Role of functionally dominant species in varying environmental regimes: evidence for the performance-enhancing effect of biodiversity.

PubMed

Langenheder, Silke; Bulling, Mark T; Prosser, James I; Solan, Martin

2012-07-30

Theory suggests that biodiversity can act as a buffer against disturbances and environmental variability via two major mechanisms: Firstly, a stabilising effect by decreasing the temporal variance in ecosystem functioning due to compensatory processes; and secondly, a performance enhancing effect by raising the level of community response through the selection of better performing species. Empirical evidence for the stabilizing effect of biodiversity is readily available, whereas experimental confirmation of the performance-enhancing effect of biodiversity is sparse. Here, we test the effect of different environmental regimes (constant versus fluctuating temperature) on bacterial biodiversity-ecosystem functioning relations. We show that positive effects of species richness on ecosystem functioning are enhanced by stronger temperature fluctuations due to the increased performance of individual species. Our results provide evidence for the performance enhancing effect and suggest that selection towards functionally dominant species is likely to benefit the maintenance of ecosystem functioning under more variable conditions.

Phase-shifting point diffraction interferometer focus-aid enhanced mask

DOEpatents

Naulleau, Patrick

2000-01-01

A phase-shifting point diffraction interferometer system (PS/PDI) employing a PS/PDI mask that includes a PDI focus aid is provided. The PDI focus aid mask includes a large or secondary reference pinhole that is slightly displaced from the true or primary reference pinhole. The secondary pinhole provides a larger capture tolerance for interferometrically performing fine focus. With the focus-aid enhanced mask, conventional methods such as the knife-edge test can be used to perform an initial (or rough) focus and the secondary (large) pinhole is used to perform interferometric fine focus. Once the system is well focused, high accuracy interferometry can be performed using the primary (small) pinhole.

Technological Advances in Interventions to Enhance Post-Stroke Gait

PubMed Central

Sheffler, Lynne R.; Chae, John

2012-01-01

Synopsis This article provides a comprehensive review of specific rehabilitation interventions used to enhance hemiparetic gait following stroke. Neurologic rehabilitation interventions may be either therapeutic resulting in enhanced motor recovery or compensatory whereby assistance or substitution for neurological deficits results in improved functional performance. Included in this review are lower extremity functional electrical stimulation (FES), body-weight supported treadmill training (BWSTT), and lower extremity robotic-assisted gait training. These post-stroke gait training therapies are predicated on activity-dependent neuroplasticity which is the concept that cortical reorganization following central nervous system injury may be induced by repetitive, skilled, and cognitively engaging active movement. All three interventions have been trialed extensively in both research and clinical settings to demonstrate a positive effect on various gait parameters and measures of walking performance. However, more evidence is necessary to determine if specific technology-enhanced gait training methods are superior to conventional gait training methods. This review provides an overview of evidence-based research which supports the efficacy of these three interventions to improve gait, as well as provide perspective on future developments to enhance post-stroke gait in neurologic rehabilitation. PMID:23598265

Image enhancement software for underwater recovery operations: User's manual

NASA Astrophysics Data System (ADS)

Partridge, William J.; Therrien, Charles W.

1989-06-01

This report describes software for performing image enhancement on live or recorded video images. The software was developed for operational use during underwater recovery operations at the Naval Undersea Warfare Engineering Station. The image processing is performed on an IBM-PC/AT compatible computer equipped with hardware to digitize and display video images. The software provides the capability to provide contrast enhancement and other similar functions in real time through hardware lookup tables, to automatically perform histogram equalization, to capture one or more frames and average them or apply one of several different processing algorithms to a captured frame. The report is in the form of a user manual for the software and includes guided tutorial and reference sections. A Digital Image Processing Primer in the appendix serves to explain the principle concepts that are used in the image processing.

Facilities Performance Indicators Report 2011-12: Tracking Your Facilities Vital Signs

ERIC Educational Resources Information Center

APPA: Association of Higher Education Facilities Officers, 2013

2013-01-01

This paper provides an expanded Web-based "Facilities Performance Indicators (FPI) Report." The purpose of APPA's Facilities Performance Indicators is to provide a representative set of statistics about facilities in educational institutions. APPA's Information and Research Committee's goal for this year was to enhance the…

Virtual fixtures as tools to enhance operator performance in telepresence environments

NASA Astrophysics Data System (ADS)

Rosenberg, Louis B.

1993-12-01

This paper introduces the notion of virtual fixtures for use in telepresence systems and presents an empirical study which demonstrates that such virtual fixtures can greatly enhance operator performance within remote environments. Just as tools and fixtures in the real world can enhance human performance by guiding manual operations, providing localizing references, and reducing the mental processing required to perform a task, virtual fixtures are computer generated percepts overlaid on top of the reflection of a remote workspace which can provide similar benefits. Like a ruler guiding a pencil in a real manipulation task, a virtual fixture overlaid on top of a remote workspace can act to reduce the mental processing required to perform a task, limit the workload of certain sensory modalities, and most of all allow precision and performance to exceed natural human abilities. Because such perceptual overlays are virtual constructions they can be diverse in modality, abstract in form, and custom tailored to individual task or user needs. This study investigates the potential of virtual fixtures by implementing simple combinations of haptic and auditory sensations as perceptual overlays during a standardized telemanipulation task.

Image enhancement for on-site X-ray nondestructive inspection of reinforced concrete structures.

PubMed

Pei, Cuixiang; Wu, Wenjing; Ueaska, Mitsuru

2016-11-22

The use of portable and high-energy X-ray system can provide a very promising approach for on-site nondestructive inspection of inner steel reinforcement of concrete structures. However, the noise properties and contrast of the radiographic images for thick concrete structures do often not meet the demands. To enhance the images, we present a simple and effective method for noise reduction based on a combined curvelet-wavelet transform and local contrast enhancement based on neighborhood operation. To investigate the performance of this method for our X-ray system, we have performed several experiments with using simulated and experimental data. With comparing to other traditional methods, it shows that the proposed image enhancement method has a better performance and can significantly improve the inspection performance for reinforced concrete structures.

Enhancing High Value Care in Gastroenterology Practice.

PubMed

Camilleri, Michael; Katzka, David A

2016-10-01

The objective of this review is to identify common areas in gastroenterology practice where studies performed provide an opportunity for enhancing value or lowering costs. We provide examples of topics in gastroenterology where clinicians could enhance value by either using less invasive testing, choosing a single best test, or by using patient symptoms to guide additional testing. The topics selected for review are selected in esophageal, pancreatic, and colorectal cancer; functional gastrointestinal diseases (irritable bowel syndrome, bacterial overgrowth, constipation); immune-mediated gastrointestinal diseases; and pancreaticobiliary pathology. We propose guidance to alter practice based on current evidence. These studies support the need to review current practice and to continue performing research to further validate the proposed guidance to enhance value of care in gastroenterology and hepatology. Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.

Performance management system enhancement and maintenance

NASA Technical Reports Server (NTRS)

Cleaver, T. G.; Ahour, R.; Johnson, B. R.

1984-01-01

The research described in this report concludes a two-year effort to develop a Performance Management System (PMS) for the NCC computers. PMS provides semi-automated monthly reports to NASA and contractor management on the status and performance of the NCC computers in the TDRSS program. Throughout 1984, PMS was tested, debugged, extended, and enhanced. Regular PMS monthly reports were produced and distributed. PMS continues to operate at the NCC under control of Bendix Corp. personnel.

Baseline Testing of the Ultracapacitor Enhanced Photovoltaic Power Station

NASA Technical Reports Server (NTRS)

Eichenberg, Dennis J.; Kolacz, John S.; Tavernelli, Paul F.

2001-01-01

The NASA John H. Glenn Research Center is developing an advanced ultracapacitor enhanced photovoltaic power station. Goals of this effort include maximizing photovoltaic power generation efficiency and extending the life of photovoltaic energy storage systems. Unique aspects of the power station include the use of a solar tracker, and ultracapacitors for energy storage. The photovoltaic power station is seen as a way to provide electric power in remote locations that would otherwise not have electric power, provide independence form utility systems, reduce pollution, reduce fossil fuel consumption, and reduce operating costs. The work was done under the Hybrid Power Management (HPM) Program, which includes the Hybrid Electric Transit Bus (HETB), and the E-Bike. The power station complements the E-Bike extremely well in that it permits the charging of the vehicle batteries in remote locations. Other applications include scientific research and medical power sources in isolated regions. The power station is an inexpensive approach to advance the state of the art in power technology in a practical application. The project transfers space technology to terrestrial use via nontraditional partners, and provides power system data valuable for future space applications. A description of the ultracapacitor enhanced power station, the results of performance testing and future power station development plans is the subject of this report. The report concludes that the ultracapacitor enhanced power station provides excellent performance, and that the implementation of ultracapacitors in the power system can provide significant performance improvements.

A culture of education: Enhancing school performance of youth living in residential group care in Ontario.

PubMed

Gharabaghi, Kiaras

2011-01-01

This article presents a synthesis of what is known about the educational experiences of youth living in residential group care based on a literature review that highlights both the experiences of the youth themselves and the operational context of residential group care in Ontario as it pertains to educational performance. The author argues that there is little emphasis on education within the residential group care sector in Ontario that could translate into more productive educational experiences for youth. The article then provides a framework for developing a culture of education for residential group care that can be acted upon expeditiously. Enhancing the educational performance of young people living in group care will require a cultural approach that provides for daily and pervasive education supports and encouragement, and aims to enhance the lived experience of young people pursuant to their education.

FELIN: tailored optronics and systems solutions for dismounted combat

NASA Astrophysics Data System (ADS)

Milcent, A. M.

2009-05-01

The FELIN French modernization program for dismounted combat provides the Armies with info-centric systems which dramatically enhance the performances of the soldier and the platoon. Sagem now has available a portfolio of various equipments, providing C4I, data and voice digital communication, and enhanced vision for day and night operations, through compact high performance electro-optics. The FELIN system provides the infantryman with a high-tech integrated and modular system which increases significantly their detection, recognition, identification capabilities, their situation awareness and information sharing, and this in any dismounted close combat situation. Among the key technologies used in this system, infrared and intensified vision provide a significant improvement in capability, observation performance and protection of the ground soldiers. This paper presents in detail the developed equipments, with an emphasis on lessons learned from the technical and operational feedback from dismounted close combat field tests.

Constructive Feedback as a Learning Tool to Enhance Students' Self-Regulation and Performance in Higher Education

ERIC Educational Resources Information Center

du Toit, Erna

2012-01-01

If feedback is provided in a way that can develop students' self-regulatory skills, it could enhance learning and, consequently, lead to improved performance. To improve teaching and learning in higher education (HE), this study sought to determine whether the feedback to first-year students affords them an opportunity to learn from it. A…

A Comparison of the Multiscale Retinex With Other Image Enhancement Techniques

NASA Technical Reports Server (NTRS)

Rahman, Zia-Ur; Woodell, Glenn A.; Jobson, Daniel J.

1997-01-01

The multiscale retinex with color restoration (MSRCR) has shown itself to be a very versatile automatic image enhancement algorithm that simultaneously provides dynamic range compression, color constancy, and color rendition. A number of algorithms exist that provide one or more of these features, but not all. In this paper we compare the performance of the MSRCR with techniques that are widely used for image enhancement. Specifically, we compare the MSRCR with color adjustment methods such as gamma correction and gain/offset application, histogram modification techniques such as histogram equalization and manual histogram adjustment, and other more powerful techniques such as homomorphic filtering and 'burning and dodging'. The comparison is carried out by testing the suite of image enhancement methods on a set of diverse images. We find that though some of these techniques work well for some of these images, only the MSRCR performs universally well on the test set.

Task automation in a successful industrial telerobot

NASA Technical Reports Server (NTRS)

Spelt, Philip F.; Jones, Sammy L.

1994-01-01

In this paper, we discuss cooperative work by Oak Ridge National Laboratory and Remotec, Inc., to automate components of the operator's workload using Remotec's Andros telerobot, thereby providing an enhanced user interface which can be retrofit to existing fielded units as well as being incorporated into new production units. Remotec's Andros robots are presently used by numerous electric utilities to perform tasks in reactors where substantial exposure to radiation exists, as well as by the armed forces and numerous law enforcement agencies. The automation of task components, as well as the video graphics display of the robot's position in the environment, will enhance all tasks performed by these users, as well as enabling performance in terrain where the robots cannot presently perform due to lack of knowledge about, for instance, the degree of tilt of the robot. Enhanced performance of a successful industrial mobile robot leads to increased safety and efficiency of performance in hazardous environments. The addition of these capabilities will greatly enhance the utility of the robot, as well as its marketability.

Potential for increased photosynthetic performance and crop productivity in response to climate change: role of CBFs and gibberellic acid

PubMed Central

Hüner, Norman P. A.; Dahal, Keshav; Kurepin, Leonid V.; Savitch, Leonid; Singh, Jas; Ivanov, Alexander G.; Kane, Khalil; Sarhan, Fathey

2014-01-01

We propose that targeting the enhanced photosynthetic performance associated with the cold acclimation of winter cultivars of rye (Secale cereale L.), wheat (Triticum aestivum L.), and Brassica napus L. may provide a novel approach to improve crop productivity under abiotic as well as biotic stress conditions. In support of this hypothesis, we provide the physiological, biochemical, and molecular evidence that the dwarf phenotype induced by cold acclimation is coupled to significant enhancement in photosynthetic performance, resistance to photoinhibition, and a decreased dependence on photoprotection through non-photochemical quenching which result in enhanced biomass production and ultimately increased seed yield. These system-wide changes at the levels of phenotype, physiology, and biochemistry appear to be governed by the family of C-repeat/dehydration-responsive family of transcription factors (CBF/DREB1). We relate this phenomenon to the semi-dwarf, gibberellic acid insensitive (GAI), cereal varieties developed during the “green revolution” of the early 1960s and 1970s. We suggest that genetic manipulation of the family of C-repeat/dehydration-responsive element binding transcription factors (CBF/DREB1) may provide a novel approach for the maintenance and perhaps even the enhancement of plant productivity under conditions of sub-optimal growth conditions predicted for our future climate. PMID:24860799

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

MSR performance enhancements and modifications at St. Lucie Power Plant

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

Rubano, V.F.; Ugelow, A.G.; Menocal, A.G.

1989-01-01

The St. Lucie Power Plant provides an excellent historical prospective on various moisture separator/reheater improvements. Between the two essentially identical units there is a total of 14 years of operating experience with various moisture separator/reheater configurations, with a combination of four different heat transfer surfaces and three moisture removal configurations. Through various modifications and enhancements, the performance and the reliability of the moisture separator/reheaters at the St. Lucie Power Plant and consequently the overall plant performance has been improved. This improvement has taken place over several years and involves changes in both the heat transfer and moisture removal areas. Thismore » paper provides an overview of the history and description of moisture separator/reheater modifications at the St. Lucie Power Plant with the resulting performance improvements.« less

The short-term stress response - Mother nature's mechanism for enhancing protection and performance under conditions of threat, challenge, and opportunity.

PubMed

Dhabhar, Firdaus S

2018-03-26

Our group has proposed that in contrast to chronic stress that can have harmful effects, the short-term (fight-or-flight) stress response (lasting for minutes to hours) is nature's fundamental survival mechanism that enhances protection and performance under conditions involving threat/challenge/opportunity. Short-term stress enhances innate/primary, adaptive/secondary, vaccine-induced, and anti-tumor immune responses, and post-surgical recovery. Mechanisms and mediators include stress hormones, dendritic cell, neutrophil, macrophage, and lymphocyte trafficking/function and local/systemic chemokine and cytokine production. Short-term stress may also enhance mental/cognitive and physical performance through effects on brain, musculo-skeletal, and cardiovascular function, reappraisal of threat/anxiety, and training-induced stress-optimization. Therefore, short-term stress psychology/physiology could be harnessed to enhance immuno-protection, as well as mental and physical performance. This review aims to provide a conceptual framework and targets for further investigation of mechanisms and conditions under which the protective/adaptive aspects of short-term stress/exercise can be optimized/harnessed, and for developing pharmacological/biobehavioral interventions to enhance health/healing, and mental/cognitive/physical performance. Copyright © 2018 Elsevier Inc. All rights reserved.

Metrics for the National SCADA Test Bed Program

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

Craig, Philip A.; Mortensen, J.; Dagle, Jeffery E.

2008-12-05

The U.S. Department of Energy Office of Electricity Delivery and Energy Reliability (DOE-OE) National SCADA Test Bed (NSTB) Program is providing valuable inputs into the electric industry by performing topical research and development (R&D) to secure next generation and legacy control systems. In addition, the program conducts vulnerability and risk analysis, develops tools, and performs industry liaison, outreach and awareness activities. These activities will enhance the secure and reliable delivery of energy for the United States. This report will describe metrics that could be utilized to provide feedback to help enhance the effectiveness of the NSTB Program.

High-performance fiber-reinforced concrete in a bridge deck.

DOT National Transportation Integrated Search

2005-01-01

The purpose of this research was to compare the performance of high-performance fiber-reinforced concrete (FRC) with that of conventional concrete in a bridge deck. FRC is expected to increase toughness, provide enhanced residual strength, and minimi...

High Resolution Near Real Time Image Processing and Support for MSSS Modernization

NASA Astrophysics Data System (ADS)

Duncan, R. B.; Sabol, C.; Borelli, K.; Spetka, S.; Addison, J.; Mallo, A.; Farnsworth, B.; Viloria, R.

2012-09-01

This paper describes image enhancement software applications engineering development work that has been performed in support of Maui Space Surveillance System (MSSS) Modernization. It also includes R&D and transition activity that has been performed over the past few years with the objective of providing increased space situational awareness (SSA) capabilities. This includes Air Force Research Laboratory (AFRL) use of an FY10 Dedicated High Performance Investment (DHPI) cluster award -- and our selection and planned use for an FY12 DHPI award. We provide an introduction to image processing of electro optical (EO) telescope sensors data; and a high resolution image enhancement and near real time processing and summary status overview. We then describe recent image enhancement applications development and support for MSSS Modernization, results to date, and end with a discussion of desired future development work and conclusions. Significant improvements to image processing enhancement have been realized over the past several years, including a key application that has realized more than a 10,000-times speedup compared to the original R&D code -- and a greater than 72-times speedup over the past few years. The latest version of this code maintains software efficiency for post-mission processing while providing optimization for image processing of data from a new EO sensor at MSSS. Additional work has also been performed to develop low latency, near real time processing of data that is collected by the ground-based sensor during overhead passes of space objects.

Employee organizational commitment and hospital performance.

PubMed

Baird, Kevin M; Tung, Amy; Yu, Yanjie

2017-09-15

There is widespread evidence of the purported benefits of employee organizational commitment (EOC) and its impact on both individual and organizational performance. This study contributes to this literature by providing a unique insight into this relationship, focusing on the interrelationship between EOC with hospital performance and the role of the provision of adequate facilities in eliciting EOC. The aim of this study was to introduce and empirically examine a new theoretical model in which it is argued that the performance of hospitals with regard to the provision of adequate facilities (medical facilities, support facilities, and staff resources) influences the level of EOC, which in turn influences hospital performance with regard to patient care and operational effectiveness. To examine the interrelationships between the provision of adequate facilities, EOC, and hospital performance, the study utilizes a survey of hospital managers. The findings support the theoretical model, with the provision of support facilities and staff resources positively indirectly associated with both patient care and operational effectiveness through their impact on EOC. The findings highlight the importance of providing adequate facilities and EOC within hospitals and suggest that CEOs and general managers should try to enhance the provision of such resources in an attempt to elicit EOC within their hospitals. The findings suggest that managers should try to enhance their provision of adequate facilities in order to elicit EOC and enhance hospital performance. With regard to medical facilities, they should consider and incorporate the latest technology and up-to-date equipment. They should also provide adequate staff resources, including appropriate numbers of beds, nurses, and doctors, to prevent "fatigue" (West, 2001, p. 41) and provide adequate support facilities.

Enhancing Global Competitiveness: Benchmarking Airline Operational Performance in Highly Regulated Environments

NASA Technical Reports Server (NTRS)

Bowen, Brent D.; Headley, Dean E.; Kane, Karisa D.

1998-01-01

Enhancing competitiveness in the global airline industry is at the forefront of attention with airlines, government, and the flying public. The seemingly unchecked growth of major airline alliances is heralded as an enhancement to global competition. However, like many mega-conglomerates, mega-airlines will face complications driven by size regardless of the many recitations of enhanced efficiency. Outlined herein is a conceptual model to serve as a decision tool for policy-makers, managers, and consumers of airline services. This model is developed using public data for the United States (U.S.) major airline industry available from the U/S. Department of Transportation, Federal Aviation Administration, the National Aeronautics and Space Administration, the National Transportation Safety Board, and other public and private sector sources. Data points include number of accidents, pilot deviations, operational performance indicators, flight problems, and other factors. Data from these sources provide opportunity to develop a model based on a complex dot product equation of two vectors. A row vector is weighted for importance by a key informant panel of government, industry, and consumer experts, while a column vector is established with the factor value. The resulting equation, known as the national Airline Quality Rating (AQR), where Q is quality, C is weight, and V is the value of the variables, is stated Q=C[i1-19] x V[i1-19]. Looking at historical patterns of AQR results provides the basis for establishment of an industry benchmark for the purpose of enhancing airline operational performance. A 7 year average of overall operational performance provides the resulting benchmark indicator. Applications from this example can be applied to the many competitive environments of the global industry and assist policy-makers faced with rapidly changing regulatory challenges.

Sources of Variability in Performance Times at the World Orienteering Championships.

PubMed

Hébert-Losier, Kim; Platt, Simon; Hopkins, William G

2015-07-01

An improvement equal to 0.3 of the typical variation in an elite athlete's race-to-race performance estimates the smallest worthwhile enhancement, which has not yet been determined for orienteers. Moreover, much of the research in high-performance orienteering has focused on physical and cognitive aspects, although course characteristics might influence race performance. Analysis of race data provides insights into environmental effects and other aspects of competitive performance. Our aim was to examine such factors in relation to World Orienteering Championships performances. We used mixed linear modelling to analyze finishing times from the three qualification rounds and final round of the sprint, middle-distance, and long-distance disciplines of World Orienteering Championships from 2006 to 2013. Models accounted for race length, distance climbed, number of controls, home advantage, venue identity, round (qualification final), athlete identity, and athlete age. Within-athlete variability (coefficient of variation, mean ± SD) was lower in the final (4.9% ± 1.4%) than in the qualification (7.3% ± 2.4%) rounds and provided estimates of smallest worthwhile enhancements of 1.0%-3.5%. The home advantage was clear in most disciplines, with distance climbed particularly impacting sprint performances. Small to very large between-venue differences were apparent. Performance predictability expressed as intraclass correlation coefficients was extremely high within years and was high to very high between years. Age of peak performance ranged from 27 to 31 yr. Our results suggest that elite orienteers should focus on training and strategies that enhance performance by at least 1.0%-3.5% for smallest worthwhile enhancement. Moreover, as greater familiarity with the terrain likely mediated the home advantage, foreign athletes would benefit from training in nations hosting the World Orienteering Championships for familiarization.

The use of medical quality indices as a performance-enhancement tool for community clinics.

PubMed

Elhayany, A

2001-12-01

One of the most important issues for a country, its population and doctors is the effective use of its health system. The extensive variation in doctors' performance leads to a tremendous waste of resources. To combat this, and at the same time ensure that medical quality plays a role when making decisions on interventions, it is essential to equip doctors and clinic directors with information on the quality of the medical care they are providing. In order to assist clinic directors in maintaining medical quality, Clalit Health Services has developed comparative medical indices enabling doctors to compare their performance to that of their colleagues, as well as to the standard and their performance over time. The development of an index to evaluate the quality of medical treatment offered in clinics provides doctors and the health system with an essential tool to lessen the existing variation among doctors and to enhance and evaluate performance.

Recent Niobium Developments for High Strength Steel Energy Applications

NASA Astrophysics Data System (ADS)

Jansto, Steven G.

Niobium-containing high strength steel materials have been developed for oil and gas pipelines, offshore platforms, nuclear plants, boilers and alternative energy applications. Recent research and the commercialization of alternative energy applications such as windtower structural supports and power transmission gear components provide enhanced performance. Through the application of these Nb-bearing steels in demanding energy-related applications, the designer and end user experience improved toughness at low temperature, excellent fatigue resistance and fracture toughness and excellent weldability. These enhancements provide structural engineers the opportunity to further improve the structural design and performance. For example, through the adoption of these Nb-containing structural materials, several design-manufacturing companies are initiating new windtower designs operating at higher energy efficiency, lower cost, and improved overall material design performance.

Enhanced two phase flow in heat transfer systems

DOEpatents

Tegrotenhuis, Ward E; Humble, Paul H; Lavender, Curt A; Caldwell, Dustin D

2013-12-03

A family of structures and designs for use in devices such as heat exchangers so as to allow for enhanced performance in heat exchangers smaller and lighter weight than other existing devices. These structures provide flow paths for liquid and vapor and are generally open. In some embodiments of the invention, these structures can also provide secondary heat transfer as well. In an evaporate heat exchanger, the inclusion of these structures and devices enhance the heat transfer coefficient of the evaporation phase change process with comparable or lower pressure drop.

Test-Enhanced Learning in an Immunology and Infectious Disease Medicinal Chemistry/Pharmacology Course.

PubMed

Hernick, Marcy

2015-09-25

Objective. To develop a series of active-learning modules that would improve pharmacy students' performance on summative assessments. Design. A series of optional online active-learning modules containing questions with multiple formats for topics in a first-year (P1) course was created using a test-enhanced learning approach. A subset of module questions was modified and included on summative assessments. Assessment. Student performance on module questions improved with repeated attempts and was predictive of student performance on summative assessments. Performance on examination questions was higher for students with access to modules than for those without access to modules. Module use appeared to have the most impact on low performing students. Conclusion. Test-enhanced learning modules with immediate feedback provide pharmacy students with a learning tool that improves student performance on summative assessments and also may improve metacognitive and test-taking skills.

Test-Enhanced Learning in an Immunology and Infectious Disease Medicinal Chemistry/Pharmacology Course

PubMed Central

2015-01-01

Objective. To develop a series of active-learning modules that would improve pharmacy students’ performance on summative assessments. Design. A series of optional online active-learning modules containing questions with multiple formats for topics in a first-year (P1) course was created using a test-enhanced learning approach. A subset of module questions was modified and included on summative assessments. Assessment. Student performance on module questions improved with repeated attempts and was predictive of student performance on summative assessments. Performance on examination questions was higher for students with access to modules than for those without access to modules. Module use appeared to have the most impact on low performing students. Conclusion. Test-enhanced learning modules with immediate feedback provide pharmacy students with a learning tool that improves student performance on summative assessments and also may improve metacognitive and test-taking skills. PMID:27168610

Application of Mental Skills Training in Surgery: A Review of Its Effectiveness and Proposed Next Steps.

PubMed

Anton, Nicholas E; Bean, Eric A; Hammonds, Samuel C; Stefanidis, Dimitrios

2017-05-01

Mental skills training, which refers to the teaching of performance enhancement and stress management psychological strategies, may benefit surgeons. Our objective was to review the application of mental skills training in surgery and contrast it to other domains, examine the effectiveness of this approach in enhancing surgical performance and reducing stress, and provide future directions for mental skills training in surgery. A systematic literature search of MEDLINE, PubMed, PsycINFO, and ClinicalKey was performed between 1996 and 2016. Keywords included were mental readiness, mental competency, mental skill, mental practice, imagery, mental imagery, mental rehearsal, stress management training, stress coping, mental training, performance enhancement, and surgery. Reviews of mental skills interventions in sport and well-regarded sport psychology textbooks were also reviewed. Primary outcome of interest was the effect of mental skills on surgical performance in the simulated or clinical environment. Of 490 identified abstracts, 28 articles met inclusion criteria and were reviewed. The majority of the literature provides evidence that mental imagery and stress management training programs are effective at enhancing surgical performance and reducing stress. Studies from other disciplines suggest that comprehensive mental skills programs may be more effective than imagery and stress management techniques alone. Given the demonstrated efficacy of mental imagery and stress management training in surgery and the incremental value of comprehensive mental skills curricula used in other domains, a concerted effort should be made to apply comprehensive mental skills curricula during surgical training.

Overview of the U.S. DOE Accident Tolerant Fuel Development Program

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

Jon Carmack; Frank Goldner; Shannon M. Bragg-Sitton

2013-09-01

The United States Fuel Cycle Research and Development Advanced Fuels Campaign has been given the responsibility to conduct research and development on enhanced accident tolerant fuels with the goal of performing a lead test assembly or lead test rod irradiation in a commercial reactor by 2022. The Advanced Fuels Campaign has defined fuels with enhanced accident tolerance as those that, in comparison with the standard UO2-Zircaloy system currently used by the nuclear industry, can tolerate loss of active cooling in the reactor core for a considerably longer time period (depending on the LWR system and accident scenario) while maintaining ormore » improving the fuel performance during normal operations and operational transients, as well as design-basis and beyond design-basis events. This paper provides an overview of the FCRD Accident Tolerant Fuel program. The ATF attributes will be presented and discussed. Attributes identified as potentially important to enhance accident tolerance include reduced hydrogen generation (resulting from cladding oxidation), enhanced fission product retention under severe accident conditions, reduced cladding reaction with high-temperature steam, and improved fuel-cladding interaction for enhanced performance under extreme conditions. To demonstrate the enhanced accident tolerance of candidate fuel designs, metrics must be developed and evaluated using a combination of design features for a given LWR design, potential improvements to that design, and the design of an advanced fuel/cladding system. The aforementioned attributes provide qualitative guidance for parameters that will be considered for fuels with enhanced accident tolerance. It may be unnecessary to improve in all attributes and it is likely that some attributes or combination of attributes provide meaningful gains in accident tolerance, while others may provide only marginal benefits. Thus, an initial step in program implementation will be the development of quantitative metrics. A companion paper in these proceedings provides an update on the status of establishing these quantitative metrics for accident tolerant LWR fuel.1 The United States FCRD Advanced Fuels Campaign has embarked on an aggressive schedule for development of enhanced accident tolerant LWR fuels. The goal of developing such a fuel system that can be deployed in the U.S. LWR fleet in the next 10 to 20 years supports the sustainability of clean nuclear power generation in the United States.« less

Photon catalysis acting as noiseless linear amplification and its application in coherence enhancement

NASA Astrophysics Data System (ADS)

Zhang, Shengli; Zhang, Xiangdong

2018-04-01

Photon catalysis is an intriguing quantum mechanical operation during which no photon is added to or subtracted from the relevant optical system. However, we prove that photon catalysis is in essence equivalent to the simpler but more efficient noiseless linear amplifier. This provides a simple and zero-energy-input method for enhancing quantum coherence. We show that the coherence enhancement holds both for a coherent state and a two-mode squeezed vacuum (TMSV) state. For the TMSV state, biside photon catalysis is shown to be equivalent to two times the single-side photon catalysis, and two times the photon catalysis does not provide a substantial enhancement of quantum coherence compared with single-side catalysis. We further extend our investigation to the performance of coherence enhancement with a more realistic photon catalysis scheme where a heralded approximated single-photon state and an on-off detector are exploited. Moreover, we investigate the influence of an imperfect photon detector and the result shows that the amplification effect of photon catalysis is insensitive to the detector inefficiency. Finally, we apply the coherence measure to quantum illumination and see the same trend of performance improvement as coherence enhancement is identified in practical quantum target detection.

Influences of Au ion radiation on microstructure and surface-enhanced Raman scattering of nanoporous copper

NASA Astrophysics Data System (ADS)

Wang, Jing; Hu, Zhaoyi; Li, Rui; Liu, Xiongjun; Xu, Chuan; Wang, Hui; Wu, Yuan; Fu, Engang; Lu, Zhaoping

2018-05-01

In this work, effects of Au ion irradiation on microstructure and surface-enhanced Raman scattering (SERS) performance of nanoporous copper (NPC) were investigated. It is found that the microstructure of NPC could be tailored by the ion irradiation dose, i.e., the pore size decreases while the ligament size significantly coarsens with the increase of the irradiation dose. In addition, the SERS enhancement for rhodamine 6G molecules was improved by Au ions irradiation at an appropriate dose. The underlying mechanism of the increase of SERS enhancement resulted from ion irradiation was discussed. Our findings could provide a new way to tune nanoporosity of nanoporous metals and improve their SERS performance.

Influences of Au ion radiation on microstructure and surface-enhanced Raman scattering of nanoporous copper.

PubMed

Wang, Jing; Hu, Zhaoyi; Li, Rui; Liu, Xiongjun; Xu, Chuan; Wang, Hui; Wu, Yuan; Fu, Engang; Lu, Zhaoping

2018-05-04

In this work, effects of Au ion irradiation on microstructure and surface-enhanced Raman scattering (SERS) performance of nanoporous copper (NPC) were investigated. It is found that the microstructure of NPC could be tailored by the ion irradiation dose, i.e., the pore size decreases while the ligament size significantly coarsens with the increase of the irradiation dose. In addition, the SERS enhancement for rhodamine 6G molecules was improved by Au ions irradiation at an appropriate dose. The underlying mechanism of the increase of SERS enhancement resulted from ion irradiation was discussed. Our findings could provide a new way to tune nanoporosity of nanoporous metals and improve their SERS performance.

Progress in performance enhancement methods for capacitive silicon resonators

NASA Astrophysics Data System (ADS)

Van Toan, Nguyen; Ono, Takahito

2017-11-01

In this paper, we review the progress in recent studies on the performance enhancement methods for capacitive silicon resonators. We provide information on various fabrication technologies and design considerations that can be employed to improve the performance of capacitive silicon resonators, including low motional resistance, small insertion loss, and high quality factor (Q). This paper contains an overview of device structures and working principles, fabrication technologies consisting of hermetic packaging, deep reactive-ion etching and neutral beam etching, and design considerations including mechanically coupled, movable electrode structures and piezoresistive heat engines.

Environmental enrichment enhances cognitive flexibility in C57BL/6 mice on a touchscreen reversal learning task.

PubMed

Zeleznikow-Johnston, Ariel; Burrows, Emma L; Renoir, Thibault; Hannan, Anthony J

2017-05-01

Environmental enrichment (EE) is any positive modification of the 'standard housing' (SH) conditions in which laboratory animals are typically held, usually involving increased opportunity for cognitive stimulation and physical activity. EE has been reported to enhance baseline performance of wild-type animals on traditional cognitive behavioural tasks. Recently, touchscreen operant testing chambers have emerged as a way of performing rodent cognitive assays, providing greater reproducibility, translatability and automatability. Cognitive tests in touchscreen chambers are performed over numerous trials and thus experimenters have the power to detect subtle enhancements in performance. We used touchscreens to analyse the effects of EE on reversal learning, visual discrimination and hippocampal-dependent spatial pattern separation and working memory. We hypothesized that EE would enhance the performance of mice on cognitive touchscreen tasks. Our hypothesis was partially supported in that EE induced enhancements in cognitive flexibility as observed in visual discrimination and reversal learning improvements. However, no other significant effects of EE on cognitive performance were observed. EE decreased the activity level of mice in the touchscreen chambers, which may influence the enrichment level of the animals. Although we did not see enhancements on all hypothesized parameters, our testing paradigm is capable of detecting EE-induced improved cognitive flexibility in mice, which has implications for both understanding the mechanisms of EE and improving screening of putative cognitive-enhancing therapeutics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Predicted Performance of a Thrust-Enhanced SR-71 Aircraft with an External Payload

NASA Technical Reports Server (NTRS)

Conners, Timothy R.

1997-01-01

NASA Dryden Flight Research Center has completed a preliminary performance analysis of the SR-71 aircraft for use as a launch platform for high-speed research vehicles and for carrying captive experimental packages to high altitude and Mach number conditions. Externally mounted research platforms can significantly increase drag, limiting test time and, in extreme cases, prohibiting penetration through the high-drag, transonic flight regime. To provide supplemental SR-71 acceleration, methods have been developed that could increase the thrust of the J58 turbojet engines. These methods include temperature and speed increases and augmentor nitrous oxide injection. The thrust-enhanced engines would allow the SR-71 aircraft to carry higher drag research platforms than it could without enhancement. This paper presents predicted SR-71 performance with and without enhanced engines. A modified climb-dive technique is shown to reduce fuel consumption when flying through the transonic flight regime with a large external payload. Estimates are included of the maximum platform drag profiles with which the aircraft could still complete a high-speed research mission. In this case, enhancement was found to increase the SR-71 payload drag capability by 25 percent. The thrust enhancement techniques and performance prediction methodology are described.

Social importance enhances prospective memory: evidence from an event-based task.

PubMed

Walter, Stefan; Meier, Beat

2017-07-01

Prospective memory performance can be enhanced by task importance, for example by promising a reward. Typically, this comes at costs in the ongoing task. However, previous research has suggested that social importance (e.g., providing a social motive) can enhance prospective memory performance without additional monitoring costs in activity-based and time-based tasks. The aim of the present study was to investigate the influence of social importance in an event-based task. We compared four conditions: social importance, promising a reward, both social importance and promising a reward, and standard prospective memory instructions (control condition). The results showed enhanced prospective memory performance for all importance conditions compared to the control condition. Although ongoing task performance was slowed in all conditions with a prospective memory task when compared to a baseline condition with no prospective memory task, additional costs occurred only when both the social importance and reward were present simultaneously. Alone, neither social importance nor promising a reward produced an additional slowing when compared to the cost in the standard (control) condition. Thus, social importance and reward can enhance event-based prospective memory at no additional cost.

Gas-exfoliated porous monolayer boron nitride for enhanced aerobic oxidative desulfurization performance.

PubMed

Wu, Yingcheng; Wu, Peiwen; Chao, Yanhong; He, Jing; Li, Hongping; Lu, Linjie; Jiang, Wei; Zhang, Beibei; Li, Huaming; Zhu, Wenshuai

2018-01-12

Hexagonal boron nitride has been regarded to be an efficient catalyst in aerobic oxidation fields, but limited by the less-exposed active sites. In this contribution, we proposed a simple green liquid nitrogen gas exfoliation strategy for preparation of porous monolayer nanosheets (BN-1). Owing to the reduced layer numbers, decreased lateral sizes and artificially-constructed pores, increased exposure of active sites was expected, further contributed to an enhanced aerobic oxidative desulfurization (ODS) performance up to ∼98% of sulfur removal, achieving ultra-deep desulfurization. This work not only introduced an excellent catalyst for aerobic ODS, but also provided a strategy for construction of some other highly-efficient monolayer two-dimensional materials for enhanced catalytic performance.

Gas-exfoliated porous monolayer boron nitride for enhanced aerobic oxidative desulfurization performance

NASA Astrophysics Data System (ADS)

Wu, Yingcheng; Wu, Peiwen; Chao, Yanhong; He, Jing; Li, Hongping; Lu, Linjie; Jiang, Wei; Zhang, Beibei; Li, Huaming; Zhu, Wenshuai

2018-01-01

Hexagonal boron nitride has been regarded to be an efficient catalyst in aerobic oxidation fields, but limited by the less-exposed active sites. In this contribution, we proposed a simple green liquid nitrogen gas exfoliation strategy for preparation of porous monolayer nanosheets (BN-1). Owing to the reduced layer numbers, decreased lateral sizes and artificially-constructed pores, increased exposure of active sites was expected, further contributed to an enhanced aerobic oxidative desulfurization (ODS) performance up to ˜98% of sulfur removal, achieving ultra-deep desulfurization. This work not only introduced an excellent catalyst for aerobic ODS, but also provided a strategy for construction of some other highly-efficient monolayer two-dimensional materials for enhanced catalytic performance.

Dietary Lactobacillus plantarum supplementation enhances growth performance and alleviates aluminum toxicity in tilapia.

PubMed

Yu, Leilei; Zhai, Qixiao; Zhu, Jiamin; Zhang, Chengcheng; Li, Tianqi; Liu, Xiaoming; Zhao, Jianxin; Zhang, Hao; Tian, Fengwei; Chen, Wei

2017-09-01

We investigated the protection offered by the probiotic Lactobacillus plantarum CCFM639 against waterborne Al exposure in tilapia. Fish were allocated to control, CCFM639-only, Al-only or Al plus CCFM639 groups. The fish were exposed to 2.73mg/L Al ions for 4 weeks. The probiotic was incorporated into the fish diet at 10 8 CFU/g and provided twice daily. Our results showed that L. plantarum CCFM639 significantly enhanced feed utilization, growth performance and antioxidant ability in the absence of waterborne Al exposure. When fish were exposed to Al, dietary supplementation with the strain effectively decreased the death rate and accumulation of Al in tissues, and enhanced growth performance. Moreover, Al-induced changes in hematobiochemical parameters and hepatic oxidative stress and histopathology were also alleviated. Therefore, L. plantarum CCFM639 may be a novel dietary supplement for fish to enhance growth performance and prevent aquaculture and food safety problems induced by Al pollution. Copyright © 2017. Published by Elsevier Inc.

Making comparative performance information more comprehensible: an experimental evaluation of the impact of formats on consumer understanding

PubMed Central

Damman, Olga C; De Jong, Anco; Hibbard, Judith H; Timmermans, Danielle R M

2016-01-01

Study objectives We aimed to investigate how different presentation formats influence comprehension and use of comparative performance information (CPI) among consumers. Methods An experimental between-subjects and within-subjects design with manipulations of CPI presentation formats. We enrolled both consumers with lower socioeconomic status (SES)/cognitive skills and consumers with higher SES/cognitive skills, recruited through an online access panel. Respondents received fictitious CPI and completed questions about interpretation and information use. Between subjects, we tested (1) displaying an overall performance score (yes/no); (2) displaying a small number of quality indicators (5 vs 9); and (3) displaying different types of evaluative symbols (star ratings, coloured dots and word icons vs numbers and bar graphs). Within subjects, we tested the effect of a reduced number of healthcare providers (5 vs 20). Data were analysed using descriptive analysis, analyses of variance and paired-sampled t tests. Results A total of 902 (43%) respondents participated. Displaying an overall performance score and the use of coloured dots and word icons particularly enhanced consumer understanding. Importantly, respondents provided with coloured dots most often correctly selected the top three healthcare providers (84.3%), compared with word icons (76.6% correct), star ratings (70.6% correct), numbers (62.0%) and bars (54.2%) when viewing performance scores of 20 providers. Furthermore, a reduced number of healthcare providers appeared to support consumers, for example, when provided with 20 providers, 69.5% correctly selected the top three, compared with 80.2% with five providers. Discussion Particular presentation formats enhanced consumer understanding of CPI, most importantly the use of overall performance scores, word icons and coloured dots, and a reduced number of providers displayed. Public report efforts should use these formats to maximise impact on consumers. PMID:26543066

Enhanced thermoelectric performance in three-dimensional superlattice of topological insulator thin films

PubMed Central

2012-01-01

We show that certain three-dimensional (3D) superlattice nanostructure based on Bi2Te3 topological insulator thin films has better thermoelectric performance than two-dimensional (2D) thin films. The 3D superlattice shows a predicted peak value of ZT of approximately 6 for gapped surface states at room temperature and retains a high figure of merit ZT of approximately 2.5 for gapless surface states. In contrast, 2D thin films with gapless surface states show no advantage over bulk Bi2Te3. The enhancement of the thermoelectric performance originates from a combination of the reduction of lattice thermal conductivity by phonon-interface scattering, the high mobility of the topologically protected surface states, the enhancement of Seebeck coefficient, and the reduction of electron thermal conductivity by energy filtering. Our study shows that the nanostructure design of topological insulators provides a possible new way of ZT enhancement. PMID:23072433

Enhanced thermoelectric performance in three-dimensional superlattice of topological insulator thin films.

PubMed

Fan, Zheyong; Zheng, Jiansen; Wang, Hui-Qiong; Zheng, Jin-Cheng

2012-10-16

We show that certain three-dimensional (3D) superlattice nanostructure based on Bi2Te3 topological insulator thin films has better thermoelectric performance than two-dimensional (2D) thin films. The 3D superlattice shows a predicted peak value of ZT of approximately 6 for gapped surface states at room temperature and retains a high figure of merit ZT of approximately 2.5 for gapless surface states. In contrast, 2D thin films with gapless surface states show no advantage over bulk Bi2Te3. The enhancement of the thermoelectric performance originates from a combination of the reduction of lattice thermal conductivity by phonon-interface scattering, the high mobility of the topologically protected surface states, the enhancement of Seebeck coefficient, and the reduction of electron thermal conductivity by energy filtering. Our study shows that the nanostructure design of topological insulators provides a possible new way of ZT enhancement.

Interactive degraded document enhancement and ground truth generation

NASA Astrophysics Data System (ADS)

Bal, G.; Agam, G.; Frieder, O.; Frieder, G.

2008-01-01

Degraded documents are frequently obtained in various situations. Examples of degraded document collections include historical document depositories, document obtained in legal and security investigations, and legal and medical archives. Degraded document images are hard to to read and are hard to analyze using computerized techniques. There is hence a need for systems that are capable of enhancing such images. We describe a language-independent semi-automated system for enhancing degraded document images that is capable of exploiting inter- and intra-document coherence. The system is capable of processing document images with high levels of degradations and can be used for ground truthing of degraded document images. Ground truthing of degraded document images is extremely important in several aspects: it enables quantitative performance measurements of enhancement systems and facilitates model estimation that can be used to improve performance. Performance evaluation is provided using the historical Frieder diaries collection.1

A guide to performance management for the Health Information Manager.

PubMed

Leggat, Sandra G

This paper provides a summary of human resource management practices that have been identified as being associated with better outcomes in performance management. In general, essential practices include transformational leadership and a coherent program of goal setting, performance monitoring and feedback. Some Health Information Managers may feel they require training assistance to develop the necessary skills in the establishment of meaningful work performance goals for staff and the provision of useful and timely feedback. This paper provides useful information to assist Health Information Managers enhance the performance of their staff.

Reproducible, high performance patch antenna array apparatus and method of fabrication

DOEpatents

Strassner, II, Bernd H.

2007-01-23

A reproducible, high-performance patch antenna array apparatus includes a patch antenna array provided on a unitary dielectric substrate, and a feed network provided on the same unitary substrate and proximity coupled to the patch antenna array. The reproducibility is enhanced by using photolithographic patterning and etching to produce both the patch antenna array and the feed network.

Information-Adaptive Image Encoding and Restoration

NASA Technical Reports Server (NTRS)

Park, Stephen K.; Rahman, Zia-ur

1998-01-01

The multiscale retinex with color restoration (MSRCR) has shown itself to be a very versatile automatic image enhancement algorithm that simultaneously provides dynamic range compression, color constancy, and color rendition. A number of algorithms exist that provide one or more of these features, but not all. In this paper we compare the performance of the MSRCR with techniques that are widely used for image enhancement. Specifically, we compare the MSRCR with color adjustment methods such as gamma correction and gain/offset application, histogram modification techniques such as histogram equalization and manual histogram adjustment, and other more powerful techniques such as homomorphic filtering and 'burning and dodging'. The comparison is carried out by testing the suite of image enhancement methods on a set of diverse images. We find that though some of these techniques work well for some of these images, only the MSRCR performs universally well oil the test set.

Human Performance Technology and Knowledge Management: A Case Study

ERIC Educational Resources Information Center

Massey, Anne P.; Montoya-Weiss, Mitzi M.; O'Driscoll, Tony M.

2005-01-01

As organizations respond to competitive environments and strive to enhance performance, knowledge management (KM) has increasingly become a strategic activity. A KM strategy entails consciously helping people share and put knowledge into action. A key challenge is how to develop and implement KM solutions that provide performance support to…

Effective Science Instruction: Impact on High-Stakes Assessment Performance

ERIC Educational Resources Information Center

Johnson, Carla C.; Zhang, Danhui; Kahle, Jane Butler

2012-01-01

This longitudinal prospective cohort study was conducted to determine the impact of effective science instruction on performance on high-stakes high school graduation assessments in science. This study provides powerful findings to support authentic science teaching to enhance long-term retention of learning and performance on state-mandated…

Performance optimization of spectral amplitude coding OCDMA system using new enhanced multi diagonal code

NASA Astrophysics Data System (ADS)

Imtiaz, Waqas A.; Ilyas, M.; Khan, Yousaf

2016-11-01

This paper propose a new code to optimize the performance of spectral amplitude coding-optical code division multiple access (SAC-OCDMA) system. The unique two-matrix structure of the proposed enhanced multi diagonal (EMD) code and effective correlation properties, between intended and interfering subscribers, significantly elevates the performance of SAC-OCDMA system by negating multiple access interference (MAI) and associated phase induce intensity noise (PIIN). Performance of SAC-OCDMA system based on the proposed code is thoroughly analyzed for two detection techniques through analytic and simulation analysis by referring to bit error rate (BER), signal to noise ratio (SNR) and eye patterns at the receiving end. It is shown that EMD code while using SDD technique provides high transmission capacity, reduces the receiver complexity, and provides better performance as compared to complementary subtraction detection (CSD) technique. Furthermore, analysis shows that, for a minimum acceptable BER of 10-9 , the proposed system supports 64 subscribers at data rates of up to 2 Gbps for both up-down link transmission.

Investigation of self-adaptive LED surgical lighting based on entropy contrast enhancing method

NASA Astrophysics Data System (ADS)

Liu, Peng; Wang, Huihui; Zhang, Yaqin; Shen, Junfei; Wu, Rengmao; Zheng, Zhenrong; Li, Haifeng; Liu, Xu

2014-05-01

Investigation was performed to explore the possibility of enhancing contrast by varying the spectral distribution (SPD) of the surgical lighting. The illumination scenes with different SPDs were generated by the combination of a self-adaptive white light optimization method and the LED ceiling system, the images of biological sample are taken by a CCD camera and then processed by an 'Entropy' based contrast evaluation model which is proposed specific for surgery occasion. Compared with the neutral white LED based and traditional algorithm based image enhancing methods, the illumination based enhancing method turns out a better performance in contrast enhancing and improves the average contrast value about 9% and 6%, respectively. This low cost method is simple, practicable, and thus may provide an alternative solution for the expensive visual facility medical instruments.

Cavity Enhanced Spectrometer performance assessment for greenhouse gas dry mole fraction measurement in humid air.

NASA Astrophysics Data System (ADS)

Laurent, Olivier; Yver Kwok, Camille; Guemri, Ali; Philippon, Carole; Rivier, Leonard; Ramonet, Michel

2017-04-01

Due to the high variability of the water vapor content in the atmosphere, the mole fraction of trace gas such as greenhouse gas (GHG) in the atmosphere is usually presented as mole fraction in dry air. In consequence, the first technology used for GHG measurement, gas chromatography or non-dispersive infra-red spectroscopy, required to dry the air sample prior to analysis at a dew point lower than -50°C. The emergence of new GHG analyzers using infrared Enhanced Cavity Spectroscopy which measure the water vapor content in the air sample, allows providing the dry mole fraction of GHG without any drying system upstream by applying appropriate correction of the water vapor effects (dilution, pressure broadening…). In the framework of ICOS, a European research infrastructure aiming to provide harmonized high precision data for advanced research on carbon cycle and GHG budgets over Europe, the Metrology Lab of the Atmosphere Thematic Centre (ATC), located at LSCE in France, is mainly dedicated to elaborating measurement protocols and evaluating performance of GHG analyzers. Among the different tests conducted to characterize the metrological performance, the Metrology Lab focuses on the water vapor correction to apply on the GHG measurement. Most of the analyzers tested at the Metrology Lab are based on Cavity Enhanced Spectroscopy measuring the ICOS mandatory species, CO2, CH4 and CO. This presentation presents the results of the performance assessment of the manufacturer built-in water vapor correction and the possible improvement. Thanks to the large number of instrument tested, the presentation provides a performance overview of the GHG analyzers deployed in the ICOS atmospheric station network. Finally the performance of the water vapor correction will be discussed in regard of the performance obtained by using a drying system.

Enhancement of Hc2 and Jc by carbon-based chemical doping

NASA Astrophysics Data System (ADS)

Yeoh, W. K.; Dou, S. X.

2007-06-01

In the past 5 years, various kinds of doping of MgB 2, including single elements (metal and non-metal), silicates, various carbon sources, and other compounds have been investigated and reported. Most nanoparticle doping leads to improvement of critical current density, Jc( H), and performance, but some types show a negative effect. In this paper, the effect of carbon doping on Jc and the upper critical field, Hc2, of MgB 2 is reviewed. Carbon substitution effects make two distinguishable contributions to the enhancement of Jc field performance: increase of Hc2 and improvement of flux pinning, both because carbon substitutes for boron in the MgB 2 lattice. Among all the carbon sources so far, nano-SiC has been confirmed to be the most effective dopant to enhance the Jc in magnetic fields and Hc2. An irreversibility field, Hirr, of 10 T has been achieved with nano-SiC doping at 20 K, exceeding Hirr of NbTi at 4.2 K. Besides that, Hc2 of carbon alloyed MgB 2 film has reached the value of 71 T. The significant enhancement in Jc( H) and Hc2 via carbon substitution has provided great potential for practical applications of MgB 2. The dual reaction model proposed by the authors’ group provides a comprehensive understanding of the mechanism of enhancement in Jc and Hc2 by chemical doping. Further improvement in self-field Jc performance while maintaining the already achieved in-field performance remains as a major challenge in the development of MgB 2.

Performance Analysis of a NASA Integrated Network Array

NASA Technical Reports Server (NTRS)

Nessel, James A.

2012-01-01

The Space Communications and Navigation (SCaN) Program is planning to integrate its individual networks into a unified network which will function as a single entity to provide services to user missions. This integrated network architecture is expected to provide SCaN customers with the capabilities to seamlessly use any of the available SCaN assets to support their missions to efficiently meet the collective needs of Agency missions. One potential optimal application of these assets, based on this envisioned architecture, is that of arraying across existing networks to significantly enhance data rates and/or link availabilities. As such, this document provides an analysis of the transmit and receive performance of a proposed SCaN inter-network antenna array. From the study, it is determined that a fully integrated internetwork array does not provide any significant advantage over an intra-network array, one in which the assets of an individual network are arrayed for enhanced performance. Therefore, it is the recommendation of this study that NASA proceed with an arraying concept, with a fundamental focus on a network-centric arraying.

Optogenetic Stimulation of Prefrontal Glutamatergic Neurons Enhances Recognition Memory.

PubMed

Benn, Abigail; Barker, Gareth R I; Stuart, Sarah A; Roloff, Eva V L; Teschemacher, Anja G; Warburton, E Clea; Robinson, Emma S J

2016-05-04

Finding effective cognitive enhancers is a major health challenge; however, modulating glutamatergic neurotransmission has the potential to enhance performance in recognition memory tasks. Previous studies using glutamate receptor antagonists have revealed that the medial prefrontal cortex (mPFC) plays a central role in associative recognition memory. The present study investigates short-term recognition memory using optogenetics to target glutamatergic neurons within the rodent mPFC specifically. Selective stimulation of glutamatergic neurons during the online maintenance of information enhanced associative recognition memory in normal animals. This cognitive enhancing effect was replicated by local infusions of the AMPAkine CX516, but not CX546, which differ in their effects on EPSPs. This suggests that enhancing the amplitude, but not the duration, of excitatory synaptic currents improves memory performance. Increasing glutamate release through infusions of the mGluR7 presynaptic receptor antagonist MMPIP had no effect on performance. These results provide new mechanistic information that could guide the targeting of future cognitive enhancers. Our work suggests that improved associative-recognition memory can be achieved by enhancing endogenous glutamatergic neuronal activity selectively using an optogenetic approach. We build on these observations to recapitulate this effect using drug treatments that enhance the amplitude of EPSPs; however, drugs that alter the duration of the EPSP or increase glutamate release lack efficacy. This suggests that both neural and temporal specificity are needed to achieve cognitive enhancement. Copyright © 2016 Benn et al.

A simulation evaluation of the engine monitoring and control system display

NASA Technical Reports Server (NTRS)

Abbott, Terence S.

1990-01-01

The Engine Monitoring and Control System (E-MACS) display is a new concept for an engine instrument display, the purpose of which is to provide an enhanced means for a pilot to control and monitor aircraft engine performance. It provides graphically-presented information about performance capabilities, current performance, and engine component or subsystem operational conditions relative to nominal conditions. The concept was evaluated by sixteen pilot-subjects against a traditional, state-of-the-art electronic engine display format. The results of this evaluation showed a substantial pilot preference for the E-MACS display relative to the traditional display. The results of the failure detection portion of the evaluation showed a 100 percent detection rate for the E-MACS display relative to a 57 percent rate for the traditional display. From these results, it is concluded that by providing this type of information in the cockpit, a reduction in pilot workload and an enhanced ability for detecting degraded or off-nominal conditions is probable, thus leading to an increase in operational safety.

Performance of a skewed semi-integral bridge : volume 1 : field monitoring.

DOT National Transportation Integrated Search

2008-01-01

This project was developed to enhance the Virginia Department of Transportation's (VDOT) in-house expertise in the design of integral bridges and to provide a resource for consultants performing design work for VDOT. It involved extensive field monit...

Providing haptic feedback in robot-assisted minimally invasive surgery: a direct optical force-sensing solution for haptic rendering of deformable bodies.

PubMed

Ehrampoosh, Shervin; Dave, Mohit; Kia, Michael A; Rablau, Corneliu; Zadeh, Mehrdad H

2013-01-01

This paper presents an enhanced haptic-enabled master-slave teleoperation system which can be used to provide force feedback to surgeons in minimally invasive surgery (MIS). One of the research goals was to develop a combined-control architecture framework that included both direct force reflection (DFR) and position-error-based (PEB) control strategies. To achieve this goal, it was essential to measure accurately the direct contact forces between deformable bodies and a robotic tool tip. To measure the forces at a surgical tool tip and enhance the performance of the teleoperation system, an optical force sensor was designed, prototyped, and added to a robot manipulator. The enhanced teleoperation architecture was formulated by developing mathematical models for the optical force sensor, the extended slave robot manipulator, and the combined-control strategy. Human factor studies were also conducted to (a) examine experimentally the performance of the enhanced teleoperation system with the optical force sensor, and (b) study human haptic perception during the identification of remote object deformability. The first experiment was carried out to discriminate deformability of objects when human subjects were in direct contact with deformable objects by means of a laparoscopic tool. The control parameters were then tuned based on the results of this experiment using a gain-scheduling method. The second experiment was conducted to study the effectiveness of the force feedback provided through the enhanced teleoperation system. The results show that the force feedback increased the ability of subjects to correctly identify materials of different deformable types. In addition, the virtual force feedback provided by the teleoperation system comes close to the real force feedback experienced in direct MIS. The experimental results provide design guidelines for choosing and validating the control architecture and the optical force sensor.

Immediate detailed feedback to test-enhanced learning: an effective online educational tool.

PubMed

Wojcikowski, Ken; Kirk, Leslie

2013-11-01

Test-enhanced learning has gained popularity because it is an effective way to increase retention of knowledge; provided the student receives the correct answer soon after the test is taken. To determine whether detailed feedback provided to test-enhanced learning questions is an effective online educational tool for improving performance on complex biomedical information exams. A series of online multiple choice tests were developed to test knowledge of biomedical information that students were expected to know after each patient-case. Following submission of the student answers, one cohort (n = 52) received answers only while the following year, a second cohort (n = 51) received the answers with detailed feedback explaining why each answer was correct or incorrect. Students in both groups progressed through the series of online tests with little assessor intervention. Students receiving the answers along with the explanations within their feedback performed significantly better in the final biomedical information exam than those students receiving correct answers only. This pilot study found that the detailed feedback to test-enhanced learning questions is an important online learning tool. The increase in student performance in the complex biomedical information exam in this study suggests that detailed feedback should be investigated not only for increasing knowledge, but also be investigated for its effect on retention and application of knowledge.

Staging of breast cancer and the advanced applications of digital mammogram: what the physician needs to know?

PubMed

Helal, Maha H; Mansour, Sahar M; Zaglol, Mai; Salaleldin, Lamia A; Nada, Omniya M; Haggag, Marwa A

2017-03-01

To study the role of advanced applications of digital mammogram, whether contrast-enhanced spectral mammography (CESM) or digital breast tomosynthesis (DBT), in the "T" staging of histologically proven breast cancer before planning for treatment management. In this prospective analysis, we evaluated 98 proved malignant breast masses regarding their size, multiplicity and the presence of associated clusters of microcalcifications. Evaluation methods included digital mammography (DM), 3D tomosynthesis and CESM. Traditional DM was first performed then in a period of 10-14-day interval; breast tomosynthesis and contrast-based mammography were performed for the involved breast only. Views at tomosynthesis were acquired in a "step-and-shoot" tube motion mode to produce multiple (11-15), low-dose images and in contrast-enhanced study, low-energy (22-33 kVp) and high-energy (44-49 kVp) exposures were taken after the i.v. injection of the contrast agent. Operative data were the gold standard reference. Breast tomosynthesis showed the highest accuracy in size assessment (n = 69, 70.4%) than contrast-enhanced (n = 49, 50%) and regular mammography (n = 59, 60.2%). Contrast-enhanced mammography presented the least performance in assessing calcifications, yet it was most sensitive in the detection of multiplicity (92.3%), followed by tomosynthesis (77%) and regular mammography (53.8%). The combined analysis of the three modalities provided an accuracy of 74% in the "T" staging of breast cancer. The combined application of tomosynthesis and contrast-enhanced digital mammogram enhanced the performance of the traditional DM and presented an informative method in the staging of breast cancer. Advances in knowledge: Staging and management planning of breast cancer can divert according to tumour size, multiplicity and the presence of microcalcifications. DBT shows sharp outlines of the tumour with no overlap tissue and spots microcalcifications. Contrast-enhanced spectral mammogram shows the extent of abnormal contrast uptake and detects multiplicity. Integrated analysis provides optimal findings for proper "T" staging of breast cancer.

