NASA Astrophysics Data System (ADS)
Ahn, Sul-Ah; Jung, Youngim
2016-10-01
The research activities of the computational physicists utilizing high performance computing are analyzed by bibliometirc approaches. This study aims at providing the computational physicists utilizing high-performance computing and policy planners with useful bibliometric results for an assessment of research activities. In order to achieve this purpose, we carried out a co-authorship network analysis of journal articles to assess the research activities of researchers for high-performance computational physics as a case study. For this study, we used journal articles of the Scopus database from Elsevier covering the time period of 2004-2013. We extracted the author rank in the physics field utilizing high-performance computing by the number of papers published during ten years from 2004. Finally, we drew the co-authorship network for 45 top-authors and their coauthors, and described some features of the co-authorship network in relation to the author rank. Suggestions for further studies are discussed.
Utilization of Screw Piles in High Seismicity Areas of Cold and Warm Permafrost
DOT National Transportation Integrated Search
2010-07-01
This work was performed in support of the AUTC project Utilization of Screw Piles in : High Seismicity Areas of Cold and Warm Permafrost under the direction of PI Dr. Kenan : Hazirbaba. Surface wave testing was performed at 30 sites in the City...
Optimization of hybrid power system composed of SMES and flywheel MG for large pulsed load
NASA Astrophysics Data System (ADS)
Niiyama, K.; Yagai, T.; Tsuda, M.; Hamajima, T.
2008-09-01
A superconducting magnetic storage system (SMES) has some advantages such as rapid large power response and high storage efficiency which are superior to other energy storage systems. A flywheel motor generator (FWMG) has large scaled capacity and high reliability, and hence is broadly utilized for a large pulsed load, while it has comparatively low storage efficiency due to high mechanical loss compared with SMES. A fusion power plant such as International Thermo-Nuclear Experimental Reactor (ITER) requires a large and long pulsed load which causes a frequency deviation in a utility power system. In order to keep the frequency within an allowable deviation, we propose a hybrid power system for the pulsed load, which equips the SMES and the FWMG with the utility power system. We evaluate installation cost and frequency control performance of three power systems combined with energy storage devices; (i) SMES with the utility power, (ii) FWMG with the utility power, (iii) both SMES and FWMG with the utility power. The first power system has excellent frequency power control performance but its installation cost is high. The second system has inferior frequency control performance but its installation cost is the lowest. The third system has good frequency control performance and its installation cost is attained lower than the first power system by adjusting the ratio between SMES and FWMG.
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.
Endogenous Groups and Dynamic Selection in Mechanism Design*
Madeira, Gabriel A.; Townsend, Robert M.
2010-01-01
We create a dynamic theory of endogenous risk sharing groups, with good internal information, and their coexistence with relative performance, individualistic regimes, which are informationally more opaque. Inequality and organizational form are determined simultaneously. Numerical techniques and succinct re-formulations of mechanism design problems with suitable choice of promised utilities allow the computation of a stochastic steady state and its transitions. Regions of low inequality and moderate to high wealth (utility promises) produce the relative performance regime, while regions of high inequality and low wealth produce the risk sharing group regime. If there is a cost to prevent coalitions, risk sharing groups emerge at high wealth levels also. Transitions from the relative performance regime to the group regime tend to occur when rewards to observed outputs exacerbate inequality, while transitions from the group regime to the relative performance regime tend to come with a decrease in utility promises. Some regions of inequality and wealth deliver long term persistence of organization form and inequality, while other regions deliver high levels of volatility. JEL Classification Numbers: D23,D71,D85,O17. PMID:20107614
ERIC Educational Resources Information Center
Federal Coordinating Council for Science, Engineering and Technology, Washington, DC.
This report presents a review of the High Performance Computing and Communications (HPCC) Program, which has as its goal the acceleration of the commercial availability and utilization of the next generation of high performance computers and networks in order to: (1) extend U.S. technological leadership in high performance computing and computer…
Development Study of Cartridge/Crucible Tube Materials
NASA Technical Reports Server (NTRS)
McKechnie, Timothy N.; ODell, Scott J.
1998-01-01
The limitations of traditional alloys and the desire for improved performance for components is driving the increased utilization of refractory metals in tile space industry. From advanced propulsion systems to high temperature furnace components for microgravity processing, refractory metals are being used for their high melting temperatures and inherent chemical stability. Techniques have been developed to produce near net shape refractory metal components utilizing vacuum plasma spraying. Material utilization is very high, and laborious machining can be avoided. As-spray formed components have been tested and found to perform adequately. However, increased mechanical and thermal properties are needed. To improve these properties, post processing thermal treatments such as hydrogen sintering and vacuum annealing have been performed. Components formed from alloys of tungsten, rhenium, tantalum, niobium, and molybdenum are discussed and a metallurgical analyses detailing the results are presented. A qualitative comparison of mechanical properties is also included.
Detrimental Effects of “Stretch” Goals in Specialty Substance Use Disorder Treatment Organizations
Lemoine, G. James; Blum, Terry C.; Roman, Paul M.
2016-01-01
Background “Stretch” goals, a rarely examined concept that represents seemingly impossible, highly ambitious organizational goals ostensibly established to fill performance gaps and motivate employees, are examined within a sample of substance use disorder (SUD) treatment centers in the United States in terms of their prevalence and effects on organizational behavior. Stretch goals are defined as “seemingly impossible” goals intended to motivate employees to achieve high performance. In light of the high level of environmental change and unpredictability faced by SUD treatment centers in recent decades, we theorize that stretch goals would be both common and often detrimental (in terms of capacity utilization rate and efficiency) in these settings. Methods In a longitudinal analysis of data from leaders of a representative U. S. national sample of 219 SUD treatment centers characterized by entrepreneurial management structures, we examined the prevalence of stretch goals and their impact on key outcome variables of capacity utilization rate and efficiency. Results Widespread adoption of stretch goals was found, with 43% of our sample falling within the stretch category. Stretch goals had a negative main effect on capacity utilization rate as compared to less ambitious challenging goals. Stretch and prior performance interacted to further predict capacity utilization rate, whereas stretch and slack resource availability interacted to predict center efficiency. Discussion Although stretch goals are frequently used in the SUD treatment industry, we find them mostly detrimental to performance. Stretch goals may enhance the efficiency of treatment centers with prior limited resource availability, but they are negatively associated with capacity utilization, especially in centers with a record of already strong performance. Despite the high prevalence of such goals and positive values centered on aspirational behavior, these results strongly suggest caution in such goal setting in SUD treatment centers. PMID:26976811
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ennis, B.M.; Maddox, I.S.
1987-02-20
A study was performed to optimize the production of solvents from whey permeate in batch fermentation using Clostridium acetobutylicum P262. Fermentations performed at relatively low pH values resulted in high solvent yields and productivities, but lactose utilization was incomplete. At higher pH values, lactose-utilization was improved but acid production dominated over solvent production. When operating at the higher pH values, an increase in the initial lactose concentration of the whey permeate resulted in lower rates of lactose utilization, and this was accompanied by increased solvent production and decreased acid production. Analysis of data from several experiments revealed a strong inversemore » relationship between solvent yield and lactose utilization rate. Thus, conditions which minimize the lactose utilization rate such as low culture pH values or high initial lactose concentrations, favor solventogenesis at the expense of acid production. 12 references.« less
NASA Technical Reports Server (NTRS)
Billings, W. W.
1981-01-01
Three types of solid state power controllers (SSPC's) for high voltage, high power DC system applications were developed. The first type utilizes a SCR power switch. The second type employes an electromechanical power switch element with solid state commutation. The third type utilizes a transistor power switch. Significant accomplishments include high operating efficiencies, fault clearing, high/low temperature performance and vacuum operation.
Reliability and Perceived Pedagogical Utility of a Weighted Music Performance Assessment Rubric
ERIC Educational Resources Information Center
Latimer, Marvin E., Jr.; Bergee, Martin J.; Cohen, Mary L.
2010-01-01
The purpose of this study was to investigate the reliability and perceived pedagogical utility of a multidimensional weighted performance assessment rubric used in Kansas state high school large-group festivals. Data were adjudicator rubrics (N = 2,016) and adjudicator and director questionnaires (N = 515). Rubric internal consistency was…
Common Factors of High Performance Teams
ERIC Educational Resources Information Center
Jackson, Bruce; Madsen, Susan R.
2005-01-01
Utilization of work teams is now wide spread in all types of organizations throughout the world. However, an understanding of the important factors common to high performance teams is rare. The purpose of this content analysis is to explore the literature and propose findings related to high performance teams. These include definition and types,…
Online performance evaluation of RAID 5 using CPU utilization
NASA Astrophysics Data System (ADS)
Jin, Hai; Yang, Hua; Zhang, Jiangling
1998-09-01
Redundant arrays of independent disks (RAID) technology is the efficient way to solve the bottleneck problem between CPU processing ability and I/O subsystem. For the system point of view, the most important metric of on line performance is the utilization of CPU. This paper first employs the way to calculate the CPU utilization of system connected with RAID level 5 using statistic average method. From the simulation results of CPU utilization of system connected with RAID level 5 subsystem can we see that using multiple disks as an array to access data in parallel is the efficient way to enhance the on-line performance of disk storage system. USing high-end disk drivers to compose the disk array is the key to enhance the on-line performance of system.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kim, Holak; Lim, Youbong; Choe, Wonho, E-mail: wchoe@kaist.ac.kr
2014-10-06
Plasma plume and thruster performance characteristics associated with multiply charged ions in a cylindrical type Hall thruster (CHT) and an annular type Hall thruster are compared under identical conditions such as channel diameter, channel depth, propellant mass flow rate. A high propellant utilization in a CHT is caused by a high ionization rate, which brings about large multiply charged ions. Ion currents and utilizations are much different due to the presence of multiply charged ions. A high multiply charged ion fraction and a high ionization rate in the CHT result in a higher specific impulse, thrust, and discharge current.
Effect of provider volume on resource utilization for surgical procedures of the knee.
Jain, Nitin; Pietrobon, Ricardo; Guller, Ulrich; Shankar, Anoop; Ahluwalia, Ajit S; Higgins, Laurence D
2005-05-01
Operating-room time and patient disposition on discharge are important determinants of healthcare resource utilization and cost. We examined the relation between these determinants and hospital/surgeon volume for anterior cruciate ligament (ACL) reconstruction and meniscectomy procedures. Patients undergoing ACL reconstruction (18,390 cases) and meniscectomy (123,012 cases) were extracted from the State Ambulatory Surgery Databases for the years 1997-2000. Surgeon and hospital volume were divided into low-, intermediate-, and high-volume categories. Multivariate logistic regression models were used to estimate the adjusted association between surgeon and hospital volume and patient discharge status and operating-room time. Patients undergoing ACL reconstruction or meniscectomy performed by low-volume surgeons were significantly more likely to be non-routinely discharged as compared to high-volume surgeons (adjusted odds ratio 3.5, 95% confidence interval 1.7-7.2 for ACL reconstruction; adjusted odds ratio 2.0, 95% confidence interval 1.6-2.3 for meniscectomy). The mean operating-room time for performing ACL reconstruction or meniscectomy was significantly higher in low- and intermediate-volume surgeons and hospitals as compared to high-volume surgeons and hospitals (p < or = 0.001). High-volume providers utilize healthcare resources more efficiently. Our findings may help surgeons and hospitals in optimizing resource utilization and cost for routinely-performed ambulatory surgery procedures.
Chau, Tom; Loertscher, Laura
2018-01-01
Background : Teaching the practice of high-value care (HVC) is an increasingly important function of graduate medical education but best practices and long-term outcomes remain unknown. Objective : Whether a multimodal curriculum designed to address specific drivers of low-value care would affect resident attitudes, skills, and performance of HVC as tested by the Internal Medicine In-Training Exam (ITE). Methods : In 2012, we performed a baseline needs assessment among internal medicine residents at a community program regarding drivers of healthcare utilization. We then created a multimodal curriculum with online interactive worksheets, lectures, and faculty buy-in to target specific skills, knowledge, and culture deficiencies. Perceived drivers of care and performance on the Internal Medicine ITE were assessed yearly through 2016. Results : Fourteen of 27 (52%) residents completed the initial needs assessment while the curriculum was eventually seen by at least 24 of 27 (89%). The ITE was taken by every resident every year. Long-term, 3-year follow-up demonstrated persistent improvement in many drivers of utilization (patient requests, reliance on subspecialists, defensive medicine, and academic curiosity) and improvement with sustained high performance on the high-value component of the ITE. Conclusion : A multimodal curriculum targeting specific drivers of low-value care can change culture and lead to sustained improvement in the practice of HVC.
Zhang, Dongdong; Wei, Dali; Li, Qi; Ge, Xin; Guo, Xuefeng; Xie, Zaiku; Ding, Weiping
2014-01-01
For production of biodiesel from bio oils by heterogeneous catalysis, high performance catalysts of transesterification and the further utilization of glycerol have been the two points of research. The process seemed easy, however, has never been well established. Here we report a novel design of catalytic distillation using hierachically integrated CNTs-based holistic catalyst to figure out the two points in one process, which shows high performance both for the conversion of bio oils to biodiesel and, unexpectedly, for the conversion of glycerol to more valuable chemicals at the same time. The method, with integration of nano, meso to macro reactor, has overwhelming advantages over common technologies using liquid acids or bases to catalyze the reactions, which suffer from the high cost of separation and unsolved utilization of glycerol. PMID:24503897
NASA Astrophysics Data System (ADS)
Zhang, Dongdong; Wei, Dali; Li, Qi; Ge, Xin; Guo, Xuefeng; Xie, Zaiku; Ding, Weiping
2014-02-01
For production of biodiesel from bio oils by heterogeneous catalysis, high performance catalysts of transesterification and the further utilization of glycerol have been the two points of research. The process seemed easy, however, has never been well established. Here we report a novel design of catalytic distillation using hierachically integrated CNTs-based holistic catalyst to figure out the two points in one process, which shows high performance both for the conversion of bio oils to biodiesel and, unexpectedly, for the conversion of glycerol to more valuable chemicals at the same time. The method, with integration of nano, meso to macro reactor, has overwhelming advantages over common technologies using liquid acids or bases to catalyze the reactions, which suffer from the high cost of separation and unsolved utilization of glycerol.
Yang, Shuo; Lin, Ling; Li, Shao Peng; Li, Qiang; Wang, Xiu Teng; Sun, Liang
2017-05-01
Utilization of fly ash is of great importance in China in the context of resource and environmental crises. Different fly ash utilization processes are proposed, and some have been practically applied. However, none of these fly ash utilization pathways has been evaluated comprehensively by integrating both environmental and economic perspectives. In this study, three high-aluminum fly ash utilization methods in Mongolia were assessed and compared based on the concept of eco-efficiency. The environmental assessment was conducted in accordance with life-cycle assessment principles, and a monetization-weighting approach was applied to obtain social willingness-to-pay as a reflection of environmental impact. The environmental assessment results revealed that the reuse of fly ash had significant advantage for saving primary resource, while solid waste, depletion of water, and global warming were the three highest environmental impacts from the life cycle perspective. The economic performance assessment showed positive net profits for fly ash utilization, but high value-added products were not necessarily indicative of better economic performance due to the relatively high operation cost. Comparison of the eco-efficiency indicators (EEIs) implied that the process of scenario 1#, which produced mullite ceramic and active calcium silicate, was the most recommended out of the three scenarios on the present scale. This judgment was consistent with the evaluation of the resource utilization rate. The present study showed that the EEI could be used to compare different fly ash utilization processes in a comprehensive and objective manner, thus providing definitive and insightful suggestions for decision-making and technical improvement.
Advanced Performance Modeling with Combined Passive and Active Monitoring
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dovrolis, Constantine; Sim, Alex
2015-04-15
To improve the efficiency of resource utilization and scheduling of scientific data transfers on high-speed networks, the "Advanced Performance Modeling with combined passive and active monitoring" (APM) project investigates and models a general-purpose, reusable and expandable network performance estimation framework. The predictive estimation model and the framework will be helpful in optimizing the performance and utilization of networks as well as sharing resources with predictable performance for scientific collaborations, especially in data intensive applications. Our prediction model utilizes historical network performance information from various network activity logs as well as live streaming measurements from network peering devices. Historical network performancemore » information is used without putting extra load on the resources by active measurement collection. Performance measurements collected by active probing is used judiciously for improving the accuracy of predictions.« less
ERIC Educational Resources Information Center
Duffin, Lisa C.; Starling, Michael P.; Day, Martha M.; Cribbs, Jennifer D.
2016-01-01
The main purpose of this quantitative study was to examine the degree to which a three-week intervention in an urban high-needs high school science classroom would influence students' (n = 51) interest, utility value, content knowledge, and intentions for future study in chemistry. The intervention consisted of an authentic, inquiry-based…
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.
Resnik, Linda; Liu, Dawei; Mor, Vince; Hart, Dennis L
2008-09-01
Little is known about organizational and service delivery factors related to quality of care in physical therapy. This study sought to identify characteristics related to differences in practice outcomes and service utilization. The sample comprised 114 outpatient clinics and 1,058 therapists who treated 16,281 patients with low back pain syndromes during the period 2000-2001. Clinics participated with the Focus on Therapeutic Outcomes, Inc (FOTO) database. Hierarchical linear models were used to risk adjust treatment outcomes and number of visits per treatment episode. Aggregated residual scores from these models were used to classify each clinic into 1 of 3 categories in each of 3 types of performance groups: (1) effectiveness, (2) utilization, and (3) overall performance (ie, composite measure of effectiveness and utilization). Relationships between clinic classification and the following independent variables were examined by multinomial logistic regression: years of therapist experience, number of physical therapists, ratio of physical therapists to physical therapist assistants, proportion of patients with low back pain syndromes, number of new patients per physical therapist per month, utilization of physical therapist assistants, and setting. Clinics that were lower utilizers of physical therapist assistants were 6.6 times more likely to be classified into the high effectiveness group compared with the low effectiveness group, 6.7 times more likely to be classified in the low utilization group compared with the high utilization group, and 12.4 times more likely to be classified in the best performance group compared with the worst performance group. Serving a higher proportion of patients with low back pain syndromes was associated with an increased likelihood of being classified in the lowest or middle group. Years of physical therapist experience was inversely associated with being classified in the middle utilization group compared with the highest utilization group. These findings suggest that, in the treatment of patients with low back pain syndromes, clinics that are low utilizers of physical therapist assistants are more likely to provide superior care (ie, better patient outcomes and lower service use).
ERIC Educational Resources Information Center
Owate, C. N.; Iroha, Okpa
2013-01-01
This study investigates the availability and utilization of school library resources by Secondary School (High School) Students. Eight Selected Secondary Schools in Rivers State, Nigeria were chosen based on their performance in external examinations and geographic locations. In carrying out the research, questionnaires were administered to both…
Evaluation of high-energy-efficiency powertrain approaches: the 1996 futurecar challenge
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sluder, S.; Duoba, M.; Larsen, R.
Twelve colleges and universities were selected to design, build, and develop a mid-size vehicle that could achieve high energy economy while maintaining the performance characteristics of today`s mid-size vehicle. Many of the teams were able to increase the fuel economy of their vehicles, but most of these increases came at the expense of decreased performance or worsened emissions. This paper evaluates and summarizes the high-energy-efficiency powertrain technology approaches that were utilized in the 1996 FutureCar Challenge, which was the first evaluation of these vehicles in a two-year program. Of the 11 vehicles evaluated in the competition, nine utilized hybrid electricmore » vehicle approaches. This paper discusses the design trade- offs made by the teams to achieve high efficiency while trying to maintain stock performance.« less
Dompnier, Benoît; Darnon, Céline; Butera, Fabrizio
2013-09-01
Research on achievement goal promotion at University has shown that performance-approach goals are perceived as a means to succeed at University (high social utility) but are not appreciated (low social desirability). We argue that such a paradox could explain why research has detected that performance-approach goals consistently predict academic grades. First-year psychology students answered a performance-approach goal scale with standard, social desirability and social utility instructions. Participants' grades were recorded at the end of the semester. Results showed that the relationship between performance-approach goals and grades was inhibited by the increase of these goals' social desirability and facilitated by the increase of their social utility, revealing that the predictive validity of performance-approach goals depends on social value. © 2013 The British Psychological Society.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Imam, Neena; Koenig, Gregory A; Machovec, Dylan
2016-01-01
Abstract: The worth of completing parallel tasks is modeled using utility functions, which monotonically-decrease with time and represent the importance and urgency of a task. These functions define the utility earned by a task at the time of its completion. The performance of such a system is measured as the total utility earned by all completed tasks over some interval of time (e.g., 24 hours). To maximize system performance when scheduling dynamically arriving parallel tasks onto a high performance computing (HPC) system that is oversubscribed and energy-constrained, we have designed, analyzed, and compared different heuristic techniques. Four utility-aware heuristics (i.e.,more » Max Utility, Max Utility-per-Time, Max Utility-per-Resource, and Max Utility-per-Energy), three FCFS-based heuristics (Conservative Backfilling, EASY Backfilling, and FCFS with Multiple Queues), and a Random heuristic were examined in this study. A technique that is often used with the FCFS-based heuristics is the concept of a permanent reservation. We compare the performance of permanent reservations with temporary place-holders to demonstrate the advantages that place-holders can provide. We also present a novel energy filtering technique that constrains the maximum energy-per-resource used by each task. We conducted a simulation study to evaluate the performance of these heuristics and techniques in an energy-constrained oversubscribed HPC environment. With place-holders, energy filtering, and dropping tasks with low potential utility, our utility-aware heuristics are able to significantly outperform the existing FCFS-based techniques.« less
ERIC Educational Resources Information Center
Brown, Kathleen M.; Anfara, Vincent A., Jr.; Roney, Kathleen
2004-01-01
Utilizing a qualitative, multisite case study design and the theoretical framework of Hoy and Hannum (1997), the design and execution of this research investigates plausible explanations for the difference in student achievement between high performing (HPS) suburban middle schools and low performing (LPS) urban middle schools. Aside from the…
Test plan : Branson TRIP travel time/data accuracy
DOT National Transportation Integrated Search
2000-04-01
In the mid 1990's the FHWA established a High Performance Concrete (HPC) program aimed at demonstrating the positive effects of utilizing HPC in bridges. Research on the benefits of using high performance concrete for bridges has shown a number of be...
Primary zinc-air batteries for space power
NASA Technical Reports Server (NTRS)
Bragg, Bobby J.; Bourland, Deborah S.; Merry, Glenn; Putt, Ron
1992-01-01
Prismatic HR and LC cells and batteries were built and tested, and they performed well with respect to the program goals of high capacity and high rate capability at specific energies. The HR batteries suffered reduced utilizations owing to dryout at the 2 and 3 A rates for the 50 C tests owing to the requirement for forced convection. The LC batteries suffered reduced utilizations under all conditions owing to the chimney effect at 1 G, although this effect would not occur at 0 G. An empirical model was developed which accurately predicted utilizations and average voltages for single cells, although thermal effects encountered during battery testing caused significant deviations, both positive and negative, from the model. Based on the encouraging results of the test program, we believe that the zinc-air primary battery of a flat, stackable configuration can serve as a high performance and safe power source for a range of space applications.
ERIC Educational Resources Information Center
Petersen, Jennifer Lee; Hyde, Janet Shibley
2017-01-01
Although many studies have documented developmental change in mathematics motivation, little is known about how these trends predict math performance. A sample of 288 participants from the United States reported their perceived math ability, math utility value and math interest in 5th, 7th and 9th grades. Latent growth curve models estimated…
High Pt utilization PEMFC electrode obtained by alternative ion-exchange/electrodeposition.
Chen, Siguo; Wei, Zidong; Li, Hua; Li, Li
2010-12-14
High Pt utilization PEMFC electrodes were prepared by an alternative ion-exchange/electrodeposition (AIEE) technique. The results demonstrated that the MEA employing an AIEE electrode with a Pt loading of 0.014 mg Pt cm(-2) exhibits performance approximately 2.2 times larger than that employing a conventional Nafion-bonded Pt/C electrode with a same Pt loading.
Performance improvement of PEFC modules with cell containing low amount of platinum
DOE Office of Scientific and Technical Information (OSTI.GOV)
Miyake, Y.; Kadowaki, M.; Hamada, A.
1996-12-31
Cell components of the PEFC module were studied to improve the module performance. The cell performance in a high air utilization region was improved by selecting an air channel design of the separator in which high air flow speed was obtained. Optimization of Teflon{reg_sign} amount on the cathode backing carbon paper also contributed the cell performance. Modifications of the gas channel design and the backing carbon paper were carried out in a 200 cm{sup 2} x 20-cell module and 36-cell module. Dependence of air utilization on module performance was remarkably improved and power density of more than 0.3 W/cm{sup 2}more » was achieved in spite of the platinum amount in the cells was decreased to 1.1 Mg/cm{sup 2}.« less
Optimal Reward Functions in Distributed Reinforcement Learning
NASA Technical Reports Server (NTRS)
Wolpert, David H.; Tumer, Kagan
2000-01-01
We consider the design of multi-agent systems so as to optimize an overall world utility function when (1) those systems lack centralized communication and control, and (2) each agents runs a distinct Reinforcement Learning (RL) algorithm. A crucial issue in such design problems is to initialize/update each agent's private utility function, so as to induce best possible world utility. Traditional 'team game' solutions to this problem sidestep this issue and simply assign to each agent the world utility as its private utility function. In previous work we used the 'Collective Intelligence' framework to derive a better choice of private utility functions, one that results in world utility performance up to orders of magnitude superior to that ensuing from use of the team game utility. In this paper we extend these results. We derive the general class of private utility functions that both are easy for the individual agents to learn and that, if learned well, result in high world utility. We demonstrate experimentally that using these new utility functions can result in significantly improved performance over that of our previously proposed utility, over and above that previous utility's superiority to the conventional team game utility.
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
2016-02-24
The Woods is a sustainable community built by Habitat for Humanity in 2013. This community comprises 30 homes that are high-performance and energy-efficient. With support from Tacoma Public Utilities and the Bonneville Power Administration, the BA-PIRC team is researching the energy performance of these homes and the ductless heat pumps they employ.
ERIC Educational Resources Information Center
Daniel, Vivian Summerour
2011-01-01
The purpose of this within-group experimental study was to find out to what extent ninth-grade students improved their science performance beyond their middle school science performance at one Georgia high school utilizing a freshman academy model. Freshman academies have been recognized as a useful tool for increasing academic performance among…
Nonproliferation Challenges in Space Defense Technology - PANEL
NASA Technical Reports Server (NTRS)
Houts, Michael G.
2016-01-01
The use of highly enriched uranium (HEU) almost always "helps" space fission systems. Nuclear Thermal Propulsion (NTP) and high power fission electric systems appear able to use < 20% enriched uranium with minimal / acceptable performance impacts. However, lower power, "entry level" systems may be needed for space fission technology to be developed and utilized. Low power (i.e. approx.1 kWe) fission systems may have an unacceptable performance penalty if LEU is used instead of HEU. Are there Ways to Support Non-Proliferation Objectives While Simultaneously Helping Enable the Development and Utilization of Modern Space Fission Power and Propulsion Systems?
Design and implementation of online automatic judging system
NASA Astrophysics Data System (ADS)
Liang, Haohui; Chen, Chaojie; Zhong, Xiuyu; Chen, Yuefeng
2017-06-01
For lower efficiency and poorer reliability in programming training and competition by currently artificial judgment, design an Online Automatic Judging (referred to as OAJ) System. The OAJ system including the sandbox judging side and Web side, realizes functions of automatically compiling and running the tested codes, and generating evaluation scores and corresponding reports. To prevent malicious codes from damaging system, the OAJ system utilizes sandbox, ensuring the safety of the system. The OAJ system uses thread pools to achieve parallel test, and adopt database optimization mechanism, such as horizontal split table, to improve the system performance and resources utilization rate. The test results show that the system has high performance, high reliability, high stability and excellent extensibility.
A High-Performing Direct Carbon Fuel Cell with a 3D Architectured Anode Operated Below 600 °C.
Wu, Wei; Zhang, Yunya; Ding, Dong; He, Ting
2018-01-01
Direct carbon fuel cells (DCFCs) are highly efficient power generators fueled by abundant and cheap solid carbons. However, the limited triple-phase boundaries (TPBs) in the fuel electrode, due to the lack of direct contact among carbon, electrode, and electrolyte, inhibit the performance and result in poor fuel utilization. To address the challenges of low carbon oxidation activity and low carbon utilization, a highly efficient, 3D solid-state architected anode is developed to enhance the performance of DCFCs below 600 °C. The cell with the 3D textile anode framework, Gd:CeO 2 -Li/Na 2 CO 3 composite electrolyte, and Sm 0.5 Sr 0.5 CoO 3 cathode demonstrates excellent performance with maximum power densities of 143, 196, and 325 mW cm -2 at 500, 550, and 600 °C, respectively. At 500 °C, the cells can be operated steadily with a rated power density of ≈0.13 W cm -2 at a constant current density of 0.15 A cm -2 with a carbon utilization over 85.5%. These results, for the first time, demonstrate the feasibility of directly electrochemical oxidation of solid carbon at 500-600 °C, representing a promising strategy in developing high-performing fuel cells and other electrochemical systems via the integration of 3D architected electrodes. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
García, J B; Tormo, José R
2003-06-01
A new tool, HPLC Studio, was developed for the comparison of high-performance liquid chromatography (HPLC) chromatograms from microbial extracts. The new utility makes it possible to create a virtual chromatogram by mixing up to 20 individual chromatograms. The virtual chromatogram is the first step in establishing a ranking of the microbial fermentation conditions based on either the area or diversity of HPLC peaks. The utility was used to maximize the diversity of secondary metabolites tested from a microorganism and therefore increase the chances of finding new lead compounds in a drug discovery program.
DOT National Transportation Integrated Search
2000-04-01
In the mid 1990s the Federal Highway Administration (FHWA) established a High Performance Concrete (HPC) program aimed at demonstrating the positive effects of utilizing HPC in bridges. Research on the benefits of using HPC for bridges has shown a nu...
DOT National Transportation Integrated Search
2000-04-01
In the mid 1990s the Federal Highway Administration (FHWA) established a High Performance Concrete (HPC) program aimed at demonstrating the positive effects of utilizing HPC in bridges. Research on the benefits of using HPC for bridges has shown a nu...
RXIO: Design and implementation of high performance RDMA-capable GridFTP
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tian, Yuan; Yu, Weikuan; Vetter, Jeffrey S.
2011-12-21
For its low-latency, high bandwidth, and low CPU utilization, Remote Direct Memory Access (RDMA) has established itself as an effective data movement technology in many networking environments. However, the transport protocols of grid run-time systems, such as GridFTP in Globus, are not yet capable of utilizing RDMA. In this study, we examine the architecture of GridFTP for the feasibility of enabling RDMA. An RDMA-capable XIO (RXIO) framework is designed and implemented to extend its XIO system and match the characteristics of RDMA. Our experimental results demonstrate that RDMA can significantly improve the performance of GridFTP, reducing the latency by 32%more » and increasing the bandwidth by more than three times. In achieving such performance improvements, RDMA dramatically cuts down CPU utilization of GridFTP clients and servers. In conclusion, these results demonstrate that RXIO can effectively exploit the benefits of RDMA for GridFTP. It offers a good prototype to further leverage GridFTP on wide-area RDMA networks.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cloutier, Deborah; Hosseini, Farshid; White, Andrew
Evidence has shown that owning and operating energy-efficient, high-performance, “green” properties results in multiple benefits including lower utility bills, higher rents, improved occupancy, and greater net operating income. However, it is difficult to isolate and control moderating factors to identify the specific drivers behind improved financial performance and value to investors that results from sustainability in real estate. DOE is interested in facilitating deeper investigation of the correlation between energy efficiency and financial performance, reducing data acquisition and matching challenges, and developing a stronger understanding of how sustainable design and energy efficiency impact value. DOE commissioned this pilot study tomore » test the logistical and empirical procedures required to establish a Commercial Real Estate Data Aggregation & Trends Analysis lab, determine the potential benefits available through the lab, and contribute to the existing body of evidence in this field.« less
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
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lubliner, Michael; Howard, Luke; Hales, David
The Woods is a Habitat for Humanity (HFH) community of ENERGY STAR Homes Northwest (ESHNW)-certified homes located in the marine climate of Tacoma/Pierce County, Washington. This research report builds on an earlier preliminary draft 2014 BA report, and includes significant billing analysis and cost effectiveness research from a collaborative, ongoing Ductless Heat Pump (DHP)research effort for Tacoma Public Utilities (TPU) and Bonneville Power Administration (BPA). This report focuses on the results of field testing, modeling, and monitoring of ductless mini-split heat pump hybrid heating systems in seven homes built and first occupied at various times between September 2013 and Octobermore » 2014. The report also provides WSU documentation of high-performance home observations, lessons learned, and stakeholder recommendations for builders of affordable high-performance housing such as HFH. Tacoma Public Utilities (TPU) and Bonneville Power Administration (BPA). This report focuses on the results of field testing, modeling, and monitoring of ductless mini-split heat pump hybrid heating systems in seven homes built and first occupied at various times between September 2013 and October 2014. The report also provides WSU documentation of high-performance home observations, lessons learned, and stakeholder recommendations for builders of affordable high-performance housing such as HFH.« less
HPC on Competitive Cloud Resources
NASA Astrophysics Data System (ADS)
Bientinesi, Paolo; Iakymchuk, Roman; Napper, Jeff
Computing as a utility has reached the mainstream. Scientists can now easily rent time on large commercial clusters that can be expanded and reduced on-demand in real-time. However, current commercial cloud computing performance falls short of systems specifically designed for scientific applications. Scientific computing needs are quite different from those of the web applications that have been the focus of cloud computing vendors. In this chapter we demonstrate through empirical evaluation the computational efficiency of high-performance numerical applications in a commercial cloud environment when resources are shared under high contention. Using the Linpack benchmark as a case study, we show that cache utilization becomes highly unpredictable and similarly affects computation time. For some problems, not only is it more efficient to underutilize resources, but the solution can be reached sooner in realtime (wall-time). We also show that the smallest, cheapest (64-bit) instance on the studied environment is the best for price to performance ration. In light of the high-contention we witness, we believe that alternative definitions of efficiency for commercial cloud environments should be introduced where strong performance guarantees do not exist. Concepts like average, expected performance and execution time, expected cost to completion, and variance measures--traditionally ignored in the high-performance computing context--now should complement or even substitute the standard definitions of efficiency.
Lee, Eunwoo; Kim, Chanhoi; Jang, Jyongsik
2013-07-29
High-performance Förster resonance energy transfer (FRET)-based dye-sensitized solar cells (DSSCs) have been successfully fabricated through the optimized design of a CdSe/CdS quantum-dot (QD) donor and a dye acceptor. This simple approach enables quantum dots and dyes to simultaneously utilize the wide solar spectrum, thereby resulting in high conversion efficiency over a wide wavelength range. In addition, major parameters that affect the FRET interaction between donor and acceptor have been investigated including the fluorescent emission spectrum of QD, and the content of deposited QDs into the TiO2 matrix. By judicious control of these parameters, the FRET interaction can be readily optimized for high photovoltaic performance. In addition, the as-synthesized water-soluble quantum dots were highly dispersed in a nanoporous TiO2 matrix, thereby resulting in excellent contact between donors and acceptors. Importantly, high-performance FRET-based DSSCs can be prepared without any infrared (IR) dye synthetic procedures. This novel strategy offers great potential for applications of dye-sensitized solar cells. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Barber, Emma L; Dusetzina, Stacie B; Stitzenberg, Karyn B; Rossi, Emma C; Gehrig, Paola A; Boggess, John F; Garrett, Joanne M
2017-06-01
To estimate variation in the use of neoadjuvant chemotherapy by high volume hospitals and to determine the association between hospital utilization of neoadjuvant chemotherapy and survival. We identified incident cases of stage IIIC or IV epithelial ovarian cancer in the National Cancer Database from 2006 to 2012. Inclusion criteria were treatment at a high volume hospital (>20 cases/year) and treatment with both chemotherapy and surgery. A logistic regression model was used to predict receipt of neoadjuvant chemotherapy based on case-mix predictors (age, comorbidities, stage etc). Hospitals were categorized by the observed-to-expected ratio for neoadjuvant chemotherapy use as low, average, or high utilization hospitals. Survival analysis was performed. We identified 11,574 patients treated at 55 high volume hospitals. Neoadjuvant chemotherapy was used for 21.6% (n=2494) of patients and use varied widely by hospital, from 5%-55%. High utilization hospitals (n=1910, 10 hospitals) had a median neoadjuvant chemotherapy rate of 39% (range 23-55%), while low utilization hospitals (n=2671, 14 hospitals) had a median rate of 10% (range 5-17%). For all ovarian cancer patients adjusting for clinical and socio-demographic factors, treatment at a hospital with average or high neoadjuvant chemotherapy utilization was associated with a decreased rate of death compared to treatment at a low utilization hospital (HR 0.90 95% CI 0.83-0.97 and HR 0.85 95% CI 0.75-0.95). Wide variation exists in the utilization of neoadjuvant chemotherapy to treat stage IIIC and IV epithelial ovarian cancer even among high volume hospitals. Patients treated at hospitals with low rates of neoadjuvant chemotherapy utilization experience decreased survival. Copyright © 2017 Elsevier Inc. All rights reserved.
Barber, Emma L; Dusetzina, Stacie B; Stitzenberg, Karyn B; Rossi, Emma C; Gehrig, Paola A; Boggess, John F; Garrett, Joanne M
2017-01-01
Objective To estimate variation in the use of neoadjuvant chemotherapy by high volume hospitals and to determine the association between hospital utilization of neoadjuvant chemotherapy and survival. Methods We identified incident cases of stage IIIC or IV epithelial ovarian cancer in the National Cancer Database from 2006–2012. Inclusion criteria were treatment at a high volume hospital (>20 cases/yr) and treatment with both chemotherapy and surgery. A logistic regression model was used to predict receipt of neoadjuvant chemotherapy based on case-mix predictors (age, comorbidities, stage etc). Hospitals were categorized by the observed-to-expected ratio for neoadjuvant chemotherapy use as low, average, or high utilization hospitals. Survival analysis was performed. Results We identified 11,574 patients treated at 55 high volume hospitals. Neoadjuvant chemotherapy was used for 21.6% (n=2494) of patients and use varied widely by hospital, from 5%–55%. High utilization hospitals (n=1910, 10 hospitals) had a median neoadjuvant chemotherapy rate of 39% (range 23–55%), while low utilization hospitals (n=2671, 14 hospitals) had a median rate of 10% (range 5–17%). For all ovarian cancer patients adjusting for clinical and socio-demographic factors, treatment at a hospital with average or high neoadjuvant chemotherapy utilization was associated with a decreased rate of death compared to treatment at a low utilization hospital (HR 0.90 95%CI 0.83–0.97 and HR 0.85 95%CI 0.75–0.95). Conclusions Wide variation exists in the utilization of neoadjuvant chemotherapy to treat stage IIIC and IV epithelial ovarian cancer even among high volume hospitals. Patients treated at hospitals with low rates of neoadjuvant chemotherapy utilization experience decreased survival. PMID:28366545
High-Switching-Ratio Photodetectors Based on Perovskite CH₃NH₃PbI₃ Nanowires.
Zhang, Xin; Liu, Caichi; Ren, Gang; Li, Shiyun; Bi, Chenghao; Hao, Qiuyan; Liu, Hui
2018-05-10
Hybrid organic-inorganic perovskite materials have attracted extensive attention due to their impressive performance in photovoltaic devices. One-dimensional perovskite CH₃NH₃PbI₃ nanomaterials, possessing unique structural features such as large surface-to-volume ratio, anisotropic geometry and quantum confinement, may have excellent optoelectronic properties, which could be utilized to fabricate high-performance photodetectors. However, in comparison to CH₃NH₃PbI₃ thin films, reports on the fabrication of CH₃NH₃PbI₃ nanowires for optoelectrical application are rather limited. Herein, a two-step spin-coating process has been utilized to fabricate pure-phase and single-crystalline CH₃NH₃PbI₃ nanowires on a substrate without mesoporous TiO₂ or Al₂O₃. The size and density of CH₃NH₃PbI₃ nanowires can be easily controlled by changing the PbI₂ precursor concentration. The as-prepared CH₃NH₃PbI₃ nanowires are utilized to fabricate photodetectors, which exhibit a fairly high switching ratio of ~600, a responsivity of 55 mA/W, and a normalized detectivity of 0.5 × 10 11 jones under 532 nm light illumination (40 mW/cm²) at a very low bias voltage of 0.1 V. The as-prepared perovskite CH₃NH₃PbI₃ nanowires with excellent optoelectronic properties are regarded to be a potential candidate for high-performance photodetector application.
Reichard, Amanda; Gulley, Stephen P; Rasch, Elizabeth K; Chan, Leighton
2015-10-01
Under the ACA, new programs are being developed to enhance care coordination and reduce health care costs among people with chronic conditions, disabilities, and high utilization of health care. However, the relationships between these groups are not well understood. Our aims were to (1) identify high utilizers of health care in the U.S. working age (18-64) population, (2) examine the overlap between this group and people with chronic conditions and/or disabilities, (3) identify predictors of high service use or cost among these subpopulations, and (4) recommend approaches for stratification of individuals with high health care utilization. Using pooled national data from the Medical Expenditure Panel Survey (2006-2008), we created indices to identify elevated or high utilization and cost groups. We performed descriptive analyses, bivariate comparisons and multivariate analyses to examine the relations between these populations and individuals with chronic conditions and/or disabilities. While the large majority of persons with high use/cost had chronic conditions, the minority of persons with chronic conditions had high health care utilization. However, among persons with chronic conditions, disability was a significant predictor of high utilization. Annual expenditures were significantly elevated among people with disabilities, particularly when activities of daily living were limited. We conclude that medical diagnosis alone is insufficient for the development of eligibility criteria for, or the evaluation of, programs intended to better the delivery or coordination of services for high utilizers of health care services. New approaches are needed to assess functional limitations and identify ongoing needs for services and supports. Published by Elsevier Inc.
Analysis of advanced optical glass and systems
NASA Technical Reports Server (NTRS)
Johnson, R. Barry; Feng, Chen
1991-01-01
Optical lens systems performance utilizing optical materials comprising reluctant glass forming compositions was studied. Such special glasses are being explored by NASA/Marshall Space Flight Center (MSFC) researchers utilizing techniques such as containerless processing in space on the MSFC Acoustic Levitation Furnace and on the High Temperature Acoustic Levitation Furnace in the conceptual design phase for the United States Microgravity Laboratory (USML) series of shuttle flights. The application of high refractive index and low dispersive power glasses in optical lens design was investigated. The potential benefits and the impacts to the optical lens design performance were evaluated. The results of the studies revealed that the use of these extraordinary glasses can result in significant optical performance improvements. Recommendations of proposed optical properties for potential new glasses were also made. Applications of these new glasses are discussed, including the impact of high refractive index and low dispersive power, improvements of the system performance by using glasses which are located outside of traditional glass map, and considerations in establishing glass properties beyond conventional glass map limits.
Distributed Accounting on the Grid
NASA Technical Reports Server (NTRS)
Thigpen, William; Hacker, Thomas J.; McGinnis, Laura F.; Athey, Brian D.
2001-01-01
By the late 1990s, the Internet was adequately equipped to move vast amounts of data between HPC (High Performance Computing) systems, and efforts were initiated to link together the national infrastructure of high performance computational and data storage resources together into a general computational utility 'grid', analogous to the national electrical power grid infrastructure. The purpose of the Computational grid is to provide dependable, consistent, pervasive, and inexpensive access to computational resources for the computing community in the form of a computing utility. This paper presents a fully distributed view of Grid usage accounting and a methodology for allocating Grid computational resources for use on a Grid computing system.
USDA-ARS?s Scientific Manuscript database
A method for the identification and quantification of citrus limonoid glucosides in juices based upon high performance liquid chromatography (HPLC) separation coupled to post-column reaction with Ehrlichs’s reagent has been developed. This method utilizes a phenyl stationary phase and an isocratic ...
ERIC Educational Resources Information Center
Smith, Eugene T.; Hill, Marc
2011-01-01
In this laboratory exercise, students develop a LabVIEW-controlled high-performance liquid chromatography system utilizing a data acquisition device, two pumps, a detector, and fraction collector. The programming experience involves a variety of methods for interface communication, including serial control, analog-to-digital conversion, and…
Turbulence modeling of free shear layers for high-performance aircraft
NASA Technical Reports Server (NTRS)
Sondak, Douglas L.
1993-01-01
The High Performance Aircraft (HPA) Grand Challenge of the High Performance Computing and Communications (HPCC) program involves the computation of the flow over a high performance aircraft. A variety of free shear layers, including mixing layers over cavities, impinging jets, blown flaps, and exhaust plumes, may be encountered in such flowfields. Since these free shear layers are usually turbulent, appropriate turbulence models must be utilized in computations in order to accurately simulate these flow features. The HPCC program is relying heavily on parallel computers. A Navier-Stokes solver (POVERFLOW) utilizing the Baldwin-Lomax algebraic turbulence model was developed and tested on a 128-node Intel iPSC/860. Algebraic turbulence models run very fast, and give good results for many flowfields. For complex flowfields such as those mentioned above, however, they are often inadequate. It was therefore deemed that a two-equation turbulence model will be required for the HPA computations. The k-epsilon two-equation turbulence model was implemented on the Intel iPSC/860. Both the Chien low-Reynolds-number model and a generalized wall-function formulation were included.
Cascade heat recovery with coproduct gas production
Brown, William R.; Cassano, Anthony A.; Dunbobbin, Brian R.; Rao, Pradip; Erickson, Donald C.
1986-01-01
A process for the integration of a chemical absorption separation of oxygen and nitrogen from air with a combustion process is set forth wherein excess temperature availability from the combustion process is more effectively utilized to desorb oxygen product from the absorbent and then the sensible heat and absorption reaction heat is further utilized to produce a high temperature process stream. The oxygen may be utilized to enrich the combustion process wherein the high temperature heat for desorption is conducted in a heat exchange preferably performed with a pressure differential of less than 10 atmospheres which provides considerable flexibility in the heat exchange.
Tse computers. [ultrahigh speed optical processing for two dimensional binary image
NASA Technical Reports Server (NTRS)
Schaefer, D. H.; Strong, J. P., III
1977-01-01
An ultra-high-speed computer that utilizes binary images as its basic computational entity is being developed. The basic logic components perform thousands of operations simultaneously. Technologies of the fiber optics, display, thin film, and semiconductor industries are being utilized in the building of the hardware.
Performance-Based Regulation In A High Distributed Energy Resources Future
DOE Office of Scientific and Technical Information (OSTI.GOV)
Newton Lowry, Mark; Woolf, Tim; Schwartz, Lisa C.
Performance-based regulation (PBR) of utilities has emerged as an important ratemaking option in the last 25 years. It has been implemented in numerous jurisdictions across the United States and is common in many other advanced industrialized countries. PBR’s appeal lies chiefly in its ability to strengthen utility performance incentives relative to traditional cost-of-service regulation (COSR). Some forms of PBR can streamline regulation and provide utilities with greater operating flexibility. Ideally, the benefits of better performance are shared by the utility and its customers. The shortcomings of traditional COSR in providing electric utilities with incentives that are aligned with certain regulatorymore » goals are becoming increasingly clear. In particular, COSR can provide strong incentives to increase electricity sales and utility rate base. Further, some parties express concern that traditional COSR does not provide utilities with appropriate financial incentives to address evolving industry challenges such as changing customer demands for electricity services, increased levels of distributed energy resources (DERs), and growing pressure to mitigate carbon dioxide emissions. In addition, attention to potential new regulatory models to support the “utility of the future” has renewed interest in PBR. This report describes key elements of PBR and explains some of the advantages and disadvantages of various PBR options. We present pertinent issues from the perspectives of utilities and customers. In practice, these different perspectives are not diametrically opposed. Nonetheless, this framework is useful for illustrating how various aspects of PBR may be viewed by those key groups. Regulators have a unique perspective, in that they must balance consumer, utility, and other interests with the goal of achieving a result that is in the overall public interest.« less
Glassman, Lisa H; Kuster, Anootnara T; Shaw, Jena A; Forman, Evan M; Izzetoglu, Meltem; Matteucci, Alyssa; Herbert, James D
2017-06-01
Functional near-infrared (fNIR) spectroscopy is a promising new technology that has demonstrated utility in the study of normal human cognition. We utilized fNIR spectroscopy to examine the effect of social anxiety and performance on hemodynamic activity in the dorsolateral prefrontal cortex (DLPFC). Socially phobic participants and non-clinical participants with varying levels of social anxiety completed a public speaking task in front of a small virtual audience while the DLPFC was being monitored by the fNIR device. The relationship between anxiety and both blood volume (BV) and deoxygenated hemoglobin (Hb) varied significantly as a function of speech performance, such that individuals with low social anxiety who performed well showed an increase in DLPFC activation relative to those who did not perform well. This result suggests that effortful thinking and/or efficient top-down inhibitory control may have been required to complete an impromptu speech task with good performance. In contrast, good performers who were highly socially anxious showed lower DLPFC activation relative to good performers who were low in social anxiety, suggesting autopilot thinking or less-effortful thinking. In poor performers, slight increases in DLPFC activation were observed from low to highly anxious individuals, which may reflect a shift from effortless thinking to heightened self-focused attention. Heightened self-focused attention, poor inhibitory control resulting in excessive fear or anxiety, or low motivation may lower performance. These results suggest that there can be different underlying mechanisms in the brain that affect the level of speech performance in individuals with varying degrees of social anxiety. This study highlights the utility of the fNIR device in the assessment of changes in DLPFC in response to exposure to realistic phobic stimuli, and further supports the potential utility of this technology in the study of the neurophysiology of anxiety disorders.
Anaerobic Threshold: Its Concept and Role in Endurance Sport
Ghosh, Asok Kumar
2004-01-01
aerobic to anaerobic transition intensity is one of the most significant physiological variable in endurance sports. Scientists have explained the term in various ways, like, Lactate Threshold, Ventilatory Anaerobic Threshold, Onset of Blood Lactate Accumulation, Onset of Plasma Lactate Accumulation, Heart Rate Deflection Point and Maximum Lactate Steady State. But all of these have great role both in monitoring training schedule and in determining sports performance. Individuals endowed with the possibility to obtain a high oxygen uptake need to complement with rigorous training program in order to achieve maximal performance. If they engage in endurance events, they must also develop the ability to sustain a high fractional utilization of their maximal oxygen uptake (%VO2 max) and become physiologically efficient in performing their activity. Anaerobic threshold is highly correlated to the distance running performance as compared to maximum aerobic capacity or VO2 max, because sustaining a high fractional utilization of the VO2 max for a long time delays the metabolic acidosis. Training at or little above the anaerobic threshold intensity improves both the aerobic capacity and anaerobic threshold level. Anaerobic Threshold can also be determined from the speed-heart rate relationship in the field situation, without undergoing sophisticated laboratory techniques. However, controversies also exist among scientists regarding its role in high performance sports. PMID:22977357
Anaerobic threshold: its concept and role in endurance sport.
Ghosh, Asok Kumar
2004-01-01
aerobic to anaerobic transition intensity is one of the most significant physiological variable in endurance sports. Scientists have explained the term in various ways, like, Lactate Threshold, Ventilatory Anaerobic Threshold, Onset of Blood Lactate Accumulation, Onset of Plasma Lactate Accumulation, Heart Rate Deflection Point and Maximum Lactate Steady State. But all of these have great role both in monitoring training schedule and in determining sports performance. Individuals endowed with the possibility to obtain a high oxygen uptake need to complement with rigorous training program in order to achieve maximal performance. If they engage in endurance events, they must also develop the ability to sustain a high fractional utilization of their maximal oxygen uptake (%VO(2) max) and become physiologically efficient in performing their activity. Anaerobic threshold is highly correlated to the distance running performance as compared to maximum aerobic capacity or VO(2) max, because sustaining a high fractional utilization of the VO(2) max for a long time delays the metabolic acidosis. Training at or little above the anaerobic threshold intensity improves both the aerobic capacity and anaerobic threshold level. Anaerobic Threshold can also be determined from the speed-heart rate relationship in the field situation, without undergoing sophisticated laboratory techniques. However, controversies also exist among scientists regarding its role in high performance sports.
An Incremental High-Utility Mining Algorithm with Transaction Insertion
Gan, Wensheng; Zhang, Binbin
2015-01-01
Association-rule mining is commonly used to discover useful and meaningful patterns from a very large database. It only considers the occurrence frequencies of items to reveal the relationships among itemsets. Traditional association-rule mining is, however, not suitable in real-world applications since the purchased items from a customer may have various factors, such as profit or quantity. High-utility mining was designed to solve the limitations of association-rule mining by considering both the quantity and profit measures. Most algorithms of high-utility mining are designed to handle the static database. Fewer researches handle the dynamic high-utility mining with transaction insertion, thus requiring the computations of database rescan and combination explosion of pattern-growth mechanism. In this paper, an efficient incremental algorithm with transaction insertion is designed to reduce computations without candidate generation based on the utility-list structures. The enumeration tree and the relationships between 2-itemsets are also adopted in the proposed algorithm to speed up the computations. Several experiments are conducted to show the performance of the proposed algorithm in terms of runtime, memory consumption, and number of generated patterns. PMID:25811038
USDA-ARS?s Scientific Manuscript database
This study evaluated dairy heifer growth performance and total tract nutrient digestion when fed diets high in dried distillers grains with solubles (DDGS) with different forage particle size. An 8-wk randomized complete block design study was conducted utilizing twenty-two Holstein heifers (123 ±...
ERIC Educational Resources Information Center
Sarwar, Shakeel; Aslam, Hassan Danyal; Rasheed, Muhammad Imran
2012-01-01
Purpose: The aim of the researchers in this endeavor is to identify the challenges and obstacles faced by beginning teachers in higher education. This study also explores practical implications and what adaptation can be utilized in order to have high performance of the beginning teachers. Design/methodology/approach: Researchers have applied…
USDA-ARS?s Scientific Manuscript database
The pigment, 8-O-methylbostrycoidin is a polyketide metabolite produced by multiple species of the fungus Fusarium that infects plant crops, including maize. A technique was developed for the analysis of 8-O-methylbostrycoidin by high performance liquid chromatography coupled to electrospray ionizat...
Wang, Chu; Li, Xianglong; Pan, Yuyu; Zhang, Shitong; Yao, Liang; Bai, Qing; Li, Weijun; Lu, Ping; Yang, Bing; Su, Shijian; Ma, Yuguang
2016-02-10
Photoluminescence (PL) efficiency and exciton utilization efficiency are two key parameters to harvest high-efficiency electroluminescence (EL) in organic light-emitting diodes (OLEDs). But it is not easy to simultaneously combine these two characteristics (high PL efficiency and high exciton utilization) into a fluorescent material. In this work, an efficient combination was achieved through two concepts of hybridized local and charge-transfer (CT) state (HLCT) and "hot exciton", in which the former is responsible for high PL efficiency while the latter contributes to high exciton utilization. On the basis of a tiny chemical modification in TPA-BZP, a green-light donor-acceptor molecule, we designed and synthesized CzP-BZP with this efficeient combination of high PL efficiency of η(PL) = 75% in the solid state and maximal exciton utilization efficiency up to 48% (especially, the internal quantum efficiency of η(IQE) = 35% substantially exceed 25% of spin statistics limit) in OLED. The nondoped OLED of CzP-BZP exhibited an excellent performance: a green emission with a CIE coordinate of (0.34, 0.60), a maximum current efficiency of 23.99 cd A(-1), and a maximum external quantum efficiency (EQE, η(EQE)) of 6.95%. This combined HLCT state and "hot exciton" strategy should be a practical way to design next-generation, low-cost, high-efficiency fluorescent OLED materials.
Superconducting Rebalance Accelerometer
NASA Technical Reports Server (NTRS)
Torti, R. P.; Gerver, M.; Leary, K. J.; Jagannathan, S.; Dozer, D. M.
1996-01-01
A multi-axis accelerometer which utilizes a magnetically-suspended, high-TC proof mass is under development. The design and performance of a single axis device which is stabilized actively in the axial direction but which utilizes ring magnets for passive radial stabilization is discussed. The design of a full six degree-of-freedom device version is also described.
