Methods for Estimating Environmental Effects and Constraints on NexGen: High Density Case Study

NASA Technical Reports Server (NTRS)

Augustine, S.; Ermatinger, C.; Graham, M.; Thompson, T.

2010-01-01

This document provides a summary of the current methods developed by Metron Aviation for the estimate of environmental effects and constraints on the Next Generation Air Transportation System (NextGen). This body of work incorporates many of the key elements necessary to achieve such an estimate. Each section contains the background and motivation for the technical elements of the work, a description of the methods used, and possible next steps. The current methods described in this document were selected in an attempt to provide a good balance between accuracy and fairly rapid turn around times to best advance Joint Planning and Development Office (JPDO) System Modeling and Analysis Division (SMAD) objectives while also supporting the needs of the JPDO Environmental Working Group (EWG). In particular this document describes methods applied to support the High Density (HD) Case Study performed during the spring of 2008. A reference day (in 2006) is modeled to describe current system capabilities while the future demand is applied to multiple alternatives to analyze system performance. The major variables in the alternatives are operational/procedural capabilities for airport, terminal, and en route airspace along with projected improvements to airframe, engine and navigational equipment.

The Development of the Concept of Work: A Case where History Can Inform Pedagogy

NASA Astrophysics Data System (ADS)

de Berg, Kevin C.

An historical analysis of the work concept with particular emphasis given to the contributions of John Smeaton and Daniel Bernouilli is provided with a view to enlightening or resolving current difficulties experienced in the teaching and learning of the concept of work and its relationship to kinetic and potential energies. An approach which emphasises the work done by both applied and resisting forces and which gives some technological significance to the (force x distance) definition of work is recommended.

Piezo-Electrochemical Energy Harvesting with Lithium-Intercalating Carbon Fibers.

PubMed

Jacques, Eric; Lindbergh, Göran; Zenkert, Dan; Leijonmarck, Simon; Kjell, Maria Hellqvist

2015-07-01

The mechanical and electrochemical properties are coupled through a piezo-electrochemical effect in Li-intercalated carbon fibers. It is demonstrated that this piezo-electrochemical effect makes it possible to harvest electrical energy from mechanical work. Continuous polyacrylonitrile-based carbon fibers that can work both as electrodes for Li-ion batteries and structural reinforcement for composites materials are used in this study. Applying a tensile force to carbon fiber bundles used as Li-intercalating electrodes results in a response of the electrode potential of a few millivolts which allows, at low current densities, lithiation at higher electrode potential than delithiation. More electrical energy is thereby released from the cell at discharge than provided at charge, harvesting energy from the mechanical work of the applied force. The measured harvested specific electrical power is in the order of 1 μW/g for current densities in the order of 1 mA/g, but this has a potential of being increased significantly.

Is current clinical practice modified about intraoperative breast irradiation?

PubMed

Massa, Michela; Franchelli, Simonetta; Panizza, Renzo; Massa, Tiberio

2016-04-01

After the results obtained in the two randomized clinical trial, the ELIOT trial and the TARGIT-A trial, a heated debate is going on concerning the question of applying intraoperative radiotherapy (IORT) instead of postoperative whole breast irradiation (WBI) after breast conservative treatment. Currently, many centers are applying the IORT following the strict selection criteria dictated by the working groups American Society for Radiation Oncology (ASTRO) and Groupe Européen de Curiethérapie-European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) and monitoring the oncological outcome together with radiation toxicity on breast tissue. The clinical experience of the Geneva University Hospital regarding the use of the Intrabeam system is evaluated and compared with current evidences.

Anode power deposition in applied-field MPD thrusters

NASA Technical Reports Server (NTRS)

Myers, Roger M.; Soulas, George C.

1992-01-01

Anode power deposition is the principle performance limiter of magnetoplasmadynamic (MPD) thrusters. Current thrusters lose between 50 and 70 percent of the input power to the anode. In this work, anode power deposition was studied for three cylindrical applied magnetic field thrusters for a range of argon propellant flow rates, discharge currents, and applied-field strengths. Between 60 and 95 percent of the anode power deposition resulted from electron current conduction into the anode, with cathode radiation depositing between 5 and 35 percent of the anode power, and convective heat transfer from the hot plasma accounting for less than 5 percent. While the fractional anode power loss decreased with increasing applied-field strength and anode size, the magnitude of the anode power increased. The rise in anode power resulted from a linear rise in the anode fall voltage with applied-field strength and anode radius. The anode fall voltage also rose with decreasing propellant flow rate. The trends indicate that the anode fall region is magnetized, and suggest techniques for reducing the anode power loss in MPD thrusters.

APPLYING DATA MINING APPROACHES TO FURTHER UNDERSTANDING CHEMICAL EFFECTS ON BIOLOGICAL SYSTEMS.

EPA Science Inventory

Correlations of bioassays and toxicity cannot be assessed at the compound level with the current toxicity database. Further work is planned for gaining molecular level knoweldge from these experiments.

Adipose-Derived Stem Cells in Functional Bone Tissue Engineering: Lessons from Bone Mechanobiology

PubMed Central

Bodle, Josephine C.; Hanson, Ariel D.

2011-01-01

This review aims to highlight the current and significant work in the use of adipose-derived stem cells (ASC) in functional bone tissue engineering framed through the bone mechanobiology perspective. Over a century of work on the principles of bone mechanosensitivity is now being applied to our understanding of bone development. We are just beginning to harness that potential using stem cells in bone tissue engineering. ASC are the primary focus of this review due to their abundance and relative ease of accessibility for autologous procedures. This article outlines the current knowledge base in bone mechanobiology to investigate how the knowledge from this area has been applied to the various stem cell-based approaches to engineering bone tissue constructs. Specific emphasis is placed on the use of human ASC for this application. PMID:21338267

Student Relevance Matters: Why Do I Have to Know This Stuff?

ERIC Educational Resources Information Center

Kolis, Mickey

2011-01-01

Classrooms are systems, schools are systems, and schooling in the United States is a big system. Changing any of those systems requires an awareness of how they work; what they produce; and where to apply time, energy, and resources. Current systems could be much better in meeting students' current and future needs. "Student Relevance Matters: Why…

Object-oriented feature-tracking algorithms for SAR images of the marginal ice zone

NASA Technical Reports Server (NTRS)

Daida, Jason; Samadani, Ramin; Vesecky, John F.

1990-01-01

An unsupervised method that chooses and applies the most appropriate tracking algorithm from among different sea-ice tracking algorithms is reported. In contrast to current unsupervised methods, this method chooses and applies an algorithm by partially examining a sequential image pair to draw inferences about what was examined. Based on these inferences the reported method subsequently chooses which algorithm to apply to specific areas of the image pair where that algorithm should work best.

77 FR 61028 - Amended Certification Regarding Eligibility To Apply for Worker Adjustment Assistance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-05

... TA-W-81,726C Leased Workers from AFEEA, All-Star, and Elwood, Working On-Site at Cinram Distribution... certification. New information revealed that the subject firm is currently doing business as Cinram Group Inc...-81,726B), and leased workers from AFEEA, All- Star, and Elwood, working on-site at Cinram...

Natural Crack Sizing Based on Eddy Current Image and Electromagnetic Field Analyses

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

Endo, H.; Uchimoto, T.; Takagi, T.

2006-03-06

An eddy current testing (ECT) system with multi-coil type probes is applied to size up cracks fabricated on austenite stainless plates. We have developed muti-channel ECT system to produce data as digital images. The probes consist of transmit-receive type sensors as elements to classify crack directions, working as two scan direction modes simultaneously. Template matching applied to the ECT images determines regions of interest in sizing up cracks. Finite element based inversion sizes up the crack depth from the measured ECT signal. The present paper demonstrates this approach for fatigue crack and stress corrosion cracking.

Employment status, working conditions and depressive symptoms among German employees born in 1959 and 1965.

PubMed

Burr, Hermann; Rauch, Angela; Rose, Uwe; Tisch, Anita; Tophoven, Silke

2015-08-01

We investigated whether (1) current employment status (regular full-time, regular part-time and marginal employment) is associated with depressive symptoms and (2) whether these associations are mediated by current working conditions and previous employment history. Two cohorts of German employees aged 46 and 52 years were selected from administrative data of the German Federal Employment Agency and answered questions about depressive symptoms (we use an applied version of BDI-V) and their current working conditions. In addition, the participants gave written consent to link register data regarding their employment histories (n = 4,207). Multiple linear regression analyses were conducted. Men experienced elevated depressive symptoms when working regular part-time; women experienced such symptoms when engaged in marginal employment. These associations decreased when we adjusted for job insecurity and rose slightly when we adjusted for leadership quality. Men and women who reported a low level of influence at work showed a higher risk of depressive symptoms. For women, the association between current employment position and depressive symptoms could be partly explained by low levels of influence at work. For men, the association between depressive symptoms and current regular part-time employment decreased when we adjusted for previous part-time employment. Conversely, for women, the association with depressive symptoms increased in current regular part-time and marginal employment when we adjusted for employment history. In both genders, the observed associations between depressive symptoms and current employment status were mediated by both current psychosocial conditions and employment history. Employees not having a regular full-time job differed from full-time employees with respect to both their current working conditions and their employment history.

Generation of a pulsed low-energy electron beam using the channel spark device

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

Elgarhy, M. A. I., E-mail: elgarhy@azhar.edu.eg; Hassaballa, S. E.; Rashed, U. M.

2015-12-15

For the generation of low-energy electron beam, the design and characteristics of channel spark discharge (CSD) operating at a low voltage are presented in this paper. The discharge voltage, discharge current, X-ray emissions, and electron beam current were experimentally determined. The effects of the applied voltage, working gas pressure, and external capacitance on the CSD and beam parameters were measured. At an applied voltage of 11 kV, an oxygen gas pressure of 25 mTorr, and an external capacitance of 16.45 nF, the maximum measured current was 900 A. The discharge current increased with the increase in the pressure and capacitance,more » while its periodic time decreased with the increase in the pressure. Two types of the discharge were identified and recorded: the hollow cathode discharge and the conduction discharge. A Faraday cup was used to measure the beam current. The maximum measured beam current was 120 A, and the beam signal exhibited two peaks. The increase in both the external capacitance and the applied discharge voltage increased the maximum electron beam current. The electron-beam pulse time decreased with the increase in the gas pressure at a constant voltage and increased with the decrease in the applied discharge voltage. At an applied voltage of 11 kV and an oxygen gas pressure of 15 mTorr, the maximum beam energy was 2.8 keV. The X-ray signal intensity decreased with the increase in the gas pressure and increased with the increase in the capacitance.« less

Current Approaches to the Assessment of Graphic Design in a Higher Education Context

ERIC Educational Resources Information Center

Giloi, Susan; du Toit, Pieter

2013-01-01

This article provides an overview of the current trends in assessment practice within the field of graphic design. The demands placed on educators to apply sound assessment practice for Higher Education subjects is as intense in the field of graphic design as in any other. Forcing the assessment of creative visual work into existing assessment…

Selection, Placement and Instatement of School Managers in Turkey: Evaluation of the Current Situation

ERIC Educational Resources Information Center

Memisoglu, Salih Pasa

2015-01-01

The aim of this study is to evaluate the new regulations and current practices in terms of how they apply--to the selection, training and instatement of school administrators in Turkey. The successful implementation of Turkish National Development Plans is closely related to the knowledge and skills of managers working at various levels in every…

Effectiveness of diadynamic currents and transcutaneous electrical nerve stimulation in disc disease lumbar part of spine.

PubMed

Ratajczak, Barbara; Hawrylak, Arletta; Demidaś, Aneta; Kuciel-Lewandowska, Jadwiga; Boerner, Ewa

2011-01-01

Back pain has multi-factorial etiology and is modified by environmental influences, character of work, and individual predispositions. The aim of this study was to compare the efficiency of analgesic DD current therapy and TENS in low back discopathy. Eighty patients (age, 45-60 years) with diagnosed low back pain syndrome due to discopathy were subjected to therapy. In the first group (DD) of 40 people, DD current therapy was applied. In the second group (TENS) of 40 people, TENS was applied. The third group of 40 people was a control group in which a functional fitness test was performed for comparison purposes. The control group was in this case an equivalent to a norm. Before the beginning and on the completion of therapy in all patients, a pain level measurement and functional fitness test were performed. On the basis of research conducted it was stated that both therapies reduce pain level effectively. Obtained analyzed results conclude that both therapies applied have an analgesic effect. DD current and TENS therapies in low back discopathy have an analgesic impact and improve functional fitness. The applied therapies have a comparable impact on researched parameters.

Evaluating the Impact of a Performance-Based Methodology on Transfer of Training

ERIC Educational Resources Information Center

Kazbour, Richard R.; McGee, Heather M.; Mooney, Timothy; Masica, Laura; Brinkerhoff, Robert O.

2013-01-01

Transfer of training is the degree to which trainees can apply the knowledge, skills, and attitudes gained in training to the job. Currently only between 5% and 20% of what is learned in training is ever applied on the job. At this time, little is known about the effects of work environment factors, such as support, feedback, and goal setting, on…

School-Based Initial Vocational Education in the Republic of Ireland: The Parity of Esteem and Fitness for Purpose of the Leaving Certificate Applied

ERIC Educational Resources Information Center

Gleeson, Jim; O'Flaherty, Joanne

2013-01-01

The Irish Leaving Certificate Applied (LCA) is a school-based, pre-vocational alternative to the "high stakes" established Leaving Certificate. Its origins lie in European Union funded "school to work" initiatives and it is currently taken to completion by some 5% of Irish senior cycle students. Since it was designed 20 years…

Gaussian white noise as a resource for work extraction.

PubMed

Dechant, Andreas; Baule, Adrian; Sasa, Shin-Ichi

2017-03-01

We show that uncorrelated Gaussian noise can drive a system out of equilibrium and can serve as a resource from which work can be extracted. We consider an overdamped particle in a periodic potential with an internal degree of freedom and a state-dependent friction, coupled to an equilibrium bath. Applying additional Gaussian white noise drives the system into a nonequilibrium steady state and causes a finite current if the potential is spatially asymmetric. The model thus operates as a Brownian ratchet, whose current we calculate explicitly in three complementary limits. Since the particle current is driven solely by additive Gaussian white noise, this shows that the latter can potentially perform work against an external load. By comparing the extracted power to the energy injection due to the noise, we discuss the efficiency of such a ratchet.

Handling Ibuprofen Increases Pain Tolerance and Decreases Perceived Pain Intensity in a Cold Pressor Test

PubMed Central

Rutchick, Abraham M.; Slepian, Michael L.

2013-01-01

Pain contributes to health care costs, missed work and school, and lower quality of life. Extant research on psychological interventions for pain has focused primarily on developing skills that individuals can apply to manage their pain. Rather than examining internal factors that influence pain tolerance (e.g., pain management skills), the current work examines factors external to an individual that can increase pain tolerance. Specifically, the current study examined the nonconscious influence of exposure to meaningful objects on the perception of pain. Participants (N = 54) completed a cold pressor test, examined either ibuprofen or a control object, then completed another cold pressor test. In the second test, participants who previously examined ibuprofen reported experiencing less intense pain and tolerated immersion longer (relative to baseline) than those who examined the control object. Theoretical and applied implications of these findings are discussed. PMID:23469170

Anarchist Epistemologies and the Separation of Science and State: The Critique and Relevance of Paul Feyerabend to Educational Foundations

ERIC Educational Resources Information Center

Wolfmeyer, Mark

2017-01-01

This article synthesizes Paul Feyerabend's controversial contributions to 20th-century philosophy of science through the synthesis of his works and the secondary literature, with specific foci on current trends in educational foundations and the potentials and pitfalls for applying Feyerabendian logics to our work. First, I situate his strains of…

Measuring Turbulence Mixing in Indonesian Seas Using Microstructure EM-APEX Floats

DTIC Science & Technology

We developed scientific plans for collaborative observational programs with Indonesian,Taiwanese, and Japanese researchers. We worked with Taiwanese...and Japanese researchers to plan and execute turbulence experiments using autonomous platforms in the SCS and Kuroshio Current. Our primary platform...and the Applied Physics Laboratory, University of Washington. We are working closely with Japanese collaborators to develop a turbulence observation

Exact simulation of integrate-and-fire models with exponential currents.

PubMed

Brette, Romain

2007-10-01

Neural networks can be simulated exactly using event-driven strategies, in which the algorithm advances directly from one spike to the next spike. It applies to neuron models for which we have (1) an explicit expression for the evolution of the state variables between spikes and (2) an explicit test on the state variables that predicts whether and when a spike will be emitted. In a previous work, we proposed a method that allows exact simulation of an integrate-and-fire model with exponential conductances, with the constraint of a single synaptic time constant. In this note, we propose a method, based on polynomial root finding, that applies to integrate-and-fire models with exponential currents, with possibly many different synaptic time constants. Models can include biexponential synaptic currents and spike-triggered adaptation currents.

Operational Analysis in the Launch Environment

NASA Technical Reports Server (NTRS)

James, George; Kaouk, Mo; Cao, Tim; Fogt, Vince; Rocha, Rodney; Schultz, Ken; Tucker, Jon-Michael; Rayos, Eli; Bell,Jeff; Alldredge, David;

Preliminary results on time-resolved ion beam induced luminescence applied to the provenance study of lapis lazuli

NASA Astrophysics Data System (ADS)

Czelusniak, C.; Palla, L.; Massi, M.; Carraresi, L.; Giuntini, L.; Re, A.; Lo Giudice, A.; Pratesi, G.; Mazzinghi, A.; Ruberto, C.; Castelli, L.; Fedi, M. E.; Liccioli, L.; Gueli, A.; Mandò, P. A.; Taccetti, F.

2016-03-01

This work will present preliminary results concerning the use of time-resolved ion beam induced luminescence applied to provenance studies of lapis lazuli. Measurements were performed at the pulsed beam facility at LABEC laboratory in Florence. Lapis lazuli is a semi-precious gemstone, used as ornament since the early civilizations that can be found in few places on Earth. The importance of this work lies in understanding the origin of various samples of lapis lazuli, from which it may be possible to gain insight into trade routes from ancient times. The samples studied in this work originated from Chile, Afghanistan, Tajikistan, Myanmar, and Siberia. The stones were irradiated with 3 MeV protons and the resulting luminescence was detected by a photomultiplier tube, whose output was acquired using a sampling digitizer VME module (CAEN/V1720). Wavelength discrimination was performed at 430 nm utilizing a range of beam currents. The results showed that, by changing the beam current intensity, one can study different features of lapis lazuli, and this may aid in distinguishing lapis lazuli from different provenances.

"As You Sow so Shall You Reap"--but What to Sow? The Common European Framework of Reference for Languages (CEFR) Applied to a Flemish Business Context

ERIC Educational Resources Information Center

Marchand, Marjan; Vercruysse, Christophe; De Wilde, Lodewijk

2013-01-01

This research project explores the relationship between the French skills taught during the Dutch-speaking professional Bachelor's of Applied Business, the perceived French language requirements for these Bachelor's graduates in the workplace, and the actual French language needs on the work floor. We review the current situation and consider how…

Electrochemical disinfection using boron-doped diamond electrode--the synergetic effects of in situ ozone and free chlorine generation.

PubMed

Rajab, Mohamad; Heim, Carolin; Letzel, Thomas; Drewes, Jörg E; Helmreich, Brigitte

2015-02-01

This work investigated the capability of using a boron-doped diamond (BDD) electrode for bacterial disinfection in different water matrices containing varying amounts of chloride. The feed water containing Pseudomonas aeruginosa was electrochemically treated while applying different electrode conditions. Depending on the applied current density and the exposure time, inactivation between 4- and 8-log of the targeted microorganisms could be achieved. The disinfection efficiency was driven by the generation of free chlorine as a function of chloride concentration in the water. A synergetic effect of generating both free chlorine and ozone in situ during the disinfection process resulted in an effective bactericidal impact. The formation of the undesired by-products chlorate and perchlorate depended on the water matrix, the applied current density and the desired target disinfection level. In case of synthetic water with a low chloride concentration (20 mg L(-1)) and an applied current density of 167 mA cm(-2), a 6-log inactivation of Pseudomonas aeruginosa could be achieved after 5 min of exposure. The overall energy consumption ranged between 0.3 and 0.6 kW h m(-3) depending on the applied current density and water chemistry. Electrochemical water disinfection represents a suitable and efficient process for producing pathogen-free water without the use of any chemicals. Copyright © 2014 Elsevier Ltd. All rights reserved.

Unpaid work in health economic evaluations.

PubMed

Krol, Marieke; Brouwer, Werner

2015-11-01

Given its societal importance, unpaid work should be included in economic evaluations of health care technology aiming to take a societal perspective. However, in practice this does not often appear to be the case. This paper provides an overview of the current place of unpaid work in economic evaluations in theory and in practice. It does so first by summarizing recommendations regarding the inclusion of unpaid labor reported in health economic textbooks and national guidelines for economic evaluations. In total, three prominent health economic text-books were studied and 28 national health economic guidelines. The paper, moreover, provides an overview of the instruments available to measure lost unpaid labor and reports on a review of the place of unpaid labor in applied economic evaluations in the area of rheumatoid arthritis. The review was conducted by examining methodology of evaluations published between 1 March 2008 and 1 March 2013. The results of this study show that little guidance is offered regarding the inclusion of unpaid labor in economic evaluations in textbooks and guidelines. The review identified five productivity costs instruments including questions about unpaid work and 33 economic evaluations of treatments for rheumatoid arthritis of which only one included unpaid work. The results indicate that unpaid work is rarely included in applied economic evaluations of treatments for rheumatoid arthritis, despite this disease expecting to be associated with lost unpaid work. Given the strong effects of certain diseases and treatments on the ability to perform unpaid work, unpaid work currently receives less attention in economic evaluations than it deserves. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthesis of FeCoNi nanoparticles by galvanostatic technique

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

Budi, Setia, E-mail: setiabudi@unj.ac.id; Department of Chemistry, Faculty of Mathematics and Sciences, Universitas Negeri Jakarta, Jl. Pemuda No.10, Rawamangun, Jakarta 13220; Hafizah, Masayu Elita

Soft magnetic nanoparticles of FeCoNi have been becoming interesting objects for many researchers due to its potential application in electronic devices. One of the most promising methods for material preparation is the electrodeposition which capable of growing nanoparticles alloy directly onto the substrate. In this paper, we report our electrodeposition studies on nanoparticles synthesis using galvanostatic electrodeposition technique. Chemical composition of the synthesized FeCoNi was successfully controlled through the adjustment of the applied currents. It is revealed that the content of each element, obtained from quantitative analysis using atomic absorption spectrometer (AAS), could be modified by the adjustment of currentmore » in which Fe and Co content decreased at larger applied currents, while Ni content increased. The nanoparticles of Co-rich FeCoNi and Ni-rich FeCoNi were obtained from sulphate electrolyte at the range of applied current investigated in this work. Broad diffracted peaks in the X-ray diffractograms indicated typical nanostructures of the solid solution of FeCoNi.« less

Electro-dewatering of wastewater sludge: An investigation of the relationship between filtrate flow rate and electric current.

PubMed

Olivier, Jérémy; Conrardy, Jean-Baptiste; Mahmoud, Akrama; Vaxelaire, Jean

2015-10-01

Compared to conventional dewatering techniques, electrical assisted mechanical dewatering, also called electro-dewatering (EDW) is an alternative and an effective technology for the dewatering of sewage sludge with low energy consumption. The objectives of this study were to evaluate the dewatering performance and to determine the influence of the process parameters (e.g. applied electric current, applied voltage, and the initial amount of dry solids) on the kinetics of EDW-process for activated urban sludge. Also significant efforts have been devoted herein to provide comprehensive information about the EDW mechanisms and to understand the relationship between these operating conditions with regards to develop a qualitative and quantitative understanding model of the electro-dewatering process and then produce a robust design methodology. The results showed a very strong correlation between the applied electric current and the filtrate flow rate and consequently the electro-dewatering kinetics. A higher applied electric current leads to faster EDW kinetics and a higher final dry solids content. In contrast, the results of this work showed a significant enhancement of the dewatering kinetics by decreasing the mass of the dry solids introduced into the cell (commonly known as the sludge loading). Copyright © 2015 Elsevier Ltd. All rights reserved.

Renormalization of Einstein gravity through a derivative-dependent field redefinition

NASA Astrophysics Data System (ADS)

Slovick, Brian

2018-01-01

This work explores an alternative solution to the problem of renormalizability in Einstein gravity. In the proposed approach, Einstein gravity is transformed into the renormalizable theory of four-derivative gravity by applying a local field redefinition containing an infinite number of higher derivatives. It is also shown that the current-current amplitude is invariant with the field redefinition, and thus the unitarity of Einstein gravity is preserved.

Tribological and Electrical Properties of Diamond-Like Carbon Films Deposited by Filtered Vacuum Arc Method for Medical Guidewire Application.

PubMed

Kang, Ki-Noh; Jeong, Hyejeong; Lee, Jaehyeong; Park, Yong Seob

2018-09-01

A good medical guidewires are used to introduce stents, catheters, and other medical devices inside the human body. In this study, diamond-like carbon (DLC) film was proposed to solve the poor adhesion problem of guidewire and to improve the tribological performance of guidewire. DLC films were fabricated on Si substrate by using FVA (Filtered Vacuum Arc) method. In this work, the tribological, structural, and electrical properties of the fabricated DLC films with various arc currents were experimentally investigated. All DLC films showed smooth and uniform surface with increasing applied arc current. The rms surface roughness was increased and the value of contact angle on the film surface was decreased with increasing arc current. The hardness and elastic modulus of DLC films were improved, and the resistivity value of DLC films were decreased with increasing arc current. These results are associated with ion bombardment effects by the applied arc current and bias voltage.

Scanning-SQUID investigation of spin-orbit torque acting on yttrium iron garnet devices

NASA Astrophysics Data System (ADS)

Rosenberg, Aaron J.; Jermain, Colin L.; Aradhya, Sriharsha V.; Brangham, Jack T.; Nowack, Katja C.; Kirtley, John R.; Yang, Fengyuan; Ralph, Daniel C.; Moler, Kathryn A.

Successful manipulation of electrically insulating magnets, such as yttrium iron garnet, by by current-driven spin-orbit torques could provide a highly efficient platform for spintronic memory. Compared to devices fabricated using magnetic metals, magnetic insulators have the advantage of the ultra-low magnetic damping and the elimination of shunting currents in the magnet that reduce the torque efficiency. Here, we apply current in the spin Hall metal β-Ta to manipulate the magnetic orientation of micron-sized, electrically-insulating yttrium iron garnet devices. We do not observe spin-torque switching even for applied currents well above the critical current expected in a macrospin switching model. This suggests either inefficient transfer of spin torque at our Ta/YIG interface or a breakdown of the macrospin approximation. This work is supported by FAME, one of six centers of STARnet sponsored by MARCO and DARPA. The SQUID microscope and sensors were developed with support from the NSF-sponsored Center NSF-NSEC 0830228, and from NSF IMR-MIP 0957616.

Extracting current induced spins from topological insulator wires: gate control of extracted spin polarization

NASA Astrophysics Data System (ADS)

Adagideli, Inanc

Spin-momentum locking featured by the surface states of 3D topological insulators (TIs) allows electrical generation of spin accumulations and provides a new avenue for spintronics applications. In this work, we explore how to extract electrically induced spins from topological insulator surfaces, where they are generated into topologically trivial metallic leads that are commonly used in conventional electronic devices. We first focus on an effective surface theory of current induced spin accumulation in topological insulators. Then we focus on a particular geometry: a metallic pocket attached to top and side faces of a 3D topological insulator quantum wire with a rectangular cross section, and explore spin extraction into topologically non-trivial materials. We find surprisingly that the doping in and/or a gate voltage applied to the metallic side pocket can control the direction of the extracted spin polarization opening the possibility for a spin transistor operation of these device geometries. We also perform numerical simulations of nonequilibrium spin accumulations generated by an applied bias in the same geometry and demonstrate the spin polarization control via applied gate voltages. Work funded by TUBITAK Grant No 114F163.

A Meta-Analysis of Self-Regulated Learning in Work-Related Training and Educational Attainment: What We Know and Where We Need to Go

ERIC Educational Resources Information Center

Sitzmann, Traci; Ely, Katherine

2011-01-01

Researchers have been applying their knowledge of goal-oriented behavior to the self-regulated learning domain for more than 30 years. This review examines the current state of research on self-regulated learning and gaps in the field's understanding of how adults regulate their learning of work-related knowledge and skills. Self-regulation theory…

The effect of work on people with severe mental illness in Taiwan using a stress-social support model: an exploratory study.

PubMed

Wu, Hui-Ching

2006-06-01

Satisfaction with quality of life is one aspect of a positive and successful life, and this remains true in the rehabilitation of people with severe mental illness. This study explores the meaning and impact of work on people with severe mental illness in Taiwan and, specifically, the value of encouraging people with severe mental illness to work to enhance their quality of life. We apply stress-social support theory (a Western model) to examine daily life and work stressors in an Eastern cultural environment (Taiwan). We use multiple regression models to analyze predictive factors for their effect on life quality. There are five categories: socio-demographic characteristics, mental illness history, current work status variables (as controls), stress variable and social support variable. Unlike Western studies, current work status, in itself, did not lead to better satisfaction with quality of life, but the stress-social support model did. The implications for rehabilitation success are discussed.

Anticipatory Understanding of Adversary Intent: A Signature-Based Knowledge System

DTIC Science & Technology

2009-06-01

concept of logical positivism has been applied more recently to all human knowledge and reflected in current data fusion research, information mining...this work has been successfully translated into useful analytical tools that can provide a rigorous and quantitative basis for predictive analysis

78 FR 55088 - DHS Data Privacy and Integrity Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-09

... education, training, and experience in the fields of data protection, privacy, and/or emerging technologies... Federal regulations. Committee History and Activities: All individuals interested in applying for Committee membership should review the history of the Committee's work. The Committee's charter and current...

Using Model-Based Reasoning for Autonomous Instrument Operation - Lessons Learned From IMAGE/LENA

NASA Technical Reports Server (NTRS)

Johnson, Michael A.; Rilee, Michael L.; Truszkowski, Walt; Bailin, Sidney C.

2001-01-01

Model-based reasoning has been applied as an autonomous control strategy on the Low Energy Neutral Atom (LENA) instrument currently flying on board the Imager for Magnetosphere-to-Aurora Global Exploration (IMAGE) spacecraft. Explicit models of instrument subsystem responses have been constructed and are used to dynamically adapt the instrument to the spacecraft's environment. These functions are cast as part of a Virtual Principal Investigator (VPI) that autonomously monitors and controls the instrument. In the VPI's current implementation, LENA's command uplink volume has been decreased significantly from its previous volume; typically, no uplinks are required for operations. This work demonstrates that a model-based approach can be used to enhance science instrument effectiveness. The components of LENA are common in space science instrumentation, and lessons learned by modeling this system may be applied to other instruments. Future work involves the extension of these methods to cover more aspects of LENA operation and the generalization to other space science instrumentation.

Measurement and Characterization of Concentrator Solar Cells II

NASA Technical Reports Server (NTRS)

Scheiman, Dave; Sater, Bernard L.; Chubb, Donald; Jenkins, Phillip; Snyder, Dave

2005-01-01

Concentrator solar cells are continuing to get more consideration for use in power systems. This interest is because concentrator systems can have a net lower cost per watt in solar cell materials plus ongoing improvements in sun-tracking technology. Quantitatively measuring the efficiency of solar cells under concentration is difficult. Traditionally, the light concentration on solar cells has been determined by using a ratio of the measured solar cell s short circuit current to that at one sun, this assumes that current changes proportionally with light intensity. This works well with low to moderate (<20 suns) concentration levels on "well-behaved" linear cells but does not apply when cells respond superlinearly, current increases faster than intensity, or sublinearly, current increases more slowly than intensity. This paper continues work on using view factors to determine the concentration level and linearity of the solar cell with mathematical view factor analysis and experimental results [1].

L.E.R.C.I.P. Internship Summary

NASA Technical Reports Server (NTRS)

Donovan, Owen

2004-01-01

I am currently working towards a double major in Computer Science and Electrical and Computer Engineering. My summer internship at NASA Glenn Research Center has allowed me to apply and further my knowledge of both of these fields. This summer is my second L.E.R.C.I.P. experience, and has worked out equally well as the first. I haven't been working on one single project this year, but instead have had a good variety of thinking work on. Thus far I have spend time on the following tasks: antenna measurements, high-temperature reliability testing, and left-handed metamaterials.

Extension of the Viscous Collision Limiting Direct Simulation Monte Carlo Technique to Multiple Species

NASA Technical Reports Server (NTRS)

Liechty, Derek S.; Burt, Jonathan M.

2016-01-01

There are many flows fields that span a wide range of length scales where regions of both rarefied and continuum flow exist and neither direct simulation Monte Carlo (DSMC) nor computational fluid dynamics (CFD) provide the appropriate solution everywhere. Recently, a new viscous collision limited (VCL) DSMC technique was proposed to incorporate effects of physical diffusion into collision limiter calculations to make the low Knudsen number regime normally limited to CFD more tractable for an all-particle technique. This original work had been derived for a single species gas. The current work extends the VCL-DSMC technique to gases with multiple species. Similar derivations were performed to equate numerical and physical transport coefficients. However, a more rigorous treatment of determining the mixture viscosity is applied. In the original work, consideration was given to internal energy non-equilibrium, and this is also extended in the current work to chemical non-equilibrium.

Application of poly (p-phenylene oxide) as blocking layer to reduce self-discharge in supercapacitors

NASA Astrophysics Data System (ADS)

Tevi, Tete; Yaghoubi, Houman; Wang, Jing; Takshi, Arash

2013-11-01

Supercapacitors are electrochemical energy storage devices with high power density. However, application of supercapacitors is limited mainly due to their high leakage current. In this work, application of an ultra-thin layer of electrodeposited poly (p-phenylene oxide) (PPO) has been investigated as a blocking layer to reduce the leakage current. The polymer was first deposited on a glassy carbon electrode. The morphology of the film was studied by atomic force microscopy (AFM), and the film thickness was estimated to be ˜1.5 nm by using the electrochemical impedance spectroscopy (EIS) technique. The same deposition method was applied to coat the surface of the activated carbon electrodes of a supercapacitor with PPO. The specific capacitance, the leakage current, and the series resistance were measured in two devices with and without the blocking layer. The results demonstrate that the application of the PPO layer reduced the leakage current by ˜78%. However, the specific capacitance was decreased by ˜56%, when the blocking layer was applied. Due to the lower rate of self-discharge, the suggested approach can be applied to fabricate devices with longer charge storage time.

Cognitive Activation by Central Thalamic Stimulation: The Yerkes-Dodson Law Revisited.

PubMed Central

Mair, Robert G.; Onos, Kristen D.; Hembrook, Jacqueline R.

2011-01-01

Central thalamus regulates forebrain arousal, influencing activity in distributed neural networks that give rise to organized actions during alert, wakeful states. Central thalamus has been implicated in working memory by the effects of lesions and microinjected drugs in this part of the brain. Lesions and drugs that inhibit neural activity have been found to impair working memory. Drugs that increase activity have been found to enhance and impair memory depending on the dose tested. Electrical deep brain stimulation (DBS) similarly enhances working memory at low stimulating currents and impairs it at higher currents. These effects are time dependent. They were observed when DBS was applied during the memory delay (retention) or choice response (retrieval) but not earlier in trials during the sample (acquisition) phase. The effects of microinjected drugs and DBS are consistent with the Yerkes-Dodson law, which describes an inverted-U relationship between arousal and behavioral performance. Alternatively these results may reflect desensitization associated with higher levels of stimulation, spread of drugs or current to adjacent structures, or activation of less sensitive neurons or receptors at higher DBS currents or drug doses. PMID:22013395

Improving U.S. Navy Foodservice Management Training. Part 1. Evaluation of the Current System

DTIC Science & Technology

1985-11-01

Experience in civilian foodservice before joining Navy? FAST FOOD FRANCHISE BAKERY RESTAURANT COFFEE SHOP CAFETERIA DELICATESSEN NONE WORKED AS...civilian foodservice since joining Navy? FAST FOOD FRANCHISE 12 8 BAKERY 15 5 RESTAURANT 12 18 COFFEE SHOP 8 — CAFETERIA 8 — DELICATESSEN — NONE...food service before joining the Navy? (PLEASE CHECK l^ THAT APPLY TO WHERE YOU WORKED) Fast Food Franchise Cafeteria Bakery Delieateesan

Developing Mathematical Habits of Mind

ERIC Educational Resources Information Center

Mark, June; Cuoco, Al; Goldenberg, E. Paul; Sword, Sarah

2010-01-01

"Mathematical habits of mind" include reasoning by continuity, looking at extreme cases, performing thought experiments, and using abstraction that mathematicians use in their work. Current recommendations emphasize the critical nature of developing these habits of mind: "Once this kind of thinking is established, students can apply it in the…

The Bayesian Revolution Approaches Psychological Development

ERIC Educational Resources Information Center

Shultz, Thomas R.

2007-01-01

This commentary reviews five articles that apply Bayesian ideas to psychological development, some with psychology experiments, some with computational modeling, and some with both experiments and modeling. The reviewed work extends the current Bayesian revolution into tasks often studied in children, such as causal learning and word learning, and…

Cognitive Psychology and Instruction. Third Edition.

ERIC Educational Resources Information Center

Bruning, Roger H.; Schraw, Gregory J.; Ronning, Royce R.

Like the earlier editions, the current text is directed at educators who are interested in understanding the principles of cognitive psychology and applying them to instruction and curriculum design. The following chapters are included: (1) "Introduction to Cognitive Psychology"; (2) "Sensory, Short-Term, and Working Memory"; (3) "Long-Term…

An organizing model for recent cognitive science work on the self.

PubMed

Pageler, Ben

2016-10-01

An organizing model of 'the self' emerges from applying various kinds of brain injury to recent cognitive science and philosophical work on 'the self'. This model unifies various contents and mechanisms central to current notions of the self. The article then highlights several criteria and aspects of this notion of self. Qualities of the right type and level of psychological significance delineate 'the self' as an organizing concept useful for recent philosophical work and cognitive science research. Copyright © 2016 Elsevier Inc. All rights reserved.

Experimental Study of Codeposition Electrochemistry Using Mixtures of ScCl 3 and YCl 3 in LiCl-KCl Eutectic Salt at 500°C

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

Shaltry, Michael R.; Yoo, Tae-Sic; Fredrickson, Guy L.

2017-09-12

Cyclic voltammetry and chronopotentiometry tests were applied to molten LiCl-KCl eutectic at 500 °C including amounts of ScCl 3 and YCl 3. The purpose of the testing was to observe the effect of applied electrical current on the codeposition of scandium and yttrium, which were chosen as surrogate elements for uranium and plutonium, respectively. Features of the work were to vary the concentration of ScCl 3 (at relatively low concentrations) as well as varying the applied current, all with a fixed concentration of YCl 3. Results of the experiments could provide insight of uranium electrorefining and may provide evidence, whichmore » suggests the electrorefiner could be operated at lower UCl 3 concentration whereby codeposition (U and Pu) could be more effectively controlled.« less

Impact of E × B flow shear on turbulence and resulting power fall-off width in H-mode plasmas in experimental advanced superconducting tokamak

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

Yang, Q. Q., E-mail: yangqq@ipp.ac.cn; Zhong, F. C., E-mail: gsxu@ipp.ac.cn, E-mail: fczhong@dhu.edu.cn; Jia, M. N.

2015-06-15

The power fall-off width in the H-mode scrape-off layer (SOL) in tokamaks shows a strong inverse dependence on the plasma current, which was noticed by both previous multi-machine scaling work [T. Eich et al., Nucl. Fusion 53, 093031 (2013)] and more recent work [L. Wang et al., Nucl. Fusion 54, 114002 (2014)] on the Experimental Advanced Superconducting Tokamak. To understand the underlying physics, probe measurements of three H-mode discharges with different plasma currents have been studied in this work. The results suggest that a higher plasma current is accompanied by a stronger E×B shear and a shorter radial correlation lengthmore » of turbulence in the SOL, thus resulting in a narrower power fall-off width. A simple model has also been applied to demonstrate the suppression effect of E×B shear on turbulence in the SOL and shows relatively good agreement with the experimental observations.« less

Stimulating thought: a functional MRI study of transcranial direct current stimulation in schizophrenia.

PubMed

Orlov, Natasza D; O'Daly, Owen; Tracy, Derek K; Daniju, Yusuf; Hodsoll, John; Valdearenas, Lorena; Rothwell, John; Shergill, Sukhi S

2017-09-01

Individuals with schizophrenia typically suffer a range of cognitive deficits, including prominent deficits in working memory and executive function. These difficulties are strongly predictive of functional outcomes, but there is a paucity of effective therapeutic interventions targeting these deficits. Transcranial direct current stimulation is a novel neuromodulatory technique with emerging evidence of potential pro-cognitive effects; however, there is limited understanding of its mechanism. This was a double-blind randomized sham controlled pilot study of transcranial direct current stimulation on a working memory (n-back) and executive function (Stroop) task in 28 individuals with schizophrenia using functional magnetic resonance imaging. Study participants received 30 min of real or sham transcranial direct current stimulation applied to the left frontal cortex. The 'real' and 'sham' groups did not differ in online working memory task performance, but the transcranial direct current stimulation group demonstrated significant improvement in performance at 24 h post-transcranial direct current stimulation. Transcranial direct current stimulation was associated with increased activation in the medial frontal cortex beneath the anode; showing a positive correlation with consolidated working memory performance 24 h post-stimulation. There was reduced activation in the left cerebellum in the transcranial direct current stimulation group, with no change in the middle frontal gyrus or parietal cortices. Improved performance on the executive function task was associated with reduced activity in the anterior cingulate cortex. Transcranial direct current stimulation modulated functional activation in local task-related regions, and in more distal nodes in the network. Transcranial direct current stimulation offers a potential novel approach to altering frontal cortical activity and exerting pro-cognitive effects in schizophrenia. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Polypyrrol/chitosan hydrogel hybrid microfiber as sensing artificial muscle

NASA Astrophysics Data System (ADS)

Ismail, Yahya A.; Martínez, Jose G.; Al Harrasi, Ahmad S.; Kim, Seon J.; Fernández Otero, Toribio F.

2011-04-01

An electrochemical actuator demands that it should act as a sensor of the working conditions for its efficient application in devices. Actuation and sensing characteristics of a biopolymer/conducting polymer hybrid microfiber artificial muscle fabricated through wet spinning of a chitosan solution followed by in situ chemical polymerization with pyrrol employing bis(triflouro methane sulfonyl) imide as dopant and ferric chloride as a catalyst is presented. The polypyrrol/chitosan hybrid microfiber was investigated by FTIR, scanning electron microscopy (SEM), electrical conductivity measurement, cyclic voltammetric and chronopotentiometric methods. The electrochemical measurements related to the sensing abilities were performed as a function of applied current, concentration and temperature keeping two of the variables constant at a given time using NaCl as electrolyte. Cyclic voltammograms confirmed that the electro activity is imparted by polypyrrol (pPy). The fiber showed an electrical conductivity of 3.21x10-1 Scm-1and an average linear electrochemical actuation strain of 0.54%. The chronopotentiometric responses during the oxidation/reduction processes of the microfiber for the different anodic/cathodic currents and the linear fit observed for the consumed electrical energy during the reaction for various applied currents suggested that it can act as a sensor of applied current. The chronopotentiometric responses and the linear fit of consumed electrical energy at different temperatures suggested that the actuator can act as a temperature sensor. Similarly a semi logarithmic dependence of the consumed electrical energy with concentration of the electrolyte during reaction is suggestive of its applicability as a concentration sensor. The demand that an electrochemical actuator to be a sensor of the working conditions, for its efficient application in devices is thus verified in this material.

Adaptive Behavioral Outcomes: Assurance of Learning and Assessment

ERIC Educational Resources Information Center

Baker, David S.; Stewart, Geoffrey T.

2012-01-01

Business schools are currently being criticized for lacking relevance to the applied working environment in which students are supposed to be prepared to make immediate contributions and reasoned independent decisions in a fluidly changing market (Haskell and Beliveau, 2010, and Michlitsch and Sidle, 2002). While technical skills (accounting,…

The Way of the Gun: Applying Lessons of Ground Combat to Pilot Training

DTIC Science & Technology

2016-02-29

actual practice repetitions.7 Current USAF Crew/Cockpit Resource Management ( CRM ) and Aerospace Physiology courses do not include any instruction on...Burke, Clint A. Bowers, and Katherine A. Wilson. Team Training in the Skies: Does Crew Resource Management ( CRM ) Training Work? Orlando, FL

78 FR 1266 - Notice of Intent To Seek Approval To Extend a Current Information Collection

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-08

... (salaries, indirect costs, equipment, etc.), and character of work (basic research, applied research, or.... SUPPLEMENTARY INFORMATION: Title of Collection: Higher Education Research and Development Survey. OMB Control... Project: The Higher Education Research and Development Survey (formerly known as the Survey of Research...

The Promise for Geomorphic Discovery in the South.

ERIC Educational Resources Information Center

Mossa, Joann

1998-01-01

Presents an overview of current geomorphic research in the southern United States. Conveys that the limited historical effort offers both challenges and opportunities for conducting geomorphic work in the region; much is unknown about these unique landscapes. States applied and theoretical geomorphology will benefit the society and future of the…

TOEFL from a Communicative Viewpoint on Language Proficiency: A Working Paper.

ERIC Educational Resources Information Center

Duran, Richard P.; And Others

The content characteristics of the Test of English as a Foreign Language (TOEFL) are examined from a communicative viewpoint, based on current theory in applied linguistics and language proficiency assessment. The study employed a four-part operational framework. The first component analyzed the communicative characteristics of a language…

Resident Assistant Workplace Motivation

ERIC Educational Resources Information Center

Boone, Katherine B.

2018-01-01

The sources of work motivation for resident assistants have received little attention in the literature over the last decade. As the role grows more complex and more expectations are added to the RA position, determining what current factors motivate students to apply for the RA position is essential. This study presents quantitative research to…

Culture and Self in Career Development: Working with American Indians

ERIC Educational Resources Information Center

Juntunen, Cindy L.; Cline, Kara

2010-01-01

The career development concerns of American Indians continue to receive limited attention in the vocational or career literature. To address this deficit, the current article will apply the cultural formulation approach to career counseling with American Indians. This article presents information on factors related to cultural and self-identity…

Lewin's Impact on Education: Instilling Cooperation and Conflict Management Skills in School Children.

ERIC Educational Resources Information Center

Maruyama, Geoffrey

1992-01-01

A Lewinian orientation to educational problems fits current innovative thinking in education (e.g., models for making education multicultural), and provides the bases of important applied work on cooperative learning techniques and constructive ways of structuring conflict within educational settings. Lewinian field theory provides a broad…

Measuring surfactant concentration in plating solutions

DOEpatents

Bonivert, William D.; Farmer, Joseph C.; Hachman, John T.

1989-01-01

An arrangement for measuring the concentration of surfactants in a electrolyte containing metal ions includes applying a DC bias voltage and a modulated voltage to a counter electrode. The phase angle between the modulated voltage and the current response to the modulated voltage at a working electrode is correlated to the surfactant concentration.

Effects of repeated bending load at room temperature for composite Nb3Sn wires

NASA Astrophysics Data System (ADS)

Awaji, Satoshi; Watanabe, Kazuo; Katagiri, Kazumune

2003-09-01

In order to realize a react and wind (R&W) method for Nb3Sn wires, the influences of a bending load at room temperature are investigated. Usually, the superconducting wires undergo bending loads at room temperature repeatedly during winding and insulation processes. We define these bending loads as 'pre-bending' treatments. We applied the pre-bending strain of 0 and 0.5% to the highly strengthened CuNb/(Nb, Ti)3Sn wires, and measured the stress/strain properties and critical currents. The improvements of stress dependence of normalized critical current and the increase of the maximum critical current by the pre-bending treatments were found. The model based on the distribution of the local tensile strain as a bending strain describes the experimental results well without the increase of the maximum critical current. When the pre-bending strain was applied, the calculated results indicate that the mechanical properties are improved due to the local work hardening, and hence the stress dependence of Ic increases.

Ratchet motion induced by a correlated stochastic force

NASA Astrophysics Data System (ADS)

Cortés, Emilio

2000-01-01

We apply a rigorous formalism we have just worked out (Cortés and Espinosa, Physica A 267 (1999) 414) about escape rates and the Hamilton-Jacobi equation, to study the ratchet motion of a Brownian particle and calculate the probability current in a periodic non-symmetric potential subject to correlated fluctuations. We are able to obtain the current behaviour as a function of the correlation time parameter and compare with other results in the literature.

A curriculum vitae that gives you a competitive edge.

PubMed

Hinck, S M

1997-07-01

All nurses with advancing careers should maintain a current curriculum vitae (CV) to chronicle professional accomplishments. Whatever the work setting, a CV can showcase skills and achievements. It is used when applying for a new position, but also within one's current situation to inform other professionals of specific interests and abilities. This article reviews nursing literature regarding preparation of a CV and suggests a format for the advanced practice nurse to use when writing a CV.

The Library Work Order Processing System: A New Approach to Motivate Employees and to Increase Production in the Technical Service Department of Mercer County Community College Library. Applied Educational Research and Evaluation.

ERIC Educational Resources Information Center

Sim, Yong Sup

After reviewing the current movement toward job enrichment, a system was designed for the technical services department of the Mercer County Community College Library. The Library Work Order Processing System, as tried between January and March, 1974, was designed to permit each worker more variety of jobs. The technical services department was…

Extraction of physical Schottky parameters using the Lambert function in Ni/AlGaN/GaN HEMT devices with defined conduction phenomena

NASA Astrophysics Data System (ADS)

Latry, O.; Divay, A.; Fadil, D.; Dherbécourt, P.

2017-01-01

Electrical characterization analyses are proposed in this work using the Lambert function on Schottky junctions in GaN wide band gap semiconductor devices for extraction of physical parameters. The Lambert function is used to give an explicit expression of the current in the Schottky junction. This function is applied with defined conduction phenomena, whereas other work presented arbitrary (or undefined) conduction mechanisms in such parameters’ extractions. Based upon AlGaN/GaN HEMT structures, extractions of parameters are undergone in order to provide physical characteristics. This work highlights a new expression of current with defined conduction phenomena in order to quantify the physical properties of Schottky contacts in AlGaN/GaN HEMT transistors. Project supported by the French Department of Defense (DGA).

