sport of basketball exposes athletes to frequent high intensity movements including sprinting, jumping, accelerations, decelerations and changes of direction during training and competition which can lead to acute and accumulated chronic fatigue. Fatigue may affect the ability of the athlete to perform over the course of a lengthy season. The ability of practitioners to quantify the workload and subsequent fatigue in basketball athletes in order to monitor and manage fatigue levels may be beneficial in maintaining high levels of performance and preventing unfavorable physical and physiological training adaptations. There is currently limited research quantifying training or competition workload outside of time motion analysis in basketball. In addition, systematic research investigating methods to monitor and manage athlete fatigue in basketball throughout a season is scarce. To effectively optimize and maintain peak training and playing performance throughout a basketball season, potential workload and fatigue monitoring strategies need to be discussed. PMID:29910323

Nickel-foam-supported ruthenium oxide/graphene sandwich composite constructed via one-step electrodeposition route for high-performance aqueous supercapacitors

NASA Astrophysics Data System (ADS)

Li, Meng; He, Hanwei

2018-05-01

A high-performance supercapacitor both considered high power and high energy density is needed for its applications such as portable electronics and electric vehicles. Herein, we construct a high-performance ruthenium oxide/graphene (RuO2-ERG) composite directly grown on Ni foam through cyclic voltammetric deposition process. The RuO2-ERG composite with sandwich structure is achieved effectively from a mixed solution of graphene oxide and ruthenium trichloride in the -1.4 V to 1.0 V potential range at a scan rate of 5 mV s-1. The electrochemical performance is optimized by tuning the concentration of the ruthenium trichloride. This integrative RuO2-ERG composite electrode can effectively maintains the accessible surface for redox reaction and stable channels for electrolyte penetration, leading to an improved electrochemical performance. Symmetrical aqueous supercapacitors based on RuO2-ERG electrodes exhibit a wider operational voltage window of 1.5 V. The optimized RuO2-ERG electrode displays a superior specific capacitance with 89% capacitance retention upon increasing the current density by 50 times. A high energy density of 43.8 W h kg-1 at a power density of 0.75 kW kg-1 is also obtained, and as high as 39.1 W h kg-1 can be retained at a power density of 37.5 kW kg-1. In addition, the capacitance retention is still maintained at 92.8% even after 10,000 cycles. The excellent electrochemical performance, long-term cycle stability, and the ease of preparation demonstrate that this typical RuO2-ERG electrode has great potentialities to develop high-performance supercapacitors.

On Adding Structure to Unstructured Overlay Networks

NASA Astrophysics Data System (ADS)

Leitão, João; Carvalho, Nuno A.; Pereira, José; Oliveira, Rui; Rodrigues, Luís

Unstructured peer-to-peer overlay networks are very resilient to churn and topology changes, while requiring little maintenance cost. Therefore, they are an infrastructure to build highly scalable large-scale services in dynamic networks. Typically, the overlay topology is defined by a peer sampling service that aims at maintaining, in each process, a random partial view of peers in the system. The resulting random unstructured topology is suboptimal when a specific performance metric is considered. On the other hand, structured approaches (for instance, a spanning tree) may optimize a given target performance metric but are highly fragile. In fact, the cost for maintaining structures with strong constraints may easily become prohibitive in highly dynamic networks. This chapter discusses different techniques that aim at combining the advantages of unstructured and structured networks. Namely we focus on two distinct approaches, one based on optimizing the overlay and another based on optimizing the gossip mechanism itself.

Highly deformation-tolerant carbon nanotube sponges as supercapacitor electrodes.

PubMed

Li, Peixu; Kong, Chuiyan; Shang, Yuanyuan; Shi, Enzheng; Yu, Yuntao; Qian, Weizhong; Wei, Fei; Wei, Jinquan; Wang, Kunlin; Zhu, Hongwei; Cao, Anyuan; Wu, Dehai

2013-09-21

Developing flexible and deformable supercapacitor electrodes based on porous materials is of high interest in energy related fields. Here, we show that carbon nanotube sponges, consisting of highly porous conductive networks, can serve as compressible and deformation-tolerant supercapacitor electrodes in aqueous or organic electrolytes. In aqueous electrolytes, the sponges maintain a similar specific capacitance (>90% of the original value) under a predefined compressive strain of 50% (corresponding to a volume reduction of 50%), and retain more than 70% of the original capacitance under 80% strain while the volume normalized capacitance increases by 3-fold. The sponge electrode maintains a stable performance after 1000 large strain compression cycles. A coin-shaped cell assembled with these sponges shows excellent stability over 15,000 charging cycles with negligible degradation after 500 cycles. Our results indicate that carbon nanotube sponges have the potential to fabricate deformable supercapacitor electrodes with stable performance.

Ergonomics Contribution in Maintainability

NASA Astrophysics Data System (ADS)

Teymourian, Kiumars; Seneviratne, Dammika; Galar, Diego

2017-09-01

The objective of this paper is to describe an ergonomics contribution in maintainability. The economical designs, inputs and training helps to increase the maintainability indicators for industrial devices. This analysis can be helpful, among other cases, to compare systems, to achieve a better design regarding maintainability requirements, to improve this maintainability under specific industrial environment and to foresee maintainability problems due to eventual changes in a device operation conditions. With this purpose, this work first introduces the notion of ergonomics and human factors, maintainability and the implementation of assessment of human postures, including some important postures to perform maintenance activities. A simulation approach is used to identify the critical posture of the maintenance personnel and implements the defined postures with minimal loads on the personnel who use the equipment in a practical scenario. The simulation inputs are given to the designers to improve the workplace/equipment in order to high level of maintainability. Finally, the work concludes summarizing the more significant aspects and suggesting future research.

Inequalities in maintenance of health and performance between young adult women and men in higher education.

PubMed

Löve, Jesper; Dellve, Lotta; Eklöf, Mats; Hagberg, Mats

2009-04-01

Because of ageing populations, most high-income countries are facing an imminent scarcity of labour. Maintenance of health and performance in young adults therefore becomes a crucial prerequisite for sustainable societies. One major obstruction to this accomplishment is the striking health inequalities between young women and young men. Previously these inequalities have mainly been studied in a cross-sectional way, focusing on ill-health. In this study, we compared the prevalence of maintained health and performance between young adult women and men and the predictors for this outcome. The cohort consisted of 1266 participants from a homogenous sample of university students in Sweden. A combined assessment of self-rated 'very good' health and un-impaired performance took place at three time points (i.e. maintained health and performance). Potential predictors covered stable conditions in health-related behaviours, conditions at work/school and work-home interference. Young women had less maintained health and performance than young men. No major differences in predictors were found. However, there was a tendency for psychosocial factors to be the most important predictors, especially in women. That young women had less maintained health and performance in a homogenous sample beyond well-known differentiating factors suggests explanations other than observable structural differences between the sexes. This was also indicated by the importance attached to perceived demands, and work-home interference, especially in women. The combination of less scheduled, and more unscheduled, schoolwork (i.e. time-flexibility) negatively affected the maintenance of health and performance in our study population, suggesting a focus for future studies.

Collagenous colitis: Requirement for high-dose budesonide as maintenance treatment.

PubMed

Fernandez-Bañares, Fernando; Piqueras, Marta; Guagnozzi, Danila; Robles, Virginia; Ruiz-Cerulla, Alexandra; Casanova, María José; Gisbert, Javier P; Busquets, David; Arguedas, Yolanda; Pérez-Aisa, Angeles; Fernández-Salazar, Luis; Lucendo, Alfredo J

2017-09-01

Controlled studies show high efficacy of budesonide in inducing short-term clinical remission in collagenous colitis (CC), but relapses are common after its withdrawal. To evaluate the need for high-dose budesonide (≥6mg/d) to maintain clinical remission in CC. Analysis of a multicentre retrospective cohort of 75 patients with CC (62.3±1.5years; 85% women) treated with budesonide in a clinical practice setting between 2013 and 2015. Frequency of budesonide (9mg/d) refractoriness and safety, and the need for high-dose budesonide to maintain clinical remission, were evaluated. Drugs used as budesonide-sparing, including azathioprine and mercaptopurine, were recorded. Logistic regression analysis was performed to evaluate the risk factors associated with the need for high-dose budesonide (≥6mg/d) to maintain clinical remission. Budesonide induced clinical remission in 92% of patients, with good tolerance. Fourteen of 68 patients (21%; 95% CI, 13-32%) needed high-dose budesonide to maintain remission. Only intake of NSAIDs at diagnosis (OR, 8.6; 95% CI, 1.6-44) was associated with the need for high-dose budesonide in the multivariate analysis. with thiopurines was effective in 5 out of 6 patients (83%; 95% CI, 44-97%), allowing for withdrawal from or a dose decrease of budesonide. One fifth of CC patients, especially those with NSAID intake at diagnosis, require high-dose budesonide (≥6mg/d) to maintain clinical remission. In this setting, thiopurines might be effective as budesonide-sparing drugs. Copyright © 2017 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Guide to Operating and Maintaining EnergySmart Schools

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

None

Through a commitment to high performance, school districts are discovering that smart energy choices can create lasting benefits for students, communities, and the environment. For example, an energy efficient school district with 4,000 students can save as much as $160,000 a year in energy costs. Over 10 years, those savings can reach $1.6 million, translating into the ability to hire more teachers, purchase more textbooks and computers, or invest in additional high performance facilities. Beyond these bottomline benefits, schools can better foster student health, decrease absenteeism, and serve as centers of community life. The U.S. Department of Energy's EnergySmart Schoolsmore » Program promotes a 30 percent improvement in existing school energy use. It also encourages the building of new schools that exceed code (ASHRAE 90.11999) by 50 percent or more. The program provides resources like this Guide to Operating and Maintaining EnergySmart Schools to assist school decisionmakers in planning, financing, operating, and maintaining energy efficient, high performance schools. It also offers education and training for building industry professionals. Operations and maintenance refer to all scheduled and unscheduled actions for preventing equipment failure or decline with the goal of increasing efficiency, reliability, and safety. A preventative maintenance program is the organized and planned performance of maintenance activities in order to prevent system or production problems or failures from occurring. In contrast, deferred maintenance or reactive maintenance (also called diagnostic or corrective maintenance) is conducted to address an existing problem. This guide is a primary resource for developing and implementing a districtor schoolwide operations and maintenance (O&M) program that focuses on energy efficiency. The EnergySmart Schools Solutions companion CD contains additional supporting information for design, renovation, and retrofit projects. The objective of this guide is to provide organizational and technical information for integrating energy and high performance facility management into existing O&M practices. The guide allows users to adapt and implement suggested O&M strategies to address specific energy efficiency goals. It recognizes and expands on existing tools and resources that are widely used throughout the high performance school industry. External resources are referenced throughout the guide and are also listed within the EnergySmart Schools O&M Resource List (Appendix J). While this guide emphasizes the impact of the energy efficiency component of O&M, it encourages taking a holistic approach to maintaining a high-performance school. This includes considering various environmental factors where energy plays an indirect or direct role. For example, indoor air quality, site selection, building orientation, and water efficiency should be considered. Resources to support these overlapping aspects will be cited throughout the guide.« less

Constellation Ground Systems Launch Availability Analysis: Enhancing Highly Reliable Launch Systems Design

NASA Technical Reports Server (NTRS)

Gernand, Jeffrey L.; Gillespie, Amanda M.; Monaghan, Mark W.; Cummings, Nicholas H.

2010-01-01

Success of the Constellation Program's lunar architecture requires successfully launching two vehicles, Ares I/Orion and Ares V/Altair, in a very limited time period. The reliability and maintainability of flight vehicles and ground systems must deliver a high probability of successfully launching the second vehicle in order to avoid wasting the on-orbit asset launched by the first vehicle. The Ground Operations Project determined which ground subsystems had the potential to affect the probability of the second launch and allocated quantitative availability requirements to these subsystems. The Ground Operations Project also developed a methodology to estimate subsystem reliability, availability and maintainability to ensure that ground subsystems complied with allocated launch availability and maintainability requirements. The verification analysis developed quantitative estimates of subsystem availability based on design documentation; testing results, and other information. Where appropriate, actual performance history was used for legacy subsystems or comparative components that will support Constellation. The results of the verification analysis will be used to verify compliance with requirements and to highlight design or performance shortcomings for further decision-making. This case study will discuss the subsystem requirements allocation process, describe the ground systems methodology for completing quantitative reliability, availability and maintainability analysis, and present findings and observation based on analysis leading to the Ground Systems Preliminary Design Review milestone.

A flexible cruciform journal bearing mount

NASA Technical Reports Server (NTRS)

Frost, A. E.; Geiger, W. A.

1973-01-01

Flexible mount achieves low roll, pitch and yaw stiffnesses while maintaining high radial stiffness by holding bearing pad in fixed relationship to deep web cruciform member and holding this member in fixed relationship to bearing support. This mount has particular application in small, high performance gas turbines.

Higher Education Administrators Roles in Fortification of Information Security Program

ERIC Educational Resources Information Center

Eyadat, Mohammad S.

2015-01-01

Information systems produce significant benefits to organizations. Therefore, organizations invest tremendous amount of money and time to obtain and manage information in order to maintain a high level of performance and to remain competitive. There are many factors that can impact the organizational information management and performance. One of…

Safety of High Speed Ground Transportation Systems : Analytical Methodology for Safety Validation of Computer Controlled Subsystems : Volume 2. Development of a Safety Validation Methodology

DOT National Transportation Integrated Search

1995-01-01

This report describes the development of a methodology designed to assure that a sufficiently high level of safety is achieved and maintained in computer-based systems which perform safety cortical functions in high-speed rail or magnetic levitation ...

4 CFR 2.4 - Merit system principles.

Code of Federal Regulations, 2011 CFR

2011-01-01

... recognition should be provided for excellence in performance. (4) All employees should maintain high standards... education and training in cases in which such education and training would result in better organizational...

Obtaining high-energy responses of nonlinear piezoelectric energy harvester by voltage impulse perturbations

NASA Astrophysics Data System (ADS)

Lan, Chunbo; Tang, Lihua; Qin, Weiyang

2017-07-01

Nonlinear energy harvesters have attracted wide research attentions to achieve broadband performances in recent years. Nonlinear structures have multiple solutions in certain frequency region that contains high-energy and low-energy orbits. It is effectively the frequency region of capturing a high-energy orbit that determines the broadband performance. Thus, maintaining large-amplitude high-energy-orbit oscillations is highly desired. In this paper, a voltage impulse perturbation approach based on negative resistance is applied to trigger high-energy-orbit responses of piezoelectric nonlinear energy harvesters. First, the mechanism of the voltage impulse perturbation and the implementation of the synthetic negative resistance circuit are discussed in detail. Subsequently, numerical simulation and experiment are conducted and the results demonstrate that the high-energy-orbit oscillations can be triggered by the voltage impulse perturbation method for both monostable and bistable configurations given various scenarios. It is revealed that the perturbation levels required to trigger and maintain high-energy-orbit oscillations are different for various excitation frequencies in the region where multiple solutions exist. The higher gain in voltage output when high-energy-orbit oscillations are captured is accompanied with the demand of a higher voltage impulse perturbation level.

Maintaining safety and high performance on shiftwork

NASA Technical Reports Server (NTRS)

Monk, T. H.; Folkard, S.; Wedderburn, A. I.

1996-01-01

This review of the shiftwork area focuses on aspects of safety and productivity. It discusses the situations in which shiftworker performance is critical, the types of problem that can develop and the reasons why shiftworker performance can be impaired. The review ends with a discnssion of the various advantages and disadvantages of several shift rotation systems, and of other possible solutions to the problem.

Technical considerations for designing low-cost, long-wave infrared objectives

NASA Astrophysics Data System (ADS)

Desroches, Gerard; Dalzell, Kristy; Robitaille, Blaise

2014-06-01

With the growth of uncooled infrared imaging in the consumer market, the balance between cost implications and performance criteria in the objective lens must be examined carefully. The increased availability of consumer-grade, long-wave infrared cameras is related to a decrease in military usage but it is also due to the decreasing costs of the cameras themselves. This has also driven up demand for low-cost, long-wave objectives that can resolve smaller pixels while maintaining high performance. Smaller pixels are traditionally associated with high cost objectives because of higher resolution requirements but, with careful consideration of all the requirements and proper selection of materials, costs can be moderated. This paper examines the cost/performance trade-off implications associated with optical and mechanical requirements of long-wave infrared objectives. Optical performance, f-number, field of view, distortion, focus range and thermal range all affect the cost of the objective. Because raw lens material cost is often the most expensive item in the construction, selection of the material as well as the shape of the lens while maintaining acceptable performance and cost targets were explored. As a result of these considerations, a low-cost, lightweight, well-performing objective was successfully designed, manufactured and tested.

Compact vibration isolation and suspension for Australian International Gravitational Observatory: Local control system

NASA Astrophysics Data System (ADS)

Dumas, Jean-Charles; Barriga, Pablo; Zhao, Chunnong; Ju, Li; Blair, David G.

2009-11-01

High performance vibration isolators are required for ground based gravitational wave detectors. To attain very high performance at low frequencies we have developed multistage isolators for the proposed Australian International Gravitational Observatory detector in Australia. New concepts in vibration isolation including self-damping, Euler springs, LaCoste springs, Roberts linkages, and double preisolation require novel sensors and actuators. Double preisolation enables internal feedback to be used to suppress low frequency seismic noise. Multidegree of freedom control systems are required to attain high performance. Here we describe the control components and control systems used to control all degrees of freedom. Feedback forces are injected at the preisolation stages and at the penultimate suspension stage. There is no direct actuation on test masses. A digital local control system hosted on a digital signal processor maintains alignment and position, corrects drifts, and damps the low frequency linear and torsional modes without exciting the very high Q-factor test mass suspension. The control system maintains an optical cavity locked to a laser with a high duty cycle even in the absence of an autoalignment system. An accompanying paper presents the mechanics of the system, and the optical cavity used to determine isolation performance. A feedback method is presented, which is expected to improve the residual motion at 1 Hz by more than one order of magnitude.

Compact vibration isolation and suspension for Australian International Gravitational Observatory: local control system.

PubMed

Dumas, Jean-Charles; Barriga, Pablo; Zhao, Chunnong; Ju, Li; Blair, David G

2009-11-01

High performance vibration isolators are required for ground based gravitational wave detectors. To attain very high performance at low frequencies we have developed multistage isolators for the proposed Australian International Gravitational Observatory detector in Australia. New concepts in vibration isolation including self-damping, Euler springs, LaCoste springs, Roberts linkages, and double preisolation require novel sensors and actuators. Double preisolation enables internal feedback to be used to suppress low frequency seismic noise. Multidegree of freedom control systems are required to attain high performance. Here we describe the control components and control systems used to control all degrees of freedom. Feedback forces are injected at the preisolation stages and at the penultimate suspension stage. There is no direct actuation on test masses. A digital local control system hosted on a digital signal processor maintains alignment and position, corrects drifts, and damps the low frequency linear and torsional modes without exciting the very high Q-factor test mass suspension. The control system maintains an optical cavity locked to a laser with a high duty cycle even in the absence of an autoalignment system. An accompanying paper presents the mechanics of the system, and the optical cavity used to determine isolation performance. A feedback method is presented, which is expected to improve the residual motion at 1 Hz by more than one order of magnitude.

Prevalence and Impact of Late Defecation in the Critically Ill, Thermally Injured Adult Patient

DTIC Science & Technology

2014-01-01

retention and maintain weight.12 The enteral feeding formula we provide is high in protein and carbohydrate and low in fat. Nutritional adequacy is...myriad of complex functions the GI tract must perform to maintain homeostasis to include: motility, absorption, endo- crinologic aspects... nutrition in the criti- cally ill adult have been well established, and current guidelines advocate beginning enteral feeding within 24 to 48 hours of

Arcjet thruster research and technology

NASA Technical Reports Server (NTRS)

Makel, Darby B.; Cann, Gordon L.

1988-01-01

The design, analysis, and performance testing of an advanced lower power arcjet is described. A high impedance, vortex stabilized 1-kw class arcjet has been studied. A baseline research thruster has been built and endurance and performance tested. This advanced arcjet has demonstrated long lifetime characteristics, but lower than expected performance. Analysis of the specific design has identified modifications which should improve performance and maintain the long life time shown by the arcjet.

19 CFR 143.6 - Failure to maintain performance standards.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 2 2010-04-01 2010-04-01 false Failure to maintain performance standards. 143.6... maintain performance standards. ABI participants must adhere to the performance requirements and... maximum of 90 days, if the participant's performance remains below standard, but, except for immediate...

Lessons From the Polio Endgame: Overcoming the Failure to Vaccinate and the Role of Subpopulations in Maintaining Transmission.

PubMed

Thompson, Kimberly M; Duintjer Tebbens, Radboud J

2017-07-01

Recent detections of circulating serotype 2 vaccine-derived poliovirus in northern Nigeria (Borno and Sokoto states) and Pakistan (Balochistan Province) and serotype 1 wild poliovirus in Pakistan, Afghanistan, and Nigeria (Borno) represent public health emergencies that require aggressive response. We demonstrate the importance of undervaccinated subpopulations, using an existing dynamic poliovirus transmission and oral poliovirus vaccine evolution model. We review the lessons learned during the polio endgame about the role of subpopulations in sustaining transmission, and we explore the implications of subpopulations for other vaccine-preventable disease eradication efforts. Relatively isolated subpopulations benefit little from high surrounding population immunity to transmission and will sustain transmission as long as they do not attain high vaccination coverage. Failing to reach such subpopulations with high coverage represents the root cause of polio eradication delays. Achieving and maintaining eradication requires addressing the weakest links, which includes immunizing populations in insecure areas and/or with disrupted or poor-performing health systems and managing the risks of individuals with primary immunodeficiencies who can excrete vaccine-derived poliovirus long-term. Eradication efforts for vaccine-preventable diseases need to create performance expectations for countries to immunize all people living within their borders and maintain high coverage with appropriate interventions.Keywords. Polio; eradication; transmission; heterogeneity. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Application of High Performance Computing for Simulations of N-Dodecane Jet Spray with Evaporation

DTIC Science & Technology

2016-11-01

sprays and develop a predictive theory for comparison to measurements in the laboratory of turbulent diesel sprays. 15. SUBJECT TERMS high...models into future simulations of turbulent jet sprays and develop a predictive theory for comparison to measurements in the lab of turbulent diesel ...A critical component of maintaining performance and durability of a diesel engine involves the formation of a fuel-air mixture as a diesel jet spray

Neuroimaging markers associated with maintenance of optimal memory performance in late-life.

PubMed

Dekhtyar, Maria; Papp, Kathryn V; Buckley, Rachel; Jacobs, Heidi I L; Schultz, Aaron P; Johnson, Keith A; Sperling, Reisa A; Rentz, Dorene M

2017-06-01

Age-related memory decline has been well-documented; however, some individuals reach their 8th-10th decade while maintaining strong memory performance. To determine which demographic and biomarker factors differentiated top memory performers (aged 75+, top 20% for memory) from their peers and whether top memory performance was maintained over 3 years. Clinically normal adults (n=125, CDR=0; age: 79.5±3.57 years) from the Harvard Aging Brain Study underwent cognitive testing and neuroimaging (amyloid PET, MRI) at baseline and 3-year follow-up. Participants were grouped into Optimal (n=25) vs. Typical (n=100) performers using performance on 3 challenging memory measures. Non-parametric tests were used to compare groups. There were no differences in age, sex, or education between Optimal vs. Typical performers. The Optimal group performed better in Processing Speed (p=0.016) and Executive Functioning (p<0.001). Optimal performers had larger hippocampal volumes at baseline compared with Typical Performers (p=0.027) but no differences in amyloid burden (p=0.442). Twenty-three of the 25 Optimal performers had longitudinal data and16 maintained top memory performance while 7 declined. Non-Maintainers additionally declined in Executive Functioning but not Processing Speed. Longitudinally, there were no hippocampal volume differences between Maintainers and Non-Maintainers, however Non-Maintainers exhibited higher amyloid burden at baseline in contrast with Maintainers (p=0.008). Excellent memory performance in late life does not guarantee protection against cognitive decline. Those who maintain an optimal memory into the 8th and 9th decades may have lower levels of AD pathology. Copyright © 2017. Published by Elsevier Ltd.

Working memory benefits creative insight, musical improvisation, and original ideation through maintained task-focused attention.

PubMed

De Dreu, Carsten K W; Nijstad, Bernard A; Baas, Matthijs; Wolsink, Inge; Roskes, Marieke

2012-05-01

Anecdotes from creative eminences suggest that executive control plays an important role in creativity, but scientific evidence is sparse. Invoking the Dual Pathway to Creativity Model, the authors hypothesize that working memory capacity (WMC) relates to creative performance because it enables persistent, focused, and systematic combining of elements and possibilities (persistence). Study 1 indeed showed that under cognitive load, participants performed worse on a creative insight task. Study 2 revealed positive associations between time-on-task and creativity among individuals high but not low in WMC, even after controlling for general intelligence. Study 3 revealed that across trials, semiprofessional cellists performed increasingly more creative improvisations when they had high rather than low WMC. Study 4 showed that WMC predicts original ideation because it allows persistent (rather than flexible) processing. The authors conclude that WMC benefits creativity because it enables the individual to maintain attention focused on the task and prevents undesirable mind wandering.

Dynamic graciloplasty for urinary incontinence: the potential for sequential closed-loop stimulation.

PubMed

Zonnevijlle, Erik D H; Perez-Abadia, Gustavo; Stremel, Richard W; Maldonado, Claudio J; Kon, Moshe; Barker, John H

2003-11-01

Muscle tissue transplantation applied to regain or dynamically assist contractile functions is known as 'dynamic myoplasty'. Success rates of clinical applications are unpredictable, because of lack of endurance, ischemic lesions, abundant scar formation and inadequate performance of tasks due to lack of refined control. Electrical stimulation is used to control dynamic myoplasties and should be improved to reduce some of these drawbacks. Sequential segmental neuromuscular stimulation improves the endurance and closed-loop control offers refinement in rate of contraction of the muscle, while function-controlling stimulator algorithms present the possibility of performing more complex tasks. An acute feasibility study was performed in anaesthetised dogs combining these techniques. Electrically stimulated gracilis-based neo-sphincters were compared to native sphincters with regard to their ability to maintain continence. Measurements were made during fast bladder pressure changes, static high bladder pressure and slow filling of the bladder, mimicking among others posture changes, lifting heavy objects and diuresis. In general, neo-sphincter and native sphincter performance showed no significant difference during these measurements. However, during high bladder pressures reaching 40 cm H(2)O the neo-sphincters maintained positive pressure gradients, whereas most native sphincters relaxed. During slow filling of the bladder the neo-sphincters maintained a controlled positive pressure gradient for a prolonged time without any form of training. Furthermore, the accuracy of these maintained pressure gradients proved to be within the limits set up by the native sphincters. Refinements using more complicated self-learning function-controlling algorithms proved to be effective also and are briefly discussed. In conclusion, a combination of sequential stimulation, closed-loop control and function-controlling algorithms proved feasible in this dynamic graciloplasty-model. Neo-sphincters were created, which would probably provide an acceptable performance, when the stimulation system could be implanted and further tested. Sizing this technique down to implantable proportions seems to be justified and will enable exploration of the possible benefits.

Alternative aggregates and materials for high friction surface treatments : [summary].

DOT National Transportation Integrated Search

2016-07-01

Researchers at the Texas A&M Transportation Institute studied the materials and practices that best eliminate premature HFST failures and reduce overall HFST costs, while maintaining or improving treatment life and friction performance.

Constellation Ground Systems Launch Availability Analysis: Enhancing Highly Reliable Launch Systems Design

NASA Technical Reports Server (NTRS)

Gernand, Jeffrey L.; Gillespie, Amanda M.; Monaghan, Mark W.; Cummings, Nicholas H.

2010-01-01

Success of the Constellation Program's lunar architecture requires successfully launching two vehicles, Ares I/Orion and Ares V/Altair, within a very limited time period. The reliability and maintainability of flight vehicles and ground systems must deliver a high probability of successfully launching the second vehicle in order to avoid wasting the on-orbit asset launched by the first vehicle. The Ground Operations Project determined which ground subsystems had the potential to affect the probability of the second launch and allocated quantitative availability requirements to these subsystems. The Ground Operations Project also developed a methodology to estimate subsystem reliability, availability, and maintainability to ensure that ground subsystems complied with allocated launch availability and maintainability requirements. The verification analysis developed quantitative estimates of subsystem availability based on design documentation, testing results, and other information. Where appropriate, actual performance history was used to calculate failure rates for legacy subsystems or comparative components that will support Constellation. The results of the verification analysis will be used to assess compliance with requirements and to highlight design or performance shortcomings for further decision making. This case study will discuss the subsystem requirements allocation process, describe the ground systems methodology for completing quantitative reliability, availability, and maintainability analysis, and present findings and observation based on analysis leading to the Ground Operations Project Preliminary Design Review milestone.

Exercise Training During Bed Rest Attenuates Deconditioning

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Hargens, Alan R. (Technical Monitor)

1995-01-01

A 30-day 6 deg. head-down bed rest study was conducted to evaluate high-intensity, short-duration, alternating isotonic cycle ergometer exercise (ITE) training and high-intensity intermittent isokinetic exercise (IKE) training regiments designed to maintain peak VO2 and muscle mass, strength, and endurance at ambulatory control levels throughout prolonged bed rest. Other elements of the deconditioning (acclimation) syndrome, such as proprioception, psychological performance, hypovolemia, water balance, body composition, and orthostatic tolerance, were also measured. Compared with response during bed rest of the no exercise (NOE) control group: the ITE training regimen (a) maintained work capacity (peak VO2), (b) maintained plasma and red cell volume, (c) induced positive body water balance, (d) decreased quality of sleep and mental concentration, and (e) had no effect on the decrease in orthostatic tolerance; the IKE training regimen (a) attenuated the decrease in peak VO2 by 50%, (b) attenuated loss of red cell volume by 40%, but had no effect on loss of plasma volume, (c) induced positive body water balance, (d) had no adverse effect on quality of sleep or concentration, and (e) had no effect on the decrease in orthostatic tolerance. These findings suggest that various elements of the deconditioning syndrome can be manipulated by duration and intensity of ITE or IKE training regiments, and that several different training protocols will be required to maintain or restore physiological and psychological performance of individuals confined to prolonged bed rest.

Microbial barrier assessment of Tyvek stopper packaging for rubber closures.

PubMed

Moldenhauer, J E; Bass, S A; Kupinski, M J; Walters, M L; Rubio, S L

1996-01-01

Two types of Tyvek and high density polyethylene or polypropylene packaging used for sterilization of rubber closures were evaluated for Microbial Barrier properties. The packaging evaluated was "Ready to Sterilize" (1) stoppers and a second test package (Test 2) which was designated as appropriate for a clean room, filled with washed and siliconized stoppers and then heat sealed. Each type of packaging was subjected to three different sterilization temperatures (125 degrees C, 128 degrees C and 131 degrees C) in a production sterilizer (15-18 psi). Following sterilization, a microbial barrier assessment was performed, using Bacillus subtilis niger (ATCC 9372), to determine whether the packaging could maintain a sterile barrier following sterilization. Results of the testing indicated that a microbial barrier was maintained for products in "Ready to Sterilize" packages at 125 degrees C and 128 degrees C. For products sterilized in the Test 2 container a microbial barrier could not be maintained at 128 degrees C, and no further testing was performed. Following sterilization at 131 degrees C physical defects were noted for the "Ready to Sterilize" bag and a microbial barrier could not be maintained.

Effect of Food Deprivation on a Delayed Nonmatch-to-place T-maze Task

PubMed Central

Jang, Eun-Hae; Ahn, Seo-Hee; Lee, Ye-Seul; Lee, Hye-Ryeon

2013-01-01

Food deprivation can affect performance on difficult cognitive task, such as the delayed nonmatch-to-place T-maze task (DNMT). The importance of food deprivation on maintaining high motivation for DNMT task has been emphasized, but not many studies have investigated the optimal conditions for depriving rodents to maximize performance. Establishing appropriate conditions for food deprivation is necessary to maintain DNMT task motivation. We applied different conditions of food deprivation (1-h food restriction vs. 1.5-g food restriction; single caging vs. group caging) and measured body weight and the number of correct choices that 8-week-old C57BL/6J mice made during the DNMT task. The 1.5-g food restriction group maintained 76.0±0.6% of their initial body weight, but the final body weight of the 1-h food restriction condition group was reduced to 62.2±0.8% of their initial body weight. These results propose that 1.5-g food restriction condition is effective condition for maintaining both body weight and motivation to complete the DNMT task. PMID:23833561

Least reliable bits coding (LRBC) for high data rate satellite communications

NASA Technical Reports Server (NTRS)

Vanderaar, Mark; Budinger, James; Wagner, Paul

1992-01-01

LRBC, a bandwidth efficient multilevel/multistage block-coded modulation technique, is analyzed. LRBC uses simple multilevel component codes that provide increased error protection on increasingly unreliable modulated bits in order to maintain an overall high code rate that increases spectral efficiency. Soft-decision multistage decoding is used to make decisions on unprotected bits through corrections made on more protected bits. Analytical expressions and tight performance bounds are used to show that LRBC can achieve increased spectral efficiency and maintain equivalent or better power efficiency compared to that of BPSK. The relative simplicity of Galois field algebra vs the Viterbi algorithm and the availability of high-speed commercial VLSI for block codes indicates that LRBC using block codes is a desirable method for high data rate implementations.

Four years of Landsat-7 on-orbit geometric calibration and performance

USGS Publications Warehouse

Lee, D.S.; Storey, James C.; Choate, M.J.; Hayes, R.W.

2004-01-01

Unlike its predecessors, Landsat-7 has undergone regular geometric and radiometric performance monitoring and calibration since launch in April 1999. This ongoing activity, which includes issuing quarterly updates to calibration parameters, has generated a wealth of geometric performance data over the four-year on-orbit period of operations. A suite of geometric characterization (measurement and evaluation procedures) and calibration (procedures to derive improved estimates of instrument parameters) methods are employed by the Landsat-7 Image Assessment System to maintain the geometric calibration and to track specific aspects of geometric performance. These include geodetic accuracy, band-to-band registration accuracy, and image-to-image registration accuracy. These characterization and calibration activities maintain image product geometric accuracy at a high level - by monitoring performance to determine when calibration is necessary, generating new calibration parameters, and verifying that new parameters achieve desired improvements in accuracy. Landsat-7 continues to meet and exceed all geometric accuracy requirements, although aging components have begun to affect performance.

Effect of temperature-humidity index on live performance in broiler chickens grown from 49 to 63 days of age

USDA-ARS?s Scientific Manuscript database

The thermal environment in poultry housing is a primary influence on production efficiency and live performance. Heavy broilers (body weight > 3.2 kg) typically require high ventilation rates to maintain thermal comfort and production efficiency. However, large birds are observed to pant in mild to ...

30 CFR 75.705-10 - Tying into energized high-voltage surface circuits.

Code of Federal Regulations, 2010 CFR

2010-07-01

....705-10 Tying into energized high-voltage surface circuits. If the work of forming an additional... performing such work must wear and employ all of the protective equipment and clothing required under the... designed for such purpose and must be adequately insulated and be maintained to protect such person from...

Beyond Standards: Excellence in the High School English Classroom.

ERIC Educational Resources Information Center

Jago, Carol

Each student is capable of achieving excellence, but it requires a nurturing, vigorous classroom environment. To help current and future high school English teachers create and maintain this kind of environment, this book offers concrete ways to reconceive what it means to foster excellent performance in the classroom and vivid examples of student…

The Effects of Verbal Instruction and Shaping to Improve Tackling by High School Football Players

ERIC Educational Resources Information Center

Harrison, Antonio M.; Pyles, David A.

2013-01-01

We evaluated verbal instruction and shaping using TAG (teaching with acoustical guidance) to improve tackling by 3 high school football players. Verbal instruction and shaping improved tackling for all 3 participants. In addition, performance was maintained as participants moved more quickly through the tackling procedure.

Analytical methodology for safety validation of computer controlled subsystems. Volume 1 : state-of-the-art and assessment of safety verification/validation methodologies

DOT National Transportation Integrated Search

1995-09-01

This report describes the development of a methodology designed to assure that a sufficiently high level of safety is achieved and maintained in computer-based systems which perform safety critical functions in high-speed rail or magnetic levitation ...

An Investigation of Factors Related to Teachers' Organizational Commitment in Rural High Schools

ERIC Educational Resources Information Center

Walker, Victoria LaShawn

2013-01-01

Relevant literature indicates that teachers who are not committed to their organization do not perform, do not provide a quality education for their students, and do not remain members of the organization; thus, making staffing, retaining, and maintaining highly qualified teachers problematic for rural schools. Limited research has been conducted…

Method and apparatus of cryogenic cooling for high temperature superconductor devices

DOEpatents

Yuan, Xing; Mine, Susumu

2005-02-15

A method and apparatus for providing cryogenic cooling to HTS devices, in particular those that are used in high-voltage electric power applications. The method involves pressurizing liquid cryogen to above one atmospheric pressure to improve its dielectric strength, while sub-cooling the liquid cryogen to below its saturation temperature in order to improve the performance of the HTS components of the device. An apparatus utilizing such a cooling method consists of a vessel that contains a pressurized gaseous cryogen region and a sub-cooled liquid cryogen bath, a liquid cryogen heating coupled with a gaseous cryogen venting scheme to maintain the pressure of the cryogen to a value in a range that corresponds to optimum dielectric strength of the liquid cryogen, and a cooling system that maintains the liquid cryogen at a temperature below its boiling point to improve the performance of HTS materials used in the device.

Functional Laser Trimming Of Thin Film Resistors On Silicon ICs

NASA Astrophysics Data System (ADS)

Mueller, Michael J.; Mickanin, Wes

1986-07-01

Modern Laser Wafer Trimming (LWT) technology achieves exceptional analog circuit performance and precision while maintain-ing the advantages of high production throughput and yield. Microprocessor-driven instrumentation has both emphasized the role of data conversion circuits and demanded sophisticated signal conditioning functions. Advanced analog semiconductor circuits with bandwidths over 1 GHz, and high precision, trimmable, thin-film resistors meet many of todays emerging circuit requirements. Critical to meeting these requirements are optimum choices of laser characteristics, proper materials, trimming process control, accurate modeling of trimmed resistor performance, and appropriate circuit design. Once limited exclusively to hand-crafted, custom integrated circuits, designs are now available in semi-custom circuit configurations. These are similar to those provided for digital designs and supported by computer-aided design (CAD) tools. Integrated with fully automated measurement and trimming systems, these quality circuits can now be produced in quantity to meet the requirements of communications, instrumentation, and signal processing markets.

New Flexible Silicone-Based EEG Dry Sensor Material Compositions Exhibiting Improvements in Lifespan, Conductivity, and Reliability

PubMed Central

Yu, Yi-Hsin; Chen, Shih-Hsun; Chang, Che-Lun; Lin, Chin-Teng; Hairston, W. David; Mrozek, Randy A.

2016-01-01

This study investigates alternative material compositions for flexible silicone-based dry electroencephalography (EEG) electrodes to improve the performance lifespan while maintaining high-fidelity transmission of EEG signals. Electrode materials were fabricated with varying concentrations of silver-coated silica and silver flakes to evaluate their electrical, mechanical, and EEG transmission performance. Scanning electron microscope (SEM) analysis of the initial electrode development identified some weak points in the sensors’ construction, including particle pull-out and ablation of the silver coating on the silica filler. The newly-developed sensor materials achieved significant improvement in EEG measurements while maintaining the advantages of previous silicone-based electrodes, including flexibility and non-toxicity. The experimental results indicated that the proposed electrodes maintained suitable performance even after exposure to temperature fluctuations, 85% relative humidity, and enhanced corrosion conditions demonstrating improvements in the environmental stability. Fabricated flat (forehead) and acicular (hairy sites) electrodes composed of the optimum identified formulation exhibited low impedance and reliable EEG measurement; some initial human experiments demonstrate the feasibility of using these silicone-based electrodes for typical lab data collection applications. PMID:27809260

New Flexible Silicone-Based EEG Dry Sensor Material Compositions Exhibiting Improvements in Lifespan, Conductivity, and Reliability.

PubMed

Yu, Yi-Hsin; Chen, Shih-Hsun; Chang, Che-Lun; Lin, Chin-Teng; Hairston, W David; Mrozek, Randy A

2016-10-31

This study investigates alternative material compositions for flexible silicone-based dry electroencephalography (EEG) electrodes to improve the performance lifespan while maintaining high-fidelity transmission of EEG signals. Electrode materials were fabricated with varying concentrations of silver-coated silica and silver flakes to evaluate their electrical, mechanical, and EEG transmission performance. Scanning electron microscope (SEM) analysis of the initial electrode development identified some weak points in the sensors' construction, including particle pull-out and ablation of the silver coating on the silica filler. The newly-developed sensor materials achieved significant improvement in EEG measurements while maintaining the advantages of previous silicone-based electrodes, including flexibility and non-toxicity. The experimental results indicated that the proposed electrodes maintained suitable performance even after exposure to temperature fluctuations, 85% relative humidity, and enhanced corrosion conditions demonstrating improvements in the environmental stability. Fabricated flat (forehead) and acicular (hairy sites) electrodes composed of the optimum identified formulation exhibited low impedance and reliable EEG measurement; some initial human experiments demonstrate the feasibility of using these silicone-based electrodes for typical lab data collection applications.

Evaluation of normal yellow dent corn and high available phosphorus corn in combination with reduced dietary phosphorus and phytase supplementation for broilers grown to market weights in litter pens.

PubMed

Yan, F; Kersey, J H; Fritts, C A; Waldroup, P W; Stilborn, H L; Crum, R C; Rice, D W; Raboy, V

2000-09-01

A study was conducted to determine the extent fecal P levels could be reduced while maintaining performance. Various strategies were employed including the use of a high available phosphorus hybrid of corn (HAPC), supplementation with phytase enzyme, and reduced dietary P levels. The use of HAPC resulted in a 50% reduction in phytate-bound dietary P as compared with a normal yellow dent corn (YDC) diet. Dietary nonphytate P was maintained at either NRC (1994) recommendations for appropriate age periods or reduced by 0.075 or 0.15%. Portions of the diets were supplemented with 1,000 units of phytase/kg. Male chicks of a commercial strain were grown to 56 d on the test diets. Broilers fed diets with HAPC had BW, feed conversion, livability, and tibia ash that were equal to or superior to those fed diets with YDC with considerably reduced fecal P content at any dietary level of nonphytate P. Phytase supplementation enabled birds to maintain live performance at lower levels of nonphytate P, further reducing the fecal P output. One of the greatest contributions of phytase was a reduction in mortality at the lower levels of nonphytate P. Dietary P levels could be reduced by 0.075% under NRC (1994) recommendations without adversely affecting live performance; a reduction of 0.15% in conjunction with phytase supplementation maintained BW, feed conversion, and livability but reduced tibia ash. The extent to which dietary P levels can be reduced over the entire feeding program is subject to further research.

A high speed sequential decoder

NASA Technical Reports Server (NTRS)

Lum, H., Jr.

1972-01-01

The performance and theory of operation for the High Speed Hard Decision Sequential Decoder are delineated. The decoder is a forward error correction system which is capable of accepting data from binary-phase-shift-keyed and quadriphase-shift-keyed modems at input data rates up to 30 megabits per second. Test results show that the decoder is capable of maintaining a composite error rate of 0.00001 at an input E sub b/N sub o of 5.6 db. This performance has been obtained with minimum circuit complexity.

Dietary Supplements and Military Divers: A Synopsis for Undersea Medical Officers

DTIC Science & Technology

2004-01-01

High Fructose Corn Syrup Na: 55 mg K: 55 mg Niacinamide, Calcium Pantothenate... Fructose Na: 120 mg K: 20 mg None Hydrade 55 10 High Fructose Corn Syrup Na: 91 mg K: 77 mg Vitamin C, Glycerol, Metabolol Endurance 133 16 Maltodextrin...sports bars are exceptional for maintaining performance standards over a longer time period. Powerade 72 19 High Fructose , Corn Syrup ,

Design options for improved performance with high-density carbon ablators and low-gas fill hohlraum targets

NASA Astrophysics Data System (ADS)

Berzak Hopkins, L.; Divol, L.; Lepape, S.; Meezan, N. B.; Dewald, E.; Ho, D.; Khan, S.; Pak, A.; Ralph, J.; Ross, J. S.

2016-10-01

Recent simulation-based and experimental work using high-density carbon ablators in unlined uranium hohlraums with 0.3 mg/cc helium fill have demonstrated round implosions with minimal evolution of Legendre moment P2 during burn. To extend this promising work, design studies have been performed to explore potential performance improvements with larger capsules, while maintaining similar case-to-capsule target ratios. We present here the results of these design studies, which will motivate a series of upcoming experiments at the National Ignition Facility. Prepared by LLNL under Contract DE-AC52-07NA27344.

Three phase power conversion system for utility interconnected PV applications

NASA Astrophysics Data System (ADS)

Porter, David G.

1999-03-01

Omnion Power Engineering Corporation has developed a new three phase inverter that improves the cost, reliability, and performance of three phase utility interconnected photovoltaic inverters. The inverter uses a new, high manufacturing volume IGBT bridge that has better thermal performance than previous designs. A custom easily manufactured enclosure was designed. Controls were simplified to increase reliability while maintaining important user features.

Industrial Energy Training and Certification

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

Glatt, Sandy; Cox, Daryl; Nimbalkar, Sachin U.

Compressed air systems, ammonia refrigeration systems, chilled water systems, steam systems, process heating systems, combined heat and power systems, pump systems and fan systems are major industrial energy systems commonly found in manufacturing facilities. Efficiency of these systems contributes significantly to whole facilities' energy performance. On the national, even international level, well-structured training and highly recognized certification programs help develop a highly-skilled and qualified workforce to maintain and improve facilities' energy performance, particularly as technologies within these systems become more advanced. The purpose of this paper is to review currently available training and certification programs focusing on these systems andmore » to identify the gap between market's needs and currently available programs. Three major conclusions are: first, most training programs focus on operations, maintenance, safety and design although some briefly touch the energy performance aspect; second, except CRES by RETA and PSA Certificate and PSAP Master Certification by HI, no other certifications had been found emphasizing on knowledge and skills for improving and maintaining these systems' energy performance; third, developing energy efficiency focused training and ANSI accredited certification programs on these energy systems will fill the gap between market's needs and currently available programs.« less

Industrial Energy Training and Certification

DOE PAGES

Glatt, Sandy; Cox, Daryl; Nimbalkar, Sachin U.; ...

2017-11-01

Compressed air systems, ammonia refrigeration systems, chilled water systems, steam systems, process heating systems, combined heat and power systems, pump systems and fan systems are major industrial energy systems commonly found in manufacturing facilities. Efficiency of these systems contributes significantly to whole facilities' energy performance. On the national, even international level, well-structured training and highly recognized certification programs help develop a highly-skilled and qualified workforce to maintain and improve facilities' energy performance, particularly as technologies within these systems become more advanced. The purpose of this paper is to review currently available training and certification programs focusing on these systems andmore » to identify the gap between market's needs and currently available programs. Three major conclusions are: first, most training programs focus on operations, maintenance, safety and design although some briefly touch the energy performance aspect; second, except CRES by RETA and PSA Certificate and PSAP Master Certification by HI, no other certifications had been found emphasizing on knowledge and skills for improving and maintaining these systems' energy performance; third, developing energy efficiency focused training and ANSI accredited certification programs on these energy systems will fill the gap between market's needs and currently available programs.« less

A Level Playing Field? How College Readiness Standards Change the Accountability Game

ERIC Educational Resources Information Center

Dahlin, Michael; Tarasawa, Beth

2013-01-01

In this follow-up to "Do High Flyers Maintain Their Altitude? Performance Trends of Top Students," the academic growth of 35,000 elementary and middle school students in 31 states, all of them high achievers within their own schools, were followed over a three-year period. Their achievement scores were matched with their associated…

Optimizing Special Educator Wellness and Job Performance through Stress Management

ERIC Educational Resources Information Center

Ansley, Brandis M.; Houchins, David; Varjas, Kris

2016-01-01

In addition to the stressors common to many K-12 teachers, such as high-stakes testing, a lack of autonomy, and high mental and emotional demands, special educators also address the unique needs of their students, team-teach, and maintain caseload responsibilities (Emery & Vandenberg, 2010). Many who enter the profession are fulfilled by the…

'Elgin-ND' spring wheat: A newly adapted cultivar to the north-central plains of the United States with high agronomic quality performance

USDA-ARS?s Scientific Manuscript database

The spring wheat (Triticum aestivum L.) industry and growers usually value adapted wheat cultivars with high quality attributes, an essential criteria for maintaining wheat as a competitive commodity at the national and international levels. Therefore, the goal of the breeding program is to develop ...

'Velva' spring wheat: An adapted cultivar to north-central plains of the United States with high agronomic and quality performance

USDA-ARS?s Scientific Manuscript database

Spring wheat (Triticum aestivum L.) growers and industry value adapted wheat cultivars with high quality attributes, essential criteria for maintaining wheat as a competitive crop in the spring wheat growing region of the United States. To address this goal, the breeding program at North Dakota Sta...

On the Improvement of Convergence Performance for Integrated Design of Wind Turbine Blade Using a Vector Dominating Multi-objective Evolution Algorithm

NASA Astrophysics Data System (ADS)

Wang, L.; Wang, T. G.; Wu, J. H.; Cheng, G. P.

2016-09-01

A novel multi-objective optimization algorithm incorporating evolution strategies and vector mechanisms, referred as VD-MOEA, is proposed and applied in aerodynamic- structural integrated design of wind turbine blade. In the algorithm, a set of uniformly distributed vectors is constructed to guide population in moving forward to the Pareto front rapidly and maintain population diversity with high efficiency. For example, two- and three- objective designs of 1.5MW wind turbine blade are subsequently carried out for the optimization objectives of maximum annual energy production, minimum blade mass, and minimum extreme root thrust. The results show that the Pareto optimal solutions can be obtained in one single simulation run and uniformly distributed in the objective space, maximally maintaining the population diversity. In comparison to conventional evolution algorithms, VD-MOEA displays dramatic improvement of algorithm performance in both convergence and diversity preservation for handling complex problems of multi-variables, multi-objectives and multi-constraints. This provides a reliable high-performance optimization approach for the aerodynamic-structural integrated design of wind turbine blade.

The Cutting Edge of High-Temperature Composites

NASA Technical Reports Server (NTRS)

2006-01-01

NASA s Ultra-Efficient Engine Technology (UEET) program was formed in 1999 at Glenn Research Center to manage an important national propulsion program for the Space Agency. The UEET program s focus is on developing innovative technologies to enable intelligent, environmentally friendly, and clean-burning turbine engines capable of reducing harmful emissions while maintaining high performance and increasing reliability. Seven technology projects exist under the program, with each project working towards specific goals to provide new technology for propulsion. One of these projects, Materials and Structures for High Performance, is concentrating on developing and demonstrating advanced high-temperature materials to enable high-performance, high-efficiency, and environmentally compatible propulsion systems. Materials include ceramic matrix composite (CMC) combustor liners and turbine vanes, disk alloys, turbine airfoil material systems, high-temperature polymer matrix composites, and lightweight materials for static engine structures.

ERCMExpress. Volume 2, Issue 2

ERIC Educational Resources Information Center

US Department of Education, 2006

2006-01-01

This issue of the Emergency Response and Crisis Management (ERCM) Technical Assistance Center's "ERCMExpress" introduces the National Clearinghouse for Educational Facilities (NCEF), a free public service that provides information on planning, designing, funding, building, improving and maintaining safe, healthy, high-performance schools. NCEF is…

β-Cobalt sulfide nanoparticles decorated graphene composite electrodes for high capacity and power supercapacitors

NASA Astrophysics Data System (ADS)

Qu, Baihua; Chen, Yuejiao; Zhang, Ming; Hu, Lingling; Lei, Danni; Lu, Bingan; Li, Qiuhong; Wang, Yanguo; Chen, Libao; Wang, Taihong

2012-11-01

Electrochemical supercapacitors have drawn much attention because of their high power and reasonably high energy densities. However, their performances still do not reach the demand of energy storage. In this paper β-cobalt sulfide nanoparticles were homogeneously distributed on a highly conductive graphene (CS-G) nanocomposite, which was confirmed by transmission electron microscopy analysis, and exhibit excellent electrochemical performances including extremely high values of specific capacitance (~1535 F g-1) at a current density of 2 A g-1, high-power density (11.98 kW kg-1) at a discharge current density of 40 A g-1 and excellent cyclic stability. The excellent electrochemical performances could be attributed to the graphene nanosheets (GNSs) which could maintain the mechanical integrity. Also the CS-G nanocomposite electrodes have high electrical conductivity. These results indicate that high electronic conductivity of graphene nanocomposite materials is crucial to achieving high power and energy density for supercapacitors.

β-Cobalt sulfide nanoparticles decorated graphene composite electrodes for high capacity and power supercapacitors.

PubMed

Qu, Baihua; Chen, Yuejiao; Zhang, Ming; Hu, Lingling; Lei, Danni; Lu, Bingan; Li, Qiuhong; Wang, Yanguo; Chen, Libao; Wang, Taihong

2012-12-21

Electrochemical supercapacitors have drawn much attention because of their high power and reasonably high energy densities. However, their performances still do not reach the demand of energy storage. In this paper β-cobalt sulfide nanoparticles were homogeneously distributed on a highly conductive graphene (CS-G) nanocomposite, which was confirmed by transmission electron microscopy analysis, and exhibit excellent electrochemical performances including extremely high values of specific capacitance (~1535 F g(-1)) at a current density of 2 A g(-1), high-power density (11.98 kW kg(-1)) at a discharge current density of 40 A g(-1) and excellent cyclic stability. The excellent electrochemical performances could be attributed to the graphene nanosheets (GNSs) which could maintain the mechanical integrity. Also the CS-G nanocomposite electrodes have high electrical conductivity. These results indicate that high electronic conductivity of graphene nanocomposite materials is crucial to achieving high power and energy density for supercapacitors.

Study of the performance of Micromegas detectors in magnetic field

NASA Astrophysics Data System (ADS)

Dimitrios, Sampsonidis

2018-02-01

Resistive Micromegas (MICRO MEsh GAseous Structure) detectors have been chosen by the ATLAS collaboration at LHC for the high luminosity upgrade, due to their capability to maintain full efficiency and high spatial resolution at high occupancy, for tracking muons in the forward region of the detector. The Inner Muon Station, in the high-rapidity region, the so called New Small Wheel (NSW), will be composed of micromegas detectors that will have to maintain good performance in the presence of magnetic field of up to about 0.3 T. The response of micromegas detectors is affected by the magnetic field, where the deflection of the drift electrons is described by the Lorentz angle, resulting in a bias in the reconstructed track position. Several test-beam campaigns have been performed to test the behaviour of small size resistive micromegas prototypes (10×10 cm2) in magnetic fields up to 1 T, using high momentum muon and hadron beams at CERN. These studies are performed in order to validate the capability of the chambers to provide unbiased tracks in the NSW conditions. Measurements of the Lorentz angle and drift velocity as a function of the magnetic field are presented and both are compared to expectations based on Garfield-Magboltz simulations. Several methods to correct the position bias are applied, based on the chamber configuration or on the knowledge of the local value of the magnetic field. The results of these studies are presented together with an overall discussion of the Micromegas tracking capability in magnetic field.

High power laser downhole cutting tools and systems

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

Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O

Downhole cutting systems, devices and methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena. Systems and devices for the laser cutting operations within a borehole in the earth. These systems and devices can deliver high power laser energy down a deep borehole, while maintaining the high power to perform cutting operations in such boreholes deep within the earth.

Personality and physiological correlates of performance decrement on a monotonous task requiring sustained attention.

DOT National Transportation Integrated Search

1973-12-01

The reductions in task load resulting from the increasing automation of air traffic control may actually increase the requirement for controllers to maintain high levels of sustained attention in order to detect infrequent system malfunctions. A prev...

Implementation of a pilot continuous monitoring system : Iowa Falls Arch Bridge : [tech transfer summary].

DOT National Transportation Integrated Search

2015-06-01

As part of designing, constructing, and maintaining the bridge infrastructure in : Iowa, the Iowa Department of Transportation (DOT) has, in recent years, focused : efforts on investigating the use of new high-performance materials, new design : conc...

Developing Administrative Vision.

ERIC Educational Resources Information Center

Chance, Edward W.

Visionary leadership has emerged as a significant characteristic of high performing school administrators. Vision provides a sense of direction for the school and facilitates accomplishment. Administrators must move from authoritarian and managerial modes of operation to proactive leadership, and maintain a focus on the vision through turmoil and…

Phenomenological Approach to Training

DTIC Science & Technology

1977-08-01

overt responses simpler discrete steps is also like digital computer performed. It will be suggested that a highly progr.ms or flowcharts , which consist...simple proficiency performance. cue/reaction Instruction. Putting this another way, try to visualize a 2-dlnenslonal flowchart it is important to... flowchart of discrete steps, but this does not and can easily apply situational context, which is explain how the orbit is maintained. The moon built

Expertise on Cognitive Workloads and Performance During Navigation and Target Detection

DTIC Science & Technology

2012-03-01

requiring little or no attention 1. Little confusion, risk, frustration, or anxiety exists and can be easily accomodated 2. Occasionally have spare...to confusion, frustration, or anxiety noticeably adds to workload. Significant compensation is required to maintain adequate performance. 3... anxiety . High to extreme determination and self- control required 59 Field Description elapsedTime (sec) Continuous measurement of time from the

Trade-offs in seedling growth and survival within and across tropical forest microhabitats

Treesearch

Faith Inman-Narahari; Rebecca Ostertag; Gregory P. Asner; Susan Cordell; Stephen P. Hubbell; Lawren Sack

2014-01-01

For niche differences to maintain coexistence of sympatric species, each species must grow and/or survive better than each of the others in at least one set of conditions (i.e., performance trade-offs). However, the extent of niche differentiation in tropical forests remains highly debated. We present the first test of performance trade-offs for wild seedlings in a...

Potential for a mycotoxin deactivator to improve growth and performance of rainbow trout fed high levels of an ethanol industry co-Product, grain distiller’s dried yeast

USDA-ARS?s Scientific Manuscript database

Co-products from the production of fuel ethanol may have the potential to be used as protein sources for Rainbow Trout Oncorhynchus mykiss if dietary supplementation strategies that can maintain fish performance can be identified. A random sample of one such co-product, grain distiller’s dried yeast...

Seamless service: maintaining momentum.

PubMed

Grinstead, N; Timoney, R

1994-01-01

Describes the process used by the Mater Infirmorum Hospital in Belfast in 1992-1994 to achieve high quality care (Seamless Service), motivate staff to deliver and measure performance. Aims of the project include focusing the organization on the customer, improving teamwork and motivation at all levels. After comprehensive data collection from GPs, patients and staff management forums developed a full TQM strategy to gain support and maintain momentum including innovative staff events (every staff member was given the opportunity to attend) where multilevel, multidisciplinary workshops enabled staff to design customer care standards, develop teams and lead customer-driven change.

Performance of high temperature heat flux plates and soil moisture probes during controlled surface fires

Treesearch

W. J. Massman; J. M. Frank; S. M. Massman; W. D. Shepperd

2003-01-01

Natural and prescribed fires play an important role in managing and maintaining most ecosystems in the western United States. The high soil temperatures associated with fire influence forests and their ability to regenerate after a fire by altering soil properties and soil chemistry and by killing microbes, plant roots, and seeds. Because prescribed fire is frequently...

Preparation of microporous Cellulose/Poly(vinylidene fluoride-hexafluoropropylene) membrane for lithium ion batteries by phase inversion method

NASA Astrophysics Data System (ADS)

Asghar, Muhammad Rehman; Zhang, Yao; Wu, Aiming; Yan, Xiaohui; Shen, Shuiyun; Ke, Changchun; Zhang, Junliang

2018-03-01

In this work, a porous and honeycomb-structured Cellulose/Poly (vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) membrane is prepared via a facile and ecofriendly phase inversion method by using glycerol as pore forming agent. Cellulose acetate, the source of cellulose, is easily converted into cellulose by hydrolysis in the presence of lithium hydroxide. Owing to the unique microstructure, the Cellulose/PVDF-HFP membrane offers several advantages, including high porosity, elevated electrolyte uptake, high ion conductivity, and wide electrochemical window (5.35 V). Compared with conventional polypropylene (PP) separator and PVDF-HFP membrane, the membrane developed in this work enables higher discharge capacity, higher lithium-ion transference number (0.89) and improved rate performance, which is able to maintain a high discharge capacity of 136 mAh g-1 at 8 C, using LiCoO2 as cathode and Li metal as anode. In addition, the Cellulose/PVDF-HFP membrane based batteries exhibit superior cycling performance that can maintain 91.7% capacity after 100 cycles at 0.2 C. The characterization and battery test results demonstrate that the membrane is highly compatible with lithium ion batteries.