Network bandwidth utilization forecast model on high bandwidth networks
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yoo, Wuchert; Sim, Alex
With the increasing number of geographically distributed scientific collaborations and the scale of the data size growth, it has become more challenging for users to achieve the best possible network performance on a shared network. We have developed a forecast model to predict expected bandwidth utilization for high-bandwidth wide area network. The forecast model can improve the efficiency of resource utilization and scheduling data movements on high-bandwidth network to accommodate ever increasing data volume for large-scale scientific data applications. Univariate model is developed with STL and ARIMA on SNMP path utilization data. Compared with traditional approach such as Box-Jenkins methodology,more » our forecast model reduces computation time by 83.2%. It also shows resilience against abrupt network usage change. The accuracy of the forecast model is within the standard deviation of the monitored measurements.« less
Network Bandwidth Utilization Forecast Model on High Bandwidth Network
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yoo, Wucherl; Sim, Alex
With the increasing number of geographically distributed scientific collaborations and the scale of the data size growth, it has become more challenging for users to achieve the best possible network performance on a shared network. We have developed a forecast model to predict expected bandwidth utilization for high-bandwidth wide area network. The forecast model can improve the efficiency of resource utilization and scheduling data movements on high-bandwidth network to accommodate ever increasing data volume for large-scale scientific data applications. Univariate model is developed with STL and ARIMA on SNMP path utilization data. Compared with traditional approach such as Box-Jenkins methodology,more » our forecast model reduces computation time by 83.2percent. It also shows resilience against abrupt network usage change. The accuracy of the forecast model is within the standard deviation of the monitored measurements.« less
Connecting Performance Analysis and Visualization to Advance Extreme Scale Computing
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bremer, Peer-Timo; Mohr, Bernd; Schulz, Martin
2015-07-29
The characterization, modeling, analysis, and tuning of software performance has been a central topic in High Performance Computing (HPC) since its early beginnings. The overall goal is to make HPC software run faster on particular hardware, either through better scheduling, on-node resource utilization, or more efficient distributed communication.
Cascade heat recovery with coproduct gas production
Brown, W.R.; Cassano, A.A.; Dunbobbin, B.R.; Rao, P.; Erickson, D.C.
1986-10-14
A process for the integration of a chemical absorption separation of oxygen and nitrogen from air with a combustion process is set forth wherein excess temperature availability from the combustion process is more effectively utilized to desorb oxygen product from the absorbent and then the sensible heat and absorption reaction heat is further utilized to produce a high temperature process stream. The oxygen may be utilized to enrich the combustion process wherein the high temperature heat for desorption is conducted in a heat exchange preferably performed with a pressure differential of less than 10 atmospheres which provides considerable flexibility in the heat exchange. 4 figs.
High-Temperature Stable Anatase Titanium Oxide Nanofibers for Lithium-Ion Battery Anodes.
Lee, Sangkyu; Eom, Wonsik; Park, Hun; Han, Tae Hee
2017-08-02
Control of the crystal structure of electrochemically active materials is an important approach to fabricating high-performance electrodes for lithium-ion batteries (LIBs). Here, we report a methodology for controlling the crystal structure of TiO 2 nanofibers by adding aluminum isopropoxide to a common sol-gel precursor solution utilized to create TiO 2 nanofibers. The introduction of aluminum cations impedes the phase transformation of electrospun TiO 2 nanofibers from the anatase to the rutile phase, which inevitably occurs in the typical annealing process utilized for the formation of TiO 2 crystals. As a result, high-temperature stable anatase TiO 2 nanofibers were created in which the crystal structure was well-maintained even at high annealing temperatures of up to 700 °C. Finally, the resulting anatase TiO 2 nanofibers were utilized to prepare LIB anodes, and their electrochemical performance was compared to pristine TiO 2 nanofibers that contain both anatase and rutile phases. Compared to the electrode prepared with pristine TiO 2 nanofibers, the electrode prepared with anatase TiO 2 nanofibers exhibited excellent electrochemical performances such as an initial Coulombic efficiency of 83.9%, a capacity retention of 89.5% after 100 cycles, and a rate capability of 48.5% at a current density of 10 C (1 C = 200 mA g -1 ).
Diagnostic utility of abdominal ultrasonography in dogs with chronic vomiting.
Leib, M S; Larson, M M; Panciera, D L; Troy, G C; Monroe, W E; Rossmeisl, J H; Forrester, S D; Herring, E S
2010-01-01
Chronic vomiting is a common problem in dogs that has many causes. Ultrasonographic descriptions of many gastrointestinal (GI) diseases have been published. However, diagnostic utility of ultrasonography in dogs with chronic vomiting has not been investigated. Diagnostic utility of abdominal ultrasound will be highest in dogs with GI neoplasia and lowest in those with inflammatory disorders. Eighty-nine pet dogs with chronic vomiting. Medical records were reviewed and the contribution of abdominal ultrasound to the clinical diagnosis was subjectively scored. In 68.5% of dogs, the reviewers thought that the same diagnosis would have been reached without performing ultrasonography. In 22.5% of dogs, the ultrasound examination was considered to be vital or beneficial to the diagnosis. Univariable analysis identified that increased diagnostic utility was associated with increasing age, a greater number of vomiting episodes per week, presence of weight loss, a greater percentage of lost body weight, and a final diagnosis of GI lymphoma or gastric adenocarcinoma. However, multivariate analysis only identified increasing age and a final diagnosis of gastric adenocarcinoma or GI lymphoma to be associated with increased diagnostic utility. In 12.4% of dogs, additional benefits of ultrasonography to case management, excluding the contribution to the vomiting problem, were identified. The diagnostic utility of abdominal ultrasonography was high in 27% of dogs. The presence of factors that are associated with high diagnostic utility is an indication to perform abdominal ultrasonography in dogs with chronic vomiting.
Control of Spin Wave Dynamics in Spatially Twisted Magnetic Structures
2017-06-27
realize high-performance spintronic and magnetic storage devices. 15. SUBJECT TERMS nano- electronics , spin, wave, magnetic, multi-functional, device 16... electronics has required us to develop high-performance and multi-functional electronic devices driven with extremely low power consumption...Spintronics”, simultaneously utilizing the charge and the spin of electrons , provides us with solutions to essential problems for semiconductor-based
Quick, Jacob A; MacIntyre, Allan D; Barnes, Stephen L
2014-02-01
Surgical airway creation has a high potential for disaster. Conventional methods can be cumbersome and require special instruments. A simple method utilizing three steps and readily available equipment exists, but has yet to be adequately tested. Our objective was to compare conventional cricothyroidotomy with the three-step method utilizing high-fidelity simulation. Utilizing a high-fidelity simulator, 12 experienced flight nurses and paramedics performed both methods after a didactic lecture, simulator briefing, and demonstration of each technique. Six participants performed the three-step method first, and the remaining 6 performed the conventional method first. Each participant was filmed and timed. We analyzed videos with respect to the number of hand repositions, number of airway instrumentations, and technical complications. Times to successful completion were measured from incision to balloon inflation. The three-step method was completed faster (52.1 s vs. 87.3 s; p = 0.007) as compared with conventional surgical cricothyroidotomy. The two methods did not differ statistically regarding number of hand movements (3.75 vs. 5.25; p = 0.12) or instrumentations of the airway (1.08 vs. 1.33; p = 0.07). The three-step method resulted in 100% successful airway placement on the first attempt, compared with 75% of the conventional method (p = 0.11). Technical complications occurred more with the conventional method (33% vs. 0%; p = 0.05). The three-step method, using an elastic bougie with an endotracheal tube, was shown to require fewer total hand movements, took less time to complete, resulted in more successful airway placement, and had fewer complications compared with traditional cricothyroidotomy. Published by Elsevier Inc.
Three-Dimensional Nanobiocomputing Architectures With Neuronal Hypercells
2007-06-01
Neumann architectures, and CMOS fabrication. Novel solutions of massive parallel distributed computing and processing (pipelined due to systolic... and processing platforms utilizing molecular hardware within an enabling organization and architecture. The design technology is based on utilizing a...Microsystems and Nanotechnologies investigated a novel 3D3 (Hardware Software Nanotechnology) technology to design super-high performance computing
Durairaju Nisshanthini, S; Teresa Infanta S, Antony K; Raja, Duraisamy Senthil; Natarajan, Karuppannan; Palaniswamy, M; Angayarkanni, Jayaraman
2015-04-01
Soil and water samples were collected from various regions of SIPCOT and nearby Vanappadi Lake, Ranipet, Tamilnadu, India. Based on their colony morphology and their stability during subculturing, 72 bacteria were isolated, of which 14 isolates were actinomycetes. Preliminary selection was carried out to exploit the ability of the microorganisms to utilize sodium cyanate as nitrogen source. Those organisms that were able to utilize cyanate were subjected to secondary screening viz., utilization of sodium cyanide as the nitrogen source. The oxygenolytic cleavage of cyanide is dependent on cyanide monooxygenase which obligately requires pterin cofactor for its activity. Based on this, the organisms capable of utilizing sodium cyanide were tested for the presence of pterin. Thin layer chromatography (TLC) of the cell extracts using n-butanol: 5 N glacial acetic acid (4:1) revealed that 10 out of 12 organisms that were able to utilize cyanide had the pterin-related blue fluorescent compound in the cell extract. The cell extracts of these 10 organisms were subjected to high performance thin layer chromatography (HPTLC) for further confirmation using a pterin standard. Based on the incubation period, cell biomass yield, peak height and area, strain VPW3 was selected and was identified as Bacillus subtilis. The Rf value of the cell extract was 0.73 which was consistent with the 0.74 Rf value of the pterin standard when scanned at 254 nm. The compound was extracted and purified by preparative High Performance Liquid Chromatography (HPLC). Characterization of the compound was performed by ultraviolet spectrum, fluorescence spectrum, Electrospray Ionization-Mass Spectrometry (ESI-MS), and Nuclear Magnetic Resonance spectroscopy (NMR). The compound is proposed to be 6-propionyl pterin (2-amino-6-propionyl-3H-pteridin-4-one).
Selective Dry Etch for Defining Ohmic Contacts for High Performance ZnO TFTs
2014-03-27
scale, high-frequency ZnO thin - film transistors (TFTs) could be fabricated. Molybdenum, tantalum, titanium tungsten 10-90, and tungsten metallic contact... thin - film transistor layout utilized in the thesis research . . . . . 42 3.4 Process Flow Diagram for Optical and e-Beam Devices...TFT thin - film transistor TLM transmission line model UV ultra-violet xvii SELECTIVE DRY ETCH FOR DEFINING OHMIC CONTACTS FOR HIGH PERFORMANCE ZnO TFTs
NASA Technical Reports Server (NTRS)
Ramsey, W. D.
1980-01-01
Inert gas performance with three types of 12 cm diameter magnetoelectrostatic containment (MESC) ion thrusters was tested. The types tested included: (1) a hemispherical shaped discharge chamber with platinum cobalt magnets; (2) three different lengths of the hemispherical chambers with samarium cobalt magnets; and (3) three lengths of the conical shaped chambers with aluminum nickel cobalt magnets. The best argon performance was produced by a 8.0 cm long conical chamber with alnico magnets. The best xenon high mass utilization performance was obtained with the same 8.0 cm long conical thruster. The hemispherical thruster obtained 75 to 87% mass utilization at 185 to 205 eV/ion of singly charged ion equivalent beam.
NASA Technical Reports Server (NTRS)
Turner, Mark G.; Reed, John A.; Ryder, Robert; Veres, Joseph P.
2004-01-01
A Zero-D cycle simulation of the GE90-94B high bypass turbofan engine has been achieved utilizing mini-maps generated from a high-fidelity simulation. The simulation utilizes the Numerical Propulsion System Simulation (NPSS) thermodynamic cycle modeling system coupled to a high-fidelity full-engine model represented by a set of coupled 3D computational fluid dynamic (CFD) component models. Boundary conditions from the balanced, steady state cycle model are used to define component boundary conditions in the full-engine model. Operating characteristics of the 3D component models are integrated into the cycle model via partial performance maps generated from the CFD flow solutions using one-dimensional mean line turbomachinery programs. This paper highlights the generation of the high-pressure compressor, booster, and fan partial performance maps, as well as turbine maps for the high pressure and low pressure turbine. These are actually "mini-maps" in the sense that they are developed only for a narrow operating range of the component. Results are compared between actual cycle data at a take-off condition and the comparable condition utilizing these mini-maps. The mini-maps are also presented with comparison to actual component data where possible.
Jung, Jae Woong; Chueh, Chu-Chen; Jen, Alex K. -Y.
2015-07-06
High-performance planar heterojunction perovskite (CH3NH3PbI3) solar cell (PVSC) is demonstrated by utilizing CuSCN as a hole-transporting layer. Efficient hole-transport and hole-extraction at the CuSCN/CH3NH3PbI3 interface facilitate the PVSCs to reach 16% power conversion efficiency (PCE). In addition, excellent transparency of CuSCN enables high-performance semitransparent PVSC (10% PCE and 25% average visible transmittance) to be realized.
Mining of high utility-probability sequential patterns from uncertain databases
Zhang, Binbin; Fournier-Viger, Philippe; Li, Ting
2017-01-01
High-utility sequential pattern mining (HUSPM) has become an important issue in the field of data mining. Several HUSPM algorithms have been designed to mine high-utility sequential patterns (HUPSPs). They have been applied in several real-life situations such as for consumer behavior analysis and event detection in sensor networks. Nonetheless, most studies on HUSPM have focused on mining HUPSPs in precise data. But in real-life, uncertainty is an important factor as data is collected using various types of sensors that are more or less accurate. Hence, data collected in a real-life database can be annotated with existing probabilities. This paper presents a novel pattern mining framework called high utility-probability sequential pattern mining (HUPSPM) for mining high utility-probability sequential patterns (HUPSPs) in uncertain sequence databases. A baseline algorithm with three optional pruning strategies is presented to mine HUPSPs. Moroever, to speed up the mining process, a projection mechanism is designed to create a database projection for each processed sequence, which is smaller than the original database. Thus, the number of unpromising candidates can be greatly reduced, as well as the execution time for mining HUPSPs. Substantial experiments both on real-life and synthetic datasets show that the designed algorithm performs well in terms of runtime, number of candidates, memory usage, and scalability for different minimum utility and minimum probability thresholds. PMID:28742847
Electric utility of the year for 1984: Potomac Electric Power
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1984-11-01
High performance, efficiency improvements, a modest construction program, a clear balance sheet, and an effort to expend power plant life were among the qualities that earned Potomac Electric Power (PEPCO) the title of 1984 Utility of the Year. Other key elements in the utility's selection were its strategy for purchasing power, a load management plan, diversified investments into subsidiary businesses, community concern that considers the aesthetics of transmission facilities, and its interest in personnel development, especially among minorities. 3 figures.
Rechargeable Al-CO2 Batteries for Reversible Utilization of CO2.
Ma, Wenqing; Liu, Xizheng; Li, Chao; Yin, Huiming; Xi, Wei; Liu, Ruirui; He, Guang; Zhao, Xian; Luo, Jun; Ding, Yi
2018-05-21
The excessive emission of CO 2 and the energy crisis are two major issues facing humanity. Thus, the electrochemical reduction of CO 2 and its utilization in metal-CO 2 batteries have attracted wide attention because the batteries can simultaneously accelerate CO 2 fixation/utilization and energy storage/release. Here, rechargeable Al-CO 2 batteries are proposed and realized, which use chemically stable Al as the anode. The batteries display small discharge/charge voltage gaps down to 0.091 V and high energy efficiencies up to 87.7%, indicating an efficient battery performance. Their chemical reaction mechanism to produce the performance is revealed to be 4Al + 9CO 2 ↔ 2Al 2 (CO 3 ) 3 + 3C, by which CO 2 is reversibly utilized. These batteries are envisaged to effectively and safely serve as a potential CO 2 fixation/utilization strategy with stable Al. © 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
FTOOLS: A FITS Data Processing and Analysis Software Package
NASA Astrophysics Data System (ADS)
Blackburn, J. Kent; Greene, Emily A.; Pence, William
1993-05-01
FTOOLS, a highly modular collection of utilities for processing and analyzing data in the FITS (Flexible Image Transport System) format, has been developed in support of the HEASARC (High Energy Astrophysics Research Archive Center) at NASA's Goddard Space Flight Center. Each utility performs a single simple task such as presentation of file contents, extraction of specific rows or columns, appending or merging tables, binning values in a column or selecting subsets of rows based on a boolean expression. Individual utilities can easily be chained together in scripts to achieve more complex operations such as the generation and displaying of spectra or light curves. The collection of utilities provides both generic processing and analysis utilities and utilities common to high energy astrophysics data sets. The FTOOLS software package is designed to be both compatible with IRAF and completely stand alone in a UNIX or VMS environment. The user interface is controlled by standard IRAF parameter files. The package is self documenting through the IRAF help facility and a stand alone help task. Software is written in ANSI C and FORTRAN to provide portability across most computer systems. The data format dependencies between hardware platforms are isolated through the FITSIO library package.
NASA Astrophysics Data System (ADS)
Daniel, Vivian Summerour
The purpose of this within-group experimental study was to find out to what extent ninth-grade students improved their science performance beyond their middle school science performance at one Georgia high school utilizing a freshman academy model. Freshman academies have been recognized as a useful tool for increasing academic performance among ninth-grade students because they address a range of academic support initiatives tailored to improve academic performance among ninth-grade students. The talent development model developed by Legters, Balfanz, Jordan, and McPartland (2002) has served as a foundational standard for many ninth grade academy programs. A cornerstone feature of this model is the creation of small learning communities used to increase ninth-grade student performance. Another recommendation was to offer credit recovery opportunities for ninth graders along with creating parent and community involvement activities to increase academic success among ninth-grade students. While the site's program included some of the initiatives outlined by the talent development model, it did not utilize all of them. The study concluded that the academy did not show a definitive increase in academic performance among ninth-grade students since most students stayed within their original performance category.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gao, Zhiming; Lin, Zhenhong; Franzese, Oscar
This paper evaluates the application of battery electric vehicles (BEVs) and genset plug-in hybrid electric vehicles (PHEVs) to Class-7 local delivery trucks and genset PHEV for Class-8 utility bucket trucks over widely real-world driving data performed by conventional heavy-duty trucks. A simulation tool based on vehicle tractive energy methodology and component efficiency for addressing component and system performance was developed to evaluate the energy consumption and performance of the trucks. As part of this analysis, various battery sizes combined with different charging powers on the E-Trucks for local delivery and utility bucket applications were investigated. The results show that themore » E-Truck applications not only reduce energy consumption but also achieve significant energy cost savings. For delivery E-Trucks, the results show that periodic stops at delivery sites provide sufficient time for battery charging, and for this reason, a high-power charger is not necessary. For utility bucket PHEV trucks, energy consumption per mile of bucket truck operation is typically higher because of longer idling times and extra high idling load associated with heavy utility work. The availability of on-route charging is typically lacking at the work sites of bucket trucks; hence, the battery size of these trucks is somewhat larger than that of the delivery trucks studied.« less
Flywheel Energy Storage Technology Workshop
NASA Astrophysics Data System (ADS)
Okain, D.; Howell, D.
Advances in recent years of high strength/lightweight materials, high performance magnetic bearings, and power electronics technology has spurred a renewed interest by the transportation, utility, and manufacturing industries in flywheel energy storage (FES) technologies. FES offers several advantages over conventional electrochemical energy storage, such as high specific energy and specific power, fast charging time, long service life, high turnaround efficiency (energy out/energy in), and no hazardous/toxic materials or chemicals are involved. Potential applications of FES units include power supplies for hybrid and electric vehicles, electric vehicle charging stations, space systems, and pulsed power devices. Also, FES units can be used for utility load leveling, uninterruptable power supplies to protect electronic equipment and electrical machinery, and for intermittent wind or photovoltaic energy sources. The purpose of this workshop is to provide a forum to highlight technologies that offer a high potential to increase the performance of FES systems and to discuss potential solutions to overcome present FES application barriers. This document consists of viewgraphs from 27 presentations.
A review of materials for spectral design coatings in signature management applications
NASA Astrophysics Data System (ADS)
Andersson, Kent E.; Škerlind, Christina
2014-10-01
The current focus in Swedish policy towards national security and high-end technical systems, together with a rapid development in multispectral sensor technology, adds to the utility of developing advanced materials for spectral design in signature management applications. A literature study was performed probing research databases for advancements. Qualitative text analysis was performed using a six-indicator instrument: spectrally selective reflectance; low gloss; low degree of polarization; low infrared emissivity; non-destructive properties in radar and in general controllability of optical properties. Trends are identified and the most interesting materials and coating designs are presented with relevant performance metrics. They are sorted into categories in the order of increasing complexity: pigments and paints, one-dimensional structures, multidimensional structures (including photonic crystals), and lastly biomimic and metamaterials. The military utility of the coatings is assessed qualitatively. The need for developing a framework for assessing the military utility of incrementally increasing the performance of spectrally selective coatings is identified.
ERIC Educational Resources Information Center
Thieken, John
2012-01-01
A sample of 127 high school Advanced Placement (AP) Calculus students from two schools was utilized to study the effects of an engineering design-based problem solving strategy on student performance with AP style Related Rate questions and changes in conceptions, beliefs, and influences. The research design followed a treatment-control multiple…
Graphics Processing Unit Assisted Thermographic Compositing
NASA Technical Reports Server (NTRS)
Ragasa, Scott; Russell, Samuel S.
2012-01-01
Objective Develop a software application utilizing high performance computing techniques, including general purpose graphics processing units (GPGPUs), for the analysis and visualization of large thermographic data sets. Over the past several years, an increasing effort among scientists and engineers to utilize graphics processing units (GPUs) in a more general purpose fashion is allowing for previously unobtainable levels of computation by individual workstations. As data sets grow, the methods to work them grow at an equal, and often greater, pace. Certain common computations can take advantage of the massively parallel and optimized hardware constructs of the GPU which yield significant increases in performance. These common computations have high degrees of data parallelism, that is, they are the same computation applied to a large set of data where the result does not depend on other data elements. Image processing is one area were GPUs are being used to greatly increase the performance of certain analysis and visualization techniques.
NASA Astrophysics Data System (ADS)
Nielsen, Christian
2016-11-01
The organic electrochemical transistor (OECT), capable of amplifying small electrical signals in an aqueous environment, is an ideal device to utilize in organic bioelectronic applications involving for example neural interfacing and diagnostics. Currently, most OECTs are fabricated with commercially available conducting poly(3,4-ethylenedioxythiophene)-based suspensions such as PEDOT:PSS and are therefore operated in depletion mode giving rise to devices that are permanently on with non-optimal operational voltage. With the aim to develop and utilize efficient accumulation mode OECT devices, we discuss here our recent results regarding the design, synthesis and performance of novel intrinsic semiconducting polymers. Covering key aspects such as ion and charge transport in the bulk semiconductor and operational voltage and stability of the materials and devices, we have elucidated important structure-property relationships. We illustrate the improvements this approach has afforded in the development of high performance accumulation mode OECT materials.
WOMBAT: A Scalable and High-performance Astrophysical Magnetohydrodynamics Code
NASA Astrophysics Data System (ADS)
Mendygral, P. J.; Radcliffe, N.; Kandalla, K.; Porter, D.; O'Neill, B. J.; Nolting, C.; Edmon, P.; Donnert, J. M. F.; Jones, T. W.
2017-02-01
We present a new code for astrophysical magnetohydrodynamics specifically designed and optimized for high performance and scaling on modern and future supercomputers. We describe a novel hybrid OpenMP/MPI programming model that emerged from a collaboration between Cray, Inc. and the University of Minnesota. This design utilizes MPI-RMA optimized for thread scaling, which allows the code to run extremely efficiently at very high thread counts ideal for the latest generation of multi-core and many-core architectures. Such performance characteristics are needed in the era of “exascale” computing. We describe and demonstrate our high-performance design in detail with the intent that it may be used as a model for other, future astrophysical codes intended for applications demanding exceptional performance.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Grubb, Daryl L.; Faircloth, Brian O.; Zediker, Mark S.
A high power laser drilling system utilizing an electric motor laser bottom hole assembly. A high power laser beam travels within the electric motor for performing a laser operation. A system includes a down hole electrical motor having a hollow rotor for conveying a high power laser beam having a wavelength less than 1060 nm through the electrical motor.
Ko, Ja Kyong; Um, Youngsoon; Lee, Sun-Mi
2016-12-01
The efficient fermentation of lignocellulosic hydrolysates in the presence of inhibitors is highly desirable for bioethanol production. Among the inhibitors, acetic acid released during the pretreatment of lignocellulose negatively affects the fermentation performance of biofuel producing organisms. In this study, we evaluated the inhibitory effects of acetic acid on glucose and xylose fermentation by a high performance engineered strain of xylose utilizing Saccharomyces cerevisiae, SXA-R2P-E, harboring a xylose isomerase based pathway. The presence of acetic acid severely decreased the xylose fermentation performance of this strain. However, the acetic acid stress was alleviated by metal ion supplementation resulting in a 52% increased ethanol production rate under 2g/L of acetic acid stress. This study shows the inhibitory effect of acetic acid on an engineered isomerase-based xylose utilizing strain and suggests a simple but effective method to improve the co-fermentation performance under acetic acid stress for efficient bioethanol production. Copyright © 2016 Elsevier Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gentile, Ann C.; Brandt, James M.; Tucker, Thomas
2011-09-01
This report provides documentation for the completion of the Sandia Level II milestone 'Develop feedback system for intelligent dynamic resource allocation to improve application performance'. This milestone demonstrates the use of a scalable data collection analysis and feedback system that enables insight into how an application is utilizing the hardware resources of a high performance computing (HPC) platform in a lightweight fashion. Further we demonstrate utilizing the same mechanisms used for transporting data for remote analysis and visualization to provide low latency run-time feedback to applications. The ultimate goal of this body of work is performance optimization in the facemore » of the ever increasing size and complexity of HPC systems.« less
High Performance Flat Plate Solar Thermal Collector Evaluation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rockenbaugh, Caleb; Dean, Jesse; Lovullo, David
2016-09-01
This report was prepared for the General Services Administration by the National Renewable Energy Laboratory. The Honeycomb Solar Thermal Collector (HSTC) is a flat plate solar thermal collector that shows promising high efficiencies over a wide range of climate zones. The technical objectives of this study are to: 1) verify collector performance, 2) compare that performance to other market-available collectors, 3) verify overheat protection, and 4) analyze the economic performance of the HSTC both at the demonstration sites and across a matrix of climate zones and utility markets.
Use and Protection of GPS Sidelobe Signals for Enhanced Navigation Performance in High Earth Orbit
NASA Technical Reports Server (NTRS)
Parker, Joel J. K.; Valdez, Jennifer E.; Bauer, Frank H.; Moreau, Michael C.
2016-01-01
GPS (Global Positioning System) Space Service Volume (SSV) signal environment is from 3,000-36,000 kilometers altitude. Current SSV specifications only capture performance provided by signals transmitted within 23.5(L1) or 26(L2-L5) off-nadir angle. Recent on-orbit data lessons learned show significant PNT (Positioning, Navigation and Timing) performance improvements when the full aggregate signal is used. Numerous military civil operational missions in High Geosynchronous Earth Orbit (HEOGEO) utilize the full signal to enhance vehicle PNT performance
Strategic rehabilitation planning of piped water networks using multi-criteria decision analysis.
Scholten, Lisa; Scheidegger, Andreas; Reichert, Peter; Maurer, Max; Mauer, Max; Lienert, Judit
2014-02-01
To overcome the difficulties of strategic asset management of water distribution networks, a pipe failure and a rehabilitation model are combined to predict the long-term performance of rehabilitation strategies. Bayesian parameter estimation is performed to calibrate the failure and replacement model based on a prior distribution inferred from three large water utilities in Switzerland. Multi-criteria decision analysis (MCDA) and scenario planning build the framework for evaluating 18 strategic rehabilitation alternatives under future uncertainty. Outcomes for three fundamental objectives (low costs, high reliability, and high intergenerational equity) are assessed. Exploitation of stochastic dominance concepts helps to identify twelve non-dominated alternatives and local sensitivity analysis of stakeholder preferences is used to rank them under four scenarios. Strategies with annual replacement of 1.5-2% of the network perform reasonably well under all scenarios. In contrast, the commonly used reactive replacement is not recommendable unless cost is the only relevant objective. Exemplified for a small Swiss water utility, this approach can readily be adapted to support strategic asset management for any utility size and based on objectives and preferences that matter to the respective decision makers. Copyright © 2013 Elsevier Ltd. All rights reserved.
Proton Exchange Membrane (PEM) Fuel Cells for Space Applications
NASA Technical Reports Server (NTRS)
Bradley, Karla
2004-01-01
This presentation will provide a summary of the PEM fuel cell development at the National Aeronautics and Space Administration, Johnson Space Center (NASA, JSC) in support of future space applications. Fuel cells have been used for space power generation due to their high energy storage density for multi-day missions. The Shuttle currently utilizes the alkaline fuel cell technology, which has highly safe and reliable performance. However, the alkaline technology has a limited life due to the corrosion inherent to the alkaline technology. PEM fuel cells are under development by industry for transportation, residential and commercial stationary power applications. NASA is trying to incorporate some of this stack technology development in the PEM fuel cells for space. NASA has some unique design and performance parameters which make developing a PEM fuel cell system more challenging. Space fuel cell applications utilize oxygen, rather than air, which yields better performance but increases the hazard level. To reduce the quantity of reactants that need to be flown in space, NASA also utilizes water separation and reactant recirculation. Due to the hazards of utilizing active components for recirculation and water separation, NASA is trying to develop passive recirculation and water separation methods. However, the ability to develop recirculation components and water separators that are gravity-independent and successfully operate over the full range of power levels is one of the greatest challenges to developing a safe and reliable PEM fuel cell system. PEM stack, accessory component, and system tests that have been performed for space power applications will be discussed.
Performance of a distributed superscalar storage server
NASA Technical Reports Server (NTRS)
Finestead, Arlan; Yeager, Nancy
1993-01-01
The RS/6000 performed well in our test environment. The potential exists for the RS/6000 to act as a departmental server for a small number of users, rather than as a high speed archival server. Multiple UniTree Disk Server's utilizing one UniTree Disk Server's utilizing one UniTree Name Server could be developed that would allow for a cost effective archival system. Our performance tests were clearly limited by the network bandwidth. The performance gathered by the LibUnix testing shows that UniTree is capable of exceeding ethernet speeds on an RS/6000 Model 550. The performance of FTP might be significantly faster if asked to perform across a higher bandwidth network. The UniTree Name Server also showed signs of being a potential bottleneck. UniTree sites that would require a high ratio of file creations and deletions to reads and writes would run into this bottleneck. It is possible to improve the UniTree Name Server performance by bypassing the UniTree LibUnix Library altogether and communicating directly with the UniTree Name Server and optimizing creations. Although testing was performed in a less than ideal environment, hopefully the performance statistics stated in this paper will give end-users a realistic idea as to what performance they can expect in this type of setup.
Efficiency Analysis of a High-Specific Impulse Hall Thruster
NASA Technical Reports Server (NTRS)
Jacobson, David (Technical Monitor); Hofer, Richard R.; Gallimore, Alec D.
2004-01-01
Performance and plasma measurements of the high-specific impulse NASA-173Mv2 Hall thruster were analyzed using a phenomenological performance model that accounts for a partially-ionized plasma containing multiply-charged ions. Between discharge voltages of 300 to 900 V, the results showed that although the net decrease of efficiency due to multiply-charged ions was only 1.5 to 3.0 percent, the effects of multiply-charged ions on the ion and electron currents could not be neglected. Between 300 to 900 V, the increase of the discharge current was attributed to the increasing fraction of multiply-charged ions, while the maximum deviation of the electron current from its average value was only +5/-14 percent. These findings revealed how efficient operation at high-specific impulse was enabled through the regulation of the electron current with the applied magnetic field. Between 300 to 900 V, the voltage utilization ranged from 89 to 97 percent, the mass utilization from 86 to 90 percent, and the current utilization from 77 to 81 percent. Therefore, the anode efficiency was largely determined by the current utilization. The electron Hall parameter was nearly constant with voltage, decreasing from an average of 210 at 300 V to an average of 160 between 400 to 900 V. These results confirmed our claim that efficient operation can be achieved only over a limited range of Hall parameters.
Jacobs, Nele; Evers, Silvia; Ament, Andre; Claes, Neree
2010-01-01
Little is known about the costs and the effects of cardiovascular prevention programs targeted at medical and behavioral risk factors. The aim was to evaluate the cost-utility of a cardiovascular prevention program in a general sample of highly educated adults after 1 year of intervention. The participants were randomly assigned to intervention (n = 208) and usual care conditions (n = 106). The intervention consisted of medical interventions and optional behavior-change interventions (e.g., a tailored Web site). Cost data were registered from a healthcare perspective, and questionnaires were used to determine effectiveness (e.g., quality-adjusted life-years [QALYs]). A cost-utility analysis and sensitivity analyses using bootstrapping were performed on the intermediate results. When adjusting for baseline utility differences, the incremental cost was 433 euros and the incremental effectiveness was 0.016 QALYs. The incremental cost-effectiveness ratio was 26,910 euros per QALY. The intervention was cost-effective compared with usual care in this sample of highly educated adults after 1 year of intervention. Increased participation would make this intervention highly cost-effective.
NASA Astrophysics Data System (ADS)
Ganguli, Anurag; Saha, Bhaskar; Raghavan, Ajay; Kiesel, Peter; Arakaki, Kyle; Schuh, Andreas; Schwartz, Julian; Hegyi, Alex; Sommer, Lars Wilko; Lochbaum, Alexander; Sahu, Saroj; Alamgir, Mohamed
2017-02-01
A key challenge hindering the mass adoption of Lithium-ion and other next-gen chemistries in advanced battery applications such as hybrid/electric vehicles (xEVs) has been management of their functional performance for more effective battery utilization and control over their life. Contemporary battery management systems (BMS) reliant on monitoring external parameters such as voltage and current to ensure safe battery operation with the required performance usually result in overdesign and inefficient use of capacity. More informative embedded sensors are desirable for internal cell state monitoring, which could provide accurate state-of-charge (SOC) and state-of-health (SOH) estimates and early failure indicators. Here we present a promising new embedded sensing option developed by our team for cell monitoring, fiber-optic (FO) sensors. High-performance large-format pouch cells with embedded FO sensors were fabricated. This second part of the paper focuses on the internal signals obtained from these FO sensors. The details of the method to isolate intercalation strain and temperature signals are discussed. Data collected under various xEV operational conditions are presented. An algorithm employing dynamic time warping and Kalman filtering was used to estimate state-of-charge with high accuracy from these internal FO signals. Their utility for high-accuracy, predictive state-of-health estimation is also explored.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kosny, Dr. Jan; Asiz, Andi; Shrestha, Som S
2015-01-01
Double wall technologies utilizing wood framing have been well-known and used in North American buildings for decades. Most of double wall designs use only natural materials such as wood products, gypsum, and cellulose fiber insulation, being one of few building envelope technologies achieving high thermal performance without use of plastic foams or fiberglass. Today, after several material and structural design modifications, these technologies are considered as highly thermally efficient, sustainable option for new constructions and sometimes, for retrofit projects. Following earlier analysis performed for U.S. Department of Energy by Fraunhofer CSE, this paper discusses different ways to build double wallsmore » and to optimize their thermal performance to minimize the space conditioning energy consumption. Description of structural configuration alternatives and thermal performance analysis are presented as well. Laboratory tests to evaluate thermal properties of used insulation and whole wall system thermal performance are also discussed in this paper. Finally, the thermal loads generated in field conditions by double walls are discussed utilizing results from a joined project performed by Zero Energy Building Research Alliance and Oak Ridge National Laboratory (ORNL), which made possible evaluation of the market viability of low-energy homes built in the Tennessee Valley. Experimental data recorded in two of the test houses built during this field study is presented in this work.« less
FTOOLS: A FITS Data Processing and Analysis Software Package
NASA Astrophysics Data System (ADS)
Blackburn, J. K.
FTOOLS, a highly modular collection of over 110 utilities for processing and analyzing data in the FITS (Flexible Image Transport System) format, has been developed in support of the HEASARC (High Energy Astrophysics Science Archive Research Center) at NASA's Goddard Space Flight Center. Each utility performs a single simple task such as presentation of file contents, extraction of specific rows or columns, appending or merging tables, binning values in a column or selecting subsets of rows based on a boolean expression. Individual utilities can easily be chained together in scripts to achieve more complex operations such as the generation and displaying of spectra or light curves. The collection of utilities provides both generic processing and analysis utilities and utilities specific to high energy astrophysics data sets used for the ASCA, ROSAT, GRO, and XTE missions. A core set of FTOOLS providing support for generic FITS data processing, FITS image analysis and timing analysis can easily be split out of the full software package for users not needing the high energy astrophysics mission utilities. The FTOOLS software package is designed to be both compatible with IRAF and completely stand alone in a UNIX or VMS environment. The user interface is controlled by standard IRAF parameter files. The package is self documenting through the IRAF help facility and a stand alone help task. Software is written in ANSI C and \\fortran to provide portability across most computer systems. The data format dependencies between hardware platforms are isolated through the FITSIO library package.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Enrico Clement, Carlos; Park, Sung-Yong, E-mail: mpeps@nus.edu.sg
2016-05-09
A high degree of beam steering is demonstrated using an electrowetting-driven liquid prism. While prism devices have typically relied on complex and expensive laboratory setups, such as high-vacuum facilities for fabrication of dielectric layers, this work utilizes a simple dip-coating method to provide an ion gel layer as a dielectric, offering 2 or 3 orders higher specific capacitance (c ≈ 10 μF/cm{sup 2}) than that of conventional dielectrics. Analytical studies present the effects of liquid selection and arrangement on overall prism performance. For experimental demonstrations of high-performance beam steering, we not only selected two immiscible liquids of water and 1-bromonaphthalene (1-BN)more » oil which provide the large refractive index difference (n{sub water} = 1.33 and n{sub 1-BN} = 1.65 at λ = 532 nm) between them, but also utilized a double-stacked prism configuration which increases the number of interfaces for incoming light to be steered. At a prism apex angle of φ = 27°, we were able to achieve significantly large beam steering of up to β = 19.06°, which is the highest beam steering performance ever demonstrated using electrowetting technology.« less
Wonczak, Stephan; Thiele, Holger; Nieroda, Lech; Jabbari, Kamel; Borowski, Stefan; Sinha, Vishal; Gunia, Wilfried; Lang, Ulrich; Achter, Viktor; Nürnberg, Peter
2015-01-01
Next generation sequencing (NGS) has been a great success and is now a standard method of research in the life sciences. With this technology, dozens of whole genomes or hundreds of exomes can be sequenced in rather short time, producing huge amounts of data. Complex bioinformatics analyses are required to turn these data into scientific findings. In order to run these analyses fast, automated workflows implemented on high performance computers are state of the art. While providing sufficient compute power and storage to meet the NGS data challenge, high performance computing (HPC) systems require special care when utilized for high throughput processing. This is especially true if the HPC system is shared by different users. Here, stability, robustness and maintainability are as important for automated workflows as speed and throughput. To achieve all of these aims, dedicated solutions have to be developed. In this paper, we present the tricks and twists that we utilized in the implementation of our exome data processing workflow. It may serve as a guideline for other high throughput data analysis projects using a similar infrastructure. The code implementing our solutions is provided in the supporting information files. PMID:25942438
Efficient hiding of confidential high-utility itemsets with minimal side effects
NASA Astrophysics Data System (ADS)
Lin, Jerry Chun-Wei; Hong, Tzung-Pei; Fournier-Viger, Philippe; Liu, Qiankun; Wong, Jia-Wei; Zhan, Justin
2017-11-01
Privacy preserving data mining (PPDM) is an emerging research problem that has become critical in the last decades. PPDM consists of hiding sensitive information to ensure that it cannot be discovered by data mining algorithms. Several PPDM algorithms have been developed. Most of them are designed for hiding sensitive frequent itemsets or association rules. Hiding sensitive information in a database can have several side effects such as hiding other non-sensitive information and introducing redundant information. Finding the set of itemsets or transactions to be sanitised that minimises side effects is an NP-hard problem. In this paper, a genetic algorithm (GA) using transaction deletion is designed to hide sensitive high-utility itemsets for PPUM. A flexible fitness function with three adjustable weights is used to evaluate the goodness of each chromosome for hiding sensitive high-utility itemsets. To speed up the evolution process, the pre-large concept is adopted in the designed algorithm. It reduces the number of database scans required for verifying the goodness of an evaluated chromosome. Substantial experiments are conducted to compare the performance of the designed GA approach (with/without the pre-large concept), with a GA-based approach relying on transaction insertion and a non-evolutionary algorithm, in terms of execution time, side effects, database integrity and utility integrity. Results demonstrate that the proposed algorithm hides sensitive high-utility itemsets with fewer side effects than previous studies, while preserving high database and utility integrity.
Promising Thermoelectric Bulk Materials with 2D Structures.
Zhou, Yiming; Zhao, Li-Dong
2017-12-01
Given that more than two thirds of all energy is lost, mostly as waste heat, in utilization processes worldwide, thermoelectric materials, which can directly convert waste heat to electricity, provide an alternative option for optimizing energy utilization processes. After the prediction that superlattices may show high thermoelectric performance, various methods based on quantum effects and superlattice theory have been adopted to analyze bulk materials, leading to the rapid development of thermoelectric materials. Bulk materials with two-dimensional (2D) structures show outstanding properties, and their high performance originates from both their low thermal conductivity and high Seebeck coefficient due to their strong anisotropic features. Here, the advantages of superlattices for enhancing the thermoelectric performance, the transport mechanism in bulk materials with 2D structures, and optimization methods are discussed. The phenomenological transport mechanism in these materials indicates that thermal conductivities are reduced in 2D materials with intrinsically short mean free paths. Recent progress in the transport mechanisms of Bi 2 Te 3 -, SnSe-, and BiCuSeO-based systems is summarized. Finally, possible research directions to enhance the thermoelectric performance of bulk materials with 2D structures are briefly considered. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Duku, Stephen Kwasi Opoku; Asenso-Boadi, Francis; Nketiah-Amponsah, Edward; Arhinful, Daniel Kojo
2016-12-01
Utilization of healthcare in Ghana's novel National Health Insurance Scheme (NHIS) has been increasing since inception with associated high claims bill which threatens the scheme's financial sustainability. This paper investigates the presence of adverse selection by assessing the effect of healthcare utilization and frequency of use on NHIS renewal. Routine enrolment and utilization data from 2008 to 2013 in two regions in Ghana was analyzed. Pearson Chi-square test was performed to test if the proportion of insured who utilize healthcare in a particular year and renew membership the following year is significantly different from those who utilize healthcare and drop-out. Logistic regressions were estimated to examine the relationship between healthcare utilization and frequency of use in previous year and NHIS renewal in current year. We found evidence suggestive of the presence of adverse selection in the NHIS. Majority of insured who utilized healthcare renewed their membership whiles most of those who did not utilize healthcare dropped out. The likelihood of renewal was significantly higher for those who utilize healthcare than those who did not and also higher for those who make more health facility visits. The NHIS claims bill is high because high risk individuals who self-select into the scheme makes more health facility visits and creates financial sustainability problems. Policy makers should adopt pragmatic ways of enforcing mandatory enrolment so that low risk individuals remain enrolled; and sustainable ways of increasing revenue whiles ensuring that the societal objectives of the scheme are not compromised.
Metabolic fuel utilization and subclinical atherosclerosis in overweight/obese subjects.
Montalcini, Tiziana; Gazzaruso, Carmine; Ferro, Yvelise; Migliaccio, Valeria; Rotundo, Stefania; Castagna, Alberto; Pujia, Arturo
2013-10-01
The utilization of different macronutrients is relevant for the risk of obesity, diabetes, or the appearing of vascular complications. The Respiratory Quotient (RQ) is a parameter measuring the fuel utilizations; in fact, it can indicate the fat stores utilization or lipogenesis activation. Aim of this study was to investigate the link between the RQ and the subclinical carotid atherosclerosis presence in overweight/obese subjects. 132 subjects with body mass index at least 25, at conventional diet, underwent an Indirect Calorimetry for the measurement of the Resting Metabolic Rate as well as the RQ and an evaluation of carotid arteries with ultrasound. Biochemical analyses were also performed. The mean age was 48 ± 12 years. There was a positive relation between carotid intima-media thickness and RQ (p = 0.010), with the high value in the subgroup with high RQ (p = 0.045 vs. group with low RQ). The RQ, an index of fuel utilization, is positively associated to subclinical carotid atherosclerosis in overweight/obese individuals.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-12-27
... potential high utilization and potential high clinical impact on TRICARE beneficiaries. If no submission is... reviewed in numerical order beginning with the test listed as having the highest priority. Those selected... laboratories that use LDTs as well as FDA approved tests. Laboratories performing moderate or high complexity...
NREL's high performance computing cluster. Education B.S., engineering, Colorado School of Mines and platforms. His experience with writing engineering applications in Python is being utilized for
Field and laboratory comparison of PM10 instruments in high winds
USDA-ARS?s Scientific Manuscript database
Instruments capable of measuring PM10 (particulate matter less than or equal to 10µm in aerodynamic diameter) concentrations may vary in performance as a result of different technologies utilized in measuring PM10. Therefore, the performance of five instruments capable of measuring PM10 concentratio...
ERIC Educational Resources Information Center
Birr, David
2000-01-01
Energy performance contracting allows schools to pay for needed new energy equipment and modernization improvements with savings from reduced utility and maintenance costs. Improved energy efficiency reduces demand for burning fossil fuels, which reduces air pollution, leading to improved learning environments and budgets (through improved average…
High-quality digital color xerography
NASA Astrophysics Data System (ADS)
Takiguchi, Koichi
1993-06-01
Image noise, tone reproduction, color reproduction, fine line reproduction, and OHP performance are the most important characteristics for a high quality color copier. Technologies enabling such quality are use of fine toner, halftone algorithm to ensure good highlight reproduction, soft roll fuser with good release performance, smooth surface and high thermal conductivity, white and smooth paper, and selection of a coating material for the surface layer of the OHP sheets. These technologies are integrated in the Fuji Xerox `A- Color' product. Utilizing 7 micrometers color toner, `A-Color' can make very high quality color copies.
High-density fuel effects. Final report, September 1985-April 1988
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rizk, N.K.; Oechsie, V.L.; Ross, P.T.
1988-08-18
The purpose of this program was to determine, by combustor rig tests and data evaluation, the effects of the high-density fuel properties on the performance and durability of the Allison T56-A-15 combustion system. Four high-density fuels in addition to baseline JP4 were evaluated in the effort. The rig-test program included: nozzle-flow bench testing, aerothermal performance and wall temperature, flame stability and ignition, injector coking and plugging, and flow-transient effect. The data-evaluation effort involved the utilization of empirical correlations in addition to analytical multidimensional tools to analyze the performance of the combustor. The modifications required to optimize the performance with high-densitymore » fuels were suggested and the expected improvement in performance was evaluated.« less
WOMBAT: A Scalable and High-performance Astrophysical Magnetohydrodynamics Code
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mendygral, P. J.; Radcliffe, N.; Kandalla, K.
2017-02-01
We present a new code for astrophysical magnetohydrodynamics specifically designed and optimized for high performance and scaling on modern and future supercomputers. We describe a novel hybrid OpenMP/MPI programming model that emerged from a collaboration between Cray, Inc. and the University of Minnesota. This design utilizes MPI-RMA optimized for thread scaling, which allows the code to run extremely efficiently at very high thread counts ideal for the latest generation of multi-core and many-core architectures. Such performance characteristics are needed in the era of “exascale” computing. We describe and demonstrate our high-performance design in detail with the intent that it maymore » be used as a model for other, future astrophysical codes intended for applications demanding exceptional performance.« less
Emerging Avenues for Utilization of Exotic Germplasm.
Wang, Cuiling; Hu, Songlin; Gardner, Candice; Lübberstedt, Thomas
2017-07-01
Breeders have been successful in increasing crop performance by exploiting genetic diversity over time. However, the reported annual yield increases are not sufficient in view of rapid human population growth and global environmental changes. Exotic germplasm possesses high levels of genetic diversity for valuable traits. However, only a small fraction of naturally occurring genetic diversity is utilized. Moreover, the yield gap between elite and exotic germplasm widens, which increases the effort needed to use exotic germplasm and to identify beneficial alleles and for their introgression. The advent of high-throughput genotyping and phenotyping technologies together with emerging biotechnologies provide new opportunities to explore exotic genetic variation. This review will summarize potential challenges for utilization of exotic germplasm and provide solutions. Copyright © 2017 Elsevier Ltd. All rights reserved.
McCue, Michael J
2002-01-01
The objective of this study was to evaluate the utilization and financial performance of children's services after the Balanced Budget Act of 1997. The author analyzed these performance factors by hospital ownership, HMO penetration, and disproportionate share hospitals. Using data from California hospitals and conducting an analysis from 1997 to 1999, the author found that public hospitals were able to increase their profits from pediatric and neonatal intensive care services. The study also revealed that DSH hospitals located in high HMO penetration markets reduced their operating losses in nursery and pediatric services.
Computational Science and Innovation
NASA Astrophysics Data System (ADS)
Dean, D. J.
2011-09-01
Simulations - utilizing computers to solve complicated science and engineering problems - are a key ingredient of modern science. The U.S. Department of Energy (DOE) is a world leader in the development of high-performance computing (HPC), the development of applied math and algorithms that utilize the full potential of HPC platforms, and the application of computing to science and engineering problems. An interesting general question is whether the DOE can strategically utilize its capability in simulations to advance innovation more broadly. In this article, I will argue that this is certainly possible.
Tanner-Smith, Emily E; Fisher, Benjamin W
2016-01-01
Many U.S. schools use visible security measures (security cameras, metal detectors, security personnel) in an effort to keep schools safe and promote adolescents' academic success. This study examined how different patterns of visible security utilization were associated with U.S. middle and high school students' academic performance, attendance, and postsecondary educational aspirations. The data for this study came from two large national surveys--the School Crime Supplement to the National Crime Victimization Survey (N = 38,707 students; 51% male, 77% White, MAge = 14.72) and the School Survey on Crime and Safety (N = 10,340 schools; average student composition of 50% male, 57% White). The results provided no evidence that visible security measures had consistent beneficial effects on adolescents' academic outcomes; some security utilization patterns had modest detrimental effects on adolescents' academic outcomes, particularly the heavy surveillance patterns observed in a small subset of high schools serving predominantly low socioeconomic students. The findings of this study provide no evidence that visible security measures have any sizeable effects on academic performance, attendance, or postsecondary aspirations among U.S. middle and high school students.
Autophagy Is a Promoter for Aerobic Exercise Performance during High Altitude Training
Zhang, Ying
2018-01-01
High altitude training is one of the effective strategies for improving aerobic exercise performance at sea level via altitude acclimatization, thereby improving oxygen transport and/or utilization. But its underlying molecular mechanisms on physiological functions and exercise performance of athletes are still vague. More recent evidence suggests that the recycling of cellular components by autophagy is an important process of the body involved in the adaptive responses to exercise. Whether high altitude training can activate autophagy or whether high altitude training can improve exercise performance through exercise-induced autophagy is still unclear. In this narrative review article, we will summarize current research advances in the improvement of exercise performance through high altitude training and its reasonable molecular mechanisms associated with autophagy, which will provide a new field to explore the molecular mechanisms of adaptive response to high altitude training. PMID:29849885
Biological and functional relevance of CASP predictions
Liu, Tianyun; Ish‐Shalom, Shirbi; Torng, Wen; Lafita, Aleix; Bock, Christian; Mort, Matthew; Cooper, David N; Bliven, Spencer; Capitani, Guido; Mooney, Sean D.
2017-01-01
Abstract Our goal is to answer the question: compared with experimental structures, how useful are predicted models for functional annotation? We assessed the functional utility of predicted models by comparing the performances of a suite of methods for functional characterization on the predictions and the experimental structures. We identified 28 sites in 25 protein targets to perform functional assessment. These 28 sites included nine sites with known ligand binding (holo‐sites), nine sites that are expected or suggested by experimental authors for small molecule binding (apo‐sites), and Ten sites containing important motifs, loops, or key residues with important disease‐associated mutations. We evaluated the utility of the predictions by comparing their microenvironments to the experimental structures. Overall structural quality correlates with functional utility. However, the best‐ranked predictions (global) may not have the best functional quality (local). Our assessment provides an ability to discriminate between predictions with high structural quality. When assessing ligand‐binding sites, most prediction methods have higher performance on apo‐sites than holo‐sites. Some servers show consistently high performance for certain types of functional sites. Finally, many functional sites are associated with protein‐protein interaction. We also analyzed biologically relevant features from the protein assemblies of two targets where the active site spanned the protein‐protein interface. For the assembly targets, we find that the features in the models are mainly determined by the choice of template. PMID:28975675
NASA Astrophysics Data System (ADS)
Ashbridge, Gayle Ann
Change management has become an imperative for organizations as they move into the 21st century; up to 75 percent of change initiatives fail. Nuclear power plants face the same challenges as industrial firms with the added challenge of deregulation. Faced with this challenge, restructuring the electric utility has raised a number of complex issues. Under traditional cost-of-service regulation, electric utilities were able to pass on their costs to consumers who absorbed them. In the new competitive environment, customers will now choose their suppliers based on the most competitive price. The purpose of this study is to determine the degree of congruence between non-supervisory and supervisory personnel regarding the perceived implementation of high performance workplace practices at a nuclear power plant. This study used as its foundation the practices identified in the Road to High Performance Workplaces: A Guide to Better Jobs and Better Business Results by the U.S. Department of Labor's Office of the American Workplace (1994). The population for this study consisted of organizational members at one nuclear power plant. Over 300 individuals completed surveys on high performance workplace practices. Two surveys were administered, one to non-supervisory personnel and one to first line supervisors and above. The determination of implementation levels was accomplished through descriptive statistical analysis. Results of the study revealed 32 areas of noncongruence between non-supervisory and supervisory personnel in regard to the perceived implementation level of the high performance workplace practices. Factor analysis further revealed that the order in which the respondents place emphasis on the variables varies between the two groups. This study provides recommendations that may improve the nuclear power plants alignment of activities. Recommendations are also provided for additional research on high-performance work practices.
Nanocellulose reinforcement of Transparent Composites
Joshua Steele; Hong Dong; James F. Snyder; Josh A. Orlicki; Richard S. Reiner; Alan W. Rudie
2012-01-01
In this work, we evaluate the impact of nanocellulose reinforcement on transparent composite properties. Due to the small diameter, high modulus, and high strength of cellulose nanocrystals, transparent composites that utilize these materials should show improvement in bulk mechanical performances without a corresponding reduction in optical properties. In this study...
This paper presents performance verification data on two types of high-rate separation devices utilized for solids removal: Vortex separation devices (a class of physical treatment technologies that use cylindrical chambers to create centrifugal forces that separate settleable so...
Solar thermal drum drying performance of prune and tomato pomaces
USDA-ARS?s Scientific Manuscript database
Fruit and vegetable pomaces are co-products of the food processing industry; they are underutilized in part because their high water activity (aw) renders them unstable. Drum drying is one method that can dry/stabilize pomaces, but current drum drying methods utilize conventional, high-environmental...
Linear actuation using milligram quantities of CL-20 and TAGDNAT.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Snedigar, Shane; Salton, Jonathan Robert; Tappan, Alexander Smith
2009-07-01
There are numerous applications for small-scale actuation utilizing pyrotechnics and explosives. In certain applications, especially when multiple actuation strokes are needed, or actuator reuse is required, it is desirable to have all gaseous combustion products with no condensed residue in the actuator cylinder. Toward this goal, we have performed experiments on utilizing milligram quantities of high explosives to drive a millimeter-diameter actuator with a stroke of 30 mm. Calculations were performed to select proper material quantities to provide 0.5 J of actuation energy. This was performed utilizing the thermochemical code Cheetah to calculate the impetus for numerous propellants and tomore » select quantities based on estimated efficiencies of these propellants at small scales. Milligram quantities of propellants were loaded into a small-scale actuator and ignited with an ignition increment and hot wire ignition. Actuator combustion chamber pressure was monitored with a pressure transducer and actuator stroke was monitored using a laser displacement meter. Total actuation energy was determined by calculating the kinetic energy of reaction mass motion against gravity. Of the materials utilized, the best performance was obtained with a mixture of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) and bis-triaminoguanidinium(3,3{prime}dinitroazotriazolate) (TAGDNAT).« less
NASA Astrophysics Data System (ADS)
Cao, Jianyun; Li, Xiaohong; Wang, Yaming; Walsh, Frank C.; Ouyang, Jia-Hu; Jia, Dechang; Zhou, Yu
2015-10-01
MnO2 is a promising electrode material for high energy supercapacitors because of its large pseudo-capacitance. However, MnO2 suffers from low electronic conductivity and poor cation diffusivity, which results in poor utilization and limited rate performance of traditional MnO2 powder electrodes, obtained by pressing a mixed paste of MnO2 powder, conductive additive and polymer binder onto metallic current collectors. Developing binder-free MnO2 electrodes by loading nanoscale MnO2 deposits on pre-fabricated device-ready electrode scaffolds is an effective way to achieve both high power and energy performance. These electrode scaffolds, with interconnected skeletons and pore structures, will not only provide mechanical support and electron collection as traditional current collectors but also fast ion transfer tunnels, leading to high MnO2 utilization and rate performance. This review covers design strategies, materials and fabrication methods for the electrode scaffolds. Rational evaluation of the true performance of these electrodes is carried out, which clarifies that some of the electrodes with as-claimed exceptional performances lack potential in practical applications due to poor mass loading of MnO2 and large dead volume of inert scaffold materials/void spaces in the electrode structure. Possible ways to meet this challenge and bring MnO2 electrodes from laboratory studies to real-world applications are considered.