Parameter reduction in nonlinear state-space identification of hysteresis

NASA Astrophysics Data System (ADS)

Fakhrizadeh Esfahani, Alireza; Dreesen, Philippe; Tiels, Koen; Noël, Jean-Philippe; Schoukens, Johan

2018-05-01

Recent work on black-box polynomial nonlinear state-space modeling for hysteresis identification has provided promising results, but struggles with a large number of parameters due to the use of multivariate polynomials. This drawback is tackled in the current paper by applying a decoupling approach that results in a more parsimonious representation involving univariate polynomials. This work is carried out numerically on input-output data generated by a Bouc-Wen hysteretic model and follows up on earlier work of the authors. The current article discusses the polynomial decoupling approach and explores the selection of the number of univariate polynomials with the polynomial degree. We have found that the presented decoupling approach is able to reduce the number of parameters of the full nonlinear model up to about 50%, while maintaining a comparable output error level.

Ambient-Pressure XPS Study of a Ni–Fe Electrocatalyst for the Oxygen Evolution Reaction

DOE PAGES

Ali-Löytty, Harri; Louie, Mary W.; Singh, Meenesh R.; ...

2016-01-05

Chemical analysis of solid–liquid interfaces under electrochemical conditions has recently become feasible due to the development of new synchrotron radiation techniques. In this paper, we report the use of “tender” X-ray ambient-pressure X-ray photoelectron spectroscopy (APXPS) to characterize a thin film of Ni–Fe oxyhydroxide electrodeposited on Au as the working electrode at different applied potentials in 0.1 M KOH as the electrolyte. Our results show that the as-prepared 7 nm thick Ni–Fe (50% Fe) film contains Fe and Ni in both their metallic as well as oxidized states, and undergoes further oxidation when the sample is subjected to electrochemical oxidation–reductionmore » cycles. Metallic Fe is oxidized to Fe 3+ and metallic Ni to Ni 2+/3+. This work shows that it is possible to monitor the chemical nature of the Ni–Fe catalyst as a function of potential when the corresponding current densities are small. This allows for operando measurements just above the onset of OER; however, current densities as they are desired in photoelectrochemical devices (~1–10 mA cm –2) could not be achieved in this work, due to ohmic losses in the thin electrolyte film. We use a two-dimensional model to describe the spatial distribution of the electrochemical potential, current density, and pH as a function of the position above the electrolyte meniscus, to provide guidance toward enabling the acquisition of operando APXPS at high current density. Finally, the shifts in binding energy of water with applied potential predicted by the model are in good agreement with the experimental values.« less

Improved curvature-based inpainting applied to fine art: recovering van Gogh's partially hidden brush strokes

NASA Astrophysics Data System (ADS)

Kuang, Yubin; Stork, David G.; Kahl, Fredrik

2011-03-01

Underdrawings and pentimenti-typically revealed through x-ray imaging and infrared reflectography-comprise important evidence about the intermediate states of an artwork and thus the working methods of its creator.1 To this end, Shahram, Stork and Donoho introduced the De-pict algorithm, which recovers layers of brush strokes in paintings with open brush work where several layers are partially visible, such as in van Gogh's Self portrait with a grey felt hat.2 While that preliminary work served as a proof of concept that computer image analytic methods could recover some occluded brush strokes, the work needed further refinement before it could be a tool for art scholars. Our current work makes several steps to improve that algorithm. Specifically, we refine the inpainting step through the inclusion of curvature-based constraints, in which a mathematical curvature penalty biases the reconstruction toward matching the artist's smooth hand motion. We refine and test our methods using "ground truth" image data: passages of four layers of brush strokes in which the intermediate layers were recorded photographically. At each successive top layer (currently identified by the user), we used k-means clustering combined with graph cuts to obtain chromatically and spatially coherent segmentation of brush strokes. We then reconstructed strokes at the deeper layer with our new curvature-based inpainting algorithm based on chromatic level lines. Our methods are clearly superior to previous versions of the De-pict algorithm on van Gogh's works giving smoother, natural strokes that more closely match the shapes of unoccluded strokes. Our improved method might be applied to the classic drip paintings of Jackson Pollock, where the drip work is more open and the physics of splashing paint ensures that the curvature more uniform than in the brush strokes of van Gogh.

Consumer-oriented social data fusion: controlled learning in social environments, social advertising, and more

NASA Astrophysics Data System (ADS)

Grewe, L.

2013-05-01

This paper explores the current practices in social data fusion and analysis as it applies to consumer-oriented applications in a slew of areas including business, economics, politics, sciences, medicine, education and more. A categorization of these systems is proposed and contributions to each area are explored preceded by a discussion of some special issues related to social data and networks. From this work, future paths of consumer-based social data analysis research and current outstanding problems are discovered.

Electrochemical Studies of Passive Film Formation and Corrosion of Friction Stir Processed Nickel Aluminum Bronze

DTIC Science & Technology

2011-06-01

between the working and reference electrodes in the cell due to the electrolyte and is calculated using equation 19 where ρ is the solution resistivity, l...the electrode and is given by equation 20 where, I is the measured cell current, Icorr is the corrosion current, Eoc is the open circuit potential...signals are applied, making Icorr related to RP , where RP is the polarization resistance as given in Equation 21 [16]. (21) The

Monitoring tooth profile faults in epicyclic gearboxes using synchronously averaged motor currents: Mathematical modeling and experimental validation

NASA Astrophysics Data System (ADS)

Ottewill, J. R.; Ruszczyk, A.; Broda, D.

2017-02-01

Time-varying transmission paths and inaccessibility can increase the difficulty in both acquiring and processing vibration signals for the purpose of monitoring epicyclic gearboxes. Recent work has shown that the synchronous signal averaging approach may be applied to measured motor currents in order to diagnose tooth faults in parallel shaft gearboxes. In this paper we further develop the approach, so that it may also be applied to monitor tooth faults in epicyclic gearboxes. A low-degree-of-freedom model of an epicyclic gearbox which incorporates the possibility of simulating tooth faults, as well as any subsequent tooth contact loss due to these faults, is introduced. By combining this model with a simple space-phasor model of an induction motor it is possible to show that, in theory, tooth faults in epicyclic gearboxes may be identified from motor currents. Applying the synchronous averaging approach to experimentally recorded motor currents and angular displacements recorded from a shaft mounted encoder, validate this finding. Comparison between experiments and theory highlight the influence of operating conditions, backlash and shaft couplings on the transient response excited in the currents by the tooth fault. The results obtained suggest that the method may be a viable alternative or complement to more traditional methods for monitoring gearboxes. However, general observations also indicate that further investigations into the sensitivity and robustness of the method would be beneficial.

A two wave cross-lagged study of work-role conflict, work-family conflict and emotional exhaustion.

PubMed

Jensen, Maria Therese

2016-12-01

By using a two-wave panel design, the present study aimed to study causal, reversed, and reciprocal relations among work-role conflict, work-family conflict, and emotional exhaustion. The Conservation of Resources theory was applied as a theoretical framework. The study was conducted in a large Norwegian oil and gas company (n = 1703). The results demonstrated positive cross-lagged effects of work-role conflict and work-family conflict on emotional exhaustion. In addition, emotional exhaustion predicted work-family conflict over time, and work-family conflict predicted work-role conflict over time, indicating the presence of reciprocal effects. The current study adds new knowledge to the positioning of work-family conflict in relation to perceived conflict in the workplace and emotional exhaustion. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

The Role of Social Work in the Defense of Reproductive Rights.

ERIC Educational Resources Information Center

Lieberman, Alice; Davis, Liane V.

1992-01-01

Discusses barriers to abortion in terms of funding and access and examines available literature on how abortion affects pregnant woman and how being denied abortion affects mother and child. Describes other threats to reproductive freedom currently wending their way through state legislatures or being applied by courts: states' responses to…

Team Performance Assessment and Measurement: Theory, Methods, and Applications. Series in Applied Psychology.

ERIC Educational Resources Information Center

Brannick, Michael T., Ed.; Salas, Eduardo, Ed.; Prince, Carolyn, Ed.

This volume presents thoughts on measuring team performance written by experts currently working with teams in fields such as training, evaluation, and process consultation. The chapters are: (1) "An Overview of Team Performance Measurement" (Michael T. Brannick and Carolyn Prince); (2) "A Conceptual Framework for Teamwork Measurement" (Terry L.…

Applied Linguistics Redux: A Derridean Exploration of Alzheimer Lifehistories

ERIC Educational Resources Information Center

Ramanathan, Vaidehi

2008-01-01

Advocating a position of self-critique, whereby we revisit our old research sites to dis-assemble our prior thinking in relation to our current cognitions, this paper offers, among other things, a critical revisitation and Derridean interpretation of one of my previous long-term, ethnographic endeavours: my extended work with the memories and…

Calibration and Temperature Profile of a Tungsten Filament Lamp

ERIC Educational Resources Information Center

de Izarra, Charles; Gitton, Jean-Michel

2010-01-01

The goal of this work proposed for undergraduate students and teachers is the calibration of a tungsten filament lamp from electric measurements that are both simple and precise, allowing to determine the temperature of tungsten filament as a function of the current intensity. This calibration procedure was first applied to a conventional filament…

Hold on to This!: Strategies for Teacher Feedback in Online Dance Courses

ERIC Educational Resources Information Center

Risner, Doug

2014-01-01

Drawn from current research on web-based learning, this practical article presents applied research and informed applications for online dance educators engaged in undergraduate and graduate dance education course work. With a focus on written assessment feedback, the author provides a review of recent literature, an overview of written feedback…

Shaping Up the Practice of Null Hypothesis Significance Testing.

ERIC Educational Resources Information Center

Wainer, Howard; Robinson, Daniel H.

2003-01-01

Discusses criticisms of null hypothesis significance testing (NHST), suggesting that historical use of NHST was reasonable, and current users should read Sir Ronald Fisher's applied work. Notes that modifications to NHST and interpretations of its outcomes might better suit the needs of modern science. Concludes that NHST is most often useful as…

Managing Marginal School Employees: Applying Standards-Based Performance Measures

ERIC Educational Resources Information Center

Fields, Lynette; Reck, Brianne; Egley, Robert

2006-01-01

This book contains a collection of case studies that provide a variety of situations in managing or working with marginal employees in a school system. Managing Marginal School Employees will serve as a primary or companion text for administrator candidates or current administrators that include dilemmas for the student to think about, discuss,…

Bourdieu and Academic Capitalism: Faculty "Habitus" in Materials Science and Engineering

ERIC Educational Resources Information Center

Mendoza, Pilar; Kuntz, Aaron M.; Berger, Joseph B.

2012-01-01

We present Bourdieu's notions of field, capital, "habitus," and strategy and how these concepts apply today in light of academic capitalism using an empirical study of faculty work in one specific field in engineering that exemplifies current tendencies brought by academic capitalism. We conclude with a discussion of practical implications.…

Current Research on Englishes in Southeast Asia

ERIC Educational Resources Information Center

Pakir, Anne

2010-01-01

Much research on world Englishes (WE) since the 1980s has yet to impact significantly upon recent applied linguistics work in the areas of instruction, curriculum, testing and policy. Much of the received wisdom has been informed by the paradigm established by the earlier study of International English (IE) and its attendant foci in teaching…

Interdisciplinary Project-Based Learning: An Online Wiki Experience in Teacher Education

ERIC Educational Resources Information Center

Biasutti, Michele; EL-Deghaidy, Heba

2015-01-01

In the current research study the use of Wikis as an online didactic tool to apply project-based learning in higher education was reported. The study was conducted in university teacher education programmes. During the online activities, participants developed interdisciplinary projects for the primary school working collaboratively in small…

Iranian Journal of Language Studies (IJLS). Volume 2, Number 1

ERIC Educational Resources Information Center

Salmani-Nodoushan, Mohammad Ali, Ed.

2008-01-01

"Iranian Journal of Language Studies" ("IJLS") is devoted to all areas of language and linguistics. Its aim is to present work of current interest in all areas of language study. No particular linguistic theories or scientific trends are favored: scientific quality and scholarly standing are the only criteria applied in the…

Evaluating a Skin Sensitization Model and Examining Common Assumptions of Skin Sensitizers (ASCCT meeting)

EPA Science Inventory

Skin sensitization is an adverse outcome that has been well studied over many decades. It was summarized using the adverse outcome pathway (AOP) framework as part of the OECD work programme (OECD, 2012). Currently there is a strong focus on how AOPs can be applied for different r...

Classroom Teachers' Feelings and Experiences in Teaching Early Reading and Writing: A Phenomenological Study

ERIC Educational Resources Information Center

Bastug, Muhammet

2016-01-01

The current study aimed to reveal classroom teachers' feelings and experiences in teaching early reading and writing. Phenomenological research design was applied in the qualitative research methodology of the study. The participants of the study were 15 classroom teachers working in different cities. The data were collected through…

Applying Best Practices to Florida Local Government Retrofit Programs

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

McIlvaine, J.; Sutherland, K.

In some communities, local government and non-profit entities have funds to purchase and renovate distressed, foreclosed homes for resale in the affordable housing market. Numerous opportunities to improve whole house energy efficiency are inherent in these comprehensive renovations. BA-PIRC worked together in a multi-year field study making recommendations in individual homes, meanwhile compiling improvement costs, projected energy savings, practical challenges, and labor force factors surrounding common energy-related renovation measures. The field study, Phase 1 of this research, resulted in a set of best practices appropriate to the current labor pool and market conditions in central Florida to achieve projected annualmore » energy savings of 15-30% and higher. This report describes Phase 2 of the work where researchers worked with a local government partner to implement and refine the 'current best practices.' A simulation study was conducted to characterize savings potential under three sets of conditions representing varying replacement needs for energy-related equipment and envelope components. The three scenarios apply readily to the general remodeling industry as for renovation of foreclosed homes for the affordable housing market. Our new local government partner, the City of Melbourne, implemented the best practices in a community-scale renovation program that included ten homes in 2012.« less

Existing Whole-House Solutions Case Study: Applying Best Practices to Florida Local Government Retrofit Programs - Central Florida

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

None

In some communities, local government and non-profit entities have funds to purchase and renovate distressed, foreclosed homes for resale in the affordable housing market. Numerous opportunities to improve whole house energy efficiency are inherent in these comprehensive renovations. BA-PIRC worked together in a multiyear field study making recommendations in individual homes, meanwhile compiling improvement costs, projected energy savings, practical challenges, and labor force factors surrounding common energy-related renovation measures. The field study, Phase 1 of this research, resulted in a set of best practices appropriate to the current labor pool and market conditions in central Florida to achieve projected annualmore » energy savings of 15%-30% and higher. This case study describes Phase 2 of the work where researchers worked with a local government partner to implement and refine the "current best practices". A simulation study was conducted to characterize savings potential under three sets of conditions representing varying replacement needs for energy-related equipment and envelope components. The three scenarios apply readily to the general remodeling industry as for renovation of foreclosed homes for the affordable housing market. The new local government partner, the City of Melbourne, implemented the best practices in a community-scale renovation program that included ten homes in 2012.« less

Applying Best Practices to Florida Local Government Retrofit Programs, Central Florida (Fact Sheet)

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

None, None

In some communities, local government and non-profit entities have funds to purchase and renovate distressed, foreclosed homes for resale in the affordable housing market. Numerous opportunities to improve whole house energy efficiency are inherent in these comprehensive renovations. BA-PIRC worked together in a multi-year field study making recommendations in individual homes, meanwhile compiling improvement costs, projected energy savings, practical challenges, and labor force factors surrounding common energy-related renovation measures. The field study, Phase 1 of this research, resulted in a set of best practices appropriate to the current labor pool and market conditions in central Florida to achieve projected annualmore » energy savings of 15-30% and higher. This report describes Phase 2 of the work where researchers worked with a local government partner to implement and refine the "current best practices". A simulation study was conducted to characterize savings potential under three sets of conditions representing varying replacement needs for energy-related equipment and envelope components. The three scenarios apply readily to the general remodeling industry as for renovation of foreclosed homes for the affordable housing market. Our new local government partner, the City of Melbourne, implemented the best practices in a community-scale renovation program that included ten homes in 2012.« less

Applying Best Practices to Florida Local Government Retrofit Programs

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

McIlvaine, J.; Sutherland, K.

In some communities, local government and non-profit entities have funds to purchase and renovate distressed, foreclosed homes for resale in the affordable housing market. Numerous opportunities to improve whole house energy efficiency are inherent in these comprehensive renovations. BA-PIRC worked together in a multiyear field study making recommendations in individual homes, meanwhile compiling improvement costs, projected energy savings, practical challenges, and labor force factors surrounding common energy-related renovation measures. The field study, Phase 1 of this research, resulted in a set of best practices appropriate to the current labor pool and market conditions in central Florida to achieve projected annualmore » energy savings of 15%-30% and higher. This report describes Phase 2 of the work where researchers worked with a local government partner to implement and refine the "current best practices". A simulation study was conducted to characterize savings potential under three sets of conditions representing varying replacement needs for energy-related equipment and envelope components. The three scenarios apply readily to the general remodeling industry as for renovation of foreclosed homes for the affordable housing market. The new local government partner, the City of Melbourne, implemented the best practices in a community-scale renovation program that included ten homes in 2012.« less

An Analysis of the Loads on and Dynamic Response of a Floating Flexible Tube in Waves and Currents

DTIC Science & Technology

2014-05-09

the tube about 4.57 meters. The CFD code associated with the SolidWorks Flow Simulation tool was applied for this application. Flow Simulation uses...Liquid-Filled Membrane Structure in Waves," Journal of Fluids and Structures, no. 9, pp. 937-956, 1995. [16] SolidWorks , " Flow Simulation 2012...influence of Reynolds number on the drag coefficient. Simulations were performed with the 100% full (solid) model with flow velocities that yielded

Graphene as current spreading layer on AlGaInP light emitting diodes

NASA Astrophysics Data System (ADS)

Guo, Xia; Feng, Yajie; Liu, Qiaoli; Hu, Anqi; He, Xiaoying; Hu, Zonghai

2018-05-01

Due to high transmittance and high mobility, graphene is one of the promising candidates for a current spreading layer, which is crucial to light emitting diode (LED) performance. In this paper, improved AlGaInP LED performance was reported after graphene was applied on the GaP surface. Due to its lowered work function difference than with the GaN material, the electrical properties remain the same without additional voltage bias. The light output power is enhanced by about 40% under the current injection of 5 mA at room temperature, which was confirmed by the light emission profile analysis in this study. Such results indicate that raphene is a promising candidate as a current spreading layer under low current injection.

Identifying the "Right Stuff": An Exploration-Focused Astronaut Job Analysis

NASA Technical Reports Server (NTRS)

Barrett, J. D.; Holland, A. W.; Vessey, W. B.

2015-01-01

Industrial and organizational (I/O) psychologists play a key role in NASA astronaut candidate selection through the identification of the competencies necessary to successfully engage in the astronaut job. A set of psychosocial competencies, developed by I/O psychologists during a prior job analysis conducted in 1996 and updated in 2003, were identified as necessary for individuals working and living in the space shuttle and on the International Space Station (ISS). This set of competencies applied to the space shuttle and applies to current ISS missions, but may not apply to longer-duration or long-distance exploration missions. With the 2015 launch of the first 12- month ISS mission and the shift in the 2020s to missions beyond low earth orbit, the type of missions that astronauts will conduct and the environment in which they do their work will change dramatically, leading to new challenges for these crews. To support future astronaut selection, training, and research, I/O psychologists in NASA's Behavioral Health and Performance (BHP) Operations and Research groups engaged in a joint effort to conduct an updated analysis of the astronaut job for current and future operations. This project will result in the identification of behavioral competencies critical to performing the astronaut job, along with relative weights for each of the identified competencies, through the application of job analysis techniques. While this job analysis is being conducted according to job analysis best practices, the project poses a number of novel challenges. These challenges include the need to identify competencies for multiple mission types simultaneously, to evaluate jobs that have no incumbents as they have never before been conducted, and working with a very limited population of subject matter experts. Given these challenges, under the guidance of job analysis experts, we used the following methods to conduct the job analysis and identify the key competencies for current and potential future missions.

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

Beilis, I. I.

Experiments in the last decade showed that for cathode spots in a magnetic field that obliquely intercepts the cathode surface, the current per spot increased with the transverse component of the magnetic field and decreased with the normal component. The present work analyzes the nature of cathode spot splitting in an oblique magnetic field. A physical model for cathode spot current splitting was developed, which considered the relation between the plasma kinetic pressure, self-magnetic pressure, and applied magnetic pressure in a current carrying cathode plasma jet. The current per spot was calculated, and it was found to increase with themore » tangential component of the magnetic field and to decrease with the normal component, which agrees well with the experimental dependence.« less

Field-effect amperometric immuno-detection of protein biomarker.

PubMed

Wang, Jiapeng; Yau, Siu-Tung

2011-11-15

The field-effect enzymatic detection technique has been applied to the amperometric immunoassay of the cancer biomarker, carcinoma antigen 125 (CA 125). The detection adopted a reagentless approach, in which the analyte, CA 125, was immobilized on the detecting electrode, which was modified using carbon nanotubes, and the detection signal was obtained by measuring the reduction peak current of the enzyme that was used to label the antibody. A gating voltage was applied to the detecting electrode, inducing increase in the signal current and therefore providing amplification of the detection signal. The voltage-controlled signal amplification of the detection system has increased the sensitivity and lowered the detection limit of the system. A detection limit of 0.9U/ml was obtained in the work. Copyright © 2011 Elsevier B.V. All rights reserved.

VERS: a virtual environment for reconstructive surgery planning

NASA Astrophysics Data System (ADS)

Montgomery, Kevin N.

1997-05-01

The virtual environment for reconstructive surgery (VERS) project at the NASA Ames Biocomputation Center is applying virtual reality technology to aid surgeons in planning surgeries. We are working with a craniofacial surgeon at Stanford to assemble and visualize the bone structure of patients requiring reconstructive surgery either through developmental abnormalities or trauma. This project is an extension of our previous work in 3D reconstruction, mesh generation, and immersive visualization. The current VR system, consisting of an SGI Onyx RE2, FakeSpace BOOM and ImmersiveWorkbench, Virtual Technologies CyberGlove and Ascension Technologies tracker, is currently in development and has already been used to visualize defects preoperatively. In the near future it will be used to more fully plan the surgery and compute the projected result to soft tissue structure. This paper presents the work in progress and details the production of a high-performance, collaborative, and networked virtual environment.

Imaging ac losses in superconducting films via scanning Hall probe microscopy

NASA Astrophysics Data System (ADS)

Dinner, Rafael B.; Moler, Kathryn A.; Feldmann, D. Matthew; Beasley, M. R.

2007-04-01

Various local probes have been applied to understanding current flow through superconducting films, which are often surprisingly inhomogeneous. Here, we show that magnetic imaging allows quantitative reconstruction of both current density J and electric field E resolved in time and space in a film carrying subcritical ac current. Current reconstruction entails inversion of the Biot-Savart law, while electric fields are reconstructed using Faraday’s law. We describe the corresponding numerical procedures, largely adapting existing work to the case of a strip carrying ac current, but including other methods of obtaining the complete electric field from the inductive portion determined by Faraday’s law. We also delineate the physical requirements behind the mathematical transformations. We then apply the procedures to images of a strip of YBa2Cu3O7-δ carrying an ac current at 400Hz . Our scanning Hall probe microscope produces a time series of magnetic images of the strip with 1μm spatial resolution and 25μs time resolution. Combining the reconstructed J and E , we obtain a complete characterization including local critical current density, E-J curves, and power losses. This analysis has a range of applications from fundamental studies of vortex dynamics to practical coated conductor development.

Evaluation of candidate working fluid formulations for the electrothermal-chemical wind tunnel

NASA Technical Reports Server (NTRS)

Akyurtlu, Jale F.; Akyurtlu, Ates

1993-01-01

A new hypersonic test facility which can simulate conditions typical of atmospheric flight at Mach numbers up to 20 is currently under study at the NASA/LaRC Hypersonic Propulsion Branch. In the proposed research, it was suggested that a combustion augmented electrothermal wind tunnel concept may be applied to the planned hypersonic testing facility. The purpose of the current investigation is to evaluate some candidate working fluid formulations which may be used in the chemical-electrothermal wind. The efforts in the initial phase of this research were concentrated on acquiring the code used by GASL to model the electrothermal wind tunnel and testing it using the conditions of GASL simulation. The early version of the general chemical kinetics code (GCKP84) was obtained from NASA and the latest updated version of the code (LSENS) was obtained from the author Dr. Bittker. Both codes are installed on a personal computer with a 486 25 MHz processor and 16 Mbyte RAM. Since the available memory was not sufficient to debug LSENS, for the current work GCKP84 was used.

FDTD-based Transcranial Magnetic Stimulation model applied to specific neurodegenerative disorders.

PubMed

Fanjul-Vélez, Félix; Salas-García, Irene; Ortega-Quijano, Noé; Arce-Diego, José Luis

2015-01-01

Non-invasive treatment of neurodegenerative diseases is particularly challenging in Western countries, where the population age is increasing. In this work, magnetic propagation in human head is modelled by Finite-Difference Time-Domain (FDTD) method, taking into account specific characteristics of Transcranial Magnetic Stimulation (TMS) in neurodegenerative diseases. It uses a realistic high-resolution three-dimensional human head mesh. The numerical method is applied to the analysis of magnetic radiation distribution in the brain using two realistic magnetic source models: a circular coil and a figure-8 coil commonly employed in TMS. The complete model was applied to the study of magnetic stimulation in Alzheimer and Parkinson Diseases (AD, PD). The results show the electrical field distribution when magnetic stimulation is supplied to those brain areas of specific interest for each particular disease. Thereby the current approach entails a high potential for the establishment of the current underdeveloped TMS dosimetry in its emerging application to AD and PD. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Exploring critical youth media practice: connections and contributions for social work.

PubMed

Johnston-Goodstar, Katie; Richards-Schuster, Katie; Sethi, Jenna K

2014-10-01

Youth media is emerging as an interdisciplinary field of practice and subject of study. Over the last two decades, there have been many efforts within communities to engage in media, especially within the fields of youth work and education. Despite the increase in practice, we found surprisingly little attention to the potential for youth media within the social work literature. Drawing on a qualitative content analysis of program descriptions from 49 youth media groups, the authors attempt to examine the current field of youth media. Using a critical media literacy framework, the authors analyze the practice of these youth media groups and apply those findings to social work practice, education, and research.

The Value of Biomedical Simulation Environments to Future Human Space Flight Missions

NASA Technical Reports Server (NTRS)

Mulugeta, Lealem; Myers, Jerry G.; Skytland, Nicholas G.; Platts, Steven H.

2010-01-01

With the ambitious goals to send manned missions to asteroids and onto Mars, substantial work will be required to ensure the well being of the men and women who will undertake these difficult missions. Unlike current International Space Station or Shuttle missions, astronauts will be required to endure long-term exposure to higher levels of radiation, isolation and reduced gravity. These new operation conditions will pose health risks that are currently not well understood and perhaps unanticipated. Therefore, it is essential to develop and apply advanced tools to predict, assess and mitigate potential hazards to astronaut health. NASA s Digital Astronaut Project (DAP) is working to develop and apply computational models of physiologic response to space flight operation conditions over various time periods and environmental circumstances. The collective application and integration of well vetted models assessing the physiology, biomechanics and anatomy is referred to as the Digital Astronaut. The Digital Astronaut simulation environment will serve as a practical working tool for use by NASA in operational activities such as the prediction of biomedical risks and functional capabilities of astronauts. In additional to space flight operation conditions, DAP s work has direct applicability to terrestrial biomedical research by providing virtual environments for hypothesis testing, experiment design, and to reduce animal/human testing. A practical application of the DA to assess pre and post flight responses to exercise is illustrated and the difficulty in matching true physiological responses is discussed.

Transcranial cerebellar direct current stimulation and transcutaneous spinal cord direct current stimulation as innovative tools for neuroscientists

PubMed Central

Priori, Alberto; Ciocca, Matteo; Parazzini, Marta; Vergari, Maurizio; Ferrucci, Roberta

2014-01-01

Two neuromodulatory techniques based on applying direct current (DC) non-invasively through the skin, transcranial cerebellar direct current stimulation (tDCS) and transcutaneous spinal DCS, can induce prolonged functional changes consistent with a direct influence on the human cerebellum and spinal cord. In this article we review the major experimental works on cerebellar tDCS and on spinal tDCS, and their preliminary clinical applications. Cerebellar tDCS modulates cerebellar motor cortical inhibition, gait adaptation, motor behaviour, and cognition (learning, language, memory, attention). Spinal tDCS influences the ascending and descending spinal pathways, and spinal reflex excitability. In the anaesthetised mouse, DC stimulation applied under the skin along the entire spinal cord may affect GABAergic and glutamatergic systems. Preliminary clinical studies in patients with cerebellar disorders, and in animals and patients with spinal cord injuries, have reported beneficial effects. Overall the available data show that cerebellar tDCS and spinal tDCS are two novel approaches for inducing prolonged functional changes and neuroplasticity in the human cerebellum and spinal cord, and both are new tools for experimental and clinical neuroscientists. PMID:24907311

Iranian Journal of Language Studies (IJLS). Volume 2, Issue 3

ERIC Educational Resources Information Center

Salmani-Nodoushan, Mohammad Ali, Ed.

2008-01-01

Iranian Journal of Language Studies (IJLS) is devoted to all areas of language and linguistics. Its aim is to present work of current interest in all areas of language study. No particular linguistic theories or scientific trends are favored: scientific quality and scholarly standing are the only criteria applied in the selection of papers…

Iranian Journal of Language Studies (IJLS). Volume 2, Issue 2

ERIC Educational Resources Information Center

Salmani-Nodoushan, Mohammad Ali, Ed.

2008-01-01

Iranian Journal of Language Studies (IJLS) is devoted to all areas of language and linguistics. Its aim is to present work of current interest in all areas of language study. No particular linguistic theories or scientific trends are favored: scientific quality and scholarly standing are the only criteria applied in the selection of papers…

Preschool for All? Examining the Current Policy Context in Light of Genishi's Research

ERIC Educational Resources Information Center

Spencer, Tamara

2014-01-01

Within United States policymaking, there is widespread recognition that universal preschool works towards a societal good, advancing children's social and academic needs while expanding the economic landscape for a nation. However, in trying to deliver these benefits, all too often educational policies apply a rigid format that overemphasizes…

Creating a Bilingual Pre-School Classroom: The Multilayered Discourses of a Bilingual Teacher

ERIC Educational Resources Information Center

Palviainen, Åsa; Mård-Miettinen, Karita

2015-01-01

Teachers have an agentive role as they interpret, evaluate and develop language policies and practices. In the current study we interviewed a bilingual pre-school teacher in Finland during the first year of implementing a new way of working bilingually with a class of monolingual children. Applying nexus analysis, we explored the teacher…

English as a Lingua Franca: An Immanent Critique

ERIC Educational Resources Information Center

O'Regan, John P.

2014-01-01

Over the past 15 years or so there has developed a school of thought within English language education and applied linguistics globally which refers to the phenomenon and use of English as a lingua franca (ELF). The thinking of ELF movement researchers has placed their work at the centre of current debates about the form, function and legitimacy…

Effective Consultation in Educational and Child Psychology Practice: Professional Training for Both Competence and Capability

ERIC Educational Resources Information Center

Kennedy, Emma Kate; Cameron, R. J.; Monsen, Jeremy

2009-01-01

How should applied psychology practitioners be prepared to meet an increasingly challenging and unpredictable working context? This article explores some of the key current issues for educational and child psychology practitioners and their professional trainers in the UK with regard to the topic of effective consultation. The article argues that…

The Link between Age, Career Goals, and Adaptive Development for Work-Related Learning among Local Government Employees

ERIC Educational Resources Information Center

Tones, Megan; Pillay, Hitendra; Kelly, Kathy

2011-01-01

More recently, lifespan development psychology models of adaptive development have been applied to the workforce to investigate ageing worker and lifespan issues. The current study uses the Learning and Development Survey (LDS) to investigate employee selection and engagement of learning and development goals and opportunities and constraints for…

Toward a Web Based Environment for Evaluation and Design of Pedagogical Hypermedia

ERIC Educational Resources Information Center

Trigano, Philippe C.; Pacurar-Giacomini, Ecaterina

2004-01-01

We are working on a method, called CEPIAH. We propose a web based system used to help teachers to design multimedia documents and to evaluate their prototypes. Our current research objectives are to create a methodology to sustain the educational hypermedia design and evaluation. A module is used to evaluate multimedia software applied in…

Perspectives on Leadership. Current Issues in Higher Education No. 1, 1979.

ERIC Educational Resources Information Center

American Association for Higher Education, Washington, DC.

Perspectives on leadership, the workplace, and changing values are presented in three papers. In "Changing the Shape of Work: Reform in Academe," Rosabeth Moss Kanter discusses the structure of academic career paths and ways to improve the quality of worklife for individuals employed in academe, applying theories she developed in her study on work…

Are You Tuned in to Your Trainees?

ERIC Educational Resources Information Center

Dutton, Gail

2011-01-01

When training outside one's culture, it's obvious that certain assumptions no longer apply. That lesson is less obvious when working with a home-grown audience. But even within a society, the cultural touchpoints depend upon the audience's age and geography. If one wants to be thought of as a leading-edge trainer, one has to stay current. That…

Shut-Up and Listen: Implications and Possibilities of Albert Memmi's Characteristics of Colonization upon the "Natural World"

ERIC Educational Resources Information Center

Blenkinsop, Sean; Affifi, Ramsey; Piersol, Laura; De Danann Sitka-Sage, Michael

2017-01-01

This paper begins by exploring the anti-colonial work of Tunisian scholar Albert Memmi in his classic book "The Colonizer and the Colonized" and determining whether the characteristics of colonization that he names can be successfully applied to the current relationship between modern humans and the "natural world". After…

Bringing the Digital World to Students: Partnering with the University Communications Office to Provide Social Media Experiential Learning Projects

ERIC Educational Resources Information Center

Childers, Courtney C.; Levenshus, Abbey B.

2016-01-01

The Accrediting Council on Education in Journalism and Mass Communications recognizes the importance of a curriculum that prepares students "to apply current tools and technologies appropriate for the communications professions in which they work, and to understand the digital world" (ACEJMC, n.d.). Infusing experiential learning into…

Iranian Journal of Language Studies (IJLS). Volume 1, Issue 4

ERIC Educational Resources Information Center

Online Submission, 2007

2007-01-01

Iranian Journal of Language Studies (IJLS) is devoted to all areas of language and linguistics. Its aim is to present work of current interest in all areas of language study. No particular linguistic theories or scientific trends are favored: scientific quality and scholarly standing are the only criteria applied in the selection of papers…

Career and Retirement Theories: Relevance for Older Workers Across Cultures

PubMed Central

Lytle, Megan C.; Foley, Pamela F.; Cotter, Elizabeth W.

2015-01-01

This paper reviews selected career development theories as well as theories specifically focused on retirement, with an emphasis on their application to retirement decisions and vocational behavior in multicultural populations. Theories are evaluated based on whether: (a) retirement was considered a stage of working life, (b) work satisfaction, motivation, and other work variables at retirement age were addressed, (c) work choices at retirement age were included, and (d) cultural and other minority status issues were either directly considered in the work/retirement decision or if the model could be reasonably applied to retirement across cultures. We provide specific recommendations for research and practice with the aim of helping practitioners and scholars conceptualize the current concerns older adults face in their working lives and during retirement planning. PMID:26101455

Career and Retirement Theories: Relevance for Older Workers Across Cultures.

PubMed

Lytle, Megan C; Foley, Pamela F; Cotter, Elizabeth W

2015-06-01

This paper reviews selected career development theories as well as theories specifically focused on retirement, with an emphasis on their application to retirement decisions and vocational behavior in multicultural populations. Theories are evaluated based on whether: (a) retirement was considered a stage of working life, (b) work satisfaction, motivation, and other work variables at retirement age were addressed, (c) work choices at retirement age were included, and (d) cultural and other minority status issues were either directly considered in the work/retirement decision or if the model could be reasonably applied to retirement across cultures. We provide specific recommendations for research and practice with the aim of helping practitioners and scholars conceptualize the current concerns older adults face in their working lives and during retirement planning.

Factors affecting the return to work of total hip arthroplasty due to of developmental hip dysplasia in in young patients.

PubMed

Oken, Fuad O; Yildirim, Ozgur A; Asilturk, Mehmet

2018-06-01

The aim of this study was to examine the factors affecting return to work after Total hip arthroplasty (THA) applied for coxarthrosis due to developmental hip dysplasia (DDH). The study included 51 patients aged <60 years in the period 2004-2010. The demographic information was recorded for all patients and the pre-postoperative Modified Harris score, EQ-5D, EQ-5D VAS and Grimby activity score. With an evaluation of the current employment status at the final follow-up examination. Preoperatively, 21 patients were employed, 16 were unemployed and 14 were housewives, none of whom were able to perform housework tasks. Postoperatively, 30 patients were employed and 10 were unemployed. One of the previously employed patients decided preoperatively to retire and was therefore not employed postoperatively. Of the 14 housewives, 9 were able to undertake the housework themselves postoperatively. The mean time of return to work was 13.4 weeks. Factors affecting finding work postoperatively were determined to be body mass index, National Occupational Level, whether or not osteotomy was applied and the preoperative duration of unemployment. As coxarthrosis associated with DDH develops earlier than primary coxarthrosis, these patients undergo surgery at a younger age and the vast majority are of working age. THA applied for coxarthrosis on the basis of DDH enables most patients to return to their preoperative work and offers the opportunity of finding work to some of those who were unemployed. This increases the contribution of these patients to the national economy.

Calcium dependent current recordings in Xenopus laevis oocytes in microgravity

NASA Astrophysics Data System (ADS)

Wuest, Simon L.; Roesch, Christian; Ille, Fabian; Egli, Marcel

2017-12-01

Mechanical unloading by microgravity (or weightlessness) conditions triggers profound adaptation processes at the cellular and organ levels. Among other mechanisms, mechanosensitive ion channels are thought to play a key role in allowing cells to transduce mechanical forces. Previous experiments performed under microgravity have shown that gravity affects the gating properties of ion channels. Here, a method is described to record a calcium-dependent current in native Xenopus laevis oocytes under microgravity conditions during a parabolic flight. A 3-voltage-step protocol was applied to provoke a calcium-dependent current. This current increased with extracellular calcium concentration and could be reduced by applying extracellular gadolinium. The custom-made ;OoClamp; hardware was validated by comparing the results of the 3-voltage-step protocol to results obtained with a well-established two-electrode voltage clamp (TEVC). In the context of the 2nd Swiss Parabolic Flight Campaign, we tested the OoClamp and the method. The setup and experiment protocol worked well in parabolic flight. A tendency that the calcium-dependent current was smaller under microgravity than under 1 g condition could be observed. However, a conclusive statement was not possible due to the small size of the data base that could be gathered.

Constraint-based integration of planning and scheduling for space-based observatory management

NASA Technical Reports Server (NTRS)

Muscettola, Nicola; Smith, Steven F.

1994-01-01

Progress toward the development of effective, practical solutions to space-based observatory scheduling problems within the HSTS scheduling framework is reported. HSTS was developed and originally applied in the context of the Hubble Space Telescope (HST) short-term observation scheduling problem. The work was motivated by the limitations of the current solution and, more generally, by the insufficiency of classical planning and scheduling approaches in this problem context. HSTS has subsequently been used to develop improved heuristic solution techniques in related scheduling domains and is currently being applied to develop a scheduling tool for the upcoming Submillimeter Wave Astronomy Satellite (SWAS) mission. The salient architectural characteristics of HSTS and their relationship to previous scheduling and AI planning research are summarized. Then, some key problem decomposition techniques underlying the integrated planning and scheduling approach to the HST problem are described; research results indicate that these techniques provide leverage in solving space-based observatory scheduling problems. Finally, more recently developed constraint-posting scheduling procedures and the current SWAS application focus are summarized.

Maximizing fluid delivered by bubble-free electroosmotic pump with optimum pulse voltage waveform.

PubMed

Tawfik, Mena E; Diez, Francisco J

2017-03-01

In generating high electroosmotic (EO) flows for use in microfluidic pumps, a limiting factor is faradaic reactions that are more pronounced at high electric fields. These reactions lead to bubble generation at the electrodes and pump efficiency reduction. The onset of gas generation for high current density EO pumping depends on many parameters including applied voltage, working fluid, and pulse duration. The onset of gas generation can be delayed and optimized for maximum volume pumped in the minimum time possible. This has been achieved through the use of a novel numerical model that predicts the onset of gas generation during EO pumping using an optimized pulse voltage waveform. This method allows applying current densities higher than previously reported. Optimal pulse voltage waveforms are calculated based on the previous theories for different current densities and electrolyte molarity. The electroosmotic pump performance is investigated by experimentally measuring the fluid volume displaced and flow rate. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Numerical investigation of the effect of driving voltage pulse shapes on the characteristics of low-pressure argon dielectric barrier discharge

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

Eslami, E., E-mail: eeslami@iust.ac.ir; Barjasteh, A.; Morshedian, N.

2015-06-15

In this work, we numerically compare the effect of a sinusoidal, triangular, and rectangular pulsed voltage profile on the calculated particle production, electric current, and gas voltage in a dielectric barrier discharge. The total argon gas pressure of 400 Pa, the distance between dielectrics of 5 mm, the dielectric thickness of 0.7 mm, and the temperature of T = 300 K were considered as input parameters. The different driving voltage pulse shapes (triangular, rectangular, and sinusoidal) are considered as applied voltage with a frequency of 7 kHz and an amplitude of 700 V peak to peak. It is shown thatmore » applying a rectangular voltage, as compared with a sinusoidal or triangle voltage, increases the current peak, while the peak width is decreased. Higher current density is related to high production of charged particles, which leads to the generation of some highly active species, such as Ar* (4s level), and Ar** (4p level) in the gap.« less

Modeling of flow-dominated MHD instabilities at WiPPAL using NIMROD

NASA Astrophysics Data System (ADS)

Flanagan, K.; McCollam, K. J.; Milhone, J.; Mirnov, V. V.; Nornberg, M. D.; Peterson, E. E.; Siller, R.; Forest, C. B.

2017-10-01

Using the NIMROD (non-ideal MHD with rotation - open discussion) code developed at UW-Madison, we model two different flow scenarios to study the onset of MHD instabilities in flow-dominated plasmas in the Big Red Ball (BRB) and the Plasma Couette Experiment (PCX). Both flows rely on volumetric current drive, where a large current is drawn through the plasma across a weak magnetic field, injecting J × B torque across the whole volume. The first scenario uses a vertical applied magnetic field and a mostly radial injected current to create Couette-like flows which may excite the magnetorotational instability (MRI). In the other scenario, a quadrupolar field is applied to create counter-rotating von Karman-like flow that demonstrates a dynamo-like instability. For both scenarios, the differences between Hall and MHD Ohm's laws are explored. The implementation of BRB geometry in NIMROD, details of the observed flows, and instability results are shown. This work was funded by DoE and NSF.

The Role of Direct Current Electric Field-Guided Stem Cell Migration in Neural Regeneration.

PubMed

Yao, Li; Li, Yongchao

2016-06-01

Effective directional axonal growth and neural cell migration are crucial in the neural regeneration of the central nervous system (CNS). Endogenous currents have been detected in many developing nervous systems. Experiments have demonstrated that applied direct current (DC) electric fields (EFs) can guide axonal growth in vitro, and attempts have been made to enhance the regrowth of damaged spinal cord axons using DC EFs in in vivo experiments. Recent work has revealed that the migration of stem cells and stem cell-derived neural cells can be guided by DC EFs. These studies have raised the possibility that endogenous and applied DC EFs can be used to direct neural tissue regeneration. Although the mechanism of EF-directed axonal growth and cell migration has not been fully understood, studies have shown that the polarization of cell membrane proteins and the activation of intracellular signaling molecules are involved in the process. The application of EFs is a promising biotechnology for regeneration of the CNS.

Cryogenic transimpedance amplifier for micromechanical capacitive sensors.

PubMed

Antonio, D; Pastoriza, H; Julián, P; Mandolesi, P

2008-08-01

We developed a cryogenic transimpedance amplifier that works at a broad range of temperatures, from room temperature down to 4 K. The device was realized with a standard complementary metal oxide semiconductor 1.5 mum process. Measurements of current-voltage characteristics, open-loop gain, input referred noise current, and power consumption are presented as a function of temperature. The transimpedance amplifier has been successfully applied to sense the motion of a polysilicon micromechanical oscillator at low temperatures. The whole device is intended to serve as a magnetometer for microscopic superconducting samples.

Realizing situation awareness within a cyber environment

NASA Astrophysics Data System (ADS)

Tadda, George; Salerno, John J.; Boulware, Douglas; Hinman, Michael; Gorton, Samuel

2006-04-01

Situation Awareness (SA) problems all require an understanding of current activities, an ability to anticipate what may happen next, and techniques to analyze the threat or impact of current activities and predictions. These processes of SA are common regardless of the domain and can be applied to the detection of cyber attacks. This paper will describe the application of a SA framework to implementing Cyber SA, describe some metrics for measuring and evaluating systems implementing Cyber SA, and discuss ongoing work in this area. We conclude with some ideas for future activities.

Optimization of niobium tunnel junctions as X-ray detectors

NASA Technical Reports Server (NTRS)

Saulnier, Gregory G.; Zacher, Robert A.; Van Vechten, Deborah; Boyer, Craig; Lovellette, Michael N.; Fritz, Gilbert G.; Soulen, Robert J.; Kang, Joonhee; Blamire, Mark; Kirk, Eugenie C. G.

1992-01-01

We report on our ongoing work using Nb/Al/AlO(x)/Nb junctions for the detection of X-rays. Detectors based on superconducting tunneling junctions offer the prospect of resolution over an order of magnitude higher than is obtainable with the current generation of semiconductor-based detectors. Results of measurements taken at 1.85 K (a temperature achievable with current space flight technology) include the current-voltage (I-V) curve, subgap current vs temperature, the dependence of the superconducting current on the applied magnetic field (Fraunhofer pattern), X-ray pulses, and the spectra from a 6 keV X-ray source which gave an intrinsic device resolution of approximately 700 eV. The collection of more than 10 exp 5 electrons per 6 keV photon is established.

Application of Ampere’s law to a non-infinite wire and to a moving charge

NASA Astrophysics Data System (ADS)

Aledealat, K.; Duston, C. L.

2018-07-01

In this work we demonstrate how to apply Ampere’s law to a non-infinite wire that is a part of a complete circuit with a steady current. We show that this can be done by considering the magnetic field from the whole circuit, without having to directly introduce the displacement current. This example can be used to isolate and clarify students’ confusion about the application of Ampere’s law to a short wire. The second part of this work focuses on the application of Ampere’s law to a non-relativistic moving charge. It exposes the students to the Dirac delta function in a physical example and guides them to finding the magnetic field of a moving charge in a reasonable way.

Fluctuating volume-current formulation of electromagnetic fluctuations in inhomogeneous media: Incandescence and luminescence in arbitrary geometries

NASA Astrophysics Data System (ADS)

Polimeridis, Athanasios G.; Reid, M. T. H.; Jin, Weiliang; Johnson, Steven G.; White, Jacob K.; Rodriguez, Alejandro W.

2015-10-01

We describe a fluctuating volume-current formulation of electromagnetic fluctuations that extends our recent work on heat exchange and Casimir interactions between arbitrarily shaped homogeneous bodies [A. W. Rodriguez, M. T. H. Reid, and S. G. Johnson, Phys. Rev. B 88, 054305 (2013), 10.1103/PhysRevB.88.054305] to situations involving incandescence and luminescence problems, including thermal radiation, heat transfer, Casimir forces, spontaneous emission, fluorescence, and Raman scattering, in inhomogeneous media. Unlike previous scattering formulations based on field and/or surface unknowns, our work exploits powerful techniques from the volume-integral equation (VIE) method, in which electromagnetic scattering is described in terms of volumetric, current unknowns throughout the bodies. The resulting trace formulas (boxed equations) involve products of well-studied VIE matrices and describe power and momentum transfer between objects with spatially varying material properties and fluctuation characteristics. We demonstrate that thanks to the low-rank properties of the associated matrices, these formulas are susceptible to fast-trace computations based on iterative methods, making practical calculations tractable. We apply our techniques to study thermal radiation, heat transfer, and fluorescence in complicated geometries, checking our method against established techniques best suited for homogeneous bodies as well as applying it to obtain predictions of radiation from complex bodies with spatially varying permittivities and/or temperature profiles.

Electron-neutrino charged-current quasi-elastic scattering in MINERvA

NASA Astrophysics Data System (ADS)

Wolcott, Jeremy

2014-03-01

The electron-neutrino charged-current quasi-elastic (CCQE) cross-section on nuclei is an important input parameter to appearance-type neutrino oscillation experiments. Current experiments typically work from the muon neutrino CCQE cross-section and apply corrections from theoretical arguments to obtain a prediction for the electron neutrino CCQE cross-section, but to date there has been no precise experimental verification of these estimates at an energy scale appropriate to such experiments. We present the current status of a direct measurement of the electron neutrino CCQE differential cross-section as a function of the squared four-momentum transfer to the nucleus, Q2, in MINERvA. This talk will discuss event selection, background constraints, and the flux prediction used in the calculation.

Design and Implement of Low Ripple and Quasi-digital Power Supply

NASA Astrophysics Data System (ADS)

Xiangli, Li; Yanjun, Wei; Hanhong, Qi; Yan, Ma

A switch linearity hybrid power supply based on single chip microcomputer is designed which merged the merits of the switching and linear power supply. Main circuit includes pre-regulator which works in switching mode and series regulator which works in linear mode. Two-stage regulation mode was adopted in the main circuit of the power. A single chip computer (SCM) and high resolution of series D/A and A/D converters are applied to control and measurement which achieved continuous adjustable and low ripple constant current or voltage power supply

ACOG committee opinion number 398, February 2008: fatigue and patient safety.

PubMed

2008-02-01

It has long been recognized that fatigue can affect human cognitive and physical function. Although there are limited published data on the effects of fatigue on health care providers, including full-time practicing physicians, there is increasing awareness within the patient safety movement that fatigue, even partial sleep deprivation, impairs performance. Most of the current literature reviews resident function after recent work reform changes. However, the information available from many studies in health care and other occupations can be applied to the work habits of practicing obstetrician-gynecologists.