Donor-Acceptor Distance Sampling Enhances the Performance of "Better than Nature" Nicotinamide Coenzyme Biomimetics.

PubMed

Geddes, Alexander; Paul, Caroline E; Hay, Sam; Hollmann, Frank; Scrutton, Nigel S

2016-09-07

Understanding the mechanisms of enzymatic hydride transfer with nicotinamide coenzyme biomimetics (NCBs) is critical to enhancing the performance of nicotinamide coenzyme-dependent biocatalysts. Here the temperature dependence of kinetic isotope effects (KIEs) for hydride transfer between "better than nature" NCBs and several ene reductase biocatalysts is used to indicate transfer by quantum mechanical tunneling. A strong correlation between rate constants and temperature dependence of the KIE (ΔΔH(⧧)) for H/D transfer implies that faster reactions with NCBs are associated with enhanced donor-acceptor distance sampling. Our analysis provides the first mechanistic insight into how NCBs can outperform their natural counterparts and emphasizes the need to optimize donor-acceptor distance sampling to obtain high catalytic performance from H-transfer enzymes.

Brief non-symbolic, approximate number practice enhances subsequent exact symbolic arithmetic in children

PubMed Central

Spelke, Elizabeth S.

2014-01-01

Recent research reveals a link between individual differences in mathematics achievement and performance on tasks that activate the approximate number system (ANS): a primitive cognitive system shared by diverse animal species and by humans of all ages. Here we used a brief experimental paradigm to test one causal hypothesis suggested by this relationship: activation of the ANS may enhance children's performance of symbolic arithmetic. Over 2 experiments, children who briefly practiced tasks that engaged primitive approximate numerical quantities performed better on subsequent exact, symbolic arithmetic problems than did children given other tasks involving comparison and manipulation of non-numerical magnitudes (brightness and length). The practice effect appeared specific to mathematics, as no differences between groups were observed on a comparable sentence completion task. These results move beyond correlational research and provide evidence that the exercise of non-symbolic numerical processes can enhance children's performance of symbolic mathematics. PMID:24462713

Technology-Enhanced Learning Environments to Solve Performance Problems: A Case of a Korean Company

ERIC Educational Resources Information Center

Kim, Min Kyu

2010-01-01

This is a case describing how technology enhanced learning environments can be used to improve employees' competence development. For this purpose, specific problematic situations in a Korean insurance company are portrayed. These situations demonstrate that everyday life in a workplace provides opportunities for learning and performance…

Feasibility of Using an Augmented Immersive Virtual Reality Learning Environment to Enhance Music Conducting Skills

ERIC Educational Resources Information Center

Orman, Evelyn K.; Price, Harry E.; Russell, Christine R.

2017-01-01

Acquiring nonverbal skills necessary to appropriately communicate and educate members of performing ensembles is essential for wind band conductors. Virtual reality learning environments (VRLEs) provide a unique setting for developing these proficiencies. For this feasibility study, we used an augmented immersive VRLE to enhance eye contact, torso…

Distributed Learning Enhances Relational Memory Consolidation

ERIC Educational Resources Information Center

Litman, Leib; Davachi, Lila

2008-01-01

It has long been known that distributed learning (DL) provides a mnemonic advantage over massed learning (ML). However, the underlying mechanisms that drive this robust mnemonic effect remain largely unknown. In two experiments, we show that DL across a 24 hr interval does not enhance immediate memory performance but instead slows the rate of…

Design of the sample cell in near-field surface-enhanced Raman scattering by finite difference time domain method

NASA Astrophysics Data System (ADS)

Li, Yaqin; Jian, Guoshu; Wu, Shifa

2006-11-01

The rational design of the sample cell may improve the sensitivity of surface-enhanced Raman scattering (SERS) detection in a high degree. Finite difference time domain (FDTD) simulations of the configuration of Ag film-Ag particles illuminated by plane wave and evanescent wave are performed to provide physical insight for design of the sample cell. Numerical solutions indicate that the sample cell can provide more "hot spots' and the massive field intensity enhancement occurs in these "hot spots'. More information on the nanometer character of the sample can be got because of gradient-field Raman (GFR) of evanescent wave.

Decoding transcriptional enhancers: Evolving from annotation to functional interpretation

PubMed Central

Engel, Krysta L.; Mackiewicz, Mark; Hardigan, Andrew A.; Myers, Richard M.; Savic, Daniel

2016-01-01

Deciphering the intricate molecular processes that orchestrate the spatial and temporal regulation of genes has become an increasingly major focus of biological research. The differential expression of genes by diverse cell types with a common genome is a hallmark of complex cellular functions, as well as the basis for multicellular life. Importantly, a more coherent understanding of gene regulation is critical for defining developmental processes, evolutionary principles and disease etiologies. Here we present our current understanding of gene regulation by focusing on the role of enhancer elements in these complex processes. Although functional genomic methods have provided considerable advances to our understanding of gene regulation, these assays, which are usually performed on a genome-wide scale, typically provide correlative observations that lack functional interpretation. Recent innovations in genome editing technologies have placed gene regulatory studies at an exciting crossroads, as systematic, functional evaluation of enhancers and other transcriptional regulatory elements can now be performed in a coordinated, high-throughput manner across the entire genome. This review provides insights on transcriptional enhancer function, their role in development and disease, and catalogues experimental tools commonly used to study these elements. Additionally, we discuss the crucial role of novel techniques in deciphering the complex gene regulatory landscape and how these studies will shape future research. PMID:27224938

Decoding transcriptional enhancers: Evolving from annotation to functional interpretation.

PubMed

Engel, Krysta L; Mackiewicz, Mark; Hardigan, Andrew A; Myers, Richard M; Savic, Daniel

2016-09-01

Deciphering the intricate molecular processes that orchestrate the spatial and temporal regulation of genes has become an increasingly major focus of biological research. The differential expression of genes by diverse cell types with a common genome is a hallmark of complex cellular functions, as well as the basis for multicellular life. Importantly, a more coherent understanding of gene regulation is critical for defining developmental processes, evolutionary principles and disease etiologies. Here we present our current understanding of gene regulation by focusing on the role of enhancer elements in these complex processes. Although functional genomic methods have provided considerable advances to our understanding of gene regulation, these assays, which are usually performed on a genome-wide scale, typically provide correlative observations that lack functional interpretation. Recent innovations in genome editing technologies have placed gene regulatory studies at an exciting crossroads, as systematic, functional evaluation of enhancers and other transcriptional regulatory elements can now be performed in a coordinated, high-throughput manner across the entire genome. This review provides insights on transcriptional enhancer function, their role in development and disease, and catalogues experimental tools commonly used to study these elements. Additionally, we discuss the crucial role of novel techniques in deciphering the complex gene regulatory landscape and how these studies will shape future research. Copyright © 2016 Elsevier Ltd. All rights reserved.

Composite Materials for Thermal Energy Storage: Enhancing Performance through Microstructures

PubMed Central

Ge, Zhiwei; Ye, Feng; Ding, Yulong

2014-01-01

Chemical incompatibility and low thermal conductivity issues of molten-salt-based thermal energy storage materials can be addressed by using microstructured composites. Using a eutectic mixture of lithium and sodium carbonates as molten salt, magnesium oxide as supporting material, and graphite as thermal conductivity enhancer, the microstructural development, chemical compatibility, thermal stability, thermal conductivity, and thermal energy storage performance of composite materials are investigated. The ceramic supporting material is essential for preventing salt leakage and hence provides a solution to the chemical incompatibility issue. The use of graphite gives a significant enhancement on the thermal conductivity of the composite. Analyses suggest that the experimentally observed microstructural development of the composite is associated with the wettability of the salt on the ceramic substrate and that on the thermal conduction enhancer. PMID:24591286

Recent Enhancements to the National Transonic Facility

NASA Technical Reports Server (NTRS)

Kilgore, W. A.; Balakrishna, S.; Bobbitt, C. W.; Underwood, P.

2003-01-01

The National Transonic Facility continues to make enhancements to provide quality data in a safe, efficient and cost effective method for aerodynamic ground testing. Recent enhancements discussed in this paper include the restoration of reliability and improved performance of the heat exchanger systems resulting in the expansion of the NTF air operations envelope. Additionally, results are presented from a continued effort to reduce model dynamics through the use of a new stiffer balance and sting

Use of Performance Measures to Evaluate, Document Competence and Deterioration of Advanced Surgical Skills Exposure for Trauma (ASSET) Surgical Skills

DTIC Science & Technology

2015-03-01

71(2):193- 7. 13. Lobel DA, Elder JB, Schirmer CM, Bowyer MW, Rezai AR. A novel craniotomy simulator provides a validated method to enhance...MW, Rezai AR. A novel craniotomy simulator provides a validated method to enhance education in the management of traumatic brain injury...comparisons are significant at pɘ.05 - Wilcoxon matched pairs) A Specialty 0 5 10 15 20 Thoracotomy in ED Repair/ Drainage Hapatic Lacs- Open Neck exploration

Thermally assisted adiabatic quantum computation.

PubMed

Amin, M H S; Love, Peter J; Truncik, C J S

2008-02-15

We study the effect of a thermal environment on adiabatic quantum computation using the Bloch-Redfield formalism. We show that in certain cases the environment can enhance the performance in two different ways: (i) by introducing a time scale for thermal mixing near the anticrossing that is smaller than the adiabatic time scale, and (ii) by relaxation after the anticrossing. The former can enhance the scaling of computation when the environment is super-Ohmic, while the latter can only provide a prefactor enhancement. We apply our method to the case of adiabatic Grover search and show that performance better than classical is possible with a super-Ohmic environment, with no a priori knowledge of the energy spectrum.

The virtues of the virtual world. Enhancing the technology/knowledge professional interface for life-long learning.

PubMed

Koerner, JoEllen Goertz

2003-01-01

Nurses are quintessential learners. Nested between the fields of science and technology, the professional mandate for life-long learning has never been greater. The expanding demands for performance and quality coupled with the reality of diminishing time and resources increasingly frustrate and challenge providers in the field. By blending the best of current training and education with the emerging potential of virtual learning, new models for enhancing clinical reasoning and performance will simplify the challenges of complexity, moving it to higher order. In this transition lies the key to restoring the joy and commitment of professional practice while enhancing the capacity to care with competence.

Enhancing and evaluating researcher performance : WisDOT RD&T peer, May 18-20, 2010.

DOT National Transportation Integrated Search

2010-05-01

The peer exchange covered a range of topics related to measuring and improving researcher : performance. On the first day, state panel participants provided overviews of their programs and the : challenges they face in keeping the quality of research...

Negative Thought Stopping. A Key to Performance Enhancement.

ERIC Educational Resources Information Center

Ziegler, Susan G.

1987-01-01

The effects of mental training on skill acquisition and performance is currently emphasized in the study of sport psychology and motor learning. This article provides the teacher and coach with general guidelines for understanding and incorporating negative thought stopping training into athletic programs. (MT)

Performance assessment of an onboard monitoring system for CMV drivers : a field operational test : research brief.

DOT National Transportation Integrated Search

2016-11-01

The primary goal of an onboard monitoring system (OBMS) is to enhance driver performance and safety. OBMSs are employed with the expectation that feedback provided concurrently (via flashing feedback lights in the vehicle) and cumulatively (via coach...

Tin Oxide Crystals Exposed by Low-Energy {110} Facets for Enhanced Electrochemical Heavy Metal Ions Sensing: X-ray Absorption Fine Structure Experimental Combined with Density-Functional Theory Evidence.

PubMed

Jin, Zhen; Yang, Meng; Chen, Shao-Hua; Liu, Jin-Huai; Li, Qun-Xiang; Huang, Xing-Jiu

2017-02-21

Herein, we revealed that the electrochemical behaviors on the detection of heavy metal ions (HMIs) would largely rely on the exposed facets of SnO 2 nanoparticles. Compared to the high-energy {221} facet, the low-energy {110} facet of SnO 2 possessed better electrochemical performance. The adsorption/desorption tests, density-functional theory (DFT) calculations, and X-ray absorption fine structure (XAFS) studies showed that the lower barrier energy of surface diffusion on {110} facet was critical for the superior electrochemical property, which was favorable for the ions diffusion on the electrode, and further leading the enhanced electrochemical performance. Through the combination of experiments and theoretical calculations, a reliable interpretation of the mechanism for electroanalysis of HMIs with nanomaterials exposed by different crystal facets has been provided. Furthermore, it provides a deep insight into understanding the key factor to improve the electrochemical performance for HMIs detection, so as to design high-performance electrochemical sensors.

Silver nanocrystal-decorated polyoxometalate single-walled nanotubes as nanoreactors for desulfurization catalysis at room temperature.

PubMed

Zhang, Hao; Xu, Xiaobin; Lin, Haifeng; Ud Din, Muhammad Aizaz; Wang, Haiqing; Wang, Xun

2017-09-14

Ultrathin nanocrystals generally provide a remarkable catalytic performance due to their high specific surface area and exposure of certain active sites. However, deactivation caused by growth and gathering limits the catalytic application of ultrathin nanocrystals. Here we report Ag nanocrystal-decorated polyoxometalate (Ag-POM) single-walled nanotubes assembled via a concise, surfactant-free soaking method as a new kind of well-defined core-sheath nanoreactor. The diameter of Ag nanocrystals inside polyoxometalate nanotubes can be controlled via simply adjusting the reactant concentration. Ag-POM provided outstanding oxidative desulfurization (ODS) catalytic performance for aromatic sulfocompounds at room temperature. It was suggested that Ag nanocrystals decorated on the inner surface played a key role in adjusting the electronic distribution and enhancing the catalytic activity. The as-prepared Ag-POM nanotubes are promising candidate catalysts with enhanced performance for practical catalytic applications in the gasoline desulfurization industry.

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

Hong, Tao; Chatterjee, Sabornie; Mahurin, Shannon M.

Amidoxime-functionalized polydimethylsiloxane (AO-PDMSPNB) membranes with various amidoxime compositions were synthesized via ring-opening metathesis polymerization followed by post-polymerization modification. Compared to other previously reported PDMS-based membranes, the amidoxime-functionalized membranes show enhanced CO 2 permeability and CO 2/N 2 selectivity. The overall gas separation performance (CO 2 permeability 6800 Barrer; CO 2/N 2 selectivity 19) of the highest performing membrane exceeds the Robeson upper bound line, and the excellent permeability of the copolymer itself provides great potential for real world applications where huge volumes of gases are separated. This study details how tuning the CO 2-philicity within rubbery polymer matrices influences gasmore » transport properties. Key parameters for tuning gas transport properties are discussed, and the experimental results show good consistency with theoretical calculations. Finally, this study provides a roadmap to enhancing gas separation performance in rubbery polymers by tuning gas solubility selectivity.« less

Implementation of Enhanced Propulsion Control Modes for Emergency Flight Operation

NASA Technical Reports Server (NTRS)

Csank, Jeffrey T.; Chin, Jeffrey C.; May, Ryan D.; Litt, Jonathan S.; Guo, Ten-Huei

2011-01-01

Aircraft engines can be effective actuators to help pilots avert or recover from emergency situations. Emergency control modes are being developed to enhance the engines performance to increase the probability of recovery under these circumstances. This paper discusses a proposed implementation of an architecture that requests emergency propulsion control modes, allowing the engines to deliver additional performance in emergency situations while still ensuring a specified safety level. In order to determine the appropriate level of engine performance enhancement, information regarding the current emergency scenario (including severity) and current engine health must be known. This enables the engine to operate beyond its nominal range while minimizing overall risk to the aircraft. In this architecture, the flight controller is responsible for determining the severity of the event and the level of engine risk that is acceptable, while the engine controller is responsible for delivering the desired performance within the specified risk range. A control mode selector specifies an appropriate situation-specific enhanced mode, which the engine controller then implements. The enhanced control modes described in this paper provide additional engine thrust or response capabilities through the modification of gains, limits, and the control algorithm, but increase the risk of engine failure. The modifications made to the engine controller to enable the use of the enhanced control modes are described, as are the interaction between the various subsystems and importantly, the interaction between the flight controller/pilot and the propulsion control system. Simulation results demonstrate how the system responds to requests for enhanced operation and the corresponding increase in performance.

Characteristics and Echogenicity of Clinical Ultrasound Contrast Agents: An In Vitro and In Vivo Comparison Study.

PubMed

Hyvelin, Jean-Marc; Gaud, Emmanuel; Costa, Maria; Helbert, Alexandre; Bussat, Philippe; Bettinger, Thierry; Frinking, Peter

2017-05-01

To compare physicochemical characteristics and in vitro and in vivo contrast-enhanced ultrasound imaging performance of 3 commercially available ultrasound contrast agents: SonoVue (Bracco Imaging SpA, Colleretto Giacosa, Italy; also marketed as Lumason in the USA), Definity (Lantheus Medical Imaging, North Billerica, MA) and Optison (GE Healthcare AS, Oslo, Norway). Physicochemical characteristics were measured with a Multisizer Coulter Counter (Beckman Coulter, Fullerton, CA). Two ultrasound systems (Aplio 500; Toshiba Medical Systems Corp, Tochigi-ken, Japan; and Logiq E9; GE Healthcare, Little Chalfont, England) were used with different transducers. Contrast enhancement was measured in vitro by dose-ranging measurements using a custom-built beaker setup; in vivo imaging performances were compared in pigs (heart and liver) and rabbits (liver). Quantitative analyses were performed with VueBox quantification software (Bracco Suisse SA, Plan-les-Ouates, Switzerland). Measured physicochemical characteristics were in agreement with those provided by the manufacturers. In vitro data demonstrated that the performance of SonoVue was similar to or better than that of Definity but superior to Optison (normalized scattered power 2- to 10-fold higher with SonoVue). Similar results were obtained in vivo, although the duration of enhancement in the pig heart was longer for SonoVue compared to Definity, and quantitative analysis revealed higher enhancement for SonoVue (1.5-fold increase). For liver imaging, SonoVue and Definity showed similar contrast enhancement and duration of enhancement, but compared to Optison, both peak enhancement and duration of enhancement were superior for SonoVue (up to 2-fold increase). Imaging performance of SonoVue was similar to or slightly better than that of Definity, but it was superior to Optison for the conditions used in this study. © 2017 by the American Institute of Ultrasound in Medicine.

Strategies for concurrent processing of complex algorithms in data driven architectures

NASA Technical Reports Server (NTRS)

Som, Sukhamoy; Stoughton, John W.; Mielke, Roland R.

1990-01-01

Performance modeling and performance enhancement for periodic execution of large-grain, decision-free algorithms in data flow architectures are discussed. Applications include real-time implementation of control and signal processing algorithms where performance is required to be highly predictable. The mapping of algorithms onto the specified class of data flow architectures is realized by a marked graph model called algorithm to architecture mapping model (ATAMM). Performance measures and bounds are established. Algorithm transformation techniques are identified for performance enhancement and reduction of resource (computing element) requirements. A systematic design procedure is described for generating operating conditions for predictable performance both with and without resource constraints. An ATAMM simulator is used to test and validate the performance prediction by the design procedure. Experiments on a three resource testbed provide verification of the ATAMM model and the design procedure.

Too Hot for Photon-Assisted Transport: Hot-Electrons Dominate Conductance Enhancement in Illuminated Single-Molecule Junctions.

PubMed

Fung, E-Dean; Adak, Olgun; Lovat, Giacomo; Scarabelli, Diego; Venkataraman, Latha

2017-02-08

We investigate light-induced conductance enhancement in single-molecule junctions via photon-assisted transport and hot-electron transport. Using 4,4'-bipyridine bound to Au electrodes as a prototypical single-molecule junction, we report a 20-40% enhancement in conductance under illumination with 980 nm wavelength radiation. We probe the effects of subtle changes in the transmission function on light-enhanced current and show that discrete variations in the binding geometry result in a 10% change in enhancement. Importantly, we prove theoretically that the steady-state behavior of photon-assisted transport and hot-electron transport is identical but that hot-electron transport is the dominant mechanism for optically induced conductance enhancement in single-molecule junctions when the wavelength used is absorbed by the electrodes and the hot-electron relaxation time is long. We confirm this experimentally by performing polarization-dependent conductance measurements of illuminated 4,4'-bipyridine junctions. Finally, we perform lock-in type measurements of optical current and conclude that currents due to laser-induced thermal expansion mask optical currents. This work provides a robust experimental framework for studying mechanisms of light-enhanced transport in single-molecule junctions and offers tools for tuning the performance of organic optoelectronic devices by analyzing detailed transport properties of the molecules involved.

Enhanced jump performance when providing augmented feedback compared to an external or internal focus of attention.

PubMed

Keller, Martin; Lauber, Benedikt; Gottschalk, Marius; Taube, Wolfgang

2015-01-01

Factors such as an external focus of attention (EF) and augmented feedback (AF) have been shown to improve performance. However, the efficacy of providing AF to enhance motor performance has never been compared with the effects of an EF or an internal focus of attention (IF). Therefore, the aim of the present study was to identify which of the three conditions (AF, EF or IF) leads to the highest performance in a countermovement jump (CMJ). Nineteen volunteers performed 12 series of 8 maximum CMJs. Changes in jump height between conditions and within the series were analysed. Jump heights differed between conditions (P < 0.001), resulting in best performance with AF (32.04 ± 7.11 cm), followed by EF (31.21 ± 6.67 cm) and IF (30.77 ± 6.87 cm). Significantly different (P < 0.001) within-series effects of higher jump heights at the end of the series in AF (+1.60%) and lower jump heights at the end of the series in EF (-1.79%) and IF (-1.68%) were observed. Muscle activity did not differ between conditions. The differences between conditions and within the series provide evidence that AF leads to higher performance and better progression within one series than EF and IF. Consequently, AF seems to outperform EF and IF when maximising jump height.

Enhancement of the Power-Conversion Efficiency of Organic Solar Cells via Unveiling an Appropriate Rational Design Strategy in Indacenodithiophene- alt-quinoxaline π-Conjugated Polymers.

PubMed

Chochos, Christos L; Singh, Ranbir; Gregoriou, Vasilis G; Kim, Min; Katsouras, Athanasios; Serpetzoglou, Efthymis; Konidakis, Ioannis; Stratakis, Emmanuel; Cho, Kilwon; Avgeropoulos, Apostolos

2018-03-28

We report on the photovoltaic parameters, photophysical properties, optoelectronic properties, self-assembly, and morphology variations in a series of high-performance donor-acceptor (D-A) π-conjugated polymers based on indacenodithiophene and quinoxaline moieties as a function of the number-average molecular weight ([Formula: see text]), the nature of aryl substituents, and the enlargement of the polymer backbone. One of the most important outcome is that from the three optimization approaches followed to tune the chemical structure toward enhanced photovoltaic performance in bulk heterojunction solar cell devices with the fullerene derivative [6,6]-phenyl-C 71 -butyric acid methyl ester as the electron acceptor, the choice of the aryl substituent is the most efficient rational design strategy. Incorporation of thienyl rings as substituents versus phenyl rings accelerates the electron-hole extraction process to the respective electrode, despite the slightly lower recombination lifetime and, thus, improves the electrical performance of the device. Single-junction solar cells based on ThIDT-TQxT feature a maximum power-conversion efficiency of 7.26%. This study provides significant insights toward understanding of the structure-properties-performance relationship for D-A π-conjugated polymers in solid state, which provide helpful inputs for the design of next-generation polymeric semiconductors for organic solar cells with enhanced performance.

Exploring the Role of Flow Experience, Learning Performance and Potential Behavior Clusters in Elementary Students' Game-Based Learning

ERIC Educational Resources Information Center

Hsieh, Ya-Hui; Lin, Yi-Chun; Hou, Huei-Tse

2016-01-01

Well-designed game-based learning can provide students with an innovative environment that may enhance students' motivation and engagement in learning and thus improve their learning performance. The purpose of this study was to examine the relationships among elementary school students' flow experience and learning performances. We also…

GUIDANCE DOCUMENT ON IMPLEMENTATION OF THE ...

EPA Pesticide Factsheets

The Agreement in Principle for the Stage 2 M-DBP Federal Advisory Committee contains a list of treatment processes and management practices for water systems to use in meeting additional Cryptosporidium treatment requirements under the LT2ESWTR. This list, termed the microbial toolbox, includes watershed control programs, alternative intake locations, pretreatment processes, additional filtration barriers, inactivation technologies, and enhanced plant performance. The intent of the microbial toolbox is to provide water systems with broad flexibility in selecting cost-effective LT2ESWTR compliance strategies. Moreover, the toolbox allows systems that currently provide additional pathogen barriers or that can demonstrate enhanced performance to receive additional Cryptosporidium treatment credit. Provide guidance to utilities with surface water supplies and to state drinking water programs on the use of different treatment technologies to reduce the level of Cryptosporidium in drinking water. Technologies included in the guidance manual may be used to achieve compliance with the requirements of the LT2ESWTR.

Evolutionary Telemetry and Command Processor (TCP) architecture

NASA Technical Reports Server (NTRS)

Schneider, John R.

1992-01-01

A low cost, modular, high performance, and compact Telemetry and Command Processor (TCP) is being built as the foundation of command and data handling subsystems for the next generation of satellites. The TCP product line will support command and telemetry requirements for small to large spacecraft and from low to high rate data transmission. It is compatible with the latest TDRSS, STDN and SGLS transponders and provides CCSDS protocol communications in addition to standard TDM formats. Its high performance computer provides computing resources for hosted flight software. Layered and modular software provides common services using standardized interfaces to applications thereby enhancing software re-use, transportability, and interoperability. The TCP architecture is based on existing standards, distributed networking, distributed and open system computing, and packet technology. The first TCP application is planned for the 94 SDIO SPAS 3 mission. The architecture enhances rapid tailoring of functions thereby reducing costs and schedules developed for individual spacecraft missions.

Motor Imagery and Tennis Serve Performance: The External Focus Efficacy

PubMed Central

Guillot, Aymeric; Desliens, Simon; Rouyer, Christelle; Rogowski, Isabelle

2013-01-01

There is now ample evidence that motor imagery (MI) contributes to enhance motor performance. Previous research also demonstrated that directing athletes’ attention to the effects of their movements on the environment is more effective than focusing on the action per se. The present study aimed therefore at evaluating whether adopting an external focus during MI contributes to enhance tennis serve performance. Twelve high-level young tennis players were included in a test-retest procedure. The effects of regular training were first evaluated. Then, players were subjected to a MI intervention during which they mentally focused on ball trajectory and specifically visualized the space above the net where the serve can be successfully hit. Serve performance was evaluated during both a validated serve test and a real match. The main results showed a significant increase in accuracy and velocity during the ecological serve test after MI practice, as well as a significant improvement in successful first serves and won points during the match. Present data therefore confirmed the efficacy of MI in combination of physical practice to improve tennis serve performance, and further provided evidence that it is feasible to adopt external attentional focus during MI. Practical applications are discussed. Key Points Motor imagery contributes to enhance tennis serve performance. Data provided evidence of the benefits of adopting an external focus of attention during imagery. Results showed significant improvement in successful first serves and won points during a real match. PMID:24149813

Using Performance Tools to Support Experiments in HPC Resilience

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

Naughton, III, Thomas J; Boehm, Swen; Engelmann, Christian

2014-01-01

The high performance computing (HPC) community is working to address fault tolerance and resilience concerns for current and future large scale computing platforms. This is driving enhancements in the programming environ- ments, specifically research on enhancing message passing libraries to support fault tolerant computing capabilities. The community has also recognized that tools for resilience experimentation are greatly lacking. However, we argue that there are several parallels between performance tools and resilience tools . As such, we believe the rich set of HPC performance-focused tools can be extended (repurposed) to benefit the resilience community. In this paper, we describe the initialmore » motivation to leverage standard HPC per- formance analysis techniques to aid in developing diagnostic tools to assist fault tolerance experiments for HPC applications. These diagnosis procedures help to provide context for the system when the errors (failures) occurred. We describe our initial work in leveraging an MPI performance trace tool to assist in provid- ing global context during fault injection experiments. Such tools will assist the HPC resilience community as they extend existing and new application codes to support fault tolerances.« less

Making comparative performance information more comprehensible: an experimental evaluation of the impact of formats on consumer understanding.

PubMed

Damman, Olga C; De Jong, Anco; Hibbard, Judith H; Timmermans, Danielle R M

2016-11-01

We aimed to investigate how different presentation formats influence comprehension and use of comparative performance information (CPI) among consumers. An experimental between-subjects and within-subjects design with manipulations of CPI presentation formats. We enrolled both consumers with lower socioeconomic status (SES)/cognitive skills and consumers with higher SES/cognitive skills, recruited through an online access panel. Respondents received fictitious CPI and completed questions about interpretation and information use. Between subjects, we tested (1) displaying an overall performance score (yes/no); (2) displaying a small number of quality indicators (5 vs 9); and (3) displaying different types of evaluative symbols (star ratings, coloured dots and word icons vs numbers and bar graphs). Within subjects, we tested the effect of a reduced number of healthcare providers (5 vs 20). Data were analysed using descriptive analysis, analyses of variance and paired-sampled t tests. A total of 902 (43%) respondents participated. Displaying an overall performance score and the use of coloured dots and word icons particularly enhanced consumer understanding. Importantly, respondents provided with coloured dots most often correctly selected the top three healthcare providers (84.3%), compared with word icons (76.6% correct), star ratings (70.6% correct), numbers (62.0%) and bars (54.2%) when viewing performance scores of 20 providers. Furthermore, a reduced number of healthcare providers appeared to support consumers, for example, when provided with 20 providers, 69.5% correctly selected the top three, compared with 80.2% with five providers. Particular presentation formats enhanced consumer understanding of CPI, most importantly the use of overall performance scores, word icons and coloured dots, and a reduced number of providers displayed. Public report efforts should use these formats to maximise impact on consumers. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Composite materials for thermal energy storage: enhancing performance through microstructures.

PubMed

Ge, Zhiwei; Ye, Feng; Ding, Yulong

2014-05-01

Chemical incompatibility and low thermal conductivity issues of molten-salt-based thermal energy storage materials can be addressed by using microstructured composites. Using a eutectic mixture of lithium and sodium carbonates as molten salt, magnesium oxide as supporting material, and graphite as thermal conductivity enhancer, the microstructural development, chemical compatibility, thermal stability, thermal conductivity, and thermal energy storage performance of composite materials are investigated. The ceramic supporting material is essential for preventing salt leakage and hence provides a solution to the chemical incompatibility issue. The use of graphite gives a significant enhancement on the thermal conductivity of the composite. Analyses suggest that the experimentally observed microstructural development of the composite is associated with the wettability of the salt on the ceramic substrate and that on the thermal conduction enhancer. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A high-performance and low cost SERS substrate of plasmonic nanopillars on plastic film fabricated by nanoimprint lithography with AAO template

NASA Astrophysics Data System (ADS)

Liu, Long; Zhang, Qian; Lu, Yuanshen; Du, Wei; Li, Bin; Cui, Yushuang; Yuan, Changsheng; Zhan, Peng; Ge, Haixiong; Wang, Zhenling; Chen, Yanfeng

2017-06-01

As a powerful spectroscopy technique, surface-enhanced Raman scattering (SERS) can provide non-destructive and sensitive characterization down to a single molecular level. Aiming to the main challenges of high-performance SERS-active substrates for their real-world applications involving the ultra-sensitive and reproducible signals detection and signal uniformity with large-area, herein, a facile and reliable strategy based on combination of thermal imprinting polycarbonate (PC) film with porous anodic aluminum oxide (AAO) mold and E-beam evaporation of gold is provided to fabricate a high-quality SERS-active substrate consisting of ultra-dense hot-spots with large-area uniformity. Two kinds of sub-10 nm gaps were obtained, including the nanogaps between the neighboring gold coated PC-nanopillars and those between gold on the top of the nanopillars and that on the base, which actually build up a three-dimensional (3D) hot-spot network for high-performance SERS detection. The effect of structural parameters on SERS enhancement was investigated numerically and experimentally, and by optimizing the structural parameters, a remarkable average SERS enhancement factor up to of 1.4×108 is achieved and it shows an excellent reproducibility with a relative standard deviation of 18%, which allows for enhanced practicability in the application of quantitative biochemical detection.

Thermal evaluation of advanced solar dynamic heat receiver performance

NASA Technical Reports Server (NTRS)

Crane, Roger A.

1989-01-01

The thermal performance of a variety of concepts for thermal energy storage as applied to solar dynamic applications is discussed. It is recognized that designs providing large thermal gradients or large temperature swings during orbit are susceptible to early mechanical failure. Concepts incorporating heat pipe technology may encounter operational limitations over sufficiently large ranges. By reviewing the thermal performance of basic designs, the relative merits of the basic concepts are compared. In addition the effect of thermal enhancement and metal utilization as applied to each design provides a partial characterization of the performance improvements to be achieved by developing these technologies.

Advancing School and Community Engagement Now for Disease Prevention (ASCEND).

PubMed

Treu, Judith A; Doughty, Kimberly; Reynolds, Jesse S; Njike, Valentine Y; Katz, David L

2017-03-01

To compare two intensity levels (standard vs. enhanced) of a nutrition and physical activity intervention vs. a control (usual programs) on nutrition knowledge, body mass index, fitness, academic performance, behavior, and medication use among elementary school students. Quasi-experimental with three arms. Elementary schools, students' homes, and a supermarket. A total of 1487 third-grade students. The standard intervention (SI) provided daily physical activity in classrooms and a program on making healthful foods, using food labels. The enhanced intervention (EI) provided these plus additional components for students and their families. Body mass index (zBMI), food label literacy, physical fitness, academic performance, behavior, and medication use for asthma or attention-deficit hyperactivity disorder (ADHD). Multivariable generalized linear model and logistic regression to assess change in outcome measures. Both the SI and EI groups gained less weight than the control (p < .001), but zBMI did not differ between groups (p = 1.00). There were no apparent effects on physical fitness or academic performance. Both intervention groups improved significantly but similarly in food label literacy (p = .36). Asthma medication use was reduced significantly in the SI group, and nonsignificantly (p = .10) in the EI group. Use of ADHD medication remained unchanged (p = .34). The standard intervention may improve food label literacy and reduce asthma medication use in elementary school children, but an enhanced version provides no further benefit.

Strategies for concurrent processing of complex algorithms in data driven architectures

NASA Technical Reports Server (NTRS)

Stoughton, John W.; Mielke, Roland R.; Som, Sukhamony

1990-01-01

The performance modeling and enhancement for periodic execution of large-grain, decision-free algorithms in data flow architectures is examined. Applications include real-time implementation of control and signal processing algorithms where performance is required to be highly predictable. The mapping of algorithms onto the specified class of data flow architectures is realized by a marked graph model called ATAMM (Algorithm To Architecture Mapping Model). Performance measures and bounds are established. Algorithm transformation techniques are identified for performance enhancement and reduction of resource (computing element) requirements. A systematic design procedure is described for generating operating conditions for predictable performance both with and without resource constraints. An ATAMM simulator is used to test and validate the performance prediction by the design procedure. Experiments on a three resource testbed provide verification of the ATAMM model and the design procedure.

The Importance of the Study of Cognitive Performance Enhancement for U.S. National Security.

PubMed

Malish, Richard G

2017-08-01

The American military is embarking on the 'Third Offset'-a strategy designed to produce seismic shifts in the future of warfare. Central to the approach is the conjoining of humans, technology, and machines to deliver a decisive advantage on the battlefield. Because technology will spread rapidly and globally, tactical overmatch will occur when American operators possess a competitive edge in cognition. Investigation of cognitive enhancing therapeutics is not widely articulated as an adjunct to the Third Offset, yet failure to study promising agents could represent a strategic vulnerability. Because of its legacy of research into therapeutic agents to enhance human-machine interplay, the aerospace medical community represents a front-running candidate to perform this work. Notably, there are strong signals emanating from gambling, academic, and video-gaming enterprises that already-developed stimulants and other agents provide cognitive benefits. These agents should be studied not only for reasons of national security, but also because cognitive enhancement may be a necessary step in the evolution of humankind. To illustrate these points, this article will assert that: 1) the need to preserve and enhance physical and cognitive health will become more and more important over the next century; 2) aeromedical specialists are in a position to take the lead in the endeavor to enhance cognition; 3) signals of enhancement of the type useful to both military and medical efforts exist aplenty in today's society; and 4) the aeromedical community should approach human enhancement research deliberately but carefully.Malish RG. The importance of the study of cognitive performance enhancement for U.S. national security. Aerosp Med Hum Perform. 2017; 88(8):773-778.

APSA - A new generation of photovoltaic solar arrays

NASA Technical Reports Server (NTRS)

Stella, P. M.; Kurland, R. M.

1989-01-01

This paper provides details on the Advanced Photovoltaic Solar Array (APSA) wing design, fabrication, and testing. The impact of array size change on performance and mechanical characteristics is discussed. Projections for future performance enhancements that may be expected through the use of advanced solar cells presently under development are examined.

34 CFR 225.20 - When may a grantee draw down funds?

Code of Federal Regulations, 2010 CFR

2010-07-01

... SECONDARY EDUCATION, DEPARTMENT OF EDUCATION CREDIT ENHANCEMENT FOR CHARTER SCHOOL FACILITIES PROGRAM What... funds after it has signed a performance agreement acceptable to the Department of Education and the... performance agreement provided that the grantee requests to draw down and spend a specific amount of funds and...

School Gardens Enhance Academic Performance and Dietary Outcomes in Children

ERIC Educational Resources Information Center

Berezowitz, Claire K.; Bontrager Yoder, Andrea B.; Schoeller, Dale A.

2015-01-01

Background: Schools face increasing demands to provide education on healthy living and improve core academic performance. Although these appear to be competing concerns, they may interact beneficially. This article focuses on school garden programs and their effects on students' academic and dietary outcomes. Methods: Database searches in CABI,…

Ultrasensitive nanoparticle enhanced laser-induced breakdown spectroscopy using a super-hydrophobic substrate coupled with magnetic confinement.

PubMed

Dong, Daming; Jiao, Leizi; Du, Xiaofan; Zhao, Chunjiang

2017-04-20

In this study, we developed a substrate to enhance the sensitivity of LIBS by 5 orders of magnitude. Using a combination of field enhancement due to the metal nanoparticles in the substrate, the aggregate effect of super-hydrophobic interfaces and magnetic confinement, we performed a quantitative measurement of copper in solution with concentrations on the ppt level. We also demonstrated that the substrate improves quantitative measurements by providing an opportunity for internal standardization.

Space station ECLSS integration analysis: Simplified General Cluster Systems Model, ECLS System Assessment Program enhancements

NASA Technical Reports Server (NTRS)

Ferguson, R. E.

1985-01-01

The data base verification of the ECLS Systems Assessment Program (ESAP) was documented and changes made to enhance the flexibility of the water recovery subsystem simulations are given. All changes which were made to the data base values are described and the software enhancements performed. The refined model documented herein constitutes the submittal of the General Cluster Systems Model. A source listing of the current version of ESAP is provided in Appendix A.

Imaging of paediatric splenic injury with contrast-enhanced ultrasonography.

PubMed

Oldenburg, Anja; Hohmann, Joachim; Skrok, Jan; Albrecht, Thomas

2004-04-01

We report two children who sustained traumatic parenchymal splenic injury and were monitored with contrast-enhanced ultrasound (CEUS). In both cases, unenhanced US failed to diagnose splenic haematoma, but the injury was well demonstrated after injection of contrast agent. In one case agreement with CT was excellent; in the other, CT was not performed due to the comprehensive information provided by CEUS.

Integrated, automated revenue management for managed care contracts.

PubMed

Burckhart, Kent

2002-04-01

Faced with increasing managed care penetration and declining net revenue in recent years, healthcare providers increasingly are emphasizing revenue management. To streamline processes and reduce costs in this area, many healthcare providers have implemented or are considering automated contract management systems. When selecting such a system, healthcare financial managers should make certain that the system can interface with both patient-accounting and decision-support systems of the organization. This integration enhances a healthcare provider's financial viability by providing integrated revenue-management capabilities to analyze projected performance of proposed managed care contracts and actual performance of existing contracts.

Enhanced photoelectrochemical performance of TiO2 nanotube arrays with coexisted Pt nanoparticles and Co-Pi cocatalysts

NASA Astrophysics Data System (ADS)

Li, Yanfang; Cao, Chang; Xie, Xinxin; Zhang, Li; Lin, Shiwei

2018-04-01

Highly-ordered TiO2 nanotube arrays (TNTAs) were prepared by electrochemical anodization. Cobalt-phosphate (Co-Pi) film fabricated by electrodeposition and Pt nanoparticles (Pt NPs) fabricated by photochemical reduction were decorated onto TNTAs to enhance the photoelectrochemical (PEC) performance together. The photocurrent density of the TNTAs/Co-Pi/Pt photoelectrode could reach 0.185 mA/cm2 at 1.23 V versus reversible hydrogen electrode under UV lamp illumination (1 mW/cm2), which is 2.65 times compared to that of the pure TNTAs photoelectrode. Electrochemistry impedance spectroscopy and Mott-Schottky analysis were conducted to explore the reasons for the enhancement of the PEC performance. Pt NPs could promote the reduction of Co(Ⅳ)-oxo intermediate to Co(II) or Co(Ⅲ) which facilitated the charge transfer in the PEC performance. The result provides a promising guideline to design a simple and efficient photoelectrode for the PEC water-splitting system.

An Application of the Impact Evaluation Process for Designing a Performance Measurement and Evaluation Framework in K-12 Environments

ERIC Educational Resources Information Center

Guerra-Lopez, Ingrid; Toker, Sacip

2012-01-01

This article illustrates the application of the Impact Evaluation Process for the design of a performance measurement and evaluation framework for an urban high school. One of the key aims of this framework is to enhance decision-making by providing timely feedback about the effectiveness of various performance improvement interventions. The…

Methyllithium-Doped Naphthyl-Containing Conjugated Microporous Polymer with Enhanced Hydrogen Storage Performance.

PubMed

Xu, Dan; Sun, Lei; Li, Gang; Shang, Jin; Yang, Rui-Xia; Deng, Wei-Qiao

2016-06-01

Hydrogen storage is a primary challenge for using hydrogen as a fuel. With ideal hydrogen storage kinetics, the weak binding strength of hydrogen to sorbents is the key barrier to obtain decent hydrogen storage performance. Here, we reported the rational synthesis of a methyllithium-doped naphthyl-containing conjugated microporous polymer with exceptional binding strength of hydrogen to the polymer guided by theoretical simulations. Meanwhile, the experimental results showed that isosteric heat can reach up to 8.4 kJ mol(-1) and the methyllithium-doped naphthyl-containing conjugated microporous polymer exhibited an enhanced hydrogen storage performance with 150 % enhancement compared with its counterpart naphthyl-containing conjugated microporous polymer. These results indicate that this strategy provides a direction for design and synthesis of new materials that meet the US Department of Energy (DOE) hydrogen storage target. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enhancing the Properties of Conductive Polymer Hydrogels by Freeze-Thaw Cycles for High-Performance Flexible Supercapacitors.

PubMed

Li, Wanwan; Lu, Han; Zhang, Ning; Ma, Mingming

2017-06-14

We report that a postsynthesis physical process (freeze-thaw cycles) can reform the microstructure of conductive polymer hydrogels from clustered nanoparticles to interconnected nanosheets, leading to enhanced mechanical and electrochemical properties. The polyaniline-poly(vinyl alcohol) hydrogel after five freeze-thaw cycles (PPH-5) showed remarkable tensile strength (16.3 MPa), large elongation at break (407%), and high electrochemical capacitance (1053 F·g -1 ). The flexible supercapacitor based on PPH-5 provided a large capacitance (420 mF·cm -2 and 210 F·g -1 ) and high energy density (18.7 W·h·kg -1 ), whose robustness was demonstrated by its 100% capacitance retention after 1000 galvanostatic charge-discharge cycles or after 1000 mechanical folding cycles. The outstanding performance enables PPH-5 based supercapacitor as a promising power device for flexible electronics, which also demonstrates the merit of freeze-thaw cycles for enhancing the performance of functional hydrogels.

Staging of breast cancer and the advanced applications of digital mammogram: what the physician needs to know?

PubMed Central

Helal, Maha H; Zaglol, Mai; Salaleldin, Lamia A; Nada, Omniya M; Haggag, Marwa A

2017-01-01

Objective: To study the role of advanced applications of digital mammogram, whether contrast-enhanced spectral mammography (CESM) or digital breast tomosynthesis (DBT), in the “T” staging of histologically proven breast cancer before planning for treatment management. Methods: In this prospective analysis, we evaluated 98 proved malignant breast masses regarding their size, multiplicity and the presence of associated clusters of microcalcifications. Evaluation methods included digital mammography (DM), 3D tomosynthesis and CESM. Traditional DM was first performed then in a period of 10–14-day interval; breast tomosynthesis and contrast-based mammography were performed for the involved breast only. Views at tomosynthesis were acquired in a “step-and-shoot” tube motion mode to produce multiple (11–15), low-dose images and in contrast-enhanced study, low-energy (22–33 kVp) and high-energy (44–49 kVp) exposures were taken after the i.v. injection of the contrast agent. Operative data were the gold standard reference. Results: Breast tomosynthesis showed the highest accuracy in size assessment (n = 69, 70.4%) than contrast-enhanced (n = 49, 50%) and regular mammography (n = 59, 60.2%). Contrast-enhanced mammography presented the least performance in assessing calcifications, yet it was most sensitive in the detection of multiplicity (92.3%), followed by tomosynthesis (77%) and regular mammography (53.8%). The combined analysis of the three modalities provided an accuracy of 74% in the “T” staging of breast cancer. Conclusion: The combined application of tomosynthesis and contrast-enhanced digital mammogram enhanced the performance of the traditional DM and presented an informative method in the staging of breast cancer. Advances in knowledge: Staging and management planning of breast cancer can divert according to tumour size, multiplicity and the presence of microcalcifications. DBT shows sharp outlines of the tumour with no overlap tissue and spots microcalcifications. Contrast-enhanced spectral mammogram shows the extent of abnormal contrast uptake and detects multiplicity. Integrated analysis provides optimal findings for proper “T” staging of breast cancer. PMID:28055247

75 FR 38107 - Agency Information Collection Activities: Proposed Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-01

... TeamSTEPPS[supreg] (aka Team Strategies and Tools for Enhancing Performance and Patient Safety) to provide an evidence-based suite of tools and strategies for training teamwork- based patient safety to... TeamSTEPPS and are afforded the opportunity to observe the tools and strategies provided in the program...

78 FR 52927 - Agency Information Collection Activities: Proposed Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-27

... TeamSTEPPS[supreg] (aka Team Strategies and Tools for Enhancing Performance and Patient Safety) to provide an evidence-based suite of tools and strategies for training teamwork- based patient safety to... strategies provided in the program in action. In addition to developing Master Trainers, AHRQ has also...

Learning to See: Enhancing Student Learning through Videotaped Feedback

ERIC Educational Resources Information Center

Yakura, Elaine K.

2009-01-01

Feedback is crucial to developing skills, but meaningful feedback is difficult to provide. Classroom videotaping can provide effective feedback on student performance, but for video feedback to be most helpful, students must develop a type of "visual intelligence"--analytical skills that increase critical thinking and self-awareness. The author…

Tolcapone-Enhanced Neurocognition in Healthy Adults: Neural Basis and Predictors.

PubMed

Bhakta, Savita G; Light, Gregory A; Talledo, Jo A; Balvaneda, Bryan; Hughes, Erica; Alvarez, Alexis; Rana, Brinda K; Young, Jared W; Swerdlow, Neal R

2017-12-01

Failure of procognitive drug trials in schizophrenia may reflect the clinical heterogeneity of schizophrenia, underscoring the need to identify biomarkers of treatment sensitivity. We used an experimental medicine design to test the procognitive effects of a putative procognitive agent, tolcapone, using an electroencephalogram-based cognitive control task in healthy subjects. Healthy men and women (n=27; ages 18-35 years), homozygous for either the Met/Met or Val/Val rs4680 genotype, received placebo and tolcapone 200 mg orally across 2 test days separated by 1 week in a double-blind, randomized, counterbalanced, within-subject design. On each test day, neurocognitive performance was assessed using the MATRICS Consensus Cognitive Battery and an electroencephalogram-based 5 Choice-Continuous Performance Test. Tolcapone enhanced visual learning in low-baseline MATRICS Consensus Cognitive Battery performers (d=0.35) and had an opposite effect in high performers (d=0.5), and enhanced verbal fluency across all subjects (P=.03) but had no effect on overall MATRICS Consensus Cognitive Battery performance. Tolcapone reduced false alarm rate (d=0.8) and enhanced frontal P200 amplitude during correctly identified nontarget trials (d=0.6) in low-baseline 5 Choice-Continuous Performance Test performers and had opposite effects in high performers (d=0.5 and d=0.25, respectively). Tolcapone's effect on frontal P200 amplitude and false alarm rate was correlated (rs=-0.4, P=.05). All neurocognitive effects of tolcapone were independent of rs4680 genotype. Tolcapone enhanced neurocognition and engaged electroencephalogram measures relevant to cognitive processes in specific subgroups of healthy individuals. These findings support an experimental medicine model for identifying procognitive treatments and provide a strong basis for future biomarker-informed procognitive studies in schizophrenia patients. © The Author 2017. Published by Oxford University Press on behalf of CINP.

Enhanced control & sensing for the REMOTEC ANDROS Mk VI robot. Final report

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

Spelt, P.F.; Harvey, H.W.

1997-08-01

This Cooperative Research and Development Agreement (CRADA) between Lockheed Marietta Energy Systems, Inc., and REMOTEC, Inc., explored methods of providing operator feedback for various work actions of the ANDROS Mk VI teleoperated robot. In a hazardous environment, an extremely heavy workload seriously degrades the productivity of teleoperated robot operators. This CRADA involved the addition of computer power to the robot along with a variety of sensors and encoders to provide information about the robot`s performance in and relationship to its environment. Software was developed to integrate the sensor and encoder information and provide control input to the robot. ANDROS Mkmore » VI robots are presently used by numerous electric utilities to perform tasks in reactors where substantial exposure to radiation exists, as well as in a variety of other hazardous environments. Further, this platform has potential for use in a number of environmental restoration tasks, such as site survey and detection of hazardous waste materials. The addition of sensors and encoders serves to make the robot easier to manage and permits tasks to be done more safely and inexpensively (due to time saved in the completion of complex remote tasks). Prior research on the automation of mobile platforms with manipulators at Oak Ridge National Laboratory`s Center for Engineering Systems Advanced Research (CESAR, B&R code KC0401030) Laboratory, a BES-supported facility, indicated that this type of enhancement is effective. This CRADA provided such enhancements to a successful working teleoperated robot for the first time. Performance of this CRADA used the CESAR laboratory facilities and expertise developed under BES funding.« less

Exploring the state of health and safety management system performance measurement in mining organizations.

PubMed

Haas, Emily Joy; Yorio, Patrick

2016-03-01

Complex arguments continue to be articulated regarding the theoretical foundation of health and safety management system (HSMS) performance measurement. The culmination of these efforts has begun to enhance a collective understanding. Despite this enhanced theoretical understanding, however, there are still continuing debates and little consensus. The goal of the current research effort was to empirically explore common methods to HSMS performance measurement in mining organizations. The purpose was to determine if value and insight could be added into the ongoing approaches of the best ways to engage in health and safety performance measurement. Nine site-level health and safety management professionals were provided with 133 practices corresponding to 20 HSMS elements, each fitting into the plan, do, check, act phases common to most HSMS. Participants were asked to supply detailed information as to how they (1) assess the performance of each practice in their organization, or (2) would assess each practice if it were an identified strategic imperative. Qualitative content analysis indicated that the approximately 1200 responses provided could be described and categorized into interventions , organizational performance , and worker performance . A discussion of how these categories relate to existing indicator frameworks is provided. The analysis also revealed divergence in two important measurement issues; (1) quantitative vs qualitative measurement and reporting; and (2) the primary use of objective or subjective metrics. In lieu of these findings we ultimately recommend a balanced measurement and reporting approach within the three metric categories and conclude with suggestions for future research.

Exploring the state of health and safety management system performance measurement in mining organizations

PubMed Central

Haas, Emily Joy; Yorio, Patrick

2016-01-01

Complex arguments continue to be articulated regarding the theoretical foundation of health and safety management system (HSMS) performance measurement. The culmination of these efforts has begun to enhance a collective understanding. Despite this enhanced theoretical understanding, however, there are still continuing debates and little consensus. The goal of the current research effort was to empirically explore common methods to HSMS performance measurement in mining organizations. The purpose was to determine if value and insight could be added into the ongoing approaches of the best ways to engage in health and safety performance measurement. Nine site-level health and safety management professionals were provided with 133 practices corresponding to 20 HSMS elements, each fitting into the plan, do, check, act phases common to most HSMS. Participants were asked to supply detailed information as to how they (1) assess the performance of each practice in their organization, or (2) would assess each practice if it were an identified strategic imperative. Qualitative content analysis indicated that the approximately 1200 responses provided could be described and categorized into interventions, organizational performance, and worker performance. A discussion of how these categories relate to existing indicator frameworks is provided. The analysis also revealed divergence in two important measurement issues; (1) quantitative vs qualitative measurement and reporting; and (2) the primary use of objective or subjective metrics. In lieu of these findings we ultimately recommend a balanced measurement and reporting approach within the three metric categories and conclude with suggestions for future research. PMID:26823642

Medical students' note-taking in a medical biochemistry course: an initial exploration.

PubMed

Morrison, Elizabeth H; McLaughlin, Calvin; Rucker, Lloyd

2002-04-01

Beginning medical students spend numerous hours every week attending basic science lectures and taking notes. Medical faculty often wonder whether they should give students pre-printed instructors' notes before lectures. Proponents of this strategy argue that provided notes enhance learning by facilitating the accurate transmission of information, while opponents counter that provided notes inhibit students' cognitive processing or even discourage students from attending lectures. Little if any research has directly addressed medical students' note-taking or the value of providing instructors' notes. The educational literature does suggest that taking lecture notes enhances university students' learning. University students perform best on post-lecture testing if they review a combination of provided notes and their own personal notes, particularly if the provided notes follow a 'skeletal' format that encourages active note-taking.

Incorporation of ionic liquid into porous polymer monoliths to enhance the separation of small molecules in reversed-phase high-performance liquid chromatography.

PubMed

Wang, Jiafei; Bai, Ligai; Wei, Zhen; Qin, Junxiao; Ma, Yamin; Liu, Haiyan

2015-06-01

An ionic liquid was incorporated into the porous polymer monoliths to afford stationary phases with enhanced chromatographic performance for small molecules in reversed-phase high-performance liquid chromatography. The effect of the ionic liquid in the polymerization mixture on the performance of the monoliths was studied in detail. While monoliths without ionic liquid exhibited poor resolution and low efficiency, the addition of ionic liquid to the polymerization mixture provides highly increased resolution and high efficiency. The chromatographic performances of the monoliths were demonstrated by the separations of various small molecules including aromatic hydrocarbons, isomers, and homologues using a binary polar mobile phase. The present column efficiency reached 27 000 plates/m, which showed that the ionic liquid monoliths are alternative stationary phases in the separation of small molecules by high-performance liquid chromatography. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Blue or red? Exploring the effect of color on cognitive task performances.

PubMed

Mehta, Ravi; Zhu, Rui Juliet

2009-02-27

Existing research reports inconsistent findings with regard to the effect of color on cognitive task performances. Some research suggests that blue or green leads to better performances than red; other studies record the opposite. Current work reconciles this discrepancy. We demonstrate that red (versus blue) color induces primarily an avoidance (versus approach) motivation (study 1, n = 69) and that red enhances performance on a detail-oriented task, whereas blue enhances performance on a creative task (studies 2 and 3, n = 208 and 118). Further, we replicate these results in the domains of product design (study 4, n = 42) and persuasive message evaluation (study 5, n = 161) and show that these effects occur outside of individuals' consciousness (study 6, n = 68). We also provide process evidence suggesting that the activation of alternative motivations mediates the effect of color on cognitive task performances.

Digital processing of Mariner 9 television data.

NASA Technical Reports Server (NTRS)

Green, W. B.; Seidman, J. B.

1973-01-01

The digital image processing performed by the Image Processing Laboratory (IPL) at JPL in support of the Mariner 9 mission is summarized. The support is divided into the general categories of image decalibration (the removal of photometric and geometric distortions from returned imagery), computer cartographic projections in support of mapping activities, and adaptive experimenter support (flexible support to provide qualitative digital enhancements and quantitative data reduction of returned imagery). Among the tasks performed were the production of maximum discriminability versions of several hundred frames to support generation of a geodetic control net for Mars, and special enhancements supporting analysis of Phobos and Deimos images.

Enhancing Effective Chemistry Learning through Hypermedia Instructional Mode of Delivery

ERIC Educational Resources Information Center

Abanikannda, Mutahir Oluwafemi

2016-01-01

This study provides a framework for the production of Hypermedia Instructional package. It also assessed the effectiveness of hypermedia instructional mode of delivery on students? performance in Chemistry. This is with a view of improving the learning of Chemistry which may eventually help to improve students? performance. The developmental study…

The Impact of a Performance Profiling Intervention on Athletes' Intrinsic Motivation

ERIC Educational Resources Information Center

Weston, Neil J. V.; Greenlees, Iain A.; Thelwell, Richard C.

2011-01-01

Originally developed by Butler (1989) with the Great Britain Olympic boxing team, performance profiling is an assessment tool primarily used by sport psychologists to enhance athlete awareness. The completed profile provides the athlete, the coach, and psychologist with a visual representation of the athlete's perception of his or her performance…

The Relationship between Student Achievement and Multilingualism: A Quantitative Causal-Comparative Study

ERIC Educational Resources Information Center

Thomson, Jennifer Barbara

2010-01-01

Student performance in basic math and reading skills in the United States trails behind other developed countries, providing the rationale for more research to determine how performance might be improved. Following evidence to conclude that multilingualism enhances cognitive, neuro-linguistic and meta-linguistic development, it is proposed that…

Fusion solution for soldier wearable gunfire detection systems

NASA Astrophysics Data System (ADS)

Cakiades, George; Desai, Sachi; Deligeorges, Socrates; Buckland, Bruce E.; George, Jemin

2012-06-01

Currently existing acoustic based Gunfire Detection Systems (GDS) such as soldier wearable, vehicle mounted, and fixed site devices provide enemy detection and localization capabilities to the user. However, the solution to the problem of portability versus performance tradeoff remains elusive. The Data Fusion Module (DFM), described herein, is a sensor/platform agnostic software supplemental tool that addresses this tradeoff problem by leveraging existing soldier networks to enhance GDS performance across a Tactical Combat Unit (TCU). The DFM software enhances performance by leveraging all available acoustic GDS information across the TCU synergistically to calculate highly accurate solutions more consistently than any individual GDS in the TCU. The networked sensor architecture provides additional capabilities addressing the multiple shooter/fire-fight problems in addition to sniper detection/localization. The addition of the fusion solution to the overall Size, Weight and Power & Cost (SWaP&C) is zero to negligible. At the end of the first-year effort, the DFM integrated sensor network's performance was impressive showing improvements upwards of 50% in comparison to a single sensor solution. Further improvements are expected when the networked sensor architecture created in this effort is fully exploited.

78 FR 42934 - Notice of Scope Rulings

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-18

... Brazil Requestor: Terphane, Inc. and Terphane, Ltda; Certain co-polymer surface films are not within the scope of the antidumping duty order, provided the performance-enhancing co-polymer layer is greater than...

Ensemble LUT classification for degraded document enhancement

NASA Astrophysics Data System (ADS)

Obafemi-Ajayi, Tayo; Agam, Gady; Frieder, Ophir

2008-01-01

The fast evolution of scanning and computing technologies have led to the creation of large collections of scanned paper documents. Examples of such collections include historical collections, legal depositories, medical archives, and business archives. Moreover, in many situations such as legal litigation and security investigations scanned collections are being used to facilitate systematic exploration of the data. It is almost always the case that scanned documents suffer from some form of degradation. Large degradations make documents hard to read and substantially deteriorate the performance of automated document processing systems. Enhancement of degraded document images is normally performed assuming global degradation models. When the degradation is large, global degradation models do not perform well. In contrast, we propose to estimate local degradation models and use them in enhancing degraded document images. Using a semi-automated enhancement system we have labeled a subset of the Frieder diaries collection.1 This labeled subset was then used to train an ensemble classifier. The component classifiers are based on lookup tables (LUT) in conjunction with the approximated nearest neighbor algorithm. The resulting algorithm is highly effcient. Experimental evaluation results are provided using the Frieder diaries collection.1

The effects of non-evaluative feedback on drivers' self-evaluation and performance.