High efficiency, long life terrestrial solar panel
NASA Technical Reports Server (NTRS)
Chao, T.; Khemthong, S.; Ling, R.; Olah, S.
1977-01-01
The design of a high efficiency, long life terrestrial module was completed. It utilized 256 rectangular, high efficiency solar cells to achieve high packing density and electrical output. Tooling for the fabrication of solar cells was in house and evaluation of the cell performance was begun. Based on the power output analysis, the goal of a 13% efficiency module was achievable.
All-printable band-edge modulated ZnO nanowire photodetectors with ultra-high detectivity
Liu, Xi; Gu, Leilei; Zhang, Qianpeng; Wu, Jiyuan; Long, Yunze; Fan, Zhiyong
2014-01-01
High-performance photodetectors are critical for high-speed optical communication and environmental sensing, and flexible photodetectors can be used for a wide range of portable or wearable applications. Here we demonstrate the all-printable fabrication of polycrystalline nanowire-based high-performance photodetectors on flexible substrates. Systematic investigations have shown their ultra-high photoconductive gain, responsivity and detectivity up to 3.3 × 1017 Jones. Further analysis shows that their high performance originates from the unique band-edge modulation along the nanowire axial direction, where the existence of Schottky barriers in series leads to highly suppressed dark current of the device and also gives rise to fast photoelectric response to low-intensity optical signal owing to barrier height modulation. The discovered rationale in this work can be utilized as guideline to design high-performance photodetectors with other nanomaterial systems. The developed fabrication scheme opens up possibility for future flexible and high-performance integrated optoelectronic sensor circuitry. PMID:24898081
All-printable band-edge modulated ZnO nanowire photodetectors with ultra-high detectivity.
Liu, Xi; Gu, Leilei; Zhang, Qianpeng; Wu, Jiyuan; Long, Yunze; Fan, Zhiyong
2014-06-05
High-performance photodetectors are critical for high-speed optical communication and environmental sensing, and flexible photodetectors can be used for a wide range of portable or wearable applications. Here we demonstrate the all-printable fabrication of polycrystalline nanowire-based high-performance photodetectors on flexible substrates. Systematic investigations have shown their ultra-high photoconductive gain, responsivity and detectivity up to 3.3 × 10(17) Jones. Further analysis shows that their high performance originates from the unique band-edge modulation along the nanowire axial direction, where the existence of Schottky barriers in series leads to highly suppressed dark current of the device and also gives rise to fast photoelectric response to low-intensity optical signal owing to barrier height modulation. The discovered rationale in this work can be utilized as guideline to design high-performance photodetectors with other nanomaterial systems. The developed fabrication scheme opens up possibility for future flexible and high-performance integrated optoelectronic sensor circuitry.
A proteomics performance standard to support measurement quality in proteomics.
Beasley-Green, Ashley; Bunk, David; Rudnick, Paul; Kilpatrick, Lisa; Phinney, Karen
2012-04-01
The emergence of MS-based proteomic platforms as a prominent technology utilized in biochemical and biomedical research has increased the need for high-quality MS measurements. To address this need, National Institute of Standards and Technology (NIST) reference material (RM) 8323 yeast protein extract is introduced as a proteomics quality control material for benchmarking the preanalytical and analytical performance of proteomics-based experimental workflows. RM 8323 yeast protein extract is based upon the well-characterized eukaryote Saccharomyces cerevisiae and can be utilized in the design and optimization of proteomics-based methodologies from sample preparation to data analysis. To demonstrate its utility as a proteomics quality control material, we coupled LC-MS/MS measurements of RM 8323 with the NIST MS Quality Control (MSQC) performance metrics to quantitatively assess the LC-MS/MS instrumentation parameters that influence measurement accuracy, repeatability, and reproducibility. Due to the complexity of the yeast proteome, we also demonstrate how NIST RM 8323, along with the NIST MSQC performance metrics, can be used in the evaluation and optimization of proteomics-based sample preparation methods. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Power Budget Analysis for High Altitude Airships
NASA Technical Reports Server (NTRS)
Choi, Sang H.; Elliott, James R.; King, Glen C.
2006-01-01
The High Altitude Airship (HAA) has various potential applications and mission scenarios that require onboard energy harvesting and power distribution systems. The energy source considered for the HAA s power budget is solar photon energy that allows the use of either photovoltaic (PV) cells or advanced thermoelectric (ATE) converters. Both PV cells and an ATE system utilizing high performance thermoelectric materials were briefly compared to identify the advantages of ATE for HAA applications in this study. The ATE can generate a higher quantity of harvested energy than PV cells by utilizing the cascaded efficiency of a three-staged ATE in a tandem mode configuration. Assuming that each stage of ATE material has the figure of merit of 5, the cascaded efficiency of a three-staged ATE system approaches the overall conversion efficiency greater than 60%. Based on this estimated efficiency, the configuration of a HAA and the power utility modules are defined.
Long-Term Reliability of a Hard-Switched Boost Power Processing Unit Utilizing SiC Power MOSFETs
NASA Technical Reports Server (NTRS)
Ikpe, Stanley A.; Lauenstein, Jean-Marie; Carr, Gregory A.; Hunter, Don; Ludwig, Lawrence L.; Wood, William; Iannello, Christopher J.; Del Castillo, Linda Y.; Fitzpatrick, Fred D.; Mojarradi, Mohammad M.;
2016-01-01
Silicon carbide (SiC) power devices have demonstrated many performance advantages over their silicon (Si) counterparts. As the inherent material limitations of Si devices are being swiftly realized, wide-band-gap (WBG) materials such as SiC have become increasingly attractive for high power applications. In particular, SiC power metal oxide semiconductor field effect transistors' (MOSFETs) high breakdown field tolerance, superior thermal conductivity and low-resistivity drift regions make these devices an excellent candidate for power dense, low loss, high frequency switching applications in extreme environment conditions. In this paper, a novel power processing unit (PPU) architecture is proposed utilizing commercially available 4H-SiC power MOSFETs from CREE Inc. A multiphase straight boost converter topology is implemented to supply up to 10 kilowatts full-scale. High Temperature Gate Bias (HTGB) and High Temperature Reverse Bias (HTRB) characterization is performed to evaluate the long-term reliability of both the gate oxide and the body diode of the SiC components. Finally, susceptibility of the CREE SiC MOSFETs to damaging effects from heavy-ion radiation representative of the on-orbit galactic cosmic ray environment are explored. The results provide the baseline performance metrics of operation as well as demonstrate the feasibility of a hard-switched PPU in harsh environments.
Frequency stabilization for mobile satellite terminals via LORAN
NASA Technical Reports Server (NTRS)
Ernst, Gregory J.; Kee, Steven M.; Marquart, Robert C.
1990-01-01
Digital satellite communication systems require careful management of frequency stability. Historically, frequency stability has been accomplished by continuously powered, high cost, high performance reference oscillators. Today's low cost mobile satellite communication equipment must operate under wide ranging environmental conditions, stabilize quickly after application of power, and provide adequate performance margin to overcome RF link impairments unique to the land mobile environment. Methods for frequency stabilization in land mobile applications must meet these objectives without incurring excessive performance degradation. A frequency stabilization scheme utilizing the LORAN (Long Range Navigation) system is presented.
High efficiency low cost monolithic module for SARSAT distress beacons
NASA Technical Reports Server (NTRS)
Petersen, Wendell C.; Siu, Daniel P.
1992-01-01
The program objectives were to develop a highly efficient, low cost RF module for SARSAT beacons; achieve significantly lower battery current drain, amount of heat generated, and size of battery required; utilize MMIC technology to improve efficiency, reliability, packaging, and cost; and provide a technology database for GaAs based UHF RF circuit architectures. Presented in viewgraph form are functional block diagrams of the SARSAT distress beacon and beacon RF module as well as performance goals, schematic diagrams, predicted performances, and measured performances for the phase modulator and power amplifier.
Importance of balanced architectures in the design of high-performance imaging systems
NASA Astrophysics Data System (ADS)
Sgro, Joseph A.; Stanton, Paul C.
1999-03-01
Imaging systems employed in demanding military and industrial applications, such as automatic target recognition and computer vision, typically require real-time high-performance computing resources. While high- performances computing systems have traditionally relied on proprietary architectures and custom components, recent advances in high performance general-purpose microprocessor technology have produced an abundance of low cost components suitable for use in high-performance computing systems. A common pitfall in the design of high performance imaging system, particularly systems employing scalable multiprocessor architectures, is the failure to balance computational and memory bandwidth. The performance of standard cluster designs, for example, in which several processors share a common memory bus, is typically constrained by memory bandwidth. The symptom characteristic of this problem is failure to the performance of the system to scale as more processors are added. The problem becomes exacerbated if I/O and memory functions share the same bus. The recent introduction of microprocessors with large internal caches and high performance external memory interfaces makes it practical to design high performance imaging system with balanced computational and memory bandwidth. Real word examples of such designs will be presented, along with a discussion of adapting algorithm design to best utilize available memory bandwidth.
175Hp contrarotating homopolar motor design report
NASA Astrophysics Data System (ADS)
Cannell, Michael J.; Drake, John L.; McConnell, Richard A.; Martino, William R.
1994-06-01
A normally conducting contrarotating homopolar motor has been designed and constructed. The reaction torque, in the outer rotor, from the inner rotor is utilized to produce true contrarotation. The machine utilizes liquid cooled conductors, high performance liquid metal current collectors, and ferrous conductors in the active region. The basic machine output is 175 hp at + or - 1,200 rpm with an input of 4 volts and 35,000 amps.
Environmental Assisted Cracking in High Hardness Armor Steel
1985-09-01
Longitudinal and transverse tension tests (ASTM E8-81) utilizing flat dogbane specimens, and subsize Charpy impact tests (ASTM 23-81) were performed on part...had been obtained. Longitudinal and transverse tension tests (ASTM E8-81) utilizing flat dogbane specimens, and subsize Charpy impact tests (ASTM 23... Charpy and tensile bar surfaces. All of the optical metallography samples were prepared using standard metallographic practices. The optical specimens
Triple effect absorption chiller utilizing two refrigeration circuits
DeVault, Robert C.
1988-01-01
A triple effect absorption method and apparatus having a high coefficient of performance. Two single effect absorption circuits are combined with heat exchange occurring between a condenser and absorber of a high temperature circuit, and a generator of a low temperature circuit. The evaporators of both the high and low temperature circuits provide cooling to an external heat load.
NASA Technical Reports Server (NTRS)
Rippel, Wally E.
1990-01-01
Metal-oxide/semiconductor-controlled thyristor (MCT) and metal-oxide/semiconductor field-effect transistor (MOSFET) connected in switching circuit to obtain better performance. Offers high utilization of silicon, low forward voltage drop during "on" period of operating cycle, fast turnon and turnoff, and large turnoff safe operating area. Includes ability to operate at high temperatures, high static blocking voltage, and ease of drive.
Kumada, H; Saito, K; Nakamura, T; Sakae, T; Sakurai, H; Matsumura, A; Ono, K
2011-12-01
Treatment planning for boron neutron capture therapy generally utilizes Monte-Carlo methods for calculation of the dose distribution. The new treatment planning system JCDS-FX employs the multi-purpose Monte-Carlo code PHITS to calculate the dose distribution. JCDS-FX allows to build a precise voxel model consisting of pixel based voxel cells in the scale of 0.4×0.4×2.0 mm(3) voxel in order to perform high-accuracy dose estimation, e.g. for the purpose of calculating the dose distribution in a human body. However, the miniaturization of the voxel size increases calculation time considerably. The aim of this study is to investigate sophisticated modeling methods which can perform Monte-Carlo calculations for human geometry efficiently. Thus, we devised a new voxel modeling method "Multistep Lattice-Voxel method," which can configure a voxel model that combines different voxel sizes by utilizing the lattice function over and over. To verify the performance of the calculation with the modeling method, several calculations for human geometry were carried out. The results demonstrated that the Multistep Lattice-Voxel method enabled the precise voxel model to reduce calculation time substantially while keeping the high-accuracy of dose estimation. Copyright © 2011 Elsevier Ltd. All rights reserved.
ERIC Educational Resources Information Center
Tanner-Smith, Emily E.; Fisher, Benjamin W.
2015-01-01
Many U.S. schools use visible security measures (security cameras, metal detectors, security personnel) in an effort to keep schools safe and promote adolescents' academic success. This study examined how different patterns of visible security utilization were associated with U.S. middle and high school students' academic performance, attendance,…
Assessment of active methods for removal of LEO debris
NASA Astrophysics Data System (ADS)
Hakima, Houman; Emami, M. Reza
2018-03-01
This paper investigates the applicability of five active methods for removal of large low Earth orbit debris. The removal methods, namely net, laser, electrodynamic tether, ion beam shepherd, and robotic arm, are selected based on a set of high-level space mission constraints. Mission level criteria are then utilized to assess the performance of each redirection method in light of the results obtained from a Monte Carlo simulation. The simulation provides an insight into the removal time, performance robustness, and propellant mass criteria for the targeted debris range. The remaining attributes are quantified based on the models provided in the literature, which take into account several important parameters pertaining to each removal method. The means of assigning attributes to each assessment criterion is discussed in detail. A systematic comparison is performed using two different assessment schemes: Analytical Hierarchy Process and utility-based approach. A third assessment technique, namely the potential-loss analysis, is utilized to highlight the effect of risks in each removal methods.
School-Based Peer Mentoring in High School: A Program Evaluation Study
ERIC Educational Resources Information Center
Cooper, Felicia Cecile
2017-01-01
The dissertation is an initial investigation of a peer mentoring program in a suburban high school in the southeastern United States. Additionally, the Peer Mentoring Program (PMP) study examined whether the Program improves academic performance and attendance, and decreases referrals. Utilizing an experimental design, a Participant and a…
Design and Evaluation of a Dynamic Dilemma Zone System for a High Speed Rural Intersection
DOT National Transportation Integrated Search
2012-08-01
The goal of this research was to develop a system that utilizes the dynamic detection technology and : to evaluate the performance of this system. The first step of this study was to select an intersection : experiencing a high frequency of crashes t...
A Standard Psychophysiological Preparation (SPP) for the evaluation of the physiological and biomechanical mechanisms responsible for performance...consumption, biomechanical parameters and performance level. The results of pilot tests (including 6-hours exposure to vibration while performing a...tracking task) verify the applicability and utility of the SPP and demonstrate that high quality, quantitative physiological and biomechanical data can
CF6 Jet Engine Performance Improvement: High Pressure Turbine Active Clearance Control
NASA Technical Reports Server (NTRS)
Rich, S. E.; Fasching, W. A.
1982-01-01
An active clearance control system was developed which reduces fuel consumption and performance degradation. This system utilizes compressor discharge air during takeoff and fan discharge air during cruise to impinge on the shroud structure to improve the thermal response. The system was evaluated in component and engine tests. The test results demonstrated a performance improvement of 0.7 percent in cruise SFC.
Multitasking 3-D forward modeling using high-order finite difference methods on the Cray X-MP/416
DOE Office of Scientific and Technical Information (OSTI.GOV)
Terki-Hassaine, O.; Leiss, E.L.
1988-01-01
The CRAY X-MP/416 was used to multitask 3-D forward modeling by the high-order finite difference method. Flowtrace analysis reveals that the most expensive operation in the unitasked program is a matrix vector multiplication. The in-core and out-of-core versions of a reentrant subroutine can perform any fraction of the matrix vector multiplication independently, a pattern compatible with multitasking. The matrix vector multiplication routine can be distributed over two to four processors. The rest of the program utilizes the microtasking feature that lets the system treat independent iterations of DO-loops as subtasks to be performed by any available processor. The availability ofmore » the Solid-State Storage Device (SSD) meant the I/O wait time was virtually zero. A performance study determined a theoretical speedup, taking into account the multitasking overhead. Multitasking programs utilizing both macrotasking and microtasking features obtained actual speedups that were approximately 80% of the ideal speedup.« less
Evanoff, Kara; Benson, Jim; Schauer, Mark; Kovalenko, Igor; Lashmore, David; Ready, W Jud; Yushin, Gleb
2012-11-27
Materials that can perform simultaneous functions allow for reductions in the total system mass and volume. Developing technologies to produce flexible batteries with good performance in combination with high specific strength is strongly desired for weight- and power-sensitive applications such as unmanned or aerospace vehicles, high-performance ground vehicles, robotics, and smart textiles. State of the art battery electrode fabrication techniques are not conducive to the development of multifunctional materials due to their inherently low strength and conductivities. Here, we present a scalable method utilizing carbon nanotube (CNT) nonwoven fabric-based technology to develop flexible, electrochemically stable (∼494 mAh·g(-1) for 150 cycles) battery anodes that can be produced on an industrial scale and demonstrate specific strength higher than that of titanium, copper, and even a structural steel. Similar methods can be utilized for the formation of various cathode and anode composites with tunable strength and energy and power densities.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chamana, Manohar; Mather, Barry A
A library of load variability classes is created to produce scalable synthetic data sets using historical high-speed raw data. These data are collected from distribution monitoring units connected at the secondary side of a distribution transformer. Because of the irregular patterns and large volume of historical high-speed data sets, the utilization of current load characterization and modeling techniques are challenging. Multi-resolution analysis techniques are applied to extract the necessary components and eliminate the unnecessary components from the historical high-speed raw data to create the library of classes, which are then utilized to create new synthetic load data sets. A validationmore » is performed to ensure that the synthesized data sets contain the same variability characteristics as the training data sets. The synthesized data sets are intended to be utilized in quasi-static time-series studies for distribution system planning studies on a granular scale, such as detailed PV interconnection studies.« less
Avulova, Svetlana; Allen, Clayton; Morgans, Alicia; Moses, Kelvin A
2018-05-10
Risk of recurrent disease for men with clinical stage 1 high-risk nonseminomatous germ cell testicular cancer (CS1 NSGCT) with lymphovascular invasion (LVI) after orchiectomy is 50% and current treatment options (surveillance [S], retroperitoneal lymph node dissection [RPLND], or 1 cycle of BEP [BEP ×1]) are associated with a 99% disease specific survival, therefore practice patterns vary. We performed a decision analysis using updated data of long-term complications for men with CS1 NSGCT with LVI to quantify and assess relative treatment values. Decision analysis included previously defined utilities (via standard gamble) for posttreatment states of living from 0 (death from disease) to 1 (alive in perfect health) and updated morbidity probabilities. We quantified the values of S, RPLND, and BEP ×1 via the rollback method. Sensitivity analyses including a range of orchiectomy cure rates and utility values were performed. Estimated probabilities favoring treatment with RPLND (0.97) or BEP ×1 (0.97) were equivalent and superior to surveillance (0.88). Sensitivity analysis of orchiectomy cure rates (50%-100%) failed to find a cure rate that favored S over BEP ×1 or RPLND. Varying utility values for cure after S from 0.92 (previously defined utility) to 1 (perfect health), failed to find a viable utility state favoring S over BEP ×1 or RPLND. An orchiectomy cure rate of ≥82% would be required for S to equal treatment of either type. We demonstrate that for surveillance to be superior to treatment with BEP ×1 or RPLND, the orchiectomy cure rate must be at least 82%, which is not expected in a patient population with high-risk CS1 NSGCT. Copyright © 2018 Elsevier Inc. All rights reserved.
Factors associated with high-quality/low-cost hospital performance.
Jiang, H Joanna; Friedman, Bernard; Begun, James W
2006-01-01
This study explores organizational and market characteristics associated with superior hospital performance in both quality and cost of care, using the Healthcare Cost and Utilization Project State Inpatient Databases for ten states in 1997 and 2001. After controlling for a variety of patient factors, we found that for-profit ownership, hospital competition, and the number of HMOs were positively associated with the likelihood of attaining high-quality/low-cost performance. Furthermore, we examined interactions between organizational and market characteristics and identified a number of significant interactions. For example, the positive likelihood associated with for-profit hospitals diminished in markets with high HMO penetration.
A new maltose-inducible high-performance heterologous expression system in Bacillus subtilis.
Yue, Jie; Fu, Gang; Zhang, Dawei; Wen, Jianping
2017-08-01
To improve heterologous proteins production, we constructed a maltose-inducible expression system in Bacillus subtilis. An expression system based on the promoter for maltose utilization constructed in B. subtilis. Successively, to improve the performance of the P malA -derived system, mutagenesis was employed by gradually shortening the length of P malA promoter and altering the spacing between the predicted MalR binding site and the -35 region. Furthermore, deletion of the maltose utilization genes (malL and yvdK) improved the P malA promoter activity. Finally, using this efficient maltose-inducible expression system, we enhanced the production of luciferase and D-aminoacylase, compared with the P hpaII system. A maltose-inducible expression system was constructed and evaluated. It could be used for high level expression of heterologous proteins production.
Conductor requirements for high-temperature superconducting utility power transformers
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pleva, E. F.; Mehrotra, V.; Schwenterly, S W
High-temperature superconducting (HTS) coated conductors in utility power transformers must satisfy a set of operating requirements that are driven by two major considerations-HTS transformers must be economically competitive with conventional units, and the conductor must be robust enough to be used in a commercial manufacturing environment. The transformer design and manufacturing process will be described in order to highlight the various requirements that it imposes on the HTS conductor. Spreadsheet estimates of HTS transformer costs allow estimates of the conductor cost required for an HTS transformer to be competitive with a similarly performing conventional unit.
Strategic groups and performance in the nursing home industry: a reexamination.
Marlin, D; Sun, M; Huonker, J W
1999-06-01
This study further examines the relationship between strategic group membership and performance in the nursing home industry. The results indicate seven strategic groups in the industry with significant between-group differences in operating margin, average profit per patient day, catheterization rate, health deficiencies, life and safety deficiencies, and efficiency in the provision of services. The authors did not, however, find significant between-group differences in pressure sore rate, the use of restraints, or in the percentage of patients with significant unplanned weight changes. The group with the highest private-pay utilization combined with high Medicare utilization generally performed the best along all indicators. Results also suggest that strategic group membership and rural/urban location have a greater impact on performance than do ownership, chain membership, or possession of a dedicated specialty care unit.
NASA Astrophysics Data System (ADS)
Ahmad, Anees; Batcheldor, Scott; Cannon, Steven C.; Roberts, Thomas E.
2002-09-01
This paper presents the lessons learned during the design and development of a high performance cooled CCD camera for military applications utilizing common commercial off the shelf (COTS) parts. Our experience showed that concurrent evaluation and testing of high risk COTS must be performed to assess their performance over the required temperature range and other special product requirements such as fuel vapor compatibility, EMI and shock susceptibility, etc. Technical, cost and schedule risks for COTS parts must also be carefully evaluated. The customer must be involved in the selection and evaluation of such parts so that the performance limitations of the selected parts are clearly understood. It is equally important to check with vendors on the availability and obsolescence of the COTS parts being considered since the electronic components are often replaced by newer, better and cheaper models in a couple of years. In summary, this paper addresses the major benefits and risks associated with using commercial and industrial parts in military products, and suggests a risk mitigation approach to ensure a smooth development phase, and predictable performance from the end product.
High Temperature Steam Electrolysis: Demonstration of Improved Long-Term Performance
DOE Office of Scientific and Technical Information (OSTI.GOV)
J. E. O'Brien; X. Zhang; R. C. O'Brien
2011-11-01
Long-term performance is an ongoing issue for hydrogen production based on high-temperature steam electrolysis (HTSE). For commercial deployment, solid-oxide electrolysis stacks must achieve high performance with long-term degradation rates of {approx}0.5%/1000 hours or lower. Significant progress has been achieved toward this goal over the past few years. This paper will provide details of progress achieved under the Idaho National Laboratory high temperature electrolysis research program. Recent long-term stack tests have achieved high initial performance with degradation rates less than 5%/khr. These tests utilize internally manifolded stacks with electrode-supported cells. The cell material sets are optimized for the electrolysis mode ofmore » operation. Details of the cells and stacks will be provided along with details of the test apparatus, procedures, and results.« less
Design and calibration of a high-frequency oscillatory ventilator.
Simon, B A; Mitzner, W
1991-02-01
High-frequency ventilation (HFV) is a modality of mechanical ventilation which presents difficult technical demands to the clinical or laboratory investigator. The essential features of an ideal HFV system are described, including wide frequency range, control of tidal volume and mean airway pressure, minimal dead space, and high effective internal impedance. The design and performance of a high-frequency oscillatory ventilation system is described which approaches these requirements. The ventilator utilizes a linear motor regulated by a closed loop controller and driving a novel frictionless double-diaphragm piston pump. Finally, the ventilator performance is tested using the impedance model of Venegas [1].
Tough, high performance, addition-type thermoplastic polymers
NASA Technical Reports Server (NTRS)
Pater, Ruth H. (Inventor)
1992-01-01
A tough, high performance polyimide is provided by reacting a triple bond conjugated with an aromatic ring in a bisethynyl compound with the active double bond in a compound containing a double bond activated toward the formation of a Diels-Adler type adduct, especially a bismaleimide, a biscitraconimide, or a benzoquinone, or mixtures thereof. Addition curing of this product produces a high linear polymeric structure and heat treating the highly linear polymeric structure produces a thermally stable aromatic addition-type thermoplastic polyimide, which finds utility in the preparation of molding compounds, adhesive compositions, and polymer matrix composites.
NASA Astrophysics Data System (ADS)
Chen, Jian; Xu, Xiaochan; Li, Tao; Pandiselvi, Kannusamy; Wang, Jingyu
2016-11-01
Efficient metal-free visible photocatalysts with high stability are highly desired for sufficient utilization of solar energy. In this work, the popular carbon nitride (CN) photocatalyst is rationally modified by acid exfoliation of molecular grafted CN, achieving improved visible-light utilization and charge carriers mobility. Moreover, the modification process tuned the surface electrical property of CN, which enabled it to be readily coupled with the oppositely charged graphene oxide during the following photo-assisted electrostatic assembly. Detailed characterizations indicate the formation of well-contacted 2D/2D heterostructure with strong interfacial interaction between the modified CN nanosheets (CNX-NSs) and reduced graphene oxide (RGO). The optimized hybrid (with a RGO ratio of 20%) exhibits the best photocatalytic performance toward MB degradation, which is almost 12.5 and 7.0 times of CN under full spectrum and visible-light irradiation, respectively. In addition, the hybrid exhibits high stability after five successive cycles with no obvious change in efficiency. Unlike pure CNX-NSs, the dye decomposition mostly depends on the H2O2 generation by a two-electron process due to the electron reservoir property of RGO. Thus the enhancement in photocatalytic activity could be ascribed to the improved light utilization and increased charge transfer ability across the interface of CNX-NSs/RGO heterostructure.
High Power Silicon Carbide (SiC) Power Processing Unit Development
NASA Technical Reports Server (NTRS)
Scheidegger, Robert J.; Santiago, Walter; Bozak, Karin E.; Pinero, Luis R.; Birchenough, Arthur G.
2015-01-01
NASA GRC successfully designed, built and tested a technology-push power processing unit for electric propulsion applications that utilizes high voltage silicon carbide (SiC) technology. The development specifically addresses the need for high power electronics to enable electric propulsion systems in the 100s of kilowatts. This unit demonstrated how high voltage combined with superior semiconductor components resulted in exceptional converter performance.
Development of a Waterproof Crack-Based Stretchable Strain Sensor Based on PDMS Shielding.
Hong, Seong Kyung; Yang, Seongjin; Cho, Seong J; Jeon, Hyungkook; Lim, Geunbae
2018-04-12
This paper details the design of a poly(dimethylsiloxane) (PDMS)-shielded waterproof crack-based stretchable strain sensor, in which the electrical characteristics and sensing performance are not influenced by changes in humidity. This results in a higher number of potential applications for the sensor. A previously developed omni-purpose stretchable strain (OPSS) sensor was used as the basis for this work, which utilizes a metal cracking structure and provides a wide sensing range and high sensitivity. Changes in the conductivity of the OPSS sensor, based on humidity conditions, were investigated along with the potential possibility of using the design as a humidity sensor. However, to prevent conductivity variation, which can decrease the reliability and sensing ability of the OPSS sensor, PDMS was utilized as a shielding layer over the OPSS sensor. The PDMS-shielded OPSS sensor showed approximately the same electrical characteristics as previous designs, including in a high humidity environment, while maintaining its strain sensing capabilities. The developed sensor shows promise for use under high humidity conditions and in underwater applications. Therefore, considering its unique features and reliable sensing performance, the developed PDMS-shielded waterproof OPSS sensor has potential utility in a wide range of applications, such as motion monitoring, medical robotics and wearable healthcare devices.
Evaluation of a black-footed ferret resource utilization function model
Eads, D.A.; Millspaugh, J.J.; Biggins, D.E.; Jachowski, D.S.; Livieri, T.M.
2011-01-01
Resource utilization function (RUF) models permit evaluation of potential habitat for endangered species; ideally such models should be evaluated before use in management decision-making. We evaluated the predictive capabilities of a previously developed black-footed ferret (Mustela nigripes) RUF. Using the population-level RUF, generated from ferret observations at an adjacent yet distinct colony, we predicted the distribution of ferrets within a black-tailed prairie dog (Cynomys ludovicianus) colony in the Conata Basin, South Dakota, USA. We evaluated model performance, using data collected during post-breeding spotlight surveys (2007-2008) by assessing model agreement via weighted compositional analysis and count-metrics. Compositional analysis of home range use and colony-level availability, and core area use and home range availability, demonstrated ferret selection of the predicted Very high and High occurrence categories in 2007 and 2008. Simple count-metrics corroborated these findings and suggested selection of the Very high category in 2007 and the Very high and High categories in 2008. Collectively, these results suggested that the RUF was useful in predicting occurrence and intensity of space use of ferrets at our study site, the 2 objectives of the RUF. Application of this validated RUF would increase the resolution of habitat evaluations, permitting prediction of the distribution of ferrets within distinct colonies. Additional model evaluation at other sites, on other black-tailed prairie dog colonies of varying resource configuration and size, would increase understanding of influences upon model performance and the general utility of the RUF. ?? 2011 The Wildlife Society.
Analytical modeling of helium turbomachinery using FORTRAN 77
NASA Astrophysics Data System (ADS)
Balaji, Purushotham
Advanced Generation IV modular reactors, including Very High Temperature Reactors (VHTRs), utilize helium as the working fluid, with a potential for high efficiency power production utilizing helium turbomachinery. Helium is chemically inert and nonradioactive which makes the gas ideal for a nuclear power-plant environment where radioactive leaks are a high concern. These properties of helium gas helps to increase the safety features as well as to decrease the aging process of plant components. The lack of sufficient helium turbomachinery data has made it difficult to study the vital role played by the gas turbine components of these VHTR powered cycles. Therefore, this research work focuses on predicting the performance of helium compressors. A FORTRAN77 program is developed to simulate helium compressor operation, including surge line prediction. The resulting design point and off design performance data can be used to develop compressor map files readable by Numerical Propulsion Simulation Software (NPSS). This multi-physics simulation software that was developed for propulsion system analysis has found applications in simulating power-plant cycles.
Maina, Ndegwa Henry; Pitkänen, Leena; Heikkinen, Sami; Tuomainen, Päivi; Virkki, Liisa; Tenkanen, Maija
2014-01-01
Dilute solutions of various dextran standards, a high-molar mass (HMM) commercial dextran from Leuconostoc spp., and HMM dextrans isolated from Weissella confusa and Leuconostoc citreum were analyzed with high-performance size-exclusion chromatography (HPSEC), asymmetric flow field-flow fractionation (AsFlFFF), and diffusion-ordered NMR spectroscopy (DOSY). HPSEC analyses were performed in aqueous and dimethyl sulfoxide (DMSO) solutions, while only aqueous solutions were utilized in AsFlFFF and DOSY. The study showed that all methods were applicable to dextran analysis, but differences between the aqueous and DMSO-based solutions were obtained for HMM samples. These differences were attributed to the presence of aggregates in aqueous solution that were less prevalent in DMSO. The study showed that DOSY provides an estimate of the size of HMM dextrans, though calibration standards may be required for each experimental set-up. To our knowledge, this is the first study utilizing these three methods in analyzing HMM dextrans. Copyright © 2013 Elsevier Ltd. All rights reserved.
ERIC Educational Resources Information Center
Giersch, Jason; Bottia, Martha Cecilia; Mickelson, Roslyn Arlin; Stearns, Elizabeth
2016-01-01
In this study we investigate Charlotte-Mecklenburg Schools (CMS) high school graduates' academic performance in the first year of college and test whether their exposure to racial segregation in high school at both the school and classroom levels affected their college freshman grade point averages. Utilizing administrative data from the Roots of…
ERIC Educational Resources Information Center
Horne, Lela M.; Rachal, John R.; Shelley, Kyna
2012-01-01
A mixed methods framework utilized quantitative and qualitative data to determine whether statistically significant differences existed between high school and GED[R] student perceptions of credential value. An exploratory factor analysis (n=326) extracted four factors and then a MANOVA procedure was performed with a stratified quota sample…
Aggregate modeling of fast-acting demand response and control under real-time pricing
Chassin, David P.; Rondeau, Daniel
2016-08-24
This paper develops and assesses the performance of a short-term demand response (DR) model for utility load control with applications to resource planning and control design. Long term response models tend to underestimate short-term demand response when induced by prices. This has two important consequences. First, planning studies tend to undervalue DR and often overlook its benefits in utility demand management program development. Second, when DR is not overlooked, the open-loop DR control gain estimate may be too low. This can result in overuse of load resources, control instability and excessive price volatility. Our objective is therefore to develop amore » more accurate and better performing short-term demand response model. We construct the model from first principles about the nature of thermostatic load control and show that the resulting formulation corresponds exactly to the Random Utility Model employed in economics to study consumer choice. The model is tested against empirical data collected from field demonstration projects and is shown to perform better than alternative models commonly used to forecast demand in normal operating conditions. Finally, the results suggest that (1) existing utility tariffs appear to be inadequate to incentivize demand response, particularly in the presence of high renewables, and (2) existing load control systems run the risk of becoming unstable if utilities close the loop on real-time prices.« less
Aggregate modeling of fast-acting demand response and control under real-time pricing
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chassin, David P.; Rondeau, Daniel
This paper develops and assesses the performance of a short-term demand response (DR) model for utility load control with applications to resource planning and control design. Long term response models tend to underestimate short-term demand response when induced by prices. This has two important consequences. First, planning studies tend to undervalue DR and often overlook its benefits in utility demand management program development. Second, when DR is not overlooked, the open-loop DR control gain estimate may be too low. This can result in overuse of load resources, control instability and excessive price volatility. Our objective is therefore to develop amore » more accurate and better performing short-term demand response model. We construct the model from first principles about the nature of thermostatic load control and show that the resulting formulation corresponds exactly to the Random Utility Model employed in economics to study consumer choice. The model is tested against empirical data collected from field demonstration projects and is shown to perform better than alternative models commonly used to forecast demand in normal operating conditions. Finally, the results suggest that (1) existing utility tariffs appear to be inadequate to incentivize demand response, particularly in the presence of high renewables, and (2) existing load control systems run the risk of becoming unstable if utilities close the loop on real-time prices.« less
Aggregate modeling of fast-acting demand response and control under real-time pricing
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chassin, David P.; Rondeau, Daniel
This paper develops and assesses the performance of a short-term demand response (DR) model for utility load control with applications to resource planning and control design. Long term response models tend to underestimate short-term demand response when induced by prices. This has two important consequences. First, planning studies tend to undervalue DR and often overlook its benefits in utility demand management program development. Second, when DR is not overlooked, the open-loop DR control gain estimate may be too low. This can result in overuse of load resources, control instability and excessive price volatility. Our objective is therefore to develop amore » more accurate and better performing short-term demand response model. We construct the model from first principles about the nature of thermostatic load control and show that the resulting formulation corresponds exactly to the Random Utility Model employed in economics to study consumer choice. The model is tested against empirical data collected from field demonstration projects and is shown to perform better than alternative models commonly used to forecast demand in normal operating conditions. The results suggest that (1) existing utility tariffs appear to be inadequate to incentivize demand response, particularly in the presence of high renewables, and (2) existing load control systems run the risk of becoming unstable if utilities close the loop on real-time prices.« less
Gryshkov, Oleksandr; Pogozhykh, Denys; Hofmann, Nicola; Pogozhykh, Olena; Mueller, Thomas; Glasmacher, Birgit
2014-01-01
Alginate cell-based therapy requires further development focused on clinical application. To assess engraftment, risk of mutations and therapeutic benefit studies should be performed in an appropriate non-human primate model, such as the common marmoset (Callithrix jacchus). In this work we encapsulated amnion derived multipotent stromal cells (MSCs) from Callithrix jacchus in defined size alginate beads using a high voltage technique. Our results indicate that i) alginate-cell mixing procedure and cell concentration do not affect the diameter of alginate beads, ii) encapsulation of high cell numbers (up to 10×106 cells/ml) can be performed in alginate beads utilizing high voltage and iii) high voltage (15–30 kV) does not alter the viability, proliferation and differentiation capacity of MSCs post-encapsulation compared with alginate encapsulated cells produced by the traditional air-flow method. The consistent results were obtained over the period of 7 days of encapsulated MSCs culture and after cryopreservation utilizing a slow cooling procedure (1 K/min). The results of this work show that high voltage encapsulation can further be maximized to develop cell-based therapies with alginate beads in a non-human primate model towards human application. PMID:25259731
Influence of Lift Offset on Rotorcraft Performance
NASA Technical Reports Server (NTRS)
Johnson, Wayne
2009-01-01
The influence of lift offset on the performance of several rotorcraft configurations is explored. A lift-offset rotor, or advancing blade concept, is a hingeless rotor that can attain good efficiency at high speed by operating with more lift on the advancing side than on the retreating side of the rotor disk. The calculated performance capability of modern-technology coaxial rotors utilizing a lift offset is examined, including rotor performance optimized for hover and high-speed cruise. The ideal induced power loss of coaxial rotors in hover and twin rotors in forward flight is presented. The aerodynamic modeling requirements for performance calculations are evaluated, including wake and drag models for the high-speed flight condition. The influence of configuration on the performance of rotorcraft with lift-offset rotors is explored, considering tandem and side-by-side rotorcraft as well as wing-rotor lift share.
Influence of Lift Offset on Rotorcraft Performance
NASA Technical Reports Server (NTRS)
Johnson, Wayne
2008-01-01
The influence of lift offset on the performance of several rotorcraft configurations is explored. A lift-offset rotor, or advancing blade concept, is a hingeless rotor that can attain good efficiency at high speed, by operating with more lift on the advancing side than on the retreating side of the rotor disk. The calculated performance capability of modern-technology coaxial rotors utilizing a lift offset is examined, including rotor performance optimized for hover and high-speed cruise. The ideal induced power loss of coaxial rotors in hover and twin rotors in forward flight is presented. The aerodynamic modeling requirements for performance calculations are evaluated, including wake and drag models for the high speed flight condition. The influence of configuration on the performance of rotorcraft with lift-offset rotors is explored, considering tandem and side-by-side rotorcraft as well as wing-rotor lift share.
Biological and functional relevance of CASP predictions.
Liu, Tianyun; Ish-Shalom, Shirbi; Torng, Wen; Lafita, Aleix; Bock, Christian; Mort, Matthew; Cooper, David N; Bliven, Spencer; Capitani, Guido; Mooney, Sean D; Altman, Russ B
2018-03-01
Our goal is to answer the question: compared with experimental structures, how useful are predicted models for functional annotation? We assessed the functional utility of predicted models by comparing the performances of a suite of methods for functional characterization on the predictions and the experimental structures. We identified 28 sites in 25 protein targets to perform functional assessment. These 28 sites included nine sites with known ligand binding (holo-sites), nine sites that are expected or suggested by experimental authors for small molecule binding (apo-sites), and Ten sites containing important motifs, loops, or key residues with important disease-associated mutations. We evaluated the utility of the predictions by comparing their microenvironments to the experimental structures. Overall structural quality correlates with functional utility. However, the best-ranked predictions (global) may not have the best functional quality (local). Our assessment provides an ability to discriminate between predictions with high structural quality. When assessing ligand-binding sites, most prediction methods have higher performance on apo-sites than holo-sites. Some servers show consistently high performance for certain types of functional sites. Finally, many functional sites are associated with protein-protein interaction. We also analyzed biologically relevant features from the protein assemblies of two targets where the active site spanned the protein-protein interface. For the assembly targets, we find that the features in the models are mainly determined by the choice of template. © 2017 The Authors Proteins: Structure, Function and Bioinformatics Published by Wiley Periodicals, Inc.
School Correlates of Academic Behaviors and Performance among McKinney-Vento Identified Youth
ERIC Educational Resources Information Center
Stone, Susan; Uretsky, Mathew
2016-01-01
We utilized a pooled sample of elementary, middle, and high school-aged children identified as homeless via definitions set forth by McKinney-Vento legislation in a large urban district in California to estimate the extent to which school factors contributed to student attendance, suspensions, test-taking behaviors, and performance on state…
Re-Examining High-Fat Diets for Sports Performance: Did We Call the 'Nail in the Coffin' Too Soon?
Burke, Louise M
2015-11-01
During the period 1985-2005, studies examined the proposal that adaptation to a low-carbohydrate (<25 % energy), high-fat (>60 % energy) diet (LCHF) to increase muscle fat utilization during exercise could enhance performance in trained individuals by reducing reliance on muscle glycogen. As little as 5 days of training with LCHF retools the muscle to enhance fat-burning capacity with robust changes that persist despite acute strategies to restore carbohydrate availability (e.g., glycogen supercompensation, carbohydrate intake during exercise). Furthermore, a 2- to 3-week exposure to minimal carbohydrate (<20 g/day) intake achieves adaptation to high blood ketone concentrations. However, the failure to detect clear performance benefits during endurance/ultra-endurance protocols, combined with evidence of impaired performance of high-intensity exercise via a down-regulation of carbohydrate metabolism led this author to dismiss the use of such fat-adaptation strategies by competitive athletes in conventional sports. Recent re-emergence of interest in LCHF diets, coupled with anecdotes of improved performance by sportspeople who follow them, has created a need to re-examine the potential benefits of this eating style. Unfortunately, the absence of new data prevents a different conclusion from being made. Notwithstanding the outcomes of future research, there is a need for better recognition of current sports nutrition guidelines that promote an individualized and periodized approach to fuel availability during training, allowing the athlete to prepare for competition performance with metabolic flexibility and optimal utilization of all muscle substrates. Nevertheless, there may be a few scenarios where LCHF diets are of benefit, or at least are not detrimental, for sports performance.
High-Performance, Multi-Node File Copies and Checksums for Clustered File Systems
NASA Technical Reports Server (NTRS)
Kolano, Paul Z.; Ciotti, Robert B.
2012-01-01
Modern parallel file systems achieve high performance using a variety of techniques, such as striping files across multiple disks to increase aggregate I/O bandwidth and spreading disks across multiple servers to increase aggregate interconnect bandwidth. To achieve peak performance from such systems, it is typically necessary to utilize multiple concurrent readers/writers from multiple systems to overcome various singlesystem limitations, such as number of processors and network bandwidth. The standard cp and md5sum tools of GNU coreutils found on every modern Unix/Linux system, however, utilize a single execution thread on a single CPU core of a single system, and hence cannot take full advantage of the increased performance of clustered file systems. Mcp and msum are drop-in replacements for the standard cp and md5sum programs that utilize multiple types of parallelism and other optimizations to achieve maximum copy and checksum performance on clustered file systems. Multi-threading is used to ensure that nodes are kept as busy as possible. Read/write parallelism allows individual operations of a single copy to be overlapped using asynchronous I/O. Multinode cooperation allows different nodes to take part in the same copy/checksum. Split-file processing allows multiple threads to operate concurrently on the same file. Finally, hash trees allow inherently serial checksums to be performed in parallel. Mcp and msum provide significant performance improvements over standard cp and md5sum using multiple types of parallelism and other optimizations. The total speed-ups from all improvements are significant. Mcp improves cp performance over 27x, msum improves md5sum performance almost 19x, and the combination of mcp and msum improves verified copies via cp and md5sum by almost 22x. These improvements come in the form of drop-in replacements for cp and md5sum, so are easily used and are available for download as open source software at http://mutil.sourceforge.net.
Achieving Literacy Excellence through Identifying and Utilizing High Yield Strategies
ERIC Educational Resources Information Center
Hardison, Ashley
2017-01-01
The purpose of this study was to delve into the literacy instructional strategies of selected high-performing K-2 teachers in a Clark County, Nevada school district. The study assessed the efficacy of teachers using five core literacy components: phonemic awareness, phonics, vocabulary, fluency, and comprehension for student achievement. High…
;Utilization of Tabula Rasa to stabilize bulk lifetimes in n-Cz silicon for high-performance solar cell /SiOx/pc-Si passivated contacts to n-type Si solar cells." Presented at the 40th IEEE Photovoltaic , and P. Stradins. "Heterojunction rear passivated contact for high efficiency n-Cz Si solar cells
A Nostrum of School Reform? Turning around Reconstituted Urban Texas High Schools
ERIC Educational Resources Information Center
Hamilton, Madlene P.; Heilig, Julian Vasquez; Pazey, Barbara L.
2014-01-01
A mainstay in NCLB and the Obama administration education plan is turning around low-performing schools. This study utilized surveys and interviews with school leaders from four turnaround urban high schools in Texas to understand student outcomes before and after school restructuring and reconstitution. Although some organizational changes were…
Hughes, Robie V; Smith, Sherrill J; Sheffield, Clair M; Wier, Grady
2013-01-01
This multi-site, quasi-experimental study examined the performance outcomes of nurses (n = 152) in a military nurse transition program. A modified-performance instrument was used to assess participants in two high-fidelity simulation scenarios. Although results indicated a significant increase in scores posttraining, only moderate interrater reliability results were found for the new instrument. These findings have implications for nurse educators assessing performance-based outcomes of new nurses completing transition programs.
Application of selected advanced technologies to high performance, single-engine, business airplanes
NASA Technical Reports Server (NTRS)
Domack, C. S.; Martin, G. L.
1984-01-01
Improvements in performance and fuel efficiency are evaluated for five new configurations of a six place, single turboprop, business airplane derived from a conventional, aluminum construction baseline aircraft. Results show the greatest performance gains for enhancements in natural laminar flow. A conceptual diesel engine provides greater fuel efficiency but reduced performance. Less significant effects are produced by the utilization of composite materials construction or by reconfiguration from tractor to pusher propeller installation.
Optimizing high performance computing workflow for protein functional annotation.
Stanberry, Larissa; Rekepalli, Bhanu; Liu, Yuan; Giblock, Paul; Higdon, Roger; Montague, Elizabeth; Broomall, William; Kolker, Natali; Kolker, Eugene
2014-09-10
Functional annotation of newly sequenced genomes is one of the major challenges in modern biology. With modern sequencing technologies, the protein sequence universe is rapidly expanding. Newly sequenced bacterial genomes alone contain over 7.5 million proteins. The rate of data generation has far surpassed that of protein annotation. The volume of protein data makes manual curation infeasible, whereas a high compute cost limits the utility of existing automated approaches. In this work, we present an improved and optmized automated workflow to enable large-scale protein annotation. The workflow uses high performance computing architectures and a low complexity classification algorithm to assign proteins into existing clusters of orthologous groups of proteins. On the basis of the Position-Specific Iterative Basic Local Alignment Search Tool the algorithm ensures at least 80% specificity and sensitivity of the resulting classifications. The workflow utilizes highly scalable parallel applications for classification and sequence alignment. Using Extreme Science and Engineering Discovery Environment supercomputers, the workflow processed 1,200,000 newly sequenced bacterial proteins. With the rapid expansion of the protein sequence universe, the proposed workflow will enable scientists to annotate big genome data.
Plug cluster engine concept for in-space missions
NASA Technical Reports Server (NTRS)
Obrien, C. J.; Aukerman, C. A.
1979-01-01
The development of a suitable orbital transfer vehicle (OTV) engine is discussed. The OTV's dimensions are limited by those of the Space Shuttle payload bay on which it will be carried. An approach to utilize the available diameter to achieve high area ratio and thus high engine performance, is presented. Unconventional nozzles, such as clusters of small thrusters around a large diameter contoured plug, are investigated to arrive at engine designs which feature lower chamber pressures, with attendant lower heat flux, lower wall temperature, longer fatigue life, and less critical turbomachinery. Attention is also given to plug nozzle technology, high area ratio module- and scarfed bell- Plug Cluster Engine (PCE) concepts, as well as PCE performance, weight, and assessment. A conceptual design of a PCE formed from a cluster of high area ratio, scarfed, bell nozzles proved to be competitive with bell and spike nozzle engines. PCE advantages cited include increased payload length due to shorter engine length, ability to increase or decrease the number of modules and thereby the thrust, and low cost due to utilization of off-the-shelf technology.
Optimizing high performance computing workflow for protein functional annotation
Stanberry, Larissa; Rekepalli, Bhanu; Liu, Yuan; Giblock, Paul; Higdon, Roger; Montague, Elizabeth; Broomall, William; Kolker, Natali; Kolker, Eugene
2014-01-01
Functional annotation of newly sequenced genomes is one of the major challenges in modern biology. With modern sequencing technologies, the protein sequence universe is rapidly expanding. Newly sequenced bacterial genomes alone contain over 7.5 million proteins. The rate of data generation has far surpassed that of protein annotation. The volume of protein data makes manual curation infeasible, whereas a high compute cost limits the utility of existing automated approaches. In this work, we present an improved and optmized automated workflow to enable large-scale protein annotation. The workflow uses high performance computing architectures and a low complexity classification algorithm to assign proteins into existing clusters of orthologous groups of proteins. On the basis of the Position-Specific Iterative Basic Local Alignment Search Tool the algorithm ensures at least 80% specificity and sensitivity of the resulting classifications. The workflow utilizes highly scalable parallel applications for classification and sequence alignment. Using Extreme Science and Engineering Discovery Environment supercomputers, the workflow processed 1,200,000 newly sequenced bacterial proteins. With the rapid expansion of the protein sequence universe, the proposed workflow will enable scientists to annotate big genome data. PMID:25313296
NASA Technical Reports Server (NTRS)
Ikpe, Stanley A.; Lauenstein, Jean-Marie; Carr, Gregory A.; Hunter, Don; Ludwig, Lawrence L.; Wood, William; Del Castillo, Linda Y.; Fitzpatrick, Fred; Chen, Yuan
2016-01-01
Silicon-Carbide device technology has generated much interest in recent years. With superior thermal performance, power ratings and potential switching frequencies over its Silicon counterpart, Silicon-Carbide offers a greater possibility for high powered switching applications in extreme environment. In particular, Silicon-Carbide Metal-Oxide- Semiconductor Field-Effect Transistors' (MOSFETs) maturing process technology has produced a plethora of commercially available power dense, low on-state resistance devices capable of switching at high frequencies. A novel hard-switched power processing unit (PPU) is implemented utilizing Silicon-Carbide power devices. Accelerated life data is captured and assessed in conjunction with a damage accumulation model of gate oxide and drain-source junction lifetime to evaluate potential system performance at high temperature environments.
Specialization and utilization after hepatectomy in academic medical centers.
Shaw, Joshua J; Santry, Heena P; Shah, Shimul A
2013-11-01
Specialized procedures such as hepatectomy are performed by a variety of specialties in surgery. We aimed to determine whether variation exists among utilization of resources, cost, and patient outcomes by specialty, surgeon case volume, and center case volume for hepatectomy. We queried centers (n = 50) in the University Health Consortium database from 2007-2010 for patients who underwent elective hepatectomy in which specialty was designated general surgeon (n = 2685; 30%) or specialist surgeon (n = 6277; 70%), surgeon volume was designated high volume (>38 cases annually) and center volume was designated high volume (>100 cases annually). We then stratified our cohort by primary diagnosis, defined as primary tumor (n = 2241; 25%), secondary tumor (n = 5466; 61%), and benign (n = 1255; 14%). Specialist surgeons performed more cases for primary malignancy (primary 26% versus 15%) while general surgeons operated more for secondary malignancies (67% versus 61%) and benign disease (18% versus 13%). Specialists were associated with a shorter total length of stay (LOS) (5 d versus 6 d; P < 0.01) and lower in-hospital morbidity (7% versus 11%; P < 0.01). Patients treated by high volume surgeons or at high volume centers were less likely to die than those treated by low volume surgeons or at low volume centers, (OR 0.55; 95% CI 0.33-0.89) and (OR 0.44; 95% CI 0.13-0.56). Surgical specialization, surgeon volume and center volume may be important metrics for quality and utilization in complex procedures like hepatectomy. Further studies are necessary to link direct factors related to hospital performance in the changing healthcare environment. Copyright © 2013 Elsevier Inc. All rights reserved.
A high-performance channel engineered charge-plasma-based MOSFET with high-κ spacer
NASA Astrophysics Data System (ADS)
Shan, Chan; Wang, Ying; Luo, Xin; Bao, Meng-tian; Yu, Cheng-hao; Cao, Fei
2017-12-01
In this paper, the performance of graded channel double-gate MOSFET (GC-DGFET) that utilizes the charge-plasma concept and a high-κ spacer is investigated through 2-D device simulations. The results demonstrate that GC-DGFET with high-κ spacer can effectively improve the ON-state driving current (ION) and reduce the OFF-leakage current (IOFF). We find that reduction of the initial energy barrier between the source and channel is the origin of this ION enhancement. The reason for the IOFF reduction is identified to be the extension of the effective channel length owing to the fringing field via high-κ spacers. Consequently, these devices offer enhanced performance by reducing the total gate-to-gate capacitance (Cgg) and decreasing the intrinsic delay (τ).
A Neutron Diffractometer for a Long Pulsed Neutron Source
NASA Astrophysics Data System (ADS)
Sokol, Paul; Wang, Cailin
Long pulsed neutron sources are being actively developed as small university based sources and are being considered for the next generation of high powered sources, such as the European Neutron Source (ESS) and the Spallation Neutron Source (SNS) second target station. New instrumentation concepts will be required to effectively utilize the full spectrum of neutrons generated by these sources. Neutron diffractometers, which utilize time-of-flight (TOF) techniques for wavelength resolution, are particularly problematic. We describe an instrument for a long pulsed source that provides resolution comparable to that obtained on short pulsed sources without the need of long incident flight paths. We accomplish this by utilizing high speed choppers to impose a time structure on the spectrum of incident neutrons. By strategically positioning these choppers the response matrix assumes a convenient form that can be deconvoluted from the measured TOF spectrum to produce the diffraction pattern of the sample. We compare the performance of this instrument to other possible diffraction instruments that could be utilized on a long pulsed source.
Life Cycle Assessment of Coal-fired Power Production
DOE Office of Scientific and Technical Information (OSTI.GOV)
Spath, P. L.; Mann, M. K.; Kerr, D. R.
1999-09-01
Coal has the largest share of utility power generation in the US, accounting for approximately 56% of all utility-produced electricity (US DOE, 1998). Therefore, understanding the environmental implications of producing electricity from coal is an important component of any plan to reduce total emissions and resource consumption. A life cycle assessment (LCA) on the production of electricity from coal was performed in order to examine the environmental aspects of current and future pulverized coal boiler systems. Three systems were examined: (1) a plant that represents the average emissions and efficiency of currently operating coal-fired power plants in the US (thismore » tells us about the status quo), (2) a new coal-fired power plant that meets the New Source Performance Standards (NSPS), and (3) a highly advanced coal-fired power plant utilizing a low emission boiler system (LEBS).« less
Subscale testing of prompt agent defeat formulations
NASA Astrophysics Data System (ADS)
Knott, A.; Stamatis, D.; Svingala, F.; Lightstone, J.; Miller, K.; Bensman, M.; Bohmke, M.
2017-01-01
There is a need to improve the current bioagent defeat systems with formulations that produce lower peak pressure and impulse, sustained high temperatures, and release of biocidal species for prompt defeat applications. In this work, explosive charge configurations similar to fuel-air explosives were detonated in a semi-enclosed chamber configuration. Binder type and fuel-to-oxidizer ratios were varied to observe the effects on combustion performance. Thermocouple measurements and high-speed video were used to monitor the combustion of the dispersed formulation. The down-selected formulations were then tested in a sub-scale vented agent defeat system developed to evaluate performance of formulations against aerosolized Bacillus thuringiensis (Bt) spores. Diagnostics including thermocouples and piezoelectric pressure gauges were utilized to characterize the detonation event. Biological sampling with surface coupons, liquid impingement, and filters of the post detonation environment were utilized to determine spore survivability and to rank the relative effectiveness of each formulation.
Shak, S
1987-01-01
LTB4 and its omega-oxidation products may be rapidly, sensitively, and specifically quantitated by the methods of solid-phase extraction and reversed-phase high-performance liquid chromatography (HPLC), which are described in this chapter. Although other techniques, such as radioimmunoassay or gas chromatography-mass spectrometry, may be utilized for quantitative analysis of the lipoxygenase products of arachidonic acid, only the technique of reversed-phase HPLC can quantitate as many as 10 metabolites in a single analysis, without prior derivatization. In this chapter, we also reviewed the chromatographic theory which we utilized in order to optimize reversed-phase HPLC analysis of LTB4 and its omega-oxidation products. With this information and a gradient HPLC system, it is possible for any investigator to develop a powerful assay for the potent inflammatory mediator, LTB4, or for any other lipoxygenase product of arachidonic acid.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Orton, Daniel J.; Tfaily, Malak M.; Moore, Ronald J.