Numerical study of the influence of applied voltage on the current balance factor of single layer organic light-emitting diodes

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

Lu, Fei-ping, E-mail: lufp-sysu@163.com; Liu, Xiao-bin; Xing, Yong-zhong

2014-04-28

Current balance factor (CBF) value, the ratio of the recombination current density and the total current density of a device, has an important function in fluorescence-based organic light-emitting diodes (OLEDs), as well as in the performance of the organic electrophosphorescent devices. This paper investigates the influence of the applied voltage of a device on the CBF value of single layer OLED based on the numerical model of a bipolar single layer OLED with organic layer trap free and without doping. Results show that the largest CBF value can be achieved when the electron injection barrier (ϕ{sub n}) is equal tomore » the hole injection barrier (ϕ{sub p}) in the lower voltage region at any instance. The largest CBF in the higher voltage region can be achieved in the case of ϕ{sub n} > ϕ{sub p} under the condition of electron mobility (μ{sub 0n}) > hole mobility (μ{sub 0p}), whereas the result for the case of μ{sub 0n} < μ{sub 0p}, is opposite. The largest CBF when μ{sub 0n} = μ{sub 0p} can be achieved in the case of ϕ{sub n} = ϕ{sub p} in the entire region of the applied voltage. In addition, the CBF value of the device increases with increasing applied voltage. The results obtained in this paper can present an in-depth understanding of the OLED working mechanism and help in the future fabrication of high efficiency OLEDs.« less

Access to workers' compensation benefits and other legal protections for work-related mental health problems: a Canadian overview.

PubMed

Lippel, Katherine; Sikka, Anette

2010-01-01

This article reports on a study of the legal and policy framework governing access, in Canada, to workers' compensation benefits for workers who are work disabled because of mental health problems attributed to stressful working conditions and events. It also provides a brief description of legislation regulating psychological harassment in Quebec and Saskatchewan. Applying classic legal methodology, the article examines the legal situation in Canada, relying on federal and provincial legislation and case law. While many of the jurisdictions studied explicitly restrict compensability to the consequences of traumatic incidents, application of this legislation is very different from one province to the next. In some provinces, legal exclusions are applied emphatically, whereas in others the workers' compensation appeal tribunals interpret the legislative exclusions much more narrowly, allowing for some access to compensation despite the legislative exclusions. Other provinces have no such exclusions and accept claims for both acute and chronic stress, although access to compensation remains more difficult for claimants with mental health problems than for those who are physically injured, regardless of where they live. The article concludes by offering an analysis of the consequences of the current situation from a public policy and public health perspective, notably underlining the negative consequences, particularly for women, of current workers' compensation policy in most Canadian provinces.

Evaluating High-Degree-and-Order Gravitational Harmonics and its Application to the State Predictions of a Lunar Orbiting Satellite

NASA Astrophysics Data System (ADS)

Song, Young-Joo; Kim, Bang-Yeop

2015-09-01

In this work, an efficient method with which to evaluate the high-degree-and-order gravitational harmonics of the nonsphericity of a central body is described and applied to state predictions of a lunar orbiter. Unlike the work of Song et al. (2010), which used a conventional computation method to process gravitational harmonic coefficients, the current work adapted a well-known recursion formula that directly uses fully normalized associated Legendre functions to compute the acceleration due to the non-sphericity of the moon. With the formulated algorithms, the states of a lunar orbiting satellite are predicted and its performance is validated in comparisons with solutions obtained from STK/Astrogator. The predicted differences in the orbital states between STK/Astrogator and the current work all remain at a position of less than 1 m with velocity accuracy levels of less than 1 mm/s, even with different orbital inclinations. The effectiveness of the current algorithm, in terms of both the computation time and the degree of accuracy degradation, is also shown in comparisons with results obtained from earlier work. It is expected that the proposed algorithm can be used as a foundation for the development of an operational flight dynamics subsystem for future lunar exploration missions by Korea. It can also be used to analyze missions which require very close operations to the moon.

R744 ejector technology future perspectives

NASA Astrophysics Data System (ADS)

Hafner, Armin; Banasiak, Krzysztof

2016-09-01

Carbon Dioxide, CO2 (R744) was one of the first commonly applied working fluids in the infancy of refrigeration more than 100 years ago. In contrast to ammonia it mainly disappeared after the first generation of synthetic refrigerants have been introduced to the market after 1930. One reason was that the transition from low-rpm belt driven compressors towards the direct electrical motor driven compressors (50-60 Hz) was not performed for CO2 compressors before the revival introduced by Gustav Lorentzen in the 90is of last century. Since 1988 an enormous R & D effort has been made to further develop CO2 refrigeration technology in spite of the opposition from the chemical industry. Today CO2 refrigeration and heat pumping technologies are accepted as viable and sustainable alternatives for several applications like commercial refrigeration, transport refrigeration, vehicle air conditioning & heat pumping, domestic hot water heat pumps and industrial applications. For some applications, the current threshold to introduce R744 technology can be overcome when the system design takes into account the advantage of the thermo dynamical- and fluid properties of CO2. I.e. the system is designed for transcritical operation with all it pros and cons and takes into consideration how to minimize the losses, and to apply the normally lost expansion work. Shortcut-designs, i.e. drop in solutions, just replacing the H(C)FC refrigeration unit with an CO2 systems adapted for higher system pressures will not result in energy efficient products. CO2 systems do offer the advantage of enabling flooded evaporators supported with adapted ejector technology. These units offer high system performances at low temperature differences and show low temperature air mal-distributions across evaporators. This work gives an overview for the development possibilities for several applications during the next years. Resulting in a further market share increase of CO2 refrigeration and heat pump systems, as energy efficient alternatives to current systems not applying natural working fluids.

Voltammetric analysis apparatus and method

DOEpatents

Almon, A.C.

1993-06-08

An apparatus and method is described for electrochemical analysis of elements in solution. An auxiliary electrode, a reference electrode, and five working electrodes are positioned in a container containing a sample solution. The working electrodes are spaced apart evenly from each other and the auxiliary electrode to minimize any inter-electrode interference that may occur during analysis. An electric potential is applied between the auxiliary electrode and each of the working electrodes. Simultaneous measurements taken of the current flow through each of the working electrodes for each given potential in a potential range are used for identifying chemical elements present in the sample solution and their respective concentrations. Multiple working electrodes enable a more positive identification to be made by providing unique data characteristic of chemical elements present in the sample solution.

The Shape of Things: The Origin of Young Children's Knowledge of the Names and Properties of Geometric Forms

ERIC Educational Resources Information Center

Verdine, Brian N.; Lucca, Kelsey R.; Golinkoff, Roberta M.; Hirsh-Pasek, Kathryn; Newcombe, Nora S.

2016-01-01

How do toddlers learn the names of geometric forms? Previous work suggests that preschoolers have fragmentary knowledge and that defining properties are not understood until well into elementary school. The current study investigated when children first begin to understand shape names and how they apply those labels to unusual instances. We tested…

Russian Language Testing and Integrated Examination for Foreign Citizens in Russia: Legislation Background and Legal Regulation Specific Features

ERIC Educational Resources Information Center

Dolzhikova, Anzhela

2015-01-01

The Russian Federation faces active law-making and legislative activities aimed at providing legal grounds for qualifying educational level of foreign nationals entering the country with the purpose to work and apply for citizenship. The article deals with the current legislation and regulations in their relationship with each other, their impact…

Does Applying Ethics in Education Have an Effective Impact in the Classroom?

ERIC Educational Resources Information Center

Eldakak, Sam

2010-01-01

Everyone believes now these days that our current age of technology where everything is available on the internet and through texts and emails, ethical issues and ethic in education are becoming major concern and very important than ever before. In the past, people needed to really work hard if they wished to obtain information for tests and…

Learning Analytics in Small-Scale Teacher-Led Innovations: Ethical and Data Privacy Issues

ERIC Educational Resources Information Center

Rodríguez-Triana, María Jesús; Martínez-Monés, Alejandra; Villagrá-Sobrino, Sara

2016-01-01

As a further step towards maturity, the field of learning analytics (LA) is working on the definition of frameworks that structure the legal and ethical issues that scholars and practitioners must take into account when planning and applying LA solutions to their learning contexts. However, current efforts in this direction tend to be focused on…

Weaving Wisdom with Hard Work: Accomplished Student Learns, Grows, and Gives Back

ERIC Educational Resources Information Center

Kuhl, Eleanor

2010-01-01

Linda Taylor (Dine) raises sheep and horses, creates sculpture, paints, teaches traditional weaving classes, hunts solo for elk and deer, and volunteers at the Methodist Thrift Shop. In the past, she has also cared for Native children in need, and she is currently applying to foster a Navajo girl. On weekends, she sells bales of hay at the…

Synthesizing Current Views of Audience: Notes toward a Fuller Understanding of Audience.

ERIC Educational Resources Information Center

Roen, Duane H.

The concept of audience has emerged as a central theme in many scholarly discussions. Walter Ong focuses on fiction and believes that what has been said about fictional narrative applies to all writing. Lev Vygotsky offers the view that students work in the zone of proximal development and observes that thought itself develops as a result of our…

Applying APPA Guidelines for Custodial Staffing: The Case of Slippery Rock University

ERIC Educational Resources Information Center

Iossifova, Albena; Hemphill, Dennis; Brest, Diana; Albert, Scott

2009-01-01

Founded in 1889, Slippery Rock University (SRU) is a state university with 8,500 students and 400 faculty. Facilities and planning (F&P) employs 178 staff, of which 50 are custodians. F&P is responsible for the maintenance of 560 acres and 60 major buildings that comprise approximately 2.3 million gross square feet. Currently work is…

Cathodal Transcranial Direct Current Stimulation Over Left Dorsolateral Prefrontal Cortex Area Promotes Implicit Motor Learning in a Golf Putting Task.

PubMed

Zhu, Frank F; Yeung, Andrew Y; Poolton, Jamie M; Lee, Tatia M C; Leung, Gilberto K K; Masters, Rich S W

2015-01-01

Implicit motor learning is characterized by low dependence on working memory and stable performance despite stress, fatigue, or multi-tasking. However, current paradigms for implicit motor learning are based on behavioral interventions that are often task-specific and limited when applied in practice. To investigate whether cathodal transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) area during motor learning suppressed working memory activity and reduced explicit verbal-analytical involvement in movement control, thereby promoting implicit motor learning. Twenty-seven healthy individuals practiced a golf putting task during a Training Phase while receiving either real cathodal tDCS stimulation over the left DLPFC area or sham stimulation. Their performance was assessed during a Test phase on another day. Verbal working memory capacity was assessed before and after the Training Phase, and before the Test Phase. Compared to sham stimulation, real stimulation suppressed verbal working memory activity after the Training Phase, but enhanced golf putting performance during the Training Phase and the Test Phase, especially when participants were required to multi-task. Cathodal tDCS over the left DLPFC may foster implicit motor learning and performance in complex real-life motor tasks that occur during sports, surgery or motor rehabilitation. Copyright © 2015 Elsevier Inc. All rights reserved.

Measurement and analysis of applied power, forces and material response in friction stir welding of aluminum alloy 6061

NASA Astrophysics Data System (ADS)

Avila, Ricardo E.

The process of Friction Stir Welding (FSW) 6061 aluminum alloy is investigated, with focus on the forces and power being applied in the process and the material response. The main objective is to relate measurements of the forces and power applied in the process with mechanical properties of the material during the dynamic process, based on mathematical modeling and aided by computer simulations, using the LS-DYNA software for finite element modeling. Results of measurements of applied forces and power are presented. The result obtained for applied power is used in the construction of a mechanical variational model of FSW, in which minimization of a functional for the applied torque is sought, leading to an expression for shear stress in the material. The computer simulations are performed by application of the Smoothed Particle Hydrodynamics (SPH) method, in which no structured finite element mesh is used to construct a spatial discretization of the model. The current implementation of SPH in LS-DYNA allows a structural solution using a plastic kinematic material model. This work produces information useful to improve understanding of the material flow in the process, and thus adds to current knowledge about the behavior of materials under processes of severe plastic deformation, particularly those processes in which deformation occurs mainly by application of shear stress, aided by thermoplastic strain localization and dynamic recrystallization.

Green extraction of natural products: concept and principles.

PubMed

Chemat, Farid; Vian, Maryline Abert; Cravotto, Giancarlo

2012-01-01

The design of green and sustainable extraction methods of natural products is currently a hot research topic in the multidisciplinary area of applied chemistry, biology and technology. Herein we aimed to introduce the six principles of green-extraction, describing a multifaceted strategy to apply this concept at research and industrial level. The mainstay of this working protocol are new and innovative technologies, process intensification, agro-solvents and energy saving. The concept, principles and examples of green extraction here discussed, offer an updated glimpse of the huge technological effort that is being made and the diverse applications that are being developed.

A full-duplex working integrated optoelectronic device for optical interconnect

NASA Astrophysics Data System (ADS)

Liu, Kai; Fan, Huize; Huang, Yongqing; Duan, Xiaofeng; Wang, Qi; Ren, Xiaomin; Wei, Qi; Cai, Shiwei

2018-05-01

In this paper, a full-duplex working integrated optoelectronic device is proposed. It is constructed by integrating a vertical cavity surface emitting laser (VCSEL) unit above a resonant cavity enhanced photodetector (RCE-PD) unit. Analysis shows that, the VCSEL unit has a threshold current of 1 mA and a slop efficiency of 0.66 W/A at 849.7 nm, the RCE-PD unit obtains its maximal absorption quantum efficiency of 90.24% at 811 nm with a FWHM of 4 nm. Moreover, the two units of the proposed integrated device can work independently from each other. So that the proposed integrated optoelectronic device can work full-duplex. It can be applied for single fiber bidirectional optical interconnects system.

Working Memory and Neurofeedback.

PubMed

YuLeung To, Eric; Abbott, Kathy; Foster, Dale S; Helmer, D'Arcy

2016-01-01

Impairments in working memory are typically associated with impairments in other cognitive faculties such as attentional processes and short-term memory. This paper briefly introduces neurofeedback as a treatment modality in general, and, more specifically, we review several of the current modalities successfully used in neurofeedback (NF) for the treatment of working memory deficits. Two case studies are presented to illustrate how neurofeedback is applied in treatment. The development of Low Resolution Electromagnetic Tomography (LORETA) and its application in neurofeedback now makes it possible to specifically target deep cortical/subcortical brain structures. Developments in neuroscience concerning neural networks, combined with highly specific yet practical NF technologies, makes neurofeedback of particular interest to neuropsychological practice, including the emergence of specific methodologies for treating very difficult working memory (WM) problems.

Graduating med-peds residents' interest in part-time employment.

PubMed

Fix, Amy L; Kaelber, David C; Melgar, Thomas A; Chamberlain, John; Cull, William; Robbins, Brett W

2011-01-01

As part-time work is becoming more popular among the primary care specialties, we examined the demographic descriptors of med-peds residents seeking and finding part-time employment upon completion of residency training. As part of the 2006 annual American Academy of Pediatrics (AAP) Graduating Med-Peds Residents Survey, we surveyed the graduating residents of all med-peds programs about their interest in and plans for part-time employment. A total of 199 (60%) of the residents responded. Of the resident respondents applying for nonfellowship jobs, 19% sought part-time positions and 10% actually accepted a part-time position. Female residents were significantly more likely than male residents to apply for part-time jobs (26% vs. 7%, P = .034). Sixty percent of female residents immediately seeking work and 58% of those going on to fellowship reported an interest in arranging a part-time or reduced-hours position at some point in the next 5 years. Part-time employment among med-peds residents applying for nonfellowship positions after graduation is similar to the current incidence of part-time employment in other fields of primary care. A much higher percentage of med-peds residents are interested in arranging part-time work within 5 years after graduation. This strong interest in part-time work has many implications for the primary care workforce. Copyright © 2011 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Drain Current Modulation of a Single Drain MOSFET by Lorentz Force for Magnetic Sensing Application.

PubMed

Chatterjee, Prasenjit; Chow, Hwang-Cherng; Feng, Wu-Shiung

2016-08-30

This paper reports a detailed analysis of the drain current modulation of a single-drain normal-gate n channel metal-oxide semiconductor field effect transistor (n-MOSFET) under an on-chip magnetic field. A single-drain n-MOSFET has been fabricated and placed in the center of a square-shaped metal loop which generates the on-chip magnetic field. The proposed device designed is much smaller in size with respect to the metal loop, which ensures that the generated magnetic field is approximately uniform. The change of drain current and change of bulk current per micron device width has been measured. The result shows that the difference drain current is about 145 µA for the maximum applied magnetic field. Such changes occur from the applied Lorentz force to push out the carriers from the channel. Based on the drain current difference, the change in effective mobility has been detected up to 4.227%. Furthermore, a detailed investigation reveals that the device behavior is quite different in subthreshold and saturation region. A change of 50.24 µA bulk current has also been measured. Finally, the device has been verified for use as a magnetic sensor with sensitivity 4.084% (29.6 T(-1)), which is very effective as compared to other previously reported works for a single device.

Electrogenic Na+/Ca2+ Exchange

PubMed Central

Danaceau, Jonathan P.; Lucero, Mary T.

2000-01-01

Olfactory receptor neurons (ORNs) from the squid, Lolliguncula brevis, respond to the odors l-glutamate or dopamine with increases in internal Ca2+ concentrations ([Ca2+]i). To directly asses the effects of increasing [Ca2+]i in perforated-patched squid ORNs, we applied 10 mM caffeine to release Ca2+ from internal stores. We observed an inward current response to caffeine. Monovalent cation replacement of Na+ from the external bath solution completely and selectively inhibited the caffeine-induced response, and ruled out the possibility of a Ca2+-dependent nonselective cation current. The strict dependence on internal Ca2+ and external Na+ indicated that the inward current was due to an electrogenic Na+/Ca2+ exchanger. Block of the caffeine-induced current by an inhibitor of Na+/Ca2+ exchange (50–100 μM 2′,4′-dichlorobenzamil) and reversibility of the exchanger current, further confirmed its presence. We tested whether Na+/Ca2+ exchange contributed to odor responses by applying the aquatic odor l-glutamate in the presence and absence of 2′,4′-dichlorobenzamil. We found that electrogenic Na+/Ca2+ exchange was responsible for ∼26% of the total current associated with glutamate-induced odor responses. Although Na+/Ca2+ exchangers are known to be present in ORNs from numerous species, this is the first work to demonstrate amplifying contributions of the exchanger current to odor transduction. PMID:10828249

Nonstandard work arrangements and worker health and safety.

PubMed

Howard, John

2017-01-01

Arrangements between those who perform work and those who provide jobs come in many different forms. Standard work arrangements now exist alongside several nonstandard arrangements: agency work, contract work, and gig work. While standard work arrangements are still the most prevalent types, the rise of nonstandard work arrangements, especially temporary agency, contract, and "gig" arrangements, and the potential effects of these new arrangements on worker health and safety have captured the attention of government, business, labor, and academia. This article describes the major work arrangements in use today, profiles the nonstandard workforce, discusses several legal questions about how established principles of labor and employment law apply to nonstandard work arrangements, summarizes findings published in the past 20 years about the health and safety risks for workers in nonstandard work arrangements, and outlines current research efforts in the area of healthy work design and worker well-being. Am. J. Ind. Med. 60:1-10, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

"GSFC FSB Application of Perspective-Based Inspections"

NASA Technical Reports Server (NTRS)

Shell, Elaine; Shull, Forrest

2004-01-01

The scope of work described in our proposal consisted of developing inspection standards targeted to Branch-specific types of defects (gained from analysis of Branch project defect histories), and including Branch-relevant perspectives and questions to guide defect detection. The tailored inspection guidelines were to be applied on real Branch projects with support as needed from the technology infusion team. This still accurately describes the scope of work performed. It was originally proposed that the Perspective-Based inspection standard would be applied on three projects within the Branch: GPM, JWST, and SDO. Rather than apply the proposed standard to all three, we inserted a new step, in which the standard was instead applied on a single pilot project, cFE (described above). This decision was a good match for the Branch goals since, due to the "design for reuse" nature of cFE, inspections played an even more crucial than usual role in that development process. Also, since cFE is being designed to provide general-purpose functionality, key representatives fiom our target projects were involved in inspections of cFE to provide perspectives from different missions. In this way, they could get some exposure to and the chance to provide feedback on the proposed standards before applying them on their own projects. The Branch-baselined standards will still be applied on GPM, JWST, and SDO, although outside the time frame of this funding. Finally, we originally proposed using the analysis of Branch defect sources to indicate in which phases Perspective-Based inspections could provide the best potential for future improvement, although experience on previous Branch projects suggested that our efforts would likely be focused on requirements and code inspections. In the actual work, we focused exclusively on requirements inspections, as this was the highest-priority work currently being done on our cFE pilot project.

Advancing knowledge in work-related rehabilitation - review of research published in the journal of WORK.

PubMed

Prodinger, Birgit; Magalhães, Lilian

2010-01-01

Many studies published in the journal WORK in the recent decades have discussed work and employment trends. However, the dimensions of these contributions over time have not been reviewed. The main objective of this study was to investigate the knowledge development in regard to work-related rehabilitation in WORK over the last two decades. A scoping review was conducted using the following five stages: (i) identifying research question, (ii) identifying relevant studies, (iii) study selection, (iv) charting, summarizing, and collating the data, and (v) reporting the results. Studies were selected from the WORK ARTicle Database. Seventy-five relevant studies were identified. The findings reflect that WORK has published papers from across the world, with most of the studies from the United States, Sweden, Canada, and Hong Kong. The complexity and multi-factorial nature of work-related rehabilitation was reflected in the application of quantitative, qualitative, and mixed method research approaches, as well as case studies. Study participants were characterized by work, and non-work related injuries, systematic diseases/chronic illness, fulfilled certain socio-demographic characteristic, and represented various stakeholders. Fewer studies drew on secondary resources. In the findings one re-occurring theme has been noted: 'maintaining/obtaining/returning to secure and stable employment/work'. Four key-reflections evolved from this scoping review that provide potential avenues for future research. These key-reflections include (i) the national, transnational and international dimension of the reviewed studies, (ii) the various societal levels informing work-related rehabilitation practices, (iii) the diversity of methodologies applied in current research, and (iv) the variability of terminology used within the reviewed studies. The journal WORK has published a variety of research over the last two decades and contributed significantly to our current understanding of work-related rehabilitation. However, further research in these reflective areas would expand the current knowledge base.

Intelligent vehicle electrical power supply system with central coordinated protection

NASA Astrophysics Data System (ADS)

Yang, Diange; Kong, Weiwei; Li, Bing; Lian, Xiaomin

2016-07-01

The current research of vehicle electrical power supply system mainly focuses on electric vehicles (EV) and hybrid electric vehicles (HEV). The vehicle electrical power supply system used in traditional fuel vehicles is rather simple and imperfect; electrical/electronic devices (EEDs) applied in vehicles are usually directly connected with the vehicle's battery. With increasing numbers of EEDs being applied in traditional fuel vehicles, vehicle electrical power supply systems should be optimized and improved so that they can work more safely and more effectively. In this paper, a new vehicle electrical power supply system for traditional fuel vehicles, which accounts for all electrical/electronic devices and complex work conditions, is proposed based on a smart electrical/electronic device (SEED) system. Working as an independent intelligent electrical power supply network, the proposed system is isolated from the electrical control module and communication network, and access to the vehicle system is made through a bus interface. This results in a clean controller power supply with no electromagnetic interference. A new practical battery state of charge (SoC) estimation method is also proposed to achieve more accurate SoC estimation for lead-acid batteries in traditional fuel vehicles so that the intelligent power system can monitor the status of the battery for an over-current state in each power channel. Optimized protection methods are also used to ensure power supply safety. Experiments and tests on a traditional fuel vehicle are performed, and the results reveal that the battery SoC is calculated quickly and sufficiently accurately for battery over-discharge protection. Over-current protection is achieved, and the entire vehicle's power utilization is optimized. For traditional fuel vehicles, the proposed vehicle electrical power supply system is comprehensive and has a unified system architecture, enhancing system reliability and security.

AC loss modelling and experiment of two types of low-inductance solenoidal coils

NASA Astrophysics Data System (ADS)

Liang, Fei; Yuan, Weijia; Zhang, Min; Zhang, Zhenyu; Li, Jianwei; Venuturumilli, Sriharsha; Patel, Jay

2016-11-01

Low-inductance solenoidal coils, which usually refer to the nonintersecting type and the braid type, have already been employed to build superconducting fault current limiters because of their fast recovery and low inductance characteristics. However, despite their usage there is still no systematical simulation work concerning the AC loss characteristics of the coils built with 2G high temperature superconducting tapes perhaps because of their complicated structure. In this paper, a new method is proposed to simulate both types of coils with 2D axisymmetric models solved by H formulation. Following the simulation work, AC losses of both types of low inductance solenoidal coils are compared numerically and experimentally, which verify that the model works well in simulating non-inductive coils. Finally, simulation works show that pitch has significant impact to AC loss of both types of coils and the inter-layer separation has different impact to the AC loss of braid type of coil in case of different applied currents. The model provides an effective tool for the design optimisation of SFCLs built with non-inductive solenoidal coils.

Continuous day-time time series of E-region equatorial electric fields derived from ground magnetic observatory data

NASA Astrophysics Data System (ADS)

Alken, P.; Chulliat, A.; Maus, S.

2012-12-01

The day-time eastward equatorial electric field (EEF) in the ionospheric E-region plays an important role in equatorial ionospheric dynamics. It is responsible for driving the equatorial electrojet (EEJ) current system, equatorial vertical ion drifts, and the equatorial ionization anomaly (EIA). Due to its importance, there is much interest in accurately measuring and modeling the EEF. However, there are limited sources of direct EEF measurements with full temporal and spatial coverage of the equatorial ionosphere. In this work, we propose a method of estimating a continuous day-time time series of the EEF at any longitude, provided there is a pair of ground magnetic observatories in the region which can accurately track changes in the strength of the EEJ. First, we derive a climatological unit latitudinal current profile from direct overflights of the CHAMP satellite and use delta H measurements from the ground observatory pair to determine the magnitude of the current. The time series of current profiles is then inverted for the EEF by solving the governing electrodynamic equations. While this method has previously been applied and validated in the Peruvian sector, in this work we demonstrate the method using a pair of magnetometers in Africa (Samogossoni, SAM, 0.18 degrees magnetic latitude and Tamanrasset, TAM, 11.5 degrees magnetic latitude) and validate the resulting EEF values against the CINDI ion velocity meter (IVM) instrument on the C/NOFS satellite. We find a very good 80% correlation with C/NOFS IVM measurements and a root-mean-square difference of 9 m/s in vertical drift velocity. This technique can be extended to any pair of ground observatories which can capture the day-time strength of the EEJ. We plan to apply this work to more observatory pairs around the globe and distribute real-time equatorial electric field values to the community.

Diagnostics and Active Control of Aircraft Interior Noise

NASA Technical Reports Server (NTRS)

Fuller, C. R.

1998-01-01

This project deals with developing advanced methods for investigating and controlling interior noise in aircraft. The work concentrates on developing and applying the techniques of Near Field Acoustic Holography (NAH) and Principal Component Analysis (PCA) to the aircraft interior noise dynamic problem. This involves investigating the current state of the art, developing new techniques and then applying them to the particular problem being studied. The knowledge gained under the first part of the project was then used to develop and apply new, advanced noise control techniques for reducing interior noise. A new fully active control approach based on the PCA was developed and implemented on a test cylinder. Finally an active-passive approach based on tunable vibration absorbers was to be developed and analytically applied to a range of test structures from simple plates to aircraft fuselages.

The Development of the Unified Protocol for the Transdiagnostic Treatment of Emotional Disorders: A Case Study

PubMed Central

Boisseau, Christina L.; Farchione, Todd J.; Fairholme, Christopher P.; Ellard, Kristen K.; Barlow, David H.

2013-01-01

A detailed description of treatment utilizing the Unified Protocol (UP), a transdiagnostic emotion-focused cognitive-behavioral treatment, is presented using a clinical case example treated during the most current phase of an ongoing randomized controlled trial of the UP. The implementation of the UP in its current, modular version is illustrated. A working case conceptualization is presented from the perspective of the UP drawing from theory and research that underlies current transdiagnostic approaches to treatment and consistent with recent dimensional classification proposals (Brown & Barlow, in press). Treatment is illustrated module-by-module describing how the principles of the UP were applied in the presented case. PMID:23997572

Skyrmion-based multi-channel racetrack

NASA Astrophysics Data System (ADS)

Song, Chengkun; Jin, Chendong; Wang, Jinshuai; Xia, Haiyan; Wang, Jianbo; Liu, Qingfang

2017-11-01

Magnetic skyrmions are promising for the application of racetrack memories, logic gates, and other nano-devices, owing to their topologically protected stability, small size, and low driving current. In this work, we propose a skyrmion-based multi-channel racetrack memory where the skyrmion moves in the selected channel by applying voltage-controlled magnetic anisotropy gates. It is demonstrated numerically that a current-dependent skyrmion Hall effect can be restrained by the additional potential of the voltage-controlled region, and the skyrmion velocity and moving channel in the racetrack can be operated by tuning the voltage-controlled magnetic anisotropy, gate position, and current density. Our results offer a potential application of racetrack memory based on skyrmions.

Theory and design of electrical rotating machinery

NASA Astrophysics Data System (ADS)

Carr, W. J., Jr.

1980-04-01

The objective of this program was to contribute toward new and improved rotating machines for Naval applications, with emphasis on superconducting machinery. Work has been performed on the theory of ac losses in multifilament superconductors and experiments were made to check the theory. A list of publications and abstracts of scientific papers published under the contract is given, and a review is given of the theory of losses. A macroscopic theory for superconductivity in multifilament superconductors was developed, and the theory was used to calculate the hysteresis and eddy current losses which occur in the presence of changing magnetic fields. Both the transverse field and the longitudinal field cases were considered, and also the self-field loss of an alternating transport current, along with some examples of the combined loss due to alternating applied field and transport current. The results are useful for the design of superconducting devices, such as superconducting motors and generators. A small amount of additional work was done on studies of novel homo- and heteropolar motors.

Tailored Electrospinning of WO₃ Nanobelts as Efficient Ultraviolet Photodetectors with Photo-Dark Current Ratios up to 1000.

PubMed

He, Zhiyang; Liu, Qiao; Hou, Huilin; Gao, Fengmei; Tang, Bin; Yang, Weiyou

2015-05-27

In this work, polycrystalline WO3 nanobelts were fabricated via an electrospinning process combined with subsequent air calcination. The resultant products were characterized by X-ray diffraction, field-emission scanning electron microscopy, and high-resolution transmission electron microscopy in regard to the structures. It has been found that the applied voltage during the electrospinning process played the determined role in the formation of the WO3 nanobelts, allowing the controlled growth of the nanobelts. The ultraviolet (UV) photodetector assembled by an individual WO3 nanobelt exhibits a high sensitivity and a precise selectivity to the different wavelength lights, with a very low dark current and typical photo-dark current ratio up to 1000, which was the highest for any WO3 photodectectors ever reported. This work could not only push forward the facile preparation of WO3 nanobelts but also represent, for the first time, the possibility that the polycrystalline WO3 nanobelts could be a promising building block for the highly efficient UV photodetectors.

Current phase relation from graphs and diagrams and application to thick ferromagnetic Josephson junctions

NASA Astrophysics Data System (ADS)

Margaris, I.; Paltoglou, V.; Flytzanis, N.

2018-05-01

In this work we present a method of representing terms in the current-phase-relation of a ballistic Josephson junction by combinations of diagrams, used in previous work to represent an equivalent of the matching condition determinant of the junction. This is accomplished by the expansion of the logarithm of this determinant in Taylor series and keeping track of surviving terms, i.e. terms that do not annihilate each other. The types of the surviving terms are represented by connected graphs, whose points represent diagrammatic terms of the determinant expansion. Then the theory is applied to obtain approximations of the current-phase relation of relatively thick ballistic ferromagnetic Josephson junctions with non-collinear magnetizations. This demonstrates the versatility of the method in developing approximations schemes and providing physical insight into the nature of contributions to the supercurrent from the available particle excitations in the junction. We also discuss the strong second harmonic contribution to the supercurrent in junctions with three mutually orthogonal magnetization vectors and a weak intermediate ferromagnet.

Spectroscopic characterization of low dose rate brachytherapy sources

NASA Astrophysics Data System (ADS)

Beach, Stephen M.

The low dose rate (LDR) brachytherapy seeds employed in permanent radioactive-source implant treatments usually use one of two radionuclides, 125I or 103Pd. The theoretically expected source spectroscopic output from these sources can be obtained via Monte Carlo calculation based upon seed dimensions and materials as well as the bare-source photon emissions for that specific radionuclide. However the discrepancies resulting from inconsistent manufacturing of sources in comparison to each other within model groups and simplified Monte Carlo calculational geometries ultimately result in undesirably large uncertainties in the Monte Carlo calculated values. This dissertation describes experimentally attained spectroscopic outputs of the clinically used brachytherapy sources in air and in liquid water. Such knowledge can then be applied to characterize these sources by a more fundamental and metro logically-pure classification, that of energy-based dosimetry. The spectroscopic results contained within this dissertation can be utilized in the verification and benchmarking of Monte Carlo calculational models of these brachytherapy sources. This body of work was undertaken to establish a usable spectroscopy system and analysis methods for the meaningful study of LDR brachytherapy seeds. The development of a correction algorithm and the analysis of the resultant spectroscopic measurements are presented. The characterization of the spectrometer and the subsequent deconvolution of the measured spectrum to obtain the true spectrum free of any perturbations caused by the spectrometer itself is an important contribution of this work. The approach of spectroscopic deconvolution that was applied in this work is derived in detail and it is applied to the physical measurements. In addition, the spectroscopically based analogs to the LDR dosimetry parameters that are currently employed are detailed, as well as the development of the theory and measurement methods to arrive at these analogs. Several dosimetrically-relevant water-equivalent plastics were also investigated for their transmission properties within a liquid water environment, as well as in air. The framework for the accurate spectrometry of LDR sources is established as a result of this dissertation work. In addition to the measurement and analysis methods, this work presents the basic measured spectroscopic characteristics of each LDR seed currently in use in the clinic today.

Intervention strategies to eliminate truck-related fatalities in surface coal mining in West Virginia.

PubMed

Zhang, Meng; Kecojevic, Vladislav

2016-01-01

The main objective of this review was to build upon a previous study on the root causes of truck-related fatalities in surface coal mining operations in West Virginia, and to develop intervention strategies to eliminate these fatalities. This review considers a two-pronged approach to accident prevention: one that is fundamental and traditional (safety regulations, training and education, and engineering of the work environment); and one that is innovative and creative (e.g., applying technological advances to better control and eliminate the root causes of accidents). Suggestions for improving current training and education system are proposed, and recommendations are provided on improving the safety of mine working conditions, specifically safety conditions on haul roads, dump sites, and loading areas. We also discuss various currently available technologies that can help prevent haul truck-related fatal accidents. The results of this review should be used by mine personnel to help create safer working conditions and decrease truck-related fatalities in surface coal mining.

One-step electrochemical deposition of Schiff base cobalt complex as effective water oxidation catalyst

NASA Astrophysics Data System (ADS)

Huang, Binbin; Wang, Yan; Zhan, Shuzhong; Ye, Jianshan

2017-02-01

Schiff base metal complexes have been applied in many fields, especially, a potential homogeneous catalyst for water splitting. However, the high overpotential, time consumed synthesis process and complicated working condition largely limit their application. In the present work, a one-step approach to fabricate Schiff base cobalt complex modified electrode is developed. Microrod clusters (MRC) and rough spherical particles (RSP) can be obtained on the ITO electrode through different electrochemical deposition condition. Both of the MRC and RSP present favorable activity for oxygen evolution reaction (OER) compared to the commercial Co3O4, taking an overpotential of 650 mV and 450 mV to drive appreciable catalytic current respectively. The highly active and stable RSP shows a Tafel plot of 84 mV dec-1 and negligible decrease of the current density for 12 h bulk electrolysis. The synthesis strategy of effective and stable catalyst in this work provide a simple method to fabricate heterogeneous OER catalyst with Schiff base metal complex.

A unified framework for mesh refinement in random and physical space

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

Li, Jing; Stinis, Panos

In recent work we have shown how an accurate reduced model can be utilized to perform mesh renement in random space. That work relied on the explicit knowledge of an accurate reduced model which is used to monitor the transfer of activity from the large to the small scales of the solution. Since this is not always available, we present in the current work a framework which shares the merits and basic idea of the previous approach but does not require an explicit knowledge of a reduced model. Moreover, the current framework can be applied for renement in both randommore » and physical space. In this manuscript we focus on the application to random space mesh renement. We study examples of increasing difficulty (from ordinary to partial differential equations) which demonstrate the effciency and versatility of our approach. We also provide some results from the application of the new framework to physical space mesh refinement.« less

Model Scaling of Hydrokinetic Ocean Renewable Energy Systems

NASA Astrophysics Data System (ADS)

von Ellenrieder, Karl; Valentine, William

2013-11-01

Numerical simulations are performed to validate a non-dimensional dynamic scaling procedure that can be applied to subsurface and deeply moored systems, such as hydrokinetic ocean renewable energy devices. The prototype systems are moored in water 400 m deep and include: subsurface spherical buoys moored in a shear current and excited by waves; an ocean current turbine excited by waves; and a deeply submerged spherical buoy in a shear current excited by strong current fluctuations. The corresponding model systems, which are scaled based on relative water depths of 10 m and 40 m, are also studied. For each case examined, the response of the model system closely matches the scaled response of the corresponding full-sized prototype system. The results suggest that laboratory-scale testing of complete ocean current renewable energy systems moored in a current is possible. This work was supported by the U.S. Southeast National Marine Renewable Energy Center (SNMREC).

Effects of electric current on individual graphene oxide sheets combining in situ transmission electron microscopy and Raman spectroscopy

NASA Astrophysics Data System (ADS)

Martín, Gemma; Varea, Aïda; Cirera, Albert; Estradé, Sònia; Peiró, Francesca; Cornet, Albert

2018-07-01

Graphene oxide (GO) is currently the object of extensive research because of its potential use in mass production of graphene-based materials, but also due to its tunability which holds great promise for new nanoscale electronic devices and sensors. To obtain a better understanding of the role of GO in electronic nano-devices, the elucidation of the effects of electrical current on a single GO sheet is of great interest. In this work, in situ transmission electron microscopy is used to study the effects of the electrical current flow through single GO sheets using an scanning tunneling microscope holder. In order to correlate the applied current with the structural properties of GO, Raman spectroscopy is carried out and data analysis is used to obtain information regarding the reduction grade and the disorder degree of the GO sheets before and after the application of current.

Effects of electric current on individual graphene oxide sheets combining in situ transmission electron microscopy and Raman spectroscopy.

PubMed

Martín, Gemma; Varea, Aïda; Cirera, Albert; Estradé, Sònia; Peiró, Francesca; Cornet, Albert

2018-04-17

Graphene oxide (GO) is currently the object of extensive research because of its potential use in mass production of graphene-based materials, but also due to its tunability which holds great promise for new nanoscale electronic devices and sensors. To obtain a better understanding of the role of GO in electronic nano-devices, the elucidation of the effects of electrical current on a single GO sheet is of great interest. In this work, in situ transmission electron microscopy is used to study the effects of the electrical current flow through single GO sheets using an scanning tunneling microscope holder. In order to correlate the applied current with the structural properties of GO, Raman spectroscopy is carried out and data analysis is used to obtain information regarding the reduction grade and the disorder degree of the GO sheets before and after the application of current.

A new composite consisting of electrosynthesized conducting polymers, graphene sheets and biosynthesized gold nanoparticles for biosensing acute lymphoblastic leukemia.

PubMed

Mazloum-Ardakani, Mohammad; Barazesh, Behnaz; Khoshroo, Alireza; Moshtaghiun, Mohammad; Sheikhha, Mohammad Hasan

2018-06-01

In this work we report the synthesis of a stable composite with excellent electrical properties, on the surface of a biosensor. Conductive polymers offer both high electrical conductivity and mechanical strength. Many reports have focused on synthesizing conductive polymers with the aid of high-cost enzymes. In the current work we introduce a novel electrochemical, one-step, facile and cost effective procedure for synthesizing poly (catechol), without using expensive enzymes. The poly (catechol) conductivity was enhanced by modification with graphene sheets and biosynthesized gold nanoparticles. Four different robust methods, DPV, EIS, CV and chronoamperometry, were used to monitor the biosensor modifications. The peak currents of the catechol (an electroactive probe) were linearly related to the logarithm of the concentrations of target DNA in the range 100.0 μM to 10.0 pM, with a detection limit of 1.0 pM for the DNA strand. The current work investigates a new, stable composite consisting of conductive polymers and nanoparticles, which was applied to the detection of acute lymphoblastic leukemia. Copyright © 2018 Elsevier B.V. All rights reserved.

Understanding the role of electron and hole trions on current transport in aluminium tris(8-hydroxyquinoline) using organic magnetoresistance

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

Zhang, Sijie; Gillin, W. P., E-mail: w.gillin@qmul.ac.uk; Materials Research Institute and School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS

The change in current through an organic light emitting diode (OLED) when it is placed in a magnetic field has been dubbed organic magnetoresistance and provides a means to understand the spin interactions that are occurring in working devices. Whilst there are a wide range of interactions that have been proposed to be the cause of the measured effects, there is still a need to identify their individual roles and in particular how they respond to an applied magnetic field. In this work, we investigate the effect of changing the balance of electron and hole injection in a simple aluminiummore » tris(8-hydroxyqinoline) based OLED and demonstrate that the triplet polaron interaction appears to be much stronger for electrons than for holes in this material.« less

Control approach development for variable recruitment artificial muscles

NASA Astrophysics Data System (ADS)

Jenkins, Tyler E.; Chapman, Edward M.; Bryant, Matthew

2016-04-01

This study characterizes hybrid control approaches for the variable recruitment of fluidic artificial muscles with double acting (antagonistic) actuation. Fluidic artificial muscle actuators have been explored by researchers due to their natural compliance, high force-to-weight ratio, and low cost of fabrication. Previous studies have attempted to improve system efficiency of the actuators through variable recruitment, i.e. using discrete changes in the number of active actuators. While current variable recruitment research utilizes manual valve switching, this paper details the current development of an online variable recruitment control scheme. By continuously controlling applied pressure and discretely controlling the number of active actuators, operation in the lowest possible recruitment state is ensured and working fluid consumption is minimized. Results provide insight into switching control scheme effects on working fluids, fabrication material choices, actuator modeling, and controller development decisions.

Electro-osmotic fluxes in multi-well electro-remediation processes.

PubMed

López-Vizcaíno, Rubén; Sáez, Cristina; Mena, Esperanza; Villaseñor, Jose; Cañizares, Pablo; Rodrigo, Manuel A

2011-01-01

In recent years, electrokinetic techniques on a laboratory scale have been studied but few applications have been assessed at full-scale. In this work, a mock-up plant with two rows of three electrodes positioned in semipermeable electrolyte wells has been used to study the electro-osmotic flux distribution. Water accumulated in the cathodic wells when an electric voltage gradient was applied between the two electrode-well rows. Likewise, slight differences in the water flux were observed depending on the position and number of electrodes used and on the voltage gradient applied. Results show that the electro-osmotic flow did not increase proportionally with the number of electrodes used. During the start-up of the study, there was an abrupt change in the current density, pH and conductivity of the soil portions closest to electrodic wells due to electrokinetic processes. These differences can be explained in terms of the complex current distributions from anode and cathode rows.

Evolution of mechanical response of sodium montmorillonite interlayer with increasing hydration by molecular dynamics.

PubMed

Schmidt, Steven R; Katti, Dinesh R; Ghosh, Pijush; Katti, Kalpana S

2005-08-16

The mechanical response of the interlayer of hydrated montmorillonite was evaluated using steered molecular dynamics. An atomic model of the sodium montmorillonite was previously constructed. In the current study, the interlayer of the model was hydrated with multiple layers of water. Using steered molecular dynamics, external forces were applied to individual atoms of the clay surface, and the response of the model was studied. The displacement versus applied stress and stress versus strain relationships of various parts of the interlayer were studied. The paper describes the construction of the model, the simulation procedure, and results of the simulations. Some results of the previous work are further interpreted in the light of the current research. The simulations provide quantitative stress deformation relationships as well as an insight into the molecular interactions taking place between the clay surface and interlayer water and cations.

White LED compared with other light sources: age-dependent photobiological effects and parameters for evaluation.

PubMed

Rebec, Katja Malovrh; Klanjšek-Gunde, Marta; Bizjak, Grega; Kobav, Matej B

2015-01-01

Ergonomic science at work and living places should appraise human factors concerning the photobiological effects of lighting. Thorough knowledge on this subject has been gained in the past; however, few attempts have been made to propose suitable evaluation parameters. The blue light hazard and its influence on melatonin secretion in age-dependent observers is considered in this paper and parameters for its evaluation are proposed. New parameters were applied to analyse the effects of white light-emitting diode (LED) light sources and to compare them with the currently applied light sources. The photobiological effects of light sources with the same illuminance but different spectral power distribution were determined for healthy 4-76-year-old observers. The suitability of new parameters is discussed. Correlated colour temperature, the only parameter currently used to assess photobiological effects, is evaluated and compared to new parameters.

Preparation, consolidation, and crystallization of bulk metallic glasses

NASA Astrophysics Data System (ADS)

Holland, Troy

Bulk metallic glasses (BMGs) have been widely researched over the last decade. Research has primarily focused on BMGs of differing compositions and conditions within 3 main subject areas: preparation, consolidation, and crystallization. This work endeavors to show the interrelationships among each area across several types of BMG. Two compositions of zirconium(Zr)-type BMGs were prepared by mechanical attrition using a high-energy ball mill. The thermal and x-ray diffraction show that by milling elemental powders it is possible to obtain metallic powders with a glassy nature. These powders were then consolidated using a novel, high current density hot press. Hot pressing by using a spark plasma sintering (SPS) device has shown itself to be very useful in consolidating hard to produce intermetallics and ceramics. By utilizing high current densities and extremely rapid heating rates, the consolidation of the Zr-type ball milled powders and a gas atomized iron(Fe)-type powder was achieved. Utilizing the Kissinger relationship between reaction temperatures and their heating rates allowed for higher peak consolidation temperatures without fully- or partially-devitrifying the powders. The current densities applied aid in the diffusion and thermodynamics of the devitrification reaction. This affect has had little to no previous research so it was necessary to determine the specific effects of applied currents upon the devitrification of BMGs. To determine the role of applied currents on crystallization, or devitrification, of BMGs required the application of differing currents at fixed annealing temperatures. Once this was achieved it was possible with small-angle neutron scattering (SANS), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM) to show that both the kinetics and thermodynamics of the devitrification reaction were affected.

Electrohydrodynamic Flows in Electrochemical Systems

NASA Technical Reports Server (NTRS)

Saville, D. A.

2005-01-01

Recent studies have established a new class of assembly processes with colloidal suspensions. Particles are driven together to form large crystalline structures in both dc and ac fields. The current work centers on this new class of flows in ac fields. In the research carried out under the current award, it was established that: (i) Small colloidal particles crystallize near an electrode due to electrohydrodynamic flows induced by an sinusoidally varying applied potential. (ii) These flows originate due to disturbances in the electrode polarization layer arising from the presence of the particles. Inasmuch as the charge and the field strength both scale on the applied field, the flows are proportional to the square of the applied voltage. (iii) Suspensions of two different sorts of particles can be crystallized and will form well-ordered binary crystals. (iv) At high frequencies the EHD flows die out. Thus, with a homogeneous system the particles become widely spaced due to dipolar repulsion. With a binary suspension, however, the particles may become attractive due to dipolar attraction arising from differences in electrokinetic dipoles. Consequently binary crystals form at both high and low frequencies.

Investigating students' view on STEM in learning about electrical current through STS approach

NASA Astrophysics Data System (ADS)

Tupsai, Jiraporn; Yuenyong, Chokchai

2018-01-01

This study aims to investigate Grade 11 students' views on Science Technology Engineering Mathematics (STEM) with the integration of learning about electrical current based on Science Technology Society (STS) approach [8]. The participants were 60 Grade 11 students in Demonstration Secondary School, Khon Kaen University, Khon Kaen Province, Thailand. The methodology is in the respect of interpretive paradigm. The teaching and learning about Electrical Current through STS approach carried out over 6 weeks. The Electrical Current unit through STS approach was developed based on framework[8] that consists of five stages including (1) identification of social issues, (2) identification of potential solutions, (3) need for knowledge, (4) decision making, and (5) socialization stage. To start with, the question "what if this world is lack of electricity" was challenged in the class in order to move students to find the problem of how to design Electricity Generation from Clean Energy. Students were expected to apply scientific and other knowledge to design of Electricity Generation. Students' views on STEM were collected during their learning by participant' observation and students' tasks. Their views on STEM were categorized when they applied their knowledge for designing the Electricity Generation. The findings indicated that students cooperatively work to solve the problem when applying knowledge about the content of Science and Mathematics and processing skill of Technology and Engineering. It showed that students held the integration of science, technology, engineering and mathematics to design their possible solutions in learning about Electrical Current. The paper also discusses implications for science teaching and learning through STS in Thailand.

An experimental and theoretical study of the dark current and x-ray sensitivity of amorphous selenium x-ray photoconductors

NASA Astrophysics Data System (ADS)

Frey, Joel Brandon

Recently, the world of diagnostic radiography has seen the integration of digital flat panel x-ray image detectors into x-ray imaging systems, replacing analog film screens. These flat panel x-ray imagers (FPXIs) have been shown to produce high quality x-ray images and provide many advantages that are inherent to a fully digital technology. Direct conversion FPXIs based on a photoconductive layer of stabilized amorphous selenium (a-Se) have been commercialized and have proven particularly effective in the field of mammography. In the operation of these detectors, incident x-ray photons are converted directly to charge carriers in the a-Se layer and drifted to electrodes on either side of the layer by a large applied field (10 V/microm). The applied field causes a dark current to flow which is not due to the incident radiation and this becomes a source of noise which can reduce the dynamic range of the detector. The level of dark current in commercialized detectors has been reduced by the deposition of thin n- and p- type blocking layers between the electrodes and the bulk of the a-Se. Despite recent research into the dark current in metal/a-Se/metal sandwich structures, much is still unknown about the true cause and nature of this phenomenon. The work in this Ph.D. thesis describes an experimental and theoretical study of the dark current in these structures. Experiments have been performed on five separate sets of a-Se samples which approximate the photoconductive layer in an FPXI. The dark current has been measured as a function of time, sample structure, applied field, sample thickness and contact metal used. This work has conclusively shown that the dark current is almost entirely due to the injection of charge carriers from the contacts and the contribution of Poole-Frenkel enhanced bulk thermal generation is negligible. There is also evidence that while the dark current is initially controlled by the injection of holes from the positive contact, several minutes after the application of the bias, the dark current due to hole injection may decay to the point where the electron current becomes significant and even dominant. These conclusions are supported by numerical calculations of the dark current transients which have been calibrated to match experimental results. Work detailed in this Ph.D. thesis also focuses on Monte Carlo modeling of the x-ray sensitivity of a-Se FPXIs. The higher the x-ray sensitivity of a detector, the lower the radiation dose required to acquire an acceptable image. FPXIs can experience a decrease in the x-ray sensitivity of the photoconductive layer with accumulating exposure, leading to a phenomenon known as "ghosting". Modeling this decrease in sensitivity can uncover the reasons behind it. The Monte Carlo model described in this thesis is a continuation of a previous model which now considers the effects of the n- and p-like blocking layers and the flow of dark current between x-ray exposures. The simulation results explain how deep trapping of photogenerated charge carriers, and the resulting effect on the electric field distribution, contribute to sensitivity loss. The model has shown excellent agreement with experimental data and has accurately predicted a sensitivity recovery once exposure has ceased which is due to primarily to the relaxation of metastable x-ray-induced carrier trap states.