Innovative Double Bypass Engine for Increased Performance

NASA Astrophysics Data System (ADS)

Manoharan, Sanjivan

Engines continue to grow in size to meet the current thrust requirements of the civil aerospace industry. Large engines pose significant transportation problems and require them to be split in order to be shipped. Thus, large amounts of time have been spent in researching methods to increase thrust capabilities while maintaining a reasonable engine size. Unfortunately, much of this research has been focused on increasing the performance and efficiencies of individual components while limited research has been done on innovative engine configurations. This thesis focuses on an innovative engine configuration, the High Double Bypass Engine, aimed at increasing fuel efficiency and thrust while maintaining a competitive fan diameter and engine length. The 1-D analysis was done in Excel and then compared to the results from Numerical Propulsion Simulation System (NPSS) software and were found to be within 4% error. Flow performance characteristics were also determined and validated against their criteria.

Central common drive to antagonistic ankle muscles in relation to short-term cocontraction training in nondancers and professional ballet dancers.

PubMed

Geertsen, S S; Kjær, M; Pedersen, K K; Petersen, T H; Perez, M A; Nielsen, J B

2013-10-01

Optimization of cocontraction of antagonistic muscles around the ankle joint has been shown to involve plastic changes in spinal and cortical neural circuitries. Such changes may explain the ability of elite ballet dancers to maintain a steady balance during various ballet postures. Here we investigated whether short-term cocontraction training in ballet dancers and nondancers leads to changes in the coupling between antagonistic ankle motor units. Eleven ballet dancers and 10 nondancers were recruited for the study. Prior to training, ballet dancers and nondancers showed an equal amount of coherence in the 15- to 35-Hz frequency band and short-term synchronization between antagonistic tibialis anterior and soleus motor units. The ballet dancers tended to be better at maintaining a stable cocontraction of the antagonistic muscles, but this difference was not significant (P = 0.09). Following 27 min of cocontraction training, the nondancers improved their performance significantly, whereas no significant improvement was observed for the ballet dancers. The nondancers showed a significant increase in 15- to 35-Hz coherence following the training, whereas the ballet dancers did not show a significant change. A group of control subjects (n = 4), who performed cocontraction of the antagonistic muscles for an equal amount of time, but without any requirement to improve their performance, showed no change in coherence. We suggest that improved ability to maintain a stable cocontraction around the ankle joint is accompanied by short-term plastic changes in the neural drive to the involved muscles, but that such changes are not necessary for maintained high-level performance.

Neurobiological findings associated with high cognitive performance in older adults: a systematic review.

PubMed

Borelli, Wyllians Vendramini; Schilling, Lucas Porcello; Radaelli, Graciane; Ferreira, Luciana Borges; Pisani, Leonardo; Portuguez, Mirna Wetters; da Costa, Jaderson Costa

2018-04-18

ABSTRACTObjectives:to perform a comprehensive literature review of studies on older adults with exceptional cognitive performance. We performed a systematic review using two major databases (MEDLINE and Web of Science) from January 2002 to November 2017. Quantitative analysis included nine of 4,457 studies and revealed that high-performing older adults have global preservation of the cortex, especially the anterior cingulate region, and hippocampal volumes larger than normal agers. Histological analysis of this group also exhibited decreased amyloid burden and neurofibrillary tangles compared to cognitively normal older controls. High performers that maintained memory ability after three years showed reduced amyloid positron emission tomography at baseline compared with high performers that declined. A single study on blood plasma found a set of 12 metabolites predicting memory maintenance of this group. Structural and molecular brain preservation of older adults with high cognitive performance may be associated with brain maintenance. The operationalized definition of high-performing older adults must be carefully addressed using appropriate age cut-off and cognitive evaluation, including memory and non-memory tests. Further studies with a longitudinal approach that include a younger control group are essential.

Performance and Reliability of Bonded Interfaces for High-temperature Packaging: Annual Progress Report

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

DeVoto, Douglas J.

2017-10-19

As maximum device temperatures approach 200 °Celsius, continuous operation, sintered silver materials promise to maintain bonds at these high temperatures without excessive degradation rates. A detailed characterization of the thermal performance and reliability of sintered silver materials and processes has been initiated for the next year. Future steps in crack modeling include efforts to simulate crack propagation directly using the extended finite element method (X-FEM), a numerical technique that uses the partition of unity method for modeling discontinuities such as cracks in a system.

Influence of gate overlap engineering on ambipolar and high frequency characteristics of tunnel-CNTFET

NASA Astrophysics Data System (ADS)

Shaker, Ahmed; Ossaimee, Mahmoud; Zekry, A.; Abouelatta, Mohamed

2015-10-01

In this paper, we have investigated the effect of gate overlapping-on-drain on the ambipolar behavior and high frequency performance of tunnel CNTFET (T-CNTFET). It is found that gate overlapping-on-drain suppresses the ambipolar behavior and improves OFF-state current. The simulation results show that there is an optimum choice for the overlapped length. On the other hand, this overlap deteriorates the high frequency performance. The high frequency figure of merit is analyzed in terms of the unit-gain cutoff frequency (fT). Further, we propose two different approaches to improve the high frequency performance of the overlapped T-CNTFET. The first one is based on inserting a high-dielectric constant material below the overlapped part of the gate and the second is based on depositing a different work function gate metal for the overlapped region. The two solutions show very good improvement in the high frequency performance with maintaining the suppression of the ambipolar characteristics.

49 CFR 18.36 - Procurement.

Code of Federal Regulations, 2014 CFR

2014-10-01

... subgrantees will maintain a contract administration system which ensures that contractors perform in... and subgrantees will maintain a written code of standards of conduct governing the performance of... resources. (9) Grantees and subgrantees will maintain records sufficient to detail the significant history...

34 CFR 80.36 - Procurement.

Code of Federal Regulations, 2014 CFR

2014-07-01

... subgrantees will maintain a contract administration system which ensures that contractors perform in... and subgrantees will maintain a written code of standards of conduct governing the performance of... resources. (9) Grantees and subgrantees will maintain records sufficient to detail the significant history...

CdS-Nanowires Flexible Photo-detector with Ag-Nanowires Electrode Based on Non-transfer Process

PubMed Central

Pei, Yanli; Pei, Ruihan; Liang, Xiaoci; Wang, Yuhao; Liu, Ling; Chen, Haibiao; Liang, Jun

2016-01-01

In this study, UV-visible flexible resistivity-type photo-detectors were demonstrated with CdS-nanowires (NWs) percolation network channel and Ag-NWs percolation network electrode. The devices were fabricated on Mixed Cellulose Esters (MCE) membrane using a lithographic filtration method combined with a facile non-transfer process. The photo-detectors demonstrated strong adhesion, fast response time, fast decay time, and high photo sensitivity. The high performance could be attributed to the high quality single crystalline CdS-NWs, encapsulation of NWs in MCE matrix and excellent interconnection of the NWs. Furthermore, the sensing performance was maintained even the device was bent at an angle of 90°. This research may pave the way for the facile fabrication of flexible photo-detectors with high performances. PMID:26899726

High forage quality helps maintain resilience to gastrointestinal parasites on sheep and goats

USDA-ARS?s Scientific Manuscript database

Control of gastrointestinal (GI) parasites (especially the blood feeder Haemonchus contortus) in small ruminants is a problem for sheep and goat producers. Gastrointestinal parasite overloads reduce livestock performance and production efficiency, and can result in increased death losses of animals...

Quality assurance and quality improvement in U.S. clinical molecular genetic laboratories.

PubMed

Chen, Bin; Richards, C Sue; Wilson, Jean Amos; Lyon, Elaine

2011-04-01

A robust quality-assurance program is essential for laboratories that perform molecular genetic testing to maintain high-quality testing and be able to address challenges associated with performance or delivery of testing services as the use of molecular genetic tests continues to expand in clinical and public health practice. This unit discusses quality-assurance and quality-improvement considerations that are critical for molecular genetic testing performed for heritable diseases and conditions. Specific discussion is provided on applying regulatory standards and best practices in establishing/verifying test performance, ensuring quality of the total testing process, monitoring and maintaining personnel competency, and continuing quality improvement. The unit provides a practical reference for laboratory professionals to use in recognizing and addressing essential quality-assurance issues in human molecular genetic testing. It should also provide useful information for genetics researchers, trainees, and fellows in human genetics training programs, as well as others who are interested in quality assurance and quality improvement for molecular genetic testing. 2011 by John Wiley & Sons, Inc.

Minimizing performance degradation induced by interfacial recombination in perovskite solar cells through tailoring of the transport layer electronic properties

NASA Astrophysics Data System (ADS)

Xu, Liang; Molaei Imenabadi, Rouzbeh; Vandenberghe, William G.; Hsu, Julia W. P.

2018-03-01

The performance of hybrid organic-inorganic metal halide perovskite solar cells is investigated using one-dimensional drift-diffusion device simulations. We study the effects of interfacial defect density, doping concentration, and electronic level positions of the charge transport layer (CTL). Choosing CTLs with a favorable band alignment, rather than passivating CTL-perovskite interfacial defects, is shown to be beneficial for maintaining high power-conversion efficiency, due to reduced minority carrier density arising from a favorable local electric field profile. Insights from this study provide theoretical guidance on practical selection of CTL materials for achieving high-performance perovskite solar cells.

Exercise countermeasures for bed-rest deconditioning

NASA Technical Reports Server (NTRS)

Greenleaf, John (Editor)

1993-01-01

The purpose for this 30-day bed rest study was to investigate the effects of short-term, high intensity isotonic and isokinetic exercise training on maintenance of working capacity (peak oxygen uptake), muscular strength and endurance, and on orthostatic tolerance, posture and gait. Other data were collected on muscle atrophy, bone mineralization and density, endocrine analyses concerning vasoactivity and fluid-electrolyte balance, muscle intermediary metabolism, and on performance and mood of the subjects. It was concluded that: The subjects maintained a relatively stable mood, high morale, and high esprit de corps throughout the study. Performance improved in nearly all tests in almost all the subjects. Isotonic training, as opposed to isokinetic exercise training, was associated more with decreasing levels of psychological tension, concentration, and motivation; and improvement in the quality of sleep. Working capacity (peak oxygen uptake) was maintained during bed rest with isotonic exercise training; it was not maintained with isokinetic or no exercise training. In general, there was no significant decrease in strength or endurance of arm or leg muscles during bed rest, in spite of some reduction in muscle size (atrophy) of some leg muscles. There was no effect of isotonic exercise training on orthostasis, since tilt-table tolerance was reduced similarly in all three groups following bed rest. Bed rest resulted in significant decreases of postural stability and self-selected step length, stride length, and walking velocity, which were not influenced by either exercise training regimen. Most pre-bed rest responses were restored by the fourth day of recovery.

Towards colorless transparent organic transistors: potential of benzothieno[3,2-b]benzothiophene-based wide-gap semiconductors.

PubMed

Moon, Hanul; Cho, Hyunsu; Kim, Mincheol; Takimiya, Kazuo; Yoo, Seunghyup

2014-05-21

Colorless, highly transparent organic thin-film transistors (TOTFTs) with high performance are realized based on benzothieno[3,2-b]benzothiophene (BTBT) derivatives that simultaneously exhibit a wide energy gap and high transport properties. Multilayer transparent source/drain electrodes maintain the transparency, and ultrathin fluoropolymer dielectric layers enable stable, low-voltage operation of the proposed TOTFTs. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Space-to-Space Power Beaming Enabling High Performance Rapid Geocentric Orbit Transfer

NASA Technical Reports Server (NTRS)

Dankanich, John W.; Vassallo, Corinne; Tadge, Megan

2015-01-01

The use of electric propulsion is more prevalent than ever, with industry pursuing all electric orbit transfers. Electric propulsion provides high mass utilization through efficient propellant transfer. However, the transfer times become detrimental as the delta V transitions from near-impulsive to low-thrust. Increasing power and therefore thrust has diminishing returns as the increasing mass of the power system limits the potential acceleration of the spacecraft. By using space-to-space power beaming, the power system can be decoupled from the spacecraft and allow significantly higher spacecraft alpha (W/kg) and therefore enable significantly higher accelerations while maintaining high performance. This project assesses the efficacy of space-to-space power beaming to enable rapid orbit transfer while maintaining high mass utilization. Concept assessment requires integrated techniques for low-thrust orbit transfer steering laws, efficient large-scale rectenna systems, and satellite constellation configuration optimization. This project includes the development of an integrated tool with implementation of IPOPT, Q-Law, and power-beaming models. The results highlight the viability of the concept, limits and paths to infusion, and comparison to state-of-the-art capabilities. The results indicate the viability of power beaming for what may be the only approach for achieving the desired transit times with high specific impulse.

Strongly Coupled Molybdenum Carbide on Carbon Sheets as a Bifunctional Electrocatalyst for Overall Water Splitting.

PubMed

Wang, Hao; Cao, Yingjie; Sun, Cheng; Zou, Guifu; Huang, Jianwen; Kuai, Xiaoxiao; Zhao, Jianqing; Gao, Lijun

2017-09-22

High-performance and affordable electrocatalysts from earth-abundant elements are desirably pursued for water splitting involving hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Here, a bifunctional electrocatalyst of highly crystalline Mo 2 C nanoparticles supported on carbon sheets (Mo 2 C/CS) was designed toward overall water splitting. Owing to the highly active catalytic nature of Mo 2 C nanoparticles, the high surface area of carbon sheets and efficient charge transfer in the strongly coupled composite, the designed catalysts show excellent bifunctional behavior with an onset potential of -60 mV for HER and an overpotential of 320 mV to achieve a current density of 10 mA cm -2 for OER in 1 m KOH while maintaining robust stability. Moreover, the electrolysis cell using the catalyst only requires a low cell voltage of 1.73 V to achieve a current density of 10 mA cm -2 and maintains the activity for more than 100 h when employing the Mo 2 C/CS catalyst as both anode and cathode electrodes. Such high performance makes Mo 2 C/CS a promising electrocatalyst for practical hydrogen production from water splitting. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

High-Performance AC Power Source by Applying Robust Stability Control Technology for Precision Material Machining

NASA Astrophysics Data System (ADS)

Chang, En-Chih

2018-02-01

This paper presents a high-performance AC power source by applying robust stability control technology for precision material machining (PMM). The proposed technology associates the benefits of finite-time convergent sliding function (FTCSF) and firefly optimization algorithm (FOA). The FTCSF maintains the robustness of conventional sliding mode, and simultaneously speeds up the convergence speed of the system state. Unfortunately, when a highly nonlinear loading is applied, the chatter will occur. The chatter results in high total harmonic distortion (THD) output voltage of AC power source, and even deteriorates the stability of PMM. The FOA is therefore used to remove the chatter, and the FTCSF still preserves finite system-state convergence time. By combining FTCSF with FOA, the AC power source of PMM can yield good steady-state and transient performance. Experimental results are performed in support of the proposed technology.

Stockpile Stewardship: How We Ensure the Nuclear Deterrent Without Testing

ScienceCinema

None

2018-01-16

In the 1990s, the U.S. nuclear weapons program shifted emphasis from developing new designs to dismantling thousands of existing weapons and maintaining a much smaller enduring stockpile. The United States ceased underground nuclear testing, and the Department of Energy created the Stockpile Stewardship Program to maintain the safety, security, and reliability of the U.S. nuclear deterrent without full-scale testing. This video gives a behind the scenes look at a set of unique capabilities at Lawrence Livermore that are indispensable to the Stockpile Stewardship Program: high performance computing, the Superblock category II nuclear facility, the JASPER a two stage gas gun, the High Explosive Applications Facility (HEAF), the National Ignition Facility (NIF), and the Site 300 contained firing facility.

Intensive Exercise Training During Bed Rest Attenuates Deconditioning

NASA Technical Reports Server (NTRS)

Greenleaf, John E.

1997-01-01

Intensive exercise training during bed rest attenuates deconditioning. Med. Sci. Sports Exerc., Vol. 29, No. 2, pp. 207-215, 1997. A 30-d 6 deg head-down bed rest project was conducted to evaluate variable high-intensity, short-duration, isotonic cycle ergometer exercise (ITE) training and high-intensity intermittent resistive isokinetic exercise (IKE) training regimens designed to maintain peak VO2 and muscle mass, strength, and endurance at ambulatory control levels throughout prolonged bed rest. Other elements of the deconditioning (adaptive) syndrome, such as proprioception, psychological performance, hypovolemia, water balance, body composition, and orthostatic tolerance, were also measured. Major findings are summarized in this paper. Compared with response during bed rest of the no exercise (NOE) control group: the ITE training regimen (a) maintained work capacity (peak VO2), (b) maintained plasma and red cell volumes, (c) induced positive body water balance, (d) decreased quality of sleep and mental concentration, and (e) had no effect on the decrease in orthostatic tolerance; the IKE training regimen (f) attenuated the decrease in peak VO2 by 50%, (g) attenuated loss of red cell volume by 40% but had no effect on loss of plasma volume, (b) induced positive body water balance, (i) had no adverse effect on quality of sleep or concentration, and 0) had no effect on the decrease in orthostatic tolerance. These findings suggest that various elements of the deconditioning syndrome can be manipulated by duration and intensity of ITE or IKE training regimens and that several different training protocols will be required to maintain or restore physiological and psychological performance of individuals confined to prolonged bed rest.

Turbulence Model Effects on Cold-Gas Lateral Jet Interaction in a Supersonic Crossflow

DTIC Science & Technology

2014-06-01

performance computing time from the U.S. Department of Defense (DOD) High Performance Computing Modernization program at the U.S. Army Research Laboratory... time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the...thanks Dr. Ross Chaplin , Defence Science Technology Laboratory, United Kingdom (UK), and Dr. David MacManus and Robert Christie, Cranfield University, UK

Kinetic Behavior of Leucine and Other Amino Acids Modulating Cognitive Performance via mTOR Pathway

DTIC Science & Technology

2011-12-02

is a potential target for modulation with leucine (or other therapeutic agents), to maintain/enhance normal functioning under stress conditions. Such... functioning under stress conditions. Such an effect has potential for optimizing warfighter cognitive performance under high demand conditions. The... Isoleucine L1 Essential Neutral Non-polar Branched chain Lysine Basic Y+ Essential Basic Polar Proline L1? Neutral Non-polar Aromatic Asparagine Neutral

Planning for Emergencies: A Guide for People with Chronic Kidney Disease

MedlinePlus

... 3. Continue to limit calcium and high-phosphorus products and maintain phosphate binder regimen. If you are unable to perform as many exchanges as usual, then follow the basic guidelines as listed in this emergency guideline, including limiting fluid and ... there anything else I ...

High Performance Artificial Muscles Using Nanofiber and Hybrid Yarns

DTIC Science & Technology

2015-07-14

provide 3.2% energy conversion efficiency (twice that of our CNT fiber muscles and 10X that of conducting polymer muscles ). They maintain stroke without...rubber dielectric muscle layer in twisted fiber drives torsional actuation. (2) One hundred times higher torsional stroke per muscle length...artificial muscles that provide giant stroke, fast response, high force generation, and long cycle life while optimizing energy conversion efficiencies

Field performance of graded northern red oak seedlings planted under four overstory treatments in Tennessee: two-year results

Treesearch

Christopher M. Oswalt; Wayne K. Clatterbuck

2005-01-01

Oak replacement persists as an obstacle to high quality hardwood management, especially on highly productive sites. Difficulties in naturally regenerating oak can be viewed as the result of social and economic constraints imposed by the biological solution, not the lack of a solution. As a result, economically viable alternatives are being explored to maintain oak as...

Architecture for improved mass transport and system performance in redox flow batteries

NASA Astrophysics Data System (ADS)

Houser, Jacob; Pezeshki, Alan; Clement, Jason T.; Aaron, Douglas; Mench, Matthew M.

2017-05-01

In this work, electrochemical performance and parasitic losses are combined in an overall system-level efficiency metric for a high performance, all-vanadium redox flow battery. It was found that pressure drop and parasitic pumping losses are relatively negligible for high performance cells, i.e., those capable of operating at a high current density while at a low flow rate. Through this finding, the Equal Path Length (EPL) flow field architecture was proposed and evaluated. This design has superior mass transport characteristics in comparison with the standard serpentine and interdigitated designs at the expense of increased pressure drop. An Aspect Ratio (AR) design is discussed and evaluated, which demonstrates decreased pressure drop compared to the EPL design, while maintaining similar electrochemical performance under most conditions. This AR design is capable of leading to improved system energy efficiency for flow batteries of all chemistries.

Police arrest and self-defence skills: performance under anxiety of officers with and without additional experience in martial arts.

PubMed

Renden, Peter G; Landman, Annemarie; Savelsbergh, Geert J P; Oudejans, Raôul R D

2015-01-01

We investigated whether officers with additional martial arts training experience performed better in arrest and self-defence scenarios under low and high anxiety and were better able to maintain performance under high anxiety than officers who just rely on regular police training. We were especially interested to find out whether training once a week would already lead to better performance under high anxiety. Officers with additional experience in kickboxing or karate/jiu-jitsu (training several times per week), or krav maga (training once a week) and officers with no additional experience performed several arrest and self-defence skills under low and high anxiety. Results showed that officers with additional experience (also those who trained once a week) performed better under high anxiety than officers with no additional experience. Still, the additional experience did not prevent these participants from performing worse under high anxiety compared to low anxiety. Implications for training are discussed. Practitioner summary: Dutch police officers train their arrest and self-defence skills only four to six hours per year. Our results indicate that doing an additional martial arts training once a week may lead to better performance under anxiety, although it cannot prevent that performance decreases under high anxiety compared to low anxiety.

Manx: Close air support aircraft preliminary design

NASA Technical Reports Server (NTRS)

Amy, Annie; Crone, David; Hendrickson, Heidi; Willis, Randy; Silva, Vince

1991-01-01

The Manx is a twin engine, twin tailed, single seat close air support design proposal for the 1991 Team Student Design Competition. It blends advanced technologies into a lightweight, high performance design with the following features: High sensitivity (rugged, easily maintained, with night/adverse weather capability); Highly maneuverable (negative static margin, forward swept wing, canard, and advanced avionics result in enhanced aircraft agility); and Highly versatile (design flexibility allows the Manx to contribute to a truly integrated ground team capable of rapid deployment from forward sites).

An open architecture for medical image workstation

NASA Astrophysics Data System (ADS)

Liang, Liang; Hu, Zhiqiang; Wang, Xiangyun

2005-04-01

Dealing with the difficulties of integrating various medical image viewing and processing technologies with a variety of clinical and departmental information systems and, in the meantime, overcoming the performance constraints in transferring and processing large-scale and ever-increasing image data in healthcare enterprise, we design and implement a flexible, usable and high-performance architecture for medical image workstations. This architecture is not developed for radiology only, but for any workstations in any application environments that may need medical image retrieving, viewing, and post-processing. This architecture contains an infrastructure named Memory PACS and different kinds of image applications built on it. The Memory PACS is in charge of image data caching, pre-fetching and management. It provides image applications with a high speed image data access and a very reliable DICOM network I/O. In dealing with the image applications, we use dynamic component technology to separate the performance-constrained modules from the flexibility-constrained modules so that different image viewing or processing technologies can be developed and maintained independently. We also develop a weakly coupled collaboration service, through which these image applications can communicate with each other or with third party applications. We applied this architecture in developing our product line and it works well. In our clinical sites, this architecture is applied not only in Radiology Department, but also in Ultrasonic, Surgery, Clinics, and Consultation Center. Giving that each concerned department has its particular requirements and business routines along with the facts that they all have different image processing technologies and image display devices, our workstations are still able to maintain high performance and high usability.

Optimizing ITO for incorporation into multilayer thin film stacks for visible and NIR applications

NASA Astrophysics Data System (ADS)

Roschuk, Tyler; Taddeo, David; Levita, Zachary; Morrish, Alan; Brown, Douglas

2017-05-01

Indium Tin Oxide, ITO, is the industry standard for transparent conductive coatings. As such, the common metrics for characterizing ITO performance are its transmission and conductivity/resistivity (or sheet resistance). In spite of its recurrent use in a broad range of technological applications, the performance of ITO itself is highly variable, depending on the method of deposition and chamber conditions, and a single well defined set of properties does not exist. This poses particular challenges for the incorporation of ITO in complex optical multilayer stacks while trying to maintain electronic performance. Complicating matters further, ITO suffers increased absorption losses in the NIR - making the ability to incorporate ITO into anti-reflective stacks crucial to optimizing overall optical performance when ITO is used in real world applications. In this work, we discuss the use of ITO in multilayer thin film stacks for applications from the visible to the NIR. In the NIR, we discuss methods to analyze and fine tune the film properties to account for, and minimize, losses due to absorption and to optimize the overall transmission of the multilayer stacks. The ability to obtain high transmission while maintaining good electrical properties, specifically low resistivity, is demonstrated. Trade-offs between transmission and conductivity with variation of process parameters are discussed in light of optimizing the performance of the final optical stack and not just with consideration to the ITO film itself.

Hierarchical NiCo2 S4 Nanotube@NiCo2 S4 Nanosheet Arrays on Ni Foam for High-Performance Supercapacitors.

PubMed

Chen, Haichao; Chen, Si; Shao, Hongyan; Li, Chao; Fan, Meiqiang; Chen, Da; Tian, Guanglei; Shu, Kangying

2016-01-01

Hierarchical NiCo2 S4 nanotube@NiCo2 S4 nanosheet arrays on Ni foam have been successfully synthesized. Owing to the unique hierarchical structure, enhanced capacitive performance can be attained. A specific capacitance up to 4.38 F cm(-2) is attained at 5 mA cm(-2) , which is much higher than the specific capacitance values of NiCo2 O4 nanosheet arrays, NiCo2 S4 nanosheet arrays and NiCo2 S4 nanotube arrays on Ni foam. The hierarchical NiCo2 S4 nanostructure shows superior cycling stability; after 5000 cycles, the specific capacitance still maintains 3.5 F cm(-2) . In addition, through the morphology and crystal structure measurement after cycling stability test, it is found that the NiCo2 S4 electroactive materials are gradually corroded; however, the NiCo2 S4 phase can still be well-maintained. Our results show that hierarchical NiCo2 S4 nanostructures are suitable electroactive materials for high performance supercapacitors. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Transfer of Training Study of Control Loader Dynamics

NASA Technical Reports Server (NTRS)

Cardullo, Frank M.; Stanco, Anthony A.; Kelly, Lon C.; Houck, Jacob A.; Grube, Richard C.

2011-01-01

The control inceptor used in a simulated vehicle is an important part in maintaining the fidelity of a simulation. The force feedback provided by the control inceptor gives the operator important cues to maintain adequate performance. The dynamics of a control inceptor are typically based on a second order spring mass damper system with damping, force gradient, breakout force, and natural frequency parameters. Changing these parameters can have a great effect on pilot or driver control of the vehicle. The neuromuscular system has a very important role in manipulating the control inceptor within a vehicle. Many studies by McRuer, Aponso, and Hess have dealt with modeling the neuromuscular system and quantifying the effects of a high fidelity control loader as compared to a low fidelity control loader. Humans are adaptive in nature and their control behavior changes based on different control loader dynamics. Humans will change their control behavior to maintain tracking bandwidth and minimize tracking error. This paper reports on a quasi-transfer of training experiment which was performed at the NASA Langley Research Center. The quasi transfer of training study used a high fidelity control loader and a low fidelity control loader. Subjects trained in both simulations and then were transferred to the high fidelity control loader simulation. The parameters for the high fidelity control loader were determined from the literature. The low fidelity control loader parameters were found through testing of a simple computer joystick. A disturbance compensatory task is employed. The compensatory task involves implementing a simple horizon out the window display. A disturbance consisting of a sum of sines is used. The task consists of the subject compensating for the disturbance on the roll angle of the aircraft. The vehicle dynamics are represented as 1/s and 1/s2. The subject will try to maintain level flight throughout the experiment. The subjects consist of non-pilots to remove any effects of pilot experience. First, this paper discusses the implementation of the disturbance compensation task. Second, the high and low fidelity parameters used within the experiment are presented. Finally, an explanation of results from the experiments is presented.

Facile and cost effective synthesis of mesoporous spinel NiCo2O4 as an anode for high lithium storage capacity

NASA Astrophysics Data System (ADS)

Jadhav, Harsharaj S.; Kalubarme, Ramchandra S.; Park, Choong-Nyeon; Kim, Jaekook; Park, Chan-Jin

2014-08-01

To fulfill the high power and high energy density demands for Li-ion batteries (LIBs) new anode materials need to be explored to replace conventional graphite. Herein, we report the urea assisted facile co-precipitation synthesis of spinel NiCo2O4 and its application as an anode material for LIBs. The synthesized NiCo2O4 exhibited an urchin-like microstructure and polycrystalline and mesoporous nature. In addition, the mesoporous NiCo2O4 electrode exhibited an initial discharge capacity of 1095 mA h g-1 and maintained a reversible capacity of 1000 mA h g-1 for 400 cycles at 0.5 C-rate. The reversible capacity of NiCo2O4 could still be maintained at 718 mA h g-1, even at 10 C. The mesoporous NiCo2O4 exhibits great potential as an anode material for LIBs with the advantages of unique performance and facile preparation.To fulfill the high power and high energy density demands for Li-ion batteries (LIBs) new anode materials need to be explored to replace conventional graphite. Herein, we report the urea assisted facile co-precipitation synthesis of spinel NiCo2O4 and its application as an anode material for LIBs. The synthesized NiCo2O4 exhibited an urchin-like microstructure and polycrystalline and mesoporous nature. In addition, the mesoporous NiCo2O4 electrode exhibited an initial discharge capacity of 1095 mA h g-1 and maintained a reversible capacity of 1000 mA h g-1 for 400 cycles at 0.5 C-rate. The reversible capacity of NiCo2O4 could still be maintained at 718 mA h g-1, even at 10 C. The mesoporous NiCo2O4 exhibits great potential as an anode material for LIBs with the advantages of unique performance and facile preparation. Electronic supplementary information (ESI) available: Experimental details and additional experimental results. See DOI: 10.1039/c4nr02183e

Precision Crystal Calorimeters in High Energy Physics

ScienceCinema

Ren-Yuan Zhu

2017-12-09

Precision crystal calorimeters traditionally play an important role in high energy physics experiments. In the last two decades, it faces a challenge to maintain its precision in a hostile radiation environment. This paper reviews the performance of crystal calorimeters constructed for high energy physics experiments and the progress achieved in understanding crystal’s radiation damage as well as in developing high quality scintillating crystals for particle physics. Potential applications of new generation scintillating crystals of high density and high light yield, such as LSO and LYSO, in particle physics experiments is also discussed.

Accelerated Application Development: The ORNL Titan Experience

DOE PAGES

Joubert, Wayne; Archibald, Richard K.; Berrill, Mark A.; ...

2015-05-09

The use of computational accelerators such as NVIDIA GPUs and Intel Xeon Phi processors is now widespread in the high performance computing community, with many applications delivering impressive performance gains. However, programming these systems for high performance, performance portability and software maintainability has been a challenge. In this paper we discuss experiences porting applications to the Titan system. Titan, which began planning in 2009 and was deployed for general use in 2013, was the first multi-petaflop system based on accelerator hardware. To ready applications for accelerated computing, a preparedness effort was undertaken prior to delivery of Titan. In this papermore » we report experiences and lessons learned from this process and describe how users are currently making use of computational accelerators on Titan.« less

Accelerated application development: The ORNL Titan experience

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

Joubert, Wayne; Archibald, Rick; Berrill, Mark

2015-08-01

The use of computational accelerators such as NVIDIA GPUs and Intel Xeon Phi processors is now widespread in the high performance computing community, with many applications delivering impressive performance gains. However, programming these systems for high performance, performance portability and software maintainability has been a challenge. In this paper we discuss experiences porting applications to the Titan system. Titan, which began planning in 2009 and was deployed for general use in 2013, was the first multi-petaflop system based on accelerator hardware. To ready applications for accelerated computing, a preparedness effort was undertaken prior to delivery of Titan. In this papermore » we report experiences and lessons learned from this process and describe how users are currently making use of computational accelerators on Titan.« less

Compact, maintainable 80-KeV neutral beam module

DOEpatents

Fink, Joel H.; Molvik, Arthur W.

1980-01-01

A compact, maintainable 80-keV arc chamber, extractor module for a neutral beam system immersed in a vacuum of <10.sup.-2 Torr, incorporating a nested 60-keV gradient shield located midway between the high voltage ion source and surrounding grounded frame. The shield reduces breakdown or arcing path length without increasing the voltage gradient, tends to keep electric fields normal to conducting surfaces rather than skewed and reduces the peak electric field around irregularities on the 80-keV electrodes. The arc chamber or ion source is mounted separately from the extractor or ion accelerator to reduce misalignment of the accelerator and to permit separate maintenance to be performed on these systems. The separate mounting of the ion source provides for maintaining same without removing the ion accelerator.

High forage quality helps maintain resilience to gastrointestinal parasites in sheep and goats

USDA-ARS?s Scientific Manuscript database

Condensed tannins (CT) in browse and forage plants can have positive or negative effects on livestock health and performance, depending on the type and concentration of CT present in the diet. Historically, bloating in ruminants was reduced or eliminated when grazing legumes that contained CT. Con...

Achieving and Maintaining Existing Building Sustainability Certification at Georgetown University

ERIC Educational Resources Information Center

Payant, Richard P.

2013-01-01

Sustainability is the promotion of high performance, healthful, energy-efficient, and environmentally stable buildings. Buildings intended for sustainable certification must meet guidelines developed by the Leadership in Energy and Environmental Design (LEED) of the U.S. Green Building Council. The problem is that LEED certification often fails to…

Small Changes Won't Assure Sustainability--but Reimagining Might

ERIC Educational Resources Information Center

Holdaway, Xarissa

2008-01-01

Almost every day, the author learns about new green buildings from press releases. One example is that of Arizona State University's new Biodesign Institute, a soaring, "uber"-chic, high-performance, Leadership in Energy and Environmental Design-certified center. However, the author maintains that such buildings are undoubtedly a step up…

Soil fungal community and fuctional diversity assessments of agroecosystems in the Southern High Plains

USDA-ARS?s Scientific Manuscript database

Soil fungi perform a variety of ecosystem functions that are crucial to maintaining agroecosystem sustainability including aggregate stability and soil carbon storage. The purpose of this study was to compare soil fungal communities and functional diversity in integrated crop and livestock (ICL) sy...

A Wireless Communications Laboratory on Cellular Network Planning

ERIC Educational Resources Information Center

Dawy, Z.; Husseini, A.; Yaacoub, E.; Al-Kanj, L.

2010-01-01

The field of radio network planning and optimization (RNPO) is central for wireless cellular network design, deployment, and enhancement. Wireless cellular operators invest huge sums of capital on deploying, launching, and maintaining their networks in order to ensure competitive performance and high user satisfaction. This work presents a lab…

Is the Shine off the A.P. Apple?

ERIC Educational Resources Information Center

Hurwitz, Nina; Hurwitz, Sol

2003-01-01

Describes challenges facing College Board's efforts to expand Advanced Placement (A.P.) courses to provide equal access to previously underserved low-performing urban and rural school students while maintaining the program's high academic standards. Includes list of strategies school boards can use to achieve greater access to A.P. courses while…

Modeling Student Success in Engineering Education

ERIC Educational Resources Information Center

Jin, Qu

2013-01-01

In order for the United States to maintain its global competitiveness, the long-term success of our engineering students in specific courses, programs, and colleges is now, more than ever, an extremely high priority. Numerous studies have focused on factors that impact student success, namely academic performance, retention, and/or graduation.…

Positive and Negative Consequences in Contingency Contracts: Their Relative Effectiveness on Arithmetic Performance.

ERIC Educational Resources Information Center

Kidd, Teresa A.; Saudargas, Richard A.

1988-01-01

The study with two elementary students who had low levels of completion and accuracy on daily arithmetic assignments found that a negative consequence was not necessary and that use of a positive component alone was sufficient to maintain high levels of completion and accuracy. (Author/DB)

Stress Training and Simulator Complexity: Why Sometimes More Is Less

ERIC Educational Resources Information Center

Tichon, Jennifer G.; Wallis, Guy M.

2010-01-01

Through repeated practice under conditions similar to those in real-world settings, simulator training prepares an individual to maintain effective performance under stressful work conditions. Interfaces offering high fidelity and immersion can more closely reproduce real-world experiences and are generally believed to result in better learning…

A tough performance simultaneous semi-interpenetrating polymer network

NASA Technical Reports Server (NTRS)

Pater, Ruth H. (Inventor)

1989-01-01

A semi-interpenetrating polyimide (semi-IPN) network and methods for making and using the same are disclosed. The semi-IPN system comprises a high performance thermosetting polyimide having an acetylene-terminated group acting as a crosslinking site and a high performance linear thermoplastic polyimide. The polymer is made by combining low viscosity precursors and low molecular weight polymers of the thermosetting and thermoplastic polyimides and allowing them to react in the immediate presence of each other to form a simultaneous semi-interpenetrating polyimide network. Provided is a high temperature system having significantly improved processability and damage tolerance while maintaining excellent thermo-oxidative stability, mechanical properties and resistance to humidity, when compared with the commercial high temperature resin, Thermid 600. This material is particularly adapted for use as a molding, adhesive and advanced composite matrix for aerospace structural and electronic applications.

Methods for enhancing the efficiency of creating a borehole using high power laser systems

DOEpatents

Zediker, Mark S.; Rinzler, Charles C.; Faircloth, Brian O.; Koblick, Yeshaya; Moxley, Joel F.

2014-06-24

Methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena to enhance the formation of Boreholes. Methods for the laser operations to reduce the critical path for forming a borehole in the earth. These methods can deliver high power laser energy down a deep borehole, while maintaining the high power to perform operations in such boreholes deep within the earth.

Soviet Relations with Japan: Poor Treatment of a Valuable Trade Partner

DTIC Science & Technology

1977-01-01

Thus, Japan has repeatedly been urged to take better advantage of the "international division of labor Ŗ since the *stable socialist foreign trade...some of the problems of the seventies, including the absence of abundant reserves of labor with which to maintain a high growth rate. An already high...and a concurrent decrease in the growth of total output (expected for a more mature economy at high performance levels). 7 must improve overall labor

A Systems Analysis to Define the Types of Rations Needed to Support Amphibious Operations

DTIC Science & Technology

1985-09-01

Navy and the individual Marine) and in cost. • RATION QUALITY - High Acceptance - Maximize Quality - Minimize Menu Cycle As one of four...maintaining high customer acceptance. Carbohydrate-enhanced A- or B-Ration menus would be provided to embarked (shipboard) Marines for approximately 72...assistance; 2) the typical dietery myth that high protein meals are what will "help me perform at my peak" would be circumvented; the Marine would

High power laser workover and completion tools and systems

DOEpatents

Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

2014-10-28

Workover and completion systems, devices and methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena. Systems and devices for the laser workover and completion of a borehole in the earth. These systems and devices can deliver high power laser energy down a deep borehole, while maintaining the high power to perform laser workover and completion operations in such boreholes deep within the earth.

High-performance supercapacitor electrode from cellulose-derived, inter-bonded carbon nanofibers

NASA Astrophysics Data System (ADS)

Cai, Jie; Niu, Haitao; Wang, Hongxia; Shao, Hao; Fang, Jian; He, Jingren; Xiong, Hanguo; Ma, Chengjie; Lin, Tong

2016-08-01

Carbon nanofibers with inter-bonded fibrous structure show high supercapacitor performance when being used as electrode materials. Their preparation is highly desirable from cellulose through a pyrolysis technique, because cellulose is an abundant, low cost natural material and its carbonization does not emit toxic substance. However, interconnected carbon nanofibers prepared from electrospun cellulose nanofibers and their capacitive behaviors have not been reported in the research literature. Here we report a facile one-step strategy to prepare inter-bonded carbon nanofibers from partially hydrolyzed cellulose acetate nanofibers, for making high-performance supercapacitors as electrode materials. The inter-fiber connection shows considerable improvement in electrode electrochemical performances. The supercapacitor electrode has a specific capacitance of ∼241.4 F g-1 at 1 A g-1 current density. It maintains high cycling stability (negligible 0.1% capacitance reduction after 10,000 cycles) with a maximum power density of ∼84.1 kW kg-1. They may find applications in the development of efficient supercapacitor electrodes for energy storage applications.

Forceps Delivery Volumes in Teaching and Nonteaching Hospitals: Are Volumes Sufficient for Physicians to Acquire and Maintain Competence?

PubMed Central

Kyser, Kathy L.; Lu, Xin; Santillan, Donna; Santillan, Mark; Caughey, Aaron B.; Wilson, Mark C.; Cram, Peter

2015-01-01

Purpose The decline in the use of forceps in operative deliveries over the last two decades raises questions about teaching hospitals' ability to provide trainees with adequate experience in the use of forceps. The authors examined: (1) the number of operative deliveries performed in teaching and nonteaching hospitals, and (2) whether teaching hospitals performed a sufficient number of forceps deliveries for physicians to acquire and maintain competence. Method The authors used State Inpatient Data from nine states to identify all women hospitalized for childbirth in 2008. They divided hospitals into three categories: major teaching, minor teaching, and nonteaching. They calculated delivery volumes (total operative, cesarean, vacuum, forceps, two or more methods) for each hospital and compared data across hospital categories. Results The sample included 1,344,305 childbirths in 835 hospitals. The mean cesarean volumes for major teaching, minor teaching, and nonteaching hospitals were 969.8, 757.8, and 406.9. The mean vacuum volumes were 301.0, 304.2, and 190.4, and the mean forceps volumes were 25.2, 15.3, and 8.9. In 2008, 31 hospitals (3.7% of all hospitals) performed no vacuum extractions, and 320 (38.3%) performed no forceps deliveries. In 2008, 13 (23%) major teaching and 44 (44%) minor teaching hospitals performed five or fewer forceps deliveries. Conclusions Low forceps delivery volumes may preclude many trainees from acquiring adequate experience and proficiency. These findings highlighted broader challenges, faced by many specialties, in ensuring that trainees and practicing physicians acquire and maintain competence in infrequently performed, highly technical procedures. PMID:24280847

Physiological Plasticity Is Important for Maintaining Sugarcane Growth under Water Deficit

PubMed Central

Marchiori, Paulo E. R.; Machado, Eduardo C.; Sales, Cristina R. G.; Espinoza-Núñez, Erick; Magalhães Filho, José R.; Souza, Gustavo M.; Pires, Regina C. M.; Ribeiro, Rafael V.

2017-01-01

The water availability at early phenological stages is critical for crop establishment and sugarcane varieties show differential performance under drought. Herein, we evaluated the relative importance of morphological and physiological plasticity of young sugarcane plants grown under water deficit, testing the hypothesis that high phenotypic plasticity is associated with drought tolerance. IACSP95-5000 is a high yielding genotype and IACSP94-2094 has good performance under water limiting environments. Plants were grown in rhizotrons for 35 days under three water availabilities: high (soil water matric potential [Ψm] higher than -20 kPa); intermediate (Ψm reached -65 and -90 kPa at the end of experimental period) and low (Ψm reached values lower than -150 kPa). Our data revealed that morphological and physiological responses of sugarcane to drought are dependent on genotype and intensity of water deficit. In general, IACSP95-5000 showed higher physiological plasticity given by leaf gas exchange and photochemical traits, whereas IACSP94-2094 showed higher morphological plasticity determined by changes in leaf area (LA) and specific LA. As IACSP94-2094 accumulated less biomass than IACSP95-5000 under varying water availability, it is suggested that high morphological plasticity does not always represent an effective advantage to maintain plant growth under water deficit. In addition, our results revealed that sugarcane varieties face water deficit using distinct strategies based on physiological or morphological changes. When the effectiveness of those changes in maintaining plant growth under low water availability is taken into account, our results indicate that the physiological plasticity is more important than the morphological one in young sugarcane plants. PMID:29326744

Steady and Unsteady Simulations of the Flow in an Impeller/Diffuser Stage

NASA Technical Reports Server (NTRS)

Canabal, Francisco; Dorney, Daniel J.; Garcia, Roberto; Turner, James E. (Technical Monitor)

2002-01-01

SLI engine designs will require pumps to throttle over a wide flow range while maintaining high performance. Unsteadiness generated by impeller/diffuser interaction is one of the major factors affecting off-design performance. Initial unsteady simulations are completed for impeller/diffuser stage. The Corsair simulations will continue across a wide flow range and for inducer/impeller/diffuser combinations. Results of unsteady simulations are being used to guide and explore new designs.

Development of high-performance blended cements

NASA Astrophysics Data System (ADS)

Wu, Zichao

2000-10-01

This thesis presents the development of high-performance blended cements from industrial by-products. To overcome the low-early strength of blended cements, several chemicals were studied as the activators for cement hydration. Sodium sulfate was discovered as the best activator. The blending proportions were optimized by Taguchi experimental design. The optimized blended cements containing up to 80% fly ash performed better than Type I cement in strength development and durability. Maintaining a constant cement content, concrete produced from the optimized blended cements had equal or higher strength and higher durability than that produced from Type I cement alone. The key for the activation mechanism was the reaction between added SO4 2- and Ca2+ dissolved from cement hydration products.

A low noise synthesizer for autotuning and performance testing of hydrogen masers

NASA Technical Reports Server (NTRS)

Cloeren, J. M.; Ingold, J. S.

1984-01-01

A low noise synthesizer has been developed for use in hydrogen maser autotuning and performance evaluation. This synthesizer replaces the frequency offset maser normally used for this purpose and allows the user to maintain all masers in the ensemble at the same frequency. The synthesizer design utilizes a quartz oscillator with a BVA resonator. The oscillator has a frequency offset of 5 X 10 to the minus 8 power. The BVA oscillator is phase-locked to a hydrogen maser by means of a high gain, high stability phase-locked loop, employing low noise multipliers as phase error amplifiers. A functional block diagram of the synthesizer and performance data will be presented.

Visual/motion cue mismatch in a coordinated roll maneuver

NASA Technical Reports Server (NTRS)

Shirachi, D. K.; Shirley, R. S.

1981-01-01

The effects of bandwidth differences between visual and motion cueing systems on pilot performance for a coordinated roll task were investigated. Visual and motion cue configurations which were acceptable and the effects of reduced motion cue scaling on pilot performance were studied to determine the scale reduction threshold for which pilot performance was significantly different from full scale pilot performance. It is concluded that: (1) the presence or absence of high frequency error information in the visual and/or motion display systems significantly affects pilot performance; and (2) the attenuation of motion scaling while maintaining other display dynamic characteristics constant, affects pilot performance.

Ultrathin Nickel Hydroxide and Oxide Nanosheets: Synthesis, Characterizations and Excellent Supercapacitor Performances

PubMed Central

Zhu, Youqi; Cao, Chuanbao; Tao, Shi; Chu, Wangsheng; Wu, Ziyu; Li, Yadong

2014-01-01

High-quality ultrathin two-dimensional nanosheets of α-Ni(OH)2 are synthesized at large scale via microwave-assisted liquid-phase growth under low-temperature atmospheric conditions. After heat treatment, non-layered NiO nanosheets are obtained while maintaining their original frame structure. The well-defined and freestanding nanosheets exhibit a micron-sized planar area and ultrathin thickness (<2 nm), suggesting an ultrahigh surface atom ratio with unique surface and electronic structure. The ultrathin 2D nanostructure can make most atoms exposed outside with high activity thus facilitate the surface-dependent electrochemical reaction processes. The ultrathin α-Ni(OH)2 and NiO nanosheets exhibit enhanced supercapacitor performances. Particularly, the α-Ni(OH)2 nanosheets exhibit a maximum specific capacitance of 4172.5 F g−1 at a current density of 1 A g−1. Even at higher rate of 16 A g−1, the specific capacitance is still maintained at 2680 F g−1 with 98.5% retention after 2000 cycles. Even more important, we develop a facile and scalable method to produce high-quality ultrathin transition metal hydroxide and oxide nanosheets and make a possibility in commercial applications. PMID:25168127

Preparation of 3D Architecture Graphdiyne Nanosheets for High-Performance Sodium-Ion Batteries and Capacitors.

PubMed

Wang, Kun; Wang, Ning; He, Jianjiang; Yang, Ze; Shen, Xiangyan; Huang, Changshui

2017-11-22

Here, we apply three-dimensional (3D) architecture graphdiyne nanosheet (GDY-NS) as anode materials for sodium-ion storage devices achieving high energy and power performance along with excellent cyclic ability. The contribution of 3D architecture nanostructure and intramolecular pores of the GDY-NS can substantially optimize the sodium storage behavior through the accommodated intramolecular pore, 3D interconnective porous structure, and increased activity sites to facilitate a fast sodium-ion-diffusion channel. The contribution of butadiyne linkages and the formation of a stable solid electrolyte interface layer are directly confirmed through the in situ Raman measurement. The GDY-NS-based sodium-ion batteries exhibit a stable reversible capacity of approximately 812 mAh g -1 at a current density of 0.05 A g -1 ; they maintain more than 405 mAh g -1 over 1000 cycles at a current density of 1 A g -1 . Furthermore, the sodium-ion capacitors could deliver a capacitance more than 200 F g -1 over 3000 cycles at 1 A g -1 and display an initial specific energy as high as 182.3 Wh kg -1 at a power density of 300 W kg -1 and maintain specific energy of 166 Wh kg -1 even at a power density of 15 000 W kg -1 . The high energy and power density along with excellent cyclic performance based on the GDY-NS anode offers a great potential toward application on next-generation energy storage devices.

Performance Characteristics For The Orbiter Camera Payload System's Large Format Camera (LFC)

NASA Astrophysics Data System (ADS)

MoIIberg, Bernard H.

1981-11-01

The Orbiter Camera Payload System, the OCPS, is an integrated photographic system which is carried into Earth orbit as a payload in the Shuttle Orbiter vehicle's cargo bay. The major component of the OCPS is a Large Format Camera (LFC) which is a precision wide-angle cartographic instrument that is capable of produc-ing high resolution stereophotography of great geometric fidelity in multiple base to height ratios. The primary design objective for the LFC was to maximize all system performance characteristics while maintaining a high level of reliability compatible with rocket launch conditions and the on-orbit environment.

High temperature solid oxide regenerative fuel cell for solar photovoltaic energy storage

NASA Technical Reports Server (NTRS)

Bents, David J.

1987-01-01

A hydrogen-oxygen regenerative fuel cell energy storage system based on high temperature solid oxide fuel cell technology is discussed which has application to darkside energy storage for solar photovoltaics. The forward and reverse operating cycles are described, and heat flow, mass, and energy balance data are presented to characterize the system's performance and the variation of performance with changing reactant storage pressure. The present system weighs less than nickel hydrogen battery systems after 0.7 darkside operation, and it maintains a specific weight advantage over radioisotope generators for discharge periods up to 72 hours.

High temperature solid oxide regenerative fuel cell for solar photovoltaic energy storage

NASA Astrophysics Data System (ADS)

Bents, David J.

A hydrogen-oxygen regenerative fuel cell energy storage system based on high temperature solid oxide fuel cell technology is discussed which has application to darkside energy storage for solar photovoltaics. The forward and reverse operating cycles are described, and heat flow, mass, and energy balance data are presented to characterize the system's performance and the variation of performance with changing reactant storage pressure. The present system weighs less than nickel hydrogen battery systems after 0.7 darkside operation, and it maintains a specific weight advantage over radioisotope generators for discharge periods up to 72 hours.

Parametric Investigation of a High-Lift Airfoil at High Reynolds Numbers

NASA Technical Reports Server (NTRS)

Lin, John C.; Dominik, Chet J.

1997-01-01

A new two-dimensional, three-element, advanced high-lift research airfoil has been tested in the NASA Langley Research Center s Low-Turbulence Pressure Tunnel at a chord Reynolds number up to 1.6 x 107. The components of this high-lift airfoil have been designed using a incompressible computational code (INS2D). The design was to provide high maximum-lift values while maintaining attached flow on the single-segment flap at landing conditions. The performance of the new NASA research airfoil is compared to a similar reference high-lift airfoil. On the new high-lift airfoil the effects of Reynolds number on slat and flap rigging have been studied experimentally, as well as the Mach number effects. The performance trend of the high-lift design is comparable to that predicted by INS2D over much of the angle-of-attack range. However, the code did not accurately predict the airfoil performance or the configuration-based trends near maximum lift where the compressibility effect could play a major role.

Marine Corps Systems Command (MCSC) Advanced Planning Briefing To Industry (APBI)

DTIC Science & Technology

2008-05-14

High force protection bill associated with establishing and maintaining a secure lodgment – Ships densely packed, assemble ashore • MPF(F) – Operates...14 May 08 EXPEDITIONARY FIGHTING VEHICLE (EFV) Provide High Speed Transport of Embarked Marine Infantry From Ships Located Beyond the Horizon to...Business Size Crafting your RFI Response DO - Focus exclusively on Past Performance Provide a “Team” Brief Focus on “non-Priorities” Include

TRIDENT II (D-5) Strategic Weapon System Guide for Potential Subcontractors.

DTIC Science & Technology

1982-01-01

pattern. Usually high technology item subcontracts are the first selected, This is followed by crit- ical, special long-lead time, common, and...performance. These disciplines provide the program with a definitive approach to maintaining high standards of reliability and readiness for weapon system...missile itself will be increased in length and diameter.. The range of the missile will be enhanced, and it will carry an increased payload. Energy

Medical and Performance Problems of Acute High Altitude-Exposure,

DTIC Science & Technology

1981-07-11

counter the respiratory alkalosis of altitude with a metabolic acidosis, thereby maintaining normal pH. The occurrence and severity of symptoms have...In chamber studies at our Institute, the role of hypocapnic alkalosis in the development of AMS was assessed by exposing subjects to simulated high...beneficial effect on symptomatology, if not by preventing the development of alkalosis ? Further- more, Why does the development of hypocapnia appear to be

Summary of the Sixth Persh Workshop: Corrosion Policy Guiding Science and Technology

DTIC Science & Technology

2016-01-01

mitigating corrosion. Corrosion affects military readiness, so corrosion prevention and control (CPC) have a high priority for the DOD since CPC is a...resulting in high -cost repairs. Corrosion mitigation is thus a key cost-effective approach for system maintainability and reduced life cycle costs. The... treatments . • Develop corrosion databases and corrosion models for predictive evaluation. Testing methods for realistic prediction of performance

Energetic Extremes in Aquatic Locomotion by Coral Reef Fishes

PubMed Central

Fulton, Christopher J.; Johansen, Jacob L.; Steffensen, John F.

2013-01-01

Underwater locomotion is challenging due to the high friction and resistance imposed on a body moving through water and energy lost in the wake during undulatory propulsion. While aquatic organisms have evolved streamlined shapes to overcome such resistance, underwater locomotion has long been considered a costly exercise. Recent evidence for a range of swimming vertebrates, however, has suggested that flapping paired appendages around a rigid body may be an extremely efficient means of aquatic locomotion. Using intermittent flow-through respirometry, we found exceptional energetic performance in the Bluelined wrasse Stethojulis bandanensis, which maintains tuna-like optimum cruising speeds (up to 1 metre s−1) while using 40% less energy than expected for their body size. Displaying an exceptional aerobic scope (22-fold above resting), streamlined rigid-body posture, and wing-like fins that generate lift-based thrust, S. bandanensis literally flies underwater to efficiently maintain high optimum swimming speeds. Extreme energetic performance may be key to the colonization of highly variable environments, such as the wave-swept habitats where S. bandanensis and other wing-finned species tend to occur. Challenging preconceived notions of how best to power aquatic locomotion, biomimicry of such lift-based fin movements could yield dramatic reductions in the power needed to propel underwater vehicles at high speed. PMID:23326566

The development and functional control of reading-comprehension behavior.

PubMed

Rosenbaum, M S; Breiling, J

1976-01-01

Reading comprehension, indicated by motor behavior and multiple-choice picture selection called for in written instructions, was taught to an autistic child using verbal prompts, modelling, and physical guidance. The child was rewarded for correct behaviors to training items; nonrewarded probes were used to assess generalization. Probable maintaining events were assessed through their sequential removal in a reversal design. Results showed: (a) following acquisition, performance was maintained at a near-100% level when candy, praise, attention, and training were removed, (b) absence of other persons was correlated with a marked decrease in performance, whereas their presence was associated with performance at near 100%, and (c) performance generalized to probes and across experimenters. Rewards, which may have been reinforcing during acquisition, did not appear necessary to maintain later performance. Instead, presence of others (a setting event) was demonstrated to have control over maintained performance.

Importance of polypyrrole in constructing 3D hierarchical carbon nanotube@MnO2 perfect core-shell nanostructures for high-performance flexible supercapacitors

NASA Astrophysics Data System (ADS)

Zhou, Jinyuan; Zhao, Hao; Mu, Xuemei; Chen, Jiayi; Zhang, Peng; Wang, Yaling; He, Yongmin; Zhang, Zhenxing; Pan, Xiaojun; Xie, Erqing

2015-08-01

This study reports the preparation of 3D hierarchical carbon nanotube (CNT) @MnO2 core-shell nanostructures under the assistance of polypyrrole (PPy). The as-prepared CNT@PPy@MnO2 core-shell structures show a perfect coating of MnO2 on each CNT and, more importantly, a robust bush-like pseudocapacitive shell to effectively increase the specific surface area and enhance the ion accessibility. As expected, a high specific capacity of 490-530 F g-1 has been achieved from CNT@PPy@MnO2 single electrodes. And about 98.5% of the capacity is retained after 1000 charge/discharge cycles at a current density of 5 A g-1. Furthermore, the assembled asymmetric CNT@PPy@MnO2//AC capacitors show the maximum energy density of 38.42 W h kg-1 (2.24 mW h cm-3) at a power density of 100 W kg-1 (5.83 mW cm-3), and they maintain 59.52% of the initial value at 10 000 W kg-1 (0.583 W cm-3). In addition, the assembled devices show high cycling stabilities (89.7% after 2000 cycles for asymmetric and 87.2% for symmetric), and a high bending stability (64.74% after 200 bending tests). This ability to obtain high energy densities at high power rates while maintaining high cycling stability demonstrates that this well-designed structure could be a promising electrode material for high-performance supercapacitors.This study reports the preparation of 3D hierarchical carbon nanotube (CNT) @MnO2 core-shell nanostructures under the assistance of polypyrrole (PPy). The as-prepared CNT@PPy@MnO2 core-shell structures show a perfect coating of MnO2 on each CNT and, more importantly, a robust bush-like pseudocapacitive shell to effectively increase the specific surface area and enhance the ion accessibility. As expected, a high specific capacity of 490-530 F g-1 has been achieved from CNT@PPy@MnO2 single electrodes. And about 98.5% of the capacity is retained after 1000 charge/discharge cycles at a current density of 5 A g-1. Furthermore, the assembled asymmetric CNT@PPy@MnO2//AC capacitors show the maximum energy density of 38.42 W h kg-1 (2.24 mW h cm-3) at a power density of 100 W kg-1 (5.83 mW cm-3), and they maintain 59.52% of the initial value at 10 000 W kg-1 (0.583 W cm-3). In addition, the assembled devices show high cycling stabilities (89.7% after 2000 cycles for asymmetric and 87.2% for symmetric), and a high bending stability (64.74% after 200 bending tests). This ability to obtain high energy densities at high power rates while maintaining high cycling stability demonstrates that this well-designed structure could be a promising electrode material for high-performance supercapacitors. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03426d

Stockpile Stewardship: How We Ensure the Nuclear Deterrent Without Testing

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

None

2014-09-04

In the 1990s, the U.S. nuclear weapons program shifted emphasis from developing new designs to dismantling thousands of existing weapons and maintaining a much smaller enduring stockpile. The United States ceased underground nuclear testing, and the Department of Energy created the Stockpile Stewardship Program to maintain the safety, security, and reliability of the U.S. nuclear deterrent without full-scale testing. This video gives a behind the scenes look at a set of unique capabilities at Lawrence Livermore that are indispensable to the Stockpile Stewardship Program: high performance computing, the Superblock category II nuclear facility, the JASPER a two stage gas gun,more » the High Explosive Applications Facility (HEAF), the National Ignition Facility (NIF), and the Site 300 contained firing facility.« less

D-Shaped Polarization Maintaining Fiber Sensor for Strain and Temperature Monitoring.