To better understand disease conditions and environmental perturbations, multi-omic studies (i.e. proteomic, lipidomic, metabolomic, etc. analyses) are vastly increasing in popularity. In a multi-omic study, a single sample is typically extracted in multiple ways and numerous analyses are performed using different instruments. Thus, one sample becomes many analyses, making high throughput and reproducible evaluations a necessity. One way to address the numerous samples and varying instrumental conditions is to utilize a flow injection analysis (FIA) system for rapid sample injection. While some FIA systems have been created to address these challenges, many have limitations such as high consumable costs, lowmore » pressure capabilities, limited pressure monitoring and fixed flow rates. To address these limitations, we created an automated, customizable FIA system capable of operating at diverse flow rates (~50 nL/min to 500 µL/min) to accommodate low- and high-flow instrument sources. This system can also operate at varying analytical throughputs from 24 to 1200 samples per day to enable different MS analysis approaches. Applications ranging from native protein analyses to molecular library construction were performed using the FIA system. The results from these studies showed a highly robust platform, providing consistent performance over many days without carryover as long as washing buffers specific to each molecular analysis were utilized.« less
Fiber supercapacitors utilizing pen ink for flexible/wearable energy storage.
Fu, Yongping; Cai, Xin; Wu, Hongwei; Lv, Zhibin; Hou, Shaocong; Peng, Ming; Yu, Xiao; Zou, Dechun
2012-11-08
A novel type of flexible fiber/wearable supercapacitor that is composed of two fiber electrodes - a helical spacer wire and an electrolyte - is demonstrated. In the carbon-based fiber supercapacitor (FSC), which has high capacitance performance, commercial pen ink is directly utilized as the electrochemical material. FSCs have potential benefits in the pursuit of low-cost, large-scale, and efficient flexible/wearable energy storage systems. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Tomasik, M
1982-01-01
Glucose utilization by the erythrocytes, lactic acid concentration in the blood and erythrocytes, and haematocrit value were determined before exercise and during one hour rest following maximal exercise in 97 individuals of either sex differing in physical efficiency. In the investigations reported by the author individuals with strikingly high physical fitness performed maximal work one-third greater than that performed by individuals with medium fitness. The serum concentration of lactic acid was in all individuals above the resting value still after 60 minutes of rest. On the other hand, this concentration returned to the normal level in the erythrocytes but only in individuals with strikingly high efficiency. Glucose utilization by the erythrocytes during the restitution period was highest immediately after the exercise in all studied individuals and showed a tendency for more rapid return to resting values again in individuals with highest efficiency. The investigation of very efficient individuals repeated twice demonstrated greater utilization of glucose by the erythrocytes at the time of greater maximal exercise. This was associated with greater lactic acid concentration in the serum and erythrocytes throughout the whole one-hour rest period. The observed facts suggest an active participation of erythrocytes in the process of adaptation of the organism to exercise.
Hill, A S; Giersch, T M; Loh, C S; Skerritt, J H
1999-10-01
A single-chain fragment (scFv) was engineered from a monoclonal antibody to high molecular weight glutenin subunits (HMW-GS), wheat flour polypeptides that play a major role in determining the mixing- and extension strength-related properties of dough and its subsequent baking performance. The scFv was expressed in a thioredoxin mutant Escherichia coli strain that allows disulfide bond formation in the cytoplasm and incorporated into a diagnostic test for wheat quality. Although the scFv lacks the more highly conserved antibody constant regions usually involved with immobilization, it was able to be directly immobilized to a polystyrene microwell solid phase without chemical or covalent modification of the protein or solid phase and utilized as a capture antibody in a double-antibody (two-site) immunoassay. In the sandwich assay, increasing HMW-GS concentrations produced increasing assay color, and highly significant correlations were obtained between optical densities obtained in the ELISA using the scFv and the content of large glutenin polymers in flours as well as measures of dough strength as measured by resistance to dough extension in rheological testing. The assay using the scFv was able to be carried out at lower flour sample extract dilutions than that required for a similar assay utilizing a monoclonal capture antibody. This research shows that engineered antibody fragments can be utilized to provide superior assay performance in two-site ELISAs over monoclonal antibodies and is the first application of an engineered antibody to the analysis of food processing quality.
Sensitivity Analysis of Hybrid Propulsion Transportation System for Human Mars Expeditions
NASA Technical Reports Server (NTRS)
Chai, Patrick R.; Joyce, Ryan T.; Kessler, Paul D.; Merrill, Raymond G.; Qu, Min
2017-01-01
The National Aeronautics and Space Administration continues to develop and refine various transportation options to successfully field a human Mars campaign. One of these transportation options is the Hybrid Transportation System which utilizes both solar electric propulsion and chemical propulsion. The Hybrid propulsion system utilizes chemical propulsion to perform high thrust maneuvers, where the delta-V is most optimal when ap- plied to save time and to leverage the Oberth effect. It then utilizes solar electric propulsion to augment the chemical burns throughout the interplanetary trajectory. This eliminates the need for the development of two separate vehicles for crew and cargo missions. Previous studies considered single point designs of the architecture, with fixed payload mass and propulsion system performance parameters. As the architecture matures, it is inevitable that the payload mass and the performance of the propulsion system will change. It is desirable to understand how these changes will impact the in-space transportation system's mass and power requirements. This study presents an in-depth sensitivity analysis of the Hybrid crew transportation system to payload mass growth and solar electric propulsion performance. This analysis is used to identify the breakpoints of the current architecture and to inform future architecture and campaign design decisions.
An empirical assessment of high-performing medical groups: results from a national study.
Shortell, Stephen M; Schmittdiel, Julie; Wang, Margaret C; Li, Rui; Gillies, Robin R; Casalino, Lawrence P; Bodenheimer, Thomas; Rundall, Thomas G
2005-08-01
The performance of medical groups is receiving increased attention. Relatively little conceptual or empirical work exists that examines the various dimensions of medical group performance. Using a national database of 693 medical groups, this article develops a scorecard approach to assessing group performance and presents a theory-driven framework for differentiating between high-performing versus low-performing medical groups. The clinical quality of care, financial performance, and organizational learning capability of medical groups are assessed in relation to environmental forces, resource acquisition and resource deployment factors, and a quality-centered culture. Findings support the utility of the performance scorecard approach and identification of a number of key factors differentiating high-performing from low-performing groups including, in particular, the importance of a quality-centered culture and the requirement of outside reporting from third party organizations. The findings hold a number of important implications for policy and practice, and the framework presented provides a foundation for future research.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Landwehr, Joshua B.; Suetterlein, Joshua D.; Marquez, Andres
2016-05-16
Since 2012, the U.S. Department of Energy’s X-Stack program has been developing solutions including runtime systems, programming models, languages, compilers, and tools for the Exascale system software to address crucial performance and power requirements. Fine grain programming models and runtime systems show a great potential to efficiently utilize the underlying hardware. Thus, they are essential to many X-Stack efforts. An abundant amount of small tasks can better utilize the vast parallelism available on current and future machines. Moreover, finer tasks can recover faster and adapt better, due to a decrease in state and control. Nevertheless, current applications have been writtenmore » to exploit old paradigms (such as Communicating Sequential Processor and Bulk Synchronous Parallel processing). To fully utilize the advantages of these new systems, applications need to be adapted to these new paradigms. As part of the applications’ porting process, in-depth characterization studies, focused on both application characteristics and runtime features, need to take place to fully understand the application performance bottlenecks and how to resolve them. This paper presents a characterization study for a novel high performance runtime system, called the Open Community Runtime, using key HPC kernels as its vehicle. This study has the following contributions: one of the first high performance, fine grain, distributed memory runtime system implementing the OCR standard (version 0.99a); and a characterization study of key HPC kernels in terms of runtime primitives running on both intra and inter node environments. Running on a general purpose cluster, we have found up to 1635x relative speed-up for a parallel tiled Cholesky Kernels on 128 nodes with 16 cores each and a 1864x relative speed-up for a parallel tiled Smith-Waterman kernel on 128 nodes with 30 cores.« less
ERIC Educational Resources Information Center
Chiado, Wendy S.
2012-01-01
Too many of our nation's youth have failed to complete high school. Determining why so many of our nation's students fail to graduate is a complex, multi-faceted problem and beyond the scope of any one study. The study presented herein utilized a thirteen-step mixed methods model developed by Leech and Onwuegbuzie (2007) to demonstrate within a…
Development of novel hybrid flexure-based microgrippers for precision micro-object manipulation.
Mohd Zubir, Mohd Nashrul; Shirinzadeh, Bijan; Tian, Yanling
2009-06-01
This paper describes the process of developing a microgripper that is capable of high precision and fidelity manipulation of micro-objects. The design adopts the concept of flexure-based hinges on its joints to provide the rotational motion, thus eliminating the inherent nonlinearities associated with the application of conventional rigid hinges. A combination of two modeling techniques, namely, pseudorigid body model and finite element analysis was utilized to expedite the prototyping procedure, which leads to the establishment of a high performance mechanism. A new hybrid compliant structure integrating cantilever beam and flexural hinge configurations within microgripper mechanism mainframe has been developed. This concept provides a novel approach to harness the advantages within each individual configuration while mutually compensating the limitations inherent between them. A wire electrodischarge machining technique was utilized to fabricate the gripper out of high grade aluminum alloy (Al 7075T6). Experimental studies were conducted on the model to obtain various correlations governing the gripper performance as well as for model verification. The experimental results demonstrate high level of compliance in comparison to the computational results. A high amplification characteristic and maximum achievable stroke of 100 microm can be achieved.
Development of novel hybrid flexure-based microgrippers for precision micro-object manipulation
NASA Astrophysics Data System (ADS)
Mohd Zubir, Mohd Nashrul; Shirinzadeh, Bijan; Tian, Yanling
2009-06-01
This paper describes the process of developing a microgripper that is capable of high precision and fidelity manipulation of micro-objects. The design adopts the concept of flexure-based hinges on its joints to provide the rotational motion, thus eliminating the inherent nonlinearities associated with the application of conventional rigid hinges. A combination of two modeling techniques, namely, pseudorigid body model and finite element analysis was utilized to expedite the prototyping procedure, which leads to the establishment of a high performance mechanism. A new hybrid compliant structure integrating cantilever beam and flexural hinge configurations within microgripper mechanism mainframe has been developed. This concept provides a novel approach to harness the advantages within each individual configuration while mutually compensating the limitations inherent between them. A wire electrodischarge machining technique was utilized to fabricate the gripper out of high grade aluminum alloy (Al 7075T6). Experimental studies were conducted on the model to obtain various correlations governing the gripper performance as well as for model verification. The experimental results demonstrate high level of compliance in comparison to the computational results. A high amplification characteristic and maximum achievable stroke of 100 μm can be achieved.
Efficient resource allocation scheme for visible-light communication system
NASA Astrophysics Data System (ADS)
Kim, Woo-Chan; Bae, Chi-Sung; Cho, Dong-Ho; Shin, Hong-Seok; Jung, D. K.; Oh, Y. J.
2009-01-01
A visible-light communication utilizing LED has many advantagies such as visibility of information, high SNR (Signal to Noise Ratio), low installation cost, usage of existing illuminators, and high security. Furthermore, exponentially increasing needs and quality of LED have helped the development of visible-light communication. The visibility is the most attractive property in visible-light communication system, but it is difficult to ensure visibility and transmission efficiency simultaneously during initial access because of the small amount of initial access process signals. In this paper, we propose an efficient resource allocation scheme at initial access for ensuring visibility with high resource utilization rate and low data transmission failure rate. The performance has been evaluated through the numerical analysis and simulation results.
Real-time computational photon-counting LiDAR
NASA Astrophysics Data System (ADS)
Edgar, Matthew; Johnson, Steven; Phillips, David; Padgett, Miles
2018-03-01
The availability of compact, low-cost, and high-speed MEMS-based spatial light modulators has generated widespread interest in alternative sampling strategies for imaging systems utilizing single-pixel detectors. The development of compressed sensing schemes for real-time computational imaging may have promising commercial applications for high-performance detectors, where the availability of focal plane arrays is expensive or otherwise limited. We discuss the research and development of a prototype light detection and ranging (LiDAR) system via direct time of flight, which utilizes a single high-sensitivity photon-counting detector and fast-timing electronics to recover millimeter accuracy three-dimensional images in real time. The development of low-cost real time computational LiDAR systems could have importance for applications in security, defense, and autonomous vehicles.
Ntofon, Okung-Dike; Channegowda, Mayur P; Efstathiou, Nikolaos; Rashidi Fard, Mehdi; Nejabati, Reza; Hunter, David K; Simeonidou, Dimitra
2013-02-25
In this paper, a novel Software-Defined Networking (SDN) architecture is proposed for high-end Ultra High Definition (UHD) media applications. UHD media applications require huge amounts of bandwidth that can only be met with high-capacity optical networks. In addition, there are requirements for control frameworks capable of delivering effective application performance with efficient network utilization. A novel SDN-based Controller that tightly integrates application-awareness with network control and management is proposed for such applications. An OpenFlow-enabled test-bed demonstrator is reported with performance evaluations of advanced online and offline media- and network-aware schedulers.
NASA Technical Reports Server (NTRS)
Babrauckas, Theresa
2000-01-01
The Affordable High Performance Computing (AHPC) project demonstrated that high-performance computing based on a distributed network of computer workstations is a cost-effective alternative to vector supercomputers for running CPU and memory intensive design and analysis tools. The AHPC project created an integrated system called a Network Supercomputer. By connecting computer work-stations through a network and utilizing the workstations when they are idle, the resulting distributed-workstation environment has the same performance and reliability levels as the Cray C90 vector Supercomputer at less than 25 percent of the C90 cost. In fact, the cost comparison between a Cray C90 Supercomputer and Sun workstations showed that the number of distributed networked workstations equivalent to a C90 costs approximately 8 percent of the C90.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Neuhauser, K.
Through discussion of five case studies (test homes), this project evaluates strategies to elevate the performance of existing homes to a level commensurate with best-in-class implementation of high-performance new construction homes. The test homes featured in this research activity participated in Deep Energy Retrofit (DER) Pilot Program sponsored by the electric and gas utility National Grid in Massachusetts and Rhode Island. Building enclosure retrofit strategies are evaluated for impact on durability and indoor air quality in addition to energy performance.
General Recommendations on Fatigue Risk Management for the Canadian Forces
2010-04-01
missions performed in aviation require an individual(s) to process large amount of information in a short period of time and to do this on a continuous...information processing required during sustained operations can deteriorate an individual’s ability to perform a task. Given the high operational tempo...memory, which, in turn, is utilized to perform human thought processes (Baddeley, 2003). While various versions of this theory exist, they all share
Large antenna experiments aboard the space shuttle: Application of nonuniform sampling techniques
NASA Technical Reports Server (NTRS)
Rahmatsamii, Y.
1988-01-01
Future satellite communication and scientific spacecraft will utilize antennas with dimensions as large as 20 meters. In order to commercially use these large, low sidelobe and multiple beam antennas, a high level of confidence must be established as to their performance in the 0-g and space environment. Furthermore, it will be desirable to demonstrate the applicability of surface compensation techniques for slowly varying surface distortions which could result from thermal effects. An overview of recent advances in performing RF measurements on large antennas is presented with emphasis given to the application of a space based far-field range utilizing the Space Shuttle and the concept of a newly developed nonuniform sampling technique.
Performance Sensitivity Studies on the PIAA Implementation of the High-Contrast Imaging Testbed
NASA Technical Reports Server (NTRS)
Sidick, Erkin; Lou, John; Shaklan, Stuart; Levine, Marie
2010-01-01
This slide presentation reviews the sensitivity studies on the Phase-Induced Amplitude Apodization (PIAA), or pupil mapping using the High-Contrast Imaging Testbed (HCIT). PIAA is a promising technique in high-dynamic range stellar coronagraph. This presentation reports on the investigation of the effects of the phase and rigid-body errors of various optics on the narrowband contrast performance of the PIAA/HCIT hybrid system. The results have shown that the 2-step wavefront control method utilizing 2-DMs is quite effective in compensating the effects of realistic phase and rigid-body errors of various optics
Improved Engine Performance and Efficiency Utilizing a Superturbocharger
2012-08-01
supercharger, turbocharger and turbo-compounder in one single device. This is accomplished by mechanically controlling the speed ratio between the...the engine. This is made possible by a high efficiency turbine wheel. Normal turbochargers must balance the turbine power against the compressor...SuperTurbocharger and compare it against the currently used turbocharger in military vehicles to evaluate the impact on performance and efficiency
ERIC Educational Resources Information Center
Hilliard, Ann T.; Newsome, Sandra S.
2013-01-01
There are many demands on schools today to perform at a high level with competence that improves teaching and learning and promotes higher student achievement. When students perform below national standards, schools may be given a "no vote of confidence" from the public. Therefore, principals in schools need to find ways to groom and…
NASA Astrophysics Data System (ADS)
Kattke, K. J.; Braun, R. J.
2011-08-01
A novel, highly integrated tubular SOFC system intended for small-scale power is characterized through a series of sensitivity analyses and parametric studies using a previously developed high-fidelity simulation tool. The high-fidelity tubular SOFC system modeling tool is utilized to simulate system-wide performance and capture the thermofluidic coupling between system components. Stack performance prediction is based on 66 anode-supported tubular cells individually evaluated with a 1-D electrochemical cell model coupled to a 3-D computational fluid dynamics model of the cell surroundings. Radiation is the dominate stack cooling mechanism accounting for 66-92% of total heat loss at the outer surface of all cells at baseline conditions. An average temperature difference of nearly 125 °C provides a large driving force for radiation heat transfer from the stack to the cylindrical enclosure surrounding the tube bundle. Consequently, cell power and voltage disparities within the stack are largely a function of the radiation view factor from an individual tube to the surrounding stack can wall. The cells which are connected in electrical series, vary in power from 7.6 to 10.8 W (with a standard deviation, σ = 1.2 W) and cell voltage varies from 0.52 to 0.73 V (with σ = 81 mV) at the simulation baseline conditions. It is observed that high cell voltage and power outputs directly correspond to tubular cells with the smallest radiation view factor to the enclosure wall, and vice versa for tubes exhibiting low performance. Results also reveal effective control variables and operating strategies along with an improved understanding of the effect that design modifications have on system performance. By decreasing the air flowrate into the system by 10%, the stack can wall temperature increases by about 6% which increases the minimum cell voltage to 0.62 V and reduces deviations in cell power and voltage by 31%. A low baseline fuel utilization is increased by decreasing the fuel flowrate and by increasing the stack current demand. Simulation results reveal fuel flow as a poor control variable because excessive tail-gas combustor temperatures limit fuel flow to below 110% of the baseline flowrate. Additionally, system efficiency becomes inversely proportional to fuel utilization over the practical fuel flow range. Stack current is found to be an effective control variable in this type of system because system efficiency becomes directly proportional to fuel utilization. Further, the integrated system acts to dampen temperature spikes when fuel utilization is altered by varying current demand. Radiation remains the dominate heat transfer mechanism within the stack even if stack surfaces are polished lowering emissivities to 0.2. Furthermore, the sensitivity studies point to an optimal system insulation thickness that balances the overall system volume and total conductive heat loss.
Seasonally Frozen Soil Effects on the Seismic Performance of Highway Bridges
DOT National Transportation Integrated Search
2011-12-01
Permafrost degradation in regions of high seismic activity increases the potential for soil liquefaction, which can be a serious threat to transportation and utility : infrastructure, as many professionals observed during the November 2002 Denali Ear...
Seasonally Frozen Soil Effects on the Seismic Performance of Highway Bridges
DOT National Transportation Integrated Search
2011-12-01
Permafrost degradation in regions of high seismic activity increases the potential for soil liquefaction, which can be a serious threat to transportation and utility infrastructure, as many professionals observed during the November 2002 Denali Earth...
Ren, Zheng; Guo, Yanbing; Gao, Pu-Xian
2015-03-20
Monolithic catalysts, also known as structured catalysts, represent an important catalyst configuration widely used in automotive, chemical, and energy industries. However, several issues associated with washcoat based monolithic catalyst preparation are ever present, such as compromised materials utilization efficiency due to a less-than-ideal wash coating process, difficulty in precise and optimum microstructure control and lack of structure-property correlation. Here, in this mini-review, we introduce the concept of nano-array catalyst, a new type of monolithic catalyst featuring high catalyst utilization efficiency, good thermal/mechanical robustness, and catalytic performance tunability. A comprehensive overview is presented with detailed discussion of the strategies for nano-arraymore » catalyst preparation and rational catalytic activity adjustment enabled by the well-defined nano-array geometry. Specifically their scalable fabrication processes are reviewed in conjunction with discussion of their various catalytic oxidation reaction performances at low temperature. Finally, we hope this review will serve as a timely and useful research guide for rational design and utilization of the new type of monolithic catalysts.« less
Hu, J-Y; Deng, Z-B; Qin, D-M
2009-12-01
JS-118 is a diacylhydrazines-type insect growth regulator used extensively in China now. An analytical method for residues determination of JS-118 in cabbage and soil samples by high performance liquid chromatography with DAD detection was established and optimized. Primary secondary amine solid phase extraction cartridge was used for sample preparation. Mean recoveries for the analyte ranged from 96.6% to 107.0% with CV value less than 4.7%. The limit of quantification is 0.01 mg/kg. Direct confirmation of JS-118 residues in samples was realized by high performance liquid chromatography-mass spectrometry. The proposed method is simple, rapid and reliable to perform and could be utilized for monitoring of pesticides residues.
Workload Characterization of CFD Applications Using Partial Differential Equation Solvers
NASA Technical Reports Server (NTRS)
Waheed, Abdul; Yan, Jerry; Saini, Subhash (Technical Monitor)
1998-01-01
Workload characterization is used for modeling and evaluating of computing systems at different levels of detail. We present workload characterization for a class of Computational Fluid Dynamics (CFD) applications that solve Partial Differential Equations (PDEs). This workload characterization focuses on three high performance computing platforms: SGI Origin2000, EBM SP-2, a cluster of Intel Pentium Pro bases PCs. We execute extensive measurement-based experiments on these platforms to gather statistics of system resource usage, which results in workload characterization. Our workload characterization approach yields a coarse-grain resource utilization behavior that is being applied for performance modeling and evaluation of distributed high performance metacomputing systems. In addition, this study enhances our understanding of interactions between PDE solver workloads and high performance computing platforms and is useful for tuning these applications.
DOT National Transportation Integrated Search
2011-04-01
The objective of this study was to determine the influence of admixtures on long term drying shrinkage and creep of high : strength concrete (HSC). Creep and shrinkage of the mix utilized in segments of the Skyway Structure of the San : Francisco-Oak...
ERIC Educational Resources Information Center
Pate, Roberta Simnacher
2012-01-01
Texas rural schools, educating more than half a million students annually, and rural schools across the nation have been under scrutiny for the inability to provide quality education through course offerings, facilities, and qualified teachers. To address this issue, the investigator utilized Spradley's (1980) seminal work, "Participant…
DOT National Transportation Integrated Search
2011-03-01
The objective of this study was to determine the influence of admixtures on long term drying shrinkage and creep of high : strength concrete (HSC). Creep and shrinkage of the mix utilized in segments of the Skyway Structure of the San : Francisco-Oak...
Ex Ovo Model for Directly Visualizing Chick Embryo Development
ERIC Educational Resources Information Center
Dorrell, Michael I.; Marcacci, Michael; Bravo, Stephen; Kurz, Troy; Tremblay, Jacob; Rusing, Jack C.
2012-01-01
We describe a technique for removing and growing chick embryos in culture that utilizes relatively inexpensive materials and requires little space. It can be readily performed in class by university, high school, or junior high students, and teachers of any grade level should be able to set it up for their students. Students will be able to…
Federal Register 2010, 2011, 2012, 2013, 2014
2012-02-16
... Utility Steam Generating Units and Standards of Performance for Fossil-Fuel-Fired Electric Utility... Performance for Fossil-Fuel-Fired Electric Utility, Industrial-Commercial-Institutional, and Small Industrial... electric utility steam generating units (EGUs) and standards of performance for fossil-fuel-fired electric...
Tuncil, Yunus E.; Xiao, Yao; Porter, Nathan T.; Reuhs, Bradley L.
2017-01-01
ABSTRACT When presented with nutrient mixtures, several human gut Bacteroides species exhibit hierarchical utilization of glycans through a phenomenon that resembles catabolite repression. However, it is unclear how closely these observed physiological changes, often measured by altered transcription of glycan utilization genes, mirror actual glycan depletion. To understand the glycan prioritization strategies of two closely related human gut symbionts, Bacteroides ovatus and Bacteroides thetaiotaomicron, we performed a series of time course assays in which both species were individually grown in a medium with six different glycans that both species can degrade. Disappearance of the substrates and transcription of the corresponding polysaccharide utilization loci (PULs) were measured. Each species utilized some glycans before others, but with different priorities per species, providing insight into species-specific hierarchical preferences. In general, the presence of highly prioritized glycans repressed transcription of genes involved in utilizing lower-priority nutrients. However, transcriptional sensitivity to some glycans varied relative to the residual concentration in the medium, with some PULs that target high-priority substrates remaining highly expressed even after their target glycan had been mostly depleted. Coculturing of these organisms in the same mixture showed that the hierarchical orders generally remained the same, promoting stable coexistence. Polymer length was found to be a contributing factor for glycan utilization, thereby affecting its place in the hierarchy. Our findings not only elucidate how B. ovatus and B. thetaiotaomicron strategically access glycans to maintain coexistence but also support the prioritization of carbohydrate utilization based on carbohydrate structure, advancing our understanding of the relationships between diet and the gut microbiome. PMID:29018117
Asynchronous threat awareness by observer trials using crowd simulation
NASA Astrophysics Data System (ADS)
Dunau, Patrick; Huber, Samuel; Stein, Karin U.; Wellig, Peter
2016-10-01
The last few years showed that a high risk of asynchronous threats is given in every day life. Especially in large crowds a high probability of asynchronous attacks is evident. High observational abilities to detect threats are desirable. Consequently highly trained security and observation personal is needed. This paper evaluates the effectiveness of a training methodology to enhance performance of observation personnel engaging in a specific target identification task. For this purpose a crowd simulation video is utilized. The study first provides a measurement of the base performance before the training sessions. Furthermore a training procedure will be performed. Base performance will then be compared to the after training performance in order to look for a training effect. A thorough evaluation of both the training sessions as well as the overall performance will be done in this paper. A specific hypotheses based metric is used. Results will be discussed in order to provide guidelines for the design of training for observational tasks.
Bussières, André E; Sales, Anne E; Ramsay, Timothy; Hilles, Steven; Grimshaw, Jeremy M
2013-01-01
Nonspecific back pain is associated with high use of diagnostic imaging in primary care, yet current evidence suggests that routine imaging of the spine is unnecessary. The objective of this study is to describe current practice patterns in spine radiograph utilization among doctors of chiropractic enrolled in an American provider network. A cross-sectional analysis of administrative claims data from one of the largest providers of complementary health care networks for health plans in the United States was performed. Survey data containing provider demographics were linked with routinely collected data on spine radiograph utilization and patient characteristics aggregated at the provider level. We calculated rates and variations of spine radiographs over 12 months. Negative binomial regression was performed to identify significant predictors of high radiograph utilization and to estimate the associated incidence risk ratio. Complete data for 6946 doctors of chiropractic and 249193 adult patients were available for analyses. In 2010, claims were paid for a total of 91542 new patient examinations and 23369 spine radiographs (including 17511 ordered within 5 days of initial patient examination). The rate of spine radiographs within 5 days of an initial patient visit was 204 per 1000 new patient examinations. Significant predictors of higher radiograph utilization rates included the following: practicing in the Midwest or South US census regions, practicing in an urban or suburban setting, chiropractic school attended, and being a male provider in full-time practice with more than 20 years of experience. Chiropractic school attended and practice location were the most influential predictors of spine radiograph utilization among network chiropractors. This information may help to inform the development and evaluation of a tailored intervention to address overuse of radiograph utilization. Copyright © 2013 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.
Saywell, R M; Bean, J A; Ludke, R L; Redman, R W; McHugh, G J
1981-01-01
To examine the relationships between measures of attending physician teams' clinical and utilization performance, inpatient hospital audits were conducted in 22 Maryland and western Pennsylvania nonfederal short-term hospitals. A total of 6,980 medical records were abstracted from eight diagnostic categories using the Payne and JCAH PEP medical audit procedures. The results indicate weak statistical associations between the two medical care evaluation audits; between clinical performance and utilization performance, as measured by appropriateness of admissions and length of stay; and between three utilization measures. Based on these findings, it does not appear valid to use performance in one area to evaluate performance in the other in order to measure or evaluate and ultimately improve physicians; clinical or utilization performance. PMID:6946048
Supporting Multiple Cognitive Processing Styles Using Tailored Support Systems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tuan Q. Tran; Karen M. Feigh; Amy R. Pritchett
According to theories of cognitive processing style or cognitive control mode, human performance is more effective when an individual’s cognitive state (e.g., intuition/scramble vs. deliberate/strategic) matches his/her ecological constraints or context (e.g., utilize intuition to strive for a "good-enough" response instead of deliberating for the "best" response under high time pressure). Ill-mapping between cognitive state and ecological constraints are believed to lead to degraded task performance. Consequently, incorporating support systems which are designed to specifically address multiple cognitive and functional states e.g., high workload, stress, boredom, and initiate appropriate mitigation strategies (e.g., reduce information load) is essential to reduce plantmore » risk. Utilizing the concept of Cognitive Control Models, this paper will discuss the importance of tailoring support systems to match an operator's cognitive state, and will further discuss the importance of these ecological constraints in selecting and implementing mitigation strategies for safe and effective system performance. An example from the nuclear power plant industry illustrating how a support system might be tailored to support different cognitive states is included.« less
The effects of anxious responding on mental arithmetic and lexical decision task performance.
Hopko, Derek R; McNeil, Daniel W; Lejuez, C W; Ashcraft, Mark H; Eifert, Georg H; Riel, Jim
2003-01-01
Anxiety-related responding and skill deficits historically are associated with performance-based problems such as mathematics anxiety, yet the relative contribution of these variables to substandard performance remains poorly understood. Utilizing a 7% carbon dioxide (CO2) gas to induce anxiety, the present study examined the impact of anxious responding on two performance tasks, mental arithmetic and lexical decision. Independent variables included math anxiety group, gender, and gas condition. Dependent variables included task performance and physiological and self-report indices of anxiety. A total of 64 university undergraduate students participated. Physiological and verbal-report measures of anxiety supported the utility of 7% carbon dioxide-enriched air as an anxiety-inducing stimulus. Behavioral disruption on performance tasks, however, did not differ as a function of carbon dioxide inhalation. Performance did differ as a function of math anxiety. High math anxious individuals generally exhibited higher error rates on mathematical tasks, particularly on tasks designed to measure advanced math skill and those requiring working memory resources. These findings are discussed with reference to processing efficiency theory, discordance among anxiety response systems, and the intricacies associated with skill measurement.
Kikui, Miki; Kida, Momoyo; Kosaka, Takayuki; Yamamoto, Masaaki; Yoshimuta, Yoko; Yasui, Sakae; Nokubi, Takashi; Maeda, Yoshinobu; Kokubo, Yoshihiro; Watanabe, Makoto; Miyamoto, Yoshihiro
2015-01-01
Abstract There are numerous reports on the relationship between regular utilization of dental care services and oral health, but most are based on questionnaires and subjective evaluation. Few have objectively evaluated masticatory performance and its relationship to utilization of dental care services. The purpose of this study was to identify the effect of regular utilization of dental services on masticatory performance. The subjects consisted of 1804 general residents of Suita City, Osaka Prefecture (760 men and 1044 women, mean age 66.5 ± 7.9 years). Regular utilization of dental services and oral hygiene habits (frequency of toothbrushing and use of interdental aids) was surveyed, and periodontal status, occlusal support, and masticatory performance were measured. Masticatory performance was evaluated by a chewing test using gummy jelly. The correlation between age, sex, regular dental utilization, oral hygiene habits, periodontal status or occlusal support, and masticatory performance was analyzed using Spearman's correlation test and t‐test. In addition, multiple linear regression analysis was carried out to investigate the relationship of regular dental utilization with masticatory performance after controlling for other factors. Masticatory performance was significantly correlated to age when using Spearman's correlation test, and to regular dental utilization, periodontal status, or occlusal support with t‐test. Multiple linear regression analysis showed that regular utilization of dental services was significantly related to masticatory performance even after adjusting for age, sex, oral hygiene habits, periodontal status, and occlusal support (standardized partial regression coefficient β = 0.055). These findings suggested that the regular utilization of dental care services is an important factor influencing masticatory performance in a Japanese urban population. PMID:29744141
Kikui, Miki; Ono, Takahiro; Kida, Momoyo; Kosaka, Takayuki; Yamamoto, Masaaki; Yoshimuta, Yoko; Yasui, Sakae; Nokubi, Takashi; Maeda, Yoshinobu; Kokubo, Yoshihiro; Watanabe, Makoto; Miyamoto, Yoshihiro
2015-12-01
There are numerous reports on the relationship between regular utilization of dental care services and oral health, but most are based on questionnaires and subjective evaluation. Few have objectively evaluated masticatory performance and its relationship to utilization of dental care services. The purpose of this study was to identify the effect of regular utilization of dental services on masticatory performance. The subjects consisted of 1804 general residents of Suita City, Osaka Prefecture (760 men and 1044 women, mean age 66.5 ± 7.9 years). Regular utilization of dental services and oral hygiene habits (frequency of toothbrushing and use of interdental aids) was surveyed, and periodontal status, occlusal support, and masticatory performance were measured. Masticatory performance was evaluated by a chewing test using gummy jelly. The correlation between age, sex, regular dental utilization, oral hygiene habits, periodontal status or occlusal support, and masticatory performance was analyzed using Spearman's correlation test and t -test. In addition, multiple linear regression analysis was carried out to investigate the relationship of regular dental utilization with masticatory performance after controlling for other factors. Masticatory performance was significantly correlated to age when using Spearman's correlation test, and to regular dental utilization, periodontal status, or occlusal support with t -test. Multiple linear regression analysis showed that regular utilization of dental services was significantly related to masticatory performance even after adjusting for age, sex, oral hygiene habits, periodontal status, and occlusal support (standardized partial regression coefficient β = 0.055). These findings suggested that the regular utilization of dental care services is an important factor influencing masticatory performance in a Japanese urban population.
Moisture Performance of High-R Wall Systems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shah, Nay B.; Kochkin, Vladimir
High-performance homes offer improved comfort, lower utility bills, and assured durability. The next generation of building enclosures is a key step toward achieving high-performance goals through decreasing energy load demand and enabling advanced space-conditioning systems. Yet the adoption of high-R enclosures and particularly high-R walls has been a slow-growing trend because mainstream builders are hesitant to make the transition. In a survey of builders on this topic, one of the challenges identifi ed is an industry-wide concern about the long-term moisture performance of energy-effi cient walls. This study takes a step toward addressing this concern through direct monitoring of themore » moisture performance of high-R walls in occupied homes in several climate zones. In addition, the robustness of the design and modeling tools for selecting high-R wall solutions is evaluated using the monitored data from the field. The information and knowledge gained through this research will provide an objective basis for decision-making so that builders can implement advanced designs with confidence.« less
High Performance Computing Modeling Advances Accelerator Science for High-Energy Physics
Amundson, James; Macridin, Alexandru; Spentzouris, Panagiotis
2014-07-28
The development and optimization of particle accelerators are essential for advancing our understanding of the properties of matter, energy, space, and time. Particle accelerators are complex devices whose behavior involves many physical effects on multiple scales. Therefore, advanced computational tools utilizing high-performance computing are essential for accurately modeling them. In the past decade, the US Department of Energy's SciDAC program has produced accelerator-modeling tools that have been employed to tackle some of the most difficult accelerator science problems. The authors discuss the Synergia framework and its applications to high-intensity particle accelerator physics. Synergia is an accelerator simulation package capable ofmore » handling the entire spectrum of beam dynamics simulations. Our authors present Synergia's design principles and its performance on HPC platforms.« less
Laser patterning of laminated structures for electroplating
Mayer, Steven T.; Evans, Leland B.
1993-01-01
A process for laser patterning of a substrate so that it can be subsequently electroplated or electrolessly plated. The process utilizes a laser to treat an inactive (inert) layer formed over an active layer to either combine or remove the inactive layer to produce a patterned active layer on which electrodeposition can occur. The process is carried out by utilizing laser alloying and laser etching, and involves only a few relatively high yield steps and can be performed on a very small scale.
Laser patterning of laminated structures for electroplating
Mayer, S.T.; Evans, L.B.
1993-11-23
A process for laser patterning of a substrate so that it can be subsequently electroplated or electrolessly plated. The process utilizes a laser to treat an inactive (inert) layer formed over an active layer to either combine or remove the inactive layer to produce a patterned active layer on which electrodeposition can occur. The process is carried out by utilizing laser alloying and laser etching, and involves only a few relatively high yield steps and can be performed on a very small scale. 9 figures.
Development of a large inert gas ion thruster
NASA Technical Reports Server (NTRS)
Steiner, G.
1982-01-01
A 30 cm inert gas electrostatic ion thruster has been developed, exhibiting excellent performance. In the development, the effective anode area was reduced by altering the magnetic field geometry to improve plasma containment, consistent with operational stability. The propellant introduction scheme has the effect of 'folding' the discharge chamber without the increased wall loss penalty associated with a longer chamber. These features contribute to a low discharge cost (eV/ion) versus mass utilization characteristic which remains relatively flat even to high mass utilizations.
Spectrum Savings from High Performance Recording and Playback Onboard the Test Article
2013-02-20
execute within a Windows 7 environment, and data is recorded on SSDs. The underlying database is implemented using MySQL . Figure 1 illustrates the... MySQL database. This is effectively the time at which the recorded data are available for retransmission. CPU and Memory utilization were collected...17.7% MySQL avg. 3.9% EQDR Total avg. 21.6% Table 1 CPU Utilization with260 Mbits/sec Load The difference between the total System CPU (27.8
1981-02-01
monotonic increasing function of true ability or performance score. A cumulative probability function is * then very convenient for describiny; one’s...possible outcomes such as test scores, grade-point averages or other common outcome variables. Utility is usually a monotonic increasing function of true ...r(0) is negative for 8 <i and positive for 0 > M, U(o) is risk-prone for low 0 values and risk-averse for high 0 values. This property is true for
NASA Astrophysics Data System (ADS)
Trinh, H. P.
2012-06-01
Utilization of new cold hypergolic propellants and leverage Missile Defense Agency technology for propulsion systems on Mars explorations will provide an increase of science payload and have significant payoffs and benefits for NASA missions.
The BioMedical Evidence Graph (BMEG) | Informatics Technology for Cancer Research (ITCR)
The BMEG is a Cancer Data integration Platform that utilizes methods collected from DREAM challenges and applied to large datasets, such as the TCGA, and makes them avalible for analysis using a high performance graph database
geospatial data analysis using parallel processing High performance computing Renewable resource technical potential and supply curve analysis Spatial database utilization Rapid analysis of large geospatial datasets energy and geospatial analysis products Research Interests Rapid, web-based renewable resource analysis
Safe, High-Performance, Sustainable Precast School Design
ERIC Educational Resources Information Center
Finsen, Peter I.
2011-01-01
School design utilizing integrated architectural and structural precast and prestressed concrete components has gained greater acceptance recently for numerous reasons, including increasingly sophisticated owners and improved learning environments based on material benefits such as: sustainability, energy efficiency, indoor air quality, storm…
High-Performance I/O: HDF5 for Lattice QCD
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kurth, Thorsten; Pochinsky, Andrew; Sarje, Abhinav
2015-01-01
Practitioners of lattice QCD/QFT have been some of the primary pioneer users of the state-of-the-art high-performance-computing systems, and contribute towards the stress tests of such new machines as soon as they become available. As with all aspects of high-performance-computing, I/O is becoming an increasingly specialized component of these systems. In order to take advantage of the latest available high-performance I/O infrastructure, to ensure reliability and backwards compatibility of data files, and to help unify the data structures used in lattice codes, we have incorporated parallel HDF5 I/O into the SciDAC supported USQCD software stack. Here we present the design andmore » implementation of this I/O framework. Our HDF5 implementation outperforms optimized QIO at the 10-20% level and leaves room for further improvement by utilizing appropriate dataset chunking.« less
High-Performance I/O: HDF5 for Lattice QCD
Kurth, Thorsten; Pochinsky, Andrew; Sarje, Abhinav; ...
2017-05-09
Practitioners of lattice QCD/QFT have been some of the primary pioneer users of the state-of-the-art high-performance-computing systems, and contribute towards the stress tests of such new machines as soon as they become available. As with all aspects of high-performance-computing, I/O is becoming an increasingly specialized component of these systems. In order to take advantage of the latest available high-performance I/O infrastructure, to ensure reliability and backwards compatibility of data files, and to help unify the data structures used in lattice codes, we have incorporated parallel HDF5 I/O into the SciDAC supported USQCD software stack. Here we present the design andmore » implementation of this I/O framework. Our HDF5 implementation outperforms optimized QIO at the 10-20% level and leaves room for further improvement by utilizing appropriate dataset chunking.« less
The AC photovoltaic module is here!
NASA Astrophysics Data System (ADS)
Strong, Steven J.; Wohlgemuth, John H.; Wills, Robert H.
1997-02-01
This paper describes the design, development, and performance results of a large-area photovoltaic module whose electrical output is ac power suitable for direct connection to the utility grid. The large-area ac PV module features a dedicated, integrally mounted, high-efficiency dc-to-ac power inverter with a nominal output of 250 watts (STC) at 120 Vac, 60 H, that is fully compatible with utility power. The module's output is connected directly to the building's conventional ac distribution system without need for any dc wiring, string combiners, dc ground-fault protection or additional power-conditioning equipment. With its advantages, the ac photovoltaic module promises to become a universal building block for use in all utility-interactive PV systems. This paper discusses AC Module design aspects and utility interface issues (including islanding).
Balancing autonomy and utilization of solar power and battery storage for demand based microgrids
NASA Astrophysics Data System (ADS)
Lawder, Matthew T.; Viswanathan, Vilayanur; Subramanian, Venkat R.
2015-04-01
The growth of intermittent solar power has developed a need for energy storage systems in order to decouple generation and supply of energy. Microgrid (MG) systems comprising of solar arrays with battery energy storage studied in this paper desire high levels of autonomy, seeking to meet desired demand at all times. Large energy storage capacity is required for high levels of autonomy, but much of this expensive capacity goes unused for a majority of the year due to seasonal fluctuations of solar generation. In this paper, a model-based study of MGs comprised of solar generation and battery storage shows the relationship between system autonomy and battery utilization applied to multiple demand cases using a single particle battery model (SPM). The SPM allows for more accurate state-of-charge and utilization estimation of the battery than previous studies of renewably powered systems that have used empirical models. The increased accuracy of battery state estimation produces a better assessment of system performance. Battery utilization will depend on the amount of variation in solar insolation as well as the type of demand required by the MG. Consumers must balance autonomy and desired battery utilization of a system within the needs of their grid.
Thermal Control Utilizing an Thermal Control Utilizing an Two-Phase Loop with High Heat Flux Source
NASA Technical Reports Server (NTRS)
Jeong, Seong-Il; Didion, Jeffrey
2004-01-01
The electric field applied in dielectric fluids causes an imbalance in the dissociation-recombination reaction generated free space charges. The generated charges are redistributed by the applied electric field resulting in the heterocharge layers in the Vicinity of the electrodes. Proper design of the electrodes generates net axial flow motion pumping the fluid. The electrohydrodynamic (EHD) conduction pump is a new device that pumps dielectric fluids utilizing heterocharge layers formed by imposition of electrostatic fields. This paper evaluates the experimental performance of a two-phase breadboard thermal control loop consisting of an EHD conduction pump, condenser, pre-heater, high heat flux evaporator (HE), transport lines, and reservoir (accumulator). The generated pressure head and the maximum applicable heat flux are experimentally determined at various applied voltages and sink temperatures. Recovery from dryout condition by increasing the applied voltage to the pump is also demonstrated.
Cardinal, L H; Carballo, P; Lorenzo, M C Cabral; García, A; Suzuki, V; Tatti, S; Vighi, S; Díaz, L B
2014-05-01
This study assessed the utility and limitations of anal cytology as a screening method for women infected with human papilloma virus (HPV) in the lower genital tract. Furthermore, this study aimed to establish risk factors for pathological anal cytology/biopsy findings, the prevalence of anatomopathological lesions associated with positive anal brushings, and the frequency of concomitant lesions of the lower genital tract. A cross-sectional, retrospective, descriptive study in 207 women with HPV-associated lesions of the lower genital tract and 25 women with immunosuppression was carried out. Anal cytology, high resolution anoscopy, and biopsy of suspicious lesions were performed. In total, 232 anal brushings were performed: 184 (79.3%) were negative, 24 (10.34%) showed atypical squamous cells of undeterminated significance, 18 (7.7%) showed low-grade squamous intraepithelial lesions, and 6 (2.6%) showed high-grade squamous intraepithelial lesion. Cytohistological correlation was obtained for 70 cases. The sensitivity of anal cytology in detecting intraepithelial lesions was 70%, whereas the specificity was 93%. The sensitivity of the method for detecting high-grade lesions (84%) was higher, than that for detecting low-grade lesions (66%). The most frequently associated pathology was vulvar lesion. It is important to perform anal brushings in women who have had lower genital tract biopsies for HPV-associated lesions due to the high prevalence of anal lesions in such patients. Anal cytology is useful for detecting high-grade lesions but the sensitivity for detecting low-grade lesions is low. It is of the utmost importance to perform high-resolution anoscopy and biopsy in women with suspicious lesions in order to confirm the pathology. Copyright © 2013 Wiley Periodicals, Inc.
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.
GaAs Supercomputing: Architecture, Language, And Algorithms For Image Processing
NASA Astrophysics Data System (ADS)
Johl, John T.; Baker, Nick C.
1988-10-01
The application of high-speed GaAs processors in a parallel system matches the demanding computational requirements of image processing. The architecture of the McDonnell Douglas Astronautics Company (MDAC) vector processor is described along with the algorithms and language translator. Most image and signal processing algorithms can utilize parallel processing and show a significant performance improvement over sequential versions. The parallelization performed by this system is within each vector instruction. Since each vector has many elements, each requiring some computation, useful concurrent arithmetic operations can easily be performed. Balancing the memory bandwidth with the computation rate of the processors is an important design consideration for high efficiency and utilization. The architecture features a bus-based execution unit consisting of four to eight 32-bit GaAs RISC microprocessors running at a 200 MHz clock rate for a peak performance of 1.6 BOPS. The execution unit is connected to a vector memory with three buses capable of transferring two input words and one output word every 10 nsec. The address generators inside the vector memory perform different vector addressing modes and feed the data to the execution unit. The functions discussed in this paper include basic MATRIX OPERATIONS, 2-D SPATIAL CONVOLUTION, HISTOGRAM, and FFT. For each of these algorithms, assembly language programs were run on a behavioral model of the system to obtain performance figures.
A simulation-based study of HighSpeed TCP and its deployment
DOE Office of Scientific and Technical Information (OSTI.GOV)
Souza, Evandro de
2003-05-01
The current congestion control mechanism used in TCP has difficulty reaching full utilization on high speed links, particularly on wide-area connections. For example, the packet drop rate needed to fill a Gigabit pipe using the present TCP protocol is below the currently achievable fiber optic error rates. HighSpeed TCP was recently proposed as a modification of TCP's congestion control mechanism to allow it to achieve reasonable performance in high speed wide-area links. In this research, simulation results showing the performance of HighSpeed TCP and the impact of its use on the present implementation of TCP are presented. Network conditions includingmore » different degrees of congestion, different levels of loss rate, different degrees of bursty traffic and two distinct router queue management policies were simulated. The performance and fairness of HighSpeed TCP were compared to the existing TCP and solutions for bulk-data transfer using parallel streams.« less
High Performance Semantic Factoring of Giga-Scale Semantic Graph Databases
DOE Office of Scientific and Technical Information (OSTI.GOV)
Joslyn, Cliff A.; Adolf, Robert D.; Al-Saffar, Sinan
2010-10-04
As semantic graph database technology grows to address components ranging from extant large triple stores to SPARQL endpoints over SQL-structured relational databases, it will become increasingly important to be able to bring high performance computational resources to bear on their analysis, interpretation, and visualization, especially with respect to their innate semantic structure. Our research group built a novel high performance hybrid system comprising computational capability for semantic graph database processing utilizing the large multithreaded architecture of the Cray XMT platform, conventional clusters, and large data stores. In this paper we describe that architecture, and present the results of our deployingmore » that for the analysis of the Billion Triple dataset with respect to its semantic factors.« less
Understanding Cognitive Performance During Robot-Assisted Surgery.
Guru, Khurshid A; Shafiei, Somayeh B; Khan, Atif; Hussein, Ahmed A; Sharif, Mohamed; Esfahani, Ehsan T
2015-10-01
To understand cognitive function of an expert surgeon in various surgical scenarios while performing robot-assisted surgery. In an Internal Review Board approved study, National Aeronautics and Space Administration-Task Load Index (NASA-TLX) questionnaire with surgical field notes were simultaneously completed. A wireless electroencephalography (EEG) headset was used to monitor brain activity during all procedures. Three key portions were evaluated: lysis of adhesions, extended lymph node dissection, and urethro-vesical anastomosis (UVA). Cognitive metrics extracted were distraction, mental workload, and mental state. In evaluating lysis of adhesions, mental state (EEG) was associated with better performance (NASA-TLX). Utilizing more mental resources resulted in better performance as self-reported. Outcomes of lysis were highly dependent on cognitive function and decision-making skills. In evaluating extended lymph node dissection, there was a negative correlation between distraction level (EEG) and mental demand, physical demand and effort (NASA-TLX). Similar to lysis of adhesion, utilizing more mental resources resulted in better performance (NASA-TLX). Lastly, with UVA, workload (EEG) negatively correlated with mental and temporal demand and was associated with better performance (NASA-TLX). The EEG recorded workload as seen here was a combination of both cognitive performance (finding solution) and motor workload (execution). Majority of workload was contributed by motor workload of an expert surgeon. During UVA, muscle memory and motor skills of expert are keys to completing the UVA. Cognitive analysis shows that expert surgeons utilized different mental resources based on their need. Copyright © 2015 Elsevier Inc. All rights reserved.
A high performance hybrid battery based on aluminum anode and LiFePO4 cathode.
Sun, Xiao-Guang; Bi, Zhonghe; Liu, Hansan; Fang, Youxing; Bridges, Craig A; Paranthaman, M Parans; Dai, Sheng; Brown, Gilbert M
2016-01-28
A novel hybrid battery utilizing an aluminum anode, a LiFePO4 cathode and an acidic ionic liquid electrolyte based on 1-ethyl-3-methylimidazolium chloride (EMImCl) and aluminum trichloride (AlCl3) (EMImCl-AlCl3, 1-1.1 in molar ratio) with or without LiAlCl4 is proposed. The hybrid ion battery delivers an initial high capacity of 160 mA h g(-1) at a current rate of C/5. It also shows good rate capability and cycling performance.
NASA Astrophysics Data System (ADS)
Janesick, James; Cheng, John; Bishop, Jeanne; Andrews, James T.; Tower, John; Walker, Jeff; Grygon, Mark; Elliot, Tom
2006-08-01
A high performance prototype CMOS imager is introduced. Test data is reviewed for different array formats that utilize 3T photo diode, 5T pinned photo diode and 6T photo gate CMOS pixel architectures. The imager allows several readout modes including progressive scan, snap and windowed operation. The new imager is built on different silicon substrates including very high resistivity epitaxial wafers for deep depletion operation. Data products contained in this paper focus on sensor's read noise, charge capacity, charge transfer efficiency, thermal dark current, RTS dark spikes, QE, pixel cross- talk and on-chip analog circuitry performance.
A high performance hybrid battery based on aluminum anode and LiFePO 4 cathode
Sun, Xiao-Guang; Bi, Zhonghe; Liu, Hansan; ...
2015-12-07
A unique battery hybrid utilizes an aluminum anode, a LiFePO 4 cathode and an acidic ionic liquid electrolyte based on 1-ethyl-3-methylimidazolium chloride (EMImCl) and aluminum trichloride (AlCl 3) (EMImCl-AlCl 3, 1-1.1 in molar ratio) with or without LiAlCl 4 is proposed. This hybrid ion battery delivers an initial high capacity of 160 mAh g -1 at a current rate of C/5. It also shows good rate capability and cycling performance.
Silicon nanowires for photovoltaic solar energy conversion.
Peng, Kui-Qing; Lee, Shuit-Tong
2011-01-11
Semiconductor nanowires are attracting intense interest as a promising material for solar energy conversion for the new-generation photovoltaic (PV) technology. In particular, silicon nanowires (SiNWs) are under active investigation for PV applications because they offer novel approaches for solar-to-electric energy conversion leading to high-efficiency devices via simple manufacturing. This article reviews the recent developments in the utilization of SiNWs for PV applications, the relationship between SiNW-based PV device structure and performance, and the challenges to obtaining high-performance cost-effective solar cells.
ERIC Educational Resources Information Center
Quintana, Elizabeth Ruiz
2015-01-01
This mixed method study explored and analyzed instructional strategies utilized by algebra teachers whose students' coursework culminated in the New York State Regents Examination in Integrated Algebra and for whom 50% of the tested cohort earned mastery level (85 or higher) on the examination. The targeted populations were eighth or ninth grade…
Assessing the Strategic Utility of the High North: The Colder War
2016-12-01
FUNDING NUMBERS 6. AUTHOR(S) Brandon J. Daigle and Brian W. James 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Postgraduate School...Monterey, CA 93943-5000 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING /MONITORING AGENCY NAME(S) AND ADDRESS(ES) N/A 10. SPONSORING...European Command GDP Gross domestic product ISR Intelligence, surveillance and reconnaissance NATO North Atlantic Treaty Organization NSR Northern
An 8-Week Ketogenic Low Carbohydrate, High Fat Diet Enhanced Exhaustive Exercise Capacity in Mice.
Ma, Sihui; Huang, Qingyi; Yada, Koichi; Liu, Chunhong; Suzuki, Katsuhiko
2018-05-25
Current fueling tactics for endurance exercise encourage athletes to ingest a high carbohydrate diet. However, athletes are not generally encouraged to use fat, the largest energy reserve in the human body. A low carbohydrate, high fat ketogenic diet (KD) is a nutritional approach ensuring that the body utilizes lipids. Although KD has been associated with weight-loss, enhanced fat utilization in muscle and other beneficial effects, there is currently no clear proof whether it could lead to performance advantage. To evaluate the effects of KD on endurance exercise capacity, we studied the performance of mice subjected to a running model after consuming KD for eight weeks. Weight dropped dramatically in KD-feeding mice, even though they ate more calories. KD-feeding mice showed enhanced running time without aggravated muscle injury. Blood biochemistry and correlation analysis indicated the potential mechanism is likely to be a keto-adaptation enhanced capacity to transport and metabolize fat. KD also showed a potential preventive effect on organ injury caused by acute exercise, although KD failed to exert protection from muscle injury. Ultimately, KD may contribute to prolonged exercise capacity.
Accelerating Large Scale Image Analyses on Parallel, CPU-GPU Equipped Systems
Teodoro, George; Kurc, Tahsin M.; Pan, Tony; Cooper, Lee A.D.; Kong, Jun; Widener, Patrick; Saltz, Joel H.
2014-01-01
The past decade has witnessed a major paradigm shift in high performance computing with the introduction of accelerators as general purpose processors. These computing devices make available very high parallel computing power at low cost and power consumption, transforming current high performance platforms into heterogeneous CPU-GPU equipped systems. Although the theoretical performance achieved by these hybrid systems is impressive, taking practical advantage of this computing power remains a very challenging problem. Most applications are still deployed to either GPU or CPU, leaving the other resource under- or un-utilized. In this paper, we propose, implement, and evaluate a performance aware scheduling technique along with optimizations to make efficient collaborative use of CPUs and GPUs on a parallel system. In the context of feature computations in large scale image analysis applications, our evaluations show that intelligently co-scheduling CPUs and GPUs can significantly improve performance over GPU-only or multi-core CPU-only approaches. PMID:25419545
Designing Agent Collectives For Systems With Markovian Dynamics
NASA Technical Reports Server (NTRS)
Wolpert, David H.; Lawson, John W.
2004-01-01
The Collective Intelligence (COIN) framework concerns the design of collectives of agents so that as those agents strive to maximize their individual utility functions, their interaction causes a provided world utility function concerning the entire collective to be also maximized. Here we show how to extend that framework to scenarios having Markovian dynamics when no re-evolution of the system from counter-factual initial conditions (an often expensive calculation) is permitted. Our approach transforms the (time-extended) argument of each agent's utility function before evaluating that function. This transformation has benefits in scenarios not involving Markovian dynamics of an agent's utility function are observable. We investigate this transformation in simulations involving both hear and quadratic (nonlinear) dynamics. In addition, we find that a certain subset of these transformations, which result in utilities that have low opacity (analogous to having high signal to noise) but are not factored (analogous to not being incentive compatible), reliably improve performance over that arising with factored utilities. We also present a Taylor Series method for the fully general nonlinear case.