Removal of ammonium ion from produced waters in petroleum offshore exploitation by a batch single-stage electrolytic process.

PubMed

de Lima, Rosilda Maria Gomes; da Silva Wildhagen, Glória Regina; da Cunha, José Waldemar Silva Dias; Afonso, Julio Carlos

2009-01-30

This work describes a batch single-stage electrochemical process to remove quantitatively the ammonium ion from produced waters from petroleum exploration of the Campos' Basin, seeking to fulfil the directories of the National Brazilian Environmental Council. The anode was made out of titanium covered by a layer of RuO(2)+TiO(2) oxides (Dimensionally Stable Anode), whereas the cathode was made out of pure titanium. Anodic and cathodic compartments were separated by a membrane. The applied current varied from 0.3 to 1.5A. As the current increased NH(4)(+) removal was faster and pH was rapidly decreased to 3. The pH of the anodic compartment increased to approximately 10. When the current was 0.92 A chlorine evolution was observed after 40 min or only 15 min when that current was 1.50 A. In this voltage a deposit containing alkali-earth metal hydroxides/sulphates was formed on the membrane surface of the cathode side, thus suggesting a diffusion process from the anodic to the cathodic compartment. The maximum current applied to the cell must not exceed approximately 0.70 A in order to avoid chlorine evolution. Ammonia removal was over 99.9 wt% at 0.68 A in about 75 min.

Tunneling mechanism and contact mechanics of colloidal nanoparticle assemblies.

PubMed

Biaye, Moussa; Zbydniewska, Ewa; Mélin, Thierry; Deresmes, Dominique; Copie, Guillaume; Cleri, Fabrizio; Sangeetha, Neralagatta; Decorde, Nicolas; Viallet, Benoit; Grisolia, Jérémie; Ressier, Laurence; Diesinger, Heinrich

2016-11-25

Nanoparticle assemblies with thiol-terminated alkyl chains are studied by conducting atomic force microscopy (c-AFM) regarding their use as strain gauges for touch-sensitive panels. Current-force spectroscopy is used as a characterization tool complementary to the macroscopic setup since it allows a bias to be applied to a limited number of junctions, overcoming the Coulomb blockade energy and focusing on the contact electromechanics and the transport mechanism across the ligand. First, transition voltage spectroscopy is applied with varying force to target the underlying tunneling mechanism by observing whether the transition between the ohmic and exponential current-voltage behavior is force-dependent. Secondly, current-force spectroscopy in the ohmic range below the transition voltage is performed. The current-force behavior of the AFM probe in contact with a nanoparticle multilayer is associated with the spread of force and current within the nanoparticle lattice and at the level of adjacent particles by detailed contact mechanics treatment. The result is twofold: concerning the architecture of sensors, this work is a sample case of contact electromechanics at scales ranging from the device scale down to the individual ligand molecule. Regarding transport across the molecule, the vacuum tunneling mechanism is favored over the conduction by coherent molecular states, which is a decision-making aid for the choice of ligand in applications.

Conceptual Framework for Speech Language Pathologists to Work with Migrants: A Focus on Malta

ERIC Educational Resources Information Center

Grech, Helen; Cheng, Li Rong Lilly

2016-01-01

The goal of this paper is to describe the current state, needs and values of migrants with a focus on relevant global issues and Malta as a case study. It also aims to review services offered to these migrants, identify aspects that require attention and draw up a framework that could be applied to enhance services to the culturally diverse…

Wall-layer model for LES with massive separation

NASA Astrophysics Data System (ADS)

Fakhari, Ahmad; Armenio, Vincenzo; Roman, Federico

2016-11-01

Currently, Wall Functions (WF) work well under specific conditions, mostly exhibit drawbacks specially in flows with separation beyond curvatures. In this work, we propose a more general WF which works well in attached and detached flows, in presence and absence of Immersed Boundaries (IB). First we modified an equilibrium stress WF for boundary-fitted geometry making dynamic the computation of the k (von Karman constant) of the log-law; the model was first applied to a periodic open channel flow, and then to the flow over a 2D single hill using uniform coarse grids; the model captured separation with reasonable accuracy. Thereafter IB Method by Roman et al. was improved to avoid momentum loss at the interface between the fluid-solid regions. This required calibration of interfacial eddy viscosity; also a random stochastic forcing was used in wall-normal direction to increase Reynolds stresses and improve mean velocity profile. Finally, to reproduce flow separation, a simplified boundary layer equation was applied to construct velocity at near wall computational nodes. The new scheme was tested on the 2D single hill and periodic hills applying Cartesian and curvilinear grids; good agreement with references was obtained with reduction in cost and complexity. Financial support from project COSMO "CFD open source per opera morta" PAR FSC 2007-2013, Friuli Venezia Giulia.

Length-dependent transport in molecular junctions based on SAMs of alkanethiols and alkanedithiols: effect of metal work function and applied bias on tunneling efficiency and contact resistance.

PubMed

Engelkes, Vincent B; Beebe, Jeremy M; Frisbie, C Daniel

2004-11-03

Nanoscopic tunnel junctions were formed by contacting Au-, Pt-, or Ag-coated atomic force microscopy (AFM) tips to self-assembled monolayers (SAMs) of alkanethiol or alkanedithiol molecules on polycrystalline Au, Pt, or Ag substrates. Current-voltage traces exhibited sigmoidal behavior and an exponential attenuation with molecular length, characteristic of nonresonant tunneling. The length-dependent decay parameter, beta, was found to be approximately 1.1 per carbon atom (C(-1)) or 0.88 A(-)(1) and was independent of applied bias (over a voltage range of +/-1.5 V) and electrode work function. In contrast, the contact resistance, R(0), extrapolated from resistance versus molecular length plots showed a notable decrease with both applied bias and increasing electrode work function. The doubly bound alkanedithiol junctions were observed to have a contact resistance approximately 1 to 2 orders of magnitude lower than the singly bound alkanethiol junctions. However, both alkanethiol and dithiol junctions exhibited the same length dependence (beta value). The resistance versus length data were also used to calculate transmission values for each type of contact (e.g., Au-S-C, Au/CH(3), etc.) and the transmission per C-C bond (T(C)(-)()(C)).

Design Science Methodology Applied to a Chemical Surveillance Tool

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

Huang, Zhuanyi; Han, Kyungsik; Charles-Smith, Lauren E.

Public health surveillance systems gain significant benefits from integrating existing early incident detection systems,supported by closed data sources, with open source data.However, identifying potential alerting incidents relies on finding accurate, reliable sources and presenting the high volume of data in a way that increases analysts work efficiency; a challenge for any system that leverages open source data. In this paper, we present the design concept and the applied design science research methodology of ChemVeillance, a chemical analyst surveillance system.Our work portrays a system design and approach that translates theoretical methodology into practice creating a powerful surveillance system built for specificmore » use cases.Researchers, designers, developers, and related professionals in the health surveillance community can build upon the principles and methodology described here to enhance and broaden current surveillance systems leading to improved situational awareness based on a robust integrated early warning system.« less

A new calibration code for the JET polarimeter.

PubMed

Gelfusa, M; Murari, A; Gaudio, P; Boboc, A; Brombin, M; Orsitto, F P; Giovannozzi, E

2010-05-01

An equivalent model of JET polarimeter is presented, which overcomes the drawbacks of previous versions of the fitting procedures used to provide calibrated results. First of all the signal processing electronics has been simulated, to confirm that it is still working within the original specifications. Then the effective optical path of both the vertical and lateral chords has been implemented to produce the calibration curves. The principle approach to the model has allowed obtaining a unique procedure which can be applied to any manual calibration and remains constant until the following one. The optical model of the chords is then applied to derive the plasma measurements. The results are in good agreement with the estimates of the most advanced full wave propagation code available and have been benchmarked with other diagnostics. The devised procedure has proved to work properly also for the most recent campaigns and high current experiments.

Reflections on the Journal of Applied Psychology for 1989 to 1994: Changes in major research themes and practices over 25 years.

PubMed

Schmitt, Neal

2017-03-01

Informal observations concerning journal content indicates that research investigating organizational behavior topics, including work on the structure of groups and determinants and consequences of group process along with the role of leadership in groups, has increased. Some topics have disappeared (e.g., job analysis, human factors, union-related work, consumer behavior) and others are declining (e.g., research methods, psychometrics). Perhaps the biggest change is in the length of articles, which is mostly a function of the inclusion of greater numbers of references and appendix material. Publishing some of this material in supplementary online materials is now current practice in the Journal of Applied Psychology. Concerns about use of journal space may also be entirely moot, if electronic publishing as opposed to print publishing becomes the norm. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Experience as Knowledge in a New Product Development Team: Implications for Knowledge Management

NASA Technical Reports Server (NTRS)

Cooper, Lynne P.

2009-01-01

This study was conducted to better understand how New Product Development (NPD) team members apply their experiences to meet the task needs of their project. Although "experience" is highly valued in team members, little research has looked specifically at experiences as a type of knowledge, and how this knowledge is used in work settings. This research evaluated nearly 200 instances where team members referenced past experiences during team meetings. During these experience exchanges, team members structured the sharing of their experiences to include three common elements: the source of the experience, the nature of the experience, and the degree of relevance to the current work of the team. The experiences fell into four categories: people (relationships), process, product, and politics. This paper describes how team members structured, applied, and integrated their individual experiences and presents the resulting implications for knowledge management systems that wish to exploit experience knowledge.

The role of high work-function metallic nanodots on the performance of a-Si:H solar cells: offering ohmic contact to light trapping.

PubMed

Kim, Jeehwan; Abou-Kandil, Ahmed; Fogel, Keith; Hovel, Harold; Sadana, Devendra K

2010-12-28

Addition of carbon into p-type "window" layers in hydrogenated amorphous silicon (a-Si:H) solar cells enhances short circuit currents and open circuit voltages by a great deal. However, a-Si:H solar cells with high carbon-doped "window" layers exhibit poor fill factors due to a Schottky barrier-like impedance at the interface between a-SiC:H windows and transparent conducting oxides (TCO), although they show maximized short circuit currents and open circuit voltages. The impedance is caused by an increasing mismatch between the work function of TCO and that of p-type a-SiC:H. Applying ultrathin high-work-function metals at the interface between the two materials results in an effective lowering of the work function mismatch and a consequent ohmic behavior. If the metal layer is sufficiently thin, then it forms nanodots rather than a continuous layer which provides light-scattering effect. We demonstrate 31% efficiency enhancement by using high-work-function materials for engineering the work function at the key interfaces to raise fill factors as well as photocurrents. The use of metallic interface layers in this work is a clear contrast to previous work where attempts were made to enhance the photocurrent using plasmonic metal nanodots on the solar cell surface.

Voltametric analysis apparatus and method

DOEpatents

Almon, Amy C.

1993-01-01

An apparatus and method for electrochemical analysis of elements in solution. An auxiliary electrode 14, a reference electrode 18, and five working electrodes 20, 22, 26, 28, and 30 are positioned in a container 12 containing a sample solution 34. The working electrodes are spaced apart evenly from each other and auxiliary electrode 14 to minimize any inter-electrode interference that may occur during analysis. An electric potential is applied between auxiliary electrode 14 and each of the working electrodes 20, 22, 26, 28, and 30. Simultaneous measurements taken of the current flow through each of the working electrodes for each given potential in a potential range are used for identifying chemical elements present in sample solution 34 and their respective concentrations. Multiple working electrodes enable a more positive identification to be made by providing unique data characteristic of chemical elements present in the sample solution.

Magnetic field manipulation of spin current in a single-molecule magnet tunnel junction with two-electron Coulomb interaction

NASA Astrophysics Data System (ADS)

Zhang, Chao; Yao, Hui; Nie, Yi-Hang; Liang, Jiu-Qing; Niu, Peng-Bin

2018-04-01

In this work, we study the generation of spin-current in a single-molecule magnet (SMM) tunnel junction with Coulomb interaction of transport electrons and external magnetic field. In the absence of field the spin-up and -down currents are symmetric with respect to the initial polarizations of molecule. The existence of magnetic field breaks the time-reversal symmetry, which leads to unsymmetrical spin currents of parallel and antiparallel polarizations. Both the amplitude and polarization direction of spin current can be controlled by the applied magnetic field. Particularly when the magnetic field increases to a certain value the spin-current with antiparallel polarization is reversed along with the magnetization reversal of the SMM. The two-electron occupation indeed enhances the transport current compared with the single-electron process. However the increase of Coulomb interaction results in the suppression of spin-current amplitude at the electron-hole symmetry point. We propose a scheme to compensate the suppression with the magnetic field.

Work-life integration in neuropsychology: a review of the existing literature and preliminary recommendations.

PubMed

Feigon, Maia; Block, Cady; Guidotti Breting, Leslie; Boxley, Laura; Dawson, Erica; Cobia, Derin

2018-02-01

The purpose of the current review paper is to identify and describe challenges to work-life integration in neuropsychology, and from this review extrapolate an initial set of recommendations and present a set of scenarios in which the recommendations might apply in the hopes of improving quality of life for current and prospective neuropsychologists. Specific areas of focus include diversity, early and mid-career transitions, and potential barriers to advancement in specific practice settings. A broad review was conducted of extant literature on work-life integration. There is scant scientific literature in this area that is specific to neuropsychologists, or even psychology as a whole. Subsequently, the majority of this review was collected from more developed literatures in business and medical fields. The authors then provided recommendations based on experiences in their respective careers. Attempts were made to promote generalizability of recommendations for neuropsychologists in different settings. Evidence supports a potentially adverse impact on quality of life and overall life satisfaction when work and personal lives conflict. This manuscript identifies some of the potential risks when work and life responsibilities are not well integrated. It is anticipated this will serve as a catalyst for future studies on work-life integration in the field of neuropsychology, specifically.

Advancing Well-Being Through Total Worker Health®.

PubMed

Schill, Anita L

2017-04-01

Total Worker Health® (TWH) is a paradigm-shifting approach to safety, health, and well-being in the workplace. It is defined as policies, programs, and practices that integrate protection from work-related safety and health hazards with promotion of injury and illness prevention efforts to advance worker well-being. The most current TWH concepts are presented, including a description of issues relevant to TWH and introduction of a hierarchy of controls applied to TWH. Total Worker Health advocates for a foundation of safety and health through which work can contribute to higher levels of well-being.

In Situ Observations of Agglomeration of Non-metallic Inclusions at Steel/Ar and Steel/Slag Interfaces by High-Temperature Confocal Laser Scanning Microscope: A Review

NASA Astrophysics Data System (ADS)

Mu, Wangzhong; Dogan, Neslihan; Coley, Kenneth S.

2018-05-01

The agglomeration behavior of non-metallic inclusions in the steelmaking process is important for controlling the cleanliness of the steel. In this work, the observation of agglomeration behaviors of inclusions at steel/Ar and steel/slag interfaces using a high-temperature confocal laser scanning microscope (HT-CLSM) is summarized. This HT-CLSM technique has been applied to observe phase transformation during solidification and heat treatment and the engulfment and pushing behavior of inclusions in front of the solidified interface. In the current work, the inclusion agglomeration behavior at steel/Ar and steel/slag interfaces is summarized and discussed. Subsequently, the development of the theoretical work investigating inclusion agglomeration at steel/Ar and steel/slag interfaces including the initial capillary force model and Kralchevsky-Paunov model is described. Finally, the Kralchevsky-Paunov model is applied to investigating nitride inclusion agglomeration at high-manganese steel/Ar interfaces. This work aims to give a critical review of the application of HT-CLSM in secondary refining as well as a better control of inclusion elimination for clean steel production.

Effect of platinum nanoparticle deposition parameters on hydrogen peroxide transduction for applications in wearable electrochemical glucose biosensors

NASA Astrophysics Data System (ADS)

Cargill, Allison A.; Neil, Kathrine M.; Hondred, John A.; McLamore, Eric S.; Claussen, Jonathan C.

2016-05-01

Enhanced interest in wearable biosensor technology over the past decade is directly related to the increasing prevalence of diabetes and the associated requirement of daily blood glucose monitoring. In this work we investigate the platinum-carbon transduction element used in traditional first-generation glucose biosensors which rely on the concentration of hydrogen peroxide produced by the glucose-glucose oxidase binding scheme. We electrodeposit platinum nanoparticles on a commercially-available screen printed carbon electrode by stepping an applied current between 0 and 7.12 mA/cm2 for a varying number of cycles. Next, we examine the trends in deposition and the effect that the number of deposition cycles has on the sensitivity of electrochemical glucose sensing. Results from this work indicate that applying platinum nanoparticles to screen printed carbon via electrodeposition from a metal salt solution improves overall biosensor sensitivity. This work also pinpoints the amount of platinum (i.e., number of deposition cycles) that maximizes biosensor sensitivity in an effort to minimize the use of the precious metals, viz., platinum, in electrode fabrication. In summary, this work quantifies the relationship between platinum electrodeposition and sensor performance, which is crucial in designing and producing cost-effective sensors.

Toroidal Ampere-Faraday Equations Solved Simultaneously with CQL3D Fokker-Planck Time-Evolution

NASA Astrophysics Data System (ADS)

Harvey, R. W. (Bob); Petrov, Yu. V. (Yuri); Forest, C. B.; La Haye, R. J.

2017-10-01

A self-consistent, time-dependent toroidal electric field calculation is a key feature of a complete 3D Fokker-Planck kinetic distribution radial transport code for f(v,theta,rho,t). We discuss benchmarking and first applications of an implementation of the Ampere-Faraday equation for the self-consistent toroidal electric field, as applied to (1) resistive turn on of applied electron cyclotron current in the DIII-D tokamak giving initial back current adjacent to the direct CD region and having possible NTM stabilization implications, and (2) runaway electron production in tokamaks due to rapid reduction of the plasma temperature as occurs in pellet injection, massive gas injection, or a plasma disruption. Our previous results assuming a constant current density (Lenz' Law) model showed that prompt ``hot-tail runaways'' dominated ``knock-on'' and Dreicer ``drizzle'' runaways; we perform full-radius modeling and examine modifications due to the more complete Ampere-Faraday solution. Presently, the implementation relies on a fixed shape eqdsk, and this limitation will be addressed in future work. Research supported by USDOE FES award ER54744.

Indigenously developed bending strain setup for I-V characterization of superconducting tapes and wires

NASA Astrophysics Data System (ADS)

Panchal, Arun; Bano, Anees; Ghate, Mahesh; Raj, Piyush; Pradhan, Subrata

2017-04-01

An indigenously developed bending strain setup to examine the effect of pure bending on critical current of superconducting tapes and strands has been presented in this paper. This set up is capable of applying various bending radius in situ at cryogenic temperature with rack and pinion gear mechanism. The bending strain applied on samples can be controlled externally by rotational input which is transferred in the form of bending radius during experiments. The working principle, design and optimization of this set up have been discussed. The performance and validation of this setup has been done on various HTS tapes and copper strands at 77 K in actual experimental facility. Effect of bending radius (15.5 mm - 48 mm) i.e. strains and ramp rate (2 A/s - 8 A/s) is observed on current capability of various HTS Tapes. It is observed that in uniform bending condition, degradation in current carrying capacity BSCCO and Di-BSCCO (˜ 30 %) is more as compare to YBCO (˜ 2.75 %) at 77 K. The effect of pure mechanical strain has been experimentally observed and presented.

Proceedings ICASS 2017

NASA Astrophysics Data System (ADS)

Fu, Qiang; Schaaf, Peter

2018-07-01

This special issue of the high impact international peer reviewed journal Applied Surface Science represents the proceedings of the 2nd International Conference on Applied Surface Science ICASS held 12-16 June 2017 in Dalian China. The conference provided a forum for researchers in all areas of applied surface science to present their work. The main topics of the conference are in line with the most popular areas of research reported in Applied Surface Science. Thus, this issue includes current research on the role and use of surfaces in chemical and physical processes, related to catalysis, electrochemistry, surface engineering and functionalization, biointerfaces, semiconductors, 2D-layered materials, surface nanotechnology, energy, new/functional materials and nanotechnology. Also the various techniques and characterization methods will be discussed. Hence, scientific research on the atomic and molecular level of material properties investigated with specific surface analytical techniques and/or computational methods is essential for any further progress in these fields.

Australian work exposures studies: occupational exposure to pesticides.

PubMed

Jomichen, Jasmine; El-Zaemey, Sonia; Heyworth, Jane S; Carey, Renee N; Darcey, Ellie; Reid, Alison; Glass, Deborah C; Driscoll, Tim; Peters, Susan; Abramson, Michael; Fritschi, Lin

2017-01-01

Pesticides are widely used in some occupational settings. Some pesticides have been classified as carcinogens; however, data on the number of workers exposed to pesticides are not available in Australia. The main aim of this study was to estimate the current prevalence of pesticide exposure in Australian workplaces. The analysis used data from the Australian Work Exposures Study, a series of nationwide telephone surveys which investigated work-related prevalence and exposure to carcinogens and asthmagens, including pesticides, among current Australian workers. Information about the respondents' current job and various demographic factors was collected in a telephone interview using the web-based tool OccIDEAS. Workers were considered exposed to pesticides if they reported applying or mixing pesticides in their current job. Of the 10 371 respondents, 410 (4%) respondents were assessed as being exposed to pesticides in the workplace, with exposure being more likely among males, individuals born in Australia, individuals with lower education level and those residing in regional or remote areas. Glyphosate was the most common active ingredient used by workers. This is the first study to describe the prevalence of occupational pesticide exposure in Australia and one of the few recent studies internationally. 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/.

The adaptive, cut-cell Cartesian approach (warts and all)

NASA Technical Reports Server (NTRS)

Powell, Kenneth G.

1995-01-01

Solution-adaptive methods based on cutting bodies out of Cartesian grids are gaining popularity now that the ways of circumventing the accuracy problems associated with small cut cells have been developed. Researchers are applying Cartesian-based schemes to a broad class of problems now, and, although there is still development work to be done, it is becoming clearer which problems are best suited to the approach (and which are not). The purpose of this paper is to give a candid assessment, based on applying Cartesian schemes to a variety of problems, of the strengths and weaknesses of the approach as it is currently implemented.

SOCAP: Lessons learned in applying SIPE-2 to the military operations crisis action planning domain

NASA Technical Reports Server (NTRS)

Desimone, Roberto

1992-01-01

This report describes work funded under the DARPA Planning and Scheduling Initiative that led to the development of SOCAP (System for Operations Crisis Action Planning). In particular, it describes lessons learned in applying SIPE-2, the underlying AI planning technology within SOCAP, to the domain of military operations deliberate and crisis action planning. SOCAP was demonstrated at the U.S. Central Command and at the Pentagon in early 1992. A more detailed report about the lessons learned is currently being prepared. This report was presented during one of the panel discussions on 'The Relevance of Scheduling to AI Planning Systems.'

Modeling the lag period and exponential growth of Listeria monocytogenes under conditions of fluctuating temperature and water activity values.

PubMed

Muñoz-Cuevas, Marina; Fernández, Pablo S; George, Susan; Pin, Carmen

2010-05-01

The dynamic model for the growth of a bacterial population described by Baranyi and Roberts (J. Baranyi and T. A. Roberts, Int. J. Food Microbiol. 23:277-294, 1994) was applied to model the lag period and exponential growth of Listeria monocytogenes under conditions of fluctuating temperature and water activity (a(w)) values. To model the duration of the lag phase, the dependence of the parameter h(0), which quantifies the amount of work done during the lag period, on the previous and current environmental conditions was determined experimentally. This parameter depended not only on the magnitude of the change between the previous and current environmental conditions but also on the current growth conditions. In an exponentially growing population, any change in the environment requiring a certain amount of work to adapt to the new conditions initiated a lag period that lasted until that work was finished. Observations for several scenarios in which exponential growth was halted by a sudden change in the temperature and/or a(w) were in good agreement with predictions. When a population already in a lag period was subjected to environmental fluctuations, the system was reset with a new lag phase. The work to be done during the new lag phase was estimated to be the workload due to the environmental change plus the unfinished workload from the uncompleted previous lag phase.

Reliability and Characteristics of Wafer-Level Chip-Scale Packages under Current Stress

NASA Astrophysics Data System (ADS)

Chen, Po-Ying; Kung, Heng-Yu; Lai, Yi-Shao; Hsiung Tsai, Ming; Yeh, Wen-Kuan

2008-02-01

In this work, we present a novel approach and method for elucidating the characteristics of wafer-level chip-scale packages (WLCSPs) for electromigration (EM) tests. The die in WLCSP was directly attached to the substrate via a soldered interconnect. The shrinking of the area of the die that is available for power, and the solder bump also shrinks the volume and increases the density of electrons for interconnect efficiency. The bump current density now approaches to 106 A/cm2, at which point the EM becomes a significant reliability issue. As known, the EM failure depends on numerous factors, including the working temperature and the under bump metallization (UBM) thickness. A new interconnection geometry is adopted extensively with moderate success in overcoming larger mismatches between the displacements of components during current and temperature changes. Both environments and testing parameters for WLCSP are increasingly demanded. Although failure mechanisms are considered to have been eliminated or at least made manageable, new package technologies are again challenging its process, integrity and reliability. WLCSP technology was developed to eliminate the need for encapsulation to ensure compatibility with smart-mount technology (SMT). The package has good handing properties but is now facing serious reliability problems. In this work, we investigated the reliability of a WLCSP subjected to different accelerated current stressing conditions at a fixed ambient temperature of 125 °C. A very strong correlation exists between the mean time to failure (MTTF) of the WLCSP test vehicle and the mean current density that is carried by a solder joint. A series of current densities were applied to the WLCSP architecture; Black's power law was employed in a failure mode simulation. Additionally, scanning electron microscopy (SEM) was adopted to determine the differences existing between high- and low-current-density failure modes.

Computational analysis of current-loss mechanisms in a post-hole convolute driven by magnetically insulated transmission lines

DOE PAGES

Rose, D.  V.; Madrid, E.  A.; Welch, D.  R.; ...

2015-03-04

Numerical simulations of a vacuum post-hole convolute driven by magnetically insulated vacuum transmission lines (MITLs) are used to study current losses due to charged particle emission from the MITL-convolute-system electrodes. This work builds on the results of a previous study [E.A. Madrid et al. Phys. Rev. ST Accel. Beams 16, 120401 (2013)] and adds realistic power pulses, Ohmic heating of anode surfaces, and a model for the formation and evolution of cathode plasmas. The simulations suggest that modestly larger anode-cathode gaps in the MITLs upstream of the convolute result in significantly less current loss. In addition, longer pulse durations leadmore » to somewhat greater current loss due to cathode-plasma expansion. These results can be applied to the design of future MITL-convolute systems for high-current pulsed-power systems.« less

Jet behaviors and ejection mode recognition of electrohydrodynamic direct-write

NASA Astrophysics Data System (ADS)

Zheng, Jianyi; Zhang, Kai; Jiang, Jiaxin; Wang, Xiang; Li, Wenwang; Liu, Yifang; Liu, Juan; Zheng, Gaofeng

2018-01-01

By introducing image recognition and micro-current testing, jet behavior research was conducted, in which the real-time recognition of ejection mode was realized. To study the factors influencing ejection modes and the current variation trends under different modes, an Electrohydrodynamic Direct-Write (EDW) system with functions of current detection and ejection mode recognition was firstly built. Then a program was developed to recognize the jet modes. As the voltage applied to the metal tip increased, four jet ejection modes in EDW occurred: droplet ejection mode, Taylor cone ejection mode, retractive ejection mode and forked ejection mode. In this work, the corresponding relationship between the ejection modes and the effect on fiber deposition as well as current was studied. The real-time identification of ejection mode and detection of electrospinning current was realized. The results in this paper are contributed to enhancing the ejection stability, providing a good technical basis to produce continuous uniform nanofibers controllably.

Monolithic integration of GMR sensors for standard CMOS-IC current sensing

NASA Astrophysics Data System (ADS)

De Marcellis, A.; Reig, C.; Cubells-Beltrán, M.-D.; Madrenas, J.; Santos, J. D.; Cardoso, S.; Freitas, P. P.

2017-09-01

In this work we report on the development of Giant Magnetoresistive (GMR) sensors for off-line current measurements in standard integrated circuits. An ASIC has been specifically designed and fabricated in the well-known AMS-0.35 μm CMOS technology, including the electronic circuitry for sensor interfacing. It implements an oscillating circuit performing a voltage-to-frequency conversion. Subsequently, a fully CMOS-compatible low temperature post-process has been applied for depositing the GMR sensing devices in a full-bridge configuration onto the buried current straps. Sensitivity and resolution of these sensors have been investigated achieving experimental results that show a detection sensitivity of about 100 Hz/mA, with a resolution of about 5 μA.

Studying Supernovae under the Current Paradigm

DOE PAGES

Fryer, Chris L.

2016-10-27

Abstract The convection-enhanced paradigm behind core-collapse supernovae (SNe) invokes a multi-physics model where convection above the proto-neutron star is able to convert the energy released in the collapse to produce the violent explosions observed as SNe. Over the past decade, the evidence in support of this engine has grown, including constraints placed by SN neutrinos, energies, progenitors and remnants. Although considerable theoretical work remains to utilize this data, our understanding of normal SNe is advancing. To achieve a deeper level of understanding, we must find ways to compare detailed simulations with the increasing set of observational data. Here we reviewmore » the current constraints and how we can apply our current understanding to broaden our understanding of these powerful engines.« less

Studying Supernovae under the Current Paradigm

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

Fryer, Chris L.

Abstract The convection-enhanced paradigm behind core-collapse supernovae (SNe) invokes a multi-physics model where convection above the proto-neutron star is able to convert the energy released in the collapse to produce the violent explosions observed as SNe. Over the past decade, the evidence in support of this engine has grown, including constraints placed by SN neutrinos, energies, progenitors and remnants. Although considerable theoretical work remains to utilize this data, our understanding of normal SNe is advancing. To achieve a deeper level of understanding, we must find ways to compare detailed simulations with the increasing set of observational data. Here we reviewmore » the current constraints and how we can apply our current understanding to broaden our understanding of these powerful engines.« less

Gate-dependent asymmetric transport characteristics in pentacene barristors with graphene electrodes.

PubMed

Hwang, Wang-Taek; Min, Misook; Jeong, Hyunhak; Kim, Dongku; Jang, Jingon; Yoo, Daekyung; Jang, Yeonsik; Kim, Jun-Woo; Yoon, Jiyoung; Chung, Seungjun; Yi, Gyu-Chul; Lee, Hyoyoung; Wang, Gunuk; Lee, Takhee

2016-11-25

We investigated the electrical characteristics and the charge transport mechanism of pentacene vertical hetero-structures with graphene electrodes. The devices are composed of vertical stacks of silicon, silicon dioxide, graphene, pentacene, and gold. These vertical heterojunctions exhibited distinct transport characteristics depending on the applied bias direction, which originates from different electrode contacts (graphene and gold contacts) to the pentacene layer. These asymmetric contacts cause a current rectification and current modulation induced by the gate field-dependent bias direction. We observed a change in the charge injection barrier during variable-temperature current-voltage characterization, and we also observed that two distinct charge transport channels (thermionic emission and Poole-Frenkel effect) worked in the junctions, which was dependent on the bias magnitude.

Electron hydrodynamics dilemma: Whirlpools or no whirlpools

NASA Astrophysics Data System (ADS)

Pellegrino, Francesco M. D.; Torre, Iacopo; Geim, Andre K.; Polini, Marco

2016-10-01

In highly viscous electron systems such as high-quality graphene above liquid nitrogen temperature, a linear response to applied electric current becomes essentially nonlocal, which can give rise to a number of new and counterintuitive phenomena including negative nonlocal resistance and current whirlpools. It has also been shown that, although both effects originate from high electron viscosity, a negative voltage drop does not principally require current backflow. In this work, we study the role of geometry on viscous flow and show that confinement effects and relative positions of injector and collector contacts play a pivotal role in the occurrence of whirlpools. Certain geometries may exhibit backflow at arbitrarily small values of the electron viscosity, whereas others require a specific threshold value for whirlpools to emerge.

Design of electrodes and current limits for low frequency electrical impedance tomography of the brain.

PubMed

Gilad, O; Horesh, L; Holder, D S

2007-07-01

For the novel application of recording of resistivity changes related to neuronal depolarization in the brain with electrical impedance tomography, optimal recording is with applied currents below 100 Hz, which might cause neural stimulation of skin or underlying brain. The purpose of this work was to develop a method for application of low frequency currents to the scalp, which delivered the maximum current without significant stimulation of skin or underlying brain. We propose a recessed electrode design which enabled current injection with an acceptable skin sensation to be increased from 100 muA using EEG electrodes, to 1 mA in 16 normal volunteers. The effect of current delivered to the brain was assessed with an anatomically realistic finite element model of the adult head. The modelled peak cerebral current density was 0.3 A/m(2), which was 5 to 25-fold less than the threshold for stimulation of the brain estimated from literature review.

Dynamic least-cost optimisation of wastewater system remedial works requirements.

PubMed

Vojinovic, Z; Solomatine, D; Price, R K

2006-01-01

In recent years, there has been increasing concern for wastewater system failure and identification of optimal set of remedial works requirements. So far, several methodologies have been developed and applied in asset management activities by various water companies worldwide, but often with limited success. In order to fill the gap, there are several research projects that have been undertaken in exploring various algorithms to optimise remedial works requirements, but mostly for drinking water supply systems, and very limited work has been carried out for the wastewater assets. Some of the major deficiencies of commonly used methods can be found in either one or more of the following aspects: inadequate representation of systems complexity, incorporation of a dynamic model into the decision-making loop, the choice of an appropriate optimisation technique and experience in applying that technique. This paper is oriented towards resolving these issues and discusses a new approach for the optimisation of wastewater systems remedial works requirements. It is proposed that the optimal problem search is performed by a global optimisation tool (with various random search algorithms) and the system performance is simulated by the hydrodynamic pipe network model. The work on assembling all required elements and the development of an appropriate interface protocols between the two tools, aimed to decode the potential remedial solutions into the pipe network model and to calculate the corresponding scenario costs, is currently underway.

A Normative Model of Work Team Effectiveness

DTIC Science & Technology

1983-11-01

Hawthc-ne studies at Western Electric Corporation, Harold Leavitt (1975) observed: Far and away the most powerful and beloved tool of applied behavioral ...scientists is the small face-to-face group. Since the Western Electric researches, behavioral scientists have been learning to understand, exploit and...integration of literature on small group behavior , see McGrath and Altman (1966). Current reviews are provided by Hare (1976), MicGrath and Kravitz (1982

Supporting Research and Development of Security Technologies through Network and Security Data Collection

DTIC Science & Technology

Research and development targeted at identifying and mitigating Internet security threats require current network data. To fulfill this need... researchers working for the Center for Applied Internet Data Analysis (CAIDA), a program at the San Diego Supercomputer Center (SDSC) which is based at the...vetted network and security researchers using the PREDICT/IMPACT portal and legal framework. We have also contributed to community building efforts that

Ergometer

NASA Technical Reports Server (NTRS)

Gause, R. L.; Bynum, B. G. (Inventor)

1973-01-01

An ergometer is described that has a pedal driven direct current motor as a load and includes a frame for supporting the body of a person in either a sitting or a prone position. The pedals may be operated by either the feet or the hands. The electrical circuitry of the ergometer includes means for limiting the load applied to the pedals as a function of work being performed, heart rate, and increases in heart rate.

On the photosynthetic potential in the very Early Archean oceans.

PubMed

Avila, Daile; Cardenas, Rolando; Martin, Osmel

2013-02-01

In this work we apply a mathematical model of photosynthesis to quantify the potential for photosynthetic life in the very Early Archean oceans. We assume the presence of oceanic blockers of ultraviolet radiation, specifically ferrous ions. For this scenario, our results suggest a potential for photosynthetic life greater than or similar to that in later eras/eons, such as the Late Archean and the current Phanerozoic eon.

Porous glass electroosmotic pumps: design and experiments.

PubMed

Yao, Shuhuai; Hertzog, David E; Zeng, Shulin; Mikkelsen, James C; Santiago, Juan G

2003-12-01

An analytical model for electroosmotic flow rate, total pump current, and thermodynamic efficiency reported in a previous paper has been applied as a design guideline to fabricate porous-structure EO pumps. We have fabricated sintered-glass EO pumps that provide maximum flow rates and pressure capacities of 33 ml/min and 1.3 atm, respectively, at applied potential 100 V. These pumps are designed to be integrated with two-phase microchannel heat exchangers with load capacities of order 100 W and greater. Experiments were conducted with pumps of various geometries and using a relevant, practical range of working electrolyte ionic concentration. Characterization of the pumping performance are discussed in the terms of porosity, tortuosity, pore size, and the dependence of zeta potential on bulk ion density of the working solution. The effects of pressure and flow rate on pump current and thermodynamic efficiency are analyzed and compared to the model prediction. In particular, we explore the important tradeoff between increasing flow rate capacity and obtaining adequate thermodynamic efficiency. This research aims to demonstrate the performance of EOF pump systems and to investigate optimal and practical pump designs. We also present a gas recombination device that makes possible the implementation of this pumping technology into a closed-flow loop where electrolytic gases are converted into water and reclaimed by the system.

Tamoxifen-loaded liposomal topical formulation arrests hair growth in mice.

PubMed

Bhatia, A; Singh, B; Amarji, B; Katare, O P

2010-08-01

For several decades, androgens have dominated endocrine research in the domain of hair growth control. However, it has long been known that oestrogens also tend to alter hair follicle (HF) growth and cycling significantly by binding to locally expressed high-affinity oestrogen receptors (ORs). Tamoxifen (TAM) is a selective OR modulator. The current work aims to investigate the effect of topically applied TAM on the hair growth of mice. Test formulations were applied once daily on the shaved back area of the mice for a period of 5 weeks. The effect of these formulations was studied by visual and histological examinations. Animals treated with saline and placebo gel formulation showed significant hair growth on the 20th day. The number and length of follicles were also found to be normal. In contrast, no hair growth was observed in the animals treated with TAM gel, even after the termination of treatment. The HFs were found to be arrested in telogen phase with clear signs of follicle dystrophy. The hair growth-retarding effect of TAM observed in the current study clearly demonstrates its OR agonistic effect on hair growth. This work also provides a distinct lead towards the possible potential of TAM liposomal gel in the treatment of hirsutism.

The effects of interfacial recombination and injection barrier on the electrical characteristics of perovskite solar cells

NASA Astrophysics Data System (ADS)

Shi, Lin Xing; Wang, Zi Shuai; Huang, Zengguang; Sha, Wei E. I.; Wang, Haoran; Zhou, Zhen

2018-02-01

Charge carrier recombination in the perovskite solar cells (PSCs) has a deep influence on the electrical performance, such as open circuit voltage, short circuit current, fill factor and ultimately power conversion efficiency. The impacts of injection barrier, recombination channels, doping properties of carrier transport layers and light intensity on the performance of PSCs are theoretically investigated by drift-diffusion model in this work. The results indicate that due to the injection barrier at the interfaces of perovskite and carrier transport layer, the accumulated carriers modify the electric field distribution throughout the PSCs. Thus, a zero electric field is generated at a specific applied voltage, with greatly increases the interfacial recombination, resulting in a local kink of current density-voltage (J-V) curve. This work provides an effective strategy to improve the efficiency of PSCs by pertinently reducing both the injection barrier and interfacial recombination.

Spin-Dependent Processes Measured without a Permanent Magnet.

PubMed

Fontanesi, Claudio; Capua, Eyal; Paltiel, Yossi; Waldeck, David H; Naaman, Ron

2018-05-07

A novel Hall circuit design that can be incorporated into a working electrode, which is used to probe spin-selective charge transfer and charge displacement processes, is reviewed herein. The general design of a Hall circuit based on a semiconductor heterostructure, which forms a shallow 2D electron gas and is used as an electrode, is described. Three different types of spin-selective processes have been studied with this device in the past: i) photoinduced charge exchange between quantum dots and the working electrode through chiral molecules is associated with spin polarization that creates a local magnetization and generates a Hall voltage; ii) charge polarization of chiral molecules by an applied voltage is accompanied by a spin polarization that generates a Hall voltage; and iii) cyclic voltammetry (current-voltage) measurements of electrochemical redox reactions that can be spin-analyzed by the Hall circuit to provide a third dimension (spin) in addition to the well-known current and voltage dimensions. The three studies reviewed open new doors into understanding both the spin current and the charge current in electronic materials and electrochemical processes. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Occupational health and safety regulations in the dairy industry.

PubMed

Reed, Sue; Douphrate, David I; Lundqvist, Peter; Jarvie, Paul; McLean, Gillian; Koehncke, Niels; Colosio, Claudio; Singh, Tanusha

2013-01-01

The application of occupational health and safety (OHS) legislation in the dairy industry varies throughout the world. Generally there is no specific OHS legislation that applies to the dairy industry and mostly in countries the current OHS legislation applies to all workplaces with specific guidelines that apply to agricultural industries. The main difference between countries is in the application of OHS legislation specifically in relation to the size of the farms. In the USA, the OHS legislation, and therefore enforcement, does not, in most cases, apply to farms with less than 11 employees, whereas in other countries there is no minimum number of employees and in some cases such as the United Kingdom and Australia it covers all people who work on the farm. The other area of difference is in the use and publication of guidelines for the industry; some countries have a wide range of guidelines whereas other counties have few. Generally, this relates to the jurisdiction of the OHS legislation, which in several countries is not at a national level such as USA, Canada, and Australia. The main principal of OHS legislation is that all workplaces, including dairy farms, should be a safe and healthy place to work, and does not vary significantly between the countries reviewed even those with prescriptive legislation.

Novel optical strategies for biodetection

NASA Astrophysics Data System (ADS)

Sakamuri, Rama M.; Wolfenden, Mark S.; Anderson, Aaron S.; Swanson, Basil I.; Schmidt, Jurgen S.; Mukundan, Harshini

2013-09-01

Although bio-detection strategies have significantly evolved in the past decade, they still suffer from many disadvantages. For one, current approaches still require confirmation of pathogen viability by culture, which is the `gold-standard' method, and can take several days to result. Second, current methods typically target protein and nucleic acid signatures and cannot be applied to other biochemical categories of biomarkers (e.g.; lipidated sugars). Lipidated sugars (e.g.; lipopolysaccharide, lipoarabinomannan) are bacterial virulence factors that are significant to pathogenicity. Herein, we present two different optical strategies for biodetection to address these two limitations. We have exploited bacterial iron sequestration mechanisms to develop a simple, specific assay for the selective detection of viable bacteria, without the need for culture. We are currently working on the use of this technology for the differential detection of two different bacteria, using siderophores. Second, we have developed a novel strategy termed `membrane insertion' for the detection of amphiphilic biomarkers (e.g. lipidated glycans) that cannot be detected by conventional approaches. We have extended this technology to the detection of small molecule amphiphilic virulence factors, such as phenolic glycolipid-1 from leprosy, which could not be directly detected before. Together, these strategies address two critical limitations in current biodetection approaches. We are currently working on the optimization of these methods, and their extension to real-world clinical samples.

Optimization of thermoacoustic engine driven thermoacoustic refrigerator using response surface methodology

NASA Astrophysics Data System (ADS)

Desai, A. B.; Desai, K. P.; Naik, H. B.; Atrey, M. D.

2017-02-01

Thermoacoustic engines (TAEs) are devices which convert heat energy into useful acoustic work whereas thermoacoustic refrigerators (TARs) convert acoustic work into temperature gradient. These devices work without any moving component. Study presented here comprises of a combination system i.e. thermoacoustic engine driven thermoacoustic refrigerator (TADTAR). This system has no moving component and hence it is easy to fabricate but at the same time it is very challenging to design and construct optimized system with comparable performance. The work presented here aims to apply optimization technique to TADTAR in the form of response surface methodology (RSM). Significance of stack position and stack length for engine stack, stack position and stack length for refrigerator stack are investigated in current work. Results from RSM are compared with results from simulations using Design Environment for Low-amplitude Thermoacoustic Energy conversion (DeltaEC) for compliance.

Application of the multi-disciplinary thematic seminar method in two homecare cases - a comparative study.

PubMed

Scandurra, Isabella; Hägglund, Maria; Koch, Sabine

2008-01-01

A significant problem with current health information technologies is that they poorly support collaborative work of healthcare professionals, sometimes leading to a fragmentation of workflow and disruption of healthcare processes. This paper presents two homecare cases, both applying multi-disciplinary thematic seminars (MdTS) as a collaborative method for user needs elicitation and requirements specification. This study describes the MdTS application to elicit user needs from different perspectives to coincide with collaborative professions' work practices in two cases. Despite different objectives, the two cases validated that MdTS emphasized the "points of intersection" in cooperative work. Different user groups with similar, yet distinct needs reached a common understanding of the entire work process, agreed upon requirements and participated in the design of prototypes supporting cooperative work. MdTS was applicable in both exploratory and normative studies aiming to elicit the specific requirements in a cooperative environment.

A fast alignment method for breast MRI follow-up studies using automated breast segmentation and current-prior registration

NASA Astrophysics Data System (ADS)

Wang, Lei; Strehlow, Jan; Rühaak, Jan; Weiler, Florian; Diez, Yago; Gubern-Merida, Albert; Diekmann, Susanne; Laue, Hendrik; Hahn, Horst K.

2015-03-01

In breast cancer screening for high-risk women, follow-up magnetic resonance images (MRI) are acquired with a time interval ranging from several months up to a few years. Prior MRI studies may provide additional clinical value when examining the current one and thus have the potential to increase sensitivity and specificity of screening. To build a spatial correlation between suspicious findings in both current and prior studies, a reliable alignment method between follow-up studies is desirable. However, long time interval, different scanners and imaging protocols, and varying breast compression can result in a large deformation, which challenges the registration process. In this work, we present a fast and robust spatial alignment framework, which combines automated breast segmentation and current-prior registration techniques in a multi-level fashion. First, fully automatic breast segmentation is applied to extract the breast masks that are used to obtain an initial affine transform. Then, a non-rigid registration algorithm using normalized gradient fields as similarity measure together with curvature regularization is applied. A total of 29 subjects and 58 breast MR images were collected for performance assessment. To evaluate the global registration accuracy, the volume overlap and boundary surface distance metrics are calculated, resulting in an average Dice Similarity Coefficient (DSC) of 0.96 and root mean square distance (RMSD) of 1.64 mm. In addition, to measure local registration accuracy, for each subject a radiologist annotated 10 pairs of markers in the current and prior studies representing corresponding anatomical locations. The average distance error of marker pairs dropped from 67.37 mm to 10.86 mm after applying registration.

Complexing agent and heavy metal removals from metal plating effluent by electrocoagulation with stainless steel electrodes.

PubMed

Kabdaşli, Işik; Arslan, Tülin; Olmez-Hanci, Tuğba; Arslan-Alaton, Idil; Tünay, Olcay

2009-06-15

In the present study, the treatability of a metal plating wastewater containing complexed metals originating from the nickel and zinc plating process by electrocoagulation using stainless steel electrodes was experimentally investigated. The study focused on the effect of important operation parameters on electrocoagulation process performance in terms of organic complex former, nickel and zinc removals as well as sludge production and specific energy consumption. The results indicated that increasing the applied current density from 2.25 to 9.0 mA/cm(2) appreciably enhanced TOC removal efficiency from 20% to 66%, but a further increase in the applied current density to 56.25 mA/cm(2) did not accelerate TOC removal rates. Electrolyte concentration did not affect the process performance significantly and the highest TOC reduction (66%) accompanied with complete heavy metal removals were achieved at the original chloride content ( approximately 1500 mg Cl/L) of the wastewater sample. Nickel removal performance was adversely affected by the decrease of initial pH from its original value of 6. Optimum working conditions for electrocoagulation of metal plating effluent were established as follows: an applied current density of 9 mA/cm(2), the effluent's original electrolyte concentration and pH of the composite sample. TOC removal rates obtained for all electrocoagulation runs fitted pseudo-first-order kinetics very well (R(2)>92-99).

Field enhanced charge carrier reconfiguration in electronic and ionic coupled dynamic polymer resistive memory.

PubMed

Zhao, Jun Hui; Thomson, Douglas J; Pilapil, Matt; Pillai, Rajesh G; Rahman, G M Aminur; Freund, Michael S

2010-04-02

Dynamic resistive memory devices based on a conjugated polymer composite (PPy(0)DBS(-)Li(+) (PPy: polypyrrole; DBS(-): dodecylbenzenesulfonate)), with field-driven ion migration, have been demonstrated. In this work the dynamics of these systems has been investigated and it has been concluded that increasing the applied field can dramatically increase the rate at which information can be 'written' into these devices. A conductance model using space charge limited current coupled with an electric field induced ion reconfiguration has been successfully utilized to interpret the experimentally observed transient conducting behaviors. The memory devices use the rising and falling transient current states for the storage of digital states. The magnitude of these transient currents is controlled by the magnitude and width of the write/read pulse. For the 500 nm length devices used in this work an increase in 'write' potential from 2.5 to 5.5 V decreased the time required to create a transient conductance state that can be converted into the digital signal by 50 times. This work suggests that the scaling of these devices will be favorable and that 'write' times for the conjugated polymer composite memory devices will decrease rapidly as ion driving fields increase with decreasing device size.