PubMed

Qazi, Hummad Habib; Mohammad, Abu Bakar; Ahmad, Harith; Zulkifli, Mohd Zamani

2016-09-15

A D-shaped polarization-maintaining fiber (PMF) as fiber optic sensor for the simultaneous monitoring of strain and the surrounding temperature is presented. A mechanical end and edge polishing system with aluminum oxide polishing film is utilized to perform sequential polishing on one side (lengthwise) of the PMF in order to fabricate a D-shaped cross-section. Experimental results show that the proposed sensor has high sensitivity of 46 pm/µε and 130 pm/°C for strain and temperature, respectively, which is significantly higher than other recently reported work (mainly from 2013) related to fiber optic sensors. The easy fabrication method, high sensitivity, and good linearity make this sensing device applicable in various applications such as health monitoring and spatial analysis of engineering structures.

D-Shaped Polarization Maintaining Fiber Sensor for Strain and Temperature Monitoring

PubMed Central

Qazi, Hummad Habib; Mohammad, Abu Bakar; Ahmad, Harith; Zulkifli, Mohd Zamani

2016-01-01

A D-shaped polarization-maintaining fiber (PMF) as fiber optic sensor for the simultaneous monitoring of strain and the surrounding temperature is presented. A mechanical end and edge polishing system with aluminum oxide polishing film is utilized to perform sequential polishing on one side (lengthwise) of the PMF in order to fabricate a D-shaped cross-section. Experimental results show that the proposed sensor has high sensitivity of 46 pm/µε and 130 pm/°C for strain and temperature, respectively, which is significantly higher than other recently reported work (mainly from 2013) related to fiber optic sensors. The easy fabrication method, high sensitivity, and good linearity make this sensing device applicable in various applications such as health monitoring and spatial analysis of engineering structures. PMID:27649195

Surface tiny grain-dependent enhanced rate performance of MoO3 nanobelts with pseudocapacitance contribution for lithium-ion battery anode

NASA Astrophysics Data System (ADS)

Cao, Liyun; He, Juju; Li, Jiayin; Yan, Jingwen; Huang, Jianfeng; Qi, Ying; Feng, Liangliang

2018-07-01

In order to improve the rate performance of MoO3, a novel MoO3 nanobelt with tiny grains on surface (named as d-MoO3) is fabricated via one-step facile hydrothermal method with citric acid adding, in which citric acid (CA) serves as a weak reductant as well as surface modification agent. When tested as an anode in LIBs, d-MoO3 displays an improved discharge capacity of 787 mAh·g-1 at 0.1 A g-1 over 100 cycles with capacity retention of ∼91% while MoO3 decays to 50 mAh·g-1 in the 100th cycle. Notably, d-MoO3 delivers enhanced rate capability (536 and 370 mAh·g-1 at high rates of 5 and 10 A g-1 respectively). We consider these excellent electrochemical properties of d-MoO3 electrode are associated with the tiny grains on MoO3 surface, which effectively maintains the electrode's structural integrity. Even though d-MoO3 nanobelt suffers from a degree of in-situ pulverization after several cycles, these pulverized active particles can still maintain stable electrochemical contact and are highly exposed to electrolyte, realizing ultrahigh e-/Li+ diffusion kinetics. In addition, part extrinsic pseudocapacitance contribution to the Li+ storage also explains the high-rate performance. Combining all these merits, d-MoO3 is potentially a high-energy, high-power and well-stable anode material for Li ion batteries (LIBs).

Flexible Fe3O4@Carbon Nanofibers Hierarchically Assembled with MnO2 Particles for High-Performance Supercapacitor Electrodes.

PubMed

Iqbal, Nousheen; Wang, Xianfeng; Babar, Aijaz Ahmed; Zainab, Ghazala; Yu, Jianyong; Ding, Bin

2017-11-09

Increasing use of wearable electronic devices have resulted in enhanced demand for highly flexible supercapacitor electrodes with superior electrochemical performance. In this study, flexible composite membranes with electrosprayed MnO 2 particles uniformly anchored on Fe 3 O 4 doped electrospun carbon nanofibers (Fe 3 O 4 @CNF Mn ) have been prepared as flexible electrodes for high-performance supercapacitors. The interconnected porous beaded structure ensures free movement of electrolyte within the composite membranes, therefore, the developed supercapacitor electrodes not only offer high specific capacitance of ~306 F/g, but also exhibit good capacitance retention of ~85% after 2000 cycles, which certify that the synthesized electrodes offer high and stable electrochemical performance. Additionally, the supercapacitors fabricated from our developed electrodes well maintain their performance under flexural stress and exhibit a very minute change in specific capacitance even up to 180° bending angle. The developed electrode fabrication strategy integrating electrospinning and electrospray techniques paves new insights into the development of potential functional nanofibrous materials for light weight and flexible wearable supercapacitors.

Parametric Study of Pulse-Combustor-Driven Ejectors at High-Pressure

NASA Technical Reports Server (NTRS)

Yungster, Shaye; Paxson, Daniel E.; Perkins, Hugh D.

2015-01-01

Pulse-combustor configurations developed in recent studies have demonstrated performance levels at high-pressure operating conditions comparable to those observed at atmospheric conditions. However, problems related to the way fuel was being distributed within the pulse combustor were still limiting performance. In the first part of this study, new configurations are investigated computationally aimed at improving the fuel distribution and performance of the pulse-combustor. Subsequent sections investigate the performance of various pulse-combustor driven ejector configurations operating at high pressure conditions, focusing on the effects of fuel equivalence ratio and ejector throat area. The goal is to design pulse-combustor-ejector configurations that maximize pressure gain while achieving a thermal environment acceptable to a turbine, and at the same time maintain acceptable levels of NO(x) emissions and flow non-uniformities. The computations presented here have demonstrated pressure gains of up to 2.8.

Student Bedtimes, Academic Performance, and Health in a Residential High School.

PubMed

Wernette, Maliah J; Emory, Jan

2017-08-01

Inadequate sleep among adolescents is considered an epidemic in the United States. Late night bedtimes could be an important factor in academic performance and health with consequences continuing throughout adulthood. The purpose of this study was to explore the relationships between late night bedtimes, academic performance (grade point average [GPA]), and utilization of health care (school nurse visits) in a residential high school. The data were collected from archival records for one academic semester. The statistical analysis employed the nonparametric Pearson's correlation coefficient ( r) with the standard level of significance (α = .05). Positive and inverse linear relationships were found between bedtime and school nurse visits ( p < .00001) and bedtime and GPA ( p = .007). The findings suggest students' late night bedtimes may be related to increased school nurse visits and lower academic performance. Adolescent late night bedtimes may be an important consideration for academic success and maintaining health in residential high schools.

Design of a new high-performance pointing controller for the Hubble Space Telescope

NASA Technical Reports Server (NTRS)

Johnson, C. D.

1993-01-01

A new form of high-performance, disturbance-adaptive pointing controller for the Hubble Space Telescope (HST) is proposed. This new controller is all linear (constant gains) and can maintain accurate 'pointing' of the HST in the face of persistent randomly triggered uncertain, unmeasurable 'flapping' motions of the large attached solar array panels. Similar disturbances associated with antennas and other flexible appendages can also be accommodated. The effectiveness and practicality of the proposed new controller is demonstrated by a detailed design and simulation testing of one such controller for a planar-motion, fully nonlinear model of HST. The simulation results show a high degree of disturbance isolation and pointing stability.

Inflight calibration technique for onboard high-gain antenna pointing. [of Mariner 10 spacecraft in Venus and Mercury flyby mission

NASA Technical Reports Server (NTRS)

Ohtakay, H.; Hardman, J. M.

1975-01-01

The X-band radio frequency communication system was used for the first time in deep space planetary exploration by the Mariner 10 Venus and Mercury flyby mission. This paper presents the technique utilized for and the results of inflight calibration of high-gain antenna (HGA) pointing. Also discussed is pointing accuracy to maintain a high data transmission rate throughout the mission, including the performance of HGA pointing during the critical period of Mercury encounter.

The efficacy of a restart break for recycling with optimal performance depends critically on circadian timing.

PubMed

Van Dongen, Hans P A; Belenky, Gregory; Vila, Bryan J

2011-07-01

Under simulated shift-work conditions, we investigated the efficacy of a restart break for maintaining neurobehavioral functioning across consecutive duty cycles, as a function of the circadian timing of the duty periods. As part of a 14-day experiment, subjects underwent two cycles of five simulated daytime or nighttime duty days, separated by a 34-hour restart break. Cognitive functioning and high-fidelity driving simulator performance were tested 4 times per day during the two duty cycles. Lapses on a psychomotor vigilance test (PVT) served as the primary outcome variable. Selected sleep periods were recorded polysomnographically. The experiment was conducted under standardized, controlled laboratory conditions with continuous monitoring. Twenty-seven healthy adults (13 men, 14 women; aged 22-39 years) participated in the study. Subjects were randomly assigned to a nighttime duty (experimental) condition or a daytime duty (control) condition. The efficacy of the 34-hour restart break for maintaining neurobehavioral functioning from the pre-restart duty cycle to the post-restart duty cycle was compared between these two conditions. Relative to the daytime duty condition, the nighttime duty condition was associated with reduced amounts of sleep, whereas sleep latencies were shortened and slow-wave sleep appeared to be conserved. Neurobehavioral performance measures ranging from lapses of attention on the PVT to calculated fuel consumption on the driving simulators remained optimal across time of day in the daytime duty schedule, but degraded across time of night in the nighttime duty schedule. The 34-hour restart break was efficacious for maintaining PVT performance and other objective neurobehavioral functioning profiles from one duty cycle to the next in the daytime duty condition, but not in the nighttime duty condition. Subjective sleepiness did not reliably track objective neurobehavioral deficits. The 34-hour restart break was adequate for maintaining performance in the case of optimal circadian placement of sleep and duty periods (control condition) but was inadequate (and perhaps even detrimental) for maintaining performance in a simulated nighttime duty schedule (experimental condition). Current US transportation hours-of-service regulations mandate time off duty but do not consider the circadian aspects of shift scheduling. Reinforcing a recent trend of applying sleep science to inform policymaking for duty and rest times, our findings indicate that restart provisions in hours-of-service regulations could be improved by taking the circadian timing of the duty schedules into account.

Multilinear Computing and Multilinear Algebraic Geometry

DTIC Science & Technology

2016-08-10

instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send...performance period of this project. 15. SUBJECT TERMS Tensors , multilinearity, algebraic geometry, numerical computations, computational tractability, high...Reset DISTRIBUTION A: Distribution approved for public release. DISTRIBUTION A: Distribution approved for public release. INSTRUCTIONS FOR COMPLETING

Specifying, Installing and Maintaining Built-Up and Modified Bitumen Roofing Systems.

ERIC Educational Resources Information Center

Hobson, Joseph W.

2000-01-01

Examines built-up, modified bitumen, and hybrid combinations of the two roofing systems and offers advise on how to assure high- quality performance and durability when using them. Included is a glossary of commercial roofing terms and asphalt roofing resources to aid in making decisions on roofing and systems product selection. (GR)

Why Is Parkinsonism Not a Feature of Human Methamphetamine Users?

ERIC Educational Resources Information Center

Moszczynska, Anna; Fitzmaurice, Paul; Ang, Lee; Kalasinsky, Kathryn S.; Schmunk, Gregory A.; Peretti, Frank J.; Aiken, Sally S.; Wickham, Dennis J.; Kish, Stephen J.

2004-01-01

For more than 50 years, methamphetamine has been a widely used stimulant drug taken to maintain wakefulness and performance and, in high doses, to cause intense euphoria. Animal studies show that methamphetamine can cause short-term and even persistent depletion of brain levels of the neurotransmitter dopamine. However, the clinical features of…

Neuromotor Issues in the Learning and Control of Golf Skill

ERIC Educational Resources Information Center

Knight, Christopher A.

2004-01-01

Theoretical and practical issues related to the neuromotor control of a golf swing are presented in this paper. The typical strategy for golf training consists of high volume repetition with an emphasis on a large variety of isolated swing characteristics. The student is frequently instructed to maintain consistent performance in each swing with…

The Effect of a Workload-Preview on Task-Prioritization and Task-Performance

ERIC Educational Resources Information Center

Minotra, Dev

2012-01-01

With increased volume and sophistication of cyber attacks in recent years, maintaining situation awareness and effective task-prioritization strategy is critical to the task of cybersecurity analysts. However, high levels of mental-workload associated with the task of cybersecurity analyst's limits their ability to prioritize tasks.…

Defending A+: how to maintain a high credit rating during a facilities overhaul.

PubMed

Ollie, Ed; Kolb-Collier, Deborah; Clay, Scott

2007-11-01

To defend its strong credit rating, New Hanover Regional Medical Center: Demonstrated a clear and cohesive vision. Improved short-term financial performance. Developed robust financial projections. Avoided reliance on a "build it and they will come" strategy. Managed construction cost risks. Minimized construction disruption. Anticipated financial market concerns and questions

Modifying Status Relations in Israel Youth: An Application of Expectation States Theory.

ERIC Educational Resources Information Center

Cohen, Elizabeth G.; Sharan, Shlomo

Group participation by Israeli youth is examined in light of the Theory of Status Characteristics and Expectation States. This theory maintains that social and/or group status influences expectations of competence and triggers self-fulfilling prophecies of performance. An experiment designed to prevent unwanted dominance of high status…

An Organic Vertical Field-Effect Transistor with Underside-Doped Graphene Electrodes.

PubMed

Kim, Jong Su; Kim, Beom Joon; Choi, Young Jin; Lee, Moo Hyung; Kang, Moon Sung; Cho, Jeong Ho

2016-06-01

High-performance vertical field-effect transistors are developed, which are based on graphene electrodes doped using the underside doping method. The underside doping method enables effective tuning of the graphene work function while maintaining the surface properties of the pristine graphene. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

GREEN + IDMaps: A practical soulution for ensuring fairness in a biased internet

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

Kapadia, A. C.; Thulasidasan, S.; Feng, W. C.

2002-01-01

GREEN is a proactive queue-management (PQM) algorithm that removes TCP's bias against connections with longer round-trip times, while maintaining high link utilization and low packet-loss. GREEN applies knowledge of the steady-state behavior of TCP connections to proactively drop packets, thus preventing congestion from ever occurring. As a result, GREEN ensures much higher fairness between flows than other active queue management schemes like Flow Random Early Drop (FRED) and Stochastic Fair Blue (SFB), which suffer in topologies where a large number of flows have widely varying round-trip times. GREEN'S performance relies on its ability to gauge a flow's round-trip time (RTT).more » In previous work, we presented results for an ideal GREEN router which has accurate RTT information for a flow. In this paper, we present a practical solution based on IDMaps, an Internet distance-estimation service, and compare its performance to an ideal GREEN router. We show that a solution based on IDMaps is practical and maintains high fairness and link utilization, and low packet-loss rates.« less

The modular modality frame model: continuous body state estimation and plausibility-weighted information fusion.

PubMed

Ehrenfeld, Stephan; Butz, Martin V

2013-02-01

Humans show admirable capabilities in movement planning and execution. They can perform complex tasks in various contexts, using the available sensory information very effectively. Body models and continuous body state estimations appear necessary to realize such capabilities. We introduce the Modular Modality Frame (MMF) model, which maintains a highly distributed, modularized body model continuously updating, modularized probabilistic body state estimations over time. Modularization is realized with respect to modality frames, that is, sensory modalities in particular frames of reference and with respect to particular body parts. We evaluate MMF performance on a simulated, nine degree of freedom arm in 3D space. The results show that MMF is able to maintain accurate body state estimations despite high sensor and motor noise. Moreover, by comparing the sensory information available in different modality frames, MMF can identify faulty sensory measurements on the fly. In the near future, applications to lightweight robot control should be pursued. Moreover, MMF may be enhanced with neural encodings by introducing neural population codes and learning techniques. Finally, more dexterous goal-directed behavior should be realized by exploiting the available redundant state representations.

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

Duchaineau, M.; Wolinsky, M.; Sigeti, D.E.

Terrain visualization is a difficult problem for applications requiring accurate images of large datasets at high frame rates, such as flight simulation and ground-based aircraft testing using synthetic sensor stimulation. On current graphics hardware, the problem is to maintain dynamic, view-dependent triangle meshes and texture maps that produce good images at the required frame rate. We present an algorithm for constructing triangle meshes that optimizes flexible view-dependent error metrics, produces guaranteed error bounds, achieves specified triangle counts directly, and uses frame-to-frame coherence to operate at high frame rates for thousands of triangles per frame. Our method, dubbed Real-time Optimally Adaptingmore » Meshes (ROAM), uses two priority queues to drive split and merge operations that maintain continuous triangulations built from pre-processed bintree triangles. We introduce two additional performance optimizations: incremental triangle stripping and priority-computation deferral lists. ROAM execution time is proportionate to the number of triangle changes per frame, which is typically a few percent of the output mesh size, hence ROAM performance is insensitive to the resolution and extent of the input terrain. Dynamic terrain and simple vertex morphing are supported.« less

Bilastine safety in drivers who need antihistamines: new evidence from high-speed simulator driving test on allergic patients.

PubMed

Demonte, A; Guanti, M B; Liberati, S; Biffi, A; Fernando, F; Fainello, M; Pepe, P

2018-02-01

Bilastine is a highly selective, non-sedating antihistamine, indicated for the symptomatic treatment of allergic rhinoconjunctivitis and urticaria. Available data suggest that bilastine interferes neither with driving ability nor with flying-related performance. However, no data are available on the effect of bilastine on the driving ability in extreme conditions. Here we analyzed the effect of 7 days treatment with 20 mg bilastine in patients with allergic rhinitis and/or chronic urticaria, on psychophysical performance assessed by the Formula One (F1) high-speed simulator-driving test. This study is a phase IV, interventional, prospective, mono-centric, single arm, open-label trial. Eighteen outpatients affected by allergic rhinitis and/or chronic urticaria, able to perform a preliminary driving test on F1 simulator were considered (V-1). First, the patients had a screening visit to assess their eligibility (V0). Visit 1 (V1), at the end of placebo before bilastine treatment and Visit 2 (V2), at the end of bilastine treatment. The primary variable parameter was the ability to maintain the vehicle in a central position at different speeds (50, 150, and 250 km/h). Bilastine had a good safety profile and was well tolerated in terms of adverse events, laboratory parameters and vital signs. Bilastine did not have any negative effect on the ability to maintain the requested path, a constant speed as well as on attention and reactivity levels, even in extreme driving conditions. This study is the first done in patients with allergic rhinitis and/or chronic urticaria using a F1-high speed simulator-driving test evaluating subjects' performance under bilastine treatment.

Vertically-aligned BCN Nanotube Arrays with Superior Performance in Electrochemical capacitors

PubMed Central

Zhou, Junshuang; Li, Na; Gao, Faming; Zhao, Yufeng; Hou, Li; Xu, Ziming

2014-01-01

Electrochemical capacitors (EC) have received tremendous interest due to their high potential to satisfy the urgent demand in many advanced applications. The development of new electrode materials is considered to be the most promising approach to enhance the EC performance substantially. Herein, we present a high-capacity capacitor material based on vertically-aligned BC2N nanotube arrays (VA-BC2NNTAs) synthesized by low temperature solvothermal route. The obtained VA-BC2NNTAs display the good aligned nonbuckled tubular structure, which could indeed advantageously enhance capacitor performance. VA-BC2NNTAs exhibit an extremely high specific capacitance, 547 Fg−1, which is about 2–6 times larger than that of the presently available carbon-based materials. Meanwhile, VA-BC2NNTAs maintain an excellent rate capability and high durability. All these characteristics endow VA-BC2NNTAs an alternative promising candidate for an efficient electrode material for electrochemical capacitors (EC). PMID:25124300

Transparent and Self-Supporting Graphene Films with Wrinkled- Graphene-Wall-Assembled Opening Polyhedron Building Blocks for High Performance Flexible/Transparent Supercapacitors.

PubMed

Li, Na; Huang, Xuankai; Zhang, Haiyan; Li, Yunyong; Wang, Chengxin

2017-03-22

Improving mass loading while maintaining high transparency and large surface area in one self-supporting graphene film is still a challenge. Unfortunately, all of these factors are absolutely essential for enhancing the energy storage performance of transparent supercapacitors for practical applications. To solve the above bottleneck problem, we produce a novel self-supporting flexible and transparent graphene film (STF-GF) with wrinkled-wall-assembled opened-hollow polyhedron building units. Taking advantage of the microscopic morphology, the STF-GF exhibits improved mass loading with high transmittance (70.2% at 550 nm), a large surface area (1105.6 m 2 /g), and good electrochemical performance: high energy (552.3 μWh/cm 3 ), power densities (561.9 mW/cm 3 ), a superlong cycle life, and good cycling stability (the capacitance retention is ∼94.8% after 20,000 cycles).

Advances of aqueous rechargeable lithium-ion battery: A review

NASA Astrophysics Data System (ADS)

Alias, Nurhaswani; Mohamad, Ahmad Azmin

2015-01-01

The electrochemical characteristic of the aqueous rechargeable lithium-ion battery has been widely investigated in efforts to design a green and safe technology that can provide a highly specific capacity, high efficiency and long life for high power applications such as the smart grid and electric vehicle. It is believed that the advantages of this battery will overcome the limitations of the rechargeable lithium-ion battery with organic electrolytes that comprise safety and create high fabrication cost issues. This review focuses on the opportunities of the aqueous rechargeable lithium-ion battery compared to the conventional rechargeable lithium-ion battery with organic-based electrolytes. Previously reported studies are briefly summarised, together with the presentation of new findings based on the conductivity, morphology, electrochemical performance and cycling stability results. The factors that influence the electrochemical performance, the challenges and potential of the aqueous rechargeable lithium-ion battery are highlighted in order to understand and maintained the excellent battery performance.

The effect of strenuous exercise and beta-adrenergic blockade on the visual performance of juvenile rainbow trout, Oncorhynchus mykiss.

PubMed

Herbert, N A; Wells, R M G

2002-12-01

It is hypothesised that the visual performance of rainbow trout, Oncorhynchus mykiss, will be impaired by strenuous exercise as a result of metabolic stress (blood lactacidosis) that activates the Root effect and limits the oxygen-carrying capacity of blood flowing to the eye. The ability to resolve high contrast objects on a moving background, as a measure of visual performance, was quantified pre- and post-exercise using the optomotor response. Strenuous exercise induced a metabolic acidosis (8.0 mmol l(-1) blood lactate) and a significant red cell swelling response but no change in the optomotor response threshold (120 min of arc) was observed. Beta-adrenergic blockade (propranolol) abolished post-exercise red cell swelling but optomotor response thresholds were still maintained at 120 min of arc despite a significant blood lactate load (7.8 mmol l(-1)). The choroid rete mirabile of the trout is extremely well developed (rete area:eye area = 0.39) and may maintain visual performance by ensuring a relatively direct supply of oxygen to the central regions of the avascular retina. Exercised fish under beta-adrenergic blockade exhibited an enhanced optomotor response at 240-300 min of arc. Assuming that these responses reflect "tunnel vision", adrenergic regulation of red cell function may preserve a high ocular PO(2) gradient that satisfies the oxygen demand of peripheral retinal cells.

Hydraulic performance of compacted clay liners under simulated daily thermal cycles.

PubMed

Aldaeef, A A; Rayhani, M T

2015-10-01

Compacted clay liners (CCLs) are commonly used as hydraulic barriers in several landfill applications to isolate contaminants from the surrounding environment and minimize the escape of leachate from the landfill. Prior to waste placement in landfills, CCLs are often exposed to temperature fluctuations which can affect the hydraulic performance of the liner. Experimental research was carried out to evaluate the effects of daily thermal cycles on the hydraulic performance of CCLs under simulated landfill conditions. Hydraulic conductivity tests were conducted on different soil specimens after being exposed to various thermal and dehydration cycles. An increase in the CCL hydraulic conductivity of up to one order of magnitude was recorded after 30 thermal cycles for soils with low plasticity index (PI = 9.5%). However, medium (PI = 25%) and high (PI = 37.2%) plasticity soils did not show significant hydraulic deviation due to their self-healing potential. Overlaying the CCL with a cover layer minimized the effects of daily thermal cycles, and maintained stable hydraulic performance in the CCLs even after exposure to 60 thermal cycles. Wet-dry cycles had a significant impact on the hydraulic aspect of low plasticity CCLs. However, medium and high plasticity CCLs maintained constant hydraulic performance throughout the test intervals. The study underscores the importance of protecting the CCL from exposure to atmosphere through covering it by a layer of geomembrane or an interim soil layer. Copyright © 2015 Elsevier Ltd. All rights reserved.

Reduced firing rates of high threshold motor units in response to eccentric overload.

PubMed

Balshaw, Tom G; Pahar, Madhu; Chesham, Ross; Macgregor, Lewis J; Hunter, Angus M

2017-01-01

Acute responses of motor units were investigated during submaximal voluntary isometric tasks following eccentric overload (EO) and constant load (CL) knee extension resistance exercise. Ten healthy resistance-trained participants performed four experimental test sessions separated by 5 days over a 20 day period. Two sessions involved constant load and the other two used eccentric overload. EO and CL used both sessions for different target knee eccentric extension phases; one at 2 sec and the other at 4 sec. Maximal voluntary contractions (MVC) and isometric trapezoid efforts for 10 sec at 70% MVC were completed before and after each intervention and decomposed electromyography was used to measure motor unit firing rate. The firing rate of later recruited, high-threshold motor units declined following the 2-sec EO but was maintained following 2sec CL (P < 0.05), whereas MUFR for all motor units were maintained for both loading types following 4-sec extension phases. MVC and rate of force development where maintained following both EO and CL and 2 and 4 sec phases. This study demonstrates a slower firing rate of high-threshold motor units following fast eccentric overload while MVC was maintained. This suggests that there was a neuromuscular stimulus without cost to the force-generating capacity of the knee extensors. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Effect of flashlight guidance on manual ventilation performance in cardiopulmonary resuscitation: A randomized controlled simulation study.

PubMed

Kim, Ji Hoon; Beom, Jin Ho; You, Je Sung; Cho, Junho; Min, In Kyung; Chung, Hyun Soo

2018-01-01

Several auditory-based feedback devices have been developed to improve the quality of ventilation performance during cardiopulmonary resuscitation (CPR), but their effectiveness has not been proven in actual CPR situations. In the present study, we investigated the effectiveness of visual flashlight guidance in maintaining high-quality ventilation performance. We conducted a simulation-based, randomized, parallel trial including 121 senior medical students. All participants were randomized to perform ventilation during 2 minutes of CPR with or without flashlight guidance. For each participant, we measured mean ventilation rate as a primary outcome and ventilation volume, inspiration velocity, and ventilation interval as secondary outcomes using a computerized device system. Mean ventilation rate did not significantly differ between flashlight guidance and control groups (P = 0.159), but participants in the flashlight guidance group exhibited significantly less variation in ventilation rate than participants in the control group (P<0.001). Ventilation interval was also more regular among participants in the flashlight guidance group. Our results demonstrate that flashlight guidance is effective in maintaining a constant ventilation rate and interval. If confirmed by further studies in clinical practice, flashlight guidance could be expected to improve the quality of ventilation performed during CPR.

3D Graphene-Ni Foam as an Advanced Electrode for High-Performance Nonaqueous Redox Flow Batteries.

PubMed

Lee, Kyubin; Lee, Jungkuk; Kwon, Kyoung Woo; Park, Min-Sik; Hwang, Jin-Ha; Kim, Ki Jae

2017-07-12

Electrodes composed of multilayered graphene grown on a metal foam (GMF) were prepared by directly growing multilayer graphene sheets on a three-dimensional (3D) Ni-foam substrate via a self-catalyzing chemical vapor deposition process. The multilayer graphene sheets are successfully grown on the Ni-foam substrate surface, maintaining the unique 3D macroporous structure of the Ni foam. The potential use of GMF electrodes in nonaqueous redox flow batteries (RFBs) is carefully examined using [Co(bpy) 3 ] +/2+ and [Fe(bpy) 3 ] 2+/3+ redox couples. The GMF electrodes display a much improved electrochemical activity and enhanced kinetics toward the [Co(bpy) 3 ] +/2+ (anolyte) and [Fe(bpy) 3 ] 2+/3+ (catholyte) redox couples, compared with the bare Ni metal foam electrodes, suggesting that the 2D graphene sheets having lots of interdomain defects provide sufficient reaction sites and secure electric-conduction pathways. Consequently, a nonaqueous RFB cell assembled with GMF electrodes exhibits high Coulombic and voltage efficiencies of 87.2 and 90.9%, respectively, at the first cycle. This performance can be maintained up to the 50th cycle without significant efficiency loss. Moreover, the importance of a rational electrode design for improving electrochemical performance is addressed.

High Energy Lithium-Ion VES Cells And Batteries Performances

NASA Astrophysics Data System (ADS)

Castric, A.-F.; Lawson, S.; Borthomieu, Y.

2011-10-01

b Saft's Space VES range of lithium-ion cells have been designed specifically to meet the satellites on-board power need, while meeting the legitimate high levels of requirements for space products. The purpose of the paper is to develop how the VES batteries designs have progressively evolved in order to accommodate the needs, requirements and constraints evolutions. The following topics will be presented: - Description of the main design features of the VES Li- ion batteries. - How the optimised battery configuration is selected against the required EOL power need or other constraints. - Presentation of the batteries performances (electrical, mechanical, thermal, interface, weight, ...). - Measures implemented in order to maintain these performances, and to guarantee the best product quality as per space standards.

Progress in the utilization of an oxide-dispersion-strengthened alloy for small engine turbine blades

NASA Technical Reports Server (NTRS)

Beatty, T. G.; Millan, P. P.

1984-01-01

The conventional means of improving gas turbine engine performance typically involves increasing the turbine inlet temperature; however, at these higher operational temperatures the high pressure turbine blades require air-cooling to maintain durability. Air-cooling imposes design, material, and economic constraints not only on the turbine blades but also on engine performance. The use of uncooled turbine blades at increased operating temperatures can offer significantly improved performance in small gas turbine engines. A program to demonstrate uncooled MA6000 high pressure turbine blades in a GTEC TFE731 turbofan engine is being conducted. The project goals include demonstration of the advantages of using uncooled MA6000 turbine blades as compared with cast directionally solidified MAR-M 247 blades.

A High Intensity Interval Training (HIIT)-Based Running Plan Improves Athletic Performance by Improving Muscle Power.

PubMed

García-Pinillos, Felipe; Cámara-Pérez, Jose C; Soto-Hermoso, Víctor M; Latorre-Román, Pedro Á

2017-01-01

García-Pinillos, F, Cámara-Pérez, JC, Soto-Hermoso, VM, and Latorre-Román, PÁ. A High Intensity Interval Training (HIIT)-based running plan improves athletic performance by improving muscle power. J Strength Cond Res 31(1): 146-153, 2017-This study aimed to examine the effect of a 5-week high-intensity intermittent training (HIIT)-based running plan on athletic performance and to compare the physiological and neuromuscular responses during a sprint-distance triathlon before and after the HIIT period. Thirteen triathletes were matched into 2 groups: the experimental group (EG) and the control group (CG). The CG was asked to maintain their normal training routines, whereas the EG maintained only their swimming and cycling routines and modified their running routine. Participants completed a sprint-distance triathlon before (pretest) and after (posttest) the intervention period. In both pretest and posttest, the participants performed 4 jumping tests: before the race (baseline), postswim, postcycling, and postrun. Additionally, heart rate was monitored (HRmean), whereas rate of perceived exertion (RPE) and blood lactate accumulation (BLa) were registered after the race. No significant differences (p ≥ 0.05) between groups were found before HIIT intervention (at pretest). Significant group-by-training interactions were found in vertical jumping ability and athletic performance: the EG improved jumping performance (∼6-9%, p ≤ 0.05, effect size (ES) > 0.7), swimming performance (p = 0.013, ES = 0.438), and running time (p = 0.001, ES = 0.667) during the competition, whereas the CG remained unchanged (p ≥ 0.05, ES < 0.4). No changes (p ≥ 0.05, ES < 0.4) were observed in RPE, HRmean, and BLa. A linear regression analysis showed that ΔCMJ predicted both the ΔRu_time (R = 0.559; p = 0.008) and the ΔOverall_time (R = 0.391; p = 0.048). This low-volume, HIIT-based running plan combined with the high training volumes of these triathletes in swimming and cycling improved athletic performance during a sprint-distance triathlon. This improvement may be due to improved neuromuscular characteristics that were transferred into improved muscle power and work economy.

Stretchable and high-performance supercapacitors with crumpled graphene papers.

PubMed

Zang, Jianfeng; Cao, Changyong; Feng, Yaying; Liu, Jie; Zhao, Xuanhe

2014-10-01

Fabrication of unconventional energy storage devices with high stretchability and performance is challenging, but critical to practical operations of fully power-independent stretchable electronics. While supercapacitors represent a promising candidate for unconventional energy-storage devices, existing stretchable supercapacitors are limited by their low stretchability, complicated fabrication process, and high cost. Here, we report a simple and low-cost method to fabricate extremely stretchable and high-performance electrodes for supercapacitors based on new crumpled-graphene papers. Electrolyte-mediated-graphene paper bonded on a compliant substrate can be crumpled into self-organized patterns by harnessing mechanical instabilities in the graphene paper. As the substrate is stretched, the crumpled patterns unfold, maintaining high reliability of the graphene paper under multiple cycles of large deformation. Supercapacitor electrodes based on the crumpled graphene papers exhibit a unique combination of high stretchability (e.g., linear strain ~300%, areal strain ~800%), high electrochemical performance (e.g., specific capacitance ~196 F g(-1)), and high reliability (e.g., over 1000 stretch/relax cycles). An all-solid-state supercapacitor capable of large deformation is further fabricated to demonstrate practical applications of the crumpled-graphene-paper electrodes. Our method and design open a wide range of opportunities for manufacturing future energy-storage devices with desired deformability together with high performance.

Stretchable and High-Performance Supercapacitors with Crumpled Graphene Papers

NASA Astrophysics Data System (ADS)

Zang, Jianfeng; Cao, Changyong; Feng, Yaying; Liu, Jie; Zhao, Xuanhe

2014-10-01

Fabrication of unconventional energy storage devices with high stretchability and performance is challenging, but critical to practical operations of fully power-independent stretchable electronics. While supercapacitors represent a promising candidate for unconventional energy-storage devices, existing stretchable supercapacitors are limited by their low stretchability, complicated fabrication process, and high cost. Here, we report a simple and low-cost method to fabricate extremely stretchable and high-performance electrodes for supercapacitors based on new crumpled-graphene papers. Electrolyte-mediated-graphene paper bonded on a compliant substrate can be crumpled into self-organized patterns by harnessing mechanical instabilities in the graphene paper. As the substrate is stretched, the crumpled patterns unfold, maintaining high reliability of the graphene paper under multiple cycles of large deformation. Supercapacitor electrodes based on the crumpled graphene papers exhibit a unique combination of high stretchability (e.g., linear strain ~300%, areal strain ~800%), high electrochemical performance (e.g., specific capacitance ~196 F g-1), and high reliability (e.g., over 1000 stretch/relax cycles). An all-solid-state supercapacitor capable of large deformation is further fabricated to demonstrate practical applications of the crumpled-graphene-paper electrodes. Our method and design open a wide range of opportunities for manufacturing future energy-storage devices with desired deformability together with high performance.

Stretchable and High-Performance Supercapacitors with Crumpled Graphene Papers

PubMed Central

Zang, Jianfeng; Cao, Changyong; Feng, Yaying; Liu, Jie; Zhao, Xuanhe

2014-01-01

Fabrication of unconventional energy storage devices with high stretchability and performance is challenging, but critical to practical operations of fully power-independent stretchable electronics. While supercapacitors represent a promising candidate for unconventional energy-storage devices, existing stretchable supercapacitors are limited by their low stretchability, complicated fabrication process, and high cost. Here, we report a simple and low-cost method to fabricate extremely stretchable and high-performance electrodes for supercapacitors based on new crumpled-graphene papers. Electrolyte-mediated-graphene paper bonded on a compliant substrate can be crumpled into self-organized patterns by harnessing mechanical instabilities in the graphene paper. As the substrate is stretched, the crumpled patterns unfold, maintaining high reliability of the graphene paper under multiple cycles of large deformation. Supercapacitor electrodes based on the crumpled graphene papers exhibit a unique combination of high stretchability (e.g., linear strain ~300%, areal strain ~800%), high electrochemical performance (e.g., specific capacitance ~196 F g−1), and high reliability (e.g., over 1000 stretch/relax cycles). An all-solid-state supercapacitor capable of large deformation is further fabricated to demonstrate practical applications of the crumpled-graphene-paper electrodes. Our method and design open a wide range of opportunities for manufacturing future energy-storage devices with desired deformability together with high performance. PMID:25270673

The Impact of Moderate and High Intensity Total Body Fatigue on Passing Accuracy in Expert and Novice Basketball Players

PubMed Central

Lyons, Mark; Al-Nakeeb, Yahya; Nevill, Alan

2006-01-01

Despite the acknowledged importance of fatigue on performance in sport, ecologically sound studies investigating fatigue and its effects on sport-specific skills are surprisingly rare. The aim of this study was to investigate the effect of moderate and high intensity total body fatigue on passing accuracy in expert and novice basketball players. Ten novice basketball players (age: 23.30 ± 1.05 yrs) and ten expert basketball players (age: 22.50 ± 0.41 yrs) volunteered to participate in the study. Both groups performed the modified AAHPERD Basketball Passing Test under three different testing conditions: rest, moderate intensity and high intensity total body fatigue. Fatigue intensity was established using a percentage of the maximal number of squat thrusts performed by the participant in one minute. ANOVA with repeated measures revealed a significant (F 2,36 = 5.252, p = 0.01) level of fatigue by level of skill interaction. On examination of the mean scores it is clear that following high intensity total body fatigue there is a significant detriment in the passing performance of both novice and expert basketball players when compared to their resting scores. Fundamentally however, the detrimental impact of fatigue on passing performance is not as steep in the expert players compared to the novice players. The results suggest that expert or skilled players are better able to cope with both moderate and high intensity fatigue conditions and maintain a higher level of performance when compared to novice players. The findings of this research therefore, suggest the need for trainers and conditioning coaches in basketball to include moderate, but particularly high intensity exercise into their skills sessions. This specific training may enable players at all levels of the game to better cope with the demands of the game on court and maintain a higher standard of play. Key Points Aim: to investigate the effect of moderate and high intensity total body fatigue on basketball-passing accuracy in expert and novice basketball players. Fatigue intensity was set as a percentage of the maximal number of squat thrusts performed by the participant in one minute. ANOVA with repeated measures revealed a significant level of fatigue by level of skill interaction. Despite a significant detriment in passing-performance in both novice and expert players following high intensity total body fatigue, this detriment was not as steep in the expert players when compared to the novice players PMID:24259994

Thermally ruggedized ITO transparent electrode films for high power optoelectronics.

PubMed

Yoo, Jae-Hyuck; Matthews, Manyalibo; Ramsey, Phil; Barrios, Antonio Correa; Carter, Austin; Lange, Andrew; Bude, Jeff; Elhadj, Selim

2017-10-16

We present two strategies to minimize laser damage in transparent conductive films. The first consists of improving heat dissipation by selection of substrates with high thermal diffusivity or by addition of capping layer heatsinks. The second is reduction of bulk energy absorption by lowering free carrier density and increasing mobility, while maintaining film conductance with thicker films. Multi-pulse laser damage tests were performed on tin-doped indium oxide (ITO) films configured to improve optical lifetime damage performance. Conditions where improvements were not observed are also described. When bulk heating is not the dominant damage process, discrete defect-induced damage limits damage behavior.

Fabrication and Testing of Microfluidic Optomechanical Oscillators

PubMed Central

Han, Kewen; Kim, Kyu Hyun; Kim, Junhwan; Lee, Wonsuk; Liu, Jing; Fan, Xudong; Carmon, Tal; Bahl, Gaurav

2014-01-01

Cavity optomechanics experiments that parametrically couple the phonon modes and photon modes have been investigated in various optical systems including microresonators. However, because of the increased acoustic radiative losses during direct liquid immersion of optomechanical devices, almost all published optomechanical experiments have been performed in solid phase. This paper discusses a recently introduced hollow microfluidic optomechanical resonator. Detailed methodology is provided to fabricate these ultra-high-Q microfluidic resonators, perform optomechanical testing, and measure radiation pressure-driven breathing mode and SBS-driven whispering gallery mode parametric vibrations. By confining liquids inside the capillary resonator, high mechanical- and optical- quality factors are simultaneously maintained. PMID:24962013

Performance of a Low-Power Cylindrical Hall Thruster

NASA Technical Reports Server (NTRS)

Polzin, Kurt A.; Markusic, Thomas E.; Stanojev, Boris J.; Dehoyos, Amado; Raitses, Yevgeny; Smirnov, Artem; Fisch, Nathaniel J.

2007-01-01

Recent mission studies have shown that a Hall thruster which operates at relatively constant thrust efficiency (45-55%) over a broad power range (300W - 3kW) is enabling for deep space science missions when compared with slate-of-the-art ion thrusters. While conventional (annular) Hall thrusters can operate at high thrust efficiency at kW power levels, it is difficult to construct one that operates over a broad power envelope down to 0 (100 W) while maintaining relatively high efficiency. In this note we report the measured performance (I(sub sp), thrust and efficiency) of a cylindrical Hall thruster operating at 0 (100 W) input power.

Challenges in Maintaining Emotion Regulation in a Sleep and Energy Deprived State Induced by the 4800Km Ultra-Endurance Bicycle Race; The Race Across AMerica (RAAM).

PubMed

Lahart, Ian M; Lane, Andrew M; Hulton, Andrew; Williams, Karen; Godfrey, Richard; Pedlar, Charles; Wilson, Mathew G; Whyte, Gregory P

2013-01-01

Multiday ultra-endurance races present athletes with a significant number of physiological and psychological challenges. We examined emotions, the perceived functionality (optimal-dysfunctional) of emotions, strategies to regulate emotions, sleep quality, and energy intake-expenditure in a four-man team participating in the Race Across AMerica (RAAM); a 4856km continuous cycle race. Cyclists reported experiencing an optimal emotional state for less than 50% of total competition, with emotional states differing significantly between each cyclist over time. Coupled with this emotional disturbance, each cyclist experienced progressively worsening sleep deprivation and daily negative energy balances throughout the RAAM. Cyclists managed less than one hour of continuous sleep per sleep episode, high sleep latency and high percentage moving time. Of note, actual sleep and sleep efficiency were better maintained during longer rest periods, highlighting the importance of a race strategy that seeks to optimise the balance between average cycling velocity and sleep time. Our data suggests that future RAAM cyclists and crew should: 1) identify beliefs on the perceived functionality of emotions in relation to best (functional-optimal) and worst (dysfunctional) performance as the starting point to intervention work; 2) create a plan for support sufficient sleep and recovery; 3) create nutritional strategies that maintain energy intake and thus reduce energy deficits; and 4) prepare for the deleterious effects of sleep deprivation so that they are able to appropriately respond to unexpected stressors and foster functional working interpersonal relationships. Key PointsCompleting the Race Across AMerica (RAAM); a 4856km continuous cycle race associated with sleep disturbance, an energy-deficient state, and experiencing intense unwanted emotions.Cyclists reported experiencing an optimal emotional state for less than 50% of total competition and actual sleep and sleep efficiency was better maintained during longer rest periods.We suggest that future RAAM cyclists and crew should:Identify individual beliefs on the perceived functionality of emotional states in relation to best (optimal) and worst (dysfunctional) performance as the starting point to identifying if emotion regulation strategies should be initiated.Plan for enhanced sleep and recovery not just plan and train for maintaining a high average velocity;Create nutritional strategies that maintain energy intake and thus reduce energy deficits;Psychologically prepare cyclists and crew for the deleterious effects of sleep deprivation so that they both are able to appropriately respond to unexpected stressors and foster functional interpersonal working relationships.

Sub-100 fs pulses from an all-polarization maintaining Yb-fiber oscillator with an anomalous dispersion higher-order-mode fiber.

PubMed

Verhoef, A J; Zhu, L; Israelsen, S Møller; Grüner-Nielsen, L; Unterhuber, A; Kautek, W; Rottwitt, K; Baltuška, A; Fernández, A

2015-10-05

We present an Yb-fiber oscillator with an all-polarization-maintaining cavity with a higher-order-mode fiber for dispersion compensation. The polarization maintaining higher order mode fiber introduces not only negative second order dispersion but also negative third order dispersion in the cavity, in contrast to dispersion compensation schemes used in previous demonstrations of all-polarization maintaining Yb-fiber oscillators. The performance of the saturable absorber mirror modelocked oscillator, that employs a free space scheme for coupling onto the saturable absorber mirror and output coupling, was investigated for different settings of the intracavity dispersion. When the cavity is operated with close to zero net dispersion, highly stable 0.5-nJ pulses externally compressed to sub-100-fs are generated. These are to our knowledge the shortest pulses generated from an all-polarization-maintaining Yb-fiber oscillator. The spectral phase of the output pulses is well behaved and can be compensated such that wing-free Fourier transform limited pulses can be obtained. Further reduction of the net intracavity third order dispersion will allow generating broader output spectra and consequently shorter pulses, without sacrificing pulse fidelity.

Importance of polypyrrole in constructing 3D hierarchical carbon nanotube@MnO2 perfect core-shell nanostructures for high-performance flexible supercapacitors.

PubMed

Zhou, Jinyuan; Zhao, Hao; Mu, Xuemei; Chen, Jiayi; Zhang, Peng; Wang, Yaling; He, Yongmin; Zhang, Zhenxing; Pan, Xiaojun; Xie, Erqing

2015-09-21

This study reports the preparation of 3D hierarchical carbon nanotube (CNT) @MnO2 core-shell nanostructures under the assistance of polypyrrole (PPy). The as-prepared CNT@PPy@MnO2 core-shell structures show a perfect coating of MnO2 on each CNT and, more importantly, a robust bush-like pseudocapacitive shell to effectively increase the specific surface area and enhance the ion accessibility. As expected, a high specific capacity of 490-530 F g(-1) has been achieved from CNT@PPy@MnO2 single electrodes. And about 98.5% of the capacity is retained after 1000 charge/discharge cycles at a current density of 5 A g(-1). Furthermore, the assembled asymmetric CNT@PPy@MnO2//AC capacitors show the maximum energy density of 38.42 W h kg(-1) (2.24 mW h cm(-3)) at a power density of 100 W kg(-1) (5.83 mW cm(-3)), and they maintain 59.52% of the initial value at 10,000 W kg(-1) (0.583 W cm(-3)). In addition, the assembled devices show high cycling stabilities (89.7% after 2000 cycles for asymmetric and 87.2% for symmetric), and a high bending stability (64.74% after 200 bending tests). This ability to obtain high energy densities at high power rates while maintaining high cycling stability demonstrates that this well-designed structure could be a promising electrode material for high-performance supercapacitors.

Stability and the Evolvability of Function in a Model Protein

PubMed Central

Bloom, Jesse D.; Wilke, Claus O.; Arnold, Frances H.; Adami, Christoph

2004-01-01

Functional proteins must fold with some minimal stability to a structure that can perform a biochemical task. Here we use a simple model to investigate the relationship between the stability requirement and the capacity of a protein to evolve the function of binding to a ligand. Although our model contains no built-in tradeoff between stability and function, proteins evolved function more efficiently when the stability requirement was relaxed. Proteins with both high stability and high function evolved more efficiently when the stability requirement was gradually increased than when there was constant selection for high stability. These results show that in our model, the evolution of function is enhanced by allowing proteins to explore sequences corresponding to marginally stable structures, and that it is easier to improve stability while maintaining high function than to improve function while maintaining high stability. Our model also demonstrates that even in the absence of a fundamental biophysical tradeoff between stability and function, the speed with which function can evolve is limited by the stability requirement imposed on the protein. PMID:15111394

76 FR 44591 - Notice of Hearing: Reconsideration of Disapproval of Indiana State Plan Amendments (SPA) 11-011

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-26

... perform abortions or maintain or operate facilities where abortions are performed, except for hospitals or... restrictions on Federal funding of abortion services. Section 1116 of the Act and Federal regulations at 42 CFR... providers that perform abortions or maintain or operate facilities where abortions are performed, except for...

Improving organizational climate for excellence in patient care.

PubMed

Arnold, Edwin

2013-01-01

Managers in health care organizations today are expected to achieve higher-quality patient care at a lower cost. Developing and maintaining a positive organizational climate can help improve motivation and foster higher employee performance. In turn, this will help the organization deliver better patient care at a lower cost. This article offers metrics for assessing organizational climate, analyzes barriers to a positive climate, and explores strategies that managers can use to build the type of climate that fosters high performance.

Efficient abstract data type components for distributed and parallel systems

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

Bastani, F.; Hilal, W.; Iyengar, S.S.

1987-10-01

One way of improving software system's comprehensibility and maintainability is to decompose it into several components, each of which encapsulates some information concerning the system. These components can be classified into four categories, namely, abstract data type, functional, interface, and control components. Such a classfication underscores the need for different specification, implementation, and performance-improvement methods for different types of components. This article focuses on the development of high-performance abstract data type components for distributed and parallel environments.

Exploiting nonlinear properties of pure and Sn-doped Bi2Te2Se for passive Q-switching of all-polarization maintaining ytterbium- and erbium-doped fiber lasers.

PubMed

Bogusławski, Jakub; Kowalczyk, Maciej; Iwanowski, Przemysław; Hruban, Andrzej; Diduszko, Ryszard; Piotrowski, Kazimierz; Dybko, Krzysztof; Wojciechowski, Tomasz; Aleszkiewicz, Marta; Sotor, Jarosław

2017-08-07

Due to their broadband nonlinear optical properties, low-dimensional materials are widely used for pulse generation in fiber and solid-state lasers. Here we demonstrate novel materials, Bi 2 Te 2 Se (BTS) and Sn-doped Bi 2 Te 2 Se (BSTS), which can be used as a universal saturable absorbers for distinct spectral regimes. The material was mechanically exfoliated from a bulk single-crystal and deposited onto a side-polished fiber. We have performed characterization of the fabricated devices and employed them in polarization-maintaining ytterbium- and erbium-doped fiber lasers. This enabled us to obtain self-starting passively Q-switched regime at 1 µm and 1.56 µm. The oscillators emitted stable, linearly polarized radiation with the highest single pulse energy approaching 692 nJ. Both lasers are characterized by the best performance observed in all-polarization maintaining Q-switched fiber lasers with recently investigated new saturable absorbers, which was enabled by a very high damage threshold of the devices. This demonstrates the great potential of the investigated materials for the ultrafast photonics community.

The Role of Boards in College Access Programs: Creating and Maintaining Quality

ERIC Educational Resources Information Center

Center for Higher Education Policy Analysis, University of Southern California, 2006

2006-01-01

Access programs are facing increased scrutiny. Not all programs are equally effective. In an environment in which resources are short, funders increasingly require criteria that enable them to make informed decisions about program quality. As elaborated in this report , one role of a high performance board is to help develop benchmarks of…

Kinks in the STEM Pipeline: Tracking STEM Graduation Rates Using Science and Mathematics Performance

ERIC Educational Resources Information Center

Redmond-Sanogo, Adrienne; Angle, Julie; Davis, Evan

2016-01-01

In an effort to maintain the global competitiveness of the United States, ensuring a strong Science, Technology, Engineering and Mathematics (STEM) workforce is essential. The purpose of this study was to identify high school courses that serve as predictors of success in college level gatekeeper courses, which in turn led to the successful…

The Effects of Self-Monitoring and Performance Feedback on the Treatment Integrity of Behavior Intervention Plan Implementation and Generalization

ERIC Educational Resources Information Center

Mouzakitis, Angela; Codding, Robin S.; Tryon, Georgiana

2015-01-01

Accurate implementation of individualized behavior intervention plans (BIPs) is a critical aspect of evidence-based practice. Research demonstrates that neither training nor consultation is sufficient to improve and maintain high rates of treatment integrity (TI). Therefore, evaluation of ongoing support strategies is needed. The purpose of this…

Neuromuscular Adaptations to Reduced Use

NASA Technical Reports Server (NTRS)

Ploutz-Snyder, Lori

2009-01-01

This viewgraph presentation reviews the studies done to reduce neuromuscular strength loss during unilateral lower limb suspension (ULLS). Since there are animals that undergo fairly long periods of muscular disuse without any or minimal muscular atrophy, there is an answer to that might be applicable to human in situations that require no muscular use to diminish the effects of muscular atrophy. Three sets of ULLS studies were reviewed indicated that muscle strength decreased more than the muscle mass. The study reviewed exercise countermeasures to combat the atrophy, including: ischemia maintained during Compound muscle action potential (CMAP), ischemia and low load exercise, Japanese kaatsu, and the potential for rehabilitation or situations where heavy loading is undesirable. Two forms of countermeasures to unloading have been successful, (1) high-load resistance training has maintained muscle mass and strength, and low load resistance training with blood flow restriction (LL(sub BFR)). The LL(sub BFR) has been shown to increase muscle mass and strength. There has been significant interest in Tourniquet training. An increase in Growth Hormone(GH) has been noted for LL(sub BFR) exercise. An experimental study with 16 subjects 8 of whom performed ULLS, and 8 of whom performed ULLS and LL(sub BFR) exercise three times per week during the ULLS. Charts show the results of the two groups, showing that performing LL(sub BFR) exercise during 30 days of ULLS can maintain muscle size and strength and even improve muscular endurance.

The effects of magnetic field in plume region on the performance of multi-cusped field thruster

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

Hu, Peng, E-mail: hupengemail@126.com; Liu, Hui, E-mail: thruster@126.com; Yu, Daren

2015-10-15

The performance characteristics of a Multi-cusped Field Thruster depending on the magnetic field in the plume region were investigated. Five magnetic field shielding rings were separately mounted near the exit of discharge channel to decrease the strength of magnetic field in the plume region in different levels, while the magnetic field in the upstream was well maintained. The test results show that the electron current increases with the decrease of magnetic field strength in the plume region, which gives rise to higher propellant utilization and lower current utilization. On the other hand, the stronger magnetic field in the plume regionmore » improves the performance at low voltages (high current mode) while lower magnetic field improves the performance at high voltages (low current mode). This work can provide some optimal design ideas of the magnetic strength in the plume region to improve the performance of thruster.« less

Radiation-grafted fluoropolymers soaked with imidazolium-based ionic liquids for high-performance ionic polymer-metal composite actuators.

PubMed

Lee, Jang Yeol; Wang, Hyuck Sik; Yoon, Bye Ri; Han, Man Jae; Jho, Jae Young

2010-11-01

On purpose to develop a polymer actuator with high stability in air-operation as well as large bending displacement, a series of ionic polymer-metal composites (IPMC) was constructed with poly(styrene sulfonate)-grafted fluoropolymers as ionomeric matrix and immidazolium-based ionic liquids (IL) as inner solvent. The prepared IPMC actuators exhibited greatly enhanced bending displacement compared to Nafion-based actuators. The actuators were stable in air-operation, maintaining initial displacement for up to 10(4) cycles or 24 h. Investigating the material parameters and morphology of the IPMCs, high ion exchange capacity of the ionomers resulted in high ion conductivity and robust electrode of IPMC, which synergistically contributed to the high bending performance. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

New technology in turbine aerodynamics

NASA Technical Reports Server (NTRS)

Glassman, A. J.; Moffitt, T. P.

1972-01-01

A cursory review is presented of some of the recent work that has been done in turbine aerodynamic research at NASA-Lewis Research Center. Topics discussed include the aerodynamic effect of turbine coolant, high work-factor (ratio of stage work to square of blade speed) turbines, and computer methods for turbine design and performance prediction. An extensive bibliography is included. Experimental cooled-turbine aerodynamics programs using two-dimensional cascades, full annular cascades, and cold rotating turbine stage tests are discussed with some typical results presented. Analytically predicted results for cooled blade performance are compared to experimental results. The problems and some of the current programs associated with the use of very high work factors for fan-drive turbines of high-bypass-ratio engines are discussed. Turbines currently being investigated make use of advanced blading concepts designed to maintain high efficiency under conditions of high aerodynamic loading. Computer programs have been developed for turbine design-point performance, off-design performance, supersonic blade profile design, and the calculation of channel velocities for subsonic and transonic flow fields. The use of these programs for the design and analysis of axial and radial turbines is discussed.

Fast, high-fidelity readout of multiple qubits

NASA Astrophysics Data System (ADS)

Bronn, N. T.; Abdo, B.; Inoue, K.; Lekuch, S.; Córcoles, A. D.; Hertzberg, J. B.; Takita, M.; Bishop, L. S.; Gambetta, J. M.; Chow, J. M.

2017-05-01

Quantum computing requires a delicate balance between coupling quantum systems to external instruments for control and readout, while providing enough isolation from sources of decoherence. Circuit quantum electrodynamics has been a successful method for protecting superconducting qubits, while maintaining the ability to perform readout [1, 2]. Here, we discuss improvements to this method that allow for fast, high-fidelity readout. Specifically, the integration of a Purcell filter, which allows us to increase the resonator bandwidth for fast readout, the incorporation of a Josephson parametric converter, which enables us to perform high-fidelity readout by amplifying the readout signal while adding the minimum amount of noise required by quantum mechanics, and custom control electronics, which provide us with the capability of fast decision and control.

Designing for Maintainability and System Availability

NASA Technical Reports Server (NTRS)

Lalli, Vincent R.; Packard, Michael H.

1997-01-01

The final goal for a delivered system (whether a car, aircraft, avionics box or computer) should be its availability to operate and perform its intended function over its expected design life. Hence, in designing a system, we cannot think in terms of delivering the system and just walking away. The system supplier needs to provide support throughout the operating life of the product. Here, supportability requires an effective combination of reliability, maintainability, logistics and operations engineering (as well as safety engineering) to have a system that is available for its intended use throughout its designated mission lifetime. Maintainability is a key driving element in the effective support and upkeep of the system as well as providing the ability to modify and upgrade the system throughout its lifetime. This paper then, will concentrate on maintainability and its integration into the system engineering and design process. The topics to be covered include elements of maintainability, the total cost of ownership, how system availability, maintenance and logistics costs and spare parts cost effect the overall program costs. System analysis and maintainability will show how maintainability fits into the overall systems approach to project development. Maintainability processes and documents will focus on how maintainability is to be performed and what documents are typically generated for a large scale program. Maintainability analysis shows how trade-offs can be performed for various alternative components. The conclusions summarize the paper and are followed by specific problems for hands-on training.

Ultrafast all-optical arithmetic logic based on hydrogenated amorphous silicon microring resonators

NASA Astrophysics Data System (ADS)

Gostimirovic, Dusan; Ye, Winnie N.

2016-03-01

For decades, the semiconductor industry has been steadily shrinking transistor sizes to fit more performance into a single silicon-based integrated chip. This technology has become the driving force for advances in education, transportation, and health, among others. However, transistor sizes are quickly approaching their physical limits (channel lengths are now only a few silicon atoms in length), and Moore's law will likely soon be brought to a stand-still despite many unique attempts to keep it going (FinFETs, high-k dielectrics, etc.). This technology must then be pushed further by exploring (almost) entirely new methodologies. Given the explosive growth of optical-based long-haul telecommunications, we look to apply the use of high-speed optics as a substitute to the digital model; where slow, lossy, and noisy metal interconnections act as a major bottleneck to performance. We combine the (nonlinear) optical Kerr effect with a single add-drop microring resonator to perform the fundamental AND-XOR logical operations of a half adder, by all-optical means. This process is also applied to subtraction, higher-order addition, and the realization of an all-optical arithmetic logic unit (ALU). The rings use hydrogenated amorphous silicon as a material with superior nonlinear properties to crystalline silicon, while still maintaining CMOS-compatibility and the many benefits that come with it (low cost, ease of fabrication, etc.). Our method allows for multi-gigabit-per-second data rates while maintaining simplicity and spatial minimalism in design for high-capacity manufacturing potential.