PubMed

Dogan, Ebru; Steg, Linda; Delhomme, Patricia; Rothengatter, Talib

2012-03-01

Drivers' tend to overestimate their competences, which may result in risk taking behavior. Providing drivers with feedback has been suggested as one of the solutions to overcome drivers' inaccurate self-evaluations. In practice, many tests and driving simulators provide drivers with non-evaluative feedback, which conveys information on the level of performance but not on what caused the performance. Is this type of feedback indeed effective in reducing self-enhancement biases? The current study aimed to investigate the effect of non-evaluative performance feedback on drivers' self-evaluations using a computerized hazard perception test. A between-subjects design was used with one group receiving feedback on performance in the hazard perception test while the other group not receiving any feedback. The results indicated that drivers had a robust self-enhancement bias in their self-evaluations regardless of the presence of performance feedback and that they systematically estimated their performance to be higher than they actually achieved in the test. Furthermore, they devalued the credibility of the test instead of adjusting their self-evaluations in order to cope with the negative feelings following the failure feedback. We discuss the theoretical and practical implications of these counterproductive effects of non-evaluative feedback. Copyright © 2011 Elsevier Ltd. All rights reserved.

Full coverage of perovskite layer onto ZnO nanorods via a modified sequential two-step deposition method for efficiency enhancement in perovskite solar cells

NASA Astrophysics Data System (ADS)

Ruankham, Pipat; Wongratanaphisan, Duangmanee; Gardchareon, Atcharawon; Phadungdhitidhada, Surachet; Choopun, Supab; Sagawa, Takashi

2017-07-01

Full coverage of perovskite layer onto ZnO nanorod substrates with less pinholes is crucial for achieving high-efficiency perovskite solar cells. In this work, a two-step sequential deposition method is modified to achieve an appropriate property of perovskite (MAPbI3) film. Surface treatment of perovskite layer and its precursor have been systematically performed and their morphologies have been investigated. By pre-wetting of lead iodide (PbI2) and letting it dry before reacting with methylammonium iodide (MAI) provide better coverage of perovskite film onto ZnO nanorod substrate than one without any treatment. An additional MAI deposition followed with toluene drop-casting technique on the perovskite film is also found to increase the coverage and enhance the transformation of PbI2 to MAPbI3. These lead to longer charge carrier lifetime, resulting in an enhanced power conversion efficiency (PCE) from 1.21% to 3.05%. The modified method could been applied to a complex ZnO nanorods/TiO2 nanoparticles substrate. The enhancement in PCE to 3.41% is observed. These imply that our introduced method provides a simple way to obtain the full coverage and better transformation to MAPbI3 phase for enhancement in performances of perovskite solar cells.

Impact of tuning CO 2-philicity in polydimethylsiloxane-based membranes for carbon dioxide separation

DOE PAGES

Hong, Tao; Chatterjee, Sabornie; Mahurin, Shannon M.; ...

2017-02-22

Amidoxime-functionalized polydimethylsiloxane (AO-PDMSPNB) membranes with various amidoxime compositions were synthesized via ring-opening metathesis polymerization followed by post-polymerization modification. Compared to other previously reported PDMS-based membranes, the amidoxime-functionalized membranes show enhanced CO 2 permeability and CO 2/N 2 selectivity. The overall gas separation performance (CO 2 permeability 6800 Barrer; CO 2/N 2 selectivity 19) of the highest performing membrane exceeds the Robeson upper bound line, and the excellent permeability of the copolymer itself provides great potential for real world applications where huge volumes of gases are separated. This study details how tuning the CO 2-philicity within rubbery polymer matrices influences gasmore » transport properties. Key parameters for tuning gas transport properties are discussed, and the experimental results show good consistency with theoretical calculations. Finally, this study provides a roadmap to enhancing gas separation performance in rubbery polymers by tuning gas solubility selectivity.« less

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

NASA Astrophysics Data System (ADS)

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

2017-03-01

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

Cholinergic enhancement reduces functional connectivity and BOLD variability in visual extrastriate cortex during selective attention

PubMed Central

Ricciardi, Emiliano; Handjaras, Giacomo; Bernardi, Giulio; Pietrini, Pietro; Furey, Maura L.

2012-01-01

Enhancing cholinergic function improves performance on various cognitive tasks and alters neural responses in task specific brain regions. Previous findings by our group strongly suggested that the changes in neural activity observed during increased cholinergic function may reflect an increase in neural efficiency that leads to improved task performance. The current study was designed to assess the effects of cholinergic enhancement on regional brain connectivity and BOLD signal variability. Nine subjects participated in a double-blind, placebo-controlled crossover functional magnetic resonance imaging (fMRI) study. Following an infusion of physostigmine (1mg/hr) or placebo, echo-planar imaging (EPI) was conducted as participants performed a selective attention task. During the task, two images comprised of superimposed pictures of faces and houses were presented. Subjects were instructed periodically to shift their attention from one stimulus component to the other and to perform a matching task using hand held response buttons. A control condition included phase-scrambled images of superimposed faces and houses that were presented in the same temporal and spatial manner as the attention task; participants were instructed to perform a matching task. Cholinergic enhancement improved performance during the selective attention task, with no change during the control task. Functional connectivity analyses showed that the strength of connectivity between ventral visual processing areas and task-related occipital, parietal and prefrontal regions was reduced significantly during cholinergic enhancement, exclusively during the selective attention task. Cholinergic enhancement also reduced BOLD signal temporal variability relative to placebo throughout temporal and occipital visual processing areas, again during the selective attention task only. Together with the observed behavioral improvement, the decreases in connectivity strength throughout task-relevant regions and BOLD variability within stimulus processing regions provide further support to the hypothesis that cholinergic augmentation results in enhanced neural efficiency. PMID:22906685

Steerable dyadic wavelet transform and interval wavelets for enhancement of digital mammography

NASA Astrophysics Data System (ADS)

Laine, Andrew F.; Koren, Iztok; Yang, Wuhai; Taylor, Fred J.

1995-04-01

This paper describes two approaches for accomplishing interactive feature analysis by overcomplete multiresolution representations. We show quantitatively that transform coefficients, modified by an adaptive non-linear operator, can make more obvious unseen or barely seen features of mammography without requiring additional radiation. Our results are compared with traditional image enhancement techniques by measuring the local contrast of known mammographic features. We design a filter bank representing a steerable dyadic wavelet transform that can be used for multiresolution analysis along arbitrary orientations. Digital mammograms are enhanced by orientation analysis performed by a steerable dyadic wavelet transform. Arbitrary regions of interest (ROI) are enhanced by Deslauriers-Dubuc interpolation representations on an interval. We demonstrate that our methods can provide radiologists with an interactive capability to support localized processing of selected (suspicion) areas (lesions). Features extracted from multiscale representations can provide an adaptive mechanism for accomplishing local contrast enhancement. By improving the visualization of breast pathology can improve changes of early detection while requiring less time to evaluate mammograms for most patients.

Enhanced Performance of a Self-Powered Organic/Inorganic Photodetector by Pyro-Phototronic and Piezo-Phototronic Effects.

PubMed

Peng, Wenbo; Wang, Xingfu; Yu, Ruomeng; Dai, Yejing; Zou, Haiyang; Wang, Aurelia C; He, Yongning; Wang, Zhong Lin

2017-06-01

Self-powered photodetectors (PDs) have long been realized by utilizing photovoltaic effect and their performances can be effectively enhanced by introducing the piezo-phototronic effect. Recently, a novel pyro-phototronic effect is invented as an alternative approach for performance enhancement of self-powered PDs. Here, a self-powered organic/inorganic PD is demonstrated and the influences of externally applied strain on the pyro-phototronic and the photovoltaic effects are thoroughly investigated. Under 325 nm 2.30 mW cm -2 UV illumination and at a -0.45% compressive strain, the PD's photocurrent is dramatically enhanced from ≈14.5 to ≈103 nA by combining the pyro-phototronic and piezo-phototronic effects together, showing a significant improvement of over 600%. Theoretical simulations have been carried out via the finite element method to propose the underlying working mechanism. Moreover, the pyro-phototronic effect can be introduced by applying a -0.45% compressive strain to greatly enhance the PD's response to 442 nm illumination, including photocurrent, rise time, and fall time. This work provides in-depth understandings about the pyro-phototronic and the piezo-phototronic effects on the performances of self-powered PD to light sources with different wavelengths and indicates huge potential of these two effects in optoelectronic devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Diagnosis of Spinal Lesions Using Heuristic and Pharmacokinetic Parameters Measured by Dynamic Contrast-Enhanced MRI.

PubMed

Lang, Ning; Yuan, Huishu; Yu, Hon J; Su, Min-Ying

2017-07-01

This study aimed to evaluate the diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in differentiation of four spinal lesions by using heuristic and pharmacokinetic parameters analyzed from DCE signal intensity time course. DCE-MRI of 62 subjects with confirmed myeloma (n = 9), metastatic cancer (n = 22), lymphoma (n = 7), and inflammatory tuberculosis (TB) (n = 24) in the spine were analyzed retrospectively. The region of interest was placed on strongly enhanced tissues. The DCE time course was categorized as the "wash-out," "plateau," or "persistent enhancement" pattern. The maximum enhancement, steepest wash-in enhancement, and wash-out slope using the signal intensity at 67 seconds after contrast injection as reference were measured. The Tofts 2-compartmental pharmacokinetic model was applied to obtain K trans and k ep . Pearson correlation between heuristic and pharmacokinetic parameters was evaluated, and receiver operating characteristic curve analysis was performed for pairwise group differentiation. The mean wash-out slope was -22% ± 10% for myeloma, 1% ± 0.4% for metastatic cancer, 3% ± 3% for lymphoma, and 7% ± 10% for TB, and it could significantly distinguish myeloma from metastasis (area under the curve [AUC] = 0.884), lymphoma (AUC = 1.0), and TB (AUC = 1.0) with P = .001, and distinguish metastasis from TB (AUC = 0.741) with P = .005. The k ep and wash-out slope were highly correlated (r = 0.92), and they showed a similar diagnostic performance. The K trans was significantly correlated with the maximum enhancement (r = 0.71) and the steepest wash-in enhancement (r = 0.85), but they had inferior diagnostic performance compared to the wash-out slope. DCE-MRI may provide additional diagnostic information, and a simple wash-out slope had the best diagnostic performance. The heuristic and pharmacokinetic parameters were highly correlated. Copyright © 2017. Published by Elsevier Inc.

Cone-Beam Computed Tomography (CBCT) Hepatic Arteriography in Chemoembolization for Hepatocellular Carcinoma: Performance Depicting Tumors and Tumor Feeders

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

Lee, In Joon; Chung, Jin Wook, E-mail: chungjw@snu.ac.kr; Yin, Yong Hu

2015-10-15

PurposeThis study was designed to analyze retrospectively the performance of cone-beam computed tomography (CBCT) hepatic arteriography in depicting tumors and their feeders and to investigate the related determining factors in chemoembolization for hepatocellular carcinoma (HCC).MethodsEighty-six patients with 142 tumors satisfying the imaging diagnosis criteria of HCC were included in this study. The performance of CBCT hepatic arteriography for chemoembolization per tumor and per patient was evaluated using maximum intensity projection images alone (MIP analysis) or MIP combined with multiplanar reformation images (MIP + MPR analysis) regarding the following three aspects: tumor depiction, confidence of tumor feeder detection, and trackability of tumor feeders.more » Tumor size, tumor enhancement, tumor location, number of feeders, diaphragmatic motion, portal vein enhancement, and hepatic artery to parenchyma enhancement ratio were regarded as potential determining factors.ResultsTumors were depicted in 125 (88.0 %) and 142 tumors (100 %) on MIP and MIP + MPR analysis, respectively. Imaging performances on MIP and MIP + MPR analysis were good enough to perform subsegmental chemoembolization without additional angiographic investigation in 88 (62.0 %) and 128 tumors (90.1 %) on per-tumor basis and in 43 (50 %) and 73 (84.9 %) on per-patient basis, respectively. Significant determining factors for performance in MIP + MPR analysis on per tumor basis were tumor size (p = 0.030), tumor enhancement (0.005), tumor location (p = 0.001), and diaphragmatic motion (p < 0.001).ConclusionsCBCT hepatic arteriography provided sufficient information for subsegmental chemoembolization by depicting tumors and their feeders in the vast majority of patients. Combined analysis of MIP and MPR images was essential to enhance the performance of CBCT hepatic arteriography.« less

Nonlinear optics in hollow-core photonic bandgap fibers.

PubMed

Bhagwat, Amar R; Gaeta, Alexander L

2008-03-31

Hollow-core photonic-bandgap fibers provide a new geometry for the realization and enhancement of many nonlinear optical effects. Such fibers offer novel guidance and dispersion properties that provide an advantage over conventional fibers for various applications. In this review we summarize the nonlinear optics experiments that have been performed using these hollow-core fibers.

Enhanced image capture through fusion

NASA Technical Reports Server (NTRS)

Burt, Peter J.; Hanna, Keith; Kolczynski, Raymond J.

1993-01-01

Image fusion may be used to combine images from different sensors, such as IR and visible cameras, to obtain a single composite with extended information content. Fusion may also be used to combine multiple images from a given sensor to form a composite image in which information of interest is enhanced. We present a general method for performing image fusion and show that this method is effective for diverse fusion applications. We suggest that fusion may provide a powerful tool for enhanced image capture with broad utility in image processing and computer vision.

Giant Enhancement of Small Photoluminescent Signals on Glass Surfaces Covered by Self-Assembled Silver Nanorings.

PubMed

Sousanis, A; Poulopoulos, P; Karoutsos, V; Trachylis, D; Politis, C

2017-02-01

Self-assembled nanostructures with the shape of nanospheres or nanorings were formed after annealing of ultrathin Ag films grown on glass, in a furnace with air at 460 °C. Intense localized surface plasmon resonances were recorded for these nanostructures with maxima at the green-blue light. The surface became functional in terms of enhancing the weak photoluminescence of glass between 2–400 times. This system provides an easy way of enhancing the photoluminescence emission of initially low performance materials.

The Combined Effects of Classroom Teaching and Learning Strategy Use on Students' Chemistry Self-Efficacy

NASA Astrophysics Data System (ADS)

Cheung, Derek

2015-02-01

For students to be successful in school chemistry, a strong sense of self-efficacy is essential. Chemistry self-efficacy can be defined as students' beliefs about the extent to which they are capable of performing specific chemistry tasks. According to Bandura (Psychol. Rev. 84:191-215, 1977), students acquire information about their level of self-efficacy from four sources: performance accomplishments, vicarious experiences, verbal persuasion, and physiological states. No published studies have investigated how instructional strategies in chemistry lessons can provide students with positive experiences with these four sources of self-efficacy information and how the instructional strategies promote students' chemistry self-efficacy. In this study, questionnaire items were constructed to measure student perceptions about instructional strategies, termed efficacy-enhancing teaching, which can provide positive experiences with the four sources of self-efficacy information. Structural equation modeling was then applied to test a hypothesized mediation model, positing that efficacy-enhancing teaching positively affects students' chemistry self-efficacy through their use of deep learning strategies such as metacognitive control strategies. A total of 590 chemistry students at nine secondary schools in Hong Kong participated in the survey. The mediation model provided a good fit to the student data. Efficacy-enhancing teaching had a direct effect on students' chemistry self-efficacy. Efficacy-enhancing teaching also directly affected students' use of deep learning strategies, which in turn affected students' chemistry self-efficacy. The implications of these findings for developing secondary school students' chemistry self-efficacy are discussed.

Self-efficacy enhancing intervention increases light physical activity in people with chronic obstructive pulmonary disease.

PubMed

Larson, Janet L; Covey, Margaret K; Kapella, Mary C; Alex, Charles G; McAuley, Edward

2014-01-01

People with chronic obstructive pulmonary disease lead sedentary lives and could benefit from increasing their physical activity. The purpose of this study was to determine if an exercise-specific self-efficacy enhancing intervention could increase physical activity and functional performance when delivered in the context of 4 months of upper body resistance training with a 12-month follow-up. IN THIS RANDOMIZED CONTROLLED TRIAL, SUBJECTS WERE ASSIGNED TO: exercise-specific self-efficacy enhancing intervention with upper body resistance training (SE-UBR), health education with upper body resistance training (ED-UBR), or health education with gentle chair exercises (ED-Chair). Physical activity was measured with an accelerometer and functional performance was measured with the Functional Performance Inventory. Forty-nine people with moderate to severe chronic obstructive pulmonary disease completed 4 months of training and provided valid accelerometry data, and 34 also provided accelerometry data at 12 months of follow-up. The self-efficacy enhancing intervention emphasized meeting physical activity guidelines and increasing moderate-to-vigorous physical activity. Differences were observed in light physical activity (LPA) after 4 months of training, time by group interaction effect (P=0.045). The SE-UBR group increased time spent in LPA by +20.68±29.30 minutes/day and the other groups decreased time spent in LPA by -22.43±47.88 minutes/day and -25.73±51.76 minutes/day. Changes in LPA were not sustained at 12-month follow-up. There were no significant changes in moderate-to-vigorous physical activity, sedentary time, or functional performance. Subjects spent most of their waking hours sedentary: 72%±9% for SE-UBR, 68%±10% for ED-UBR, and 74%±9% for ED-Chair. The self-efficacy enhancing intervention produced a modest short-term increase in LPA. Further work is needed to increase the magnitude and duration of effect, possibly by targeting LPA.

The Impact of Organismal Innovation on Functional and Ecological Diversification.

PubMed

Wainwright, Peter C; Price, Samantha A

2016-09-01

Innovations in organismal functional morphology are thought to be a major force in shaping evolutionary patterns, with the potential to drive adaptive radiation and influence the evolutionary prospects for lineages. But the evolutionary consequences of innovation are diverse and usually do not result in adaptive radiation. What factors shape the macroevolutionary impact of innovations? We assert that little is known in general about the macroevolutionary outcomes associated with functional innovations and we discuss a framework for studying biological innovations in an evolutionary context. Innovations are novel functional mechanisms that enhance organismal performance. The ubiquity of trade-offs in functional systems means that enhanced performance on one axis often occurs at the expense of performance on another axis, such that many innovations result in an exchange of performance capabilities, rather than an expansion. Innovations may open up new resources for exploitation but their consequences for functional and ecological diversification depend heavily on the adaptive landscape around these novel resources. As an example of a broader program that we imagine, we survey five feeding innovations in labrid fishes, an exceptionally successful and ecologically diverse group of reef fishes, and explore their impact on the rate of evolution of jaw functional morphology. All of the innovations provide performance enhancements and result in changes in patterns of resource use, but most are not associated with subsequent functional diversification or substantial ecological diversification. Because selection acts on a specific performance enhancement and not on the evolutionary potential of an innovation, the enhancement of diversity may be highly serendipitous. The macroevolutionary potential of innovations depends critically on the interaction between the performance enhancement and the ecological opportunity that is exposed. © The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Using "human state aware" robots to enhance physical human-robot interaction in a cooperative scenario.

PubMed

Guerrero, Carlos Rodriguez; Fraile Marinero, Juan Carlos; Turiel, Javier Perez; Muñoz, Victor

2013-11-01

Human motor performance, speed and variability are highly susceptible to emotional states. This paper reviews the impact of the emotions on the motor control performance, and studies the possibility of improving the perceived skill/challenge relation on a multimodal neural rehabilitation scenario, by means of a biocybernetic controller that modulates the assistance provided by a haptic controlled robot in reaction to undesirable physical and mental states. Results from psychophysiological, performance and self assessment data for closed loop experiments in contrast with their open loop counterparts, suggest that the proposed method had a positive impact on the overall challenge/skill relation leading to an enhanced physical human-robot interaction experience. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

The impact of maths support tutorials on mathematics confidence and academic performance in a cohort of HE Animal Science students

PubMed Central

Amory, Jonathan

2014-01-01

Students embarking on a bioscience degree course, such as Animal Science, often do not have sufficient experience in mathematics. However, mathematics forms an essential and integral part of any bioscience degree and is essential to enhance employability. This paper presents the findings of a project looking at the effect of mathematics tutorials on a cohort of first year animal science and management students. The results of a questionnaire, focus group discussions and academic performance analysis indicate that small group tutorials enhance students’ confidence in maths and improve students’ academic performance. Furthermore, student feedback on the tutorial programme provides a deeper insight into student experiences and the value students assign to the tutorials. PMID:25024925

The impact of maths support tutorials on mathematics confidence and academic performance in a cohort of HE Animal Science students.

PubMed

van Veggel, Nieky; Amory, Jonathan

2014-01-01

Students embarking on a bioscience degree course, such as Animal Science, often do not have sufficient experience in mathematics. However, mathematics forms an essential and integral part of any bioscience degree and is essential to enhance employability. This paper presents the findings of a project looking at the effect of mathematics tutorials on a cohort of first year animal science and management students. The results of a questionnaire, focus group discussions and academic performance analysis indicate that small group tutorials enhance students' confidence in maths and improve students' academic performance. Furthermore, student feedback on the tutorial programme provides a deeper insight into student experiences and the value students assign to the tutorials.

Compact self-powered synchronous energy extraction circuit design with enhanced performance

NASA Astrophysics Data System (ADS)

Liu, Weiqun; Zhao, Caiyou; Badel, Adrien; Formosa, Fabien; Zhu, Qiao; Hu, Guangdi

2018-04-01

Synchronous switching circuit is viewed as an effective solution of enhancing the generator’s performance and providing better adaptability for load variations. A critical issue for these synchronous switching circuits is the self-powered realization. In contrast with other methods, the electronic breaker possesses the advantage of simplicity and reliability. However, beside the energy consumption of the electronic breakers, the parasitic capacitance decreases the available piezoelectric voltage. In this technical note, a new compact design of the self-powered switching circuit using electronic breaker is proposed. The envelope diodes are excluded and only a single envelope capacitor is used. The parasitic capacitance is reduced to half with boosted performance while the components are reduced with cost saved.

ATAMM enhancement and multiprocessing performance evaluation

NASA Technical Reports Server (NTRS)

Stoughton, John W.

1994-01-01

The algorithm to architecture mapping model (ATAAM) is a Petri net based model which provides a strategy for periodic execution of a class of real-time algorithms on multicomputer dataflow architecture. The execution of large-grained, decision-free algorithms on homogeneous processing elements is studied. The ATAAM provides an analytical basis for calculating performance bounds on throughput characteristics. Extension of the ATAMM as a strategy for cyclo-static scheduling provides for a truly distributed ATAMM multicomputer operating system. An ATAAM testbed consisting of a centralized graph manager and three processors is described using embedded firmware on 68HC11 microcontrollers.

Comprehensive study of thin film evaporation from nanoporous membranes for enhanced thermal management

NASA Astrophysics Data System (ADS)

Wilke, Kyle; Barabadi, Banafsheh; Lu, Zhengmao; Zhang, Tiejun; Wang, Evelyn

Performance of emerging electronics is often dictated by the ability to dissipate heat generated in the device. Thin film evaporation from nanopores promises enhanced thermal management by reducing the thermal transport resistance across the liquid film while providing capillary pumping. We present a study of the dependence of evaporation from nanopores on a variety of geometric parameters. Anodic aluminum oxide membranes were used as an experimental template. A biphilic treatment was also used to create a hydrophobic section of the pore to control meniscus location. We demonstrated different heat transfer regimes and observed more than an order of magnitude increase in dissipated heat flux by confining fluid within the nanopore. Pore diameter had little effect on evaporation performance at pore radii of this length scale due to the negligible conduction resistance from the pore wall to the evaporating interface. The dissipated heat flux scaled linearly with porosity as the evaporative area increased. Furthermore, it was demonstrated that moving the meniscus as little as 1 μm into the pore could decrease performance significantly. The results provide a better understanding of evaporation from nanopores and provide guidance in future device design.

Limitation of Optical Enhancement in Ultra-thin Solar Cells Imposed by Contact Selectivity.

PubMed

Islam, Raisul; Saraswat, Krishna

2018-06-11

Ultra-thin crystalline silicon (c-Si) solar cell suffers both from poor light absorption and minority carrier recombination at the contacts resulting in low contact selectivity. Yet most of the research focuses on improving the light absorption by introducing novel light trapping technique. Our work shows that for ultra-thin absorber, the benefit of optical enhancement is limited by low contact selectivity. Using simulation we observe that performance enhancement from light trapping starts to saturate as the absorber scales down because of the increase in probability of the photo-generated carriers to recombine at the metal contact. Therefore, improving the carrier selectivity of the contacts, which reduces the recombination at contacts, is important to improve the performance of the solar cell beyond what is possible by enhancing light absorption only. The impact of improving contact selectivity increases as the absorber thickness scales below 20 micrometer (μm). Light trapping provides better light management and improving contact selectivity provides better photo-generated carrier management. When better light management increases the number of photo-generated carriers, better carrier management is a useful optimization knob to achieve the efficiency close to the thermodynamic limit. Our work explores a design trade-off in detail which is often overlooked by the research community.

Enhanced Supercapacitor Performance Using Electropolymerization of Self-Doped Polyaniline on Carbon Film.

PubMed

Wang, Po-Hsin; Wang, Tzong-Liu; Lin, Wen-Churng; Lin, Hung-Yin; Lee, Mei-Hwa; Yang, Chien-Hsin

2018-03-31

In this work, we electrochemically deposited self-doped polyanilines (SPANI) on the surface of carbon-nanoparticle (CNP) film, enhancing the superficial faradic reactions in supercapacitors and thus improving their performance. SPANI was electrodeposited on the CNP-film employing electropolymerization of aniline (AN) and o-aminobenzene sulfonic acid (SAN) comonomers in solution. Here, SAN acts in dual roles of a self-doped monomer while it also provides an acidic environment which is suitable for electropolymerization. The performance of SPANI-CNP-based supercapacitors significantly depends upon the mole ratio of AN/SAN. Supercapacitor performance was investigated by using cyclic voltammetry (CV), galvanostatic charge and discharge (GCD), and electrochemical impedance spectroscopy (EIS). The optimal performance of SPANI-CNP-based supercapacitor exists at AN/SAN ratio of 1.0, having the specific capacitance of 273.3 Fg -1 at the charging current density of 0.5 Ag -1 .

Personality and job performance: the Big Five revisited.

PubMed

Hurtz, G M; Donovan, J J

2000-12-01

Prior meta-analyses investigating the relation between the Big 5 personality dimensions and job performance have all contained a threat to construct validity, in that much of the data included within these analyses was not derived from actual Big 5 measures. In addition, these reviews did not address the relations between the Big 5 and contextual performance. Therefore, the present study sought to provide a meta-analytic estimate of the criterion-related validity of explicit Big 5 measures for predicting job performance and contextual performance. The results for job performance closely paralleled 2 of the previous meta-analyses, whereas analyses with contextual performance showed more complex relations among the Big 5 and performance. A more critical interpretation of the Big 5-performance relationship is presented, and suggestions for future research aimed at enhancing the validity of personality predictors are provided.

An Integrated Architecture for On-Board Aircraft Engine Performance Trend Monitoring and Gas Path Fault Diagnostics

NASA Technical Reports Server (NTRS)

Simon, Donald L.

2010-01-01

Aircraft engine performance trend monitoring and gas path fault diagnostics are closely related technologies that assist operators in managing the health of their gas turbine engine assets. Trend monitoring is the process of monitoring the gradual performance change that an aircraft engine will naturally incur over time due to turbomachinery deterioration, while gas path diagnostics is the process of detecting and isolating the occurrence of any faults impacting engine flow-path performance. Today, performance trend monitoring and gas path fault diagnostic functions are performed by a combination of on-board and off-board strategies. On-board engine control computers contain logic that monitors for anomalous engine operation in real-time. Off-board ground stations are used to conduct fleet-wide engine trend monitoring and fault diagnostics based on data collected from each engine each flight. Continuing advances in avionics are enabling the migration of portions of the ground-based functionality on-board, giving rise to more sophisticated on-board engine health management capabilities. This paper reviews the conventional engine performance trend monitoring and gas path fault diagnostic architecture commonly applied today, and presents a proposed enhanced on-board architecture for future applications. The enhanced architecture gains real-time access to an expanded quantity of engine parameters, and provides advanced on-board model-based estimation capabilities. The benefits of the enhanced architecture include the real-time continuous monitoring of engine health, the early diagnosis of fault conditions, and the estimation of unmeasured engine performance parameters. A future vision to advance the enhanced architecture is also presented and discussed

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.

Do it well and do it right: The impact of service climate and ethical climate on business performance and the boundary conditions.

PubMed

Jiang, Kaifeng; Hu, Jia; Hong, Ying; Liao, Hui; Liu, Songbo

2016-11-01

Prior research has demonstrated that service climate can enhance unit performance by guiding employees' service behavior to satisfy customers. Extending this literature, we identified ethical climate toward customers as another indispensable organizational climate in service contexts and examined how and when service climate operates in conjunction with ethical climate to enhance business performance of service units. Based on data collected in 2 phases over 6 months from multiple sources of 196 movie theaters, we found that service climate and ethical climate had disparate impacts on business performance, operationalized as an index of customer attendance rate and operating income per labor hour, by enhancing service behavior and reducing unethical behavior, respectively. Furthermore, we found that service behavior and unethical behavior interacted to affect business performance, in such a way that service behavior was more positively related to business performance when unethical behavior was low than when it was high. This interactive effect between service and unethical behaviors was further strengthened by high market turbulence and competitive intensity. These findings provide new insight into theoretical development of service management and offer practical implications about how to maximize business performance of service units by managing organizational climates and employee behaviors synergistically. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Colour in Learning: Its Effect on the Retention Rate of Graduate Students

ERIC Educational Resources Information Center

Olurinola, Oluwakemi; Tayo, Omoniyi

2015-01-01

Cognitive psychologists have discovered different design principles to enhance memory performance. It has been said that retrieving process depends on many variables and one of them is colour. This paper provides an overview of research on colour and learning. It includes the effect of colour on attention, retention and memory performance, and…

DNP enhanced NMR with flip-back recovery

NASA Astrophysics Data System (ADS)

Björgvinsdóttir, Snædís; Walder, Brennan J.; Pinon, Arthur C.; Yarava, Jayasubba Reddy; Emsley, Lyndon

2018-03-01

DNP methods can provide significant sensitivity enhancements in magic angle spinning solid-state NMR, but in systems with long polarization build up times long recycling periods are required to optimize sensitivity. We show how the sensitivity of such experiments can be improved by the classic flip-back method to recover bulk proton magnetization following continuous wave proton heteronuclear decoupling. Experiments were performed on formulations with characteristic build-up times spanning two orders of magnitude: a bulk BDPA radical doped o-terphenyl glass and microcrystalline samples of theophylline, L-histidine monohydrochloride monohydrate, and salicylic acid impregnated by incipient wetness. For these systems, addition of flip-back is simple, improves the sensitivity beyond that provided by modern heteronuclear decoupling methods such as SPINAL-64, and provides optimal sensitivity at shorter recycle delays. We show how to acquire DNP enhanced 2D refocused CP-INADEQUATE spectra with flip-back recovery, and demonstrate that the flip-back recovery method is particularly useful in rapid recycling regimes. We also report Overhauser effect DNP enhancements of over 70 at 592.6 GHz/900 MHz.

Enhanced control and sensing for the REMOTEC ANDROS Mk VI robot. CRADA final report

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

Spelt, P.F.; Harvey, H.W.

1998-08-01

This Cooperative Research and Development Agreement (CRADA) between Lockheed Martin Energy Systems, Inc., and REMOTEC, Inc., explored methods of providing operator feedback for various work actions of the ANDROS Mk VI teleoperated robot. In a hazardous environment, an extremely heavy workload seriously degrades the productivity of teleoperated robot operators. This CRADA involved the addition of computer power to the robot along with a variety of sensors and encoders to provide information about the robot`s performance in and relationship to its environment. Software was developed to integrate the sensor and encoder information and provide control input to the robot. ANDROS Mkmore » VI robots are presently used by numerous electric utilities to perform tasks in reactors where substantial exposure to radiation exists, as well as in a variety of other hazardous environments. Further, this platform has potential for use in a number of environmental restoration tasks, such as site survey and detection of hazardous waste materials. The addition of sensors and encoders serves to make the robot easier to manage and permits tasks to be done more safely and inexpensively (due to time saved in the completion of complex remote tasks). Prior research on the automation of mobile platforms with manipulators at Oak Ridge National Laboratory`s Center for Engineering Systems Advanced Research (CESAR, B&R code KC0401030) Laboratory, a BES-supported facility, indicated that this type of enhancement is effective. This CRADA provided such enhancements to a successful working teleoperated robot for the first time. Performance of this CRADA used the CESAR laboratory facilities and expertise developed under BES funding.« less

Myths and realities of electronics maintenance.

PubMed

Harris, Douglas H

2008-06-01

The author presents and discusses discoveries and developments contributing to enhanced electronics maintenance performance. This body of research is viewed from the vantage point of Nick Bond's 1970 Ely Award-winning article in Human Factors, "Some Persistent Myths About Military Electronics Maintenance." Bond identified a set of myths and summarized research that not only produced information and techniques leading to demonstrably improved maintenance performance but also exploded many unfounded beliefs that were commonly held before the research had been conducted and the findings disseminated. The period from 1964 through 1986, as reflected by publications in the journal, was a productive period of research that led to greater understanding of human factors in electronics maintenance and to numerous advances that contributed, ultimately, to more effective maintenance performance. Technological advances, combined with what we learned about maintenance performance, have substantially reduced the maintenance burden and enhanced the maintenance of electronic systems. Some of the principal lessons learned from this research on electronics maintenance apply to understanding the effects of equipment complexity, providing an optimal role for automation, designing more appropriate on-the-job training, and enhancing troubleshooting skills.

Maneuverability by the sea lion Zalophus californianus: turning performance of an unstable body design.

PubMed

Fish, Frank E; Hurley, Jenifer; Costa, Daniel P

2003-02-01

Maneuverability is critical to the performance of fast-swimming marine mammals that use rapid turns to catch prey. Overhead video recordings were analyzed for two sea lions (Zalophus californianus) turning in the horizontal plane. Unpowered turns were executed by body flexion in conjunction with use of the pectoral and pelvic flippers, which were used as control surfaces. A 90 degree bank angle was used in the turns to vertically orient the control surfaces. Turning radius was dependent on body mass and swimming velocity. Relative minimum radii were 9-17% of body length and were equivalent for pinnipeds and cetaceans. However, Zalophus had smaller turning radii at higher speeds than cetaceans. Rate of turn was inversely related to turn radius. The highest turn rate observed in Zalophus was 690 degrees s(-1). Centripetal acceleration measured up to 5.1 g for Zalophus. Comparison with other marine mammals indicates that Zalophus has a morphology that enhances instability, thus providing enhanced turning performance. Enhanced turning performance is necessary for sea lions to forage after highly elusive prey in structurally complex environments.

Fast assembling microarrays of superparamagnetic Fe3O4@Au nanoparticle clusters as reproducible substrates for surface-enhanced Raman scattering

NASA Astrophysics Data System (ADS)

Ye, Min; Wei, Zewen; Hu, Fei; Wang, Jianxin; Ge, Guanglu; Hu, Zhiyuan; Shao, Mingwang; Lee, Shuit-Tong; Liu, Jian

2015-08-01

It is currently a very active research area to develop new types of substrates which integrate various nanomaterials for surface-enhanced Raman scattering (SERS) techniques. Here we report a unique approach to prepare SERS substrates with reproducible performance. It features silicon mold-assisted magnetic assembling of superparamagnetic Fe3O4@Au nanoparticle clusters (NCs) into arrayed microstructures on a wafer scale. This approach enables the fabrication of both silicon-based and hydrogel-based substrates in a sequential manner. We have demonstrated that strong SERS signals can be harvested from these substrates due to an efficient coupling effect between Fe3O4@Au NCs, with enhancement factors >106. These substrates have been confirmed to provide reproducible SERS signals, with low variations in different locations or batches of samples. We investigate the spatial distributions of electromagnetic field enhancement around Fe3O4@Au NCs assemblies using finite-difference-time-domain (FDTD) simulations. The procedure to prepare the substrates is straightforward and fast. The silicon mold can be easily cleaned out and refilled with Fe3O4@Au NCs assisted by a magnet, therefore being re-useable for many cycles. Our approach has integrated microarray technologies and provided a platform for thousands of independently addressable SERS detection, in order to meet the requirements of a rapid, robust, and high throughput performance.It is currently a very active research area to develop new types of substrates which integrate various nanomaterials for surface-enhanced Raman scattering (SERS) techniques. Here we report a unique approach to prepare SERS substrates with reproducible performance. It features silicon mold-assisted magnetic assembling of superparamagnetic Fe3O4@Au nanoparticle clusters (NCs) into arrayed microstructures on a wafer scale. This approach enables the fabrication of both silicon-based and hydrogel-based substrates in a sequential manner. We have demonstrated that strong SERS signals can be harvested from these substrates due to an efficient coupling effect between Fe3O4@Au NCs, with enhancement factors >106. These substrates have been confirmed to provide reproducible SERS signals, with low variations in different locations or batches of samples. We investigate the spatial distributions of electromagnetic field enhancement around Fe3O4@Au NCs assemblies using finite-difference-time-domain (FDTD) simulations. The procedure to prepare the substrates is straightforward and fast. The silicon mold can be easily cleaned out and refilled with Fe3O4@Au NCs assisted by a magnet, therefore being re-useable for many cycles. Our approach has integrated microarray technologies and provided a platform for thousands of independently addressable SERS detection, in order to meet the requirements of a rapid, robust, and high throughput performance. Electronic supplementary information (ESI) available: XRD, reflection spectra, zeta potential, TEM images, evaluations of reproducibility, EDS, tables of EF and RSD values of different substrates. See DOI: 10.1039/c5nr02491a

Logo recognition using alpha-rooted phase correlation in the radon transform domain

NASA Astrophysics Data System (ADS)

DelMarco, Stephen

2009-08-01

Alpha-rooted phase correlation (ARPC) is a recently-developed variant of classical phase correlation that includes a Fourier domain image enhancement operation. ARPC combines classical phase correlation with alpha-rooting to provide tunable image enhancement. The alpha-rooting parameters may be adjusted to provide a tradeoff between height and width of the ARPC main lobe. A high narrow main lobe peak provides high matching accuracy for aligned images, but reduced matching performance for misaligned logos. A lower, wider peak trades matching accuracy on aligned logos, for improved matching performance on misaligned imagery. Previously, we developed ARPC and used it in the spatial domain for logo recognition as part of an overall automated document analysis problem. However, spatial domain ARPC performance can be sensitive to logo misalignments, including rotational misalignment. In this paper we use ARPC as a match metric in the radon transform domain for logo recognition. In the radon transform domain, rotational misalignments correspond to translations in the radon transform angle parameter. These translations are captured by ARPC, thereby producing rotation-invariant logo matching. In the paper, we first present an overview of ARPC, and then describe the logo matching algorithm. We present numerical performance results demonstrating matching tolerance to rotational misalignments. We demonstrate robustness of the radon transform domain rotation estimation to noise. We present logo verification and recognition performance results using the proposed approach on a public domain logo database. We compare performance results to performance obtained using spatial domain ARPC, and state-of-the-art SURF features, for logos in salt-and-pepper noise.

Is ginseng an ergogenic aid?

PubMed

Bahrke, Michael S; Morgan, William P; Stegner, Aaron

2009-06-01

Ginseng is one of the most popular herbal supplements in the world. Although it is used for the treatment and prevention of many ailments, it is also used to increase work efficiency and is purported to increase energy and physical stamina. Athletes use ginseng for its alleged performance-enhancing attributes. However, many studies examining the pharmacological effects of ginseng on physical performance have not employed sound scientific design and methodology. The purpose of this review is to provide an update on published empirical research focusing primarily on the efficacy of ginseng with respect to physical and athletic performance. Despite attempts in recent investigations to improve on the scientific rigor used in examining the ergogenic properties of ginseng, the authors conclude that many of the same methodological shortcomings observed in earlier studies persist. Enhanced physical performance after ginseng administration in well-designed investigations remains to be demonstrated.

Highly Ordered Periodic Au/TiO₂ Hetero-Nanostructures for Plasmon-Induced Enhancement of the Activity and Stability for Ethanol Electro-oxidation.

PubMed

Jin, Zhao; Wang, Qiyu; Zheng, Weitao; Cui, Xiaoqiang

2016-03-02

The catalytic electro-oxidation of ethanol is the essential technique for direct alcohol fuel cells (DAFCs) in the area of alternative energy for the ability of converting the chemical energy of alcohol into the electric energy directly. Developing highly efficient and stable electrode materials with antipoisoning ability for ethanol electro-oxidation remains a challenge. A highly ordered periodic Au-nanoparticle (NP)-decorated bilayer TiO2 nanotube (BTNT) heteronanostructure was fabricated by a two-step anodic oxidation of Ti foil and the subsequent photoreduction of HAuCl4. The plasmon-induced charge separation on the heterointerface of Au/TiO2 electrode enhances the electrocatalytic activity and stability for the ethanol oxidation under visible light irradiation. The highly ordered periodic heterostructure on the electrode surface enhanced the light harvesting and led to the greater performance of ethanol electro-oxidation under irradiation compared with the ordinary Au NPs-decorated monolayer TiO2 nanotube (MTNT). This novel Au/TiO2 electrode also performed a self-cleaning property under visible light attributed to the enhanced electro-oxidation of the adsorbed intermediates. This light-driven enhancement of the electrochemical performances provides a development strategy for the design and construction of DAFCs.

Sentinel-3 SAR Altimetry over Coastal and Open Ocean: performance assessment and improved retrieval methods in the ESA SCOOP Project.

NASA Astrophysics Data System (ADS)

Benveniste, J.; Cotton, D.; Moreau, T.; Raynal, M.; Varona, E.; Cipollini, P.; Cancet, M.; Martin, F.; Fenoglio-Marc, L.; Naeije, M.; Fernandes, J.; Lazaro, C.; Restano, M.; Ambrózio, A.

2017-12-01

The ESA Sentinel-3 satellite, launched in February 2016 as a part of the Copernicus programme, is the second satellite to operate a SAR mode altimeter. The Sentinel 3 Synthetic Aperture Radar Altimeter (SRAL) is based on the heritage from Cryosat-2, but this time complemented by a Microwave Radiometer (MWR) to provide a wet troposphere correction, and operating at Ku and C-Bands to provide an accurate along-track ionospheric correction. The SRAL is operated in SAR mode over the whole ocean and promises increased performance w.r.t. conventional altimetry. SCOOP (SAR Altimetry Coastal & Open Ocean Performance) is a project funded under the ESA SEOM (Scientific Exploitation of Operational Missions) Programme Element, started in September 2015, to characterise the expected performance of Sentinel-3 SRAL SAR mode altimeter products, in the coastal zone and open-ocean, and then to develop and evaluate enhancements to the baseline processing scheme in terms of improvements to ocean measurements. There is also a work package to develop and evaluate an improved Wet Troposphere correction for Sentinel-3, based on the measurements from the on-board MWR, further enhanced mostly in the coastal and polar regions using third party data, and provide recommendations for use. In this presentation we present results from the SCOOP project that demonstrate the excellent performance of SRAL in terms of measurement precision, and we illustrate the development and testing of new processing approaches designed specifically to improve performance close to the coast. The SCOOP test data sets and relevant documentation are available to external researchers on application to the project team. At the end of the project recommendations for further developments and implementations will be provided through a scientific roadmap.

Explaining Match Outcome During The Men’s Basketball Tournament at The Olympic Games

PubMed Central

Leicht, Anthony S.; Gómez, Miguel A.; Woods, Carl T.

2017-01-01

In preparation for the Olympics, there is a limited opportunity for coaches and athletes to interact regularly with team performance indicators providing important guidance to coaches for enhanced match success at the elite level. This study examined the relationship between match outcome and team performance indicators during men’s basketball tournaments at the Olympic Games. Twelve team performance indicators were collated from all men’s teams and matches during the basketball tournament of the 2004-2016 Olympic Games (n = 156). Linear and non-linear analyses examined the relationship between match outcome and team performance indicator characteristics; namely, binary logistic regression and a conditional interference (CI) classification tree. The most parsimonious logistic regression model retained ‘assists’, ‘defensive rebounds’, ‘field-goal percentage’, ‘fouls’, ‘fouls against’, ‘steals’ and ‘turnovers’ (delta AIC <0.01; Akaike weight = 0.28) with a classification accuracy of 85.5%. Conversely, four performance indicators were retained with the CI classification tree with an average classification accuracy of 81.4%. However, it was the combination of ‘field-goal percentage’ and ‘defensive rebounds’ that provided the greatest probability of winning (93.2%). Match outcome during the men’s basketball tournaments at the Olympic Games was identified by a unique combination of performance indicators. Despite the average model accuracy being marginally higher for the logistic regression analysis, the CI classification tree offered a greater practical utility for coaches through its resolution of non-linear phenomena to guide team success. Key points A unique combination of team performance indicators explained 93.2% of winning observations in men’s basketball at the Olympics. Monitoring of these team performance indicators may provide coaches with the capability to devise multiple game plans or strategies to enhance their likelihood of winning. Incorporation of machine learning techniques with team performance indicators may provide a valuable and strategic approach to explain patterns within multivariate datasets in sport science. PMID:29238245

VRX-03011, a novel 5-HT4 agonist, enhances memory and hippocampal acetylcholine efflux.

PubMed

Mohler, Eric G; Shacham, Sharon; Noiman, Silvia; Lezoualc'h, Frank; Robert, Sylvain; Gastineau, Monique; Rutkowski, Joseph; Marantz, Yael; Dumuis, Aline; Bockaert, Joel; Gold, Paul E; Ragozzino, Michael E

2007-09-01

Recent evidence suggests that 5-hydroxytryptamine (5-HT)(4) receptor activity enhances cognition and provides neuroprotection. Here we report the effects of VRX-03011, a novel partial 5-HT(4) agonist, that is both potent (K(i) approximately 30 nM) and highly selective (K(i) > 5 microM for all other 5-HT receptors tested). In separate experiments, rats received VRX-03011 (0.1-10 mg/kg i.p.) 30 min prior to spontaneous alternation testing in a no-delay or a 30-s delay condition. VRX-03011 (1, 5 and 10 mg/kg, but not 0.1 mg/kg) significantly enhanced delayed spontaneous alternation performance while none of the doses enhanced performance in the no-delay test. VRX-03011 (1 and 5 mg/kg) concomitantly enhanced hippocampal acetylcholine output and delayed spontaneous alternation scores compared to that of vehicle controls, but had no effect on hippocampal acetylcholine release under a resting condition. Moreover, suboptimal doses of VRX-03011 and the acetylcholinesterase inhibitor galanthamine combined to enhance memory. VRX-03011 also regulated amyloid precursor protein (APP) metabolism by inducing a concentration-dependent increase in the non-amyloidogenic soluble form of APP (sAPPalpha) with an EC(50) approximately 1--10 nM. VRX-03011 had no effect on contractile properties in guinea pig ileum or colon preparations with an EC(50) > 10 microM and did not alter rat intestinal transit at doses up to 10 mg/kg. These findings suggest that VRX-03011 may represent a novel treatment for Alzheimer's disease that reduces cognitive impairments and provides neuroprotection without gastrointestinal side effects.

Nanowire-based thermoelectrics

NASA Astrophysics Data System (ADS)

Ali, Azhar; Chen, Yixi; Vasiraju, Venkata; Vaddiraju, Sreeram

2017-07-01

Research on thermoelectrics has seen a huge resurgence since the early 1990s. The ability of tuning a material’s electrical and thermal transport behavior upon nanostructuring has led to this revival. Nevertheless, thermoelectric performances of nanowires and related materials lag far behind those achieved with thin-film superlattices and quantum dot-based materials. This is despite the fact that nanowires offer many distinct advantages in enhancing the thermoelectric performances of materials. The simplicity of the strategy is the first and foremost advantage. For example, control of the nanowire diameters and their surface roughnesses will aid in enhancing their thermoelectric performances. Another major advantage is the possibility of obtaining high thermoelectric performances using simpler nanowire chemistries (e.g., elemental and binary compound semiconductors), paving the way for the fabrication of thermoelectric modules inexpensively from non-toxic elements. In this context, the topical review provides an overview of the current state of nanowire-based thermoelectrics. It concludes with a discussion of the future vision of nanowire-based thermoelectrics, including the need for developing strategies aimed at the mass production of nanowires and their interface-engineered assembly into devices. This eliminates the need for trial-and-error strategies and complex chemistries for enhancing the thermoelectric performances of materials.

The Performance Improvement of N2 Plasma Treatment on ZrO2 Gate Dielectric Thin-Film Transistors with Atmospheric Pressure Plasma-Enhanced Chemical Vapor Deposition IGZO Channel.

PubMed

Wu, Chien-Hung; Huang, Bo-Wen; Chang, Kow-Ming; Wang, Shui-Jinn; Lin, Jian-Hong; Hsu, Jui-Mei

2016-06-01

The aim of this paper is to illustrate the N2 plasma treatment for high-κ ZrO2 gate dielectric stack (30 nm) with indium-gallium-zinc-oxide (IGZO) thin-film transistors (TFTs). Experimental results reveal that a suitable incorporation of nitrogen atoms could enhance the device performance by eliminating the oxygen vacancies and provide an amorphous surface with better surface roughness. With N2 plasma treated ZrO2 gate, IGZO channel is fabricated by atmospheric pressure plasma-enhanced chemical vapor deposition (AP-PECVD) technique. The best performance of the AP-PECVD IGZO TFTs are obtained with 20 W-90 sec N2 plasma treatment with field-effect mobility (μ(FET)) of 22.5 cm2/V-s, subthreshold swing (SS) of 155 mV/dec, and on/off current ratio (I(on)/I(off)) of 1.49 x 10(7).

Enhanced terahertz imaging system performance analysis and design tool for concealed weapon identification

NASA Astrophysics Data System (ADS)

Murrill, Steven R.; Franck, Charmaine C.; Espinola, Richard L.; Petkie, Douglas T.; De Lucia, Frank C.; Jacobs, Eddie L.

2011-11-01

The U.S. Army Research Laboratory (ARL) and the U.S. Army Night Vision and Electronic Sensors Directorate (NVESD) have developed a terahertz-band imaging system performance model/tool for detection and identification of concealed weaponry. The details of the MATLAB-based model which accounts for the effects of all critical sensor and display components, and for the effects of atmospheric attenuation, concealment material attenuation, and active illumination, were reported on at the 2005 SPIE Europe Security & Defence Symposium (Brugge). An advanced version of the base model that accounts for both the dramatic impact that target and background orientation can have on target observability as related to specular and Lambertian reflections captured by an active-illumination-based imaging system, and for the impact of target and background thermal emission, was reported on at the 2007 SPIE Defense and Security Symposium (Orlando). This paper will provide a comprehensive review of an enhanced, user-friendly, Windows-executable, terahertz-band imaging system performance analysis and design tool that now includes additional features such as a MODTRAN-based atmospheric attenuation calculator and advanced system architecture configuration inputs that allow for straightforward performance analysis of active or passive systems based on scanning (single- or line-array detector element(s)) or staring (focal-plane-array detector elements) imaging architectures. This newly enhanced THz imaging system design tool is an extension of the advanced THz imaging system performance model that was developed under the Defense Advanced Research Project Agency's (DARPA) Terahertz Imaging Focal-Plane Technology (TIFT) program. This paper will also provide example system component (active-illumination source and detector) trade-study analyses using the new features of this user-friendly THz imaging system performance analysis and design tool.

Advanced Liquid Cooling for a Traction Drive Inverter Using Jet Impingement and Microfinned Enhanced Surfaces: Preprint

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

Waye, S. K.; Narumanchi, S.; Mihalic, M.

2014-08-01

Jet impingement on plain and micro-finned enhanced surfaces was compared to a traditional channel flow configuration. The jets provide localized cooling to areas heated by the insulated-gate bipolar transistor and diode devices. Enhanced microfinned surfaces increase surface area and thermal performance. Using lighter materials and designing the fluid path to manage pressure losses increases overall performance while reducing weight, volume, and cost. Powering four diodes in the center power module of the inverter and computational fluid dynamics (CFD) modeling was used to characterize the baseline as well as jet-impingement-based heat exchangers. CFD modeling showed the thermal performance improvements should holdmore » for a fully powered inverter. Increased thermal performance was observed for the jet-impingement configurations when tested at full inverter power (40 to 100 kW output power) on a dynamometer. The reliability of the jets and enhanced surfaces over time was also investigated. Experimentally, the junction-to- coolant thermal resistance was reduced by up to 12.5% for jet impingement on enhanced surfaces s compared to the baseline channel flow configuration. Base plate-to-coolant (convective) resistance was reduced by up to 37.0% for the jet-based configuration compared to the baseline, suggesting that while improvements to the cooling side reduce overall resistance, reducing the passive stack resistance may contribute to lowering overall junction-to-coolant resistance. Full inverter power testing showed reduced thermal resistance from the middle of the module baseplate to coolant of up to 16.5%. Between the improvement in thermal performance and pumping power, the coefficient of performance improved by up to 13% for the jet-based configuration.« less

Reflection: moving from a mandatory ritual to meaningful professional development.

PubMed

Murdoch-Eaton, Deborah; Sandars, John

2014-03-01

Reflection has become established as a key principle underpinning maintenance of standards within professional education and practice. A requirement to evidence reflection within performance review is intended to develop a transformative approach to practice, identify developmental goals, and ultimately, improve healthcare. However, some applications have taken an excessively instrumental approach to the evidencing of reflection, and while they have provided useful templates or framing devices for recording individualistic reflective practice, they potentially have distorted the original intentions. This article revisits the educational theory underpinning the importance of reflection for enhancing performance and considers how to enhance its value within current paediatric practice.

75 FR 7628 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Joint Venture...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-22

... nanocomposites, nanocrystals dispersed in polymers, to create materials with enhanced performance and new functionality that cannot be provided by polymers or traditional composites. Patricia A. Brink, Deputy Director...

Feedforward Self-Modeling Enhances Skill Acquisition in Children Learning Trampoline Skills

PubMed Central

Ste-Marie, Diane M.; Vertes, Kelly; Rymal, Amanda M.; Martini, Rose

2011-01-01

The purpose of this research was to examine whether children would benefit from a feedforward self-modeling (FSM) video and to explore possible explanatory mechanisms for the potential benefits, using a self-regulation framework. To this end, children were involved in learning two five-skill trampoline routines. For one of the routines, a FSM video was provided during acquisition, whereas only verbal instructions were provided for the alternate routine. The FSM involved editing video footage such that it showed the learner performing the trampoline routine at a higher skill level than their current capability. Analyses of the data showed that while physical performance benefits were observed for the routine that was learned with the FSM video, no differences were obtained in relation to the self-regulatory measures. Thus, the FSM video enhanced motor skill acquisition, but this could not be explained by changes to the varied self-regulatory processes examined. PMID:21779270

Sub-50-nm self-assembled nanotextures for enhanced broadband antireflection in silicon solar cells.

PubMed

Rahman, Atikur; Ashraf, Ahsan; Xin, Huolin; Tong, Xiao; Sutter, Peter; Eisaman, Matthew D; Black, Charles T

2015-01-21

Materials providing broadband light antireflection have applications as highly transparent window coatings, military camouflage, and coatings for efficiently coupling light into solar cells and out of light-emitting diodes. In this work, densely packed silicon nanotextures with feature sizes smaller than 50 nm enhance the broadband antireflection compared with that predicted by their geometry alone. A significant fraction of the nanotexture volume comprises a surface layer whose optical properties differ substantially from those of the bulk, providing the key to improved performance. The nanotexture reflectivity is quantitatively well-modelled after accounting for both its profile and changes in refractive index at the surface. We employ block copolymer self-assembly for precise and tunable nanotexture design in the range of ~10-70 nm across macroscopic solar cell areas. Implementing this efficient antireflection approach in crystalline silicon solar cells significantly betters the performance gain compared with an optimized, planar antireflection coating.

Third-generation intelligent IR focal plane arrays

NASA Astrophysics Data System (ADS)

Caulfield, H. John; Jack, Michael D.; Pettijohn, Kevin L.; Schlesselmann, John D.; Norworth, Joe

1998-03-01

SBRC is at the forefront of industry in developing IR focal plane arrays including multi-spectral technology and '3rd generation' functions that mimic the human eye. 3rd generation devices conduct advanced processing on or near the FPA that serve to reduce bandwidth while performing needed functions such as automatic target recognition, uniformity correction and dynamic range enhancement. These devices represent a solution for processing the exorbitantly high bandwidth coming off large area FPAs without sacrificing systems sensitivity. SBRC's two-color approach leverages the company's HgCdTe technology to provide simultaneous multiband coverage, from short through long wave IR, with near theoretical performance. IR systems that are sensitive to different spectral bands achieve enhanced capabilities for target identification and advanced discrimination. This paper will provide a summary of the issues, the technology and the benefits of SBRC's third generation smart and two-color FPAs.

Feedforward self-modeling enhances skill acquisition in children learning trampoline skills.

PubMed

Ste-Marie, Diane M; Vertes, Kelly; Rymal, Amanda M; Martini, Rose

2011-01-01

The purpose of this research was to examine whether children would benefit from a feedforward self-modeling (FSM) video and to explore possible explanatory mechanisms for the potential benefits, using a self-regulation framework. To this end, children were involved in learning two five-skill trampoline routines. For one of the routines, a FSM video was provided during acquisition, whereas only verbal instructions were provided for the alternate routine. The FSM involved editing video footage such that it showed the learner performing the trampoline routine at a higher skill level than their current capability. Analyses of the data showed that while physical performance benefits were observed for the routine that was learned with the FSM video, no differences were obtained in relation to the self-regulatory measures. Thus, the FSM video enhanced motor skill acquisition, but this could not be explained by changes to the varied self-regulatory processes examined.

Twelve tips to promote successful development of a learner performance dashboard within a medical education program.

PubMed

Boscardin, Christy; Fergus, Kirkpatrick B; Hellevig, Bonnie; Hauer, Karen E

2017-11-09

Easily accessible and interpretable performance data constitute critical feedback for learners that facilitate informed self-assessment and learning planning. To provide this feedback, there has been a proliferation of educational dashboards in recent years. An educational (learner) dashboard systematically delivers timely and continuous feedback on performance and can provide easily visualized and interpreted performance data. In this paper, we provide practical tips for developing a functional, user-friendly individual learner performance dashboard and literature review of dashboard development, assessment theory, and users' perspectives. Considering key design principles and maximizing current technological advances in data visualization techniques can increase dashboard utility and enhance the user experience. By bridging current technology with assessment strategies that support learning, educators can continue to improve the field of learning analytics and design of information management tools such as dashboards in support of improved learning outcomes.

Facile synthesis of NiAl-layered double hydroxide/graphene hybrid with enhanced electrochemical properties for detection of dopamine

NASA Astrophysics Data System (ADS)

Li, Meixia; Zhu, Jun E.; Zhang, Lili; Chen, Xu; Zhang, Huimin; Zhang, Fazhi; Xu, Sailong; Evans, David G.

2011-10-01

Layered double hydroxides (LDHs), also known as hydrotalcite-like anionic clays, have been investigated widely as promising electrochemical active materials. Due to the inherently weak conductivity, the electrochemical properties of LDHs were improved typically by utilization of either functional molecules intercalated between LDH interlayer galleries, or proteins confined between exfoliated LDH nanosheets. Here, we report a facile protocol to prepare NiAl-LDH/graphene (NiAl-LDH/G) nanocomposites using a conventional coprecipitation process under low-temperature conditions and subsequent reduction of the supporting graphene oxide. Electrochemical tests showed that the NiAl-LDH/G modified electrode exhibited highly enhanced electrochemical performance of dopamine electrooxidation in comparison with the pristine NiAl-LDH modified electrode. Results of high-resolution transmission electron microscopy and Raman spectra provide convincing information on the nanostructure and composition underlying the enhancement. Our results of the NiAl-LDH/G modified electrodes with the enhanced electrochemical performance may allow designing a variety of promising hybrid sensors via a simple and feasible approach.Layered double hydroxides (LDHs), also known as hydrotalcite-like anionic clays, have been investigated widely as promising electrochemical active materials. Due to the inherently weak conductivity, the electrochemical properties of LDHs were improved typically by utilization of either functional molecules intercalated between LDH interlayer galleries, or proteins confined between exfoliated LDH nanosheets. Here, we report a facile protocol to prepare NiAl-LDH/graphene (NiAl-LDH/G) nanocomposites using a conventional coprecipitation process under low-temperature conditions and subsequent reduction of the supporting graphene oxide. Electrochemical tests showed that the NiAl-LDH/G modified electrode exhibited highly enhanced electrochemical performance of dopamine electrooxidation in comparison with the pristine NiAl-LDH modified electrode. Results of high-resolution transmission electron microscopy and Raman spectra provide convincing information on the nanostructure and composition underlying the enhancement. Our results of the NiAl-LDH/G modified electrodes with the enhanced electrochemical performance may allow designing a variety of promising hybrid sensors via a simple and feasible approach. Electronic supplementary information (ESI) available: Fig. S1 showing 2D fast Fourier transform (FFT) image of NiAl-LDH phase in NiAl-LDH/G composites, and Fig. S2 showing CV curve of the pristine G modified electrode. See DOI: 10.1039/c1nr10592b.