[Evidence of work-related musculo-skeletal disorders of the upper extremities and current methods of risk assessment: can Charlie Chaplin give us any suggestions in "modern times"].

PubMed

Apostoli, P; Sala, Emma

2009-01-01

in some sequences of the film "Modern Times" Chaplin is clearly involved in activities at high risk for work-related musculo-skeletal disorders of the upper extremities (UEWMSDs), but evidence and perception of any complaint are not evident. To evaluate the extent of the biomechanical risk using current risk assessment methods and discuss the possible reasons for lack of complaints. we made an analysis using six of the current methods for ergonomic risk assessment (State of Washington, check list OCRA, HAL by ACGIH, RULA Strain Index, OREGE). All the methods applied demonstrated high-to-very high levels of biomechanical risk for the upper extremities, with evident psychic effects but without apparent musculo-skeletal disorders. The discrepancy between evident psychological disorders ad apparent absence of UEWMSDs are discussed as being due to either: an artistic choice by Charlie Chaplin who focused on the aspects thought to be more immediately and easily comic; the short duration of the physical load exertion; or because of a different perception of muscular work and fatigue that was also typical until the 1970's and 1980's, which also confirmed the principles and practices of our preventive and medical disciplines at that time.

PT -symmetric gain and loss in a rotating Bose-Einstein condensate

NASA Astrophysics Data System (ADS)

Haag, Daniel; Dast, Dennis; Cartarius, Holger; Wunner, Günter

2018-03-01

PT -symmetric quantum mechanics allows finding stationary states in mean-field systems with balanced gain and loss of particles. In this work we apply this method to rotating Bose-Einstein condensates with contact interaction which are known to support ground states with vortices. Due to the particle exchange with the environment transport phenomena through ultracold gases with vortices can be studied. We find that even strongly interacting rotating systems support stable PT -symmetric ground states, sustaining a current parallel and perpendicular to the vortex cores. The vortices move through the nonuniform particle density and leave or enter the condensate through its borders creating the required net current.

Highly tunable charge and spin transport in silicene junctions: phase transitions and half-metallic states.

PubMed

Mahdavifar, Maryam; Khoeini, Farhad

2018-08-10

We report peculiar charge and spin transport properties in S-shaped silicene junctions with the Kane-Mele tight-binding model. In this work, we investigate the effects of electric and exchange fields on the charge and spin transport properties. Our results show that by applying a perpendicular electric field, metal-semiconductor and also semimetal-semiconductor phase transitions occur in our systems. Furthermore, full spin current can be obtained in the structures, so the half-metallic states are observable. Our results enable us to control charge and spin currents and provide new opportunities and applications in silicene-based electronics, optoelectronics, and spintronics.

Tomographic reconstruction of layered tissue structures

NASA Astrophysics Data System (ADS)

Hielscher, Andreas H.; Azeez-Jan, Mohideen; Bartel, Sebastian

2001-11-01

In recent years the interest in the determination of optical properties of layered tissue structure has resurfaced. Applications include, for example, studies on layered skin tissue and underlying muscles, imaging of the brain underneath layers of skin, skull, and meninges, and imaging of the fetal head in utero beneath the layered structures of the maternal abdomen. In this work we approach the problem of layered structures in the framework of model-based iterative image reconstruction schemes. These schemes are currently developed to determine the optical properties inside tissue from measurement on the surface. If applied to layered structure these techniques yield substantial improvements over currently available semi-analytical approaches.

Working memory, situation models, and synesthesia

DOE PAGES

Radvansky, Gabriel A.; Gibson, Bradley S.; McNerney, M. Windy

2013-03-04

Research on language comprehension suggests a strong relationship between working memory span measures and language comprehension. However, there is also evidence that this relationship weakens at higher levels of comprehension, such as the situation model level. The current study explored this relationship by comparing 10 grapheme–color synesthetes who have additional color experiences when they read words that begin with different letters and 48 normal controls on a number of tests of complex working memory capacity and processing at the situation model level. On all tests of working memory capacity, the synesthetes outperformed the controls. Importantly, there was no carryover benefitmore » for the synesthetes for processing at the situation model level. This reinforces the idea that although some aspects of language comprehension are related to working memory span scores, this applies less directly to situation model levels. As a result, this suggests that theories of working memory must take into account this limitation, and the working memory processes that are involved in situation model construction and processing must be derived.« less

Working memory, situation models, and synesthesia

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

Radvansky, Gabriel A.; Gibson, Bradley S.; McNerney, M. Windy

Research on language comprehension suggests a strong relationship between working memory span measures and language comprehension. However, there is also evidence that this relationship weakens at higher levels of comprehension, such as the situation model level. The current study explored this relationship by comparing 10 grapheme–color synesthetes who have additional color experiences when they read words that begin with different letters and 48 normal controls on a number of tests of complex working memory capacity and processing at the situation model level. On all tests of working memory capacity, the synesthetes outperformed the controls. Importantly, there was no carryover benefitmore » for the synesthetes for processing at the situation model level. This reinforces the idea that although some aspects of language comprehension are related to working memory span scores, this applies less directly to situation model levels. As a result, this suggests that theories of working memory must take into account this limitation, and the working memory processes that are involved in situation model construction and processing must be derived.« less

Organizational culture and a safety-conscious work environment: The mediating role of employee communication satisfaction.

PubMed

Silla, Inmaculada; Navajas, Joaquin; Koves, G Kenneth

2017-06-01

A safety-conscious work environment allows high-reliability organizations to be proactive regarding safety and enables employees to feel free to report any concern without fear of retaliation. Currently, research on the antecedents to safety-conscious work environments is scarce. Structural equation modeling was applied to test the mediating role of employee communication satisfaction in the relationship between constructive culture and a safety-conscious work environment in several nuclear power plants. Employee communication satisfaction partially mediated the positive relationships between a constructive culture and a safety-conscious work environment. Constructive cultures in which cooperation, supportive relationships, individual growth and high performance are encouraged facilitate the establishment of a safety-conscious work environment. This influence is partially explained by increased employee communication satisfaction. Constructive cultures should be encouraged within organizations. In addition, managers should promote communication policies and practices that support a safety-conscious work environment. Copyright © 2017 Elsevier Ltd and National Safety Council. All rights reserved.

Current conserving theory at the operator level

NASA Astrophysics Data System (ADS)

Yuan, Jiangtao; Wang, Yin; Wang, Jian

The basic assumption of quantum transport in mesoscopic systems is that the total charge inside the scattering region is zero. This means that the potential deep inside reservoirs is effectively screened and therefore the electric field at interface of scattering region is zero. Thus the current conservation condition can be satisfied automatically which is an important condition in mesoscopic transport. So far the current conserving ac theory is well developed by considering the displacement current which is due to Coulomb interaction if we just focus on the average current. However, the frequency dependent shot noise does not satisfy the conservation condition since we do not consider the current conservation at the operator level. In this work, we formulate a generalized current conserving theory at the operator level using non-equilibrium Green's function theory which could be applied to both average current and frequency dependent shot noise. A displacement operator is derived for the first time so that the frequency dependent correlation of displacement currents could be investigated. Moreover, the equilibrium shot noise is investigated and a generalized fluctuation-dissipation relationship is presented.

High speed transition prediction

NASA Technical Reports Server (NTRS)

Gasperas, Gediminis

1993-01-01

The main objective of this work period was to develop, maintain and exercise state-of-the-art methods for transition prediction in supersonic flow fields. Basic state and stability codes, acquired during the last work period, were exercised and applied to calculate the properties of various flowfields. The development of a code for the prediction of transition location using a currently novel method (the PSE or Parabolized Stability Equation method), initiated during the last work period and continued during the present work period, was cancelled at mid-year for budgetary reasons. Other activities during this period included the presentation of a paper at the APS meeting in Tallahassee, Florida entitled 'Stability of Two-Dimensional Compressible Boundary Layers', as well as the initiation of a paper co-authored with H. Reed of the Arizona State University entitled 'Stability of Boundary Layers'.

Boundary-Layer Control: In Memory of Bill Reynolds

NASA Astrophysics Data System (ADS)

Kim, John

2004-11-01

Professor Bill Reynolds (1933-2004) inspired many students and colleagues with his never-ending curiosity and thought-provoking ideas. Bill's relentless energy, together with his hallmark can-do character and do-it-yourself attitude, led to many seminal contributions to mechanical engineering in general, and fluid mechanics in particular. He has left a lasting impact on many of us, especially for those who had the privilege of working closely with him. Some of my current work on boundary-layer control, the use of neural networks in particular, were inspired by many discussions with Bill. He was among the first to see the potential of control-theoretic approaches for flow control, which has become the main thrust of my current research. Without his continued encouragement, I would not have been deeply involved in this line of research; and perhaps, we would not have seen the current flurry of research activities in applying modern control theories to flow control. In memory of Bill Reynolds, who himself has contributed much to flow control, an analysis of boundary-layer control from a linear system perspective will be presented.

A novel modeling to predict the critical current behavior of Nb3Sn PIT strand under transverse load based on a scaling law and Finite Element Analysis

NASA Astrophysics Data System (ADS)

Wang, Tiening; Chiesa, Luisa; Takayasu, Makoto; Bordini, Bernardo

2014-09-01

Superconducting Nb3Sn Powder-In-Tube (PIT) strands could be used for the superconducting magnets of the next generation Large Hadron Collider. The strands are cabled into the typical flat Rutherford cable configuration. During the assembly of a magnet and its operation the strands experience not only longitudinal but also transverse load due to the pre-compression applied during the assembly and the Lorentz load felt when the magnets are energized. To properly design the magnets and guarantee their safe operation, mechanical load effects on the strand superconducting properties are studied extensively; particularly, many scaling laws based on tensile load experiments have been established to predict the critical current dependence on strain. However, the dependence of the superconducting properties on transverse load has not been extensively studied so far. One of the reasons is that transverse loading experiments are difficult to conduct due to the small diameter of the strand (about 1 mm) and the data currently available do not follow a common measurement standard making the comparison between different data sets difficult. Recently at the University of Geneva, a new device has been developed to characterize the critical current of Nb3Sn strands under transverse loads. In this work we present a new 2D Finite Element Analysis (FEA) to predict the electro-mechanical response of a PIT strand that was tested at the University of Geneva when transverse load is applied. The FEA provides the strain map for the superconducting filaments when the load is applied. Those strain maps are then used to evaluate the critical current behavior of a PIT strand using a recently developed scaling law that correlates the superconducting properties of a wire with the strain invariants due to the load applied on the superconductor. The benefits and limitations of this method are discussed based on the comparison between the critical current simulation results obtained with the filament strain map and the experimental results available for PIT strands.

The Integration of Environmental Constraints into Tidal Array Optimisation

NASA Astrophysics Data System (ADS)

du Feu, Roan; de Trafford, Sebastian; Culley, Dave; Hill, Jon; Funke, Simon W.; Kramer, Stephan C.; Piggott, Matthew D.

2015-04-01

It has been estimated by The Carbon Trust that the marine renewable energy sector, of which tidal stream turbines are projected to play a large part, could produce 20% of the UK's present electricity requirements. This has lead to the important question of how this technology can be deployed in an economically and environmentally friendly manner. Work is currently under way to understand how the tidal turbines that constitute an array can be arranged to maximise the total power generated by that array. The work presented here continues this through the inclusion of environmental constraints. The benefits of the renewable energy sector to our environment at large are not in question. However, the question remains as to the effects this burgeoning sector will have on local environments, and how to mitigate these effects if they are detrimental. For example, the presence of tidal arrays can, through altering current velocity, drastically change the sediment transport into and out of an area along with re-suspending existing sediment. This can have the effects of scouring or submerging habitat, mobilising contaminants within the existing sediment, reducing food supply and altering the turbidity of the water. All of which greatly impact upon any fauna in the affected region. This work pays particular attention to the destruction of habitat of benthic fauna, as this is quantifiable as a direct result of change in the current speed; a primary factor in determining sediment accumulation on the sea floor. OpenTidalFarm is an open source tool that maximises the power generated by an array through repositioning the turbines within it. It currently uses a 2D shallow water model with turbines represented as bump functions of increased friction. The functional of interest, power extracted by the array, is evaluated from the flow field which is calculated at each iteration using a finite element method. A gradient-based local optimisation is then used through solving the associated adjoint equations, and the turbines are repositioned accordingly. The use of local optimisation drastically reduces the number of iterations therefore allowing each iteration to be more expensive. This means that this technique can be readily applied to large arrays and also that there is enough leeway in computational cost that additional constraints or functionals can be introduced without the model becoming impractical to apply. The work presented here utilises OpenTidalFarm and incorporates into it ecological and sedimentological constraints that limit the extent to which the array can alter the current speed in specified locations. The addition of these constraints will likely affect the total power generated by the array, and this work details our first steps in investigating the trade off between the maximisation of power generation and the limitation of the array's impact upon its environment.

Research review for information management

NASA Technical Reports Server (NTRS)

Bishop, Peter C.

1988-01-01

The goal of RICIS research in information management is to apply currently available technology to existing problems in information management. Research projects include the following: the Space Business Research Center (SBRC), the Management Information and Decision Support Environment (MIDSE), and the investigation of visual interface technology. Several additional projects issued reports. New projects include the following: (1) the AdaNET project to develop a technology transfer network for software engineering and the Ada programming language; and (2) work on designing a communication system for the Space Station Project Office at JSC. The central aim of all projects is to use information technology to help people work more productively.

The Stanford how things work project

NASA Technical Reports Server (NTRS)

Fikes, Richard; Gruber, Tom; Iwasaki, Yumi

1994-01-01

We provide an overview of the Stanford How Things Work (HTW) project, an ongoing integrated collection of research activities in the Knowledge Systems Laboratory at Stanford University. The project is developing technology for representing knowledge about engineered devices in a form that enables the knowledge to be used in multiple systems for multiple reasoning tasks and reasoning methods that enable the represented knowledge to be effectively applied to the performance of the core engineering task of simulating and analyzing device behavior. The central new capabilities currently being developed in the project are automated assistance with model formulation and with verification that a design for an electro-mechanical device satisfies its functional specification.

Engineering paradigms and anthropogenic global change

NASA Astrophysics Data System (ADS)

Bohle, Martin

2016-04-01

This essay discusses 'paradigms' as means to conceive anthropogenic global change. Humankind alters earth-systems because of the number of people, the patterns of consumption of resources, and the alterations of environments. This process of anthropogenic global change is a composite consisting of societal (in the 'noosphere') and natural (in the 'bio-geosphere') features. Engineering intercedes these features; e.g. observing stratospheric ozone depletion has led to understanding it as a collateral artefact of a particular set of engineering choices. Beyond any specific use-case, engineering works have a common function; e.g. civil-engineering intersects economic activity and geosphere. People conceive their actions in the noosphere including giving purpose to their engineering. The 'noosphere' is the ensemble of social, cultural or political concepts ('shared subjective mental insights') of people. Among people's concepts are the paradigms how to shape environments, production systems and consumption patterns given their societal preferences. In that context, engineering is a means to implement a given development path. Four paradigms currently are distinguishable how to make anthropogenic global change happening. Among the 'engineering paradigms' for anthropogenic global change, 'adaptation' is a paradigm for a business-as-usual scenario and steady development paths of societies. Applying this paradigm implies to forecast the change to come, to appropriately design engineering works, and to maintain as far as possible the current production and consumption patterns. An alternative would be to adjust incrementally development paths of societies, namely to 'dovetail' anthropogenic and natural fluxes of matter and energy. To apply that paradigm research has to identify 'natural boundaries', how to modify production and consumption patterns, and how to tackle process in the noosphere to render alterations of common development paths acceptable. A further alternative, the paradigm of 'ecomodernism' implies to accentuate some of the current development paths of societies with the goal to 'decouple' anthropogenic and natural fluxes of matter and energy. Applying the paradigm 'geoengineering', engineering works shall 'modulate' natural fluxes of matter to counter the effect of anthropogenic fluxes of matter instead to alter the development paths of societies. Thus, anthropogenic global change is a composite process in which engineering intercedes the 'noosphere' and in the 'bio-geosphere'. Paradigms 'how to engineering earth systems' reflect different concepts ('shared subjective insights') how to combine knowledge with use, function and purpose. Currently, four paradigms are distinguishable how to engineer anthropogenic global change. They convene recipes human activity and bio-geosphere should intersect.

Description of research interests and current work related to automating software design

NASA Technical Reports Server (NTRS)

Kaindl, Hermann

1992-01-01

Enclosed is a list of selected and recent publications. Most of these publications concern applied research in the areas of software engineering and human-computer interaction. It is felt that domain-specific knowledge plays a major role in software development. Additionally, it is believed that improvements in the general software development process (e.g., object-oriented approaches) will have to be combined with the use of large domain-specific knowledge bases.

Doped carbon nanostructure field emitter arrays for infrared imaging

DOEpatents

Korsah, Kofi [Knoxville, TN; Baylor, Larry R [Farragut, TN; Caughman, John B [Oak Ridge, TN; Kisner, Roger A [Knoxville, TN; Rack, Philip D [Knoxville, TN; Ivanov, Ilia N [Knoxville, TN

2009-10-27

An infrared imaging device and method for making infrared detector(s) having at least one anode, at least one cathode with a substrate electrically connected to a plurality of doped carbon nanostructures; and bias circuitry for applying an electric field between the anode and the cathode such that when infrared photons are adsorbed by the nanostructures the emitted field current is modulated. The detectors can be doped with cesium to lower the work function.

Nuclear propulsion control and health monitoring

NASA Technical Reports Server (NTRS)

Walter, P. B.; Edwards, R. M.

1993-01-01

An integrated control and health monitoring architecture is being developed for the Pratt & Whitney XNR2000 nuclear rocket. Current work includes further development of the dynamic simulation modeling and the identification and configuration of low level controllers to give desirable performance for the various operating modes and faulted conditions. Artificial intelligence and knowledge processing technologies need to be investigated and applied in the development of an intelligent supervisory controller module for this control architecture.

Nuclear propulsion control and health monitoring

NASA Astrophysics Data System (ADS)

Walter, P. B.; Edwards, R. M.

1993-11-01

An integrated control and health monitoring architecture is being developed for the Pratt & Whitney XNR2000 nuclear rocket. Current work includes further development of the dynamic simulation modeling and the identification and configuration of low level controllers to give desirable performance for the various operating modes and faulted conditions. Artificial intelligence and knowledge processing technologies need to be investigated and applied in the development of an intelligent supervisory controller module for this control architecture.

European Science Notes Information Bulletin (ESNIB) Reports on Current European/Middle Eastern Science

DTIC Science & Technology

1988-11-01

campus of the brane electric fields; and double layer Symposia included were on ceramics, Consejo Superior de Investigaciones structure theory and...units of the Ecole Nationale Superieure des Mines de Paris (ENSMP) - is discussed. Studies at the Center for Applied Mathematics include work for...Workshop on Low-Temperature Devices for De - tection of Low Energy Neutrino and Dark Matter are discussed. The topics are: the motivating ex

Application of Non-destructive Methods of Stress-strain State at Hazardous Production Facilities

NASA Astrophysics Data System (ADS)

Shram, V.; Kravtsova, Ye; Selsky, A.; Bezborodov, Yu; Lysyannikova, N.; Lysyannikov, A.

2016-06-01

The paper deals with the sources of accidents in distillation columns, on the basis of which the most dangerous defects are detected. The analysis of the currently existing methods of non-destructive testing of the stress-strain state is performed. It is proposed to apply strain and acoustic emission techniques to continuously monitor dangerous objects, which helps prevent the possibility of accidents, as well as reduce the work.

Applied Behavior Analysis, Autism, and Occupational Therapy: A Search for Understanding.

PubMed

Welch, Christie D; Polatajko, H J

2016-01-01

Occupational therapists strive to be mindful, competent practitioners and continuously look for ways to improve practice. Applied behavior analysis (ABA) has strong evidence of effectiveness in helping people with autism achieve goals, yet it does not seem to be implemented in occupational therapy practice. To better understand whether ABA could be an evidence-based option to expand occupational therapy practice, the authors conducted an iterative, multiphase investigation of relevant literature. Findings suggest that occupational therapists apply developmental and sensory approaches to autism treatment. The occupational therapy literature does not reflect any use of ABA despite its strong evidence base. Occupational therapists may currently avoid using ABA principles because of a perception that ABA is not client centered. ABA principles and occupational therapy are compatible, and the two could work synergistically. Copyright © 2016 by the American Occupational Therapy Association, Inc.

Nuclear Security Applications of Antineutrino Detectors: Current Capabilities and Future Prospects

DOE PAGES

Bernstein, Adam; Baldwin, George; Boyer, Brian; ...

2010-12-10

Antineutrinos are electrically neutral, nearly massless fundamental particles produced in large numbers in the cores of nuclear reactors and in nuclear explosions. In the half century since their discovery, major advances in the understanding of their properties, and in detector technology, have opened the door to a new discipline—Applied Antineutrino Physics. Because antineutrinos are inextricably linked to the process of nuclear fission, there are many applications of interest in nuclear nonproliferation. This work presents a comprehensive survey of applied antineutrino physics relevant for nonproliferation, summarizes recent advances in the field, describes the overlap of this nascent discipline with other ongoingmore » fundamental and applied antineutrino research, and charts a course for research and development for future applications. It is intended as a resource for policymakers, researchers, and the wider nuclear nonproliferation community.« less

Applied Information Systems Research Program Workshop

NASA Technical Reports Server (NTRS)

1991-01-01

The first Applied Information Systems Research Program (AISRP) Workshop provided the impetus for several groups involved in information systems to review current activities. The objectives of the workshop included: (1) to provide an open forum for interaction and discussion of information systems; (2) to promote understanding by initiating a dialogue with the intended benefactors of the program, the scientific user community, and discuss options for improving their support; (3) create an advocacy in having science users and investigators of the program meet together and establish the basis for direction and growth; and (4) support the future of the program by building collaborations and interaction to encourage an investigator working group approach for conducting the program.

The Effect of the Traveling Magnetic Field (TMF) on the Buoyancy-Induced Convection in the Vertical Bridgman growth of Germanium

NASA Technical Reports Server (NTRS)

Yesilyurt, S.; Motakef, S.; Grugel, R.; Mazuruk, K.

2003-01-01

A traveling magnetic field (TMF) is created by means of applying out-of-phase currents to a number of coils. When applied to a conducting melt inside a cylindrical container, the TMF induces a Lorentz force that acts in the meridional directions (radial and axial), unlike the application of a rotating magnetic field (RMF), which creates a force in the azimuthal direction. In this work, we present a computational study of the TMF and its application to the Bridgman growth of the Ge. To quantify the effect of the TMF on the solid-melt interface, we use the maximum (magnitude-wise) tangential shear at the interface.

Strain System for the Motion Base Shuttle Mission Simulator

NASA Technical Reports Server (NTRS)

Huber, David C.; Van Vossen, Karl G.; Kunkel, Glenn W.; Wells, Larry W.

2010-01-01

The Motion Base Shuttle Mission Simulator (MBSMS) Strain System is an innovative engineering tool used to monitor the stresses applied to the MBSMS motion platform tilt pivot frames during motion simulations in real time. The Strain System comprises hardware and software produced by several different companies. The system utilizes a series of strain gages, accelerometers, orientation sensor, rotational meter, scanners, computer, and software packages working in unison. By monitoring and recording the inputs applied to the simulator, data can be analyzed if weld cracks or other problems are found during routine simulator inspections. This will help engineers diagnose problems as well as aid in repair solutions for both current as well as potential problems.

Food applications of natural antimicrobial compounds.

PubMed

Lucera, Annalisa; Costa, Cristina; Conte, Amalia; Del Nobile, Matteo A

2012-01-01

In agreement with the current trend of giving value to natural and renewable resources, the use of natural antimicrobial compounds, particularly in food and biomedical applications, becomes very frequent. The direct addition of natural compounds to food is the most common method of application, even if numerous efforts have been made to find alternative solutions to the aim of avoiding undesirable inactivation. Dipping, spraying, and coating treatment of food with active solutions are currently applied to product prior to packaging as valid options. The aim of the current work is to give an overview on the use of natural compounds in food sector. In particular, the review will gather numerous case-studies of meat, fish, dairy products, minimally processed fruit and vegetables, and cereal-based products where these compounds found application.

Food applications of natural antimicrobial compounds

PubMed Central

Lucera, Annalisa; Costa, Cristina; Conte, Amalia; Del Nobile, Matteo A.

2012-01-01

In agreement with the current trend of giving value to natural and renewable resources, the use of natural antimicrobial compounds, particularly in food and biomedical applications, becomes very frequent. The direct addition of natural compounds to food is the most common method of application, even if numerous efforts have been made to find alternative solutions to the aim of avoiding undesirable inactivation. Dipping, spraying, and coating treatment of food with active solutions are currently applied to product prior to packaging as valid options. The aim of the current work is to give an overview on the use of natural compounds in food sector. In particular, the review will gather numerous case-studies of meat, fish, dairy products, minimally processed fruit and vegetables, and cereal-based products where these compounds found application. PMID:23060862

Time resolved Thomson scattering diagnostic of pulsed gas metal arc welding (GMAW) process

NASA Astrophysics Data System (ADS)

Kühn-Kauffeldt, M.; Marquès, J. L.; Schein, J.

2014-11-01

In this work a Thomson scattering diagnostic technique was applied to obtain time resolved electron temperature and density values during a gas metal arc welding (GMAW) process. The investigated GMAW process was run with aluminum wire (AlMg 4,5 Mn) with 1.2 mm diameter as a wire electrode, argon as a shielding gas and peak currents in the range of 400 A. Time resolved measurements could be achieved by triggering the laser pulse at shifted time positions with respect to the current pulse driving the process. Time evaluation of resulting electron temperatures and densities is used to investigate the state of the plasma in different phases of the current pulse and to determine the influence of the metal vapor and droplets on the plasma properties.

Switched integration amplifier-based photocurrent meter for accurate spectral responsivity measurement of photometers.

PubMed

Park, Seongchong; Hong, Kee-Suk; Kim, Wan-Seop

2016-03-20

This work introduces a switched integration amplifier (SIA)-based photocurrent meter for femtoampere (fA)-level current measurement, which enables us to measure a 10⁷ dynamic range of spectral responsivity of photometers even with a common lamp-based monochromatic light source. We described design considerations and practices about operational amplifiers (op-amps), switches, readout methods, etc., to compose a stable SIA of low offset current in terms of leakage current and gain peaking in detail. According to the design, we made six SIAs of different integration capacitance and different op-amps and evaluated their offset currents. They showed an offset current of (1.5-85) fA with a slow variation of (0.5-10) fA for an hour under opened input. Applying a detector to the SIA input, the offset current and its variation were increased and the SIA readout became noisier due to finite shunt resistance and nonzero shunt capacitance of the detector. One of the SIAs with 10 pF nominal capacitance was calibrated using a calibrated current source at the current level of 10 nA to 1 fA and at the integration time of 2 to 65,536 ms. As a result, we obtained a calibration formula for integration capacitance as a function of integration time rather than a single capacitance value because the SIA readout showed a distinct dependence on integration time at a given current level. Finally, we applied it to spectral responsivity measurement of a photometer. It is demonstrated that the home-made SIA of 10 pF was capable of measuring a 10⁷ dynamic range of spectral responsivity of a photometer.

The concept of value stream mapping to reduce of work-time waste as applied the smart construction management

NASA Astrophysics Data System (ADS)

Elizar, Suripin, Wibowo, Mochamad Agung

2017-11-01

Delays in construction sites occur due to systematic additions of time waste in various activities that are part of the construction process. Work-time waste is non-adding value activity which used to differentiate between physical construction waste found on site and other waste which occurs during the construction process. The aim of this study is identification using the concept of Value Stream Mapping (VSM) to reduce of work-time waste as applied the smart construction management.VSM analysis is a method of business process improvement. The application of VSM began in the manufacturing community. The research method base on theoretically informed case study and literature review. The data have collected using questionnaire through personal interviews from 383 respondents on construction project in Indonesia. The results show that concept of VSM can identify causes of work-time waste. Base on result of questioners and quantitative approach analysis was obtained 29 variables that influence of work-time waste or non-value-adding activities. Base on three cases of construction project founded that average 14.88% of working time was classified as waste. Finally, the concept of VSM can recommend to identification of systematic for reveal current practices and opportunities for improvement towards global challenges. The concept of value stream mapping can help optimize to reduce work-time waste and improve quality standard of construction management. The concept is also can help manager to make a decision to reduce work-time waste so as to obtain of result in more efficient for performance and sustainable construction project.

Promoting convergence: The Phi spiral in abduction of mouse corneal behaviors

PubMed Central

Rhee, Jerry; Nejad, Talisa Mohammad; Comets, Olivier; Flannery, Sean; Gulsoy, Eine Begum; Iannaccone, Philip; Foster, Craig

2015-01-01

Why do mouse corneal epithelial cells display spiraling patterns? We want to provide an explanation for this curious phenomenon by applying an idealized problem solving process. Specifically, we applied complementary line-fitting methods to measure transgenic epithelial reporter expression arrangements displayed on three mature, live enucleated globes to clarify the problem. Two prominent logarithmic curves were discovered, one of which displayed the ϕ ratio, an indicator of an optimal configuration in phyllotactic systems. We then utilized two different computational approaches to expose our current understanding of the behavior. In one procedure, which involved an isotropic mechanics-based finite element method, we successfully produced logarithmic spiral curves of maximum shear strain based pathlines but computed dimensions displayed pitch angles of 35° (ϕ spiral is ∼17°), which was altered when we fitted the model with published measurements of coarse collagen orientations. We then used model-based reasoning in context of Peircean abduction to select a working hypothesis. Our work serves as a concise example of applying a scientific habit of mind and illustrates nuances of executing a common method to doing integrative science. © 2014 Wiley Periodicals, Inc. Complexity 20: 22–38, 2015 PMID:25755620

Multi-frequency spin manipulation using rapidly tunable superconducting coplanar waveguide microresonators

DOE PAGES

Asfaw, A. T.; Sigillito, A. J.; Tyryshkin, A. M.; ...

2017-07-17

In this work, we demonstrate the use of frequency-tunable superconducting NbTiN coplanar waveguide microresonators for multi-frequency pulsed electron spin resonance (ESR) experiments. By applying a bias current to the center pin, the resonance frequency (~7.6 GHz) can be continuously tuned by as much as 95 MHz in 270 ns without a change in the quality factor of 3000 at 2 K. We demonstrate the ESR performance of our resonators by measuring donor spin ensembles in silicon and show that adiabatic pulses can be used to overcome magnetic field inhomogeneities and microwave power limitations due to the applied bias current. Wemore » take advantage of the rapid tunability of these resonators to manipulate both phosphorus and arsenic spins in a single pulse sequence, demonstrating pulsed double electron-electron resonance. Our NbTiN resonator design is useful for multi-frequency pulsed ESR and should also have applications in experiments where spin ensembles are used as quantum memories.« less

Multi-frequency spin manipulation using rapidly tunable superconducting coplanar waveguide microresonators

NASA Astrophysics Data System (ADS)

Asfaw, A. T.; Sigillito, A. J.; Tyryshkin, A. M.; Schenkel, T.; Lyon, S. A.

2017-07-01

In this work, we demonstrate the use of frequency-tunable superconducting NbTiN coplanar waveguide microresonators for multi-frequency pulsed electron spin resonance (ESR) experiments. By applying a bias current to the center pin, the resonance frequency (˜7.6 GHz) can be continuously tuned by as much as 95 MHz in 270 ns without a change in the quality factor of 3000 at 2 K. We demonstrate the ESR performance of our resonators by measuring donor spin ensembles in silicon and show that adiabatic pulses can be used to overcome magnetic field inhomogeneities and microwave power limitations due to the applied bias current. We take advantage of the rapid tunability of these resonators to manipulate both phosphorus and arsenic spins in a single pulse sequence, demonstrating pulsed double electron-electron resonance. Our NbTiN resonator design is useful for multi-frequency pulsed ESR and should also have applications in experiments where spin ensembles are used as quantum memories.

Reduction of magneto rheological dampers stiffness by incorporating of an eddy current damper

NASA Astrophysics Data System (ADS)

Asghar Maddah, Ali; Hojjat, Yousef; Reza Karafi, Mohammad; Reza Ashory, Mohammad

2017-05-01

In this paper, a hybrid damper is developed to achieve lower stiffness compared to magneto rheological dampers. The hybrid damper consists of an eddy current damper (ECD) and a Magneto Rheological Damper (MRD). The aim of this research is to reduce the stiffness of MRDs with equal damping forces. This work is done by adding an eddy current passive damper to a semi-active MRD. The ECDs are contactless dampers which show an almost viscous damping behavior without increasing the stiffness of a system. However, MRDs increase damping and stiffness of a system simultaneously, when a magnetic field is applied. Damping of each part is studied theoretically and experimentally. A semi-empirical model is developed to explain the viscoelastic behavior of the damper. The experimental results showed that the hybrid damper is able to dissipate energy as much as those of MRDs while its stiffness is 12% lower at a zero excitation current.

A zero-liquid-discharge scheme for vanadium extraction process by electrodialysis-based technology.

PubMed

Wang, Meng; Xing, Hong-Bo; Jia, Yu-Xiang; Ren, Qing-Chun

2015-12-30

The sharp increase of demand for vanadium makes the treatment of the wastewater generated from its extraction process become an urgent problem. In this study, a hybrid process coupling the electrodialysis with the cooling crystallization is put forward for upgrading the conventional vanadium extraction process to zero discharge. Accordingly, the objective of this work lies in evaluating the feasibility of the proposed scheme on the basis of a systematic study on the influences of membrane types and operating parameters on the electrodialysis performance. The results indicate that the relative importance of osmosis and electro-osmosis to overall water transport is closely related to the applied current density. The increase in the applied current density and the decrease in the mole ratio of water and salt flux will contribute to the concentration degree. Moreover, it is worth noting that a relatively large concentration ratio can result in the remarkable decrease of current efficiency and increase of energy consumption. In general, the reclamation scheme can easily achieve the recovered water with relatively low salt content and the highly concentrated Na2SO4 solution (e.g., 300 g/L) for producing high-purity sodium sulphate crystals. Copyright © 2015. Published by Elsevier B.V.

Auditory Attention and Comprehension During a Simulated Night Shift: Effects of Task Characteristics.

PubMed

Pilcher, June J; Jennings, Kristen S; Phillips, Ginger E; McCubbin, James A

2016-11-01

The current study investigated performance on a dual auditory task during a simulated night shift. Night shifts and sleep deprivation negatively affect performance on vigilance-based tasks, but less is known about the effects on complex tasks. Because language processing is necessary for successful work performance, it is important to understand how it is affected by night work and sleep deprivation. Sixty-two participants completed a simulated night shift resulting in 28 hr of total sleep deprivation. Performance on a vigilance task and a dual auditory language task was examined across four testing sessions. The results indicate that working at night negatively impacts vigilance, auditory attention, and comprehension. The effects on the auditory task varied based on the content of the auditory material. When the material was interesting and easy, the participants performed better. Night work had a greater negative effect when the auditory material was less interesting and more difficult. These findings support research that vigilance decreases during the night. The results suggest that auditory comprehension suffers when individuals are required to work at night. Maintaining attention and controlling effort especially on passages that are less interesting or more difficult could improve performance during night shifts. The results from the current study apply to many work environments where decision making is necessary in response to complex auditory information. Better predicting the effects of night work on language processing is important for developing improved means of coping with shiftwork. © 2016, Human Factors and Ergonomics Society.

Effects of electrostimulation on the vastus medialis in the deoxygenation and the blood volume signals obtained by near-infrared spectroscopy

NASA Astrophysics Data System (ADS)

Verdaguer-Codina, Joan

1996-12-01

The electrotherapy field has been generated as a technique to improve the muscles of people affected by various pathologies. For this reason the electrotherapy is increasing its use as part of a treatment in muscle therapy. However there are not studies related to electrostimulation and near-IR spectroscopy. This work was designed to assess by near-IR spectroscopy the effects of electrostimulation in the vastus medialis, applying a tetanic contraction in this muscle with a compensated rectangular impulse at 100Hz, tolerating the subject 10mA of current. In the results obtained, we have not observed significant variations in the deoxygenation and blood volume signals, whereas as light change was observed comparing the calibration signals before and after to apply electrostimulation. It is postulated that electrostimulation only increases the diameter of the vessels, because the muscle doesn't do a metabolic work, and the heart rate frequency of the subject has not increased.

A Study on Passive and Electrochemical Response of Pure Nickel in Borate Buffer Solutions: Effect of Cold Deformation

NASA Astrophysics Data System (ADS)

Fattah-alhosseini, Arash; Naseri, Majid; Gashti, Seyed Omid; Vafaeian, Saeed; Keshavarz, Mohsen K.

2018-06-01

In the present work, influences of the cold deformation on electrochemical and passive response of pure nickel in three solutions with adjusted pH values of 8.5, 9.0, and 9.5 at 298 ± 1 K (25 ± 1 °C) were investigated. A cold deformation process was applied by means of cold rolling. Implementation of the cold deformation process resulted in samples having a finer microstructure. Also, the cold work and grain refinement led to increased hardness. In addition, open-circuit potential and potentiodynamic polarization tests were performed and results showed that corrosion current density was reduced by applying the cold deformation. Moreover, the results of the electrochemical impedance spectroscopy and Mott-Schottky analyses indicated higher corrosion resistance of pure nickel after cold deformation. This behavior is attributed to the growth of much thicker, with less point defects, passive layer on the surface of cold-deformed samples.

An ionization region model of the reactive Ar/O2 high power impulse magnetron sputtering discharge

NASA Astrophysics Data System (ADS)

Gudmundsson, J. T.; Lundin, D.; Brenning, N.; Raadu, M. A.; Huo, Chunqing; Minea, T. M.

2016-12-01

A new reactive ionization region model (R-IRM) is developed to describe the reactive Ar/O2 high power impulse magnetron sputtering (HiPIMS) discharge with a titanium target. It is then applied to study the temporal behavior of the discharge plasma parameters such as electron density, the neutral and ion composition, the ionization fraction of the sputtered vapor, the oxygen dissociation fraction, and the composition of the discharge current. We study and compare the discharge properties when the discharge is operated in the two well established operating modes, the metal mode and the poisoned mode. Experimentally, it is found that in the metal mode the discharge current waveform displays a typical non-reactive evolution, while in the poisoned mode the discharge current waveform becomes distinctly triangular and the current increases significantly. Using the R-IRM we explore the current increase and find that when the discharge is operated in the metal mode Ar+ and Ti+ -ions contribute most significantly (roughly equal amounts) to the discharge current while in the poisoned mode the Ar+ -ions contribute most significantly to the discharge current and the contribution of O+ -ions, Ti+ -ions, and secondary electron emission is much smaller. Furthermore, we find that recycling of atoms coming from the target, that are subsequently ionized, is required for the current generation in both modes of operation. From the R-IRM results it is found that in the metal mode self-sputter recycling dominates and in the poisoned mode working gas recycling dominates. We also show that working gas recycling can lead to very high discharge currents but never to a runaway. It is concluded that the dominating type of recycling determines the discharge current waveform.

Applying mobile and pervasive computer technology to enhance coordination of work in a surgical ward.

PubMed

Hansen, Thomas Riisgaard; Bardram, Jakob E

2007-01-01

Collaboration, coordination, and communication are crucial in maintaining an efficient and smooth flow of work in an operating ward. This coordination, however, often comes at a high price in terms of unsuccessfully trying to get hold of people, disturbing telephone calls, looking for people, and unnecessary stress. To accommodate this situation and to increase the quality of work in operating wards, we have designed a set of pervasive computer systems which supports what we call context-mediated communication and awareness. These systems use large interactive displays, video streaming from key locations, tracking systems, and mobile devices to support social awareness and different types of communication modalities relevant to the current context. In this paper we report qualitative data from a one-year deployment of the system in a local hospital. Overall, this study shows that 75% of the participants strongly agreed that these systems had made their work easier.

[Development of performance evaluation and management system on advanced schistosomiasis medical treatment].

PubMed

Zhou, Xiao-Rong; Huang, Shui-Sheng; Gong, Xin-Guo; Cen, Li-Ping; Zhang, Cong; Zhu, Hong; Yang, Jun-Jing; Chen, Li

2012-04-01

To construct a performance evaluation and management system on advanced schistosomiasis medical treatment, and analyze and evaluate the work of the advanced schistosomiasis medical treatment over the years. By applying the database management technique and C++ programming technique, we inputted the information of the advanced schistosomiasis cases into the system, and comprehensively evaluated the work of the advanced schistosomiasis medical treatment through the cost-effect analysis, cost-effectiveness analysis, and cost-benefit analysis. We made a set of software formula about cost-effect analysis, cost-effectiveness analysis, and cost-benefit analysis. This system had many features such as clear building, easy to operate, friendly surface, convenient information input and information search. It could benefit the performance evaluation of the province's advanced schistosomiasis medical treatment work. This system can satisfy the current needs of advanced schistosomiasis medical treatment work and can be easy to be widely used.

A Novel Approach to Apply Gait Synchronized External Forces on the Pelvis using A-TPAD to Reduce Walking Effort

PubMed Central

Vashista, Vineet; Khan, Moiz; Agrawal, Sunil K.

2017-01-01

In this paper, we develop an intervention to apply external gait synchronized forces on the pelvis to reduce the user’s effort during walking. A cable-driven robot was used to apply the external forces and an adaptive frequency oscillator scheme was developed to adapt the timing of force actuation to the gait frequency during walking. The external forces were directed in the sagittal plane to assist the trailing leg during the forward propulsion and vertical deceleration of the pelvis during the gait cycle. A pilot experiment with five healthy subjects was conducted. The results showed that the subjects applied lower ground reaction forces in the vertical and anterior-posterior directions during the late stance phase. In summary, the current work provides a novel approach to study the role of external pelvic forces in altering the walking effort. These studies can provide better understanding for designing exoskeletons and prosthetic devices to reduce the overall walking effort. PMID:29623294

Problems of Determining the Content of Cr(VI) in Raw Materials and Materials Containing Chromite Ore.

PubMed

Stec, Katarzyna

2017-11-02

Materials made with chromite ore are widely applied in the industry metallurgy as well as in the foundry industry. The oxidation number of chromium in these materials is both (III) and (VI). Currently there are no procedures allowing proper determination of chrome in chromite ores and ore-containing materials. The analytical methods applied, which are dedicated to a very narrow range of materials, e.g., cement, and cannot be applied in the case of materials which, apart from trace amounts of Cr(VI), contain mainly compounds of Cr(III), Fe(III) as well as trace compounds of Cu(II), Ni(II) and V(V). In the work particular attention has been paid to the preparation of test samples and creating measurement conditions in which interferences from Cr(III) and Fe(III) spectral lines could be minimized. Two separate instrumental measurement techniques have been applied: Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP AES) and the spectrophotometric method using diphenylcarbazide.

The Affordable Care Act: a case study for understanding and applying complexity concepts to health care reform.

PubMed

Larkin, D Justin; Swanson, R Chad; Fuller, Spencer; Cortese, Denis A

2016-02-01

The current health system in the United States is the result of a history of patchwork policy decisions and cultural assumptions that have led to persistent contradictions in practice, gaps in coverage, unsustainable costs, and inconsistent outcomes. In working toward a more efficient health system, understanding and applying complexity science concepts will allow for policy that better promotes desired outcomes and minimizes the effects of unintended consequences. This paper will consider three applied complexity science concepts in the context of the Patient Protection and Affordable Care Act (PPACA): developing a shared vision around reimbursement for value, creating an environment for emergence through simple rules, and embracing transformational leadership at all levels. Transforming the US health system, or any other health system, will be neither easy nor quick. Applying complexity concepts to health reform efforts, however, will facilitate long-term change in all levels, leading to health systems that are more effective, efficient, and equitable. © 2014 John Wiley & Sons, Ltd.

Electric field effects on current–voltage relationships in microfluidic channels presenting multiple working electrodes in the weak-coupling limit

DOE PAGES

Contento, Nicholas M.; Bohn, Paul W.

2014-05-23

While electrochemical methods are well suited for lab-on-a-chip applications, reliably coupling multiple, electrode-controlled processes in a single microfluidic channel remains a considerable challenge, because the electric fields driving electrokinetic flow make it difficult to establish a precisely known potential at the working electrode(s). The challenge of coupling electrochemical detection with microchip electrophoresis is well known; however, the problem is general, arising in other multielectrode arrangements with applications in enhanced detection and chemical processing. Here, we study the effects of induced electric fields on voltammetric behavior in a microchannel containing multiple in-channel electrodes, using a Fe(CN) 6 3/4- model system. Whenmore » an electric field is induced by applying a cathodic potential at one inchannel electrode, the half-wave potential (E 1/2) for the oxidation of ferrocyanide at an adjacent electrode shifts to more negative potentials. The E 1/2 value depends linearly on the electric field current at a separate in-channel electrode. The observed shift in E 1/2 is quantitatively described by a model, which accounts for the change in solution potential caused by the iR drop along the length of the microchannel. The model, which reliably captures changes in electrode location and solution conductivity, apportions the electric field potential between iR drop and electrochemical potential components, enabling the study of microchannel electric field magnitudes at low applied potentials. In the system studied, the iR component of the electric field potential increases exponentially with applied current before reaching an asymptotic value near 80 % of the total applied potential. The methods described will aid in the development and interpretation of future microchip electrochemistry methods, particularly those that benefit from the coupling of electrokinetic and electrochemical phenomena at low voltages.« less

Electrophysiology of connection current spikes.

PubMed

Fish, Raymond M; Geddes, Leslie A

2008-12-01

Connection to a 60-Hz or other voltage source can result in cardiac dysrhythmias, a startle reaction, muscle contractions, and a variety of other physiological responses. Such responses can lead to injury, especially if significant ventricular cardiac dysrhythmias occur, or if a person is working at some height above ground and falls as a result of a musculoskeletal response. Physiological reactions are known to relate to intensity and duration of current exposure. The connection current that flows is a function of the applied voltage at the instant of connection, and the electrical impedance encountered by the voltage source in contact with the skin or other body tissues. In this article we describe a rarely investigated phenomenon, namely a contact, or connection, current spike that is many times higher than the steady-state current. This current spike occurs when an electrical connection is made at a non-zero voltage time in a sine wave or other waveform. Such current spikes may occur when electronic or manual switching or connecting of conductors occurs in electronic instrumentation connected to a patient. These findings are relevant to medical devices and instrumentation and to electrical safety in general.

Silviculture for a declining species, Cerulean Warbler: 10-year results of a pilot study in the Mississippi Alluvial Valley

Treesearch

Paul B. Hamel; Mike Staten; Ray Souter; Carl G. Smith III; Gene Holland

2016-01-01

We report on the current status of a long-term study of Cerulean Warbler (Setophaga cerulea) response to silviculture on a 58-ha tract in Desha County, Arkansas. The work involved a 10 year premanipulation monitoring of the birds on the tract, followed by implementation of a split plot comparison of alternative treatments, each applied to a randomly selected half of...

Gate length scaling optimization of FinFETs

NASA Astrophysics Data System (ADS)

Chen, Shoumian; Shang, Enming; Hu, Shaojian

2018-06-01

This paper introduces a device performance optimization approach for the FinFET through optimization of the gate length. As a result of reducing the gate length, the leakage current (Ioff) increases, and consequently, the stress along the channel enhances which leads to an increase in the drive current (Isat) of the PMOS. In order to sustain Ioff, work function is adjusted to offset the effect of the increased stress. Changing the gate length of the transistor yields different drive currents when the leakage current is fixed by adjusting the work function. For a given device, an optimal gate length is found to provide the highest drive current. As an example, for a standard performance device with Ioff = 1 nA/um, the best performance Isat = 856 uA/um is at L = 34 nm for 14 nm FinFET and Isat = 1130 uA/um at L = 21 nm for 7 nm FinFET. A 7 nm FinFET will exhibit performance boost of 32% comparing with 14 nm FinFET. However, applying the same method to a 5 nm FinFET, the performance boosting is out of expectance comparing to the 7 nm FinFET, which is due to the severe short-channel-effect and the exhausted channel stress in the FinFET.

Low eddy current RF shielding enclosure designs for 3T MR applications.

PubMed

Lee, Brian J; Watkins, Ronald D; Chang, Chen-Ming; Levin, Craig S

2018-03-01

Magnetic resonance-compatible medical devices operate within the MR environment while benefitting from the superior anatomic information of MRI. Avoiding electromagnetic interference between such instrumentation and the MR system is crucial. In this work, various shielding configurations for positron emission tomography (PET) detectors were studied and analyzed regarding radiofrequency (RF) shielding effectiveness and gradient-induced eddy current performances. However, the results of this work apply to shielding considerations for any MR-compatible devices. Six shielding enclosure configurations with various thicknesses, patterns, and materials were designed: solid and segmented copper, phosphor bronze mesh (PBM), and carbon fiber composite (CFC). A series of tests was performed on RF shielding effectiveness and the gradient-induced eddy current. For the shielding effectiveness, the solid copper with various thickness and PBM configurations yield significantly better shielding effectiveness (>15 dB) compared with CFC and segmented configurations. For the gradient-induced eddy current performance, the solid copper shielding configurations with different thicknesses showed significantly worse results, up to a factor of 3.89 dB, compared with the segmented copper, PBM, and the CFC configurations. We evaluated the RF shielding effectiveness and the gradient-induced eddy current artifacts of several shielding designs, and only the PBM showed positive outcomes for both aspects. Magn Reson Med 79:1745-1752, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Current-driven non-linear magnetodynamics in exchange-biased spin valves

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

Seinige, Heidi; Wang, Cheng; Tsoi, Maxim, E-mail: tsoi@physics.utexas.edu

2015-05-07

This work investigates the excitation of parametric resonance in exchange-biased spin valves (EBSVs). Using a mechanical point contact, high density dc and microwave currents were injected into the EBSV sample. Observing the reflected microwave power and the small rectification voltage that develops across the contact allows detecting the current-driven magnetodynamics not only in the bulk sample but originating exclusively from the small contact region. In addition to ferromagnetic resonance (FMR), parametric resonance at twice the natural FMR frequency was observed. In contrast to FMR, this non-linear resonance was excited only in the vicinity of the point contact where current densitiesmore » are high. Power-dependent measurements displayed a typical threshold-like behavior of parametric resonance and a broadening of the instability region with increasing power. Parametric resonance showed a linear shift as a function of applied dc bias which is consistent with the field-like spin-transfer torque induced by current on magnetic moments in EBSV.« less

In-Situ Transfer Standard and Coincident-View Intercomparisons for Sensor Cross-Calibration

NASA Technical Reports Server (NTRS)

Thome, Kurt; McCorkel, Joel; Czapla-Myers, Jeff

2013-01-01

There exist numerous methods for accomplishing on-orbit calibration. Methods include the reflectance-based approach relying on measurements of surface and atmospheric properties at the time of a sensor overpass as well as invariant scene approaches relying on knowledge of the temporal characteristics of the site. The current work examines typical cross-calibration methods and discusses the expected uncertainties of the methods. Data from the Advanced Land Imager (ALI), Advanced Spaceborne Thermal Emission and Reflection and Radiometer (ASTER), Enhanced Thematic Mapper Plus (ETM+), Moderate Resolution Imaging Spectroradiometer (MODIS), and Thematic Mapper (TM) are used to demonstrate the limits of relative sensor-to-sensor calibration as applied to current sensors while Landsat-5 TM and Landsat-7 ETM+ are used to evaluate the limits of in situ site characterizations for SI-traceable cross calibration. The current work examines the difficulties in trending of results from cross-calibration approaches taking into account sampling issues, site-to-site variability, and accuracy of the method. Special attention is given to the differences caused in the cross-comparison of sensors in radiance space as opposed to reflectance space. The results show that cross calibrations with absolute uncertainties lesser than 1.5 percent (1 sigma) are currently achievable even for sensors without coincident views.