Development of Plant Control Diagnosis Technology and Increasing Its Applications

NASA Astrophysics Data System (ADS)

Kugemoto, Hidekazu; Yoshimura, Satoshi; Hashizume, Satoru; Kageyama, Takashi; Yamamoto, Toru

A plant control diagnosis technology was developed to improve the performance of plant-wide control and maintain high productivity of plants. The control performance diagnosis system containing this technology picks out the poor performance loop, analyzes the cause, and outputs the result on the Web page. Meanwhile, the PID tuning tool is used to tune extracted loops from the control performance diagnosis system. It has an advantage of tuning safely without process changes. These systems are powerful tools to do Kaizen (continuous improvement efforts) step by step, coordinating with the operator. This paper describes a practical technique regarding the diagnosis system and its industrial applications.

Study on Brewster angle thin film polarizer using hafnia-silica mixture as high-refractive-index material

NASA Astrophysics Data System (ADS)

Xu, Nuo; Zhu, Meiping; Sun, Jian; Chai, Yingjie; Kui, Yi; Zhao, Yuanan; Shao, Jianda

2018-02-01

Two kinds of polarizer coatings were prepared by electron beam evaporation, using HfO2-SiO2 mixture and HfO2 as the high-refractive-index materials, respectively. The HfO2-SiO2 mixture layer was implemented by coevaporating SiO2 and metal Hf, the materials were deposited at an oxygen atmosphere to achieve stoichiometric coatings. The certain HfO2 and SiO2 content ratio is controlled by adjusting the deposition rate of HfO2 and SiO2 using individual quartz crystal monitor. The spectral performance, surface and interfacial properties, as well as the laser-induced damage performance were studied and compared. Comparing with polarizer coating using HfO2 as high-refractive-index material, the polarizer coating using HfO2-SiO2 mixture as high-refractive-index material shows better performance with broader polarizing bandwidth, lower surface roughness, better interfacial property while maintaining high laser-induced damage threshold.

New support for high-performance liquid chromatography based on silica coated with alumina particles.

PubMed

Silveira, José Leandro R; Dib, Samia R; Faria, Anizio M

2014-01-01

A new material based on silica coated with alumina nanoparticles was proposed for use as a chromatographic support for reversed-phase high-performance liquid chromatography. Alumina nanoparticles were synthesized by a sol-gel process in reversed micelles composed of sodium bis(2-ethylhexyl)sulfosuccinate, and the support material was formed by the self-assembly of alumina layers on silica spheres. Spectroscopic and (29)Si nuclear magnetic resonance results showed evidence of chemical bonds between the alumina nanoparticles and the silica spheres, while morphological characterizations showed that the aluminized silica maintained the morphological properties of silica desired for chromatographic purposes after alumina incorporation. Stability studies indicated that bare silica showed high dissolution (~83%), while the aluminized silica remained practically unchanged (99%) after passing one liter of the alkaline mobile phase, indicating high stability under alkaline conditions. The C18 bonded aluminized silica phase showed great potential for use in high-performance liquid chromatography to separate basic molecules in the reversed-phase mode.

Graphene-Encapsulated Nanosheet-Assembled Zinc-Nickel-Cobalt Oxide Microspheres for Enhanced Lithium Storage.

PubMed

Zhang, Qiaobao; Chen, Huixin; Han, Xiang; Cai, Junjie; Yang, Yong; Liu, Meilin; Zhang, Kaili

2016-01-01

The appropriate combination of hierarchical transition-metal oxide (TMO) micro-/nanostructures constructed from porous nanobuilding blocks with graphene sheets (GNS) in a core/shell geometry is highly desirable for high-performance lithium-ion batteries (LIBs). A facile and scalable process for the fabrication of 3D hierarchical porous zinc-nickel-cobalt oxide (ZNCO) microspheres constructed from porous ultrathin nanosheets encapsulated by GNS to form a core/shell geometry is reported for improved electrochemical performance of the TMOs as an anode in LIBs. By virtue of their intriguing structural features, the produced ZNCO/GNS core/shell hybrids exhibit an outstanding reversible capacity of 1015 mA h g(-1) at 0.1 C after 50 cycles. Even at a high rate of 1 C, a stable capacity as high as 420 mA h g(-1) could be maintained after 900 cycles, which suggested their great potential as efficient electrodes for high-performance LIBs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Synapse Project: Engagement in mentally challenging activities enhances neural efficiency.

PubMed

McDonough, Ian M; Haber, Sara; Bischof, Gérard N; Park, Denise C

2015-01-01

Correlational and limited experimental evidence suggests that an engaged lifestyle is associated with the maintenance of cognitive vitality in old age. However, the mechanisms underlying these engagement effects are poorly understood. We hypothesized that mental effort underlies engagement effects and used fMRI to examine the impact of high-challenge activities (digital photography and quilting) compared with low-challenge activities (socializing or performing low-challenge cognitive tasks) on neural function at pretest, posttest, and one year after the engagement program. In the scanner, participants performed a semantic-classification task with two levels of difficulty to assess the modulation of brain activity in response to task demands. The High-Challenge group, but not the Low-Challenge group, showed increased modulation of brain activity in medial frontal, lateral temporal, and parietal cortex-regions associated with attention and semantic processing-some of which were maintained a year later. This increased modulation stemmed from decreases in brain activity during the easy condition for the High-Challenge group and was associated with time committed to the program, age, and cognition. Sustained engagement in cognitively demanding activities facilitated cognition by increasing neural efficiency. Mentally-challenging activities may be neuroprotective and an important element to maintaining a healthy brain into late adulthood.

Direct numerical simulation of turbulent channel flow over a liquid-infused micro-grooved surface

NASA Astrophysics Data System (ADS)

Chang, Jaehee; Jung, Taeyong; Choi, Haecheon; Kim, John

2016-11-01

Recently a superhydrophobic surface has drawn much attention as a passive device to achieve high drag reduction. Despite the high performance promised at ideal conditions, maintaining the interface in real flow conditions is an intractable problem. A non-wetting surface, known as the slippery liquid-infused porous surface (SLIPS) or the lubricant-impregnated surface (LIS), has shown a potential for drag reduction, as the working fluid slips at the interface but cannot penetrate into the lubricant layer. In the present study, we perform direct numerical simulation of turbulent channel flow over a liquid-infused micro-grooved surface to investigate the effects of this surface on the interfacial slip and drag reduction. The flow rate of water is maintained constant corresponding to Reτ 180 in a fully developed turbulent channel flow, and the lubricant layer is shear-driven by the turbulent water flow. The lubricant layer is also simulated with the assumption that the interface is flat (i.e. the surface tension effect is neglected). The solid substrate in which the lubricant is infused is modelled as straight ridges using an immersed boundary method. DNS results show that drag reduction by the liquid-infused surface is highly dependent on the viscosity of the lubricant.

The Synapse Project: Engagement in mentally challenging activities enhances neural efficiency

PubMed Central

McDonough, Ian M.; Haber, Sara; Bischof, Gérard N.; Park, Denise C.

2015-01-01

Purpose: Correlational and limited experimental evidence suggests that an engaged lifestyle is associated with the maintenance of cognitive vitality in old age. However, the mechanisms underlying these engagement effects are poorly understood. We hypothesized that mental effort underlies engagement effects and used fMRI to examine the impact of high-challenge activities (digital photography and quilting) compared with low-challenge activities (socializing or performing low-challenge cognitive tasks) on neural function at pretest, posttest, and one year after the engagement program. Methods: In the scanner, participants performed a semantic-classification task with two levels of difficulty to assess the modulation of brain activity in response to task demands. Results: The High-Challenge group, but not the Low-Challenge group, showed increased modulation of brain activity in medial frontal, lateral temporal, and parietal cortex—regions associated with attention and semantic processing—some of which were maintained a year later. This increased modulation stemmed from decreases in brain activity during the easy condition for the High-Challenge group and was associated with time committed to the program, age, and cognition. Conclusions: Sustained engagement in cognitively demanding activities facilitated cognition by increasing neural efficiency. Mentally-challenging activities may be neuroprotective and an important element to maintaining a healthy brain into late adulthood. PMID:26484698

Least Reliable Bits Coding (LRBC) for high data rate satellite communications

NASA Technical Reports Server (NTRS)

Vanderaar, Mark; Wagner, Paul; Budinger, James

1992-01-01

An analysis and discussion of a bandwidth efficient multi-level/multi-stage block coded modulation technique called Least Reliable Bits Coding (LRBC) is presented. LRBC uses simple multi-level component codes that provide increased error protection on increasingly unreliable modulated bits in order to maintain an overall high code rate that increases spectral efficiency. Further, soft-decision multi-stage decoding is used to make decisions on unprotected bits through corrections made on more protected bits. Using analytical expressions and tight performance bounds it is shown that LRBC can achieve increased spectral efficiency and maintain equivalent or better power efficiency compared to that of Binary Phase Shift Keying (BPSK). Bit error rates (BER) vs. channel bit energy with Additive White Gaussian Noise (AWGN) are given for a set of LRB Reed-Solomon (RS) encoded 8PSK modulation formats with an ensemble rate of 8/9. All formats exhibit a spectral efficiency of 2.67 = (log2(8))(8/9) information bps/Hz. Bit by bit coded and uncoded error probabilities with soft-decision information are determined. These are traded with with code rate to determine parameters that achieve good performance. The relative simplicity of Galois field algebra vs. the Viterbi algorithm and the availability of high speed commercial Very Large Scale Integration (VLSI) for block codes indicates that LRBC using block codes is a desirable method for high data rate implementations.

The Performance of Grant Maintained Schools in England: An Experiment in Autonomy.

ERIC Educational Resources Information Center

Levacic, Rosalind; Hardman, Jason

1999-01-01

Examines recruitment and examination performance of 327 British grant-maintained schools from 1991 to 1996, compared to 108 local education authority schools. The GM schools' apparently higher performance may be attributed to having fewer socially disadvantaged students and reducing this proportion over time. Implications are discussed. Contains…

Processes Contributing to the Maintenance of Flying Phobia: A Narrative Review

PubMed Central

Clark, Gavin I.; Rock, Adam J.

2016-01-01

Flying phobia is a highly prevalent anxiety disorder, which causes sufferers significant distress and life interference. The processes which maintain flying phobia remain poorly understood. A systematic search of the literature was performed to identify what research has been conducted into the processes which may be involved in the fear of flying and whether processes which are believed to maintain other anxiety disorder diagnoses have been investigated in flying phobia. The results of the literature review are presented and related to existing cognitive behavioral theory and research. The results indicate that little research has been conducted into a number of areas considered important in the wider cognitive behavioral literature on anxiety disorders: namely attention, mental imagery, memory, worry, and safety-seeking behaviors. The review proposes a hypothetical model, derived from cognitive behavioral theory, for the processes which may be involved in maintaining flying phobia, and considers a number of areas for future research. PMID:27313550

Northwest Energy Efficient Manufactured Housing Program: High Performance Manufactured Home Prototyping and Construction Development

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

Hewes, Tom; Peeks, Brady

2013-11-01

The Building America Partnership for Improved Residential Construction, the Bonneville Power Administration (BPA), and Northwest Energy Works (NEW), the current Northwest Energy Efficient Manufactured Housing Program (NEEM) administrator, have been collaborating to conduct research on new specifications that would improve on the energy requirements of a NEEM home. In its role as administrator, NEW administers the technical specs, performs research and engineering analysis, implements ongoing construction quality management procedures, and maintains a central database with home tracking. This project prototyped and assessed the performances of cost-effective high performance building assemblies and mechanical systems that are not commonly deployed in themore » manufacturing setting. The package of measures is able to reduce energy used for space conditioning, water heating and lighting by 50 percent over typical manufactured homes produced in the northwest.« less

Northwest Energy Efficient Manufactured Housing Program: High Performance Manufactured Home Prototyping and Construction Development

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

Hewes, Tom; Peeks, Brady

2013-11-01

The Building America Partnership for Improved Residential Construction, the Bonneville Power Administration (BPA), and Northwest Energy Works (NEW), the current Northwest Energy Efficient Manufactured Housing Program (NEEM) administrator, have been collaborating to conduct research on new specifications that would improve on the energy requirements of a NEEM home. In its role as administrator, NEW administers the technical specs, performs research and engineering analysis, implements ongoing construction quality management procedures, and maintains a central database with home tracking. This project prototyped and assessed the performances of cost-effective high performance building assemblies and mechanical systems that are not commonly deployed in themore » manufacturing setting. The package of measures is able to reduce energy used for space conditioning, water heating and lighting by 50% over typical manufactured homes produced in the northwest.« less

Performance and optimization of a derated ion thruster for auxiliary propulsion

NASA Technical Reports Server (NTRS)

Patterson, Michael J.; Foster, John E.

1991-01-01

The characteristics and implications of use of a derated ion thruster for north-south stationkeeping (NSSK) propulsion are discussed. A derated thruster is a 30 cm diameter primary propulsion ion thruster operated at highly throttled conditions appropriate to NSSK functions. The performance characteristics of a 30 cm ion thruster are presented, emphasizing throttled operation at low specific impulse and high thrust-to-power ratio. Performance data and component erosion are compared to other NSSK ion thrusters. Operations benefits derived from the performance advantages of the derated approach are examined assuming an INTELSAt 7-type spacecraft. Minimum ground test facility pumping capabilities required to maintain facility enhanced accelerator grid erosion at acceptable levels in a lifetest are quantified as a function of thruster operating condition. Approaches to reducing the derated thruster mass and volume are also discussed.

Designing Inter-Organisational Collectivities for Dynamic Fit: Stability, maneuvrability and Application in Disaster Relief Endeavours

DTIC Science & Technology

2011-01-01

changed consumer preferences . Hence, static stability limits initial performance deviation (e.g., maintaining desired airplane altitude, maintaining...by changed consumer preferences . Hence, dynamic stability limits the duration of performance deviation (e.g., maintaining desired airplane altitude...altitude from wind gust. Initial resistance to deviation in profit level from change in consumer preferences . Dynamic stability Quickness of a

Range Performance of Bombers Powered by Turbine-Propeller Power Plants

NASA Technical Reports Server (NTRS)

Cline, Charles W.

1950-01-01

Calculations have been made to find range? attainable by bombers of gross weights from l40,000 to 300,000 pounds powered by turbine-propeller power plants. Only conventional configurations were considered and emphasis was placed upon using data for structural and aerodynamic characteristics which are typical of modern military airplanes. An effort was made to limit the various parameters invoked in the airplane configuration to practical values. Therefore, extremely high wing loadings, large amounts of sweepback, and very high aspect ratios have not been considered. Power-plant performance was based upon the performance of a typical turbine-propeller engine equipped with propellers designed to maintain high efficiencies at high-subsonic speeds. Results indicated, in general, that the greatest range, for a given gross weight, is obtained by airplanes of high wing loading, unless the higher cruising speeds associated with the high-wing-loading airplanes require-the use of thinner wing sections. Further results showed the effect of cruising at-high speeds, of operation at very high altitudes, and of carrying large bomb loads.

A high-performance supercapacitor electrode based on N-doped porous graphene

NASA Astrophysics Data System (ADS)

Dai, Shuge; Liu, Zhen; Zhao, Bote; Zeng, Jianhuang; Hu, Hao; Zhang, Qiaobao; Chen, Dongchang; Qu, Chong; Dang, Dai; Liu, Meilin

2018-05-01

The development of high-performance supercapacitors (SCs) often faces some contradictory and competing requirements such as excellent rate capability, long cycling life, and high energy density. One effective strategy is to explore electrode materials of high capacitance, electrode architectures of fast charge and mass transfer, and electrolytes of wide voltage window. Here we report a facile and readily scalable strategy to produce high-performance N-doped graphene with a high specific capacitance (∼390 F g-1). A symmetric SC device with a wide voltage window of 3.5 V is also successfully fabricated based on the N-doped graphene electrode. More importantly, the as-assembled symmetric SC delivers a high energy density of 55 Wh kg-1 at a power density of 1800 W kg-1 while maintaining superior cycling life (retaining 96.6% of the initial capacitance after 20,000 cycles). Even at a power density as high as 8800 W kg-1, it still retains an energy density of 29 Wh kg-1, higher than those of previously reported graphene-based symmetric SCs.

Enhanced treatment efficiency of an anaerobic sequencing batch reactor (ASBR) for cassava stillage with high solids content.

PubMed

Luo, Gang; Xie, Li; Zhou, Qi

2009-06-01

Cassava stillage is a high strength organic wastewater with high suspended solids (SS) content. The efficiency of cassava stillage treatment using an anaerobic sequencing batch reactor (ASBR) was significantly enhanced by discharging settled sludge to maintain a lower sludge concentration (about 30 g/L) in the reactor. Three hydraulic retention times (HRTs), namely 10 d, 7.5 d, 5 d, were evaluated at this condition. The study demonstrated that at an HRT of 5 d and an organic loading rate (OLR) of 11.3 kg COD/(m(3) d), the total chemical oxygen demand (TCOD) and soluble COD (SCOD) removal efficiency can still be maintained at above 80%. The settleability of digested cassava stillage was improved significantly, and thus only a small amount of settled sludge needed to be discharged to maintain the sludge concentration in the reactor. Furthermore, the performance of ASBR operated at low and high sludge concentration (about 79.5 g/L without sludge discharged) was evaluated at an HRT of 5 d. The TCOD removal efficiency and SS in the effluent were 61% and 21.9 g/L respectively at high sludge concentration, while the values were 85.1% and 2.4 g/L at low sludge concentration. Therefore, low sludge concentration is recommended for ASBR treating cassava stillage at an HRT 5 d due to lower TCOD and SS in the effluent, which could facilitate post-treatment.

Wind tunnel testing of low-drag airfoils

NASA Technical Reports Server (NTRS)

Harvey, W. Donald; Mcghee, R. J.; Harris, C. D.

1986-01-01

Results are presented for the measured performance recently obtained on several airfoil concepts designed to achieve low drag by maintaining extensive regions of laminar flow without compromising high-lift performance. The wind tunnel results extend from subsonic to transonic speeds and include boundary-layer control through shaping and suction. The research was conducted in the NASA Langley 8-Ft Transonic Pressure Tunnel (TPT) and Low Turbulence Pressure Tunnel (LTPT) which have been developed for testing such low-drag airfoils. Emphasis is placed on identifying some of the major factors influencing the anticipated performance of low-drag airfoils.

Neuron-Inspired Fe3O4/Conductive Carbon Filament Network for High-Speed and Stable Lithium Storage.

PubMed

Hao, Shu-Meng; Li, Qian-Jie; Qu, Jin; An, Fei; Zhang, Yu-Jiao; Yu, Zhong-Zhen

2018-05-17

Construction of a continuous conductance network with high electron-transfer rate is extremely important for high-performance energy storage. Owing to the highly efficient mass transport and information transmission, neurons are exactly a perfect model for electron transport, inspiring us to design a neuron-like reaction network for high-performance lithium-ion batteries (LIBs) with Fe 3 O 4 as an example. The reactive cores (Fe 3 O 4 ) are protected by carbon shells and linked by carbon filaments, constituting an integrated conductance network. Thus, once the reaction starts, the electrons released from every Fe 3 O 4 cores are capable of being transferred rapidly through the whole network directly to the external circuit, endowing the nanocomposite with tremendous rate performance and ultralong cycle life. After 1000 cycles at current densities as high as 1 and 2 A g -1 , charge capacities of the as-synthesized nanocomposite maintain 971 and 715 mA h g -1 , respectively, much higher than those of reported Fe 3 O 4 -based anode materials. The Fe 3 O 4 -based conductive network provides a new idea for future developments of high-rate-performance LIBs.

Two-dimensional ultra-thin SiO(x) (0 < x < 2) nanosheets with long-term cycling stability as lithium ion battery anodes.

PubMed

Sun, Lin; Su, Tingting; Xu, Lei; Liu, Meipin; Du, Hong-Bin

2016-03-21

Ultra-thin SiO(x) (0 < x < 2) nanosheets were obtained via a convenient solvothermal route from a Zintl compound CaSi2. After carbon coating, the SiOx@C nanosheet anodes exhibit high capacity, good rate and superior cycling performance for high-capacity lithium ion battery applications. The specific capacity can be maintained as high as 760 mA h g(-1) with almost no capacity decay after 400 cycles at a current density of 0.5 A g(-1).

Intraspecific variation and species coexistence.

PubMed

Lichstein, Jeremy W; Dushoff, Jonathan; Levin, Simon A; Pacala, Stephen W

2007-12-01

We use a two-species model of plant competition to explore the effect of intraspecific variation on community dynamics. The competitive ability ("performance") of each individual is assigned by an independent random draw from a species-specific probability distribution. If the density of individuals competing for open space is high (e.g., because fecundity is high), species with high maximum (or large variance in) performance are favored, while if density is low, species with high typical (e.g., mean) performance are favored. If there is an interspecific mean-variance performance trade-off, stable coexistence can occur across a limited range of intermediate densities, but the stabilizing effect of this trade-off appears to be weak. In the absence of this trade-off, one species is superior. In this case, intraspecific variation can blur interspecific differences (i.e., shift the dynamics toward what would be expected in the neutral case), but the strength of this effect diminishes as competitor density increases. If density is sufficiently high, the inferior species is driven to extinction just as rapidly as in the case where there is no overlap in performance between species. Intraspecific variation can facilitate coexistence, but this may be relatively unimportant in maintaining diversity in most real communities.

Performance of salmon fishery portfolios across western North America.

PubMed

Griffiths, Jennifer R; Schindler, Daniel E; Armstrong, Jonathan B; Scheuerell, Mark D; Whited, Diane C; Clark, Robert A; Hilborn, Ray; Holt, Carrie A; Lindley, Steven T; Stanford, Jack A; Volk, Eric C

2014-12-01

Quantifying the variability in the delivery of ecosystem services across the landscape can be used to set appropriate management targets, evaluate resilience and target conservation efforts. Ecosystem functions and services may exhibit portfolio-type dynamics, whereby diversity within lower levels promotes stability at more aggregated levels. Portfolio theory provides a framework to characterize the relative performance among ecosystems and the processes that drive differences in performance. We assessed Pacific salmon Oncorhynchus spp. portfolio performance across their native latitudinal range focusing on the reliability of salmon returns as a metric with which to assess the function of salmon ecosystems and their services to humans. We used the Sharpe ratio (e.g. the size of the total salmon return to the portfolio relative to its variability (risk)) to evaluate the performance of Chinook and sockeye salmon portfolios across the west coast of North America. We evaluated the effects on portfolio performance from the variance of and covariance among salmon returns within each portfolio, and the association between portfolio performance and watershed attributes. We found a positive latitudinal trend in the risk-adjusted performance of Chinook and sockeye salmon portfolios that also correlated negatively with anthropogenic impact on watersheds (e.g. dams and land-use change). High-latitude Chinook salmon portfolios were on average 2·5 times more reliable, and their portfolio risk was mainly due to low variance in the individual assets. Sockeye salmon portfolios were also more reliable at higher latitudes, but sources of risk varied among the highest performing portfolios. Synthesis and applications . Portfolio theory provides a straightforward method for characterizing the resilience of salmon ecosystems and their services. Natural variability in portfolio performance among undeveloped watersheds provides a benchmark for restoration efforts. Locally and regionally, assessing the sources of portfolio risk can guide actions to maintain existing resilience (protect habitat and disturbance regimes that maintain response diversity; employ harvest strategies sensitive to different portfolio components) or improve restoration activities. Improving our understanding of portfolio reliability may allow for management of natural resources that is robust to ongoing environmental change. Portfolio theory provides a straightforward method for characterizing the resilience of salmon ecosystems and their services. Natural variability in portfolio performance among undeveloped watersheds provides a benchmark for restoration efforts. Locally and regionally, assessing the sources of portfolio risk can guide actions to maintain existing resilience (protect habitat and disturbance regimes that maintain response diversity; employ harvest strategies sensitive to different portfolio components) or improve restoration activities. Improving our understanding of portfolio reliability may allow for management of natural resources that is robust to ongoing environmental change.

Performance of salmon fishery portfolios across western North America

PubMed Central

Griffiths, Jennifer R; Schindler, Daniel E; Armstrong, Jonathan B; Scheuerell, Mark D; Whited, Diane C; Clark, Robert A; Hilborn, Ray; Holt, Carrie A; Lindley, Steven T; Stanford, Jack A; Volk, Eric C

2014-01-01

Quantifying the variability in the delivery of ecosystem services across the landscape can be used to set appropriate management targets, evaluate resilience and target conservation efforts. Ecosystem functions and services may exhibit portfolio-type dynamics, whereby diversity within lower levels promotes stability at more aggregated levels. Portfolio theory provides a framework to characterize the relative performance among ecosystems and the processes that drive differences in performance. We assessed Pacific salmon Oncorhynchus spp. portfolio performance across their native latitudinal range focusing on the reliability of salmon returns as a metric with which to assess the function of salmon ecosystems and their services to humans. We used the Sharpe ratio (e.g. the size of the total salmon return to the portfolio relative to its variability (risk)) to evaluate the performance of Chinook and sockeye salmon portfolios across the west coast of North America. We evaluated the effects on portfolio performance from the variance of and covariance among salmon returns within each portfolio, and the association between portfolio performance and watershed attributes. We found a positive latitudinal trend in the risk-adjusted performance of Chinook and sockeye salmon portfolios that also correlated negatively with anthropogenic impact on watersheds (e.g. dams and land-use change). High-latitude Chinook salmon portfolios were on average 2·5 times more reliable, and their portfolio risk was mainly due to low variance in the individual assets. Sockeye salmon portfolios were also more reliable at higher latitudes, but sources of risk varied among the highest performing portfolios. Synthesis and applications. Portfolio theory provides a straightforward method for characterizing the resilience of salmon ecosystems and their services. Natural variability in portfolio performance among undeveloped watersheds provides a benchmark for restoration efforts. Locally and regionally, assessing the sources of portfolio risk can guide actions to maintain existing resilience (protect habitat and disturbance regimes that maintain response diversity; employ harvest strategies sensitive to different portfolio components) or improve restoration activities. Improving our understanding of portfolio reliability may allow for management of natural resources that is robust to ongoing environmental change. Portfolio theory provides a straightforward method for characterizing the resilience of salmon ecosystems and their services. Natural variability in portfolio performance among undeveloped watersheds provides a benchmark for restoration efforts. Locally and regionally, assessing the sources of portfolio risk can guide actions to maintain existing resilience (protect habitat and disturbance regimes that maintain response diversity; employ harvest strategies sensitive to different portfolio components) or improve restoration activities. Improving our understanding of portfolio reliability may allow for management of natural resources that is robust to ongoing environmental change. PMID:25552746

Antifouling property of highly oleophobic substrates for solar cell surfaces

NASA Astrophysics Data System (ADS)

Fukada, Kenta; Nishizawa, Shingo; Shiratori, Seimei

2014-03-01

Reduction of solar cell conversion efficiency by bird spoor or oil smoke is a common issue. Maintaining the surface of solar cells clean to retain the incident light is of utmost importance. In this respect, there has been growing interest in the area of superhydrophobicity for developing water repelling and self-cleaning surfaces. This effect is inspired by lotus leaves that have micro papillae covered with hydrophobic wax nanostructures. Superhydrophobic surfaces on transparent substrates have been developed for removing contaminants from solar cell surfaces. However, oil cannot be removed by superhydrophobic effect. In contrast, to prevent bird spoor, a highly oleophobic surface is required. In a previous study, we reported transparent-type fabrics comprising nanoparticles with a nano/micro hierarchical structure that ensured both oleophobicity and transparency. In the current study, we developed new highly oleophobic stripes that were constructed into semi-transparent oleophobic surfaces for solar cells. Solar cell performance was successfully maintained; the total transmittance was a key factor for determining conversion efficiency.

Hierarchically porous carbon derived from banana peel for lithium sulfur battery with high areal and gravimetric sulfur loading

NASA Astrophysics Data System (ADS)

Li, Fanqun; Qin, Furong; Zhang, Kai; Fang, Jing; Lai, Yanqing; Li, Jie

2017-09-01

Facile and sustainable route is developed to convert biomass into hierarchically porous carbon matrix cooperating with highly conductive graphene. By tailoring the porosity of the carbon matrix to promote fast mass transfer and cooperating highly conductive interconnected graphene frameworks to accelerate the electron transport, the carbon sulfur cathodes simultaneously achieve high areal and gravimetric sulfur loading/content (6 mg cm-2/67 wt%) and deliver outstanding electrochemical performance. After 100 cyclic discharge-charge test at the current density of 0.2 C, the reversible capacity maintains at 707 mA h g-1.

Silicon/copper dome-patterned electrodes for high-performance hybrid supercapacitors.

PubMed

Liu, Xuyan; Jung, Hun-Gi; Kim, Sang-Ok; Choi, Ho-Suk; Lee, Sangwha; Moon, Jun Hyuk; Lee, Joong Kee

2013-12-02

This study proposes a method for manufacturing high-performance electrode materials in which controlling the shape of the current collector and electrode material for a Li-ion capacitor (LIC). In particular, the proposed LIC manufacturing method maintains the high voltage of a cell by using a microdome-patterned electrode material, allowing for reversible reactions between the Li-ion and the active material for an extended period of time. As a result, the LICs exhibit initial capacities of approximately 42 F g⁻¹, even at 60 A g⁻¹. The LICs also exhibit good cycle performance up to approximately 15,000 cycles. In addition, these advancements allow for a considerably higher energy density than other existing capacitor systems. The energy density of the proposed LICs is approximately nine, two, and 1.5 times higher than those of the electrochemical double layer capacitor (EDLC), AC/LiMn₂O₄ hybrid capacitor, and intrinsic Si/AC LIC, respectively.

Silicon/copper dome-patterned electrodes for high-performance hybrid supercapacitors

NASA Astrophysics Data System (ADS)

Liu, Xuyan; Jung, Hun-Gi; Kim, Sang-Ok; Choi, Ho-Suk; Lee, Sangwha; Moon, Jun Hyuk; Lee, Joong Kee

2013-12-01

This study proposes a method for manufacturing high-performance electrode materials in which controlling the shape of the current collector and electrode material for a Li-ion capacitor (LIC). In particular, the proposed LIC manufacturing method maintains the high voltage of a cell by using a microdome-patterned electrode material, allowing for reversible reactions between the Li-ion and the active material for an extended period of time. As a result, the LICs exhibit initial capacities of approximately 42 F g-1, even at 60 A g-1. The LICs also exhibit good cycle performance up to approximately 15,000 cycles. In addition, these advancements allow for a considerably higher energy density than other existing capacitor systems. The energy density of the proposed LICs is approximately nine, two, and 1.5 times higher than those of the electrochemical double layer capacitor (EDLC), AC/LiMn2O4 hybrid capacitor, and intrinsic Si/AC LIC, respectively.

High-precision buffer circuit for suppression of regenerative oscillation

NASA Technical Reports Server (NTRS)

Tripp, John S.; Hare, David A.; Tcheng, Ping

1995-01-01

Precision analog signal conditioning electronics have been developed for wind tunnel model attitude inertial sensors. This application requires low-noise, stable, microvolt-level DC performance and a high-precision buffered output. Capacitive loading of the operational amplifier output stages due to the wind tunnel analog signal distribution facilities caused regenerative oscillation and consequent rectification bias errors. Oscillation suppression techniques commonly used in audio applications were inadequate to maintain the performance requirements for the measurement of attitude for wind tunnel models. Feedback control theory is applied to develop a suppression technique based on a known compensation (snubber) circuit, which provides superior oscillation suppression with high output isolation and preserves the low-noise low-offset performance of the signal conditioning electronics. A practical design technique is developed to select the parameters for the compensation circuit to suppress regenerative oscillation occurring when typical shielded cable loads are driven.

High-performance fiber optic link for ECM antenna remoting

NASA Astrophysics Data System (ADS)

Edge, Colin; Burgess, John W.; Wale, Michael J.; Try, Nicholas W.

1998-11-01

The ability to remotely radiate microwave signals has become an essential feature of modern electronic counter-measures (ECM) systems. The use of fiber optics allows remote microwave links to be constructed which have very low propagation loss and dispersion, are very flexible and light in weight, and have a high degree of immunity from external electromagnetic fields, crosstalk and environmental effects. This combination of desirable characteristics are very beneficial to avionic ECM antenna remoting as well as many other applications. GEC-Marconi have developed high performance fiber components for use in a towed radar decoy. The resulting rugged and compact optical transmitter and receiver modules have been developed and proven to maintain the required performance over the full hostile range of environmental conditions encountered on a fast jet. Packaged fiber optic links have been produced which can achieve a compression dynamic range of greater than 87 dB in 1 MHz bandwidth over a 2 to 18 GHz.

Microchip Electrophoresis at Elevated Temperatures and High Separation Field Strengths

PubMed Central

Mitra, Indranil; Marczak, Steven P.; Jacobson, Stephen C.

2014-01-01

We report free-solution microchip electrophoresis performed at elevated temperatures and high separation field strengths. We used microfluidic devices with 11-cm long separation channels to conduct separations at temperatures between 22 (ambient) and 45 °C and field strengths from 100 to 1000 V/cm. To evaluate separation performance, N-glycans were used as a model system and labeled with 8-aminopyrene-1,3,6-trisulfonic acid to impart charge for electrophoresis and render them fluorescent. Typically, increased diffusivity at higher temperatures leads to increased axial dispersion and poor separation performance; however, we demonstrate that sufficiently high separation field strengths can be used to offset the impact of increased diffusivity in order to maintain separation efficiency. Efficiencies for these free-solution separations are the same at temperatures of 25, 35, and 45 °C with separation field strengths ≥500 V/cm. PMID:24114979

Executive Functioning in Highly Talented Soccer Players

PubMed Central

Verburgh, Lot; Scherder, Erik J. A.; van Lange, Paul A.M.; Oosterlaan, Jaap

2014-01-01

Executive functions might be important for successful performance in sports, particularly in team sports requiring quick anticipation and adaptation to continuously changing situations in the field. The executive functions motor inhibition, attention and visuospatial working memory were examined in highly talented soccer players. Eighty-four highly talented youth soccer players (mean age 11.9), and forty-two age-matched amateur soccer players (mean age 11.8) in the age range 8 to 16 years performed a Stop Signal task (motor inhibition), the Attention Network Test (alerting, orienting, and executive attention) and a visuospatial working memory task. The highly talented soccer players followed the talent development program of the youth academy of a professional soccer club and played at the highest national soccer competition for their age. The amateur soccer players played at a regular soccer club in the same geographical region as the highly talented soccer players and play in a regular regional soccer competition. Group differences were tested using analyses of variance. The highly talented group showed superior motor inhibition as measured by stop signal reaction time (SSRT) on the Stop Signal task and a larger alerting effect on the Attention Network Test, indicating an enhanced ability to attain and maintain an alert state. No group differences were found for orienting and executive attention and visuospatial working memory. A logistic regression model with group (highly talented or amateur) as dependent variable and executive function measures that significantly distinguished between groups as predictors showed that these measures differentiated highly talented soccer players from amateur soccer players with 89% accuracy. Highly talented youth soccer players outperform youth amateur players on suppressing ongoing motor responses and on the ability to attain and maintain an alert state; both may be essential for success in soccer. PMID:24632735

Material handling robot system for flow-through storage applications

NASA Astrophysics Data System (ADS)

Dill, James F.; Candiloro, Brian; Downer, James; Wiesman, Richard; Fallin, Larry; Smith, Ron

1999-01-01

This paper describes the design, development and planned implementation of a system of mobile robots for use in flow through storage applications. The robots are being designed with on-board embedded controls so that they can perform their tasks as semi-autonomous workers distributed within a centrally controlled network. On the storage input side, boxes will be identified by bar-codes and placed into preassigned flow through bins. On the shipping side, orders will be forwarded to the robots from a central order processing station and boxes will be picked from designated storage bins following proper sequencing to permit direct loading into trucks for shipping. Because of the need to maintain high system availability, a distributed control strategy has been selected. When completed, the system will permit robots to be dynamically reassigned responsibilities if an individual unit fails. On-board health diagnostics and condition monitoring will be used to maintain high reliability of the units.

The Design & Development of the Ocean Color Instrument Precision Superduplex Hybrid Bearing Cartridge

NASA Technical Reports Server (NTRS)

Schepis, Joseph; Woodard, Timothy; Hakun, Claef; Bergandy, Konrad; Church, Joseph; Ward, Peter; Lee, Michael; Conti, Alfred; Guzek, Jeffrey

2018-01-01

A high precision, high-resolution Ocean Color Imaging (OCI) instrument is under development for the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission which requires a pair of medium speed mechanisms to scan the ocean surface continuously. The design of the rotating telescope (RT) mechanism operating at 360 RPM and the half-angle mirror (HAM) mechanism synchronized at 180 RPM was concern for maintaining pointing precision over the required life and continuous operations. An effort was undertaken with the manufacturer to design and analyze a special bearing configuration to minimize axial and radial runout, minimize torque, and maintain nominal contact stresses and stiffness over the operating temperature range and to maximize life. The bearing design, development effort, analysis and testing will be discussed as will the technical challenges that this specific design imposed upon the mechanism engineers. Bearing performance, runout as achieved and verified during encoder installation and operating torque will be described.

Bosch CO2 Reduction System Development

NASA Technical Reports Server (NTRS)

Holmes, R. F.; King, C. D.; Keller, E. E.

1975-01-01

Refinements in the design of a Bosch CO2 reduction unit for spacecraft O2 production are described. Sealing of the vacuum insulation jacket was simplified so that high vacuum and high insulation performance are easily maintained. The device includes a relatively simple concentric shell recuperative heat exchanger which operates at approximately 95% temperature effectiveness and helps lower power consumption. The influence of reactor temperature, pressure, and recycle gas composition on power consumption was investigated. In general, precise control is not required since power consumption is not very sensitive to moderate variations of these parameters near their optimum values. There are two process rate control modes which match flow rate to process demand. Catalyst conditioning, support, and packing pattern developments assure consistent starts, reduced energy consumption, and extended cartridge life. Operation levels for four or five men were maintained with overall power input values of 50 to 60 watts per man.

Alertness management in two-person long-haul flight operations

NASA Technical Reports Server (NTRS)

Rosekind, M. R.; Gander, P. H.

1992-01-01

Long-haul flight operations involve cumulative sleep loss, circadian disruption, and extended and irregular duty schedules. These factors reduce pilot alertness and performance on the flightdeck. Conceptually and operationally, alertness management in flight operations can be divided into preventive strategies and operational countermeasures. Preventive strategies are utilized prior to a duty period to mitigate or reduce the effects of sleep loss, circadian disruption and fatigue during subsequent flight operations. Operational countermeasures are used during operations as acute techniques for maintaining performance and alertness. Results from previous NASA Ames field studies document the sleep loss and circadian disruption in three-person long-haul flying and illustrate the application of preventive strategies and operational countermeasures. One strategy that can be used in both a preventive and operational manner is strategic napping. The application and effectiveness of strategic napping in long-haul operations will be discussed. Finally, long-haul flying in two-person highly automated aircraft capable of extended range operations will create new challenges to maintaining pilot alertness and performance. Alertness management issues in this flight environment will be explored.

An interferometer for high-resolution optical surveillance from GEO - internal metrology breadboard

NASA Astrophysics Data System (ADS)

Bonino, L.; Bresciani, F.; Piasini, G.; Pisani, M.; Cabral, A.; Rebordão, J.; Musso, F.

2017-11-01

This paper describes the internal metrology breadboard development activities performed in the frame of the EUCLID CEPA 9 RTP 9.9 "High Resolution Optical Satellite Sensor" project of the WEAO Research Cell by AAS-I and INETI. The Michelson Interferometer Testbed demonstrates the possibility of achieving a cophasing condition between two arms of the optical interferometer starting from a large initial white light Optical Path Difference (OPD) unbalance and of maintaining the fringe pattern stabilized in presence of disturbances.

Scalable Production Method for Graphene Oxide Water Vapor Separation Membranes

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

Fifield, Leonard S.; Shin, Yongsoon; Liu, Wei

ABSTRACT Membranes for selective water vapor separation were assembled from graphene oxide suspension using techniques compatible with high volume industrial production. The large-diameter graphene oxide flake suspensions were synthesized from graphite materials via relatively efficient chemical oxidation steps with attention paid to maintaining flake size and achieving high graphene oxide concentrations. Graphene oxide membranes produced using scalable casting methods exhibited water vapor flux and water/nitrogen selectivity performance meeting or exceeding that of membranes produced using vacuum-assisted laboratory techniques. (PNNL-SA-117497)

Filter line wiring designs in aircraft

NASA Astrophysics Data System (ADS)

Rowe, Richard M.

1990-10-01

The paper presents a harness design using a filter-line wire technology and appropriate termination methods to help meet high-energy radiated electromagnetic field (HERF) requirements for protection against the adverse effects of EMI on electrical and avionic systems. Filter-line interconnect harnessing systems discussed consist of high-performance wires and cables; when properly wired they suppress conducted and radiated EMI above 100 MHz. Filter-line termination devices include backshell adapters, braid splicers, and shield terminators providing 360-degree low-impedance terminations and enhancing maintainability of the system.

Nickel-Hydrogen Battery Fault Clearing at Low State of Charge

NASA Technical Reports Server (NTRS)

Lurie, C.

1997-01-01

Fault clearing currents were achieved and maintained at discharge rates from C/2 to C/3 at high and low states of charge. The fault clearing plateau voltage is strong function of: discharge current, and voltage-prior-to-the-fault-clearing-event and a weak function of state of charge. Voltage performance, for the range of conditions reported, is summarized.

Articulated, Performance-Based Instruction Objectives Guide for Air Conditioning, Refrigeration, and Heating. Volume II (Second Year).

ERIC Educational Resources Information Center

Henderson, William Edward, Jr., Ed.

This articulation guide contains 17 units of instruction for the second year of a two-year vocational program designed to prepare the high school graduate to install, maintain, and repair various types of residential and commercial heating, air conditioning, and refrigeration equipment. The units are designed to help the student to expand and…

AHPCRC - Army High Performance Computing Research Center

DTIC Science & Technology

2008-01-01

University) Birds and insects use complex flapping and twisting wing motions to maneuver, hover, avoid obstacles, and maintain or regain their...vehicles for use in sensing, surveillance, and wireless communications. HPC simulations examine plunging, pitching, and twisting motions of aeroelastic...wings, to optimize the amplitudes and frequencies of flapping and twisting motions for the maximum amount of thrust. Several methods of calculation

Purge-Alert | High-Performance Computing | NREL

Science.gov Websites

and maintain if you want notifications for files that will be removed within 7 days. Simply add a single email address to this file: /scratch/$USER/.notify-email The email you will receive will provide instructions as to where the files are located. You will only receive emails if there are files that will be

Promoting Lifelong Physical Activity and High Level Performance: Realising an Achievable Aim for Physical Education

ERIC Educational Resources Information Center

MacNamara, Aine; Collins, Dave; Bailey, Richard; Toms, Martin; Ford, Paul; Pearce, Gemma

2011-01-01

Background: Even though all school-aged children in most countries experience some form of curricular physical education many do not maintain a lifelong involvement in sport or physical activity. From a theoretical perspective, the development models that dominate sport are limited by their staged and linear approaches to development (e.g. Cote's…

Hold Firm: Gifted Learners Value Standing One's Ground in Disagreements with a Friend

ERIC Educational Resources Information Center

Chichekian, Tanya; Shore, Bruce M.

2017-01-01

Seventy-four students in three different Grade 9 classrooms of high-performing learners from the same suburban, comprehensive secondary school, completed a questionnaire focused on their preferences for a friend to stand by his or her position in case of a disagreement, to maintain their own position themselves, and to modify their own stance.…

Articulated, Performance-Based Instruction Objectives Guide for Air Conditioning, Refrigeration, and Heating (Environmental Control System Installer/Servicer). Edition I.

ERIC Educational Resources Information Center

Henderson, William Edward, Jr., Ed.

This articulation guide contains 17 units of instruction for the first year of a two-year vocational program designed to prepare the high school graduate to install, maintain, and repair various types of residential and commercial heating, air conditioning, and refrigeration equipment. The units are to introduce the student to fundamental theories…

Maintaining the Access Mission: Open Access Universities and the Challenges of Performance-Based Funding

ERIC Educational Resources Information Center

Mathuews, Katy; Pulcini, Brad

2017-01-01

For the purposes of this article, open access universities are defined as bachelor's degree-granting institutions that do not restrict admission on the basis of ACT/SAT scores, high school grade point average, and the like. Typically, the mission of an open access university is to provide all students with the opportunity to pursue a degree. The…

Multipass reconfiguration of the HELEN Nd:glass laser at the Atomic Weapons Establishment.

PubMed

Norman, Michael J; Andrew, James E; Bett, Thomas H; Clifford, Roger K; England, John E; Hopps, Nicholas W; Parker, Kenneth W; Porter, Kenneth; Stevenson, Mark

2002-06-20

The HELEN high-power Nd:glass laser has been rebuilt in a new multipass configuration that requires fewer components to maintain existing performance. This is expected to lead to greater system availability and reduced running costs. We describe the new design, discuss some of the key issues that had to be addressed, and present operational results.

Nutrient Requirements for High Stress Environments

DTIC Science & Technology

1988-04-20

Certain types of stress can cause increased nutrient requirements to maintain physiological or psychological performance levels; however, not all stress...elicits * this response and relatively few nutrient requirements are actually increased. Environmental stress sometimes causes increased energy...influence of "stress" is superimposed upon the dose-response curve. It is known that certain types of stress can result in an increased requirement for

Integrating Computer Architectures into the Design of High-Performance Controllers

NASA Technical Reports Server (NTRS)

Jacklin, Stephen A.; Leyland, Jane A.; Warmbrodt, William

1986-01-01

Modern control systems must typically perform real-time identification and control, as well as coordinate a host of other activities related to user interaction, on-line graphics, and file management. This paper discusses five global design considerations that are useful to integrate array processor, multimicroprocessor, and host computer system architecture into versatile, high-speed controllers. Such controllers are capable of very high control throughput, and can maintain constant interaction with the non-real-time or user environment. As an application example, the architecture of a high-speed, closed-loop controller used to actively control helicopter vibration will be briefly discussed. Although this system has been designed for use as the controller for real-time rotorcraft dynamics and control studies in a wind-tunnel environment, the control architecture can generally be applied to a wide range of automatic control applications.

Compliance and High Reliability in a Complex Healthcare Organization.

PubMed

Simon, Maxine dellaBadia

2018-01-01

When considering the impact of regulation on healthcare, visualize a spider's web. The spider weaves sections together to create the whole, with each fiber adding to the structure to support its success or lead to its failure. Each section is dependent on the others, and all must be aligned to maintain the structure. Outside forces can cause a shift in the web's fragile equilibrium.The interdependence of the sections of the spider's web is similar to the way hospital departments and services work together. An organization's structure must be shaped to support its mission and vision. At the same time, the business of healthcare requires the development and achievement of operational objectives and financial performance goals. Establishing a culture that is flexible enough to permit creativity, provide resiliency, and manage complexity as the organization grows is fundamental to success. An organization must address each of these factors while maintaining stability, carrying out its mission, and fostering improvement.Nature's order maintains the spider's web. Likewise, regulation can strengthen healthcare organizations by initiating disruptive changes that can support efforts to achieve and sustain high reliability in the delivery of care. To that end, leadership must be willing to provide the necessary vision and resources.

Perturbed Partial Cavity Drag Reduction at High Reynolds Numbers

NASA Astrophysics Data System (ADS)

Makiharju, Simo; Elbing, Brian; Wiggins, Andrew; Dowling, David; Perlin, Marc; Ceccio, Steven

2010-11-01

Ventilated partial cavities were investigated at Reynolds numbers to 80 million. These cavities could be suitable for friction drag reduction on ocean going vessels and thereby lead to environmental and economical benefits. The test model was a 3.05 m wide by 12.9 m long flat plate, with a 0.18 m backward-facing step and a cavity-terminating beach, which had an adjustable slope, tilt and height. The step and beach trapped a ventilated partial cavity over the longitudinal mid-section of the model. Large-scale flow perturbations, mimicking the effect of ambient ocean waves were investigated. For the conditions tested a cavity could be maintained under perturbed flow conditions when the gas flux supplied was greater than the minimum required to maintain a cavity under steady conditions, with larger perturbations requiring more excess gas flux to maintain the cavity. High-speed video was used to observe the unsteady three dimensional cavity closure, the overall cavity shape, and the cavity oscillations. Cavities with friction drag reduction exceeding 95% were attained at optimal conditions. A simplified energy cost-benefit analysis of partial cavity drag reduction was also performed. The results suggest that PCDR could potentially lead to energy savings.

High Reliability Engine Control Demonstrated for Aircraft Engines

NASA Technical Reports Server (NTRS)

Guo, Ten-Huei

1999-01-01

For a dual redundant-control system, which is typical for short-haul aircraft, if a failure is detected in a control sensor, the engine control is transferred to a safety mode and an advisory is issued for immediate maintenance action to replace the failed sensor. The safety mode typically results in severely degraded engine performance. The goal of the High Reliability Engine Control (HREC) program was to demonstrate that the neural-network-based sensor validation technology can safely operate an engine by using the nominal closed-loop control during and after sensor failures. With this technology, engine performance could be maintained, and the sensor could be replaced as a conveniently scheduled maintenance action.

Thermally ruggedized ITO transparent electrode films for high power optoelectronics

DOE PAGES

Yoo, Jae-Hyuck; Matthews, Manyalibo; Ramsey, Phil; ...

2017-10-06

Here, we present two strategies to minimize laser damage in transparent conductive films. The first consists of improving heat dissipation by selection of substrates with high thermal diffusivity or by addition of capping layer heatsinks. The second is reduction of bulk energy absorption by lowering free carrier density and increasing mobility, while maintaining film conductance with thicker films. Multi-pulse laser damage tests were performed on tin-doped indium oxide (ITO) films configured to improve optical lifetime damage performance. Conditions where improvements were not observed are also described. Finally, when bulk heating is not the dominant damage process, discrete defect-induced damage limitsmore » damage behavior.« less

Molecular Spring Enabled High-Performance Anode for Lithium Ion Batteries

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

Zheng, Tianyue; Jia, Zhe; Lin, Na

Flexible butyl interconnection segments are synthetically incorporated into an electronically conductive poly(pyrene methacrylate) homopolymer and its copolymer. The insertion of butyl segment makes the pyrene polymer more flexible, and can better accommodate deformation. This new class of flexible and conductive polymers can be used as a polymer binder and adhesive to facilitate the electrochemical performance of a silicon/graphene composite anode material for lithium ion battery application. They act like a “spring” to maintain the electrode mechanical and electrical integrity. High mass loading and high areal capacity, which are critical design requirements of high energy batteries, have been achieved in themore » electrodes composed of the novel binders and silicon/graphene composite material. A remarkable area capacity of over 5 mAh/cm 2 and volumetric capacity of over 1700 Ah/L have been reached at a high current rate of 333 mA/g.« less

Molecular Spring Enabled High-Performance Anode for Lithium Ion Batteries

DOE PAGES

Zheng, Tianyue; Jia, Zhe; Lin, Na; ...

2017-11-29

Flexible butyl interconnection segments are synthetically incorporated into an electronically conductive poly(pyrene methacrylate) homopolymer and its copolymer. The insertion of butyl segment makes the pyrene polymer more flexible, and can better accommodate deformation. This new class of flexible and conductive polymers can be used as a polymer binder and adhesive to facilitate the electrochemical performance of a silicon/graphene composite anode material for lithium ion battery application. They act like a “spring” to maintain the electrode mechanical and electrical integrity. High mass loading and high areal capacity, which are critical design requirements of high energy batteries, have been achieved in themore » electrodes composed of the novel binders and silicon/graphene composite material. A remarkable area capacity of over 5 mAh/cm 2 and volumetric capacity of over 1700 Ah/L have been reached at a high current rate of 333 mA/g.« less

High-pressure endurable flexible tactile actuator based on microstructured dielectric elastomer

NASA Astrophysics Data System (ADS)

Pyo, Dongbum; Ryu, Semin; Kyung, Ki-Uk; Yun, Sungryul; Kwon, Dong-Soo

2018-02-01

We demonstrate a robust flexible tactile actuator that is capable of working under high external pressures. The tactile actuator is based on a pyramidal microstructured dielectric elastomer layer inducing variation in both mechanical and dielectric properties. The vibrational performance of the actuator can be modulated by changing the geometric parameter of the microstructures. We evaluated the performance of the actuator under high-pressure loads up to 25 kPa, which is over the typical range of pressure applied when humans touch or manipulate objects. Due to the benefit of nonlinearity of the pyramidal structure, the actuator could maintain high mechanical output under various external pressures in the frequency range of 100-200 Hz, which is the most sensitive to vibration acceleration for human finger pads. The responses are not only fast, reversible, and highly durable under consecutive cyclic operations, but also large enough to impart perceivable vibrations for haptic feedback on practical wearable device applications.

Tunable Core-Shell Single-Walled Carbon Nanotube-Cu2S Networked Nanocomposites as High-Performance Cathodes for Lithium-ion Batteries

DOE PAGES

Meng, Xiangbo; Riha, Shannon C.; Libera, Joseph A.; ...

2015-01-24

In this study, nanoscale copper(I) sulfide (n-Cu2S) was deposited over networks of single-walled carbon nanotubes (SWCNTs) by atomic layer deposition (ALD). This synthetic route provides a high degree of control for tuning the materials properties. The resulting core shell SWCNT-n-Cu2S composite structure ensures an intimate contact between the two components while maintaining a high porosity for efficient transport of charges. Indeed, electrochemical testing demonstrates that these nanocomposites are promising as cathodes in lithium-ion batteries (LIBs), exhibiting excellent stability over 200 discharge-charge cycles with a sustainable, high capacity of 260 mAh g(-1) (92% of the theoretical value in terms of Cu2S)more » and >99% Coulombic efficiency. This work establishes a general strategy for developing high-performance nanoscale electrode materials.« less

Environmental performance, profitability, asset utilization, debt monitoring and firm value

NASA Astrophysics Data System (ADS)

Bukit, R. Br; Haryanto, B.; Ginting, P.

2018-02-01

The growing issue on firm value shows that firm value is not only determined by the firm ability to increase financial profit, but also by the company's concern in maintaining the environmental condition. The industrial development produces waste that pollutes the environment that has potential to serious impact on the next life. In addition to provide financial benefits, companies are increasingly facing pressure to be socially responsible for the survival of the company. However, past findings demonstrate that the effect of environmental performance, profitability, and asset utilization to the firm’s value are still unclear. This study aims to test whether environmental performance, firm profitability and asset utilization can effectively enhance firm value in two different conditions: intensive debt monitoring and less intensive debt monitoring. Sample of companies is taken from the list of Indonesia Stock Exchange during the period of 2013 to 2015. Using multiple regression analysis, discloses that: in intensive monitoring, managers tend to have high firm value when company has high environmental performance and or high profitability and high asset utilization. Monitoring system needs to be intensified especially for companies with the above characteristics.

Functional integration and self-template synthesis of hollow core-shell carbon mesoporous spheres/Fe3O4/nitrogen-doped graphene to enhance catalytic activity in DSSCs.

PubMed

Yao, Jixin; Zhang, Kang; Wang, Wen; Zuo, Xueqin; Yang, Qun; Tang, Huaibao; Wu, Mingzai; Li, Guang

2018-05-03

Excellent corrosion resistance is crucial for photovoltaic devices to acquire high and stable performance under high corrosive complicated environments. Creative inspiration comes from sandwich construction, whereby Fe3O4 nanoparticles were anchored onto hollow core-shell carbon mesoporous microspheres and wrapped by N-graphene nanosheets (HCCMS/Fe3O4@N-RGO) to obtain integrated high corrosive resistance and stability. The as-prepared multiple composite material possesses outstanding performance as a result of structure optimization, performance improvement, and interface synergy. Therefore, it can effectively suppress corrosion from the electrolyte in recycled tests many times, indicating the ultrahigh corrosion resistance life of this double carbon-based nanocomposite. Furthermore, the electrical conductivity and conversion efficiency of the composite are well maintained due to the triple synergistic interactions, which could serve as a guideline in establishing high-performance multifunctional HCCMS/Fe3O4@N-RGO with great prospects in energy devices, such as lithium batteries, supercapacitors and electrode materials, etc.

L-lactic acid and sodium p-toluenesulfonate co-doped polypyrrole for high performance cathode in sodium ion battery

NASA Astrophysics Data System (ADS)

Liao, Qishu; Hou, Hongying; Liu, Xianxi; Yao, Yuan; Dai, Zhipeng; Yu, Chengyi; Li, Dongdong

2018-04-01

In this work, polypyrrole (PPy) was co-doped with L-lactic acid (LA) and sodium p-toluenesulfonate (TsONa) for high performance cathode in sodium ion battery (SIB) via facile one-step electropolymerization on Fe foil. The as-synthesized LA/TsONa co-doped PPy cathode was investigated in terms of scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), galvanostatic charge/discharge and cyclic voltammetry (CV). The results suggested that some oval-bud-like LA/TsONa co-doped PPy particles did form and tightly combine with the surface of Fe foil; furthermore, LA/TsONa co-doped PPy cathode also delivered higher electrochemical performances than TsONa mono-doped PPy cathode. For example, the initial specific discharge capacity was as high as about 124 mAh/g, and the reversible specific capacity still maintained at about 110 mAh/g even after 50 cycles, higher than those of TsONa mono-doped PPy cathode. The synergy effect of multi components of LA/TsONa co-doped PPy cathode should be responsible for high electrochemical performances.

A multifunctional biphasic water splitting catalyst tailored for integration with high-performance semiconductor photoanodes

NASA Astrophysics Data System (ADS)

Yang, Jinhui; Cooper, Jason K.; Toma, Francesca M.; Walczak, Karl A.; Favaro, Marco; Beeman, Jeffrey W.; Hess, Lucas H.; Wang, Cheng; Zhu, Chenhui; Gul, Sheraz; Yano, Junko; Kisielowski, Christian; Schwartzberg, Adam; Sharp, Ian D.

2017-03-01

Artificial photosystems are advanced by the development of conformal catalytic materials that promote desired chemical transformations, while also maintaining stability and minimizing parasitic light absorption for integration on surfaces of semiconductor light absorbers. Here, we demonstrate that multifunctional, nanoscale catalysts that enable high-performance photoelectrochemical energy conversion can be engineered by plasma-enhanced atomic layer deposition. The collective properties of tailored Co3O4/Co(OH)2 thin films simultaneously provide high activity for water splitting, permit efficient interfacial charge transport from semiconductor substrates, and enhance durability of chemically sensitive interfaces. These films comprise compact and continuous nanocrystalline Co3O4 spinel that is impervious to phase transformation and impermeable to ions, thereby providing effective protection of the underlying substrate. Moreover, a secondary phase of structurally disordered and chemically labile Co(OH)2 is introduced to ensure a high concentration of catalytically active sites. Application of this coating to photovoltaic p+n-Si junctions yields best reported performance characteristics for crystalline Si photoanodes.

American College of Sports Medicine position stand. Nutrition and athletic performance.

PubMed

Rodriguez, Nancy R; Di Marco, Nancy M; Langley, Susie

2009-03-01

It is the position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine that physical activity, athletic performance, and recovery from exercise are enhanced by optimal nutrition. These organizations recommend appropriate selection of foods and fluids, timing of intake, and supplement choices for optimal health and exercise performance. This updated position paper couples a rigorous, systematic, evidence-based analysis of nutrition and performance-specific literature with current scientific data related to energy needs, assessment of body composition, strategies for weight change, nutrient and fluid needs, special nutrient needs during training and competition, the use of supplements and ergogenic aids, nutrition recommendations for vegetarian athletes, and the roles and responsibilities of the sports dietitian. Energy and macronutrient needs, especially carbohydrate and protein, must be met during times of high physical activity to maintain body weight, replenish glycogen stores, and provide adequate protein to build and repair tissue. Fat intake should be sufficient to provide the essential fatty acids and fat-soluble vitamins and to contribute energy for weight maintenance. Although exercise performance can be affected by body weight and composition, these physical measures should not be a criterion for sports performance and daily weigh-ins are discouraged. Adequate food and fluid should be consumed before, during, and after exercise to help maintain blood glucose concentration during exercise, maximize exercise performance, and improve recovery time. Athletes should be well hydrated before exercise and drink enough fluid during and after exercise to balance fluid losses. Sports beverages containing carbohydrates and electrolytes may be consumed before, during, and after exercise to help maintain blood glucose concentration, provide fuel for muscles, and decrease risk of dehydration and hyponatremia. Vitamin and mineral supplements are not needed if adequate energy to maintain body weight is consumed from a variety of foods. However, athletes who restrict energy intake, use severe weight-loss practices, eliminate one or more food groups from their diet, or consume unbalanced diets with low micronutrient density may require supplements. Because regulations specific to nutritional ergogenic aids are poorly enforced, they should be used with caution and only after careful product evaluation for safety, efficacy, potency, and legality. A qualified sports dietitian and, in particular, the Board Certified Specialist in Sports Dietetics in the United States, should provide individualized nutrition direction and advice after a comprehensive nutrition assessment.