2015-06-01
A METHOD TO PREDICT COMPRESSOR STALL IN THE TF34-100 TURBOFAN ENGINE UTILIZING REAL-TIME PERFORMANCE...THE TF34-100 TURBOFAN ENGINE UTILIZING REAL-TIME PERFORMANCE DATA THESIS Presented to the Faculty Department of Systems Engineering and...036 A METHOD TO PREDICT COMPRESSOR STALL IN THE TF34-100 TURBOFAN ENGINE UTILIZING REAL-TIME PERFORMANCE DATA Shuxiang ‘Albert’ Li, BS
Multi-Ferroic Polymer Nanoparticle Composites for Next Generation Metamaterials
2014-07-28
particle size of magnetite nanoparticles. The PI will continue to develop composites that could be utilized for developing high- bandwidth radio frequency...to improve the efficiency and decrease the size of the device. High performance stretchable magneto-dielectric materials can be accomplished using...nanoparticles oxidize at dimensions smaller than the critical size for superparamagnetic to ferromagnetic transition, which is essential for minimal
WinHPC System Policies | High-Performance Computing | NREL
requiring high CPU utilization or large amounts of memory should be run on the worker nodes. WinHPC02 is not associated data are removed when NREL worker status is discontinued. Users should make arrangements to save other users. Licenses are returned to the license pool when other users close the application or after
Reweighted mass center based object-oriented sparse subspace clustering for hyperspectral images
NASA Astrophysics Data System (ADS)
Zhai, Han; Zhang, Hongyan; Zhang, Liangpei; Li, Pingxiang
2016-10-01
Considering the inevitable obstacles faced by the pixel-based clustering methods, such as salt-and-pepper noise, high computational complexity, and the lack of spatial information, a reweighted mass center based object-oriented sparse subspace clustering (RMC-OOSSC) algorithm for hyperspectral images (HSIs) is proposed. First, the mean-shift segmentation method is utilized to oversegment the HSI to obtain meaningful objects. Second, a distance reweighted mass center learning model is presented to extract the representative and discriminative features for each object. Third, assuming that all the objects are sampled from a union of subspaces, it is natural to apply the SSC algorithm to the HSI. Faced with the high correlation among the hyperspectral objects, a weighting scheme is adopted to ensure that the highly correlated objects are preferred in the procedure of sparse representation, to reduce the representation errors. Two widely used hyperspectral datasets were utilized to test the performance of the proposed RMC-OOSSC algorithm, obtaining high clustering accuracies (overall accuracy) of 71.98% and 89.57%, respectively. The experimental results show that the proposed method clearly improves the clustering performance with respect to the other state-of-the-art clustering methods, and it significantly reduces the computational time.
Flight control systems development of highly maneuverable aircraft technology /HiMAT/ vehicle
NASA Technical Reports Server (NTRS)
Petersen, K. L.
1979-01-01
The highly maneuverable aircraft technology (HiMAT) program was conceived to demonstrate advanced technology concepts through scaled-aircraft flight tests using a remotely piloted technique. Closed-loop primary flight control is performed from a ground-based cockpit, utilizing a digital computer and up/down telemetry links. A backup flight control system for emergency operation resides in an onboard computer. The onboard systems are designed to provide fail-operational capabilities and utilize two microcomputers, dual uplink receiver/decoders, and redundant hydraulic actuation and power systems. This paper discusses the design and validation of the primary and backup digital flight control systems as well as the unique pilot and specialized systems interfaces.
The Newick utilities: high-throughput phylogenetic tree processing in the UNIX shell.
Junier, Thomas; Zdobnov, Evgeny M
2010-07-01
We present a suite of Unix shell programs for processing any number of phylogenetic trees of any size. They perform frequently-used tree operations without requiring user interaction. They also allow tree drawing as scalable vector graphics (SVG), suitable for high-quality presentations and further editing, and as ASCII graphics for command-line inspection. As an example we include an implementation of bootscanning, a procedure for finding recombination breakpoints in viral genomes. C source code, Python bindings and executables for various platforms are available from http://cegg.unige.ch/newick_utils. The distribution includes a manual and example data. The package is distributed under the BSD License. thomas.junier@unige.ch
Chopra, Karan; Gowda, Arvind U; Morrow, Chris; Holton, Luther; Singh, Devinder P
2016-04-01
Complex abdominal wall reconstruction is beset by postoperative complications. A recent meta-analysis comparing the use of closed-incision negative-pressure therapy to standard dressings found a statistically significant reduction in surgical-site infection. The use of closed-incision negative-pressure therapy is gaining acceptance in this population; however, the economic impact of this innovative dressing remains unknown. In this study, a cost-utility analysis was performed assessing closed-incision negative-pressure therapy and standard dressings following closure of abdominal incisions in high-risk patients. Cost-utility methodology involved reviewing literature related to closed-incision negative-pressure therapy in abdominal wall surgery, obtaining utility estimates to calculate quality-adjusted life-year scores for successful surgery and surgery complicated by surgical-site infection, summing costs using Medicare Current Procedural Terminology codes, and creating a decision tree illuminating the most cost-effective dressing strategy. One-way sensitivity analysis was performed to assess the robustness of the results. The aforementioned meta-analysis comparing closed-incision negative-pressure therapy to standard dressings included a subset of five studies assessing abdominal wall surgery in 829 patients (260 closed-incision negative-pressure therapy and 569 standard dressings). Decision tree analysis revealed an estimated savings of $1546.52 and a gain of 0.0024 quality-adjusted life-year with closed-incision negative-pressure therapy compared with standard dressings; therefore, closed-incision negative-pressure therapy is a dominant treatment strategy. One-way sensitivity analysis revealed that closed-incision negative-pressure therapy is a cost-effective option when the surgical-site infection rate is greater than 16.39 percent. The use of closed-incision negative-pressure therapy is cost-saving following closure of abdominal incisions in high-risk patients.
Study on Endurance and Performance of Impregnated Ruthenium Catalyst for Thruster System.
Kim, Jincheol; Kim, Taegyu
2018-02-01
Performance and endurance of the Ru catalyst were studied for nitrous oxide monopropellant thruster system. The thermal decomposition of N2O requires a considerably high temperature, which make it difficult to be utilized as a thruster propellant, while the propellant decomposition temperature can be reduced by using the catalyst through the decomposition reaction with the propellant. However, the catalyst used for the thruster was frequently exposed to high temperature and high-pressure environment. Therefore, the state change of the catalyst according to the thruster operation was analyzed. Characterization of catalyst used in the operation condition of the thruster was performed using FE-SEM and EDS. As a result, performance degradation was occurred due to the volatilization of Ru catalyst and reduction of the specific surface area according to the phase change of Al2O3.
NASA Astrophysics Data System (ADS)
Sun, Zhipeng; Firdoz, Shaik; Ying-Xuan Yap, Esther; Li, Lan; Lu, Xianmao
2013-05-01
We report a hierarchical Ni@MnO2 structure consisting of MnO2 nanowires supported on hollow Ni dendrites for high-performance supercapacitors. The Ni@MnO2 structure, which was prepared via a facile electrodeposition method, is highly porous and appears like a forest of pine trees grown vertically on a substrate. At a MnO2 mass loading of 0.35 mg cm-2, the Ni@MnO2 electrode demonstrated a specific capacitance of 1125 F g-1 that is close to the theoretical value. In addition, a remarkable high-rate performance (766 F g-1 at a discharge current density of 100 A g-1) was achieved. Electrochemical tests in a two-electrode configuration for the Ni@MnO2 structure with a high MnO2 loading of 3.6 mg cm-2 showed a low equivalent series resistance (ESR) of 1 Ω and a high specific power of 72 kW kg-1. This superior performance can be attributed to the highly porous and hierarchical structure of Ni@MnO2 that favors rapid diffusion of an electrolyte, highly conductive pathway for electron transport, and efficient material utilization.We report a hierarchical Ni@MnO2 structure consisting of MnO2 nanowires supported on hollow Ni dendrites for high-performance supercapacitors. The Ni@MnO2 structure, which was prepared via a facile electrodeposition method, is highly porous and appears like a forest of pine trees grown vertically on a substrate. At a MnO2 mass loading of 0.35 mg cm-2, the Ni@MnO2 electrode demonstrated a specific capacitance of 1125 F g-1 that is close to the theoretical value. In addition, a remarkable high-rate performance (766 F g-1 at a discharge current density of 100 A g-1) was achieved. Electrochemical tests in a two-electrode configuration for the Ni@MnO2 structure with a high MnO2 loading of 3.6 mg cm-2 showed a low equivalent series resistance (ESR) of 1 Ω and a high specific power of 72 kW kg-1. This superior performance can be attributed to the highly porous and hierarchical structure of Ni@MnO2 that favors rapid diffusion of an electrolyte, highly conductive pathway for electron transport, and efficient material utilization. Electronic supplementary information (ESI) available: More TEM and SEM images, digital photo, XPS, and XRD of the samples. See DOI: 10.1039/c3nr00209h
NASA Technical Reports Server (NTRS)
Shoji, J. M.; Larson, V. R.
1976-01-01
The application of advanced liquid-bipropellant rocket engine analysis techniques has been utilized for prediction of the potential delivered performance and the design of thruster wall cooling schemes for laser-heated rocket thrusters. Delivered specific impulse values greater than 1000 lbf-sec/lbm are potentially achievable based on calculations for thrusters designed for 10-kW and 5000-kW laser beam power levels. A thruster wall-cooling technique utilizing a combination of regenerative cooling and a carbon-seeded hydrogen boundary layer is presented. The flowing carbon-seeded hydrogen boundary layer provides radiation absorption of the heat radiated from the high-temperature plasma. Also described is a forced convection thruster wall cooling design for an experimental test thruster.
NASA Technical Reports Server (NTRS)
Leifer, Larry; Michalowski, Stefan; Vanderloos, Machiel
1991-01-01
The Stanford/VA Interactive Robotics Laboratory set out in 1978 to test the hypothesis that industrial robotics technology could be applied to serve the manipulation needs of severely impaired individuals. Five generations of hardware, three generations of system software, and over 125 experimental subjects later, we believe that genuine utility is achievable. The experience includes development of over 65 task applications using voiced command, joystick control, natural language command and 3D object designation technology. A brief foray into virtual environments, using flight simulator technology, was instructive. If reality and virtuality come for comparable prices, you cannot beat reality. A detailed review of assistive robot anatomy and the performance specifications needed to achieve cost/beneficial utility will be used to support discussion of the future of rehabilitation telerobotics. Poised on the threshold of commercial viability, but constrained by the high cost of technically adequate manipulators, this worthy application domain flounders temporarily. In the long run, it will be the user interface that governs utility.
Straub, Anthony P; Elimelech, Menachem
2017-11-07
Low-grade heat energy from sources below 100 °C is available in massive quantities around the world, but cannot be converted to electricity effectively using existing technologies due to variability in the heat output and the small temperature difference between the source and environment. The recently developed thermo-osmotic energy conversion (TOEC) process has the potential to harvest energy from low-grade heat sources by using a temperature difference to create a pressurized liquid flux across a membrane, which can be converted to mechanical work via a turbine. In this study, we perform the first analysis of energy efficiency and the expected performance of the TOEC technology, focusing on systems utilizing hydrophobic porous vapor-gap membranes and water as a working fluid. We begin by developing a framework to analyze realistic mass and heat transport in the process, probing the impact of various membrane parameters and system operating conditions. Our analysis reveals that an optimized system can achieve heat-to-electricity energy conversion efficiencies up to 4.1% (34% of the Carnot efficiency) with hot and cold working temperatures of 60 and 20 °C, respectively, and an operating pressure of 5 MPa (50 bar). Lower energy efficiencies, however, will occur in systems operating with high power densities (>5 W/m 2 ) and with finite-sized heat exchangers. We identify that the most important membrane properties for achieving high performance are an asymmetric pore structure, high pressure resistance, a high porosity, and a thickness of 30 to 100 μm. We also quantify the benefits in performance from utilizing deaerated water streams, strong hydrodynamic mixing in the membrane module, and high heat exchanger efficiencies. Overall, our study demonstrates the promise of full-scale TOEC systems to extract energy from low-grade heat and identifies key factors for performance optimization moving forward.
The Case of Nuclear Propulsion
NASA Technical Reports Server (NTRS)
Koroteev, Anatoly S.; Ponomarev-Stepnoi, Nicolai N.; Smetannikov, Vladimir P.; Gafarov, Albert A.; Houts, Mike; VanDyke, Melissa; Godfroy, Tom; Martin, James; Bragg-Sitton, Shannon; Dickens, Ricky
2003-01-01
Fission technology can enable rapid, affordable access to any point in the solar system. If fission propulsion systems are to be developed to their full potential; however, near-term customers must be identified and initial fission systems successfully developed, launched, and utilized. Successful utilization will simultaneously develop the infrastructure and experience necessary for developing even higher power and performance systems. To be successful, development programs must devise strategies for rapidly converting paper reactor concepts into actual flight hardware. One approach to accomplishing this is to design highly testable systems, and to structure the program to contain frequent, significant hardware milestones. This paper discusses ongoing efforts in Russia and the United States aimed at enabling near-term utilization of space fission systems.
Jiao, Zhengbo; Chen, Tao; Xiong, Jinyan; Wang, Teng; Lu, Gongxuan; Ye, Jinhua; Bi, Yingpu
2013-01-01
Well-aligned TiO2 nanotube arrays have become of increasing significance because of their unique highly ordered array structure, high specific surface area, unidirectional charge transfer and transportation features. However, their poor visible light utilization as well as the high recombination rate of photoexcited electron-hole pairs greatly limited their practical applications. Herein, we demonstrate the fabrication of visible-light-responsive heterostructured Cr-doped SrTiO3/TiO2 nanotube arrays by a simple hydrothermal method, which facilitate efficient charge separation and thus improve the photoelectrochemical as well as photocatalytic performances.
On the Impact of Execution Models: A Case Study in Computational Chemistry
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chavarría-Miranda, Daniel; Halappanavar, Mahantesh; Krishnamoorthy, Sriram
2015-05-25
Efficient utilization of high-performance computing (HPC) platforms is an important and complex problem. Execution models, abstract descriptions of the dynamic runtime behavior of the execution stack, have significant impact on the utilization of HPC systems. Using a computational chemistry kernel as a case study and a wide variety of execution models combined with load balancing techniques, we explore the impact of execution models on the utilization of an HPC system. We demonstrate a 50 percent improvement in performance by using work stealing relative to a more traditional static scheduling approach. We also use a novel semi-matching technique for load balancingmore » that has comparable performance to a traditional hypergraph-based partitioning implementation, which is computationally expensive. Using this study, we found that execution model design choices and assumptions can limit critical optimizations such as global, dynamic load balancing and finding the correct balance between available work units and different system and runtime overheads. With the emergence of multi- and many-core architectures and the consequent growth in the complexity of HPC platforms, we believe that these lessons will be beneficial to researchers tuning diverse applications on modern HPC platforms, especially on emerging dynamic platforms with energy-induced performance variability.« less
Progress and Design Concerns of Nanostructured Solar Energy Harvesting Devices.
Leung, Siu-Fung; Zhang, Qianpeng; Tavakoli, Mohammad Mahdi; He, Jin; Mo, Xiaoliang; Fan, Zhiyong
2016-05-01
Integrating devices with nanostructures is considered a promising strategy to improve the performance of solar energy harvesting devices such as photovoltaic (PV) devices and photo-electrochemical (PEC) solar water splitting devices. Extensive efforts have been exerted to improve the power conversion efficiencies (PCE) of such devices by utilizing novel nanostructures to revolutionize device structural designs. The thicknesses of light absorber and material consumption can be substantially reduced because of light trapping with nanostructures. Meanwhile, the utilization of nanostructures can also result in more effective carrier collection by shortening the photogenerated carrier collection path length. Nevertheless, performance optimization of nanostructured solar energy harvesting devices requires a rational design of various aspects of the nanostructures, such as their shape, aspect ratio, periodicity, etc. Without this, the utilization of nanostructures can lead to compromised device performance as the incorporation of these structures can result in defects and additional carrier recombination. The design guidelines of solar energy harvesting devices are summarized, including thin film non-uniformity on nanostructures, surface recombination, parasitic absorption, and the importance of uniform distribution of photo-generated carriers. A systematic view of the design concerns will assist better understanding of device physics and benefit the fabrication of high performance devices in the future. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
A Multi-Method Approach for Proteomic Network Inference in 11 Human Cancers.
Şenbabaoğlu, Yasin; Sümer, Selçuk Onur; Sánchez-Vega, Francisco; Bemis, Debra; Ciriello, Giovanni; Schultz, Nikolaus; Sander, Chris
2016-02-01
Protein expression and post-translational modification levels are tightly regulated in neoplastic cells to maintain cellular processes known as 'cancer hallmarks'. The first Pan-Cancer initiative of The Cancer Genome Atlas (TCGA) Research Network has aggregated protein expression profiles for 3,467 patient samples from 11 tumor types using the antibody based reverse phase protein array (RPPA) technology. The resultant proteomic data can be utilized to computationally infer protein-protein interaction (PPI) networks and to study the commonalities and differences across tumor types. In this study, we compare the performance of 13 established network inference methods in their capacity to retrieve the curated Pathway Commons interactions from RPPA data. We observe that no single method has the best performance in all tumor types, but a group of six methods, including diverse techniques such as correlation, mutual information, and regression, consistently rank highly among the tested methods. We utilize the high performing methods to obtain a consensus network; and identify four robust and densely connected modules that reveal biological processes as well as suggest antibody-related technical biases. Mapping the consensus network interactions to Reactome gene lists confirms the pan-cancer importance of signal transduction pathways, innate and adaptive immune signaling, cell cycle, metabolism, and DNA repair; and also suggests several biological processes that may be specific to a subset of tumor types. Our results illustrate the utility of the RPPA platform as a tool to study proteomic networks in cancer.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Auld, Joshua; Hope, Michael; Ley, Hubert
This paper discusses the development of an agent-based modelling software development kit, and the implementation and validation of a model using it that integrates dynamic simulation of travel demand, network supply and network operations. A description is given of the core utilities in the kit: a parallel discrete event engine, interprocess exchange engine, and memory allocator, as well as a number of ancillary utilities: visualization library, database IO library, and scenario manager. The overall framework emphasizes the design goals of: generality, code agility, and high performance. This framework allows the modeling of several aspects of transportation system that are typicallymore » done with separate stand-alone software applications, in a high-performance and extensible manner. The issue of integrating such models as dynamic traffic assignment and disaggregate demand models has been a long standing issue for transportation modelers. The integrated approach shows a possible way to resolve this difficulty. The simulation model built from the POLARIS framework is a single, shared-memory process for handling all aspects of the integrated urban simulation. The resulting gains in computational efficiency and performance allow planning models to be extended to include previously separate aspects of the urban system, enhancing the utility of such models from the planning perspective. Initial tests with case studies involving traffic management center impacts on various network events such as accidents, congestion and weather events, show the potential of the system.« less
NASA Technical Reports Server (NTRS)
Lohner, Kevin A. (Inventor); Mays, Jeffrey A. (Inventor); Sevener, Kathleen M. (Inventor)
2004-01-01
A method for designing and assembling a high performance catalyst bed gas generator for use in decomposing propellants, particularly hydrogen peroxide propellants, for use in target, space, and on-orbit propulsion systems and low-emission terrestrial power and gas generation. The gas generator utilizes a sectioned catalyst bed system, and incorporates a robust, high temperature mixed metal oxide catalyst. The gas generator requires no special preheat apparatus or special sequencing to meet start-up requirements, enabling a fast overall response time. The high performance catalyst bed gas generator system has consistently demonstrated high decomposition efficiency, extremely low decomposition roughness, and long operating life on multiple test articles.
Utility functions and resource management in an oversubscribed heterogeneous computing environment
Khemka, Bhavesh; Friese, Ryan; Briceno, Luis Diego; ...
2014-09-26
We model an oversubscribed heterogeneous computing system where tasks arrive dynamically and a scheduler maps the tasks to machines for execution. The environment and workloads are based on those being investigated by the Extreme Scale Systems Center at Oak Ridge National Laboratory. Utility functions that are designed based on specifications from the system owner and users are used to create a metric for the performance of resource allocation heuristics. Each task has a time-varying utility (importance) that the enterprise will earn based on when the task successfully completes execution. We design multiple heuristics, which include a technique to drop lowmore » utility-earning tasks, to maximize the total utility that can be earned by completing tasks. The heuristics are evaluated using simulation experiments with two levels of oversubscription. The results show the benefit of having fast heuristics that account for the importance of a task and the heterogeneity of the environment when making allocation decisions in an oversubscribed environment. Furthermore, the ability to drop low utility-earning tasks allow the heuristics to tolerate the high oversubscription as well as earn significant utility.« less
Operating room efficiency improvement after implementation of a postoperative team assessment.
Porta, Christopher R; Foster, Andrew; Causey, Marlin W; Cordier, Patricia; Ozbirn, Roger; Bolt, Stephen; Allison, Dennis; Rush, Robert
2013-03-01
Operating room time is highly resource intensive, and delays can be a source of lost revenue and surgeon frustration. Methods to decrease these delays are important not only for patient care, but to maximize operating room resource utilization. The purpose of this study was to determine the root cause of operating room delays in a standardized manner to help improve overall operating room efficiency. We performed a single-center prospective observational study analyzing operating room utilization and efficiency after implementing an executive-driven standardized postoperative team debriefing system from January 2010 to December 2010. A total of 11,342 procedures were performed over the 1-y study period (elective 86%, urgent 11%, and emergent 3%), with 1.3 million min of operating room time, 865,864 min of surgeon operative time (62.5%), and 162,958 min of anesthesia time (11.8%). Overall, the average operating room delay was 18 min and varied greatly based on the surgical specialty. The longest delays were due to need for radiology (40 min); other significant delays were due to supply issues (22.7 min), surgeon issues (18 min), nursing issues (14 min), and room turnover (14 min). Over the 1-y period, there was a decrease in mean delay duration, averaging a decrease in delay of 0.147 min/mo with an overall 9% decrease in the mean delay times. With regard to overall operating room utilization, there was a 39% decrease in overall un-utilized available OR time that was due to delays, improving efficiency by 2334 min (212 min/mo). During this study interval no sentinel events occurred in the operating room. A standardized postoperative debrief tracking system is highly beneficial in identifying and reducing overall operative delays and improving operating room utilization. Published by Elsevier Inc.
High-Cost Patients: Hot-Spotters Don't Explain the Half of It.
Lee, Natalie S; Whitman, Noah; Vakharia, Nirav; Taksler, Glen B; Rothberg, Michael B
2017-01-01
Understanding resource utilization patterns among high-cost patients may inform cost reduction strategies. To identify patterns of high-cost healthcare utilization and associated clinical diagnoses and to quantify the significance of hot-spotters among high-cost users. Retrospective analysis of high-cost patients in 2012 using data from electronic medical records, internal cost accounting, and the Centers for Medicare and Medicaid Services. K-medoids cluster analysis was performed on utilization measures of the highest-cost decile of patients. Clusters were compared using clinical diagnoses. We defined "hot-spotters" as those in the highest-cost decile with ≥4 hospitalizations or ED visits during the study period. A total of 14,855 Medicare Fee-for-service beneficiaries identified by the Medicare Quality Resource and Use Report as having received 100 % of inpatient care and ≥90 % of primary care services at Cleveland Clinic Health System (CCHS) in Northeast Ohio. The highest-cost decile was selected from this population. Healthcare utilization and diagnoses. The highest-cost decile of patients (n = 1486) accounted for 60 % of total costs. We identified five patient clusters: "Ambulatory," with 0 admissions; "Surgical," with a median of 2 surgeries; "Critically Ill," with a median of 4 ICU days; "Frequent Care," with a median of 2 admissions, 3 ED visits, and 29 outpatient visits; and "Mixed Utilization," with 1 median admission and 1 ED visit. Cancer diagnoses were prevalent in the Ambulatory group, care complications in the Surgical group, cardiac diseases in the Critically Ill group, and psychiatric disorders in the Frequent Care group. Most hot-spotters (55 %) were in the "frequent care" cluster. Overall, hot-spotters represented 9 % of the high-cost population and accounted for 19 % of their overall costs. High-cost patients are heterogeneous; most are not so-called "hot-spotters" with frequent admissions. Effective interventions to reduce costs will require a more multi-faceted approach to the high-cost population.
A magnesium–sodium hybrid battery with high operating voltage
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dong, Hui; Li, Yifei; Liang, Yanliang
2016-06-10
We report a high performance magnesium-sodium hybrid battery utilizing a magnesium-sodium dual-salt electrolyte, a magnesium anode, and a Berlin green cathode. The cell delivers an average discharge voltage of 2.2 V and a reversible capacity of 143 mAh g -1. We also demonstrate the cell with an energy density of 135 Wh kg -1 and a high power density of up to 1.67 kW kg -1.
Evaluation of SuperLU on multicore architectures
NASA Astrophysics Data System (ADS)
Li, X. S.
2008-07-01
The Chip Multiprocessor (CMP) will be the basic building block for computer systems ranging from laptops to supercomputers. New software developments at all levels are needed to fully utilize these systems. In this work, we evaluate performance of different high-performance sparse LU factorization and triangular solution algorithms on several representative multicore machines. We included both Pthreads and MPI implementations in this study and found that the Pthreads implementation consistently delivers good performance and that a left-looking algorithm is usually superior.
Van, Ngoc Huynh; Lee, Jae-Hyun; Sohn, Jung Inn; Cha, Seung Nam; Whang, Dongmok; Kim, Jong Min; Kang, Dae Joon
2014-05-21
We successfully fabricated nanowire-based complementary metal-oxide semiconductor (NWCMOS) inverter devices by utilizing n- and p-type Si nanowire field-effect-transistors (NWFETs) via a low-temperature fabrication processing technique. We demonstrate that NWCMOS inverter devices can be operated at less than 1 V, a significantly lower voltage than that of typical thin-film based complementary metal-oxide semiconductor (CMOS) inverter devices. This low-voltage operation was accomplished by controlling the threshold voltage of the n-type Si NWFETs through effective management of the nanowire (NW) doping concentration, while realizing high voltage gain (>10) and ultra-low static power dissipation (≤3 pW) for high-performance digital inverter devices. This result offers a viable means of fabricating high-performance, low-operation voltage, and high-density digital logic circuits using a low-temperature fabrication processing technique suitable for next-generation flexible electronics.
NASA Astrophysics Data System (ADS)
Fan, Xingye; Wang, Xiaolei; Li, Ge; Yu, Aiping; Chen, Zhongwei
2016-09-01
A highly flexible electrodes based on electrodeposited MnO2 and polypyrrole composite on carbon cloth is designed and developed by a facile in-situ electrodeposition technique. Such flexible composite electrodes with multiply layered structure possess a high specific capacitance of 325 F g-1 at a current density of 0.2 A g-1, and an excellent rate capability with a capacitance retention of 70% at a high current density of 5.0 A g-1. The superior electrochemical performance is mainly due to the unique electrode with improved ion- and electron-transportation pathways as well as the efficient utilization of active materials and electrode robustness. The excellent electrochemical performance and the low cost property endow this flexible nanocomposite electrode with great promise in applications of flexible supercapacitors.
NASA Astrophysics Data System (ADS)
Maisonny, R.; Ribière, M.; Toury, M.; Plewa, J. M.; Caron, M.; Auriel, G.; d'Almeida, T.
2016-12-01
The performance of a 1 MV pulsed high-power linear transformer driver accelerator were extensively investigated based on a numerical approach which utilizes both electromagnetic and Monte Carlo simulations. Particle-in-cell calculations were employed to examine the beam dynamics throughout the magnetically insulated transmission line which governs the coupling between the generator and the electron diode. Based on the information provided by the study of the beam dynamics, and using Monte Carlo methods, the main properties of the resulting x radiation were predicted. Good agreement was found between these simulations and experimental results. This work provides a detailed understanding of mechanisms affecting the performances of this type of high current, high-voltage pulsed accelerator, which are very promising for a growing number of applications.
RESOLVE Mission Architecture for Lunar Resource Prospecting and Utilization
NASA Technical Reports Server (NTRS)
George, J. A.; Mattes, G. W.; Rogers, K. N.; Magruder, D. F.; Paz, A. J.; Vaccaro, H. M.; Baird, R. S.; Sanders, G. B.; Smith, J. T.; Quinn, J. W.;
2012-01-01
Design Reference Mission (DRM) evaluations were performed for The Regolith & Environment Science, and Oxygen & Lunar Volatile Extraction (RESOLVE) project to determine future flight mission feasibility and understand potential mission environment impacts on hardware requirements, science/resource assessment objectives, and mission planning. DRM version 2.2 (DRM 2.2) is presented for a notional flight of the RESOLVE payload for lunar resource ground truth and utilization (Figure 1) [1]. The rover/payload deploys on a 10 day surface mission to the Cabeus crater near the lunar south pole in May of 2016. A drill, four primary science instruments, and a high temperature chemical reactor will acquire and characterize water and other volatiles in the near sub-surface, and perform demonstrations of In-Situ Re-source Utilization (ISRU). DRM 2.2 is a reference point, and will be periodically revised to accommodate and incorporate changes to project approach or implementation, and to explore mission alternatives such as landing site or opportunity.
Enhancing the Photovoltaic Performance of Perovskite Solar Cells with a Down-Conversion Eu-Complex.
Jiang, Ling; Chen, Wangchao; Zheng, Jiawei; Zhu, Liangzheng; Mo, Li'e; Li, Zhaoqian; Hu, Linhua; Hayat, Tasawar; Alsaedi, Ahmed; Zhang, Changneng; Dai, Songyuan
2017-08-16
Organometal halide perovskite solar cells (PSCs) have shown high photovoltaic performance but poor utilization of ultraviolet (UV) irradiation. Lanthanide complexes have a wide absorption range in the UV region and they can down-convert the absorbed UV light into visible light, which provides a possibility for PSCs to utilize UV light for higher photocurrent, efficiency, and stability. In this study, we use a transparent luminescent down-converting layer (LDL) of Eu-4,7-diphenyl-1,10-phenanthroline (Eu-complex) to improve the light utilization efficiency of PSCs. Compared with the uncoated PSC, the PSC coated with Eu-complex LDL on the reverse of the fluorine-doped tin oxide glass displayed an enhancement of 11.8% in short-circuit current density (J sc ) and 15.3% in efficiency due to the Eu-complex LDL re-emitting UV light (300-380 nm) in the visible range. It is indicated that the Eu-complex LDL plays the role of enhancing the power conversion efficiency as well as reducing UV degradation for PSCs.
Home Lighting Assessment for Clients With Low Vision
Bhorade, Anjali; Gordon, Mae; Hollingsworth, Holly; Engsberg, Jack E.; Baum, M. Carolyn
2013-01-01
OBJECTIVE. The goal was to develop an objective, comprehensive, near-task home lighting assessment for older adults with low vision. METHOD. A home lighting assessment was developed and tested with older adults with low vision. Interrater and test–retest reliability studies were conducted. Clinical utility was assessed by occupational therapists with expertise in low vision rehabilitation. RESULTS. Interrater reliability was high (intraclass correlation coefficient [ICC] = .83–1.0). Test–retest reliability was moderate (ICC = .67). Responses to a Clinical Utility Feedback Form developed for this study indicated that the Home Environment Lighting Assessment (HELA) has strong clinical utility. CONCLUSION. The HELA provides a structured tool to describe the quantitative and qualitative aspects of home lighting environments where near tasks are performed and can be used to plan lighting interventions. The HELA has the potential to affect assessment and intervention practices of rehabilitation professionals in the area of low vision and improve near-task performance of people with low vision. PMID:24195901
a New Golf-Swing Robot Model Utilizing Shaft Elasticity
NASA Astrophysics Data System (ADS)
Suzuki, S.; Inooka, H.
1998-10-01
The performance of golf clubs and balls is generally evaluated by using golf-swing robots that conventionally have two or three joints with completely interrelated motion. This interrelation allows the user of this robot to specify only the initial posture and swing velocity of the robot and therefore the swing motion of this type of robot cannot be subtly adjusted to the specific characteristics of individual golf clubs. Consequently, golf-swing robots cannot accurately emulate advanced golfers, and this causes serious problems for the evaluation of golf club performance. In this study, a new golf-swing robot that can adjust its motion to both a specified value of swing velocity and the specific characteristics of individual golf clubs was analytically investigated. This robot utilizes the dynamic interference force produced by its swing motion and by shaft vibration and can therefore emulate advanced golfers and perform highly reliable evaluations of golf clubs.
An artificial compound eye of photon Sieves
NASA Astrophysics Data System (ADS)
Jiang, Wenbo; Hu, Song; He, Yu; Bu, Yun
2015-11-01
The compound eye of insects has numerous extraordinary optical performances, such as minimum chromatic aberration, wide-angle field of view, and high sensitivity to the incidence light. Inspired by these unique performances, we present a novel artificial compound eye of photon sieves in this paper, where the photon sieves play the roles of insects' ommatidia. These photon sieves have the same focal length. The incidence light can be focused into the same focal plane and produce the superposition effect, the utilization ratio of energy can be largely improved. Through the numerical simulation, the results show that this novel structure has similar focusing performance with the conventional photon sieves, but has higher utilization ratio of energy and wider angle field of view than that of the conventional photon sieves. Our findings provide a new direction for optics and biology researchers, which will be beneficial for medical imaging, astronomy, etc.
Biochemical methane potential (BMP) of artichoke waste: the inoculum effect.
Fabbri, Andrea; Serranti, Silvia; Bonifazi, Giuseppe
2014-03-01
The aim of this work was to investigate anaerobic digestibility of artichoke waste resulting from industrial transformation. A series of batch anaerobic digestion tests was performed in order to evaluate the biochemical methane potential of the matrix in respect of the process. A comparison of the different performances of the laboratory-scale reactors operating in mesophilic conditions and utilizing three different values of the inoculum/substrate ratio was carried out. The best performance was achieved with an inoculum/substrate ratio of 2. Artichoke-processing byproducts showed a classical organic waste decomposition behaviour: a fast start-up phase, an acclimation stage, and a final stabilization phase. Following this approach, artichoke waste reached chemical oxygen demand removal of about 90% in 40 days. The high methane yield (average 408.62 mL CH4 gvs (-1) voltatile solids), makes artichoke waste a good product to be utilized in anaerobic digestion plants for biogas production.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kelley, B. M.
The electric utility industry is undergoing significant transformations in its operation model, including a greater emphasis on automation, monitoring technologies, and distributed energy resource management systems (DERMS). With these changes and new technologies, while driving greater efficiencies and reliability, these new models may introduce new vectors of cyber attack. The appropriate cybersecurity controls to address and mitigate these newly introduced attack vectors and potential vulnerabilities are still widely unknown and performance of the control is difficult to vet. This proposal argues that modeling and simulation (M&S) is a necessary tool to address and better understand these problems introduced by emergingmore » technologies for the grid. M&S will provide electric utilities a platform to model its transmission and distribution systems and run various simulations against the model to better understand the operational impact and performance of cybersecurity controls.« less
Van Hooren, Bas; Zolotarjova, Julia
2017-07-01
Van Hooren, B and Zolotarjova, J. The difference between countermovement and squat jump performances: a review of underlying mechanisms with practical applications. J Strength Cond Res 31(7): 2011-2020, 2017-Two movements that are widely used to monitor athletic performance are the countermovement jump (CMJ) and squat jump (SJ). Countermovement jump performance is almost always better than SJ performance, and the difference in performance is thought to reflect an effective utilization of the stretch-shortening cycle. However, the mechanisms responsible for the performance-enhancing effect of the stretch-shortening cycle are frequently undefined. Uncovering and understanding these mechanisms is essential to make an inference regarding the difference between the jumps. Therefore, we will review the potential mechanisms that explain the better performance in a CMJ as compared with a SJ. It is concluded that the difference in performance may primarily be related to the greater uptake of muscle slack and the buildup of stimulation during the countermovement in a CMJ. Elastic energy may also have a small contribution to an enhanced CMJ performance. Therefore, a larger difference between the jumps is not necessarily a better indicator of high-intensity sports performance. Although a larger difference may reflect the utilization of elastic energy in a small-amplitude CMJ as a result of a well-developed capability to co-activate muscles and quickly build up stimulation, a larger difference may also reflect a poor capability to reduce the degree of muscle slack and build up stimulation in the SJ. Because the capability to reduce the degree of muscle slack and quickly build up stimulation in the SJ may be especially important to high-intensity sports performance, training protocols might concentrate on attaining a smaller difference between the jumps.
NASA Astrophysics Data System (ADS)
Xie, Hongbo; Mao, Chensheng; Ren, Yongjie; Zhu, Jigui; Wang, Chao; Yang, Lei
2017-10-01
In high precision and large-scale coordinate measurement, one commonly used approach to determine the coordinate of a target point is utilizing the spatial trigonometric relationships between multiple laser transmitter stations and the target point. A light receiving device at the target point is the key element in large-scale coordinate measurement systems. To ensure high-resolution and highly sensitive spatial coordinate measurement, a high-performance and miniaturized omnidirectional single-point photodetector (OSPD) is greatly desired. We report one design of OSPD using an aspheric lens, which achieves an enhanced reception angle of -5 deg to 45 deg in vertical and 360 deg in horizontal. As the heart of our OSPD, the aspheric lens is designed in a geometric model and optimized by LightTools Software, which enables the reflection of a wide-angle incident light beam into the single-point photodiode. The performance of home-made OSPD is characterized with working distances from 1 to 13 m and further analyzed utilizing developed a geometric model. The experimental and analytic results verify that our device is highly suitable for large-scale coordinate metrology. The developed device also holds great potential in various applications such as omnidirectional vision sensor, indoor global positioning system, and optical wireless communication systems.
Cryogenic lifetime tests on a commercial epoxy resin high voltage bushing
DOE Office of Scientific and Technical Information (OSTI.GOV)
Schwenterly, S W; Pleva, Ed; Ha, Tam T
2012-06-12
High-temperature superconducting (HTS) power devices operating in liquid nitrogen frequently require high-voltage bushings to carry the current leads from the superconducting windings to the room temperature grid connections. Oak Ridge National Laboratory is collaborating with Waukesha Electric Systems, SuperPower, and Southern California Edison to develop and demonstrate an HTS utility power transformer. Previous dielectric high voltage tests in support of this program have been carried out in test cryostats with commercial epoxy resin bushings from Electro Composites Inc. (ECI). Though the bushings performed well in these short-term tests, their long-term operation at high voltage in liquid nitrogen needs to bemore » verified for use on the utility grid. Long-term tests are being carried out on a sample 28-kV-class ECI bushing. The bushing has a monolithic cast, cycloaliphatic resin body and is fire- and shatter-resistant. The test cryostat is located in an interlocked cage and is energized at 25 kVac around the clock. Liquid nitrogen (LN) is automatically refilled every 9.5 hours. Partial discharge, capacitance, and leakage resistance tests are periodically performed to check for deviations from factory values. At present, over 2400 hours have been accumulated with no changes in these parameters. The tests are scheduled to run for four to six months.« less
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.
Cryogenic lifetime tests on a commercial epoxy resin high voltage bushing
NASA Astrophysics Data System (ADS)
Schwenterly, S. W.; Pleva, E. F.; Ha, T. T.
2012-06-01
High-temperature superconducting (HTS) power devices operating in liquid nitrogen frequently require high-voltage bushings to carry the current leads from the superconducting windings to the room temperature grid connections. Oak Ridge National Laboratory (ORNL) is collaborating with Waukesha Electric Systems (WES), SuperPower (SP), and Southern California Edison (SCE) to develop and demonstrate an HTS utility power transformer. Previous dielectric high voltage tests in support of this program have been carried out in test cryostats with commercial epoxy resin bushings from Electro Composites Inc. (ECI). Though the bushings performed well in these short-term tests, their long-term operation at high voltage in liquid nitrogen (LN) needs to be verified for use on the utility grid. Long-term tests are being carried out on a sample 28-kV-rms-class ECI bushing. The bushing has a monolithic cast, cycloaliphatic resin body and is fire- and shatter-resistant. The test cryostat is located in an interlocked cage and is continuously energized at 25 kVac rms. LN is automatically refilled every 9.5 hours. Partial discharge, capacitance, and leakage resistance tests are periodically performed to check for deviations from factory values. At present, over 2400 hours have been accumulated with no changes in these parameters. The tests are scheduled to run for four to six months.
Generic Divide and Conquer Internet-Based Computing
NASA Technical Reports Server (NTRS)
Radenski, Atanas; Follen, Gregory J. (Technical Monitor)
2001-01-01
The rapid growth of internet-based applications and the proliferation of networking technologies have been transforming traditional commercial application areas as well as computer and computational sciences and engineering. This growth stimulates the exploration of new, internet-oriented software technologies that can open new research and application opportunities not only for the commercial world, but also for the scientific and high -performance computing applications community. The general goal of this research project is to contribute to better understanding of the transition to internet-based high -performance computing and to develop solutions for some of the difficulties of this transition. More specifically, our goal is to design an architecture for generic divide and conquer internet-based computing, to develop a portable implementation of this architecture, to create an example library of high-performance divide-and-conquer computing agents that run on top of this architecture, and to evaluate the performance of these agents. We have been designing an architecture that incorporates a master task-pool server and utilizes satellite computational servers that operate on the Internet in a dynamically changing large configuration of lower-end nodes provided by volunteer contributors. Our designed architecture is intended to be complementary to and accessible from computational grids such as Globus, Legion, and Condor. Grids provide remote access to existing high-end computing resources; in contrast, our goal is to utilize idle processor time of lower-end internet nodes. Our project is focused on a generic divide-and-conquer paradigm and its applications that operate on a loose and ever changing pool of lower-end internet nodes.
UTILIZATION OF SCRAP PREPREG WASTES AS A REINFORCEMENT IN A WHOLLY RECYCLED PLASTIC - PHASE II
Foster-Miller is proposing to combine Municipal Solid Waste (MSW) commingled plastics with a high performance reinforcement (scrap prepreg) to form a durable and cost competitive wood substitute with superior moisture, rodent and insect resistance. This proposed technology ...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nagarajan, Adarsh; Coddington, Michael H.; Brown, David
Voltage regulators perform as desired when regulating from the source to the load and when regulating from a strong source (utility) to a weak source (distributed generation). (See the glossary for definitions of a strong source and weak source.) Even when the control is provisioned for reverse operation, it has been observed that tap-changing voltage regulators do not perform as desired in reverse when attempting regulation from the weak source to the strong source. The region of performance that is not as well understood is the regulation between sources that are approaching equal strength. As part of this study, wemore » explored all three scenarios: regulator control from a strong source to a weak source (classic case), control from a weak source to a strong source (during reverse power flow), and control between equivalent sources.« less
Detonation Performance Analyses for Recent Energetic Molecules
NASA Astrophysics Data System (ADS)
Stiel, Leonard; Samuels, Philip; Spangler, Kimberly; Iwaniuk, Daniel; Cornell, Rodger; Baker, Ernest
2017-06-01
Detonation performance analyses were conducted for a number of evolving and potential high explosive materials. The calculations were completed for theoretical maximum densities of the explosives using the Jaguar thermo-chemical equation of state computer programs for performance evaluations and JWL/JWLB equations of state parameterizations. A number of recently synthesized materials were investigated for performance characterizations and comparisons to existing explosives, including TNT, RDX, HMX, and Cl-20. The analytic cylinder model was utilized to establish cylinder and Gurney velocities as functions of the radial expansions of the cylinder for each explosive. The densities and heats of formulation utilized in the calculations are primarily experimental values from Picatinny Arsenal and other sources. Several of the new materials considered were predicted to have enhanced detonation characteristics compared to conventional explosives. In order to confirm the accuracy of the Jaguar and analytic cylinder model results, available experimental detonation and Gurney velocities for representative energetic molecules and their formulations were compared with the corresponding calculated values. Close agreement was obtained with most of the data. Presently at NATO.
Emission calculations for a scramjet powered hypersonic transport
NASA Technical Reports Server (NTRS)
Lezberg, E. A.
1973-01-01
Calculations of exhaust emissions from a scramjet powered hypersonic transport burning hydrogen fuel were performed over a range of Mach numbers of 5 to 12 to provide input data for wake mixing calculations and forecasts of future levels of pollutants in the stratosphere. The calculations were performed utilizing a one-dimensional chemical kinetics computer program for the combustor and exhaust nozzle of a fixed geometry dual-mode scramjet engine. Inlet conditions to the combustor and engine size was based on a vehicle of 227,000 kg (500,000 lb) gross take of weight with engines sized for Mach 8 cruise. Nitric oxide emissions were very high for stoichiometric engine operation but for Mach 6 cruise at reduced equivalence ratio are in the range predicted for an advanced supersonic transport. Combustor designs which utilize fuel staging and rapid expansion to minimize residence time at high combustion temperatures were found to be effective in preventing nitric oxide formation from reaching equilibrium concentrations.
Direct growth of single-crystalline III–V semiconductors on amorphous substrates
Chen, Kevin; Kapadia, Rehan; Harker, Audrey; ...
2016-01-27
The III–V compound semiconductors exhibit superb electronic and optoelectronic properties. Traditionally, closely lattice-matched epitaxial substrates have been required for the growth of high-quality single-crystal III–V thin films and patterned microstructures. To remove this materials constraint, here we introduce a growth mode that enables direct writing of single-crystalline III–V’s on amorphous substrates, thus further expanding their utility for various applications. The process utilizes templated liquid-phase crystal growth that results in user-tunable, patterned micro and nanostructures of single-crystalline III–V’s of up to tens of micrometres in lateral dimensions. InP is chosen as a model material system owing to its technological importance. Themore » patterned InP single crystals are configured as high-performance transistors and photodetectors directly on amorphous SiO 2 growth substrates, with performance matching state-of-the-art epitaxially grown devices. In conclusion, the work presents an important advance towards universal integration of III–V’s on application-specific substrates by direct growth.« less
An Analysis of Organizational Performance Based on Hospital Specialization Level and Strategy Type
Kim, Han-Sung; Kim, Young-Hoon; Woo, Jung-Sik; Hyun, Sook-Jung
2015-01-01
Introduction Hospitals are studying the focused factory concept and attempting to increase their power in a competitive industry by becoming more specialized. Methodology This study uses the information theory index (ITI) and the Herfindahl-Hirschman index (HHI) to analyze the extent of specialization by Korean hospitals that receive national health insurance reimbursements. Hierarchical regression analysis is used to assess the impact of hospital specialization on the following four aspects of operational performance: productivity, profitability, efficiency and quality of care. Study Results The results show that a focused strategy (high HHI) improves the income and adjusted number of patients per specialist through the efficient utilization of human resources. However, a diversified strategy (high ITI) improves the hospital utilization ratio, income per bed and adjusted number of patients per bed (controlling for material resources such as beds). In addition, as the concentration index increases, case-mix mortality rates and referral rates decrease, indicating that specialization has a positive relationship with quality of care. PMID:26218570
An Analysis of Organizational Performance Based on Hospital Specialization Level and Strategy Type.
Kim, Han-Sung; Kim, Young-Hoon; Woo, Jung-Sik; Hyun, Sook-Jung
2015-01-01
Hospitals are studying the focused factory concept and attempting to increase their power in a competitive industry by becoming more specialized. This study uses the information theory index (ITI) and the Herfindahl-Hirschman index (HHI) to analyze the extent of specialization by Korean hospitals that receive national health insurance reimbursements. Hierarchical regression analysis is used to assess the impact of hospital specialization on the following four aspects of operational performance: productivity, profitability, efficiency and quality of care. The results show that a focused strategy (high HHI) improves the income and adjusted number of patients per specialist through the efficient utilization of human resources. However, a diversified strategy (high ITI) improves the hospital utilization ratio, income per bed and adjusted number of patients per bed (controlling for material resources such as beds). In addition, as the concentration index increases, case-mix mortality rates and referral rates decrease, indicating that specialization has a positive relationship with quality of care.
Direct growth of single-crystalline III–V semiconductors on amorphous substrates
Chen, Kevin; Kapadia, Rehan; Harker, Audrey; Desai, Sujay; Seuk Kang, Jeong; Chuang, Steven; Tosun, Mahmut; Sutter-Fella, Carolin M.; Tsang, Michael; Zeng, Yuping; Kiriya, Daisuke; Hazra, Jubin; Madhvapathy, Surabhi Rao; Hettick, Mark; Chen, Yu-Ze; Mastandrea, James; Amani, Matin; Cabrini, Stefano; Chueh, Yu-Lun; Ager III, Joel W.; Chrzan, Daryl C.; Javey, Ali
2016-01-01
The III–V compound semiconductors exhibit superb electronic and optoelectronic properties. Traditionally, closely lattice-matched epitaxial substrates have been required for the growth of high-quality single-crystal III–V thin films and patterned microstructures. To remove this materials constraint, here we introduce a growth mode that enables direct writing of single-crystalline III–V's on amorphous substrates, thus further expanding their utility for various applications. The process utilizes templated liquid-phase crystal growth that results in user-tunable, patterned micro and nanostructures of single-crystalline III–V's of up to tens of micrometres in lateral dimensions. InP is chosen as a model material system owing to its technological importance. The patterned InP single crystals are configured as high-performance transistors and photodetectors directly on amorphous SiO2 growth substrates, with performance matching state-of-the-art epitaxially grown devices. The work presents an important advance towards universal integration of III–V's on application-specific substrates by direct growth. PMID:26813257
Nuclear fuels for very high temperature applications
NASA Astrophysics Data System (ADS)
Lundberg, L. B.; Hobbins, R. R.
The success of the development of nuclear thermal propulsion devices and thermionic space nuclear power generation systems depends on the successful utilization of nuclear fuel materials at temperatures in the range 2000 to 3500 K. Problems associated with the utilization of uranium bearing fuel materials at these very high temperatures while maintaining them in the solid state for the required operating times are addressed. The critical issues addressed include evaporation, melting, reactor neutron spectrum, high temperature chemical stability, fabrication, fission induced swelling, fission product release, high temperature creep, thermal shock resistance, and fuel density, both mass and fissile atom. Candidate fuel materials for this temperature range are based on UO2 or uranium carbides. Evaporation suppression, such as a sealed cladding, is required for either fuel base. Nuclear performance data needed for design are sparse for all candidate fuel forms in this temperature range, especially at the higher temperatures.
Three-dimensional patterning in polymer optical waveguides using focused ion beam milling
NASA Astrophysics Data System (ADS)
Kruse, Kevin; Burrell, Derek; Middlebrook, Christopher
2016-07-01
Waveguide (WG) photonic-bridge taper modules are designed for symmetric planar coupling between silicon WGs and single-mode fibers (SMFs) to minimize photonic chip and packaging footprint requirements with improving broadband functionality. Micromachined fabrication and evaluation of polymer WG tapers utilizing high-resolution focused ion beam (FIB) milling is performed and presented. Polymer etch rates utilizing the FIB and optimal methods for milling polymer tapers are identified for three-dimensional patterning. Polymer WG tapers with low sidewall roughness are manufactured utilizing FIB milling and optically tested for fabrication loss. FIB platforms utilize a focused beam of ions (Ga+) to etch submicron patterns into substrates. Fabricating low-loss polymer WG taper prototypes with the FIB before moving on to mass-production techniques provides theoretical understanding of the polymer taper and its feasibility for connectorization devices between silicon WGs and SMFs.
Contrast-to-noise ratio in magnification mammography: a Monte Carlo study
NASA Astrophysics Data System (ADS)
Koutalonis, M.; Delis, H.; Spyrou, G.; Costaridou, L.; Tzanakos, G.; Panayiotakis, G.
2007-06-01
Magnification views are a common way to perform a secondary examination when suspicious abnormalities are found in a screening mammogram. The visibility of microcalcifications and breast lesions is restricted by the compromise between the image quality and the absorbed dose. In this study, image quality characteristics in magnification mammography were evaluated based on Monte Carlo techniques. A breast phantom was utilized, simulating a homogeneous mixture of adipose and glandular tissue in various percentages of glandularity, containing inhomogeneities of various sizes and compositions. The effect of the magnification degree, breast glandularity, tube voltage and anode/filter material combination on image quality characteristics was investigated in terms of a contrast-to-noise ratio (CNR). A performance index PIν was introduced in order to study the overall performance of various anode/filter combinations under different exposure parameters. Results demonstrate that CNR is improved with the degree of magnification and degraded as the breast glandularity is increased. Degree of magnification 1.3 offers the best overall performance for most of the anode/filter combinations utilized. Under magnification conditions, the role of dose is demoted against the image quality, as magnification views are secondary, diagnostic examinations and not screening procedures oriented to non-symptomatic women. For decreased image quality weighting, some anode/filter combinations different from Mo/0.030mmMo can be utilized as they offer a similar performance index. However, if the desired weighting for the image quality is high, the Mo/0.030mmMo combination has the best overall performance.
Siliquini, R; Saulle, R; Rabacchi, G; Bert, F; Massimi, A; Bulzomì, V; Boccia, A; La Torre, G
2012-01-01
Objective of this pilot study was to evaluate the reliability and validity of the web-based questionnaire in pregnant women as a tool to examine prevalence, knowledge and attitudes about internet utilization for health-related purposes, in a sample of Italian pregnant women. The questionnaire was composed by 9 sections for a total of 73 items. Reliability analysis was tested and content validity was evaluated using Cronbach's alpha to check internal consistency. Statistical analysis was performed through SPSS 13.0. Questionnaire was administered to 56 pregnant women. The higher value of Cronbach's alpha resulted on 61 items: alpha = 0.786 (n. 73 items: alpha = 0.579). High rate of pregnant women generally utilized internet (87.5%) and the 92.1% confirmed to use internet with the focus to acquire information about pregnancy (p < 0.0001). The questionnaire showed a good reliability property in the pilot study. In terms of internal consistency and validity appeared to have a good performance. Given the high prevalence of pregnant women that use internet to search information about their pregnancy status, professional healthcare workers should give advice regarding official websites where they could retrieve safe information and learn knowledge based on scientific evidence.
Malaria rapid diagnostic tests in elimination settings—can they find the last parasite?
McMorrow, M. L.; Aidoo, M.; Kachur, S. P.
2016-01-01
Rapid diagnostic tests (RDTs) for malaria have improved the availability of parasite-based diagnosis throughout the malaria-endemic world. Accurate malaria diagnosis is essential for malaria case management, surveillance, and elimination. RDTs are inexpensive, simple to perform, and provide results in 15–20 min. Despite high sensitivity and specificity for Plasmodium falciparum infections, RDTs have several limitations that may reduce their utility in low-transmission settings: they do not reliably detect low-density parasitaemia (≤200 parasites/μL), many are less sensitive for Plasmodium vivax infections, and their ability to detect Plasmodium ovale and Plasmodium malariae is unknown. Therefore, in elimination settings, alternative tools with higher sensitivity for low-density infections (e.g. nucleic acid-based tests) are required to complement field diagnostics, and new highly sensitive and specific field-appropriate tests must be developed to ensure accurate diagnosis of symptomatic and asymptomatic carriers. As malaria transmission declines, the proportion of low-density infections among symptomatic and asymptomatic persons is likely to increase, which may limit the utility of RDTs. Monitoring malaria in elimination settings will probably depend on the use of more than one diagnostic tool in clinical-care and surveillance activities, and the combination of tools utilized will need to be informed by regular monitoring of test performance through effective quality assurance. PMID:21910780
Aircraft flight test trajectory control
NASA Technical Reports Server (NTRS)
Menon, P. K. A.; Walker, R. A.
1988-01-01
Two control law design techniques are compared and the performance of the resulting controllers evaluated. The design requirement is for a flight test trajectory controller (FTTC) capable of closed-loop, outer-loop control of an F-15 aircraft performing high-quality research flight test maneuvers. The maneuver modeling, linearization, and design methodologies utilized in this research, are detailed. The results of applying these FTTCs to a nonlinear F-15 simulation are presented.
The eye-tracking computer device for communication in amyotrophic lateral sclerosis.