Temperature dependency of state of charge inhomogeneities and their equalization in cylindrical lithium-ion cells

NASA Astrophysics Data System (ADS)

Osswald, P. J.; Erhard, S. V.; Rheinfeld, A.; Rieger, B.; Hoster, H. E.; Jossen, A.

2016-10-01

The influence of cell temperature on the current density distribution and accompanying inhomogeneities in state of charge (SOC) during cycling is analyzed in this work. To allow for a detailed insight in the electrochemical behavior of the cell, commercially available 26650 cells were modified to allow for measuring local potentials at four different, nearly equidistant positions along the electrodes. As a follow-up to our previous work investigating local potentials within a cell, we apply this method for studying SOC deviations and their sensitivity to cell temperature. The local potential distribution was studied during constant current discharge operations for various current rates and discharge pulses in order to evoke local inhomogeneities for temperatures ranging from 10 °C to 40 °C. Differences in local potentials were considered for estimating local SOC variations within the electrodes. It could be observed that even low currents such as 0.1C can lead to significant inhomogeneities, whereas a higher cell temperature generally results in more pronounced inhomogeneities. A rapid SOC equilibration can be observed if the variation in the SOC distribution corresponds to a considerable potential difference defined by the open circuit voltage of either the positive or negative electrode. With increasing temperature, accelerated equalization effects can be observed.

Resistive switching near electrode interfaces: Estimations by a current model

NASA Astrophysics Data System (ADS)

Schroeder, Herbert; Zurhelle, Alexander; Stemmer, Stefanie; Marchewka, Astrid; Waser, Rainer

2013-02-01

The growing resistive switching database is accompanied by many detailed mechanisms which often are pure hypotheses. Some of these suggested models can be verified by checking their predictions with the benchmarks of future memory cells. The valence change memory model assumes that the different resistances in ON and OFF states are made by changing the defect density profiles in a sheet near one working electrode during switching. The resulting different READ current densities in ON and OFF states were calculated by using an appropriate simulation model with variation of several important defect and material parameters of the metal/insulator (oxide)/metal thin film stack such as defect density and its profile change in density and thickness, height of the interface barrier, dielectric permittivity, applied voltage. The results were compared to the benchmarks and some memory windows of the varied parameters can be defined: The required ON state READ current density of 105 A/cm2 can only be achieved for barriers smaller than 0.7 eV and defect densities larger than 3 × 1020 cm-3. The required current ratio between ON and OFF states of at least 10 requests defect density reduction of approximately an order of magnitude in a sheet of several nanometers near the working electrode.

Vapor deposition polymerization of aniline on 3D hierarchical porous carbon with enhanced cycling stability as supercapacitor electrode

NASA Astrophysics Data System (ADS)

Zhao, Yufeng; Zhang, Zhi; Ren, Yuqin; Ran, Wei; Chen, Xinqi; Wu, Jinsong; Gao, Faming

2015-07-01

In this work, a polyaniline coated hierarchical porous carbon (HPC) composite (PANI@HPC) is developed using a vapor deposition polymerization technique. The as synthesized composite is applied as the supercapacitor electrode material, and presents a high specific capacitance of 531 F g-1 at current density of 0.5 A g-1 and superior cycling stability of 96.1% (after 10,000 charge-discharge cycles at current density of 10 A g-1). This can be attributed to the maximized synergistic effect of PANI and HPC. Furthermore, an aqueous symmetric supercapacitor device based on PANI@HPC is fabricated, demonstrating a high specific energy of 17.3 Wh kg-1.

Fabrication of a porous material with a porosity gradient by a pulsed electric current sintering process

NASA Astrophysics Data System (ADS)

Suk, Myung-Jin; Choi, Sung-II; Kim, Ji-Soon; Kim, Young Do; Kwon, Young-Soon

2003-12-01

A porous structure with a porosity gradient can be applied to the preparation of continuous FGM, where liquid or chemical vapor of the second phase is infiltrated into the graded pores. It also has applications in skeletal implant materials and ultrafiltration media. An attempt was made to fabricate a porous material with a porosity gradient by means of a pulsed electric current sintering (PECS) process. The present work describes not only the measured value of the temperature difference between the upper and lower part of the specimen, which brings about a gradual change in pore distribution, but also the sintering characteristics of the porous structure obtained by the pressureless PECS process.

Interaction of MRI field gradients with the human body.

PubMed

Glover, P M

2009-11-07

In this review, the effects of low-frequency electromagnetic fields encountered specifically during magnetic resonance imaging (MRI) are examined. The primary biological effect at frequencies of between 100 and 5000 Hz (typical of MRI magnetic field gradient switching) is peripheral nerve stimulation, the result of which can be a mild tingling and muscle twitching to a sensation of pain. The models for nerve stimulation and how they are related to the rate of change of magnetic field are examined. The experimental measurements, and analytic and computational modelling work in this area are reviewed. The review concludes with a discussion of current regulation in this area and current practice as both are applied to MRI.

Public Outreach and Educational Experiences in Mexico and Latin American communities in California

NASA Astrophysics Data System (ADS)

Andres De Leo-Winkler, Mario; Canalizo, Gabriela; Pichardo, Barbara; Arias, Brenda

2015-08-01

I have created and applied diverse methods in public outreach at National Autonomous Univerisity of Mexico (UNAM) since 2001.A student-led volunteer astronomical club has been created, the biggest in Mexico. We serve over 10,000 people per year. We have created public outreach activities for the general audience: archeo-astronomical outings, scientific movie debates, conferences, courses, public telescope viewings. We have also worked with juvenile delinquents to offer them scientific opportunities when released from jail.I've also created and worked the social media for the Institute of Astronomy UNAM, which is currently the biggest social media site on astronomy in Spanish in the world. I've created and organized a mass photo exhibition (over 1 million people served) for the Institute of Astronomy, UNAM which was citizen-funded through an online platform, the first of its kind in the country. Together with my colleages, we created workshops on astronomy for children with the Mexican's government funding.I've participated in several radio and television programs/capsules designed to bring astronomy to the general audience, one in particular ("Astrophysics for Dummies") was very successful in nation-wide Mexican radio.I am currently applying all experiences to develop a new public outreach project on astronomy for the University of California - Riverside and its on-campus and surrounding Latin American communities. We are offering new workshops for blind and deaf children. We want to integrate the Latino community to our outreach activities and offer science in their language in a simple and entertaining fashion. We have also successfully applied astrophotography as a course which brings social-science and arts undergraduate students into natural sciences.Sharing experiences, success and failure stories will help new and experienced educators and public outreach professionals learn and better from past experiences.

Trends in optical coherence tomography applied to medical imaging

NASA Astrophysics Data System (ADS)

Podoleanu, Adrian G.

2014-01-01

The number of publications on optical coherence tomography (OCT) continues to double every three years. Traditionally applied to imaging the eye, OCT is now being extended to fields outside ophthalmology and optometry. Widening its applicability, progress in the core engine of the technology, and impact on development of novel optical sources, make OCT a very active and rapidly evolving field. Trends in the developments of different specific devices, such as optical sources, optical configurations and signal processing will be presented. Encompassing studies on both the configurations as well as on signal processing themes, current research in Kent looks at combining spectral domain with time domain imaging for long axial range and simultaneous imaging at several depths. Results of the collaborative work of the Applied Optics Group in Kent with organisers of this conference will be presented, with reference to 3D monitoring of abfraction.

Climate conditions, workplace heat and occupational health in South-East Asia in the context of climate change.

PubMed

Kjellstrom, Tord; Lemke, Bruno; Otto, Matthias

2017-09-01

Occupational health is particularly affected by high heat exposures in workplaces, which will be an increasing problem as climate change progresses. People working in jobs of moderate or heavy work intensity in hot environments are at particular risk, owing to exposure to high environmental heat and internal heat production. This heat needs to be released to protect health, and such release is difficult or impossible at high temperatures and high air humidity. A range of clinical health effects can occur, and the heat-related physical exhaustion leads to a reduction of work capacity and labour productivity, which may cause substantial economic losses. Current trends in countries of the World Health Organization South-East Asia Region are towards higher ambient heat levels during large parts of each year, and modelling indicates continuing trends, which will particularly affect low-income individuals and communities. Prevention activities need to address the climate policies of each country, and to apply currently available heat-reducing technologies in workplaces whenever possible. Work activities can be adjusted to reduce exposure to daily heat peaks or seasonal heat concerns. Application of basic occupational health principles, such as supply of drinking water, enforcement of rest periods and training of workers and supervisors, is essential.

Theoretical evidence of maximum intracellular currents versus frequency in an Escherichia coli cell submitted to AC voltage.

PubMed

Xavier, Pascal; Rauly, Dominique; Chamberod, Eric; Martins, Jean M F

2017-04-01

In this work, the problem of intracellular currents in longilinear bacteria, such as Escherichia coli, suspended in a physiological medium and submitted to a harmonic voltage (AC), is analyzed using the Finite-Element-based software COMSOL Multiphysics. Bacterium was modeled as a cylindrical capsule, ended by semi-spheres and surrounded by a dielectric cell wall. An equivalent single-layer cell wall was defined, starting from the well-recognized three-shell modeling approach. The bacterium was considered immersed in a physiological medium, which was also taken into account in the modeling. A new complex transconductance was thus introduced, relating the complex ratio between current inside the bacterium and voltage applied between two parallel equipotential planes, separated by a realistic distance. When voltage was applied longitudinally relative to the bacterium main axis, numerical results in terms of frequency response in the 1-20 MHz range for E. coli cells revealed that transconductance magnitude exhibited a maximum at a frequency depending on the cell wall capacitance. This occurred in spite of the purely passive character of the model and could be explained by an equivalent electrical network giving very similar results and showing special conditions for lateral paths of the currents through the cell wall. It is shown that the main contribution to this behavior is due to the conductive part of the current. Bioelectromagnetics. 38:213-219, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

High-conductance low-voltage organic thin film transistor with locally rearranged poly(3-hexylthiophene) domain by current annealing on plastic substrate

NASA Astrophysics Data System (ADS)

Pei, Zingway; Tsai, Hsing-Wang; Lai, Hsin-Cheng

2016-02-01

The organic material based thin film transistors (TFTs) are attractive for flexible optoelectronics applications due to the ability of lager area fabrication by solution and low temperature process on plastic substrate. Recently, the research of organic TFT focus on low operation voltage and high output current to achieve a low power organic logic circuit for optoelectronic device,such as e-paper or OLED displayer. To obtain low voltage and high output current, high gate capacitance and high channel mobility are key factors. The well-arranged polymer chain by a high temperature postannealing, leading enhancement conductivity of polymer film was a general method. However, the thermal annealing applying heat for all device on the substrate and may not applicable to plastic substrate. Therefore, in this work, the low operation voltage and high output current of polymer TFTs was demonstrated by locally electrical bias annealing. The poly(styrene-comethyl methacrylate) (PS-r-PMMA) with ultra-thin thickness is used as gate dielectric that the thickness is controlled by thermal treatment after spin coated on organic electrode. In electrical bias-annealing process, the PS-r- PMMA is acted a heating layer. After electrical bias-annealing, the polymer TFTs obtain high channel mobility at low voltage that lead high output current by a locally annealing of P3HT film. In the future, the locally electrical biasannealing method could be applied on plastic substrate for flexible optoelectronic application.

History of mathematics and history of science reunited?

PubMed

Gray, Jeremy

2011-09-01

For some years now, the history of modern mathematics and the history of modern science have developed independently. A step toward a reunification that would benefit both disciplines could come about through a revived appreciation of mathematical practice. Detailed studies of what mathematicians actually do, whether local or broadly based, have often led in recent work to examinations of the social, cultural, and national contexts, and more can be done. Another recent approach toward a historical understanding of the abstractness of modern mathematics has been to see it as a species of modernism, and this thesis will be tested by the raft of works on the history of modern applied mathematics currently under way.

Strategies for a Creative Future with Computer Science, Quality Design and Communicability

NASA Astrophysics Data System (ADS)

Cipolla Ficarra, Francisco V.; Villarreal, Maria

In the current work is presented the importance of the two-way triad between computer science, design and communicability. It is demonstrated how the principles of quality of software engineering are not universal since they are disappearing inside university training. Besides, a short analysis of the term "creativity" males apparent the existence of plagiarism as a human factor that damages the future of communicability applied to the on-line and off-line contents of the open software. A set of measures and guidelines are presented so that the triad works again correctly in the next years to foster the qualitative design of the interactive systems on-line and/or off-line.

Hybrid Particle-Element Simulation of Impact on Composite Orbital Debris Shields

NASA Technical Reports Server (NTRS)

Fahrenthold, Eric P.

2004-01-01

This report describes the development of new numerical methods and new constitutive models for the simulation of hypervelocity impact effects on spacecraft. The research has included parallel implementation of the numerical methods and material models developed under the project. Validation work has included both one dimensional simulations, for comparison with exact solutions, and three dimensional simulations of published hypervelocity impact experiments. The validated formulations have been applied to simulate impact effects in a velocity and kinetic energy regime outside the capabilities of current experimental methods. The research results presented here allow for the expanded use of numerical simulation, as a complement to experimental work, in future design of spacecraft for hypervelocity impact effects.

New Evidence on What Works in Effective Public Reporting.

PubMed

Sandmeyer, Brent; Fraser, Irene

2016-06-01

To describe the current state of the public reporting field and provide guidance to public report producers based on the evidence. Public reports should address the questions and priorities that consumers actually have; present information credibly and in a way that is understood by the intended audience; reach the intended audience; and enable consumers to act on the information. Public reports have advanced greatly in recent years, but there remains much room for improvement. Report producers should continually evaluate their reports and apply the latest evidence to maximize their usefulness and impact. © Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Intuitive Physics: Current Research and Controversies.

PubMed

Kubricht, James R; Holyoak, Keith J; Lu, Hongjing

2017-10-01

Early research in the field of intuitive physics provided extensive evidence that humans succumb to common misconceptions and biases when predicting, judging, and explaining activity in the physical world. Recent work has demonstrated that, across a diverse range of situations, some biases can be explained by the application of normative physical principles to noisy perceptual inputs. However, it remains unclear how knowledge of physical principles is learned, represented, and applied to novel situations. In this review we discuss theoretical advances from heuristic models to knowledge-based, probabilistic simulation models, as well as recent deep-learning models. We also consider how recent work may be reconciled with earlier findings that favored heuristic models. Copyright © 2017 Elsevier Ltd. All rights reserved.

Canceling buoyancy of gaseous fuel flames in a gravitational environment using an ion-driven wind.

PubMed

Papac, M J; Dunn-Rankin, D

2006-09-01

Electric fields applied to combustion plasmas can be used to manipulate the thermofluid flow field to reduce buoyant forces and, hence, convection in locations near and within the flame. The resulting flow field is similar to that which is obtained in microgravity. Previous work has shown that buoyancy is modified in a non-premixed methane-air capillary flame when it burns in a capillary-to-plane configuration and an electric field is applied, and that regions of neutral or microbuoyancy exist, as indicated by the examined temperature and oxidizer profiles. The aim of this article is to examine in more detail this microbuoyancy condition and the coupling between the ion wind and resulting thermofluid flow field. To this end, the voltage-current characteristics (VCC) of CH4, C2H2, C2H4, C2H6, and C3H8 are measured and compared. Soot generated in the C2H(X) and propane flames lead to a hysteresis in the VCC curve whereby increased sooting leads to lower ion currents at constant flow rates and applied potentials. Buoyancy regimes for these flames in this configuration are determined. Methane can achieve the highest flow rate without sooting at the microbuoyant condition, and does not exhibit hysteresis in the VCC for the flow rates examined here. Furthermore, in this geometry, the microbuoyant condition for methane is found to coincide with ion current saturation when the capillary-to-plane distance is varied. These results allow for several simplifications to be made when modeling the flame at these conditions: the imposition of a spherical flame boundary with known ion current, and negligible recombination in the domain.

3-D residual eddy current field characterisation: applied to diffusion weighted magnetic resonance imaging.

PubMed

O'Brien, Kieran; Daducci, Alessandro; Kickler, Nils; Lazeyras, Francois; Gruetter, Rolf; Feiweier, Thorsten; Krueger, Gunnar

2013-08-01

Clinical use of the Stejskal-Tanner diffusion weighted images is hampered by the geometric distortions that result from the large residual 3-D eddy current field induced. In this work, we aimed to predict, using linear response theory, the residual 3-D eddy current field required for geometric distortion correction based on phantom eddy current field measurements. The predicted 3-D eddy current field induced by the diffusion-weighting gradients was able to reduce the root mean square error of the residual eddy current field to ~1 Hz. The model's performance was tested on diffusion weighted images of four normal volunteers, following distortion correction, the quality of the Stejskal-Tanner diffusion-weighted images was found to have comparable quality to image registration based corrections (FSL) at low b-values. Unlike registration techniques the correction was not hindered by low SNR at high b-values, and results in improved image quality relative to FSL. Characterization of the 3-D eddy current field with linear response theory enables the prediction of the 3-D eddy current field required to correct eddy current induced geometric distortions for a wide range of clinical and high b-value protocols.

Local structure studies of materials using pair distribution function analysis

NASA Astrophysics Data System (ADS)

Peterson, Joseph W.

A collection of pair distribution function studies on various materials is presented in this dissertation. In each case, local structure information of interest pushes the current limits of what these studies can accomplish. The goal is to provide insight into the individual material behaviors as well as to investigate ways to expand the current limits of PDF analysis. Where possible, I provide a framework for how PDF analysis might be applied to a wider set of material phenomena. Throughout the dissertation, I discuss 0 the capabilities of the PDF method to provide information pertaining to a material's structure and properties, ii) current limitations in the conventional approach to PDF analysis, iii) possible solutions to overcome certain limitations in PDF analysis, and iv) suggestions for future work to expand and improve the capabilities PDF analysis.

Induced Eddy Currents in Simple Conductive Geometries: Mathematical Formalism Describes the Excitation of Electrical Eddy Currents in a Time-Varying Magnetic Field

DOE PAGES

Nagel, James R.

2017-12-22

In this paper, a complete mathematical formalism is introduced to describe the excitation of electrical eddy currents due to a time-varying magnetic field. The process works by applying a quasistatic approximation to Ampere's law and then segregating the magnetic field into impressed and induced terms. The result is a nonhomogeneous vector Helmholtz equation that can be analytically solved for many practical geometries. Four demonstration cases are then solved under a constant excitation field over all space—an infinite slab in one dimension, a longitudinal cylinder in two dimensions, a transverse cylinder in two dimensions, and a sphere in three dimensions. Numericalmore » simulations are also performed in parallel with analytic computations, all of which verify the accuracy of the derived expressions.« less

Thermal diode utilizing asymmetric contacts to heat baths.

PubMed

Komatsu, Teruhisa S; Ito, Nobuyasu

2010-01-01

We propose a simple thermal diode passively acting as a rectifier of heat current. The key design of the diode is the size asymmetry of the areas in contact with two distinct heat baths. The heat-conducting medium is liquid, inside of which gaslike regions are induced depending on the applied conditions. Simulating nanoscale systems of this diode, the rectification of heat current is demonstrated. If the packing density of the medium and the working regime of temperature are properly chosen, the heat current is effectively cut off when the heat bath with narrow contact is hotter, but it flows normally under opposite temperature conditions. In the former case, the gaslike region is induced in the system and it acts as a thermal insulator because it covers the entire narrow area of contact with the bath.

Induced Eddy Currents in Simple Conductive Geometries: Mathematical Formalism Describes the Excitation of Electrical Eddy Currents in a Time-Varying Magnetic Field

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

Nagel, James R.

In this paper, a complete mathematical formalism is introduced to describe the excitation of electrical eddy currents due to a time-varying magnetic field. The process works by applying a quasistatic approximation to Ampere's law and then segregating the magnetic field into impressed and induced terms. The result is a nonhomogeneous vector Helmholtz equation that can be analytically solved for many practical geometries. Four demonstration cases are then solved under a constant excitation field over all space—an infinite slab in one dimension, a longitudinal cylinder in two dimensions, a transverse cylinder in two dimensions, and a sphere in three dimensions. Numericalmore » simulations are also performed in parallel with analytic computations, all of which verify the accuracy of the derived expressions.« less

First studies of bottom boundary currents in the Ría de Vigo (NW Iberian upwelling system)

NASA Astrophysics Data System (ADS)

Villacieros-Robineau, N.; Herrera, J. H.; Castro, C. G.; Piedracoba, S.; Rosón, G.

2012-04-01

The NW Iberian Upwelling system has a set of physical and chemical characteristics that determine the ecology at the coast, specifically inside the Rías Baixas where activities like raft culture have a significant weight in the local economy. Although several studies have dealt with the physical processes driving the rías general circulation, no previous research has faced the study of bottom boundary currents. This work studies the behavior of bottom currents inside the Rías Baixas and identifies their possible forcing mechanism. For tackling this issue, high resolution time series of bottom currents by means of a downwards looking ADCP (3-5 meters above the bottom) were recorded at one site in the Ría de Vigo covering the four seasons of the climate year 2004 - 2005. Our analysis shows that most of the time (aprox. 70 -80%), the bottom currents respond to a logarithmic profile being possible to apply the law of the wall. This pattern can be applied to the residual component and also to the tidal component of the currents. Based on this logarithmic fit, we have obtained characteristic parameters like shear stress and shear velocity. Our results point to a coupling among shear stress, shelf winds and runoff. Other important conclusion is the relative importance of tidal shear stress versus residual shear stress because the typical assumption of tidal has more influence is not true always. In some occasions when there are neap tides and high shelf winds the residual stress could be just three times the tidal ones.

Depinning of the transverse domain wall trapped at magnetic impurities patterned in planar nanowires: Control of the wall motion using low-intensity and short-duration current pulses

NASA Astrophysics Data System (ADS)

Paixão, E. L. M.; Toscano, D.; Gomes, J. C. S.; Monteiro, M. G.; Sato, F.; Leonel, S. A.; Coura, P. Z.

2018-04-01

Understanding and controlling of domain wall motion in magnetic nanowires is extremely important for the development and production of many spintronic devices. It is well known that notches are able to pin domain walls, but their pinning potential strength are too strong and it demands high-intensity current pulses to achieve wall depinning in magnetic nanowires. However, traps of pinning can be also originated from magnetic impurities, consisting of located variations of the nanowire's magnetic properties, such as exchange stiffness constant, saturation magnetization, anisotropy constant, damping parameter, and so on. In this work, we have performed micromagnetic simulations to investigate the depinning mechanism of a transverse domain wall (TDW) trapped at an artificial magnetic defect using spin-polarized current pulses. In order to create pinning traps, a simplified magnetic impurity model, only based on a local reduction of the exchange stiffness constant, have been considered. In order to provide a background for experimental studies, we have varied the parameter related to the pinning potential strength of the magnetic impurity. By adjusting the pinning potential of magnetic impurities and choosing simultaneously a suitable current pulse, we have found that it is possible to obtain domain wall depinning by applying low-intensity and short-duration current pulses. Furthermore, it was considered a planar magnetic nanowire containing a linear distribution of equally-spaced magnetic impurities and we have demonstrated the position control of a single TDW by applying sequential current pulses; that means the wall movement from an impurity to another.

Single shot trajectory design for region-specific imaging using linear and nonlinear magnetic encoding fields.

PubMed

Layton, Kelvin J; Gallichan, Daniel; Testud, Frederik; Cocosco, Chris A; Welz, Anna M; Barmet, Christoph; Pruessmann, Klaas P; Hennig, Jürgen; Zaitsev, Maxim

2013-09-01

It has recently been demonstrated that nonlinear encoding fields result in a spatially varying resolution. This work develops an automated procedure to design single-shot trajectories that create a local resolution improvement in a region of interest. The technique is based on the design of optimized local k-space trajectories and can be applied to arbitrary hardware configurations that employ any number of linear and nonlinear encoding fields. The trajectories designed in this work are tested with the currently available hardware setup consisting of three standard linear gradients and two quadrupolar encoding fields generated from a custom-built gradient insert. A field camera is used to measure the actual encoding trajectories up to third-order terms, enabling accurate reconstructions of these demanding single-shot trajectories, although the eddy current and concomitant field terms of the gradient insert have not been completely characterized. The local resolution improvement is demonstrated in phantom and in vivo experiments. Copyright © 2012 Wiley Periodicals, Inc.

Transport properties of initially neutral gas disturbed by intense electron beam

NASA Astrophysics Data System (ADS)

Angus, Justin; Swanekamp, Steve; Schumer, Joseph; Mosher, Dave; Ottinger, Paul

2013-10-01

The behavior of intense electron beams (those with current densities on the order of hundreds of kA/cm2 and beam rise times on the order of 100 ns) traveling through gaseous mediums depends strongly on the transport properties of the medium. For example, the conductivity of the medium, which is very sensitive to the ionization state and temperature of the gas, has a strong influence on the beam behavior through the plasma return current. Since the beam is responsible for ionizing and heating the gas, self-consistently solving for the gas transport properties and the beam propagation is essential for an accurate description of the system. An advanced gas chemistry model to describe the transport properties of a strongly disturbed gaseous system is presented in this work. A focal point of this work is an accurate description of the medium's conductivity as the gas progresses from its weakly ionized state, where swarm models are valid, to a strongly ionized state where the Spitzer-Harm model applies. NRL Karle Fellowship

Conductive diamond sono-electrochemical disinfection (CDSED) for municipal wastewater reclamation.

PubMed

Llanos, Javier; Cotillas, Salvador; Cañizares, Pablo; Rodrigo, Manuel A

2015-01-01

In the present work, the disinfection of actual effluents from a municipal wastewater treatment plant (WWTP) by a conductive diamond sono-electrochemical process was assessed. First, efficiency of single electrodisinfection process with diamond anodes (without the contribution of ultrasounds) was studied, finding that the total disinfection can be attained at current charges applied below 0.02kAhm(-3). It was also found that the main disinfection mechanism is the attack of Escherichia coli (E. coli) by the disinfectants produced in the electrochemical cell and that the production of chlorates is avoided when working at current densities not higher than 1.27Am(-2). Next, a marked synergistic effect was found when coupling ultrasound (US) irradiation to the electrochemical system (sono-electrochemical disinfection). This increase in the disinfection rate was found to be related to the suppression of the agglomeration of E. coli cells and the enhancement in the production of disinfectant species. Copyright © 2014 Elsevier B.V. All rights reserved.

A review of research on the environmental impact of e-business and ICT.

PubMed

Yi, Lan; Thomas, Hywel R

2007-08-01

This paper attempts to provide a review of the current state of the art of how e-business/ICT affects the environment. The work reviewed is in various forms including journal papers and thesis which have been peer-reviewed, as well as other resources such as projects and project reports, conference and symposia, and websites. It is claimed that the research examined has captured the most important work to date, either for a general knowledge of this new area or for background study by experts carrying out future research. The review has found that the currently dominant approach is either a micro-level case study approach or a macro-level statistical approach. It is concluded that a more predictive and empirical model, which can be applied within a sector of society, should be more beneficial in the long term. This approach should help simulate potential impacts resulting from changes of indicators, so that positive effects can be promoted and negative ones alleviated proactively, rather than knowing and accepting outcomes passively.

Applying Semantic Web Services and Wireless Sensor Networks for System Integration

NASA Astrophysics Data System (ADS)

Berkenbrock, Gian Ricardo; Hirata, Celso Massaki; de Oliveira Júnior, Frederico Guilherme Álvares; de Oliveira, José Maria Parente

In environments like factories, buildings, and homes automation services tend to often change during their lifetime. Changes are concerned to business rules, process optimization, cost reduction, and so on. It is important to provide a smooth and straightforward way to deal with these changes so that could be handled in a faster and low cost manner. Some prominent solutions use the flexibility of Wireless Sensor Networks and the meaningful description of Semantic Web Services to provide service integration. In this work, we give an overview of current solutions for machinery integration that combine both technologies as well as a discussion about some perspectives and open issues when applying Wireless Sensor Networks and Semantic Web Services for automation services integration.

Differential electrolytic potentiometric titration method for the determination of ciprofloxacin in drug formulations.

PubMed

Abulkibash, Abdalla M; Sultan, Salah M; Al-Olyan, Abeer M; Al-Ghannam, Sheikha M

2003-10-17

A simple and rapid differential electrolytic potentiometric titration method for the determination of ciprofloxacin was developed. The work is based on the fast complexation reaction between iron(III) and ciprofloxacin in a ratio of 1:3, respectively, in sulfuric acid media of 0.09 mol dm(-3). Among the electrodes tested silver amalgam electrodes were found to be a suitable indicating system. By applying a current density of 0.5 muA cm(-2) to these electrodes and using iron(III) solution of 0.097 mol dm(-3) as a titrant, normal titration curves were obtained. The method was successfully applied for the determination of ciprofloxacin in drug formulations as low as 4.0 ppm.

Applications of Electrical Impedance Tomography (EIT): A Short Review

NASA Astrophysics Data System (ADS)

Kanti Bera, Tushar

2018-03-01

Electrical Impedance Tomography (EIT) is a tomographic imaging method which solves an ill posed inverse problem using the boundary voltage-current data collected from the surface of the object under test. Though the spatial resolution is comparatively low compared to conventional tomographic imaging modalities, due to several advantages EIT has been studied for a number of applications such as medical imaging, material engineering, civil engineering, biotechnology, chemical engineering, MEMS and other fields of engineering and applied sciences. In this paper, the applications of EIT have been reviewed and presented as a short summary. The working principal, instrumentation and advantages are briefly discussed followed by a detail discussion on the applications of EIT technology in different areas of engineering, technology and applied sciences.

Verification of short lead time forecast models: applied to Kp and Dst forecasting

NASA Astrophysics Data System (ADS)

Wintoft, Peter; Wik, Magnus

2016-04-01

In the ongoing EU/H2020 project PROGRESS models that predicts Kp, Dst, and AE from L1 solar wind data will be used as inputs to radiation belt models. The possible lead times from L1 measurements are shorter (10s of minutes to hours) than the typical duration of the physical phenomena that should be forecast. Under these circumstances several metrics fail to single out trivial cases, such as persistence. In this work we explore metrics and approaches for short lead time forecasts. We apply these to current Kp and Dst forecast models. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 637302.

The impact of funding deadlines on personal workloads, stress and family relationships: a qualitative study of Australian researchers

PubMed Central

Herbert, Danielle L; Coveney, John; Clarke, Philip; Graves, Nicholas; Barnett, Adrian G

2014-01-01

Objective To examine the impact of applying for funding on personal workloads, stress and family relationships. Design Qualitative study of researchers preparing grant proposals. Setting Web-based survey on applying for the annual National Health and Medical Research Council (NHMRC) Project Grant scheme. Participants Australian researchers (n=215). Results Almost all agreed that preparing their proposals always took top priority over other work (97%) and personal (87%) commitments. Almost all researchers agreed that they became stressed by the workload (93%) and restricted their holidays during the grant writing season (88%). Most researchers agreed that they submitted proposals because chance is involved in being successful (75%), due to performance requirements at their institution (60%) and pressure from their colleagues to submit proposals (53%). Almost all researchers supported changes to the current processes to submit proposals (95%) and peer review (90%). Most researchers (59%) provided extensive comments on the impact of writing proposals on their work life and home life. Six major work life themes were: (1) top priority; (2) career development; (3) stress at work; (4) benefits at work; (5) time spent at work and (6) pressure from colleagues. Six major home life themes were: (1) restricting family holidays; (2) time spent on work at home; (3) impact on children; (4) stress at home; (5) impact on family and friends and (6) impact on partner. Additional impacts on the mental health and well-being of researchers were identified. Conclusions The process of preparing grant proposals for a single annual deadline is stressful, time consuming and conflicts with family responsibilities. The timing of the funding cycle could be shifted to minimise applicant burden, give Australian researchers more time to work on actual research and to be with their families. PMID:24682577

The impact of funding deadlines on personal workloads, stress and family relationships: a qualitative study of Australian researchers.

PubMed

Herbert, Danielle L; Coveney, John; Clarke, Philip; Graves, Nicholas; Barnett, Adrian G

2014-03-28

To examine the impact of applying for funding on personal workloads, stress and family relationships. Qualitative study of researchers preparing grant proposals. Web-based survey on applying for the annual National Health and Medical Research Council (NHMRC) Project Grant scheme. Australian researchers (n=215). Almost all agreed that preparing their proposals always took top priority over other work (97%) and personal (87%) commitments. Almost all researchers agreed that they became stressed by the workload (93%) and restricted their holidays during the grant writing season (88%). Most researchers agreed that they submitted proposals because chance is involved in being successful (75%), due to performance requirements at their institution (60%) and pressure from their colleagues to submit proposals (53%). Almost all researchers supported changes to the current processes to submit proposals (95%) and peer review (90%). Most researchers (59%) provided extensive comments on the impact of writing proposals on their work life and home life. Six major work life themes were: (1) top priority; (2) career development; (3) stress at work; (4) benefits at work; (5) time spent at work and (6) pressure from colleagues. Six major home life themes were: (1) restricting family holidays; (2) time spent on work at home; (3) impact on children; (4) stress at home; (5) impact on family and friends and (6) impact on partner. Additional impacts on the mental health and well-being of researchers were identified. The process of preparing grant proposals for a single annual deadline is stressful, time consuming and conflicts with family responsibilities. The timing of the funding cycle could be shifted to minimise applicant burden, give Australian researchers more time to work on actual research and to be with their families.

Recent progress in high gain InAs avalanche photodiodes (Presentation Recording)

NASA Astrophysics Data System (ADS)

Bank, Seth; Maddox, Scott J.; Sun, Wenlu; Nair, Hari P.; Campbell, Joe C.

2015-08-01

InAs possesses nearly ideal material properties for the fabrication of near- and mid-infrared avalanche photodiodes (APDs), which result in strong electron-initiated impact ionization and negligible hole-initiated impact ionization [1]. Consequently, InAs multiplication regions exhibit several appealing characteristics, including extremely low excess noise factors and bandwidth independent of gain [2], [3]. These properties make InAs APDs attractive for a number of near- and mid-infrared sensing applications including remote gas sensing, light detection and ranging (LIDAR), and both active and passive imaging. Here, we discuss our recent advances in the growth and fabrication of high gain, low noise InAs APDs. Devices yielded room temperature multiplication gains >300, with much reduced (~10x) lower dark current densities. We will also discuss a likely key contributor to our current performance limitations: silicon diffusion into the intrinsic (multiplication) region from the underlying n-type layer during growth. Future work will focus on increasing the intrinsic region thickness, targeting gains >1000. This work was supported by the Army Research Office (W911NF-10-1-0391). [1] A. R. J. Marshall, C. H. Tan, M. J. Steer, and J. P. R. David, "Electron dominated impact ionization and avalanche gain characteristics in InAs photodiodes," Applied Physics Letters, vol. 93, p. 111107, 2008. [2] A. R. J. Marshall, A. Krysa, S. Zhang, A. S. Idris, S. Xie, J. P. R. David, and C. H. Tan, "High gain InAs avalanche photodiodes," in 6th EMRS DTC Technical Conference, Edinburgh, Scotland, UK, 2009. [3] S. J. Maddox, W. Sun, Z. Lu, H. P. Nair, J. C. Campbell, and S. R. Bank, "Enhanced low-noise gain from InAs avalanche photodiodes with reduced dark current and background doping," Applied Physics Letters, vol. 101, no. 15, pp. 151124-151124-3, Oct. 2012.

Multiscale Modeling of Carbon Fiber Reinforced Polymer (CFRP) for Integrated Computational Materials Engineering Process

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

Gao, Jiaying; Liang, Biao; Zhang, Weizhao

In this work, a multiscale modeling framework for CFRP is introduced to study hierarchical structure of CFRP. Four distinct scales are defined: nanoscale, microscale, mesoscale, and macroscale. Information at lower scales can be passed to higher scale, which is beneficial for studying effect of constituents on macroscale part’s mechanical property. This bottom-up modeling approach enables better understanding of CFRP from finest details. Current study focuses on microscale and mesoscale. Representative volume element is used at microscale and mesoscale to model material’s properties. At microscale, unidirection CFRP (UD) RVE is used to study properties of UD. The UD RVE can bemore » modeled with different volumetric fraction to encounter non-uniform fiber distribution in CFRP part. Such consideration is important in modeling uncertainties at microscale level. Currently, we identified volumetric fraction as the only uncertainty parameters in UD RVE. To measure effective material properties of UD RVE, periodic boundary conditions (PBC) are applied to UD RVE to ensure convergence of obtained properties. Properties of UD is directly used at mesoscale woven RVE modeling, where each yarn is assumed to have same properties as UD. Within woven RVE, there can be many potential uncertainties parameters to consider for a physical modeling of CFRP. Currently, we will consider fiber misalignment within yarn and angle between wrap and weft yarns. PBC is applied to woven RVE to calculate its effective material properties. The effect of uncertainties are investigated quantitatively by Gaussian process. Preliminary results of UD and Woven study are analyzed for efficacy of the RVE modeling. This work is considered as the foundation for future multiscale modeling framework development for ICME project.« less

The mental health benefits of work: do they apply to poor single mothers?

PubMed

Zabkiewicz, Denise

2010-01-01

The relationship between employment and improved mental health is well documented. However, no research has examined whether this relationship applies to poor single mothers. Given recent changes in the labor market where poor women are disproportionately employed in unstable jobs, the competing demands of work and childcare may operate to prevent poor women from reaping the mental health benefits of employment. Understanding these connections has become more salient not just for mental health epidemiology but for policies targeting employment and poverty. This study draws on four waves of data from the Welfare Client Longitudinal Study. Generalized estimating equations are utilized to assess the role of current employment and employment continuity on the depression status of poor single mothers over time. Through a comparison of results drawn from a dichotomous categorization of current employment with results drawn from measures of employment continuity, this study is also able to assess whether it is employment per se or the characteristics of employment that matter. Overall, the results from this study suggest that current employment improves the mental health of many poor single mothers. However, the circumstances most likely to improve their mental health are full-time or stable, longer term employment. The results from this study are of concern given that the lack of employment continuity is a growing trend in the U.S. labor market and poor women are disproportionately employed in these types of unstable jobs. These findings, thus, have wide-reaching implications for welfare policy as they provide an important and timely perspective in our understanding of the impact of the changing face of employment on poor women.

Current Density Scaling in Electrochemical Flow Capacitors

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

Hoyt, NC; Wainright, JS; Savinell, RF

Electrochemical flow capacitors (EFCs) are a recently developed energy storage technology. One of the principal performance metrics of an EFC is the steady-state electrical current density that it can accept or deliver. Numerical models exist to predict this performance for specific cases, but here we present a study of how the current varies with respect to the applied cell voltage, flow rate, cell dimensions, and slurry properties using scaling laws. The scaling relationships are confirmed by numerical simulations and then subsequently by comparison to results from symmetric cell EFC experiments. This modeling approach permits the delimitation of three distinct operationalmore » regimes dependent on the values of two nondimensional combinations of the pertinent variables (specifically, a capacitive Graetz number and a conductivity ratio). Lastly, the models and nondimensional numbers are used to provide design guidance in terms of criteria for proper EFC operation. (C) The Author(s) 2015. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. All rights reserved.« less

[Physical therapy for idiopathic scoliosis].

PubMed

Steffan, K

2015-11-01

The objective is the description and summary of the current state of idiopathic scoliosis treatment with physical therapy based on new scientific knowledge and concluded from more than 15 years of experience as a leading physician in two well-known clinics specializing in the conservative treatment of scoliosis. Based on current scientific publications on physical therapy in scoliosis treatment and resulting from the considerable personal experience gained working with conservative treatment and consulting scoliosis patients (as inpatients and outpatients), the current methods of physical therapy have been compared and evaluated. Physical therapy according to Schroth and Vojta therapy are at present the most common and effective methods in the physical treatment of idiopathic scoliosis. These methods can be applied during inpatient or outpatient treatment or intensified in the practice of specialized therapists. As there are only a few scientific studies on this subject, the author's findings are based mainly on his own experiences of the conservative treatment of idiopathic scoliosis. Athough these experiences are the results of over 15 years of working in the field of therapy, and the Schroth method in combination with corrective bracing presents highly promising results, it would nevertheless be desirable to conduct detailed scientific studies to verify the effectiveness of conservative treatment.

Dynamic optimization of ISR sensors using a risk-based reward function applied to ground and space surveillance scenarios

NASA Astrophysics Data System (ADS)

DeSena, J. T.; Martin, S. R.; Clarke, J. C.; Dutrow, D. A.; Newman, A. J.

2012-06-01

As the number and diversity of sensing assets available for intelligence, surveillance and reconnaissance (ISR) operations continues to expand, the limited ability of human operators to effectively manage, control and exploit the ISR ensemble is exceeded, leading to reduced operational effectiveness. Automated support both in the processing of voluminous sensor data and sensor asset control can relieve the burden of human operators to support operation of larger ISR ensembles. In dynamic environments it is essential to react quickly to current information to avoid stale, sub-optimal plans. Our approach is to apply the principles of feedback control to ISR operations, "closing the loop" from the sensor collections through automated processing to ISR asset control. Previous work by the authors demonstrated non-myopic multiple platform trajectory control using a receding horizon controller in a closed feedback loop with a multiple hypothesis tracker applied to multi-target search and track simulation scenarios in the ground and space domains. This paper presents extensions in both size and scope of the previous work, demonstrating closed-loop control, involving both platform routing and sensor pointing, of a multisensor, multi-platform ISR ensemble tasked with providing situational awareness and performing search, track and classification of multiple moving ground targets in irregular warfare scenarios. The closed-loop ISR system is fullyrealized using distributed, asynchronous components that communicate over a network. The closed-loop ISR system has been exercised via a networked simulation test bed against a scenario in the Afghanistan theater implemented using high-fidelity terrain and imagery data. In addition, the system has been applied to space surveillance scenarios requiring tracking of space objects where current deliberative, manually intensive processes for managing sensor assets are insufficiently responsive. Simulation experiment results are presented. The algorithm to jointly optimize sensor schedules against search, track, and classify is based on recent work by Papageorgiou and Raykin on risk-based sensor management. It uses a risk-based objective function and attempts to minimize and balance the risks of misclassifying and losing track on an object. It supports the requirement to generate tasking for metric and feature data concurrently and synergistically, and account for both tracking accuracy and object characterization, jointly, in computing reward and cost for optimizing tasking decisions.

Hot-spot heating susceptibility due to reverse bias operating conditions

NASA Technical Reports Server (NTRS)

Gonzalez, C. C.

1985-01-01

Because of field experience (indicating that cell and module degradation could occur as a result of hot spot heating), a laboratory test was developed at JPL to determine hot spot susceptibility of modules. The initial hot spot testing work at JPL formed a foundation for the test development. Test parameters are selected as follows. For high shunt resistance cells, the applied back bias test current is set equal to the test cell current at maximum power. For low shunt resistance cells, the test current is set equal to the cell short circuit current. The shadow level is selected to conform to that which would lead to maximum back bias voltage under the appropriate test current level. The test voltage is determined by the bypass diode frequency. The test conditions are meant to simulate the thermal boundary conditions for 100 mW/sq cm, 40C ambient environment. The test lasts 100 hours. A key assumption made during the development of the test is that no current imbalance results from the connecting of multiparallel cell strings. Therefore, the test as originally developed was applicable for single string case only.

Force and Moment Plots from Pacejka 2002 Magic Formula Tire Model Coefficients

DTIC Science & Technology

2010-09-01

Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including...failing to comply with a collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE 10 SEP 2010 2. REPORT...forces and moments applied to the tires. Many vehicle simulation programs such as MSC.Software ADAMS, Altair HyperWorks MotionSolve, etc. use the Magic

Plasma sheath effects on ion collection by a pinhole

NASA Technical Reports Server (NTRS)

Herr, Joel L.; Snyder, David B.

1993-01-01

This work presents tables to assist in the evaluation of pinhole collection effects on spacecraft. These tables summarize results of a computer model which tracks particle trajectories through a simplified electric field in the plasma sheath. A technique is proposed to account for plasma sheath effects in the application of these results and scaling rules are proposed to apply the calculations to specific situations. This model is compared to ion current measurements obtained by another worker, and the agreement is very good.

State of Practice Report: Essential Technical and Nontechnical Issues Related to Designing SoS Platform Architectures

DTIC Science & Technology

2015-05-01

This material is based upon work funded and supported by the Department of Defense under Contract No. FA8721-05- C -0003 with Carnegie Mellon...SoS), each of us summons a slightly different im- age. Some current examples of SoS contexts illustrate the various meanings that we apply to the term...vehicles, including ships, aircraft , and ground vehicles, are considered platforms in the DoD context. The concept of “platform architecture” in this

Full-Scale Turbofan-Engine Turbine-Transfer Function Determination Using Three Internal Sensors

NASA Technical Reports Server (NTRS)

Hultgren, Lennart S.

2012-01-01

Noise-source separation techniques, using three engine-internal sensors, are applied to existing static-engine test data to determine the turbine transfer function for the currently subdominant combustion noise. The results are used to assess the combustion-noise prediction capability of the Aircraft Noise Prediction Program (ANOPP) and an improvement to the combustion-noise module GECOR is suggested. The work was carried out in response to the NASA Fundamental Aeronautics Subsonic Fixed Wing Program s Reduced-Perceived-Noise Technical Challenge.

The non-commutative topology of two-dimensional dirty superconductors

NASA Astrophysics Data System (ADS)

De Nittis, Giuseppe; Schulz-Baldes, Hermann

2018-01-01

Non-commutative analysis tools have successfully been applied to the integer quantum Hall effect, in particular for a proof of the stability of the Hall conductance in an Anderson localization regime and of the bulk-boundary correspondence. In this work, these techniques are implemented to study two-dimensional dirty superconductors described by Bogoliubov-de Gennes Hamiltonians. After a thorough presentation of the basic framework and the topological invariants, Kubo formulas for the thermal, thermoelectric and spin Hall conductance are analyzed together with the corresponding edge currents.

Fitness, autonomic regulation and orthostatic tolerance

NASA Technical Reports Server (NTRS)

Buckey, Jay C.

1991-01-01

Work on this grant has consisted of two major studies of cardiovascular regulation in athletes along with several smaller supporting studies. This summary will give a brief overview of two major studies, and then conclude with an analysis of what the findings from these studies mean practically, and how they can be applied to current problems with post-flight orthostatic intolerance. The first study addresses a cross-sectional analysis of orthostatic intolerance in highly aerobically trained individuals; the second addresses ventricular pressure/volume relationships in athletes.

Cooperative Conflict Avoidance Sensor Trade Study Report, Version 2

NASA Technical Reports Server (NTRS)

2004-01-01

This study develops evaluation criteria for systems and technologies against the Cooperative Conflict Avoidance (CCA) requirements for unmanned flight at and above FL430 as part of Step 1 of the Access-5 program. These evaluation criteria are then applied to both current and future technologies to identify those which might be used to provide an Equivalent Level of Safety (ELOS) for CCA. This document provides the results of this analysis of various systems and technologies intended for evaluation as part of the CCA work package.

Microeconomics of 300-mm process module control

NASA Astrophysics Data System (ADS)

Monahan, Kevin M.; Chatterjee, Arun K.; Falessi, Georges; Levy, Ady; Stoller, Meryl D.

2001-08-01

Simple microeconomic models that directly link metrology, yield, and profitability are rare or non-existent. In this work, we validate and apply such a model. Using a small number of input parameters, we explain current yield management practices in 200 mm factories. The model is then used to extrapolate requirements for 300 mm factories, including the impact of simultaneous technology transitions to 130nm lithography and integrated metrology. To support our conclusions, we use examples relevant to factory-wide photo module control.

An investigation of the role of current and future remote sensing data systems in numerical meteorology

NASA Technical Reports Server (NTRS)

Diak, George R.; Smith, William L.

1992-01-01

A flexible system for performing observing system simulation experiments which made contributions to meteorology across all elements of the observing system simulation experiment (OSSE) components was developed. Future work will seek better understanding of the links between satellite-measured radiation and radiative transfer in the clear, cloudy and precipitating atmosphere and investigate how that understanding might be applied to improve the depiction of the initial state and the treatment of physical processes in forecast models of the atmosphere.

Natural Language Processing as a Discipline at LLNL

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

Firpo, M A

The field of Natural Language Processing (NLP) is described as it applies to the needs of LLNL in handling free-text. The state of the practice is outlined with the emphasis placed on two specific aspects of NLP: Information Extraction and Discourse Integration. A brief description is included of the NLP applications currently being used at LLNL. A gap analysis provides a look at where the technology needs work in order to meet the needs of LLNL. Finally, recommendations are made to meet these needs.

Keeping nurses at work: a duration analysis.

PubMed

Holmås, Tor Helge

2002-09-01

A shortage of nurses is currently a problem in several countries, and an important question is therefore how one can increase the supply of nursing labour. In this paper, we focus on the issue of nurses leaving the public health sector by utilising a unique data set containing information on both the supply and demand side of the market. To describe the exit rate from the health sector we apply a semi-parametric hazard rate model. In the estimations, we correct for unobserved heterogeneity by both a parametric (Gamma) and a non-parametric approach. We find that both wages and working conditions have an impact on nurses' decision to quit. Furthermore, failing to correct for the fact that nurses' income partly consists of compensation for inconvenient working hours results in a considerable downward bias of the wage effect. Copyright 2002 John Wiley & Sons, Ltd.