Understanding the Size-Dependent Sodium Storage Properties of Na2C6O6-Based Organic Electrodes for Sodium-Ion Batteries.

PubMed

Wang, Yaqun; Ding, Yu; Pan, Lijia; Shi, Ye; Yue, Zhuanghao; Shi, Yi; Yu, Guihua

2016-05-11

Organic electroactive materials represent a new generation of sustainable energy storage technology due to their unique features including environmental benignity, material sustainability, and highly tailorable properties. Here a carbonyl-based organic salt Na2C6O6, sodium rhodizonate (SR) dibasic, is systematically investigated for high-performance sodium-ion batteries. A combination of structural control, electrochemical analysis, and computational simulation show that rational morphological control can lead to significantly improved sodium storage performance. A facile antisolvent method was developed to synthesize microbulk, microrod, and nanorod structured SRs, which exhibit strong size-dependent sodium ion storage properties. The SR nanorod exhibited the best performance to deliver a reversible capacity of ∼190 mA h g(-1) at 0.1 C with over 90% retention after 100 cycles. At a high rate of 10 C, 50% of the capacity can be obtained due to enhanced reaction kinetics, and such high electrochemical activity maintains even at 80 °C. These results demonstrate a generic design route toward high-performance organic-based electrode materials for beyond Li-ion batteries. Using such a biomass-derived organic electrode material enables access to sustainable energy storage devices with low cost, high electrochemical performance and thermal stability.

The development of a general purpose ARM-based processing unit for the ATLAS TileCal sROD

NASA Astrophysics Data System (ADS)

Cox, M. A.; Reed, R.; Mellado, B.

2015-01-01

After Phase-II upgrades in 2022, the data output from the LHC ATLAS Tile Calorimeter will increase significantly. ARM processors are common in mobile devices due to their low cost, low energy consumption and high performance. It is proposed that a cost-effective, high data throughput Processing Unit (PU) can be developed by using several consumer ARM processors in a cluster configuration to allow aggregated processing performance and data throughput while maintaining minimal software design difficulty for the end-user. This PU could be used for a variety of high-level functions on the high-throughput raw data such as spectral analysis and histograms to detect possible issues in the detector at a low level. High-throughput I/O interfaces are not typical in consumer ARM System on Chips but high data throughput capabilities are feasible via the novel use of PCI-Express as the I/O interface to the ARM processors. An overview of the PU is given and the results for performance and throughput testing of four different ARM Cortex System on Chips are presented.

Coaxial-cable structure composite cathode material with high sulfur loading for high performance lithium-sulfur batteries

NASA Astrophysics Data System (ADS)

Li, Qiang; Zhang, Zhian; Guo, Zaiping; Zhang, Kai; Lai, Yanqing; Li, Jie

2015-01-01

Hollow carbon nanofiber@nitrogen-doped porous carbon (HCNF@NPC) coaxial-cable structure composite, which is carbonized from HCNF@polydopamine, is prepared as an improved high conductive carbon matrix for encapsulating sulfur as a composite cathode material for lithium-sulfur batteries. The prepared HCNF@NPC-S composite with high sulfur content of approximately 80 wt% shows an obvious coaxial-cable structure with an NPC layer coating on the surface of the linear HCNFs along the length and sulfur homogeneously distributes in the coating layer. This material exhibits much better electrochemical performance than the HCNF-S composite, delivers initial discharge capacity of 982 mAh g-1 and maintains a high capacity retention rate of 63% after 200 cycles at a high current density of 837.5 mA g-1. The significantly enhanced electrochemical performance of the HCNF@NPC-S composite is attributed to the unique coaxial-cable structure, in which the linear HCNF core provides electronic conduction pathways and works as mechanical support, and the NPC shell with nitrogen-doped and porous structure can trap sulfur/polysulfides and provide Li+ conductive pathways.

Seedling performance covaries with dormancy thresholds: maintaining cryptic seed heteromorphism in a fire-prone system.

PubMed

Liyanage, Ganesha S; Ayre, David J; Ooi, Mark K J

2016-11-01

The production of morphologically different seeds or fruits by the same individual plant is known as seed heteromorphism. Such variation is expected to be selected for in disturbance-prone environments to allow germination into inherently variable regeneration niches. However, there are few demonstrations that heteromorphic seed characteristics should be favored by selection or how they may be maintained. In fire-prone ecosystems, seed heteromorphism is found in the temperatures needed to break physical dormancy, with seeds responding to high or low temperatures, ensuring emergence under variable fire-regime-related soil heating. Because of the relationship between dormancy-breaking temperature thresholds and fire severity, we hypothesize that different post-fire resource conditions have selected for covarying seedling traits, which contribute to maintenance of such heteromorphism. Seeds with low thresholds emerge into competitive conditions, either after low-severity fire or in vegetation gaps, and are therefore likely to experience selection for seedling characteristics that make them good competitors. On the other hand, high-temperature-threshold seeds would emerge into less competitive environments, indicative of stand-clearing high-severity fires, and would not experience the same selective forces. We identified high and low-threshold seed morphs via dormancy-breaking heat treatments and germination trials for two study species and compared seed mass and other morphological characteristics between morphs. We then grew seedlings from the two different morphs, with and without competition, and measured growth and biomass allocation as indicators of seedling performance. Seedlings from low-threshold seeds of both species performed better than their high-threshold counterparts, growing more quickly under competitive conditions, confirming that different performance can result from this seed characteristic. Seed mass or appearance did not differ between morphs, indicating that dormancy-breaking temperature threshold variation is a form of cryptic heteromorphism. The potential shown for the selective influence of different post-fire environmental conditions on seedling performance provides evidence of a mechanism for the maintenance of heteromorphic variation in dormancy-breaking temperature thresholds. © 2016 The Authors. Ecology, published by Wiley Periodicals, Inc., on behalf of the Ecological Society of America.

High-sensitivity high-selectivity detection of CWAs and TICs using tunable laser photoacoustic spectroscopy

NASA Astrophysics Data System (ADS)

Pushkarsky, Michael; Webber, Michael; Patel, C. Kumar N.

2005-03-01

We provide a general technique for evaluating the performance of an optical sensor for the detection of chemical warfare agents (CWAs) in realistic environments and present data from a simulation model based on a field deployed discretely tunable 13CO2 laser photoacoustic spectrometer (L-PAS). Results of our calculations show the sensor performance in terms of usable sensor sensitivity as a function of probability of false positives (PFP). The false positives arise from the presence of many other gases in the ambient air that could be interferents. Using the L-PAS as it exists today, we can achieve a detection threshold of about 4 ppb for the CWAs while maintaining a PFP of less than 1:106. Our simulation permits us to vary a number of parameters in the model to provide guidance for performance improvement. We find that by using a larger density of laser lines (such as those obtained through the use of tunable semiconductor lasers), improving the detector noise and maintaining the accuracy of laser frequency determination, optical detection schemes can make possible CWA sensors having sub-ppb detection capability with <1:108 PFP. We also describe the results of a preliminary experiment that verifies the results of the simulation model. Finally, we discuss the use of continuously tunable quantum cascade lasers in L-PAS for CWA and TIC detection.

Parametric Study of Pulse-Combustor-Driven Ejectors at High-Pressure

NASA Technical Reports Server (NTRS)

Yungster, Shaye; Paxson, Daniel E.; Perkins, Hugh D.

2015-01-01

Pulse-combustor configurations developed in recent studies have demonstrated performance levels at high-pressure operating conditions comparable to those observed at atmospheric conditions. However, problems related to the way fuel was being distributed within the pulse combustor were still limiting performance. In the first part of this study, new configurations are investigated computationally aimed at improving the fuel distribution and performance of the pulse-combustor. Subsequent sections investigate the performance of various pulse-combustor driven ejector configurations operating at highpressure conditions, focusing on the effects of fuel equivalence ratio and ejector throat area. The goal is to design pulse-combustor-ejector configurations that maximize pressure gain while achieving a thermal environment acceptable to a turbine, and at the same time maintain acceptable levels of NOx emissions and flow non-uniformities. The computations presented here have demonstrated pressure gains of up to 2.8%.

Highly efficient growth of vertically aligned carbon nanotubes on Fe-Ni based metal alloy foils for supercapacitors

NASA Astrophysics Data System (ADS)

Amalina Raja Seman, Raja Noor; Asyadi Azam, Mohd; Ambri Mohamed, Mohd

2016-12-01

Supercapacitors are highly promising energy devices with superior charge storage performance and a long lifecycle. Construction of the supercapacitor cell, especially electrode fabrication, is critical to ensure good performance in applications. This work demonstrates direct growth of vertically aligned carbon nanotubes (CNTs) on Fe-Ni based metal alloy foils, namely SUS 310S, Inconel 600 and YEF 50, and their use in symmetric vertically aligned CNT supercapacitor electrodes. Alumina and cobalt thin film catalysts were deposited onto the foils, and then CNT growth was performed using alcohol catalytic chemical vapour deposition. By this method, vertically aligned CNTs were successfully grown and used directly as a binder-free supercapacitor electrode to deliver excellent electrochemical performance. The device showed relatively good specific capacitance, a superior rate capability and excellent cycle stability, maintaining about 96% capacitance up to 1000 cycles.

Design and evaluation of a hybrid storage system in HEP environment

NASA Astrophysics Data System (ADS)

Xu, Qi; Cheng, Yaodong; Chen, Gang

2017-10-01

Nowadays, the High Energy Physics experiments produce a large amount of data. These data are stored in mass storage systems which need to balance the cost, performance and manageability. In this paper, a hybrid storage system including SSDs (Solid-state Drive) and HDDs (Hard Disk Drive) is designed to accelerate data analysis and maintain a low cost. The performance of accessing files is a decisive factor for the HEP computing system. A new deployment model of Hybrid Storage System in High Energy Physics is proposed which is proved to have higher I/O performance. The detailed evaluation methods and the evaluations about SSD/HDD ratio, and the size of the logic block are also given. In all evaluations, sequential-read, sequential-write, random-read and random-write are all tested to get the comprehensive results. The results show the Hybrid Storage System has good performance in some fields such as accessing big files in HEP.

Organic content influences sediment microbial fuel cell performance and community structure.

PubMed

Zhao, Qing; Li, Ruying; Ji, Min; Ren, Zhiyong Jason

2016-11-01

This study constructed sediment microbial fuel cells (SMFCs) with different organic loadings without the amendment of external substrates, and it investigated how such variation affects electricity generation and microbial community structure. Results found sediment characteristics significantly influenced SMFC performance and appropriate organic content is important to maintain stable power outputs. SMFCs with loss of ignition (LOI) of 5% showed the most reliable performance in this study, while high organic content (LOI 10-16%) led to higher but very unstable voltage output because of biogas accumulation and worm activities. SMFCs with low organic content (1-3%) showed low power output. Different bacterial communities were found in SMFCs shown various power generation performance even those with similar organic contents. Thermodesulfovibrionaceae was found closely related to the system startup and Desulfobulbaceae showed great abundance in SMFCs with high power production. Copyright © 2016 Elsevier Ltd. All rights reserved.

A scalable SIMD digital signal processor for high-quality multifunctional printer systems

NASA Astrophysics Data System (ADS)

Kang, Hyeong-Ju; Choi, Yongwoo; Kim, Kimo; Park, In-Cheol; Kim, Jung-Wook; Lee, Eul-Hwan; Gahang, Goo-Soo

2005-01-01

This paper describes a high-performance scalable SIMD digital signal processor (DSP) developed for multifunctional printer systems. The DSP supports a variable number of datapaths to cover a wide range of performance and maintain a RISC-like pipeline structure. Many special instructions suitable for image processing algorithms are included in the DSP. Quad/dual instructions are introduced for 8-bit or 16-bit data, and bit-field extraction/insertion instructions are supported to process various data types. Conditional instructions are supported to deal with complex relative conditions efficiently. In addition, an intelligent DMA block is integrated to align data in the course of data reading. Experimental results show that the proposed DSP outperforms a high-end printer-system DSP by at least two times.

An experimental heat wave changes immune defense and life history traits in a freshwater snail.

PubMed

Leicht, Katja; Jokela, Jukka; Seppälä, Otto

2013-12-01

The predicted increase in frequency and severity of heat waves due to climate change is expected to alter disease dynamics by reducing hosts' ability to resist infections. This could take place via two different mechanisms: (1) through general reduction in hosts' performance under harsh environmental conditions and/or (2) through altered resource allocation that reduces expression of defense traits in order to maintain other traits. We tested these alternative hypotheses by measuring the effect of an experimental heat wave (25 vs. 15°C) on the constitutive level of immune defense (hemocyte concentration, phenoloxidase [PO]-like activity, antibacterial activity of hemolymph), and life history traits (growth and number of oviposited eggs) of the great pond snail Lymnaea stagnalis. We also manipulated the exposure time to high temperature (1, 3, 5, 7, 9, or 11 days). We found that if the exposure to high temperature lasted <1 week, immune function was not affected. However, when the exposure lasted longer than that, the level of snails' immune function (hemocyte concentration and PO-like activity) was reduced. Snails' growth and reproduction increased within the first week of exposure to high temperature. However, longer exposures did not lead to a further increase in cumulative reproductive output. Our results show that short experimental heat waves do not alter immune function but lead to plastic responses that increase snails' growth and reproduction. Thus, although the relative expression of traits changes, short experimental heat waves do not impair snails' defenses. Negative effects on performance get pronounced when the heat waves are prolonged suggesting that high performance cannot be maintained over long time periods. This ultimately reduces the levels of defense traits.

Adaptive optics for MOSAIC: design and performance of the wide(st)-field AO system for the E-ELT

NASA Astrophysics Data System (ADS)

Morris, Tim; Basden, Alastair; Buey, Tristan; Chemla, Fanny; Conan, Jean-Marc; Fitzsimons, Ewan; Fusco, Thierry; Gendron, Eric; Hammer, Francois; Jagourel, Pascal; Morel, Carine; Myers, Richard; Neichel, Benoit; Petit, Cyril; Rodrigues, Myriam; Rousset, Gérard

2016-07-01

MOSAIC is the proposed multiple-object spectrograph for the E-ELT that will utilise the widest possible field of view provided by the telescope. In terms of adaptive optics, there are two distinct operating modes required to meet the top-level science requirements. The MOSAIC High Multiplex Mode (HMM) requires either seeing-limited or GLAO correction within a 0.6 (NIR) and 0.9 (VIS) arcsecond sub-fields over the widest possible field for a few hundred objects. To achieve seeing limited operation whilst maintaining the maximum unvignetted field of view for scientific observation will require recreating some of the functionality present in the Pre-Focal Station relating to control of the E-ELT active optics. MOSAIC High Definition Mode Control (HDM) requires a 25% Ensquared Energy (EE) within 150mas in the H-band element for approximately 10 targets distributed across the full E-ELT field, implying the use of Multiple Object AO (MOAO). Initial studies have shown that to meet the EE requirements whilst maintaining high-sky coverage will require the combination of wavefront signals from both high-order NGS and LGS to provide a tomographic estimate for the correction to be applied to the open-loop MOAO DMs. In this paper we present the current MOSAIC AO design and provide the first performance estimates for the baseline instrument design. We then report on the various trade-offs that will be investigated throughout the course of the Phase A study, such as the requirement to mix NGS and LGS signals tomographically. Finally, we discuss how these will impact the AO architecture, the MOSAIC design and ultimately the scientific performance of this wide-field workhorse instrument at the E-ELT.

Heavy Analysis and Light Virtualization of Water Use Data with Python

NASA Astrophysics Data System (ADS)

Kim, H.; Bijoor, N.; Famiglietti, J. S.

2014-12-01

Water utilities possess a large amount of water data that could be used to inform urban ecohydrology, management decisions, and conservation policies, but such data are rarely analyzed owing to difficulty in analyzation, visualization, and interpretion. We have developed a high performance computing resource for this purpose. We partnered with 6 water agencies in Orange County who provided 10 years of parcel-level monthly water use billing data for a pilot study. The first challenge that we overcame was to refine all human errors and unify the many different formats of data over all agencies. Second, we tested and applied experimental approaches to the data, including complex calculations, with high efficiency. Third, we developed a method to refine the data so it can be browsed along a time series index and/or geo-spatial queries with high efficiency, no matter how large the data. Python scientific libraries were the best match to handle arbitrary data sets in our environment. Further milestones include agency entry, sets of formulae, and maintaining 15M rows X 70 columns of data with high performance of cpu-bound processes. To deal with billions of rows, we performed an analysis virtualization stack by leveraging iPython parallel computing. With this architecture, one agency could be considered one computing node or virtual machine that maintains its own data sets respectively. For example, a big agency could use a large node, and a small agency could use a micro node. Under the minimum required raw data specs, more agencies could be analyzed. The program developed in this study simplifies data analysis, visualization, and interpretation of large water datasets, and can be used to analyze large data volumes from water agencies nationally or worldwide.

Orion Exploration Flight Test-1 Post-Flight Navigation Performance Assessment Relative to the Best Estimated Trajectory

NASA Technical Reports Server (NTRS)

Gay, Robert S.; Holt, Greg N.; Zanetti, Renato

2016-01-01

This paper details the post-flight navigation performance assessment of the Orion Exploration Flight Test-1 (EFT-1). Results of each flight phase are presented: Ground Align, Ascent, Orbit, and Entry Descent and Landing. This study examines the on-board Kalman Filter uncertainty along with state deviations relative to the Best Estimated Trajectory (BET). Overall the results show that the Orion Navigation System performed as well or better than expected. Specifically, the Global Positioning System (GPS) measurement availability was significantly better than anticipated at high altitudes. In addition, attitude estimation via processing GPS measurements along with Inertial Measurement Unit (IMU) data performed very well and maintained good attitude throughout the mission.

Opening the black box in nursing work and management practice: the role of ward managers.

PubMed

Townsend, Keith; Wilkinson, Adrian; Kellner, Ashlea

2015-03-01

This paper aims to identify and explore key obstacles preventing ward managers from effectively performing the human resource management (HRM) responsibilities required in their role. In the context of increasing costs and the decentralisation of responsibility to ward level, the relevance of the ward manager role within the 'black box' between human resource management and firm performance is becoming increasingly pertinent. This paper presents an intensive case study including 37 interviews across all levels of a hospital where senior management attempted to shift to a high performance model of human resource management. The findings indicated that ward managers played a critical role in maintaining and improving employee performance, although they were restricted from effectively performing their responsibilities due to budget pressure and limited managerial skill development. Our findings support the contention that hospitals would benefit from focusing on the critical role of the ward manager as the central locus of influence in high performance human resource management (HPHRM) systems. Investment into high performance human resource management is discouraged if the hospital cannot adequately enable ward managers who are responsible for implementation. Introduction of managerial skills training to potential and existing ward managers is critical. © 2013 John Wiley & Sons Ltd.

Synergistic doping of fullerene electron transport layer and colloidal quantum dot solids enhances solar cell performance.

PubMed

Yuan, Mingjian; Voznyy, Oleksandr; Zhitomirsky, David; Kanjanaboos, Pongsakorn; Sargent, Edward H

2015-02-04

The spatial location of the predominant source of performance-limiting recombination in today's best colloidal quantum dot (CQD) cells is identified, pinpointing the TiO2:CQD junction; then, a highly n-doped PCBM layer is introduced at the CQD:TiO2 heterointerface. An n-doped PCBM layer is essential to maintain the depletion region and allow for efficient current extraction, thereby producing a record 8.9% in overall power conversion efficiency. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Maintain workplace civility by sharing the vow of personal responsibility.

PubMed

Chism, Marlene

2012-01-01

Office gossip, power struggles, employee burnout, and short fuses are becoming more the rule than the exception in running a medical practice. The difficult conversation avoided today can turn into the lawsuit 15 years later. Managers often find it hard to confront high performers and authority figures in the workplace. In order to deal with disruptive behavior and incivility before it ruins the medical practice, practice managers should institute the four steps outlined in this article plus the Vow of Personal Responsibility to improve clarity, teamwork, and personal performance.

A Linux Workstation for High Performance Graphics

NASA Technical Reports Server (NTRS)

Geist, Robert; Westall, James

2000-01-01

The primary goal of this effort was to provide a low-cost method of obtaining high-performance 3-D graphics using an industry standard library (OpenGL) on PC class computers. Previously, users interested in doing substantial visualization or graphical manipulation were constrained to using specialized, custom hardware most often found in computers from Silicon Graphics (SGI). We provided an alternative to expensive SGI hardware by taking advantage of third-party, 3-D graphics accelerators that have now become available at very affordable prices. To make use of this hardware our goal was to provide a free, redistributable, and fully-compatible OpenGL work-alike library so that existing bodies of code could simply be recompiled. for PC class machines running a free version of Unix. This should allow substantial cost savings while greatly expanding the population of people with access to a serious graphics development and viewing environment. This should offer a means for NASA to provide a spectrum of graphics performance to its scientists, supplying high-end specialized SGI hardware for high-performance visualization while fulfilling the requirements of medium and lower performance applications with generic, off-the-shelf components and still maintaining compatibility between the two.

Humate-assisted Synthesis of MoS2/C Nanocomposites via Co-Precipitation/Calcination Route for High Performance Lithium Ion Batteries

NASA Astrophysics Data System (ADS)

Geng, Qin; Tong, Xin; Wenya, Gideon Evans; Yang, Chao; Wang, Jide; Maloletnev, A. S.; Wang, Zhiming M.; Su, Xintai

2018-04-01

A facile, cost-effective, non-toxic, and surfactant-free route has been developed to synthesize MoS2/carbon (MoS2/C) nanocomposites. Potassium humate consists of a wide variety of oxygen-containing functional groups, which is considered as promising candidates for functionalization of graphene. Using potassium humate as carbon source, two-dimensional MoS2/C nanosheets with irregular shape were synthesized via a stabilized co-precipitation/calcination process. Electrochemical performance of the samples as an anode of lithium ion battery was measured, demonstrating that the MoS2/C nanocomposite calcinated at 700 °C (MoS2/C-700) electrode showed outstanding performance with a high discharge capacity of 554.9 mAh g- 1 at a current density of 100 mA g- 1 and the Coulomb efficiency of the sample maintained a high level of approximately 100% after the first 3 cycles. Simultaneously, the MoS2/C-700 electrode exhibited good cycling stability and rate performance. The success in synthesizing MoS2/C nanocomposites via co-precipitation/calcination route may pave a new way to realize promising anode materials for high-performance lithium ion batteries.

The effects of short term detraining and retraining on physical fitness in elite soccer players

PubMed Central

2018-01-01

Purpose The aim of this study was to examine the effects of aerobic high-intensity training with reduced volume and training cessation on body composition and physical fitness after the end of season and the time required to recapture physical fitness with intensified retraining following two weeks of detraining in elite soccer players. Method Twenty male semi-professional soccer players participated in this study. The soccer players were assigned to either a group that completed high-intensity aerobic training (HAT, n = 10) or to a detraining and retraining group (DHAT, n = 10) for a 5-week period immediately after the end of the season. The first 2 weeks of the period, members of the HAT group performed high-intensity aerobic exercise (80–90% of HRmax, 12 min × 3, three times per week), whereas members of the DHAT group abstained from any physical activity. During the subsequent 3 weeks, members of both the HAT and DHAT groups completed high-intensity aerobic exercise. Exercise performance testing and body composition analysis were performed before; after 2 weeks of detraining; and at 1, 2 and 3 weeks of retraining. Results Intensified high-intensity training for 5 weeks maintained the performance in the Yo-Yo Intermittent Recovery level 2 test (Yo-Yo IR2) and repeated sprints at any time point (P > 0.05). However 2 weeks of detraining resulted in significant decreases in the performance on the Yo-Yo IR2 (P < 0.01) and repeated sprints test (P < 0.05). Performance on the Yo-Yo IR2 enhanced after 2 weeks of retraining and was maintained up to 3 weeks after retraining, with no significant differences between conditions (P > 0.05). In addition, repeated sprint performance markedly decreased after the detraining period (P < 0.05) and was continuously lower compared to the baseline at 2 weeks after retraining (P < 0.05). Furthermore, this value reached baseline level at the end of the experimental period (P > 0.05). There were no significant differences between conditions in body composition, performance of agility, or sprint ability throughout the 5-week experimental period (P > 0.05). Conclusions The present data suggest that short-term detraining after the competitive season can markedly decrease performances in the Yo-Yo IR2 test and repeated sprints. To return to a previous level of ability on the Yo-Yo IR2 and/or sprint test with retraining through high-intensity aerobic training after a period of detraining, a similar or longer period of retraining is required. However, the high-intensity training with reduced amount of training after competitive season can prevent reductions in physical fitness. PMID:29746505

The Efficacy of a Restart Break for Recycling with Optimal Performance Depends Critically on Circadian Timing

PubMed Central

Van Dongen, Hans P.A.; Belenky, Gregory; Vila, Bryan J.

2011-01-01

Objectives: Under simulated shift-work conditions, we investigated the efficacy of a restart break for maintaining neurobehavioral functioning across consecutive duty cycles, as a function of the circadian timing of the duty periods. Design: As part of a 14-day experiment, subjects underwent two cycles of five simulated daytime or nighttime duty days, separated by a 34-hour restart break. Cognitive functioning and high-fidelity driving simulator performance were tested 4 times per day during the two duty cycles. Lapses on a psychomotor vigilance test (PVT) served as the primary outcome variable. Selected sleep periods were recorded polysomnographically. Setting: The experiment was conducted under standardized, controlled laboratory conditions with continuous monitoring. Participants: Twenty-seven healthy adults (13 men, 14 women; aged 22–39 years) participated in the study. Interventions: Subjects were randomly assigned to a nighttime duty (experimental) condition or a daytime duty (control) condition. The efficacy of the 34-hour restart break for maintaining neurobehavioral functioning from the pre-restart duty cycle to the post-restart duty cycle was compared between these two conditions. Results: Relative to the daytime duty condition, the nighttime duty condition was associated with reduced amounts of sleep, whereas sleep latencies were shortened and slow-wave sleep appeared to be conserved. Neurobehavioral performance measures ranging from lapses of attention on the PVT to calculated fuel consumption on the driving simulators remained optimal across time of day in the daytime duty schedule, but degraded across time of night in the nighttime duty schedule. The 34-hour restart break was efficacious for maintaining PVT performance and other objective neurobehavioral functioning profiles from one duty cycle to the next in the daytime duty condition, but not in the nighttime duty condition. Subjective sleepiness did not reliably track objective neurobehavioral deficits. Conclusions: The 34-hour restart break was adequate for maintaining performance in the case of optimal circadian placement of sleep and duty periods (control condition) but was inadequate (and perhaps even detrimental) for maintaining performance in a simulated nighttime duty schedule (experimental condition). Current US transportation hours-of-service regulations mandate time off duty but do not consider the circadian aspects of shift scheduling. Reinforcing a recent trend of applying sleep science to inform policymaking for duty and rest times, our findings indicate that restart provisions in hours-of-service regulations could be improved by taking the circadian timing of the duty schedules into account. Citation: Van Dongen HPA; Belenky G; Vila BJ. The efficacy of a restart break for recycling with optimal performance depends critically on circadian timing. SLEEP 2011;34(7):917-929. PMID:21731142

Automated identification of drug and food allergies entered using non-standard terminology.

PubMed

Epstein, Richard H; St Jacques, Paul; Stockin, Michael; Rothman, Brian; Ehrenfeld, Jesse M; Denny, Joshua C

2013-01-01

An accurate computable representation of food and drug allergy is essential for safe healthcare. Our goal was to develop a high-performance, easily maintained algorithm to identify medication and food allergies and sensitivities from unstructured allergy entries in electronic health record (EHR) systems. An algorithm was developed in Transact-SQL to identify ingredients to which patients had allergies in a perioperative information management system. The algorithm used RxNorm and natural language processing techniques developed on a training set of 24 599 entries from 9445 records. Accuracy, specificity, precision, recall, and F-measure were determined for the training dataset and repeated for the testing dataset (24 857 entries from 9430 records). Accuracy, precision, recall, and F-measure for medication allergy matches were all above 98% in the training dataset and above 97% in the testing dataset for all allergy entries. Corresponding values for food allergy matches were above 97% and above 93%, respectively. Specificities of the algorithm were 90.3% and 85.0% for drug matches and 100% and 88.9% for food matches in the training and testing datasets, respectively. The algorithm had high performance for identification of medication and food allergies. Maintenance is practical, as updates are managed through upload of new RxNorm versions and additions to companion database tables. However, direct entry of codified allergy information by providers (through autocompleters or drop lists) is still preferred to post-hoc encoding of the data. Data tables used in the algorithm are available for download. A high performing, easily maintained algorithm can successfully identify medication and food allergies from free text entries in EHR systems.

The DOE ETV-1 Electric Test Vehicle. Phase 3: Performance Testing and system evaluation

NASA Technical Reports Server (NTRS)

Kurtz, D.

1981-01-01

Engineering tests were conducted in order to characterize overall system performance and component efficiencies within the system environment. A dynamometer was used in order to minimize the ambient effects and large uncertainties present in track testing. Extensive test requirements were defined and procedures were carefully controlled in order to maintain a high degree of credibility. Limited track testing was performed in order to corroborate the dynamometer results. Test results include an energy flow analysis through the major subsystems and incorporate the aerodynamic and rolling losses under cyclic and various steady speed conditions. The major output from all relevant dynamometer and track tests is also included.

Ambient-temperature NO oxidation over amorphous CrOx-ZrO 2 mixed oxide catalysts: Significant promoting effect of ZrO 2

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

Wang, Aiyong; Guo, Yanglong; Gao, Feng

2017-03-01

Three series of Cr-based mixed oxides (Cr-Co, Cr-Fe, and Cr-Ni oxides) with high specific surface areas and amorphous textures are synthesized using a novel sol-gel method. These mixed oxides, in comparison to their pure metal oxide (CrOx, Co3O4, FeOx and NiO) counterparts, display enhanced performance for catalytic oxidation of low-concentration NO at room temperature. Over best performing catalysts, 100% NO conversion can be maintained up to 30 h of operation at a high space velocity of 45,000 ml g-1 h-1. The amorphous structure is found to be critical for these catalysts to maintain high activity and durability. Cr/M (M=Co, Femore » and Ni) molar ratio, nitrate precursor decomposition temperature and catalyst calcination temperature are important criteria for the synthesis of the highly active catalysts. This work was supported by National Basic Research Program of China (2013CB933200), National Natural Science Foundation of China (21577035, 21577034), Commission of Science and Technology of Shanghai Municipality (15DZ1205305) and 111 Project (B08021). Aiyong Wang gratefully acknowledges the China Scholarship Council for the Joint-Training Scholarship Program with the Pacific Northwest National Laboratory (PNNL). PNNL is operated for the U.S. Department of Energy (DOE) by Battelle. FG and CHFP are supported by the U.S. DOE/Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office.« less

New insight in the structural features of haloadaptation in α-amylases from halophilic Archaea following homology modeling strategy: folded and stable conformation maintained through low hydrophobicity and highly negative charged surface

NASA Astrophysics Data System (ADS)

Zorgani, Mohamed Amine; Patron, Kevin; Desvaux, Mickaël

2014-07-01

Proteins from halophilic archaea, which live in extreme saline conditions, have evolved to remain folded, active and stable at very high ionic strengths. Understanding the mechanism of haloadaptation is the first step toward engineering of halostable biomolecules. Amylases are one of the main enzymes used in industry. Yet, no three-dimensional structure has been experimentally resolved for α-amylases from halophilic archaea. In this study, homology structure modeling of α-amylases from the halophilic archaea Haloarcula marismortui, Haloarcula hispanica, and Halalkalicoccus jeotgali were performed. The resulting models were subjected to energy minimization, evaluation, and structural analysis. Calculations of the amino acid composition, salt bridges and hydrophobic interactions were also performed and compared to a set of non-halophilic counterparts. It clearly appeared that haloarchaeal α-amylases exhibited lower propensities for helix formation and higher propensities for coil-forming regions. Furthermore, they could maintain a folded and stable conformation in high salt concentration through highly negative charged surface with over representation of acidic residues, especially Asp, and low hydrophobicity with increase of salt bridges and decrease in hydrophobic interactions on the protein surface. This study sheds some light on the stability of α-amylases from halophilic archaea and provides strong basis not only to understand haloadaptation mechanisms of proteins in microorganisms from hypersalines environments but also for biotechnological applications.

New insight in the structural features of haloadaptation in α-amylases from halophilic Archaea following homology modeling strategy: folded and stable conformation maintained through low hydrophobicity and highly negative charged surface.

PubMed

Zorgani, Mohamed Amine; Patron, Kevin; Desvaux, Mickaël

2014-07-01

Proteins from halophilic archaea, which live in extreme saline conditions, have evolved to remain folded, active and stable at very high ionic strengths. Understanding the mechanism of haloadaptation is the first step toward engineering of halostable biomolecules. Amylases are one of the main enzymes used in industry. Yet, no three-dimensional structure has been experimentally resolved for α-amylases from halophilic archaea. In this study, homology structure modeling of α-amylases from the halophilic archaea Haloarcula marismortui, Haloarcula hispanica, and Halalkalicoccus jeotgali were performed. The resulting models were subjected to energy minimization, evaluation, and structural analysis. Calculations of the amino acid composition, salt bridges and hydrophobic interactions were also performed and compared to a set of non-halophilic counterparts. It clearly appeared that haloarchaeal α-amylases exhibited lower propensities for helix formation and higher propensities for coil-forming regions. Furthermore, they could maintain a folded and stable conformation in high salt concentration through highly negative charged surface with over representation of acidic residues, especially Asp, and low hydrophobicity with increase of salt bridges and decrease in hydrophobic interactions on the protein surface. This study sheds some light on the stability of α-amylases from halophilic archaea and provides strong basis not only to understand haloadaptation mechanisms of proteins in microorganisms from hypersalines environments but also for biotechnological applications.

Oxygen delivery does not limit thermal tolerance in a tropical eurythermal crustacean.

PubMed

Ern, Rasmus; Huong, Do Thi Thanh; Phuong, Nguyen Thanh; Wang, Tobias; Bayley, Mark

2014-03-01

In aquatic environments, rising water temperatures reduce water oxygen content while increasing oxygen demand, leading several authors to propose cardiorespiratory oxygen transport capacity as the main determinant of aquatic animal fitness. It has also been argued that tropical species, compared with temperate species, live very close to their upper thermal limit and hence are vulnerable to even small elevations in temperature. Little, however, is known about physiological responses to high temperatures in tropical species. Here we report that the tropical giant freshwater shrimp (Macrobrachium rosenbergii) maintains normal growth when challenged by a temperature rise of 6°C above the present day average (from 27°C to 33°C). Further, by measuring heart rate, gill ventilation rate, resting and maximum oxygen uptake, and hemolymph lactate, we show that oxygen transport capacity is maintained up to the critical maximum temperature around 41°C. In M. rosenbergii heart rate and gill ventilation rate increases exponentially until immediately below critical temperatures and at 38°C animals still retained more than 76% of aerobic scope measured at 30°C, and there was no indication of anaerobic metabolism at the high temperatures. Our study shows that the oxygen transport capacity is maintained at high temperatures, and that other mechanisms, such as protein dysfunction, are responsible for the loss of ecological performance at elevated temperatures.

Efficient security mechanisms for mHealth applications using wireless body sensor networks.

PubMed

Sahoo, Prasan Kumar

2012-01-01

Recent technological advances in wireless communications and physiological sensing allow miniature, lightweight, ultra-low power, intelligent monitoring devices, which can be integrated into a Wireless Body Sensor Network (WBSN) for health monitoring. Physiological signals of humans such as heartbeats, temperature and pulse can be monitored from a distant location using tiny biomedical wireless sensors. Hence, it is highly essential to combine the ubiquitous computing with mobile health technology using wireless sensors and smart phones to monitor the well-being of chronic patients such as cardiac, Parkinson and epilepsy patients. Since physiological data of a patient are highly sensitive, maintaining its confidentiality is highly essential. Hence, security is a vital research issue in mobile health (mHealth) applications, especially if a patient has an embarrassing disease. In this paper a three tier security architecture for the mHealth application is proposed, in which light weight data confidentiality and authentication protocols are proposed to maintain the privacy of a patient. Moreover, considering the energy and hardware constraints of the wireless body sensors, low complexity data confidential and authentication schemes are designed. Performance evaluation of the proposed architecture shows that they can satisfy the energy and hardware limitations of the sensors and still can maintain the secure fabrics of the wireless body sensor networks. Besides, the proposed schemes can outperform in terms of energy consumption, memory usage and computation time over standard key establishment security scheme.

Efficient Security Mechanisms for mHealth Applications Using Wireless Body Sensor Networks

PubMed Central

Sahoo, Prasan Kumar

2012-01-01

Recent technological advances in wireless communications and physiological sensing allow miniature, lightweight, ultra-low power, intelligent monitoring devices, which can be integrated into a Wireless Body Sensor Network (WBSN) for health monitoring. Physiological signals of humans such as heartbeats, temperature and pulse can be monitored from a distant location using tiny biomedical wireless sensors. Hence, it is highly essential to combine the ubiquitous computing with mobile health technology using wireless sensors and smart phones to monitor the well-being of chronic patients such as cardiac, Parkinson and epilepsy patients. Since physiological data of a patient are highly sensitive, maintaining its confidentiality is highly essential. Hence, security is a vital research issue in mobile health (mHealth) applications, especially if a patient has an embarrassing disease. In this paper a three tier security architecture for the mHealth application is proposed, in which light weight data confidentiality and authentication protocols are proposed to maintain the privacy of a patient. Moreover, considering the energy and hardware constraints of the wireless body sensors, low complexity data confidential and authentication schemes are designed. Performance evaluation of the proposed architecture shows that they can satisfy the energy and hardware limitations of the sensors and still can maintain the secure fabrics of the wireless body sensor networks. Besides, the proposed schemes can outperform in terms of energy consumption, memory usage and computation time over standard key establishment security scheme. PMID:23112734

Effects of dietary fat on muscle substrates, metabolism, and performance in athletes.

PubMed

Vogt, Michael; Puntschart, Adrian; Howald, Hans; Mueller, Bruno; Mannhart, Christoph; Gfeller-Tuescher, Liliane; Mullis, Primus; Hoppeler, Hans

2003-06-01

The present investigation aimed at identifying differences in muscle structural composition, substrate selection, and performance capacity in highly trained endurance athletes as a consequence of consuming a high-fat or a low-fat diet. Eleven duathletes ingested high-fat (53% fat; HF) or high-carbohydrate diets (17% fat; LF) for 5 wk in a randomized crossover design. In m. vastus lateralis, oxidative capacity estimated as volume of mitochondria per volume of muscle fiber (HF: 9.86 +/- 0.36 vs LF: 9.79 +/- 0.52%, mean +/- SE) was not different after the two diet periods. Intramyocellular lipid (IMCL) was significantly increased after HF compared with LF (1.54 +/- 0.27% vs 0.69 +/- 0.09%, P = 0.0076). Glycogen content was lower after HF than after LF, but this difference was not statistically significant (487.8 +/- 38.2 vs 534.4 +/- 32.6 mmol x kg-1 dry weight, P = 0.2454). Maximal power and [OV0312]O(2max) (63.6 +/- 0.9 vs 63.9 +/- 1.2 mL O(2) x min-1 x kg-1 on HF and LF) during an incremental exercise test to exhaustion were not different between the two diet periods. Total work output during a 20-min all-out time trial (298 +/- 6 vs 297 +/- 7 W) on a bicycle ergometer as well as half-marathon running time (80 min 12 s +/- 86 s vs 80 min 24 s +/- 82 s) were not different between HF and LF. Blood lactate concentrations and respiratory exchange ratios (RER) were significantly lower after HF than after LF at rest and during all submaximal exercise loads. Muscle glycogen stores were maintained after a 5-wk high-fat diet period whereas IMCL content was more than doubled. Endurance performance capacity was maintained at moderate to high-exercise intensities with a significantly larger contribution of lipids to total energy turnover.

Extension of the operational regime of the LHD towards a deuterium experiment

NASA Astrophysics Data System (ADS)

Takeiri, Y.; Morisaki, T.; Osakabe, M.; Yokoyama, M.; Sakakibara, S.; Takahashi, H.; Nakamura, Y.; Oishi, T.; Motojima, G.; Murakami, S.; Ito, K.; Ejiri, A.; Imagawa, S.; Inagaki, S.; Isobe, M.; Kubo, S.; Masamune, S.; Mito, T.; Murakami, I.; Nagaoka, K.; Nagasaki, K.; Nishimura, K.; Sakamoto, M.; Sakamoto, R.; Shimozuma, T.; Shinohara, K.; Sugama, H.; Watanabe, K. Y.; Ahn, J. W.; Akata, N.; Akiyama, T.; Ashikawa, N.; Baldzuhn, J.; Bando, T.; Bernard, E.; Castejón, F.; Chikaraishi, H.; Emoto, M.; Evans, T.; Ezumi, N.; Fujii, K.; Funaba, H.; Goto, M.; Goto, T.; Gradic, D.; Gunsu, Y.; Hamaguchi, S.; Hasegawa, H.; Hayashi, Y.; Hidalgo, C.; Higashiguchi, T.; Hirooka, Y.; Hishinuma, Y.; Horiuchi, R.; Ichiguchi, K.; Ida, K.; Ido, T.; Igami, H.; Ikeda, K.; Ishiguro, S.; Ishizaki, R.; Ishizawa, A.; Ito, A.; Ito, Y.; Iwamoto, A.; Kamio, S.; Kamiya, K.; Kaneko, O.; Kanno, R.; Kasahara, H.; Kato, D.; Kato, T.; Kawahata, K.; Kawamura, G.; Kisaki, M.; Kitajima, S.; Ko, W. H.; Kobayashi, M.; Kobayashi, S.; Kobayashi, T.; Koga, K.; Kohyama, A.; Kumazawa, R.; Lee, J. H.; López-Bruna, D.; Makino, R.; Masuzaki, S.; Matsumoto, Y.; Matsuura, H.; Mitarai, O.; Miura, H.; Miyazawa, J.; Mizuguchi, N.; Moon, C.; Morita, S.; Moritaka, T.; Mukai, K.; Muroga, T.; Muto, S.; Mutoh, T.; Nagasaka, T.; Nagayama, Y.; Nakajima, N.; Nakamura, Y.; Nakanishi, H.; Nakano, H.; Nakata, M.; Narushima, Y.; Nishijima, D.; Nishimura, A.; Nishimura, S.; Nishitani, T.; Nishiura, M.; Nobuta, Y.; Noto, H.; Nunami, M.; Obana, T.; Ogawa, K.; Ohdachi, S.; Ohno, M.; Ohno, N.; Ohtani, H.; Okamoto, M.; Oya, Y.; Ozaki, T.; Peterson, B. J.; Preynas, M.; Sagara, S.; Saito, K.; Sakaue, H.; Sanpei, A.; Satake, S.; Sato, M.; Saze, T.; Schmitz, O.; Seki, R.; Seki, T.; Sharov, I.; Shimizu, A.; Shiratani, M.; Shoji, M.; Skinner, C.; Soga, R.; Stange, T.; Suzuki, C.; Suzuki, Y.; Takada, S.; Takahata, K.; Takayama, A.; Takayama, S.; Takemura, Y.; Takeuchi, Y.; Tamura, H.; Tamura, N.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Tanaka, T.; Tanaka, Y.; Toda, S.; Todo, Y.; Toi, K.; Toida, M.; Tokitani, M.; Tokuzawa, T.; Tsuchiya, H.; Tsujimura, T.; Tsumori, K.; Usami, S.; Velasco, J. L.; Wang, H.; Watanabe, T.-H.; Watanabe, T.; Yagi, J.; Yajima, M.; Yamada, H.; Yamada, I.; Yamagishi, O.; Yamaguchi, N.; Yamamoto, Y.; Yanagi, N.; Yasuhara, R.; Yatsuka, E.; Yoshida, N.; Yoshinuma, M.; Yoshimura, S.; Yoshimura, Y.

2017-10-01

As the finalization of a hydrogen experiment towards the deuterium phase, the exploration of the best performance of hydrogen plasma was intensively performed in the large helical device. High ion and electron temperatures, T i and T e, of more than 6 keV were simultaneously achieved by superimposing high-power electron cyclotron resonance heating onneutral beam injection (NBI) heated plasma. Although flattening of the ion temperature profile in the core region was observed during the discharges, one could avoid degradation by increasing the electron density. Another key parameter to present plasma performance is an averaged beta value ≤ft< β \\right> . The high ≤ft< β \\right> regime around 4% was extended to an order of magnitude lower than the earlier collisional regime. Impurity behaviour in hydrogen discharges with NBI heating was also classified with a wide range of edge plasma parameters. The existence of a no impurity accumulation regime, where the high performance plasma is maintained with high power heating  >10 MW, was identified. Wide parameter scan experiments suggest that the toroidal rotation and the turbulence are the candidates for expelling impurities from the core region.

Effective Thermal Conductivity of High Temperature Insulations for Reusable Launch Vehicles

NASA Technical Reports Server (NTRS)

Daryabeigi, Kamran

1999-01-01

An experimental apparatus was designed to measure the effective thermal conductivity of various high temperature insulations subject to large temperature gradients representative of typical launch vehicle re-entry aerodynamic heating conditions. The insulation sample cold side was maintained around room temperature, while the hot side was heated to temperatures as high as 1800 degrees Fahrenheit. The environmental pressure was varied from 0.0001 to 760 torr. All the measurements were performed in a dry gaseous nitrogen environment. The effective thermal conductivity of Saffil, Q-Fiber felt, Cerachrome, and three multi-layer insulation configurations were measured.

Scalable Synthesis of Defect Abundant Si Nanorods for High-Performance Li-Ion Battery Anodes.

PubMed

Wang, Jing; Meng, Xiangcai; Fan, Xiulin; Zhang, Wenbo; Zhang, Hongyong; Wang, Chunsheng

2015-06-23

Microsized nanostructured silicon-carbon composite is a promising anode material for high energy Li-ion batteries. However, large-scale synthesis of high-performance nano-Si materials at a low cost still remains a significant challenge. We report a scalable low cost method to synthesize Al/Na-doped and defect-abundant Si nanorods that have excellent electrochemical performance with high first-cycle Coulombic efficiency (90%). The unique Si nanorods are synthesized by acid etching the refined and rapidly solidified eutectic Al-Si ingot. To maintain the high electronic conductivity, a thin layer of carbon is then coated on the Si nanorods by carbonization of self-polymerized polydopamine (PDA) at 800 °C. The carbon coated Si nanorods (Si@C) electrode at 0.9 mg cm(-2) loading (corresponding to area-specific-capacity of ∼2.0 mAh cm(-2)) exhibits a reversible capacity of ∼2200 mAh g(-1) at 100 mA g(-1) current, and maintains ∼700 mAh g(-1) over 1000 cycles at 1000 mA g(-1) with a capacity decay rate of 0.02% per cycle. High Coulombic efficiencies of 87% in the first cycle and ∼99.7% after 5 cycles are achieved due to the formation of an artificial Al2O3 solid electrolyte interphase (SEI) on the Si surface, and the low surface area (31 m(2) g(-1)), which has never been reported before for nano-Si anodes. The excellent electrochemical performance results from the massive defects (twins, stacking faults, dislocations) and Al/Na doping in Si nanorods induced by rapid solidification and Na salt modifications; this greatly enhances the robustness of Si from the volume changes and alleviates the mechanical stress/strain of the Si nanorods during the lithium insertion/extraction process. Introducing massive defects and Al/Na doping in eutectic Si nanorods for Li-ion battery anodes is unexplored territory. We venture this uncharted territory to commercialize this nanostructured Si anode for the next generation of Li-ion batteries.

Apparatus for performing high-temperature fiber push-out testing

NASA Technical Reports Server (NTRS)

Eldridge, Jeffrey I. (Inventor); Ebihara, Ben T. (Inventor)

1994-01-01

The apparatus disclosed in the present invention measures the force at which a fiber resist the motion of an indenter driven at constant speed. This apparatus conducts these test in a vacuum of about 10(exp -6) tort and at temperatures up to 1100 C. Temperature and vacuum environment are maintained while controlling indenter motion, sample position, and providing magnified visual inspection during the test.

Quantitative Determination of Compound Classes in Jet Turbine Fuels by High Performance Liquid Chromatography/Differential Refractive Index Detection. Part 2.

DTIC Science & Technology

1984-12-31

Code) Washington, DC 20375-5000 8a AEO UDN POSRN FIESMO 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGANIZATION (if aplicable ) Naa i ~ Proulion...pentane mobile phase was maintained at a flow rate of 6.0 ml/min with a Milton Roy Constametric pump operating in the 400-600 psi range. The injector was

Miniature rotary actuator

NASA Technical Reports Server (NTRS)

Fink, R. A.; Ellis, R. C.

1996-01-01

The trend toward smaller satellites has challenged component manufacturers to reduce the size, weight, and cost of their products while maintaining high performance. Both a new stepper motor and a new harmonic drive were developed to meet this need. The resulting actuator embodies small angle stepper technology usually reserved for larger units and incorporates an integral approach to harmonic drive design. By product simplifications, costs were significantly reduced over prior designs.

Using Cryptography to Improve Conjunction Analysis

NASA Astrophysics Data System (ADS)

Hemenway, B.; Welser, B.; Baiocchi, D.

2012-09-01

Coordination of operations between satellite operators is becoming increasingly important to prevent collisions. Unfortunately, this coordination is often handicapped by a lack of trust. Coordination and cooperation between satellite operators can take many forms, however, one specific area where cooperation between operators would yield significant benefits is in the computation of conjunction analyses. Passively collected orbital are of generally of too low fidelity to be of use in conjunction analyses. Each operator, however, maintains high fidelity data about their own satellites. These high fidelity data are significantly more valuable in calculating conjunction analyses than the lower-fidelity data. If operators were to share their high fidelity data overall space situational awareness could be improved. At present, many operators do not share data and as a consequence space situational awareness suffers. Restrictive data sharing policies are primarily motivated by privacy concerns on the part of the satellite operators, as each operator is reluctant or unwilling to share data that might compromise its political or commercial interests. In order to perform the necessary conjunction analyses while still maintaining the privacy of their own data, a few operators have entered data sharing agreements. These operators provide their private data to a trusted outside party, who then performs the conjunction analyses and reports the results to the operators. These types of agreements are not an ideal solution as they require a degree of trust between the parties, and the cost of employing the trusted party can be large. In this work, we present and analyze cryptographic tools that would allow satellite operators to securely calculate conjunction analyses without the help of a trusted outside party, while provably maintaining the privacy of their own orbital information. For example, recent advances in cryptographic protocols, specifically in the area of secure Multiparty Computation (MPC) have the potential to allow satellite operators to perform the necessary conjunction analyses without the need to reveal their orbital information to anyone. This talk will describe how MPC works, and how we propose to use it to facilitate secure information sharing between satellite operators.

Iconic memory requires attention

PubMed Central

Persuh, Marjan; Genzer, Boris; Melara, Robert D.

2012-01-01

Two experiments investigated whether attention plays a role in iconic memory, employing either a change detection paradigm (Experiment 1) or a partial-report paradigm (Experiment 2). In each experiment, attention was taxed during initial display presentation, focusing the manipulation on consolidation of information into iconic memory, prior to transfer into working memory. Observers were able to maintain high levels of performance (accuracy of change detection or categorization) even when concurrently performing an easy visual search task (low load). However, when the concurrent search was made difficult (high load), observers' performance dropped to almost chance levels, while search accuracy held at single-task levels. The effects of attentional load remained the same across paradigms. The results suggest that, without attention, participants consolidate in iconic memory only gross representations of the visual scene, information too impoverished for successful detection of perceptual change or categorization of features. PMID:22586389

Iconic memory requires attention.

PubMed

Persuh, Marjan; Genzer, Boris; Melara, Robert D

2012-01-01

Two experiments investigated whether attention plays a role in iconic memory, employing either a change detection paradigm (Experiment 1) or a partial-report paradigm (Experiment 2). In each experiment, attention was taxed during initial display presentation, focusing the manipulation on consolidation of information into iconic memory, prior to transfer into working memory. Observers were able to maintain high levels of performance (accuracy of change detection or categorization) even when concurrently performing an easy visual search task (low load). However, when the concurrent search was made difficult (high load), observers' performance dropped to almost chance levels, while search accuracy held at single-task levels. The effects of attentional load remained the same across paradigms. The results suggest that, without attention, participants consolidate in iconic memory only gross representations of the visual scene, information too impoverished for successful detection of perceptual change or categorization of features.

Adaptive image coding based on cubic-spline interpolation

NASA Astrophysics Data System (ADS)

Jiang, Jian-Xing; Hong, Shao-Hua; Lin, Tsung-Ching; Wang, Lin; Truong, Trieu-Kien

2014-09-01

It has been investigated that at low bit rates, downsampling prior to coding and upsampling after decoding can achieve better compression performance than standard coding algorithms, e.g., JPEG and H. 264/AVC. However, at high bit rates, the sampling-based schemes generate more distortion. Additionally, the maximum bit rate for the sampling-based scheme to outperform the standard algorithm is image-dependent. In this paper, a practical adaptive image coding algorithm based on the cubic-spline interpolation (CSI) is proposed. This proposed algorithm adaptively selects the image coding method from CSI-based modified JPEG and standard JPEG under a given target bit rate utilizing the so called ρ-domain analysis. The experimental results indicate that compared with the standard JPEG, the proposed algorithm can show better performance at low bit rates and maintain the same performance at high bit rates.

Performance of InGaAs short wave infrared avalanche photodetector for low flux imaging

NASA Astrophysics Data System (ADS)

Singh, Anand; Pal, Ravinder

2017-11-01

Opto-electronic performance of the InGaAs/i-InGaAs/InP short wavelength infrared focal plane array suitable for high resolution imaging under low flux conditions and ranging is presented. More than 85% quantum efficiency is achieved in the optimized detector structure. Isotropic nature of the wet etching process poses a challenge in maintaining the required control in the small pitch high density detector array. Etching process is developed to achieve low dark current density of 1 nA/cm2 in the detector array with 25 µm pitch at 298 K. Noise equivalent photon performance less than one is achievable showing single photon detection capability. The reported photodiode with low photon flux is suitable for active cum passive imaging, optical information processing and quantum computing applications.

Lean, premixed, prevaporized fuel combustor conceptual design study

NASA Technical Reports Server (NTRS)

Fiorentino, A. J.; Greene, W.; Kim, J.

1979-01-01

Four combustor concepts, designed for the energy efficient engine, utilize variable geometry or other flow modulation techniques to control the equivalence ratio of the initial burning zone. Lean conditions are maintained at high power to control oxides of nitrogen while near stoichometric conditions are maintained at low power for low CO and THC emissions. Each concept was analyzed and ranked for its potential in meeting the goals of the program. Although the primary goal of the program is a low level of nitric oxide emissions at stratospheric cruise conditions, both the ground level EPA emission standards and combustor performance and operational requirements typical of advanced subsonic aircraft engines are retained as goals as well. Based on the analytical projections made, two of the concepts offer the potential of achieving the emission goals; however, the projected operational characteristics and reliability of any concept to perform satisfactorily over an entire aircraft flight envelope would require extensive experimental substantiation before engine adaptation can be considered.

Wind alters landing dynamics in bumblebees.

PubMed

Chang, Jeremy J; Crall, James D; Combes, Stacey A

2016-09-15

Landing is an important but understudied behavior that flying animals must perform constantly. In still air, insects decelerate smoothly prior to landing by employing the relatively simple strategy of maintaining a constant rate of image expansion during their approach. However, it is unclear whether insects employ this strategy when faced with challenging flight environments. Here, we tested the effects of wind on bumblebees (Bombus impatiens) landing on flowers. We find that bees' approach paths to flowers shift from multidirectional in still air to unidirectional in wind, regardless of flower orientation. In addition, bees landing in a 3.5 m s -1 headwind do not decelerate smoothly, but rather maintain a high flight speed until contact, resulting in higher peak decelerations upon impact. These findings suggest that wind has a strong influence on insect landing behavior and performance, with important implications for the design of micro aerial vehicles and the ecomechanics of insect flight. © 2016. Published by The Company of Biologists Ltd.

Effects of organic composition on mesophilic anaerobic digestion of food waste.

PubMed

Li, Yangyang; Jin, Yiying; Borrion, Aiduan; Li, Hailong; Li, Jinhui

2017-11-01

Anaerobic digestion of food waste (FW) has been widely investigated, however, little is known about the influence of organic composition on the FW digestion process. This study aims to identify the optimum composition ratios of carbohydrate (CA), protein (CP) and lipid (EE) for maintaining high methane yield and process stability. The results show that the CA-CP-EE ratio was significantly correlated with performance and degradability parameters. Controlling the CA-CP-EE ratio higher than 1.89 (CA higher than 8.3%, CP lower than 5.0%, and EE lower than 5.6%) could be an effective way to maintain stable digestion and achieve higher methane production (385-627mL/gVS) and shorter digestion retention (196-409h). The CA-CP-EE ratio could be used as an important indicator for digestion performance. To effectively evaluate organic reduction, the concentration and removal efficiency of organic compositions in both solid phases and total FW should be considered. Copyright © 2017. Published by Elsevier Ltd.

Space Station Freedom electric power system availability study

NASA Technical Reports Server (NTRS)

Turnquist, Scott R.

1990-01-01

The results are detailed of follow-on availability analyses performed on the Space Station Freedom electric power system (EPS). The scope includes analyses of several EPS design variations, these are: the 4-photovoltaic (PV) module baseline EPS design, a 6-PV module EPS design, and a 3-solar dynamic module EPS design which included a 10 kW PV module. The analyses performed included: determining the discrete power levels that the EPS will operate at upon various component failures and the availability of each of these operating states; ranking EPS components by the relative contribution each component type gives to the power availability of the EPS; determining the availability impacts of including structural and long-life EPS components in the availability models used in the analyses; determining optimum sparing strategies, for storing space EPS components on-orbit, to maintain high average-power-capability with low lift-mass requirements; and analyses to determine the sensitivity of EPS-availability to uncertainties in the component reliability and maintainability data used.

Extremely stretchable and conductive water-repellent coatings for low-cost ultra-flexible electronics

PubMed Central

Mates, Joseph E.; Bayer, Ilker S.; Palumbo, John M.; Carroll, Patrick J.; Megaridis, Constantine M.

2015-01-01

Rapid advances in modern electronics place ever-accelerating demands on innovation towards more robust and versatile functional components. In the flexible electronics domain, novel material solutions often involve creative uses of common materials to reduce cost, while maintaining uncompromised performance. Here we combine a commercially available paraffin wax–polyolefin thermoplastic blend (elastomer matrix binder) with bulk-produced carbon nanofibres (charge percolation network for electron transport, and for imparting nanoscale roughness) to fabricate adherent thin-film composite electrodes. The simple wet-based process produces composite films capable of sustained ultra-high strain (500%) with resilient electrical performance (resistances of the order of 101–102 Ω sq−1). The composites are also designed to be superhydrophobic for long-term corrosion protection, even maintaining extreme liquid repellency at severe strain. Comprised of inexpensive common materials applied in a single step, the present scalable approach eliminates manufacturing obstacles for commercially viable wearable electronics, flexible power storage devices and corrosion-resistant circuits. PMID:26593742

Performance Evaluation of Communication Software Systems for Distributed Computing

NASA Technical Reports Server (NTRS)

Fatoohi, Rod

1996-01-01

In recent years there has been an increasing interest in object-oriented distributed computing since it is better quipped to deal with complex systems while providing extensibility, maintainability, and reusability. At the same time, several new high-speed network technologies have emerged for local and wide area networks. However, the performance of networking software is not improving as fast as the networking hardware and the workstation microprocessors. This paper gives an overview and evaluates the performance of the Common Object Request Broker Architecture (CORBA) standard in a distributed computing environment at NASA Ames Research Center. The environment consists of two testbeds of SGI workstations connected by four networks: Ethernet, FDDI, HiPPI, and ATM. The performance results for three communication software systems are presented, analyzed and compared. These systems are: BSD socket programming interface, IONA's Orbix, an implementation of the CORBA specification, and the PVM message passing library. The results show that high-level communication interfaces, such as CORBA and PVM, can achieve reasonable performance under certain conditions.