Enhanced change detection performance reveals improved strategy use in avid action video game players.

PubMed

Clark, Kait; Fleck, Mathias S; Mitroff, Stephen R

2011-01-01

Recent research has shown that avid action video game players (VGPs) outperform non-video game players (NVGPs) on a variety of attentional and perceptual tasks. However, it remains unknown exactly why and how such differences arise; while some prior research has demonstrated that VGPs' improvements stem from enhanced basic perceptual processes, other work indicates that they can stem from enhanced attentional control. The current experiment used a change-detection task to explore whether top-down strategies can contribute to VGPs' improved abilities. Participants viewed alternating presentations of an image and a modified version of the image and were tasked with detecting and localizing the changed element. Consistent with prior claims of enhanced perceptual abilities, VGPs were able to detect the changes while requiring less exposure to the change than NVGPs. Further analyses revealed this improved change detection performance may result from altered strategy use; VGPs employed broader search patterns when scanning scenes for potential changes. These results complement prior demonstrations of VGPs' enhanced bottom-up perceptual benefits by providing new evidence of VGPs' potentially enhanced top-down strategic benefits. Copyright © 2010 Elsevier B.V. All rights reserved.

Pediatric digital chest imaging.

PubMed

Tarver, R D; Cohen, M; Broderick, N J; Conces, D J

1990-01-01

The Philips Computed Radiography system performs well with pediatric portable chest radiographs, handling the throughout of a busy intensive care service 24 hours a day. Images are excellent and routinely provide a conventional (unenhanced) image and an edge-enhanced image. Radiation dose is decreased by the lowered frequency of repeat examinations and the ability of the plates to respond to a much lower dose and still provide an adequate image. The high quality and uniform density of serial PCR portable radiographs greatly enhances diagnostic content of the films. Decreased resolution has not been a problem clinically. Image manipulation and electronic transfer to remote viewing stations appear to be helpful and are currently being evaluated further. The PCR system provides a marked improvement in pediatric portable chest radiology.

Enhancing the Benefit of the Chemical Mixture Methodology: A Report on Methodology Testing and Potential Approaches for Improving Performance

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

Yu, Xiao-Ying; Yao, Juan; He, Hua

2012-01-01

Extensive testing shows that the current version of the Chemical Mixture Methodology (CMM) is meeting its intended mission to provide conservative estimates of the health effects from exposure to airborne chemical mixtures. However, the current version of the CMM could benefit from several enhancements that are designed to improve its application of Health Code Numbers (HCNs) and employ weighting factors to reduce over conservatism.

An Enhanced Reservation-Based MAC Protocol for IEEE 802.15.4 Networks

PubMed Central

Afonso, José A.; Silva, Helder D.; Macedo, Pedro; Rocha, Luis A.

2011-01-01

The IEEE 802.15.4 Medium Access Control (MAC) protocol is an enabling standard for wireless sensor networks. In order to support applications requiring dedicated bandwidth or bounded delay, it provides a reservation-based scheme named Guaranteed Time Slot (GTS). However, the GTS scheme presents some drawbacks, such as inefficient bandwidth utilization and support to a maximum of only seven devices. This paper presents eLPRT (enhanced Low Power Real Time), a new reservation-based MAC protocol that introduces several performance enhancing features in comparison to the GTS scheme. This MAC protocol builds on top of LPRT (Low Power Real Time) and includes various mechanisms designed to increase data transmission reliability against channel errors, improve bandwidth utilization and increase the number of supported devices. A motion capture system based on inertial and magnetic sensors has been used to validate the protocol. The effectiveness of the performance enhancements introduced by each of the new features is demonstrated through the provision of both simulation and experimental results. PMID:22163826

Water-processed carbon nanotube/graphene hybrids with enhanced field emission properties

NASA Astrophysics Data System (ADS)

Song, Meng; Xu, Peng; Song, Yenan; Wang, Xu; Li, Zhenhua; Shang, Xuefu; Wu, Huizhen; Zhao, Pei; Wang, Miao

2015-09-01

Integrating carbon nanotubes (CNTs) and graphene into hybrid structures provides a novel approach to three dimensional (3D) materials with advantageous properties. Here we present a water-processing method to create integrated CNT/graphene hybrids and test their field emission properties. With an optimized mass ratio of CNTs to graphene, the hybrid shows a significantly enhanced field emission performance, such as turn-on electric field of 0.79 V/μm, threshold electric field of 1.05 V/μm, maximum current density of 0.1 mA/cm2, and field enhancement factor of ˜1.3 × 104. The optimized mass ratio for field emission emphasizes the importance of both CNTs and graphene in the hybrid. We also hypothesize a possible mechanism for this enhanced field emission performance from the CNT/graphene hybrid. During the solution treatment, graphene oxide behaves as surfactant sheets for CNTs to form a well dispersed solution, which leads to a better organized 3D structure with more conducting channels for electron transport.

Correlates of quality educational programs.

PubMed

Chester, Deborah R; Tracy, Jessamyn A; Earp, Emily; Chauhan, Reetu

2002-06-01

Preliminary evaluation findings are presented that explore relationships between educational program quality and program characteristics such as program type, security level, aftercare, teacher certification, facility size, and private versus public provider. Several program characteristics are found to be related to measurements of educational program quality. Among the major quality characteristics are proportion of program teachers that are professionally certified, smaller sized facilities versus larger facilities, level of aftercare services, and provider sources, with private for-profit providers being the lowest performing and public providers being the highest performing. The article closes with description of the Juvenile Justice Educational Enhancement Program's continuing evaluation of correlates to educational program quality through the continued development of a comprehensive database.

Surface modification of nanoporous anodic alumina photonic crystals for photocatalytic applications

NASA Astrophysics Data System (ADS)

Lim, Siew Yee; Law, Cheryl Suwen; Santos, Abel

2018-01-01

Herein, we report on the development of a rationally designed composite photocatalyst material by combining nanoporous anodic alumina-rugate filters (NAA-RFs) with photo-active layers of titanium dioxide (TiO2). NAA-RFs are synthesised by sinusoidal pulse anodisation and subsequently functionalised with TiO2 by sol-gel method to provide the photonic structures with photocatalytic properties. We demonstrate that the characteristic photonic stopband (PSB) of the surface-modified NAA-RFs can be precisely tuned across the UV-visible-NIR spectrum to enhance the photon-toelectron conversion of TiO2 by `slow photon effect'. We systematically investigate the effect of the anodisation parameters (i.e. anodisation period and pore widening time) on the position of the PSB of NAA-RFs as well as the photocatalytic performances displayed by these photonic crystal structures. When the edges of the PSB of surfacemodified NAA-RFs are positioned closely to the absorption peak of the model organic dye (i.e. methyl orange - MO), the photocatalytic performance of the system to degrade these molecules is enhanced under simulated solar light irradiation due to slow photon effect. Our investigation also reveals that the photocatalytic activity of surface-modified NAA-RFs is independent of slow photon effect and enhances with increasing period length (i.e. increasing anodisation period) of the photonic structures when there is no overlap between the PSB and the absorption peak of MO. This study therefore provides a rationale towards the photocatalytic enhancement of photonic crystals by a rational design of the PSB, creating new opportunities for the future development of high-performance photocatalysts.

The potential for gaming techniques in radiology education and practice.

PubMed

Reiner, Bruce; Siegel, Eliot

2008-02-01

Traditional means of communication, education and training, and research have been dramatically transformed with the advent of computerized medicine, and no other medical specialty has been more greatly affected than radiology. Of the myriad of newer computer applications currently available, computer gaming stands out for its unique potential to enhance end-user performance and job satisfaction. Research in other disciplines has demonstrated computer gaming to offer the potential for enhanced decision making, resource management, visual acuity, memory, and motor skills. Within medical imaging, video gaming provides a novel means to enhance radiologist and technologist performance and visual perception by increasing attentional capacity, visual field of view, and visual-motor coordination. These enhancements take on heightened importance with the increasing size and complexity of three-dimensional imaging datasets. Although these operational gains are important in themselves, psychologic gains intrinsic to video gaming offer the potential to reduce stress and improve job satisfaction by creating a fun and engaging means of spirited competition. By creating customized gaming programs and rewards systems, video game applications can be customized to the skill levels and preferences of individual users, thereby creating a comprehensive means to improve individual and collective job performance.

ASME Nuclear Crane Standards for Enhanced Crane Safety and Increased Profit

NASA Astrophysics Data System (ADS)

Parkhurst, Stephen N.

2000-01-01

The ASME NOG-1 standard, 'Rules for Construction of Overhead and Gantry Cranes', covers top running cranes for nuclear facilities; with the ASME NUM-1 standard, 'Rules for Construction of Cranes, Monorails, and Hoists', covering the single girder, underhung, wall and jib cranes, as well as the monorails and hoists. These two ASME nuclear crane standards provide criteria for designing, inspecting and testing overhead handling equipment with enhanced safety to meet the 'defense-in-depth' approach of the United States Nuclear Regulatory Commission (USNRC) documents NUREG 0554 and NUREG 0612. In addition to providing designs for enhanced safety, the ASME nuclear crane standards provide a basis for purchasing overhead handling equipment with standard safety features, based upon accepted engineering principles, and including performance and environmental parameters specific to nuclear facilities. The ASME NOG-1 and ASME NUM-1 standards not only provide enhanced safety for handling a critical load, but also increase profit by minimizing the possibility of load drops, by reducing cumbersome operating restrictions, and by providing the foundation for a sound licensing position. The ASME nuclear crane standards can also increase profit by providing the designs and information to help ensure that the right standard equipment is purchased. Additionally, the ASME nuclear crane standards can increase profit by providing designs and information to help address current issues, such as the qualification of nuclear plant cranes for making 'planned engineered lifts' for steam generator replacement and decommissioning.

A Novel Approach to Noise-Filtering Based on a Gain-Scheduling Neural Network Architecture

NASA Technical Reports Server (NTRS)

Troudet, T.; Merrill, W.

1994-01-01

A gain-scheduling neural network architecture is proposed to enhance the noise-filtering efficiency of feedforward neural networks, in terms of both nominal performance and robustness. The synergistic benefits of the proposed architecture are demonstrated and discussed in the context of the noise-filtering of signals that are typically encountered in aerospace control systems. The synthesis of such a gain-scheduled neurofiltering provides the robustness of linear filtering, while preserving the nominal performance advantage of conventional nonlinear neurofiltering. Quantitative performance and robustness evaluations are provided for the signal processing of pitch rate responses to typical pilot command inputs for a modern fighter aircraft model.

Enhanced electrochemical performance of monoclinic WO3 thin film with redox additive aqueous electrolyte.

PubMed

Shinde, Pragati A; Lokhande, Vaibhav C; Chodankar, Nilesh R; Ji, Taeksoo; Kim, Jin Hyeok; Lokhande, Chandrakant D

2016-12-01

To achieve the highest electrochemical performance for supercapacitor, it is very essential to find out a suitable pair of an active electrode material and an electrolyte. In the present work, a simple approach is employed to enhance the supercapacitor performance of WO3 thin film. The WO3 thin film is prepared by a simple and cost effective chemical bath deposition method and its electrochemical performance is tested in conventional (H2SO4) and redox additive [H2SO4+hydroquinone (HQ)] electrolytes. Two-fold increment in electrochemical performance for WO3 thin film is observed in redox additive aqueous electrolyte compared to conventional electrolyte. WO3 thin film showed maximum specific capacitance of 725Fg(-1), energy density of 25.18Whkg(-1) at current density of 7mAcm(-2) with better cycling stability in redox electrolyte. This strategy provides the versatile way for designing the high performance energy storage devices. Copyright © 2016 Elsevier Inc. All rights reserved.

Optimal Doppler centroid estimation for SAR data from a quasi-homogeneous source

NASA Technical Reports Server (NTRS)

Jin, M. Y.

1986-01-01

This correspondence briefly describes two Doppler centroid estimation (DCE) algorithms, provides a performance summary for these algorithms, and presents the experimental results. These algorithms include that of Li et al. (1985) and a newly developed one that is optimized for quasi-homogeneous sources. The performance enhancement achieved by the optimal DCE algorithm is clearly demonstrated by the experimental results.

Finite wordlength implementation of a megachannel digital spectrum analyzer

NASA Technical Reports Server (NTRS)

Satorius, E. H.; Grimm, M. J.; Zimmerman, G. A.; Wilck, H. C.

1986-01-01

The results of an extensive system analysis of the megachannel spectrum analyzer currently being developed for use in various applications of the Deep Space Network are presented. The intent of this analysis is to quantify the effects of digital quantization errors on system performance. The results of this analysis provide useful guidelines for choosing various system design parameters to enhance system performance.

Impact of Providing Compassion on Job Performance and Mental Health: The Moderating Effect of Interpersonal Relationship Quality.

PubMed

Chu, Li-Chuan

2017-07-01

To examine the relationships of providing compassion at work with job performance and mental health, as well as to identify the role of interpersonal relationship quality in moderating these relationships. This study adopted a two-stage survey completed by 235 registered nurses employed by hospitals in Taiwan. All hypotheses were tested using hierarchical regression analyses. The results show that providing compassion is an effective predictor of job performance and mental health, whereas interpersonal relationship quality can moderate the relationships of providing compassion with job performance and mental health. When nurses are frequently willing to listen, understand, and help their suffering colleagues, the enhancement engendered by providing compassion can improve the provider's job performance and mental health. Creating high-quality relationships in the workplace can strengthen the positive benefits of providing compassion. Motivating employees to spontaneously exhibit compassion is crucial to an organization. Hospitals can establish value systems, belief systems, and cultural systems that support a compassionate response to suffering. In addition, nurses can internalize altruistic belief systems into their own personal value systems through a long process of socialization in the workplace. © 2017 Sigma Theta Tau International.

Image contrast enhancement with brightness preservation using an optimal gamma correction and weighted sum approach

NASA Astrophysics Data System (ADS)

Jiang, G.; Wong, C. Y.; Lin, S. C. F.; Rahman, M. A.; Ren, T. R.; Kwok, Ngaiming; Shi, Haiyan; Yu, Ying-Hao; Wu, Tonghai

2015-04-01

The enhancement of image contrast and preservation of image brightness are two important but conflicting objectives in image restoration. Previous attempts based on linear histogram equalization had achieved contrast enhancement, but exact preservation of brightness was not accomplished. A new perspective is taken here to provide balanced performance of contrast enhancement and brightness preservation simultaneously by casting the quest of such solution to an optimization problem. Specifically, the non-linear gamma correction method is adopted to enhance the contrast, while a weighted sum approach is employed for brightness preservation. In addition, the efficient golden search algorithm is exploited to determine the required optimal parameters to produce the enhanced images. Experiments are conducted on natural colour images captured under various indoor, outdoor and illumination conditions. Results have shown that the proposed method outperforms currently available methods in contrast to enhancement and brightness preservation.

34 CFR 403.204 - What are the State's responsibilities for program evaluation and improvement?

Code of Federal Regulations, 2011 CFR

2011-07-01

... has not made sufficient progress in meeting the standards and measures developed as required by §§ 403... technical assistance and program activities the State will provide to enhance the performance of the...

Flexible photonic payload for broadband telecom satellites: from concepts to system demonstrators

NASA Astrophysics Data System (ADS)

Sotom, M.; Aveline, M.; Barbaste, R.; Benazet, B.; Le Kernec, A.; Magnaval, J.; Picq, M.

2017-09-01

In the last decade, Thales Alenia Space has put significant research effort in photonic technologies for satellite applications, with the objective to provide telecom payload systems with enhanced functionality, higher performance and lower costs.

The effects of substitute multisensory feedback on task performance and the sense of presence in a virtual reality environment

PubMed Central

Milella, Ferdinando; Pinto, Carlo; Cant, Iain; White, Mark; Meyer, Georg

2018-01-01

Objective and subjective measures of performance in virtual reality environments increase as more sensory cues are delivered and as simulation fidelity increases. Some cues (colour or sound) are easier to present than others (object weight, vestibular cues) so that substitute cues can be used to enhance informational content in a simulation at the expense of simulation fidelity. This study evaluates how substituting cues in one modality by alternative cues in another modality affects subjective and objective performance measures in a highly immersive virtual reality environment. Participants performed a wheel change in a virtual reality (VR) environment. Auditory, haptic and visual cues, signalling critical events in the simulation, were manipulated in a factorial design. Subjective ratings were recorded via questionnaires. The time taken to complete the task was used as an objective performance measure. The results show that participants performed best and felt an increased sense of immersion and involvement, collectively referred to as ‘presence’, when substitute multimodal sensory feedback was provided. Significant main effects of audio and tactile cues on task performance and on participants' subjective ratings were found. A significant negative relationship was found between the objective (overall completion times) and subjective (ratings of presence) performance measures. We conclude that increasing informational content, even if it disrupts fidelity, enhances performance and user’s overall experience. On this basis we advocate the use of substitute cues in VR environments as an efficient method to enhance performance and user experience. PMID:29390023

The effects of substitute multisensory feedback on task performance and the sense of presence in a virtual reality environment.

PubMed

Cooper, Natalia; Milella, Ferdinando; Pinto, Carlo; Cant, Iain; White, Mark; Meyer, Georg

2018-01-01

Objective and subjective measures of performance in virtual reality environments increase as more sensory cues are delivered and as simulation fidelity increases. Some cues (colour or sound) are easier to present than others (object weight, vestibular cues) so that substitute cues can be used to enhance informational content in a simulation at the expense of simulation fidelity. This study evaluates how substituting cues in one modality by alternative cues in another modality affects subjective and objective performance measures in a highly immersive virtual reality environment. Participants performed a wheel change in a virtual reality (VR) environment. Auditory, haptic and visual cues, signalling critical events in the simulation, were manipulated in a factorial design. Subjective ratings were recorded via questionnaires. The time taken to complete the task was used as an objective performance measure. The results show that participants performed best and felt an increased sense of immersion and involvement, collectively referred to as 'presence', when substitute multimodal sensory feedback was provided. Significant main effects of audio and tactile cues on task performance and on participants' subjective ratings were found. A significant negative relationship was found between the objective (overall completion times) and subjective (ratings of presence) performance measures. We conclude that increasing informational content, even if it disrupts fidelity, enhances performance and user's overall experience. On this basis we advocate the use of substitute cues in VR environments as an efficient method to enhance performance and user experience.

A parallel-processing approach to computing for the geographic sciences; applications and systems enhancements

USGS Publications Warehouse

Crane, Michael; Steinwand, Dan; Beckmann, Tim; Krpan, Greg; Liu, Shu-Guang; Nichols, Erin; Haga, Jim; Maddox, Brian; Bilderback, Chris; Feller, Mark; Homer, George

2001-01-01

The overarching goal of this project is to build a spatially distributed infrastructure for information science research by forming a team of information science researchers and providing them with similar hardware and software tools to perform collaborative research. Four geographically distributed Centers of the U.S. Geological Survey (USGS) are developing their own clusters of low-cost, personal computers into parallel computing environments that provide a costeffective way for the USGS to increase participation in the high-performance computing community. Referred to as Beowulf clusters, these hybrid systems provide the robust computing power required for conducting information science research into parallel computing systems and applications.

A solar-thermal energy harvesting scheme: enhanced heat capacity of molten HITEC salt mixed with Sn/SiOx core-shell nanoparticles

NASA Astrophysics Data System (ADS)

Lai, Chih-Chung; Chang, Wen-Chih; Hu, Wen-Liang; Wang, Zhiming M.; Lu, Ming-Chang; Chueh, Yu-Lun

2014-04-01

We demonstrated enhanced solar-thermal storage by releasing the latent heat of Sn/SiOx core-shell nanoparticles (NPs) embedded in a eutectic salt. The microstructures and chemical compositions of Sn/SiOx core-shell NPs were characterized. In situ heating XRD provides dynamic crystalline information about the Sn/SiOx core-shell NPs during cyclic heating processes. The latent heat of ~29 J g-1 for Sn/SiOx core-shell NPs was measured, and 30% enhanced heat capacity was achieved from 1.57 to 2.03 J g-1 K-1 for the HITEC solar salt without and with, respectively, a mixture of 5% Sn/SiOx core-shell NPs. In addition, an endurance cycle test was performed to prove a stable operation in practical applications. The approach provides a method to enhance energy storage in solar-thermal power plants.We demonstrated enhanced solar-thermal storage by releasing the latent heat of Sn/SiOx core-shell nanoparticles (NPs) embedded in a eutectic salt. The microstructures and chemical compositions of Sn/SiOx core-shell NPs were characterized. In situ heating XRD provides dynamic crystalline information about the Sn/SiOx core-shell NPs during cyclic heating processes. The latent heat of ~29 J g-1 for Sn/SiOx core-shell NPs was measured, and 30% enhanced heat capacity was achieved from 1.57 to 2.03 J g-1 K-1 for the HITEC solar salt without and with, respectively, a mixture of 5% Sn/SiOx core-shell NPs. In addition, an endurance cycle test was performed to prove a stable operation in practical applications. The approach provides a method to enhance energy storage in solar-thermal power plants. Electronic supplementary information (ESI) available: Detailed experimental results are included for the following: SEM images of the HITEC molten salt with and without a mixture of Sn/SiOx core-shell NPs; statistical diameter distribution of pure Sn and Sn/SiOx core-shell NPs; the HAADF image and EDS linescan profile of a Sn/SiOx core-shell NP; XRD analysis for Sn NPs annealing at different heating temperatures; the XRD spectra of Sn/SiOx core-shell NPs before and after RTA for the shell protection test. See DOI: 10.1039/c3nr06810b

Evaluation of a shared-work program for reducing assistance provided to supported workers with severe multiple disabilities.

PubMed

Parsons, Marsha B; Reid, Dennis H; Green, Carolyn W; Browning, Leah B; Hensley, Mary B

2002-01-01

Concern has been expressed recently regarding the need to enhance the performance of individuals with highly significant disabilities in community-based, supported jobs. We evaluated a shared-work program for reducing job coach assistance provided to three workers with severe multiple disabilities in a publishing company. Following systematic observations of the assistance provided as each worker worked on entire job tasks, steps comprising the tasks were then re-assigned across workers. The re-assignment involved assigning each worker only those task steps for which the respective worker received the least amount of assistance (e.g., re-assigning steps that a worker could not complete due to physical disabilities), and ensuring the entire tasks were still completed by combining steps performed by all three workers. The shared-work program was accompanied by reductions in job coach assistance provided to each worker. Work productivity of the supported workers initially decreased but then increased to a level equivalent to the higher ranges of baseline productivity. These results suggested that the shared-work program appears to represent a viable means of enhancing supported work performance of people with severe multiple disabilities in some types of community jobs. Future research needs discussed focus on evaluating shared-work approaches with other jobs, and developing additional community work models specifically for people with highly significant disabilities.

[Performance enhancement by carbohydrate intake during sport: effects of carbohydrates during and after high-intensity exercise].

PubMed

Beelen, Milou; Cermak, Naomi M; van Loon, Luc J C

2015-01-01

Endogenous carbohydrate availability does not provide sufficient energy for prolonged moderate to high-intensity exercise. Carbohydrate ingestion during high-intensity exercise can therefore enhance performance.- For exercise lasting 1 to 2.5 hours, athletes are advised to ingest 30-60 g of carbohydrates per hour.- Well-trained endurance athletes competing for longer than 2.5 hours at high intensity can metabolise up to 90 g of carbohydrates per hour, provided that a mixture of glucose and fructose is ingested.- Athletes participating in intermittent or team sports are advised to follow the same strategies but the timing of carbohydrate intake depends on the type of sport.- If top performance is required again within 24 hours after strenuous exercise, the advice is to supplement endogenous carbohydrate supplies quickly within the first few hours post-exercise by ingesting large amounts of carbohydrate (1.2 g/kg/h) or a lower amount of carbohydrate (0.8 g/kg/h) with a small amount of protein (0.2-0.4 g/kg/h).

Physiological response to water immersion: a method for sport recovery?

PubMed

Wilcock, Ian M; Cronin, John B; Hing, Wayne A

2006-01-01

Recovery from exercise can be an important factor in performance during repeated bouts of exercise. In a tournament situation, where athletes may compete numerous times over a few days, enhancing recovery may provide a competitive advantage. One method that is gaining popularity as a means to enhance post-game or post-training recovery is immersion in water. Much of the literature on the ability of water immersion as a means to improve athletic recovery appears to be based on anecdotal information, with limited research on actual performance change. Water immersion may cause physiological changes within the body that could improve recovery from exercise. These physiological changes include intracellular-intravascular fluid shifts, reduction of muscle oedema and increased cardiac output (without increasing energy expenditure), which increases blood flow and possible nutrient and waste transportation through the body. Also, there may be a psychological benefit to athletes with a reduced cessation of fatigue during immersion. Water temperature alters the physiological response to immersion and cool to thermoneutral temperatures may provide the best range for recovery. Further performance-orientated research is required to determine whether water immersion is beneficial to athletes.

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

DOE PAGES

Yang, Jinhui; Cooper, Jason K.; Toma, Francesca M.; ...

2016-11-07

Artificial photosystems are advanced by the development of conformal catalytic materials that promote desired chemical transformations, while also maintaining stability and minimizing parasitic light absorption for integration on surfaces of semiconductor light absorbers. We demonstrate that multifunctional, nanoscale catalysts that enable high-performance photoelectrochemical energy conversion can be engineered by plasma-enhanced atomic layer deposition. The collective properties of tailored Co 3 O 4 /Co(OH) 2 thin films simultaneously provide high activity for water splitting, permit efficient interfacial charge transport from semiconductor substrates, and enhance durability of chemically sensitive interfaces. Furthermore, these films comprise compact and continuous nanocrystalline Co 3 O 4more » spinel that is impervious to phase transformation and impermeable to ions, thereby providing effective protection of the underlying substrate. Moreover, a secondary phase of structurally disordered and chemically labile Co(OH) 2 is introduced to ensure a high concentration of catalytically active sites. Application of this coating to photovoltaic p + n-Si junctions yields best reported performance characteristics for crystalline Si photoanodes.« less

Transfer as a function of exploration and stabilization in original practice.

PubMed

Pacheco, Matheus M; Newell, Karl M

2015-12-01

The identification of practice conditions that provide flexibility to perform successfully in transfer is a long-standing issue in motor learning but is still not well understood. Here we investigated the hypothesis that a search strategy that encompasses both exploration and stabilization of the perceptual-motor workspace will enhance performance in transfer. Twenty-two participants practiced a virtual projection task (120 trials on each of 3 days) and subsequently performed two transfer conditions (20 trials/condition) with different constraints in the angle to project the object. The findings revealed a quadratic relation between exploration in practice (indexed by autocorrelation and distribution of error) and subsequent performance error in transfer. The integration of exploration and stabilization of the perceptual-motor workspace enhances transfer to tasks with different constraints on the scaling of motor output. Copyright © 2015 Elsevier B.V. All rights reserved.

Plan-graph Based Heuristics for Conformant Probabilistic Planning

NASA Technical Reports Server (NTRS)

Ramakrishnan, Salesh; Pollack, Martha E.; Smith, David E.

2004-01-01

In this paper, we introduce plan-graph based heuristics to solve a variation of the conformant probabilistic planning (CPP) problem. In many real-world problems, it is the case that the sensors are unreliable or take too many resources to provide knowledge about the environment. These domains are better modeled as conformant planning problems. POMDP based techniques are currently the most successful approach for solving CPP but have the limitation of state- space explosion. Recent advances in deterministic and conformant planning have shown that plan-graphs can be used to enhance the performance significantly. We show that this enhancement can also be translated to CPP. We describe our process for developing the plan-graph heuristics and estimating the probability of a partial plan. We compare the performance of our planner PVHPOP when used with different heuristics. We also perform a comparison with a POMDP solver to show over a order of magnitude improvement in performance.

Performance Enhancement Strategies for Multi-Block Overset Grid CFD Applications

NASA Technical Reports Server (NTRS)

Djomehri, M. Jahed; Biswas, Rupak

2003-01-01

The overset grid methodology has significantly reduced time-to-solution of highfidelity computational fluid dynamics (CFD) simulations about complex aerospace configurations. The solution process resolves the geometrical complexity of the problem domain by using separately generated but overlapping structured discretization grids that periodically exchange information through interpolation. However, high performance computations of such large-scale realistic applications must be handled efficiently on state-of-the-art parallel supercomputers. This paper analyzes the effects of various performance enhancement strategies on the parallel efficiency of an overset grid Navier-Stokes CFD application running on an SGI Origin2000 machinc. Specifically, the role of asynchronous communication, grid splitting, and grid grouping strategies are presented and discussed. Details of a sophisticated graph partitioning technique for grid grouping are also provided. Results indicate that performance depends critically on the level of latency hiding and the quality of load balancing across the processors.

Evaluation of the influence of mechanical activation on physical and chemical properties of municipal solid waste incineration sludge.

PubMed

Caprai, V; Florea, M V A; Brouwers, H J H

2018-06-15

Despite numerous studies concerning the application of by-products in the construction field, municipal solid waste incineration (MSWI) residues are not widely used as secondary building materials. In some European countries, washing treatment to the full bottom ash (BA) fraction (0-32 mm) is applied, isolating more contaminated particles, smaller than 0.063 mm. Therefore, a MWSI sludge is produced, having a high moisture content, and thus a limited presence of soluble species. In order to enhance its performance as building material, here, dry mechanical activation is applied on MSWI sludge. Thereafter, a reactivity comparison between reference BA and untreated and treated MSWI sludge is provided, evaluating their behaviour in the presence of cement and their pozzolanic activity. Moreover, the mechanical performances, as 25% substitution of Portland cement (PC) are assessed, based on the EN 450. Mechanical activation enhances MSWI sludge physically due to the improved particle morphology and packing. Chemically, the hydration degree of PC is enhanced by the MSWI sludge by ≈25%. The milling treatment proved to be beneficial to the residues performances in the presence of PC, providing 32% higher strength than untreated sample. Environmentally, the compliance with the unshaped material legislation is successfully verified, according to the Soil Quality Decree. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of enhancing agglutination reaction using gold nanoparticle for pre-transfusion testing.

PubMed

Choktaweesak, N; Krasathong, P; Ammaranond, P

2016-10-01

To explore an alternative way for antibody detection testing, the examination of gold nanoparticle solution for enhancing unexpected antibodies for pre-transfusion testing was investigated. Exposure of foreign antigens on red blood cells from transfusion can trigger the immune system to produce unexpected antibodies. This immunological response may cause the complication to future transfusion. For detection of unexpected antibodies, the antibody screening test is performed approximately 30-60 min. To reduce turnaround time, enhancing reagent, low-ionic strength solution (LISS), is widely used. However, cost of enhancing reagent is an issue which has concerned in resource limited countries. Gold nanoparticle solution can increase red blood cells agglutination reaction. To solve this issue, study of gold nanoparticle solution was investigated. Samples were performed comparing between LISS and gold nanoparticle solution at antiglobulin phase. After reading the agglutination reaction, supernatants were collected and measured at the optical density at 760 nm by spectrophotometer. The optical density in the tube of gold nanoparticle solution was higher than in the tube of 2-5% cell suspension and monoclonal antibody. It has been observed that gold nanoparticle solution enhanced the reaction of agglutination 98% while LISS enhanced the agglutination only 60·8%. Employing a commercially available enhancing reagent, parallel samples confirmed results providing validation of the assay. It approximately costs $1 US dollars compared to $30 for a commercially available reagent. The low cost and yet effective time-consuming test for antibody screening is a practical and viable solution alternative way for performing in antibody screening test in resource limited countries. © 2016 British Blood Transfusion Society.

A solar-thermal energy harvesting scheme: enhanced heat capacity of molten HITEC salt mixed with Sn/SiO(x) core-shell nanoparticles.

PubMed

Lai, Chih-Chung; Chang, Wen-Chih; Hu, Wen-Liang; Wang, Zhiming M; Lu, Ming-Chang; Chueh, Yu-Lun

2014-05-07

We demonstrated enhanced solar-thermal storage by releasing the latent heat of Sn/SiO(x) core-shell nanoparticles (NPs) embedded in a eutectic salt. The microstructures and chemical compositions of Sn/SiO(x) core-shell NPs were characterized. In situ heating XRD provides dynamic crystalline information about the Sn/SiO(x) core-shell NPs during cyclic heating processes. The latent heat of ∼29 J g(-1) for Sn/SiO(x) core-shell NPs was measured, and 30% enhanced heat capacity was achieved from 1.57 to 2.03 J g(-1) K(-1) for the HITEC solar salt without and with, respectively, a mixture of 5% Sn/SiO(x) core-shell NPs. In addition, an endurance cycle test was performed to prove a stable operation in practical applications. The approach provides a method to enhance energy storage in solar-thermal power plants.

A Decision Support Framework for Feasibility Analysis of International Space Station (ISS) Research Capability Enhancing Options

NASA Technical Reports Server (NTRS)

Ortiz, James N.; Scott,Kelly; Smith, Harold

2004-01-01

The assembly and operation of the ISS has generated significant challenges that have ultimately impacted resources available to the program's primary mission: research. To address this, program personnel routinely perform trade-off studies on alternative options to enhance research. The approach, content level of analysis and resulting outputs of these studies vary due to many factors, however, complicating the Program Manager's job of selecting the best option. To address this, the program requested a framework be developed to evaluate multiple research-enhancing options in a thorough, disciplined and repeatable manner, and to identify the best option on the basis of cost, benefit and risk. The resulting framework consisted of a systematic methodology and a decision-support toolset. The framework provides quantifiable and repeatable means for ranking research-enhancing options for the complex and multiple-constraint domain of the space research laboratory. This paper describes the development, verification and validation of this framework and provides observations on its operational use.

A Computer Code for Gas Turbine Engine Weight And Disk Life Estimation

NASA Technical Reports Server (NTRS)

Tong, Michael T.; Ghosn, Louis J.; Halliwell, Ian; Wickenheiser, Tim (Technical Monitor)

2002-01-01

Reliable engine-weight estimation at the conceptual design stage is critical to the development of new aircraft engines. It helps to identify the best engine concept amongst several candidates. In this paper, the major enhancements to NASA's engine-weight estimate computer code (WATE) are described. These enhancements include the incorporation of improved weight-calculation routines for the compressor and turbine disks using the finite-difference technique. Furthermore, the stress distribution for various disk geometries was also incorporated, for a life-prediction module to calculate disk life. A material database, consisting of the material data of most of the commonly-used aerospace materials, has also been incorporated into WATE. Collectively, these enhancements provide a more realistic and systematic way to calculate the engine weight. They also provide additional insight into the design trade-off between engine life and engine weight. To demonstrate the new capabilities, the enhanced WATE code is used to perform an engine weight/life trade-off assessment on a production aircraft engine.

Relationships among providing maternal, child, and adolescent health services; implementing various financial strategy responses; and performance of local health departments.

PubMed

Issel, L Michele; Olorunsaiye, Comfort; Snebold, Laura; Handler, Arden

2015-04-01

We explored the relationships between local health department (LHD) structure, capacity, and macro-context variables and performance of essential public health services (EPHS). In 2012, we assessed a stratified, random sample of 195 LHDs that provided data via an online survey regarding performance of EPHS, the services provided or contracted out, the financial strategies used in response to budgetary pressures, and the extent of collaborations. We performed weighted analyses that included analysis of variance, pairwise correlations by jurisdiction population size, and linear regressions. On average, LHDs provided approximately 13 (36%) of 35 possible services either directly or by contract. Rather than cut services or externally consolidating, LHDs took steps to generate more revenue and maximize capacity. Higher LHD performance of EPHS was significantly associated with delivering more services, initiating more financial strategies, and engaging in collaboration, after adjusting for the effects of the Affordable Care Act and jurisdiction size. During changing economic and health care environments, we found that strong structural capacity enhanced local health department EPHS performance for maternal, child, and adolescent health.

Bingo! Externally-Supported Performance Intervention for Deficient Visual Search in Normal Aging, Parkinson’s Disease and Alzheimer’s Disease

PubMed Central

Laudate, Thomas M.; Neargarder, Sandy; Dunne, Tracy E.; Sullivan, Karen D.; Joshi, Pallavi; Gilmore, Grover C.; Riedel, Tatiana M.; Cronin-Golomb, Alice

2011-01-01

External support may improve task performance regardless of an individual’s ability to compensate for cognitive deficits through internally-generated mechanisms. We investigated if performance of a complex, familiar visual search task (the game of bingo) could be enhanced in groups with suboptimal vision by providing external support through manipulation of task stimuli. Participants were 19 younger adults, 14 individuals with probable Alzheimer’s disease (AD), 13 AD-matched healthy adults, 17 non-demented individuals with Parkinson’s disease (PD), and 20 PD-matched healthy adults. We varied stimulus contrast, size, and visual complexity during game play. The externally-supported performance interventions of increased stimulus size and decreased complexity resulted in improvements in performance by all groups. Performance improvement through increased stimulus size and decreased complexity was demonstrated by all groups. AD also obtained benefit from increasing contrast, presumably by compensating for their contrast sensitivity deficit. The general finding of improved performance across healthy and afflicted groups suggests the value of visual support as an easy-to-apply intervention to enhance cognitive performance. PMID:22066941

The status of penile enhancement procedures.

PubMed

Vardi, Yoram; Gruenwald, Ilan

2009-11-01

Most men who request surgical penile enhancement have a normal-sized and fully functional penis but visualize their penises as small (psychological dysmorphism). This fact by itself leads to controversy regarding the true indications for penile enhancement procedures in men without micropenis. One of the typical aspects of penile enhancement is the lack of true methodological evaluation of the more commonly performed procedures. Even recently, only few solid scientific studies are available which can shed some light on results and outcome of these controversial procedures. Although some additional data has emerged during the past year, there is still no consensus in regard to indications and surgical techniques used for penile augmentation or penile girth enhancement. There is further need for more studies to provide a better overview of the value and worthiness of these procedures.

From recording discrete actions to studying continuous goal-directed behaviours in team sports.

PubMed

Correia, Vanda; Araújo, Duarte; Vilar, Luís; Davids, Keith

2013-01-01

This paper highlights the importance of examining interpersonal interactions in performance analysis of team sports, predicated on the relationship between perception and action, compared to the traditional cataloguing of actions by individual performers. We discuss how ecological dynamics may provide a potential unifying theoretical and empirical framework to achieve this re-emphasis in research. With reference to data from illustrative studies on performance analysis and sport expertise, we critically evaluate some of the main assumptions and methodological approaches with regard to understanding how information influences action and decision-making during team sports performance. Current data demonstrate how the understanding of performance behaviours in team sports by sport scientists and practitioners may be enhanced with a re-emphasis in research on the dynamics of emergent ongoing interactions. Ecological dynamics provides formal and theoretically grounded descriptions of player-environment interactions with respect to key performance goals and the unfolding information of competitive performance. Developing these formal descriptions and explanations of sport performance may provide a significant contribution to the field of performance analysis, supporting design and intervention in both research and practice.

Guidelines for design, installation, and maintenance of a waterproof wearing surface for timber bridge decks

Treesearch

Richard E. Weyers; Joseph R. Loferski; J. Daniel Dolan; John E. Haramis; Joseph H. Howard; Lola Hislop

2001-01-01

To enhance long-term timber bridge performance, timber material must be protected from moisture. Wearing surfaces made of asphalt pavement with and without a waterproof membrane have been used to provide protection from moisture on timber decks. This type of wearing surface also protects the deck from other damage while providing a smooth, skid-resistant surface....

Influence of wire-coil inserts on the thermo-hydraulic performance of a flat-plate solar collector

NASA Astrophysics Data System (ADS)

Herrero Martín, R.; García, A.; Pérez-García, J.

2012-11-01

Enhancement techniques can be applied to flat-plate liquid solar collectors towards more compact and efficient designs. For the typical operating mass flow rates in flat-plate solar collectors, the most suitable technique is inserted devices. Based on previous studies from the authors, wire coils were selected for enhancing heat transfer. This type of inserted device provides better results in laminar, transitional and low turbulence fluid flow regimes. To test the enhanced solar collector and compare with a standard one, an experimental side-by-side solar collector test bed was designed and constructed. The testing set up was fully designed following the requirements of EN12975-2 and allow us to accomplish performance tests under the same operating conditions (mass flow rate, inlet fluid temperature and weather conditions). This work presents the thermal efficiency curves of a commercial and an enhanced solar collector, for the standardized mass flow rate per unit of absorber area of 0.02 kg/sm2 (in useful engineering units 144 kg/h for water as working fluid and 2 m2 flat-plate solar collector of absorber area). The enhanced collector was modified inserting spiral wire coils of dimensionless pitch p/D = 1 and wire-diameter e/D = 0.0717. The friction factor per tube has been computed from the overall pressure drop tests across the solar collectors. The thermal efficiency curves of both solar collectors, a standard and an enhanced collector, are presented. The enhanced solar collector increases the thermal efficiency by 15%. To account for the overall enhancement a modified performance evaluation criterion (R3m) is proposed. The maximum value encountered reaches 1.105 which represents an increase in useful power of 10.5% for the same pumping power consumption.

Using an Audience Response System Smartphone App to Improve Resident Education in the Pediatric Intensive Care Unit.

PubMed

Chung, Hoyoung; Kallay, Tom; Anas, Nick; Bruno, Diana; Decamps, Jose; Evans, Darci; Vilasagar, Niveditha; Mink, Richard B

2018-01-01

In the Pediatric Intensive Care Unit (PICU), most teaching occurs during bedside rounds, but technology now provides new opportunities to enhance education. Specifically, smartphone apps allow rapid communication between instructor and student. We hypothesized that using an audience response system (ARS) app can identify resident knowledge gaps, guide teaching, and enhance education in the PICU. Third-year pediatric residents rotating through the PICU participated in ARS-based education or received traditional teaching. Before rounds, experimental subjects completed an ARS quiz using the Socrative app. Concomitantly, the fellow leading rounds predicted quiz performance. Then, discussion points based on the incorrect answers were used to guide instruction. Scores on the pre-rotation test were similar between groups. On the post-rotation examination, ARS participants did not increase their scores more than controls. The fellow's prediction of performance was poor. Residents felt that the method enhanced their education whereas fellows reported that it improved their teaching efficiency. Although there was no measurable increase in knowledge using the ARS app, it may still be a useful tool to rapidly assess learners and help instructors provide learner-centered education.

Telemetry-Enhancing Scripts

NASA Technical Reports Server (NTRS)

Maimone, Mark W.

2009-01-01

Scripts Providing a Cool Kit of Telemetry Enhancing Tools (SPACKLE) is a set of software tools that fill gaps in capabilities of other software used in processing downlinked data in the Mars Exploration Rovers (MER) flight and test-bed operations. SPACKLE tools have helped to accelerate the automatic processing and interpretation of MER mission data, enabling non-experts to understand and/or use MER query and data product command simulation software tools more effectively. SPACKLE has greatly accelerated some operations and provides new capabilities. The tools of SPACKLE are written, variously, in Perl or the C or C++ language. They perform a variety of search and shortcut functions that include the following: Generating text-only, Event Report-annotated, and Web-enhanced views of command sequences; Labeling integer enumerations with their symbolic meanings in text messages and engineering channels; Systematic detecting of corruption within data products; Generating text-only displays of data-product catalogs including downlink status; Validating and labeling of commands related to data products; Performing of convenient searches of detailed engineering data spanning multiple Martian solar days; Generating tables of initial conditions pertaining to engineering, health, and accountability data; Simplified construction and simulation of command sequences; and Fast time format conversions and sorting.

MMW radar enhanced vision systems: the Helicopter Autonomous Landing System (HALS) and Radar-Enhanced Vision System (REVS) are rotary and fixed wing enhanced flight vision systems that enable safe flight operations in degraded visual environments

NASA Astrophysics Data System (ADS)

Cross, Jack; Schneider, John; Cariani, Pete

2013-05-01

Sierra Nevada Corporation (SNC) has developed rotary and fixed wing millimeter wave radar enhanced vision systems. The Helicopter Autonomous Landing System (HALS) is a rotary-wing enhanced vision system that enables multi-ship landing, takeoff, and enroute flight in Degraded Visual Environments (DVE). HALS has been successfully flight tested in a variety of scenarios, from brown-out DVE landings, to enroute flight over mountainous terrain, to wire/cable detection during low-level flight. The Radar Enhanced Vision Systems (REVS) is a fixed-wing Enhanced Flight Vision System (EFVS) undergoing prototype development testing. Both systems are based on a fast-scanning, threedimensional 94 GHz radar that produces real-time terrain and obstacle imagery. The radar imagery is fused with synthetic imagery of the surrounding terrain to form a long-range, wide field-of-view display. A symbology overlay is added to provide aircraft state information and, for HALS, approach and landing command guidance cuing. The combination of see-through imagery and symbology provides the key information a pilot needs to perform safe flight operations in DVE conditions. This paper discusses the HALS and REVS systems and technology, presents imagery, and summarizes the recent flight test results.

Evaluation of Fused Synthetic and Enhanced Vision Display Concepts for Low-Visibility Approach and Landing

NASA Technical Reports Server (NTRS)

Bailey, Randall E.; Kramer, Lynda J.; Prinzel, Lawrence J., III; Wilz, Susan J.

2009-01-01

NASA is developing revolutionary crew-vehicle interface technologies that strive to proactively overcome aircraft safety barriers that would otherwise constrain the full realization of the next generation air transportation system. A piloted simulation experiment was conducted to evaluate the complementary use of Synthetic and Enhanced Vision technologies. Specific focus was placed on new techniques for integration and/or fusion of Enhanced and Synthetic Vision and its impact within a two-crew flight deck during low-visibility approach and landing operations. Overall, the experimental data showed that significant improvements in situation awareness, without concomitant increases in workload and display clutter, could be provided by the integration and/or fusion of synthetic and enhanced vision technologies for the pilot-flying and the pilot-not-flying. Improvements in lateral path control performance were realized when the Head-Up Display concepts included a tunnel, independent of the imagery (enhanced vision or fusion of enhanced and synthetic vision) presented with it. During non-normal operations, the ability of the crew to handle substantial navigational errors and runway incursions were neither improved nor adversely impacted by the display concepts. The addition of Enhanced Vision may not, of itself, provide an improvement in runway incursion detection without being specifically tailored for this application.

Enhanced thermal conductivity oxide nuclear fuels by co-sintering with BeO: II. Fuel performance and neutronics

NASA Astrophysics Data System (ADS)

McCoy, Kevin; Mays, Claude

2008-04-01

The fuel rod performance and neutronics of enhanced thermal conductivity oxide (ECO) nuclear fuel with BeO have been compared to those of standard UO 2 fuel. The standards of comparison were that the ECO fuel should have the same infinite neutron-multiplication factor kinf at end of life and provide the same energy extraction per fuel assembly over its lifetime. The BeO displaces some uranium, so equivalence with standard UO 2 fuel was obtained by increasing the burnup and slightly increasing the enrichment. The COPERNIC fuel rod performance code was adapted to account for the effect of BeO on thermal properties. The materials considered were standard UO 2, UO 2 with 4.0 vol.% BeO, and UO 2 with 9.6 vol.% BeO. The smaller amount of BeO was assumed to provide increases in thermal conductivity of 0, 5, or 10%, whereas the larger amount was assumed to provide an increase of 50%. A significant improvement in performance was seen, as evidenced by reduced temperatures, internal rod pressures, and fission gas release, even with modest (5-10%) increases in thermal conductivity. The benefits increased monotonically with increasing thermal conductivity. Improvements in LOCA initialization performance were also seen. A neutronic calculation considered a transition from standard UO 2 fuel to ECO fuel. The calculation indicated that only a small increase in enrichment is required to maintain the kinf at end of life. The smallness of the change was attributed to the neutron-multiplication reaction of Be with fast neutrons and the moderating effect of BeO. Adoption of ECO fuel was predicted to provide a net reduction in uranium cost. Requirements for industrial hygiene were found to be comparable to those for processing of UO 2.

Performance scaling via passive pulse shaping in cavity-enhanced optical parametric chirped-pulse amplification.

PubMed

Siddiqui, Aleem M; Moses, Jeffrey; Hong, Kyung-Han; Lai, Chien-Jen; Kärtner, Franz X

2010-06-15

We show that an enhancement cavity seeded at the full repetition rate of the pump laser can automatically reshape small-signal gain across the interacting pulses in an optical parametric chirped-pulse amplifier for close-to-optimal operation, significantly increasing both the gain bandwidth and the conversion efficiency, in addition to boosting gain for high-repetition-rate amplification. Applied to a degenerate amplifier, the technique can provide an octave-spanning gain bandwidth.

Twisted Vanes Would Enhance Fuel/Air Mixing In Turbines

NASA Technical Reports Server (NTRS)

Nguyen, H. Lee; Micklow, Gerald J.; Dogra, Anju S.

1994-01-01

Computations of flow show performance of high-shear airblast fuel injector in gas-turbine engine enhanced by use of appropriately proportioned twisted (instead of flat) dome swirl vanes. Resultant more nearly uniform fuel/air mixture burns more efficiently, emitting smaller amounts of nitrogen oxides. Twisted-vane high-shear airblast injectors also incorporated into paint sprayers, providing advantages of low pressure drop characteristic of airblast injectors in general and finer atomization of advanced twisted-blade design.

Optofluidic Microsystems for Chemical and Biological Analysis

PubMed Central

Fan, Xudong; White, Ian M.

2011-01-01

Optofluidics – the synergistic integration of photonics and microfluidics – has recently emerged as a new analytical field that provides a number of unique characteristics for enhanced sensing performance and simplification of microsystems. In this review, we describe various optofluidic architectures developed in the past five years, emphasize the mechanisms by which optofluidics enhances bio/chemical analysis capabilities, including sensing and the precise control of biological micro/nanoparticles, and envision new research directions to which optofluidics leads. PMID:22059090

Deconvoluting the Photonic and Electronic Response of 2D Materials: The Case of MoS2.

PubMed

Zhang, Kehao; Borys, Nicholas J; Bersch, Brian M; Bhimanapati, Ganesh R; Xu, Ke; Wang, Baoming; Wang, Ke; Labella, Michael; Williams, Teague A; Haque, Md Amanul; Barnard, Edward S; Fullerton-Shirey, Susan; Schuck, P James; Robinson, Joshua A

2017-12-05

Evaluating and tuning the properties of two-dimensional (2D) materials is a major focus of advancing 2D science and technology. While many claim that the photonic properties of a 2D layer provide evidence that the material is "high quality", this may not be true for electronic performance. In this work, we deconvolute the photonic and electronic response of synthetic monolayer molybdenum disulfide. We demonstrate that enhanced photoluminescence can be robustly engineered via the proper choice of substrate, where growth of MoS 2 on r-plane sapphire can yield >100x enhancement in PL and carrier lifetime due to increased molybdenum-oxygen bonding compared to that of traditionally grown MoS 2 on c-plane sapphire. These dramatic enhancements in optical properties are similar to those of super-acid treated MoS 2 , and suggest that the electronic properties of the MoS 2 are also superior. However, a direct comparison of the charge transport properties indicates that the enhanced PL due to increased Mo-O bonding leads to p-type compensation doping, and is accompanied by a 2x degradation in transport properties compared to MoS 2 grown on c-plane sapphire. This work provides a foundation for understanding the link between photonic and electronic performance of 2D semiconducting layers, and demonstrates that they are not always correlated.

Deconvoluting the Photonic and Electronic Response of 2D Materials: The Case of MoS 2

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

Zhang, Kehao; Borys, Nicholas J.; Bersch, Brian M.

Evaluating and tuning the properties of two-dimensional (2D) materials is a major focus of advancing 2D science and technology. While many claim that the photonic properties of a 2D layer provide evidence that the material is "high quality", this may not be true for electronic performance. In this work, we deconvolute the photonic and electronic response of synthetic monolayer molybdenum disulfide. We demonstrate that enhanced photoluminescence can be robustly engineered via the proper choice of substrate, where growth of MoS 2 on r-plane sapphire can yield > 100x enhancement in PL and carrier lifetime due to increased molybdenum-oxygen bonding comparedmore » to that of traditionally grown MoS 2 on c-plane sapphire. These dramatic enhancements in optical properties are similar to those of super-acid treated MoS 2 , and suggest that the electronic properties of the MoS 2 are also superior. However, a direct comparison of the charge transport properties indicates that the enhanced PL due to increased Mo-O bonding leads to p-type compensation doping, and is accompanied by a 2x degradation in transport properties compared to MoS 2 grown on c-plane sapphire. This work provides a foundation for understanding the link between photonic and electronic performance of 2D semiconducting layers, and demonstrates that they are not always correlated.« less

Deconvoluting the Photonic and Electronic Response of 2D Materials: The Case of MoS 2

DOE PAGES

Zhang, Kehao; Borys, Nicholas J.; Bersch, Brian M.; ...

2017-12-05

Evaluating and tuning the properties of two-dimensional (2D) materials is a major focus of advancing 2D science and technology. While many claim that the photonic properties of a 2D layer provide evidence that the material is "high quality", this may not be true for electronic performance. In this work, we deconvolute the photonic and electronic response of synthetic monolayer molybdenum disulfide. We demonstrate that enhanced photoluminescence can be robustly engineered via the proper choice of substrate, where growth of MoS 2 on r-plane sapphire can yield > 100x enhancement in PL and carrier lifetime due to increased molybdenum-oxygen bonding comparedmore » to that of traditionally grown MoS 2 on c-plane sapphire. These dramatic enhancements in optical properties are similar to those of super-acid treated MoS 2 , and suggest that the electronic properties of the MoS 2 are also superior. However, a direct comparison of the charge transport properties indicates that the enhanced PL due to increased Mo-O bonding leads to p-type compensation doping, and is accompanied by a 2x degradation in transport properties compared to MoS 2 grown on c-plane sapphire. This work provides a foundation for understanding the link between photonic and electronic performance of 2D semiconducting layers, and demonstrates that they are not always correlated.« less

Kernel-Based Relevance Analysis with Enhanced Interpretability for Detection of Brain Activity Patterns

PubMed Central

Alvarez-Meza, Andres M.; Orozco-Gutierrez, Alvaro; Castellanos-Dominguez, German

2017-01-01

We introduce Enhanced Kernel-based Relevance Analysis (EKRA) that aims to support the automatic identification of brain activity patterns using electroencephalographic recordings. EKRA is a data-driven strategy that incorporates two kernel functions to take advantage of the available joint information, associating neural responses to a given stimulus condition. Regarding this, a Centered Kernel Alignment functional is adjusted to learning the linear projection that best discriminates the input feature set, optimizing the required free parameters automatically. Our approach is carried out in two scenarios: (i) feature selection by computing a relevance vector from extracted neural features to facilitating the physiological interpretation of a given brain activity task, and (ii) enhanced feature selection to perform an additional transformation of relevant features aiming to improve the overall identification accuracy. Accordingly, we provide an alternative feature relevance analysis strategy that allows improving the system performance while favoring the data interpretability. For the validation purpose, EKRA is tested in two well-known tasks of brain activity: motor imagery discrimination and epileptic seizure detection. The obtained results show that the EKRA approach estimates a relevant representation space extracted from the provided supervised information, emphasizing the salient input features. As a result, our proposal outperforms the state-of-the-art methods regarding brain activity discrimination accuracy with the benefit of enhanced physiological interpretation about the task at hand. PMID:29056897

Assessment of MCRM Boost Assist from Orbit for Deep Space Missions

NASA Technical Reports Server (NTRS)

2000-01-01

Report provides results of analysis for the beamed energy driven MHD Chemical Rocket Motor (MCRM) for application to boost from orbit to escape for deep space and interplanetary missions. Parametric analyses were performed in the mission to determine operating regime for which the MCRM provides significant propulsion performance enhancement. Analysis of the MHD accelerator was performed numerical computational methods to determine design and operational features necessary to achieve Isp on the order of 2,000 to 3,000 seconds. Algorithms were developed to scale weights for the accelerator and power supply. Significant improvement in propulsion system performance can be achieved with the beamed energy driven MCRM. The limiting factor on achievable vehicle acceleration is the specific power of the rectenna.

Video instrumentation for radionuclide angiocardiography.

NASA Technical Reports Server (NTRS)

Kriss, J. P.

1973-01-01

Two types of videoscintiscopes for performing radioisotopic angiocardiography with a scintillation camera are described, and use of these instruments in performing clinical studies is illustrated. Radionuclide angiocardiography is a simple, quick and accurate procedure recommended as a screening test for patients with a variety of congenital and acquired cardiovascular lesions. When performed in conjunction with coronary arterial catheterization, dynamic radionuclide angiography may provide useful information about regional myocardial perfusion. Quantitative capabilities greatly enhance the potential of this diagnostic tool.

Discussion of the quality control and performance testing of ultrasound diagnostic equipment

NASA Astrophysics Data System (ADS)

Jiang, Junjie

2018-03-01

In recent years, with the rapid development of ultrasonography, the application and popularization of new technology used in ultrasound equipment, the level of providing diagnostic information for doctors enhances unceasingly, which has become the indispensable diagnostic tool for medical institutions. The performance of equipment is directly related to the doctor’s diagnosis and the patient’s health, therefore, it is very important to choose a good method for quality control and performance testing.

Operational considerations of the Advanced Photovoltaic Solar Array

NASA Technical Reports Server (NTRS)

Stella, Paul M.; Kurland, Richard M.

1992-01-01

Issues affecting the long-term operational performance of the Advanced Photovoltaic Solar Array (APSA) are discussed, with particular attention given to circuit electrical integrity from shadowed and cracked cell modules. The successful integration of individual advanced array components provides a doubling of array specific performance from the previous NASA-developed advanced array (SAFE). Flight test modules both recently fabricated and under fabrication are described. The development of advanced high-performance blanket technology for future APSA enhancement is presented.

Operational considerations of the Advanced Photovoltaic Solar Array

NASA Astrophysics Data System (ADS)

Stella, Paul M.; Kurland, Richard M.

Issues affecting the long-term operational performance of the Advanced Photovoltaic Solar Array (APSA) are discussed, with particular attention given to circuit electrical integrity from shadowed and cracked cell modules. The successful integration of individual advanced array components provides a doubling of array specific performance from the previous NASA-developed advanced array (SAFE). Flight test modules both recently fabricated and under fabrication are described. The development of advanced high-performance blanket technology for future APSA enhancement is presented.

Teleradiology from the provider's perspective-cost analysis for a mid-size university hospital.

PubMed

Rosenberg, Christian; Kroos, Kristin; Rosenberg, Britta; Hosten, Norbert; Flessa, Steffen

2013-08-01

Real costs of teleradiology services have not been systematically calculated. Pricing policies are not evidence-based. This study aims to prove the feasibility of performing an original cost analysis for teleradiology services and show break-even points to perform cost-effective practice. Based on the teleradiology services provided by the Greifswald University Hospital in northeastern Germany, a detailed process analysis and an activity-based costing model revealed costs per service unit according to eight examination categories. The Monte Carlo method was used to simulate the cost amplitude and identify pricing thresholds. Twenty-two sub-processes and four staff categories were identified. The average working time for one unit was 55 (x-ray) to 72 min (whole-body CT). Personnel costs were dominant (up to 68 %), representing lower limit costs. The Monte Carlo method showed the cost distribution per category according to the deficiency risk. Avoiding deficient pricing by a likelihood of 90 % increased the cost of a cranial CT almost twofold as compared with the lower limit cost. Original cost analysis is possible when providing teleradiology services with complex statutory requirements in place. Methodology and results provide useful data to help enhance efficiency in hospital management as well as implement realistic reimbursement fees. • Analysis of original costs of teleradiology is possible for a providing hospital • Results discriminate pricing thresholds and lower limit costs to perform cost-effective practice • The study methods represent a managing tool to enhance efficiency in providing facilities • The data are useful to help represent telemedicine services in regular medical fee schedules.

Performance enhancement of bridge bracing under service and extreme loads.

DOT National Transportation Integrated Search

2010-12-01

The purpose of this study was to develop and demonstrate the concept of retrofitting bridge brace elements with fiber reinforced composites in order to provide restraint against buckling. The advanced materials consisted of a combination of fiber rei...

FogEye UV Sensor System Performance Characteristics

DOT National Transportation Integrated Search

2004-03-01

The primary objective of the FogEye Evaluation Program is to determine whether coupled ultra-violet sources and detectors may provide enhancements to safety on the airport surface. The results of this effort will be used to complete the evaluation of...