Femtosecond Pulse Characterization as Applied to One-Dimensional Photonic Band Edge Structures

NASA Technical Reports Server (NTRS)

Fork, Richard L.; Gamble, Lisa J.; Diffey, William M.

1999-01-01

The ability to control the group velocity and phase of an optical pulse is important to many current active areas of research. Electronically addressable one-dimensional photonic crystals are an attractive candidate to achieve this control. This report details work done toward the characterization of photonic crystals and improvement of the characterization technique. As part of the work, the spectral dependence of the group delay imparted by a GaAs/AlAs photonic crystal was characterized. Also, a first generation an electrically addressable photonic crystal was tested for the ability to electronically control the group delay. The measurement technique, using 100 femtosecond continuum pulses was improved to yield high spectral resolution (1.7 nanometers) and concurrently with high temporal resolution (tens of femtoseconds). Conclusions and recommendations based upon the work done are also presented.

Organic field effect transistor composed by fullerene C60 and heterojunctions

NASA Astrophysics Data System (ADS)

Vasconcelos, Railson C.; Aleixo, Vicente F. P.; Del Nero, Jordan

2017-02-01

We present a study of the complex electronic behavior of a fullerene (C60) molecule attached to six leads (heterojunctions), which works as a three-dimension rectifier. In addition, we confirmed that the fullerene works not only as an electron donor, but also as barrier and transport channel to electrons through the molecule. Moreover, when the phenylpropanodinilla (PPP) lead is orthogonally subjected to bias voltage, the charge distribution and the current displays regions of saturation and resonance similar to semiconductor devices. In order to understand the electronic transport in the molecule, we applied non-equilibrium green function (NEGF) method and performed Fowler-Nordheim (FN) and Millikan-Lauritsen (ML) analyses. The ML curves proved to be sufficient to describe the FN characteristics. In this work, we report the theoretical design for electronic transport of a 3D device (6-terminal).

Current status on the application of image processing of digital intraoral radiographs amongst general dental practitioners.

PubMed

Tohidast, Parisa; Shi, Xie-Qi

2016-01-01

The objectives of this study were to present the subjective knowledge level and the use of image processing on digital intraoral radiographs amongst general dental practitioners at Distriktståndvrden AB, Stockholm. A questionnaire, consisting of12 questions, was sent to 12 dental prac- tices in Stockholm. Additionally, 2000 radiographs were randomly selected from these clinics for evaluation of applied image processing and its effect on image quality. Descriptive and analytical statistical methods were applied to present the current status of the use of image proces- sing alternatives for the dentists' daily clinical work. 50 out of 53 dentists participated in the survey.The survey showed that most of dentists in.this study had received education on image processing at some stage of their career. No correlations were found between application of image processing on one side and educa- tion received with regards to image processing, previous working experience, age and gender on the other. Image processing in terms of adjusting brightness and contrast was frequently used. Overall, in this study 24.5% of the 200 images were actually image processed in practice, in which 90% of the images were improved or maintained in image quality. According to our survey, image processing is experienced to be frequently used by the dentists at Distriktstandvåden AB for diagnosing anatomical and pathological changes using intraoral radiographs. 24.5% of the 200 images were actually image processed in terms of adjusting brightness and/or contrast. In the present study we did not found that the dentists' age, gender, previous working experience and education in image processing influence their viewpoint towards the application of image processing.

Clinician Experiences Assessing Work Disability Related to Mental Disorders

PubMed Central

Dewa, Carolyn S.; Hees, Hiske; Trojanowski, Lucy; Schene, Aart H.

2015-01-01

Objective Medical certification is one of the basic administrative mechanisms used by social policies aimed at income protection. The assessment of work disability is central to the income protection application. Yet, there is evidence suggesting that determining work disability related to mental disorders is challenging. Although essential to the disability application process, few studies have looked at physician and other clinician experiences with the process. However, this type of information is critical to developing processes to support providers who participate in the assessments. This purpose of this paper is to explore the experiences of physicians and other clinicians assessing public long-term work disability related to mental disorders. Methods This is an exploratory and descriptive study using qualitative methods. Clinician input was gathered through focus groups and individual in-depth interviews. Verbatim transcripts were analyzed to identify recurrent and significant themes that arose during the focus groups and individual interviews. Results Many of the experiences that the clinicians in this sample discussed related to the difficulty of trying to fill the roles of advocate and medical expert as well as the challenge of determining the impact of functional capacity and work ability. The findings also highlight the current gap in knowledge about the factors that affect successful functioning in general and at work in particular. Conclusions Given the challenges created by the current state of knowledge, it may be useful to consider a category of “partial disability”. In addition, the fact that work disability depends on the interaction between the experience of the mental disorder and specific job requirements and the fact that people applying for public long-term disability are not working, it might be helpful to offer a clear description and guidelines of the meaning of work ability. PMID:25789478

Quench dynamics of the Josephson current in a topological Josephson junction

NASA Astrophysics Data System (ADS)

Sun, Dihao; Liu, Jie

2018-01-01

The 4 π -periodic Josephson effect is a distinguishing feature of a topological Josephson junction. However, stringent conditions make it hard to observe in experiments. In this work, we study the transient transport properties in a topological Josephson junction numerically. We show that the 4 π Josephson current can be sustained under nonequilibrium conditions. The properties of the Josephson current are analyzed for different conditions and three main regimes are identified. First, when both the superconducting wires of the Josephson junction lie in the topologically nontrivial region, a 4 π Josephson current can appear upon suddenly applying a dc voltage. Second, when one superconducting wire lies in the trivial region, while the other wire lies in the nontrivial region, the Josephson current is 2 π periodic but the component of the higher-order Josephson current increases. Third, when both wires lie in the trivial region, a stable 2 π Josephson current is observed. Most importantly, the fractional Josephson effect is fragile in the presence of disorder. Hence experiments should be designed carefully to eliminate the effect of disorder. These results could be helpful to optimize fine-tuning of the experimental parameters to observe the 4 π -periodic Josephson current in a topological Josephson junction.

Precision envelope detector and linear rectifier circuitry

DOEpatents

Davis, Thomas J.

1980-01-01

Disclosed is a method and apparatus for the precise linear rectification and envelope detection of oscillatory signals. The signal is applied to a voltage-to-current converter which supplies current to a constant current sink. The connection between the converter and the sink is also applied through a diode and an output load resistor to a ground connection. The connection is also connected to ground through a second diode of opposite polarity from the diode in series with the load resistor. Very small amplitude voltage signals applied to the converter will cause a small change in the output current of the converter, and the difference between the output current and the constant current sink will be applied either directly to ground through the single diode, or across the output load resistor, dependent upon the polarity. Disclosed also is a full-wave rectifier utilizing constant current sinks and voltage-to-current converters. Additionally, disclosed is a combination of the voltage-to-current converters with differential integrated circuit preamplifiers to boost the initial signal amplitude, and with low pass filtering applied so as to obtain a video or signal envelope output.

Effects of Distress and Eustress on Changes in Fatigue from Waking to Working.

PubMed

Parker, Kelsey N; Ragsdale, Jennifer M

2015-11-01

As a potential indicator of strain, fatigue is an important outcome in occupational health research. The current study examined the influence of positive (eustress) and negative (distress) work experiences on changes in fatigue from morning to at-work. It was expected that within-person changes in fatigue from waking to working would be moderated by employees' experiences of stress, pain, happiness, and meaningfulness at work. Data on 1,195 full-time working adults were collected through the Bureau of Labor Statistics' 2010 American Time Use Study (ATUS) using a day reconstruction method to assess fatigue at two time points (morning and during work) and employees' eustress and distress experiences during work. Multilevel modeling showed that the indicators of distress, stress and pain, predicted higher morning fatigue and stronger increases in fatigue during the workday. The indicators of eustress, happiness and meaningfulness, predicted lower fatigue at both time points but not temporal changes. These results contribute to understanding changes in employees' fatigue and suggest that the differential effects of distress and eustress experiences at work may be important to consider in fatigue management interventions. © 2015 The International Association of Applied Psychology.

Transient tracking of low and high-order eccentricity-related components in induction motors via TFD tools

NASA Astrophysics Data System (ADS)

Climente-Alarcon, V.; Antonino-Daviu, J.; Riera-Guasp, M.; Pons-Llinares, J.; Roger-Folch, J.; Jover-Rodriguez, P.; Arkkio, A.

2011-02-01

The present work is focused on the diagnosis of mixed eccentricity faults in induction motors via the study of currents demanded by the machine. Unlike traditional methods, based on the analysis of stationary currents (Motor Current Signature Analysis (MCSA)), this work provides new findings regarding the diagnosis approach proposed by the authors in recent years, which is mainly focused on the fault diagnosis based on the analysis of transient quantities, such as startup or plug stopping currents (Transient Motor Current Signature Analysis (TMCSA)), using suitable time-frequency decomposition (TFD) tools. The main novelty of this work is to prove the usefulness of tracking the transient evolution of high-order eccentricity-related harmonics in order to diagnose the condition of the machine, complementing the information obtained with the low-order components, whose transient evolution was well characterised in previous works. Tracking of high-order eccentricity-related harmonics during the transient, through their associated patterns in the time-frequency plane, may significantly increase the reliability of the diagnosis, since the set of fault-related patterns arising after application of the corresponding TFD tool is very unlikely to be caused by other faults or phenomena. Although there are different TFD tools which could be suitable for the transient extraction of these harmonics, this paper makes use of a Wigner-Ville distribution (WVD)-based algorithm in order to carry out the time-frequency decomposition of the startup current signal, since this is a tool showing an excellent trade-off between frequency resolution at both high and low frequencies. Several simulation results obtained with a finite element-based model and experimental results show the validity of this fault diagnosis approach under several faulty and operating conditions. Also, additional signals corresponding to the coexistence of the eccentricity and other non-fault related phenomena making difficult the diagnosis (fluctuating load torque) are included in the paper. Finally, a comparison with an alternative TFD tool - the discrete wavelet transform (DWT) - applied in previous papers, is also carried out in the contribution. The results are promising regarding the usefulness of the methodology for the reliable diagnosis of eccentricities and for their discrimination against other phenomena.

Analytical approaches to image orientation and stereo digitization applied in the Budnlab software. (Polish Title: Rozwiazania analityczne zwiazane z obsluga procesu orientacji zdjec oraz wykonywaniem opracowan wektorowych w programie Bundlab)

NASA Astrophysics Data System (ADS)

Kolecki, J.

2015-12-01

The Bundlab software has been developed mainly for academic and research application. This work can be treated as a kind of a report describing the current state of the development of this computer program, focusing especially on the analytical solutions. Firstly, the overall characteristics of the software are provided. Then the description of the image orientation procedure starting from the relative orientation is addressed. The applied solution is based on the coplanarity equation parametrized with the essential matrix. The problem is reformulated in order to solve it using methods of algebraic geometry. The solution is followed by the optimization involving the least square criterion. The formation of the image block from the oriented models as well as the absolute orientation procedure were implemented using the Horn approach as a base algorithm. The second part of the paper is devoted to the tools and methods applied in the stereo digitization module. The solutions that support the user and improve the accuracy are given. Within the paper a few exemplary applications and products are mentioned. The work finishes with the concepts of development and improvements of existing functions.

Solid-State Fault Current Limiter Development : Design and Testing Update of a 15kV SSCL Power Stack

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

Dr. Ram Adapa; Mr. Dante Piccone

2012-04-30

ABSTRACT The Solid-State Fault Current Limiter (SSCL) is a promising technology that can be applied to utility power delivery systems to address the problem of increasing fault currents associated with load growth. As demand continues to grow, more power is added to utility system either by increasing generator capacity or by adding distributed generators, resulting in higher available fault currents, often beyond the capabilities of the present infrastructure. The SSCL is power-electronics based equipment designed to work with the present utility system to address this problem. The SSCL monitors the line current and dynamically inserts additional impedance into the linemore » in the event of a fault being detected. The SSCL is based on a modular design and can be configured for 5kV through 69kV systems at nominal current ratings of 1000A to 4000A. Results and Findings This report provides the final test results on the development of 15kV class SSCL single phase power stack. The scope of work included the design of the modular standard building block sub-assemblies, the design and manufacture of the power stack and the testing of the power stack for the key functional tests of continuous current capability and fault current limiting action. Challenges and Objectives Solid-State Current Limiter technology impacts a wide spectrum of utility engineering and operating personnel. It addresses the problems associated with load growth both at Transmission and Distribution class networks. The design concept is pioneering in terms of developing the most efficient and compact power electronics equipment for utility use. The initial test results of the standard building blocks are promising. The independent laboratory tests of the power stack are promising. However the complete 3 phase system needs rigorous testing for performance and reliability. Applications, Values, and Use The SSCL is an intelligent power-electronics device which is modular in design and can provide current limiting or current interrupting capabilities. It can be applied to variety of applications from distribution class to transmission class power delivery grids and networks. It can also be applied to single major commercial and industrial loads and distributed generator supplies. The active switching of devices can be further utilized for protection of substation transformers. The stress on the system can be reduced substantially improving the life of the power system. It minimizes the voltage sag by speedy elimination of heavy fault currents and promises to be an important element of the utility power system. DOE Perspective This development effort is now focused on a 15kV system. This project will help mitigate the challenges of increasing available fault current. DOE has made a major contribution in providing a cost effective SSCL designed to integrate seamlessly into the Transmission and Distribution networks of today and the future. Approach SSCL development program for a 69kV SSCL was initiated which included the use of the Super GTO advanced semiconductor device which won the 2007 R&D100 Award. In the beginning, steps were identified to accomplish the economically viable design of a 69kV class Solid State Current Limiter that is extremely reliable, cost effective, and compact enough to be applied in urban transmission. The prime thrust in design and development was to encompass the 1000A and the 3000A ratings and provide a modular design to cover the wide range of applications. The focus of the project was then shifted to a 15kV class SSCL. The specifications for the 15kV power stack are reviewed. The design changes integrated into the 15kV power stack are discussed. In this Technical Update the complete project is summarized followed by a detailed test report. The power stack independent high voltage laboratory test requirements and results are presented. Keywords Solid State Current Limiter, SSCL, Fault Current Limiter, Fault Current Controller, Power electronics controller, Intelligent power-electronics Device, IED« less

Frequency Rectification Applied to Piezoelectric Energy Harvesting and Improving Available Power of Piezoelectric Motors

NASA Astrophysics Data System (ADS)

Kuroda, Kazuaki; LCGT Collaboration

Piezoelectric materials are just now, within the last decade, coming into their own as a commercial material. Capable of converting energy from the mechanical domain to the electrical domain; piezos are ideal sensors, vibration dampers, energy harvesters, and actuators. Frequency rectification, or the conversion of small, high frequency piezoelectric vibrations into useful low frequency actuation, is required to obtain widespread industrial use of piezoelectric devices. This work examines three manifestations of piezoelectric frequency rectification: energy harvesting, a hydraulic motor, and friction based commercial-off-the-shelf motors. An energy harvesting device is developed, manufactured, and tested in this work, resulting in the development of a high Energy Density (J/m 3), high Power Density (W/m3) energy harvester. The device is shown to have an Energy Density nearly twice that of a similar conventional energy harvesting device. The result of this work is the development of an energy harvesting system that generates more energy in a given volume of piezoelectric material, opening the possibility of miniaturization of energy harvesting devices. Also presented is an effort to integrate a high frequency, high flow rate micromachined valve array into a PiezoHydraulic Pump (PHP), enabling resonant operation of the PHP. Currently, the device is limited by the resonant frequency of the proprietary passive check valves. The PHP is fully characterized, and the microvalve array is tested to determine its resonant frequency in a fluid medium. The valve testing resulted in a resonant frequency of 6.9 kHz, slightly lower than the target operating frequency of 10 kHz. Finally, the results of an examination of frequency rectification as applied to COTS piezoelectric motors are presented. Currently, motors are almost universally characterized based upon their available mechanical power. A better comparison is one based upon the actual Energy Density of the piezoelectric material utilized in the motor compared to the theoretical maximum Energy Density under the motor operating conditions (i.e., frequency, applied electric field). The result of this work is a more descriptive metric to evaluate piezoelectric motors that provides information on the effectiveness of the motor drive train; that is, how effectively the motion of the piezoelectric is transferred to the outside world.

Electric stimulation at 448 kHz promotes proliferation of human mesenchymal stem cells.

PubMed

Hernández-Bule, María Luisa; Paíno, Carlos Luis; Trillo, María Ángeles; Úbeda, Alejandro

2014-01-01

Capacitive-resistive electric transfer (CRET) is a non invasive electrothermal therapy that applies electric currents within the 400 kHz - 450 kHz frequency range to the treatment of musculoskeletal lesions. Evidence exists that electric currents and electric or magnetic fields can influence proliferative and/or differentiating processes involved in tissue regeneration. This work investigates proliferative responses potentially underlying CRET effects on tissue repair. XTT assay, flow cytometry, immunofluorescence and Western Blot analyses were conducted to asses viability, proliferation and differentiation of adipose-derived stem cells (ADSC) from healthy donors, after short, repeated (5 m On/4 h Off) in vitro stimulation with a 448-kHz electric signal currently used in CRET therapy, applied at a subthermal dose of 50 μA/mm(2) RESULTS: The treatment induced PCNA and ERK1/2 upregulation, together with significant increases in the fractions of ADSC undergoing cycle phases S, G2 and M, and enhanced cell proliferation rate. This proliferative effect did not compromise the multipotential ability of ADSC for subsequent adipogenic, chondrogenic or osteogenic differentiation. These data identify cellular and molecular phenomena potentially underlying the response to CRET and indicate that CRET-induced lesion repair could be mediated by stimulation of the proliferation of stem cells present in the injured tissues. © 2014 S. Karger AG, Basel.

A new theoretical formulation of coupling thermo-electric breakdown in LDPE film under dc high applied fields

NASA Astrophysics Data System (ADS)

Boughariou, F.; Chouikhi, S.; Kallel, A.; Belgaroui, E.

2015-12-01

In this paper, we present a new theoretical and numerical formulation for the electrical and thermal breakdown phenomena, induced by charge packet dynamics, in low-density polyethylene (LDPE) insulating film under dc high applied field. The theoretical physical formulation is composed by the equations of bipolar charge transport as well as by the thermo-electric coupled equation associated for the first time in modeling to the bipolar transport problem. This coupled equation is resolved by the finite-element numerical model. For the first time, all bipolar transport results are obtained under non-uniform temperature distributions in the sample bulk. The principal original results show the occurring of very sudden abrupt increase in local temperature associated to a very sharp increase in external and conduction current densities appearing during the steady state. The coupling between these electrical and thermal instabilities reflects physically the local coupling between electrical conduction and thermal joule effect. The results of non-uniform temperature distributions induced by non-uniform electrical conduction current are also presented for several times. According to our formulation, the strong injection current is the principal factor of the electrical and thermal breakdown of polymer insulating material. This result is shown in this work. Our formulation is also validated experimentally.

Development of a Josephson vortex two-state system based on a confocal annular Josephson junction

NASA Astrophysics Data System (ADS)

Monaco, Roberto; Mygind, Jesper; Koshelets, Valery P.

2018-07-01

We report theoretical and experimental work on the development of a Josephson vortex two-state system based on a confocal annular Josephson tunnel junction (CAJTJ). The key ingredient of this geometrical configuration is a periodically variable width that generates a spatial vortex potential with bistable states. This intrinsic vortex potential can be tuned by an externally applied magnetic field and tilted by a bias current. The two-state system is accurately modeled by a one-dimensional sine-Gordon like equation by means of which one can numerically calculate both the magnetic field needed to set the vortex in a given state as well as the vortex-depinning currents. Experimental data taken at 4.2 {{K}} on high-quality Nb/Al-AlOx/Nb CAJTJs with an individual trapped fluxon advocate the presence of a robust and finely tunable double-well potential for which reliable manipulation of the vortex state has been classically demonstrated. The vortex is prepared in a given potential by means of an externally applied magnetic field, while the state readout is accomplished by measuring the vortex-depinning current in a small magnetic field. Our proof of principle experiment convincingly demonstrates that the proposed vortex two-state system based on CAJTJs is robust and workable.

An Evaluation of Bipolar Junction Transistors as Dosimeter for Megavoltage Electron Beams

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

Passos, Renan Garcia de; Vidal da Silva, Rogerio Matias; Silva, Malana Marcelina Almeida

Dosimetry is an extremely important field in medical applications of radiation and nowadays, electron beam is a good option for superficial tumor radiotherapy. Normally, the applied dose to the patient both in diagnostic and therapy must be monitored to prevent injuries and ensure the success of the treatment, therefore, we should always look for improving of the dosimetric methods. Accordingly, the aim of this work is about the use of a bipolar junction transistor (BJT) for electron beam dosimetry. After previous studies, such an electronic device can work as a dosimeter when submitted to ionizing radiation of photon beam. Actually,more » a typical BJT consists of two PN semiconductor junctions resulting in the NPN structure device, for while, and each semiconductor is named as collector (C), base (B) and emitter (E), respectively. Although the transistor effect, which corresponds to the current amplification, be accurately described by the quantum physics, one can utilize a simple concept from the circuit theory: the base current IB (input signal) is amplified by a factor of β resulting in the collector current IC (output signal) at least one hundred times greater the IB. In fact, the BJT is commonly used as a current amplifier with gain β=I{sub C}/I{sub B}, therefore, it was noticed that this parameter is altered when the device is exposed to ionizing radiation. The current gain alteration can be explained by the trap creation and the positive charges build up, beside the degradation of the lattice structure. Then, variations of the gain of irradiated transistors may justify their use as a dosimeter. Actually, the methodology is based on the measurements of the I{sub C} variations whereas I{sub B} is maintained constant. BC846 BJT type was used for dose monitoring from passive-mode measurements: evaluation of its electrical characteristic before and after irradiation procedure. Thus, IC readings were plotted as a function of the applied dose in 6 MeV electron beam from a linear accelerator, Clinac iX. The results show that this new methodology could be an alternative to study the dose in superficial tumors in radiation oncology. (authors)« less

Marital status and work-related health limitation: a longitudinal study of young adult and middle-aged Americans.

PubMed

Lo, Celia C; Cheng, Tyrone C; Simpson, Gaynell M

2016-01-01

The literature establishes clearly the health benefit of marriage. Much less clear from published data is whether work-related health (dis)advantages accruing to marital transitions persist over time or are limited to the short term. Informed by the marital resources and marital crisis perspectives, this study sought links between marital status measured via three approaches and work-related health limitation, exploring these relationships across genders. The study employed data from eight recent waves (1996-2010) of the National Longitudinal Survey of Youth. It applied generalized estimating equations to estimate the impacts, on work-related health limitation, of current marital status; of marital transition 2 years in the past; and of marital transition 8 years in the past. Our gender-specific results indicated that lower likelihood of work-related health limitation was associated with a married status, a stable married status, and an entry into marriage. Results are consistent overall with the marital resources perspective. The use of three different approaches to evaluate the relationship of marital status to work-related health limitation may explain the gender-specific results.

Cochrane Rehabilitation Methodology Committee: an international survey of priorities for future work.

PubMed

Levack, William M; Meyer, Thorsten; Negrini, Stefano; Malmivaara, Antti

2017-10-01

Cochrane Rehabilitation aims to improve the application of evidence-based practice in rehabilitation. It also aims to support Cochrane in the production of reliable, clinically meaningful syntheses of evidence related to the practice of rehabilitation, while accommodating the many methodological challenges facing the field. To this end, Cochrane Rehabilitation established a Methodology Committee to examine, explore and find solutions for the methodological challenges related to evidence synthesis and knowledge translation in rehabilitation. We conducted an international online survey via Cochrane Rehabilitation networks to canvass opinions regarding the future work priorities for this committee and to seek information on people's current capabilities to assist with this work. The survey findings indicated strongest interest in work on how reviewers have interpreted and applied Cochrane methods in reviews on rehabilitation topics in the past, and on gathering a collection of existing publications on review methods for undertaking systematic reviews relevant to rehabilitation. Many people are already interested in contributing to the work of the Methodology Committee and there is a large amount of expertise for this work in the extended Cochrane Rehabilitation network already.

Automatic Satellite Telemetry Analysis for SSA using Artificial Intelligence Techniques

NASA Astrophysics Data System (ADS)

Stottler, R.; Mao, J.

In April 2016, General Hyten, commander of Air Force Space Command, announced the Space Enterprise Vision (SEV) (http://www.af.mil/News/Article-Display/Article/719941/hyten-announces-space-enterprise-vision/). The SEV addresses increasing threats to space-related systems. The vision includes an integrated approach across all mission areas (communications, positioning, navigation and timing, missile warning, and weather data) and emphasizes improved access to data across the entire enterprise and the ability to protect space-related assets and capabilities. "The future space enterprise will maintain our nation's ability to deliver critical space effects throughout all phases of conflict," Hyten said. Satellite telemetry is going to become available to a new audience. While that telemetry information should be valuable for achieving Space Situational Awareness (SSA), these new satellite telemetry data consumers will not know how to utilize it. We were tasked with applying AI techniques to build an infrastructure to process satellite telemetry into higher abstraction level symbolic space situational awareness and to initially populate that infrastructure with useful data analysis methods. We are working with two organizations, Montana State University (MSU) and the Air Force Academy, both of whom control satellites and therefore currently analyze satellite telemetry to assess the health and circumstances of their satellites. The design which has resulted from our knowledge elicitation and cognitive task analysis is a hybrid approach which combines symbolic processing techniques of Case-Based Reasoning (CBR) and Behavior Transition Networks (BTNs) with current Machine Learning approaches. BTNs are used to represent the process and associated formulas to check telemetry values against anticipated problems and issues. CBR is used to represent and retrieve BTNs that represent an investigative process that should be applied to the telemetry in certain circumstances. Machine Learning is used to learn normal patterns of telemetry, learn pre-mission simulated telemetry patterns that represent known problems, and detect both pre-trained known and unknown abnormalities in real-time. The operational system is currently being implemented and applied to real satellite telemetry data. This paper presents the design, examples, and results of the first version as well as planned future work.

A Theoretical Investigation of the Effects of Cs and O2 Adsorbates on Field Emission Properties of Single Wall Carbon Nanotubes

NASA Astrophysics Data System (ADS)

Akdim, Brahim; Duan, Xiaofeng; Pachter, Ruth

2003-03-01

We present a comprehensive theoretical study on the effects of Cs and O2 adsorbates on the field emission properties of single-wall carbon nanotubes (SWCNTs). Experimentally, O2 adsorption was shown to cause current suppression [1], while a current enhancement has been reported for Cs deposition on CNTs [2]. In this work, we investigated the adsorption mechanisms of Cs and O2 at the tips of capped and uncapped C(5,5) CNTs, using density functional theory, in order to gain insight into the effects on emission characteristics. Structural and electronic properties will be discussed in detail. We also report on the effects of an applied field on the reaction mechanisms. [1] S. C. Lim, Y. C. Choi, H. J. Jeong, Y. M. Shin, K. H. An, D. J. Bae, Y. H. Lee, N. S. Lee, and J. M. Kim, Adv. Mater. 13, 1563 (2001). [2] A. Wadhawan, R. E. Stallcup II, and J. M. Perez, Apply. Phys. Lett. 78, 108 (2001).

A modification of Murray's law for shear-thinning rheology.

PubMed

McGah, Patrick M; Capobianchi, Massimo

2015-05-01

This study reformulates Murray's well-known principle of minimum work as applied to the cardiovascular system to include the effects of the shear-thinning rheology of blood. The viscous behavior is described using the extended modified power law (EMPL), which is a time-independent, but shear-thinning rheological constitutive equation. The resulting minimization problem is solved numerically for typical parameter ranges. The non-Newtonian analysis still predicts the classical cubic diameter dependence of the volume flow rate and the cubic branching law. The current analysis also predicts a constant wall shear stress throughout the vascular tree, albeit with a numerical value about 15-25% higher than the Newtonian analysis. Thus, experimentally observed deviations from the cubic branching law or the predicted constant wall shear stress in the vasculature cannot likely be attributed to blood's shear-thinning behavior. Further differences between the predictions of the non-Newtonian and the Newtonian analyses are highlighted, and the limitations of the Newtonian analysis are discussed. Finally, the range and limits of applicability of the current results as applied to the human arterial tree are also discussed.

A nonlinear model for ionic polymer metal composites as actuators

NASA Astrophysics Data System (ADS)

Bonomo, C.; Fortuna, L.; Giannone, P.; Graziani, S.; Strazzeri, S.

2007-02-01

This paper introduces a comprehensive nonlinear dynamic model of motion actuators based on ionic polymer metal composites (IPMCs) working in air. Significant quantities ruling the acting properties of IPMC-based actuators are taken into account. The model is organized as follows. As a first step, the dependence of the IPMC absorbed current on the voltage applied across its thickness is taken into account; a nonlinear circuit model is proposed to describe this relationship. In a second step the transduction of the absorbed current into the IPMC mechanical reaction is modelled. The model resulting from the cascade of both the electrical and the electromechanical stages represents a novel contribution in the field of IPMCs, capable of describing the electromechanical behaviour of these materials and predicting relevant quantities in a large range of applied signals. The effect of actuator scaling is also investigated, giving interesting support to the activities involved in the design of actuating devices based on these novel materials. Evidence of the excellent agreement between the estimations obtained by using the proposed model and experimental signals is given.

A new Method for Determining the Interplanetary Current-Sheet Local Orientation

NASA Astrophysics Data System (ADS)

Blanco, J. J.; Rodríguez-pacheco, J.; Sequeiros, J.

2003-03-01

In this work we have developed a new method for determining the interplanetary current sheet local parameters. The method, called `HYTARO' (from Hyperbolic Tangent Rotation), is based on a modified Harris magnetic field. This method has been applied to a pool of 57 events, all of them recorded during solar minimum conditions. The model performance has been tested by comparing both, its outputs and noise response, with these of the `classic MVM' (from Minimum Variance Method). The results suggest that, despite the fact that in many cases they behave in a similar way, there are specific crossing conditions that produce an erroneous MVM response. Moreover, our method shows a lower noise level sensitivity than that of MVM.

In-vitro tomography and non-destructive imaging at depth of pharmaceutical solid dosage forms.

PubMed

Zeitler, J Axel; Gladden, Lynn F

2009-01-01

Tomographic imaging techniques offer new prospects for a better understanding of the quality, performance and release mechanisms of pharmaceutical solid dosage forms. It is only over the last fifteen years that tomography has been applied for the in-vitro characterisation of dosage forms. This review aims to introduce the concept of tomography in a pharmaceutical context, and describes the current state-of-the-art of the four most promising techniques: X-ray computed microtomography, magnetic resonance imaging, terahertz imaging and optical coherence tomography. The basic working principles of the techniques are introduced and the current pharmaceutical applications of the technologies are discussed, together with a comparison of their specific strengths and weaknesses. Possible future developments in these fields are also discussed.

Embedded Wing Propulsion Conceptual Study

NASA Technical Reports Server (NTRS)

Kim, Hyun D.; Saunders, John D.

2003-01-01

As a part of distributed propulsion work under NASA's Revolutionary Aeropropulsion Concepts or RAC project, a new propulsion-airframe integrated vehicle concept called Embedded Wing Propulsion (EWP) is developed and examined through system and computational fluid dynamics (CFD) studies. The idea behind the concept is to fully integrate a propulsion system within a wing structure so that the aircraft takes full benefits of coupling of wing aerodynamics and the propulsion thrust stream. The objective of this study is to assess the feasibility of the EWP concept applied to large transport aircraft such as the Blended-Wing-Body aircraft. In this paper, some of early analysis and current status of the study are presented. In addition, other current activities of distributed propulsion under the RAC project are briefly discussed.

Bell's "Theorem": loopholes vs. conceptual flaws

NASA Astrophysics Data System (ADS)

Kracklauer, A. F.

2017-12-01

An historical overview and detailed explication of a critical analysis of what has become known as Bell's Theorem to the effect that, it should be impossible to extend Quantum Theory with the addition of local, real variables so as to obtain a version free of the ambiguous and preternatural features of the currently accepted interpretations is presented. The central point on which this critical analysis, due originally to Edwin Jaynes, is that Bell incorrectly applied probabilistic formulas involving conditional probabilities. In addition, mathematical technicalities that have complicated the understanding of the logical or mathematical setting in which current theory and experimentation are embedded, are discussed. Finally, some historical speculations on the sociological environment, in particular misleading aspects, in which recent generations of physicists lived and worked are mentioned.

Using the Practice Environment Scale of the Nursing Work Index on Asian nurses.

PubMed

Liou, Shwu-Ru; Cheng, Ching-Yu

2009-01-01

Researchers have used the Practice Environment Scale of the Nursing Work Index (PES-NWI) to examine the perception of practice environment among U.S. nurses in general; however, the scale has not been used to measure perceptions specifically among Asian nurses working in the United States, the largest group of international nurses in the nation. The purpose of this study was to test the reliability and the validity of the PES-NWI scale when applied to Asian nurses working in the United States. The study used a cross-sectional design with snowball sampling. Data from 230 Asian nurses who were born in Far Eastern countries and had worked at least 6 months in their current job at a U.S. hospital were analyzed, using Cronbach's alpha, item-total and interitem correlation, and factor analysis. The Cronbach's alpha for the PES-NWI was.96, and the item-total correlation coefficients ranged from.49 to.79. Five factors, which explained 59.12% of variance in the perception of practice environment, emerged: Nurse Participation and Development; Nurse Manager Ability, Leadership, and Support of Nurses; Nursing Foundations for Quality of Care; Staffing and Resource Adequacy; and Collegial Nurse-Physician Relations. Four derived factors were reconstructed, and one factor was renamed based on the meanings of scale items that were included in the factor. Study findings demonstrate that the PES-NWI is a reliable and a valid scale when applied to Asian nurses working in the United States. Findings also indicate that Asian nurses perceive practice environments differently than do American nurses, most likely due to dissimilar cultural beliefs. A better understanding of these differences may help develop more individualized support for Asian nurses as they adapt to working in the United States.

Intense deformation field at oceanic front inferred from directional sea surface roughness observations

NASA Astrophysics Data System (ADS)

Rascle, Nicolas; Molemaker, Jeroen; Marié, Louis; Nouguier, Frédéric; Chapron, Bertrand; Lund, Björn; Mouche, Alexis

2017-06-01

Fine-scale current gradients at the ocean surface can be observed by sea surface roughness. More specifically, directional surface roughness anomalies are related to the different horizontal current gradient components. This paper reports results from a dedicated experiment during the Lagrangian Submesoscale Experiment (LASER) drifter deployment. A very sharp front, 50 m wide, is detected simultaneously in drifter trajectories, sea surface temperature, and sea surface roughness. A new observational method is applied, using Sun glitter reflections during multiple airplane passes to reconstruct the multiangle roughness anomaly. This multiangle anomaly is consistent with wave-current interactions over a front, including both cross-front convergence and along-front shear with cyclonic vorticity. Qualitatively, results agree with drifters and X-band radar observations. Quantitatively, the sharpness of roughness anomaly suggests intense current gradients, 0.3 m s-1 over the 50 m wide front. This work opens new perspectives for monitoring intense oceanic fronts using drones or satellite constellations.

Using the living laboratory framework as a basis for understanding next-generation analyst work

NASA Astrophysics Data System (ADS)

McNeese, Michael D.; Mancuso, Vincent; McNeese, Nathan; Endsley, Tristan; Forster, Pete

2013-05-01

The preparation of next generation analyst work requires alternative levels of understanding and new methodological departures from the way current work transpires. Current work practices typically do not provide a comprehensive approach that emphasizes the role of and interplay between (a) cognition, (b) emergent activities in a shared situated context, and (c) collaborative teamwork. In turn, effective and efficient problem solving fails to take place, and practice is often composed of piecemeal, techno-centric tools that isolate analysts by providing rigid, limited levels of understanding of situation awareness. This coupled with the fact that many analyst activities are classified produces a challenging situation for researching such phenomena and designing and evaluating systems to support analyst cognition and teamwork. Through our work with cyber, image, and intelligence analysts we have realized that there is more required of researchers to study human-centered designs to provide for analyst's needs in a timely fashion. This paper identifies and describes how The Living Laboratory Framework can be utilized as a means to develop a comprehensive, human-centric, and problem-focused approach to next generation analyst work, design, and training. We explain how the framework is utilized for specific cases in various applied settings (e.g., crisis management analysis, image analysis, and cyber analysis) to demonstrate its value and power in addressing an area of utmost importance to our national security. Attributes of analyst work settings are delineated to suggest potential design affordances that could help improve cognitive activities and awareness. Finally, the paper puts forth a research agenda for the use of the framework for future work that will move the analyst profession in a viable manner to address the concerns identified.

Inferring functional connectivity in MRI using Bayesian network structure learning with a modified PC algorithm

PubMed Central

Iyer, Swathi; Shafran, Izhak; Grayson, David; Gates, Kathleen; Nigg, Joel; Fair, Damien

2013-01-01

Resting state functional connectivity MRI (rs-fcMRI) is a popular technique used to gauge the functional relatedness between regions in the brain for typical and special populations. Most of the work to date determines this relationship by using Pearson's correlation on BOLD fMRI timeseries. However, it has been recognized that there are at least two key limitations to this method. First, it is not possible to resolve the direct and indirect connections/influences. Second, the direction of information flow between the regions cannot be differentiated. In the current paper, we follow-up on recent work by Smith et al (2011), and apply a Bayesian approach called the PC algorithm to both simulated data and empirical data to determine whether these two factors can be discerned with group average, as opposed to single subject, functional connectivity data. When applied on simulated individual subjects, the algorithm performs well determining indirect and direct connection but fails in determining directionality. However, when applied at group level, PC algorithm gives strong results for both indirect and direct connections and the direction of information flow. Applying the algorithm on empirical data, using a diffusion-weighted imaging (DWI) structural connectivity matrix as the baseline, the PC algorithm outperformed the direct correlations. We conclude that, under certain conditions, the PC algorithm leads to an improved estimate of brain network structure compared to the traditional connectivity analysis based on correlations. PMID:23501054

Electromechanical properties of superconducting MgB2 wire

NASA Astrophysics Data System (ADS)

Salama, K.; Zhou, Y. X.; Hanna, M.; Alessandrini, M.; Putman, P. T.; Fang, H.

2005-12-01

The current-carrying capability of superconducting wires is degraded by stress. Therefore electromechanical properties are one of the key feedback parameters needed for progress in conductor applications. In this work, uniaxial tensile stresses and bending stresses were applied to Fe /MgB2 wires at room temperature, followed by measurement of critical current using a transport method at 4.2 K. Basic mechanical properties were calculated from the measured stress-strain characteristics. The irreversible tensile strain at which the critical current density of MgB2 wire starts to degrade was found to be 0.5%. In addition, the degradation of Ic with decreasing bending diameters was found to be very rapid for wires that were deformed after the heat treatment that forms the MgB2 compound, while not much degradation of Ic was found for wires that were bent before being annealed. SEM observations confirmed that cracks could be healed by post-annealing.

Improving off-state leakage characteristics for high voltage AlGaN/GaN-HFETs on Si substrates

NASA Astrophysics Data System (ADS)

Moon, Sung-Woon; Twynam, John; Lee, Jongsub; Seo, Deokwon; Jung, Sungdal; Choi, Hong Goo; Shim, Heejae; Yim, Jeong Soon; Roh, Sungwon D.

2014-06-01

We present a reliable process and design technique for realizing high voltage AlGaN/GaN hetero-junction field effect transistors (HFETs) on Si substrates with very low and stable off-state leakage current characteristics. In this work, we have investigated the effects of the surface passivation layer, prepared by low pressure chemical vapor deposition (LPCVD) of silicon nitride (SiNx), and gate bus isolation design on the off-state leakage characteristics of metal-oxide-semiconductor (MOS) gate structure-based GaN HFETs. The surface passivated devices with gate bus isolation fully surrounding the source and drain regions showed extremely low off-state leakage currents of less than 20 nA/mm at 600 V, with very small variation. These techniques were successfully applied to high-current devices with 80-mm gate width, yielding excellent off-state leakage characteristics within a drain voltage range 0-700 V.

Porosity and thickness effect of porous silicon layer on photoluminescence spectra

NASA Astrophysics Data System (ADS)

Husairi, F. S.; Eswar, K. A.; Guliling, Muliyadi; Khusaimi, Z.; Rusop, M.; Abdullah, S.

2018-05-01

The porous silicon nanostructures was prepared by electrochemical etching of p-type silicon wafer. Porous silicon prepared by using different current density and fix etching time with assistance of halogen lamp. The physical structure of porous silicon measured by the parameters used which know as experimental factor. In this work, we select one of those factors to correlate which optical properties of porous silicon. We investigated the surface morphology by using Surface Profiler (SP) and photoluminescence using Photoluminescence (PL) spectrometer. Different physical characteristics of porous silicon produced when current density varied. Surface profiler used to measure the thickness of porous and the porosity calculated using mass different of silicon. Photoluminescence characteristics of porous silicon depend on their morphology because the size and distribution of pore its self will effect to their exciton energy level. At J=30 mA/cm2 the shorter wavelength produced and it followed the trend of porosity with current density applied.

Idealized model of polar cap currents, fields, and auroras

NASA Technical Reports Server (NTRS)

Cornwall, J. M.

1985-01-01

During periods of northward Bz, the electric field applied to the magnetosphere is generally opposite to that occurring during southward Bz and complicated patterns of convection result, showing some features reversed in comparison with the southward Bz case. A study is conducted of a simple generalization of early work on idealized convection models, which allows for coexistence of sunward convection over the central polar cap and antisunward convection elsewhere in the cap. The present model, valid for By approximately 0, has a four-cell convection pattern and is based on the combination of ionospheric current conservation with a relation between parallel auroral currents and parallel potential drops. Global magnetospheric issues involving, e.g., reconnection are not considered. The central result of this paper is an expression giving the parallel potential drop for polar cap auroras (with By approximately 0) in terms of the polar cap convection field profile.

Direct determination of creatinine based on poly(ethyleneimine)/phosphotungstic acid multilayer modified electrode.

PubMed

Han, Ping; Xu, Shimei; Feng, Shun; Hao, Yanjun; Wang, Jide

2016-05-01

In this work, the direct determination of creatinine was achieved using a poly(ethyleneimine)/phosphotungstic acid multilayer modified electrode with the assistance of Copper(II) ions by cyclic voltammetry. The quantity of creatinine were determined by measuring the redox peak current of Cu(II)-creatinine complex/Cu(I)-creatinine complex. Factors affecting the response current of creatinine at the modified electrode were optimized. A linear relationship between the response current and the concentration of creatinine ranging from 0.125 to 62.5μM was obtained with a detection limit of 0.06μM. The proposed method was applied to determine creatinine in human urine, and satisfied results were gotten which was validated in accordance with high performance liquid chromatography. The proposed electrode provided a promising alternative in routine sensing for creatinine without enzymatic assistance. Copyright © 2016 Elsevier B.V. All rights reserved.

Ab-Initio analysis of TlBr: limiting the ionic current without degrading the electronic one

NASA Astrophysics Data System (ADS)

Rocha Leao, Cedric; Lordi, Vincenzo

2011-03-01

Although TlBr in principle presents all the theoretical requirements for making high resolution room temperature radiation detectors, practical applications of TlBr have proven to be nonviable due to the polarization that is observed in the crystal after relatively short periods of operation. This polarization, that is believed to be caused by accumulation of oppositely charged ionic species at the ends of the crystal, results in an electric field that opposes that of the applied bias, counter-acting its effect. In this work, we use state of the art quantum modeling to benchmark the theoretical limits for the performance of TlBr as a radiation detector, showing that the best experimental reports demonstrate near-ideal electronic characteristics. We then propose a model to inhibit the detrimental ionic current in the material without impacting the excellent properties of the electronic current. Prepared by LLNL under Contract DE-AC52-07NA27344.

Design of Diaphragm and Coil for Stable Performance of an Eddy Current Type Pressure Sensor.

PubMed

Lee, Hyo Ryeol; Lee, Gil Seung; Kim, Hwa Young; Ahn, Jung Hwan

2016-07-01

The aim of this work was to develop an eddy current type pressure sensor and investigate its fundamental characteristics affected by the mechanical and electrical design parameters of sensor. The sensor has two key components, i.e., diaphragm and coil. On the condition that the outer diameter of sensor is 10 mm, two key parts should be designed so as to keep a good linearity and sensitivity. Experiments showed that aluminum is the best target material for eddy current detection. A round-grooved diaphragm is suggested in order to measure more precisely its deflection caused by applied pressures. The design parameters of a round-grooved diaphragm can be selected depending on the measuring requirements. A developed pressure sensor with diaphragm of t = 0.2 mm and w = 1.05 mm was verified to measure pressure up to 10 MPa with very good linearity and errors of less than 0.16%.

Influence of electrodes on the 448 kHz electric currents created by radiofrequency: A finite element study.

PubMed

Spottorno, J; Gonzalez de Vega, C; Buenaventura, M; Hernando, A

2017-01-01

Radiofrequency is a technology used in physical rehabilitation by physicians and physiotherapists for more than fifteen years, although there exist doubts on how it works. Indiba is a particular method that applies a voltage difference of 448 KHz between two electrodes, creating an electric current between them. These electrodes are an active one that is placed on different areas of the body and a passive one that is left on the same position during the treatment. There are two different types of active electrodes: the capacitive one and the resistive one. In this paper, it has been studied how the different electrodes affect the current density inside the body and thus how they affect the efficacy of the treatment. It shows how finite element calculations should help physicians in order to better understand its behavior and improve the treatments.

Tsunami Detection by High Frequency Radar Beyond the Continental Shelf: II. Extension of Time Correlation Algorithm and Validation on Realistic Case Studies

NASA Astrophysics Data System (ADS)

Grilli, Stéphan T.; Guérin, Charles-Antoine; Shelby, Michael; Grilli, Annette R.; Moran, Patrick; Grosdidier, Samuel; Insua, Tania L.

2017-08-01

In past work, tsunami detection algorithms (TDAs) have been proposed, and successfully applied to offline tsunami detection, based on analyzing tsunami currents inverted from high-frequency (HF) radar Doppler spectra. With this method, however, the detection of small and short-lived tsunami currents in the most distant radar ranges is challenging due to conflicting requirements on the Doppler spectra integration time and resolution. To circumvent this issue, in Part I of this work, we proposed an alternative TDA, referred to as time correlation (TC) TDA, that does not require inverting currents, but instead detects changes in patterns of correlations of radar signal time series measured in pairs of cells located along the main directions of tsunami propagation (predicted by geometric optics theory); such correlations can be maximized when one signal is time-shifted by the pre-computed long wave propagation time. We initially validated the TC-TDA based on numerical simulations of idealized tsunamis in a simplified geometry. Here, we further develop, extend, and apply the TC algorithm to more realistic tsunami case studies. These are performed in the area West of Vancouver Island, BC, where Ocean Networks Canada recently deployed a HF radar (in Tofino, BC), to detect tsunamis from far- and near-field sources, up to a 110 km range. Two case studies are considered, both simulated using long wave models (1) a far-field seismic, and (2) a near-field landslide, tsunami. Pending the availability of radar data, a radar signal simulator is parameterized for the Tofino HF radar characteristics, in particular its signal-to-noise ratio with range, and combined with the simulated tsunami currents to produce realistic time series of backscattered radar signal from a dense grid of cells. Numerical experiments show that the arrival of a tsunami causes a clear change in radar signal correlation patterns, even at the most distant ranges beyond the continental shelf, thus making an early tsunami detection possible with the TC-TDA. Based on these results, we discuss how the new algorithm could be combined with standard methods proposed earlier, based on a Doppler analysis, to develop a new tsunami detection system based on HF radar data, that could increase warning time. This will be the object of future work, which will be based on actual, rather than simulated, radar data.

Physical therapists' management of rheumatoid arthritis: results of a Dutch survey.

PubMed

Hurkmans, E J; Li, L; Verhoef, J; Vliet Vlieland, T P M

2012-09-01

For tailored implementation of evidence-based recommendations and guidelines on physical therapy in patients with rheumatoid arthritis (RA), insight into current physical therapy practice is needed. Two hundred and fifty general physical therapists and 211 specialized physical therapists with advanced arthritis training were sent a questionnaire to assess the frequency with which they applied a set of assessments (n = 10) and interventions (n = 7) included in a Dutch physical therapy guideline for RA. Differences between general and specialist physical therapists were analysed using Student's t-tests or chi-square tests where appropriate. In total, 233 physical therapists (51%) responded. Of these, 96 (41%) had completed an additional arthritis course and were designated as specialist physical therapists. Among the physical therapists who returned the questionnaire, 69% (or more) reported that they 'always' assessed limitations in daily functioning, pain, morning stiffness, muscle strength, joint range of motion, joint stability, gait and limitations in leisure activities as part of their initial assessment, and 37% and 48% reported 'always' to assess aerobic capacity and limitations in work situations, respectively. Concerning interventions, exercise therapy and education were 'always' applied by 70% and 68% of the responders, respectively. Only a minority of responders reported 'always' applying ultrasound, electrical stimulation, heat therapy, massage and passive mobilizations (0%, 0%, 5%, 5% and 14%, respectively). Apart from aerobic capacity and work limitations, all other assessments were reported as 'always' applied by significantly (p < 0.05) more specialist physical therapists than general physical therapists. Regarding interventions, significantly more specialist physical therapists reported that they 'always' applied exercise therapy and education. Significantly fewer specialist physical therapists than in the general group reported 'always' using heat therapy, massage and mobilizations (p < 0.05). The majority of physical therapists reported that they 'always' applied most of the assessments and interventions recommended in a Dutch physical therapy guideline for the management of RA. Areas for improvement include the assessment of aerobic capacity and work limitations. The observed differences between specialist and general physical therapists support the added value of advanced arthritis courses. Copyright © 2012 John Wiley & Sons, Ltd.

Predicting individual action switching in covert and continuous interactive tasks using the fluid events model

DOE PAGES

Radvansky, Gabriel A.; D’Mello, Sidney K.; Abbott, Robert G.; ...