Study of Stand-Alone Microgrid under Condition of Faults on Distribution Line

NASA Astrophysics Data System (ADS)

Malla, S. G.; Bhende, C. N.

2014-10-01

The behavior of stand-alone microgrid is analyzed under the condition of faults on distribution feeders. During fault since battery is not able to maintain dc-link voltage within limit, the resistive dump load control is presented to do so. An inverter control is proposed to maintain balanced voltages at PCC under the unbalanced load condition and to reduce voltage unbalance factor (VUF) at load points. The proposed inverter control also has facility to protect itself from high fault current. Existing maximum power point tracker (MPPT) algorithm is modified to limit the speed of generator during fault. Extensive simulation results using MATLAB/SIMULINK established that the performance of the controllers is quite satisfactory under different fault conditions as well as unbalanced load conditions.

TM-30 Guidance

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

Royer, Michael P.

Minimum color quality standards are necessary, because the light sources most efficient at producing lumens are impractical for use in architectural lighting due to poor color rendition. Thus, accurate measures of color rendition and accompanying performance criteria are essential for helping technology developers and users balance tradeoffs between energy efficiency and lighting quality. Setting higher color-rendition criteria while maintaining use of CRI (e.g., CRI ≥ 90) may filter out some unacceptable light sources, but also filters out many highly desirable light sources and requires a greater tradeoff with energy efficiency. In contrast, specifying color rendition using TM-30 Rf, Rg, andmore » Rcs,h1 has been shown to be effective for differentiating desirable sources while maintaining flexibility for technology development and energy efficiency.« less

Components for IFOG based inertial measurement units using active and passive polymer materials

NASA Astrophysics Data System (ADS)

Ashley, Paul R.; Temmen, Mark G.; Diffey, William M.; Sanghadasa, Mohan; Bramson, Michael D.; Lindsay, Geoffrey A.; Guenthner, Andrew J.

2006-08-01

Highly accurate, compact, and low cost inertial measurement units (IMUs) are needed for precision guidance in navigation systems. Active and passive polymer materials have been successfully used in fabricating two of the key guided-wave components, the phase modulator and the optical transceiver, for IMUs based on the interferometric fiber optic gyroscope (IFOG) technology. Advanced hybrid waveguide fabrication processes and novel optical integration techniques have been introduced. Backscatter compensated low loss phase modulators with low half-wave drive voltage (V π) have been fabricated with CLD- and FTC- type high performance electro-optic chromophores. A silicon-bench architecture has been used in fabricating high gain low noise transceivers with high optical power while maintaining the spectral quality and long lifetime. Gyro bias stability of less than 0.02 deg/hr has been demonstrated with these components. A review of the novel concepts introduced, fabrication and integration techniques developed and performance achieved are presented.

Ambient temperature NO oxidation over Cr-based amorphous mixed oxide catalysts: effects from the second oxide components

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

Wang, Aiyong; Lin, Bo; Zhang, Hanlei

2017-01-01

Three series of Cr-based mixed oxides (Cr-Co, Cr-Fe, and Cr-Ni oxides) with high specific surface areas and amorphous textures were synthesized using a novel sol-gel method. These mixed oxides, in comparison to their pure metal oxide (CrOx, Co3O4, FeOx and NiO) counterparts, display enhanced performance for catalytic oxidation of low-concentration NO at room temperature. The best performing catalysts achieve 100% NO conversion for ~30 h of operation at a high space velocity of 45,000 ml g-1 h-1. The amorphous structure was found to be critical for these catalysts to maintain high activity and durability. Control of Cr/M (M=Co, Fe andmore » Ni) molar ratio, nitrate precursor decomposition temperature and catalyst calcination temperature was key to the synthesis of these highly active catalysts.« less

High performance 3D adaptive filtering for DSP based portable medical imaging systems

NASA Astrophysics Data System (ADS)

Bockenbach, Olivier; Ali, Murtaza; Wainwright, Ian; Nadeski, Mark

2015-03-01

Portable medical imaging devices have proven valuable for emergency medical services both in the field and hospital environments and are becoming more prevalent in clinical settings where the use of larger imaging machines is impractical. Despite their constraints on power, size and cost, portable imaging devices must still deliver high quality images. 3D adaptive filtering is one of the most advanced techniques aimed at noise reduction and feature enhancement, but is computationally very demanding and hence often cannot be run with sufficient performance on a portable platform. In recent years, advanced multicore digital signal processors (DSP) have been developed that attain high processing performance while maintaining low levels of power dissipation. These processors enable the implementation of complex algorithms on a portable platform. In this study, the performance of a 3D adaptive filtering algorithm on a DSP is investigated. The performance is assessed by filtering a volume of size 512x256x128 voxels sampled at a pace of 10 MVoxels/sec with an Ultrasound 3D probe. Relative performance and power is addressed between a reference PC (Quad Core CPU) and a TMS320C6678 DSP from Texas Instruments.

Localised hyperthermia in rodent models using an MRI-compatible high-intensity focused ultrasound system

PubMed Central

Bing, Chenchen; Nofiele, Joris; Staruch, Robert; Ladouceur-Wodzak, Michelle; Chatzinoff, Yonatan; Ranjan, Ashish; Chopra, Rajiv

2015-01-01

Purpose Localised hyperthermia in rodent studies is challenging due to the small target size. This study describes the development and characterisation of an MRI-compatible high-intensity focused ultrasound (HIFU) system to perform localised mild hyperthermia treatments in rodent models. Material and methods The hyperthermia platform consisted of an MRI-compatible small animal HIFU system, focused transducers with sector-vortex lenses, a custom-made receive coil, and means to maintain systemic temperatures of rodents. The system was integrated into a 3T MR imager. Control software was developed to acquire images, process temperature maps, and adjust output power using a proportional-integral-derivative feedback control algorithm. Hyperthermia exposures were performed in tissue-mimicking phantoms and in a rodent model (n = 9). During heating, an ROI was assigned in the heated region for temperature control and the target temperature was 42 °C; 30 min mild hyperthermia treatment followed by a 10-min cooling procedure was performed on each animal. Results 3D-printed sector-vortex lenses were successful at creating annular focal regions which enables customisation of the heating volume. Localised mild hyperthermia performed in rats produced a mean ROI temperature of 42.1 ± 0.3 °C. The T10 and T90 percentiles were 43.2 ± 0.4 °C and 41.0 ± 0.3 °C, respectively. For a 30-min treatment, the mean time duration between 41–45 °C was 31.1 min within the ROI. Conclusions The MRI-compatible HIFU system was successfully adapted to perform localised mild hyperthermia treatment in rodent models. A target temperature of 42 °C was well-maintained in a rat thigh model for 30 min. PMID:26540488

Effect of Recycle Sludge on Anaerobic Digestion of Palm Oil Mill Effluent in A Thermophilic Continuous Digester

NASA Astrophysics Data System (ADS)

Irvan; Trisakti, B.; Tomiuchi, Y.; Harahap, U.; Daimon, H.

2017-06-01

The objective of this research is to maintain short retention time and high degradation of palm oil mill effluent (POME) to biogas by applying recycle sludge. Fresh POME from Rambutan Mill without further treatment was used as feed. Two lab-scale digesters supported from Metawater Co. Ltd. have been applied to treat POME at thermophilic (55°C) condition. Both digesters were operated under intermittent operation mode. Experiments were performed in two methods: with and without recycle sludge. Hydraulic retention time (HRT) of both methods was maintained at 6 days, while sludge retention time (SRT) was maintained at various days. The result showed that by extending SRT in return sludge process where 25% of digested slurry recycled to the digester, improvement of volatile solid (VS) decomposition was obtained around 84% at HRT of 6 days and SRT of 21 days. Then, chemical oxygen demand (COD) removal efficiency could be reached until 85% by using recycle sludge.

Software Coherence in Multiprocessor Memory Systems. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Bolosky, William Joseph

1993-01-01

Processors are becoming faster and multiprocessor memory interconnection systems are not keeping up. Therefore, it is necessary to have threads and the memory they access as near one another as possible. Typically, this involves putting memory or caches with the processors, which gives rise to the problem of coherence: if one processor writes an address, any other processor reading that address must see the new value. This coherence can be maintained by the hardware or with software intervention. Systems of both types have been built in the past; the hardware-based systems tended to outperform the software ones. However, the ratio of processor to interconnect speed is now so high that the extra overhead of the software systems may no longer be significant. This issue is explored both by implementing a software maintained system and by introducing and using the technique of offline optimal analysis of memory reference traces. It finds that in properly built systems, software maintained coherence can perform comparably to or even better than hardware maintained coherence. The architectural features necessary for efficient software coherence to be profitable include a small page size, a fast trap mechanism, and the ability to execute instructions while remote memory references are outstanding.

MAINTAINING DATA QUALITY IN THE PERFORMANCE OF A LARGE SCALE INTEGRATED MONITORING EFFORT

EPA Science Inventory

Macauley, John M. and Linda C. Harwell. In press. Maintaining Data Quality in the Performance of a Large Scale Integrated Monitoring Effort (Abstract). To be presented at EMAP Symposium 2004: Integrated Monitoring and Assessment for Effective Water Quality Management, 3-7 May 200...

19 CFR 143.6 - Failure to maintain performance standards.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 19 Customs Duties 2 2011-04-01 2011-04-01 false Failure to maintain performance standards. 143.6 Section 143.6 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) SPECIAL ENTRY PROCEDURES Automated Broker Interface § 143.6 Failure to...

Moving Cages Further Offshore: Effects on Southern Bluefin Tuna, T. maccoyii, Parasites, Health and Performance

PubMed Central

Kirchhoff, Nicole T.; Rough, Kirsty M.; Nowak, Barbara F.

2011-01-01

The effects of offshore aquaculture on SBT health (particularly parasitic infections and haematology) and performance were the main aim of this study. Two cohorts of ranched Southern Bluefin tuna (SBT) (Thunnus maccoyii) were monitored throughout the commercial season, one maintained in the traditional near shore tuna farming zone and one maintained further offshore. SBT maintained offshore had reduced mortality, increased condition index at week 6 post transfer, reduced blood fluke and sealice loads, and haematological variables such as haemoglobin or lysozyme equal to or exceeding near shore maintained fish. The offshore cohort had no Cardicola forsteri and a 5% prevalence of Caligus spp., compared to a prevalence of 85% for Cardicola forsteri and 55% prevalence for Caligus spp. near shore at 6 weeks post transfer. This study is the first of its kind to examine the effects of commercial offshore sites on farmed fish parasites, health and performance. PMID:21901129

Results from core-edge experiments in high Power, high performance plasmas on DIII-D

DOE PAGES

Petrie, T. W.; Fenstermacher, M. E.; Holcomb, C. T.; ...

2016-12-24

Here, significant challenges to reducing divertor heat flux in highly powered near-double null divertor (DND) hybrid plasmas, while still maintaining both high performance metrics and low enough density for application of RF heating, are identified. For these DNDs on DIII-D, the scaling of the peak heat flux at the outer target (q ⊥ P) ∝ [P SOL x I P] 0.92 for P SOL = 8-19 MW and I P = 1.0–1.4 MA, and is consistent with standard ITPA scaling for single-null H-mode plasmas. Two divertor heat flux reduction methods were tested. First, applying the puff-and-pump radiating divertor to DIII-Dmore » plasmas may be problematical at high power and H98 (≥ 1.5) due to improvement in confinement time with deuterium gas puffing which can lead to unacceptably high core density under certain conditions. Second, q ⊥ P for these high performance DNDs was reduced by ≈35% when an open divertor is closed on the common flux side of the outer divertor target (“semi-slot”) but also that heating near the slot opening is a significant source for impurity contamination of the core.« less

Benchtop evaluation of pressure barrier insufflator and standard insufflator systems.

PubMed

Nepple, Kenneth G; Kallogjeri, Dorina; Bhayani, Sam B

2013-01-01

Previous experimental research has reported minimal differences in pressure maintenance between different versions of standard insufflators (SI). However, a recent report identified potential clinical benefits with a valveless pressure barrier insufflator (PBI). We sought to perform a benchtop objective evaluation of SI and PBI systems. A rigid box system with continuous pressure manometry was used to evaluate a PBI (Surgiquest Airseal) and two SIs (SI1 = Stryker PneumoSure High Flow Insufflator and SI2 = Storz SCB Thermoflator). Pressure maintenance of 15 mmHg was evaluated during experimental conditions of leakage from a 5 mm port site, leakage from a 12 mm port site, and continuous suction. With leakage from the 5 mm port site, the PBI maintained pressure of >13 mmHg whereas the pressures dropped moderately with the SI1 (7-13 mmHg) and SI2 insufflators (3-7 mmHg) and did not regain goal pressure until leakage was stopped. With leakage from 12 mm port site, the PBI pressure decreased to 9-11 mmHg, whereas the SI1 and SI2 lost insufflation pressures completely. The PBI maintained pressure of >11 mmHg during continuous suction while the SI1 and SI2 lost pressure entirely, and actually showed negative pressure from air suction into the rigid box system. When evaluated statistically with the mixed model repeated measures ANOVA, the SI1 and SI2 performed similarly while the PBI maintained increased pressure. In the experimental rigid box system, the PBI more successfully maintained pressure in response to leakage and suction than SIs.

Gene masking - a technique to improve accuracy for cancer classification with high dimensionality in microarray data.

PubMed

Saini, Harsh; Lal, Sunil Pranit; Naidu, Vimal Vikash; Pickering, Vincel Wince; Singh, Gurmeet; Tsunoda, Tatsuhiko; Sharma, Alok

2016-12-05

High dimensional feature space generally degrades classification in several applications. In this paper, we propose a strategy called gene masking, in which non-contributing dimensions are heuristically removed from the data to improve classification accuracy. Gene masking is implemented via a binary encoded genetic algorithm that can be integrated seamlessly with classifiers during the training phase of classification to perform feature selection. It can also be used to discriminate between features that contribute most to the classification, thereby, allowing researchers to isolate features that may have special significance. This technique was applied on publicly available datasets whereby it substantially reduced the number of features used for classification while maintaining high accuracies. The proposed technique can be extremely useful in feature selection as it heuristically removes non-contributing features to improve the performance of classifiers.

Design and performance of an ultra-flexible two-photon microscope for in vivo research.

PubMed

Mayrhofer, Johannes M; Haiss, Florent; Haenni, Dominik; Weber, Stefan; Zuend, Marc; Barrett, Matthew J P; Ferrari, Kim David; Maechler, Philipp; Saab, Aiman S; Stobart, Jillian L; Wyss, Matthias T; Johannssen, Helge; Osswald, Harald; Palmer, Lucy M; Revol, Vincent; Schuh, Claus-Dieter; Urban, Claus; Hall, Andrew; Larkum, Matthew E; Rutz-Innerhofer, Edith; Zeilhofer, Hanns Ulrich; Ziegler, Urs; Weber, Bruno

2015-11-01

We present a cost-effective in vivo two-photon microscope with a highly flexible frontend for in vivo research. Our design ensures fast and reproducible access to the area of interest, including rotation of imaging plane, and maximizes space for auxiliary experimental equipment in the vicinity of the animal. Mechanical flexibility is achieved with large motorized linear stages that move the objective in the X, Y, and Z directions up to 130 mm. 360° rotation of the frontend (rotational freedom for one axis) is achieved with the combination of a motorized high precision bearing and gearing. Additionally, the modular design of the frontend, based on commercially available optomechanical parts, allows straightforward updates to future scanning technologies. The design exceeds the mobility of previous movable microscope designs while maintaining high optical performance.

Design and performance of an ultra-flexible two-photon microscope for in vivo research

PubMed Central

Mayrhofer, Johannes M.; Haiss, Florent; Haenni, Dominik; Weber, Stefan; Zuend, Marc; Barrett, Matthew J. P.; Ferrari, Kim David; Maechler, Philipp; Saab, Aiman S.; Stobart, Jillian L.; Wyss, Matthias T.; Johannssen, Helge; Osswald, Harald; Palmer, Lucy M.; Revol, Vincent; Schuh, Claus-Dieter; Urban, Claus; Hall, Andrew; Larkum, Matthew E.; Rutz-Innerhofer, Edith; Zeilhofer, Hanns Ulrich; Ziegler, Urs; Weber, Bruno

2015-01-01

We present a cost-effective in vivo two-photon microscope with a highly flexible frontend for in vivo research. Our design ensures fast and reproducible access to the area of interest, including rotation of imaging plane, and maximizes space for auxiliary experimental equipment in the vicinity of the animal. Mechanical flexibility is achieved with large motorized linear stages that move the objective in the X, Y, and Z directions up to 130 mm. 360° rotation of the frontend (rotational freedom for one axis) is achieved with the combination of a motorized high precision bearing and gearing. Additionally, the modular design of the frontend, based on commercially available optomechanical parts, allows straightforward updates to future scanning technologies. The design exceeds the mobility of previous movable microscope designs while maintaining high optical performance. PMID:26600989

High Sensitivity and Specificity of Clinical Microscopy in Rural Health Facilities in Western Kenya Under an External Quality Assurance Program

PubMed Central

Wafula, Rebeccah; Sang, Edna; Cheruiyot, Olympia; Aboto, Angeline; Menya, Diana; O'Meara, Wendy Prudhomme

2014-01-01

Microscopic diagnosis of malaria is a well-established and inexpensive technique that has the potential to provide accurate diagnosis of malaria infection. However, it requires both training and experience. Although it is considered the gold standard in research settings, the sensitivity and specificity of routine microscopy for clinical care in the primary care setting has been reported to be unacceptably low. We established a monthly external quality assurance program to monitor the performance of clinical microscopy in 17 rural health centers in western Kenya. The average sensitivity over the 12-month period was 96% and the average specificity was 88%. We identified specific contextual factors that contributed to inadequate performance. Maintaining high-quality malaria diagnosis in high-volume, resource-constrained health facilities is possible. PMID:24935953

Energy dashboard for real-time evaluation of a heat pump assisted solar thermal system

NASA Astrophysics Data System (ADS)

Lotz, David Allen

The emergence of net-zero energy buildings, buildings that generate at least as much energy as they consume, has lead to greater use of renewable energy sources such as solar thermal energy. One example is a heat pump assisted solar thermal system, which uses solar thermal collectors with an electrical heat pump backup to supply space heating and domestic hot water. The complexity of such a system can be somewhat problematic for monitoring and maintaining a high level of performance. Therefore, an energy dashboard was developed to provide comprehensive and user friendly performance metrics for a solar heat pump system. Once developed, the energy dashboard was tested over a two-week period in order to determine the functionality of the dashboard program as well as the performance of the heating system itself. The results showed the importance of a user friendly display and how each metric could be used to better maintain and evaluate an energy system. In particular, Energy Factor (EF), which is the ratio of output energy (collected energy) to input energy (consumed energy), was a key metric for summarizing the performance of the heating system. Furthermore, the average EF of the solar heat pump system was 2.29, indicating an efficiency significantly higher than traditional electrical heating systems.

Flexible high-speed CODEC

NASA Technical Reports Server (NTRS)

Segallis, Greg P.; Wernlund, Jim V.; Corry, Glen

1993-01-01

This report is prepared by Harris Government Communication Systems Division for NASA Lewis Research Center under contract NAS3-25087. It is written in accordance with SOW section 4.0 (d) as detailed in section 2.6. The purpose of this document is to provide a summary of the program, performance results and analysis, and a technical assessment. The purpose of this program was to develop a flexible, high-speed CODEC that provides substantial coding gain while maintaining bandwidth efficiency for use in both continuous and bursted data environments for a variety of applications.

Design of a high-efficiency seven-port beam splitter using a dual duty cycle grating structure.

PubMed

Wen, Fung Jacky; Chung, Po Sheun

2011-07-01

In this paper, we propose a compact seven-port beam splitter which is constructed using only a single-layer high-density grating with a dual duty cycle structure. The properties of this grating are investigated by a simplified modal method. The diffraction efficiency can be achieved around 10% more than conventional Dammann gratings while the uniformity can still be maintained at less than 1%. The effect of deviations from the design parameters on the performance of the grating is also presented.

Engine for the next-generation launcher

NASA Astrophysics Data System (ADS)

Beichel, Rudi; Grey, Jerry

1995-05-01

The proposed dual-fuel/dual-expansion engine for the Reusable Launch Vehicle (RLV) could solve the vehicle's need for a high-performance, lightweight, low-cost, maintainable engine. The features that make dual-fuel/dual-expansion engine a prime candidate for RLV include oxygen-rich combustion, high-pressure staged-combustion cycle and dual-fuel operation. Cost-reducing, reliability-enhancing innovations such as the elimination of regenerative cooling, elimination of gimbaling and replacement of kerosene-based hydrocarbon fuel by subcooled propane have also made the this type of engine an attractive option.

Atropos: specific, sensitive, and speedy trimming of sequencing reads.

PubMed

Didion, John P; Martin, Marcel; Collins, Francis S

2017-01-01

A key step in the transformation of raw sequencing reads into biological insights is the trimming of adapter sequences and low-quality bases. Read trimming has been shown to increase the quality and reliability while decreasing the computational requirements of downstream analyses. Many read trimming software tools are available; however, no tool simultaneously provides the accuracy, computational efficiency, and feature set required to handle the types and volumes of data generated in modern sequencing-based experiments. Here we introduce Atropos and show that it trims reads with high sensitivity and specificity while maintaining leading-edge speed. Compared to other state-of-the-art read trimming tools, Atropos achieves significant increases in trimming accuracy while remaining competitive in execution times. Furthermore, Atropos maintains high accuracy even when trimming data with elevated rates of sequencing errors. The accuracy, high performance, and broad feature set offered by Atropos makes it an appropriate choice for the pre-processing of Illumina, ABI SOLiD, and other current-generation short-read sequencing datasets. Atropos is open source and free software written in Python (3.3+) and available at https://github.com/jdidion/atropos.

The effects of mobile applications in cardiopulmonary assessment education.

PubMed

Yoo, In-Young; Lee, Young-Mi

2015-02-01

Mobile applications can be used as effective simulations for nursing education. However, little is known regarding the effects of mobile application-mediated training on nursing. The aim of this study was to determine the effectiveness of mobile applications by comparing the effectiveness of a high-fidelity human patient simulator to that of a mobile application on student learning. Following lectures on the lungs and the heart, twenty-two students were separated into two groups to perform a simulation exercise. Then, the students' education effects were evaluated based on their knowledge of lung and heart assessments, their clinical assessment skill, and satisfaction with their education. After four weeks, the mobile application group maintained their knowledge, whereas the high-fidelity human patient simulator group exhibited significantly decreased knowledge of the lung assessment. Knowledge of the heart assessment was significantly increased in both groups. There was no significant difference in clinical assessment skill or educational satisfaction between the groups. We found that mobile applications provide educational tools similarly effective to a high-fidelity human patient simulator to maintain memory and to teach cardiopulmonary assessment skills. Copyright © 2014 Elsevier Ltd. All rights reserved.

Atropos: specific, sensitive, and speedy trimming of sequencing reads

PubMed Central

Collins, Francis S.

2017-01-01

A key step in the transformation of raw sequencing reads into biological insights is the trimming of adapter sequences and low-quality bases. Read trimming has been shown to increase the quality and reliability while decreasing the computational requirements of downstream analyses. Many read trimming software tools are available; however, no tool simultaneously provides the accuracy, computational efficiency, and feature set required to handle the types and volumes of data generated in modern sequencing-based experiments. Here we introduce Atropos and show that it trims reads with high sensitivity and specificity while maintaining leading-edge speed. Compared to other state-of-the-art read trimming tools, Atropos achieves significant increases in trimming accuracy while remaining competitive in execution times. Furthermore, Atropos maintains high accuracy even when trimming data with elevated rates of sequencing errors. The accuracy, high performance, and broad feature set offered by Atropos makes it an appropriate choice for the pre-processing of Illumina, ABI SOLiD, and other current-generation short-read sequencing datasets. Atropos is open source and free software written in Python (3.3+) and available at https://github.com/jdidion/atropos. PMID:28875074

Very high pressure liquid chromatography using fully porous particles: quantitative analysis of fast gradient separations without post-run times.

PubMed

Stankovich, Joseph J; Gritti, Fabrice; Stevenson, Paul G; Beaver, Lois Ann; Guiochon, Georges

2014-01-10

Using a column packed with fully porous particles, four methods for controlling the flow rates at which gradient elution runs are conducted in very high pressure liquid chromatography (VHPLC) were tested to determine whether reproducible thermal conditions could be achieved, such that subsequent analyses would proceed at nearly the same initial temperature. In VHPLC high flow rates are achieved, producing fast analyses but requiring high inlet pressures. The combination of high flow rates and high inlet pressures generates local heat, leading to temperature changes in the column. Usually in this case a post-run time is input into the analytical method to allow the return of the column temperature to its initial state. An alternative strategy involves operating the column without a post-run equilibration period and maintaining constant temperature variations for subsequent analysis after conducting one or a few separations to bring the column to a reproducible starting temperature. A liquid chromatography instrument equipped with a pressure controller was used to perform constant pressure and constant flow rate VHPLC separations. Six replicate gradient separations of a nine component mixture consisting of acetophenone, propiophenone, butyrophenone, valerophenone, hexanophenone, heptanophenone, octanophenone, benzophenone, and acetanilide dissolved in water/acetonitrile (65:35, v/v) were performed under various experimental conditions: constant flow rate, two sets of constant pressure, and constant pressure operation with a programmed flow rate. The relative standard deviations of the response factors for all the analytes are lower than 5% across the methods. Programming the flow rate to maintain a fairly constant pressure instead of using instrument controlled constant pressure improves the reproducibility of the retention times by a factor of 5, when plotting the chromatograms in time. Copyright © 2013 Elsevier B.V. All rights reserved.

Exploring Cloud Computing for Large-scale Scientific Applications

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

Lin, Guang; Han, Binh; Yin, Jian

This paper explores cloud computing for large-scale data-intensive scientific applications. Cloud computing is attractive because it provides hardware and software resources on-demand, which relieves the burden of acquiring and maintaining a huge amount of resources that may be used only once by a scientific application. However, unlike typical commercial applications that often just requires a moderate amount of ordinary resources, large-scale scientific applications often need to process enormous amount of data in the terabyte or even petabyte range and require special high performance hardware with low latency connections to complete computation in a reasonable amount of time. To address thesemore » challenges, we build an infrastructure that can dynamically select high performance computing hardware across institutions and dynamically adapt the computation to the selected resources to achieve high performance. We have also demonstrated the effectiveness of our infrastructure by building a system biology application and an uncertainty quantification application for carbon sequestration, which can efficiently utilize data and computation resources across several institutions.« less

High-Efficiency Plug-and-Play Source of Heralded Single Photons

NASA Astrophysics Data System (ADS)

Montaut, Nicola; Sansoni, Linda; Meyer-Scott, Evan; Ricken, Raimund; Quiring, Viktor; Herrmann, Harald; Silberhorn, Christine

2017-08-01

Reliable generation of single photons is of key importance for fundamental physical experiments and to demonstrate quantum protocols. Waveguide-based photon-pair sources have shown great promise in this regard due to their large spectral tunability, high generation rates, and long temporal coherence of the photon wave packet. However, integrating such sources with fiber-optic networks often results in a strong degradation of performance. We answer this challenge by presenting an alignment-free source of photon pairs in the telecommunications band that maintains heralding efficiency >50 % even after fiber pigtailing, photon separation, and pump suppression. The source combines this outstanding performance in heralding efficiency with a compact, stable, and easy-to-use "plug-and-play" package: one simply connects a laser to the input and detectors to the output, and the source is ready to use. This high performance can be achieved even outside the lab without the need for alignment which makes the source extremely useful for any experiment or demonstration needing heralded single photons.

Effect of sludge retention time on continuous-flow system with enhanced biological phosphorus removal granules at different COD loading.

PubMed

Li, Dong; Lv, Yufeng; Zeng, Huiping; Zhang, Jie

2016-11-01

The effect of sludge retention time (SRT) on the continuous-flow system with enhanced biological phosphorus removal (EBPR) granules at different COD loading was investigated during the operation of more than 220days. And the results showed that when the system operated at long SRT (30days) and low COD loading (200mg·L(-1)), it could maintain excellent performance. However, long SRT and high COD loading (300mg·L(-1)) deteriorated the settling ability of granules and the performance of system and resulted in the overgrowth of filamentous bacteria. Meanwhile, the transformation of poly-β-hydroxyalkanoates (PHAs) and glycogen in metabolism process was inhibited. Moreover, the results of pyrosequencing indicated that filamentous bacteria had a competitive advantage over polyphosphate-accumulating organisms (PAOs) at high COD loading and long SRT. The PAOs specious of Candidatus_Accumlibater and system performance increased obviously when the SRT was reduced to 20days at high COD loading. Copyright © 2016 Elsevier Ltd. All rights reserved.

3D-hybrid material design with electron/lithium-ion dual-conductivity for high-performance Li-sulfur batteries

NASA Astrophysics Data System (ADS)

Zhao, Yan; Tan, Rui; Yang, Jie; Wang, Kai; Gao, Rongtan; Liu, Dong; Liu, Yidong; Yang, Jinlong; Pan, Feng

2017-02-01

We report a novel 3D-hybrid cathode material with three-dimensional (3D) N-GO/CNT framework to load sulfur (77.6 wt %), and sulfonated polyaniline (SPANI) of coating layer. Used as a cathode material, it possesses a high capacity (1196 mAh g-1@0.3 A g-1@1.6 mg cm-2), excellent charging-discharging rate (680 mAh g-1@7.5 A g-1) and long-life performance (maintaining 71.1% capacity over 450 cycles), which is mainly attributed to the benefits of excellent electronic/Li-ionic dual-conductivity and confinement effect of the 3D-hybrid N-GO/CNT framework coated by self-doping conducting polymer SPANI. Thus, a 3D sulfur cathode modified with electronic/Li-ionic dual-conduction network can significantly enhance the electrochemical performance and stability, and this novel type of material is very promising for commercial applications that require high energy and power density, long life, and excellent abuse tolerance.

Aerocapture Guidance and Performance at Mars for High-Mass Systems

NASA Technical Reports Server (NTRS)

Zumwalt, Carlie H.; Sostaric, Ronald r.; Westhelle, Carlos H.; Cianciolo, Alicia Dwyer

2010-01-01

The objective of this study is to understand the performance associated with using the aerocapture maneuver to slow high-mass systems from an Earth-approach trajectory into orbit around Mars. This work is done in conjunction with the Mars Entry Descent and Landing Systems Analysis (EDL-SA) task to explore candidate technologies necessary for development in order to land large-scale payloads on the surface of Mars. Among the technologies considered include hypersonic inflatable aerodynamic decelerators (HIADs) and rigid mid-lift to drag (L/D) aeroshells. Nominal aerocapture trajectories were developed for the mid-L/D aeroshell and two sizes of HIADs, and Monte Carlo analysis was completed to understand sensitivities to dispersions. Additionally, a study was completed in order to determine the size of the larger of the two HIADs which would maintain design constraints on peak heat rate and diameter. Results show that each of the three aeroshell designs studied is a viable option for landing high-mass payloads as none of the three exceed performance requirements.

[Vascular adrenal cyst causing difficult to control high blood pressure].

PubMed

García Escudero, D; Torres Roca, M; Hernández Contreras, M E; Sánchez Rodríguez, C; Oñate Celdrán, J

Hypertension is a prevalent disease in developed countries. Adrenal masses, and especially adrenal cysts, are a rare and usually asymptomatic finding, which can go unnoticed or be detected as incidental findings in imaging tests. These circumstances make the multidisciplinary approach mandatory. The case is presented on a 72 year-old woman with uncontrolled high blood pressure referred to the Urology Department due to the incidental finding of a right retroperitoneal mass. A functional and imaging study was performed, establishing a diagnosis of adrenal cyst causing hypertensive symptoms. A literature search was performed in order to assess diagnostic and therapeutic approaches. With the diagnosis of adrenal cyst causing uncontrolled high blood pressure, a right laparoscopic adrenalectomy was performed. After surgery the patient has maintained blood pressure within the normal range. A multidisciplinary approach is necessary for the management of rare diseases. The surgical approach, if possible, should be laparoscopic. Copyright © 2017 SEH-LELHA. Publicado por Elsevier España, S.L.U. All rights reserved.

Silicon/copper dome-patterned electrodes for high-performance hybrid supercapacitors

PubMed Central

Liu, Xuyan; Jung, Hun-Gi; Kim, Sang-Ok; Choi, Ho-Suk; Lee, Sangwha; Moon, Jun Hyuk; Lee, Joong Kee

2013-01-01

This study proposes a method for manufacturing high-performance electrode materials in which controlling the shape of the current collector and electrode material for a Li-ion capacitor (LIC). In particular, the proposed LIC manufacturing method maintains the high voltage of a cell by using a microdome-patterned electrode material, allowing for reversible reactions between the Li-ion and the active material for an extended period of time. As a result, the LICs exhibit initial capacities of approximately 42 F g−1, even at 60 A g−1. The LICs also exhibit good cycle performance up to approximately 15,000 cycles. In addition, these advancements allow for a considerably higher energy density than other existing capacitor systems. The energy density of the proposed LICs is approximately nine, two, and 1.5 times higher than those of the electrochemical double layer capacitor (EDLC), AC/LiMn2O4 hybrid capacitor, and intrinsic Si/AC LIC, respectively. PMID:24292725

Ultrafast surface modification of Ni3S2 nanosheet arrays with Ni-Mn bimetallic hydroxides for high-performance supercapacitors.

PubMed

Zou, Xu; Sun, Qing; Zhang, Yuxin; Li, Guo-Dong; Liu, Yipu; Wu, Yuanyuan; Yang, Lan; Zou, Xiaoxin

2018-03-14

Amorphous Ni-Mn bimetallic hydroxide film on the three-dimensional nickle foam (NF)-supported conductive Ni 3 S 2 nanosheets (denoted as Ni-Mn-OH@Ni 3 S 2 /NF) is successfully synthesized by an ultrafast process (5 s). The fascinating structural characteristic endows Ni-Mn-OH@Ni 3 S 2 /NF electrodes better electrochemical performance. The specific capacitance of 2233.3 F g -1 at a current density of 15 A g -1 can achieve high current density charge and discharge at 20/30 A g -1 that the corresponding capacitance is 1529.16 and 1350 F g -1 , respectively. As well as good cycling performance after 1000 cycles can maintain 72% at 15 A g -1 . The excellent performance can be attributed to unique surface modification nanostructures and the synergistic effect of the bimetallic hydroxide film. The impressive results provide new opportunity to produce advanced electrode materials by simple and green route and this material is expected to apply in high energy density storage systems.

Performance Characteristics of a PEM Fuel Cell with Parallel Flow Channels at Different Cathode Relative Humidity Levels

PubMed Central

Lee, Pil Hyong; Hwang, Sang Soon

2009-01-01

In fuel cells flow configuration and operating conditions such as cell temperature, humidity at each electrode and stoichiometric number are very crucial for improving performance. Too many flow channels could enhance the performance but result in high parasite loss. Therefore a trade-off between pressure drop and efficiency of a fuel cell should be considered for optimum design. This work focused on numerical simulation of the effects of operating conditions, especially cathode humidity, with simple micro parallel flow channels. It is known that the humidity at the cathode flow channel becomes very important for enhancing the ion conductivity of polymer membrane because fully humidified condition was normally set at anode. To investigate the effect of humidity on the performance of a fuel cell, in this study humidification was set to 100% at the anode flow channel and was changed by 0–100% at the cathode flow channel. Results showed that the maximum power density could be obtained under 60% humidified condition at the cathode where oxygen concentration was moderately high while maintaining high ion conductivity at a membrane. PMID:22291556

Performance Characteristics of a PEM Fuel Cell with Parallel Flow Channels at Different Cathode Relative Humidity Levels.

PubMed

Lee, Pil Hyong; Hwang, Sang Soon

2009-01-01

In fuel cells flow configuration and operating conditions such as cell temperature, humidity at each electrode and stoichiometric number are very crucial for improving performance. Too many flow channels could enhance the performance but result in high parasite loss. Therefore a trade-off between pressure drop and efficiency of a fuel cell should be considered for optimum design. This work focused on numerical simulation of the effects of operating conditions, especially cathode humidity, with simple micro parallel flow channels. It is known that the humidity at the cathode flow channel becomes very important for enhancing the ion conductivity of polymer membrane because fully humidified condition was normally set at anode. To investigate the effect of humidity on the performance of a fuel cell, in this study humidification was set to 100% at the anode flow channel and was changed by 0-100% at the cathode flow channel. Results showed that the maximum power density could be obtained under 60% humidified condition at the cathode where oxygen concentration was moderately high while maintaining high ion conductivity at a membrane.

Feedback control and heat transfer measurements in a Rayleigh-Bénard convection cell

NASA Astrophysics Data System (ADS)

Vial, M.; Hernández, R. H.

2017-07-01

We report experimental results on the heat transfer and instability onset of a Rayleigh-Bénard convection cell of aspect ratios 6:3:1 filled with a high Prandtl aqueous solution of glycerol under feedback control. We investigate the transient and stationary response of both local temperature readings and heat transfer fluxes on the Rayleigh Bénard cell in both conductive and convective states when we perform two independent feedback control actions on both hot and cold walls. We evaluate the performance of both controllers to maintain a temperature gradient independently if the system is below or above the convection threshold. As the convection cell can be rotated at 180° about the shorter axis of the cell, it was possible to perform transitions between thermal conduction and convection regimes and vice versa under a constant temperature difference maintained by both independent controllers. The experimental setup provided an accurate measurement of the critical Rayleigh number and the evolution of the Nusselt number as a function of the Rayleigh number in the moderately supercritical regime (R a <1 04). Flow visualizations show a steady cellular convection pattern formed by 6 transverse rolls throughout the range of Rayleigh numbers.

Nursing performance under high workload: a diary study on the moderating role of selection, optimization and compensation strategies.

PubMed

Baethge, Anja; Müller, Andreas; Rigotti, Thomas

2016-03-01

The aim of this study was to investigate whether selective optimization with compensation constitutes an individualized action strategy for nurses wanting to maintain job performance under high workload. High workload is a major threat to healthcare quality and performance. Selective optimization with compensation is considered to enhance the efficient use of intra-individual resources and, therefore, is expected to act as a buffer against the negative effects of high workload. The study applied a diary design. Over five consecutive workday shifts, self-report data on workload was collected at three randomized occasions during each shift. Self-reported job performance was assessed in the evening. Self-reported selective optimization with compensation was assessed prior to the diary reporting. Data were collected in 2010. Overall, 136 nurses from 10 German hospitals participated. Selective optimization with compensation was assessed with a nine-item scale that was specifically developed for nursing. The NASA-TLX scale indicating the pace of task accomplishment was used to measure workload. Job performance was assessed with one item each concerning performance quality and forgetting of intentions. There was a weaker negative association between workload and both indicators of job performance in nurses with a high level of selective optimization with compensation, compared with nurses with a low level. Considering the separate strategies, selection and compensation turned out to be effective. The use of selective optimization with compensation is conducive to nurses' job performance under high workload levels. This finding is in line with calls to empower nurses' individual decision-making. © 2015 John Wiley & Sons Ltd.

Functional integrity of flexible n-channel metal-oxide-semiconductor field-effect transistors on a reversibly bistable platform

NASA Astrophysics Data System (ADS)

Alfaraj, Nasir; Hussain, Aftab M.; Torres Sevilla, Galo A.; Ghoneim, Mohamed T.; Rojas, Jhonathan P.; Aljedaani, Abdulrahman B.; Hussain, Muhammad M.

2015-10-01

Flexibility can bring a new dimension to state-of-the-art electronics, such as rollable displays and integrated circuit systems being transformed into more powerful resources. Flexible electronics are typically hosted on polymeric substrates. Such substrates can be bent and rolled up, but cannot be independently fixed at the rigid perpendicular position necessary to realize rollable display-integrated gadgets and electronics. A reversibly bistable material can assume two stable states in a reversible way: flexibly rolled state and independently unbent state. Such materials are used in cycling and biking safety wristbands and a variety of ankle bracelets for orthopedic healthcare. They are often wrapped around an object with high impulsive force loading. Here, we study the effects of cumulative impulsive force loading on thinned (25 μm) flexible silicon-based n-channel metal-oxide-semiconductor field-effect transistor devices housed on a reversibly bistable flexible platform. We found that the transistors have maintained their high performance level up to an accumulated 180 kN of impact force loading. The gate dielectric layers have maintained their reliability, which is evidenced by the low leakage current densities. Also, we observed low variation in the effective electron mobility values, which manifests that the device channels have maintained their carrier transport properties.

High Performance Computing Innovation Service Portal Study (HPC-ISP)

DTIC Science & Technology

2009-04-01

threatened by global competition. It is essential that these suppliers remain competitive and maintain their technological advantage . In this increasingly...place themselves, as well as customers who rely on them, in competitive jeopardy. Despite the potential competitive advantage associated with adopting...computing users into the HPC fold and to enable more entry-level users to exploit HPC more fully for competitive advantage . About half of the surveyed

Validation of the Information/Communications Technology Literacy Test

DTIC Science & Technology

2016-10-01

nested set. Table 11 presents the results of incremental validity analyses for job knowledge/performance criteria by MOS. Figure 7 presents much...Systems Operator-Analyst (25B) and Nodal Network Systems Operator-Maintainer (25N) MOS. This report documents technical procedures and results of the...research effort. Results suggest that the ICTL test has potential as a valid and highly efficient predictor of valued outcomes in Signal school MOS. Not

Validation of Alternatives to High Volatile Organic Compound Solvents Used in Aeronautical Antifriction Bearing Cleaning

DTIC Science & Technology

2006-10-17

Name, address, telephone number, and technical point of contact at company supplying product. (3) Material safety data sheet (MSDS) and label...existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments...Depot level maintenance cleaning. Data analysis and interpretation are based on analytical test results as well as visual inspections performed on

Gastric band tubing-related complication during pregnancy.

PubMed

Ongso, Yuni F; Beh, Han N

2017-11-01

In the past few decades, laparoscopic adjustable gastric banding is one of the most common bariatric procedures performed to treat morbid obesity. Device-related complication such as connection-tubing problem is rare. Here we present a case of gastric band tubing complication during pregnancy. This case illustrates the need to maintain high index of suspicion of gastric band device-related complication during pregnancy and early referral for bariatric surgical assessment is recommended.

Polymer excipients enable sustained drug release in low pH from mechanically strong inorganic geopolymers.

PubMed

Jämstorp, Erik; Yarra, Tejaswi; Cai, Bing; Engqvist, Håkan; Bredenberg, Susanne; Strømme, Maria

2012-01-01

Improving acid resistance, while maintaining the excellent mechanical stability is crucial in the development of a sustained and safe oral geopolymer dosage form for highly potent opioids. In the present work, commercially available Methacrylic acid-ethyl acrylate copolymer, Polyethylene-glycol (PEG) and Alginate polymer excipients were included in dissolved or powder form in geopolymer pellets to improve the release properties of Zolpidem, herein acting as a model drug for the highly potent opioid Fentanyl. Scanning electron microscopy, compression strength tests and drug release experiments, in gastric pH 1 and intestinal pH 6.8 conditions, were performed. The polymer excipients, with an exception for PEG, reduced the drug release rate in pH 1 due to their ability to keep the pellets in shape, in combination with the introduction of an insoluble excipient, and thereby maintain a barrier towards drug diffusion and release. Neither geopolymer compression strength nor the release in pH 6.8 was considerably impaired by the incorporation of the polymer excipients. The geopolymer/polymer composites combine high mechanical strength and good release properties under both gastric and intestinal pH conditions, and are therefore promising oral dosage forms for sustained release of highly potent opioids.

The insulation performance of reactive parylene films in implantable electronic devices

PubMed Central

Seymour, John P.; Elkasabi, Yaseen; Chen, Hsien-yeh; Lahann, Joerg; Kipke, Daryl R.

2009-01-01

Parylene-C (poly-chloro-p-xylylene) is an appropriate material for use in an implantable, microfabricated device. It is hydrophobic, conformally deposited, has a low dielectric constant, and superb biocompatibility. Yet for many bioelectrical applications, its poor wet adhesion may be an impassable shortcoming. This research contrasts parylene-C and poly(p-xylylene) functionalized with reactive group X (PPX-X) layers using long-term electrical soak and adhesion tests. The reactive parylene was made of complementary derivatives having aldehyde and aminomethyl side groups (PPX-CHO and PPX-CH2NH2 respectively). These functional groups have previously been shown to covalently react together after heating. Electrical testing was conducted in saline at 37°C on interdigitated electrodes with either parylene-C or reactive parylene as the metal layer interface. Results showed that reactive parylene devices maintained the highest impedance. Heat-treated PPX-X device impedance was 800% greater at 10 kHz and 70% greater at 1Hz relative to heated parylene-C controls after 60 days. Heat treatment proved to be critical for maintaining high impedance of both parylene-C and the reactive parylene. Adhesion measurements showed improved wet metal adhesion for PPX-X, which corresponds well with its excellent high frequency performance. PMID:19703712

Practical polarization maintaining optical fibre temperature sensor for harsh environment application

NASA Astrophysics Data System (ADS)

Yang, Yuanhong; Xia, Haiyun; Jin, Wei

2007-10-01

A reflection spot temperature sensor was proposed based on the polarization mode interference in polarization maintaining optical fibre (PMF) and the phenomenon that the propagation constant difference of the two orthogonal polarization modes in stressing structures PMF is sensitive to temperature and the sensing equation was obtained. In this temperature sensor, a broadband source was used to suppress the drift due to polarization coupling in lead-in/lead-out PMF. A characteristic and performance investigation proved this sensor to be practical, flexible and precise. Experimental results fitted the theory model very well and the noise-limited minimum detectable temperature variation is less than 0.01 °C. The electric arc processing was investigated and the differential propagation constant modifying the PMF probe is performed. For the demand of field hot-spot monitoring of huge power transformers, a remote multi-channel temperature sensor prototype has been made and tested. Specially coated Panda PMF that can stand high temperatures up to 250 °C was fabricated and used as probe fibres. The sensor probes were sealed within thin quartz tubes that have high voltage insulation and can work in a hot oil and vapour environment. Test results show that the accuracy of the system is better than ±0.5 °C within 0 °C to 200 °C.

Situational awareness and its application in the delivery suite.

PubMed

Edozien, Leroy C

2015-01-01

The delivery suite is a high-risk environment. Transitions between low-risk and high-risk can be swift, and sentinel events can occur without warning. The prevention of accidents in this environment rests on the vigilance of the individual practitioner at the frontline. It is, therefore, important that the individual practitioner should develop and maintain the cognitive skills to anticipate, recognize, and intercept unfolding error chains. This commentary gives an overview of a nontechnical skill that is essential for safe practice in a delivery suite: situational awareness. A basic description of situational awareness is provided, using examples of loss of situational awareness in the delivery suite and examples of simple interventions that could promote situational awareness. Involuntary automaticity readily creeps in during performance of routine tasks, and cognitive overload could deplete attentional resources that are, by nature, limited. Strategies and tactics for maintaining situational awareness include proactively seeking and managing information on unfolding events, continually updating individual and team mental models, mindful use of checklists and scoreboards, and avoidance of attentional blindness. These simple interventions require minimal financial resources but could immensely enhance clinical performance and patient safety. Situational awareness should be included in the training of obstetrician-gynecologists and other staff working in a delivery suite.

In situ polarized 3He system for the Magnetism Reflectometer at the Spallation Neutron Source.

PubMed

Tong, X; Jiang, C Y; Lauter, V; Ambaye, H; Brown, D; Crow, L; Gentile, T R; Goyette, R; Lee, W T; Parizzi, A; Robertson, J L

2012-07-01

We report on the in situ polarized (3)He neutron polarization analyzer developed for the time-of-flight Magnetism Reflectometer at the Spallation Neutron Source at Oak Ridge National Laboratory. Using the spin exchange optical pumping method, we achieved a (3)He polarization of 76% ± 1% and maintained it for the entire three-day duration of the test experiment. Based on transmission measurements with unpolarized neutrons, we show that the average analyzing efficiency of the (3)He system is 98% for the neutron wavelength band of 2-5 Å. Using a highly polarized incident neutron beam produced by a supermirror bender polarizer, we obtained a flipping ratio of >100 with a transmission of 25% for polarized neutrons, averaged over the wavelength band of 2-5 Å. After the cell was depolarized for transmission measurements, it was reproducibly polarized and this performance was maintained for three weeks. A high quality polarization analysis experiment was performed on a reference sample of Fe/Cr multilayer with strong spin-flip off-specular scattering. Using a combination of the position sensitive detector, time-of-flight method, and the excellent parameters of the (3)He cell, the polarization analysis of the two-dimensional maps of reflected, refracted, and off-specular scattered intensity above and below the horizon were obtained, simultaneously.

Significantly Increasing the Ductility of High Performance Polymer Semiconductors through Polymer Blending.

PubMed

Scott, Joshua I; Xue, Xiao; Wang, Ming; Kline, R Joseph; Hoffman, Benjamin C; Dougherty, Daniel; Zhou, Chuanzhen; Bazan, Guillermo; O'Connor, Brendan T

2016-06-08

Polymer semiconductors based on donor-acceptor monomers have recently resulted in significant gains in field effect mobility in organic thin film transistors (OTFTs). These polymers incorporate fused aromatic rings and have been designed to have stiff planar backbones, resulting in strong intermolecular interactions, which subsequently result in stiff and brittle films. The complex synthesis typically required for these materials may also result in increased production costs. Thus, the development of methods to improve mechanical plasticity while lowering material consumption during fabrication will significantly improve opportunities for adoption in flexible and stretchable electronics. To achieve these goals, we consider blending a brittle donor-acceptor polymer, poly[4-(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)-alt-[1,2,5]thiadiazolo[3,4-c]pyridine] (PCDTPT), with ductile poly(3-hexylthiophene). We found that the ductility of the blend films is significantly improved compared to that of neat PCDTPT films, and when the blend film is employed in an OTFT, the performance is largely maintained. The ability to maintain charge transport character is due to vertical segregation within the blend, while the improved ductility is due to intermixing of the polymers throughout the film thickness. Importantly, the application of large strains to the ductile films is shown to orient both polymers, which further increases charge carrier mobility. These results highlight a processing approach to achieve high performance polymer OTFTs that are electrically and mechanically optimized.

[Portal perfusion with right gastroepiploic vein flow in liver transplant].

PubMed

Mendoza-Sánchez, Federico; Javier-Haro, Francisco; Mendoza-Medina, Diego Federico; González-Ojeda, Alejandro; Cortés-Lares, José Antonio; Fuentes-Orozco, Clotilde

Liver transplantation in patients with liver cirrhosis, portal vein thrombosis, and cavernous transformation of the portal vein, is a complex procedure with high possibility of liver graft dysfunction. It is performed in 2-19% of all liver transplants, and has a significantly high mortality rate in the post-operative period. Other procedures to maintain portal perfusion have been described, however there are no reports of liver graft perfusion using right gastroepiploic vein. A 20 year-old female diagnosed with cryptogenic cirrhosis, with a Child-Pugh score of 7 points (class "B"), and MELD score of 14 points, with thrombosis and cavernous transformation of the portal vein, severe portal hypertension, splenomegaly, a history of upper gastrointestinal bleeding due to oesophageal varices, and left renal agenesis. The preoperative evaluation for liver transplantation was completed, and the right gastroepiploic vein of 1-cm diameter was observed draining to the infrahepatic inferior vena cava and right suprarenal vein. An orthotopic liver transplantation was performed from a non-living donor (deceased on January 30, 2005) using the Piggy-Back technique. Portal vein perfusion was maintained using the right gastroepiploic vein, and the outcome was satisfactory. The patient was discharged 13 days after surgery. Liver transplantation was performed satisfactorily, obtaining an acceptable outcome. In this case, the portal perfusion had adequate blood flow through the right gastroepiploic vein. Copyright © 2015 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

Design and Follow-on from 50 kJ Fusion Yield using High-Density Carbon Capsules at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Berzak Hopkins, L.; Lepape, S.; Divol, L.; Pak, A.; Goyon, C.; Dewald, E.; Ho, D. D.; Khan, S. F.; Weber, C.; Meezan, N. B.; Biener, J.; Grim, G.; Ma, T.; Milovich, J. L.; Moore, A. S.; Nikroo, A.; Ross, J. S.; Stadermann, M.; Volegov, P.; Wild, C.; Callahan, D. A.; Hurricane, O. A.; Hsing, W. W.; Town, R. P. J.; Edwards, M. J.

2017-10-01

We have demonstrated nearly 3x alpha-heating at the National Ignition Facility by using tungsten-doped High-Density Carbon (HDC) capsules in low gasfill, unlined, uranium (DU) hohlraums. Shot N170601 achieved a primary neutron yield of 1.5 x 1016 neutrons with a Deuterium-Tritium ion temperature of 4.7 keV. Predecessor experiments demonstrated high-performing, efficient performance, as noted through high neutron yield production per laser energy input. Building on these `subscale' results, follow-on experiments utilize an 8% larger target than the predecessor campaign, to increase the capsule surface area and absorbed energy. The capsule fill tube has been reduced in size from 10 to 5 micron diameter, and the laser design implements a new, ``drooping'' technique for the end of the pulse, to reduce the time between laser shut-off and capsule peak emission while still maintaining capsule mass remaining. Design of the current platform as well as avenues to potentially improve performance based on these experiments will be discussed. Work performed under the auspices of the U.S. D.O.E. by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

Operational Issues in the Development of a Cost-Effective Reusable LOX/LH2 Engine

NASA Technical Reports Server (NTRS)

Ballard, Richard O.

2003-01-01

The NASA Space Launch Initiative (SLI) was initiated in early 2001 to conduct technology development and to reduce the business and technical risk associated with developing the next-generation reusable launch system. In the field of main propulsion, two LOXLH2 rocket engine systems, the Pratt & Whitney / Aerojet Joint Venture (JV) COBRA and the Rocketdyne RS-83, were funded to develop a safe, economical, and reusable propulsion system. Given that a large-thrust reusable rocket engine program had not been started in the U.S. since 1971, with the Space Shuttle Main Engine (SSME), this provided an opportunity to build on the experience developed on the SSME system, while exploiting advances in technology that had occurred in the intervening 30 years. One facet of engine development that was identified as being especially vital in order to produce an optimal system was in the areas of operability and maintainability. In order to achieve the high levels of performance required by the Space Shuttle, the SSME system is highly complex with very tight tolerances and detailed requirements. Over the lifetime of the SSME program, the engine has required a high level of manpower to support the performance of inspections, maintenance (scheduled and unscheduled) and operations (prelaunch and post-flight). As a consequence, the labor- intensive needs of the SSME provide a significant impact to the overall cost efficiency of the Space Transportation System (STS). One of the strategic goals of the SLI is to reduce cost by requiring the engine(s) to be easier (Le. less expensive) to operate and maintain. The most effective means of accomplishing this goal is to infuse the operability and maintainability features into the engine design from the start. This paper discusses some of the operational issues relevant to a reusable LOx/LH2 main engine, and the means by which their impact is mitigated in the design phase.

High sodium intake during postnatal phases induces an increase in arterial blood pressure in adult rats.

PubMed

Moreira, M C S; da Silva, E F; Silveira, L L; de Paiva, Y B; de Castro, C H; Freiria-Oliveira, A H; Rosa, D A; Ferreira, P M; Xavier, C H; Colombari, E; Pedrino, Gustavo R

2014-12-28

Epigenetic studies suggest that diseases that develop in adulthood are related to certain conditions to which the individual is exposed during the initial stages of life. Experimental evidence has demonstrated that offspring born to mothers maintained on high-Na diets during pregnancy have higher mean arterial pressure (MAP) in adulthood. Although these studies have demonstrated the importance of prenatal phases to hypertension development, no evidence regarding the role of high Na intake during postnatal phases in the development of this pathology has been reported. Therefore, in the present study, the effects of Na overload during childhood on induced water and Na intakes and on cardiovascular parameters in adulthood were evaluated. Experiments were carried out in two groups of 21-d-old rats: experimental group, maintained on hypertonic saline (0.3 m-NaCl) solution and food for 60 d, and control group, maintained on tap water and food. Later, both groups were given water and food for 15 d (recovery period). After the recovery period, chronic cannulation of the right femoral artery was performed in unanaesthetised rats to record baseline MAP and heart rate (HR). The experimental group was found to have increased basal MAP (98.6 (sem 2.6) v. 118.3 (sem 2.7) mmHg, P< 0.05) and HR (365.4 (sem 12.2) v. 398.2 (sem 7.5) beats per min, P< 0.05). There was a decrease in the baroreflex index in the experimental group when compared with that in the control group. A water and Na intake test was performed using furosemide. Na depletion was found to induce an increase in Na intake in both the control and experimental groups (12.1 (sem 0.6) ml and 7.8 (sem 1.1), respectively, P< 0.05); however, this increase was of lower magnitude in the experimental group. These results demonstrate that postnatal Na overload alters behavioural and cardiovascular regulation in adulthood.

40 CFR 60.203 - Monitoring of operations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Phosphate..., calibrate, maintain, and operate a monitoring device which can be used to determine the mass flow of... maintain a daily record of equivalent P2O5 feed by first determining the total mass rate in Mg/hr of...

40 CFR Table 2 to Subpart Kkkkk of... - Operating Limits

Code of Federal Regulations, 2011 CFR

2011-07-01

.... Maintain the average scrubber pressure drop for each 3-hour block period at or above the average pressure drop established during the performance test; andb. Maintain the average scrubber liquid pH for each 3-hour block period at or above the average scrubber liquid pH established during the performance test...

Work-family conflicts and work performance.

PubMed

Roth, Lawrence; David, Emily M

2009-08-01

Prior research indicates that work-family conflict interferes with family far more than it interferes with work. Conservation of resources provides a possible explanation: when shifting resources from family is no longer sufficient to maintain satisfactory work performance, then workers must acquire additional resources or reduce investments in work. One source of such additional resources could be high performance peers in the work group. The performance of workers with resource-rich peers may be less adversely affected by work-family conflict. In this study, 136 employees of a wholesale distribution firm (61% women, 62% minority) working in groups of 7 to 11 in manual labor and low-level administrative jobs rated their own work-to-family conflict. Their supervisors rated workers' performance. Hierarchical regression analysis indicated that work-to-family conflict increasingly adversely affected job performance as work group performance decreased. Hence, work group performance may be an important moderator of the effects of work-family conflict.

Interferometric sensor based on the polarization-maintaining fibers

NASA Astrophysics Data System (ADS)

Cubik, Jakub; Kepak, Stanislav; Doricak, Jan; Vašinek, Vladimir; Liner, Andrej; Papes, Martin

2012-01-01

The interferometers composed of optical fibers are due to its high sensitivity capable of to measure various influences affecting the fiber. These influences may be bending or different sorts of fiber deformations, vibration, temperature, etc. In this case the vibration is the measured quantity, which is evaluated by analyzing the interference fringes representing changes in the fiber. Was used a Mach-Zehnder interferometer composed of the polarization maintaining elements. The polarization maintaining elements were used because of high sensitivity to polarization state inside the interferometer. The light was splitted into the two optical paths, where the first one is the reference fiber and it is separated from the actual phenomenon, and the second one is measuring fiber, which is directly exposed to vibration transmission from the underlying surface. The light source was narrowband DFB laser serating at a wavelength of 1550nm and as a detector an InGaAs PIN photodiode were used in this measurement. The electrical signal from the photodiode was amplified and fed into the measuring card. On the incoming signal the FFT was applied, which performs the transformation into the frequency domain and the results were further evaluated by software. We were evaluating the characteristic frequencies and their amplitude ratios. The frequency responses are unique for a given phenomenon, thus it is possible to identify recurring events by the characteristic frequencies and their amplitude ratios. The frequency range was limited by the properties of the used speaker, by the frequency characteristics of the filter in the amplifier and used resonant element. For the experiment evaluation the repeated impact of the various spherical objects on the surface board was performed and measured. The stability of amplitude and frequency and also the frequency range was verified in this measurement.