Lutein and brain function

USDA-ARS?s Scientific Manuscript database

Lutein is one of the most prevalent carotenoids in nature and in the human diet. Together with zeaxanthin, it is highly concentrated in macular pigment in the foveal retina of primates, attenuating blue light exposure, providing protection from photo-oxidation and enhancing visual performance. Rece...

Revolutionary Design for Astronaut Exploration — Beyond the Bio-Suit System

NASA Astrophysics Data System (ADS)

Newman, Dava J.; Canina, Marita; Trotti, Guillermo L.

2007-01-01

The Bio-Suit System is designed to revolutionize human space exploration by providing enhanced astronaut extravehicular activity (EVA) locomotion and performance based on the concepts of a `second skin' capability. The novel Bio-Suit concept provides an overall exploration system realized through symbiotic relationships between a suite of advanced technologies, creative design, human modeling and analysis, and new mission operations techniques. By working at the intersection of engineering, design, life sciences and operations, new emergent capabilities and interrelationships result for applications to space missions, medical rehabilitation, and extreme sports activities. In many respects, the Bio-Suit System mimics Nature (biomimetics). For example, the second skin is capable of augmenting our biological skin by providing mechanical counter-pressure. We have designed and tested prototypes that prove mechanical counter-pressure feasibility. The `epidermis' of our second skin suit is patterned from 3D laser scans that incorporate human skin strain field maps for maximum mobility and natural movements, while requiring minimum energy expenditure for exploration tasks. We provide a technology roadmap for future design, pressure production and technology investments for the Bio-Suit System. Woven into the second skin are active materials to enhance human performance as well as to provide necessary performance metrics (i.e., energy expenditure). Wearable technologies will be embedded throughout the Bio-Suit System to place the explorer in an information-rich environment enabling real-time mission planning, prediction, and visualization. The Bio-Suit System concept augments human capabilities by coupling human and robotic abilities into a hybrid of the two, to the point where the explorer is hardly aware of the boundary between innate human performance and robotic activities.

Robust binarization of degraded document images using heuristics

NASA Astrophysics Data System (ADS)

Parker, Jon; Frieder, Ophir; Frieder, Gideon

2013-12-01

Historically significant documents are often discovered with defects that make them difficult to read and analyze. This fact is particularly troublesome if the defects prevent software from performing an automated analysis. Image enhancement methods are used to remove or minimize document defects, improve software performance, and generally make images more legible. We describe an automated, image enhancement method that is input page independent and requires no training data. The approach applies to color or greyscale images with hand written script, typewritten text, images, and mixtures thereof. We evaluated the image enhancement method against the test images provided by the 2011 Document Image Binarization Contest (DIBCO). Our method outperforms all 2011 DIBCO entrants in terms of average F1 measure - doing so with a significantly lower variance than top contest entrants. The capability of the proposed method is also illustrated using select images from a collection of historic documents stored at Yad Vashem Holocaust Memorial in Israel.

Enhancing managerial effectiveness in dietetics.

PubMed

Hoover, L W

1983-01-01

Environmental pressures from such sources as economic conditions, the government, third-party payers, and inter-institutional competition create managerial challenges. Although cost-containment has received considerable attention, long-term cost-effectiveness is probably the significant issue. Dietitians must become more cost-conscious and effective in resource management to attain desired performance outcomes. Some of the skills and characteristics essential to managerial effectiveness are a marketing orientation, systems design skill, quantitative operations management techniques, financial expertise, and leadership. These abilities facilitate decision-making and achievement of long-term cost-effectiveness. Curriculum enhancement and continuing education are two strategies for improving managerial competency in the dietetics profession. In dietetics education, study of management topics should be enhanced to provide more advanced coverage of management theories and quantitative models so that managerial performance can be at a higher level of sophistication and competency. To assure the viability of the dietetics profession, the emphasis on management must be more comprehensive and rigorous.

Tone Language Speakers and Musicians Share Enhanced Perceptual and Cognitive Abilities for Musical Pitch: Evidence for Bidirectionality between the Domains of Language and Music

PubMed Central

Bidelman, Gavin M.; Hutka, Stefanie; Moreno, Sylvain

2013-01-01

Psychophysiological evidence suggests that music and language are intimately coupled such that experience/training in one domain can influence processing required in the other domain. While the influence of music on language processing is now well-documented, evidence of language-to-music effects have yet to be firmly established. Here, using a cross-sectional design, we compared the performance of musicians to that of tone-language (Cantonese) speakers on tasks of auditory pitch acuity, music perception, and general cognitive ability (e.g., fluid intelligence, working memory). While musicians demonstrated superior performance on all auditory measures, comparable perceptual enhancements were observed for Cantonese participants, relative to English-speaking nonmusicians. These results provide evidence that tone-language background is associated with higher auditory perceptual performance for music listening. Musicians and Cantonese speakers also showed superior working memory capacity relative to nonmusician controls, suggesting that in addition to basic perceptual enhancements, tone-language background and music training might also be associated with enhanced general cognitive abilities. Our findings support the notion that tone language speakers and musically trained individuals have higher performance than English-speaking listeners for the perceptual-cognitive processing necessary for basic auditory as well as complex music perception. These results illustrate bidirectional influences between the domains of music and language. PMID:23565267

Nanoparticle-Enhanced Silver-Nanowire Plasmonic Electrodes for High-Performance Organic Optoelectronic Devices.

PubMed

Kim, Taehyo; Kang, Saewon; Heo, Jungwoo; Cho, Seungse; Kim, Jae Won; Choe, Ayoung; Walker, Bright; Shanker, Ravi; Ko, Hyunhyub; Kim, Jin Young

2018-05-21

Improved performance in plasmonic organic solar cells (OSCs) and organic light-emitting diodes (OLEDs) via strong plasmon-coupling effects generated by aligned silver nanowire (AgNW) transparent electrodes decorated with core-shell silver-silica nanoparticles (Ag@SiO 2 NPs) is demonstrated. NP-enhanced plasmonic AgNW (Ag@SiO 2 NP-AgNW) electrodes enable substantially enhanced radiative emission and light absorption efficiency due to strong hybridized plasmon coupling between localized surface plasmons (LSPs) and propagating surface plasmon polaritons (SPPs) modes, which leads to improved device performance in organic optoelectronic devices (OODs). The discrete dipole approximation (DDA) calculation of the electric field verifies a strongly enhanced plasmon-coupling effect caused by decorating core-shell Ag@SiO 2 NPs onto the AgNWs. Notably, an electroluminescence efficiency of 25.33 cd A -1 (at 3.2 V) and a power efficiency of 25.14 lm W -1 (3.0 V) in OLEDs, as well as a power conversion efficiency (PCE) value of 9.19% in OSCs are achieved using hybrid Ag@SiO 2 NP-AgNW films. These are the highest values reported to date for optoelectronic devices based on AgNW electrodes. This work provides a new design platform to fabricate high-performance OODs, which can be further explored in various plasmonic and optoelectronic devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Micropore Geometry Manipulation by Macroscopic Deformation Based on Shape Memory Effect in Porous PLLA Membrane and its Enhanced Separation Performance.

PubMed

Zhao, Jingxin; Yang, Qiucheng; Wang, Tao; Wang, Lian; You, Jichun; Li, Yongjin

2017-12-20

An effective strategy to tailor the microporous structures has been developed based on the shape memory effect in porous poly(l-lactic acid) membranes in which tiny crystals and amorphous matrix play the roles of shape-fixed phase and reversible-phase, respectively. Our results indicate that not only PLLA membranes but micropores exhibit shape memory properties. The proportional deformations on two scales have been achieved by uniaxial or biaxial tension, providing a facile way to manipulate continuously the size and the orientation degree of pores on microscale. The enhanced separation performance has been validated by taking polystyrene colloids with varying diameters as an example.

Competitive position of natural gas: Industrial baking and frying. May 1988

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

Not Available

The summary of reports GRI-88/0020 and GRI-88/0042 provides the results of studies performed to determine the status of natural gas technologies in the industrial baking and frying markets and to identify R D to enhance the performance of these technologies. The studies indicate that natural gas will continue to be the most economical energy source for industrial baking and frying.

A National Study Comparing Baldrige Core Values and Concepts with AACN Indicators of Quality: Facilitating CCNE-Baccalaureate Colleges of Nursing Move toward More Effective Continuous Performance Improvement Practices

ERIC Educational Resources Information Center

Mattin, Deborah C.

2013-01-01

The AACN has asked academic leaders to align the performance of their organizations to the prescribed standards within the "Essentials of Baccalaureate Education for Professional Nursing" Practice document and has provided indicators of quality suggestions for program enhancement as a means of promoting continuous performance…

Primary Care-Mental Health Integration in the Veterans Affairs Health System: Program Characteristics and Performance.

PubMed

Cornwell, Brittany L; Brockmann, Laurie M; Lasky, Elaine C; Mach, Jennifer; McCarthy, John F

2018-06-01

The Veterans Health Administration (VHA) has achieved substantial national implementation of primary care-mental health integration (PC-MHI) services. However, little is known regarding program characteristics, variation in characteristics across settings, or associations between program fidelity and performance. This study identified core elements of PC-MHI services and evaluated their associations with program characteristics and performance. A principal-components analysis (PCA) of reports from 349 sites identified factors associated with PC-MHI fidelity. Analyses assessed the correlation among factors and between each factor and facility type (medical center or community-based outpatient clinic), primary care population size, and performance indicators (receipt of PC-MHI services, same-day access to mental health and primary care services, and extended duration of services). PCA identified seven factors: core implementation, care management (CM) assessments and supervision, CM supervision receipt, colocated collaborative care (CCC) by prescribing providers, CCC by behavioral health providers, participation in patient aligned care teams (PACTs) for special populations, and treatment of complex mental health conditions. Sites serving larger populations had greater core implementation scores. Medical centers and sites serving larger populations had greater scores for CCC by prescribing providers, CM assessments and supervision, and participation in PACTs. Greater core implementation scores were associated with greater same-day access. Sites with greater scores for CM assessments and supervision had lower scores for treatment of complex conditions. Outpatient clinics and sites serving smaller populations experienced challenges in integrated care implementation. To enhance same-day access, VHA should continue to prioritize PC-MHI implementation. Providing brief, problem-focused care may enhance CM implementation.

Relationships between core factors of knowledge management in hospital nursing organisations and outcomes of nursing performance.

PubMed

Lee, Eun Ju; Kim, Hong Soon; Kim, Hye Young

2014-12-01

The study was conducted to investigate the levels of implementation of knowledge management and outcomes of nursing performance, to examine the relationships between core knowledge management factors and nursing performance outcomes and to identify core knowledge management factors affecting these outcomes. Effective knowledge management is very important to achieve strong organisational performance. The success or failure of knowledge management depends on how effectively an organisation's members share and use their knowledge. Because knowledge management plays a key role in enhancing nursing performance, identifying the core factors and investigating the level of knowledge management in a given hospital are priorities to ensure a high quality of nursing for patients. The study employed a descriptive research procedure. The study sample consisted of 192 nurses registered in three large healthcare organisations in South Korea. The variables demographic characteristics, implementation of core knowledge management factors and outcomes of nursing performance were examined and analysed in this study. The relationships between the core knowledge management factors and outcomes of nursing performance as well as the factors affecting the performance outcomes were investigated. A knowledge-sharing culture and organisational learning were found to be core factors affecting nursing performance. The study results provide basic data that can be used to formulate effective knowledge management strategies for enhancing nursing performance in hospital nursing organisations. In particular, prioritising the adoption of a knowledge-sharing culture and organisational learning in knowledge management systems might be one method for organisations to more effectively manage their knowledge resources and thus to enhance the outcomes of nursing performance and achieve greater business competitiveness. The study results can contribute to the development of effective and efficient knowledge management systems and strategies for enhancing knowledge-sharing culture and organisational learning that can improve both the productivity and competitiveness of healthcare organisations. © 2014 John Wiley & Sons Ltd.

Enhanced photocatalytic performance of KNbO3(100)/reduced graphene oxide nanocomposites investigated using first-principles calculations: RGO reductivity effect

NASA Astrophysics Data System (ADS)

Zhang, Pan; Shen, Yanqing; Wu, Wenjing; Li, Jun; Zhou, Zhongxiang

2018-03-01

Although a number of various reduced graphene oxide (RGO)-based nanomaterials with enhanced photocatalytic performance have recently been characterized, the effect of RGO reductivity on their performance is still not clear. Herein, KNbO3(100) surface modification with three RGO sheets of different reductivity is investigated using first-principles calculations, revealing that increasing RGO reductivity enhances the photocatalytic performance of KNbO3(100)/RGO nanocomposites. In contrast to CeO2/RGO nanocomposites, the O atoms of RGO inhibit the photoactivity of KNbO3/RGO nanocomposites by restraining the effect of inducing a red shift of the corresponding photocatalytic absorption spectra by C 2p states. Increased RGO reductivity extends its absorption edge to the visible light region of the optical absorption and also promotes charge transfer from the KNbO3(100) surface to RGO sheets, in contrast to the behavior observed for g-C3N4/RGO composites. Overall, this work provides a reasonable explanation of controversial experimental results obtained previously, paving the way to the development of highly efficient RGO-based photocatalysts and promoting further photocatalytic applications of KNbO3/RGO nanocomposites.

The Influence of the Inner Topology of Cooling Units on the Performance of Automotive Exhaust-Based Thermoelectric Generators

NASA Astrophysics Data System (ADS)

Zhu, D. C.; Su, C. Q.; Deng, Y. D.; Wang, Y. P.; Liu, X.

2017-11-01

Automotive exhaust-based thermoelectric generators are currently a hot topic in energy recovery. The waste heat of automotive exhaust gas can be converted into electricity by means of thermoelectric modules. Generally, inserting fins into the cooling unit contributes to enhancing the heat transfer for a higher power output. However, the introduction of fins will result in a pressure drop in the cooling system. In current research, in order to enhance the heat transfer and avoid a large pressure drop, a cooling unit with cylindrical grooves on the interior surface was proposed. To evaluate the performance of the cylindrical grooves, different inner topologies, including a smooth interior surface,a smooth interior surface with inserted fins and an interior surface with cylindrical grooves, were compared. The results revealed that compared with the smooth interior surface, the smooth interior surface with inserted fins and the interior surface with cylindrical grooves both enhanced the heat transfer, but the interior surface with cylindrical grooves obtained a lower pressure drop. To improve the performance of the cylindrical grooves, different groove-depth ratios were tried, and the results showed that a groove-depth ratio of 0.081 could provide the best overall performance.

The Influence of the Inner Topology of Cooling Units on the Performance of Automotive Exhaust-Based Thermoelectric Generators

NASA Astrophysics Data System (ADS)

Zhu, D. C.; Su, C. Q.; Deng, Y. D.; Wang, Y. P.; Liu, X.

2018-06-01

Automotive exhaust-based thermoelectric generators are currently a hot topic in energy recovery. The waste heat of automotive exhaust gas can be converted into electricity by means of thermoelectric modules. Generally, inserting fins into the cooling unit contributes to enhancing the heat transfer for a higher power output. However, the introduction of fins will result in a pressure drop in the cooling system. In current research, in order to enhance the heat transfer and avoid a large pressure drop, a cooling unit with cylindrical grooves on the interior surface was proposed. To evaluate the performance of the cylindrical grooves, different inner topologies, including a smooth interior surface,a smooth interior surface with inserted fins and an interior surface with cylindrical grooves, were compared. The results revealed that compared with the smooth interior surface, the smooth interior surface with inserted fins and the interior surface with cylindrical grooves both enhanced the heat transfer, but the interior surface with cylindrical grooves obtained a lower pressure drop. To improve the performance of the cylindrical grooves, different groove-depth ratios were tried, and the results showed that a groove-depth ratio of 0.081 could provide the best overall performance.

Performance enhancement in a semi-autonomous confined microsociety

NASA Technical Reports Server (NTRS)

Brady, J. V.; Bernstein, D. J.; Foltin, R. W.; Nellis, M. J.

1988-01-01

Research in a continuously programmed human experimental laboratory has been directed toward identifying, defining, and expanding generalized knowledge concerning motivational factors within the structure of human behavioral repertoires that maintain and enhance performance. Participants (in groups of three) engaged in a series of repetitive work activities (e.g., word sorting and rug-hooking) for extended periods each day, while living continuously in a residential laboratory. Other parts of the day were spent either interacting socially with other participants or engaging in individual recreational activities. The percentage of time devoted to the various work tasks provided the basis for selecting one activity that occurred with high frequency and one with low frequency. Performance of the low-frequency activity was then required in order to gain access to the high-frequency activity. Under such contingencies, time devoted to the original low-frequency activity increased greatly, and the participants consistently did more than the required amount of the low-frequency work than was necessary to restore access to the restricted work activity. The theoretical significance of these findings resides in the clear demonstration that a time-based model of value applies as well to the enhancement of work-like performance as it does to voluntarily selected or preferred recreational activities.

The Personal Mobility and Manipulation Appliance (PerMMA): a robotic wheelchair with advanced mobility and manipulation.

PubMed

Wang, Hongwu; Grindle, Garrett G; Candiotti, Jorge; Chung, Chengshiu; Shino, Motoki; Houston, Elaine; Cooper, Rory A

2012-01-01

The Personal Mobility and Manipulation Appliance (PerMMA) is a recently developed personal assistance robot developed to provide people with disabilities and older adults enhanced assistance in both mobility and manipulation, which are two fundamental components for independently activities of daily life performing, community participation, and quality of life. Technologies to assist with mobility and manipulation are among the most important tools for clinicians, end users and caregivers; however, there are currently few systems that provide practical and coordinated assistance with mobility and manipulation tasks. The PerMMA was not only developed and evaluated to provide users and caregivers enhanced mobility and manipulation options, but also as a clinical tool as well as research platform. The development and evaluation of PerMMA are presented in the paper.

Amplify-and-forward cooperative diversity for green UWB-based WBSNs.

PubMed

Shaban, Heba; Abou El-Nasr, Mohamad

2013-01-01

This paper proposes a novel green cooperative diversity technique based on suboptimal template-based ultra-wideband (UWB) wireless body sensor networks (WBSNs) using amplify-and-forward (AF) relays. In addition, it analyzes the bit-error-rate (BER) performance of the proposed nodes. The analysis is based on the moment-generating function (MGF) of the total signal-to-noise ratio (SNR) at the destination. It also provides an approximate value for the total SNR. The analysis studies the performance of equally correlated binary pulse position modulation (EC-BPPM) assuming the sinusoidal and square suboptimal template pulses. Numerical results are provided for the performance evaluation of optimal and suboptimal template-based nodes with and without relay cooperation. Results show that one relay node provides ~23 dB performance enhancement at 1e - 3 BER, which mitigates the effect of the nondesirable non-line-of-sight (NLOS) links in WBSNs.

Amplify-and-Forward Cooperative Diversity for Green UWB-Based WBSNs

PubMed Central

2013-01-01

This paper proposes a novel green cooperative diversity technique based on suboptimal template-based ultra-wideband (UWB) wireless body sensor networks (WBSNs) using amplify-and-forward (AF) relays. In addition, it analyzes the bit-error-rate (BER) performance of the proposed nodes. The analysis is based on the moment-generating function (MGF) of the total signal-to-noise ratio (SNR) at the destination. It also provides an approximate value for the total SNR. The analysis studies the performance of equally correlated binary pulse position modulation (EC-BPPM) assuming the sinusoidal and square suboptimal template pulses. Numerical results are provided for the performance evaluation of optimal and suboptimal template-based nodes with and without relay cooperation. Results show that one relay node provides ~23 dB performance enhancement at 1e − 3 BER, which mitigates the effect of the nondesirable non-line-of-sight (NLOS) links in WBSNs. PMID:24307880

Enhancing End-to-End Performance of Information Services Over Ka-Band Global Satellite Networks

NASA Technical Reports Server (NTRS)

Bhasin, Kul B.; Glover, Daniel R.; Ivancic, William D.; vonDeak, Thomas C.

1997-01-01

The Internet has been growing at a rapid rate as the key medium to provide information services such as e-mail, WWW and multimedia etc., however its global reach is limited. Ka-band communication satellite networks are being developed to increase the accessibility of information services via the Internet at global scale. There is need to assess satellite networks in their ability to provide these services and interconnect seamlessly with existing and proposed terrestrial telecommunication networks. In this paper the significant issues and requirements in providing end-to-end high performance for the delivery of information services over satellite networks based on various layers in the OSI reference model are identified. Key experiments have been performed to evaluate the performance of digital video and Internet over satellite-like testbeds. The results of the early developments in ATM and TCP protocols over satellite networks are summarized.

Limb-Enhancer Genie: An accessible resource of accurate enhancer predictions in the developing limb

DOE PAGES

Monti, Remo; Barozzi, Iros; Osterwalder, Marco; ...

2017-08-21

Epigenomic mapping of enhancer-associated chromatin modifications facilitates the genome-wide discovery of tissue-specific enhancers in vivo. However, reliance on single chromatin marks leads to high rates of false-positive predictions. More sophisticated, integrative methods have been described, but commonly suffer from limited accessibility to the resulting predictions and reduced biological interpretability. Here we present the Limb-Enhancer Genie (LEG), a collection of highly accurate, genome-wide predictions of enhancers in the developing limb, available through a user-friendly online interface. We predict limb enhancers using a combination of > 50 published limb-specific datasets and clusters of evolutionarily conserved transcription factor binding sites, taking advantage ofmore » the patterns observed at previously in vivo validated elements. By combining different statistical models, our approach outperforms current state-of-the-art methods and provides interpretable measures of feature importance. Our results indicate that including a previously unappreciated score that quantifies tissue-specific nuclease accessibility significantly improves prediction performance. We demonstrate the utility of our approach through in vivo validation of newly predicted elements. Moreover, we describe general features that can guide the type of datasets to include when predicting tissue-specific enhancers genome-wide, while providing an accessible resource to the general biological community and facilitating the functional interpretation of genetic studies of limb malformations.« less

Assessment of mass detection performance in contrast enhanced digital mammography

NASA Astrophysics Data System (ADS)

Carton, Ann-Katherine; de Carvalho, Pablo M.; Li, Zhijin; Dromain, Clarisse; Muller, Serge

2015-03-01

We address the detectability of contrast-agent enhancing masses for contrast-agent enhanced spectral mammography (CESM), a dual-energy technique providing functional projection images of breast tissue perfusion and vascularity using simulated CESM images. First, the realism of simulated CESM images from anthropomorphic breast software phantoms generated with a software X-ray imaging platform was validated. Breast texture was characterized by power-law coefficients calculated in data sets of real clinical and simulated images. We also performed a 2-alternative forced choice (2-AFC) psychophysical experiment whereby simulated and real images were presented side-by-side to an experienced radiologist to test if real images could be distinguished from the simulated images. It was found that texture in our simulated CESM images has a fairly realistic appearance. Next, the relative performance of human readers and previously developed mathematical observers was assessed for the detection of iodine-enhancing mass lesions containing different contrast agent concentrations. A four alternative-forced-choice (4 AFC) task was designed; the task for the model and human observer was to detect which one of the four simulated DE recombined images contained an iodineenhancing mass. Our results showed that the NPW and NPWE models largely outperform human performance. After introduction of an internal noise component, both observers approached human performance. The CHO observer performs slightly worse than the average human observer. There is still work to be done in improving model observers as predictors of human-observer performance. Larger trials could also improve our test statistics. We hope that in the future, this framework of software breast phantoms, virtual image acquisition and processing, and mathematical observers can be beneficial to optimize CESM imaging techniques.

Predicting students' intention to use stimulants for academic performance enhancement.

PubMed

Ponnet, Koen; Wouters, Edwin; Walrave, Michel; Heirman, Wannes; Van Hal, Guido

2015-02-01

The non-medical use of stimulants for academic performance enhancement is becoming a more common practice among college and university students. The objective of this study is to gain a better understanding of students' intention to use stimulant medication for the purpose of enhancing their academic performance. Based on an extended model of Ajzen's theory of planned behavior, we examined the predictive value of attitude, subjective norm, perceived behavioral control, psychological distress, procrastination, substance use, and alcohol use on students' intention to use stimulants to improve their academic performance. The sample consisted of 3,589 Flemish university and college students (mean age: 21.59, SD: 4.09), who participated anonymously in an online survey conducted in March and April 2013. Structural equation modeling was used to investigate the relationships among the study variables. Our results indicate that subjective norm is the strongest predictor of students' intention to use stimulant medication, followed by attitude and perceived behavioral control. To a lesser extent, procrastinating tendencies, psychological distress, and substance abuse contribute to students' intention. Conclusions/ Importance: Based on these findings, we provide several recommendations on how to curtail students' intention to use stimulant medication for the purpose of improving their academic performance. In addition, we urge researchers to identify other psychological variables that might be related to students' intention.

Enhanced photoluminescence of Si nanocrystals-doped cellulose nanofibers by plasmonic light scattering

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

Sugimoto, Hiroshi; Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Rokkodai, Nada, Kobe 657-8501; Zhang, Ran

2015-07-27

We report the development of bio-compatible cellulose nanofibers doped with light emitting silicon nanocrystals and Au nanoparticles via facile electrospinning. By performing photoluminescence (PL) spectroscopy as a function of excitation wavelength, we demonstrate plasmon-enhanced PL by a factor of 2.2 with negligible non-radiative quenching due to plasmon-enhanced scattering of excitation light from Au nanoparticles to silicon nanocrystals inside the nanofibers. These findings provide an alternative approach for the development of plasmon-enhanced active systems integrated within the compact nanofiber geometry. Furthermore, bio-compatible light-emitting nanofibers prepared by a cost-effective solution-based processing are very promising platforms for biophotonic applications such as fluorescence sensingmore » and imaging.« less

Local contrast-enhanced MR images via high dynamic range processing.

PubMed

Chandra, Shekhar S; Engstrom, Craig; Fripp, Jurgen; Neubert, Ales; Jin, Jin; Walker, Duncan; Salvado, Olivier; Ho, Charles; Crozier, Stuart

2018-09-01

To develop a local contrast-enhancing and feature-preserving high dynamic range (HDR) image processing algorithm for multichannel and multisequence MR images of multiple body regions and tissues, and to evaluate its performance for structure visualization, bias field (correction) mitigation, and automated tissue segmentation. A multiscale-shape and detail-enhancement HDR-MRI algorithm is applied to data sets of multichannel and multisequence MR images of the brain, knee, breast, and hip. In multisequence 3T hip images, agreement between automatic cartilage segmentations and corresponding synthesized HDR-MRI series were computed for mean voxel overlap established from manual segmentations for a series of cases. Qualitative comparisons between the developed HDR-MRI and standard synthesis methods were performed on multichannel 7T brain and knee data, and multisequence 3T breast and knee data. The synthesized HDR-MRI series provided excellent enhancement of fine-scale structure from multiple scales and contrasts, while substantially reducing bias field effects in 7T brain gradient echo, T 1 and T 2 breast images and 7T knee multichannel images. Evaluation of the HDR-MRI approach on 3T hip multisequence images showed superior outcomes for automatic cartilage segmentations with respect to manual segmentation, particularly around regions with hyperintense synovial fluid, across a set of 3D sequences. The successful combination of multichannel/sequence MR images into a single-fused HDR-MR image format provided consolidated visualization of tissues within 1 omnibus image, enhanced definition of thin, complex anatomical structures in the presence of variable or hyperintense signals, and improved tissue (cartilage) segmentation outcomes. © 2018 International Society for Magnetic Resonance in Medicine.

Strategies and techniques to enhance constructed wetland performance for sustainable wastewater treatment.

PubMed

Wu, Haiming; Fan, Jinlin; Zhang, Jian; Ngo, Huu Hao; Guo, Wenshan; Liang, Shuang; Hu, Zhen; Liu, Hai

2015-10-01

Constructed wetlands (CWs) have been used as an alternative to conventional technologies for wastewater treatment for more than five decades. Recently, the use of various modified CWs to improve treatment performance has also been reported in the literature. However, the available knowledge on various CW technologies considering the intensified and reliable removal of pollutants is still limited. Hence, this paper aims to provide an overview of the current development of CW strategies and techniques for enhanced wastewater treatment. Basic information on configurations and characteristics of different innovations was summarized. Then, overall treatment performance of those systems and their shortcomings were further discussed. Lastly, future perspectives were also identified for specialists to design more effective and sustainable CWs. This information is used to inspire some novel intensifying methodologies, and benefit the successful applications of potential CW technologies.

Acoustic and Aerothermal Performance Test of the Axisymmetric Coannular Ejector Nozzle. Volume 2; Acoustic Performance

NASA Technical Reports Server (NTRS)

Herkes, William

2000-01-01

Acoustic and propulsion performance testing of a model-scale Axisymmetric Coannular Ejector nozzle was conducted in the Boeing Low-speed Aeroacoustic Facility. This nozzle is a plug nozzle with an ejector design to provide aspiration of about 20% of the engine flow. A variety of mixing enhancers were designed to promote mixing of the engine and the aspirated flows. These included delta tabs, tone-injection rods, and wheeler ramps. This report addresses the acoustic aspects of the testing. The spectral characteristics of the various configurations of the nozzle are examined on a model-scale basis. This includes indentifying particular noise sources contributing to the spectra and the data are projected to full-scale flyover conditions to evaluate the effectiveness of the nozzle, and of the various mixing enhancers, on reducing the Effective Perceived Noise Levels.

7 CFR 275.10 - Scope and purpose.

Code of Federal Regulations, 2010 CFR

2010-01-01

... to enhanced funding. (b) The objectives of quality control reviews are to provide: (1) A systematic... FOOD STAMP AND FOOD DISTRIBUTION PROGRAM PERFORMANCE REPORTING SYSTEM Quality Control (QC) Reviews... responsible for conducting quality control reviews. For food stamp quality control reviews, a sample of...

Improving Rural Emergency Medical Services (EMS) through transportation system enhancements Phase II.

DOT National Transportation Integrated Search

2015-12-01

Providing acute medical care outside of the hospital, Emergency Medical Services (EMS) is crucial in rural environments where hospitals are not close by and are difficult to access. Establishing EMS performance measures is critical in improving a rur...

MEASUREMENT OF HYDRAULIC CONDUCTIVITY DISTRIBUTIONS: A MANUAL OF PRACTICE

EPA Science Inventory

The ability of hydrologists to perform field measurements of aquifer hydraulic properties must be enhanced in order to significantly improve the capacity to solve groundwater contamination problems at Superfund and other sites. The primary purpose of this manual is to provide ne...

MEASUREMENT OF HYDRAULIC CONDUCTIVITY DISTRIBUTIONS: A MANUAL OF PRACTICE

EPA Science Inventory

The ability of hydrologists to perform field measurements of aquifer hydraulic properties must be enhanced in order to significantly improve the capacity to solve groundwater contamination problems at Superfund and other sites. he primary purpose of this manual is to provide new ...

PERFORMANCE, RELIABILITY, AND IMPROVEMENT OF A TISSUE-SPECIFIC METABOLIC SIMULATOR

EPA Science Inventory

A methodology is described that has been used to build and enhance a simulator for rat liver metabolism providing reliable predictions within a large chemical domain. The tissue metabolism simulator (TIMES) utilizes a heuristic algorithm to generate plausible metabolic maps using...

Semiannual Report: Oct 1, 2000 - Mar 31, 2001

EPA Pesticide Factsheets

Semiannual Report #EPA-350-K-01-001, May, 2001. Our new structure provides a solid foundation for the OIG's efforts to continuously improve its performance, and I am certain that it will greatly enhance our ability to be agents of positive change.

The mental cost of cognitive enhancement.

PubMed

Iuculano, Teresa; Cohen Kadosh, Roi

2013-03-06

Noninvasive brain stimulation provides a potential tool for affecting brain functions in the typical and atypical brain and offers in several cases an alternative to pharmaceutical intervention. Some studies have suggested that transcranial electrical stimulation (TES), a form of noninvasive brain stimulation, can also be used to enhance cognitive performance. Critically, research so far has primarily focused on optimizing protocols for effective stimulation, or assessing potential physical side effects of TES while neglecting the possibility of cognitive side effects. We assessed this possibility by targeting the high-level cognitive abilities of learning and automaticity in the mathematical domain. Notably, learning and automaticity represent critical abilities for potential cognitive enhancement in typical and atypical populations. Over 6 d, healthy human adults underwent cognitive training on a new numerical notation while receiving TES to the posterior parietal cortex or the dorsolateral prefrontal cortex. Stimulation to the the posterior parietal cortex facilitated numerical learning, whereas automaticity for the learned material was impaired. In contrast, stimulation to the dorsolateral prefrontal cortex impaired the learning process, whereas automaticity for the learned material was enhanced. The observed double dissociation indicates that cognitive enhancement through TES can occur at the expense of other cognitive functions. These findings have important implications for the future use of enhancement technologies for neurointervention and performance improvement in healthy populations.

Mental workload and performance experiment (15-IML-1)

NASA Technical Reports Server (NTRS)

Alexander, Harold L.

1992-01-01

Whether on Earth or in space, people tend to work more productively in settings designed for efficiency and comfort. Because comfortable and stress-free working environments enhance performance and contribute to congenial relationships among co-workers, the living and working arrangements for spacecraft to be used for missions lasting months or years assume particular importance. The Mental Workload and Performance Experiment (MWPE), in part, examines the appropriate design of workstations for performance of various tasks in microgravity, by providing a variable-configuration workstation that may be adjusted by the astronauts.

Enhanced Internet firewall design using stateful filters final report

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

Hutchins, J.A.; Simons, R.W.

1997-08-01

The current state-of-the-art in firewall design provides a lot of security for company networks, but normally at the expense of performance and/or functionality. Sandia researched a new approach to firewall design which incorporates a highly stateful approach, allowing much more flexibility for protocol checking and manipulation while retaining performance. A prototype system was built and multiple protocol policy modules implemented to test the concept. The resulting system, though implemented on a low-power workstation, performed almost at the same performance as Sandia`s current firewall.

Enhancing the Performance of Passive Teleoperation Systems via Cutaneous Feedback.

PubMed

Pacchierotti, Claudio; Tirmizi, Asad; Bianchini, Gianni; Prattichizzo, Domenico

2015-01-01

We introduce a novel method to improve the performance of passive teleoperation systems with force reflection. It consists of integrating kinesthetic haptic feedback provided by common grounded haptic interfaces with cutaneous haptic feedback. The proposed approach can be used on top of any time-domain control technique that ensures a stable interaction by scaling down kinesthetic feedback when this is required to satisfy stability conditions (e.g., passivity) at the expense of transparency. Performance is recovered by providing a suitable amount of cutaneous force through custom wearable cutaneous devices. The viability of the proposed approach is demonstrated through an experiment of perceived stiffness and an experiment of teleoperated needle insertion in soft tissue.

Microbial fuel cell (MFC) power performance improvement through enhanced microbial electrogenicity.

PubMed

Li, Ming; Zhou, Minghua; Tian, Xiaoyu; Tan, Chaolin; McDaniel, Cameron T; Hassett, Daniel J; Gu, Tingyue

Within the past 5 years, tremendous advances have been made to maximize the performance of microbial fuel cells (MFCs) for both "clean" bioenergy production and bioremediation. Most research efforts have focused on parameters including (i) optimizing reactor configuration, (ii) electrode construction, (iii) addition of redox-active, electron donating mediators, (iv) biofilm acclimation and feed nutrient adjustment, as well as (v) other parameters that contribute to enhanced MFC performance. To date, tremendous advances have been made, but further improvements are needed for MFCs to be economically practical. In this review, the diversity of electrogenic microorganisms and microbial community changes in mixed cultures are discussed. More importantly, different approaches including chemical/genetic modifications and gene regulation of exoelectrogens, synthetic biology approaches and bacterial community cooperation are reviewed. Advances in recent years in metagenomics and microbiomes have allowed researchers to improve bacterial electrogenicity of robust biofilms in MFCs using novel, unconventional approaches. Taken together, this review provides some important and timely information to researchers who are examining additional means to enhance power production of MFCs. Copyright © 2018 Elsevier Inc. All rights reserved.

Design and testing of artifact-suppressed adaptive histogram equalization: a contrast-enhancement technique for display of digital chest radiographs.

PubMed

Rehm, K; Seeley, G W; Dallas, W J; Ovitt, T W; Seeger, J F

1990-01-01

One of the goals of our research in the field of digital radiography has been to develop contrast-enhancement algorithms for eventual use in the display of chest images on video devices with the aim of preserving the diagnostic information presently available with film, some of which would normally be lost because of the smaller dynamic range of video monitors. The ASAHE algorithm discussed in this article has been tested by investigating observer performance in a difficult detection task involving phantoms and simulated lung nodules, using film as the output medium. The results of the experiment showed that the algorithm is successful in providing contrast-enhanced, natural-looking chest images while maintaining diagnostic information. The algorithm did not effect an increase in nodule detectability, but this was not unexpected because film is a medium capable of displaying a wide range of gray levels. It is sufficient at this stage to show that there is no degradation in observer performance. Future tests will evaluate the performance of the ASAHE algorithm in preparing chest images for video display.

Optimal exposure techniques for iodinated contrast enhanced breast CT

NASA Astrophysics Data System (ADS)

Glick, Stephen J.; Makeev, Andrey

2016-03-01

Screening for breast cancer using mammography has been very successful in the effort to reduce breast cancer mortality, and its use has largely resulted in the 30% reduction in breast cancer mortality observed since 1990 [1]. However, diagnostic mammography remains an area of breast imaging that is in great need for improvement. One imaging modality proposed for improving the accuracy of diagnostic workup is iodinated contrast-enhanced breast CT [2]. In this study, a mathematical framework is used to evaluate optimal exposure techniques for contrast-enhanced breast CT. The ideal observer signal-to-noise ratio (i.e., d') figure-of-merit is used to provide a task performance based assessment of optimal acquisition parameters under the assumptions of a linear, shift-invariant imaging system. A parallel-cascade model was used to estimate signal and noise propagation through the detector, and a realistic lesion model with iodine uptake was embedded into a structured breast background. Ideal observer performance was investigated across kVp settings, filter materials, and filter thickness. Results indicated many kVp spectra/filter combinations can improve performance over currently used x-ray spectra.

Instructional design strategies for health behavior change.

PubMed

Kinzie, Mable B

2005-01-01

To help health educators build upon the best of different health behavior change theories, this paper offers a unified set of instructional design strategies for health education interventions. This set draws upon the recommendations of Rosenstock (Health Belief Model), Bandura (Social Cognitive Theory), and Dearing (Diffusion Theory), and uses a modified Events of Instruction framework (adapted from Robert Gagne): gain attention (convey health threats and benefits), present stimulus material (tailor message to audience knowledge and values, demonstrate observable effectiveness, make behaviors easy-to-understand and do), provide guidance (use trustworthy models to demonstrate), elicit performance and provide feedback (to enhance trialability, develop proficiency and self-efficacy), enhance retention and transfer (provide social supports and deliver behavioral cues). Sample applications of these strategies are provided. A brief review of research on adolescent smoking prevention enables consideration of the frequency with which these strategies are used, and possible patterns between strategy use and behavioral outcomes.

A radar data processing and enhancement system

NASA Technical Reports Server (NTRS)

Anderson, K. F.; Wrin, J. W.; James, R.

1986-01-01

This report describes the space position data processing system of the NASA Western Aeronautical Test Range. The system is installed at the Dryden Flight Research Facility of NASA Ames Research Center. This operational radar data system (RADATS) provides simultaneous data processing for multiple data inputs and tracking and antenna pointing outputs while performing real-time monitoring, control, and data enhancement functions. Experience in support of the space shuttle and aeronautical flight research missions is described, as well as the automated calibration and configuration functions of the system.

NASA Human Health and Performance Information Architecture Panel

NASA Technical Reports Server (NTRS)

Johnson-Throop, Kathy; Kadwa, Binafer; VanBaalen, Mary

2014-01-01

The Human Health and Performance (HH&P) Directorate at NASA's Johnson Space Center has a mission to enable optimization of human health and performance throughout all phases of spaceflight. All HH&P functions are ultimately aimed at achieving this mission. Our activities enable mission success, optimizing human health and productivity in space before, during, and after the actual spaceflight experience of our crews, and include support for ground-based functions. Many of our spaceflight innovations also provide solutions for terrestrial challenges, thereby enhancing life on Earth.

Sol-gel-processed yttrium-doped NiO as hole transport layer in inverted perovskite solar cells for enhanced performance

NASA Astrophysics Data System (ADS)

Hu, Zijun; Chen, Da; Yang, Pan; Yang, Lijun; Qin, Laishun; Huang, Yuexiang; Zhao, Xiaochong

2018-05-01

In this work, high-performance inverted planar perovskite solar cells (PSCs) using sol-gel processed Y-doped NiO thin films as hole transport layer (HTL) were demonstrated. Y-doped NiO thin films containing different Y doping concentrations were successfully prepared through a simple sol-gel process. The Y doping could significantly improve the electrical conductivity of NiO thin film, and the photovoltaic performance of Y-doped NiO HTL-based PSC devices outperformed that of the pristine NiO HTL-based device. Notably, the PSC using a 5%Y-NiO HTL exhibited the champion performance with an open-circuit voltage (Voc) of 1.00 V, a short circuit current density (Jsc) of 23.82 mA cm-2, a fill factor (FF) of 68% and a power conversion efficiency (PCE) of 16.31%, resulting in a 27.62% enhancement in PCE in comparison with the NiO device. The enhanced performance of the Y-doped NiO device could be attributed to the improved hole mobility, the high quality compact active layer morphology, the more efficient charge extraction from perovskite absorber as well as the lower recombination probability of charge carriers. Thus, this work provides a simple and effective approach to improve the electrical conductivity of p-type NiO thin films for use as a promising HTL in high performance PSCs.

Real-time Enhancement, Registration, and Fusion for a Multi-Sensor Enhanced Vision System

NASA Technical Reports Server (NTRS)

Hines, Glenn D.; Rahman, Zia-ur; Jobson, Daniel J.; Woodell, Glenn A.

2006-01-01

Over the last few years NASA Langley Research Center (LaRC) has been developing an Enhanced Vision System (EVS) to aid pilots while flying in poor visibility conditions. The EVS captures imagery using two infrared video cameras. The cameras are placed in an enclosure that is mounted and flown forward-looking underneath the NASA LaRC ARIES 757 aircraft. The data streams from the cameras are processed in real-time and displayed on monitors on-board the aircraft. With proper processing the camera system can provide better-than- human-observed imagery particularly during poor visibility conditions. However, to obtain this goal requires several different stages of processing including enhancement, registration, and fusion, and specialized processing hardware for real-time performance. We are using a real-time implementation of the Retinex algorithm for image enhancement, affine transformations for registration, and weighted sums to perform fusion. All of the algorithms are executed on a single TI DM642 digital signal processor (DSP) clocked at 720 MHz. The image processing components were added to the EVS system, tested, and demonstrated during flight tests in August and September of 2005. In this paper we briefly discuss the EVS image processing hardware and algorithms. We then discuss implementation issues and show examples of the results obtained during flight tests. Keywords: enhanced vision system, image enhancement, retinex, digital signal processing, sensor fusion

Infrared small target enhancement: grey level mapping based on improved sigmoid transformation and saliency histogram

NASA Astrophysics Data System (ADS)

Wan, Minjie; Gu, Guohua; Qian, Weixian; Ren, Kan; Chen, Qian

2018-06-01

Infrared (IR) small target enhancement plays a significant role in modern infrared search and track (IRST) systems and is the basic technique of target detection and tracking. In this paper, a coarse-to-fine grey level mapping method using improved sigmoid transformation and saliency histogram is designed to enhance IR small targets under different backgrounds. For the stage of rough enhancement, the intensity histogram is modified via an improved sigmoid function so as to narrow the regular intensity range of background as much as possible. For the part of further enhancement, a linear transformation is accomplished based on a saliency histogram constructed by averaging the cumulative saliency values provided by a saliency map. Compared with other typical methods, the presented method can achieve both better visual performances and quantitative evaluations.

Enhanced Time Out: An Improved Communication Process.

PubMed

Nelson, Patricia E

2017-06-01

An enhanced time out is an improved communication process initiated to prevent such surgical errors as wrong-site, wrong-procedure, or wrong-patient surgery. The enhanced time out at my facility mandates participation from all members of the surgical team and requires designated members to respond to specified time out elements on the surgical safety checklist. The enhanced time out incorporated at my facility expands upon the safety measures from the World Health Organization's surgical safety checklist and ensures that all personnel involved in a surgical intervention perform a final check of relevant information. Initiating the enhanced time out at my facility was intended to improve communication and teamwork among surgical team members and provide a highly reliable safety process to prevent wrong-site, wrong-procedure, and wrong-patient surgery. Copyright © 2017 AORN, Inc. Published by Elsevier Inc. All rights reserved.

Interacting with target tracking algorithms in a gaze-enhanced motion video analysis system

NASA Astrophysics Data System (ADS)

Hild, Jutta; Krüger, Wolfgang; Heinze, Norbert; Peinsipp-Byma, Elisabeth; Beyerer, Jürgen

2016-05-01

Motion video analysis is a challenging task, particularly if real-time analysis is required. It is therefore an important issue how to provide suitable assistance for the human operator. Given that the use of customized video analysis systems is more and more established, one supporting measure is to provide system functions which perform subtasks of the analysis. Recent progress in the development of automated image exploitation algorithms allow, e.g., real-time moving target tracking. Another supporting measure is to provide a user interface which strives to reduce the perceptual, cognitive and motor load of the human operator for example by incorporating the operator's visual focus of attention. A gaze-enhanced user interface is able to help here. This work extends prior work on automated target recognition, segmentation, and tracking algorithms as well as about the benefits of a gaze-enhanced user interface for interaction with moving targets. We also propose a prototypical system design aiming to combine both the qualities of the human observer's perception and the automated algorithms in order to improve the overall performance of a real-time video analysis system. In this contribution, we address two novel issues analyzing gaze-based interaction with target tracking algorithms. The first issue extends the gaze-based triggering of a target tracking process, e.g., investigating how to best relaunch in the case of track loss. The second issue addresses the initialization of tracking algorithms without motion segmentation where the operator has to provide the system with the object's image region in order to start the tracking algorithm.

Performance Management in Healthcare Organizations: Concept and Practicum.

PubMed

Dimitropoulos, Panagiotis E

2017-01-01

Organizational performance can create and sustain competitive advantages for corporations and even improve their sustainability and future prospects. Health care organizations present a sector where performance management is structured by multiple dimensions. The scope of this study is to analyze the issue of performance management in healthcare organizations and specifically the implementation of the Balanced Scorecard (BSC) methodology on organizations providing health services. The study provides a discussion on the BSC development process, the steps that management has to take in order to prepare the implementation of the BSC and finally discusses a practical example of a scorecard with specific strategic goals and performance indicators. Managers of healthcare organizations and specifically those providing services to the elderly and the general population could use the propositions of the study as a roadmap for processing, analyzing, evaluating and implementing the balanced scorecard approach in their organizations' daily operations. BSC methodology can give an advantage in terms of enhanced stakeholder management and preservation within a highly volatile and competitive economic environment.

Effects of contour enhancement on low-vision preference and visual search.

PubMed

Satgunam, Premnandhini; Woods, Russell L; Luo, Gang; Bronstad, P Matthew; Reynolds, Zachary; Ramachandra, Chaithanya; Mel, Bartlett W; Peli, Eli

2012-09-01

To determine whether image enhancement improves visual search performance and whether enhanced images were also preferred by subjects with vision impairment. Subjects (n = 24) with vision impairment (vision: 20/52 to 20/240) completed visual search and preference tasks for 150 static images that were enhanced to increase object contours' visual saliency. Subjects were divided into two groups and were shown three enhancement levels. Original and medium enhancements were shown to both groups. High enhancement was shown to group 1, and low enhancement was shown to group 2. For search, subjects pointed to an object that matched a search target displayed at the top left of the screen. An "integrated search performance" measure (area under the curve of cumulative correct response rate over search time) quantified performance. For preference, subjects indicated the preferred side when viewing the same image with different enhancement levels on side-by-side high-definition televisions. Contour enhancement did not improve performance in the visual search task. Group 1 subjects significantly (p < 0.001) rejected the High enhancement, and showed no preference for medium enhancement over the original images. Group 2 subjects significantly preferred (p < 0.001) both the medium and the low enhancement levels over original. Contrast sensitivity was correlated with both preference and performance; subjects with worse contrast sensitivity performed worse in the search task (ρ = 0.77, p < 0.001) and preferred more enhancement (ρ = -0.47, p = 0.02). No correlation between visual search performance and enhancement preference was found. However, a small group of subjects (n = 6) in a narrow range of mid-contrast sensitivity performed better with the enhancement, and most (n = 5) also preferred the enhancement. Preferences for image enhancement can be dissociated from search performance in people with vision impairment. Further investigations are needed to study the relationships between preference and performance for a narrow range of mid-contrast sensitivity where a beneficial effect of enhancement may exist.

An Aerodynamic Performance Evaluation of the NASA/Ames Research Center Advanced Concepts Flight Simulator. M.S. Thesis

NASA Technical Reports Server (NTRS)

Donohue, Paul F.

1987-01-01

The results of an aerodynamic performance evaluation of the National Aeronautics and Space Administration (NASA)/Ames Research Center Advanced Concepts Flight Simulator (ACFS), conducted in association with the Navy-NASA Joint Institute of Aeronautics, are presented. The ACFS is a full-mission flight simulator which provides an excellent platform for the critical evaluation of emerging flight systems and aircrew performance. The propulsion and flight dynamics models were evaluated using classical flight test techniques. The aerodynamic performance model of the ACFS was found to realistically represent that of current day, medium range transport aircraft. Recommendations are provided to enhance the capabilities of the ACFS to a level forecast for 1995 transport aircraft. The graphical and tabular results of this study will establish a performance section of the ACFS Operation's Manual.

Realistic training for effective crew performance

NASA Technical Reports Server (NTRS)

Foushee, H. C.

1985-01-01

Evaluation of incident and accident statistics reveals that most problems occur not because of a lack of proficiency in pilot training, but because of the inability to coordinate skills into effective courses of action. Line-Oriented Flight Training (LOFT) and Cockpit Resource Management (CRM) programs provide training which will develop both individual crew member skills, as well as those associated with effective group function. A study conducted by NASA at the request of the U.S. Congress supports the argument for training that enhances crew performance in addition to providing individual technical skills, and is described in detail.

Application of Reinforcement Learning in Cognitive Radio Networks: Models and Algorithms

PubMed Central

Yau, Kok-Lim Alvin; Poh, Geong-Sen; Chien, Su Fong; Al-Rawi, Hasan A. A.

2014-01-01

Cognitive radio (CR) enables unlicensed users to exploit the underutilized spectrum in licensed spectrum whilst minimizing interference to licensed users. Reinforcement learning (RL), which is an artificial intelligence approach, has been applied to enable each unlicensed user to observe and carry out optimal actions for performance enhancement in a wide range of schemes in CR, such as dynamic channel selection and channel sensing. This paper presents new discussions of RL in the context of CR networks. It provides an extensive review on how most schemes have been approached using the traditional and enhanced RL algorithms through state, action, and reward representations. Examples of the enhancements on RL, which do not appear in the traditional RL approach, are rules and cooperative learning. This paper also reviews performance enhancements brought about by the RL algorithms and open issues. This paper aims to establish a foundation in order to spark new research interests in this area. Our discussion has been presented in a tutorial manner so that it is comprehensive to readers outside the specialty of RL and CR. PMID:24995352

Enhanced Photocurrent in BiFeO3 Materials by Coupling Temperature and Thermo-Phototronic Effects for Self-Powered Ultraviolet Photodetector System.

PubMed

Qi, Jia; Ma, Nan; Ma, Xiaochen; Adelung, Rainer; Yang, Ya

2018-04-25

Ferroelectric materials can be utilized for fabricating photodetectors because of the photovoltaic effect. Enhancing the photovoltaic performance of ferroelectric materials is still a challenge. Here, a self-powered ultraviolet (UV) photodetector is designed based on the ferroelectric BiFeO 3 (BFO) material, exhibiting a high current/voltage response to 365 nm light in heating/cooling states. The photovoltaic performance of the BFO-based device can be well modulated by applying different temperature variations, where the output current and voltage can be enhanced by 60 and 75% in heating and cooling states, respectively. The enhancement mechanism of the photocurrent is associated with both temperature effect and thermo-phototronic effect in the photovoltaic process. Moreover, a 4 × 4 matrix photodetector array has been designed for detecting the 365 nm light distribution in the cooling state by utilizing photovoltage signals. This study clarifies the role of the temperature effect and the thermo-phototronic effect in the photovoltaic process of the BFO material and provides a feasible route for pushing forward practical applications of self-powered UV photodetectors.

High-performance flexible surface-enhanced Raman scattering substrates fabricated by depositing Ag nanoislands on the dragonfly wing

NASA Astrophysics Data System (ADS)

Wang, Yuhong; Wang, Mingli; Shen, Lin; Sun, Xin; Shi, Guochao; Ma, Wanli; Yan, Xiaoya

2018-04-01

Natural dragonfly wing (DW), as a template, was deposited on noble metal sliver (Ag) nanoislands by magnetron sputtering to fabricate a flexible, low-cost, large-scale and environment-friendly surface-enhanced Raman scattering (SERS) substrate (Ag/DW substrate). Generally, materials with regular surface nanostructures are chosen for the templates, the selection of our new material with irregular surface nanostructures for substrates provides a new idea for the preparation of high-performance SERS-active substrates and many biomimetic materials. The optimum sputtering time of metal Ag was also investigated at which the prepared SERS-active substrates revealed remarkable SERS activities to 4-aminothiophenol (4-ATP) and crystal violet (CV). Even more surprisingly, the Ag/DW substrate with such an irregular template had reached the enhancement factor (EF) of ∼1.05 × 105 and the detection limit of 10-10 M to 4-ATP. The 3D finite-different time-domain (3D-FDTD) simulation illustrated that the "hot spots" between neighbouring Ag nanoislands at the top of pillars played a most important role in generating electromagnetic (EM) enhancement and strengthening Raman signals.

High power, gel polymer lithium-ion cells with improved low temperature performance for NASA and DoD applications

NASA Technical Reports Server (NTRS)

Smart, M. C.; Ratnakumar, B. V.; Whitcanack, L. D.; Chin, K. B.; Surampudi, S.; Narayanan, S. R.; Alamgir, Mohamed; Yu, Ji-Sang; Plichta, Edward P.

2004-01-01

Both NASA and the U.S. Army have interest in developing secondary energy storage devices that are capable of meeting the demanding performance requirements of aerospace and man-portable applications. In order to meet these demanding requirements, gel-polymer electrolyte-based lithium-ion cells are being actively considered, due to their promise of providing high specific energy and enhanced safety aspects.

Performance and cost improvements in the display control module for DVE

NASA Astrophysics Data System (ADS)

Thomas, J.; Lorimer, S.,

2009-05-01

The DCM for the Drivers Vision Enhancer system is the display part of a relatively low cost IR imaging system for land-vehicles. Recent changes to operational needs, associated with asymmetrical warfare have added daytime operations to the uses for this mature system. This paper will discuss cost/performance tradeoffs and provide thoughts for "DVE of the future" in light of these new operational needs for the system.

Big data computing: Building a vision for ARS information management

USDA-ARS?s Scientific Manuscript database

Improvements are needed within the ARS to increase scientific capacity and keep pace with new developments in computer technologies that support data acquisition and analysis. Enhancements in computing power and IT infrastructure are needed to provide scientists better access to high performance com...

Gas separation mechanism of CO 2 selective amidoxime-poly(1-trimethylsilyl-1-propyne) membranes

DOE PAGES

Feng, Hongbo; Hong, Tao; Mahurin, Shannon Mark; ...

2017-05-09

Polymeric membranes for CO 2 separation have drawn significant attention in academia and industry. We prepared amidoxime-functionalized poly(1-trimethylsilyl-1-propyne) (AO-PTMSP) membranes through hydrosilylation and post-polymerization modification. Compared to neat PTMSP membranes, the AO-PTMSP membranes showed significant enhancements in CO 2/N 2 gas separation performance (CO 2 permeability ~6000 Barrer; CO 2/N 2 selectivity 17). This systematic study provides clear guidelines on how to tune the CO 2-philicity within PTMSP matrices and the effects on gas selectivity. Key parameters for elucidating the gas transport mechanism were discussed based on CO 2 sorption measurements and fractional free volume estimates. The effect of themore » AO content on CO 2/N 2 selectivity was further examined by means of density functional theory calculations. Here, both experimental and theoretical data provide consistent results that conclusively show that CO 2/N 2 separation performance is enhanced by increased CO 2 polymer interactions.« less

Gas separation mechanism of CO 2 selective amidoxime-poly(1-trimethylsilyl-1-propyne) membranes

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

Feng, Hongbo; Hong, Tao; Mahurin, Shannon Mark

Polymeric membranes for CO 2 separation have drawn significant attention in academia and industry. We prepared amidoxime-functionalized poly(1-trimethylsilyl-1-propyne) (AO-PTMSP) membranes through hydrosilylation and post-polymerization modification. Compared to neat PTMSP membranes, the AO-PTMSP membranes showed significant enhancements in CO 2/N 2 gas separation performance (CO 2 permeability ~6000 Barrer; CO 2/N 2 selectivity 17). This systematic study provides clear guidelines on how to tune the CO 2-philicity within PTMSP matrices and the effects on gas selectivity. Key parameters for elucidating the gas transport mechanism were discussed based on CO 2 sorption measurements and fractional free volume estimates. The effect of themore » AO content on CO 2/N 2 selectivity was further examined by means of density functional theory calculations. Here, both experimental and theoretical data provide consistent results that conclusively show that CO 2/N 2 separation performance is enhanced by increased CO 2 polymer interactions.« less

Mn-Based Cathode with Synergetic Layered-Tunnel Hybrid Structures and Their Enhanced Electrochemical Performance in Sodium Ion Batteries.

PubMed

Wu, Zhen-Guo; Li, Jun-Tao; Zhong, Yan-Jun; Guo, Xiao-Dong; Huang, Ling; Zhong, Ben-He; Agyeman, Daniel-Adjei; Lim, Jin-Myoung; Kim, Du-Ho; Cho, Maeng-Hyo; Kang, Yong-Mook

2017-06-28

A synergistic approach for advanced cathode materials is proposed. Sodium manganese oxide with a layered-tunnel hybrid structure was designed, synthesized, and subsequently investigated. The layered-tunnel hybrid structure provides fast Na ion diffusivity and high structural stability thanks to the tunnel phase, enabling high rate capability and greatly improved cycling stability compared to that of the pure P2 layered phase while retaining the high specific capacity of the P2 layered phase. The hybrid structure provided a decent discharge capacity of 133.4 mAh g -1 even at 8 C, which exceeds the reported best rate capability for Mn-based cathodes. It also displayed an impressive cycling stability, maintaining 83.3 mAh g -1 after 700 cycles at 10 C. Theoretical calculation and the potentiostatic intermittent titration technique (PITT) demonstrated that this hybrid structure helps enhance Na ion diffusivity during charge and discharge, attaining, as a result, an unprecendented electrochemical performance.

Resourcing interventions enhance psychology support capabilities in special operations forces.

PubMed

Myatt, Craig A; Auzenne, J W

2012-01-01

This study provides an examination of approaches to United States Government (USG) resourcing interventions on a national scale that enhance psychology support capabilities in the Special Operations Forces (SOF) community. A review of Congressional legislation and resourcing trends in the form of authorizations and appropriations since 2006 demonstrates how Congress supported enhanced psychology support capabilities throughout the Armed Forces and in SOF supporting innovative command interests that address adverse affects of operations tempo behavioral effects (OTBE). The formulation of meaningful metrics to address SOF specific command interests led to a personnel tempo (PERSTEMPO) analysis in response to findings compiled by the Preservation of the Force and Families (POTFF) Task Force. The review of PERSTEMPO data at subordinate command and unit levels enhances the capability of SOF leaders to develop policy and guidance on training and operational planning that mitigates OTBE and maximizes resourcing authorizations. A major challenge faced by the DoD is in providing behavioral healthcare that meets public and legislative demands while proving suitable and sustainable at all levels of military operations: strategic, operational, and tactical. Current legislative authorizations offer a mechanism of command advocacy for resourced multi-functional program development that enhances psychology support capabilities while reinforcing SOF readiness and performance. 2012.

Entanglement-enhanced lidars for simultaneous range and velocity measurements

NASA Astrophysics Data System (ADS)

Zhuang, Quntao; Zhang, Zheshen; Shapiro, Jeffrey H.