Spataro, R; Ciriacono, M; Manno, C; La Bella, V
2014-07-01
To explore the effectiveness of communication and the variables affecting the eye-tracking computer system (ETCS) utilization in patients with late-stage amyotrophic lateral sclerosis (ALS). We performed a telephone survey on 30 patients with advanced non-demented ALS that were provisioned an ECTS device. Median age at interview was 55 years (IQR = 48-62), with a relatively high education (13 years, IQR = 8-13). A one-off interview was made and answers were later provided with the help of the caregiver. The interview included items about demographic and clinical variables affecting the daily ETCS utilization. The median time of ETCS device possession was 15 months (IQR = 9-20). The actual daily utilization was 300 min (IQR = 100-720), mainly for the communication with relatives/caregiver, internet surfing, e-mailing, and social networking. 23.3% of patients with ALS (n = 7) had a low daily ETCS utilization; most reported causes were eye-gaze tiredness and oculomotor dysfunction. Eye-tracking computer system is a valuable device for AAC in patients with ALS, and it can be operated with a good performance. The development of oculomotor impairment may limit its functional use. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Ahn, Cheol Hyoun; Senthil, Karuppanan; Cho, Hyung Koun; Lee, Sang Yeol
2013-01-01
High-performance thin-film transistors (TFTs) are the fundamental building blocks in realizing the potential applications of the next-generation displays. Atomically controlled superlattice structures are expected to induce advanced electric and optical performance due to two-dimensional electron gas system, resulting in high-electron mobility transistors. Here, we have utilized a semiconductor/insulator superlattice channel structure comprising of ZnO/Al2O3 layers to realize high-performance TFTs. The TFT with ZnO (5 nm)/Al2O3 (3.6 nm) superlattice channel structure exhibited high field effect mobility of 27.8 cm2/Vs, and threshold voltage shift of only < 0.5 V under positive/negative gate bias stress test during 2 hours. These properties showed extremely improved TFT performance, compared to ZnO TFTs. The enhanced field effect mobility and stability obtained for the superlattice TFT devices were explained on the basis of layer-by-layer growth mode, improved crystalline nature of the channel layers, and passivation effect of Al2O3 layers. PMID:24061388
Category Learning Strategies in Younger and Older Adults: Rule Abstraction and Memorization
Wahlheim, Christopher N.; McDaniel, Mark A.; Little, Jeri L.
2016-01-01
Despite the fundamental role of category learning in cognition, few studies have examined how this ability differs between younger and older adults. The present experiment examined possible age differences in category learning strategies and their effects on learning. Participants were trained on a category determined by a disjunctive rule applied to relational features. The utilization of rule- and exemplar-based strategies was indexed by self-reports and transfer performance. Based on self-reported strategies, both age groups had comparable frequencies of rule- and exemplar-based learners, but older adults had a higher frequency of intermediate learners (i.e., learners not identifying with a reliance on either rule- or exemplar-based strategies). Training performance was higher for younger than older adults regardless of the strategy utilized, showing that older adults were impaired in their ability to learn the correct rule or to remember exemplar-label associations. Transfer performance converged with strategy reports in showing higher fidelity category representations for younger adults. Younger adults with high working memory capacity were more likely to use an exemplar-based strategy, and older adults with high working memory capacity showed better training performance. Age groups did not differ in their self-reported memory beliefs, and these beliefs did not predict training strategies or performance. Overall, the present results contradict earlier findings that older adults prefer rule- to exemplar-based learning strategies, presumably to compensate for memory deficits. PMID:26950225
Chiew, Kimberly S.; Braver, Todd S.
2013-01-01
Motivational manipulations, such as the presence of performance-contingent reward incentives, can have substantial influences on cognitive control. Previous evidence suggests that reward incentives may enhance cognitive performance specifically through increased preparatory, or proactive, control processes. The present study examined reward influences on cognitive control dynamics in the AX-Continuous Performance Task (AX-CPT), using high-resolution pupillometry. In the AX-CPT, contextual cues must be actively maintained over a delay in order to appropriately respond to ambiguous target probes. A key feature of the task is that it permits dissociable characterization of preparatory, proactive control processes (i.e., utilization of context) and reactive control processes (i.e., target-evoked interference resolution). Task performance profiles suggested that reward incentives enhanced proactive control (context utilization). Critically, pupil dilation was also increased on reward incentive trials during context maintenance periods, suggesting trial-specific shifts in proactive control, particularly when context cues indicated the need to overcome the dominant target response bias. Reward incentives had both transient (i.e., trial-by-trial) and sustained (i.e., block-based) effects on pupil dilation, which may reflect distinct underlying processes. The transient pupillary effects were present even when comparing against trials matched in task performance, suggesting a unique motivational influence of reward incentives. These results suggest that pupillometry may be a useful technique for investigating reward motivational signals and their dynamic influence on cognitive control. PMID:23372557
NASA Astrophysics Data System (ADS)
Raghavan, Ajay; Kiesel, Peter; Sommer, Lars Wilko; Schwartz, Julian; Lochbaum, Alexander; Hegyi, Alex; Schuh, Andreas; Arakaki, Kyle; Saha, Bhaskar; Ganguli, Anurag; Kim, Kyung Ho; Kim, ChaeAh; Hah, Hoe Jin; Kim, SeokKoo; Hwang, Gyu-Ok; Chung, Geun-Chang; Choi, Bokkyu; Alamgir, Mohamed
2017-02-01
A key challenge hindering the mass adoption of Lithium-ion and other next-gen chemistries in advanced battery applications such as hybrid/electric vehicles (xEVs) has been management of their functional performance for more effective battery utilization and control over their life. Contemporary battery management systems (BMS) reliant on monitoring external parameters such as voltage and current to ensure safe battery operation with the required performance usually result in overdesign and inefficient use of capacity. More informative embedded sensors are desirable for internal cell state monitoring, which could provide accurate state-of-charge (SOC) and state-of-health (SOH) estimates and early failure indicators. Here we present a promising new embedded sensing option developed by our team for cell monitoring, fiber-optic sensors. High-performance large-format pouch cells with embedded fiber-optic sensors were fabricated. The first of this two-part paper focuses on the embedding method details and performance of these cells. The seal integrity, capacity retention, cycle life, compatibility with existing module designs, and mass-volume cost estimates indicate their suitability for xEV and other advanced battery applications. The second part of the paper focuses on the internal strain and temperature signals obtained from these sensors under various conditions and their utility for high-accuracy cell state estimation algorithms.
Time-Series Forecast Modeling on High-Bandwidth Network Measurements
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yoo, Wucherl; Sim, Alex
With the increasing number of geographically distributed scientific collaborations and the growing sizes of scientific data, it has become challenging for users to achieve the best possible network performance on a shared network. In this paper, we have developed a model to forecast expected bandwidth utilization on high-bandwidth wide area networks. The forecast model can improve the efficiency of the resource utilization and scheduling of data movements on high-bandwidth networks to accommodate ever increasing data volume for large-scale scientific data applications. A univariate time-series forecast model is developed with the Seasonal decomposition of Time series by Loess (STL) and themore » AutoRegressive Integrated Moving Average (ARIMA) on Simple Network Management Protocol (SNMP) path utilization measurement data. Compared with the traditional approach such as Box-Jenkins methodology to train the ARIMA model, our forecast model reduces computation time up to 92.6 %. It also shows resilience against abrupt network usage changes. Finally, our forecast model conducts the large number of multi-step forecast, and the forecast errors are within the mean absolute deviation (MAD) of the monitored measurements.« less
Time-Series Forecast Modeling on High-Bandwidth Network Measurements
Yoo, Wucherl; Sim, Alex
2016-06-24
With the increasing number of geographically distributed scientific collaborations and the growing sizes of scientific data, it has become challenging for users to achieve the best possible network performance on a shared network. In this paper, we have developed a model to forecast expected bandwidth utilization on high-bandwidth wide area networks. The forecast model can improve the efficiency of the resource utilization and scheduling of data movements on high-bandwidth networks to accommodate ever increasing data volume for large-scale scientific data applications. A univariate time-series forecast model is developed with the Seasonal decomposition of Time series by Loess (STL) and themore » AutoRegressive Integrated Moving Average (ARIMA) on Simple Network Management Protocol (SNMP) path utilization measurement data. Compared with the traditional approach such as Box-Jenkins methodology to train the ARIMA model, our forecast model reduces computation time up to 92.6 %. It also shows resilience against abrupt network usage changes. Finally, our forecast model conducts the large number of multi-step forecast, and the forecast errors are within the mean absolute deviation (MAD) of the monitored measurements.« less
NASA Technical Reports Server (NTRS)
Morgan, Philip E.
2004-01-01
This final report contains reports of research related to the tasks "Scalable High Performance Computing: Direct and Lark-Eddy Turbulent FLow Simulations Using Massively Parallel Computers" and "Devleop High-Performance Time-Domain Computational Electromagnetics Capability for RCS Prediction, Wave Propagation in Dispersive Media, and Dual-Use Applications. The discussion of Scalable High Performance Computing reports on three objectives: validate, access scalability, and apply two parallel flow solvers for three-dimensional Navier-Stokes flows; develop and validate a high-order parallel solver for Direct Numerical Simulations (DNS) and Large Eddy Simulation (LES) problems; and Investigate and develop a high-order Reynolds averaged Navier-Stokes turbulence model. The discussion of High-Performance Time-Domain Computational Electromagnetics reports on five objectives: enhancement of an electromagnetics code (CHARGE) to be able to effectively model antenna problems; utilize lessons learned in high-order/spectral solution of swirling 3D jets to apply to solving electromagnetics project; transition a high-order fluids code, FDL3DI, to be able to solve Maxwell's Equations using compact-differencing; develop and demonstrate improved radiation absorbing boundary conditions for high-order CEM; and extend high-order CEM solver to address variable material properties. The report also contains a review of work done by the systems engineer.
Advanced x-ray imaging spectrometer
NASA Technical Reports Server (NTRS)
Callas, John L. (Inventor); Soli, George A. (Inventor)
1998-01-01
An x-ray spectrometer that also provides images of an x-ray source. Coded aperture imaging techniques are used to provide high resolution images. Imaging position-sensitive x-ray sensors with good energy resolution are utilized to provide excellent spectroscopic performance. The system produces high resolution spectral images of the x-ray source which can be viewed in any one of a number of specific energy bands.
Sandra, Koen; Pereira, Alberto Dos Santos; Vanhoenacker, Gerd; David, Frank; Sandra, Pat
2010-06-18
A lipidomics strategy, combining high resolution reversed-phase liquid chromatography (RPLC) with high resolution quadrupole time-of-flight mass spectrometry (QqTOF), is described. The method has carefully been assessed in both a qualitative and a quantitative fashion utilizing human blood plasma. The inherent low technical variability associated with the lipidomics method allows to measure 65% of the features with an intensity RSD value below 10%. Blood plasma lipid spike-in experiments demonstrate that relative concentration differences smaller than 25% can readily be revealed by means of a t-test. Utilizing an advanced identification strategy, it is shown that the detected features mainly originate from (lyso-)phospholipids, sphingolipids, mono-, di- and triacylglycerols and cholesterol esters. The high resolution offered by the up-front RPLC step further allows to discriminate various isomeric species associated with the different lipid classes. The added value of utilizing a Jetstream electrospray ionization (ESI) source over a regular ESI source in lipidomics is for the first time demonstrated. In addition, the application of ultra high performance LC (UHPLC) up to 1200bar to extend the peak capacity or increase productivity is discussed. Copyright (c) 2010 Elsevier B.V. All rights reserved.
High-performance solid-state supercapacitors based on graphene-ZnO hybrid nanocomposites.
Li, Zijiong; Zhou, Zhihua; Yun, Gaoqian; Shi, Kai; Lv, Xiaowei; Yang, Baocheng
2013-11-12
In this paper, we report a facile low-cost synthesis of the graphene-ZnO hybrid nanocomposites for solid-state supercapacitors. Structural analysis revealed a homogeneous distribution of ZnO nanorods that are inserted in graphene nanosheets, forming a sandwiched architecture. The material exhibited a high specific capacitance of 156 F g-1 at a scan rate of 5 mV.s-1. The fabricated solid-state supercapacitor device using these graphene-ZnO hybrid nanocomposites exhibits good supercapacitive performance and long-term cycle stability. The improved supercapacitance property of these materials could be ascribed to the increased conductivity of ZnO and better utilization of graphene. These results demonstrate the potential of the graphene-ZnO hybrid nanocomposites as an electrode in high-performance supercapacitors.
High-performance solid-state supercapacitors based on graphene-ZnO hybrid nanocomposites
NASA Astrophysics Data System (ADS)
Li, Zijiong; Zhou, Zhihua; Yun, Gaoqian; Shi, Kai; Lv, Xiaowei; Yang, Baocheng
2013-11-01
In this paper, we report a facile low-cost synthesis of the graphene-ZnO hybrid nanocomposites for solid-state supercapacitors. Structural analysis revealed a homogeneous distribution of ZnO nanorods that are inserted in graphene nanosheets, forming a sandwiched architecture. The material exhibited a high specific capacitance of 156 F g-1 at a scan rate of 5 mV.s-1. The fabricated solid-state supercapacitor device using these graphene-ZnO hybrid nanocomposites exhibits good supercapacitive performance and long-term cycle stability. The improved supercapacitance property of these materials could be ascribed to the increased conductivity of ZnO and better utilization of graphene. These results demonstrate the potential of the graphene-ZnO hybrid nanocomposites as an electrode in high-performance supercapacitors.
High-performance supercapacitors based on hollow polyaniline nanofibers by electrospinning.
Miao, Yue-E; Fan, Wei; Chen, Dan; Liu, Tianxi
2013-05-22
Hollow polyaniline (PANI) nanofibers with controllable wall thickness are fabricated by in situ polymerization of aniline using the electrospun poly(amic acid) fiber membrane as a template. A maximum specific capacitance of 601 F g(-1) has been achieved at 1 A g(-1), suggesting the potential application of hollow PANI nanofibers for supercapacitors. The superior electrochemical performance of the hollow nanofibers is attributed to their hollow structure, thin wall thickness, and orderly pore passages, which can drastically facilitate the ion diffusion and improve the utilization of the electroactive PANI during the charge-discharge processes. Furthermore, the high flexibility of the self-standing fiber membrane template provides possibilities for the facile construction and fabrication of conducting polymers with hollow nanostructures, which may find potential applications in various high-performance electrochemical devices.
High-performance solid-state supercapacitors based on graphene-ZnO hybrid nanocomposites
2013-01-01
In this paper, we report a facile low-cost synthesis of the graphene-ZnO hybrid nanocomposites for solid-state supercapacitors. Structural analysis revealed a homogeneous distribution of ZnO nanorods that are inserted in graphene nanosheets, forming a sandwiched architecture. The material exhibited a high specific capacitance of 156 F g−1 at a scan rate of 5 mV.s−1. The fabricated solid-state supercapacitor device using these graphene-ZnO hybrid nanocomposites exhibits good supercapacitive performance and long-term cycle stability. The improved supercapacitance property of these materials could be ascribed to the increased conductivity of ZnO and better utilization of graphene. These results demonstrate the potential of the graphene-ZnO hybrid nanocomposites as an electrode in high-performance supercapacitors. PMID:24215772
High performance semantic factoring of giga-scale semantic graph databases.
DOE Office of Scientific and Technical Information (OSTI.GOV)
al-Saffar, Sinan; Adolf, Bob; Haglin, David
2010-10-01
As semantic graph database technology grows to address components ranging from extant large triple stores to SPARQL endpoints over SQL-structured relational databases, it will become increasingly important to be able to bring high performance computational resources to bear on their analysis, interpretation, and visualization, especially with respect to their innate semantic structure. Our research group built a novel high performance hybrid system comprising computational capability for semantic graph database processing utilizing the large multithreaded architecture of the Cray XMT platform, conventional clusters, and large data stores. In this paper we describe that architecture, and present the results of our deployingmore » that for the analysis of the Billion Triple dataset with respect to its semantic factors, including basic properties, connected components, namespace interaction, and typed paths.« less
Guo, Jian; Huang, Siyao; Chen, Yefu; Guo, Xuewu; Xiao, Dongguang
2018-04-30
Aureobasidium pullulans is a yeast-like fungus that can ferment xylose to generate high-value-added products, such as pullulan, heavy oil, and melanin. The combinatorial expression of two xylose reductase (XR) genes and two xylitol dehydrogenase (XDH) genes from Spathaspora passalidarum and the heterologous expression of the Piromyces sp. xylose isomerase (XI) gene were induced in A. pullulans to increase the consumption capability of A. pullulans on xylose. The overexpression of XYL1.2 (encoding XR) and XYL2.2 (encoding XDH) was the most beneficial for xylose utilization, resulting in a 17.76% increase in consumed xylose compared with the parent strain, whereas the introduction of the Piromyces sp. XI pathway failed to enhance xylose utilization efficiency. Mutants with superior xylose fermentation performance exhibited increased intracellular reducing equivalents. The fermentation performance of all recombinant strains was not affected when glucose or sucrose was utilized as the carbon source. The strain with overexpression of XYL1.2 and XYL2.2 exhibited excellent fermentation performance with mimicked hydrolysate, and pullulan production increased by 97.72% compared with that of the parent strain. The present work indicates that the P4 mutant (using the XR/XDH pathway) with overexpressed XYL1.2 and XYL2.2 exhibited the best xylose fermentation performance. The P4 strain showed the highest intracellular reducing equivalents and XR and XDH activity, with consequently improved pullulan productivity and reduced melanin production. This valuable development in aerobic fermentation by the P4 strain may provide guidance for the biotransformation of xylose to high-value products by A. pullulans through genetic approach.
Hardware Based Technology Assessment in Support of Near-Term Space Fission Missions
NASA Technical Reports Server (NTRS)
Houts, Mike; VanDyke, Melissa; Godfroy, Tom; Martin, James; BraggSitton, Shannon; Carter, Robert; Dickens, Ricky; Salvail, Pat; Williams, Eric; Harper, Roger
2003-01-01
Fission technology can enable rapid, affordable access to any point in the solar system. If fission propulsion systems are to be developed to their full potential; however, near-term customers must be identified and initial fission systems successfully developed, launched, and utilized. Successful utilization will most likely occur if frequent, significant hardware-based milestones can be achieved throughout the program. Achieving these milestones will depend on the capability to perform highly realistic non-nuclear testing of nuclear systems. This paper discusses ongoing and potential research that could help achieve these milestones.
Aluminum-stabilized NB3SN superconductor
Scanlan, Ronald M.
1988-01-01
An aluminum-stabilized Nb.sub.3 Sn superconductor and process for producing same, utilizing ultrapure aluminum. Ductile components are co-drawn with aluminum to produce a conductor suitable for winding magnets. After winding, the conductor is heated to convert it to the brittle Nb.sub.3 Sn superconductor phase, using a temperature high enough to perform the transformation but still below the melting point of the aluminum. This results in reaction of substantially all of the niobium, while providing stabilization and react-in-place features which are beneficial in the fabrication of magnets utilizing superconducting materials.
Fission Technology for Exploring and Utilizing the Solar System
NASA Technical Reports Server (NTRS)
Houts, Mike; VanDyke, Melissa; Godfroy, Tom; Pedersen, Kevin; Martin, James; Dickens, Ricky; Salvail, Pat; Hrbub, Ivana; Schmidt, George R. (Technical Monitor)
2000-01-01
Fission technology can enable rapid, affordable access to any point in the solar system. Potential fission-based transportation options include bimodal nuclear thermal rockets, high specific energy propulsion systems, and pulsed fission propulsion systems. In-space propellant re-supply enhances the effective performance of all systems, but requires significant infrastructure development. Safe, timely, affordable utilization of first-generation space fission propulsion systems will enable the development of more advanced systems. First generation space systems will build on over 45 years of US and international space fission system technology development to minimize cost,
Volterra equalization of complex modulation utilizing frequency chirp in directly modulated lasers
NASA Astrophysics Data System (ADS)
Hu, Shaohua; Yi, Xingwen; Zhang, Jing; Song, Yang; Zhu, Mingyue; Qiu, Kun
2018-02-01
We apply Volterra-based equalization for complex modulated optical signals utilizing the frequency chirp in DMLs. We experimentally demonstrate that the higher order Volterra filter is necessary in the higher speed transmissions. For further study, we isolate the adiabatic chirp by injection locking and realize the optical PM transmission. We make a comparison among IM, FM and PM with Volterra equalization, finding that PM and FM are more power insensitive and suitable for high speed, power limited fiber transmission. The performance can be further improved by exploiting the diversity gain.
User-centered design to improve clinical decision support in primary care.
Brunner, Julian; Chuang, Emmeline; Goldzweig, Caroline; Cain, Cindy L; Sugar, Catherine; Yano, Elizabeth M
2017-08-01
A growing literature has demonstrated the ability of user-centered design to make clinical decision support systems more effective and easier to use. However, studies of user-centered design have rarely examined more than a handful of sites at a time, and have frequently neglected the implementation climate and organizational resources that influence clinical decision support. The inclusion of such factors was identified by a systematic review as "the most important improvement that can be made in health IT evaluations." (1) Identify the prevalence of four user-centered design practices at United States Veterans Affairs (VA) primary care clinics and assess the perceived utility of clinical decision support at those clinics; (2) Evaluate the association between those user-centered design practices and the perceived utility of clinical decision support. We analyzed clinic-level survey data collected in 2006-2007 from 170 VA primary care clinics. We examined four user-centered design practices: 1) pilot testing, 2) provider satisfaction assessment, 3) formal usability assessment, and 4) analysis of impact on performance improvement. We used a regression model to evaluate the association between user-centered design practices and the perceived utility of clinical decision support, while accounting for other important factors at those clinics, including implementation climate, available resources, and structural characteristics. We also examined associations separately at community-based clinics and at hospital-based clinics. User-centered design practices for clinical decision support varied across clinics: 74% conducted pilot testing, 62% conducted provider satisfaction assessment, 36% conducted a formal usability assessment, and 79% conducted an analysis of impact on performance improvement. Overall perceived utility of clinical decision support was high, with a mean rating of 4.17 (±.67) out of 5 on a composite measure. "Analysis of impact on performance improvement" was the only user-centered design practice significantly associated with perceived utility of clinical decision support, b=.47 (p<.001). This association was present in hospital-based clinics, b=.34 (p<.05), but was stronger at community-based clinics, b=.61 (p<.001). Our findings are highly supportive of the practice of analyzing the impact of clinical decision support on performance metrics. This was the most common user-centered design practice in our study, and was the practice associated with higher perceived utility of clinical decision support. This practice may be particularly helpful at community-based clinics, which are typically less connected to VA medical center resources. Published by Elsevier B.V.
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.
Second United States Microgravity Laboratory: One Year Report. Volume 1
NASA Technical Reports Server (NTRS)
Vlasse, M (Editor); McCauley, D. (Editor); Walker, C. (Editor)
1998-01-01
This document reports the one year science results for the important and highly successful Second United States Microgravity Laboratory (USML-2). The USML-2 mission consisted of a pressurized Spacelab module where the crew performed experiments. The mission also included a Glovebox where the crew performed additional experiments for the investigators. Together, about 36 major scientific experiments were performed, advancing the state of knowledge in fields such as fluid physics, solidification of metals, alloys, and semiconductors, combustion, and the growth of protein crystals. The results demonstrate the range of quality science that can be conducted utilizing orbital laboratories in microgravity and provide a look forward to a highly productive Space Station era.
Rapid prototype fabrication processes for high-performance thrust cells
NASA Technical Reports Server (NTRS)
Hunt, K.; Chwiedor, T.; Diab, J.; Williams, R.
1994-01-01
The Thrust Cell Technologies Program (Air Force Phillips Laboratory Contract No. F04611-92-C-0050) is currently being performed by Rocketdyne to demonstrate advanced materials and fabrication technologies which can be utilized to produce low-cost, high-performance thrust cells for launch and space transportation rocket engines. Under Phase 2 of the Thrust Cell Technologies Program (TCTP), rapid prototyping and investment casting techniques are being employed to fabricate a 12,000-lbf thrust class combustion chamber for delivery and hot-fire testing at Phillips Lab. The integrated process of investment casting directly from rapid prototype patterns dramatically reduces design-to-delivery cycle time, and greatly enhances design flexibility over conventionally processed cast or machined parts.
Second United States Microgravity Laboratory: One Year Report. Volume 2
NASA Technical Reports Server (NTRS)
Vlasse, M. (Editor); McCauley, D. (Editor); Walker, C. (Editor)
1998-01-01
This document reports the one year science results for the important and highly successful Second United States Microgravity Laboratory (USML-2). The USML-2 mission consisted of a pressurized Spacelab module where the crew performed experiments. The mission also included a Glovebox where the crew performed additional experiments for the investigators. Together, about 36 major scientific experiments were performed, advancing the state of knowledge in fields such as fluid physics, solidification of metals, alloys, and semiconductors, combustion, and the growth of protein crystals. The results demonstrate the range of quality science that can be conducted utilizing orbital laboratories in microgravity and provide a look forward to a highly productive Space Station era.
NASA Astrophysics Data System (ADS)
Chen, Haichao; Jiang, Jianjun; Zhang, Li; Xia, Dandan; Zhao, Yuandong; Guo, Danqing; Qi, Tong; Wan, Houzhao
2014-05-01
Self-standing NiCo2S4 nanotube arrays have been in situ grown on Ni foam by the anion-exchange reaction and directly used as the electrode for supercapacitors. The NiCo2S4 nanotube in the arrays effectively reduces the inactive material and increases the electroactive surface area because of the ultrathin wall, which is quite competent to achieve high utilization efficiency at high electroactive materials mass loading. The NiCo2S4 nanotube arrays hybrid electrode exhibits an ultrahigh specific capacitance of 14.39 F cm-2 at 5 mA cm-2 with excellent rate performance (67.7% retention for current increases 30 times) and cycling stability (92% retention after 5000 cycles) at a high mass loading of 6 mg cm-2. High areal capacitance (4.68 F cm-2 at 10 mA cm-2), high energy density (31.5 Wh kg-1 at 156.6 W kg-1) and high power density (2348.5 W kg-1 at 16.6 Wh kg-1) can be achieved by assembling asymmetric supercapacitor with reduced graphene oxide at a total active material mass loading as high as 49.5 mg. This work demonstrates that NiCo2S4 nanotube arrays structure is a superior electroactive material for high-performance supercapacitors even at a mass loading of potential application-specific scale.
Sample-ready multiplex qPCR assay for detection of malaria
2014-01-01
Background Microscopy and antigen detecting rapid diagnostic tests are the diagnostic tests of choice in management of clinical malaria. However, due to their limitations, the need to utilize more sensitive methods such as real-time PCR (qPCR) is evident as more studies are now utilizing molecular methods in detection of malaria. Some of the challenges that continue to limit the widespread utilization of qPCR include lack of assay standardization, assay variability, risk of contamination, and the need for cold-chain. Lyophilization of molecular assays can overcome some of these limitations and potentially enable widespread qPCR utilization. Methods A recently published multiplex malaria qPCR assay was lyophilized by freezing drying into Sample-Ready™ format (MMSR). MMSR assay contained all the required reagents for qPCR including primers and probes, requiring only the addition of water and sample to perform qPCR. The performance of the MMSR assay was compared to the non-freeze dried, “wet” assay. Stability studies were done by maintaining the MMSR assays at four different ambient temperatures of 4°C, room temperature (RT), 37°C and 42°C over a period of 42 days, tested at seven-day intervals. Plasmodium falciparum and Plasmodium vivax DNAs were used for analysis of the MMSR assay either as single or mixed parasites, at two different concentrations. The CT values and the standard deviations (SD) were used in the analysis of the assay performance. Results The limit of detection for the MMSR assay was 0.244 parasites/μL for Plasmodium spp. (PLU) and P. falciparum (FAL) assay targets compared to “wet” assay which was 0.39 and 3.13 parasites/μL for PLU and FAL assay targets, respectively. The MMSR assay performed with high efficiencies similar to those of the “wet” assay and was stable at 37°C for 42 days, with estimated shelf-life of 5 months. When used to analyse field clinical samples, MMSR assay performed with 100% sensitivity and specificity compared to the “wet” assay. Conclusion The MMSR assay has the same robust performance characteristics as the “wet” assay and is highly stable. Availability of MMSR assay allows flexibility and provides an option in choosing assay for malaria diagnostics depending on the application, needs and budget. PMID:24767409
Sample-ready multiplex qPCR assay for detection of malaria.
Kamau, Edwin; Alemayehu, Saba; Feghali, Karla C; Juma, Dennis W; Blackstone, George M; Marion, William R; Obare, Peter; Ogutu, Bernhards; Ockenhouse, Christian F
2014-04-25
Microscopy and antigen detecting rapid diagnostic tests are the diagnostic tests of choice in management of clinical malaria. However, due to their limitations, the need to utilize more sensitive methods such as real-time PCR (qPCR) is evident as more studies are now utilizing molecular methods in detection of malaria. Some of the challenges that continue to limit the widespread utilization of qPCR include lack of assay standardization, assay variability, risk of contamination, and the need for cold-chain. Lyophilization of molecular assays can overcome some of these limitations and potentially enable widespread qPCR utilization. A recently published multiplex malaria qPCR assay was lyophilized by freezing drying into Sample-Ready™ format (MMSR). MMSR assay contained all the required reagents for qPCR including primers and probes, requiring only the addition of water and sample to perform qPCR. The performance of the MMSR assay was compared to the non-freeze dried, "wet" assay. Stability studies were done by maintaining the MMSR assays at four different ambient temperatures of 4°C, room temperature (RT), 37°C and 42°C over a period of 42 days, tested at seven-day intervals. Plasmodium falciparum and Plasmodium vivax DNAs were used for analysis of the MMSR assay either as single or mixed parasites, at two different concentrations. The CT values and the standard deviations (SD) were used in the analysis of the assay performance. The limit of detection for the MMSR assay was 0.244 parasites/μL for Plasmodium spp. (PLU) and P. falciparum (FAL) assay targets compared to "wet" assay which was 0.39 and 3.13 parasites/μL for PLU and FAL assay targets, respectively. The MMSR assay performed with high efficiencies similar to those of the "wet" assay and was stable at 37°C for 42 days, with estimated shelf-life of 5 months. When used to analyse field clinical samples, MMSR assay performed with 100% sensitivity and specificity compared to the "wet" assay. The MMSR assay has the same robust performance characteristics as the "wet" assay and is highly stable. Availability of MMSR assay allows flexibility and provides an option in choosing assay for malaria diagnostics depending on the application, needs and budget.
The 1987 Ground Vortex Workshop
NASA Technical Reports Server (NTRS)
Margason, Richard J. (Editor)
1988-01-01
The purpose of this workshop was to discuss the current understanding of the ground vortex phenomena and their effects on aircraft, and to establish directions for further research on advanced, high-performance aircraft designs, particularly those concepts utilizing powered-lift systems; e.g., V/STOL. ASTOVL, and STOL aircraft.
Computer-Aided Design and Optimization of High-Performance Vacuum Electronic Devices
2006-08-15
approximations to the metric, and space mapping wherein low-accuracy (coarse mesh) solutions can potentially be used more effectively in an...interface and algorithm development. • Work on space - mapping or related methods for utilizing models of varying levels of approximation within an
High resolution A/D conversion based on piecewise conversion at lower resolution
Terwilliger, Steve [Albuquerque, NM
2012-06-05
Piecewise conversion of an analog input signal is performed utilizing a plurality of relatively lower bit resolution A/D conversions. The results of this piecewise conversion are interpreted to achieve a relatively higher bit resolution A/D conversion without sampling frequency penalty.
Chen, Zhihang; Li, Hua; Tian, Ran; Duan, Huanan; Guo, Yiping; Chen, Yujie; Zhou, Jie; Zhang, Chunmei; Dugnani, Roberto; Liu, Hezhou
2016-06-06
In this work it is shown how porous graphene aerogels fabricated by an eco-friendly and simple technological process, could be used as electrodes in lithium- ion batteries. The proposed graphene framework exhibited excellent performance including high reversible capacities, superior cycling stability and rate capability. A significantly lower temperature (75 °C) than the one currently utilized in battery manufacturing was utilized for self-assembly hence providing potential significant savings to the industrial production. After annealing at 600 °C, the formation of Sn-C-O bonds between the SnO2 nanoparticles and the reduced graphene sheets will initiate synergistic effect and improve the electrochemical performance. The XPS patterns revealed the formation of Sn-C-O bonds. Both SEM and TEM imaging of the electrode material showed that the three dimensional network of graphene aerogels and the SnO2 particles were distributed homogeneously on graphene sheets. Finally, the electrochemical properties of the samples as active anode materials for lithium-ion batteries were tested and examined by constant current charge-discharge cycling and the finding fully described in this manuscript.
DOE Office of Scientific and Technical Information (OSTI.GOV)
The Woods is a Habitat for Humanity (HFH) community of ENERGY STAR Homes (c) Northwest (ESHNW)-certified homes located in the marine climate of Tacoma/Pierce County, Washington. This research report builds on an earlier preliminary draft 2014 BA report, and includes significant billing analysis and cost effectiveness research from a collaborative, ongoing Ductless Heat Pump (DHP) research effort for Tacoma Public Utilities (TPU) and Bonneville Power Administration (BPA). This report focuses on the results of field testing, modeling, and monitoring of ductless mini-split heat pump hybrid heating systems in seven homes built and first occupied at various times between September 2013more » and October 2014. The report also provides WSU documentation of high-performance home observations, lessons learned, and stakeholder recommendations for builders of affordable high-performance housing such as HFH.« less
Programming with BIG data in R: Scaling analytics from one to thousands of nodes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Schmidt, Drew; Chen, Wei -Chen; Matheson, Michael A.
Here, we present a tutorial overview showing how one can achieve scalable performance with R. We do so by utilizing several package extensions, including those from the pbdR project. These packages consist of high performance, high-level interfaces to and extensions of MPI, PBLAS, ScaLAPACK, I/O libraries, profiling libraries, and more. While these libraries shine brightest on large distributed platforms, they also work rather well on small clusters and often, surprisingly, even on a laptop with only two cores. Our tutorial begins with recommendations on how to get more performance out of your R code before considering parallel implementations. Because Rmore » is a high-level language, a function can have a deep hierarchy of operations. For big data, this can easily lead to inefficiency. Profiling is an important tool to understand the performance of an R code for both serial and parallel improvements.« less
Student Bedtimes, Academic Performance, and Health in a Residential High School.
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.
Improved LED backlight with unique color and intensity control and NVIS capability
NASA Astrophysics Data System (ADS)
Herman, Robert; Zagar, Pete; Ulijasz, Ted; Hansen, Hans C.; Ellner, Fred
2006-05-01
Currently deployed conventional flat panel AMLCD displays employ fluorescent lamp backlights to achieve the required lighting levels for cockpits in high performance aircraft. Advances have been made in backlighting technology by replacing fluorescent lamps with high performance LEDs. However, these new LED-based backlights are lacking in control of color and luminance intensity especially when related to NVIS requirements in a cockpit. This paper describes a unique integration of LED, electronic, and optical components to meet the requirements of high performance aircraft over their extreme range of operating environments. The LED-based backlight utilizes state-of-art components to enable daylight, night, and NVIS requirements to be implemented in a simple cost-effective package. The performance results presented highlight the advantages of this new design when compared to currently available backlighting designs. Techniques as described in section 2 of this paper are covered under patent application to the US and International Patent Offices.
Programming with BIG data in R: Scaling analytics from one to thousands of nodes
Schmidt, Drew; Chen, Wei -Chen; Matheson, Michael A.; ...
2016-11-09
Here, we present a tutorial overview showing how one can achieve scalable performance with R. We do so by utilizing several package extensions, including those from the pbdR project. These packages consist of high performance, high-level interfaces to and extensions of MPI, PBLAS, ScaLAPACK, I/O libraries, profiling libraries, and more. While these libraries shine brightest on large distributed platforms, they also work rather well on small clusters and often, surprisingly, even on a laptop with only two cores. Our tutorial begins with recommendations on how to get more performance out of your R code before considering parallel implementations. Because Rmore » is a high-level language, a function can have a deep hierarchy of operations. For big data, this can easily lead to inefficiency. Profiling is an important tool to understand the performance of an R code for both serial and parallel improvements.« less
Methods for enhancing the efficiency of creating a borehole using high power laser systems
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.
High power laser workover and completion tools and systems
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.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-20
... Standards of Performance for Fossil-Fuel-Fired, Electric Utility, Industrial-Commercial-Institutional, and... Fossil fuel-fired electric utility steam generating units. Federal Government 22112 Fossil fuel-fired... 22112 Fossil fuel-fired electric utility steam generating units owned by municipalities. 921150 Fossil...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-20
... Standards of Performance for Fossil-Fuel-Fired, Electric Utility, Industrial-Commercial-Institutional, and... following: Category NAICS \\1\\ Examples of regulated entities Industry 221112 Fossil fuel-fired electric utility steam generating units. Federal Government 22112 Fossil fuel-fired electric utility steam...
NASA Astrophysics Data System (ADS)
Zhou, X. L.; Zhao, T. S.; Zeng, Y. K.; An, L.; Wei, L.
2016-10-01
In this work, a high-performance porous electrode, made of KOH-activated carbon-cloth, is developed for vanadium redox flow batteries (VRFBs). The macro-scale porous structure in the carbon cloth formed by weaving the carbon fibers in an ordered manner offers a low tortuosity (∼1.1) and a broad pore distribution from 5 μm to 100 μm, rendering the electrode a high hydraulic permeability and high effective ionic conductivity, which are beneficial for the electrolyte flow and ion transport through the porous electrode. The use of KOH activation method to create nano-scale pores on the carbon-fiber surfaces leads to a significant increase in the surface area for redox reactions from 2.39 m2 g-1 to 15.4 m2 g-1. The battery assembled with the present electrode delivers an energy efficiency of 80.1% and an electrolyte utilization of 74.6% at a current density of 400 mA cm-2, as opposed to an electrolyte utilization of 61.1% achieved by using a conventional carbon-paper electrode. Such a high performance is mainly attributed to the combination of the excellent mass/ion transport properties and the high surface area rendered by the present electrode. It is suggested that the KOH-activated carbon-cloth electrode is a promising candidate in redox flow batteries.
Optima MDxt: A high throughput 335 keV mid-dose implanter
DOE Office of Scientific and Technical Information (OSTI.GOV)
Eisner, Edward; David, Jonathan; Justesen, Perry
2012-11-06
The continuing demand for both energy purity and implant angle control along with high wafer throughput drove the development of the Axcelis Optima MDxt mid-dose ion implanter. The system utilizes electrostatic scanning, an electrostatic parallelizing lens and an electrostatic energy filter to produce energetically pure beams with high angular integrity. Based on field proven components, the Optima MDxt beamline architecture offers the high beam currents possible with singly charged species including arsenic at energies up to 335 keV as well as large currents from multiply charged species at energies extending over 1 MeV. Conversely, the excellent energy filtering capability allowsmore » high currents at low beam energies, since it is safe to utilize large deceleration ratios. This beamline is coupled with the >500 WPH capable endstation technology used on the Axcelis Optima XEx high energy ion implanter. The endstation includes in-situ angle measurements of the beam in order to maintain excellent beam-to-wafer implant angle control in both the horizontal and vertical directions. The Optima platform control system provides new generation dose control system that assures excellent dosimetry and charge control. This paper will describe the features and technologies that allow the Optima MDxt to provide superior process performance at the highest wafer throughput, and will provide examples of the process performance achievable.« less
Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-12
... Units and Standards of Performance for Fossil-Fuel-Fired Electric Utility, Industrial-Commercial...- and Oil-fired Electric Utility Steam Generating Units and Standards of Performance for Fossil-Fuel... Units and Standards of Performance for Fossil-Fuel-Fired Electric Utility, Industrial-Commercial...
Cable testing for Fermilab's high field magnets using small racetrack coils
DOE Office of Scientific and Technical Information (OSTI.GOV)
Feher, S.; Ambrosio, G.; Andreev, N.
As part of the High Field Magnet program at Fermilab simple magnets have been designed utilizing small racetrack coils based on a sound mechanical structure and bladder technique developed by LBNL. Two of these magnets have been built in order to test Nb{sub 3}Sn cables used in cos-theta dipole models. The powder-in-tube strand based cable exhibited excellent performance. It reached its critical current limit within 14 quenches. Modified jelly roll strand based cable performance was limited by magnetic instabilities at low fields as previously tested dipole models which used similar cable.
Development of a magnetically suspended momentum wheel
NASA Technical Reports Server (NTRS)
Hamilton, S. B.
1973-01-01
An engineering model of a magnetically suspended momentum wheel was designed, fabricated, and tested under laboratory conditions. The basic unit consisted of two magnet bearings, a sculptured aluminum rotor, brushless dc spin motor, and electronics. The magnet bearings, utilizing rare-earth cobltrat-samarium magnets were active radially and passive axially. The results of the program showed that momentum wheels with magnetic bearings are feasible and operable, and that magnetic bearings of this type are capable of being used for applications where high capacity, high stiffness, and low power consumption are required. The tests performed developed criteria for improved performance for future designs.
1983-07-18
architecture . Design , performance, and cost of BRISC is presented. Performance is shown to be better than high end mainframes such as the IBM 3081 and Amdahl 470V/8 on integer benchmarks written in C, Pascal and LISP. The cost, conservatively estimated to be $132,400 is about the same as a high end minicomputer such as the VAX-11/780. BRISC has a CPU cycle time of 46 ns, providing a RISC I instruction execution rate of greater than 15 MIPs. BRISC is designed with a Structured Computer Aided Logic Design System (SCALD) by Valid Logic Systems. An evaluation of the utility of
Magnetic bearings for inertial energy storage
NASA Technical Reports Server (NTRS)
Rodriguez, G. Ernest; Eakin, Vickie
1987-01-01
Advanced flywheels utilizing high strength fibers must operate at high rotational speeds and as such must operate in vacuum to reduce windage losses. The utilization of magnetic bearings in the flywheels overcome lubrication and seal problems, resulting in an energy storage system offering potential improvements over conventional electrochemical energy storage. Magnetic bearings evolved in the 1950s from the simple application of permanent magnets positioned to exert repulsive forces to the present where permanent magnets and electromagnets have been combined to provide axial and radial suspension. Further development of magnetic suspension has led to the design of a shaftless flywheel system for aerospace application. Despite the lack of proof of concept, integrated magnetic suspension in inertial storage systems can provide significant performance improvements to warrant development and tests.
The Newick utilities: high-throughput phylogenetic tree processing in the Unix shell
Junier, Thomas; Zdobnov, Evgeny M.
2010-01-01
Summary: We present a suite of Unix shell programs for processing any number of phylogenetic trees of any size. They perform frequently-used tree operations without requiring user interaction. They also allow tree drawing as scalable vector graphics (SVG), suitable for high-quality presentations and further editing, and as ASCII graphics for command-line inspection. As an example we include an implementation of bootscanning, a procedure for finding recombination breakpoints in viral genomes. Availability: C source code, Python bindings and executables for various platforms are available from http://cegg.unige.ch/newick_utils. The distribution includes a manual and example data. The package is distributed under the BSD License. Contact: thomas.junier@unige.ch PMID:20472542
Advanced Engine Health Management Applications of the SSME Real-Time Vibration Monitoring System
NASA Technical Reports Server (NTRS)
Fiorucci, Tony R.; Lakin, David R., II; Reynolds, Tracy D.; Turner, James E. (Technical Monitor)
2000-01-01
The Real Time Vibration Monitoring System (RTVMS) is a 32-channel high speed vibration data acquisition and processing system developed at Marshall Space Flight Center (MSFC). It Delivers sample rates as high as 51,200 samples/second per channel and performs Fast Fourier Transform (FFT) processing via on-board digital signal processing (DSP) chips in a real-time format. Advanced engine health assessment is achieved by utilizing the vibration spectra to provide accurate sensor validation and enhanced engine vibration redlines. Discrete spectral signatures (such as synchronous) that are indicators of imminent failure can be assessed and utilized to mitigate catastrophic engine failures- a first in rocket engine health assessment. This paper is presented in viewgraph form.
Manchikanti, Laxmaiah; Helm, Standiford; Pampati, Vidyasagar; Racz, Gabor B
2015-06-01
The increase in the number of interventions for the management of chronic pain and associated escalation of healthcare costs has captured the attention of health policymakers, in no small part due to the lack of documentation of efficacy, cost-effectiveness, or cost utility analysis. A recent cost utility analysis of caudal epidural injections in managing chronic low back pain of various pathologies showed a high cost utility with improvement in quality of life years, competitive with various other modalities of treatments. However, there are no analyses derived from high-quality controlled studies related to the cost utility of percutaneous adhesiolysis in the treatment of post-lumbar surgery syndrome or lumbar central spinal stenosis. This analysis is based on 2 previously published controlled studies. To assess the cost utility of percutaneous adhesiolysis procedures in managing chronic low back and lower extremity pain secondary to post-lumbar surgery syndrome and lumbar central spinal stenosis. A private, specialty referral interventional pain management center in the United States. Two controlled studies were conducted assessing the clinical effectiveness of percutaneous adhesiolysis for post-lumbar surgery syndrome and lumbar central spinal stenosis in an interventional pain management setting utilizing contemporary interventional pain management practices. A cost utility analysis was performed with direct payment data for a total of 130 patients in treatment groups over a 2-year period. Various outcome measures were included with significant improvement, defined as at least 50% improvement with reduction in pain and disability status. The results of 2 controlled studies of low back pain with 60 and 70 patients and a 2-year follow-up with the actual reimbursement data showed cost utility for 1 year of quality-adjusted life year (QALY) of USD $2,652 for post-lumbar surgery syndrome and USD $2,649 for lumbar central spinal stenosis. The results of this assessment show that the cost utility of managing chronic, intractable low back pain with percutaneous adhesiolysis at a QALY that is similar or lower in price than medical therapy only, physical therapy, manipulation, spinal cord stimulation, and surgery. The limitations of this cost utility analysis are that it is a single-center evaluation, with the inclusion of costs of adhesiolysis procedures in an ambulatory surgery center and physician visits, rather than all related costs including drug therapy and costs of disability in multiple settings. This cost utility analysis of percutaneous adhesiolysis in the treatment of post-lumbar surgery syndrome and lumbar central spinal stenosis shows the clinical effectiveness and cost utility of these procedures at USD $2,650 per one year of QALY when performed in an ambulatory surgery center. © 2014 World Institute of Pain.
Jones, Andrew M; Vanhatalo, Anni
2017-03-01
The curvilinear relationship between power output and the time for which it can be sustained is a fundamental and well-known feature of high-intensity exercise performance. This relationship 'levels off' at a 'critical power' (CP) that separates power outputs that can be sustained with stable values of, for example, muscle phosphocreatine, blood lactate, and pulmonary oxygen uptake ([Formula: see text]), from power outputs where these variables change continuously with time until their respective minimum and maximum values are reached and exercise intolerance occurs. The amount of work that can be done during exercise above CP (the so-called W') is constant but may be utilized at different rates depending on the proximity of the exercise power output to CP. Traditionally, this two-parameter CP model has been employed to provide insights into physiological responses, fatigue mechanisms, and performance capacity during continuous constant power output exercise in discrete exercise intensity domains. However, many team sports (e.g., basketball, football, hockey, rugby) involve frequent changes in exercise intensity and, even in endurance sports (e.g., cycling, running), intensity may vary considerably with environmental/course conditions and pacing strategy. In recent years, the appeal of the CP concept has been broadened through its application to intermittent high-intensity exercise. With the assumptions that W' is utilized during work intervals above CP and reconstituted during recovery intervals below CP, it can be shown that performance during intermittent exercise is related to four factors: the intensity and duration of the work intervals and the intensity and duration of the recovery intervals. However, while the utilization of W' may be assumed to be linear, studies indicate that the reconstitution of W' may be curvilinear with kinetics that are highly variable between individuals. This has led to the development of a new CP model for intermittent exercise in which the balance of W' remaining ([Formula: see text]) may be calculated with greater accuracy. Field trials of athletes performing stochastic exercise indicate that this [Formula: see text] model can accurately predict the time at which W' tends to zero and exhaustion is imminent. The [Formula: see text] model potentially has important applications in the real-time monitoring of athlete fatigue progression in endurance and team sports, which may inform tactics and influence pacing strategy.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Subekti, M.; Center for Development of Reactor Safety Technology, National Nuclear Energy Agency of Indonesia, Puspiptek Complex BO.80, Serpong-Tangerang, 15340; Ohno, T.
2006-07-01
The neuro-expert has been utilized in previous monitoring-system research of Pressure Water Reactor (PWR). The research improved the monitoring system by utilizing neuro-expert, conventional noise analysis and modified neural networks for capability extension. The parallel method applications required distributed architecture of computer-network for performing real-time tasks. The research aimed to improve the previous monitoring system, which could detect sensor degradation, and to perform the monitoring demonstration in High Temperature Engineering Tested Reactor (HTTR). The developing monitoring system based on some methods that have been tested using the data from online PWR simulator, as well as RSG-GAS (30 MW research reactormore » in Indonesia), will be applied in HTTR for more complex monitoring. (authors)« less
CTF (Subchannel) Calculations and Validation L3:VVI.H2L.P15.01
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gordon, Natalie
The goal of the Verification and Validation Implementation (VVI) High to Low (Hi2Lo) process is utilizing a validated model in a high resolution code to generate synthetic data for improvement of the same model in a lower resolution code. This process is useful in circumstances where experimental data does not exist or it is not sufficient in quantity or resolution. Data from the high-fidelity code is treated as calibration data (with appropriate uncertainties and error bounds) which can be used to train parameters that affect solution accuracy in the lower-fidelity code model, thereby reducing uncertainty. This milestone presents a demonstrationmore » of the Hi2Lo process derived in the VVI focus area. The majority of the work performed herein describes the steps of the low-fidelity code used in the process with references to the work detailed in the companion high-fidelity code milestone (Reference 1). The CASL low-fidelity code used to perform this work was Cobra Thermal Fluid (CTF) and the high-fidelity code was STAR-CCM+ (STAR). The master branch version of CTF (pulled May 5, 2017 – Reference 2) was utilized for all CTF analyses performed as part of this milestone. The statistical and VVUQ components of the Hi2Lo framework were performed using Dakota version 6.6 (release date May 15, 2017 – Reference 3). Experimental data from Westinghouse Electric Company (WEC – Reference 4) was used throughout the demonstrated process to compare with the high-fidelity STAR results. A CTF parameter called Beta was chosen as the calibration parameter for this work. By default, Beta is defined as a constant mixing coefficient in CTF and is essentially a tuning parameter for mixing between subchannels. Since CTF does not have turbulence models like STAR, Beta is the parameter that performs the most similar function to the turbulence models in STAR. The purpose of the work performed in this milestone is to tune Beta to an optimal value that brings the CTF results closer to those measured in the WEC experiments.« less
Generic Divide and Conquer Internet-Based Computing
NASA Technical Reports Server (NTRS)
Follen, Gregory J. (Technical Monitor); Radenski, Atanas
2003-01-01
The growth of Internet-based applications and the proliferation of networking technologies have been transforming traditional commercial application areas as well as computer and computational sciences and engineering. This growth stimulates the exploration of Peer to Peer (P2P) software technologies that can open new research and application opportunities not only for the commercial world, but also for the scientific and high-performance computing applications community. The general goal of this project is to achieve better understanding of the transition to Internet-based high-performance computing and to develop solutions for some of the technical challenges of this transition. In particular, we are interested in creating long-term motivation for end users to provide their idle processor time to support computationally intensive tasks. We believe that a practical P2P architecture should provide useful service to both clients with high-performance computing needs and contributors of lower-end computing resources. To achieve this, we are designing dual -service architecture for P2P high-performance divide-and conquer computing; we are also experimenting with a prototype implementation. Our proposed architecture incorporates a master server, utilizes dual satellite servers, and operates on the Internet in a dynamically changing large configuration of lower-end nodes provided by volunteer contributors. A dual satellite server comprises a high-performance computing engine and a lower-end contributor service engine. The computing engine provides generic support for divide and conquer computations. The service engine is intended to provide free useful HTTP-based services to contributors of lower-end computing resources. Our proposed architecture is complementary to and accessible from computational grids, such as Globus, Legion, and Condor. Grids provide remote access to existing higher-end computing resources; in contrast, our goal is to utilize idle processor time of lower-end Internet nodes. Our project is focused on a generic divide and conquer paradigm and on mobile applications of this paradigm that can operate on a loose and ever changing pool of lower-end Internet nodes.
Nonlinear stability and control study of highly maneuverable high performance aircraft
NASA Technical Reports Server (NTRS)
Mohler, R. R.
1993-01-01
This project is intended to research and develop new nonlinear methodologies for the control and stability analysis of high-performance, high angle-of-attack aircraft such as HARV (F18). Past research (reported in our Phase 1, 2, and 3 progress reports) is summarized and more details of final Phase 3 research is provided. While research emphasis is on nonlinear control, other tasks such as associated model development, system identification, stability analysis, and simulation are performed in some detail as well. An overview of various models that were investigated for different purposes such as an approximate model reference for control adaptation, as well as another model for accurate rigid-body longitudinal motion is provided. Only a very cursory analysis was made relative to type 8 (flexible body dynamics). Standard nonlinear longitudinal airframe dynamics (type 7) with the available modified F18 stability derivatives, thrust vectoring, actuator dynamics, and control constraints are utilized for simulated flight evaluation of derived controller performance in all cases studied.
High-performance indium gallium phosphide/gallium arsenide heterojunction bipolar transistors
NASA Astrophysics Data System (ADS)
Ahmari, David Abbas
Heterojunction bipolar transistors (HBTs) have demonstrated the high-frequency characteristics as well as the high linearity, gain, and power efficiency necessary to make them attractive for a variety of applications. Specific applications for which HBTs are well suited include amplifiers, analog-to-digital converters, current sources, and optoelectronic integrated circuits. Currently, most commercially available HBT-based integrated circuits employ the AlGaAs/GaAs material system in applications such as a 4-GHz gain block used in wireless phones. As modern systems require higher-performance and lower-cost devices, HBTs utilizing the newer, InGaP/GaAs and InP/InGaAs material systems will begin to dominate the HBT market. To enable the widespread use of InGaP/GaAs HBTs, much research on the fabrication, performance, and characterization of these devices is required. This dissertation will discuss the design and implementation of high-performance InGaP/GaAs HBTs as well as study HBT device physics and characterization.
NASA Astrophysics Data System (ADS)
Al-Asadi, Ahmed S.; Henley, Luke Alexander; Wasala, Milinda; Muchharla, Baleeswaraiah; Perea-Lopez, Nestor; Carozo, Victor; Lin, Zhong; Terrones, Mauricio; Mondal, Kanchan; Kordas, Krisztian; Talapatra, Saikat
2017-03-01
Carbon nanotube/metal oxide based hybrids are envisioned as high performance electrochemical energy storage electrodes since these systems can provide improved performances utilizing an electric double layer coupled with fast faradaic pseudocapacitive charge storage mechanisms. In this work, we show that high performance supercapacitor electrodes with a specific capacitance of ˜192 F/g along with a maximum energy density of ˜3.8 W h/kg and a power density of ˜ 28 kW/kg can be achieved by synthesizing zinc oxide nanowires (ZnO NWs) directly on top of aligned multi-walled carbon nanotubes (MWCNTs). In comparison to pristine MWCNTs, these constitute a 12-fold of increase in specific capacitance as well as corresponding power and energy density values. These electrodes also possess high cycling stability and were able to retain ˜99% of their specific capacitance value over 2000 charging discharging cycles. These findings indicate potential use of a MWCNT/ZnO NW hybrid material for future electrochemical energy storage applications.
Electro-optical characterization of GaAs solar cells
NASA Technical Reports Server (NTRS)
Olsen, Larry C.; Dunham, Glen; Addis, F. W.; Huber, Dan; Daling, Dave
1987-01-01
The electro-optical characterization of gallium arsenide p/n solar cells is discussed. The objective is to identify and understand basic mechanisms which limit the performance of high efficiency gallium arsenide solar cells. The approach involves conducting photoresponse and temperature dependent current-voltage measurements, and interpretation of the data in terms of theory to determine key device parameters. Depth concentration profiles are also utilized in formulating a model to explain device performance.
Performance Evaluation of FAST TCP Traffic-Flows in Multihomed MANETs
NASA Astrophysics Data System (ADS)
Mudassir, Mumajjed Ul; Akram, Adeel
In Mobile Ad hoc Networks (MANETs) an efficient communication protocol is required at the transport layer. Mobile nodes moving around will have temporary and rather short-lived connectivity with each other and the Internet, thus requiring efficient utilization of network resources. Moreover the problems arising due to high mobility, collision and congestion must also be considered. Multihoming allows higher reliability and enhancement of network throughput. FAST TCP is a new promising transport layer protocol developed for high-speed high-latency networks. In this paper, we have analyzed the performance of FAST TCP traffic flows in multihomed MANETs and compared it with standard TCP (TCP Reno) traffic flows in non-multihomed MANETs.
Hu, Yuanyuan; Rengert, Zachary D; McDowell, Caitlin; Ford, Michael J; Wang, Ming; Karki, Akchheta; Lill, Alexander T; Bazan, Guillermo C; Nguyen, Thuc-Quyen
2018-04-24
Solution-processed organic field-effect transistors (OFETs) were fabricated with the addition of an organic salt, trityl tetrakis(pentafluorophenyl)borate (TrTPFB), into thin films of donor-acceptor copolymer semiconductors. The performance of OFETs is significantly enhanced after the organic salt is incorporated. TrTPFB is confirmed to p-dope the organic semiconductors used in this study, and the doping efficiency as well as doping physics was investigated. In addition, systematic electrical and structural characterizations reveal how the doping enhances the performance of OFETs. Furthermore, it is shown that this organic salt doping method is feasible for both p- and n-doping by using different organic salts and, thus, can be utilized to achieve high-performance OFETs and organic complementary circuits.