All 2D materials as electrodes for high power hybrid energy storage applications

NASA Astrophysics Data System (ADS)

Kato, Keiko; Sayed, Farheen N.; Babu, Ganguli; Ajayan, Pulickel M.

2018-04-01

Achieving both high energy and power densities from energy storage devices is a core strategy to meet the increasing demands of high performance portable electronics and electric transportation systems. Li-ion capacitor is a promising hybrid technology that strategically exploits high energy density from a Li-ion battery electrode and high power density from a supercapacitor electrode. However, the performance and safety of hybrid devices are still major concerns due to the use of graphite anodes which form passivation layers with organic electrolytes at lower potentials. Here, we explore 2D nanosheets as both anode and cathode electrodes to build a high power system without compromising energy density. Owing to the high electrical conductivity and multivalent redox activity at higher potentials, the Li-ion intercalation electrode is capable of maintaining large energy density at higher current rates with less safety risk than conventional systems. Hybrid devices consisting of all in all 2D electrodes deliver energy density as high as 121 Wh g-1 (at 240 W kg-1) and retains 29 Wh g-1 at high power density of 3600 W kg-1.

Improving UV Resistance of High Performance Fibers

NASA Astrophysics Data System (ADS)

Hassanin, Ahmed

High performance fibers are characterized by their superior properties compared to the traditional textile fibers. High strength fibers have high modules, high strength to weight ratio, high chemical resistance, and usually high temperature resistance. It is used in application where superior properties are needed such as bulletproof vests, ropes and cables, cut resistant products, load tendons for giant scientific balloons, fishing rods, tennis racket strings, parachute cords, adhesives and sealants, protective apparel and tire cords. Unfortunately, Ultraviolet (UV) radiation causes serious degradation to the most of high performance fibers. UV lights, either natural or artificial, cause organic compounds to decompose and degrade, because the energy of the photons of UV light is high enough to break chemical bonds causing chain scission. This work is aiming at achieving maximum protection of high performance fibers using sheathing approaches. The sheaths proposed are of lightweight to maintain the advantage of the high performance fiber that is the high strength to weight ratio. This study involves developing three different types of sheathing. The product of interest that need be protected from UV is braid from PBO. First approach is extruding a sheath from Low Density Polyethylene (LDPE) loaded with different rutile TiO2 % nanoparticles around the braid from the PBO. The results of this approach showed that LDPE sheath loaded with 10% TiO2 by weight achieved the highest protection compare to 0% and 5% TiO2. The protection here is judged by strength loss of PBO. This trend noticed in different weathering environments, where the sheathed samples were exposed to UV-VIS radiations in different weatheromter equipments as well as exposure to high altitude environment using NASA BRDL balloon. The second approach is focusing in developing a protective porous membrane from polyurethane loaded with rutile TiO2 nanoparticles. Membrane from polyurethane loaded with 4% rutile TiO2 nanoparticles showed excellent protection of braid from PBO. Only 7.5% strength loss was observed. To optimize the degree of protection of the sheath loaded with UV blocker particles, computational models were developed to optimize the protective layer thickness/weight and the amount of UV particles that provide the maximum protection with lightest weight of the protective layer and minimum amount of UV particles. The simulated results were found to be higher that the experimental results due to the tendency of nanoparticles to be agglomerated in real experiments. The third approach to achieve a maximum protection with the minimum weight added is constructing a sleeve from SpectraRTM (Ultra High Molecular Weight Polyethylene (UHMWPE) high performance fiber), which is known to resist UV, woven fabric. Covering the braid from PBO fiber with Spectra RTM woven fabric provide hybrid structure with two compatible components that can share the load and thus maintain the high strength to weight ratio. Although the SpectraRTM fabric had maximum cover factor, 20 % of visible light and about 15 % of UV were able to penetrate the fabric. This transmittance of UV-VIS light negatively affected the protection performance of the SpectraRTM woven fabric layer. It is thought that SpectraRTM fabric be coated with a thin layer (mentioned earlier) containing UV blocker for additional protection while maintain strength contribution to the hybrid structure. To maximize the strength to weight ratio of the hybrid structure (with core from PBO braid and sheath from SpectraRTM woven fabric) an established finite element model was utilized. The theoretical results using the finite element theory indicated that by controlling the bending rigidity of the filling yarn of the SpectraRTM fabric, the extension at peak load of woven fabric in warp direction (loading direction) could be controlled to match the braid extension at peak load. The match in the extension at peak load of the two components of the hybrid structure allowed the maximum strength to weight ratio. Thus, the SpectraRTM woven layer could achieve both the protection from UV and the load share in the hybrid structure.

ASDTIC: A feedback control innovation

NASA Technical Reports Server (NTRS)

Lalli, V. R.; Schoenfeld, A. D.

1972-01-01

The ASDTIC (Analog Signal to Discrete Time Interval Converter) control subsystem provides precise output control of high performance aerospace power supplies. The key to ASDTIC operation is that it stably controls output by sensing output energy change as well as output magnitude. The ASDTIC control subsystem and control module were developed to improve power supply performance during static and dynamic input voltage and output load variations, to reduce output voltage or current regulation due to component variations or aging, to maintain a stable feedback control with variations in the loop gain or loop time constants, and to standardize the feedback control subsystem for power conditioning equipment.

Field programmable gate array-assigned complex-valued computation and its limits

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

Bernard-Schwarz, Maria, E-mail: maria.bernardschwarz@ni.com; Institute of Applied Physics, TU Wien, Wiedner Hauptstrasse 8, 1040 Wien; Zwick, Wolfgang

We discuss how leveraging Field Programmable Gate Array (FPGA) technology as part of a high performance computing platform reduces latency to meet the demanding real time constraints of a quantum optics simulation. Implementations of complex-valued operations using fixed point numeric on a Virtex-5 FPGA compare favorably to more conventional solutions on a central processing unit. Our investigation explores the performance of multiple fixed point options along with a traditional 64 bits floating point version. With this information, the lowest execution times can be estimated. Relative error is examined to ensure simulation accuracy is maintained.

Method for improving performance of high temperature superconductors within a magnetic field

DOEpatents

Wang, Haiyan; Foltyn, Stephen R.; Maiorov, Boris A.; Civale, Leonardo

2010-01-05

The present invention provides articles including a base substrate including a layer of an oriented cubic oxide material having a rock-salt-like structure layer thereon; and, a buffer layer upon the oriented cubic oxide material having a rock-salt-like structure layer, the buffer layer having an outwardly facing surface with a surface morphology including particulate outgrowths of from 10 nm to 500 run in size at the surface, such particulate outgrowths serving as flux pinning centers whereby the article maintains higher performance within magnetic fields than similar articles without the necessary density of such outgrowths.

Scanner baseliner monitoring and control in high volume manufacturing

NASA Astrophysics Data System (ADS)

Samudrala, Pavan; Chung, Woong Jae; Aung, Nyan; Subramany, Lokesh; Gao, Haiyong; Gomez, Juan-Manuel

2016-03-01

We analyze performance of different customized models on baseliner overlay data and demonstrate the reduction in overlay residuals by ~10%. Smart Sampling sets were assessed and compared with the full wafer measurements. We found that performance of the grid can still be maintained by going to one-third of total sampling points, while reducing metrology time by 60%. We also demonstrate the feasibility of achieving time to time matching using scanner fleet manager and thus identify the tool drifts even when the tool monitoring controls are within spec limits. We also explore the scanner feedback constant variation with illumination sources.

ASDTIC - A feedback control innovation.

NASA Technical Reports Server (NTRS)

Lalli, V. R.; Schoenfeld, A. D.

1972-01-01

The ASDTIC (analog signal to discrete time interval converter) control subsystem provides precise output control of high performance aerospace power supplies. The key to ASDTIC operation is that it stably controls output by sensing output energy change as well as output magnitude. The ASDTIC control subsystem and control module were developed to improve power supply performance during static and dynamic input voltage and output load variations, to reduce output voltage or current regulation due to component variations or aging, to maintain a stable feedback control with variations in the loop gain or loop time constants, and to standardize the feedback control subsystem for power conditioning equipment.

Computing a Comprehensible Model for Spam Filtering

NASA Astrophysics Data System (ADS)

Ruiz-Sepúlveda, Amparo; Triviño-Rodriguez, José L.; Morales-Bueno, Rafael

In this paper, we describe the application of the Desicion Tree Boosting (DTB) learning model to spam email filtering.This classification task implies the learning in a high dimensional feature space. So, it is an example of how the DTB algorithm performs in such feature space problems. In [1], it has been shown that hypotheses computed by the DTB model are more comprehensible that the ones computed by another ensemble methods. Hence, this paper tries to show that the DTB algorithm maintains the same comprehensibility of hypothesis in high dimensional feature space problems while achieving the performance of other ensemble methods. Four traditional evaluation measures (precision, recall, F1 and accuracy) have been considered for performance comparison between DTB and others models usually applied to spam email filtering. The size of the hypothesis computed by a DTB is smaller and more comprehensible than the hypothesis computed by Adaboost and Naïve Bayes.

Fabrication of PVDF-TrFE based bilayered PbTiO3/PVDF-TrFE films capacitor

NASA Astrophysics Data System (ADS)

Nurbaya, Z.; Wahid, M. H.; Rozana, M. D.; Annuar, I.; Alrokayan, S. A. H.; Khan, H. A.; Rusop, M.

2016-07-01

Development of high performance capacitor is reaching towards new generation where the ferroelectric materials take places as the active dielectric layer. The motivation of this study is to produce high capacitance device with long life cycle. This was configured by preparing bilayered films where lead titanate as an active dielectric layer and stacked with the top dielectric layer, poly(vinyledenefluoride-trifluoroethylene). Both of them are being referred that have one in common which is ferroelectric behavior. Therefore the combination of ceramic and polymer ferroelectric material could perform optimum dielectric characteristic for capacitor applications. The fabrication was done by simple sol-gel spin coating method that being varied at spinning speed property for polymer layers, whereas maintaining the ceramic layer. The characterization of PVDF-TrFE/PbTiO3 was performed according to metal-insulator-metal stacked capacitor measurement which includes structural, dielectric, and ferroelectric measurement.

Integrated numerical modeling of a laser gun injector

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

Liu, H.; Benson, S.; Bisognano, J.

1993-06-01

CEBAF is planning to incorporate a laser gun injector into the linac front end as a high-charge cw source for a high-power free electron laser and nuclear physics. This injector consists of a DC laser gun, a buncher, a cryounit and a chicane. The performance of the injector is predicted based on integrated numerical modeling using POISSON, SUPERFISH and PARMELA. The point-by-point method incorporated into PARMELA by McDonald is chosen for space charge treatment. The concept of ``conditioning for final bunching`` is employed to vary several crucial parameters of the system for achieving highest peak current while maintaining low emittancemore » and low energy spread. Extensive parameter variation studies show that the design will perform beyond the specifications for FEL operations aimed at industrial applications and fundamental scientific research. The calculation also shows that the injector will perform as an extremely bright cw electron source.« less

Photonic crystal fiber technology for high-performance all-fiber monolithic ultrafast fiber amplifiers

NASA Astrophysics Data System (ADS)

Papior, Sidsel R.; Weirich, Johannes; Johansen, Mette M.; Jakobsen, Christian; Michieletto, Mattia; Triches, Marco; Kristensen, Torben; Olesen, Anders S.; Petersen, Christian; Andersen, Thomas V.; Maack, Martin D.; Alkeskjold, Thomas T.

2018-02-01

Photonic crystal fiber (PCF) technology for ultrafast fiber amplifiers traditionally uses air holes as key elements for large mode area (LMA) fiber designs. These air holes are crucial for the performance of high-end LMA PCFs, but makes splicing and interfacing more complex. To reduce this complexity in mid-range amplifiers, we present single-mode polarization-maintaining Yb-doped LMA PCFs without air holes for easier splicing into monolithic all-fiber amplifier designs. A 30 μm core all-solid spliceable PCF is presented, and amplification of 1064 nm light above 50 W with an optical to optical efficiency of 80 % is demonstrated. Furthermore, to demonstrate the excellent reliability of PCF based monolithic amplifiers, we demonstrate ultra-longterm performance data of > 35 khrs on a 14 μm core step-index type PCF amplifier with low long-term power degradation slope of < 1.5 % / 10,000 h.

Optimized Carbonate and Ester-Based Li-Ion Electrolytes

NASA Technical Reports Server (NTRS)

Smart, Marshall; Bugga, Ratnakumar

2008-01-01

To maintain high conductivity in low temperatures, electrolyte co-solvents have been designed to have a high dielectric constant, low viscosity, adequate coordination behavior, and appropriate liquid ranges and salt solubilities. Electrolytes that contain ester-based co-solvents in large proportion (greater than 50 percent) and ethylene carbonate (EC) in small proportion (less than 20 percent) improve low-temperature performance in MCMB carbon-LiNiCoO2 lithium-ion cells. These co-solvents have been demonstrated to enhance performance, especially at temperatures down to 70 C. Low-viscosity, ester-based co-solvents were incorporated into multi-component electrolytes of the following composition: 1.0 M LiPF6 in ethylene carbonate (EC) + ethyl methyl carbonate (EMC) + X (1:1:8 volume percent) [where X = methyl butyrate (MB), ethyl butyrate EB, methyl propionate (MP), or ethyl valerate (EV)]. These electrolyte formulations result in improved low-temperature performance of lithium-ion cells, with dramatic results at temperatures below 40 C.

High-Performance Lithium-Air Battery with a Coaxial-Fiber Architecture.

PubMed

Zhang, Ye; Wang, Lie; Guo, Ziyang; Xu, Yifan; Wang, Yonggang; Peng, Huisheng

2016-03-24

The lithium-air battery has been proposed as the next-generation energy-storage device with a much higher energy density compared with the conventional lithium-ion battery. However, lithium-air batteries currently suffer enormous problems including parasitic reactions, low recyclability in air, degradation, and leakage of liquid electrolyte. Besides, they are designed into a rigid bulk structure that cannot meet the flexible requirement in the modern electronics. Herein, for the first time, a new family of fiber-shaped lithium-air batteries with high electrochemical performances and flexibility has been developed. The battery exhibited a discharge capacity of 12,470 mAh g(-1) and could stably work for 100 cycles in air; its electrochemical performances were well maintained under bending and after bending. It was also wearable and formed flexible power textiles for various electronic devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Estimating Driving Performance Based on EEG Spectrum Analysis

NASA Astrophysics Data System (ADS)

Lin, Chin-Teng; Wu, Ruei-Cheng; Jung, Tzyy-Ping; Liang, Sheng-Fu; Huang, Teng-Yi

2005-12-01

The growing number of traffic accidents in recent years has become a serious concern to society. Accidents caused by driver's drowsiness behind the steering wheel have a high fatality rate because of the marked decline in the driver's abilities of perception, recognition, and vehicle control abilities while sleepy. Preventing such accidents caused by drowsiness is highly desirable but requires techniques for continuously detecting, estimating, and predicting the level of alertness of drivers and delivering effective feedbacks to maintain their maximum performance. This paper proposes an EEG-based drowsiness estimation system that combines electroencephalogram (EEG) log subband power spectrum, correlation analysis, principal component analysis, and linear regression models to indirectly estimate driver's drowsiness level in a virtual-reality-based driving simulator. Our results demonstrated that it is feasible to accurately estimate quantitatively driving performance, expressed as deviation between the center of the vehicle and the center of the cruising lane, in a realistic driving simulator.

Optimization of the scan protocols for CT-based material extraction in small animal PET/CT studies

NASA Astrophysics Data System (ADS)

Yang, Ching-Ching; Yu, Jhih-An; Yang, Bang-Hung; Wu, Tung-Hsin

2013-12-01

We investigated the effects of scan protocols on CT-based material extraction to minimize radiation dose while maintaining sufficient image information in small animal studies. The phantom simulation experiments were performed with the high dose (HD), medium dose (MD) and low dose (LD) protocols at 50, 70 and 80 kVp with varying mA s. The reconstructed CT images were segmented based on Hounsfield unit (HU)-physical density (ρ) calibration curves and the dual-energy CT-based (DECT) method. Compared to the (HU;ρ) method performed on CT images acquired with the 80 kVp HD protocol, a 2-fold improvement in segmentation accuracy and a 7.5-fold reduction in radiation dose were observed when the DECT method was performed on CT images acquired with the 50/80 kVp LD protocol, showing the possibility to reduce radiation dose while achieving high segmentation accuracy.

Kinetics and intrapulmonary disposition of tilmicosin after single and repeated oral bolus administrations to rabbits.

PubMed

Gallina, G; Lucatello, L; Drigo, I; Cocchi, M; Scandurra, S; Agnoletti, F; Montesissa, C

2010-06-01

Tilmicosin (TIM, Pulmotil) was administered to eight rabbits by oral gavage at a dose of 12.5 mg/kg body weight for 2, 5, and 7 days, and its plasma kinetics and intrapulmonary disposition were investigated. TIM concentrations in plasma samples collected after days 1 and 6 of treatment were measured by high-performance liquid chromatography with ultraviolet detection. The pharmacokinetic parameters, obtained by non-compartmental analysis of TIM plasma concentrations, did not show any significant variations between days 1 and 6. From the second day of treatment, TIM concentrations attained in lung tissue and pulmonary alveolar macrophages (PAM) exceeded those in plasma by 7- and 400-fold, respectively, and high levels were maintained in lung tissues during the entire treatment duration. After the first day of withdrawal, a fast decline in TIM levels in both plasma and lung tissue was observed, but in PAM, much higher concentrations were maintained after 3 days of TIM withdrawal.

Energy Efficient Image/Video Data Transmission on Commercial Multi-Core Processors

PubMed Central

Lee, Sungju; Kim, Heegon; Chung, Yongwha; Park, Daihee

2012-01-01

In transmitting image/video data over Video Sensor Networks (VSNs), energy consumption must be minimized while maintaining high image/video quality. Although image/video compression is well known for its efficiency and usefulness in VSNs, the excessive costs associated with encoding computation and complexity still hinder its adoption for practical use. However, it is anticipated that high-performance handheld multi-core devices will be used as VSN processing nodes in the near future. In this paper, we propose a way to improve the energy efficiency of image and video compression with multi-core processors while maintaining the image/video quality. We improve the compression efficiency at the algorithmic level or derive the optimal parameters for the combination of a machine and compression based on the tradeoff between the energy consumption and the image/video quality. Based on experimental results, we confirm that the proposed approach can improve the energy efficiency of the straightforward approach by a factor of 2∼5 without compromising image/video quality. PMID:23202181

Maintaining work capacity in the aged worker via progressive resistance training: the implications for occupational therapy practitioners.

PubMed

Branch, N G

1998-01-01

Society has an interest in maintaining the work capacity of its aging workers. Fewer and fewer younger workers are entering the workforce to replace older citizens no longer able to perform the worker role. There is a demonstrated relationship between increased strength and work capacity, yet the occupational therapy literature emphasizes generalized exercise programming. This type of programming is ineffective at building strength in the elderly worker. High intensity progressive resistance exercise (PRE) can increase strength in the very old worker, yet therapists are hesitant to employ PRE, perhaps due to a potential bias against the use of high intensity PRE with this cohort. Use of PRE may present some difficulties in the clinical situation where continual supervision and resistance training equipment is not available. The adaptive use of functional activities as a resistance training strategy to build strength may be able to overcome the difficulties attendant with the use of PRE while preserving its benefits. Several other implications for occupational therapy practitioners are discussed.

Thermally stable, highly efficient, ultraflexible organic photovoltaics

PubMed Central

Xu, Xiaomin; Fukuda, Kenjiro; Karki, Akchheta; Park, Sungjun; Kimura, Hiroki; Jinno, Hiroaki; Watanabe, Nobuhiro; Yamamoto, Shuhei; Shimomura, Satoru; Kitazawa, Daisuke; Yokota, Tomoyuki; Umezu, Shinjiro; Nguyen, Thuc-Quyen; Someya, Takao

2018-01-01

Flexible photovoltaics with extreme mechanical compliance present appealing possibilities to power Internet of Things (IoT) sensors and wearable electronic devices. Although improvement in thermal stability is essential, simultaneous achievement of high power conversion efficiency (PCE) and thermal stability in flexible organic photovoltaics (OPVs) remains challenging due to the difficulties in maintaining an optimal microstructure of the active layer under thermal stress. The insufficient thermal capability of a plastic substrate and the environmental influences cannot be fully expelled by ultrathin barrier coatings. Here, we have successfully fabricated ultraflexible OPVs with initial efficiencies of up to 10% that can endure temperatures of over 100 °C, maintaining 80% of the initial efficiency under accelerated testing conditions for over 500 hours in air. Particularly, we introduce a low-bandgap poly(benzodithiophene-cothieno[3,4-b]thiophene) (PBDTTT) donor polymer that forms a sturdy microstructure when blended with a fullerene acceptor. We demonstrate a feasible way to adhere ultraflexible OPVs onto textiles through a hot-melt process without causing severe performance degradation. PMID:29666257

Attitude maneuvers of a solar-powered electric orbital transfer vehicle

NASA Astrophysics Data System (ADS)

Jenkin, Alan B.

1992-08-01

Attitude maneuver requirements of a solar-powered electric orbital transfer vehicle have been studied in detail. This involved evaluation of the yaw, pitch, and roll profiles and associated angular accelerations needed to simultaneously steer the vehicle thrust vector and maintain the solar array pointed toward the sun. Maintaining the solar array pointed exactly at the sun leads to snap roll maneuvers which have very high (theoretically unbounded) accelerations, thereby imposing large torque requirements. The problem is exacerbated by the large solar arrays which are needed to generate the high levels of power needed by electric propulsion devices. A method of eliminating the snap roll maneuvers is presented. The method involves the determination of relaxed roll profiles which approximate a forced transition between alternate exact roll profiles and incur only small errors in solar array pointing. The method makes it feasible to perform the required maneuvers using currently available attitude control technology such as reaction wheels, hot gas jets, or gimballed main engines.

GPU Accelerated Prognostics

NASA Technical Reports Server (NTRS)

Gorospe, George E., Jr.; Daigle, Matthew J.; Sankararaman, Shankar; Kulkarni, Chetan S.; Ng, Eley

2017-01-01

Prognostic methods enable operators and maintainers to predict the future performance for critical systems. However, these methods can be computationally expensive and may need to be performed each time new information about the system becomes available. In light of these computational requirements, we have investigated the application of graphics processing units (GPUs) as a computational platform for real-time prognostics. Recent advances in GPU technology have reduced cost and increased the computational capability of these highly parallel processing units, making them more attractive for the deployment of prognostic software. We present a survey of model-based prognostic algorithms with considerations for leveraging the parallel architecture of the GPU and a case study of GPU-accelerated battery prognostics with computational performance results.

Improved performance of the microbial electrolysis desalination and chemical-production cell with enlarged anode and high applied voltages.

PubMed

Ye, Bo; Luo, Haiping; Lu, Yaobin; Liu, Guangli; Zhang, Renduo; Li, Xiao

2017-11-01

The aim of this study was to improve performance of the microbial electrolysis desalination and chemical-production cell (MEDCC) using enlarged anode and high applied voltages. MEDCCs with anode lengths of 9 and 48cm (i.e., the 9cm-anode MEDCC and 48cm-anode MEDCC, respectively) were tested under different voltages (1.2-3.0V). Our results demonstrated for the first time that the MEDCC could maintain high performance even under the applied voltage higher than that for water dissociation (i.e., 1.8V). Under the applied voltage of 2.5V, the maximum current density in the 48cm-anode MEDCC reached 32.8±2.6A/m 2 , which is one of the highest current densities reported so far in the bioelectrochemical system (BES). The relative abundance of Geobacter was changed along the anode length. Our results show the great potential of the BES with enlarged anode and high applied voltages. Copyright © 2017 Elsevier Ltd. All rights reserved.

In-situ growth of high-performance all-solid-state electrode for flexible supercapacitors based on carbon woven fabric/ polyaniline/ graphene composite

NASA Astrophysics Data System (ADS)

Lin, Yingxi; Zhang, Haiyan; Deng, Wentao; Zhang, Danfeng; Li, Na; Wu, Qibai; He, Chunhua

2018-04-01

For the development of wearable electronic devices, it is crucial to develop energy storage components combining high-capacity and flexibility. Herein, an all-solid-state supercapacitor is prepared through an in-situ "growth and wrapping" method. The electrode contains polyaniline deposited on a carbon woven fabric and wrapped with a graphene-based envelop. The hybrid electrode exhibits excellent mechanical and electrochemical performance. The optimized few layer graphene wrapping layer provides for a conductive network, which effectively enhances the cycling stability as 88.9% of the starting capacitance is maintained after 5000 charge/discharge cycles. Furthermore, the assembled device delivers a high areal capacity (of 790 F cm-2) at the current density of 1 A cm-2, a high areal energy (28.21 uWh cm-2) at the power densities of 0.12 mW cm-2 and shows no significant decrease in the performance with a bending angle of 180°. This unique flexible supercapacitor thus exhibits great potential for wearable electronics.

A multifunctional biphasic water splitting catalyst tailored for integration with high-performance semiconductor photoanodes

DOE PAGES

Yang, Jinhui; Cooper, Jason K.; Toma, Francesca M.; ...

2016-11-07

Artificial photosystems are advanced by the development of conformal catalytic materials that promote desired chemical transformations, while also maintaining stability and minimizing parasitic light absorption for integration on surfaces of semiconductor light absorbers. We demonstrate that multifunctional, nanoscale catalysts that enable high-performance photoelectrochemical energy conversion can be engineered by plasma-enhanced atomic layer deposition. The collective properties of tailored Co 3 O 4 /Co(OH) 2 thin films simultaneously provide high activity for water splitting, permit efficient interfacial charge transport from semiconductor substrates, and enhance durability of chemically sensitive interfaces. Furthermore, these films comprise compact and continuous nanocrystalline Co 3 O 4more » spinel that is impervious to phase transformation and impermeable to ions, thereby providing effective protection of the underlying substrate. Moreover, a secondary phase of structurally disordered and chemically labile Co(OH) 2 is introduced to ensure a high concentration of catalytically active sites. Application of this coating to photovoltaic p + n-Si junctions yields best reported performance characteristics for crystalline Si photoanodes.« less

Position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and athletic performance.

PubMed

Rodriguez, Nancy R; DiMarco, Nancy M; Langley, Susie

2009-03-01

It is the position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine that physical activity, athletic performance, and recovery from exercise are enhanced by optimal nutrition. These organizations recommend appropriate selection of foods and fluids, timing of intake, and supplement choices for optimal health and exercise performance. This updated position paper couples a rigorous, systematic, evidence-based analysis of nutrition and performance-specific literature with current scientific data related to energy needs, assessment of body composition, strategies for weight change, nutrient and fluid needs, special nutrient needs during training and competition, the use of supplements and ergogenic aids, nutrition recommendations for vegetarian athletes, and the roles and responsibilities of sports dietitians. Energy and macronutrient needs, especially carbohydrate and protein, must be met during times of high physical activity to maintain body weight, replenish glycogen stores, and provide adequate protein to build and repair tissue. Fat intake should be sufficient to provide the essential fatty acids and fat-soluble vitamins, as well as contribute energy for weight maintenance. Although exercise performance can be affected by body weight and composition, these physical measures should not be a criterion for sports performance and daily weigh-ins are discouraged. Adequate food and fluid should be consumed before, during, and after exercise to help maintain blood glucose concentration during exercise, maximize exercise performance, and improve recovery time. Athletes should be well hydrated before exercise and drink enough fluid during and after exercise to balance fluid losses. Sports beverages containing carbohydrates and electrolytes may be consumed before, during, and after exercise to help maintain blood glucose concentration, provide fuel for muscles, and decrease risk of dehydration and hyponatremia. Vitamin and mineral supplements are not needed if adequate energy to maintain body weight is consumed from a variety of foods. However, athletes who restrict energy intake, use severe weight-loss practices, eliminate one or more food groups from their diet, or consume unbalanced diets with low micronutrient density, may require supplements. Because regulations specific to nutritional ergogenic aids are poorly enforced, they should be used with caution, and only after careful product evaluation for safety, efficacy, potency, and legality. A qualified sports dietitian and in particular in the United States, a Board Certified Specialist in Sports Dietetics, should provide individualized nutrition direction and advice subsequent to a comprehensive nutrition assessment.

Scalable 96-well Plate Based iPSC Culture and Production Using a Robotic Liquid Handling System.

PubMed

Conway, Michael K; Gerger, Michael J; Balay, Erin E; O'Connell, Rachel; Hanson, Seth; Daily, Neil J; Wakatsuki, Tetsuro

2015-05-14

Continued advancement in pluripotent stem cell culture is closing the gap between bench and bedside for using these cells in regenerative medicine, drug discovery and safety testing. In order to produce stem cell derived biopharmaceutics and cells for tissue engineering and transplantation, a cost-effective cell-manufacturing technology is essential. Maintenance of pluripotency and stable performance of cells in downstream applications (e.g., cell differentiation) over time is paramount to large scale cell production. Yet that can be difficult to achieve especially if cells are cultured manually where the operator can introduce significant variability as well as be prohibitively expensive to scale-up. To enable high-throughput, large-scale stem cell production and remove operator influence novel stem cell culture protocols using a bench-top multi-channel liquid handling robot were developed that require minimal technician involvement or experience. With these protocols human induced pluripotent stem cells (iPSCs) were cultured in feeder-free conditions directly from a frozen stock and maintained in 96-well plates. Depending on cell line and desired scale-up rate, the operator can easily determine when to passage based on a series of images showing the optimal colony densities for splitting. Then the necessary reagents are prepared to perform a colony split to new plates without a centrifugation step. After 20 passages (~3 months), two iPSC lines maintained stable karyotypes, expressed stem cell markers, and differentiated into cardiomyocytes with high efficiency. The system can perform subsequent high-throughput screening of new differentiation protocols or genetic manipulation designed for 96-well plates. This technology will reduce the labor and technical burden to produce large numbers of identical stem cells for a myriad of applications.

Does greater specific leaf area plasticity help plants to maintain a high performance when shaded?

PubMed

Liu, Yanjie; Dawson, Wayne; Prati, Daniel; Haeuser, Emily; Feng, Yanhao; van Kleunen, Mark

2016-12-01

It is frequently assumed that phenotypic plasticity can be very advantageous for plants, because it may increase environmental tolerance (fitness homeostasis). This should, however, only hold for plastic responses that are adaptive, i.e. increase fitness. Numerous studies have shown shade-induced increases in specific leaf area (SLA), and there is wide consensus that this plastic response optimizes light capture and thus has to be adaptive. However, it has rarely been tested whether this is really the case. In order to identify whether SLA plasticity does contribute to the maintenance of high biomass of plant species under shaded conditions, a meta-analytical approach was employed. The data set included 280 species and 467 individual studies from 32 publications and two unpublished experiments. Plants increased their SLA by 55·4 % on average when shaded, while they decreased their biomass by 59·9 %. Species with a high SLA under high-light control conditions showed a significantly greater ability to maintain biomass production under shade overall. However, in contrast to the expectation of a positive relationship between SLA plasticity and maintenance of plant biomass, the results indicated that species with greater SLA plasticity were less able to maintain biomass under shade. Although a high SLA per se contributes to biomass homeostasis, there was no evidence that plasticity in SLA contributes to this. Therefore, it is argued that some of the plastic changes that are frequently thought to be adaptive might simply reflect passive responses to the environment, or result as by-products of adaptive plastic responses in other traits. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Performance during a strenuous swimming session is associated with high blood lactate: pyruvate ratio and hypoglycemia in fasted rats

PubMed Central

Travassos, P.B.; Godoy, G.; De Souza, H.M.; Curi, R.; Bazotte, R.B.

2018-01-01

The aim of this study was to investigate the effect of lactatemia elevation and glycemia reduction on strenuous swimming performance in fasted rats. Three rats were placed in a swimming tank at the same time. The first rat was removed immediately (control group) and the remaining ones were submitted to a strenuous swimming session. After the second rat was exhausted (Exh group), the third one was immediately removed from the water (Exe group). According to the period of time required for exhaustion, the rats were divided into four groups: low performance (3–7 min), low-intermediary performance (8–12 min), high-intermediary performance (13–17 min), and high performance (18–22 min). All rats were removed from the swimming tanks and immediately killed by decapitation for blood collection or anesthetized for liver perfusion experiments. Blood glucose, lactate, and pyruvate concentrations, blood lactate/pyruvate ratio, and liver lactate uptake and its conversion to glucose were evaluated. Exhaustion in low and low-intermediary performance were better associated with higher lactate/pyruvate ratio. On the other hand, exhaustion in high-intermediary and high performance was better associated with hypoglycemia. Lactate uptake and glucose production from lactate in livers from the Exe and Exh groups were maintained. We concluded that there is a time sequence in the participation of lactate/pyruvate ratio and hypoglycemia in performance during an acute strenuous swimming section in fasted rats. The liver had an important participation in preventing hyperlactatemia and hypoglycemia during swimming through lactate uptake and its conversion to glucose. PMID:29590261

Performance during a strenuous swimming session is associated with high blood lactate: pyruvate ratio and hypoglycemia in fasted rats.

PubMed

Travassos, P B; Godoy, G; De Souza, H M; Curi, R; Bazotte, R B

2018-03-26

The aim of this study was to investigate the effect of lactatemia elevation and glycemia reduction on strenuous swimming performance in fasted rats. Three rats were placed in a swimming tank at the same time. The first rat was removed immediately (control group) and the remaining ones were submitted to a strenuous swimming session. After the second rat was exhausted (Exh group), the third one was immediately removed from the water (Exe group). According to the period of time required for exhaustion, the rats were divided into four groups: low performance (3-7 min), low-intermediary performance (8-12 min), high-intermediary performance (13-17 min), and high performance (18-22 min). All rats were removed from the swimming tanks and immediately killed by decapitation for blood collection or anesthetized for liver perfusion experiments. Blood glucose, lactate, and pyruvate concentrations, blood lactate/pyruvate ratio, and liver lactate uptake and its conversion to glucose were evaluated. Exhaustion in low and low-intermediary performance were better associated with higher lactate/pyruvate ratio. On the other hand, exhaustion in high-intermediary and high performance was better associated with hypoglycemia. Lactate uptake and glucose production from lactate in livers from the Exe and Exh groups were maintained. We concluded that there is a time sequence in the participation of lactate/pyruvate ratio and hypoglycemia in performance during an acute strenuous swimming section in fasted rats. The liver had an important participation in preventing hyperlactatemia and hypoglycemia during swimming through lactate uptake and its conversion to glucose.

Hierarchical cobalt poly-phosphide hollow spheres as highly active and stable electrocatalysts for hydrogen evolution over a wide pH range

NASA Astrophysics Data System (ADS)

Wu, Tianli; Pi, Mingyu; Wang, Xiaodeng; Guo, Weimeng; Zhang, Dingke; Chen, Shijian

2018-01-01

Exploring highly-efficient and low-cost non-noble metal electrocatalyst toward the hydrogen evolution reaction (HER) is highly desired for renewable energy system but remains challenging. In this work, three dimensional hierarchical porous cobalt poly-phosphide hollow spheres (CoP3 HSs) were prepared by topotactic phosphidation of the cobalt-based precursor via vacuum encapsulation technique. As a porous HER cathode, the CoP3 HSs delivers remarkable electrocatalytic performance over the wide pH range. It needs overpotentials of -69 mV and -118 mV with a small Tafel slope of 51 mV dec-1 to obtain current densities of 10 mA cm-2 and 50 mA cm-2, respectively, and maintains its electrocatalytic performance over 30 h in acidic solution. In addition, CoP3 also exhibit superior electrocatalytic performance and stability under neutral and alkaline conditions for the HER. Both experimental measurements and density functional theory (DFT) calculations are performed to explore the mechanism behind the excellent HER performance. The results of our study make the porous CoP3 HSs as a promising electrocatalyst for practical applications toward energy conversion system and present a new way for designing and fabricating HER electrodes through high degree of phosphorization and nano-porous architecture.

High-Contrast Coronagraph Performance in the Presence of DM Actuator Defects

NASA Technical Reports Server (NTRS)

Sidick, Erkin; Shaklan, Stuart; Cady, Eric

2015-01-01

Deformable Mirrors (DMs) are critical elements in high contrast coronagraphs, requiring precision and stability measured in picometers to enable detection of Earth-like exoplanets. Occasionally DM actuators or their associated cables or electronics fail, requiring a wavefront control algorithm to compensate for actuators that may be displaced from their neighbors by hundreds of nanometers. We have carried out experiments on our High-Contrast Imaging Testbed (HCIT) to study the impact of failed actuators in partial fulfillment of the Terrestrial Planet Finder Coronagraph optical model validation milestone. We show that the wavefront control algorithm adapts to several broken actuators and maintains dark-hole contrast in broadband light.

High-contrast coronagraph performance in the presence of DM actuator defects

NASA Astrophysics Data System (ADS)

Sidick, Erkin; Shaklan, Stuart; Cady, Eric

2015-09-01

Deformable Mirrors (DMs) are critical elements in high contrast coronagraphs, requiring precision and stability measured in picometers to enable detection of Earth-like exoplanets. Occasionally DM actuators or their associated cables or electronics fail, requiring a wavefront control algorithm to compensate for actuators that may be displaced from their neighbors by hundreds of nanometers. We have carried out experiments on our High-Contrast Imaging Testbed (HCIT) to study the impact of failed actuators in partial fulfilment of the Terrestrial Planet Finder Coronagraph optical model validation milestone. We show that the wavefront control algorithm adapts to several broken actuators and maintains dark-hole contrast in broadband light.

Information-theoretic CAD system in mammography: Entropy-based indexing for computational efficiency and robust performance

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

Tourassi, Georgia D.; Harrawood, Brian; Singh, Swatee

2007-08-15

We have previously presented a knowledge-based computer-assisted detection (KB-CADe) system for the detection of mammographic masses. The system is designed to compare a query mammographic region with mammographic templates of known ground truth. The templates are stored in an adaptive knowledge database. Image similarity is assessed with information theoretic measures (e.g., mutual information) derived directly from the image histograms. A previous study suggested that the diagnostic performance of the system steadily improves as the knowledge database is initially enriched with more templates. However, as the database increases in size, an exhaustive comparison of the query case with each stored templatemore » becomes computationally burdensome. Furthermore, blind storing of new templates may result in redundancies that do not necessarily improve diagnostic performance. To address these concerns we investigated an entropy-based indexing scheme for improving the speed of analysis and for satisfying database storage restrictions without compromising the overall diagnostic performance of our KB-CADe system. The indexing scheme was evaluated on two different datasets as (i) a search mechanism to sort through the knowledge database, and (ii) a selection mechanism to build a smaller, concise knowledge database that is easier to maintain but still effective. There were two important findings in the study. First, entropy-based indexing is an effective strategy to identify fast a subset of templates that are most relevant to a given query. Only this subset could be analyzed in more detail using mutual information for optimized decision making regarding the query. Second, a selective entropy-based deposit strategy may be preferable where only high entropy cases are maintained in the knowledge database. Overall, the proposed entropy-based indexing scheme was shown to reduce the computational cost of our KB-CADe system by 55% to 80% while maintaining the system's diagnostic performance.« less

Polarization-maintaining performance of large effective area, higher order modes fiber in a coiled configuration

NASA Astrophysics Data System (ADS)

Ahmad, Raja; Nicholson, Jeffrey W.; Abedin, Kazi S.; Westbrook, Paul S.; Headley, Clifford; Wisk, Patrick W.; Monberg, Eric M.; Yan, Man F.; DiGiovanni, David J.

2018-02-01

Scaling the power-level of fiber sources has many practical advantages, while also enabling fundamental studies on the light-matter interaction in amorphous guiding media. In order to scale the power-level of fiber-sources without encountering nonlinear impairments, a strategy is to increase the effective-area of the guided optical-mode. Increasing the effective-area of the fundamental mode in a fiber, however, presents the challenges of increased susceptibility to mode-distortion and effective-area-reduction under the influence of bends. Therefore, higher-order-mode (HOM) fibers, which guide light in large effective-area (Aeff) Bessel-like modes, are a good candidate for scaling the power-level of robust fiber-sources. Many applications of high-power fiber-sources also demand a deterministic control on the polarization-state of light. Furthermore, a polarization-maintaining (PM)-type HOM fiber can afford the added possibility of coherent-beam combination and polarization multiplexing of high-power fiber-lasers. Previously, we reported polarization-maintaining operation in a 1.3 m length of PM-HOM fiber that was held straight. The PM-HOM fiber guided Bessel-like modes with Aeff ranging from 1200-2800 μm2. In this work, we report, for the first time, that the polarization-extinction-ratio (PER) of the HOM exceeds 10 dB in an 8 m long fiber that is coiled down to a diameter of 40 cm. This opens a path towards compact and polarization-controlled high-power fiber-systems.

Turbomachine Sealing and Secondary Flows. Part 1; Review of Sealing Performance, Customer, Engine Designer, and Research Issues

NASA Technical Reports Server (NTRS)

Hendricks, R. C.; Steinetz, B. M.; Braun, M. J.

2004-01-01

Although forces outside our control shape our industry, turbomachine sealing research, design, and customer agendas established in 1978 by Ludwig, Campbell, and Smith in terms of specific fuel consumption and performance remain as objectives today. Advances have been made because failures of the space shuttle main engine turbomachinery ushered in a new understanding of sealing in high-power-density systems. Further, it has been shown that changes in sealing, especially for high-pressure rotors, dramatically change the performance of the entire engine or turbomachine. Maintaining seal leakages and secondary flows within engine design specifications remains the most efficient and cost effective way to enhance performance and minimize maintenance costs. This three-part review summarizes experiences, ideas, successes, and failures by NASA and the U.S. aerospace industry in secondary flow management in advanced turbomachinery. Part 1 presents system sealing, part 2 system rotordynamics, and part 3 modeling, with some overlap of each part.

An integrated framework for high level design of high performance signal processing circuits on FPGAs

NASA Astrophysics Data System (ADS)

Benkrid, K.; Belkacemi, S.; Sukhsawas, S.

2005-06-01

This paper proposes an integrated framework for the high level design of high performance signal processing algorithms' implementations on FPGAs. The framework emerged from a constant need to rapidly implement increasingly complicated algorithms on FPGAs while maintaining the high performance needed in many real time digital signal processing applications. This is particularly important for application developers who often rely on iterative and interactive development methodologies. The central idea behind the proposed framework is to dynamically integrate high performance structural hardware description languages with higher level hardware languages in other to help satisfy the dual requirement of high level design and high performance implementation. The paper illustrates this by integrating two environments: Celoxica's Handel-C language, and HIDE, a structural hardware environment developed at the Queen's University of Belfast. On the one hand, Handel-C has been proven to be very useful in the rapid design and prototyping of FPGA circuits, especially control intensive ones. On the other hand, HIDE, has been used extensively, and successfully, in the generation of highly optimised parameterisable FPGA cores. In this paper, this is illustrated in the construction of a scalable and fully parameterisable core for image algebra's five core neighbourhood operations, where fully floorplanned efficient FPGA configurations, in the form of EDIF netlists, are generated automatically for instances of the core. In the proposed combined framework, highly optimised data paths are invoked dynamically from within Handel-C, and are synthesized using HIDE. Although the idea might seem simple prima facie, it could have serious implications on the design of future generations of hardware description languages.

Position Control of Tendon-Driven Fingers

NASA Technical Reports Server (NTRS)

Abdallah, Muhammad E.; Platt, Robert, Jr.; Hargrave, B.; Pementer, Frank

2011-01-01

Conventionally, tendon-driven manipulators implement some force control scheme based on tension feedback. This feedback allows the system to ensure that the tendons are maintained taut with proper levels of tensioning at all times. Occasionally, whether it is due to the lack of tension feedback or the inability to implement sufficiently high stiffnesses, a position control scheme is needed. This work compares three position controllers for tendon-driven manipulators. A new controller is introduced that achieves the best overall performance with regards to speed, accuracy, and transient behavior. To compensate for the lack of tension feedback, the controller nominally maintains the internal tension on the tendons by implementing a two-tier architecture with a range-space constraint. These control laws are validated experimentally on the Robonaut-2 humanoid hand. I

[Therapeutic strategies against myasthenia gravis].

PubMed

Utsugisawa, Kimiaki; Nagane, Yuriko

2013-05-01

Many patients with myasthenia gravis (MG) still find it difficult to maintain daily activities due to chronic residual fatigability and long-term side effects of oral corticosteroids, since full remission is not common. Our analysis demonstrated that disease severity, oral corticosteroids, and depressive state are the major factors negatively associated with QOL, and that QOL of MM status patients taking < or = 5 mg prednisolne/day is identically good as that seen in CSR and is a target of treatment. In order to achieve early MM or better status with prednisolne < or = 5 mg/day, we advocate the early aggressive treatment strategy that can achieve early improvement by performing an aggressive therapy using combined treatment with plasmapheresis and high-dose intravenous methylprednisolone and then maintain an improved status using low-dose oral corticosteroids and calcineurin inhibitors.

Mode evolution in polarization maintain few mode fibers and applications in mode-division-multiplexing systems

NASA Astrophysics Data System (ADS)

Li, Yan; Zeng, Xinglin; Mo, Qi; Li, Wei; Liu, Zhijian; Wu, Jian

2016-10-01

In few-mode polarization-maintaining-fiber (FM-PMF), the effective-index splitting exists not only between orthogonally polarization state but also between degenerated modes within a high-order mode group. Hence besides the polarization state evolution, the mode patterns in each LP set are need to be analyzed. In this letter, the completed firstorder mode (LP11 mode) evolution in PM-FMF is analyzed and represented by analogous Jones vector and Poincarésphere respectively. Furthermore, with Jones matrix analysis, the modal dynamics in FM-PMFs is conveniently analyzed. The conclusions are used to propose a PM-FMF based LP11 mode rotator and an PM-FMF based OAM generator. Both simulation and experiments are conducted to investigate performance of the two devices.

Albion: the UK 3rd generation high-performance thermal imaging programme

NASA Astrophysics Data System (ADS)

McEwen, R. K.; Lupton, M.; Lawrence, M.; Knowles, P.; Wilson, M.; Dennis, P. N. J.; Gordon, N. T.; Lees, D. J.; Parsons, J. F.

2007-04-01

The first generation of high performance thermal imaging sensors in the UK was based on two axis opto-mechanical scanning systems and small (4-16 element) arrays of the SPRITE detector, developed during the 1970s. Almost two decades later, a 2nd Generation system, STAIRS C was introduced, based on single axis scanning and a long linear array of approximately 3000 elements. The UK has now begun the industrialisation of 3 rd Generation High Performance Thermal Imaging under a programme known as "Albion". Three new high performance cadmium mercury telluride arrays are being manufactured. The CMT material is grown by MOVPE on low cost substrates and bump bonded to the silicon read out circuit (ROIC). To maintain low production costs, all three detectors are designed to fit with existing standard Integrated Detector Cooling Assemblies (IDCAs). The two largest focal planes are conventional devices operating in the MWIR and LWIR spectral bands. A smaller format LWIR device is also described which has a smart ROIC, enabling much longer stare times than are feasible with conventional pixel circuits, thus achieving very high sensitivity. A new reference surface technology for thermal imaging sensors is described, based on Negative Luminescence (NL), which offers several advantages over conventional peltier references, improving the quality of the Non-Uniformity Correction (NUC) algorithms.

High voltage performance of a dc photoemission electron gun with centrifugal barrel-polished electrodes

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

Hernandez-Garcia, C.; Bullard, D.; Hannon, F.

The design and fabrication of electrodes for direct current (dc) high voltage photoemission electron guns can significantly influence their performance, most notably in terms of maximum achievable bias voltage. Proper electrostatic design of the triple-point junction shield electrode minimizes the risk of electrical breakdown (arcing) along the insulator-cable plug interface, while the electrode shape is designed to maintain <10 MV/m at the desired operating voltage aiming at little or no field emission once conditioned. Typical electrode surface preparation involves diamond-paste polishing by skilled personnel, requiring several weeks of effort per electrode. In this work, we describe a centrifugal barrel-polishing techniquemore » commonly used for polishing the interior surface of superconducting radio frequency cavities but implemented here for the first time to polish electrodes for dc high voltage photoguns. The technique reduced polishing time from weeks to hours while providing surface roughness comparable to that obtained with diamond-paste polishing and with unprecedented consistency between different electrode samples. We present electrode design considerations and high voltage conditioning results to 360 kV (~11 MV/m), comparing barrel-polished electrode performance to that of diamond-paste polished electrodes. Here, tests were performed using a dc high voltage photogun with an inverted-geometry ceramic insulator design.« less

High voltage performance of a dc photoemission electron gun with centrifugal barrel-polished electrodes

DOE PAGES

Hernandez-Garcia, C.; Bullard, D.; Hannon, F.; ...

2017-09-11

The design and fabrication of electrodes for direct current (dc) high voltage photoemission electron guns can significantly influence their performance, most notably in terms of maximum achievable bias voltage. Proper electrostatic design of the triple-point junction shield electrode minimizes the risk of electrical breakdown (arcing) along the insulator-cable plug interface, while the electrode shape is designed to maintain <10 MV/m at the desired operating voltage aiming at little or no field emission once conditioned. Typical electrode surface preparation involves diamond-paste polishing by skilled personnel, requiring several weeks of effort per electrode. In this work, we describe a centrifugal barrel-polishing techniquemore » commonly used for polishing the interior surface of superconducting radio frequency cavities but implemented here for the first time to polish electrodes for dc high voltage photoguns. The technique reduced polishing time from weeks to hours while providing surface roughness comparable to that obtained with diamond-paste polishing and with unprecedented consistency between different electrode samples. We present electrode design considerations and high voltage conditioning results to 360 kV (~11 MV/m), comparing barrel-polished electrode performance to that of diamond-paste polished electrodes. Here, tests were performed using a dc high voltage photogun with an inverted-geometry ceramic insulator design.« less

High voltage performance of a dc photoemission electron gun with centrifugal barrel-polished electrodes

NASA Astrophysics Data System (ADS)

Hernandez-Garcia, C.; Bullard, D.; Hannon, F.; Wang, Y.; Poelker, M.

2017-09-01

The design and fabrication of electrodes for direct current (dc) high voltage photoemission electron guns can significantly influence their performance, most notably in terms of maximum achievable bias voltage. Proper electrostatic design of the triple-point junction shield electrode minimizes the risk of electrical breakdown (arcing) along the insulator-cable plug interface, while the electrode shape is designed to maintain <10 MV/m at the desired operating voltage aiming at little or no field emission once conditioned. Typical electrode surface preparation involves diamond-paste polishing by skilled personnel, requiring several weeks of effort per electrode. In this work, we describe a centrifugal barrel-polishing technique commonly used for polishing the interior surface of superconducting radio frequency cavities but implemented here for the first time to polish electrodes for dc high voltage photoguns. The technique reduced polishing time from weeks to hours while providing surface roughness comparable to that obtained with diamond-paste polishing and with unprecedented consistency between different electrode samples. We present electrode design considerations and high voltage conditioning results to 360 kV (˜11 MV/m), comparing barrel-polished electrode performance to that of diamond-paste polished electrodes. Tests were performed using a dc high voltage photogun with an inverted-geometry ceramic insulator design.

Automated condition-invariable neurite segmentation and synapse classification using textural analysis-based machine-learning algorithms

PubMed Central

Kandaswamy, Umasankar; Rotman, Ziv; Watt, Dana; Schillebeeckx, Ian; Cavalli, Valeria; Klyachko, Vitaly

2013-01-01

High-resolution live-cell imaging studies of neuronal structure and function are characterized by large variability in image acquisition conditions due to background and sample variations as well as low signal-to-noise ratio. The lack of automated image analysis tools that can be generalized for varying image acquisition conditions represents one of the main challenges in the field of biomedical image analysis. Specifically, segmentation of the axonal/dendritic arborizations in brightfield or fluorescence imaging studies is extremely labor-intensive and still performed mostly manually. Here we describe a fully automated machine-learning approach based on textural analysis algorithms for segmenting neuronal arborizations in high-resolution brightfield images of live cultured neurons. We compare performance of our algorithm to manual segmentation and show that it combines 90% accuracy, with similarly high levels of specificity and sensitivity. Moreover, the algorithm maintains high performance levels under a wide range of image acquisition conditions indicating that it is largely condition-invariable. We further describe an application of this algorithm to fully automated synapse localization and classification in fluorescence imaging studies based on synaptic activity. Textural analysis-based machine-learning approach thus offers a high performance condition-invariable tool for automated neurite segmentation. PMID:23261652

High-throughput, Highly Sensitive Analyses of Bacterial Morphogenesis Using Ultra Performance Liquid Chromatography*

PubMed Central

Desmarais, Samantha M.; Tropini, Carolina; Miguel, Amanda; Cava, Felipe; Monds, Russell D.; de Pedro, Miguel A.; Huang, Kerwyn Casey

2015-01-01

The bacterial cell wall is a network of glycan strands cross-linked by short peptides (peptidoglycan); it is responsible for the mechanical integrity of the cell and shape determination. Liquid chromatography can be used to measure the abundance of the muropeptide subunits composing the cell wall. Characteristics such as the degree of cross-linking and average glycan strand length are known to vary across species. However, a systematic comparison among strains of a given species has yet to be undertaken, making it difficult to assess the origins of variability in peptidoglycan composition. We present a protocol for muropeptide analysis using ultra performance liquid chromatography (UPLC) and demonstrate that UPLC achieves resolution comparable with that of HPLC while requiring orders of magnitude less injection volume and a fraction of the elution time. We also developed a software platform to automate the identification and quantification of chromatographic peaks, which we demonstrate has improved accuracy relative to other software. This combined experimental and computational methodology revealed that peptidoglycan composition was approximately maintained across strains from three Gram-negative species despite taxonomical and morphological differences. Peptidoglycan composition and density were maintained after we systematically altered cell size in Escherichia coli using the antibiotic A22, indicating that cell shape is largely decoupled from the biochemistry of peptidoglycan synthesis. High-throughput, sensitive UPLC combined with our automated software for chromatographic analysis will accelerate the discovery of peptidoglycan composition and the molecular mechanisms of cell wall structure determination. PMID:26468288

Pilot plant demonstration of stable and efficient high rate biological nutrient removal with low dissolved oxygen conditions.

PubMed

Keene, Natalie A; Reusser, Steve R; Scarborough, Matthew J; Grooms, Alan L; Seib, Matt; Santo Domingo, Jorge; Noguera, Daniel R

2017-09-15

Aeration in biological nutrient removal (BNR) processes accounts for nearly half of the total electricity costs at many wastewater treatment plants. Even though conventional BNR processes are usually operated to have aerated zones with high dissolved oxygen (DO) concentrations, recent research has shown that nitrification can be maintained using very low-DO concentrations (e.g., below 0.2 mg O 2 /L), and therefore, it may be possible to reduce energy use and costs in BNR facilities by decreasing aeration. However, the effect of reduced aeration on enhanced biological phosphorus removal (EBPR) is not understood. In this study, we investigated, at the pilot-scale level, the effect of using minimal aeration on the performance of an EBPR process. Over a 16-month operational period, we performed stepwise decreases in aeration, reaching an average DO concentration of 0.33 mg O 2 /L with stable operation and nearly 90% phosphorus removal. Under these low-DO conditions, nitrification efficiency was maintained, and nearly 70% of the nitrogen was denitrified, without the need for internal recycling of high nitrate aeration basin effluent to the anoxic zone. At the lowest DO conditions used, we estimate a 25% reduction in energy use for aeration compared to conventional BNR operation. Our improved understanding of the efficiency of low-DO BNR contributes to the global goal of reducing energy consumption during wastewater treatment operations. Copyright © 2017 Elsevier Ltd. All rights reserved.

High-Q Wafer Level Package Based on Modified Tri-Layer Anodic Bonding and High Performance Getter and Its Evaluation for Micro Resonant Pressure Sensor.

PubMed

Wang, Liying; Du, Xiaohui; Wang, Lingyun; Xu, Zhanhao; Zhang, Chenying; Gu, Dandan

2017-03-16

In order to achieve and maintain a high quality factor (high-Q) for the micro resonant pressure sensor, this paper presents a new wafer level package by adopting cross-layer anodic bonding technique of the glass/silicon/silica (GSS) stackable structure and integrated Ti getter. A double-layer structure similar to a silicon-on-insulator (SOI) wafer is formed after the resonant layer and the pressure-sensitive layer are bonded by silicon direct bonding (SDB). In order to form good bonding quality between the pressure-sensitive layer and the glass cap layer, the cross-layer anodic bonding technique is proposed for vacuum package by sputtering Aluminum (Al) on the combination wafer of the pressure-sensitive layer and the resonant layer to achieve electrical interconnection. The model and the bonding effect of this technique are discussed. In addition, in order to enhance the performance of titanium (Ti) getter, the prepared and activation parameters of Ti getter under different sputtering conditions are optimized and discussed. Based on the optimized results, the Ti getter (thickness of 300 nm to 500 nm) is also deposited on the inside of the glass groove by magnetron sputtering to maintain stable quality factor (Q). The Q test of the built testing system shows that the number of resonators with a Q value of more than 10,000 accounts for more than 73% of the total. With an interval of 1.5 years, the Q value of the samples remains almost constant. It proves the proposed cross-layer anodic bonding and getter technique can realize high-Q resonant structure for long-term stable operation.

Ultrahigh-power supercapacitors based on highly conductive graphene nanosheet/nanometer-sized carbide-derived carbon frameworks.

PubMed

Yan, Pengtao; Zhang, Xuesha; Hou, Meiling; Liu, Yanyan; Liu, Ting; Liu, Kang; Zhang, Ruijun

2018-06-22

In order to develop energy storage devices with high power performance, electrodes should hold well-defined pathways for efficient ionic and electronic transport. Herein, we demonstrate a highly conductive graphene nanosheet/nanometer-sized carbide-derived carbon framework (hcGNS/nCDC). In this architecture, nCDC possesses short transport paths for electrolyte ions, thus ensuring the rapid ions transportation. The excellent electrical conductivity of hcGNS can reduce the electrode internal resistance for the supercapacitor and thus endows the hcGNS/nCDC composite electrodes with excellent electronic transportation performance. Electrochemical measurements show that the cyclic voltammogram of hcGNS/nCDC can maintain a rectangular-like shape with the increase of the scan rate from 5 mV s -1 to 20 V s -1 , and the specific capacitance retention is up to 51% even at a high scan rate of 20 V s -1 , suggesting ultrahigh power performance, which, to the best of our knowledge, is among the best power performances reported so far for the carbon materials. Furthermore, the hcGNS/nCDC composite also shows an excellent cycling stability (no drop in its capacitance occurs even after 10000 cycles). This work demonstrates the advantage in the ultrahigh power performance for the framework having both short transport pathways for electrolyte ions and high electrical conductivity.

Ultrahigh-power supercapacitors based on highly conductive graphene nanosheet/nanometer-sized carbide-derived carbon frameworks

NASA Astrophysics Data System (ADS)

Yan, Pengtao; Zhang, Xuesha; Hou, Meiling; Liu, Yanyan; Liu, Ting; Liu, Kang; Zhang, Ruijun

2018-06-01

In order to develop energy storage devices with high power performance, electrodes should hold well-defined pathways for efficient ionic and electronic transport. Herein, we demonstrate a highly conductive graphene nanosheet/nanometer-sized carbide-derived carbon framework (hcGNS/nCDC). In this architecture, nCDC possesses short transport paths for electrolyte ions, thus ensuring the rapid ions transportation. The excellent electrical conductivity of hcGNS can reduce the electrode internal resistance for the supercapacitor and thus endows the hcGNS/nCDC composite electrodes with excellent electronic transportation performance. Electrochemical measurements show that the cyclic voltammogram of hcGNS/nCDC can maintain a rectangular-like shape with the increase of the scan rate from 5 mV s‑1 to 20 V s‑1, and the specific capacitance retention is up to 51% even at a high scan rate of 20 V s‑1, suggesting ultrahigh power performance, which, to the best of our knowledge, is among the best power performances reported so far for the carbon materials. Furthermore, the hcGNS/nCDC composite also shows an excellent cycling stability (no drop in its capacitance occurs even after 10000 cycles). This work demonstrates the advantage in the ultrahigh power performance for the framework having both short transport pathways for electrolyte ions and high electrical conductivity.