2017-10-01

Lidar is a well-known optical technology for measuring a target's range and radial velocity. We describe two lidar systems that use entanglement between transmitted signals and retained idlers to obtain significant quantum enhancements in simultaneous measurements of these parameters. The first entanglement-enhanced lidar circumvents the Arthurs-Kelly uncertainty relation for simultaneous measurements of range and radial velocity from the detection of a single photon returned from the target. This performance presumes there is no extraneous (background) light, but is robust to the round-trip loss incurred by the signal photons. The second entanglement-enhanced lidar—which requires a lossless, noiseless environment—realizes Heisenberg-limited accuracies for both its range and radial-velocity measurements, i.e., their root-mean-square estimation errors are both proportional to 1 /M when M signal photons are transmitted. These two lidars derive their entanglement-based enhancements from the use of a unitary transformation that takes a signal-idler photon pair with frequencies ωS and ωI and converts it to a signal-idler photon pair whose frequencies are (ωS+ωI)/2 and (ωS-ωI)/2 . Insight into how this transformation provides its benefits is provided through an analogy to continuous-variable superdense coding.

Students Apply Research Methods to Consumer Decisions About Cognitive Enhancing Drinks

PubMed Central

Walters, Charles B.; Hill, Katherine G.; Zavilla, Anastasia R.; Erickson, Cynthia A.

2014-01-01

The goal of this class project was to provide students with a hands-on research experience that allowed autonomy, but eliminated duplication of effort and could be completed within one semester. Our resources were limited to a small supply budget and an introductory psychology subject pool. Six students from a behavioral neuroscience class tested claims made by a drink company that their product improves cognitive function. The students each chose a cognitive task for their part of the project. The tasks included the Donders Reaction Time Task, the Stroop Task, the Raven’s Progressive Matrices, a short-term memory span test, the Rey-Osterrieth Complex Figure Test and a simple measure of prefrontal EEG activity. Participants were randomly assigned to an experimental or control drink. The experimental group received the putative cognitive enhancing drink and the control group received a placebo drink that was very similar in color and taste. The two drinks shared no active ingredients. Results suggest that the putative cognitive enhancing drink did not improve performance on any of the tasks and decreased performance on the short-term memory task. These findings are discussed in regard to implications for consumers as well as further research into supplements and their ability to improve cognitive performance. Each student presented his/her results at a university-wide research conference. This project provided a rich experience in which students had the opportunity to carry out a research project from conception to presentation. PMID:25565916

Enhancement of discharge performance of Li/CF x cell by thermal treatment of CF x cathode material

NASA Astrophysics Data System (ADS)

Zhang, Sheng S.; Foster, Donald; Read, Jeffrey

In this work we demonstrate that the thermal treatment of CF x cathode material just below the decomposition temperature can enhance discharge performance of Li/CF x cells. The performance enhancement becomes more effective when heating a mixture of CF x and citric acid (CA) since CA serves as an extra carbon source. Discharge experiments show that the thermal treatment not only reduces initial voltage delay, but also raises discharge voltage. Whereas the measurement of powder impedance indicates the thermal treatment does not increase electronic conductivity of CF x material. Based on these facts, we propose that the thermal treatment results in a limited decomposition of CF x, which yields a subfluorinated carbon (CF x- δ), instead of a highly conductive carbon. In the case of CF x/AC mixture, the AC provides extra carbon that reacts with F 2 and fluorocarbon radicals generated by the thermal decomposition of CF x to form subfluorinated carbon. The process of thermal treatment is studied by thermogravimetric analysis and X-ray diffraction, and the effect of treatment conditions such as heating temperature, heating time and CF x/CA ratio on the discharge performance of CF x cathode is discussed. As an example, a Li/CF x cell using CF x treated with CA at 500 °C under nitrogen for 2 h achieved theretical specific capacity when being discharged at C/5. Impedance analysis indicates that the enhanced performance is attributed to a significant reduction in the cell reaction resistance.

Do Glucose and Caffeine Nasal Sprays Influence Exercise or Cognitive Performance?

PubMed

De Pauw, Kevin; Roelands, Bart; Van Cutsem, Jeroen; Decroix, Lieselot; Valente, Angelica; Taehee, Kim; Lettan, Robert B; Carrillo, Andres E; Meeusen, Romain

2017-10-01

Nasal spray (NAS) containing caffeine (CAF) or glucose (GLUC) activates sensory(motor) cortices. To investigate the influence of CAF or GLUC NAS on exercise and cognitive performance. Eleven male subjects (age 22 ± 2 y) performed a maximal cycle test and 2 familiarization and 3 experimental trials. Each trial included a 30-s Wingate test and a 30-min time-trial (TT) performance test interspersed by 15 min of rest. Before and after each exercise test a Stroop task was conducted. Placebo NAS with or without CAF or GLUC was provided before each exercise session and at each completed 25% of the TT. Exercise-performance, physiological, and cognitive measures were obtained. Magnitude-based inferences determined the likelihood that NAS solutions would be beneficial, trivial, or negative to exercise-performance measures based on the smallest worthwhile effect. Physiological and cognitive measures were analyzed using (non)parametric tests (P < .05). GLUC NAS substantially increased the average power output during the TT (very likely beneficial: 98%). No further worthwhile exercise-performance enhancements were found for both substances. In addition, no significant differences in physiological and cognitive measures were observed. In line with mouth rinsing, GLUC was shown to substantially enhance endurance performance, probably due to the activation of the olfactory pathway and/or extra-oral sweet-taste receptors. GLUC NAS enhances endurance performance, which indicates a novel administration route. The higher activity in sensory brain cortices probably elicited the ergogenic effect. However, no further physiological and cognitive changes occurred, indicating that higher doses of substrates might be required.

Effects of peer social interaction on performance during computerized cognitive remediation therapy in patients with early course schizophrenia: A pilot study.

PubMed

Sandoval, Luis R; González, Betzamel López; Stone, William S; Guimond, Synthia; Rivas, Cristina Torres; Sheynberg, David; Kuo, Susan S; Eack, Shaun; Keshavan, Matcheri S

2017-09-04

Recent studies show that computer-based training enhances cognition in schizophrenia; furthermore, socialization has also been found to improve cognitive functions. It is generally believed that non-social cognitive remediation using computer exercises would be a pre-requisite for therapeutic benefits from social cognitive training. However, it is also possible that social interaction by itself enhances non-social cognitive functions; this possibility has scarcely been explored in schizophrenia patients. This pilot study examined the effects of computer-based neurocognitive training, along with social interaction either with a peer (PSI) or without one (N-PSI). We hypothesized that PSI will enhance cognitive performance during computerized exercises in schizophrenia, as compared with N-PSI. Sixteen adult participants diagnosed with schizophrenia or schizoaffective disorder participating in an ongoing trial of Cognitive Enhancement Therapy completed several computerized neurocognitive remediation training sessions (the Orientation Remedial Module©, or ORM), either with a peer or without a peer. We observed a significant interaction between the effect of PSI and performance on the different cognitive exercises (p<0.05). More precisely, when patients performed the session with PSI, they demonstrated better cognitive performances than with N-PSI in the ORM exercise that provides training in processing speed, alertness, and reaction time (the standard Attention Reaction Conditioner, or ARC) (p<0.01, corrected). PSI did not significantly affect other cognitive domains such as target detection and spatial attention. Our findings suggest that PSI could improve cognitive performance, such as processing speed, during computerized cognitive training in schizophrenia. Additional studies investigating the effect of PSI during cognitive remediation are needed to further evaluate this hypothesis. Copyright © 2017. Published by Elsevier B.V.

Acceleration feedback of a current-following synchronized control algorithm for telescope elevation axis

NASA Astrophysics Data System (ADS)

Tang, Tao; Zhang, Tong; Du, Jun-Feng; Ren, Ge; Tian, Jing

2016-11-01

This paper proposes a dual-motor configuration to enhance closed-loop performance of a telescope control system. Two identical motors are mounted on each side of a U-type frame to drive the telescope elevation axis instead of a single motor drive, which is usually used in a classical design. This new configuration and mechanism can reduce the motor to half the size used in the former design, and it also provides some other advantages. A master-slave current control mode is employed to synchronize the two motors. Acceleration feedback control is utilized to further enhance the servo performance. Extensive experiments are used to validate the effectiveness of the proposed control algorithm in synchronization, disturbance attenuation and low-velocity tracking.

A statistical model for predicting muscle performance

NASA Astrophysics Data System (ADS)

Byerly, Diane Leslie De Caix

The objective of these studies was to develop a capability for predicting muscle performance and fatigue to be utilized for both space- and ground-based applications. To develop this predictive model, healthy test subjects performed a defined, repetitive dynamic exercise to failure using a Lordex spinal machine. Throughout the exercise, surface electromyography (SEMG) data were collected from the erector spinae using a Mega Electronics ME3000 muscle tester and surface electrodes placed on both sides of the back muscle. These data were analyzed using a 5th order Autoregressive (AR) model and statistical regression analysis. It was determined that an AR derived parameter, the mean average magnitude of AR poles, significantly correlated with the maximum number of repetitions (designated Rmax) that a test subject was able to perform. Using the mean average magnitude of AR poles, a test subject's performance to failure could be predicted as early as the sixth repetition of the exercise. This predictive model has the potential to provide a basis for improving post-space flight recovery, monitoring muscle atrophy in astronauts and assessing the effectiveness of countermeasures, monitoring astronaut performance and fatigue during Extravehicular Activity (EVA) operations, providing pre-flight assessment of the ability of an EVA crewmember to perform a given task, improving the design of training protocols and simulations for strenuous International Space Station assembly EVA, and enabling EVA work task sequences to be planned enhancing astronaut performance and safety. Potential ground-based, medical applications of the predictive model include monitoring muscle deterioration and performance resulting from illness, establishing safety guidelines in the industry for repetitive tasks, monitoring the stages of rehabilitation for muscle-related injuries sustained in sports and accidents, and enhancing athletic performance through improved training protocols while reducing injury.

The Enhanced Musical Rhythmic Perception in Second Language Learners

PubMed Central

Roncaglia-Denissen, M. Paula; Roor, Drikus A.; Chen, Ao; Sadakata, Makiko

2016-01-01

Previous research suggests that mastering languages with distinct rather than similar rhythmic properties enhances musical rhythmic perception. This study investigates whether learning a second language (L2) contributes to enhanced musical rhythmic perception in general, regardless of first and second languages rhythmic properties. Additionally, we investigated whether this perceptual enhancement could be alternatively explained by exposure to musical rhythmic complexity, such as the use of compound meter in Turkish music. Finally, it investigates if an enhancement of musical rhythmic perception could be observed among L2 learners whose first language relies heavily on pitch information, as is the case with tonal languages. Therefore, we tested Turkish, Dutch and Mandarin L2 learners of English and Turkish monolinguals on their musical rhythmic perception. Participants’ phonological and working memory capacities, melodic aptitude, years of formal musical training and daily exposure to music were assessed to account for cultural and individual differences which could impact their rhythmic ability. Our results suggest that mastering a L2 rather than exposure to musical rhythmic complexity could explain individuals’ enhanced musical rhythmic perception. An even stronger enhancement of musical rhythmic perception was observed for L2 learners whose first and second languages differ regarding their rhythmic properties, as enhanced performance of Turkish in comparison with Dutch L2 learners of English seem to suggest. Such a stronger enhancement of rhythmic perception seems to be found even among L2 learners whose first language relies heavily on pitch information, as the performance of Mandarin L2 learners of English indicates. Our findings provide further support for a cognitive transfer between the language and music domain. PMID:27375469

Coupling internal cerebellar models enhances online adaptation and supports offline consolidation in sensorimotor tasks

PubMed Central

Passot, Jean-Baptiste; Luque, Niceto R.; Arleo, Angelo

2013-01-01

The cerebellum is thought to mediate sensorimotor adaptation through the acquisition of internal models of the body-environment interaction. These representations can be of two types, identified as forward and inverse models. The first predicts the sensory consequences of actions, while the second provides the correct commands to achieve desired state transitions. In this paper, we propose a composite architecture consisting of multiple cerebellar internal models to account for the adaptation performance of humans during sensorimotor learning. The proposed model takes inspiration from the cerebellar microcomplex circuit, and employs spiking neurons to process information. We investigate the intrinsic properties of the cerebellar circuitry subserving efficient adaptation properties, and we assess the complementary contributions of internal representations by simulating our model in a procedural adaptation task. Our simulation results suggest that the coupling of internal models enhances learning performance significantly (compared with independent forward and inverse models), and it allows for the reproduction of human adaptation capabilities. Furthermore, we provide a computational explanation for the performance improvement observed after one night of sleep in a wide range of sensorimotor tasks. We predict that internal model coupling is a necessary condition for the offline consolidation of procedural memories. PMID:23874289

Enhanced photoelectrochemical water splitting performance of anodic TiO(2) nanotube arrays by surface passivation.

PubMed

Gui, Qunfang; Xu, Zhen; Zhang, Haifeng; Cheng, Chuanwei; Zhu, Xufei; Yin, Min; Song, Ye; Lu, Linfeng; Chen, Xiaoyuan; Li, Dongdong

2014-10-08

One-dimensional anodic titanium oxide nanotube (TONT) arrays provide a direct pathway for charge transport, and thus hold great potential as working electrodes for electrochemical energy conversion and storage devices. However, the prominent surface recombination due to the large amount surface defects hinders the performance improvement. In this work, the surface states of TONTs were passivated by conformal coating of high-quality Al2O3 onto the tubular structures using atomic layer deposition (ALD). The modified TONT films were subsequently employed as anodes for photoelectrochemical (PEC) water splitting. The photocurrent (0.5 V vs Ag/AgCl) recorded under air mass 1.5 global illumination presented 0.8 times enhancement on the electrode with passivation coating. The reduction of surface recombination rate is responsible for the substantially improved performance, which is proposed to have originated from a decreased interface defect density in combination with a field-effect passivation induced by a negative fixed charge in the Al2O3 shells. These results not only provide a physical insight into the passivation effect, but also can be utilized as a guideline to design other energy conversion devices.

Performance measurement in cancer care: uses and challenges.

PubMed

Lazar, G S; Desch, C E

1998-05-15

Unnecessary, inappropriate, and futile care are given in all areas of health care including cancer care. Not only does such care increase costs and waste precious resources, but patients may have adverse outcomes when the wrong care is given. One of the ways to address this issue is to measure performance with the use of administrative data sets. Through performance measurement, the best providers can be chosen, providers can be rewarded on the basis of the quality of their performance, opportunities for improvement can be identified, and variation in practice can be minimized. Purchasers should take leadership role in creating data sets that will enhance, clinical performance. Specifically, purchasers should require the following from payers: 1) staging information; 2) requirements and/or incentives for proper International Classification of Diseases coding, including other important (comorbid) conditions; 3) incentives or requirements for proper data collection if the payer is using a reimbursement strategy that places the risk on the provider; and 4) a willingness to collect and report information to providers of care, with a view toward increasing quality and decreasing the costs of cancer care. Demanding better clinical performance can lead to better outcomes. Once good data is presented to patients and providers, better clinical behavior and improved cancer care systems will quickly follow.

From smallpox eradication to contemporary global health initiatives: enhancing human capacity towards a global public health goal.

PubMed

Tarantola, Daniel; Foster, Stanley O

2011-12-30

The eradication of smallpox owes its success first and foremost to the thousands of lay health workers and community members who, throughout the campaign and across continents, took on the roles of advocates, educators, vaccinators, care providers and contributors to epidemic surveillance and containment. Bangladesh provides a good example where smallpox eradication and the capacity enhancement needed to achieve this goal resulted in a two-way mutually beneficial process. Smallpox-dedicated staff provided community members with information guidance, support and tools. In turn, communities not only created the enabling environment for smallpox program staff to perform their work but acquired the capacity to perform essential eradication tasks. Contemporary global health programmes can learn much from these core lessons including: the pivotal importance of supporting community aspirations, capacity and resilience; the critical need to enhance commitment, capacity and accountability across the workforce; and the high value of attentive human resources management and support. We owe to subsequent global disease control, elimination and eradication ventures recognition of the need for social and behavioural science to inform public health strategies; the essential roles that civil society organizations and public-private partnerships can play in public health discourse and action; the overall necessity of investing in broad-based health system strengthening; and the utility of applying human rights principles, norms and standards to public health policy and practice. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Using a Low Cost Flight Simulation Environment for Interdisciplinary Education

NASA Technical Reports Server (NTRS)

Khan, M. Javed; Rossi, Marcia; ALi, Syed F.

2004-01-01

A multi-disciplinary and inter-disciplinary education is increasingly being emphasized for engineering undergraduates. However, often the focus is on interaction between engineering disciplines. This paper discusses the experience at Tuskegee University in providing interdisciplinary research experiences for undergraduate students in both Aerospace Engineering and Psychology through the utilization of a low cost flight simulation environment. The environment, which is pc-based, runs a low-cost of-the-shelf software and is configured for multiple out-of-the-window views and a synthetic heads down display with joystick, rudder and throttle controls. While the environment is being utilized to investigate and evaluate various strategies for training novice pilots, students were involved to provide them with experience in conducting such interdisciplinary research. On the global inter-disciplinary level these experiences included developing experimental designs and research protocols, consideration of human participant ethical issues, and planning and executing the research studies. During the planning phase students were apprised of the limitations of the software in its basic form and the enhancements desired to investigate human factors issues. A number of enhancements to the flight environment were then undertaken, from creating Excel macros for determining the performance of the 'pilots', to interacting with the software to provide various audio/video cues based on the experimental protocol. These enhancements involved understanding the flight model and performance, stability & control issues. Throughout this process, discussions of data analysis included a focus from a human factors perspective as well as an engineering point of view.

Evaluation and Sustainability of the Healthy Learners Asthma Initiative

ERIC Educational Resources Information Center

Splett, Patricia L.; Erickson, Cecelia D.; Belseth, Stephanie B.; Jensen, Charlotte

2006-01-01

The Healthy Learners Asthma Initiative (HLAI) involved collaboration between Minneapolis Public Schools (MPS), local health care providers/payors, parents, and other partners. The intervention included development of enhanced asthma care in school health offices and clinic performance improvement projects to foster adoption of National Institutes…

Detection Performance Evaluation of the ASDE-3 Using Fixed Frequency and Frequency-Agile Operation

DOT National Transportation Integrated Search

1981-03-01

The ASDE-3 (Airport Surface Detection Equipment) Radar design has many features to enhance operational usefulness. The purpose of all these features is to provide a better airport surface surveillance display for the control power tower cab. One of t...

Dance Training for Gymnastics.

ERIC Educational Resources Information Center

Pica, Rae

This book views gymnastics as both sport and art and provides gymnasts with an introduction to the types of dance training that can enhance their performances. Dance training routines that incorporate several dance styles are presented to help gymnasts acquire polish, prevent injuries, improve their body alignment, express their creativity, and…

Fuzzy entropy thresholding and multi-scale morphological approach for microscopic image enhancement

NASA Astrophysics Data System (ADS)

Zhou, Jiancan; Li, Yuexiang; Shen, Linlin

2017-07-01

Microscopic images provide lots of useful information for modern diagnosis and biological research. However, due to the unstable lighting condition during image capturing, two main problems, i.e., high-level noises and low image contrast, occurred in the generated cell images. In this paper, a simple but efficient enhancement framework is proposed to address the problems. The framework removes image noises using a hybrid method based on wavelet transform and fuzzy-entropy, and enhances the image contrast with an adaptive morphological approach. Experiments on real cell dataset were made to assess the performance of proposed framework. The experimental results demonstrate that our proposed enhancement framework increases the cell tracking accuracy to an average of 74.49%, which outperforms the benchmark algorithm, i.e., 46.18%.

Landsat-7 Enhanced Thematic Mapper plus radiometric calibration

USGS Publications Warehouse

Markham, B.L.; Boncyk, Wayne C.; Helder, D.L.; Barker, J.L.

1997-01-01

Landsat-7 is currently being built and tested for launch in 1998. The Enhanced Thematic Mapper Plus (ETM+) sensor for Landsat-7, a derivative of the highly successful Thematic Mapper (TM) sensors on Landsats 4 and 5, and the Landsat-7 ground system are being built to provide enhanced radiometric calibration performance. In addition, regular vicarious calibration campaigns are being planned to provide additional information for calibration of the ETM+ instrument. The primary upgrades to the instrument include the addition of two solar calibrators: the full aperture solar calibrator, a deployable diffuser, and the partial aperture solar calibrator, a passive device that allows the ETM+ to image the sun. The ground processing incorporates for the first time an off-line facility, the Image Assessment System (IAS), to perform calibration, evaluation and analysis. Within the IAS, processing capabilities include radiometric artifact characterization and correction, radiometric calibration from the multiple calibrator sources, inclusion of results from vicarious calibration and statistical trending of calibration data to improve calibration estimation. The Landsat Product Generation System, the portion of the ground system responsible for producing calibrated products, will incorporate the radiometric artifact correction algorithms and will use the calibration information generated by the IAS. This calibration information will also be supplied to ground processing systems throughout the world.

Performance-enhancing drugs on the web: a growing public-health issue.

PubMed

Brennan, Brian P; Kanayama, Gen; Pope, Harrison G

2013-01-01

Today's Internet provides extensive "underground" guidelines for obtaining and using illicit substances, including especially anabolic-androgenic steroids (AAS) and other appearance- and performance-enhancing drugs (APEDs). We attempted to qualitatively characterize APED-related Internet sites. We used relevant Internet search terms (eg, "steroids bodybuilding" and "buy steroids online") to assess (i) the numbers of site visitors; (ii) offers of drugs for sale; and (iii) the quality of online medical information. We also chose the examples of (iv) "site-enhancing oils" and (v) "cattle implants" to illustrate the volume of available Internet information as compared with that in the medical literature. We found thousands of sites involving AAS and other APEDs. Most sites presented an unabashedly pro-drug position, often openly questioning the qualifications and motivations of mainstream medical practitioners. Offers of AAS and other APEDs for sale, together with medical advice of varying legitimacy, was widespread across sites. Importantly, many sites provided detailed guidelines for exotic forms of APED use, some likely associated with serious health risks, which are probably unknown to most practicing clinicians. It seems important for practitioners to be aware of the extent of this "underground literature," which may strongly influence their patients' decisions about use and abuse of APEDs. Copyright © American Academy of Addiction Psychiatry.

Kent County Health Department: Using an Agency Strategic Plan to Drive Improvement.

PubMed

Saari, Chelsey K

The Kent County Health Department (KCHD) was accredited by the Public Health Accreditation Board (PHAB) in September 2014. Although Michigan has had a state-level accreditation process for local health departments since the late 1990s, the PHAB accreditation process presented a unique opportunity for KCHD to build on successes achieved through state accreditation and enhance performance in all areas of KCHD programs, services, and operations. PHAB's standards, measures, and peer-review process provided a standardized and structured way to identify meaningful opportunities for improvement and to plan and implement strategies for enhanced performance and established a platform for being recognized nationally as a high-performing local health department. The current case report highlights the way in which KCHD has developed and implemented its strategic plan to guide efforts aimed at addressing gaps identified through the accreditation process and to drive overall improvement within our agency.

Neurofeedback as supplementary training for optimizing athletes' performance: A systematic review with implications for future research.

PubMed

Mirifar, Arash; Beckmann, Jürgen; Ehrlenspiel, Felix

2017-04-01

Self-regulation plays an important role in enhancing human performance. Neurofeedback is a promising noninvasive approach for modifying human brain oscillation and can be utilized in developing skills for self-regulation of brain activity. So far, the effectiveness of neurofeedback has been evaluated with regard to not only its application in clinical populations but also the enhancement of performance in general. However, reviews of the application of neurofeedback training in the sports domain are absent, although this application goes back to 1991, when it was first applied in archery. Sport scientists have shown an increasing interest in this topic in recent years. This article provides an overview of empirical studies examining the effects of neurofeedback in sports and evaluates these studies against cardinal and methodological criteria. Furthermore, it includes guidelines and suggestions for future evaluations of neurofeedback training in sports. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of music on cognitive performance: insight from neurobiological and animal studies.

PubMed

Rickard, Nikki S; Toukhsati, Samia R; Field, Simone E

2005-12-01

The past 50 years have seen numerous claims that music exposure enhances human cognitive performance. Critical evaluation of studies across a variety of contexts, however, reveals important methodological weaknesses. The current article argues that an interdisciplinary approach is required to advance this research. A case is made for the use of appropriate animal models to avoid many confounds associated with human music research. Although such research has validity limitations for humans, reductionist methodology enables a more controlled exploration of music's elementary effects. This article also explores candidate mechanisms for this putative effect. A review of neurobiological evidence from human and comparative animal studies confirms that musical stimuli modify autonomic and neurochemical arousal indices, and may also modify synaptic plasticity. It is proposed that understanding how music affects animals provides a valuable conjunct to human research and may be vital in uncovering how music might be used to enhance cognitive performance.

Synthetic control of manganese birnessite: Impact of crystallite size on Li, Na, and Mg based electrochemistry

DOE PAGES

Yin, Jiefu; Takeuchi, Esther S.; Takeuchi, Kenneth J.; ...

2016-08-12

We demonstrated the synthesis and characterization of Mg-birnessite (Mg xMnO 2) with different crystallite sizes, prepared though low temperature precipitation and ion exchange. The influence of crystallite size on electrochemical performance of Mg-birnessite was studied for the first time, where material with smaller crystallite size was demonstrated to have enhanced capacity and rate capability in Li ion, Na ion, and Mg ion based electrolytes. Cation diffusion using GITT type testing demonstrated the ion diffusion coefficient of Mg 2+ was ~10× lower compared with Li + and Na +. This work illustrates that tuning of inorganic materials properties can lead tomore » significant enhancement of electrochemical performance in lithium, sodium as well as magnesium based batteries for materials such as Mg-birnessite and provides a deliberate approach to improve electrochemical performance.« less

An FEC Adaptive Multicast MAC Protocol for Providing Reliability in WLANs

NASA Astrophysics Data System (ADS)

Basalamah, Anas; Sato, Takuro

For wireless multicast applications like multimedia conferencing, voice over IP and video/audio streaming, a reliable transmission of packets within short delivery delay is needed. Moreover, reliability is crucial to the performance of error intolerant applications like file transfer, distributed computing, chat and whiteboard sharing. Forward Error Correction (FEC) is frequently used in wireless multicast to enhance Packet Error Rate (PER) performance, but cannot assure full reliability unless coupled with Automatic Repeat Request forming what is knows as Hybrid-ARQ. While reliable FEC can be deployed at different levels of the protocol stack, it cannot be deployed on the MAC layer of the unreliable IEEE802.11 WLAN due to its inability to exchange ACKs with multiple recipients. In this paper, we propose a Multicast MAC protocol that enhances WLAN reliability by using Adaptive FEC and study it's performance through mathematical analysis and simulation. Our results show that our protocol can deliver high reliability and throughput performance.

Augmented Reality to Preserve Hidden Vestiges in Historical Cities. a Case Study

NASA Astrophysics Data System (ADS)

Martínez, J. L.; Álvareza, S.; Finat, J.; Delgado, F. J.; Finat, J.

2015-02-01

Mobile devices provide an increasingly sophisticated support to enhanced experiences and understanding the remote past in an interactive way. The use of augmented reality technologies allows to develop mobile applications for indoor exploration of virtually reconstructed archaeological places. In our work we have built a virtual reconstruction of a Roman Villa with data arising from an urgent partial excavation which were performed in order to build a car parking in the historical city of Valladolid (Spain). In its current state, the archaeological site is covered by an urban garden. Localization and tracking are performed using a combination of GPS and inertial sensors of the mobile device. In this work we prove how to perform an interactive navigation around the 3D virtual model showing an interpretation of the way it was. The user experience is enhanced by answering some simple questions, performing minor tasks and puzzles which are presented with multimedia contents linked to key features of the archaeological site.

Performance Enhancing Diets and the PRISE Protocol to Optimize Athletic Performance

PubMed Central

Arciero, Paul J.; Ward, Emery

2015-01-01

The training regimens of modern-day athletes have evolved from the sole emphasis on a single fitness component (e.g., endurance athlete or resistance/strength athlete) to an integrative, multimode approach encompassing all four of the major fitness components: resistance (R), interval sprints (I), stretching (S), and endurance (E) training. Athletes rarely, if ever, focus their training on only one mode of exercise but instead routinely engage in a multimode training program. In addition, timed-daily protein (P) intake has become a hallmark for all athletes. Recent studies, including from our laboratory, have validated the effectiveness of this multimode paradigm (RISE) and protein-feeding regimen, which we have collectively termed PRISE. Unfortunately, sports nutrition recommendations and guidelines have lagged behind the PRISE integrative nutrition and training model and therefore limit an athletes' ability to succeed. Thus, it is the purpose of this review to provide a clearly defined roadmap linking specific performance enhancing diets (PEDs) with each PRISE component to facilitate optimal nourishment and ultimately optimal athletic performance. PMID:25949823

Antibacterial surface modified of novel nanocomposite sulfonated polyethersulfone/polyrhodanine membrane

NASA Astrophysics Data System (ADS)

Rostam, Abbas Babaei; Peyravi, Majid; Ghorbani, Mohsen; Jahanshahi, Mohsen

2018-01-01

In this study, sulfonated-polyethersulfone/polyrhodanine (SPES/PRh) membranes with antibacterial behavior were fabricated. Polyethersulfone (PES) sulfonation was performed to enhance its hydrophilicity and next polyrhodanine nanoparticles (PRhNPs) were synthesized along with the sulfonated PES (SPES) by polyrhodanine (PRh) in situ polymerization. The sulfonation step also helps making composite membrane due to development of probable bondings and polymers engagements. The constructed membranes characterization was performed by FTIR, FESEM, contact angle, 1H NMR, TGA and EDS analyses. SPES/PRh membrane had enhanced hydrophilicity and consequently better fluxes for aqueous solutions. The composite SPES/PRh membrane flux was improved to 139/78 L/m2 h comparing 58.21 L/m2 h for SPES one. Membrane operational performances, antibacterial and antibiofouling tests showed improved flux, better rejection and appropriate antibacterial and antibiofouling properties for SPES/PRh membrane. The 100% bacteria mortality for specified concentrations and appropriate inhibition zones up to 9 mm have been achieved. It is generally a suitable membrane to provide proper performance beside antibacterial and antibiofouling behavior.

Enhanced Large Solid Rocket Motor Understanding Through Performance Margin Testing: RSRM Five-Segment Engineering Test Motor (ETM-3)

NASA Technical Reports Server (NTRS)

Huppi, Hal; Tobias, Mark; Seiler, James

2003-01-01

The Five-Segment Engineering Test Motor (ETM-3) is an extended length reusable solid rocket motor (RSRM) intended to increase motor performance and internal environments above the current four-segment RSRM flight motor. The principal purpose of ETM-3 is to provide a test article for RSRM component margin testing. As the RSRM and Space Shuttle in general continue to age, replacing obsolete materials becomes an ever-increasing issue. Having a five-segment motor that provides environments in excess of normal opera- tion allows a mechanism to subject replacement materials to a more severe environment than experienced in flight. Additionally, ETM-3 offers a second design data point from which to develop and/or validate analytical models that currently have some level of empiricism associated with them. These enhanced models have the potential to further the understanding of RSRM motor performance and solid rocket motor (SRM) propulsion in general. Furthermore, these data could be leveraged to support a five-segment booster (FSB) development program should the Space Shuttle program choose to pursue this option for abort mode enhancements during the ascent phase. A tertiary goal of ETM-3 is to challenge both the ATK Thiokol Propulsion and NASA MSFC technical personnel through the design and analysis of a large solid rocket motor without the benefit of a well-established performance database such as the RSRM. The end result of this undertaking will be a more competent and experienced workforce for both organizations. Of particular interest are the motor design characteristics and the systems engineering approach used to conduct a complex yet successful large motor static test. These aspects of ETM-3 and more will be summarized.

Enhanced performance of an S-band fiber laser using a thulium-doped photonic crystal fiber

NASA Astrophysics Data System (ADS)

Muhammad, A. R.; Emami, S. D.; Hmood, J. K.; Sayar, K.; Penny, R.; Abdul-Rashid, H. A.; Ahmad, H.; Harun, S. W.

2014-11-01

This work proposes a new method to enhance the performance of an S-band fiber laser by using a thulium-doped photonic crystal fiber (PCF). The proposed method is based on amplified spontaneous emission (ASE) suppression provided by the thulium-doped PCF unique geometric structure. The enhanced performance of this filter based PCF is dependent on the short and long cut-off wavelength characteristics that define the fiber transmission window. Realizing the short wavelength cut-off location requires the PCF cladding to be doped with a high index material, which provides a refractive index difference between the core and cladding region. Achieving the long cut-off wavelength necessitates enlarging the size of the air holes surrounding the rare-earth doped core region. The PCF structure is optimized so as to achieve the desired ASE suppression regions of below 0.8 μm and above 1.8 μm. The laser performance is simulated for different host media, namely pure silica, alumino-silicate, and fluoride-based fiber ZBLAN based on this thulium-doped PCF design. The host media spectroscopic details, including lifetime variations and quantum efficiency effect on the lasing emission are also discussed. Information on the filter based PCF design is gathered via a full-vectorial finite element method analysis and specifically a numerical modelling solution for the energy level rate equation using the Runge-Kutta method. Results are analyzed for gain improvement, lasing cavity, laser efficiency and effect of core size diameter variation. Results are compared with conventional thulium-doped fiber and thulium-doped PCF for every single host media. We observe that the ZBLAN host media is the most promising candidate due to its greater quantum efficiency.

The Impact of parasitic loss on solar cells with plasmonic nano-textured rear reflectors.

PubMed

Disney, Claire E R; Pillai, Supriya; Green, Martin A

2017-10-09

Significant photocurrent enhancement has been demonstrated using plasmonic light-trapping structures comprising nanostructured metallic features at the rear of the cell. These structures have conversely been identified as suffering heightened parasitic absorption into the metal at certain resonant wavelengths severely mitigating benefits of light trapping. In this study, we undertook simulations exploring the relationship between enhanced absorption into the solar cell, and parasitic losses in the metal. These simulations reveal that resonant wavelengths associated with high parasitic losses in the metal could also be associated with high absorption enhancement in the solar cell. We identify mechanisms linking these parasitic losses and absorption enhancements, but found that by ensuring correct design, the light trapping structures will have a positive impact on the overall solar cell performance. Our results clearly show that the large angle scattering provided by the plasmonic nanostructures is the reason for the enhanced absorption observed in the solar cells.

Resumption of dynamism in damaged networks of coupled oscillators

NASA Astrophysics Data System (ADS)

Kundu, Srilena; Majhi, Soumen; Ghosh, Dibakar

2018-05-01

Deterioration in dynamical activities may come up naturally or due to environmental influences in a massive portion of biological and physical systems. Such dynamical degradation may have outright effect on the substantive network performance. This requires us to provide some proper prescriptions to overcome undesired circumstances. In this paper, we present a scheme based on external feedback that can efficiently revive dynamism in damaged networks of active and inactive oscillators and thus enhance the network survivability. Both numerical and analytical investigations are performed in order to verify our claim. We also provide a comparative study on the effectiveness of this mechanism for feedbacks to the inactive group or to the active group only. Most importantly, resurrection of dynamical activity is realized even in time-delayed damaged networks, which are considered to be less persistent against deterioration in the form of inactivity in the oscillators. Furthermore, prominence in our approach is substantiated by providing evidence of enhanced network persistence in complex network topologies taking small-world and scale-free architectures, which makes the proposed remedy quite general. Besides the study in the network of Stuart-Landau oscillators, affirmative influence of external feedback has been justified in the network of chaotic Rössler systems as well.

Semi-conducting single-walled carbon nanotubes are detrimental when compared to metallic single-walled carbon nanotubes for electrochemical applications.

PubMed

Dong, Qi; Nasir, Muhammad Zafir Mohamad; Pumera, Martin

2017-10-18

As-synthetized single walled carbon nanotubes (SWCNTs) contain both metallic and semiconducting nanotubes. For the electronics, it is desirable to separate semiconducting SWCNTs (s-SWCNTs) from the metallic ones as s-SWCNTs provide desirable electronic properties. Here we test whether ultrapure semi-conducting single-walled carbon nanotubes (s-SWCNTs) provide advantageous electrochemical properties over the as prepared SWCNTs which contain a mixture of semiconducting and metallic CNTs. We test them as a transducer platform which enhanced the detection of target analytes (ascorbic acid, dopamine, uric acid) when compared to a bare glassy carbon (GC) electrode. Despite that, the two materials exhibit significantly different electrochemical properties and performances. A mixture of m-SWCNTs and s-SWCNTs demonstrated superior performance over ultrapure s-SWCNTs with greater peak currents and pronounced shift in peak potentials to lower values in cyclic and differential pulse voltammetry for the detection of target analytes. The mixture of m- and s-SWCNTs displayed about a 4 times improved heterogeneous electron transfer rate as compared to bare GC and a 2 times greater heterogeneous electron transfer rate than s-SWCNTs, demonstrating that ultrapure SWCNTs do not provide any major enhancement over the as prepared SWCNTs.

Multi-tap complex-coefficient incoherent microwave photonic filters based on optical single-sideband modulation and narrow band optical filtering.

PubMed

Sagues, Mikel; García Olcina, Raimundo; Loayssa, Alayn; Sales, Salvador; Capmany, José

2008-01-07

We propose a novel scheme to implement tunable multi-tap complex coefficient filters based on optical single sideband modulation and narrow band optical filtering. A four tap filter is experimentally demonstrated to highlight the enhanced tuning performance provided by complex coefficients. Optical processing is performed by the use of a cascade of four phase-shifted fiber Bragg gratings specifically fabricated for this purpose.

Optimizing performance through intrinsic motivation and attention for learning: The OPTIMAL theory of motor learning.

PubMed

Wulf, Gabriele; Lewthwaite, Rebecca

2016-10-01

Effective motor performance is important for surviving and thriving, and skilled movement is critical in many activities. Much theorizing over the past few decades has focused on how certain practice conditions affect the processing of task-related information to affect learning. Yet, existing theoretical perspectives do not accommodate significant recent lines of evidence demonstrating motivational and attentional effects on performance and learning. These include research on (a) conditions that enhance expectancies for future performance, (b) variables that influence learners' autonomy, and (c) an external focus of attention on the intended movement effect. We propose the OPTIMAL (Optimizing Performance through Intrinsic Motivation and Attention for Learning) theory of motor learning. We suggest that motivational and attentional factors contribute to performance and learning by strengthening the coupling of goals to actions. We provide explanations for the performance and learning advantages of these variables on psychological and neuroscientific grounds. We describe a plausible mechanism for expectancy effects rooted in responses of dopamine to the anticipation of positive experience and temporally associated with skill practice. Learner autonomy acts perhaps largely through an enhanced expectancy pathway. Furthermore, we consider the influence of an external focus for the establishment of efficient functional connections across brain networks that subserve skilled movement. We speculate that enhanced expectancies and an external focus propel performers' cognitive and motor systems in productive "forward" directions and prevent "backsliding" into self- and non-task focused states. Expected success presumably breeds further success and helps consolidate memories. We discuss practical implications and future research directions.

β-Alanine supplementation and military performance.

PubMed

Hoffman, Jay R; Stout, Jeffrey R; Harris, Roger C; Moran, Daniel S

2015-12-01

During sustained high-intensity military training or simulated combat exercises, significant decreases in physical performance measures are often seen. The use of dietary supplements is becoming increasingly popular among military personnel, with more than half of the US soldiers deployed or garrisoned reported to using dietary supplements. β-Alanine is a popular supplement used primarily by strength and power athletes to enhance performance, as well as training aimed at improving muscle growth, strength and power. However, there is limited research examining the efficacy of β-alanine in soldiers conducting operationally relevant tasks. The gains brought about by β-alanine use by selected competitive athletes appears to be relevant also for certain physiological demands common to military personnel during part of their training program. Medical and health personnel within the military are expected to extrapolate and implement relevant knowledge and doctrine from research performed on other population groups. The evidence supporting the use of β-alanine in competitive and recreational athletic populations suggests that similar benefits would also be observed among tactical athletes. However, recent studies in military personnel have provided direct evidence supporting the use of β-alanine supplementation for enhancing combat-specific performance. This appears to be most relevant for high-intensity activities lasting 60-300 s. Further, limited evidence has recently been presented suggesting that β-alanine supplementation may enhance cognitive function and promote resiliency during highly stressful situations.

Contralateral Bimodal Stimulation: A Way to Enhance Speech Performance in Arabic-Speaking Cochlear Implant Patients.

PubMed

Abdeltawwab, Mohamed M; Khater, Ahmed; El-Anwar, Mohammad W

2016-01-01

The combination of acoustic and electric stimulation as a way to enhance speech recognition performance in cochlear implant (CI) users has generated considerable interest in the recent years. The purpose of this study was to evaluate the bimodal advantage of the FS4 speech processing strategy in combination with hearing aids (HA) as a means to improve low-frequency resolution in CI patients. Nineteen postlingual CI adults were selected to participate in this study. All patients wore implants on one side and HA on the contralateral side with residual hearing. Monosyllabic word recognition, speech in noise, and emotion and talker identification were assessed using CI with fine structure processing/FS4 and high-definition continuous interleaved sampling strategies, HA alone, and a combination of CI and HA. The bimodal stimulation showed improvement in speech performance and emotion identification for the question/statement/order tasks, which was statistically significant compared to patients with CI alone, but there were no significant statistical differences in intragender talker discrimination and emotion identification for the happy/angry/neutral tasks. The poorest performance was obtained with HA only, and it was statistically significant compared to the other modalities. The bimodal stimulation showed enhanced speech performance in CI patients, and it improves the limitations provided by electric or acoustic stimulation alone. © 2016 S. Karger AG, Basel.

Influence of perforated triple wing vortex generator on a turbulent flow through a circular tube

NASA Astrophysics Data System (ADS)

Gautam, Abhishek; Pandey, Lokesh; Singh, Satyendra

2018-02-01

Numerous studies has been observed in terms of enhancement of heat transfer by using passive techniques. In present work, a very unique perforated triple wing vortex generator has been used as an insert geometry, with different geometrical parameters of twist ratio (l/D = 2, 3 & 4) and Porosity (P A /T A = 0%, 10%, 20% & 30%). The experimentation has been performed for the wide range of Re (Re), varying between 3200 to 20,600, in order to investigate effect on heat transfer (Nu), friction factor (f) & thermal performance factor (η) in circular tube HEs with respect to different geometrical and flow parameters. Experimentation has been performed in 1.5 m length of test section with 68 mm diameter. Heat flux of 1000 W/m2 has been provided on the test section with the help of variable voltage transformer connected with Nicrome wire coiled heater located on the test section. There is a significant enhancement has been observed in terms of heat enhancement and pressure drop over the smooth tube. The experimental result shows 4.8 times improvement in heat transfer and 1.63 times improvement in thermal performance as compared to smooth tube HE. The statistical correlations have also been presented for Nu, f and η.

Shuttle performance enhancements using an OMS payload bay kit

NASA Technical Reports Server (NTRS)

Templin, Kevin C.; Mallini, Charles J.

1991-01-01

The study focuses on the use of an orbital maneuvering system (OMS) payload bay kit (PBK) designed to utilize OMS tanks identical to those currently employed in the Orbiter OMS pods. Emphasis is placed on payload deployment capability and payload servicing/reboost capability augmentation from the point of view of payload mass, maximum deployment altitudes, and initial retrieval and final deployment altitudes. The deployment, servicing, and reboost requirements of the Hubble Space Telescope and Advanced X-ray and Astrophysics Facility are analyzed in order to show the benefits an OMS PBK can provide for these missions. It is shown that OMS PBKs can provide the required capability enhancement necessary to support deployment, reboost, and servicing of payloads requiring altitudes greater than 325 nautical miles.

Transgenic plants with enhanced growth characteristics

DOEpatents

Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

2016-09-06

The invention relates to transgenic plants exhibiting dramatically enhanced growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, more efficient nitrogen utilization, increased tolerance to high salt conditions, and increased biomass yields. In one embodiment, transgenic plants engineered to over-express both glutamine phenylpyruvate transaminase (GPT) and glutamine synthetase (GS) are provided. The GPT+GS double-transgenic plants of the invention consistently exhibit enhanced growth characteristics, with T0 generation lines showing an increase in biomass over wild type counterparts of between 50% and 300%. Generations that result from sexual crosses and/or selfing typically perform even better, with some of the double-transgenic plants achieving an astounding four-fold biomass increase over wild type plants.

A new rate-dependent model for high-frequency tracking performance enhancement of piezoactuator system

NASA Astrophysics Data System (ADS)

Tian, Lizhi; Xiong, Zhenhua; Wu, Jianhua; Ding, Han

2017-05-01

Feedforward-feedback control is widely used in motion control of piezoactuator systems. Due to the phase lag caused by incomplete dynamics compensation, the performance of the composite controller is greatly limited at high frequency. This paper proposes a new rate-dependent model to improve the high-frequency tracking performance by reducing dynamics compensation error. The rate-dependent model is designed as a function of the input and input variation rate to describe the input-output relationship of the residual system dynamics which mainly performs as phase lag in a wide frequency band. Then the direct inversion of the proposed rate-dependent model is used to compensate the residual system dynamics. Using the proposed rate-dependent model as feedforward term, the open loop performance can be improved significantly at medium-high frequency. Then, combining the with feedback controller, the composite controller can provide enhanced close loop performance from low frequency to high frequency. At the frequency of 1 Hz, the proposed controller presents the same performance as previous methods. However, at the frequency of 900 Hz, the tracking error is reduced to be 30.7% of the decoupled approach.

75 FR 23269 - Agency Information Collection Activities: Proposed Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-03

... training, knowledge, and skills to their organizations, local areas, regions, and states. This study is... Strategies and Tools for Enhancing Performance and Patient Safety) to provide an evidence-based suite of tools and strategies for training teamwork- based patient safety to health care professionals. In 2007...

Using Electronic Assessment Systems to Enhance Instruction

ERIC Educational Resources Information Center

Domagala, Jospeh F.

2017-01-01

Teachers in the classroom need to be able to modify instruction in a meaningful way that helps students to improve academically. School districts provide electronic assessment data which helps teachers identify areas for improvement within their instruction. Electronic performance assessment systems can be an effective means of assisting schools…

The Impact of Feedback as Formative Assessment on Student Performance

ERIC Educational Resources Information Center

Owen, Leanne

2016-01-01

This article provides an evaluation of the redesign of a research methods course intended to enhance students' learning for understanding and transfer. Drawing on principles of formative assessment from the existing academic literature, the instructor introduced a number of increasingly complex low-stakes assignments for students to complete prior…

The Effect of Online Systems Analysis Training on Aerospace Industry Business Performance: A Qualitative Study

ERIC Educational Resources Information Center

Burk, Erlan

2012-01-01

Aerospace companies needed additional research on technology-based training to verify expectations when enhancing human capital through online systems analysis training. The research for online systems analysis training provided aerospace companies a means to verify expectations for systems analysis technology-based training on business…

Nanocomposite film prepared by depositing xylan on cellulose nanowhiskers matrix

Treesearch

Qining Sun; Anurag Mandalika; Thomas Elder; Sandeep S. Nair; Xianzhi Meng; Fang Huang; Art J. Ragauskas

2014-01-01

Novel bionanocomposite films have been prepared by depositing xylan onto cellulose nanowhiskers through a pH adjustment. Analysis of strength properties, water vapour transmission, transparency, surface morphology and thermal decomposition showed the enhancement of film performance. This provides a new green route to the utilization of biomass for sustainable...

Comparison of biochemical and microscopic methods for quantification of mycorrhizal fungi in soil and roots

USDA-ARS?s Scientific Manuscript database

Arbuscular mycorrhizal fungi (AMF) are well-known plant symbionts which provide enhanced phosphorus uptake as well as other benefits to their host plants. Quantification of mycorrhizal biomass and root colonization has traditionally been performed by root staining and microscopic examination methods...

A Peer-Reviewed Research Assignment for Large Classes.

ERIC Educational Resources Information Center

Henderson, LaRhee; Buising, Charisse

2000-01-01

Introduces a writing exercise students work on in collaborative groups. Aims to enhance students' scientific research paper writing skills and provide experience working in collaborative groups. Presents evaluation criteria for peer-group evaluation of a poster presentation, intra-group evaluation of peer performance, and peer-group evaluation of…

Putting a Studio in the Mix

ERIC Educational Resources Information Center

Criswell, Chad

2013-01-01

Being able to record the work of young musicians is beneficial on a number of levels. From an educational standpoint, listening to recordings of rehearsals and performances can provide students with many different opportunities for critical evaluation and enhanced learning. The growth of digital music distribution in the past decade has sparked a…

Design optimization of steel frames using an enhanced firefly algorithm

NASA Astrophysics Data System (ADS)

Carbas, Serdar

2016-12-01

Mathematical modelling of real-world-sized steel frames under the Load and Resistance Factor Design-American Institute of Steel Construction (LRFD-AISC) steel design code provisions, where the steel profiles for the members are selected from a table of steel sections, turns out to be a discrete nonlinear programming problem. Finding the optimum design of such design optimization problems using classical optimization techniques is difficult. Metaheuristic algorithms provide an alternative way of solving such problems. The firefly algorithm (FFA) belongs to the swarm intelligence group of metaheuristics. The standard FFA has the drawback of being caught up in local optima in large-sized steel frame design problems. This study attempts to enhance the performance of the FFA by suggesting two new expressions for the attractiveness and randomness parameters of the algorithm. Two real-world-sized design examples are designed by the enhanced FFA and its performance is compared with standard FFA as well as with particle swarm and cuckoo search algorithms.

Multifunctional Nano-engineered Polymer Surfaces with Enhanced Mechanical Resistance and Superhydrophobicity

NASA Astrophysics Data System (ADS)

Hernández, Jaime J.; Monclús, Miguel A.; Navarro-Baena, Iván; Viela, Felipe; Molina-Aldareguia, Jon M.; Rodríguez, Isabel

2017-03-01

This paper presents a multifunctional polymer surface that provides superhydrophobicity and self-cleaning functions together with an enhancement in mechanical and electrical performance. These functionalities are produced by nanoimprinting high aspect ratio pillar arrays on polymeric matrix incorporating functional reinforcing elements. Two distinct matrix-filler systems are investigated specifically, Carbon Nanotube reinforced Polystyrene (CNT-PS) and Reduced Graphene Oxide reinforced Polyvinylidene Difluoride (RGO-PVDF). Mechanical characterization of the topographies by quantitative nanoindentation and nanoscratch tests are performed to evidence a considerable increase in stiffness, Young’s modulus and critical failure load with respect to the pristine polymers. The improvement on the mechanical properties is rationalized in terms of effective dispersion and penetration of the fillers into the imprinted structures as determined by confocal Raman and SEM studies. In addition, an increase in the degree of crystallization for the PVDF-RGO imprinted nanocomposite possibly accounts for the larger enhancement observed. Improvement of the mechanical ruggedness of functional textured surfaces with appropriate fillers will enable the implementation of multifunctional nanotextured materials in real applications.

Boosted output performance of triboelectric nanogenerator via electric double layer effect

PubMed Central

Chun, Jinsung; Ye, Byeong Uk; Lee, Jae Won; Choi, Dukhyun; Kang, Chong-Yun; Kim, Sang-Woo; Wang, Zhong Lin; Baik, Jeong Min

2016-01-01

For existing triboelectric nanogenerators (TENGs), it is important to explore unique methods to further enhance the output power under realistic environments to speed up their commercialization. We report here a practical TENG composed of three layers, in which the key layer, an electric double layer, is inserted between a top layer, made of Al/polydimethylsiloxane, and a bottom layer, made of Al. The efficient charge separation in the middle layer, based on Volta's electrophorus, results from sequential contact configuration of the TENG and direct electrical connection of the middle layer to the earth. A sustainable and enhanced output performance of 1.22 mA and 46.8 mW cm−2 under low frequency of 3 Hz is produced, giving over 16-fold enhancement in output power and corresponding to energy conversion efficiency of 22.4%. Finally, a portable power-supplying system, which provides enough d.c. power for charging a smart watch or phone battery, is also successfully developed. PMID:27703165

Enhancing the Photovoltaic Performance of Perovskite Solar Cells with a Down-Conversion Eu-Complex.

PubMed

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.

Cross-Layer Algorithms for QoS Enhancement in Wireless Multimedia Sensor Networks

NASA Astrophysics Data System (ADS)

Saxena, Navrati; Roy, Abhishek; Shin, Jitae

A lot of emerging applications like advanced telemedicine and surveillance systems, demand sensors to deliver multimedia content with precise level of QoS enhancement. Minimizing energy in sensor networks has been a much explored research area but guaranteeing QoS over sensor networks still remains an open issue. In this letter we propose a cross-layer approach combining Network and MAC layers, for QoS enhancement in wireless multimedia sensor networks. In the network layer a statistical estimate of sensory QoS parameters is performed and a nearoptimal genetic algorithmic solution is proposed to solve the NP-complete QoS-routing problem. On the other hand the objective of the proposed MAC algorithm is to perform the QoS-based packet classification and automatic adaptation of the contention window. Simulation results demonstrate that the proposed protocol is capable of providing lower delay and better throughput, at the cost of reasonable energy consumption, in comparison with other existing sensory QoS protocols.

WSe2 nanoribbons: new high-performance thermoelectric materials.

PubMed

Chen, Kai-Xuan; Luo, Zhi-Yong; Mo, Dong-Chuan; Lyu, Shu-Shen

2016-06-28

In this work, for the first time, we systematically investigate the ballistic transport properties of WSe2 nanoribbons using first-principles methods. Armchair nanoribbons with narrow ribbon width are mostly semiconductive but the zigzag nanoribbons are metallic. Surprisingly, an enhancement in thermoelectric performance is discovered moving from monolayers to nanoribbons, especially armchair ones. The maximum room-temperature thermoelectric figure of merit of 2.2 for an armchair nanoribbon is discovered. This may be contributed to by the effects of the disordered edges, owing to the existence of dangling bonds at the ribbon edge. H-passivation has turned out to be an effective way to stabilize the edge atoms, which enhances the thermodynamic stability of the nanoribbons. In addition, after H-passivation, all of the armchair nanoribbons exhibit semiconductive properties with similar band gaps (∼1.3 eV). Our work provides instructional theoretical evidence for the application of armchair WSe2 nanoribbons as promising thermoelectric materials. The enhancement mechanism of the disordered edge effect can also encourage further exploration to achieve outstanding thermoelectric materials.

Enhanced Peroxidase-Like Performance of Gold Nanoparticles by Hot Electrons.

PubMed

Wang, Chen; Shi, Yi; Dan, Yuan-Yuan; Nie, Xing-Guo; Li, Jian; Xia, Xing-Hua

2017-05-17

Enzyme mimics have been widely used as alternatives to natural enzymes. However, the catalytic performances of enzyme mimics are often decreased due to different spatial structures or absence of functional groups compared to natural enzymes. Here, we report a highly efficient enzyme-like catalytic performance of gold nanoparticles (AuNPs) by visible-light stimulation. The enzyme-like reaction is evaluated by the catalytic reaction of AuNPs oxidizing a typical chromogenic substrate 3,3',5,5'-tetramethylbenzydine (TMB) with hydrogen peroxide as an oxidant. From investigations of the wavelength-dependent reaction rate, radical capture, hole-donor addition, and dark-field scattering spectroscopy experiments, it is revealed that the strong plasmonic absorption of AuNPs facilitates generation of hot electrons, which are transfered from AuNPs to the adsorbed reactant molecule, greatly promoting the catalytic performance of the enzyme-like catalytic reaction. The present work provides a simple method for improving the performance of enzyme mimics, which is expected to find further application in the field of plasmon-enhanced biocatalysis and biosensors. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Real-time Enhancement, Registration, and Fusion for an Enhanced Vision System

NASA Technical Reports Server (NTRS)

Hines, Glenn D.; Rahman, Zia-ur; Jobson, Daniel J.; Woodell, Glenn A.

2006-01-01

Over the last few years NASA Langley Research Center (LaRC) has been developing an Enhanced Vision System (EVS) to aid pilots while flying in poor visibility conditions. The EVS captures imagery using two infrared video cameras. The cameras are placed in an enclosure that is mounted and flown forward-looking underneath the NASA LaRC ARIES 757 aircraft. The data streams from the cameras are processed in real-time and displayed on monitors on-board the aircraft. With proper processing the camera system can provide better-than-human-observed imagery particularly during poor visibility conditions. However, to obtain this goal requires several different stages of processing including enhancement, registration, and fusion, and specialized processing hardware for real-time performance. We are using a real-time implementation of the Retinex algorithm for image enhancement, affine transformations for registration, and weighted sums to perform fusion. All of the algorithms are executed on a single TI DM642 digital signal processor (DSP) clocked at 720 MHz. The image processing components were added to the EVS system, tested, and demonstrated during flight tests in August and September of 2005. In this paper we briefly discuss the EVS image processing hardware and algorithms. We then discuss implementation issues and show examples of the results obtained during flight tests.

Piezo-phototronic effect enhanced photo-detector based on ZnO nano-arrays/NiO structure

NASA Astrophysics Data System (ADS)

Sun, Jingchang; Li, Peida; Gao, Ruixue; Lu, Xue; Li, Chengren; Lang, Yueyi; Zhang, Xiwen; Bian, Jiming

2018-01-01

A photo-detector with n-ZnO nano-arrays/p-NiO film structure was synthesized on flexible Ni foil substrate. In contrast to conventional detectors that detect only the photon energies greater than the band gap of working materials, the visible light with smaller photon energies (3.0 eV) than the band gap of both ZnO (3.3 eV) and NiO (3.7 eV) can be sensitively detected by this detector due to the spatially indirect type-II transition between ZnO nano-arrays and NiO film. The increase in output currents of the photo-detector with illumination density was observed at both forward and reverse bias, and it can be further enhanced by exerting external compressive strain along the c axis of ZnO nano-arrays by piezo-phototronic effect. A maximum enhancement of 1020% of the responsivity (R) was achieved under external compressive strain. The similar behaviors were demonstrated at four different excitation wavelengths (325, 365, 388 and 405 nm), providing compelling evidence that the responses performance of the photo-detector can be effectively enhanced using piezo-phototronic effect. Moreover, the piezo-phototronic effect enhanced performance can be well elucidated by the corresponding energy band diagram.

Transcription through enhancers suppresses their activity in Drosophila

PubMed Central

2013-01-01

Background Enhancer elements determine the level of target gene transcription in a tissue-specific manner, providing for individual patterns of gene expression in different cells. Knowledge of the mechanisms controlling enhancer action is crucial for understanding global regulation of transcription. In particular, enhancers are often localized within transcribed regions of the genome. A number of experiments suggest that transcription can have both positive and negative effects on regulatory elements. In this study, we performed direct tests for the effect of transcription on enhancer activity. Results Using a transgenic reporter system, we investigated the relationship between the presence of pass-through transcription and the activity of Drosophila enhancers controlling the expression of the white and yellow genes. The results show that transcription from different promoters affects the activity of enhancers, counteracting their ability to activate the target genes. As expected, the presence of a transcriptional terminator between the inhibiting promoter and the affected enhancer strongly reduces the suppression. Moreover, transcription leads to dislodging of the Zeste protein that is responsible for the enhancer-dependent regulation of the white gene, suggesting a 'transcription interference’ mechanism for this regulation. Conclusions Our findings suggest a role for pass-through transcription in negative regulation of enhancer activity. PMID:24279291

Spatial resolution enhancement of terrestrial features using deconvolved SSM/I microwave brightness temperatures

NASA Technical Reports Server (NTRS)

Farrar, Michael R.; Smith, Eric A.

1992-01-01

A method for enhancing the 19, 22, and 37 GHz measurements of the SSM/I (Special Sensor Microwave/Imager) to the spatial resolution and sampling density of the high resolution 85-GHz channel is presented. An objective technique for specifying the tuning parameter, which balances the tradeoff between resolution and noise, is developed in terms of maximizing cross-channel correlations. Various validation procedures are performed to demonstrate the effectiveness of the method, which hopefully will provide researchers with a valuable tool in multispectral applications of satellite radiometer data.

Lipopolysaccharide-Induced Toxic Shock Syndrome in Rabbits.

PubMed

Stach, Christopher S; Schlievert, Patrick M

2016-01-01

Enhancement of susceptibility to lipopolysaccharide (LPS; endotoxin) is a defining characteristic of Staphylococcus aureus superantigens. At the time of this publication, there are 24 identified staphylococcal superantigens (SAgs), some of which have yet to be fully characterized. Testing the capacity of superantigens to potentiate LPS sensitivity is essential to characterize the role of these proteins in disease development. Here we describe how to perform studies of the enhancement of LPS-induced toxic shock syndrome in rabbits. This protocol also provides information on a second important activity of superantigens: the production of fever.

Method and apparatus for enhancing reactor air-cooling system performance

DOEpatents

Hunsbedt, Anstein

1996-01-01

An enhanced decay heat removal system for removing heat from the inert gas-filled gap space between the reactor vessel and the containment vessel of a liquid metal-cooled nuclear reactor. Multiple cooling ducts in flow communication with the inert gas-filled gap space are incorporated to provide multiple flow paths for the inert gas to circulate to heat exchangers which remove heat from the inert gas, thereby introducing natural convection flows in the inert gas. The inert gas in turn absorbs heat directly from the reactor vessel by natural convection heat transfer.