A high performance parallel algorithm for 1-D FFT
DOE Office of Scientific and Technical Information (OSTI.GOV)
Agarwal, R.C.; Gustavson, F.G.; Zubair, M.
1994-12-31
In this paper the authors propose a parallel high performance FFT algorithm based on a multi-dimensional formulation. They use this to solve a commonly encountered FFT based kernel on a distributed memory parallel machine, the IBM scalable parallel system, SP1. The kernel requires a forward FFT computation of an input sequence, multiplication of the transformed data by a coefficient array, and finally an inverse FFT computation of the resultant data. They show that the multi-dimensional formulation helps in reducing the communication costs and also improves the single node performance by effectively utilizing the memory system of the node. They implementedmore » this kernel on the IBM SP1 and observed a performance of 1.25 GFLOPS on a 64-node machine.« less
Designing Agent Collectives For Systems With Markovian Dynamics
NASA Technical Reports Server (NTRS)
Wolpert, David H.; Lawson, John W.; Clancy, Daniel (Technical Monitor)
2001-01-01
The "Collective Intelligence" (COIN) framework concerns the design of collectives of agents so that as those agents strive to maximize their individual utility functions, their interaction causes a provided "world" utility function concerning the entire collective to be also maximized. Here we show how to extend that framework to scenarios having Markovian dynamics when no re-evolution of the system from counter-factual initial conditions (an often expensive calculation) is permitted. Our approach transforms the (time-extended) argument of each agent's utility function before evaluating that function. This transformation has benefits in scenarios not involving Markovian dynamics, in particular scenarios where not all of the arguments of an agent's utility function are observable. We investigate this transformation in simulations involving both linear and quadratic (nonlinear) dynamics. In addition, we find that a certain subset of these transformations, which result in utilities that have low "opacity (analogous to having high signal to noise) but are not "factored" (analogous to not being incentive compatible), reliably improve performance over that arising with factored utilities. We also present a Taylor Series method for the fully general nonlinear case.
A CROSS-SPECIES MODE OF ACTION INFORMATION ASSESSMENT: A CASE STUDY OF BISPHENOL A
A case study assessing the utility of this approach was performed for bisphenol A (BPA). BPA, a component of polycarbonate plastics, epoxy resins, and polyester resins, was selected because it is a high production volume chemical; data have been identified for both vertebrate an...
Modality Specificity and Integration in Working Memory: Insights from Visuospatial Bootstrapping
ERIC Educational Resources Information Center
Allen, Richard J.; Havelka, Jelena; Falcon, Thomas; Evans, Sally; Darling, Stephen
2015-01-01
The question of how meaningful associations between verbal and spatial information might be utilized to facilitate working memory performance is potentially highly instructive for models of memory function. The present study explored how separable processing capacities within specialized domains might each contribute to this, by examining the…
USDA-ARS?s Scientific Manuscript database
Capillary electrophoresis (CE) and reversed-phase high performance liquid chromatography (RP-HPLC) analysis were utilized to detect differences in the sarcoplasmic protein profiles of beef strip loins subjected to aging and hydrodynamic pressure processing (HDP) treatments. At 48 h postmortem, stri...
SVM classifier on chip for melanoma detection.
Afifi, Shereen; GholamHosseini, Hamid; Sinha, Roopak
2017-07-01
Support Vector Machine (SVM) is a common classifier used for efficient classification with high accuracy. SVM shows high accuracy for classifying melanoma (skin cancer) clinical images within computer-aided diagnosis systems used by skin cancer specialists to detect melanoma early and save lives. We aim to develop a medical low-cost handheld device that runs a real-time embedded SVM-based diagnosis system for use in primary care for early detection of melanoma. In this paper, an optimized SVM classifier is implemented onto a recent FPGA platform using the latest design methodology to be embedded into the proposed device for realizing online efficient melanoma detection on a single system on chip/device. The hardware implementation results demonstrate a high classification accuracy of 97.9% and a significant acceleration factor of 26 from equivalent software implementation on an embedded processor, with 34% of resources utilization and 2 watts for power consumption. Consequently, the implemented system meets crucial embedded systems constraints of high performance and low cost, resources utilization and power consumption, while achieving high classification accuracy.
NASA Astrophysics Data System (ADS)
Matahari, Rho Natta; Putra, Nandy; Ariantara, Bambang; Amin, Muhammad; Prawiro, Erwin
2017-02-01
High number of preterm births is one of the issues in improving health standard. The effort to help premature babies is hampered by high cost of NICU care in hospital. In addition, uneven distribution of electricity to remote area made it hard to operate the incubator. Utilization of phase change material beeswax to non-electricity incubator as heating element becomes alternative option to save premature babies. The objective of this experiment is to investigate the most efficient mass of beeswax according to Indonesian National Standard to earn over time and ideal temperature of incubator. Experiment was performed using prototype incubator, which utilizes natural convection phenomenon in the heating process of incubator. Utilization of fin is to accelerate heat distribution in the incubator. Result of experiment showed that the most efficient mass of PCM is 3 kg, which has 2.45 hours of running time for maintaining temperature of incubator in range of 32-36 °C.
Angenent, Largus T; Sung, Shihwu; Raskin, Lutgarde
2002-11-01
Changes in methanogenic population levels were followed during startup of a full-scale, farm-based anaerobic sequencing batch reactor (ASBR) and these changes were linked to operational and performance data. The ASBR was inoculated with anaerobic digester sludge from a municipal wastewater treatment facility. During an acclimation period of approximately 3 months, the ASBR content was diluted to maintain a total ammonia-N level of approximately 2000mg l(-1). After this acclimation period, the volatile solids loading rate was increased to its design value of 1.7g l(-1) day(-1) with a 15-day hydraulic retention time, which increased the total ammonia-N level in the ASBR to approximately 3,600 mg l(-1). The 16S ribosomal RNA (rRNA) levels of the acetate-utilizing methanogens of the genus Methanosarcina decreased from 3.8% to 1.2% (expressed as a percentage of the total 16S rRNA levels) during this period, while the 16S rRNA levels of Methanosaeta concilii remained low (below 2.2%). Methane production and reactor performance were not affected as the 16S rRNA levels of the hydrogen-utilizing methanogens of the order Methanomicrobiales increased from 2.3% to 7.0%. Hence, it is likely that during operation with high ammonia levels, the major route of methane production is through a syntrophic relationship between acetate-oxidizing bacteria and hydrogen-utilizing methanogens. Anaerobic digestion at total ammonia-N levels exceeding 3500mg l(-1) was sustainable apparently due to the acclimation of hydrogen-utilizing methanogens to high ammonia levels.
NASA Astrophysics Data System (ADS)
Xu, XiaoLong; Qi, CongYu; Hao, ZhenDong; Wang, Hao; Jiu, JinTing; Liu, JingBing; Yan, Hui; Suganuma, Katsuaki
2018-03-01
The requirement of energy-storage equipment needs to develop the lithium ion battery (LIB) with high electrochemical performance. The surface modification of commercial LiFePO4 (LFP) by utilizing zeolitic imidazolate frameworks-8 (ZIF-8) offers new possibilities for commercial LFP with high electrochemical performances. In this work, the carbonized ZIF-8 (CZIF-8) was coated on the surface of LFP particles by the in situ growth and carbonization of ZIF-8. Transmission electron microscopy indicates that there is an approximate 10 nm coating layer with metal zinc and graphite-like carbon on the surface of LFP/CZIF-8 sample. The N2 adsorption and desorption isotherm suggests that the coating layer has uniform and simple connecting mesopores. As cathode material, LFP/CZIF-8 cathode-active material delivers a discharge specific capacity of 159.3 mAh g-1 at 0.1C and a discharge specific energy of 141.7 mWh g-1 after 200 cycles at 5.0C (the retention rate is approximate 99%). These results are attributed to the synergy improvement of the conductivity, the lithium ion diffusion coefficient, and the degree of freedom for volume change of LFP/CZIF-8 cathode. This work will contribute to the improvement of the cathode materials of commercial LIB.[Figure not available: see fulltext.
Solution processed integrated pixel element for an imaging device
NASA Astrophysics Data System (ADS)
Swathi, K.; Narayan, K. S.
2016-09-01
We demonstrate the implementation of a solid state circuit/structure comprising of a high performing polymer field effect transistor (PFET) utilizing an oxide layer in conjunction with a self-assembled monolayer (SAM) as the dielectric and a bulk-heterostructure based organic photodiode as a CMOS-like pixel element for an imaging sensor. Practical usage of functional organic photon detectors requires on chip components for image capture and signal transfer as in the CMOS/CCD architecture rather than simple photodiode arrays in order to increase speed and sensitivity of the sensor. The availability of high performing PFETs with low operating voltage and photodiodes with high sensitivity provides the necessary prerequisite to implement a CMOS type image sensing device structure based on organic electronic devices. Solution processing routes in organic electronics offers relatively facile procedures to integrate these components, combined with unique features of large-area, form factor and multiple optical attributes. We utilize the inherent property of a binary mixture in a blend to phase-separate vertically and create a graded junction for effective photocurrent response. The implemented design enables photocharge generation along with on chip charge to voltage conversion with performance parameters comparable to traditional counterparts. Charge integration analysis for the passive pixel element using 2D TCAD simulations is also presented to evaluate the different processes that take place in the monolithic structure.
Plotting performance improvement progress through the development of a trauma dashboard.
Hochstuhl, Diane C; Elwell, Sean
2014-01-01
Performance improvement processes are the core of a pediatric trauma program. The ability to identify, resolve, and trend specific indicators related to patient care and to show effective loop closure can be especially challenging. Using the hospital's overall quality process as a template, the trauma program built its own electronic dashboard. Our maturing trauma PI program now guides the overall trauma care. All departments own at least one performance indicator and must provide action plans for improvement. Utilization of an electronic dashboard for trauma performance improvement has provided a highly visible scorecard, which highlights successes and tracks areas needing improvement.
ERIC Educational Resources Information Center
Felner, Robert D.; Bolton, Natalie; Seitsinger, Anne M.; Brand, Stephen; Burns, Amy
2008-01-01
This article reports on one ongoing statewide effort to create a high-quality data reporting and utilization system (i.e., High-Performance Learning Community [HiPlaces] Assessment) to inform educational accountability and improvement efforts system. This effort has undergoing refinement for more than a decade. The article describes the features…
A Novel Approach to Develop the Lower Order Model of Multi-Input Multi-Output System
NASA Astrophysics Data System (ADS)
Rajalakshmy, P.; Dharmalingam, S.; Jayakumar, J.
2017-10-01
A mathematical model is a virtual entity that uses mathematical language to describe the behavior of a system. Mathematical models are used particularly in the natural sciences and engineering disciplines like physics, biology, and electrical engineering as well as in the social sciences like economics, sociology and political science. Physicists, Engineers, Computer scientists, and Economists use mathematical models most extensively. With the advent of high performance processors and advanced mathematical computations, it is possible to develop high performing simulators for complicated Multi Input Multi Ouptut (MIMO) systems like Quadruple tank systems, Aircrafts, Boilers etc. This paper presents the development of the mathematical model of a 500 MW utility boiler which is a highly complex system. A synergistic combination of operational experience, system identification and lower order modeling philosophy has been effectively used to develop a simplified but accurate model of a circulation system of a utility boiler which is a MIMO system. The results obtained are found to be in good agreement with the physics of the process and with the results obtained through design procedure. The model obtained can be directly used for control system studies and to realize hardware simulators for boiler testing and operator training.
ReHypar: A Recursive Hybrid Chunk Partitioning Method Using NAND-Flash Memory SSD
Park, Sung-Soon; Lim, Cheol-Su
2014-01-01
Due to the rapid development of flash memory, SSD is considered to be the replacement of HDD in the storage market. Although SSD retains several promising characteristics, such as high random I/O performance and nonvolatility, its high expense per capacity is the main obstacle in replacing HDD in all storage solutions. An alternative is to provide a hybrid structure where a small portion of SSD address space is combined with the much larger HDD address space. In such a structure, maximizing the space utilization of SSD in a cost-effective way is extremely important to generate high I/O performance. We developed ReHypar (recursive hybrid chunk partitioning) that enables improving the space utilization of SSD in the hybrid structure. The first objective of ReHypar is to mitigate the fragmentation overhead of SSD address space, by reusing the remaining free space of I/O units as much as possible. Furthermore, ReHypar allows defining several, logical data sections in SSD address space, with each of those sections being configured with the different I/O unit. We integrated ReHypar with ext2 and ext4 and evaluated it using two public benchmarks including IOzone and Postmark. PMID:24987741
SAFARI optical system architecture and design concept
NASA Astrophysics Data System (ADS)
Pastor, Carmen; Jellema, Willem; Zuluaga-Ramírez, Pablo; Arrazola, David; Fernández-Rodriguez, M.; Belenguer, Tomás.; González Fernández, Luis M.; Audley, Michael D.; Evers, Jaap; Eggens, Martin; Torres Redondo, Josefina; Najarro, Francisco; Roelfsema, Peter
2016-07-01
SpicA FAR infrared Instrument, SAFARI, is one of the instruments planned for the SPICA mission. The SPICA mission is the next great leap forward in space-based far-infrared astronomy and will study the evolution of galaxies, stars and planetary systems. SPICA will utilize a deeply cooled 2.5m-class telescope, provided by European industry, to realize zodiacal background limited performance, and high spatial resolution. The instrument SAFARI is a cryogenic grating-based point source spectrometer working in the wavelength domain 34 to 230 μm, providing spectral resolving power from 300 to at least 2000. The instrument shall provide low and high resolution spectroscopy in four spectral bands. Low Resolution mode is the native instrument mode, while the high Resolution mode is achieved by means of a Martin-Pupplet interferometer. The optical system is all-reflective and consists of three main modules; an input optics module, followed by the Band and Mode Distributing Optics and the grating Modules. The instrument utilizes Nyquist sampled filled linear arrays of very sensitive TES detectors. The work presented in this paper describes the optical design architecture and design concept compatible with the current instrument performance and volume design drivers.
Cost-utility analyses of drug therapies in breast cancer: a systematic review.
Nerich, Virginie; Saing, Sopany; Gamper, Eva Maria; Kemmler, Georg; Daval, Franck; Pivot, Xavier; Holzner, Bernhard
2016-10-01
The economic evaluation (EE) of health care products has become a necessity. Their quality must be high in order to trust the results and make informed decisions. While cost-utility analyses (CUAs) should be preferred to cost-effectiveness analyses in the oncology area, the quality of breast cancer (BC)-related CUA has been given little attention so far. Thus, firstly, a systematic review of published CUA related to drug therapies for BC, gene expression profiling, and HER2 status testing was performed. Secondly, the quality of selected CUA was assessed and the factors associated with a high-quality CUA identified. The systematic literature search was conducted in PubMed, MEDLINE/EMBASE, and Cochrane to identify published CUA between 2000 and 2014. After screening and data extraction, the quality of each selected CUA was assessed by two independent reviewers, using the checklist proposed by Drummond et al. The analysis of factors associated with a high-quality CUA (defined as a Drummond score ≥7) was performed using a two-step approach. Our systematic review was based on 140 CUAs and showed a wide variety of methodological approaches, including differences in the perspective adopted, the time horizon, measurement of cost and effectiveness, and more specially health-state utility values (HSUVs). The median Drummond score was 7 [range 3-10]. Only one in two of the CUA (n = 74) had a Drummond score ≥7, synonymous of "high quality." The statistically significant predictors of a high-quality CUA were article with "gene expression profiling" topic (p = 0.001), consulting or pharmaceutical company as main location of first author (p = 0.004), and articles with both incremental cost-utility ratio and incremental cost-effectiveness ratio as outcomes of EE (p = 0.02). Our systematic review identified only 140 CUAs published over the past 15 years with one in two of high quality. It showed a wide variety of methodological approaches, especially focused on HSUVs. A critical appraisal of utility values is necessary to better understand one of the main difficulties encountered by authors and propose areas for improvement to increase the quality of CUA. Since the last 5 years, there is a tendency toward an improvement in the quality of these studies, probably coupled with economic context, a better and widely spreading of recommendations and thus appropriation by medical practitioners. That being said, there is an urgent need for mandatory use of European and international recommendations to ensure quality of such approaches and to allow easy comparison.
Magnetic Flux Compression Concept for Nuclear Pulse Propulsion and Power
NASA Technical Reports Server (NTRS)
Litchford, Ronald J.
2000-01-01
The desire for fast, efficient interplanetary transport requires propulsion systems having short acceleration times and very high specific impulse attributes. Unfortunately, most highly efficient propulsion systems which are within the capabilities of present day technologies are either very heavy or yield very low impulse such that the acceleration time to final velocity is too long to be of lasting interest, One exception, the nuclear thermal thruster, could achieve the desired acceleration but it would require inordinately large mass ratios to reach the range of desired final velocities. An alternative approach, among several competing concepts that are beyond our modern technical capabilities, is a pulsed thermonuclear device utilizing microfusion detonations. In this paper, we examine the feasibility of an innovative magnetic flux compression concept for utilizing microfusion detonations, assuming that such low yield nuclear bursts can be realized in practice. In this concept, a magnetic field is compressed between an expanding detonation driven diamagnetic plasma and a stationary structure formed from a high temperature superconductor (HTSC). In general, we are interested in accomplishing two important functions: (1) collimation of a hot diamagnetic plasma for direct thrust production; and (2) pulse power generation for dense plasma ignition. For the purposes of this research, it is assumed that rnicrofusion detonation technology may become available within a few decades, and that this approach could capitalize on recent advances in inertial confinement fusion ICF) technologies including magnetized target concepts and antimatter initiated nuclear detonations. The charged particle expansion velocity in these detonations can be on the order of 10 (exp 6)- 10 (exp 7) meters per second, and, if effectively collimated by a magnetic nozzle, can yield the Isp and the acceleration levels needed for practical interplanetary spaceflight. The ability to ignite pure fusion micro-bursts with reasonable levels of input energy is an equally challenging scientific problem. It remains to be seen, however, whether an effective ignition driver can be developed which meets the requirements for practical spaceflight application (namely high power density, compactness, low weight, and low cost). In this paper, system level performance and design issues are examined including generator performance, magnetic flux compression processes, magnetic diffusion processes, high temperature superconductor (HTSC) material properties, plasmadynamic processes, detonation plasma expansion processes, magnetohydrodynamic instabilities, magnetic nozzle performance, and thrust production performance. Representative generator performance calculations based on a simplified skin layer formulation are presented as well as the results of exploratory small-scale laboratory experiments on magnetic flux diffusion in HTSC materials. In addition, planned follow-on scientific feasibility experiments are described which utilize high explosive detonations and high energy gas discharges to simulate the plasma conditions associated with thermonuclear micro-detonations.
Investigation of self-excited induction generators for wind turbine applications
DOE Office of Scientific and Technical Information (OSTI.GOV)
Muljadi, E.; Butterfield, C.P.; Sallan, J.
2000-02-28
The use of squirrel-cage induction machines in wind generation is widely accepted as a generator of choice. The squirrel-cage induction machine is simple, reliable, cheap, lightweight, and requires very little maintenance. Generally, the induction generator is connected to the utility at constant frequency. With a constant frequency operation, the induction generator operates at practically constant speed (small range of slip). The wind turbine operates in optimum efficiency only within a small range of wind speed variation. The variable-speed operation allows an increase in energy captured and reduces both the torque peaks in the drive train and the power fluctuations sentmore » to the utility. In variable-speed operation, an induction generator needs an interface to convert the variable frequency output of the generator to the fixed frequency at the utility. This interface can be simplified by using a self-excited generator because a simple diode bridge is required to perform the ac/dc conversion. The subsequent dc/ac conversion can be performed using different techniques. The use of a thyristor bridge is readily available for large power conversion and has a lower cost and higher reliability. The firing angle of the inverter bridge can be controlled to track the optimum power curve of the wind turbine. With only diodes and thyristors used in power conversion, the system can be scaled up to a very high voltage and high power applications. This paper analyzes the operation of such a system applied to a 1/3-hp self-excited induction generator. It includes the simulations and tests performed for the different excitation configurations.« less
Static Converter for High Energy Utilization, Modular, Small Nuclear Power Plants
DOE Office of Scientific and Technical Information (OSTI.GOV)
El-Genk, Mohamed S.; Tournier, Jean-Michel P.
2002-07-01
This paper presents and analyzes the performance of high efficiency, high total energy utilization, static converters, which could be used in conjunction with small nuclear reactor plants in remote locations and in undersea applications, requiring little or no maintenance. The converters consist of a top cycle of Alkali Metal Thermal-to-Electric Conversion (AMTEC) units and PbTe thermoelectric (TE) bottom cycle. In addition to converting the reactor thermal power to electricity at 1150 K or less, at a thermodynamic efficiency in the low to mid thirties, the heat rejection from the TE bottom cycle could be used for space heating, industrial processing,more » or sea water desalination. The results indicated that for space heating applications, where the rejected thermal power from the TE bottom cycle is removed by natural convection of ambient air, a total utilization of the reactor thermal power of > 80% is possible. When operated at 1030 K, potassium AMTEC/TE converters are not only more efficient than the sodium AMTEC/TE converters but produce more electrical power. The present analysis showed that a single converter could be sized to produce up to 100 kWe and 70 kWe, for the Na-AMTEC/TE units when operating at 1150 K and the K-AMTEC/TE units when operating at 1030 K, respectively. Such modularity is an added advantage to the high-energy utilization of the present AMTEC/TE converters. (authors)« less
Emitter utilization in heterojunction bipolar transistors
NASA Astrophysics Data System (ADS)
Quach, T.; Jenkins, T.; Barrette, J.; Bozada, C.; Cerny, C.; Desalvo, G.; Dettmer, R.; Ebel, J.; Gillespie, J.; Havasy, C.; Ito, C.; Nakano, K.; Pettiford, C.; Sewell, J.; Via, D.; Anholt, R.
1997-09-01
We compare measured collector current densities, cutoff frequencies ( ft), and transducer gains for thermally shunted heterojunction bipolar transistors with 2-16 μm emitter dot diameters or 2-8 μm emitter bar widths with models of the emitter utilization factors. Models that do not take emitter resistance into account predict that the d.c. utilization factors are below 0.7 for collector current densities greater than 6 × 10 4 A cm -2 and emitter diameters or widths greater than 8 μm. However, because the current gains are compressed by the emitter resistances at those current densities, the measured utilization factors are close to 1, which agrees with models that include emitter resistance. A.c. utilization factors are evident in the transistor Y parameters. For example, Re|Y 21z.sfnc drops off at high frequencies more steeply in HBTs with large emitter diameters or widths than in small ones. However, measured data shows that the HBT a.c. current gains h21 or ft values are not influenced by the a.c. utilization factor. A.c. utilization effects on HBT performance parameters such as small signal and power gains, output power, and power added efficiency are also examined.
Nanostructured manganese oxide thin films as electrode material for supercapacitors
NASA Astrophysics Data System (ADS)
Xia, Hui; Lai, Man On; Lu, Li
2011-01-01
Electrochemical capacitors, also called supercapacitors, are alternative energy storage devices, particularly for applications requiring high power densities. Recently, manganese oxides have been extensively evaluated as electrode materials for supercapacitors due to their low cost, environmental benignity, and promising supercapacitive performance. In order to maximize the utilization of manganese oxides as the electrode material for the supercapacitors and improve their supercapacitive performance, the nanostructured manganese oxides have therefore been developed. This paper reviews the synthesis of the nanostructured manganese oxide thin films by different methods and the supercapacitive performance of different nanostructures.
NASA Astrophysics Data System (ADS)
de Waal, V. J.
1983-02-01
The present investigation deals with the design, fabrication, and limitations of very sensitive SQUID (Superconducting Quantum Interference Device) magnetometers. The SQUID magnetometer is based on a utilization of the Josephson effect. A description of the theoretical background is provided, and high performance DC SQUIDs with submicron niobium Josephson junctions are discussed, taking into account design considerations, fabrication, junction characterization, the performance of the SQUID and input coil, and the gradiometer performance. The simulation and optimization of a DC SQUID with finite capacitance is considered, giving attention to the implementation of a simulation procedure on a hybrid computer.
Dynamic shear deformation in high purity Fe
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cerreta, Ellen K; Bingert, John F; Trujillo, Carl P
2009-01-01
The forced shear test specimen, first developed by Meyer et al. [Meyer L. et al., Critical Adiabatic Shear Strength of Low Alloyed Steel Under Compressive Loading, Metallurgical Applications of Shock Wave and High Strain Rate Phenomena (Marcel Decker, 1986), 657; Hartmann K. et al., Metallurgical Effects on Impact Loaded Materials, Shock Waves and High Strain rate Phenomena in Metals (Plenum, 1981), 325-337.], has been utilized in a number of studies. While the geometry of this specimen does not allow for the microstructure to exactly define the location of shear band formation and the overall mechanical response of a specimen ismore » highly sensitive to the geometry utilized, the forced shear specimen is useful for characterizing the influence of parameters such as strain rate, temperature, strain, and load on the microstructural evolution within a shear band. Additionally, many studies have utilized this geometry to advance the understanding of shear band development. In this study, by varying the geometry, specifically the ratio of the inner hole to the outer hat diameter, the dynamic shear localization response of high purity Fe was examined. Post mortem characterization was performed to quantify the width of the localizations and examine the microstructural and textural evolution of shear deformation in a bcc metal. Increased instability in mechanical response is strongly linked with development of enhanced intergranular misorientations, high angle boundaries, and classical shear textures characterized through orientation distribution functions.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lawder, Matthew T.; Viswanathan, Vilayanur V.; Subramanian, Venkat R.
The growth of intermittent solar power has developed a need for energy storage systems in order to decouple generation and supply of energy. Microgrid (MG) systems comprising of solar arrays with battery energy storage studied in this paper desire high levels of autonomy, seeking to meet desired demand at all times. Large energy storage capacity is required for high levels of autonomy, but much of this expensive capacity goes unused for a majority of the year due to seasonal fluctuations of solar generation. In this paper, a model-based study of MGs comprised of solar generation and battery storage shows themore » relationship between system autonomy and battery utilization applied to multiple demand cases using a single particle battery model (SPM). The SPM allows for more accurate state-of-charge and utilization estimation of the battery than previous studies of renewably powered systems that have used empirical models. The increased accuracy of battery state estimation produces a better assessment of system performance. Battery utilization will depend on the amount of variation in solar insolation as well as the type of demand required by the MG. Consumers must balance autonomy and desired battery utilization of a system within the needs of their grid.« less
Evidence of clinical utility: an unmet need in molecular diagnostics for patients with cancer.
Parkinson, David R; McCormack, Robert T; Keating, Susan M; Gutman, Steven I; Hamilton, Stanley R; Mansfield, Elizabeth A; Piper, Margaret A; Deverka, Patricia; Frueh, Felix W; Jessup, J Milburn; McShane, Lisa M; Tunis, Sean R; Sigman, Caroline C; Kelloff, Gary J
2014-03-15
This article defines and describes best practices for the academic and business community to generate evidence of clinical utility for cancer molecular diagnostic assays. Beyond analytical and clinical validation, successful demonstration of clinical utility involves developing sufficient evidence to demonstrate that a diagnostic test results in an improvement in patient outcomes. This discussion is complementary to theoretical frameworks described in previously published guidance and literature reports by the U.S. Food and Drug Administration, Centers for Disease Control and Prevention, Institute of Medicine, and Center for Medical Technology Policy, among others. These reports are comprehensive and specifically clarify appropriate clinical use, adoption, and payer reimbursement for assay manufacturers, as well as Clinical Laboratory Improvement Amendments-certified laboratories, including those that develop assays (laboratory developed tests). Practical criteria and steps for establishing clinical utility are crucial to subsequent decisions for reimbursement without which high-performing molecular diagnostics will have limited availability to patients with cancer and fail to translate scientific advances into high-quality and cost-effective cancer care. See all articles in this CCR Focus section, "The Precision Medicine Conundrum: Approaches to Companion Diagnostic Co-development." ©2014 AACR.
Low cost high efficiency GaAs monolithic RF module for SARSAT distress beacons
NASA Technical Reports Server (NTRS)
Petersen, W. C.; Siu, D. P.; Cook, H. F.
1991-01-01
Low cost high performance (5 Watts output) 406 MHz beacons are urgently needed to realize the maximum utilization of the Search and Rescue Satellite-Aided Tracking (SARSAT) system spearheaded in the U.S. by NASA. Although current technology can produce beacons meeting the output power requirement, power consumption is high due to the low efficiency of available transmitters. Field performance is currently unsatisfactory due to the lack of safe and reliable high density batteries capable of operation at -40 C. Low cost production is also a crucial but elusive requirement for the ultimate wide scale utilization of this system. Microwave Monolithics Incorporated (MMInc.) has proposed to make both the technical and cost goals for the SARSAT beacon attainable by developing a monolithic GaAs chip set for the RF module. This chip set consists of a high efficiency power amplifier and a bi-phase modulator. In addition to implementing the RF module in Monolithic Microwave Integrated Circuit (MMIC) form to minimize ultimate production costs, the power amplifier has a power-added efficiency nearly twice that attained with current commercial technology. A distress beacon built using this RF module chip set will be significantly smaller in size and lighter in weight due to a smaller battery requirement, since the 406 MHz signal source and the digital controller have far lower power consumption compared to the 5 watt power amplifier. All the program tasks have been successfully completed. The GaAs MMIC RF module chip set has been designed to be compatible with the present 406 MHz signal source and digital controller. A complete high performance low cost SARSAT beacon can be realized with only additional minor iteration and systems integration.
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.
Large Area Field of View for Fast Temporal Resolution Astronomy
NASA Astrophysics Data System (ADS)
Covarrubias, Ricardo A.
2018-01-01
Scientific CMOS (sCMOS) technology is especially relevant for high temporal resolution astronomy combining high resolution, large field of view with very fast frame rates, without sacrificing ultra-low noise performance. Solar Astronomy, Near Earth Object detections, Space Debris Tracking, Transient Observations or Wavefront Sensing are among the many applications this technology can be utilized. Andor Technology is currently developing the next-generation, very large area sCMOS camera with an extremely low noise, rapid frame rates, high resolution and wide dynamic range.
A magnesium–sodium hybrid battery with high operating voltage
Dong, Hui; Li, Yifei; Liang, Yanliang; ...
2016-06-10
Here, we report a high performance magnesium-sodium hybrid battery utilizing a magnesium-sodium dual-salt electrolyte, a magnesium anode, and a Berlin green cathode. The cell delivers an average discharge voltage of 2.2 V and a reversible capacity of 143 mA h g –1. We also demonstrate the cell with an energy density of 135 W h kg –1 and a high power density of up to 1.67 kW kg –1.
Peng, Jun; Liu, Donghao; Shi, Tian; Tian, Huairu; Hui, Xuanhong; He, Hua
2017-07-01
Although stir bar sportive extraction was thought to be a highly efficiency and simple pretreatment approach, its wide application was limited by low selectivity, short service life, and relatively high cost. In order to improve the performance of the stir bar, molecular imprinted polymers and magnetic carbon nanotubes were combined in the present study. In addition, two monomers were utilized to intensify the selectivity of molecularly imprinted polymers. Fourier transform infrared spectroscopy, scanning electron microscopy, and selectivity experiments showed that the molecularly imprinted polymeric stir bar was successfully prepared. Then micro-extraction based on the obtained stir bar was coupled with HPLC for determination of trace cefaclor and cefalexin in environmental water. This approach had the advantages of stir bar sportive extraction, high selectivity of molecular imprinted polymers, and high sorption efficiency of carbon nanotubes. To utilize this pretreatment approach, pH, extraction time, stirring speed, elution solvent, and elution time were optimized. The LOD and LOQ of cefaclor were found to be 3.5 ng · mL -1 and 12.0 ng · mL -1 , respectively; the LOD and LOQ of cefalexin were found to be 3.0 ng · mL -1 and 10.0 ng · mL -1 , respectively. The recoveries of cefaclor and cefalexin were 86.5 ~ 98.6%. The within-run precision and between-run precision were acceptable (relative standard deviation <7%). Even when utilized in more than 14 cycles, the performance of the stir bar did not decrease dramatically. This demonstrated that the molecularly imprinted polymeric stir bar based micro-extraction was a convenient, efficient, low-cost, and a specific method for enrichment of cefaclor and cefalexin in environmental samples.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kurth, Thorsten; Pochinsky, Andrew; Sarje, Abhinav
Practitioners of lattice QCD/QFT have been some of the primary pioneer users of the state-of-the-art high-performance-computing systems, and contribute towards the stress tests of such new machines as soon as they become available. As with all aspects of high-performance-computing, I/O is becoming an increasingly specialized component of these systems. In order to take advantage of the latest available high-performance I/O infrastructure, to ensure reliability and backwards compatibility of data files, and to help unify the data structures used in lattice codes, we have incorporated parallel HDF5 I/O into the SciDAC supported USQCD software stack. Here we present the design andmore » implementation of this I/O framework. Our HDF5 implementation outperforms optimized QIO at the 10-20% level and leaves room for further improvement by utilizing appropriate dataset chunking.« less
NASA Astrophysics Data System (ADS)
Ndokosho, Johnson; Hoko, Zvikomborero; Makurira, Hodson
More than 90% of urban water supply and sanitation services in developing countries are provided by public organizations. However, public provision of services has been inherently inefficient. As a result a number of initiatives have emerged in recent years with a common goal to improve service delivery. In Namibia, the water sector reform resulted in the creation of a public utility called the Namibia Water Corporation (NAMWATER) which is responsible for bulk water supply countrywide. Since its inception in 1998, NAMWATER has been experiencing poor financial performance. This paper presents the findings of a case study that compared the management approaches of NAMWATER to the New Public Management (NPM) paradigm. The focus of the NPM approach is for the public water sector to mirror private sector methods of management so that public utilities can accrue the benefits of effectiveness, efficiency and flexibility often associated with private sector. The study tools used were a combination of literature review, interviews and questionnaires. It was found out that NAMWATER has a high degree of autonomy in its operations, albeit government approved tariffs and sourcing of external financing. The utility reports to government annually to account for results. The utility embraces a notion of good corporate culture and adheres to sound management practices. NAMWATER demonstrated a strong market-orientation indicated by the outsourcing of non-core functions but benchmarking was poorly done. NAMWATER’s customer-orientation is poor as evidenced by the lack of customer care facilities. NAMWATER’s senior management delegated operational authority to lower management to facilitate flexibility and eliminate bottlenecks. The lower management is in turn held accountable for performance by the senior management. There are no robust methods of ensuring sufficient accountability indicated by absence of performance contracts or service level agreements. It was concluded that NAMWATER’s management approaches adhere to the NPM paradigm but some NPM core-ideas such as customer orientation and external accountability (performance contracts) were visibly missing.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-08-02
... Electric Utility Steam Generating Units and Standards of Performance for Fossil-Fuel-Fired Electric Utility...-fired Electric Utility Steam Generating Units and Standards of Performance for Fossil-Fuel-Fired...
Improving surgeon utilization in an orthopedic department using simulation modeling
Simwita, Yusta W; Helgheim, Berit I
2016-01-01
Purpose Worldwide more than two billion people lack appropriate access to surgical services due to mismatch between existing human resource and patient demands. Improving utilization of existing workforce capacity can reduce the existing gap between surgical demand and available workforce capacity. In this paper, the authors use discrete event simulation to explore the care process at an orthopedic department. Our main focus is improving utilization of surgeons while minimizing patient wait time. Methods The authors collaborated with orthopedic department personnel to map the current operations of orthopedic care process in order to identify factors that influence poor surgeons utilization and high patient waiting time. The authors used an observational approach to collect data. The developed model was validated by comparing the simulation output with the actual patient data that were collected from the studied orthopedic care process. The authors developed a proposal scenario to show how to improve surgeon utilization. Results The simulation results showed that if ancillary services could be performed before the start of clinic examination services, the orthopedic care process could be highly improved. That is, improved surgeon utilization and reduced patient waiting time. Simulation results demonstrate that with improved surgeon utilizations, up to 55% increase of future demand can be accommodated without patients reaching current waiting time at this clinic, thus, improving patient access to health care services. Conclusion This study shows how simulation modeling can be used to improve health care processes. This study was limited to a single care process; however the findings can be applied to improve other orthopedic care process with similar operational characteristics. PMID:29355193
Diagnostic utility of abdominal ultrasonography in dogs with chronic diarrhea.
Leib, M S; Larson, M M; Grant, D C; Monroe, W E; Troy, G C; Panciera, D L; Rossmeisl, J H; Werre, S R
2012-01-01
Chronic diarrhea is common in dogs and has many causes. Ultrasonographic descriptions of many gastrointestinal diseases have been published, but the diagnostic utility of ultrasonography in dogs with chronic diarrhea has not been investigated. Diagnostic utility of abdominal ultrasound will be highest in dogs with GI neoplasia and lowest in those with inflammatory disorders. 87 pet dogs with chronic diarrhea. Prospective study in which medical records were reviewed and contribution of abdominal ultrasound toward making diagnosis was scored. In 57/87 (66%) of dogs, the same diagnosis would have been reached without ultrasonography. In 13/87 (15%) of dogs, the ultrasound examination was vital or beneficial to making the diagnosis. Univariable analysis identified that increased diagnostic utility was associated with weight loss (P = .0086), palpation of an abdominal or rectal mass (P = .0031), diseases that commonly have mass lesions visible on ultrasound examination (P < .0001), and a final diagnosis of GI neoplasia. Multivariable regression indicated that utility of abdominal ultrasonography would be 30 times more likely to be high in dogs in which an abdominal or rectal mass was palpated (odds ratio 30.5, 95% CI 5.5-169.6) (P < .0001) versus dogs without a palpable mass. In 15/87 (17%) of dogs, additional benefits of ultrasonography to case management, independent of the contribution to the diagnosis of diarrhea, were identified. Overall, the diagnostic utility of abdominal ultrasonography was low in dogs with chronic diarrhea. Identification of factors associated with high diagnostic utility is an indication to perform abdominal ultrasonography in dogs with chronic diarrhea. Copyright © 2012 by the American College of Veterinary Internal Medicine.
NASA Technical Reports Server (NTRS)
Herrera, J. I.; Reddoch, T. W.; Lawler, J. S.
1985-01-01
As efforts are accelerated to improve the overall capability and performance of wind electric systems, increased attention to variable speed configurations has developed. A number of potentially viable configurations have emerged. Various attributes of variable speed systems need to be carefully tested to evaluate their performance from the utility points of view. With this purpose, the NASA experimental variable speed constant frequency (VSCF) system has been tested. In order to determine the usefulness of these systems in utility applications, tests are required to resolve issues fundamental to electric utility systems. Legitimate questions exist regarding how variable speed generators will influence the performance of electric utility systems; therefore, tests from a utility perspective, have been performed on the VSCF system and an induction generator at an operating power level of 30 kW on a system rated at 200 kVA and 0.8 power factor.
"Take the Volume Pledge" may result in disparity in access to care.
Blanco, Barbara A; Kothari, Anai N; Blackwell, Robert H; Brownlee, Sarah A; Yau, Ryan M; Attisha, John P; Ezure, Yoshiki; Pappas, Sam; Kuo, Paul C; Abood, Gerard J
2017-03-01
"Take the Volume Pledge" proposes restricting pancreatectomies to hospitals that perform ≥20 per year. Our purpose was to identify those factors that characterize patients at risk for loss of access to pancreatic cancer care with enforcement of volume standards. Using the Healthcare Cost and Utilization Project State Inpatient Database from Florida, we identified patients who underwent pancreatectomy for pancreatic malignancy from 2007-2011. American Hospital Association and United States Census Bureau data were linked to patient-level data. High-volume hospitals were defined as performing ≥20 pancreatic resections per year. Univariable and multivariable statistics compared patient characteristics and utilization of high-volume hospitals. Classification and Regression Tree modeling was used to predict patients at risk for losing access to care. Our study included 1,663 patients. Five high-volume hospitals were identified, and they treated 1,056 (63.5%) patients. Patients residing far from high-volume hospitals, in areas with the highest population density, non-Caucasian ethnicity, and greater income had decreased odds of obtaining care at high-volume hospitals. Using these factors, we developed a Classification and Regression Tree-based predictive tool to identify these patients. Implementation of "Take the Volume Pledge" is an important step toward improving pancreatectomy outcomes; however, policymakers must consider the potential impact on limiting access and possible health disparities that may arise. Copyright © 2016 Elsevier Inc. All rights reserved.
Chen, Jun-Yang; Lau, Yong-Chang; Coey, J. M. D.; Li, Mo; Wang, Jian-Ping
2017-01-01
The magnetic tunnel junction (MTJ) using MgO barrier is one of most important building blocks for spintronic devices and has been widely utilized as miniaturized magentic sensors. It could play an important role in wearable medical devices if they can be fabricated on flexible substrates. The required stringent fabrication processes to obtain high quality MgO-barrier MTJs, however, limit its integration with flexible electronics devices. In this work, we have developed a method to fabricate high-performance MgO-barrier MTJs directly onto ultrathin flexible silicon membrane with a thickness of 14 μm and then transfer-and-bond to plastic substrates. Remarkably, such flexible MTJs are fully functional, exhibiting a TMR ratio as high as 190% under bending radii as small as 5 mm. The devices‘ robustness is manifested by its retained excellent performance and unaltered TMR ratio after over 1000 bending cycles. The demonstrated flexible MgO-barrier MTJs opens the door to integrating high-performance spintronic devices in flexible and wearable electronics devices for a plethora of biomedical sensing applications. PMID:28150807
Chen, Jun-Yang; Lau, Yong-Chang; Coey, J M D; Li, Mo; Wang, Jian-Ping
2017-02-02
The magnetic tunnel junction (MTJ) using MgO barrier is one of most important building blocks for spintronic devices and has been widely utilized as miniaturized magentic sensors. It could play an important role in wearable medical devices if they can be fabricated on flexible substrates. The required stringent fabrication processes to obtain high quality MgO-barrier MTJs, however, limit its integration with flexible electronics devices. In this work, we have developed a method to fabricate high-performance MgO-barrier MTJs directly onto ultrathin flexible silicon membrane with a thickness of 14 μm and then transfer-and-bond to plastic substrates. Remarkably, such flexible MTJs are fully functional, exhibiting a TMR ratio as high as 190% under bending radii as small as 5 mm. The devices' robustness is manifested by its retained excellent performance and unaltered TMR ratio after over 1000 bending cycles. The demonstrated flexible MgO-barrier MTJs opens the door to integrating high-performance spintronic devices in flexible and wearable electronics devices for a plethora of biomedical sensing applications.
Fang, Wei; Ni, Zhaohui; Qian, Jiaqi
2014-01-01
The proportion of end-stage renal disease (ESRD) patients on peritoneal dialysis (PD) has increased very fast in China over the last decade. Renji Hospital, affiliated with Shanghai Jiaotong University School of Medicine, is a recognized high-quality PD unit with a high PD utilization rate, excellent patient and technique survival (1-year and 5-year patient survival rate of 93% and 71%, and 1-year and 5-year technique survival of 96% and 82%, respectively), low peritonitis rate and a well-documented good quality of life of the treated patients. We believe that a dedicated and experienced PD team, a structured patient training program, continuous patient support, establishing and utilizing standardized protocols, starting PD with low dialysis dose, monitoring key performance indicators (KPIs), and continuous quality improvement (CQI) are the key factors underlying this successful PD program. PMID:24962961
Lee, Jin Hong; Lee, Albert S; Lee, Jong-Chan; Hong, Soon Man; Hwang, Seung Sang; Koo, Chong Min
2017-02-01
A new methodology for fabrication of inorganic-organic hybrid ionogels and scaffolds is developed through facile cross-linking and solution extraction of a newly developed ionic polyhedral oligomeric silsesquioxane with inorganic core. Through design of various cationic tertiary amines, as well as cross-linkable functional groups on each arm of the inorganic core, high-performance ionogels are fabricated with excellent electrochemical stability and unique ion conduction behavior, giving superior lithium ion battery performance. Moreover, through solvent extraction of the liquid components, hybrid scaffolds with well-defined, interconnected mesopores are utilized as heterogeneous catalysts for the CO 2 -catalyzed cycloaddition of epoxides. Excellent catalytic performance, as well as highly efficient recyclability are observed when compared to other previous literature materials.
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 novel way to upgrade the coarse part of a high calcium fly ash for reuse into cement systems.
Antiohos, S K; Tsimas, S
2007-01-01
Reject fly ash (rFA) represents a significant portion of the fly ashes produced from coal-fired power plants. Due to the high carbon content and large particle mean diameter, rFA is not utilized in the construction sector (for example, as supplementary cementing material) and is currently dumped into landfills, thus representing an additional environmental burden. Recently, the feasibility of using rFA in a relatively small number of applications, like solidification/stabilization of other wastes, has been investigated by different researchers. However, as the overall amount of fly ash utilized in such applications is still limited, there is a need to investigate other possibilities for rFA utilization starting from a deeper understanding of its properties. In the work presented herein, mechanical and hydration properties of cementitious materials prepared by blending the coarse fraction of a lignite high-calcium fly ash with ordinary cement were monitored and compared with the respective ones of a good quality fly ash-cement mixture. The results of this work reveal that a relatively cheap, bilateral classification-grinding method is able to promote the pozzolanic behavior of the rFAs, so that the overall performances of rFA containing cements are drastically improved. The evaluation of these results supports the belief that appropriate utilization of non-standardized materials may lead to new environmental-friendly products of superior quality.
Feasibility and clinical utility of ultra-widefield indocyanine green angiography.
Klufas, Michael A; Yannuzzi, Nicolas A; Pang, Claudine E; Srinivas, Sowmya; Sadda, Srinivas R; Freund, K Bailey; Kiss, Szilárd
2015-03-01
To evaluate the feasibility and clinical utility of a novel noncontact scanning laser ophthalmoscope-based ultra-widefield indocyanine green angiographic system. Ultra-widefield indocyanine green angiographic images were captured using a modified Optos P200Tx that produced high-resolution images of the choroidal vasculature with up to a 200° field. Ultra-widefield indocyanine green angiography was performed on patients with a variety of retinal conditions to assess utility of this imaging technique for diagnostic purposes and disease treatment monitoring. Ultra-widefield indocyanine green angiography was performed on 138 eyes of 69 patients. Mean age was 58 ± 16.9 years (range, 24-85 years). The most common ocular pathologies imaged included central serous chorioretinopathy (24 eyes), uveitis (various subtypes, 16 eyes), age-related macular degeneration (12 eyes), and polypoidal choroidal vasculopathy (4 eyes). In all eyes evaluated with ultra-widefield indocyanine green angiography, high-resolution images of choroidal and retinal circulation were obtained with sufficient detail out to 200° of the fundus. In this series of 138 eyes, scanning laser ophthalmoscope-based ultra-widefield indocyanine green angiography was clinically practical and provided detailed images of both the central and peripheral choroidal circulation. Future studies are needed to refine the clinical value of this imaging modality and the significance of peripheral choroidal vascular changes in the diagnosis, monitoring, and treatment of ocular diseases.
Moisture and Structural Analysis for High Performance Hybrid Wall Assemblies
DOE Office of Scientific and Technical Information (OSTI.GOV)
Grin, A.; Lstiburek, J.
2012-09-01
Based on past experience in the Building America program, BSC has found that combinations of materials and approaches—in other words, systems—usually provide optimum performance. Integration is necessary, as described in this research project. The hybrid walls analyzed utilize a combination of exterior insulation, diagonal metal strapping, and spray polyurethane foam and leave room for cavity-fill insulation. These systems can provide effective thermal, air, moisture, and water barrier systems in one assembly and provide structure.
Maximum likelihood convolutional decoding (MCD) performance due to system losses
NASA Technical Reports Server (NTRS)
Webster, L.
1976-01-01
A model for predicting the computational performance of a maximum likelihood convolutional decoder (MCD) operating in a noisy carrier reference environment is described. This model is used to develop a subroutine that will be utilized by the Telemetry Analysis Program to compute the MCD bit error rate. When this computational model is averaged over noisy reference phase errors using a high-rate interpolation scheme, the results are found to agree quite favorably with experimental measurements.
Unified, Cross-Platform, Open-Source Library Package for High-Performance Computing
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kozacik, Stephen
Compute power is continually increasing, but this increased performance is largely found in sophisticated computing devices and supercomputer resources that are difficult to use, resulting in under-utilization. We developed a unified set of programming tools that will allow users to take full advantage of the new technology by allowing them to work at a level abstracted away from the platform specifics, encouraging the use of modern computing systems, including government-funded supercomputer facilities.
Pneumatic Muscle Actuated Equipment for Continuous Passive Motion
NASA Astrophysics Data System (ADS)
Deaconescu, Tudor T.; Deaconescu, Andrea I.
2009-10-01
Applying continuous passive rehabilitation movements as part of the recovery programme of patients with post-traumatic disabilities of the bearing joints of the inferior limbs requires the development of new high performance equipment. This chapter discusses a study of the kinematics and performance of such a new, continuous passive motion based rehabilitation system actuated by pneumatic muscles. The utilized energy source is compressed air ensuring complete absorption of the end of stroke shocks, thus minimizing user discomfort.
NASA Astrophysics Data System (ADS)
Fotin, Sergei V.; Yin, Yin; Haldankar, Hrishikesh; Hoffmeister, Jeffrey W.; Periaswamy, Senthil
2016-03-01
Computer-aided detection (CAD) has been used in screening mammography for many years and is likely to be utilized for digital breast tomosynthesis (DBT). Higher detection performance is desirable as it may have an impact on radiologist's decisions and clinical outcomes. Recently the algorithms based on deep convolutional architectures have been shown to achieve state of the art performance in object classification and detection. Similarly, we trained a deep convolutional neural network directly on patches sampled from two-dimensional mammography and reconstructed DBT volumes and compared its performance to a conventional CAD algorithm that is based on computation and classification of hand-engineered features. The detection performance was evaluated on the independent test set of 344 DBT reconstructions (GE SenoClaire 3D, iterative reconstruction algorithm) containing 328 suspicious and 115 malignant soft tissue densities including masses and architectural distortions. Detection sensitivity was measured on a region of interest (ROI) basis at the rate of five detection marks per volume. Moving from conventional to deep learning approach resulted in increase of ROI sensitivity from 0:832 +/- 0:040 to 0:893 +/- 0:033 for suspicious ROIs; and from 0:852 +/- 0:065 to 0:930 +/- 0:046 for malignant ROIs. These results indicate the high utility of deep feature learning in the analysis of DBT data and high potential of the method for broader medical image analysis tasks.
Utilizing Fission Technology to Enable Rapid and Affordable Access to any Point in the Solar System
NASA Technical Reports Server (NTRS)
Houts, Mike; Bonometti, Joe; Morton, Jeff; Hrbud, Ivana; Bitteker, Leo; VanDyke, Melissa; Godfroy, T.; Pedersen, K.; Dobson, C.; Patton, B.;
2000-01-01
Fission technology can enable rapid, affordable access to any point in the solar system. Potential fission-based transportation options include bimodal nuclear thermal rockets, high specific energy propulsion systems, and pulsed fission propulsion systems. In-space propellant re-supply enhances the effective performance of all systems, but requires significant infrastructure development. Safe, timely, affordable utilization of first-generation space fission propulsion systems will enable the development of more advanced systems. First generation systems can build on over 45 years of US and international space fission system technology development to minimize cost.
NASA Technical Reports Server (NTRS)
1973-01-01
A technology utilization program is presented for the dissemination of information on technological developments which have potential utility outside the aerospace and nuclear communities. Discussion is restricted to the effects of hydrogen on a variety of metal alloys, and the mechanical properties of some recently developed alloys. Hydrogen at both low and high pressure is shown to have adverse effects on alloys such as ultrahigh-strength steels, irradiated steels, columbium, inconel alloys, titanium alloys, and certain stainless steels. The mechanical and physical properties of a wide range of alloys, their performance at elevated temperatures, and some of the processes involved in their development are also considered.
Conceptual design of closed Brayton cycle for coal-fired power generation
NASA Technical Reports Server (NTRS)
Shah, R. P.; Corman, J. C.
1977-01-01
The objectives to be realized in developing a closed cycle gas turbine are (1) to exploit high temperature gas turbine technology while maintaining a working fluid which is free from combustion gas contamination, (2) to achieve compact turbo-equipment designs through pressurization of the working fluid, and (3) to obtain relatively simple cycle configurations. The technical/economic performance of a specific closed cycle gas turbine system was evaluated through the development of a conceptual plant and system design. This energy conversion system is designed for electric utility service and to utilize coal directly in an environmentally acceptable manner.
Recent results and new hardware developments for protein crystal growth in microactivity
NASA Technical Reports Server (NTRS)
Delucas, L. J.; Long, M. M.; Moore, K. M.; Smith, C.; Carson, M.; Narayana, S. V. L.; Carter, D.; Clark, A. D., Jr.; Nanni, R. G.; Ding, J.
1993-01-01
Protein crystal growth experiments have been performed on 16 space shuttle missions since April, 1985. The initial experiments utilized vapor diffusion crystallization techniques similar to those used in laboratories for earth-based experiments. More recent experiments have utilized temperature induced crystallization as an alternative method for growing high quality protein crystals in microgravity. Results from both vapor diffusion and temperature induced crystallization experiments indicate that proteins grown in microgravity may be larger, display more uniform morphologies, and yield diffraction data to significantly higher resolutions than the best crystals of these proteins grown on earth.
Aluminum-stabilized Nb/sub 3/Sn superconductor
Scanlan, R.M.
1984-02-10
This patent discloses an aluminum-stabilized Nb/sub 3/Sn superconductor and process for producing same, utilizing ultrapure aluminum. Ductile components are co-drawn with aluminum to produce a conductor suitable for winding magnets. After winding, the conductor is heated to convert it to the brittle Nb/sub 3/Sn superconductor phase, using a temperature high enough to perform the transformation but still below the melting point of the aluminum. This results in reaction of substantially all of the niobium, while providing stabilization and react-in-place features which are beneficial in the fabrication of magnets utilizing superconducting materials.
Aluminum-stabilized Nb[sub 3]Sn superconductor
Scanlan, R.M.
1988-05-10
Disclosed are an aluminum-stabilized Nb[sub 3]Sn superconductor and process for producing same, utilizing ultrapure aluminum. Ductile components are co-drawn with aluminum to produce a conductor suitable for winding magnets. After winding, the conductor is heated to convert it to the brittle Nb[sub 3]Sn superconductor phase, using a temperature high enough to perform the transformation but still below the melting point of the aluminum. This results in reaction of substantially all of the niobium, while providing stabilization and react-in-place features which are beneficial in the fabrication of magnets utilizing superconducting materials. 4 figs.
NASA Astrophysics Data System (ADS)
Wisniewski, Charles F.; Hewett, Kevin B.; Manke, Gerald C., II; Randall Truman, C.; Hager, Gordon D.
2003-03-01
Experimental techniques have been developed to directly measure the concentration of fluorine atoms, the gain length and the small signal gain in a hydrogen fluoride 5 cm slit nozzle laser. A gas phase titration technique was utilized to measure the fluorine atom concentration using HCl as the titrant. The gain length was measured using a pitot probe to locate the interface of the primary flow with the high Mach number shroud flows. A tunable diode laser was utilized to perform small signal gain measurements on HF overtone ( ν=2→0) transitions.
ADAMS executive and operating system
NASA Technical Reports Server (NTRS)
Pittman, W. D.
1981-01-01
The ADAMS Executive and Operating System, a multitasking environment under which a variety of data reduction, display and utility programs are executed, a system which provides a high level of isolation between programs allowing them to be developed and modified independently, is described. The Airborne Data Analysis/Monitor System (ADAMS) was developed to provide a real time data monitoring and analysis capability onboard Boeing commercial airplanes during flight testing. It inputs sensor data from an airplane performance data by applying transforms to the collected sensor data, and presents this data to test personnel via various display media. Current utilization and future development are addressed.
NASA Astrophysics Data System (ADS)
McBride, William R.; McBride, Daniel R.
2016-08-01
The Daniel K. Inouye Solar Telescope (DKIST) will be the largest solar telescope in the world, with a 4-meter off-axis primary mirror and 16 meter rotating Coudé laboratory within the telescope pier. The off-axis design requires a mount similar to an 8-meter on-axis telescope. Both the telescope mount and the Coudé laboratory utilize a roller bearing technology in place of the more commonly used hydrostatic bearings. The telescope enclosure utilizes a crawler mechanism for the altitude axis. As these mechanisms have not previously been used in a telescope, understanding the vibration characteristics and the potential impact on the telescope image is important. This paper presents the methodology used to perform jitter measurements of the enclosure and the mount bearings and servo system in a high-noise environment utilizing seismic accelerometers and high dynamic-range data acquisition equipment, along with digital signal processing (DSP) techniques. Data acquisition and signal processing were implemented in MATLAB. In the factory acceptance testing of the telescope mount, multiple accelerometers were strategically located to capture the six axes-of-motion of the primary and secondary mirror dummies. The optical sensitivity analysis was used to map these mirror mount displacements and rotations into units of image motion on the focal plane. Similarly, tests were done with the Coudé rotator, treating the entire rotating instrument lab as a rigid body. Testing was performed by recording accelerometer data while the telescope control system performed tracking operations typical of various observing scenarios. The analysis of the accelerometer data utilized noise-averaging fast Fourier transform (FFT) routines, spectrograms, and periodograms. To achieve adequate dynamic range at frequencies as low as 3Hz, the use of special filters and advanced windowing functions were necessary. Numerous identical automated tests were compared to identify and select the data sets with the lowest level of external interference. Similar testing was performed on the telescope enclosure during the factory test campaign. The vibration of the enclosure altitude and azimuth mechanisms were characterized. This paper details jitter tests using accelerometers placed in locations that allowed the motion of the assemblies to be measured while the control system performed various moves typical of on-sky observations. The measurements were converted into the rigid body motion of the structures and mapped into image motion using the telescope's optical sensitivity analysis.