42 CFR 493.1425 - Standard; Testing personnel responsibilities.

Code of Federal Regulations, 2014 CFR

2014-10-01

... education, training or experience, and technical abilities. (b) Each individual performing moderate... analyses, reporting and maintaining records of patient test results; (2) Maintain records that demonstrate...

42 CFR 493.1425 - Standard; Testing personnel responsibilities.

Code of Federal Regulations, 2013 CFR

2013-10-01

... education, training or experience, and technical abilities. (b) Each individual performing moderate... analyses, reporting and maintaining records of patient test results; (2) Maintain records that demonstrate...

42 CFR 493.1425 - Standard; Testing personnel responsibilities.

Code of Federal Regulations, 2012 CFR

2012-10-01

... education, training or experience, and technical abilities. (b) Each individual performing moderate... analyses, reporting and maintaining records of patient test results; (2) Maintain records that demonstrate...

Gene expression cross-profiling in genetically modified industrial Saccharomyces cerevisiae strains during high-temperature ethanol production from xylose.

PubMed

Ismail, Ku Syahidah Ku; Sakamoto, Takatoshi; Hatanaka, Haruyo; Hasunuma, Tomohisa; Kondo, Akihiko

2013-01-10

Production of ethanol from xylose at high temperature would be an economical approach since it reduces risk of contamination and allows both the saccharification and fermentation steps in SSF to be running at elevated temperature. Eight recombinant xylose-utilizing Saccharomyces cerevisiae strains developed from industrial strains were constructed and subjected to high-temperature fermentation at 38 °C. The best performing strain was sun049T, which produced up to 15.2 g/L ethanol (63% of the theoretical production), followed by sun048T and sun588T, both with 14.1 g/L ethanol produced. Via transcriptomic analysis, expression profiling of the top three best ethanol producing strains compared to a negative control strain, sun473T, led to the discovery of genes in common that were regulated in the same direction. Identification of the 20 most highly up-regulated and the 20 most highly down-regulated genes indicated that the cells regulate their central metabolism and maintain the integrity of the cell walls in response to high temperature. We also speculate that cross-protection in the cells occurs, allowing them to maintain ethanol production at higher concentration under heat stress than the negative controls. This report provides further transcriptomics information in the interest of producing a robust microorganism for high-temperature ethanol production utilizing xylose. Copyright © 2012 Elsevier B.V. All rights reserved.

ATLID beam steering mechanism and derived new piezoelectric-based devices for optical applications

NASA Astrophysics Data System (ADS)

Bourgain, F.; Barillot, F.; Belly, C.; Claeyssen, F.

2015-09-01

In Space & Defence (as well as in many others fields), there is a trend for miniaturisation in active optics requiring new actuators. Applications also often require the ability to withstand high vibrations and shocks levels, as well as vacuum compatibility for space applications. A new generation of small and smart actuators such as piezoelectric (piezo) actuators, are resolving this trend, thanks to their capacity to offer high energy density and to support both extreme and various requirements. This paper first presents the BSM mechanism and its requirements, the technologies involved in the design and the validation campaign results. Secondly, a derived XY piezoelectric positioning stage based on the same APA® and associated Strain Gage sensing technology is presented with its associated performances. Finally, a new piezoelectric motor based on the APA® technology, which allows the combination of long stroke while maintaining high resolution positioning of optical elements, is presented with experimental performances.

Hierarchical porous poly (ether sulfone) membranes with excellent capacity retention for vanadium flow battery application

NASA Astrophysics Data System (ADS)

Chen, Dongju; Li, Dandan; Li, Xianfeng

2017-06-01

A hierarchical poly (ether sulfone) (PES) porous membrane is facilely fabricated via a hard template method for vanadium flow battery (VFB) application. The construction of this hierarchical porous membrane is prepared via removing templates (phenolphthalein). The pore size can be well controlled by optimizing the template content in the cast solution, ensuring the membrane conductivity and selectively. The prepared hierarchical porous membrane can combine high ion selectivity with high proton conductivity, which renders a good electrochemical performance in a VFB. The optimized hierarchical porous membrane shows a columbic efficiency of 94.52% and energy efficiency of 81.66% along with a superior ability to maintain stable capacity over extended cycling at a current density of 80 mA cm-2. The characteristics of low cost, proven chemical stability and high electrochemical performance afford the hierarchical PES porous membrane great prospect in VFB application.

Faunus: An object oriented framework for molecular simulation

PubMed Central

Lund, Mikael; Trulsson, Martin; Persson, Björn

2008-01-01

Background We present a C++ class library for Monte Carlo simulation of molecular systems, including proteins in solution. The design is generic and highly modular, enabling multiple developers to easily implement additional features. The statistical mechanical methods are documented by extensive use of code comments that – subsequently – are collected to automatically build a web-based manual. Results We show how an object oriented design can be used to create an intuitively appealing coding framework for molecular simulation. This is exemplified in a minimalistic C++ program that can calculate protein protonation states. We further discuss performance issues related to high level coding abstraction. Conclusion C++ and the Standard Template Library (STL) provide a high-performance platform for generic molecular modeling. Automatic generation of code documentation from inline comments has proven particularly useful in that no separate manual needs to be maintained. PMID:18241331

High sensitivity and specificity of clinical microscopy in rural health facilities in western Kenya under an external quality assurance program.

PubMed

Wafula, Rebeccah; Sang, Edna; Cheruiyot, Olympia; Aboto, Angeline; Menya, Diana; O'Meara, Wendy Prudhomme

2014-09-01

Microscopic diagnosis of malaria is a well-established and inexpensive technique that has the potential to provide accurate diagnosis of malaria infection. However, it requires both training and experience. Although it is considered the gold standard in research settings, the sensitivity and specificity of routine microscopy for clinical care in the primary care setting has been reported to be unacceptably low. We established a monthly external quality assurance program to monitor the performance of clinical microscopy in 17 rural health centers in western Kenya. The average sensitivity over the 12-month period was 96% and the average specificity was 88%. We identified specific contextual factors that contributed to inadequate performance. Maintaining high-quality malaria diagnosis in high-volume, resource-constrained health facilities is possible. © The American Society of Tropical Medicine and Hygiene.

The Case for Modular Redundancy in Large-Scale High Performance Computing Systems

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

Engelmann, Christian; Ong, Hong Hoe; Scott, Stephen L

2009-01-01

Recent investigations into resilience of large-scale high-performance computing (HPC) systems showed a continuous trend of decreasing reliability and availability. Newly installed systems have a lower mean-time to failure (MTTF) and a higher mean-time to recover (MTTR) than their predecessors. Modular redundancy is being used in many mission critical systems today to provide for resilience, such as for aerospace and command \\& control systems. The primary argument against modular redundancy for resilience in HPC has always been that the capability of a HPC system, and respective return on investment, would be significantly reduced. We argue that modular redundancy can significantly increasemore » compute node availability as it removes the impact of scale from single compute node MTTR. We further argue that single compute nodes can be much less reliable, and therefore less expensive, and still be highly available, if their MTTR/MTTF ratio is maintained.« less

Development of an Isolator System for PET Drug Compounding with Sterilization and Dispensing Units.

PubMed

Waki, Atsuo; Hashimoto, Yuuki; Suzuki, Hisashi; Mizukawa, Yousuke; Kinoshita, Toshiaki; Ichihara, Hironobu; Kaneko, Izumi; Iwakuma, Kazuko; Kawamura, Kazuki; Zhang, Ming-Rong; Fujibayashi, Yasuhisa

2016-01-01

To maintain sterility of PET drug is the most important for in-house positron emission tomography (PET) drug manufacturing, and sanitary control of the laboratory to perform aseptic procedure is the key point for the sterility of PET drugs. However, rigorous sanitary control affects both the high cost and the low efficiency. To conquer those, we developed an isolator system especially for PET drug compounding including sterilization and dispensing units. This system consists of a HEPA unit for inlet and outlet, positive regulation of the ear inside isolator, a sterilizer with vapored hydrogen peroxide and a dispenser with self-shield for radiation. We set the materials for the dispenser through gloves, and the compounding such as sterilization and dispensing PET drugs to the containers is performed automatically without radiation. High level assurance of PET drug sterility is expected to be accomplished in the PET centers of the hospitals without high level sanitary control.

Development of circulation control technology for powered-lift STOL aircraft

NASA Technical Reports Server (NTRS)

Englar, Robert J.

1987-01-01

The flow entraining capabilities of the Circulation Control Wing high lift system were employed to provide an even stronger STOL potential when synergistically combined with upper surface mounted engines. The resulting configurations generate very high supercirculation lift in addition to a vertical component of the pneumatically deflected engine thrust. A series of small scale wind tunnel tests and full scale static thrust deflection tests are discussed which provide a sufficient data base performance. These tests results show thrust deflections of greater than 90 deg produced pneumatically by nonmoving aerodynamic surfaces, and the ability to maintain constant high lift while varying the propulsive force from high thrust recovery required for short takeoff to high drag generation required for short low speed landings.

Assessing potency of high- and low-preference reinforcers with respect to response rate and response patterns.

PubMed

Penrod, Becky; Wallace, Michele D; Dyer, Edwin J

2008-01-01

Previous research has suggested that the availability of high-preference stimuli may override the reinforcing efficacy of concurrently available low-preference stimuli under relatively low schedule requirements (e.g., fixed-ratio 1 schedule). It is unknown if similar effects would be obtained under higher schedule requirements. Thus, the current study compared high-preference and low-preference reinforcers under progressively increasing schedule requirements. Results for 3 of the 4 participants indicated that high-preference stimuli maintained responding under higher schedule requirements relative to low-preference stimuli. For 1 participant, high-preference and low-preference stimuli were demonstrated to be equally effective reinforcers under increasing schedule requirements. Implications with respect to rate of performance and response patterns are discussed.

Physiological and biological factors associated with a 24 h treadmill ultra-marathon performance.

PubMed

Millet, G Y; Banfi, J C; Kerherve, H; Morin, J B; Vincent, L; Estrade, C; Geyssant, A; Feasson, L

2011-02-01

The purpose of this study was to examine the physiological and biological factors associated with ultra-endurance performance. Fourteen male runners volunteered to run on a treadmill as many kilometers as possible over a 24-h period (24TR). Maximal oxygen uptake (VO(2max)), velocity associated with VO(2max)(VO(2max)) and running economy (RE) at 8 km/h were measured. A muscle biopsy was also performed in the vastus lateralis muscle. The subjects ran 149.2 ± 15.7 km in 18 h 39 ± 41 min of effective attendance on the treadmill, corresponding to 39.4 ± 4.2% of . Standard multiple-regression analysis showed that performance was significantly (R(2) = 0.82; P = 0.005) related to VO(2max) and specific endurance, i.e. the average speed sustained over the 24TR expressed in . VO(2max) was associated with a high capillary tortuosity (R(2) = 0.66; P = 0.01). Specific endurance was significantly related to RE and citrate synthase activity. It is concluded that a high VO(2max) and an associated developed capillary network are essential for ultra-endurance running performance. The ability to maintain a high %VO(2max) over a 24TR is another factor associated with performance and is mainly related to RE and high mitochondrial oxidative capacity in the vastus lateralis. © 2009 John Wiley & Sons A/S.

Use of PZT's for adaptive control of Fabry-Perot etalon plate figure

NASA Technical Reports Server (NTRS)

Skinner, WIlbert; Niciejewski, R.

2005-01-01

A Fabry Perot etalon, consisting of two spaced and reflective glass flats, provides the mechanism by which high resolution spectroscopy may be performed over narrow spectral regions. Space based applications include direct measurements of Doppler shifts of airglow absorption and emission features and the Doppler broadening of spectral lines. The technique requires a high degree of parallelism between the two flats to be maintained through harsh launch conditions. Monitoring and adjusting the plate figure by illuminating the Fabry Perot interferometer with a suitable monochromatic source may be performed on orbit to actively control of the parallelism of the flats. This report describes the use of such a technique in a laboratory environment applied to a piezo-electric stack attached to the center of a Fabry Perot etalon.

Prediction of pilot-aircraft stability boundaries and performance contours

NASA Technical Reports Server (NTRS)

Stengel, R. F.; Broussard, J. R.

1977-01-01

Control-theoretic pilot models can provide important new insights regarding the stability and performance characteristics of the pilot-aircraft system. Optimal-control pilot models can be formed for a wide range of flight conditions, suggesting that the human pilot can maintain stability if he adapts his control strategy to the aircraft's changing dynamics. Of particular concern is the effect of sub-optimal pilot adaptation as an aircraft transitions from low to high angle-of-attack during rapid maneuvering, as the changes in aircraft stability and control response can be extreme. This paper examines the effects of optimal and sub-optimal effort during a typical 'high-g' maneuver, and it introduces the concept of minimum-control effort (MCE) adaptation. Limited experimental results tend to support the MCE adaptation concept.

Acousto-optic time- and space-integrating spotlight-mode SAR processor

NASA Astrophysics Data System (ADS)

Haney, Michael W.; Levy, James J.; Michael, Robert R., Jr.

1993-09-01

The technical approach and recent experimental results for the acousto-optic time- and space- integrating real-time SAR image formation processor program are reported. The concept overcomes the size and power consumption limitations of electronic approaches by using compact, rugged, and low-power analog optical signal processing techniques for the most computationally taxing portions of the SAR imaging problem. Flexibility and performance are maintained by the use of digital electronics for the critical low-complexity filter generation and output image processing functions. The results include a demonstration of the processor's ability to perform high-resolution spotlight-mode SAR imaging by simultaneously compensating for range migration and range/azimuth coupling in the analog optical domain, thereby avoiding a highly power-consuming digital interpolation or reformatting operation usually required in all-electronic approaches.

Deep Throttle Turbopump Technology Design Concepts

NASA Technical Reports Server (NTRS)

Guinzburg, Adiel; Williams, Morgan; Ferguson, Tom; Garcia, Roberto (Technical Monitor)

2002-01-01

The objective of this project is to increase the throttling range of turbopumps from 30 to 120% of the design value, while maintaining high performance levels. Details are given on wide flow range issues, H-Q characteristics, stall characteristics, energy levels, pressure fluctuations at impeller exit, WFR impeller characteristics, commercial diffuser pumps, slotted or tandem vanes, leading edge characteristics, leading edge models, throat models, diffusion passage models, computational fluid dynamics (CFD) methodologies, and CFD flow cases.

Other Defense Organizations and Defense Finance and Accounting Service Controls Over High-Risk Transactions Were Not Effective

DTIC Science & Technology

2016-03-28

Management (DHA- CRM ), agreed with Recommendations 1 and 2. The Chief stated that the service-level agreements should be updated to provide...descriptive language on the defined roles and responsibilities. In some instances, DHA- CRM personnel find it difficult to identify responsible parties at...that it maintains a universe of all accounting transactions processed daily to include disbursements. Additionally, DHA- CRM personnel perform a

Gastric band tubing-related complication during pregnancy

PubMed Central

Beh, Han N

2017-01-01

Abstract In the past few decades, laparoscopic adjustable gastric banding is one of the most common bariatric procedures performed to treat morbid obesity. Device-related complication such as connection-tubing problem is rare. Here we present a case of gastric band tubing complication during pregnancy. This case illustrates the need to maintain high index of suspicion of gastric band device-related complication during pregnancy and early referral for bariatric surgical assessment is recommended. PMID:29218217

The growing importance of costs and ways to maintain cost control on a large program in today's competitive environment

NASA Technical Reports Server (NTRS)

Newman, J. J.; Grimes, D. W.; Gaetano, F. W.

1973-01-01

Discussion of management techniques that make it possible to overcome inflationary and developmental cost rises while holding schedule and performance fixed in scientific space programs. The techniques reviewed pertain to high personnel motivation, continual review of contract rigidity for de facto modification by senior judgment, standardization vs design innovation, cooperative customer/contractor goal orientation vs task orientation, and deep real-time management visibility.

NASA SMD Airborne Science Capabilities for Development and Testing of New Instruments

NASA Technical Reports Server (NTRS)

Fladeland, Matthew

2015-01-01

The SMD NASA Airborne Science Program operates and maintains a fleet of highly modified aircraft to support instrument development, satellite instrument calibration, data product validation and earth science process studies. This poster will provide an overview of aircraft available to NASA researchers including performance specifications and modifications for instrument support, processes for requesting aircraft time and developing cost estimates for proposals, and policies and procedures required to ensure safety of flight.

Low-Carbohydrate-High-Fat Diet: Can it Help Exercise Performance?

PubMed Central

Borer, Katarina; Lin, Po-Ju

2017-01-01

Abstract Low-carbohydrate-high-fat (LCHF) diets have been used as a means of weight loss and control of symptoms in several clinical conditions. There is emerging evidence that the metabolic changes induced by LCHF diets enhance endurance performance. The aims of this review are to examine the evidence of LCHF diets in improving various aspects of athletic performance. Long-term LCHF dietary intake may help control body weight and fat mass while maintaining lean body mass in athletes in weight-sensitive sports. LCHF-adapted endurance athletes can reach the maximal fat oxidation rate of approximately 1.5 g/min, with a lower carbohydrate oxidation rate and similar muscle glycogen content and a resynthesis rate compared to their counterparts consuming high-carbohydrate-low-fat (HCLF) diets. The elevated fat oxidation rate and glycogen sparing effect may improve performance in ultra-endurance events. These metabolic changes may also prevent the decline in performance in later stages of repeated high-intensity movements, in which the aerobic metabolism becomes more important. However, elevated blood concentrations of non-esterified fatty acids and ammonia during exercise after LCHF diets may lead to early development of central fatigue. It appears that at least several months of adaptation to a LCHF diet are required for the metabolic changes and restoration of muscle glycogen to occur. Further investigations on LCHF diets are needed regarding (1) performance after weight loss in weight-categorized sports; (2) repeated high-intensity exercise performance; (3) development of central fatigue during endurance events; (4) perceptual-motor performance during prolonged intermittent sports; and (5) ideal dietary fatty acid compositions. PMID:28469746

Low-Carbohydrate-High-Fat Diet: Can it Help Exercise Performance?

PubMed

Chang, Chen-Kang; Borer, Katarina; Lin, Po-Ju

2017-02-01

Low-carbohydrate-high-fat (LCHF) diets have been used as a means of weight loss and control of symptoms in several clinical conditions. There is emerging evidence that the metabolic changes induced by LCHF diets enhance endurance performance. The aims of this review are to examine the evidence of LCHF diets in improving various aspects of athletic performance. Long-term LCHF dietary intake may help control body weight and fat mass while maintaining lean body mass in athletes in weight-sensitive sports. LCHF-adapted endurance athletes can reach the maximal fat oxidation rate of approximately 1.5 g/min, with a lower carbohydrate oxidation rate and similar muscle glycogen content and a resynthesis rate compared to their counterparts consuming high-carbohydrate-low-fat (HCLF) diets. The elevated fat oxidation rate and glycogen sparing effect may improve performance in ultra-endurance events. These metabolic changes may also prevent the decline in performance in later stages of repeated high-intensity movements, in which the aerobic metabolism becomes more important. However, elevated blood concentrations of non-esterified fatty acids and ammonia during exercise after LCHF diets may lead to early development of central fatigue. It appears that at least several months of adaptation to a LCHF diet are required for the metabolic changes and restoration of muscle glycogen to occur. Further investigations on LCHF diets are needed regarding (1) performance after weight loss in weight-categorized sports; (2) repeated high-intensity exercise performance; (3) development of central fatigue during endurance events; (4) perceptual-motor performance during prolonged intermittent sports; and (5) ideal dietary fatty acid compositions.

The Effect of COD Concentration Containing Leaves Litter, Canteen and Composite Waste to the Performance of Solid Phase Microbial Fuel Cell (SMFC)

NASA Astrophysics Data System (ADS)

Samudro, Ganjar; Syafrudin; Nugraha, Winardi Dwi; Sutrisno, Endro; Priyambada, Ika Bagus; Muthi'ah, Hilma; Sinaga, Glory Natalia; Hakiem, Rahmat Tubagus

2018-02-01

This research is conducted to analyze and determine the optimum of COD concentration containing leaves litter, canteen and composite waste to power density and COD removal efficiency as the indicator of SMFC performance. COD as the one of organic matter parameters perform as substrate, nutrient and dominating the whole process of SMFC. Leaves litter and canteen based food waste were obtained from TPST UNDIP in Semarang and treated in SMFC reactor. Its reactor was designed 2 liter volume and equipped by homemade graphene electrodes that were utilized at the surface of organic waste as cathode and in a half of reactor height as anode. COD concentration was initially characterized and became variations of initial COD concentration. Waste volume was maintained 2/3 of volume of reactor. Bacteria sources as the important process factor in SMFC were obtained from river sediment which contain bacteroides and exoelectrogenic bacteria. Temperature and pH were not maintained while power density and COD concentration were periodically observed and measured during 44 days. The results showed that power density up to 4 mW/m2 and COD removal efficiency performance up to 70% were reached by leaves litter, canteen and composite waste at days 11 up to days 44 days. Leaves litter contain 16,567 mg COD/l providing higher COD removal efficiency reached approximately 87.67%, more stable power density reached approximately 4.71 mW/m2, and faster optimum time in the third day than canteen based food waste and composite waste. High COD removal efficiency has not yet resulted in high power density.

Improved functionality of graphene and carbon nanotube hybrid foam architecture by UV-ozone treatment

NASA Astrophysics Data System (ADS)

Wang, Wei; Ruiz, Isaac; Lee, Ilkeun; Zaera, Francisco; Ozkan, Mihrimah; Ozkan, Cengiz S.

2015-04-01

Optimization of the electrode/electrolyte double-layer interface is a key factor for improving electrode performance of aqueous electrolyte based supercapacitors (SCs). Here, we report the improved functionality of carbon materials via a non-invasive, high-throughput, and inexpensive UV generated ozone (UV-ozone) treatment. This process allows precise tuning of the graphene and carbon nanotube hybrid foam (GM) transitionally from ultrahydrophobic to hydrophilic within 60 s. The continuous tuning of surface energy can be controlled by simply varying the UV-ozone exposure time, while the ozone-oxidized carbon nanostructure maintains its integrity. Symmetric SCs based on the UV-ozone treated GM foam demonstrated enhanced rate performance. This technique can be readily applied to other CVD-grown carbonaceous materials by taking advantage of its ease of processing, low cost, scalability, and controllability.Optimization of the electrode/electrolyte double-layer interface is a key factor for improving electrode performance of aqueous electrolyte based supercapacitors (SCs). Here, we report the improved functionality of carbon materials via a non-invasive, high-throughput, and inexpensive UV generated ozone (UV-ozone) treatment. This process allows precise tuning of the graphene and carbon nanotube hybrid foam (GM) transitionally from ultrahydrophobic to hydrophilic within 60 s. The continuous tuning of surface energy can be controlled by simply varying the UV-ozone exposure time, while the ozone-oxidized carbon nanostructure maintains its integrity. Symmetric SCs based on the UV-ozone treated GM foam demonstrated enhanced rate performance. This technique can be readily applied to other CVD-grown carbonaceous materials by taking advantage of its ease of processing, low cost, scalability, and controllability. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr06795a

Intrinsically stretchable and healable semiconducting polymer for organic transistors

DOE PAGES

Oh, Jin Young; Rondeau-Gagné, Simon; Chiu, Yu-Cheng; ...

2016-11-16

Developing a molecular design paradigm for conjugated polymers applicable to intrinsically stretchable semiconductors is crucial toward the next generation of wearable electronics. Current molecular design rules for high charge carrier mobility semiconducting polymers are unable to render the fabricated devices simultaneously stretchable and mechanically robust. Here in this paper, we present a new design concept to address the above challenge, while maintaining excellent electronic performance. This concept involves introducing chemical moieties to promote dynamic non-covalent crosslinking of the conjugated polymers. These non-covalent covalent crosslinking moieties are able to undergo an energy dissipation mechanism through breakage of bonds when strain ismore » applied, while retaining its high charge transport ability. As a result, our polymer is able to recover its high mobility performance (>1 cm 2/Vs) even after 100 cycles at 100% applied strain. Furthermore, we observed that the polymer can be efficiently repaired and/or healed with a simple heat and solvent treatment. These improved mechanical properties of our fabricated stretchable semiconductor enabled us to fabricate highly stretchable and high performance wearable organic transistors. This material design concept should illuminate and advance the pathways for future development of fully stretchable and healable skin-inspired wearable electronics.« less

Intrinsically stretchable and healable semiconducting polymer for organic transistors

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

Oh, Jin Young; Rondeau-Gagné, Simon; Chiu, Yu-Cheng

Developing a molecular design paradigm for conjugated polymers applicable to intrinsically stretchable semiconductors is crucial toward the next generation of wearable electronics. Current molecular design rules for high charge carrier mobility semiconducting polymers are unable to render the fabricated devices simultaneously stretchable and mechanically robust. Here in this paper, we present a new design concept to address the above challenge, while maintaining excellent electronic performance. This concept involves introducing chemical moieties to promote dynamic non-covalent crosslinking of the conjugated polymers. These non-covalent covalent crosslinking moieties are able to undergo an energy dissipation mechanism through breakage of bonds when strain ismore » applied, while retaining its high charge transport ability. As a result, our polymer is able to recover its high mobility performance (>1 cm 2/Vs) even after 100 cycles at 100% applied strain. Furthermore, we observed that the polymer can be efficiently repaired and/or healed with a simple heat and solvent treatment. These improved mechanical properties of our fabricated stretchable semiconductor enabled us to fabricate highly stretchable and high performance wearable organic transistors. This material design concept should illuminate and advance the pathways for future development of fully stretchable and healable skin-inspired wearable electronics.« less

40 CFR Table 2 to Subpart Dddd of... - Operating Requirements

Code of Federal Regulations, 2011 CFR

2011-07-01

... minimum temperature established during the performance test Maintain the 3-hour block average THC... representative sample of the catalyst at least every 12 months Maintain the 3-hour block average THC... established according to § 63.2262(m) Maintain the 24-hour block average THC concentration a in the biofilter...

40 CFR Table 2 to Subpart Dddd of... - Operating Requirements

Code of Federal Regulations, 2010 CFR

2010-07-01

... minimum temperature established during the performance test Maintain the 3-hour block average THC... representative sample of the catalyst at least every 12 months Maintain the 3-hour block average THC... established according to § 63.2262(m) Maintain the 24-hour block average THC concentration a in the biofilter...

49 CFR 384.229 - Skills test examiner auditing and monitoring.

Code of Federal Regulations, 2014 CFR

2014-10-01

... overt monitoring must be performed at least once every year; (c) Establish and maintain a database to...; (d) Establish and maintain a database of all third party testers and examiners, which at a minimum... examiner; (e) Establish and maintain a database of all State CDL skills examiners, which at a minimum...

49 CFR 384.229 - Skills test examiner auditing and monitoring.

Code of Federal Regulations, 2013 CFR

2013-10-01

... overt monitoring must be performed at least once every year; (c) Establish and maintain a database to...; (d) Establish and maintain a database of all third party testers and examiners, which at a minimum... examiner; (e) Establish and maintain a database of all State CDL skills examiners, which at a minimum...

Electrostatic Self-Assembly of Sandwich-Like CoAl-LDH/Polypyrrole/Graphene Nanocomposites with Enhanced Capacitive Performance.

PubMed

Zhang, Yu; Du, Dongfeng; Li, Xuejin; Sun, Hongman; Li, Li; Bai, Peng; Xing, Wei; Xue, Qingzhong; Yan, Zifeng

2017-09-20

A novel sandwich-like composite with ultrathin CoAl-layered double hydroxide (LDH) nanoplates electrostatically assembled on both sides of two-dimensional polypyrrole/graphene (PG) substrate has been successfully fabricated using facile hydrothermal techniques. The PG not only serves as an excellent conductive and structural scaffold to enhance the transmission of electrons and prevent aggregation of CoAl-LDH nanoplates but also contributes to the enhancement of the specific capacitance. Owing to the homogeneous dispersion of CoAl-LDH nanoplates and its intimate interaction with PG substrate, the resulting CoAl-LDH/PG nanocomposite material exhibits excellent capacitive performance, for example, enhanced gravimetric specific capacitance (864 F g -1 at 1 A g -1 ), high rate performance (75% retention at 20 A g -1 ), and excellent cycle life (almost no degradation in supercapacitor performance after 5000 cycles) in aqueous KOH solution. Furthermore, the assembled asymmetric capacitor is able to deliver a superhigh energy density of 46.8 Wh kg -1 at 1.2 kW kg -1 and maintain 90.1% of its initial capacitance after 10 000 cycles. These results indicate a rational assembly strategy toward a high-performance pseudocapacitive electrode material with excellent rate performance, high specific capacitance, and outstanding cycle stability.

Statistical methodologies for the control of dynamic remapping

NASA Technical Reports Server (NTRS)

Saltz, J. H.; Nicol, D. M.

1986-01-01

Following an initial mapping of a problem onto a multiprocessor machine or computer network, system performance often deteriorates with time. In order to maintain high performance, it may be necessary to remap the problem. The decision to remap must take into account measurements of performance deterioration, the cost of remapping, and the estimated benefits achieved by remapping. We examine the tradeoff between the costs and the benefits of remapping two qualitatively different kinds of problems. One problem assumes that performance deteriorates gradually, the other assumes that performance deteriorates suddenly. We consider a variety of policies for governing when to remap. In order to evaluate these policies, statistical models of problem behaviors are developed. Simulation results are presented which compare simple policies with computationally expensive optimal decision policies; these results demonstrate that for each problem type, the proposed simple policies are effective and robust.

The Impact of Trajectory Prediction Uncertainty on Air Traffic Controller Performance and Acceptability

NASA Technical Reports Server (NTRS)

Mercer, Joey S.; Bienert, Nancy; Gomez, Ashley; Hunt, Sarah; Kraut, Joshua; Martin, Lynne; Morey, Susan; Green, Steven M.; Prevot, Thomas; Wu, Minghong G.

2013-01-01

A Human-In-The-Loop air traffic control simulation investigated the impact of uncertainties in trajectory predictions on NextGen Trajectory-Based Operations concepts, seeking to understand when the automation would become unacceptable to controllers or when performance targets could no longer be met. Retired air traffic controllers staffed two en route transition sectors, delivering arrival traffic to the northwest corner-post of Atlanta approach control under time-based metering operations. Using trajectory-based decision-support tools, the participants worked the traffic under varying levels of wind forecast error and aircraft performance model error, impacting the ground automations ability to make accurate predictions. Results suggest that the controllers were able to maintain high levels of performance, despite even the highest levels of trajectory prediction errors.

Teaching Young Children with Special Needs and Their Peers to Play Board Games: Effects of a Least to Most Prompting Procedure to Increase Independent Performance.

PubMed

Davis-Temple, Janet; Jung, Sunhwa; Sainato, Diane M

2014-05-01

We investigated the effects of a least to most prompting procedure on the performance of board game steps and game-related on-task behavior of young children with special needs and their typically developing peers. This study was conducted employing a concurrent multiple baseline design across participants. After teaching the board game steps using a systematic prompting strategy, the participants demonstrated increases in the performance of board game steps and game-related on-task behavior. In addition, the participants maintained high levels of performance and game-related on-task behavior during post-game training. The effects of teaching board games using prompting strategies, implications for practice, and areas for future study are presented.

Sustained attention performance during sleep deprivation: evidence of state instability

NASA Technical Reports Server (NTRS)

Doran, S. M.; Van Dongen, H. P.; Dinges, D. F.

2001-01-01

Nathaniel Kleitman was the first to observe that sleep deprivation in humans did not eliminate the ability to perform neurobehavioral functions, but it did make it difficult to maintain stable performance for more than a few minutes. To investigate variability in performance as a function of sleep deprivation, n = 13 subjects were tested every 2 hours on a 10-minute, sustained-attention, psychomotor vigilance task (PVT) throughout 88 hours of total sleep deprivation (TSD condition), and compared to a control group of n = 15 subjects who were permitted a 2-hour nap every 12 hours (NAP condition) throughout the 88-hour period. PVT reaction time means and standard deviations increased markedly among subjects and within each individual subject in the TSD condition relative to the NAP condition. TSD subjects also had increasingly greater performance variability as a function of time on task after 18 hours of wakefulness. During sleep deprivation, variability in PVT performance reflected a combination of normal timely responses, errors of omission (i.e., lapses), and errors of commission (i.e., responding when no stimulus was present). Errors of omission and errors of commission were highly intercorrelated across deprivation in the TSD condition (r = 0.85, p = 0.0001), suggesting that performance instability is more likely to include compensatory effort than a lack of motivation. The marked increases in PVT performance variability as sleep loss continued supports the "state instability" hypothesis, which posits that performance during sleep deprivation is increasingly variable due to the influence of sleep initiating mechanisms on the endogenous capacity to maintain attention and alertness, thereby creating an unstable state that fluctuates within seconds and that cannot be characterized as either fully awake or asleep.

Laser direct writing of carbon/Au composite electrodes for high-performance micro-supercapacitors

NASA Astrophysics Data System (ADS)

Cai, Jinguang; Watanabe, Akira; Lv, Chao

2017-02-01

Micro-supercapacitors with small size, light weight, flexibility while maintaining high energy and power output are required for portable miniaturized electronics. The fabrication methods and materials should be cost-effective, scalable, and easily integrated to current electronic industry. Carbon materials have required properties for high-performance flexible supercapacitors, including high specific surface areas, electrochemical stability, and high electrical conductivity, as well as the high mechanical tolerance. Laser direct writing method is a non-contact, efficient, single-step fabrication technique without requirements of masks, post-processing, and complex clean room, which is a useful patterning technique, and can be easily integrated with current electronic product lines for commercial use. Previously we have reported micro-supercapacitors fabricated by laser direct writing on polyimide films in air or Ar, which showed highcapacitive performance. However, the conductivity of the carbon materials is still low for fast charge-discharge use. Here, we demonstrated the fabrication of flexible carbon/Au composite high-performance MSCs by first laser direct writing on commercial polyimide films followed by spin-coating Au nanoparticles ink and second in-situ laser direct writing using the low-cost semiconductor laser. As-prepared micro-supercapacitors show an improved conductivity and capacitance of 1.17 mF/cm2 at a high scanning rate of 10,000 mV/s, which is comparable to the reported capacitance of carbon-based micro-supercapacitors. In addition, the micro-supercapacitors have high bend tolerance and long-cycle stability.

Monitoring of the physical status of Mars-500 subjects as a model of structuring an automated system in support of the training process in an exploration mission

NASA Astrophysics Data System (ADS)

Fomina, Elena; Savinkina, Alexandra; Kozlovskaya, Inesa; Lysova, Nataliya; Angeli, Tomas; Chernova, Maria; Uskov, Konstantin; Kukoba, Tatyana; Sonkin, Valentin; Ba, Norbert

Physical training sessions aboard the ISS are performed under the permanent continuous control from Earth. Every week the instructors give their recommendations on how to proceed with the training considering the results of analysis of the daily records of training cosmonauts and data of the monthly fitness testing. It is obvious that in very long exploration missions this system of monitoring will be inapplicable. For this reason we venture to develop an automated system to control the physical training process using the current ISS locomotion test parameters as the leading criteria. Simulation of an extended exploration mission in experiment MARS-500 enabled the trial application of the automated system for assessing shifts in cosmonauts’ physical status in response to exercises of varying category and dismissal periods. Methods. Six subjects spent 520 days in the analog of an interplanetary vehicle at IBMP (Moscow). A variety of training regimens and facilities were used to maintain a high level of physical performance of the subjects. The resistance exercises involved expanders, strength training device (MDS) and vibrotraining device (Galileo). The cycling exercises were performed on the bicycle ergometer (VB-3) and a treadmill with the motor in or out of motion. To study the effect of prolonged periods of dismissal from training on physical performance, the training flow was interrupted for a month once in the middle and then at the end of isolation. In addition to the in-flight locomotion test integrated into the automated training control system, the physical status of subjects was attested by analysis of the records of the monthly incremental testing on the bicycle ergometer and MDS. Results. It was demonstrated that the recommended training regimens maintained high physical performance levels despite the limited motor activities in isolation. According to the locomotion testing, the subjects increased velocity significantly and reduced the physiological cost (heart rate/velocity ratio) considerably which suggested improvement of their physical status. On the contrary, dismissals from training caused a significant loss in subjects' preferential velocities together with a significant rise in the physiological cost of locomotion. In conclusion, passive training (treadmill motor out of motion) was shown to be the most effective regimen for maintaining physical performance in the condition of low-level motor activities. The results of the experiment evidence that further development of the automated training control system should go on with the emphasis placed on individualization of training regimens through incorporation additionally of neuromuscular and vegetative functional tests.

Supine Lower Body Negative Pressure Exercise Maintains Upright Exercise Capacity in Male Twins during 30 Days of Bed Rest

NASA Technical Reports Server (NTRS)

Lee, Stuart M. C.; Schneider, Suzanne M.; Boda, Wanda L.; Watenpaugh, Donald E.; Macias, Brandon R.; Meyer, R. Scott; Hargens, Alan R.

2006-01-01

Exercise capacity is reduced following both short and long duration exposures to microgravity. We have shown previously that supine lower body negative pressure with exercise (LBNP(sub ex) maintains upright exercise capacity in men after 5d and 15d bed rest, as a simulation of microgravity. We hypothesized that LBNP(sub ex) would protect upright exercise capacity (VO2pk) and sprint performance in eight sets of identical male twins during a 30-d bed rest. Twins within each set were randomly assigned to either a control group (CON) who performed no exercise or to an exercise group (EX) who performed a 40-min interval (40-80% pre-BR VO2pk) LBNP(sub ex) (55+/-4 mmHg) exercise protocol, plus 5 min of resting LBNP, 6 d/wk. LBNP produced footward force equivalent to 1.0- 1.2 times body weight. Pre- and post-bed rest, subjects completed an upright graded exercise test to volitional fatigue and sprint test of 30.5 m. After bed rest, VO2pk was maintained in the EX subjects (-3+/-3%), but was significantly decreased in the CON subjects (-24+/-4%). Sprint time also was increased in the CON subjects (24+/-8%), but maintained in the EX group (8+/-2%). The performance of a supine, interval exercise protocol with LBNP maintains upright exercise capacity and sprint performance during 30 d of bed rest. This exercise countermeasure protocol may help prevent microgravity-induced deconditioning during long duration space flight.

The AMPK β2 subunit is required for energy homeostasis during metabolic stress.

PubMed

Dasgupta, Biplab; Ju, Jeong Sun; Sasaki, Yo; Liu, Xiaona; Jung, Su-Ryun; Higashida, Kazuhiko; Lindquist, Diana; Milbrandt, Jeffrey

2012-07-01

AMP activated protein kinase (AMPK) plays a key role in the regulatory network responsible for maintaining systemic energy homeostasis during exercise or nutrient deprivation. To understand the function of the regulatory β2 subunit of AMPK in systemic energy metabolism, we characterized β2 subunit-deficient mice. Using these mutant mice, we demonstrated that the β2 subunit plays an important role in regulating glucose, glycogen, and lipid metabolism during metabolic stress. The β2 mutant animals failed to maintain euglycemia and muscle ATP levels during fasting. In addition, β2-deficient animals showed classic symptoms of metabolic syndrome, including hyperglycemia, glucose intolerance, and insulin resistance when maintained on a high-fat diet (HFD), and were unable to maintain muscle ATP levels during exercise. Cell surface-associated glucose transporter levels were reduced in skeletal muscle from β2 mutant animals on an HFD. In addition, they displayed poor exercise performance and impaired muscle glycogen metabolism. These mutant mice had decreased activation of AMPK and deficits in PGC1α-mediated transcription in skeletal muscle. Our results highlight specific roles of AMPK complexes containing the β2 subunit and suggest the potential utility of AMPK isoform-specific pharmacological modulators for treatment of metabolic, cardiac, and neurological disorders.

Few-layered Ni(OH)2 nanosheets for high-performance supercapacitors

NASA Astrophysics Data System (ADS)

Sun, Wenping; Rui, Xianhong; Ulaganathan, Mani; Madhavi, Srinivasan; Yan, Qingyu

2015-11-01

Few-layered Ni(OH)2 nanosheets (4-5 nm in thickness) are synthesized towards high-performance supercapacitors. The ultrathin Ni(OH)2 nanosheets show high specific capacitance and good rate capability in both three-electrode and asymmetric devices. In the three-electrode device, the Ni(OH)2 nanosheets deliver a high capacitance of 2064 F g-1 at 2 A g-1, and the capacitance still has a retention of 1837 F g-1 at a high current density of 20 A g-1. Such excellent performance is by far one of the best for Ni(OH)2 electrodes. In the two-electrode asymmetric device, the specific capacitance is 248 F g-1 at 1 A g-1, and reaches 113 F g-1 at 20 A g-1. The capacitance of the asymmetric device maintains to be 166 F g-1 during the 4000th cycle at 2 A g-1, suggesting good cycling stability of the device. Besides, the asymmetric device exhibits gravimetric energy density of 22 Wh kg-1 at a power density of 0.8 kW kg-1. The present results demonstrate that the ultrathin Ni(OH)2 nanosheets are highly attractive electrode materials for achieving fast charging/discharging and high-capacity supercapacitors.

Bimodal Nuclear Thermal Rocket Sizing and Trade Matrix for Lunar, Near Earth Asteroid and Mars Missions

NASA Astrophysics Data System (ADS)

McCurdy, David R.; Krivanek, Thomas M.; Roche, Joseph M.; Zinolabedini, Reza

2006-01-01

The concept of a human rated transport vehicle for various near earth missions is evaluated using a liquid hydrogen fueled Bimodal Nuclear Thermal Propulsion (BNTP) approach. In an effort to determine the preliminary sizing and optimal propulsion system configuration, as well as the key operating design points, an initial investigation into the main system level parameters was conducted. This assessment considered not only the performance variables but also the more subjective reliability, operability, and maintainability attributes. The SIZER preliminary sizing tool was used to facilitate rapid modeling of the trade studies, which included tank materials, propulsive versus an aero-capture trajectory, use of artificial gravity, reactor chamber operating pressure and temperature, fuel element scaling, engine thrust rating, engine thrust augmentation by adding oxygen to the flow in the nozzle for supersonic combustion, and the baseline turbopump configuration to address mission redundancy and safety requirements. A high level system perspective was maintained to avoid focusing solely on individual component optimization at the expense of system level performance, operability, and development cost.

History-based route selection for reactive ad hoc routing protocols

NASA Astrophysics Data System (ADS)

Medidi, Sirisha; Cappetto, Peter

2007-04-01

Ad hoc networks rely on cooperation in order to operate, but in a resource constrained environment not all nodes behave altruistically. Selfish nodes preserve their own resources and do not forward packets not in their own self interest. These nodes degrade the performance of the network, but judicious route selection can help maintain performance despite this behavior. Many route selection algorithms place importance on shortness of the route rather than its reliability. We introduce a light-weight route selection algorithm that uses past behavior to judge the quality of a route rather than solely on the length of the route. It draws information from the underlying routing layer at no extra cost and selects routes with a simple algorithm. This technique maintains this data in a small table, which does not place a high cost on memory. History-based route selection's minimalism suits the needs the portable wireless devices and is easy to implement. We implemented our algorithm and tested it in the ns2 environment. Our simulation results show that history-based route selection achieves higher packet delivery and improved stability than its length-based counterpart.

The perspective effects of various seed coating substances on rice seed variety Khao DAWK Mali 105 storability I: the case study of physiological properties.

PubMed

Thobunluepop, P; Pawelzik, E; Vearasilp, S

2008-10-01

This study aimed to evaluate the perspective changes of several physiological performances of rice seeds cv. KDML 105 which were coated with various seed coating substances [chemical fungicide, captan (CA) and biological coating polymers; chitosan-lignosulphonate polymer (CL) and eugenol incorporated into chitosan-lignosulphonate polymer (E + CL)] during storage (12 months). CA significantly increased seed moisture content and seed water activity through out the storage period. The qualities and viability of the seeds were seriously declined by this treatment. Moreover, CA inhibited the shoot and root development, seedling dry weight accumulation, delayed the seed germination and seedling growth rate. CA treated seeds were susceptible to stress conditions that declined the seed germination potential under cold, high moisture and temperature stress conditions. Nevertheless, CL and E + CL coating polymer could maintain seed storability, which significantly improved seed germination and seedling performances. These improvements were attributed to maintain the nutritive reserve and dehydrogenase activity in seeds. Moreover, the biological seed treatment stimulated the embryo growth and so speeding up the seedling emergence when compared untreated seeds.

Effect of carbon-sulphur bond in a sulphur/dehydrogenated polyacrylonitrile/reduced graphene oxide composite cathode for lithium-sulphur batteries

NASA Astrophysics Data System (ADS)

Konarov, Aishuak; Bakenov, Zhumabay; Yashiro, Hitoshi; Sun, Yang-Kook; Myung, Seung-Taek

2017-07-01

A S/DPAN (dehydrogenated polyacrylonitrile) composite shows promising electrode performances as a cathode material for Li-S batteries though its electric conductivity is insufficient for high rate tests. In an attempt to enhance the electric conductivity, the S/DPAN composite is attached on reduced graphene oxide (rGO) sheets via self-assembling modification. As a result, the conductivity improves to ∼10-4 S cm-1, and the S/DPAN/rGO composite thereby delivers approximately 90% of the theoretical capacity of sulphur at a rate of 0.2C (0.34 A g-1) over 700 mAh (g-S)-1 even at 2C (3.4 A g-1). We first report on the Csbnd S bond between sulphur and DPAN in a composite that maintains the bond even after an extensive cycling test, as confirmed by time-of-flight secondary-ion mass spectroscopy (ToF-SIMS). These synergistic effects enable facile electron transport such that the S/DPAN/rGO composite electrode is able to maintain superior electrode performances.

Wind, Wave, and Tidal Energy Without Power Conditioning

NASA Technical Reports Server (NTRS)

Jones, Jack A.

2013-01-01

Most present wind, wave, and tidal energy systems require expensive power conditioning systems that reduce overall efficiency. This new design eliminates power conditioning all, or nearly all, of the time. Wind, wave, and tidal energy systems can transmit their energy to pumps that send high-pressure fluid to a central power production area. The central power production area can consist of a series of hydraulic generators. The hydraulic generators can be variable displacement generators such that the RPM, and thus the voltage, remains constant, eliminating the need for further power conditioning. A series of wind blades is attached to a series of radial piston pumps, which pump fluid to a series of axial piston motors attached to generators. As the wind is reduced, the amount of energy is reduced, and the number of active hydraulic generators can be reduced to maintain a nearly constant RPM. If the axial piston motors have variable displacement, an exact RPM can be maintained for all, or nearly all, wind speeds. Analyses have been performed that show over 20% performance improvements with this technique over conventional wind turbines

High-order asynchrony-tolerant finite difference schemes for partial differential equations

NASA Astrophysics Data System (ADS)

Aditya, Konduri; Donzis, Diego A.

2017-12-01

Synchronizations of processing elements (PEs) in massively parallel simulations, which arise due to communication or load imbalances between PEs, significantly affect the scalability of scientific applications. We have recently proposed a method based on finite-difference schemes to solve partial differential equations in an asynchronous fashion - synchronization between PEs is relaxed at a mathematical level. While standard schemes can maintain their stability in the presence of asynchrony, their accuracy is drastically affected. In this work, we present a general methodology to derive asynchrony-tolerant (AT) finite difference schemes of arbitrary order of accuracy, which can maintain their accuracy when synchronizations are relaxed. We show that there are several choices available in selecting a stencil to derive these schemes and discuss their effect on numerical and computational performance. We provide a simple classification of schemes based on the stencil and derive schemes that are representative of different classes. Their numerical error is rigorously analyzed within a statistical framework to obtain the overall accuracy of the solution. Results from numerical experiments are used to validate the performance of the schemes.

Design and evaluation of aircraft heat source systems for use with high-freezing point fuels

NASA Technical Reports Server (NTRS)

Pasion, A. J.

1979-01-01

The objectives were the design, performance and economic analyses of practical aircraft fuel heating systems that would permit the use of high freezing-point fuels on long-range aircraft. Two hypothetical hydrocarbon fuels with freezing points of -29 C and -18 C were used to represent the variation from current day jet fuels. A Boeing 747-200 with JT9D-7/7A engines was used as the baseline aircraft. A 9300 Km mission was used as the mission length from which the heat requirements to maintain the fuel above its freezing point was based.

DLA based compressed sensing for high resolution MR microscopy of neuronal tissue

NASA Astrophysics Data System (ADS)

Nguyen, Khieu-Van; Li, Jing-Rebecca; Radecki, Guillaume; Ciobanu, Luisa

2015-10-01

In this work we present the implementation of compressed sensing (CS) on a high field preclinical scanner (17.2 T) using an undersampling trajectory based on the diffusion limited aggregation (DLA) random growth model. When applied to a library of images this approach performs better than the traditional undersampling based on the polynomial probability density function. In addition, we show that the method is applicable to imaging live neuronal tissues, allowing significantly shorter acquisition times while maintaining the image quality necessary for identifying the majority of neurons via an automatic cell segmentation algorithm.

A distributed infrastructure for publishing VO services: an implementation

NASA Astrophysics Data System (ADS)

Cepparo, Francesco; Scagnetto, Ivan; Molinaro, Marco; Smareglia, Riccardo

2016-07-01

This contribution describes both the design and the implementation details of a new solution for publishing VO services, enlightening its maintainable, distributed, modular and scalable architecture. Indeed, the new publisher is multithreaded and multiprocess. Multiple instances of the modules can run on different machines to ensure high performance and high availability, and this will be true both for the interface modules of the services and the back end data access ones. The system uses message passing to let its components communicate through an AMQP message broker that can itself be distributed to provide better scalability and availability.

The 77 K operation of a multi-resonant power converter

NASA Technical Reports Server (NTRS)

Ray, Biswajit; Gerber, Scott S.; Patterson, Richard L.; Myers, Ira T.

1995-01-01

The liquid-nitrogen temperature (77 K) operation of a 55 W, 200 kHz, 48/28 V zero-voltage switching multi-resonant dc/dc converter designed with commercially available components is reported. Upon dipping the complete converter (power and control circuits) into liquid-nitrogen, the converter performance improved as compared to the room-temperature operation. The switching frequency, resonant frequency, and the characteristic impedance did not change significantly. Accordingly, the zero-voltage switching was maintained from no-load to full-load for the specified line variations. Cryoelectronics can provide high density power converters, especially for high power applications.

Numerical method for high accuracy index of refraction estimation for spectro-angular surface plasmon resonance systems.

PubMed

Alleyne, Colin J; Kirk, Andrew G; Chien, Wei-Yin; Charette, Paul G

2008-11-24

An eigenvector analysis based algorithm is presented for estimating refractive index changes from 2-D reflectance/dispersion images obtained with spectro-angular surface plasmon resonance systems. High resolution over a large dynamic range can be achieved simultaneously. The method performs well in simulations with noisy data maintaining an error of less than 10(-8) refractive index units with up to six bits of noise on 16 bit quantized image data. Experimental measurements show that the method results in a much higher signal to noise ratio than the standard 1-D weighted centroid dip finding algorithm.

New High Index Optical Glasses

NASA Astrophysics Data System (ADS)

Blair, Gerald E.; Greco, Edgar J.; DeJager, Donald; Wylot, James M.

1982-02-01

The pioneering work of Charles W. Frederick and George W. Morey on the design by Frederick of an "ideal photographic lens" using hypothetical glasses, and the subsequent discovery and development of rare-element borate glasses by Morey, has been resumed at Eastman Kodak. New ultra-high index, low dispersion crown glasses and companion flint glasses have been developed, based on the needs dictated by lens design studies for novel fast cine' and still camera lenses. These new glasses reduce the number of elements required in a lens while maintaining or improving lens performance. Composition studies leading to these new glasses will be discussed.

Accelerated damage visualization using binary search with fixed pitch-catch distance laser ultrasonic scanning

NASA Astrophysics Data System (ADS)

Park, Byeongjin; Sohn, Hoon

2017-07-01

Laser ultrasonic scanning, especially full-field wave propagation imaging, is attractive for damage visualization thanks to its noncontact nature, sensitivity to local damage, and high spatial resolution. However, its practicality is limited because scanning at a high spatial resolution demands a prohibitively long scanning time. Inspired by binary search, an accelerated damage visualization technique is developed to visualize damage with a reduced scanning time. The pitch-catch distance between the excitation point and the sensing point is also fixed during scanning to maintain a high signal-to-noise ratio (SNR) of measured ultrasonic responses. The approximate damage boundary is identified by examining the interactions between ultrasonic waves and damage observed at the scanning points that are sparsely selected by a binary search algorithm. Here, a time-domain laser ultrasonic response is transformed into a spatial ultrasonic domain response using a basis pursuit approach so that the interactions between ultrasonic waves and damage, such as reflections and transmissions, can be better identified in the spatial ultrasonic domain. Then, the area inside the identified damage boundary is visualized as damage. The performance of the proposed damage visualization technique is validated excusing a numerical simulation performed on an aluminum plate with a notch and experiments performed on an aluminum plate with a crack and a wind turbine blade with delamination. The proposed damage visualization technique accelerates the damage visualization process in three aspects: (1) the number of measurements that is necessary for damage visualization is dramatically reduced by a binary search algorithm; (2) the number of averaging that is necessary to achieve a high SNR is reduced by maintaining the wave propagation distance short; and (3) with the proposed technique, the same damage can be identified with a lower spatial resolution than the spatial resolution required by full-field wave propagation imaging.

Facilitated charge transport in ternary interconnected electrodes for flexible supercapacitors with excellent power characteristics

NASA Astrophysics Data System (ADS)

Chen, Wanjun; He, Yongmin; Li, Xiaodong; Zhou, Jinyuan; Zhang, Zhenxing; Zhao, Changhui; Gong, Chengshi; Li, Shuankui; Pan, Xiaojun; Xie, Erqing

2013-11-01

Flexible and high performance supercapacitors are very critical in modern society. In order to develop the flexible supercapacitors with high power density, free-standing and flexible three-dimensional graphene/carbon nanotubes/MnO2 (3DG/CNTs/MnO2) composite electrodes with interconnected ternary 3D structures were fabricated, and the fast electron and ion transport channels were effectively constructed in the rationally designed electrodes. Consequently, the obtained 3DG/CNTs/MnO2 composite electrodes exhibit superior specific capacitance and rate capability compared to 3DG/MnO2 electrodes. Furthermore, the 3DG/CNTs/MnO2 based asymmetric supercapacitor demonstrates the maximum energy and power densities of 33.71 W h kg-1 and up to 22 727.3 W kg-1, respectively. Moreover, the asymmetric supercapacitor exhibits excellent cycling stability with 95.3% of the specific capacitance maintained after 1000 cycle tests. Our proposed synthesis strategy to construct the novel ternary 3D structured electrodes can be efficiently applied to other high performance energy storage/conversion systems.Flexible and high performance supercapacitors are very critical in modern society. In order to develop the flexible supercapacitors with high power density, free-standing and flexible three-dimensional graphene/carbon nanotubes/MnO2 (3DG/CNTs/MnO2) composite electrodes with interconnected ternary 3D structures were fabricated, and the fast electron and ion transport channels were effectively constructed in the rationally designed electrodes. Consequently, the obtained 3DG/CNTs/MnO2 composite electrodes exhibit superior specific capacitance and rate capability compared to 3DG/MnO2 electrodes. Furthermore, the 3DG/CNTs/MnO2 based asymmetric supercapacitor demonstrates the maximum energy and power densities of 33.71 W h kg-1 and up to 22 727.3 W kg-1, respectively. Moreover, the asymmetric supercapacitor exhibits excellent cycling stability with 95.3% of the specific capacitance maintained after 1000 cycle tests. Our proposed synthesis strategy to construct the novel ternary 3D structured electrodes can be efficiently applied to other high performance energy storage/conversion systems. Electronic supplementary information (ESI) available: Additional experimental details; calculations of the specific capacitances, and energy and power densities; additional SEM and optical images; XPS results; additional electrochemical results. See DOI: 10.1039/c3nr03923d

Fitness characteristics of a suburban special weapons and tactics team.

PubMed

Pryor, Riana R; Colburn, Deanna; Crill, Matthew T; Hostler, David P; Suyama, J

2012-03-01

Special Weapons and Tactics (SWAT) operators are specialized law enforcement officers who traditionally perform their duties with higher anticipated workloads because of additional body armor, weapons, and equipment used for enhanced operations and protection. This elevated workload increases the need for SWAT operators to improve or maintain their physical fitness to consistently perform routine operations. Typical tasks require trunk rotation, overhead upper extremity use, upper and lower body strength use, and long waiting periods followed by explosive movements while wearing additional equipment. Eleven male SWAT operators from 1 SWAT team performed flexibility, strength, power, and aerobic capacity tests and a variety of job-related tasks. Data were compared with age- and gender-based normative data. Fitness testing revealed that officers ranked high on tests of muscular strength (leg strength, 90th percentile; bench press, 85th percentile); however, body composition (55th percentile), core body strength, and flexibility ranked lower. Furthermore, aerobic capacity and muscular power had a wide range of scores and were also not ideal to support maximal performance during routine operations. These data can assist exercise specialists choose fitness programs specifically for job-related tasks of SWAT operators when creating fitness programs. Fitness programming for law enforcement should focus on improving aerobic fitness, flexibility, core strength, and muscular power while maintaining muscular strength to meet the needs of these specialized officers.

Role of nutrition in performance enhancement and postexercise recovery

PubMed Central

Beck, Kathryn L; Thomson, Jasmine S; Swift, Richard J; von Hurst, Pamela R

2015-01-01

A number of factors contribute to success in sport, and diet is a key component. An athlete’s dietary requirements depend on several aspects, including the sport, the athlete’s goals, the environment, and practical issues. The importance of individualized dietary advice has been increasingly recognized, including day-to-day dietary advice and specific advice before, during, and after training and/or competition. Athletes use a range of dietary strategies to improve performance, with maximizing glycogen stores a key strategy for many. Carbohydrate intake during exercise maintains high levels of carbohydrate oxidation, prevents hypoglycemia, and has a positive effect on the central nervous system. Recent research has focused on athletes training with low carbohydrate availability to enhance metabolic adaptations, but whether this leads to an improvement in performance is unclear. The benefits of protein intake throughout the day following exercise are now well recognized. Athletes should aim to maintain adequate levels of hydration, and they should minimize fluid losses during exercise to no more than 2% of their body weight. Supplement use is widespread in athletes, with recent interest in the beneficial effects of nitrate, beta-alanine, and vitamin D on performance. However, an unregulated supplement industry and inadvertent contamination of supplements with banned substances increases the risk of a positive doping result. Although the availability of nutrition information for athletes varies, athletes will benefit from the advice of a registered dietician or nutritionist. PMID:26316828

All-fiber probe for optical coherence tomography with an extended depth of focus by a high-efficient fiber-based filter

NASA Astrophysics Data System (ADS)

Qiu, Jianrong; Shen, Yi; Shangguan, Ziwei; Bao, Wen; Yang, Shanshan; Li, Peng; Ding, Zhihua

2018-04-01

Although methods have been proposed to maintain high transverse resolution over an increased depth range, it is not straightforward to scale down the bulk-optic solutions to minimized probes of optical coherence tomography (OCT). In this paper, we propose a high-efficient fiber-based filter in an all-fiber OCT probe to realize an extended depth of focus (DOF) while maintaining a high transverse resolution. Mode interference in the probe is exploited to modulate the complex field with controllable radial distribution. The principle of DOF extension by the fiber-based filter is theoretically analyzed. Numerical simulations are conducted to evaluate the performances of the designed probes. A DOF extension ratio of 2.6 over conventional Gaussian beam is obtainable in one proposed probe under a focused beam diameter of 4 . 6 μm. Coupling efficiencies of internal interfaces of the proposed probe are below -40 dB except the last probe-air interface, which can also be depressed to be -44 dB after minor modification in lengths for the filter. Length tolerance of the proposed probe is determined to be - 28 / + 20 μm, which is readily satisfied in fabrication. With the merits of extended-DOF, high-resolution, high-efficiency and easy-fabrication, the proposed probe is promising in endoscopic applications.