Technical Excellence: A Requirement for Good Engineering

NASA Technical Reports Server (NTRS)

Gill, Paul S.; Vaughan, William W.

2008-01-01

Technical excellence is a requirement for good engineering. Technical excellence has many different ways of expressing itself within engineering. NASA has initiatives that address the enhancement of the Agency's technical excellence and thrust to maintain the associated high level of performance by the Agency on current programs/projects and as it moves into the Constellation Program and the return to the Moon with plans to visit Mars. This paper addresses some of the key initiatives associated with NASA's technical excellence thrust. Examples are provided to illustrate some results being achieved and plans to enhance these initiatives.

Elastomeric Cellular Structure Enhanced by Compressible Liquid Filler

NASA Astrophysics Data System (ADS)

Sun, Yueting; Xu, Xiaoqing; Xu, Chengliang; Qiao, Yu; Li, Yibing

2016-05-01

Elastomeric cellular structures provide a promising solution for energy absorption. Their flexible and resilient nature is particularly relevant to protection of human bodies. Herein we develop an elastomeric cellular structure filled with nanoporous material functionalized (NMF) liquid. Due to the nanoscale infiltration in NMF liquid and its interaction with cell walls, the cellular structure has a much enhanced mechanical performance, in terms of loading capacity and energy absorption density. Moreover, it is validated that the structure is highly compressible and self-restoring. Its hyper-viscoelastic characteristics are elucidated.

Enhancing intensity and refractive index sensing capability with infrared plasmonic perfect absorbers.

PubMed

Cheng, Fei; Yang, Xiaodong; Gao, Jie

2014-06-01

An infrared refractive index sensor based on plasmonic perfect absorbers for glucose concentration sensing is experimentally demonstrated. Utilizing substantial absorption contrast between a perfect absorber (∼98% at normal incidence) and a non-perfect absorber upon the refractive index change, a maximum value of figure of merit (FOM^*) about 55 and a bulk wavelength sensitivity about 590  nm/RIU are achieved. The demonstrated sensing platform provides great potential in improving the performance of plasmonic refractive index sensors and developing future surface enhanced infrared spectroscopy.

Some practical universal noiseless coding techniques, part 2

NASA Technical Reports Server (NTRS)

Rice, R. F.; Lee, J. J.

1983-01-01

This report is an extension of earlier work (Part 1) which provided practical adaptive techniques for the efficient noiseless coding of a broad class of data sources characterized by only partially known and varying statistics (JPL Publication 79-22). The results here, while still claiming such general applicability, focus primarily on the noiseless coding of image data. A fairly complete and self-contained treatment is provided. Particular emphasis is given to the requirements of the forthcoming Voyager II encounters of Uranus and Neptune. Performance evaluations are supported both graphically and pictorially. Expanded definitions of the algorithms in Part 1 yield a computationally improved set of options for applications requiring efficient performance at entropies above 4 bits/sample. These expanded definitions include as an important subset, a somewhat less efficient but extremely simple "FAST' compressor which will be used at the Voyager Uranus encounter. Additionally, options are provided which enhance performance when atypical data spikes may be present.

Communication analysis for the expendable explorer spacecraft

NASA Technical Reports Server (NTRS)

1990-01-01

This report provides the results of communication analysis for the baseline and enhanced performance spacecraft designs proposed for Expendable Explorer Spacecraft (EES) series of missions. Five classes of orbits (Geosynchronous, Circular-28 degree inclination, Polar-90 degree inclination, Sunsynchronous-97 degree inclination, Molniya orbit) and a set of candidate instrument payloads provided by the ESS Study Manager were used to formulate the basis for the ESS Communications Study. The study was performed to assess the feasibility of using Space Network or ground stations for supporting the communications, tracking and data handling of the candidate instruments that are proposed to be launched into the desired orbit.

Critical validation studies of neurofeedback.

PubMed

Gruzelier, John; Egner, Tobias

2005-01-01

The field of neurofeedback training has proceeded largely without validation. In this article the authors review studies directed at validating sensory motor rhythm, beta and alpha-theta protocols for improving attention, memory, and music performance in healthy participants. Importantly, benefits were demonstrable with cognitive and neurophysiologic measures that were predicted on the basis of regression models of learning to enhance sensory motor rhythm and beta activity. The first evidence of operant control over the alpha-theta ratio is provided, together with remarkable improvements in artistic aspects of music performance equivalent to two class grades in conservatory students. These are initial steps in providing a much needed scientific basis to neurofeedback.

NASA research in aircraft propulsion

NASA Technical Reports Server (NTRS)

Beheim, M. A.

1982-01-01

A broad overview of the scope of research presently being supported by NASA in aircraft propulsion is presented with emphasis on Lewis Research Center activities related to civil air transports, CTOL and V/STOL systems. Aircraft systems work is performed to identify the requirements for the propulsion system that enhance the mission capabilities of the aircraft. This important source of innovation and creativity drives the direction of propulsion research. In a companion effort, component research of a generic nature is performed to provide a better basis for design and provides an evolutionary process for technological growth that increases the capabilities of all types of aircraft. Both are important.

Embedded assessment algorithms within home-based cognitive computer game exercises for elders.

PubMed

Jimison, Holly; Pavel, Misha

2006-01-01

With the recent consumer interest in computer-based activities designed to improve cognitive performance, there is a growing need for scientific assessment algorithms to validate the potential contributions of cognitive exercises. In this paper, we present a novel methodology for incorporating dynamic cognitive assessment algorithms within computer games designed to enhance cognitive performance. We describe how this approach works for variety of computer applications and describe cognitive monitoring results for one of the computer game exercises. The real-time cognitive assessments also provide a control signal for adapting the difficulty of the game exercises and providing tailored help for elders of varying abilities.

Judgments about illegal performance-enhancing substances: reasoned, reactive, or both?

PubMed

Dodge, Tonya; Stock, Michelle; Litt, Dana

2013-07-01

This study applied aspects of the Theory of Reasoned Action and the Prototype/Willingness model to understand cognitions associated with the use of illegal performance-enhancing substances. There were two study objectives. One was to investigate whether the illegal-is-effective heuristic (i.e. belief that illegal performance-enhancing substances are more effective than legal performance-enhancing substances) affects willingness to use illegal performance-enhancing substances. The second was to examine whether attitudes, norms, and prototypes influence the willingness and intentions to use illegal performance-enhancing substances. The illegal-is-effective heuristic was a significant predictor of willingness but was not a significant predictor of intentions. Implications for future research and prevention efforts are discussed.

Neutron reflecting supermirror structure

DOEpatents

Wood, J.L.

1992-12-01

An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources. 2 figs.

Neutron reflecting supermirror structure

DOEpatents

Wood, James L.

1992-01-01

An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources.

Stereoscopic Three-Dimensional Neuroanatomy Lectures Enhance Neurosurgical Training: Prospective Comparison with Traditional Teaching.

PubMed

Clark, Anna D; Guilfoyle, Mathew R; Candy, Nicholas G; Budohoski, Karol P; Hofmann, Riikka; Barone, Damiano G; Santarius, Thomas; Kirollos, Ramez W; Trivedi, Rikin A

2017-12-01

Stereoscopic three-dimensional (3D) imaging is increasingly used in the teaching of neuroanatomy and although this is mainly aimed at undergraduate medical students, it has enormous potential for enhancing the training of neurosurgeons. This study aims to assess whether 3D lecturing is an effective method of enhancing the knowledge and confidence of neurosurgeons and how it compares with traditional two-dimensional (2D) lecturing and cadaveric training. Three separate teaching sessions for neurosurgical trainees were organized: 1) 2D course (2D lecture + cadaveric session), 2) 3D lecture alone, and 3) 3D course (3D lecture + cadaveric session). Before and after each session, delegates were asked to complete questionnaires containing questions relating to surgical experience, anatomic knowledge, confidence in performing procedures, and perceived value of 3D, 2D, and cadaveric teaching. Although both 2D and 3D lectures and courses were similarly effective at improving self-rated knowledge and understanding, the 3D lecture and course were associated with significantly greater gains in confidence reported by the delegates for performing a subfrontal approach and sylvian fissure dissection. Stereoscopic 3D lectures provide neurosurgical trainees with greater confidence for performing standard operative approaches and enhances the benefit of subsequent practical experience in developing technical skills in cadaveric dissection. Copyright © 2017. Published by Elsevier Inc.

Incorporation of metal-organic framework HKUST-1 into porous polymer monolithic capillary columns to enhance the chromatographic separation of small molecules.

PubMed

Yang, Shengchao; Ye, Fanggui; Lv, Qinghui; Zhang, Cong; Shen, Shufen; Zhao, Shulin

2014-09-19

Metal-organic framework (MOF) HKUST-1 nanoparticles have been incorporated into poly(glycidyl methacrylate-co-ethylene dimethacrylate) (HKUST-1-poly(GMA-co-EDMA)) monoliths to afford stationary phases with enhanced chromatographic performance of small molecules in the reversed phase capillary liquid chromatography. The effect of HKUST-1 nanoparticles in the polymerization mixture on the performance of the monolithic column was explored in detail. While the bare poly(GMA-co-EDMA) monolith exhibited poor resolution (Rs<1.0) and low efficiency (800-16,300plates/m), addition of a small amount of HKUST-1 nanoparticles to the polymerization mixture provide high increased resolution (Rs≥1.3) and high efficiency ranged from 16,300 to 44,300plates/m. Chromatographic performance of HKUST-1-poly(GMA-co-EDMA) monolith was demonstrated by separation of various analytes including polycyclic aromatic hydrocarbons, ethylbenzene and styrene, phenols and aromatic acids using a binary polar mobile phase (CH3CN/H2O). The HKUST-1-poly(GMA-co-EDMA) monolith displayed enhanced hydrophobic and π-π interaction characteristics in the reversed phase separation of test analytes compared to the bare poly(GMA-co-EDMA) monolith. The experiment results showed that HKUST-1-poly(GMA-co-EDMA) monoliths are an alternative to enhance the chromatographic separation of small molecules. Copyright © 2014 Elsevier B.V. All rights reserved.

Leveraging Quick Response Code Technology to Facilitate Simulation-Based Leaderboard Competition.

PubMed

Chang, Todd P; Doughty, Cara B; Mitchell, Diana; Rutledge, Chrystal; Auerbach, Marc A; Frisell, Karin; Jani, Priti; Kessler, David O; Wolfe, Heather; MacKinnon, Ralph J; Dewan, Maya; Pirie, Jonathan; Lemke, Daniel; Khattab, Mona; Tofil, Nancy; Nagamuthu, Chenthila; Walsh, Catharine M

2018-02-01

Leaderboards provide feedback on relative performance and a competitive atmosphere for both self-guided improvement and social comparison. Because simulation can provide substantial quantitative participant feedback, leaderboards can be used, not only locally but also in a multidepartment, multicenter fashion. Quick Response (QR) codes can be integrated to allow participants to access and upload data. We present the development, implementation, and initial evaluation of an online leaderboard employing principles of gamification using points, badges, and leaderboards designed to enhance competition among healthcare providers. This article details the fundamentals behind the development and implementation of a user-friendly, online, multinational leaderboard that employs principles of gamification to enhance competition and integrates a QR code system to promote both self-reporting of performance data and data integrity. An open-ended survey was administered to capture perceptions of leaderboard implementation. Conceptual step-by-step instructions detailing how to apply the QR code system to any leaderboard using simulated or real performance metrics are outlined using an illustrative example of a leaderboard that employed simulated cardiopulmonary resuscitation performance scores to compare participants across 17 hospitals in 4 countries for 16 months. The following three major descriptive categories that captured perceptions of leaderboard implementation emerged from initial evaluation data from 10 sites: (1) competition, (2) longevity, and (3) perceived deficits. A well-designed leaderboard should be user-friendly and encompass best practices in gamification principles while collecting and storing data for research analyses. Easy storage and export of data allow for longitudinal record keeping that can be leveraged both to track compliance and to enable social competition.

Modeling the effects of contrast enhancement on target acquisition performance

NASA Astrophysics Data System (ADS)

Du Bosq, Todd W.; Fanning, Jonathan D.

2008-04-01

Contrast enhancement and dynamic range compression are currently being used to improve the performance of infrared imagers by increasing the contrast between the target and the scene content, by better utilizing the available gray levels either globally or locally. This paper assesses the range-performance effects of various contrast enhancement algorithms for target identification with well contrasted vehicles. Human perception experiments were performed to determine field performance using contrast enhancement on the U.S. Army RDECOM CERDEC NVESD standard military eight target set using an un-cooled LWIR camera. The experiments compare the identification performance of observers viewing linearly scaled images and various contrast enhancement processed images. Contrast enhancement is modeled in the US Army thermal target acquisition model (NVThermIP) by changing the scene contrast temperature. The model predicts improved performance based on any improved target contrast, regardless of feature saturation or enhancement. To account for the equivalent blur associated with each contrast enhancement algorithm, an additional effective MTF was calculated and added to the model. The measured results are compared with the predicted performance based on the target task difficulty metric used in NVThermIP.

Analyzing the application of silicon-silver-2D nanomaterial-Al2O3 heterojunction in plasmonic sensor and its performance evaluation

NASA Astrophysics Data System (ADS)

Sharma, Anuj K.

2018-03-01

A semiconductor-metal-dielectric heterojunction system, generally useful in enhancing the efficiency of solar cells, is explored to design a high performance optical sensor based on surface plasmon resonance in near infrared (NIR). Silicon is considered as light coupling material and different 2D nanomaterials such as graphene, MoS2, and MoSe2 are explored to enhance the sensor's performance in terms of its figure of merit (FOM). An Al2O3 interlayer with a few nanometers of thickness is introduced, which acts as a critical component to significantly enhance the sensor's FOM. It is observed that an Al2O3 interlayer of around 9 nm thickness is able to many-fold upturn the sensor's FOM. As another important finding, silver layer thickness of around 60 nm is found to be highly useful to achieve high values of FOM. It is established through results that operating at longer NIR wavelength leads to greater FOM for any choice of 2D nanomaterial and any thickness of Al2O3 interlayer. Proposed sensor provides significantly greater FOM than previous works on SPR sensors.

Enhancement of anodic biofilm formation and current output in microbial fuel cells by composite modification of stainless steel electrodes

NASA Astrophysics Data System (ADS)

Liang, Yuxiang; Feng, Huajun; Shen, Dongsheng; Li, Na; Guo, Kun; Zhou, Yuyang; Xu, Jing; Chen, Wei; Jia, Yufeng; Huang, Bin

2017-02-01

In this paper, we first systematically investigate the current output performance of stainless steel electrodes (SS) modified by carbon coating (CC), polyaniline coating (PANI), neutral red grafting (NR), surface hydrophilization (SDBS), and heat treatment (HEAT). The maximum current density of 13.0 A m-2 is obtained on CC electrode (3.0 A m-2 of the untreated anode). Such high performance should be attributed to its large effective surface area, which is 2.3 times that of the unmodified electrode. Compared with SS electrode, about 3-fold increase in current output is achieved with PANI. Functionalization with hydrophilic group and electron medium result in the current output rising to 1.5-2 fold, through enhancing bioadhesive and electron transport rate, respectively. CC modification is the best choice of single modification for SS electrode in this study. However, this modification is not perfect because of its poor hydrophilicity. So CC electrode is modified by SDBS for further enhancing the current output to 16 A m-2. These results could provide guidance for the choice of suitable single modification on SS electrodes and a new method for the perfection of electrode performance through composite modification.

Graphene Oxide by UV-Ozone Treatment as an Efficient Hole Extraction Layer for Highly Efficient and Stable Polymer Solar Cells.

PubMed

Xia, Yingdong; Pan, Yufeng; Zhang, Haijuan; Qiu, Jian; Zheng, Yiting; Chen, Yonghua; Huang, Wei

2017-08-09

The hole extraction layer has a significant impact on the achievement of high-efficiency polymer solar cells (PSCs). Here, we report an efficient approach to direct UV-ozone treatment by larger device performance enhancement employing graphene oxide (GO). The dramatic performance enhancement of PSCs with the P3HT:PCBM blend as an active layer was demonstrated by the UV-ozone treatment of GO for 30 min: best power conversion efficiency (PCE) of 4.18%, fill factor of 0.63, J sc of 10.94 mA cm -2 , and V oc of 0.61 V, which are significantly higher than those of the untreated GO (1.82%) and highly comparable PEDOT:PSS-based PSCs (3.73%). In addition, PSCs with UV-ozone-treated GO showed a longer stability than PSCs with PEDOT:PSS. The significant enhancement of PCEs of PSCs can be attributed to the fact that ozone molecules can oxidize GO into CO 2 and leave highly conductive graphene particles. We suggest that this simple UV-ozone treatment can provide an efficient method for highly efficient GO hole extraction in high-performance PSCs.

Durable and self-hydrating tungsten carbide-based composite polymer electrolyte membrane fuel cells.

PubMed

Zheng, Weiqing; Wang, Liang; Deng, Fei; Giles, Stephen A; Prasad, Ajay K; Advani, Suresh G; Yan, Yushan; Vlachos, Dionisios G

2017-09-04

Proton conductivity of the polymer electrolyte membranes in fuel cells dictates their performance and requires sufficient water management. Here, we report a simple, scalable method to produce well-dispersed transition metal carbide nanoparticles. We demonstrate that these, when added as an additive to the proton exchange Nafion membrane, provide significant enhancement in power density and durability over 100 hours, surpassing both the baseline Nafion and platinum-containing recast Nafion membranes. Focused ion beam/scanning electron microscope tomography reveals the key membrane degradation mechanism. Density functional theory exposes that OH• and H• radicals adsorb more strongly from solution and reactions producing OH• are significantly more endergonic on tungsten carbide than on platinum. Consequently, tungsten carbide may be a promising catalyst in self-hydrating crossover gases while retarding desorption of and capturing free radicals formed at the cathode, resulting in enhanced membrane durability.The proton conductivity of polymer electrolyte membranes in fuel cells dictates their performance, but requires sufficient water management. Here, the authors report a simple method to produce well-dispersed transition metal carbide nanoparticles as additives to enhance the performance of Nafion membranes in fuel cells.

Project Loon based augmentation for global ionospheric modeling over Southern Hemisphere

NASA Astrophysics Data System (ADS)

Wang, Cheng; Shi, Chuang; Zhang, Hongping

2017-04-01

Global ionospheric products of vertical total electron content (VTEC) derived from GNSS measurements may have low accuracy over oceans and southern latitudes where there are not rich observations. Project Loon provides a great opportunity to enhance the measurements over those areas. In this contribution, a simulation of Project Loon based augmentation for global ionospheric modeling is performed by using the international reference ionosphere (IRI) which could simulate VTEC measurements for the balloons. The performance of the enhanced method based on simulation of Project Loon is investigated by comparing with VTEC maps from Ionosphere Associate Analysis Centers (IAACs) as well as IGS final GIMs. The comparison indicates that there is a better consistency between the VTEC maps by the enhanced method and IGS final GIMs. Also, obvious improvements of RMS maps in GIMs for the middle latitudes and southern latitudes are enabled by the augmentation of Project Loon. Additionally, JASON data are used to validate the specific improvement of the VTEC maps. The results show that the performance of VTEC maps is improved slightly, especially in southern latitudes. It is possible that the VTEC maps could be improved significantly by using real GPS measurements from balloons of Project Loon in the near future.

Project Loon based augmentation for global ionospheric modeling over Southern Hemisphere.

PubMed

Wang, Cheng; Shi, Chuang; Zhang, Hongping

2017-04-06

Global ionospheric products of vertical total electron content (VTEC) derived from GNSS measurements may have low accuracy over oceans and southern latitudes where there are not rich observations. Project Loon provides a great opportunity to enhance the measurements over those areas. In this contribution, a simulation of Project Loon based augmentation for global ionospheric modeling is performed by using the international reference ionosphere (IRI) which could simulate VTEC measurements for the balloons. The performance of the enhanced method based on simulation of Project Loon is investigated by comparing with VTEC maps from Ionosphere Associate Analysis Centers (IAACs) as well as IGS final GIMs. The comparison indicates that there is a better consistency between the VTEC maps by the enhanced method and IGS final GIMs. Also, obvious improvements of RMS maps in GIMs for the middle latitudes and southern latitudes are enabled by the augmentation of Project Loon. Additionally, JASON data are used to validate the specific improvement of the VTEC maps. The results show that the performance of VTEC maps is improved slightly, especially in southern latitudes. It is possible that the VTEC maps could be improved significantly by using real GPS measurements from balloons of Project Loon in the near future.

Project Loon based augmentation for global ionospheric modeling over Southern Hemisphere

PubMed Central

Wang, Cheng; Shi, Chuang; Zhang, Hongping

2017-01-01

Global ionospheric products of vertical total electron content (VTEC) derived from GNSS measurements may have low accuracy over oceans and southern latitudes where there are not rich observations. Project Loon provides a great opportunity to enhance the measurements over those areas. In this contribution, a simulation of Project Loon based augmentation for global ionospheric modeling is performed by using the international reference ionosphere (IRI) which could simulate VTEC measurements for the balloons. The performance of the enhanced method based on simulation of Project Loon is investigated by comparing with VTEC maps from Ionosphere Associate Analysis Centers (IAACs) as well as IGS final GIMs. The comparison indicates that there is a better consistency between the VTEC maps by the enhanced method and IGS final GIMs. Also, obvious improvements of RMS maps in GIMs for the middle latitudes and southern latitudes are enabled by the augmentation of Project Loon. Additionally, JASON data are used to validate the specific improvement of the VTEC maps. The results show that the performance of VTEC maps is improved slightly, especially in southern latitudes. It is possible that the VTEC maps could be improved significantly by using real GPS measurements from balloons of Project Loon in the near future. PMID:28383058

Contextual predictability enhances reading performance in patients with schizophrenia.

PubMed

Fernández, Gerardo; Guinjoan, Salvador; Sapognikoff, Marcelo; Orozco, David; Agamennoni, Osvaldo

2016-07-30

In the present work we analyzed fixation duration in 40 healthy individuals and 18 patients with chronic, stable SZ during reading of regular sentences and proverbs. While they read, their eye movements were recorded. We used lineal mixed models to analyze fixation durations. The predictability of words N-1, N, and N+1 exerted a strong influence on controls and SZ patients. The influence of the predictabilities of preceding, current, and upcoming words on SZ was clearly reduced for proverbs in comparison to regular sentences. Both controls and SZ readers were able to use highly predictable fixated words for an easier reading. Our results suggest that SZ readers might compensate attentional and working memory deficiencies by using stored information of familiar texts for enhancing their reading performance. The predictabilities of words in proverbs serve as task-appropriate cues that are used by SZ readers. To the best of our knowledge, this is the first study using eyetracking for measuring how patients with SZ process well-defined words embedded in regular sentences and proverbs. Evaluation of the resulting changes in fixation durations might provide a useful tool for understanding how SZ patients could enhance their reading performance. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Experimental febrile seizures induce age-dependent structural plasticity and improve memory in mice.

PubMed

Tao, K; Ichikawa, J; Matsuki, N; Ikegaya, Y; Koyama, R

2016-03-24

Population-based studies have demonstrated that children with a history of febrile seizure (FS) perform better than age-matched controls at hippocampus-dependent memory tasks. Here, we report that FSs induce two distinct structural reorganizations in the hippocampus and bidirectionally modify future learning abilities in an age-dependent manner. Compared with age-matched controls, adult mice that had experienced experimental FSs induced by hyperthermia (HT) on postnatal day 14 (P14-HT) performed better in a cognitive task that requires dentate granule cells (DGCs). The enhanced memory performance correlated with an FS-induced persistent increase in the density of large mossy fiber terminals (LMTs) of the DGCs. The memory enhancement was not observed in mice that had experienced HT-induced seizures at P11 which exhibited abnormally located DGCs in addition to the increased LMT density. The ectopic DGCs of the P11-HT mice were abolished by the diuretic bumetanide, and this pharmacological treatment unveiled the masked memory enhancement. Thus, this work provides a novel basis for age-dependent structural plasticity in which FSs influence future brain function. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Improvement of signal to noise ratio of time domain mutliplexing fiber Bragg grating sensor network with Golay complementary codes

NASA Astrophysics Data System (ADS)

Elgaud, M. M.; Zan, M. S. D.; Abushagur, A. G.; Bakar, A. Ashrif A.

2017-07-01

This paper reports the employment of autocorrelation properties of Golay complementary codes (GCC) to enhance the performance of the time domain multiplexing fiber Bragg grating (TDM-FBG) sensing network. By encoding the light from laser with a stream of non-return-to-zero (NRZ) form of GCC and launching it into the sensing area that consists of the FBG sensors, we have found that the FBG signals can be decoded correctly with the autocorrelation calculations, confirming the successful demonstration of coded TDM-FBG sensor network. OptiGrating and OptiSystem simulators were used to design customized FBG sensors and perform the coded TDM-FBG sensor simulations, respectively. Results have substantiated the theoretical dependence of SNR enhancement on the code length of GCC, where the maximum SNR improvement of about 9 dB is achievable with the use of 256 bits of GCC compared to that of 4 bits case. Furthermore, the GCC has also extended the strain exposure up to 30% higher compared to the maximum of the conventional single pulse case. The employment of GCC in the TDM-FBG sensor system provides overall performance enhancement over the conventional single pulse case, under the same conditions.

Should performance-enhancing drugs in sport be legalized under medical supervision?

PubMed

Wiesing, Urban

2011-02-01

This review examines the question of whether performance-enhancing drugs should be permitted in sport under the control of physicians, and evaluates the expected outcomes of such a scenario. Such a change in regulation would need to be tightly controlled because of the risks involved. The results of legalizing performance-enhancing drugs in competitive sport would be either unhelpful or negative, and the unwanted aspects of doping control would not disappear. Athletes, including children and adolescents who wanted to pursue competitive sports, would be forced to take additional, avoidable health risks. The 'natural lottery' of athletic talents would be compensated for only partially by use of performance-enhancing agents. It would also be complemented by another 'natural lottery' of variable responses to doping measures, combined with the inventiveness of doping doctors. There would be no gain in 'justice' (i.e. fairer results that reflected efforts made) for athletes as a result of legalizing doping. Legalization would not reduce restrictions on athletes' freedom; the control effort would remain the same, if not increased. Extremely complicated international regulations would have to be adopted. The game of the 'tortoise and the hare' between doping athletes and inspectors would remain because prohibited but not identifiable practices could still provide additional benefits from use of permissible drugs. Audience mistrust, particularly toward athletes who achieved outstanding feats, would remain because it would still be possible that these athletes were reliant on illegal doping practices. Doping entails exposing the athletes to avoidable risks that do not need to be taken to increase the appeal of a sport. Most importantly, the function of sport as a role model would definitely be damaged. It is not necessary to clarify the question of what constitutes the 'spirit of sport' and whether this may be changed. From a practical point of view, a legalization of performance-enhancing drugs in sport should not be considered for the simple reason that it has no advantages but many disadvantages.

Development of high performance refractory fibers with enhanced insulating properties and longer service lifetimes

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

Martin, P.C.; DePoorter, G.L.; Munoz, D.R.

1991-02-01

We have initiated a three phase investigation of the development of high performance refractory fibers with enhanced insulating properties and longer usable lifetimes. This report presents the results of the first phase of the study, performed from Aug. 1989 through Feb. 1991, which shows that significant energy saving are possible through the use of high temperature insulating fibers that better retain their efficient insulating properties during the service lifetime of the fibers. The remaining phases of this program include the pilot scale development and then full scale production feasibility development and evaluation of enhanced high temperature refractory insulting fibers. Thismore » first proof of principle phase of the program presents a summary of the current use patterns of refractory fibers, a laboratory evaluation of the high temperature performance characteristics of selected typical refractory fibers and an analysis of the potential energy savings through the use of enhanced refractory fibers. The current use patterns of refractory fibers span a wide range of industries and high temperature furnaces within those industries. The majority of high temperature fiber applications are in furnaces operating between 2000 and 26000{degrees}F. The fibers used in furnaces operating within this range provide attractive thermal resistance and low thermal storage at reasonable cost. A series of heat treatment studies performed for this phase of the program has shown that the refractory fibers, as initially manufactured, have attractive thermal conductivities for high temperature applications but the fibers go through rapid devitrification and subsequent crystal growth upon high temperature exposure. Development of improved fibers, maintaining the favorable characteristics of the existing as-manufactured fibers, could save between 1 and 4% of the energy consumed in high temperature furnaces using refractory fibers.« less

Environmental heat stress enhances mental fatigue during sustained attention task performing: evidence from an ASL perfusion study.

PubMed

Qian, Shaowen; Li, Min; Li, Guoying; Liu, Kai; Li, Bo; Jiang, Qingjun; Li, Li; Yang, Zhen; Sun, Gang

2015-03-01

This study was to investigate the potential enhancing effect of heat stress on mental fatigue progression during sustained attention task using arterial spin labeling (ASL) imaging. Twenty participants underwent two thermal exposures in an environmental chamber: normothermic (NT) condition (25°C, 1h) and hyperthermic (HT) condition (50°C, 1h). After thermal exposure, they performed a twenty-minute psychomotor vigilance test (PVT) in the scanner. Behavioral analysis revealed progressively increasing subjective fatigue ratings and reaction time as PVT progressed. Moreover, heat stress caused worse performance. Perfusion imaging analyses showed significant resting-state cerebral blood flow (CBF) alterations after heat exposure. Specifically, increased CBF mainly gathered in thalamic-brainstem area while decreased CBF predominantly located in fronto-parietal areas, anterior cingulate cortex, posterior cingulate cortex, and medial frontal cortex. More importantly, diverse CBF distributions and trend of changes between both conditions were observed as the fatigue level progressed during subsequent PVT task. Specifically, higher CBF and enhanced rising trend were presented in superior parietal lobe, precuneus, posterior cingulate cortex and anterior cingulate cortex, while lower CBF or inhibited rising trend was found in dorsolateral frontal cortex, medial frontal cortex, inferior parietal lobe and thalamic-brainstem areas. Furthermore, the decrease of post-heat resting-state CBF in fronto-parietal cortex was correlated with subsequent slower reaction time, suggesting prior disturbed resting-state CBF might be indicator of performance potential and fatigue level in following task. These findings may provide proof for such a view: heat stress has a potential fatigue-enhancing effect when individual is performing highly cognition-demanding attention task. Copyright © 2014 Elsevier B.V. All rights reserved.

Modifications to the rapid melt/rapid quench and transparent polymer video furnaces for the KC-135

NASA Technical Reports Server (NTRS)

Smith, Guy A.; Kosten, Sue E.; Workman, Gary L.

1990-01-01

Given here is a summary of tasks performed on two furnace systems, the Transparent Polymer (TPF) and the Rapid Melt/Rapid Quench (RMRQ) furnaces, to be used aboard NASA's KC-135. It was determined that major changes were needed for both furnaces to operate according to the scientific investigators' experiment parameters. Discussed here are what the problems were, what was required to solve the problems, and possible future enhancements. It was determined that the enhancements would be required for the furnaces to perform at their optimal levels. Services provided include hardware and software modifications, Safety DataPackage documentation, ground based testing, transportation to and from Ellington Air Field, operation of hardware during KC-135 flights, and post-flight data processing.

Nanoantenna-Enhanced Infrared Spectroscopic Chemical Imaging.

PubMed

Kühner, Lucca; Hentschel, Mario; Zschieschang, Ute; Klauk, Hagen; Vogt, Jochen; Huck, Christian; Giessen, Harald; Neubrech, Frank

2017-05-26

Spectroscopic infrared chemical imaging is ideally suited for label-free and spatially resolved characterization of molecular species, but often suffers from low infrared absorption cross sections. Here, we overcome this limitation by utilizing confined electromagnetic near-fields of resonantly excited plasmonic nanoantennas, which enhance the molecular absorption by orders of magnitude. In the experiments, we evaporate microstructured chemical patterns of C 60 and pentacene with nanometer thickness on top of homogeneous arrays of tailored nanoantennas. Broadband mid-infrared spectra containing plasmonic and vibrational information were acquired with diffraction-limited resolution using a two-dimensional focal plane array detector. Evaluating the enhanced infrared absorption at the respective frequencies, spatially resolved chemical images were obtained. In these chemical images, the microstructured chemical patterns are only visible if nanoantennas are used. This confirms the superior performance of our approach over conventional spectroscopic infrared imaging. In addition to the improved sensitivity, our technique provides chemical selectivity, which would not be available with plasmonic imaging that is based on refractive index sensing. To extend the accessible spectral bandwidth of nanoantenna-enhanced spectroscopic imaging, we employed nanostructures with dual-band resonances, providing broadband plasmonic enhancement and sensitivity. Our results demonstrate the potential of nanoantenna-enhanced spectroscopic infrared chemical imaging for spatially resolved characterization of organic layers with thicknesses of several nanometers. This is of potential interest for medical applications which are currently hampered by state-of-art infrared techniques, e.g., for distinguishing cancerous from healthy tissues.

Enhancing board oversight on quality of hospital care: an agency theory perspective.

PubMed

Jiang, H Joanna; Lockee, Carlin; Fraser, Irene

2012-01-01

Community hospitals in the United States are almost all governed by a governing board that is legally accountable for the quality of care provided. Increasing pressures for better quality and safety are prompting boards to strengthen their oversight function on quality. In this study, we aimed to provide an update to prior research by exploring the role and practices of governing boards in quality oversight through the lens of agency theory and comparing hospital quality performance in relation to the adoption of those practices. Data on board practices from a survey conducted by The Governance Institute in 2007 were merged with data on hospital quality drawn from two federal sources that measured processes of care and mortality. The study sample includes 445 public and private not-for-profit hospitals. We used factor analysis to explore the underlying dimensions of board practices. We further compared hospital quality performance by the adoption of each individual board practice. Consistent with the agency theory, the 13 board practices included in the survey appear to center around enhancing accountability of the board, management, and the medical staff. Reviewing the hospital's quality performance on a regular basis was the most common practice. A number of board practices, not examined in prior research, showed significant association with better performance on process of care and/or risk-adjusted mortality: requiring major new clinical programs to meet quality-related criteria, setting some quality goals at the "theoretical ideal" level, requiring both the board and the medical staff to be as involved as management in setting the agenda for discussion on quality, and requiring the hospital to report its quality/safety performance to the general public. Hospital governing boards should examine their current practices and consider adopting those that would enhance the accountability of the board itself, management, and the medical staff.

Enhancing social participation in young people with communication disabilities living in rural Australia: outcomes of a home-based intervention for using social media.

PubMed

Raghavendra, Parimala; Newman, Lareen; Grace, Emma; Wood, Denise

2015-01-01

The purpose of this study is to investigate the effectiveness of a home-based intervention using social media to enhance social networks of young people with disabilities and communication difficulties. Eight young people (M(age) = 15.4 years) with communication disabilities participated from two rural Australian towns. The intervention provided assistive technology and training to learn social media use. A mixed-method design combined pre- and post-assessments measuring changes in performance, satisfaction with performance, attainment on social media goals, and social network extension, and interviews investigated the way in which the intervention influenced social participation. Participants showed an increase in performance, and satisfaction with performance, on the Canadian Occupational Performance Measure; paired t-tests showed statistical significance at p <0.01. Wilcoxon Signed Ranks revealed a significant increase in the number of online communication partners, p <0.05. The interviews highlighted participants' and parents' perceptions of increased social connections, improved communication frequency and nature, and speech intelligibility and literacy as a result of the intervention. The findings suggest that learning to use social media leads to increase in social participation among rural-based young people with communication disabilities. In order to benefit from advantages of learning to use social media in rural areas, parents and service providers need knowledge and skills to integrate assistive technology with the Internet needs of this group.

Holographic radar imaging privacy techniques utilizing dual-frequency implementation

NASA Astrophysics Data System (ADS)

McMakin, Douglas L.; Hall, Thomas E.; Sheen, David M.

2008-04-01

Over the last 15 years, the Pacific Northwest National Laboratory has performed significant research and development activities to enhance the state of the art of holographic radar imaging systems to be used at security checkpoints for screening people for concealed threats hidden under their garments. These enhancement activities included improvements to privacy techniques to remove human features and providing automatic detection of body-worn concealed threats. The enhanced privacy and detection methods used both physical and software imaging techniques. The physical imaging techniques included polarization-diversity illumination and reception, dual-frequency implementation, and high-frequency imaging at 60 GHz. Software imaging techniques to enhance the privacy of the person under surveillance included extracting concealed threat artifacts from the imagery to automatically detect the threat. This paper will focus on physical privacy techniques using dual-frequency implementation.

Blue-Enriched Light Enhances Alertness but Impairs Accurate Performance in Evening Chronotypes Driving in the Morning.

PubMed

Rodríguez-Morilla, Beatriz; Madrid, Juan A; Molina, Enrique; Pérez-Navarro, José; Correa, Ángel

2018-01-01

Attention maintenance is highly demanding and typically leads to vigilance decrement along time on task. Therefore, performance in tasks involving vigilance maintenance for long periods, such as driving, tends to deteriorate over time. Cognitive performance has been demonstrated to fluctuate over 24 h of the day (known as circadian oscillations), thus showing peaks and troughs depending on the time of day (leading to optimal and suboptimal times of day, respectively). Consequently, vigilance decrements are more pronounced along time on task when it is performed at suboptimal times of day. According to research, light exposure (especially blue-enriched white) enhances alertness. Thus, it has been proposed to prevent the vigilance decrement under such adverse circumstances. We aimed to explore the effects of blue-enriched white light (vs. dim light) on the performance of a simulated driving task at a suboptimal time of day. A group of evening-types was tested at 8 am, as this chronotype had previously shown their largest vigilance decrement at that time. In the dim light condition, vigilance decrements were expected on both subjective (as increments in the Karolinska Sleepiness Scale scores) and behavioral measures [as slower reaction times (RTs) in the auditory Psychomotor Vigilance Task, slower RTs to unexpected events during driving, and deteriorated driving accuracy along time on task]. Physiological activation was expected to decrease (as indexed by an increase of the distal-proximal temperature gradient, DPG). Under blue-enriched white light, all these trends should be attenuated. Results from the control dim light condition replicated the vigilance decrement in all measures. Most important, the blue-enriched white light attenuated this decrement, leading to both lower DPG and faster RTs. However, it impaired accuracy of driving performance, and did not have any effect on subjective sleepiness. We conclude that exposure to blue-enriched light provides an effective countermeasure to enhance vigilance performance at suboptimal times of day, according to measures such as RTs. However, it should be considered that alerting effects of light could impair accuracy in precision tasks as keeping a proper car position. The current findings provide ergonomic implications for safety and fatigue related management systems.

Going Boldly Beyond: Progress on NASA's Space Launch System

NASA Technical Reports Server (NTRS)

Singer, Jody; Crumbly, Chris

2013-01-01

NASA's Space Launch System is implementing an evolvable configuration approach to system development in a resource-constrained era. Legacy systems enable non-traditional development funding and contribute to sustainability and affordability. Limited simultaneous developments reduce cost and schedule risk. Phased approach to advanced booster development enables innovation and competition, incrementally demonstrating affordability and performance enhancements. Advanced boosters will provide performance for the most capable heavy lift launcher in history, enabling unprecedented space exploration benefiting all of humanity.

An Enhanced Secure Identity-Based Certificateless Public Key Authentication Scheme for Vehicular Sensor Networks.

PubMed

Li, Congcong; Zhang, Xi; Wang, Haiping; Li, Dongfeng

2018-01-11

Vehicular sensor networks have been widely applied in intelligent traffic systems in recent years. Because of the specificity of vehicular sensor networks, they require an enhanced, secure and efficient authentication scheme. Existing authentication protocols are vulnerable to some problems, such as a high computational overhead with certificate distribution and revocation, strong reliance on tamper-proof devices, limited scalability when building many secure channels, and an inability to detect hardware tampering attacks. In this paper, an improved authentication scheme using certificateless public key cryptography is proposed to address these problems. A security analysis of our scheme shows that our protocol provides an enhanced secure anonymous authentication, which is resilient against major security threats. Furthermore, the proposed scheme reduces the incidence of node compromise and replication attacks. The scheme also provides a malicious-node detection and warning mechanism, which can quickly identify compromised static nodes and immediately alert the administrative department. With performance evaluations, the scheme can obtain better trade-offs between security and efficiency than the well-known available schemes.

Multi-Image Registration for an Enhanced Vision System

NASA Technical Reports Server (NTRS)

Hines, Glenn; Rahman, Zia-Ur; Jobson, Daniel; Woodell, Glenn

2002-01-01

An Enhanced Vision System (EVS) utilizing multi-sensor image fusion is currently under development at the NASA Langley Research Center. The EVS will provide enhanced images of the flight environment to assist pilots in poor visibility conditions. Multi-spectral images obtained from a short wave infrared (SWIR), a long wave infrared (LWIR), and a color visible band CCD camera, are enhanced and fused using the Retinex algorithm. The images from the different sensors do not have a uniform data structure: the three sensors not only operate at different wavelengths, but they also have different spatial resolutions, optical fields of view (FOV), and bore-sighting inaccuracies. Thus, in order to perform image fusion, the images must first be co-registered. Image registration is the task of aligning images taken at different times, from different sensors, or from different viewpoints, so that all corresponding points in the images match. In this paper, we present two methods for registering multiple multi-spectral images. The first method performs registration using sensor specifications to match the FOVs and resolutions directly through image resampling. In the second method, registration is obtained through geometric correction based on a spatial transformation defined by user selected control points and regression analysis.

Performance Enhancement of Pharmacokinetic Diffuse Fluorescence Tomography by Use of Adaptive Extended Kalman Filtering.

PubMed

Wang, Xin; Wu, Linhui; Yi, Xi; Zhang, Yanqi; Zhang, Limin; Zhao, Huijuan; Gao, Feng

2015-01-01

Due to both the physiological and morphological differences in the vascularization between healthy and diseased tissues, pharmacokinetic diffuse fluorescence tomography (DFT) can provide contrast-enhanced and comprehensive information for tumor diagnosis and staging. In this regime, the extended Kalman filtering (EKF) based method shows numerous advantages including accurate modeling, online estimation of multiparameters, and universal applicability to any optical fluorophore. Nevertheless the performance of the conventional EKF highly hinges on the exact and inaccessible prior knowledge about the initial values. To address the above issues, an adaptive-EKF scheme is proposed based on a two-compartmental model for the enhancement, which utilizes a variable forgetting-factor to compensate the inaccuracy of the initial states and emphasize the effect of the current data. It is demonstrated using two-dimensional simulative investigations on a circular domain that the proposed adaptive-EKF can obtain preferable estimation of the pharmacokinetic-rates to the conventional-EKF and the enhanced-EKF in terms of quantitativeness, noise robustness, and initialization independence. Further three-dimensional numerical experiments on a digital mouse model validate the efficacy of the method as applied in realistic biological systems.

Development of An Intelligent Flight Propulsion Control System

NASA Technical Reports Server (NTRS)

Calise, A. J.; Rysdyk, R. T.; Leonhardt, B. K.

1999-01-01

The initial design and demonstration of an Intelligent Flight Propulsion and Control System (IFPCS) is documented. The design is based on the implementation of a nonlinear adaptive flight control architecture. This initial design of the IFPCS enhances flight safety by using propulsion sources to provide redundancy in flight control. The IFPCS enhances the conventional gain scheduled approach in significant ways: (1) The IFPCS provides a back up flight control system that results in consistent responses over a wide range of unanticipated failures. (2) The IFPCS is applicable to a variety of aircraft models without redesign and,(3) significantly reduces the laborious research and design necessary in a gain scheduled approach. The control augmentation is detailed within an approximate Input-Output Linearization setting. The availability of propulsion only provides two control inputs, symmetric and differential thrust. Earlier Propulsion Control Augmentation (PCA) work performed by NASA provided for a trajectory controller with pilot command input of glidepath and heading. This work is aimed at demonstrating the flexibility of the IFPCS in providing consistency in flying qualities under a variety of failure scenarios. This report documents the initial design phase where propulsion only is used. Results confirm that the engine dynamics and associated hard nonlineaaities result in poor handling qualities at best. However, as demonstrated in simulation, the IFPCS is capable of results similar to the gain scheduled designs of the NASA PCA work. The IFPCS design uses crude estimates of aircraft behaviour. The adaptive control architecture demonstrates robust stability and provides robust performance. In this work, robust stability means that all states, errors, and adaptive parameters remain bounded under a wide class of uncertainties and input and output disturbances. Robust performance is measured in the quality of the tracking. The results demonstrate the flexibility of the IFPCS architecture and the ability to provide robust performance under a broad range of uncertainty. Robust stability is proved using Lyapunov like analysis. Future development of the IFPCS will include integration of conventional control surfaces with the use of propulsion augmentation, and utilization of available lift and drag devices, to demonstrate adaptive control capability under a greater variety of failure scenarios. Further work will specifically address the effects of actuator saturation.

High-Throughput Fabrication of Ultradense Annular Nanogap Arrays for Plasmon-Enhanced Spectroscopy.

PubMed

Cai, Hongbing; Meng, Qiushi; Zhao, Hui; Li, Mingling; Dai, Yanmeng; Lin, Yue; Ding, Huaiyi; Pan, Nan; Tian, Yangchao; Luo, Yi; Wang, Xiaoping

2018-06-13

The confinement of light into nanometer-sized metallic nanogaps can lead to an extremely high field enhancement, resulting in dramatically enhanced absorption, emission, and surface-enhanced Raman scattering (SERS) of molecules embedded in nanogaps. However, low-cost, high-throughput, and reliable fabrication of ultra-high-dense nanogap arrays with precise control of the gap size still remains a challenge. Here, by combining colloidal lithography and atomic layer deposition technique, a reproducible method for fabricating ultra-high-dense arrays of hexagonal close-packed annular nanogaps over large areas is demonstrated. The annular nanogap arrays with a minimum diameter smaller than 100 nm and sub-1 nm gap width have been produced, showing excellent SERS performance with a typical enhancement factor up to 3.1 × 10 6 and a detection limit of 10 -11 M. Moreover, it can also work as a high-quality field enhancement substrate for studying two-dimensional materials, such as MoSe 2 . Our method provides an attractive approach to produce controllable nanogaps for enhanced light-matter interaction at the nanoscale.

Identifying Key Performance Indicators for Holistic Hospital Management with a Modified DEMATEL Approach.

PubMed

Si, Sheng-Li; You, Xiao-Yue; Liu, Hu-Chen; Huang, Jia

2017-08-19

Performance analysis is an important way for hospitals to achieve higher efficiency and effectiveness in providing services to their customers. The performance of the healthcare system can be measured by many indicators, but it is difficult to improve them simultaneously due to the limited resources. A feasible way is to identify the central and influential indicators to improve healthcare performance in a stepwise manner. In this paper, we propose a hybrid multiple criteria decision making (MCDM) approach to identify key performance indicators (KPIs) for holistic hospital management. First, through integrating evidential reasoning approach and interval 2-tuple linguistic variables, various assessments of performance indicators provided by healthcare experts are modeled. Then, the decision making trial and evaluation laboratory (DEMATEL) technique is adopted to build an interactive network and visualize the causal relationships between the performance indicators. Finally, an empirical case study is provided to demonstrate the proposed approach for improving the efficiency of healthcare management. The results show that "accidents/adverse events", "nosocomial infection", ''incidents/errors", "number of operations/procedures" are significant influential indicators. Also, the indicators of "length of stay", "bed occupancy" and "financial measures" play important roles in performance evaluation of the healthcare organization. The proposed decision making approach could be considered as a reference for healthcare administrators to enhance the performance of their healthcare institutions.

Multiple template-based image matching using alpha-rooted quaternion phase correlation

NASA Astrophysics Data System (ADS)

DelMarco, Stephen

2010-04-01

In computer vision applications, image matching performed on quality-degraded imagery is difficult due to image content distortion and noise effects. State-of-the art keypoint based matchers, such as SURF and SIFT, work very well on clean imagery. However, performance can degrade significantly in the presence of high noise and clutter levels. Noise and clutter cause the formation of false features which can degrade recognition performance. To address this problem, previously we developed an extension to the classical amplitude and phase correlation forms, which provides improved robustness and tolerance to image geometric misalignments and noise. This extension, called Alpha-Rooted Phase Correlation (ARPC), combines Fourier domain-based alpha-rooting enhancement with classical phase correlation. ARPC provides tunable parameters to control the alpha-rooting enhancement. These parameter values can be optimized to tradeoff between high narrow correlation peaks, and more robust wider, but smaller peaks. Previously, we applied ARPC in the radon transform domain for logo image recognition in the presence of rotational image misalignments. In this paper, we extend ARPC to incorporate quaternion Fourier transforms, thereby creating Alpha-Rooted Quaternion Phase Correlation (ARQPC). We apply ARQPC to the logo image recognition problem. We use ARQPC to perform multiple-reference logo template matching by representing multiple same-class reference templates as quaternion-valued images. We generate recognition performance results on publicly-available logo imagery, and compare recognition results to results generated from standard approaches. We show that small deviations in reference templates of sameclass logos can lead to improved recognition performance using the joint matching inherent in ARQPC.

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.

Clinical utility of dual-energy contrast-enhanced spectral mammography for breast microcalcifications without associated mass: a preliminary analysis.

PubMed

Cheung, Yun-Chung; Tsai, Hsiu-Pei; Lo, Yung-Feng; Ueng, Shir-Hwa; Huang, Pei-Chin; Chen, Shin-Chih

2016-04-01

To assess the utility of dual-energy contrast-enhanced spectral mammography (DE-CESM) for evaluation of suspicious malignant microcalcifications. Two hundred and fifty-six DE-CESMs were reviewed from 2012-2013, 59 cases fulfilled the following criteria and were enrolled for analysis: (1) suspicious malignant microcalcifications (BI-RADS 4) on mammogram, (2) no related mass, (3) with pathological diagnoses. The microcalcification morphology and associated enhancement were reviewed to analyse the accuracy of the diagnosis and cancer size measurements versus the results of pathology. Of the 59 microcalcifications, 22 were diagnosed as cancers, 19 were atypical lesions and 18 were benign lesions. Twenty (76.9 %) cancers, three (11.55 %) atypia and three (11.55 %) benign lesions revealed enhancement. The true-positive rate of intermediate- and high-concern microcalcifications was significantly higher than that of low-concern lesions (93.75 % vs. 50 %). Overall, the diagnostic sensitivity of enhancement was 90.9 %, with 83.78 % specificity, 76.92 % positive predictive value, 93.94 % negative predictive value and 86.4 % accuracy. Performance was good (AUC = 0.87) according to a ROC curve and cancer size correlation with a mean difference of 0.05 cm on a Bland-Altman plot. DE-CESM provides additional enhancement information for diagnosing breast microcalcifications and measuring cancer sizes with high correlation to surgicohistology. • DE-CESM provides additional enhancement information for diagnosing suspicious breast microcalcifications. • The enhanced cancer size closely correlates to microscopy by Bland-Altman plot. • DE-CESM could be considered for evaluation of suspicious malignant microcalcifications.

Enhancing space transportation: The NASA program to develop electric propulsion

NASA Technical Reports Server (NTRS)

Bennett, Gary L.; Watkins, Marcus A.; Byers, David C.; Barnett, John W.

1990-01-01

The NASA Office of Aeronautics, Exploration, and Technology (OAET) supports a research and technology (R and T) program in electric propulsion to provide the basis for increased performance and life of electric thruster systems which can have a major impact on space system performance, including orbital transfer, stationkeeping, and planetary exploration. The program is oriented toward providing high-performance options that will be applicable to a broad range of near-term and far-term missions and vehicles. The program, which is being conducted through the Jet Propulsion Laboratory (JPL) and Lewis Research Center (LeRC) includes research on resistojet, arcjets, ion engines, magnetoplasmadynamic (MPD) thrusters, and electrodeless thrusters. Planning is also under way for nuclear electric propulsion (NEP) as part of the Space Exploration Initiative (SEI).

Managing hospital quality performance in two related areas: patient care and customer service.

PubMed

Dwore, R B

1993-01-01

The Joint Commission on Accreditation of Healthcare Organization's new emphasis on continuous quality improvement provides hospitals with an opportunity to enhance both customer service as well as patient care. Both are expected by patients and delivered by providers. Patient care is the core product; customer service augments it by adding value and providing the opportunity for a competitive advantage. This article discusses issues for administrators to consider before including customer service as a component of continuous quality improvement and then presents methods for bringing about change.

Medical School Anatomy and Pathology Workshops for High School Students Enhance Learning and Provide Inspiration for Careers in Medicine

PubMed Central

Fenderson, Bruce A.; Veloski, J. Jon; Livesey, Michael; Wojdon-Smith, Tracey

2016-01-01

“Anatomy and Pathology Workshop” is a cadaver-based outreach program that models medical education to large groups of high school students. This study was designed to evaluate the impact of this program on students’ knowledge of anatomy and interest in biomedical science. A total of 144 high school students participated in the workshop in 2015. Preworkshop and postworkshop assessments were administered to assess students’ learning. A postworkshop survey was conducted to solicit students’ reflections and feedback. It was found that student performance in the postworkshop examination (mean 78%) had significantly improved when compared to the performance in the preexamination (mean 54%), indicating that this program enhances learning. Students were also inspired to consider opportunities in medicine and allied health professions—97% indicated that they had a better understanding of medical education; 95% agreed that they had better understanding of the human body; 84% thought anatomy was interesting and exciting; and 62% of the students indicated that they looked forward to studying medicine or another health profession. Students rated the instructors highly—95% agreed that the instructors were professional and served as role models. Medical/graduate student instructors were also highly regarded by the high school students—96% thought it was valuable to have student instructors and 94% thought that student instructors were caring and enthusiastic about teaching. In summary, this study demonstrates that outreach programs provided by medical schools help young adults during their formative years by modeling professionalism, providing role models, enhancing learning, and encouraging many to consider opportunities in the health professions. PMID:28725784

E-Learning as an Emerging Technology in India

ERIC Educational Resources Information Center

Grover, Pooja; Gupta, Nehta

2010-01-01

E-learning is a combination of learning services and technology that allow us to provide high value integrated learning any time, any place. It is about a new blend of resources, interactivity, performance support and structured learning activities. This methodology makes use of various types of technologies in order to enhance or transform the…

Enhancing Classroom Performance: A Technology Design to Support the Integration of Collaborative Learning and Participative Teams

ERIC Educational Resources Information Center

Marsh, Michael T.; Taylor, Ronald; Holoviak, Stephen J.

2008-01-01

Integral components of today's successful business models frequently include information technology, effective collaboration, and participative teamwork among employees. It is in the best interest of students for educators to provide classrooms that reflect a profitable practitioner's environment. Students studying for careers in business should…

Performance Assessment of Hearing Protection and Communication Enhancement Devices: Peltor Comtac III and IV

DTIC Science & Technology

2015-07-01

providing a hear-thru, or active capability while mitigating hearing loss and tinnitus caused by exposure to loud, steady-state and impulse noise. Active...loss and tinnitus caused by exposure to loud, steady-state and impulse noise. The general approach was to use ANSI standard measurement procedures

Using Tagteach to Improve the Proficiency of Dance Movements

ERIC Educational Resources Information Center

Quinn, Mallory J.; Miltenberger, Raymond G.; Fogel, Victoria A.

2015-01-01

Behavioral research to enhance sports performance has been conducted in numerous sports domains and often involves feedback from the coach to the student. One promising form of feedback is the use of an acoustical stimulus such as a clicker to provide more immediate feedback. Similar to clicker training with animals, acoustical stimuli are used…

Independent Learning Modules Enhance Student Performance and Understanding of Anatomy

ERIC Educational Resources Information Center

Serrat, Maria A.; Dom, Aaron M.; Buchanan, James T., Jr.; Williams, Alison R.; Efaw, Morgan L.; Richardson, Laura L.

2014-01-01

Didactic lessons are only one part of the multimodal teaching strategies used in gross anatomy courses today. Increased emphasis is placed on providing more opportunities for students to develop lifelong learning and critical thinking skills during medical training. In a pilot program designed to promote more engaged and independent learning in…

Improving Workplace-Based Assessment and Feedback by an E-Portfolio Enhanced with Learning Analytics

ERIC Educational Resources Information Center

van der Schaaf, Marieke; Donkers, Jeroen; Slof, Bert; Moonen-van Loon, Joyce; van Tartwijk, Jan; Driessen, Eric; Badii, Atta; Serban, Ovidiu; Ten Cate, Olle

2017-01-01

Electronic portfolios (E-portfolios) are crucial means for workplace-based assessment and feedback. Although E-portfolios provide a useful approach to view each learner's progress, so far options for personalized feedback and potential data about a learner's performances at the workplace often remain unexploited. This paper advocates that…

The Effects of Item by Item Feedback Given during an Ability Test.

ERIC Educational Resources Information Center

Whetton, C.; Childs, R.

1981-01-01

Answer-until-correct (AUC) is a procedure for providing feedback during a multiple-choice test, giving an increased range of scores. The performance of secondary students on a verbal ability test using AUC procedures was compared with a group using conventional instructions. AUC scores considerably enhanced reliability but not validity.…

Fathers Caring for Children: Research and Resources.

ERIC Educational Resources Information Center

Seward, Rudy Ray; Yeatts, Dale E.

This paper reviews studies examining the amount of time spent by fathers and mothers in child care activities, characteristics of fathers who spend more time with their children, ways to enhance fathers' child care performance, and the role of parent education in fatherhood. The paper also contains a list of organizations providing resources or…

76 FR 12395 - Data Collection Available for Public Comments and Recommendations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-07

... performance of the function of the agency, whether the burden estimates are accurate, and if there are ways to minimize the estimated burden and enhance the quality of the collection, to Barbara Brannan, Management... Companies to provide bonding for small contractors. The information collected on these forms is used to...

The Cafeteria Workers' Skills Enhancement Training Program. Performance Report.

ERIC Educational Resources Information Center

Burt, Miriam

A program was conducted by the Food and Beverage Workers Union in Washington, D.C., to provide workplace literacy classes for food service workers in the city's government agencies, universities, and museums. A curriculum for workplace literacy skills was developed, sites were selected, and students were recruited. From a target audience of…

Design and Implementation of a Learning Analytics Toolkit for Teachers

ERIC Educational Resources Information Center

Dyckhoff, Anna Lea; Zielke, Dennis; Bultmann, Mareike; Chatti, Mohamed Amine; Schroeder, Ulrik

2012-01-01

Learning Analytics can provide powerful tools for teachers in order to support them in the iterative process of improving the effectiveness of their courses and to collaterally enhance their students' performance. In this paper, we present the theoretical background, design, implementation, and evaluation details of eLAT, a Learning Analytics…

Tools for Schools: Filtration for Improved Air Quality. Technical Services Bulletin.

ERIC Educational Resources Information Center

2001

This product bulletin addresses air pollution control in educational facilities to enhance educational performance, provides air quality recommendations for schools, and examines the filtration needs of various school areas. The types of air particles typically present are highlighted, and the use of proper filtration to control gases and vapors…

Does Private Tutoring Increase Students' Academic Performance? Evidence from Turkey

ERIC Educational Resources Information Center

Berberoglu, Giray; Tansel, Aysit

2014-01-01

This paper investigates the effectiveness of private tutoring in Turkey. The authors introduce their study by providing some background information on the two major national examinations and three different kinds of tutoring. They then describe how they aimed to analyse whether attending private tutoring centres (PTCs) enhances Turkish students'…

75 FR 19673 - Petition for Exemption From the Vehicle Theft Prevention Standard; Saab

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-15

... module (BCM), passive entry passive start module (PEPS), intrusion/inclination sensor, an immobilizer... must be performed by communication between the PEPS and the BCM jointly with the UID (key fob... Saab 9-3, has been designed to enhance the functionality and theft protection provided by Saab's first...

Rethinking Teachers' Goal Orientations: Conceptual and Methodological Enhancements

ERIC Educational Resources Information Center

Nitsche, Sebastian; Dickhauser, Oliver; Fasching, Michaela S.; Dresel, Markus

2011-01-01

The article provides a theoretical extension of the goal orientation approach for teaching by proposing three different competence facets of learning goals and four types of addressees for performance approach and avoidance goals. On the basis of responses from 495 teacher trainees and 224 in-service teachers, the development and validation of an…

Policy and Barriers Related to Implementing Adult E-Learning in Taiwan

ERIC Educational Resources Information Center

Chung, Hsiu-Ying; Lee, Gwo-Guang; Liu, Shih-Hwa

2014-01-01

The work quality of public servants direct affects a country's administrative performance, and the Taiwan government has recently invested a considerable amount of funds in constructing e-government learning platforms and developing digital courses to provide all public servants with sufficient on-the-job training and enhance the quality of human…

Sleep-Related Improvements in Motor Learning Following Mental Practice

ERIC Educational Resources Information Center

Debarnot, Ursula; Creveaux, Thomas; Collet, Christian; Gemignani, Angelo; Massarelli, Raphael; Doyon, Julien; Guillot, Aymeric

2009-01-01

A wide range of experimental studies have provided evidence that a night of sleep may enhance motor performance following physical practice (PP), but little is known, however, about its effect after motor imagery (MI). Using an explicitly learned pointing task paradigm, thirty participants were assigned to one of three groups that differed in the…

The Responsible Use of Youth Fitness Testing to Enhance Student Motivation, Enjoyment, and Performance

ERIC Educational Resources Information Center

Wiersma, Lenny D.; Sherman, Clay P.