Can We Train Machine Learning Methods to Outperform the High-dimensional Propensity Score Algorithm?
Karim, Mohammad Ehsanul; Pang, Menglan; Platt, Robert W
2018-03-01
The use of retrospective health care claims datasets is frequently criticized for the lack of complete information on potential confounders. Utilizing patient's health status-related information from claims datasets as surrogates or proxies for mismeasured and unobserved confounders, the high-dimensional propensity score algorithm enables us to reduce bias. Using a previously published cohort study of postmyocardial infarction statin use (1998-2012), we compare the performance of the algorithm with a number of popular machine learning approaches for confounder selection in high-dimensional covariate spaces: random forest, least absolute shrinkage and selection operator, and elastic net. Our results suggest that, when the data analysis is done with epidemiologic principles in mind, machine learning methods perform as well as the high-dimensional propensity score algorithm. Using a plasmode framework that mimicked the empirical data, we also showed that a hybrid of machine learning and high-dimensional propensity score algorithms generally perform slightly better than both in terms of mean squared error, when a bias-based analysis is used.
Locketz, Garrett D; Lui, Justin T; Chan, Sonny; Salisbury, Kenneth; Dort, Joseph C; Youngblood, Patricia; Blevins, Nikolas H
2017-06-01
Objective To evaluate the effect of anatomy-specific virtual reality (VR) surgical rehearsal on surgeon confidence and temporal bone dissection performance. Study Design Prospective pre- and poststudy of a novel virtual surgical rehearsal platform. Setting Academic otolaryngology-head and neck surgery residency training programs. Subjects and Methods Sixteen otolaryngology-head and neck surgery residents from 2 North American training institutions were recruited. Surveys were administered to assess subjects' baseline confidence in performing 12 subtasks of cortical mastoidectomy with facial recess. A cadaver temporal bone was randomly assigned to each subject. Cadaver specimens were scanned with a clinical computed tomography protocol, allowing the creation of anatomy-specific models for use in a VR surgical rehearsal platform. Subjects then rehearsed a virtual mastoidectomy on data sets derived from their specimens. Surgical confidence surveys were administered again. Subjects then dissected assigned cadaver specimens, which were blindly graded with a modified Welling scale. A final survey assessed the perceived utility of rehearsal on dissection performance. Results Of 16 subjects, 14 (87.5%) reported a significant increase in overall confidence after conducting an anatomy-specific VR rehearsal. A significant correlation existed between perceived utility of rehearsal and confidence improvement. The effect of rehearsal on confidence was dependent on trainee experience and the inherent difficulty of the surgical subtask. Postrehearsal confidence correlated strongly with graded dissection performance. Subjects rated anatomy-specific rehearsal as having a moderate to high contribution to their dissection performance. Conclusion Anatomy-specific virtual rehearsal improves surgeon confidence in performing mastoid dissection, dependent on surgeon experience and task difficulty. The subjective confidence gained through rehearsal correlates positively with subsequent objective dissection performance.
Test sensitivity is important for detecting variability in pointing comprehension in canines.
Pongrácz, Péter; Gácsi, Márta; Hegedüs, Dorottya; Péter, András; Miklósi, Adám
2013-09-01
Several articles have been recently published on dogs' (Canis familiaris) performance in two-way object choice experiments in which subjects had to find hidden food by utilizing human pointing. The interpretation of results has led to a vivid theoretical debate about the cognitive background of human gestural signal understanding in dogs, despite the fact that many important details of the testing method have not yet been standardized. We report three experiments that aim to reveal how some procedural differences influence adult companion dogs' performance in these tests. Utilizing a large sample in Experiment 1, we provide evidence that neither the keeping conditions (garden/house) nor the location of the testing (outdoor/indoor) affect a dogs' performance. In Experiment 2, we compare dogs' performance using three different types of pointing gestures. Dogs' performance varied between momentary distal and momentary cross-pointing but "low" and "high" performer dogs chose uniformly better than chance level if they responded to sustained pointing gestures with reinforcement (food reward and a clicking sound; "clicker pointing"). In Experiment 3, we show that single features of the aforementioned "clicker pointing" method can slightly improve dogs' success rate if they were added one by one to the momentary distal pointing method. These results provide evidence that although companion dogs show a robust performance at different testing locations regardless of their keeping conditions, the exact execution of the human gesture and additional reinforcement techniques have substantial effect on the outcomes. Consequently, researchers should standardize their methodology before engaging in debates on the comparative aspects of socio-cognitive skills because the procedures they utilize may differ in sensitivity for detecting differences.
Model based adaptive control of a continuous capture process for monoclonal antibodies production.
Steinebach, Fabian; Angarita, Monica; Karst, Daniel J; Müller-Späth, Thomas; Morbidelli, Massimo
2016-04-29
A two-column capture process for continuous processing of cell-culture supernatant is presented. Similar to other multicolumn processes, this process uses sequential countercurrent loading of the target compound in order maximize resin utilization and productivity for a given product yield. The process was designed using a novel mechanistic model for affinity capture, which takes both specific adsorption as well as transport through the resin beads into account. Simulations as well as experimental results for the capture of an IgG antibody are discussed. The model was able to predict the process performance in terms of yield, productivity and capacity utilization. Compared to continuous capture with two columns operated batch wise in parallel, a 2.5-fold higher capacity utilization was obtained for the same productivity and yield. This results in an equal improvement in product concentration and reduction of buffer consumption. The developed model was used not only for the process design and optimization but also for its online control. In particular, the unit operating conditions are changed in order to maintain high product yield while optimizing the process performance in terms of capacity utilization and buffer consumption also in the presence of changing upstream conditions and resin aging. Copyright © 2016 Elsevier B.V. All rights reserved.
Saeedi, Ramyar; Purath, Janet; Venkatasubramanian, Krishna; Ghasemzadeh, Hassan
2014-01-01
Mobile wearable sensors have demonstrated great potential in a broad range of applications in healthcare and wellness. These technologies are known for their potential to revolutionize the way next generation medical services are supplied and consumed by providing more effective interventions, improving health outcomes, and substantially reducing healthcare costs. Despite these potentials, utilization of these sensor devices is currently limited to lab settings and in highly controlled clinical trials. A major obstacle in widespread utilization of these systems is that the sensors need to be used in predefined locations on the body in order to provide accurate outcomes such as type of physical activity performed by the user. This has reduced users' willingness to utilize such technologies. In this paper, we propose a novel signal processing approach that leverages feature selection algorithms for accurate and automatic localization of wearable sensors. Our results based on real data collected using wearable motion sensors demonstrate that the proposed approach can perform sensor localization with 98.4% accuracy which is 30.7% more accurate than an approach without a feature selection mechanism. Furthermore, utilizing our node localization algorithm aids the activity recognition algorithm to achieve 98.8% accuracy (an increase from 33.6% for the system without node localization).
NASA Astrophysics Data System (ADS)
Tambara, Lucas Antunes; Tonfat, Jorge; Santos, André; Kastensmidt, Fernanda Lima; Medina, Nilberto H.; Added, Nemitala; Aguiar, Vitor A. P.; Aguirre, Fernando; Silveira, Marcilei A. G.
2017-02-01
The increasing system complexity of FPGA-based hardware designs and shortening of time-to-market have motivated the adoption of new designing methodologies focused on addressing the current need for high-performance circuits. High-Level Synthesis (HLS) tools can generate Register Transfer Level (RTL) designs from high-level software programming languages. These tools have evolved significantly in recent years, providing optimized RTL designs, which can serve the needs of safety-critical applications that require both high performance and high reliability levels. However, a reliability evaluation of HLS-based designs under soft errors has not yet been presented. In this work, the trade-offs of different HLS-based designs in terms of reliability, resource utilization, and performance are investigated by analyzing their behavior under soft errors and comparing them to a standard processor-based implementation in an SRAM-based FPGA. Results obtained from fault injection campaigns and radiation experiments show that it is possible to increase the performance of a processor-based system up to 5,000 times by changing its architecture with a small impact in the cross section (increasing up to 8 times), and still increasing the Mean Workload Between Failures (MWBF) of the system.
Zhao, Wenchao; Ye, Long; Zhang, Shaoqing; Fan, Bin; Sun, Mingliang; Hou, Jianhui
2014-01-01
Interfacial buffer layers often attribute the improved device performance in organic optoelectronic device. Herein, a water-soluble hydrochloric acid doped polyanilines (HAPAN) were utilized as p-type electrode buffer layer in highly efficient polymer solar cells (PSC) based on PBDTTT-EFT and several representative polymers. The PBDTTT-EFT-based conventional PSC featuring ultrathin HAPAN (1.3 nm) delivered high PCE approximately 9%, which is one of the highest values among conventional PSC devices. Moreover, ultrathin HAPAN also exhibited wide applicability in a variety of efficient photovoltaic polymers including PBDTTT-C-T, PTB7, PBDTBDD, PBTTDPP-T, PDPP3T and P3HT. The excellent performances were originated from the high transparency, small film roughness and suitable work function. PMID:25300365
Multidisciplinary Shape Optimization of a Composite Blended Wing Body Aircraft
NASA Astrophysics Data System (ADS)
Boozer, Charles Maxwell
A multidisciplinary shape optimization tool coupling aerodynamics, structure, and performance was developed for battery powered aircraft. Utilizing high-fidelity computational fluid dynamics analysis tools and a structural wing weight tool, coupled based on the multidisciplinary feasible optimization architecture; aircraft geometry is modified in the optimization of the aircraft's range or endurance. The developed tool is applied to three geometries: a hybrid blended wing body, delta wing UAS, the ONERA M6 wing, and a modified ONERA M6 wing. First, the optimization problem is presented with the objective function, constraints, and design vector. Next, the tool's architecture and the analysis tools that are utilized are described. Finally, various optimizations are described and their results analyzed for all test subjects. Results show that less computationally expensive inviscid optimizations yield positive performance improvements using planform, airfoil, and three-dimensional degrees of freedom. From the results obtained through a series of optimizations, it is concluded that the newly developed tool is both effective at improving performance and serves as a platform ready to receive additional performance modules, further improving its computational design support potential.
Finite element analysis as a design tool for thermoplastic vulcanizate glazing seals
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gase, K.M.; Hudacek, L.L.; Pesevski, G.T.
1998-12-31
There are three materials that are commonly used in commercial glazing seals: EPDM, silicone and thermoplastic vulcanizates (TPVs). TPVs are a high performance class of thermoplastic elastomers (TPEs), where TPEs have elastomeric properties with thermoplastic processability. TPVs have emerged as materials well suited for use in glazing seals due to ease of processing, economics and part design flexibility. The part design and development process is critical to ensure that the chosen TPV provides economics, quality and function in demanding environments. In the design and development process, there is great value in utilizing dual durometer systems to capitalize on the benefitsmore » of soft and rigid materials. Computer-aided design tools, such as Finite Element Analysis (FEA), are effective in minimizing development time and predicting system performance. Examples of TPV glazing seals will illustrate the benefits of utilizing FEA to take full advantage of the material characteristics, which results in functional performance and quality while reducing development iterations. FEA will be performed on two glazing seal profiles to confirm optimum geometry.« less
Cycle Trades for Nuclear Thermal Rocket Propulsion Systems
NASA Technical Reports Server (NTRS)
White, C.; Guidos, M.; Greene, W.
2003-01-01
Nuclear fission has been used as a reliable source for utility power in the United States for decades. Even in the 1940's, long before the United States had a viable space program, the theoretical benefits of nuclear power as applied to space travel were being explored. These benefits include long-life operation and high performance, particularly in the form of vehicle power density, enabling longer-lasting space missions. The configurations for nuclear rocket systems and chemical rocket systems are similar except that a nuclear rocket utilizes a fission reactor as its heat source. This thermal energy can be utilized directly to heat propellants that are then accelerated through a nozzle to generate thrust or it can be used as part of an electricity generation system. The former approach is Nuclear Thermal Propulsion (NTP) and the latter is Nuclear Electric Propulsion (NEP), which is then used to power thruster technologies such as ion thrusters. This paper will explore a number of indirect-NTP engine cycle configurations using assumed performance constraints and requirements, discuss the advantages and disadvantages of each cycle configuration, and present preliminary performance and size results. This paper is intended to lay the groundwork for future efforts in the development of a practical NTP system or a combined NTP/NEP hybrid system.
Novel Miscanthus Germplasm-Based Value Chains: A Life Cycle Assessment
Wagner, Moritz; Kiesel, Andreas; Hastings, Astley; Iqbal, Yasir; Lewandowski, Iris
2017-01-01
In recent years, considerable progress has been made in miscanthus research: improvement of management practices, breeding of new genotypes, especially for marginal conditions, and development of novel utilization options. The purpose of the current study was a holistic analysis of the environmental performance of such novel miscanthus-based value chains. In addition, the relevance of the analyzed environmental impact categories was assessed. A Life Cycle Assessment was conducted to analyse the environmental performance of the miscanthus-based value chains in 18 impact categories. In order to include the substitution of a reference product, a system expansion approach was used. In addition, a normalization step was applied. This allowed the relevance of these impact categories to be evaluated for each utilization pathway. The miscanthus was cultivated on six sites in Europe (Aberystwyth, Adana, Moscow, Potash, Stuttgart and Wageningen) and the biomass was utilized in the following six pathways: (1) small-scale combustion (heat)—chips; (2) small-scale combustion (heat)—pellets; (3) large-scale combustion (CHP)—biomass baled for transport and storage; (4) large-scale combustion (CHP)—pellets; (5) medium-scale biogas plant—ensiled miscanthus biomass; and (6) large-scale production of insulation material. Thus, in total, the environmental performance of 36 site × pathway combinations was assessed. The comparatively high normalized results of human toxicity, marine, and freshwater ecotoxicity, and freshwater eutrophication indicate the relevance of these impact categories in the assessment of miscanthus-based value chains. Differences between the six sites can almost entirely be attributed to variations in biomass yield. However, the environmental performance of the utilization pathways analyzed varied widely. The largest differences were shown for freshwater and marine ecotoxicity, and freshwater eutrophication. The production of insulation material had the lowest impact on the environment, with net benefits in all impact categories expect three (marine eutrophication, human toxicity, agricultural land occupation). This performance can be explained by the multiple use of the biomass, first as material and subsequently as an energy carrier, and by the substitution of an emission-intensive reference product. The results of this study emphasize the importance of assessing all environmental impacts when selecting appropriate utilization pathways. PMID:28642784
DOE Office of Scientific and Technical Information (OSTI.GOV)
Senthil, K.; Mitra, S.; Sandeep, S., E-mail: sentilk@barc.gov.in
In a multi-gigawatt pulsed power system like KALI-30 GW, insulation coordination is required to achieve high voltages ranging from 0.3 MV to 1 MV. At the same time optimisation of the insulation parameters is required to minimize the inductance of the system, so that nanoseconds output can be achieved. The KALI-30GW pulse power system utilizes a combination of Perspex, delrin, epoxy, transformer oil, nitrogen/SF{sub 6} gas and vacuum insulation at its various stages in compressing DC high voltage to a nanoseconds pulse. This paper describes the operation and performance of the system from 400 kV to 1030 kV output voltagemore » pulse and insulation parameters utilized for obtaining peak 1 MV output. (author)« less
NASA Technical Reports Server (NTRS)
Houts, Michael G.
2012-01-01
Fission power and propulsion systems can enable exciting space exploration missions. These include bases on the moon and Mars; and the exploration, development, and utilization of the solar system. In the near-term, fission surface power systems could provide abundant, constant, cost-effective power anywhere on the surface of the Moon or Mars, independent of available sunlight. Affordable access to Mars, the asteroid belt, or other destinations could be provided by nuclear thermal rockets. In the further term, high performance fission power supplies could enable both extremely high power levels on planetary surfaces and fission electric propulsion vehicles for rapid, efficient cargo and crew transfer. Advanced fission propulsion systems could eventually allow routine access to the entire solar system. Fission systems could also enable the utilization of resources within the solar system.
Development of Nonlinear Flight Mechanical Model of High Aspect Ratio Light Utility Aircraft
NASA Astrophysics Data System (ADS)
Bahri, S.; Sasongko, R. A.
2018-04-01
The implementation of Flight Control Law (FCL) for Aircraft Electronic Flight Control System (EFCS) aims to reduce pilot workload, while can also enhance the control performance during missions that require long endurance flight and high accuracy maneuver. In the development of FCL, a quantitative representation of the aircraft dynamics is needed for describing the aircraft dynamics characteristic and for becoming the basis of the FCL design. Hence, a 6 Degree of Freedom nonlinear model of a light utility aircraft dynamics, also called the nonlinear Flight Mechanical Model (FMM), is constructed. This paper shows the construction of FMM from mathematical formulation, the architecture design of FMM, the trimming process and simulations. The verification of FMM is done by analysis of aircraft behaviour in selected trimmed conditions.
One-step sub-10 μm patterning of carbon-nanotube thin films for transparent conductor applications.
Fukaya, Norihiro; Kim, Dong Young; Kishimoto, Shigeru; Noda, Suguru; Ohno, Yutaka
2014-04-22
We propose a technique for one-step micropatterning of as-grown carbon-nanotube films on a plastic substrate with sub-10 μm resolution on the basis of the dry transfer process. By utilizing this technique, we demonstrated the novel high-performance flexible carbon-nanotube transparent conductive film with a microgrid structure, which enabled improvement of the performance over the trade-off between the sheet resistance and transmittance of a conventional uniform carbon-nanotube film. The sheet resistance was reduced by 46% at its maximum by adding the microgrid, leading to a value of 53 Ω/sq at a transmittance of 80%. We also demonstrated easy fabrication of multitouch projected capacitive sensors with 12 × 12 electrodes. The technique is quite promising for energy-saving production of transparent conductor devices with 100% material utilization.
Container System Hardware Status Report
1986-01-01
includes the proureentofeight SL-7 class high - speed containerships and their Subsequent conversion to a cargo configuration specifically designed for...wide, 53.5-in high , 242-in long, and Weighs 4,000 lbs. The MILVAN chassis were competitively procured from incustry utilizing a performance military...accept load transfer from a cargo ship and equipped with a ramp for Roll On/Roll Off (RO/RO) discharge systems. The LAMP-H will :1replace the LARC-LX
Large laser projection displays utilizing all-solid-state RGB lasers
NASA Astrophysics Data System (ADS)
Xu, Zuyan; Bi, Yong
2005-01-01
RGB lasers projection displays have the advantages of producing large color triangle, high color saturation and high image resolution. In this report, with more than 4W white light synthesized by red (671nm), green (532nm) and blue (473nm) lasers, a RGB laser projection display system based on diode pumped solid-state lasers is developed and the performance of brilliant and vivid DVD dynamitic pictures on 60 inch screen is demonstrated.
DOE Zero Energy Ready Home Case Study: Greenhill Contracting, Inc., Hickory Ridge
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pacific Northwest National Laboratory
Greenhill Contracting built this 3,912-ft2 house in Gardiner, New York, to the high-performance criteria of the DOE Zero Energy Ready Home (ZERH) program. A highly efficient air-source heat pump heats and cools the home’s interior, while the roof-mounted photovoltaic system offsets electricity usage to cut energy bills to nearly zero. Many months the home owners see a credit on their utility bill.
An update of commercial infrared sensing and imaging instruments
NASA Technical Reports Server (NTRS)
Kaplan, Herbert
1989-01-01
A classification of infrared sensing instruments by type and application, listing commercially available instruments, from single point thermal probes to on-line control sensors, to high speed, high resolution imaging systems is given. A review of performance specifications follows, along with a discussion of typical thermographic display approaches utilized by various imager manufacturers. An update report on new instruments, new display techniques and newly introduced features of existing instruments is given.
MOD-0A 200 kW wind turbine generator design and analysis report
NASA Astrophysics Data System (ADS)
Anderson, T. S.; Bodenschatz, C. A.; Eggers, A. G.; Hughes, P. S.; Lampe, R. F.; Lipner, M. H.; Schornhorst, J. R.
1980-08-01
The design, analysis, and initial performance of the MOD-OA 200 kW wind turbine generator at Clayton, NM is documented. The MOD-OA was designed and built to obtain operation and performance data and experience in utility environments. The project requirements, approach, system description, design requirements, design, analysis, system tests, installation, safety considerations, failure modes and effects analysis, data acquisition, and initial performance for the wind turbine are discussed. The design and analysis of the rotor, drive train, nacelle equipment, yaw drive mechanism and brake, tower, foundation, electricl system, and control systems are presented. The rotor includes the blades, hub, and pitch change mechanism. The drive train includes the low speed shaft, speed increaser, high speed shaft, and rotor brake. The electrical system includes the generator, switchgear, transformer, and utility connection. The control systems are the blade pitch, yaw, and generator control, and the safety system. Manual, automatic, and remote control are discussed. Systems analyses on dynamic loads and fatigue are presented.
MOD-0A 200 kW wind turbine generator design and analysis report
NASA Technical Reports Server (NTRS)
Anderson, T. S.; Bodenschatz, C. A.; Eggers, A. G.; Hughes, P. S.; Lampe, R. F.; Lipner, M. H.; Schornhorst, J. R.
1980-01-01
The design, analysis, and initial performance of the MOD-OA 200 kW wind turbine generator at Clayton, NM is documented. The MOD-OA was designed and built to obtain operation and performance data and experience in utility environments. The project requirements, approach, system description, design requirements, design, analysis, system tests, installation, safety considerations, failure modes and effects analysis, data acquisition, and initial performance for the wind turbine are discussed. The design and analysis of the rotor, drive train, nacelle equipment, yaw drive mechanism and brake, tower, foundation, electricl system, and control systems are presented. The rotor includes the blades, hub, and pitch change mechanism. The drive train includes the low speed shaft, speed increaser, high speed shaft, and rotor brake. The electrical system includes the generator, switchgear, transformer, and utility connection. The control systems are the blade pitch, yaw, and generator control, and the safety system. Manual, automatic, and remote control are discussed. Systems analyses on dynamic loads and fatigue are presented.
Developing a scalable inert gas ion thruster
NASA Technical Reports Server (NTRS)
James, E.; Ramsey, W.; Steiner, G.
1982-01-01
Analytical studies to identify and then design a high performance scalable ion thruster operating with either argon or xenon for use in large space systems are presented. The magnetoelectrostatic containment concept is selected for its efficient ion generation capabilities. The iterative nature of the bounding magnetic fields allows the designer to scale both the diameter and length, so that the thruster can be adapted to spacecraft growth over time. Three different thruster assemblies (conical, hexagonal and hemispherical) are evaluated for a 12 cm diameter thruster and performance mapping of the various thruster configurations shows that conical discharge chambers produce the most efficient discharge operation, achieving argon efficiencies of 50-80% mass utilization at 240-310 eV/ion and xenon efficiencies of 60-97% at 240-280 eV/ion. Preliminary testing of the large 30 cm thruster, using argon propellant, indicates a 35% improvement over the 12 cm thruster in mass utilization efficiency. Since initial performance is found to be better than projected, a larger 50 cm thruster is already in the development stage.
USDA-ARS?s Scientific Manuscript database
High volume instrumentation (HVITM) and advanced fiber information system (AFIS) measurements are increasingly being utilized as primary and routine means of acquiring fiber quality data by cotton breeders and fiber processors. There is amount of information regarding fiber and yarn qualities, but l...
Airborne ultrasound applied to anthropometry--physical and technical principles.
Lindström, K; Mauritzson, L; Benoni, G; Willner, S
1983-01-01
Airborne ultrasound has been utilized for remote measurement of distance, direction, size, form, volume and velocity. General anthropometrical measurements are performed with a newly constructed real-time linear array scanner. To make full use of the method, we expect a rapid development of high-frequency ultrasound transducers for use in air.
ERIC Educational Resources Information Center
Xia, Saihua
2009-01-01
This paper investigates ESL learners' awareness of pragmatic skills utilizing an activity-theory driven approach to perform an inquiry task into problem-solving service call conversations (PSSCs) between native speakers (NS) and non-native speakers of English (NNSs). Eight high-intermediate ESL learners, from five different language backgrounds,…
This presentation will focus on validation testing performed on a three-lamp low-pressure high-output (LPHO) TrojanUVSwiftTM UV reactor using MS2, Bacillus Pumilus, and live adenovirus as the test microbes. An adjustable sensor was used to help determine the optimal sensor locati...
Effects of dehydration methods on characteristics of fibrous networks from un-tanned hides
USDA-ARS?s Scientific Manuscript database
To improve prospective markets and to secure a viable future for the hides and leather industries, it is important to develop new uses and novel biobased products from hides. We hypothesize collagen fiber networks derived from un-tanned hides can be utilized to prepare high performance green compos...
Effects of dehydration methods on the characteristics of fibrous networks from un-tanned hides
USDA-ARS?s Scientific Manuscript database
To improve prospective markets and to secure a viable future for the hides and leather industries, it is important to develop new uses and novel biobased products from hides. We hypothesize collagen fiber networks derived from un-tanned hides can be utilized to prepare high performance green compos...
Implementing Enrichment Clusters in Elementary Schools: Lessons Learned
ERIC Educational Resources Information Center
Fiddyment, Gail E.
2014-01-01
Enrichment clusters offer a way for schools to encourage a high level of learning as students and adults work together to develop a product, service, or performance by applying advanced knowledge and authentic processes to real-world problems. This study utilized a qualitative research design to examine the perceptions and experiences of two…
We used chromatography modeling software to assist in HPLC method development, with the goal
of enhancing separations through the exclusive use of gradient time and column temperature. We
surveyed nine stationary phases for their utility in pigment purification and natur...
Traditional developmental neurotoxicity tests performed in vivo are costly, time-consuming and utilize a large number of animals. In order to address these inefficiencies, in vitro models of neuronal development have been used in a first tier screening approach for developmenta...
Work Experience Employability Skills, Junior High.
ERIC Educational Resources Information Center
Mims, Murry; And Others
Educators have long recognized the need for schools to train students adequately for the world of work. This training includes both the necessary technical skills and employability skills. This document, the Employability Skills Guide, is Duval County Schools' part of such a plan to meet this need. The performance objectives utilized in this guide…
Application of Algebra Curriculum-Based Measurements for Decision Making in Middle and High School
ERIC Educational Resources Information Center
Johnson, Evelyn S.; Galow, Patricia A.; Allenger, Robert
2013-01-01
This article reports the results of a study examining the utility of curriculum-based measurement (CBM) in algebra for predicting performance on a state math assessment and informing instructional placement decisions for students in seventh, eighth, and tenth grades. Students completed six Basic Skills algebra probes across different time…
NASA Astrophysics Data System (ADS)
Barua, Shaswat; Chattopadhyay, Pronobesh; Phukan, Mayur M.; Konwar, Bolin K.; Karak, Niranjan
2014-12-01
Hyperbranched epoxy MWCNT-CuO-nystatin nanocomposite has been presented here as an advanced antimicrobial high performance material. The material showed significant improvement of mechanical properties (tensile strength from 38 to 63 MPa) over the pristine matrix without effecting elongation. MWCNT was modified by a non-ionic surfactant, triton X-100, wherein copper oxide nanoparticles were anchored in situ by a ‘green’ method. Further, sonochemical immobilization of nystatin enhanced the stability of the system. The immobilized nanohybrid system was incorporated into the hyperbranched matrix in 1, 2 and 3 wt%. The resultant system proved its ability to prevent bacterial, fungal and microalgal fouling against the tested strains, Staphylococcus aureus, Candida albicans and Chlorella sp. Additionally, this system is quite compatible with rat heart cells. Furthermore, in vivo assessment showed that this could be utilized as an implantable antimicrobial biomaterial. Thus, the overall study pointed out that the prepared material may have immense utility in marine industry as well as in biomedical domain to address microbial fouling, without inducing any toxicity to higher organisms.
NASA Astrophysics Data System (ADS)
Shaat, Musbah; Bader, Faouzi
2010-12-01
Cognitive Radio (CR) systems have been proposed to increase the spectrum utilization by opportunistically access the unused spectrum. Multicarrier communication systems are promising candidates for CR systems. Due to its high spectral efficiency, filter bank multicarrier (FBMC) can be considered as an alternative to conventional orthogonal frequency division multiplexing (OFDM) for transmission over the CR networks. This paper addresses the problem of resource allocation in multicarrier-based CR networks. The objective is to maximize the downlink capacity of the network under both total power and interference introduced to the primary users (PUs) constraints. The optimal solution has high computational complexity which makes it unsuitable for practical applications and hence a low complexity suboptimal solution is proposed. The proposed algorithm utilizes the spectrum holes in PUs bands as well as active PU bands. The performance of the proposed algorithm is investigated for OFDM and FBMC based CR systems. Simulation results illustrate that the proposed resource allocation algorithm with low computational complexity achieves near optimal performance and proves the efficiency of using FBMC in CR context.
Using immersive simulation for training first responders for mass casualty incidents.
Wilkerson, William; Avstreih, Dan; Gruppen, Larry; Beier, Klaus-Peter; Woolliscroft, James
2008-11-01
A descriptive study was performed to better understand the possible utility of immersive virtual reality simulation for training first responders in a mass casualty event. Utilizing a virtual reality cave automatic virtual environment (CAVE) and high-fidelity human patient simulator (HPS), a group of experts modeled a football stadium that experienced a terrorist explosion during a football game. Avatars (virtual patients) were developed by expert consensus that demonstrated a spectrum of injuries ranging from death to minor lacerations. A group of paramedics was assessed by observation for decisions made and action taken. A critical action checklist was created and used for direct observation and viewing videotaped recordings. Of the 12 participants, only 35.7% identified the type of incident they encountered. None identified a secondary device that was easily visible. All participants were enthusiastic about the simulation and provided valuable comments and insights. Learner feedback and expert performance review suggests that immersive training in a virtual environment has the potential to be a powerful tool to train first responders for high-acuity, low-frequency events, such as a terrorist attack.
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
Contribution of Nanostructures in High Performance Solar Cells
NASA Astrophysics Data System (ADS)
Aly, Abouelmaaty M.; Ebrahim, Essamudin A.; Sweelem, Emad
2017-11-01
Nanotechnology has great contributions in various fields, especially in solar energy conversion through solar cells (SCs). Nanostructured SCs can provide high performance with lower fabrication costs. The transition from fossil fuel energy to renewable sustainable energy represents a major technological challenge for the world. In the last years, the industry of SCs has grown rapidly due to strong attention in renewable energy in order to handle the problem of global climate change that is now believed to occur due to use of the fossil fuels. Cost is an influential factor in the eventual success of any solar technology, since inexpensive SCs are needed to produce electricity, especially for rural areas and for third world countries. Therefore, new developments in nanotechnology may open the door for the production of inexpensive and more efficient SCs by reducing the manufacturing costs of SCs. Utilizing nanotechnology in cheaper SCs will help maintain the environment. This article covers a review of the progress that has been made to-date to enhance efficiencies of various nanostructures used in SCs, including utilizations of all the wavelengths present in of the solar spectrum.
NASA Astrophysics Data System (ADS)
Jeon, Yukwon; Kim, Dong Jun; Koh, Jong Kwan; Ji, Yunseong; Kim, Jong Hak; Shul, Yong-Gun
2015-11-01
Polymer electrolyte membrane fuel cell is a promising zero-emission power generator for stationary/automotive applications. However, key issues, such as performance and costs, are still remained for an economical commercialization. Here, we fabricated a high-performance membrane electrode assembly (MEA) using an interfacial design based on well-arrayed micro-patterned membranes including circles, squares and hexagons with different sizes, which are produced by a facile elastomeric mold method. The best MEA performance is achieved using patterned Nafion membrane with a circle 2 μm in size, which exhibited a very high power density of 1906 mW/cm2 at 75 °C and Pt loading of 0.4 mg/cm2 with 73% improvement compared to the commercial membrane. The improved performance are attributed to the decreased MEA resistances and increased surface area for higher Pt utilization of over 80%. From these enhanced properties, it is possible to operate at lower Pt loading of 0.2 mg/cm2 with an outstanding performance of 1555 mW/cm2 and even at air/low humidity operations.
Client/Server data serving for high performance computing
NASA Technical Reports Server (NTRS)
Wood, Chris
1994-01-01
This paper will attempt to examine the industry requirements for shared network data storage and sustained high speed (10's to 100's to thousands of megabytes per second) network data serving via the NFS and FTP protocol suite. It will discuss the current structural and architectural impediments to achieving these sorts of data rates cost effectively today on many general purpose servers and will describe and architecture and resulting product family that addresses these problems. The sustained performance levels that were achieved in the lab will be shown as well as a discussion of early customer experiences utilizing both the HIPPI-IP and ATM OC3-IP network interfaces.
The Cardiovascular Physiology of Sports and Exercise.
Opondo, Mildred A; Sarma, Satyam; Levine, Benjamin D
2015-07-01
Athletes represent the extremes of human performance. Many of their remarkable abilities stem from a cardiovascular system that has adapted to meet the metabolic needs of exercising muscle. A large and compliant heart is a hallmark feature of athletes who engage in highly aerobic events. Despite high fitness levels, athletes may present with symptoms that limit performance. Understanding and dissecting these limitations requires a strong background in sports science and the factors that determine sports capabilities. This article reviews the basic principles of exercise physiology, cardiovascular adaptations unique to the "athlete's heart," and the utility of exercise testing in athletes. Copyright © 2015 Elsevier Inc. All rights reserved.
Kawooya, Michael G.; Pariyo, George; Malwadde, Elsie Kiguli; Byanyima, Rosemary; Kisembo, Harrient
2012-01-01
Objectives: Uganda, has limited health resources and improving performance of personnel involved in imaging is necessary for efficiency. The objectives of the study were to develop and pilot imaging user performance indices, document non-tangible aspects of performance, and propose ways of improving performance. Materials and Methods: This was a cross-sectional survey employing triangulation methodology, conducted in Mulago National Referral Hospital over a period of 3 years from 2005 to 2008. The qualitative study used in-depth interviews, focus group discussions, and self-administered questionnaires, to explore clinicians’ and radiologists’ performancerelated views. Results: The study came up with following indices: appropriate service utilization (ASU), appropriateness of clinician's nonimaging decisions (ANID), and clinical utilization of imaging results (CUI). The ASU, ANID, and CUI were: 94%, 80%, and 97%, respectively. The clinician's requisitioning validity was high (positive likelihood ratio of 10.6) contrasting with a poor validity for detecting those patients not needing imaging (negative likelihood ratio of 0.16). Some requisitions were inappropriate and some requisition and reports lacked detail, clarity, and precision. Conclusion: Clinicians perform well at imaging requisition-decisions but there are issues in imaging requisitioning and reporting that need to be addressed to improve performance. PMID:23230543
NASA Technical Reports Server (NTRS)
Foushee, H. C.; Lauber, J. K.; Baetge, M. M.; Acomb, D. B.
1986-01-01
Excessive flightcrew fatigue has potentially serious safety consequences. Laboratory studies have implicated fatigue as a causal factor associated with varying levels of performance deterioration depending on the amount of fatigue and the type of measure utilized in assessing performance. These studies have been of limited utility because of the difficulty of relating laboratory task performance to the demands associated with the operation of a complex aircraft. The performance of 20 volunteer twin-jet transport crews is examined in a full-mission simulator scenario that included most aspects of an actual line operation. The scenario included both routine flight operations and an unexpected mechanical abnormality which resulted in a high level of crew workload. Half of the crews flew the simulation within two to three hours after completing a three-day, high-density, short-haul duty cycle (Post-Duty condition). The other half flew the scenario after a minimum of three days off duty (Pre-Duty) condition). The results revealed that, not surprisingly, Post-Duty crews were significantly more fatigued than Pre-Duty crews. However, a somewhat counter-intuitive pattern of results emerged on the crew performancemeasures. In general, the performance of Post-Duty crews was significantly better than that of Pre-Duty crews, as rated by an expert observer on a number of dimensions relevant to flight safety. Analyses of the flightcrew communication patterns revealed that Post-Duty crews communicated significantly more overall, suggesting, as has previous research, that communication is a good predictor of overall crew performance.
Kim, Joo Hyun; Fu, Kun; Choi, Junghyun; Kil, Kichun; Kim, Jeonghyun; Han, Xiaogang; Hu, Liangbing; Paik, Ungyu
2015-01-01
Lithium-sulfur batteries show great potential to compete with lithium-ion batteries due to the fact that sulfur can deliver a high theoretical capacity of 1672 mAh/g and a high theoretical energy density of 2500 Wh/kg. But it has several problems to be solved in order to achieve high sulfur utilization with high Coulombic efficiency and long cycle life of Li-S batteries. These problems are mainly caused by the dissoluble polysulfide species, which are a series of complex reduced sulfur products, associating with shuttle effect between electrodes as well as side reactions on lithium metal anode. To alleviate these challenges, we developed a sulfur-carbon nanotube (S/SWNT) composite coated with polyaniline (PANI) polymer as polysulfide block to achieve high sulfur utilization, high Coulombic efficiency, and long cycle life. The PANI coated S/SWNT composite showed a superior specific capacity of 1011 mAh/g over 100 cycles and a good rate retention, demonstrating the synergic contribution of porous carbon and conducting polymer protection to address challenges underlying sulfur cathode. PMID:25752298
Hatziandreu, E J; Brown, R E; Revicki, D A; Turner, R; Martindale, J; Levine, S; Siegel, J E
1994-03-01
The objective of this study was to model, for patients at risk of recurrent depression, the cost-utility of maintenance therapy with sertraline compared with treatment of acute episodes with dothiepin ('episodic treatment'). Using clinical decision analysis techniques, a Markov state-transition model was constructed to estimate the lifetime costs and quality-adjusted life-years (QALYs) of the 2 therapeutic strategies. The model follows 2 cohorts of 35-year-old women at high risk for recurrent depression over their lifetimes. Model construction and relevant data (probabilities) for performing the analysis were based on existing clinical knowledge. Two physician panels were used to obtain estimates of recurrence probabilities not available in the literature, health utilities, and resource consumption. Costs were obtained from published sources. The baseline analysis showed that it costs 2172 British pounds sterling ($US3692, 1991 currency) to save an additional QALY with sertraline maintenance treatment. Sensitivity analysis showed that the incremental cost-utility ratio ranged from 557 British pounds sterling to 5260 British pounds sterling per QALY. Overall, the resulting ratios are considered to be well within the range of cost-utility ratios that support the adoption and appropriate utilisation of a technology. Based on the study assumptions, long term maintenance treatment with sertraline appears to be clinically and economically justified choice for patients at high risk of recurrent depression.
Overcoming the Adoption Barrier to Electric Flight
NASA Technical Reports Server (NTRS)
Borer, Nicholas K.; Nickol, Craig L.; Jones, Frank P.; Yasky, Richard J.; Woodham, Kurt; Fell, Jared S.; Litherland, Brandon L.; Loyselle, Patricia L.; Provenza, Andrew J.; Kohlman, Lee W.;
2016-01-01
Electrically-powered aircraft can enable dramatic increases in efficiency and reliability, reduced emissions, and reduced noise as compared to today's combustion-powered aircraft. This paper describes a novel flight demonstration concept that will enable the benefits of electric propulsion, while keeping the extraordinary convenience and utility of common fuels available at today's airports. A critical gap in airborne electric propulsion research is addressed by accommodating adoption at the integrated aircraft-airport systems level, using a confluence of innovative but proven concepts and technologies in power generation and electricity storage that need to reside only on the airframe. Technical discriminators of this demonstrator concept include (1) a novel, high-efficiency power system that utilizes advanced solid oxide fuel cells originally developed for ultra-long-endurance aircraft, coupled with (2) a high-efficiency, high-power electric propulsion system selected from mature products to reduce technical risk, assembled into (3) a modern, high-performance demonstration platform to provide useful and compelling data, both for the targeted early adopters and the eventual commercial market.
Hybrid photovoltaic and thermoelectric module for high concentration solar system
NASA Astrophysics Data System (ADS)
Tamaki, Ryo; Toyoda, Takeshi; Tamura, Yoichi; Matoba, Akinari; Minamikawa, Toshiharu; Tokuda, Masayuki; Masui, Megumi; Okada, Yoshitaka
2017-09-01
A photovoltaic (PV) and thermoelectric (TE) hybrid module was developed for application to high concentration solar systems. The waste heat from the solar cells under concentrated light illumination was utilized to generate additional electricity by assembling TE devices below the multi-junction solar cells (MJSCs). Considering the high operating temperature of the PV and TE hybrid module compared with conventional concentrator PV modules, the TE device could compensate a part of the MJSC efficiency degradation at high temperature. The performance investigation clarified the feasibility of the hybrid PV and TE module under highly concentrated sunlight illumination.
Naked-eye fingerprinting of single nucleotide polymorphisms on psoriasis patients
NASA Astrophysics Data System (ADS)
Valentini, Paola; Marsella, Alessandra; Tarantino, Paolo; Mauro, Salvatore; Baglietto, Silvia; Congedo, Maurizio; Paolo Pompa, Pier
2016-05-01
We report a low-cost test, based on gold nanoparticles, for the colorimetric (naked-eye) fingerprinting of a panel of single nucleotide polymorphisms (SNPs), relevant for the personalized therapy of psoriasis. Such pharmacogenomic tests are not routinely performed on psoriasis patients, due to the high cost of standard technologies. We demonstrated high sensitivity and specificity of our colorimetric test by validating it on a cohort of 30 patients, through a double-blind comparison with two state-of-the-art instrumental techniques, namely reverse dot blotting and sequencing, finding 100% agreement. This test offers high parallelization capabilities and can be easily generalized to other SNPs of clinical relevance, finding broad utility in diagnostics and pharmacogenomics.We report a low-cost test, based on gold nanoparticles, for the colorimetric (naked-eye) fingerprinting of a panel of single nucleotide polymorphisms (SNPs), relevant for the personalized therapy of psoriasis. Such pharmacogenomic tests are not routinely performed on psoriasis patients, due to the high cost of standard technologies. We demonstrated high sensitivity and specificity of our colorimetric test by validating it on a cohort of 30 patients, through a double-blind comparison with two state-of-the-art instrumental techniques, namely reverse dot blotting and sequencing, finding 100% agreement. This test offers high parallelization capabilities and can be easily generalized to other SNPs of clinical relevance, finding broad utility in diagnostics and pharmacogenomics. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr02200f
Oasis: A high-level/high-performance open source Navier-Stokes solver
NASA Astrophysics Data System (ADS)
Mortensen, Mikael; Valen-Sendstad, Kristian
2015-03-01
Oasis is a high-level/high-performance finite element Navier-Stokes solver written from scratch in Python using building blocks from the FEniCS project (fenicsproject.org). The solver is unstructured and targets large-scale applications in complex geometries on massively parallel clusters. Oasis utilizes MPI and interfaces, through FEniCS, to the linear algebra backend PETSc. Oasis advocates a high-level, programmable user interface through the creation of highly flexible Python modules for new problems. Through the high-level Python interface the user is placed in complete control of every aspect of the solver. A version of the solver, that is using piecewise linear elements for both velocity and pressure, is shown to reproduce very well the classical, spectral, turbulent channel simulations of Moser et al. (1999). The computational speed is strongly dominated by the iterative solvers provided by the linear algebra backend, which is arguably the best performance any similar implicit solver using PETSc may hope for. Higher order accuracy is also demonstrated and new solvers may be easily added within the same framework.
Utility-based early modulation of processing distracting stimulus information.
Wendt, Mike; Luna-Rodriguez, Aquiles; Jacobsen, Thomas
2014-12-10
Humans are selective information processors who efficiently prevent goal-inappropriate stimulus information to gain control over their actions. Nonetheless, stimuli, which are both unnecessary for solving a current task and liable to cue an incorrect response (i.e., "distractors"), frequently modulate task performance, even when consistently paired with a physical feature that makes them easily discernible from target stimuli. Current models of cognitive control assume adjustment of the processing of distractor information based on the overall distractor utility (e.g., predictive value regarding the appropriate response, likelihood to elicit conflict with target processing). Although studies on distractor interference have supported the notion of utility-based processing adjustment, previous evidence is inconclusive regarding the specificity of this adjustment for distractor information and the stage(s) of processing affected. To assess the processing of distractors during sensory-perceptual phases we applied EEG recording in a stimulus identification task, involving successive distractor-target presentation, and manipulated the overall distractor utility. Behavioral measures replicated previously found utility modulations of distractor interference. Crucially, distractor-evoked visual potentials (i.e., posterior N1) were more pronounced in high-utility than low-utility conditions. This effect generalized to distractors unrelated to the utility manipulation, providing evidence for item-unspecific adjustment of early distractor processing to the experienced utility of distractor information. Copyright © 2014 the authors 0270-6474/14/3416720-06$15.00/0.
Team Formation and Communication Restrictions in Collectives
NASA Technical Reports Server (NTRS)
Agogino, Adrian K.; Turner, Kagan
2003-01-01
A collective of agents often needs to maximize a "world utility" function which rates the performance of an entire system, while subject to communication restrictions among the agents. Such communication restrictions make it difficult for agents which try to pursue their own "private" utilities to take actions that also help optimize the world utility. Team formation presents a solution to this problem, where by joining other agents, an agent can significantly increase its knowledge about the environment and improve its chances of both optimizing its own utility and that its doing so will contribute to the world utility. In this article we show how utilities that have been previously shown to be effective in collectives can be modified to be more effective in domains with moderate communication restrictions resulting in performance improvements of up to 75%. Additionally we show that even severe communication constraints can be overcome by forming teams where each agent of a team shares the same utility, increasing performance an additional 25%. We show that utilities and team sizes can be manipulated to form the best compromise between how "aligned" an agent s utility is with the world utility and how easily an agent can learn that utility.
Space Station Human Factors: Designing a Human-Robot Interface
NASA Technical Reports Server (NTRS)
Rochlis, Jennifer L.; Clarke, John Paul; Goza, S. Michael
2001-01-01
The experiments described in this paper are part of a larger joint MIT/NASA research effort and focus on the development of a methodology for designing and evaluating integrated interfaces for highly dexterous and multifunctional telerobot. Specifically, a telerobotic workstation is being designed for an Extravehicular Activity (EVA) anthropomorphic space station telerobot called Robonaut. Previous researchers have designed telerobotic workstations based upon performance of discrete subsets of tasks (for example, peg-in-hole, tracking, etc.) without regard for transitions that operators go through between tasks performed sequentially in the context of larger integrated tasks. The experiments presented here took an integrated approach to describing teleoperator performance and assessed how subjects operating a full-immersion telerobot perform during fine position and gross position tasks. In addition, a Robonaut simulation was also developed as part of this research effort, and experimentally tested against Robonaut itself to determine its utility. Results show that subject performance of teleoperated tasks using both Robonaut and the simulation are virtually identical, with no significant difference between the two. These results indicate that the simulation can be utilized as both a Robonaut training tool, and as a powerful design platform for telepresence displays and aids.
Enabling Efficient Climate Science Workflows in High Performance Computing Environments
NASA Astrophysics Data System (ADS)
Krishnan, H.; Byna, S.; Wehner, M. F.; Gu, J.; O'Brien, T. A.; Loring, B.; Stone, D. A.; Collins, W.; Prabhat, M.; Liu, Y.; Johnson, J. N.; Paciorek, C. J.
2015-12-01
A typical climate science workflow often involves a combination of acquisition of data, modeling, simulation, analysis, visualization, publishing, and storage of results. Each of these tasks provide a myriad of challenges when running on a high performance computing environment such as Hopper or Edison at NERSC. Hurdles such as data transfer and management, job scheduling, parallel analysis routines, and publication require a lot of forethought and planning to ensure that proper quality control mechanisms are in place. These steps require effectively utilizing a combination of well tested and newly developed functionality to move data, perform analysis, apply statistical routines, and finally, serve results and tools to the greater scientific community. As part of the CAlibrated and Systematic Characterization, Attribution and Detection of Extremes (CASCADE) project we highlight a stack of tools our team utilizes and has developed to ensure that large scale simulation and analysis work are commonplace and provide operations that assist in everything from generation/procurement of data (HTAR/Globus) to automating publication of results to portals like the Earth Systems Grid Federation (ESGF), all while executing everything in between in a scalable environment in a task parallel way (MPI). We highlight the use and benefit of these tools by showing several climate science analysis use cases they have been applied to.
Santoro, Carlo; Gokhale, Rohan; Mecheri, Barbara; D'Epifanio, Alessandra; Licoccia, Silvia; Serov, Alexey; Artyushkova, Kateryna; Atanassov, Plamen
2017-08-24
Iron(II) phthalocyanine (FePc) deposited onto two different carbonaceous supports was synthesized through an unconventional pyrolysis-free method. The obtained materials were studied in the oxygen reduction reaction (ORR) in neutral media through incorporation in an air-breathing cathode structure and tested in an operating microbial fuel cell (MFC) configuration. Rotating ring disk electrode (RRDE) analysis revealed high performances of the Fe-based catalysts compared with that of activated carbon (AC). The FePc supported on Black-Pearl carbon black [Fe-BP(N)] exhibits the highest performance in terms of its more positive onset potential, positive shift of the half-wave potential, and higher limiting current as well as the highest power density in the operating MFC of (243±7) μW cm -2 , which was 33 % higher than that of FePc supported on nitrogen-doped carbon nanotubes (Fe-CNT(N); 182±5 μW cm -2 ). The power density generated by Fe-BP(N) was 92 % higher than that of the MFC utilizing AC; therefore, the utilization of platinum group metal-free catalysts can boost the performances of MFCs significantly. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Investigation of two-phase thermosyphon performance filled with modern HFC refrigerants
NASA Astrophysics Data System (ADS)
Gorecki, Grzegorz
2018-02-01
Two-phase closed thermosyphons (TPCTs) are widely utilized as heat exchanger elements in waste heat recovery systems and as passive heating/cooling devices. They are popular because of their high thermal conductivity, simple construction and reliability. Previous researches indicate that refrigerants are performing better than typical TPCT working fluids like deionized water or alcohols in the low temperature range. In the present study three HFC (Hydrofluorocarbons) refrigerants were tested: R134a, R404A and R407C. The total length of the investigated TPCT is 550 mm with equal length (245 mm) condenser and evaporator sections. Its outer diameter is 22 mm with 1 mm wall thickness. The evaporator section was heated by hot water with varying inlet temperature by 5 K step in the range of 288 K - 323 K. The condenser was cooled by cold water with inlet temperature kept at a constant value of 283 K. It was found that using R134a and R404A as working fluids heat transfer rates are the highest. For both refrigerants 10% is optimal filling ratio. They can be utilized interchangeably because the differences between their throughputs are within uncertainty bands. R407C performance was 50% lower. Other disadvantages of using this refrigerant are relatively high working pressures and higher optimal filling ratio (30%).
Investigation of two-phase thermosyphon performance filled with modern HFC refrigerants
NASA Astrophysics Data System (ADS)
Gorecki, Grzegorz
2018-07-01
Two-phase closed thermosyphons (TPCTs) are widely utilized as heat exchanger elements in waste heat recovery systems and as passive heating/cooling devices. They are popular because of their high thermal conductivity, simple construction and reliability. Previous researches indicate that refrigerants are performing better than typical TPCT working fluids like deionized water or alcohols in the low temperature range. In the present study three HFC (Hydrofluorocarbons) refrigerants were tested: R134a, R404A and R407C. The total length of the investigated TPCT is 550 mm with equal length (245 mm) condenser and evaporator sections. Its outer diameter is 22 mm with 1 mm wall thickness. The evaporator section was heated by hot water with varying inlet temperature by 5 K step in the range of 288 K - 323 K. The condenser was cooled by cold water with inlet temperature kept at a constant value of 283 K. It was found that using R134a and R404A as working fluids heat transfer rates are the highest. For both refrigerants 10% is optimal filling ratio. They can be utilized interchangeably because the differences between their throughputs are within uncertainty bands. R407C performance was 50% lower. Other disadvantages of using this refrigerant are relatively high working pressures and higher optimal filling ratio (30%).
NASA Astrophysics Data System (ADS)
Yamazaki, Shigeaki; Ito, Tatsuya; Murakumo, Yuka; Naitou, Masashi; Shimooka, Toshiharu; Yamagata, Masaki; Ishikawa, Masashi
2016-09-01
We propose novel hybrid capacitors (HCs) with electrolyte-involved redox reactions of bromide or iodide species by pretreatment of an activated carbon positive electrode. The treatment is simple; impregnation of pores at an activated carbon fiber cloth (ACFC) as a positive electrode with bromine- or iodine-containing water before cell assembly. The treated positive electrode is applied to a HC cell with a non-treated negative electrode of ACFC and its electrochemical performance is investigated by galvanostatic cycling and leakage current tests. Few studies on such "electrolytic" charge storage systems have provided acceptable capacitor performance because of inevitable self-discharge caused by diffusion of charged species form an electrode to the other one through an electrolyte. Nevertheless, our electrolyte-redox-based HCs show excellent performance without undesirable diffusion of charged species. Moreover, the present HC utilizing a bromide redox system fulfills a practical cell voltage of 1.8 V in spite of an aqueous electrolyte system. This high voltage provides excellent energy density, which is 5 times higher than that in a conventional aqueous electric double-layer capacitor (EDLC), and 1.2 times higher even than that in a 2.7 V-class non-aqueous EDLC, while keeping high charge-discharge rate capability.
Variable Gravity Effects on the Cooling Performance of a Single Phase Confined Spray
NASA Technical Reports Server (NTRS)
Michalak, Travis; Yerkes, Kirk; Baysinger, Karri; McQuillen, John
2005-01-01
The objective of this paper is to discuss the testing of a spray cooling experiment designed to be flown on NASA's KC-135 Reduced Gravity Testing Platform. Spray cooling is an example of a thermal management technique that may be utilized in high flux heat acquisition and high thermal energy transport concepts. Many researchers have investigated the utility of spray cooling for the thermal management of devices generating high heat fluxes. However, there has been little research addressing the physics and ultimate performance of spray cooling in a variable gravity environment. An experimental package, consisting of a spray chamber coupled to a fluid delivery loop system, was fabricated for variable gravity flight tests. The spray chamber contains two opposing nozzles spraying on target Indium Tin Oxide (ITO) heaters. These heaters are mounted on glass pedestals, which are part of a sump system to remove unconstrained liquid from the test chamber. Liquid is collected in the sumps and returned to the fluid delivery loop. Thermocouples mounted in and around the pedestals are used to determine both the heat loss through the underside of the IT0 heater and the heat extracted by the spray. A series of flight tests were carried out aboard the KC-135, utilizing the ability of the aircraft to produce various gravity conditions. During the flight tests, for a fixed flow rate, heat input was varied at 20, 30, 50, and 80W with variable gravities of 0.01, 0.16, 0.36, and 1.8g. Flight test data was compared to terrestrial baseline data in addition to analytical and numerical solutions to evaluate the heat transfer in the heater and support structure . There were significant differences observed in the spray cooling performance as a result of variable gravity conditions and heat inputs. In general, the Nussult number at the heater surface was found to increase with decreasing gravity conditions for heat loads greater than 30W.
NASA Astrophysics Data System (ADS)
O'Malley, D.; Vesselinov, V. V.
2017-12-01
Classical microprocessors have had a dramatic impact on hydrology for decades, due largely to the exponential growth in computing power predicted by Moore's law. However, this growth is not expected to continue indefinitely and has already begun to slow. Quantum computing is an emerging alternative to classical microprocessors. Here, we demonstrated cutting edge inverse model analyses utilizing some of the best available resources in both worlds: high-performance classical computing and a D-Wave quantum annealer. The classical high-performance computing resources are utilized to build an advanced numerical model that assimilates data from O(10^5) observations, including water levels, drawdowns, and contaminant concentrations. The developed model accurately reproduces the hydrologic conditions at a Los Alamos National Laboratory contamination site, and can be leveraged to inform decision-making about site remediation. We demonstrate the use of a D-Wave 2X quantum annealer to solve hydrologic inverse problems. This work can be seen as an early step in quantum-computational hydrology. We compare and contrast our results with an early inverse approach in classical-computational hydrology that is comparable to the approach we use with quantum annealing. Our results show that quantum annealing can be useful for identifying regions of high and low permeability within an aquifer. While the problems we consider are small-scale compared to the problems that can be solved with modern classical computers, they are large compared to the problems that could be solved with early classical CPUs. Further, the binary nature of the high/low permeability problem makes it well-suited to quantum annealing, but challenging for classical computers.