2008-01-01

While physical fitness testing has the potential to invoke embarrassment and anxiety, strategies can be developed that can motivate students to exert maximal effort, provide positive feedback on skill improvement, and encourage students to set fitness goals that can be achieved through developmentally appropriate physical activities. The purpose…

Method of Creating Micro-scale Silver Telluride Grains Covered with Bismuth Nanoparticles

NASA Technical Reports Server (NTRS)

Park, Yeonjoon (Inventor); Lee, Kunik (Inventor); Kim, Hyun-Jung (Inventor); Choi, Sang Hyouk (Inventor); King, Glen C. (Inventor)

2014-01-01

Provided is a method of enhancing thermoelectric performance by surrounding crystalline semiconductors with nanoparticles by contacting a bismuth telluride material with a silver salt under a substantially inert atmosphere and a temperature approximately near the silver salt decomposition temperature; and recovering a metallic bismuth decorated material comprising silver telluride crystal grains.

Acute kidney injury and hyperbilirubinemia in a young male after ingestion of Tribulus terrestris.

PubMed

Ryan, Margaret; Lazar, Ira; Nadasdy, Gyongyi M; Nadasdy, Tibor; Satoskar, Anjali A

2015-03-01

Acute tubular necrosis (ATN), especially from toxic injury is frequently accompanied by tubular casts and crystals. Myeloma casts, myoglobin, red blood cell and granular casts are well described. However, bile casts in tubules are rarely seen. We describe a case of Tribulus terrestris toxicity in a young healthy male, presenting with severe hyperbilirubinemia followed by acute renal failure and bile containing casts in the tubules. Tribulus terrestris is an herb often used by athletes as a nutritional supplement for performance enhancement. Although it is thought to be relatively safe, serious side effects have been reported before. Our aim is to increase awareness of the potential toxicities of performance enhancing herbal medications. These are often sold over-the-counter and therefore casually used, especially by young healthy individuals. Beneficial effects are controversial. Under-reporting by patients and infrequent documentation by health-care providers can delay diagnosis. We elaborately describe the kidney biopsy findings in Tribulus terrestris toxicity, and also provide a concise overview of the spectrum of tubular casts and their staining patterns, found in various kidney diseases.

Display technologies for augmented reality

NASA Astrophysics Data System (ADS)

Lee, Byoungho; Lee, Seungjae; Jang, Changwon; Hong, Jong-Young; Li, Gang

2018-02-01

With the virtue of rapid progress in optics, sensors, and computer science, we are witnessing that commercial products or prototypes for augmented reality (AR) are penetrating into the consumer markets. AR is spotlighted as expected to provide much more immersive and realistic experience than ordinary displays. However, there are several barriers to be overcome for successful commercialization of AR. Here, we explore challenging and important topics for AR such as image combiners, enhancement of display performance, and focus cue reproduction. Image combiners are essential to integrate virtual images with real-world. Display performance (e.g. field of view and resolution) is important for more immersive experience and focus cue reproduction may mitigate visual fatigue caused by vergence-accommodation conflict. We also demonstrate emerging technologies to overcome these issues: index-matched anisotropic crystal lens (IMACL), retinal projection displays, and 3D display with focus cues. For image combiners, a novel optical element called IMACL provides relatively wide field of view. Retinal projection displays may enhance field of view and resolution of AR displays. Focus cues could be reconstructed via multi-layer displays and holographic displays. Experimental results of our prototypes are explained.

An overview of active flow control actuators and applications (presentation video)

NASA Astrophysics Data System (ADS)

Brzozowski, Daniel; Whalen, Edward A.

2014-04-01

Active Flow Control (AFC) is an emerging technology which promises performance enhancements to both military and civilian aircraft. A technique which uses energy input at discrete locations to manipulate the flow over an aerodynamic surface, AFC may be used to reduce drag, prevent flow separation, and enable otherwise-infeasible aerodynamic designs. Additional applications include shear layer and turbulence control for aero-optics applications and mixing enhancement for thermal applications. Many AFC applications call for a high frequency fluidic perturbation provided by an electrically-powered actuator. In these instances, piezoelectric (PZT) materials have served as the workhorse for flow control actuators, such as the widely-studied synthetic jet. Because the PZT materials form the critical component of the actuator, the maximum performance of the synthetic jet (velocity and momentum output) is limited by the physical limitations of the PZT material. The purpose of this presentation is to provide a high level overview of AFC actuators and applications in an attempt to engage the smart materials community and encourage advanced material development in support of these crucial applications.

Improved design for a low temperature scanning tunneling microscope with an in situ tip treatment stage.

PubMed

Kim, J-J; Joo, S H; Lee, K S; Yoo, J H; Park, M S; Kwak, J S; Lee, Jinho

2017-04-01

The Low Temperature Scanning Tunneling Microscope (LT-STM) is an extremely valuable tool not only in surface science but also in condensed matter physics. For years, numerous new ideas have been adopted to perfect LT-STM performances-Ultra-Low Vibration (ULV) laboratory and the rigid STM head design are among them. Here, we present three improvements for the design of the ULV laboratory and the LT-STM: tip treatment stage, sample cleaving stage, and vibration isolation system. The improved tip treatment stage enables us to perform field emission for the purpose of tip treatment in situ without exchanging samples, while our enhanced sample cleaving stage allows us to cleave samples at low temperature in a vacuum without optical access by a simple pressing motion. Our newly designed vibration isolation system provides efficient space usage while maintaining vibration isolation capability. These improvements enhance the quality of spectroscopic imaging experiments that can last for many days and provide increased data yield, which we expect can be indispensable elements in future LT-STM designs.

The Athletic Trainer's Role in Modifying Nutritional Behaviors of Adolescent Athletes: Putting Theory into Practice

PubMed Central

Hackman, Robert M.; Katra, Jane E.; Geertsen, Susan M.

1992-01-01

Nutritional practices influence athletic performance and recovery from injury. The athletic trainer is ideally positioned to effect dietary changes with adolescent athletes—a group at high-risk for nutritional imbalances. Research shows that young adults generally do not change dietary practices when given factual nutrition and health information. This article provides a variety of behavior change strategies, based on models derived from health education and health psychology, which are likely to influence dietary choices. Promoting self-efficacy by enhancing perception of choice and control, peer modeling, cooperative support networks, goal-setting techniques, and behavioral self-monitoring may provide the motivational framework necessary to enhance dietary compliance. Dietary behavior change techniques are a valuable part of an athletic trainer's resources. PMID:16558172

Floating compression of Ag nanowire networks for effective strain release of stretchable transparent electrodes

NASA Astrophysics Data System (ADS)

Pyo, Jun Beom; Kim, Byoung Soo; Park, Hyunchul; Kim, Tae Ann; Koo, Chong Min; Lee, Jonghwi; Son, Jeong Gon; Lee, Sang-Soo; Park, Jong Hyuk

2015-10-01

Manipulation of the configuration of Ag nanowire (NW) networks has been pursued to enhance the performance of stretchable transparent electrodes. However, it has remained challenging due to the high Young's modulus and low yield strain of Ag NWs, which lead to their mechanical failure when subjected to structural deformation. We demonstrate that floating a Ag NW network on water and subsequent in-plane compression allows convenient development of a wavy configuration in the Ag NW network, which can release the applied strain. A greatly enhanced electromechanical stability of Ag NW networks can be achieved due to their wavy configuration, while the NW networks maintain the desirable optical and electrical properties. Moreover, the produced NW networks can be transferred to a variety of substrates, offering flexibility for device fabrication. The Ag NW networks with wavy configurations are used as compliant electrodes for dielectric elastomer actuators. The study demonstrates their promising potential to provide improved performance for soft electronic devices.Manipulation of the configuration of Ag nanowire (NW) networks has been pursued to enhance the performance of stretchable transparent electrodes. However, it has remained challenging due to the high Young's modulus and low yield strain of Ag NWs, which lead to their mechanical failure when subjected to structural deformation. We demonstrate that floating a Ag NW network on water and subsequent in-plane compression allows convenient development of a wavy configuration in the Ag NW network, which can release the applied strain. A greatly enhanced electromechanical stability of Ag NW networks can be achieved due to their wavy configuration, while the NW networks maintain the desirable optical and electrical properties. Moreover, the produced NW networks can be transferred to a variety of substrates, offering flexibility for device fabrication. The Ag NW networks with wavy configurations are used as compliant electrodes for dielectric elastomer actuators. The study demonstrates their promising potential to provide improved performance for soft electronic devices. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03814f

Geometrically confined ultrasmall gadolinium oxide nanoparticles boost the T1 contrast ability

NASA Astrophysics Data System (ADS)

Ni, Kaiyuan; Zhao, Zhenghuan; Zhang, Zongjun; Zhou, Zijian; Yang, Li; Wang, Lirong; Ai, Hua; Gao, Jinhao

2016-02-01

High-performance magnetic resonance imaging (MRI) contrast agents and novel contrast enhancement strategies are urgently needed for sensitive and accurate diagnosis. Here we report a strategy to construct a new T1 contrast agent based on the Solomon-Bloembergen-Morgan (SBM) theory. We loaded the ultrasmall gadolinium oxide nanoparticles into worm-like interior channels of mesoporous silica nanospheres (Gd2O3@MSN nanocomposites). This unique structure endows the nanocomposites with geometrical confinement, high molecular tumbling time, and a large coordinated number of water molecules, which results in a significant enhancement of the T1 contrast with longitudinal proton relaxivity (r1) as high as 45.08 mM-1 s-1. Such a high r1 value of Gd2O3@MSN, compared to those of ultrasmall Gd2O3 nanoparticles and gadolinium-based clinical contrast agents, is mainly attributed to the strong geometrical confinement effect. This strategy provides new guidance for developing various high-performance T1 contrast agents for sensitive imaging and disease diagnosis.High-performance magnetic resonance imaging (MRI) contrast agents and novel contrast enhancement strategies are urgently needed for sensitive and accurate diagnosis. Here we report a strategy to construct a new T1 contrast agent based on the Solomon-Bloembergen-Morgan (SBM) theory. We loaded the ultrasmall gadolinium oxide nanoparticles into worm-like interior channels of mesoporous silica nanospheres (Gd2O3@MSN nanocomposites). This unique structure endows the nanocomposites with geometrical confinement, high molecular tumbling time, and a large coordinated number of water molecules, which results in a significant enhancement of the T1 contrast with longitudinal proton relaxivity (r1) as high as 45.08 mM-1 s-1. Such a high r1 value of Gd2O3@MSN, compared to those of ultrasmall Gd2O3 nanoparticles and gadolinium-based clinical contrast agents, is mainly attributed to the strong geometrical confinement effect. This strategy provides new guidance for developing various high-performance T1 contrast agents for sensitive imaging and disease diagnosis. Electronic supplementary information (ESI) available: Supplementary Fig. S1-S6. See DOI: 10.1039/c5nr08402d

Transgenic plants with enhanced growth characteristics

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

Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

The invention relates to transgenic plants exhibiting dramatically enhanced growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, more efficient nitrogen utilization, increased tolerance to high salt conditions, and increased biomass yields. In one embodiment, transgenic plants engineered to over-express both glutamine phenylpyruvate transaminase (GPT) and glutamine synthetase (GS) are provided. The GPT+GS double-transgenic plants of the invention consistently exhibit enhanced growth characteristics, with T0 generation lines showing an increase in biomass over wild type counterparts of between 50% and 300%. Generations that result from sexual crosses and/or selfing typically perform even better, with some of themore » double-transgenic plants achieving an astounding four-fold biomass increase over wild type plants.« less

Recovery of Background Structures in Nanoscale Helium Ion Microscope Imaging.

PubMed

Carasso, Alfred S; Vladár, András E

2014-01-01

This paper discusses a two step enhancement technique applicable to noisy Helium Ion Microscope images in which background structures are not easily discernible due to a weak signal. The method is based on a preliminary adaptive histogram equalization, followed by 'slow motion' low-exponent Lévy fractional diffusion smoothing. This combined approach is unexpectedly effective, resulting in a companion enhanced image in which background structures are rendered much more visible, and noise is significantly reduced, all with minimal loss of image sharpness. The method also provides useful enhancements of scanning charged-particle microscopy images obtained by composing multiple drift-corrected 'fast scan' frames. The paper includes software routines, written in Interactive Data Language (IDL),(1) that can perform the above image processing tasks.

Medium scale carbon nanotube thin film integrated circuits on flexible plastic substrates

DOEpatents

Rogers, John A; Cao, Qing; Alam, Muhammad; Pimparkar, Ninad

2015-02-03

The present invention provides device components geometries and fabrication strategies for enhancing the electronic performance of electronic devices based on thin films of randomly oriented or partially aligned semiconducting nanotubes. In certain aspects, devices and methods of the present invention incorporate a patterned layer of randomly oriented or partially aligned carbon nanotubes, such as one or more interconnected SWNT networks, providing a semiconductor channel exhibiting improved electronic properties relative to conventional nanotubes-based electronic systems.

The Automation-by-Expertise-by-Training Interaction.

PubMed

Strauch, Barry

2017-03-01

I introduce the automation-by-expertise-by-training interaction in automated systems and discuss its influence on operator performance. Transportation accidents that, across a 30-year interval demonstrated identical automation-related operator errors, suggest a need to reexamine traditional views of automation. I review accident investigation reports, regulator studies, and literature on human computer interaction, expertise, and training and discuss how failing to attend to the interaction of automation, expertise level, and training has enabled operators to commit identical automation-related errors. Automated systems continue to provide capabilities exceeding operators' need for effective system operation and provide interfaces that can hinder, rather than enhance, operator automation-related situation awareness. Because of limitations in time and resources, training programs do not provide operators the expertise needed to effectively operate these automated systems, requiring them to obtain the expertise ad hoc during system operations. As a result, many do not acquire necessary automation-related system expertise. Integrating automation with expected operator expertise levels, and within training programs that provide operators the necessary automation expertise, can reduce opportunities for automation-related operator errors. Research to address the automation-by-expertise-by-training interaction is needed. However, such research must meet challenges inherent to examining realistic sociotechnical system automation features with representative samples of operators, perhaps by using observational and ethnographic research. Research in this domain should improve the integration of design and training and, it is hoped, enhance operator performance.

Using Gagne's theory to teach chest X-ray interpretation.

PubMed

Belfield, Jane

2010-03-01

as a Radiologist providing teaching for medical students and junior doctors, I have spent time devising lesson plans. It is vital to know the aims and objectives prior to teaching sessions in order that the students benefit as much as possible. This article describes a lesson plan for interpretation of a chest X-Ray using a theory described by Robert Gagne. Gagne developed a model of instructional design, which provides information and interaction to enhance the learning process. This model is based on nine instructional events used during a teaching session. These are: gaining attention, informing the learner of the objective, stimulating recall of prior material, presenting the stimulus material, providing learning guidance, eliciting the performance, providing feedback, assessing the performance and enhancing retention and transfer. this article uses the nine points described by Gagne and describes a model of how to teach chest X-ray interpretation. Each of Gagne's points is illustrated with a specific example of how this would fit into the Radiology teaching session. Gagne's theory of instructional design can be adapted depending on the subject being taught. It is useful, both for the teacher and the student, to prepare a lesson plan in advance with knowledge of required aims and objectives. Having run teaching sessions which use Gagne's theory, students have given very positive feedback and as a teacher I found the lesson ran more smoothly. Blackwell Publishing Ltd 2010.

Generalized PSF modeling for optimized quantitation in PET imaging.

PubMed

Ashrafinia, Saeed; Mohy-Ud-Din, Hassan; Karakatsanis, Nicolas A; Jha, Abhinav K; Casey, Michael E; Kadrmas, Dan J; Rahmim, Arman

2017-06-21

Point-spread function (PSF) modeling offers the ability to account for resolution degrading phenomena within the PET image generation framework. PSF modeling improves resolution and enhances contrast, but at the same time significantly alters image noise properties and induces edge overshoot effect. Thus, studying the effect of PSF modeling on quantitation task performance can be very important. Frameworks explored in the past involved a dichotomy of PSF versus no-PSF modeling. By contrast, the present work focuses on quantitative performance evaluation of standard uptake value (SUV) PET images, while incorporating a wide spectrum of PSF models, including those that under- and over-estimate the true PSF, for the potential of enhanced quantitation of SUVs. The developed framework first analytically models the true PSF, considering a range of resolution degradation phenomena (including photon non-collinearity, inter-crystal penetration and scattering) as present in data acquisitions with modern commercial PET systems. In the context of oncologic liver FDG PET imaging, we generated 200 noisy datasets per image-set (with clinically realistic noise levels) using an XCAT anthropomorphic phantom with liver tumours of varying sizes. These were subsequently reconstructed using the OS-EM algorithm with varying PSF modelled kernels. We focused on quantitation of both SUV mean and SUV max , including assessment of contrast recovery coefficients, as well as noise-bias characteristics (including both image roughness and coefficient of-variability), for different tumours/iterations/PSF kernels. It was observed that overestimated PSF yielded more accurate contrast recovery for a range of tumours, and typically improved quantitative performance. For a clinically reasonable number of iterations, edge enhancement due to PSF modeling (especially due to over-estimated PSF) was in fact seen to lower SUV mean bias in small tumours. Overall, the results indicate that exactly matched PSF modeling does not offer optimized PET quantitation, and that PSF overestimation may provide enhanced SUV quantitation. Furthermore, generalized PSF modeling may provide a valuable approach for quantitative tasks such as treatment-response assessment and prognostication.

The Controlled Ecological Life Support System Antarctic Analog Project: Prototype Crop Production and Water Treatment System Performance

NASA Technical Reports Server (NTRS)

Bubenheim, David L.; Flynn, Michael T.; Bates, Maynard; Schlick, Greg; Kliss, Mark (Technical Monitor)

1997-01-01

The Controlled Ecological Life Support System (CELSS) Antarctic Analog Project (CAAP), is a joint endeavor between the National Science Foundation, Office of Polar Programs (NSF-OPP) and the NASA. The fundamental objective is to develop, deploy, and operate a testbed of advanced life support technologies at the Amundsen-Scott South Pole Station that enable the objectives of both the NSF and NASA. The functions of food production, water purification, and waste treatment, recycle and reduction provided by CAAP will improve the quality of life for the South Pole inhabitants, reduce logistics dependence, enhance safety and minimize environmental impacts associated with human presence on the polar plateau. Because of the analogous technical, scientific, and mission features with Planetary missions such as a mission to Mars, CAAP provides NASA with a method for validating technologies and overall approaches to supporting humans. Prototype systems for sewage treatment, water recycle and crop production are being evaluated at Ames Research Center. The product water from sewage treatment using a Wiped-Film Rotating Disk is suitable for input to the crop production system. The crop production system has provided an enhanced level of performance compared with projected performance for plant-based life support: an approximate 50% increase in productivity per unit area, more than a 65% decrease in power for plant lighting, and more than a 75% decrease in the total power requirement to produce an equivalent mass of edible biomass.

A comprehensive survey of the relationship between self-efficacy and performance for the governmental auditors.

PubMed

Su, Jau-Ming; Lee, Shue-Ching; Tsai, Sang-Bing; Lu, Tzu-Li

2016-01-01

As governmental auditing is involved in evaluating the legitimacy, economy, efficiency, and effectiveness of how the various administrative branches use their allocated resources to optimize the government's functions, it is expected that the performance of the auditors in charge are strongly influenced by their respective qualities such as self-efficacy and experience, etc. To further understand the factors that may enhance their performance and to ultimately provide practical recommendations for the audit authorities, we have surveyed about 50 % of all the governmental auditors in Taiwan. The result showed that any auditing experience and professionalization do positively influence the professional awareness, and acquired knowledge and skillset of an auditor can effectively improve his or her professional judgment. We also found that perceived ability, problem-solving skills, and resource sharing may significantly impact any performance involved. Our study provides a workable management guidelines for strengthening the self-efficacy of audit authorities in Taiwan.

Protocol for Uniformly Measuring and Expressing the Performance of Energy Storage Systems

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

Conover, David R.; Crawford, Aladsair J.; Viswanathan, Vilayanur V.

2014-06-01

The Protocol for Uniformly Measuring and Expressing the Performance of Energy Storage Systems (PNNL-22010) was first issued in November 2012 as a first step toward providing a foundational basis for developing an initial standard for the uniform measurement and expression of energy storage system (ESS) performance. Its subsequent use in the field and review by the protocol working group and most importantly the users’ subgroup and the thermal subgroup has led to the fundamental modifications reflected in this update of the 2012 Protocol. As an update of the 2012 Protocol, this document (the June 2014 Protocol) is intended to supersedemore » its predecessor and be used as the basis for measuring and expressing ESS performance. The foreword provides general and specific details about what additions, revisions, and enhancements have been made to the 2012 Protocol and the rationale for them in arriving at the June 2014 Protocol.« less

Optimal cube-connected cube multiprocessors

NASA Technical Reports Server (NTRS)

Sun, Xian-He; Wu, Jie

1993-01-01

Many CFD (computational fluid dynamics) and other scientific applications can be partitioned into subproblems. However, in general the partitioned subproblems are very large. They demand high performance computing power themselves, and the solutions of the subproblems have to be combined at each time step. The cube-connect cube (CCCube) architecture is studied. The CCCube architecture is an extended hypercube structure with each node represented as a cube. It requires fewer physical links between nodes than the hypercube, and provides the same communication support as the hypercube does on many applications. The reduced physical links can be used to enhance the bandwidth of the remaining links and, therefore, enhance the overall performance. The concept and the method to obtain optimal CCCubes, which are the CCCubes with a minimum number of links under a given total number of nodes, are proposed. The superiority of optimal CCCubes over standard hypercubes was also shown in terms of the link usage in the embedding of a binomial tree. A useful computation structure based on a semi-binomial tree for divide-and-conquer type of parallel algorithms was identified. It was shown that this structure can be implemented in optimal CCCubes without performance degradation compared with regular hypercubes. The result presented should provide a useful approach to design of scientific parallel computers.

Performance-Enhancing Drugs on the Web: A Growing Public-Health Issue

PubMed Central

Brennan, Brian P.; Kanayama, Gen; Pope, Harrison G.

2012-01-01

Background and Objectives Today’s Internet provides extensive “underground” guidelines for obtaining and using illicit substances, including especially anabolic-androgenic steroids (AAS) and other appearance- and performance-enhancing drugs (APEDs). We attempted to qualitatively characterize APED-related Internet sites. Methods We used relevant Internet search terms (e.g., “steroids bodybuilding” and “buy steroids online”), to assess 1) the numbers of site visitors; 2) offers of drugs for sale; and 3) the quality of online medical information. We also chose the examples of 4) “site-enhancing oils” and 5) “cattle implants” to illustrate the volume of available Internet information as compared with that in the medical literature. Results We found thousands of sites involving AAS and other APEDs. Most sites presented an unabashedly pro-drug position, often openly questioning the qualifications and motivations of mainstream medical practitioners. Offers of AAS and other APEDs for sale, together with medical advice of varying legitimacy, was widespread across sites. Importantly, many sites provided detailed guidelines for exotic forms of APED use, some likely associated with serious health risks, which are probably unknown to most practicing clinicians. Conclusions and Scientific Significance It seems important for practitioners to be aware of the extent of this “underground literature,” which may strongly influence their patients’ decisions about use and abuse of APEDs. PMID:23414502

Nano-Photonic Structures for Light Trapping in Ultra-Thin Crystalline Silicon Solar Cells

PubMed Central

Pathi, Prathap; Peer, Akshit; Biswas, Rana

2017-01-01

Thick wafer-silicon is the dominant solar cell technology. It is of great interest to develop ultra-thin solar cells that can reduce materials usage, but still achieve acceptable performance and high solar absorption. Accordingly, we developed a highly absorbing ultra-thin crystalline Si based solar cell architecture using periodically patterned front and rear dielectric nanocone arrays which provide enhanced light trapping. The rear nanocones are embedded in a silver back reflector. In contrast to previous approaches, we utilize dielectric photonic crystals with a completely flat silicon absorber layer, providing expected high electronic quality and low carrier recombination. This architecture creates a dense mesh of wave-guided modes at near-infrared wavelengths in the absorber layer, generating enhanced absorption. For thin silicon (<2 μm) and 750 nm pitch arrays, scattering matrix simulations predict enhancements exceeding 90%. Absorption approaches the Lambertian limit at small thicknesses (<10 μm) and is slightly lower (by ~5%) at wafer-scale thicknesses. Parasitic losses are ~25% for ultra-thin (2 μm) silicon and just 1%–2% for thicker (>100 μm) cells. There is potential for 20 μm thick cells to provide 30 mA/cm2 photo-current and >20% efficiency. This architecture has great promise for ultra-thin silicon solar panels with reduced material utilization and enhanced light-trapping. PMID:28336851

Nano-photonic structures for light trapping in ultra-thin crystalline silicon solar cells

DOE PAGES

Pathi, Prathap; Peer, Akshit; Biswas, Rana

2017-01-13

Thick wafer-silicon is the dominant solar cell technology. It is of great interest to develop ultra-thin solar cells that can reduce materials usage, but still achieve acceptable performance and high solar absorption. Accordingly, we developed a highly absorbing ultra-thin crystalline Si based solar cell architecture using periodically patterned front and rear dielectric nanocone arrays which provide enhanced light trapping. The rear nanocones are embedded in a silver back reflector. In contrast to previous approaches, we utilize dielectric photonic crystals with a completely flat silicon absorber layer, providing expected high electronic quality and low carrier recombination. This architecture creates a densemore » mesh of wave-guided modes at near-infrared wavelengths in the absorber layer, generating enhanced absorption. For thin silicon (<2 μm) and 750 nm pitch arrays, scattering matrix simulations predict enhancements exceeding 90%. Absorption approaches the Lambertian limit at small thicknesses (<10 μm) and is slightly lower (by ~5%) at wafer-scale thicknesses. Parasitic losses are ~25% for ultra-thin (2 μm) silicon and just 1%–2% for thicker (>100 μm) cells. There is potential for 20 μm thick cells to provide 30 mA/cm2 photo-current and >20% efficiency. Furthermore, this architecture has great promise for ultra-thin silicon solar panels with reduced material utilization and enhanced light-trapping.« less

Nano-photonic structures for light trapping in ultra-thin crystalline silicon solar cells

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

Pathi, Prathap; Peer, Akshit; Biswas, Rana

Thick wafer-silicon is the dominant solar cell technology. It is of great interest to develop ultra-thin solar cells that can reduce materials usage, but still achieve acceptable performance and high solar absorption. Accordingly, we developed a highly absorbing ultra-thin crystalline Si based solar cell architecture using periodically patterned front and rear dielectric nanocone arrays which provide enhanced light trapping. The rear nanocones are embedded in a silver back reflector. In contrast to previous approaches, we utilize dielectric photonic crystals with a completely flat silicon absorber layer, providing expected high electronic quality and low carrier recombination. This architecture creates a densemore » mesh of wave-guided modes at near-infrared wavelengths in the absorber layer, generating enhanced absorption. For thin silicon (<2 μm) and 750 nm pitch arrays, scattering matrix simulations predict enhancements exceeding 90%. Absorption approaches the Lambertian limit at small thicknesses (<10 μm) and is slightly lower (by ~5%) at wafer-scale thicknesses. Parasitic losses are ~25% for ultra-thin (2 μm) silicon and just 1%–2% for thicker (>100 μm) cells. There is potential for 20 μm thick cells to provide 30 mA/cm2 photo-current and >20% efficiency. Furthermore, this architecture has great promise for ultra-thin silicon solar panels with reduced material utilization and enhanced light-trapping.« less

Nano-Photonic Structures for Light Trapping in Ultra-Thin Crystalline Silicon Solar Cells.

PubMed

Pathi, Prathap; Peer, Akshit; Biswas, Rana

2017-01-13

Thick wafer-silicon is the dominant solar cell technology. It is of great interest to develop ultra-thin solar cells that can reduce materials usage, but still achieve acceptable performance and high solar absorption. Accordingly, we developed a highly absorbing ultra-thin crystalline Si based solar cell architecture using periodically patterned front and rear dielectric nanocone arrays which provide enhanced light trapping. The rear nanocones are embedded in a silver back reflector. In contrast to previous approaches, we utilize dielectric photonic crystals with a completely flat silicon absorber layer, providing expected high electronic quality and low carrier recombination. This architecture creates a dense mesh of wave-guided modes at near-infrared wavelengths in the absorber layer, generating enhanced absorption. For thin silicon (<2 μm) and 750 nm pitch arrays, scattering matrix simulations predict enhancements exceeding 90%. Absorption approaches the Lambertian limit at small thicknesses (<10 μm) and is slightly lower (by ~5%) at wafer-scale thicknesses. Parasitic losses are ~25% for ultra-thin (2 μm) silicon and just 1%-2% for thicker (>100 μm) cells. There is potential for 20 μm thick cells to provide 30 mA/cm² photo-current and >20% efficiency. This architecture has great promise for ultra-thin silicon solar panels with reduced material utilization and enhanced light-trapping.

Max CAPR: high-resolution 3D contrast-enhanced MR angiography with acquisition times under 5 seconds.

PubMed

Haider, Clifton R; Borisch, Eric A; Glockner, James F; Mostardi, Petrice M; Rossman, Phillip J; Young, Phillip M; Riederer, Stephen J

2010-10-01

High temporal and spatial resolution is desired in imaging of vascular abnormalities having short arterial-to-venous transit times. Methods that exploit temporal correlation to reduce the observed frame time demonstrate temporal blurring, obfuscating bolus dynamics. Previously, a Cartesian acquisition with projection reconstruction-like (CAPR) sampling method has been demonstrated for three-dimensional contrast-enhanced angiographic imaging of the lower legs using two-dimensional sensitivity-encoding acceleration and partial Fourier acceleration, providing 1mm isotropic resolution of the calves, with 4.9-sec frame time and 17.6-sec temporal footprint. In this work, the CAPR acquisition is further undersampled to provide a net acceleration approaching 40 by eliminating all view sharing. The tradeoff of frame time and temporal footprint in view sharing is presented and characterized in phantom experiments. It is shown that the resultant 4.9-sec acquisition time, three-dimensional images sets have sufficient spatial and temporal resolution to clearly portray arterial and venous phases of contrast passage. It is further hypothesized that these short temporal footprint sequences provide diagnostic quality images. This is tested and shown in a series of nine contrast-enhanced MR angiography patient studies performed with the new method.

Reduced graphene oxide/molecular imprinted polymer-organic thin film transistor for amino acid detection

NASA Astrophysics Data System (ADS)

Halim, Nurul Farhanah AB.; Musa, Nur Hazwani; Zakaria, Zulkhairi; Von Schleusingen, Mubaraq; Ahmad, Mohd Noor; Derman, Nazree; Shakaff, Ali Yeon Md.

2017-03-01

This works reports the electrical performance of reduced graphene oxide (RGO)/Molecular imprinted polymer (MIP)- organic thin film transistor (OTFT) for amino-acid detection, serine. These biomimetic sensors consider MIP as man-tailored biomimetic recognition sites that play an important role in signal transduction. MIP provides recognition sites compatible with serine molecules was developed by dispersing serine with methylacrylate acid (MAA) as functional monomer and Ethylene glycol dimethylacrylate (EGDMA) as cross-linker. The imprinted polymeric were mixed with reduced graphene oxide to produced sensing layer for the sensor. RGO-MIP layer was introduced between source and drain of OTFT via spin coating as a detecting layer for serine molecules. RGO was introduced into MIP, to allow a highly conductive sensing material thus enhanced selectivity and sensitivity of the sensor. By analyzing the electrical performance of the sensors, the performances of OTFT sensor enhanced with RGO/MIP interlayer and OTFT sensor with MIP interlayer when exposed to serine analyte were obtained. The results showed that there were remarkable shifts of drain current (ID) obtained from OTFT sensor with RGO/MIP interlayer after exposed to serine analyte. Moreover, the sensitivity of OTFT sensor with RGO/MIP interlayer was nearly higher than the OTFT sensor with MIP interlayer. Hence, it proved that RGO successfully enhanced the sensing performance of OTFT sensor.

Band-to-Band Tunneling-Dominated Thermo-Enhanced Field Electron Emission from p-Si/ZnO Nanoemitters.

PubMed

Huang, Zhizhen; Huang, Yifeng; Xu, Ningsheng; Chen, Jun; She, Juncong; Deng, Shaozhi

2018-06-13

Thermo-enhancement is an effective way to achieve high performance field electron emitters, and enables the individually tuning on the emission current by temperature and the electron energy by voltage. The field emission current from metal or n-doped semiconductor emitter at a relatively lower temperature (i.e., < 1000 K) is less temperature sensitive due to the weak dependence of free electron density on temperature, while that from p-doped semiconductor emitter is restricted by its limited free electron density. Here, we developed full array of uniform individual p-Si/ZnO nanoemitters and demonstrated the strong thermo-enhanced field emission. The mechanism of forming uniform nanoemitters with well Si/ZnO mechanical joint in the nanotemplates was elucidated. No current saturation was observed in the thermo-enhanced field emission measurements. The emission current density showed about ten-time enhancement (from 1.31 to 12.11 mA/cm 2 at 60.6 MV/m) by increasing the temperature from 323 to 623 K. The distinctive performance did not agree with the interband excitation mechanism but well-fit to the band-to-band tunneling model. The strong thermo-enhancement was proposed to be benefit from the increase of band-to-band tunneling probability at the surface portion of the p-Si/ZnO nanojunction. This work provides promising cathode for portable X-ray tubes/panel, ionization vacuum gauges and low energy electron beam lithography, in where electron-dose control at a fixed energy is needed.

Self-Assembled Multilayer Structure and Enhanced Thermochromic Performance of Spinodally Decomposed TiO2-VO2 Thin Film.

PubMed

Sun, Guangyao; Zhou, Huaijuan; Cao, Xun; Li, Rong; Tazawa, Masato; Okada, Masahisa; Jin, Ping

2016-03-23

Composite films of VO2-TiO2 were deposited on sapphire (11-20) substrate by cosputtering method. Self-assembled well-ordered multilayer structure with alternating Ti- and V-rich epitaxial thin layer was obtained by thermal annealing via a spinodal decomposition mechanism. The structured thermochromic films demonstrate superior optical modulation upon phase transition, with significantly reduced transition temperature. The results provide a facile and novel approach to fabricate smart structures with excellent performance.

Ferroelectric-Driven Performance Enhancement of Graphene Field-Effect Transistors Based on Vertical Tunneling Heterostructures.

PubMed

Yuan, Shuoguo; Yang, Zhibin; Xie, Chao; Yan, Feng; Dai, Jiyan; Lau, Shu Ping; Chan, Helen L W; Hao, Jianhua

2016-12-01

A vertical graphene heterostructure field-effect transistor (VGHFET) using an ultrathin ferroelectric film as a tunnel barrier is developed. The heterostructure is capable of providing new degrees of tunability and functionality via coupling between the ferroelectricity and the tunnel current of the VGHFET, which results in a high-performance device. The results pave the way for developing novel atomic-scale 2D heterostructures and devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Limitations of contrast enhancement for infrared target identification

NASA Astrophysics Data System (ADS)

Du Bosq, Todd W.; Fanning, Jonathan D.

2009-05-01

Contrast enhancement and dynamic range compression are currently being used to improve the performance of infrared imagers by increasing the contrast between the target and the scene content. Automatic contrast enhancement techniques do not always achieve this improvement. In some cases, the contrast can increase to a level of target saturation. This paper assesses the range-performance effects of contrast enhancement for target identification as a function of image saturation. Human perception experiments were performed to determine field performance using contrast enhancement on the U.S. Army RDECOM CERDEC NVESD standard military eight target set using an un-cooled LWIR camera. The experiments compare the identification performance of observers viewing contrast enhancement processed images at various levels of saturation. Contrast enhancement is modeled in the U.S. Army thermal target acquisition model (NVThermIP) by changing the scene contrast temperature. The model predicts improved performance based on any improved target contrast, regardless of specific feature saturation or enhancement. The measured results follow the predicted performance based on the target task difficulty metric used in NVThermIP for the non-saturated cases. The saturated images reduce the information contained in the target and performance suffers. The model treats the contrast of the target as uniform over spatial frequency. As the contrast is enhanced, the model assumes that the contrast is enhanced uniformly over the spatial frequencies. After saturation, the spatial cues that differentiate one tank from another are located in a limited band of spatial frequencies. A frequency dependent treatment of target contrast is needed to predict performance of over-processed images.

Properties and Performance Attributes of Novel Co-Extruded Polyolefin Battery Separator Materials. Part 1; Mechanical Properties

NASA Technical Reports Server (NTRS)

Baldwin, Richard S.; Guzik, Monica; Skierski, Michael

2011-01-01

As NASA prepares for its next era of manned spaceflight missions, advanced energy storage technologies are being developed and evaluated to address future mission needs and technical requirements and to provide new mission-enabling technologies. Cell-level components for advanced lithium-ion batteries possessing higher energy, more reliable performance and enhanced, inherent safety characteristics are actively under development within the NASA infrastructure. A key component for safe and reliable cell performance is the cell separator, which separates the two energetic electrodes and functions to prevent the occurrence of an internal short-circuit while enabling ionic transport. Recently, a new generation of co-extruded separator films has been developed by ExxonMobil Chemical and introduced into their battery separator product portfolio. Several grades of this new separator material have been evaluated with respect to dynamic mechanical properties and safety-related performance attributes. This paper presents the results of these evaluations in comparison to a current state-ofthe-practice separator material. The results are discussed with respect to potential opportunities to enhance the inherent safety characteristics and reliability of future, advanced lithium-ion cell chemistries.

Thermal Characterization for a Modular 3-D Multichip Module

NASA Technical Reports Server (NTRS)

Fan, Mark S.; Plante, Jeannette; Shaw, Harry

2000-01-01

NASA Goddard Space Flight Center has designed a high-density modular 3-D multichip module (MCM) for future spaceflight use. This MCM features a complete modular structure, i.e., each stack can be removed from the package without damaging the structure. The interconnection to the PCB is through the Column Grid Array (CGA) technology. Because of its high-density nature, large power dissipation from multiple layers of circuitry is anticipated and CVD diamond films are used in the assembly for heat conduction enhancement. Since each stacked layer dissipates certain amount of heat, designing effective heat conduction paths through each stack and balancing the heat dissipation within each stack for optimal thermal performance become a challenging task. To effectively remove the dissipated heat from the package, extensive thermal analysis has been performed with finite element methods. Through these analyses, we are able to improve the thermal design and increase the total wattage of the package for maximum electrical performance. This paper provides details on the design-oriented thermal analysis and performance enhancement. It also addresses issues relating to contact thermal resistance between the diamond film and the metallic heat conduction paths.

Enhancement of Cognitive Functions by Aronia melanocarpa Elliot Through an Intermittent Ultrasonication Extraction Process.

PubMed

Kim, Nam Young; Lee, Hyeon Yong

2016-03-01

To increase the cognitive enhancement provided by Aronia melanocarpa Elliot (Aronia), Aronia was extracted using 70% ethanol solvent and six cycles of intermittent ultrasonication at 120 KHz for 50 min, followed by a rest for 10 min (UE), and was also extracted using 70% ethanol for 24 h at 80°C (EE) as a control process. In both in vivo water maze and passive avoidance tests, the UE showed better performance enhancement than the EE: in the water maze, mice treated with EE and UE showed escape latencies of 62.6 s and 54.3 s, respectively; for passive avoidance, they showed retention times of 45.9 s and 38.9 s, respectively. UE downregulated the expression level of acetylcholinesterase genes to 1.46 times compared with 1.72 for EE. However, there were no significant histological differences in the hippocampus between the mice fed with EE and those fed UE. Additionally, the UE was confirmed to have a greater antioxidant effect, 0.728 versus 0.561 for EE. Comparison of the high-performance liquid chromatography chromatograms of the extracts demonstrates that the intermittent ultrasonication process may improve the cognitive activities of Aronia by eluting higher amounts of cyanidin-3-galactoside (C3G). This work is the first to report that the crude extract from the intermittent ultrasonication process provided better cognitive enhancement than a single major bioactive substance, C3G itself, possibly through the synergistic effects of other anthocyanins present in the extract, such as delphine galactoside, cyanidin arabinoside, and cyanidin glucoside. We also believe that these findings may provide a reliable basis for developing natural plant drugs to compensate for the side effects of purified and/or chemically synthesized single-component drugs rather than to compete with them.

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

Simunovic, Srdjan; Piro, Markus H.A.

Thermochimica is a software library that determines a unique combination of phases and their compositions at thermochemical equilibrium. Thermochimica can be used for stand-alone calculations or it can be directly coupled to other codes. This release of the software does not have a graphical user interface (GUI) and it can be executed from the command line or from an Application Programming Interface (API). Also, it is not intended for thermodynamic model development or for constructing phase diagrams. The main purpose of the software is to be directly coupled with a multi-physics code to provide material properties and boundary conditions formore » various physical phenomena. Significant research efforts have been dedicated to enhance computational performance through advanced algorithm development, such as improved estimation techniques and non-linear solvers. Various useful parameters can be provided as output from Thermochimica, such as: determination of which phases are stable at equilibrium, the mass of solution species and phases at equilibrium, mole fractions of solution phase constituents, thermochemical activities (which are related to partial pressures for gaseous species), chemical potentials of solution species and phases, and integral Gibbs energy (referenced relative to standard state). The overall goal is to provide an open source computational tool to enhance the predictive capability of multi-physics codes without significantly impeding computational performance.« less

Social Skills Training and ADHD-What Works?

PubMed

Mikami, Amori Yee; Smit, Sophie; Khalis, Adri

2017-10-30

Many children and adolescents with attention-deficit/hyperactivity disorder (ADHD) have difficulties in their social skills and peer relationships. Because social problems exacerbate later maladjustment in ADHD populations, it is important to address this serious impairment. Although social skills training (SST) is a common intervention approach, evidence to date suggests that SST has limited efficacy, at least when provided in traditional, clinic-based settings. The current review summarizes recent advances to traditional SST approaches that may potentially enhance their efficacy. We identify two promising directions in which SST may be modified to make it more efficacious for ADHD populations. The first direction involves providing increased reinforcement and reminders of appropriate social behavior at the point of performance to youth with ADHD (e.g., in vivo, in real life peer situations as opposed to in the clinic). We note the importance of ensuring that youth with ADHD are receptive to such reminders. The second direction involves encouraging peers to be more socially accepting and inclusive of youth with ADHD. This avenue has been understudied in the literature to date. SST for children and adolescents with ADHD may be enhanced by providing more in vivo reminders and feedback at the point of performance and by making efforts to alter peers' impressions about youth with ADHD.

Data management system advanced development

NASA Technical Reports Server (NTRS)

Douglas, Katherine; Humphries, Terry

1990-01-01

The Data Management System (DMS) Advanced Development task provides for the development of concepts, new tools, DMS services, and for the testing of the Space Station DMS hardware and software. It also provides for the development of techniques capable of determining the effects of system changes/enhancements, additions of new technology, and/or hardware and software growth on system performance. This paper will address the built-in characteristics which will support network monitoring requirements in the design of the evolving DMS network implementation, functional and performance requirements for a real-time, multiprogramming, multiprocessor operating system, and the possible use of advanced development techniques such as expert systems and artificial intelligence tools in the DMS design.

Learning-performance distinction and memory processes for motor skills: a focused review and perspective.

PubMed

Kantak, Shailesh S; Winstein, Carolee J

2012-03-01

Behavioral research in cognitive psychology provides evidence for an important distinction between immediate performance that accompanies practice and long-term performance that reflects the relative permanence in the capability for the practiced skill (i.e. learning). This learning-performance distinction is strikingly evident when challenging practice conditions may impair practice performance, but enhance long-term retention of motor skills. A review of motor learning studies with a specific focus on comparing differences in performance between that at the end of practice and at delayed retention suggests that the delayed retention or transfer performance is a better indicator of motor learning than the performance at (or end of) practice. This provides objective evidence for the learning-performance distinction. This behavioral evidence coupled with an understanding of the motor memory processes of encoding, consolidation and retrieval may provide insight into the putative mechanism that implements the learning-performance distinction. Here, we propose a simplistic empirically-based framework--motor behavior-memory framework--that integrates the temporal evolution of motor memory processes with the time course of practice and delayed retention frequently used in behavioral motor learning paradigms. In the context of the proposed framework, recent research has used noninvasive brain stimulation to decipher the role of each motor memory process, and specific cortical brain regions engaged in motor performance and learning. Such findings provide beginning insights into the relationship between the time course of practice-induced performance changes and motor memory processes. This in turn has promising implications for future research and practical applications. Copyright © 2011 Elsevier B.V. All rights reserved.

System performance enhancement with pre-distorted OOFDM signal waveforms in DM/DD systems.

PubMed

Sánchez, C; Ortega, B; Capmany, J

2014-03-24

In this work we propose a pre-distortion technique for the mitigation of the nonlinear distortion present in directly modulated/detected OOFDM systems and explore the system performance achieved under varying system parameters. Simulation results show that the proposed pre-distortion technique efficiently mitigates the nonlinear distortion, achieving transmission information rates around 40 Gbits/s and 18.5 Gbits/s over 40 km and 100 km of single mode fiber links, respectively, under optimum operating conditions. Moreover, the proposed pre-distortion technique can potentially provide higher system performance to that obtained with nonlinear equalization at the receiver.

Dexterous programmable robot and control system

NASA Astrophysics Data System (ADS)

Engler, Charles D., Jr.

1995-09-01

An anatomically correct, humanlike, mechanical arm and hand is provided that an operator can control to perform with the dexterity and compliance of a human hand. Being humanlike and robotic enhances the device's control and gripper dexterity. Control of the movement of the arm and hand is performed or guided by a 'teach glove' worn by the operator. As he or she performs some hand manipulation, a controller stores signals from sensors on the exoskeleton. The sensors monitor the operator's finger-joint movement positions. These values are later translated into actuator control signals for servomotors, eventually duplicating the operator's movement.

MSFC Skylab Apollo Telescope Mount summary mission report

NASA Technical Reports Server (NTRS)

Morse, A. R.

1974-01-01

A summary of the Apollo Telescope Mount (ATM) performance during the 8.5-month Skylab mission is presented. A brief description of each ATM system, system performance summaries, discussion of all significant ATM anomalies which occurred during the Skylab mission, and, in an appendix, a summary of the Skylab ATM Calibration Rocket Project (CALROC) are provided. The text is supplemented and amplified by photographs, drawings, curves, and tables. The report shows that the ATM not only met, but exceeded premission performance criteria, and that participation of man in space for this scientific investigation greatly enhanced the quality and quantity of the data attained.

Improved Electrochemical Performance of LiFePO4@N-Doped Carbon Nanocomposites Using Polybenzoxazine as Nitrogen and Carbon Sources.

PubMed

Wang, Ping; Zhang, Geng; Li, Zhichen; Sheng, Wangjian; Zhang, Yichi; Gu, Jiangjiang; Zheng, Xinsheng; Cao, Feifei

2016-10-03

Polybenzoxazine is used as a novel carbon and nitrogen source for coating LiFePO 4 to obtain LiFePO 4 @nitrogen-doped carbon (LFP@NC) nanocomposites. The nitrogen-doped graphene-like carbon that is in situ coated on nanometer-sized LiFePO 4 particles can effectively enhance the electrical conductivity and provide fast Li + transport paths. When used as a cathode material for lithium-ion batteries, the LFP@NC nanocomposite (88.4 wt % of LiFePO 4 ) exhibits a favorable rate performance and stable cycling performance.

Telerobotics for Human Exploration: Enhancing Crew Capabilities in Deep Space

NASA Technical Reports Server (NTRS)

Fong, Terrence

2013-01-01

Future space missions in Earth orbit, to the Moon, and to other distant destinations offer many new opportunities for exploration. But, astronaut time will always be limited and some work will not be feasible or efficient for humans to perform manually. Telerobots, however, can complement human explorers, performing work under remote control from Earth, orbit or nearby habitats. A central challenge, therefore, is to understand how humans and remotely operated robots can be jointly employed to maximize mission performance and success. This presentation provides an overview of the key issues with using telerobots for human exploration.

Performance Evaluation of Cognitive Interference Channels Using a Spectrum Overlay Strategy

NASA Technical Reports Server (NTRS)

Knoblock, Eric J.

2018-01-01

The use of cognitive radios (CR) and cooperative communications techniques may assist in interference mitigation via sensing of the environment and dynamically altering communications parameters through the use of various mechanisms - one of which is the overlay technique. This report provides a performance analysis of an interference channel with a cognitive transceiver operating in an overlay configuration to evaluate the gains from using cognition. As shown in this report, a cognitive transceiver can simultaneously share spectrum while enhancing performance of non-cognitive nodes via knowledge of the communications channel as well as knowledge of neighboring users' modulation and coding schemes.

Pay-for-performance as a method to establish the business case for quality.

PubMed

Wheeler, John R C; White, Bert; Rauscher, Simone; Nahra, Tammie A; Reiter, Kristin L; Curtin, Kathleen M; Damberg, Cheryl L

2007-01-01

One of the major reasons providers give for not implementing promising quality-enhancing interventions (QEI) is that no "business case" for quality has been made. This article clarifies the concepts of the business case for quality and the related economic case for quality and identifies the perspectives of the various actors in health care financing, production, and consumption decisions. A methodology to evaluate the business case for quality from the perspective of payers and providers is presented. The article then uses implemented QEIs to show how a pay-for-performance (P4P) program can alter the business cases for payers and providers. Specifically, the P4P programs described in this article allow a provider to implement a QEI with the financial alignment of the payer in order to achieve financial and non-financial benefits. In some cases, providers and payers may be able to establish P4P programs providing net benefits for both parties.

Automated inspection of hot steel slabs

DOEpatents

Martin, R.J.

1985-12-24

The disclosure relates to a real time digital image enhancement system for performing the image enhancement segmentation processing required for a real time automated system for detecting and classifying surface imperfections in hot steel slabs. The system provides for simultaneous execution of edge detection processing and intensity threshold processing in parallel on the same image data produced by a sensor device such as a scanning camera. The results of each process are utilized to validate the results of the other process and a resulting image is generated that contains only corresponding segmentation that is produced by both processes. 5 figs.

Method and apparatus for enhancing reactor air-cooling system performance

DOEpatents

Hunsbedt, A.

1996-03-12

An enhanced decay heat removal system is disclosed for removing heat from the inert gas-filled gap space between the reactor vessel and the containment vessel of a liquid metal-cooled nuclear reactor. Multiple cooling ducts in flow communication with the inert gas-filled gap space are incorporated to provide multiple flow paths for the inert gas to circulate to heat exchangers which remove heat from the inert gas, thereby introducing natural convection flows in the inert gas. The inert gas in turn absorbs heat directly from the reactor vessel by natural convection heat transfer. 6 figs.

Metamaterials Application in Sensing

PubMed Central

Chen, Tao; Li, Suyan; Sun, Hui

2012-01-01

Metamaterials are artificial media structured on a size scale smaller than wavelength of external stimuli, and they can exhibit a strong localization and enhancement of fields, which may provide novel tools to significantly enhance the sensitivity and resolution of sensors, and open new degrees of freedom in sensing design aspect. This paper mainly presents the recent progress concerning metamaterials-based sensing, and detailedly reviews the principle, detecting process and sensitivity of three distinct types of sensors based on metamaterials, as well as their challenges and prospects. Moreover, the design guidelines for each sensor and its performance are compared and summarized. PMID:22736975

Enhancement of the static extinction ratio by using a dual-section distributed feedback laser integrated with an electro-absorption modulator

NASA Astrophysics Data System (ADS)

Cho, Chun-Hyung; Kim, Jongseong; Sung, Hyuk-Kee

2016-09-01

We report on the enhancement of the static extinction ratio by using a dual-section distributed feedback laser diode integrated with an electro-absorption modulator. A directly- modulated dual-section laser can provide improved modulation performance under a low bias level ( i.e., below the threshold level) compared with a standard directly-modulated laser. By combining the extinction ratio from a dual-section laser with that from an electro-absorption modulator section, a total extinction ratio of 49.6. dB are successfully achieved.

Automated inspection of hot steel slabs

DOEpatents

Martin, Ronald J.

1985-01-01

The disclosure relates to a real time digital image enhancement system for performing the image enhancement segmentation processing required for a real time automated system for detecting and classifying surface imperfections in hot steel slabs. The system provides for simultaneous execution of edge detection processing and intensity threshold processing in parallel on the same image data produced by a sensor device such as a scanning camera. The results of each process are utilized to validate the results of the other process and a resulting image is generated that contains only corresponding segmentation that is produced by both processes.

Safety and performance benefits of arginine supplements for military personnel: a systematic review.

PubMed

Brooks, James R; Oketch-Rabah, Hellen; Low Dog, Tieraona; Gorecki, Dennis K J; Barrett, Marilyn L; Cantilena, Louis; Chung, Mei; Costello, Rebecca B; Dwyer, Johanna; Hardy, Mary L; Jordan, Scott A; Maughan, Ronald J; Marles, Robin J; Osterberg, Robert E; Rodda, Bruce E; Wolfe, Robert R; Zuniga, Jorge M; Valerio, Luis G; Jones, Donnamaria; Deuster, Patricia; Giancaspro, Gabriel I; Sarma, Nandakumara D

2016-11-01

Dietary supplements are widely used by military personnel and civilians for promotion of health. The objective of this evidence-based review was to examine whether supplementation with l-arginine, in combination with caffeine and/or creatine, is safe and whether it enhances athletic performance or improves recovery from exhaustion for military personnel. Information from clinical trials and adverse event reports were collected from 17 databases and 5 adverse event report portals. Studies and reports were included if they evaluated the safety and the putative outcomes of enhanced performance or improved recovery from exhaustion associated with the intake of arginine alone or in combination with caffeine and/or creatine in healthy adults aged 19 to 50 years. Information related to population, intervention, comparator, and outcomes was abstracted. Of the 2687 articles screened, 62 articles meeting the inclusion criteria were analyzed. Strength of evidence was assessed in terms of risk of bias, consistency, directness, and precision. Most studies had few participants and suggested risk of bias that could negatively affect the results. l-Arginine supplementation provided little enhancement of athletic performance or improvements in recovery. Short-term supplementation with arginine may result in adverse gastrointestinal and cardiovascular effects. No information about the effects of arginine on the performance of military personnel was available. The available information does not support the use of l-arginine, either alone or in combination with caffeine, creatine, or both, to enhance athletic performance or improve recovery from exhaustion. Given the information gaps, an evidence-based review to assess the safety or effectiveness of multi-ingredient dietary supplements was not feasible, and therefore the development of a computational model-based approach to predict the safety of multi-ingredient dietary supplements is recommended. © The Author(s) 2016. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Combined Dynamic Time Warping with Multiple Sensors for 3D Gesture Recognition

PubMed Central

2017-01-01

Cyber-physical systems, which closely integrate physical systems and humans, can be applied to a wider range of applications through user movement analysis. In three-dimensional (3D) gesture recognition, multiple sensors are required to recognize various natural gestures. Several studies have been undertaken in the field of gesture recognition; however, gesture recognition was conducted based on data captured from various independent sensors, which rendered the capture and combination of real-time data complicated. In this study, a 3D gesture recognition method using combined information obtained from multiple sensors is proposed. The proposed method can robustly perform gesture recognition regardless of a user’s location and movement directions by providing viewpoint-weighted values and/or motion-weighted values. In the proposed method, the viewpoint-weighted dynamic time warping with multiple sensors has enhanced performance by preventing joint measurement errors and noise due to sensor measurement tolerance, which has resulted in the enhancement of recognition performance by comparing multiple joint sequences effectively. PMID:28817094

ISSN exercise & sport nutrition review: research & recommendations

PubMed Central

2010-01-01

Sports nutrition is a constantly evolving field with hundreds of research papers published annually. For this reason, keeping up to date with the literature is often difficult. This paper is a five year update of the sports nutrition review article published as the lead paper to launch the JISSN in 2004 and presents a well-referenced overview of the current state of the science related to how to optimize training and athletic performance through nutrition. More specifically, this paper provides an overview of: 1.) The definitional category of ergogenic aids and dietary supplements; 2.) How dietary supplements are legally regulated; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of the ergogenic value of nutrition and dietary supplementation in regards to weight gain, weight loss, and performance enhancement. Our hope is that ISSN members and individuals interested in sports nutrition find this review useful in their daily practice and consultation with their clients.

Combined Dynamic Time Warping with Multiple Sensors for 3D Gesture Recognition.

PubMed

Choi, Hyo-Rim; Kim, TaeYong

2017-08-17

Cyber-physical systems, which closely integrate physical systems and humans, can be applied to a wider range of applications through user movement analysis. In three-dimensional (3D) gesture recognition, multiple sensors are required to recognize various natural gestures. Several studies have been undertaken in the field of gesture recognition; however, gesture recognition was conducted based on data captured from various independent sensors, which rendered the capture and combination of real-time data complicated. In this study, a 3D gesture recognition method using combined information obtained from multiple sensors is proposed. The proposed method can robustly perform gesture recognition regardless of a user's location and movement directions by providing viewpoint-weighted values and/or motion-weighted values. In the proposed method, the viewpoint-weighted dynamic time warping with multiple sensors has enhanced performance by preventing joint measurement errors and noise due to sensor measurement tolerance, which has resulted in the enhancement of recognition performance by comparing multiple joint sequences effectively.

Novel reverse osmosis membranes composed of modified PVA/Gum Arabic conjugates: Biofouling mitigation and chlorine resistance enhancement.

PubMed

Falath, Wail; Sabir, Aneela; Jacob, Karl I

2017-01-02

A novel crosslinked Poly (vinyl alcohol) (PVA) reverse osmosis (RO) thin film membrane conjugated with Gum Arabic (GA) with superb performance and features was synthesized for water desalination. RO membrane desalination parameters, such as hydrophilicity, surface roughness, water permeability, salt rejection, Chlorine resistance and biofouling resistance were evaluated using a dead end RO filtration unit. The incorporation of Pluronic F127 and the conjugation of Gum Arabic improved the overall RO performance of the membranes. This study has shown that the membrane PVA-GA-5 that contains 0.9wt% Gum Arabic provided excellent permeation, salt rejection, Chlorine and biofouling resistance and mechanical strength. The most remarkable result to arise from this research is that the overall RO performance enhancement has been achieved while utilizing PVA/Gum Arabic as a separation layer without the use of a substrate, which eliminates negative effects associated with the use of a substrate like internal concentration polarization. Copyright © 2016 Elsevier Ltd. All rights reserved.

Alternating InGaN barriers with GaN barriers for enhancing optical performance in InGaN light-emitting diodes

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

Yang, Yujue; Zeng, Yiping, E-mail: ypzeng@semi.ac.cn

2015-01-21

InGaN-based light-emitting diodes (LEDs) with some specific designs on the quantum barrier layers by alternating InGaN barriers with GaN barriers are proposed and studied numerically. In the proposed structure, simulation results show that the carriers are widely dispersed in the multi-quantum well active region, and the radiative recombination rate is efficiently improved and the electron leakage is suppressed accordingly, due to the appropriate band engineering. The internal quantum efficiency and light-output power are thus markedly enhanced and the efficiency droop is smaller, compared to the original structures with GaN barriers or InGaN barriers. Moreover, the gradually decrease of indium compositionmore » in the alternating quantum barriers can further promote the LED performance because of the more uniform carrier distribution, which provides us a simple but highly effective approach for high-performance LED applications.« less

Development of new two-dimensional spectral/spatial code based on dynamic cyclic shift code for OCDMA system

NASA Astrophysics Data System (ADS)

Jellali, Nabiha; Najjar, Monia; Ferchichi, Moez; Rezig, Houria

2017-07-01

In this paper, a new two-dimensional spectral/spatial codes family, named two dimensional dynamic cyclic shift codes (2D-DCS) is introduced. The 2D-DCS codes are derived from the dynamic cyclic shift code for the spectral and spatial coding. The proposed system can fully eliminate the multiple access interference (MAI) by using the MAI cancellation property. The effect of shot noise, phase-induced intensity noise and thermal noise are used to analyze the code performance. In comparison with existing two dimensional (2D) codes, such as 2D perfect difference (2D-PD), 2D Extended Enhanced Double Weight (2D-Extended-EDW) and 2D hybrid (2D-FCC/MDW) codes, the numerical results show that our proposed codes have the best performance. By keeping the same code length and increasing the spatial code, the performance of our 2D-DCS system is enhanced: it provides higher data rates while using lower transmitted power and a smaller spectral width.