2016-01-27

The Fluid Events Model is aimed at predicting changes in the actions people take on a moment-by-moment basis. In contrast with other research on action selection, this work does not investigate why some course of action was selected, but rather the likelihood of discontinuing the current course of action and selecting another in the near future. This is done using both task-based and experience-based factors. Prior work evaluated this model in the context of trial-by-trial, independent, interactive events, such as choosing how to copy a figure of a line drawing. In this paper, we extend this model to more covertmore » event experiences, such as reading narratives, as well as to continuous interactive events, such as playing a video game. To this end, the model was applied to existing data sets of reading time and event segmentation for written and picture stories. It was also applied to existing data sets of performance in a strategy board game, an aerial combat game, and a first person shooter game in which a participant’s current state was dependent on prior events. The results revealed that the model predicted behavior changes well, taking into account both the theoretically defined structure of the described events, as well as a person’s prior experience. Hence, theories of event cognition can benefit from efforts that take into account not only how events in the world are structured, but also how people experience those events.« less

Predicting Individual Action Switching in Covert and Continuous Interactive Tasks Using the Fluid Events Model

PubMed Central

Radvansky, Gabriel A.; D’Mello, Sidney K.; Abbott, Robert G.; Bixler, Robert E.

2016-01-01

The Fluid Events Model is aimed at predicting changes in the actions people take on a moment-by-moment basis. In contrast with other research on action selection, this work does not investigate why some course of action was selected, but rather the likelihood of discontinuing the current course of action and selecting another in the near future. This is done using both task-based and experience-based factors. Prior work evaluated this model in the context of trial-by-trial, independent, interactive events, such as choosing how to copy a figure of a line drawing. In this paper, we extend this model to more covert event experiences, such as reading narratives, as well as to continuous interactive events, such as playing a video game. To this end, the model was applied to existing data sets of reading time and event segmentation for written and picture stories. It was also applied to existing data sets of performance in a strategy board game, an aerial combat game, and a first person shooter game in which a participant’s current state was dependent on prior events. The results revealed that the model predicted behavior changes well, taking into account both the theoretically defined structure of the described events, as well as a person’s prior experience. Thus, theories of event cognition can benefit from efforts that take into account not only how events in the world are structured, but also how people experience those events. PMID:26858673

Predicting Individual Action Switching in Covert and Continuous Interactive Tasks Using the Fluid Events Model.

PubMed

Radvansky, Gabriel A; D'Mello, Sidney K; Abbott, Robert G; Bixler, Robert E

2016-01-01

The Fluid Events Model is aimed at predicting changes in the actions people take on a moment-by-moment basis. In contrast with other research on action selection, this work does not investigate why some course of action was selected, but rather the likelihood of discontinuing the current course of action and selecting another in the near future. This is done using both task-based and experience-based factors. Prior work evaluated this model in the context of trial-by-trial, independent, interactive events, such as choosing how to copy a figure of a line drawing. In this paper, we extend this model to more covert event experiences, such as reading narratives, as well as to continuous interactive events, such as playing a video game. To this end, the model was applied to existing data sets of reading time and event segmentation for written and picture stories. It was also applied to existing data sets of performance in a strategy board game, an aerial combat game, and a first person shooter game in which a participant's current state was dependent on prior events. The results revealed that the model predicted behavior changes well, taking into account both the theoretically defined structure of the described events, as well as a person's prior experience. Thus, theories of event cognition can benefit from efforts that take into account not only how events in the world are structured, but also how people experience those events.

Predicting individual action switching in covert and continuous interactive tasks using the fluid events model

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

Radvansky, Gabriel A.; D’Mello, Sidney K.; Abbott, Robert G.

The Fluid Events Model is aimed at predicting changes in the actions people take on a moment-by-moment basis. In contrast with other research on action selection, this work does not investigate why some course of action was selected, but rather the likelihood of discontinuing the current course of action and selecting another in the near future. This is done using both task-based and experience-based factors. Prior work evaluated this model in the context of trial-by-trial, independent, interactive events, such as choosing how to copy a figure of a line drawing. In this paper, we extend this model to more covertmore » event experiences, such as reading narratives, as well as to continuous interactive events, such as playing a video game. To this end, the model was applied to existing data sets of reading time and event segmentation for written and picture stories. It was also applied to existing data sets of performance in a strategy board game, an aerial combat game, and a first person shooter game in which a participant’s current state was dependent on prior events. The results revealed that the model predicted behavior changes well, taking into account both the theoretically defined structure of the described events, as well as a person’s prior experience. Hence, theories of event cognition can benefit from efforts that take into account not only how events in the world are structured, but also how people experience those events.« less

Oscillating field current drive experiments in the Madison Symmetric Torus

NASA Astrophysics Data System (ADS)

Blair, Arthur P., Jr.

Oscillating Field Current Drive (OFCD) is an inductive current drive method for toroidal pinches. To test OFCD, two 280 Hz 2 MVA oscillators were installed in the toroidal and poloidal magnetic field circuits of the Madison Symmetric Torus (MST) Reversed Field Pinch (RFP.) Partial sustainment experiments were conducted where the two voltage oscillations were superimposed on the standard MST power supplies. Supplementary current drive of about 10% has been demonstrated, comparable to theoretical predictions. However, maximum current drive does not coincide with maximum helicity injection rate - possibly due to an observed dependence of core and edge tearing modes on the relative phase of the oscillators. A dependence of wall interactions on phase was also observed, the largest interaction coinciding with negative current drive. Experiments were conducted at 280 and 530 Hz. 530 Hz proved to be too high and yielded little or no net current drive. Experiments at 280 Hz proved more fruitful. A 1D relaxed state model was used to predict the effects of voltage amplitudes, frequencies, and waveforms on performance and to optimize the design of OFCD hardware. Predicted current drive was comparable to experimental values, though the aforementioned phase dependence was not. Comparisons were also made with a more comprehensive 3D model which proved to be a more accurate predictor of current drive. Both 1D and 3D models predicted the feasability of full sustainment via OFCD. Experiments were also conducted with only the toroidal field oscillator applied. An entrainment of the natural sawtooth frequency to our applied oscillation was observed as well as a slow modulation of the edge tearing mode amplitudes. A large modulation (20 to 80 eV) of the ion temperature was also observed that can be partially accounted for by collisional heating via magnetic pumping. Work is in progress to increase the power of the existing OFCD hardware.

Energetics of Single Substitutional Impurities in NiTi

NASA Technical Reports Server (NTRS)

Good, Brian S.; Noebe, Ronald

2003-01-01

Shape-memory alloys are of considerable current interest, with applications ranging from stents to Mars rover components. In this work, we present results on the energetics of single substitutional impurities in B2 NiTi. Specifically, energies of Pd, Pt, Zr and Hf impurities at both Ni and Ti sites are computed. All energies are computed using the CASTEP ab initio code, and, for comparison, using the quantum approximate energy method of Bozzolo, Ferrante and Smith. Atomistic relaxation in the vicinity of the impurities is investigated via quantum approximate Monte Carlo simulation, and in cases where the relaxation is found to be important, the resulting relaxations are applied to the ab initio calculations. We compare our results with available experimental work.

Evaluation of Supercapacitors Effects on Hybrid Energy Systems for Automotive

NASA Astrophysics Data System (ADS)

Lungoci, Carmen; Helerea, Elena

This work aims at evaluating the effects of the supercapacitors presence in hybrid energy systems used in automotive. The design and the electrical schema of a hybrid energy system that contains batteries and supercapacitors and propel a synchronous motor are purposed. The motor operating regime is described, detailing the drive evolution of the cycle speed imposed. In these conditions, to model the systems behavior, simulations developed in Matlab/Simulink environment are carried out. Two energies management strategies for the ensemble energy system-motor are implemented. Simulations are done and the energy management is discussed, making the comparative analyses. Applying a current control strategy on the supercapacitors, under two working conditions, functional diagrams are showed and compared. The results obtained highlight the advantages of the supercapacitors.

Magnetically tunable 1D Coulomb drag: Theory

NASA Astrophysics Data System (ADS)

Tylan-Tyler, Anthony; Tang, Yuhe; Levy, Jeremy

In this work, we examine the Coulomb drag effect in 1D nanowires in close proximity, focusing on experimental parameters relevant to complex-oxide nanostructures. Previous work on this problem examined Coulomb drag through quantum point contacts, where effective capacitive coupling between the 2D leads of the system generates the drag voltage. In our case, the entire system is composed of 1D components and thus a more careful treatment of the Coulomb interactions is required. This more complex environment then leads to the ability to switch the drag voltage by an applied magnetic field without altering the current supplied to the drive system. We gratefully acknowledge financial support from ONR N00014-15-1-2847 and DOE DE-SC0014417.

Integrating Rehabilitation Engineering Technology With Biologics

PubMed Central

Collinger, Jennifer L.; Dicianno, Brad E.; Weber, Douglas J.; Cui, Xinyan Tracy; Wang, Wei; Brienza, David M.; Boninger, Michael L.

2017-01-01

Rehabilitation engineers apply engineering principles to improve function or to solve challenges faced by persons with disabilities. It is critical to integrate the knowledge of biologics into the process of rehabilitation engineering to advance the field and maximize potential benefits to patients. Some applications in particular demonstrate the value of a symbiotic relationship between biologics and rehabilitation engineering. In this review we illustrate how researchers working with neural interfaces and integrated prosthetics, assistive technology, and biologics data collection are currently integrating these 2 fields. We also discuss the potential for further integration of biologics and rehabilitation engineering to deliver the best technologies and treatments to patients. Engineers and clinicians must work together to develop technologies that meet clinical needs and are accessible to the intended patient population. PMID:21703573

Performance Evaluation of Various STL File Mesh Refining Algorithms Applied for FDM-RP Process

NASA Astrophysics Data System (ADS)

Ledalla, Siva Rama Krishna; Tirupathi, Balaji; Sriram, Venkatesh

2018-06-01

Layered manufacturing machines use the stereolithography (STL) file to build parts. When a curved surface is converted from a computer aided design (CAD) file to STL, it results in a geometrical distortion and chordal error. Parts manufactured with this file, might not satisfy geometric dimensioning and tolerance requirements due to approximated geometry. Current algorithms built in CAD packages have export options to globally reduce this distortion, which leads to an increase in the file size and pre-processing time. In this work, different mesh subdivision algorithms are applied on STL file of a complex geometric features using MeshLab software. The mesh subdivision algorithms considered in this work are modified butterfly subdivision technique, loops sub division technique and general triangular midpoint sub division technique. A comparative study is made with respect to volume and the build time using the above techniques. It is found that triangular midpoint sub division algorithm is more suitable for the geometry under consideration. Only the wheel cap part is then manufactured on Stratasys MOJO FDM machine. The surface roughness of the part is measured on Talysurf surface roughness tester.

Probabilistic framework for product design optimization and risk management

NASA Astrophysics Data System (ADS)

Keski-Rahkonen, J. K.

2018-05-01

Probabilistic methods have gradually gained ground within engineering practices but currently it is still the industry standard to use deterministic safety margin approaches to dimensioning components and qualitative methods to manage product risks. These methods are suitable for baseline design work but quantitative risk management and product reliability optimization require more advanced predictive approaches. Ample research has been published on how to predict failure probabilities for mechanical components and furthermore to optimize reliability through life cycle cost analysis. This paper reviews the literature for existing methods and tries to harness their best features and simplify the process to be applicable in practical engineering work. Recommended process applies Monte Carlo method on top of load-resistance models to estimate failure probabilities. Furthermore, it adds on existing literature by introducing a practical framework to use probabilistic models in quantitative risk management and product life cycle costs optimization. The main focus is on mechanical failure modes due to the well-developed methods used to predict these types of failures. However, the same framework can be applied on any type of failure mode as long as predictive models can be developed.

Measuring Plasma Formation Field Strength and Current Loss in Pulsed Power Diodes

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

Johnston, Mark D.; Patel, Sonal G.; Falcon, Ross Edward

This LDRD investigated plasma formation, field strength, and current loss in pulsed power diodes. In particular the Self-Magnetic Pinch (SMP) e-beam diode was studied on the RITS-6 accelerator. Magnetic fields of a few Tesla and electric fields of several MV/cm were measured using visible spectroscopy techniques. The magnetic field measurements were then used to determine the current distribution in the diode. This distribution showed that significant beam current extends radially beyond the few millimeter x-ray focal spot diameter. Additionally, shielding of the magnetic field due to dense electrode surface plasmas was observed, quantified, and found to be consistent with themore » calculated Spitzer resistivity. In addition to the work on RITS, measurements were also made on the Z-machine looking to quantify plasmas within the power flow regions. Measurements were taken in the post-hole convolute and final feed gap regions on Z. Dopants were applied to power flow surfaces and measured spectroscopically. These measurements gave species and density/temperature estimates. Preliminary B-field measurements in the load region were attempted as well. Finally, simulation work using the EMPHASIS, electromagnetic particle in cell code, was conducted using the Z MITL conditions. The purpose of these simulations was to investigate several surface plasma generations models under Z conditions for comparison with experimental data.« less

Modelling the electric field and the current density generated by cerebellar transcranial DC stimulation in humans.

PubMed

Parazzini, Marta; Rossi, Elena; Ferrucci, Roberta; Liorni, Ilaria; Priori, Alberto; Ravazzani, Paolo

2014-03-01

Transcranial Direct Current Stimulation (tDCS) over the cerebellum (or cerebellar tDCS) modulates working memory, changes cerebello-brain interaction, and affects locomotion in humans. Also, the use of tDCS has been proposed for the treatment of disorders characterized by cerebellar dysfunction. Nonetheless, the electric field (E) and current density (J) spatial distributions generated by cerebellar tDCS are unknown. This work aimed to estimate E and J distributions during cerebellar tDCS. Computational electromagnetics techniques were applied in three human realistic models of different ages and gender. The stronger E and J occurred mainly in the cerebellar cortex, with some spread (up to 4%) toward the occipital cortex. Also, changes by ±1cm in the position of the active electrode resulted in a small effect (up to 4%) in the E and J spatial distribution in the cerebellum. Finally, the E and J spreads to the brainstem and the heart were negligible, thus further supporting the safety of this technique. Despite inter-individual differences, our modeling study confirms that the cerebellum is the structure mainly involved by cerebellar tDCS. Modeling approach reveals that during cerebellar tDCS the current spread to other structures outside the cerebellum is unlike to produce functional effects. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Organizational climate and culture: Reflections on the history of the constructs in the Journal of Applied Psychology.

PubMed

Schneider, Benjamin; González-Romá, Vicente; Ostroff, Cheri; West, Michael A

2017-03-01

We review the literature on organizational climate and culture paying specific attention to articles published in the Journal of Applied Psychology (JAP) since its first volume in 1917. The article traces the history of the 2 constructs though JAP has been far more important for climate than culture research. We distinguish 4 main periods: the pre-1971 era, with pioneering work on exploring conceptualization and operationalizations of the climate construct; the 1971-1985 era, with foundational work on aggregation issues, outcome-focused climates (on safety and service) and early writings on culture; the 1986-1999 era, characterized by solidification of a focused climate approach to understanding organizational processes (justice, discrimination) and outcomes (safety, service) and the beginnings of survey approaches to culture; and the 2000-2014 era, characterized by multilevel work on climate, climate strength, demonstrated validity for a climate approach to outcomes and processes, and the relationship between leadership and climate and culture. We summarize and comment on the major theory and research achievements in each period, showing trends observed in the literature and how JAP has contributed greatly to moving research on these constructs, especially climate, forward. We also recommend directions for future research given the current state of knowledge. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Application of an interactive water simulation model in urban water management: a case study in Amsterdam.

PubMed

Leskens, J G; Brugnach, M; Hoekstra, A Y

2014-01-01

Water simulation models are available to support decision-makers in urban water management. To use current water simulation models, special expertise is required. Therefore, model information is prepared prior to work sessions, in which decision-makers weigh different solutions. However, this model information quickly becomes outdated when new suggestions for solutions arise and are therefore limited in use. We suggest that new model techniques, i.e. fast and flexible computation algorithms and realistic visualizations, allow this problem to be solved by using simulation models during work sessions. A new Interactive Water Simulation Model was applied for two case study areas in Amsterdam and was used in two workshops. In these workshops, the Interactive Water Simulation Model was positively received. It included non-specialist participants in the process of suggesting and selecting possible solutions and made them part of the accompanying discussions and negotiations. It also provided the opportunity to evaluate and enhance possible solutions more often within the time horizon of a decision-making process. Several preconditions proved to be important for successfully applying the Interactive Water Simulation Model, such as the willingness of the stakeholders to participate and the preparation of different general main solutions that can be used for further iterations during a work session.

How authors did it - a methodological analysis of recent engineering education research papers in the European Journal of Engineering Education

NASA Astrophysics Data System (ADS)

Malmi, Lauri; Adawi, Tom; Curmi, Ronald; de Graaff, Erik; Duffy, Gavin; Kautz, Christian; Kinnunen, Päivi; Williams, Bill

2018-03-01

We investigated research processes applied in recent publications in the European Journal of Engineering Education (EJEE), exploring how papers link to theoretical work and how research processes have been designed and reported. We analysed all 155 papers published in EJEE in 2009, 2010 and 2013, classifying the papers using a taxonomy of research processes in engineering education research (EER) (Malmi et al. 2012). The majority of the papers presented either empirical work (59%) or were case reports (27%). Our main findings are as follows: (1) EJEE papers build moderately on a wide selection of theoretical work; (2) a great majority of papers have a clear research strategy, but data analysis methods are mostly simple descriptive statistics or simple/undocumented qualitative research methods; and (3) there are significant shortcomings in reporting research questions, methodology and limitations of studies. Our findings are consistent with and extend analyses of EER papers in other publishing venues; they help to build a clearer picture of the research currently published in EJEE and allow us to make recommendations for consideration by the editorial team of the journal. Our employed procedure also provides a framework that can be applied to monitor future global evolution of this and other EER journals.

Scanning electrochemical microscopy based evaluation of influence of pH on bioelectrochemical activity of yeast cells - Saccharomyces cerevisiae.

PubMed

Ramanavicius, A; Morkvenaite-Vilkonciene, I; Kisieliute, A; Petroniene, J; Ramanaviciene, A

2017-01-01

In this research scanning electrochemical microscopy was applied for the investigation of immobilized yeast Saccharomyces cerevisiae cells. Two redox mediators based system was applied in order to increase the efficiency of charge transfer from yeast cells. 9,10-phenanthrenequinone (PQ) was applied as a lipophilic redox mediator, which has the ability to cross the cell's membrane; another redox mediator was ferricyanide, which acted as a hydrophylic electron acceptor able to transfer electrons from the PQ to the working electrode of SECM. Hill's function was applied to determine the optimal pH for this described SECM-based system. The influence of pH on cell viability could be well described by Hill's function. It was determined that at pH 6.5 the PQ has a minimal toxic influence on yeast cells, and the kinetics of metabolic processes in cells as well as electron transfer rate achieved in consecutive action of both redox mediators were appropriate to achieve optimal current signals. Copyright © 2016 Elsevier B.V. All rights reserved.

Molecular modeling: An open invitation for applied mathematics

NASA Astrophysics Data System (ADS)

Mezey, Paul G.

2013-10-01

Molecular modeling methods provide a very wide range of challenges for innovative mathematical and computational techniques, where often high dimensionality, large sets of data, and complicated interrelations imply a multitude of iterative approximations. The physical and chemical basis of these methodologies involves quantum mechanics with several non-intuitive aspects, where classical interpretation and classical analogies are often misleading or outright wrong. Hence, instead of the everyday, common sense approaches which work so well in engineering, in molecular modeling one often needs to rely on rather abstract mathematical constraints and conditions, again emphasizing the high level of reliance on applied mathematics. Yet, the interdisciplinary aspects of the field of molecular modeling also generates some inertia and perhaps too conservative reliance on tried and tested methodologies, that is at least partially caused by the less than up-to-date involvement in the newest developments in applied mathematics. It is expected that as more applied mathematicians take up the challenge of employing the latest advances of their field in molecular modeling, important breakthroughs may follow. In this presentation some of the current challenges of molecular modeling are discussed.

A Systematic Literature Review of Agents Applied in Healthcare.

PubMed

Isern, David; Moreno, Antonio

2016-02-01

Intelligent agents and healthcare have been intimately linked in the last years. The intrinsic complexity and diversity of care can be tackled with the flexibility, dynamics and reliability of multi-agent systems. The purpose of this review is to show the feasibility of applying intelligent agents in the healthcare domain and use the findings to provide a discussion of current trends and devise future research directions. A review of the most recent literature (2009-2014) of applications of agents in healthcare is discussed, and two classifications considering the main goal of the health systems as well as the main actors involved have been investigated. This review shows that the number of published works exhibits a growing interest of researchers in this field in a wide range of applications.

An operational approach to high resolution agro-ecological zoning in West-Africa.

PubMed

Le Page, Y; Vasconcelos, Maria; Palminha, A; Melo, I Q; Pereira, J M C

2017-01-01

The objective of this work is to develop a simple methodology for high resolution crop suitability analysis under current and future climate, easily applicable and useful in Least Developed Countries. The approach addresses both regional planning in the context of climate change projections and pre-emptive short-term rural extension interventions based on same-year agricultural season forecasts, while implemented with off-the-shelf resources. The developed tools are applied operationally in a case-study developed in three regions of Guinea-Bissau and the obtained results, as well as the advantages and limitations of methods applied, are discussed. In this paper we show how a simple approach can easily generate information on climate vulnerability and how it can be operationally used in rural extension services.

From endosymbiosis to holobionts: Evaluating a conceptual legacy.

PubMed

O'Malley, Maureen A

2017-12-07

In her influential 1967 paper, Lynn Margulis synthesized a range of data to support the idea of endosymbiosis. Building on the success of this work, she applied the same methodology to promote the role of symbiosis more generally in evolution. As part of this broader project, she coined the term 'holobiont' to refer to a unified entity of symbiont and host. This concept is now applied with great gusto in microbiome research, and often implies not just a physiological unit but also various senses of an evolving system. My analysis will track how Margulis came to propose the term, its current use in microbiome research, and how those applications link back to Margulis. I then evaluate what contemporary use says about Margulis's legacy for microbiome research. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Attributes of a Variable-Diameter Rotor System Applied to Civil Tiltrotor Aircraft

NASA Technical Reports Server (NTRS)

Brender, Scott; Mark, Hans; Aguilera, Frank

1996-01-01

The attributes of a variable diameter rotor concept applied to civil tiltrotor aircraft are investigated using the V/STOL aircraft sizing and performance computer program (VASCOMP). To begin, civil tiltrotor viability issues that motivate advanced rotor designs are discussed. Current work on the variable diameter rotor and a theoretical basis for the advantages of the rotor system are presented. The size and performance of variable diameter and conventional tiltrotor designs for the same baseline mission are then calculated using a modified NASA Ames version of VASCOMP. The aircraft are compared based on gross weight, fuel required, engine size, and autorotative performance for various hover disk loading values. Conclusions about the viability of the resulting designs are presented and a program for further variable diameter rotor research is recommended.

Probing longitudinal modes evolution of a InGaN green laser diode

NASA Astrophysics Data System (ADS)

Chen, Yi-Hsi; Lin, Wei-Chen; Chen, Hong-Zui; Shy, Jow-Tsong; Chui, Hsiang-Chen

2018-06-01

This study aims to investigate the longitudinal mode evolution of a InGaN green laser diode. A spectrometer with a 3-pm resolution was employed to obtain the emission spectra of a green laser diode, at a wavelength of around 520 nm, as a function of applied current and temperature. The spectral behavior of the laser modes with applied current was investigated. Right above the lasing threshold, the green diode laser emitted single longitudinal mode output. With increasing applied current, the number of the longitudinal modes increased. Up to ten lasing modes oscillated within the entire gain profile when the applied currents were tuned to 2.2Ith. Subsequently, a multi-Lorentzian profile model was adopted to analyze the spectra and observe how the modes evolved with temperature and applied current.

Progress Toward Accurate Measurements of Power Consumptions of DBD Plasma Actuators

NASA Technical Reports Server (NTRS)

Ashpis, David E.; Laun, Matthew C.; Griebeler, Elmer L.

2012-01-01

The accurate measurement of power consumption by Dielectric Barrier Discharge (DBD) plasma actuators is a challenge due to the characteristics of the actuator current signal. Micro-discharges generate high-amplitude, high-frequency current spike transients superimposed on a low-amplitude, low-frequency current. We have used a high-speed digital oscilloscope to measure the actuator power consumption using the Shunt Resistor method and the Monitor Capacitor method. The measurements were performed simultaneously and compared to each other in a time-accurate manner. It was found that low signal-to-noise ratios of the oscilloscopes used, in combination with the high dynamic range of the current spikes, make the Shunt Resistor method inaccurate. An innovative, nonlinear signal compression circuit was applied to the actuator current signal and yielded excellent agreement between the two methods. The paper describes the issues and challenges associated with performing accurate power measurements. It provides insights into the two methods including new insight into the Lissajous curve of the Monitor Capacitor method. Extension to a broad range of parameters and further development of the compression hardware will be performed in future work.

Bringing Together Users and Developers of Forest Biomass Maps

NASA Technical Reports Server (NTRS)

Brown, Molly E.; Macauley, Molly

2011-01-01

Forests store carbon and thus represent important sinks for atmospheric carbon dioxide. Reducing uncertainty in current estimates of the amount of carbon in standing forests will improve precision of estimates of anthropogenic contributions to carbon dioxide in the atmosphere due to deforestation. Although satellite remote sensing has long been an important tool for mapping land cover, until recently aboveground forest biomass estimates have relied mostly on systematic ground sampling of forests. In alignment with fiscal year 2010 congressional direction, NASA has initiated work toward a carbon monitoring system (CMS) that includes both maps of forest biomass and total carbon flux estimates. A goal of the project is to ensure that the products are useful to a wide community of scientists, managers, and policy makers, as well as to carbon cycle scientists. Understanding the needs and requirements of these data users is helpful not just to the NASA CMS program but also to the entire community working on carbon-related activities. To that end, this meeting brought together a small group of natural resource managers and policy makers who use information on forests in their work with NASA scientists who are working to create aboveground forest biomass maps. These maps, derived from combining remote sensing and ground plots, aim to be more accurate than current inventory approaches when applied at local and regional scales.

Electronics and Software Engineer for Robotics Project Intern

NASA Technical Reports Server (NTRS)

Teijeiro, Antonio

2017-01-01

I was assigned to mentor high school students for the 2017 First Robotics Competition. Using a team based approach, I worked with the students to program the robot and applied my electrical background to build the robot from start to finish. I worked with students who had an interest in electrical engineering to teach them about voltage, current, pulse width modulation, solenoids, electromagnets, relays, DC motors, DC motor controllers, crimping and soldering electrical components, Java programming, and robotic simulation. For the simulation, we worked together to generate graphics files, write simulator description format code, operate Linux, and operate SOLIDWORKS. Upon completion of the FRC season, I transitioned over to providing full time support for the LCS hardware team. During this phase of my internship I helped my co-intern write test steps for two networking hardware DVTs , as well as run cables and update cable running lists.

Self-Oscillating Josephson Quantum Heat Engine

NASA Astrophysics Data System (ADS)

Marchegiani, G.; Virtanen, P.; Giazotto, F.; Campisi, M.

2016-11-01

The design of a mesoscopic self-oscillating heat engine that works thanks to purely quantum effects is presented. The proposed scheme is amenable to experimental implementation with current state-of-the-art nanotechnology and materials. One of the main features of the structure is its versatility: The engine can deliver work to a generic load without galvanic contact. This versatility makes it a promising building block for low-temperature on-chip energy-management applications. The heat engine consists of a circuit featuring a thermoelectric element based on a ferromagnetic insulator-superconductor tunnel junction and a Josephson weak link that realizes a purely quantum dc-ac converter. This makeup enables the contactless transfer of work to the load (a generic RL circuit). The performance of the heat engine is investigated as a function of the thermal gradient applied to the thermoelectric junction. Power up to 1 pW can be delivered to a load RL=10 Ω .

New methods for accelerating the convergence of molecular electronic integrals over exponential type orbitals

NASA Astrophysics Data System (ADS)

Safouhi, Hassan; Hoggan, Philip

2003-01-01

This review on molecular integrals for large electronic systems (MILES) places the problem of analytical integration over exponential-type orbitals (ETOs) in a historical context. After reference to the pioneering work, particularly by Barnett, Shavitt and Yoshimine, it focuses on recent progress towards rapid and accurate analytic solutions of MILES over ETOs. Software such as the hydrogenlike wavefunction package Alchemy by Yoshimine and collaborators is described. The review focuses on convergence acceleration of these highly oscillatory integrals and in particular it highlights suitable nonlinear transformations. Work by Levin and Sidi is described and applied to MILES. A step by step description of progress in the use of nonlinear transformation methods to obtain efficient codes is provided. The recent approach developed by Safouhi is also presented. The current state of the art in this field is summarized to show that ab initio analytical work over ETOs is now a viable option.

Modelling and simulation of “Free Cooling” process applied to building construction

NASA Astrophysics Data System (ADS)

Ousegui, A.; Asbik, M.

2018-05-01

Thermal energy storage systems (TES), using phase change material (PCM) in building walls, consists a hot topic within the research community currently. In the present work, a numerical model is developed to simulate free cooling of air-PCM heat exchanger in both charging and discharging steps. The studied case is taken from experimental work. The domain consists in two parallel plates made of Paraffin as PCM, separate by a gap where air circulates. The flow and temperature can be adjusted. The goal is to calculate the temperature of the air at the outlet, in order to analyse the performance of the device. A good agreement was founded between experimental and numerical results. The analysis of the influence of the flow rate on the efficiency of the process confirms a previous works, that the heating flow rate should be higher than cooling one.

Parallel, Asynchronous Executive (PAX): System concepts, facilities, and architecture

NASA Technical Reports Server (NTRS)

Jones, W. H.

1983-01-01

The Parallel, Asynchronous Executive (PAX) is a software operating system simulation that allows many computers to work on a single problem at the same time. PAX is currently implemented on a UNIVAC 1100/42 computer system. Independent UNIVAC runstreams are used to simulate independent computers. Data are shared among independent UNIVAC runstreams through shared mass-storage files. PAX has achieved the following: (1) applied several computing processes simultaneously to a single, logically unified problem; (2) resolved most parallel processor conflicts by careful work assignment; (3) resolved by means of worker requests to PAX all conflicts not resolved by work assignment; (4) provided fault isolation and recovery mechanisms to meet the problems of an actual parallel, asynchronous processing machine. Additionally, one real-life problem has been constructed for the PAX environment. This is CASPER, a collection of aerodynamic and structural dynamic problem simulation routines. CASPER is not discussed in this report except to provide examples of parallel-processing techniques.

MALDI-MS analysis and imaging of small molecule metabolites with 1,5-diaminonaphthalene (DAN).

PubMed

Korte, Andrew R; Lee, Young Jin

2014-08-01

1,5-Diaminonaphthalene (DAN) has previously been reported as an effective matrix for matrix-assisted laser desorption ionization-mass spectrometry of phospholipids. In the current work, we investigate the use of DAN as a matrix for small metabolite analysis in negative ion mode. DAN was found to provide superior ionization to the compared matrices for MW < ~400 Da; however, 9-aminoacridine (9-AA) was found to be superior for a uridine diphosphate standard (MW 566 Da). DAN was also found to provide a more representative profile of a natural phospholipid mixture than 9-AA. Finally, DAN and 9-AA were applied for imaging of metabolites directly from corn leaf sections. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Current distribution within parallel-connected battery cells

NASA Astrophysics Data System (ADS)

Brand, Martin J.; Hofmann, Markus H.; Steinhardt, Marco; Schuster, Simon F.; Jossen, Andreas

2016-12-01

Parallel connections can be found in many battery applications. Therefore, it is of high interest to understand how the current distributes within parallel battery cells. However, the number of publications on this topic is comparably low. Furthermore, the measurement set-ups are often not clearly defined in existing publications and it is likely that additional impedances distorted the measured current distributions. In this work, the principles of current distributions within parallel-connected battery cells are investigated theoretically, with an equivalent electric circuit model, and by measurements. A measurement set-up is developed that does not significantly influence the measurements, as proven by impedance spectroscopy. On this basis, two parameter scenarios are analyzed: the ΔR scenario stands for battery cells with differing impedances but similar capacities and the ΔC scenario for differing capacities and similar impedances. Out of 172 brand-new lithium-ion battery cells, pairs are built to practically represent the ΔR and ΔC scenarios. If a charging pulse is applied to the ΔR scenario, currents initially divide according to the current divider but equalize in constant current phases. The current divider has no effect on ΔC pairs but, as a rule of thumb for long-term loads, currents divide according to the battery cell capacities.

Stress, burnout and doctors' attitudes to work are determined by personality and learning style: a twelve year longitudinal study of UK medical graduates.

PubMed

McManus, I C; Keeling, A; Paice, E

2004-08-18

The study investigated the extent to which approaches to work, workplace climate, stress, burnout and satisfaction with medicine as a career in doctors aged about thirty are predicted by measures of learning style and personality measured five to twelve years earlier when the doctors were applicants to medical school or were medical students. Prospective study of a large cohort of doctors. The participants were first studied when they applied to any of five UK medical schools in 1990. Postal questionnaires were sent to all doctors with a traceable address on the current or a previous Medical Register. The current questionnaire included measures of Approaches to Work, Workplace Climate, stress (General Health Questionnaire), burnout (Maslach Burnout Inventory), and satisfaction with medicine as a career and personality (Big Five). Previous questionnaires had included measures of learning style (Study Process Questionnaire) and personality. Doctors' approaches to work were predicted by study habits and learning styles, both at application to medical school and in the final year. How doctors perceive their workplace climate and workload is predicted both by approaches to work and by measures of stress, burnout and satisfaction with medicine. These characteristics are partially predicted by trait measures of personality taken five years earlier. Stress, burnout and satisfaction also correlate with trait measures of personality taken five years earlier. Differences in approach to work and perceived workplace climate seem mainly to reflect stable, long-term individual differences in doctors themselves, reflected in measures of personality and learning style.

Stress, burnout and doctors' attitudes to work are determined by personality and learning style: A twelve year longitudinal study of UK medical graduates

PubMed Central

McManus, IC; Keeling, A; Paice, E

2004-01-01

Background The study investigated the extent to which approaches to work, workplace climate, stress, burnout and satisfaction with medicine as a career in doctors aged about thirty are predicted by measures of learning style and personality measured five to twelve years earlier when the doctors were applicants to medical school or were medical students. Methods Prospective study of a large cohort of doctors. The participants were first studied when they applied to any of five UK medical schools in 1990. Postal questionnaires were sent to all doctors with a traceable address on the current or a previous Medical Register. The current questionnaire included measures of Approaches to Work, Workplace Climate, stress (General Health Questionnaire), burnout (Maslach Burnout Inventory), and satisfaction with medicine as a career and personality (Big Five). Previous questionnaires had included measures of learning style (Study Process Questionnaire) and personality. Results Doctors' approaches to work were predicted by study habits and learning styles, both at application to medical school and in the final year. How doctors perceive their workplace climate and workload is predicted both by approaches to work and by measures of stress, burnout and satisfaction with medicine. These characteristics are partially predicted by trait measures of personality taken five years earlier. Stress, burnout and satisfaction also correlate with trait measures of personality taken five years earlier. Conclusions Differences in approach to work and perceived workplace climate seem mainly to reflect stable, long-term individual differences in doctors themselves, reflected in measures of personality and learning style. PMID:15317650

Occupational exposure to carcinogens in Australian road transport workers.

PubMed

Si, Si; Carey, Renee; Reid, Alison; Peters, Susan; Glass, Deborah D; Driscoll, Timothy; Darcey, Ellie; Fritschi, Lin

2016-01-01

Road transport workers (RTWs) are at high risk of exposure to several occupational carcinogens. However, there are gaps in knowledge regarding the extent and the circumstances of exposure. As a sub-study of the Australian Work Exposures Study, this study investigated the prevalence of occupational exposure in Australian RTWs. A random sample of Australian working population was invited to a telephone interview regarding their current jobs. An automated expert-assessment procedure was applied to self-reported job-related tasks using a web-based application. 162 RTWs were included in this study. RTWs were exposed to diesel exhaust (97%), solar ultraviolet radiation (78%), environmental tobacco smoke (55%), benzene (29%), silica (15%), and asbestos (10%) at work. Besides driving on roads, vehicle maintenance-related tasks were the major source of carcinogen exposures among RTWs. Most RTWs are exposed to at least one carcinogen at work. We have identified tasks where the use of control measures could potentially reduce exposures. © 2015 Wiley Periodicals, Inc.

Applying gene flow science to environmental policy needs: a boundary work perspective.

PubMed

Ridley, Caroline E; Alexander, Laurie C

2016-08-01

One application of gene flow science is the policy arena. In this article, we describe two examples in which the topic of gene flow has entered into the U.S. national environmental policymaking process: regulation of genetically engineered crops and clarification of the jurisdictional scope of the Clean Water Act. We summarize both current scientific understanding and the legal context within which gene flow science has relevance. We also discuss the process by which scientific knowledge has been synthesized and communicated to decision-makers in these two contexts utilizing the concept of 'boundary work'. Boundary organizations, the work they engage in to bridge the worlds of science, policy, and practice, and the boundary objects they produce to translate scientific knowledge existed in both examples. However, the specific activities and attributes of the objects produced varied based on the needs of the decision-makers. We close with suggestions for how scientists can contribute to or engage in boundary work with policymakers.

Development and Testing of Space Fission Technology at NASA-MSFC

NASA Technical Reports Server (NTRS)

Polzin, Kurt; Pearson, J. Boise; Houts, Michael

2008-01-01

The Early Flight Fission Test Facility (EFF-TF) at NASA-Marshall Space Flight Center (MSFC) provides a capability to perform hardware-directed activities to support multiple inspace nuclear reactor concepts by using a non-nuclear test methodology. This includes fabrication and testing at both the module/component level and near prototypic reactor configurations allowing for realistic thermal-hydraulic evaluations of systems. The EFF-TF is currently performing non-nuclear testing of hardware to support a technology development effort related to an affordable fission surface power (AFSP) system that could be deployed on the Lunar surface. The AFSP system is presently based on a pumped liquid metal-cooled reactor design, which builds on US and Russian space reactor technology as well as extensive US and international terrestrial liquid metal reactor experience. An important aspect of the current hardware development effort is the information and insight that can be gained from experiments performed in a relevant environment using realistic materials. This testing can often deliver valuable data and insights with a confidence that is not otherwise available or attainable. While the project is currently focused on potential fission surface power for the lunar surface, many of the present advances, testing capabilities, and lessons learned can be applied to the future development of a low-cost in-space fission power system. The potential development of such systems would be useful in fulfilling the power requirements for certain electric propulsion systems (magnetoplasmadynamic thruster, high-power Hall and ion thrusters). In addition, inspace fission power could be applied towards meeting spacecraft and propulsion needs on missions further from the Sun, where the usefulness of solar power is diminished. The affordable nature of the fission surface power system that NASA may decide to develop in the future might make derived systems generally attractive for powering spacecraft and propulsion systems in space. This presentation will discuss work on space nuclear systems that has been performed at MSFC's EFF-TF over the past 10 years. Emphasis will be place on both ongoing work related to FSP and historical work related to in-space systems potentially useful for powering electric propulsion systems.

Equity and working time: a challenge to achieve.

PubMed

Fischer, Frida Marina; Rotenberg, Lúcia; de Castro Moreno, Claudia Roberta

2004-01-01

Equity is a humanitarian issue that gained strength during the transition from the 20th to the 21st century due to the mounting global discussion and social crisis involving human rights, health, and work. This article aims at (1) introducing the concept of equity as it applies to work environments, particularly to situations involving demanding work schedules, (2) discussing the role of science in equity issues related to work, (3) introducing a new scientific society dedicated to working-time issues, and (4) presenting an overview of new research on working time and health as addressed by the series of manuscripts published in this special issue of Chronobiology International devoted to the XVIth International Symposium on Night and Shiftwork, held in Santos, Brazil, November 2003. The concept of equity has a political as a well as a scientific dimension. Many worldwide organizations, e.g., civil society, academia, and occupational health research institutions, advocate prompt actions toward equity as a strategy to attain sustainable development and to reduce poverty. The analyses of current tendencies in work settings reveal a general situation of disrespect for equity principles, which is expressed by heavy workloads, long work hours, poor work conditions, and deregulation of established labor laws, mainly in (but not restricted to) developing countries. In spite of the great contribution of science in the past five decades, obstacles stand in the way of effectively improving good working conditions, particularly in times of precarious employment. The Working Time Society is a new scientific society that aims at promoting research into working time and health and offers practical advice on how to minimize adverse effects of working hours on workers' health and well-being. An updated view of the research on working times and health includes studies on the relationship between work schedules, worker health, and well-being; effects of night and shiftwork on the internal synchronization of circadian rhythms and laboratory and field interventions; new methods of investigation or new approaches in shift-work studies; and prediction of risks in night and shift work. Current tendencies of work organization contribute to the amplification of inequality across groups and populations, revealing that equity remains a challenge to achieve.

Simultaneous particle image velocimetry and chemiluminescence visualization of millisecond-pulsed current-voltage-induced perturbations of a premixed propane/air flame

NASA Astrophysics Data System (ADS)

Schmidt, Jacob; Kostka, Stanislav; Lynch, Amy; Ganguly, Biswa

2011-09-01

The effects of millisecond-wide, pulsed current-voltage-induced behavior in premixed laminar flames have been investigated through the simultaneous collection of particle image velocimetry (PIV) and chemiluminescence data with particular attention paid to the onset mechanisms. Disturbances caused by applied voltages of 2 kV over a 30-mm gap to a downward propagating, atmospheric pressure, premixed propane/air flame with a flow speed near 2 m/s and an equivalence ratio of 1.06 are investigated. The combined PIV and chemiluminescence-based experimental data show the observed disturbance originates only in or near the cathode fall region very close to the burner base. The data also suggest that the coupling mechanism responsible for the flame disturbance behavior is fluidic in nature, developing from the radial positive chemi-ion distribution and an ion-drift current-induced net body force that acts along the annular space discharge distribution in the reaction zone in or near the cathode fall. This net body force causes a reduction in flow speed above these near cathodic regions causing the base of the flame to laterally spread. Also, this effect seems to produce a velocity gradient leading to the transition of a laminar flame to turbulent combustion for higher applied current-voltage conditions as shown in previous work (Marcum and Ganguly in Combust Flame 143:27-36, 2005; Schmidt and Ganguly in 48th AIAA aerospace sciences meeting. Orlando, 2010).

Throughput Enhancement of Car Exhaust Fabrication Line by Applying MOST

NASA Astrophysics Data System (ADS)

Hanash, E. A. H.; Karim, A. N. M.; Tanjong Tuan, Saravanan; Mohiuddin, A. K. M.

2017-03-01

In the fiercely competitive world market of today, manufacturers are facing increasingly tougher challenges and are compelled to find ways for productivity enhancement wherever possible in the whole supply chain. Nevertheless there are many facets in business process which can be explored for possible improvement, an immediate focus goes for the involved processes to re-engineer the activities in different workstations for an efficient and balanced assembly or fabrication line. In this paper an industrial case on fabrication line of a car exhaust system is presented to illustrate the scope of improvement by applying the MOST (Maynard’s Operation Sequence Technique) in streamlining the activities followed by assembly line balancing (ALB). The whole process of conducting various tasks is investigated to find out the lapses or wastes, to search for better option and to set the standard times for the tasks. Then individual workstation time is worked out by summing up the standard times of the involved tasks or activities and the concept of ALB is attempted to balance the fabrication line. So by possible reduction or elimination of the identified wastes or lapses workstation times including the bottleneck station are lowered. As a result the throughput of car exhaust systems is enhanced. According to the current practice, the Takt time is set at 3 minutes. However, upon an analysis through use of the MOST, the bottleneck station time is found to be as low as 1.27 minutes. Thus an opportunity of meeting the current level of demand with significantly lower workforce (with 2 operators instead of 5) is revealed. Alternatively, if necessary, an increased workload can be assigned for the current level of workforce. Moreover, with proper distribution of activities among the workstations using the concept of ALB, the line efficiency is found to be improved. So the line balance loss in the current setup of production line is also possible to be largely reduced. Thus daily production of car exhaust, if modified with suggested changes with the current workforce, could be more than double compared to the current daily output. Hence, effectiveness of the MOST followed by ALB applications to expose and remove the operational wastes in the work flow is reiterated with enhanced throughput.

A high-precision voltage source for EIT

PubMed Central

Saulnier, Gary J; Liu, Ning; Ross, Alexander S

2006-01-01

Electrical impedance tomography (EIT) utilizes electrodes placed on the surface of a body to determine the complex conductivity distribution within the body. EIT can be performed by applying currents through the electrodes and measuring the electrode voltages or by applying electrode voltages and measuring the currents. Techniques have also been developed for applying the desired currents using voltage sources. This paper describes a voltage source for use in applied-voltage EIT that includes the capability of measuring both the applied voltage and applied current. A calibration circuit and calibration algorithm are described which enables all voltage sources in an EIT system to be calibrated to a common standard. The calibration minimizes the impact of stray shunt impedance, passive component variability and active component non-ideality. Simulation data obtained using PSpice are used to demonstrate the effectiveness of the circuits and calibration algorithm. PMID:16636413

Working beyond 65: a qualitative study of perceived hazards and discomforts at work.

PubMed

Reynolds, Frances; Farrow, Alexandra; Blank, Alison

2013-01-01

This qualitative study explored self-reports of hazards and discomforts in the workplace and coping strategies among those choosing to work beyond the age of 65 years. 30 people aged 66-91 years took part. Most worked part-time in professional or administrative roles. Each participant engaged in one semi-structured interview. Participants described some hazards and discomforts in their current work, but no recent accidents. The main age-related discomfort was tiredness. Other hazards that recurred in participants' accounts were physical demands of the job, driving, and interpersonal difficulties such as client or customer complaints, and in very rare cases, bullying. Most work-related hazards (e.g. prolonged sitting at computers, lifting heavy items and driving) were thought likely to affect any worker regardless of age. Coping strategies included making adaptations to age-related changes (such as decreased stamina) by keeping fit and being open about difficulties to colleagues, reducing hours of work, altering roles at work, limiting driving, applying expertise derived from previous work experiences, being assertive, using authority and status, and (among the minority employed in larger organisations) making use of supportive company/organisational policies and practices. Participants described taking individual responsibility for managing hazards at work and perceived little or no elevation of risk linked to age.

Mitigation of PID in commercial PV modules using current interruption method

NASA Astrophysics Data System (ADS)

Bora, Birinchi; Oh, Jaewon; Tatapudi, Sai; Sastry, Oruganty S.; Kumar, Rajesh; Prasad, Basudev; Tamizhmani, Govindasamy

2017-08-01

Potential-induced degradation (PID) is known to have a very severe effect on the reliability of PV modules. PID is caused due to the leakage of current from the cell circuit to the grounded frame under humid conditions of high voltage photovoltaic (PV) systems. There are multiple paths for the current leakage. The most dominant leakage path is from the cell to the frame through encapsulant, glass bulk and glass surface. This dominant path can be prevented by interrupting the electrical conductivity at the glass surface. In our previous works related to this topic, we demonstrated the effectiveness of glass surface conductivity interruption technique using one-cell PV coupons. In this work, we demonstrate the effectiveness of this technique using a full size commercial module susceptible to PID. The interruption of surface conductivity of the commercial module was achieved by attaching a narrow, thin flexible glass strips, from Corning, called Willow Glass on the glass surface along the inner edges of the frame. The flexible glass strip was attached to the module glass surface by heating the glass strip with an ionomer adhesive underneath using a handheld heat gun. The PID stress test was performed at 60°C and 85% RH for 96 hours at -600 V. Pre- and post-PID characterizations including I-V and electroluminescence were carried out to determine the performance loss and affected cell areas. This work demonstrates that the PID issue can be effectively addressed by using this current interruption technique. An important benefit of this approach is that this interruption technique can be applied after manufacturing the modules and after installing the modules in the field as well.

Real-time design with peer tasks

NASA Technical Reports Server (NTRS)

Goforth, Andre; Howes, Norman R.; Wood, Jonathan D.; Barnes, Michael J.

1995-01-01

We introduce a real-time design methodology for large scale, distributed, parallel architecture, real-time systems (LDPARTS), as an alternative to those methods using rate or dead-line monotonic analysis. In our method the fundamental units of prioritization, work items, are domain specific objects with timing requirements (deadlines) found in user's specification. A work item consists of a collection of tasks of equal priority. Current scheduling theories are applied with artifact deadlines introduced by the designer whereas our method schedules work items to meet user's specification deadlines (sometimes called end-to-end deadlines). Our method supports these scheduling properties. Work item scheduling is based on domain specific importance instead of task level urgency and still meets as many user specification deadlines as can be met by scheduling tasks with respect to urgency. Second, the minimum (closest) on-line deadline that can be guaranteed for a work item of highest importance, scheduled at run time, is approximately the inverse of the throughput, measured in work items per second. Third, throughput is not degraded during overload and instead of resorting to task shedding during overload, the designer can specify which work items to shed. We prove these properties in a mathematical model.

40 CFR 63.9635 - How do I demonstrate continuous compliance with the work practice standards that apply to me?

Code of Federal Regulations, 2010 CFR

2010-07-01

... compliance with the work practice standards that apply to me? 63.9635 Section 63.9635 Protection of... demonstrate continuous compliance with the work practice standards that apply to me? (a) You must demonstrate continuous compliance with the work practice standard requirements in § 63.9591 by operating in accordance...

'I think positivity breeds positivity': a qualitative exploration of the role of family members in supporting those with chronic musculoskeletal pain to stay at work.

PubMed

McCluskey, Serena; de Vries, Haitze; Reneman, Michiel; Brooks, Joanna; Brouwer, Sandra

2015-07-22

It is proposed that family members are important sources of support in helping those with chronic musculoskeletal pain to remain at work, but the phenomenon remains largely unexplored. The aim of this study was to examine the extent and nature of support provided by family members in this respect. Qualitative data were collected from workers and their 'significant others' (spouses/partners/close family members) in two un-related studies focused on working with pain; one conducted in the United Kingdom (n = 10 dyads) and one in the Netherlands (n = 21 dyads). Thematic analysis techniques were applied to both sets of data independently, and findings were then assimilated to establish common themes. Findings were broadly similar in both studies. Workers acknowledged significant other support in helping them to manage their pain and remain at work, and their descriptions of the type of support provided and required were echoed by their significant others. Three common themes were identified - 'connectivity', 'activity' and 'positivity'. Worker and significant other responses were largely congruent, but significant others provided more in-depth information on the nature of their support, their concerns and the impact on their relationship. This research presents novel insights about the specific contribution made by significant others in helping their relatives with chronic musculoskeletal pain to stay at work. These findings add to the under-represented 'social' dimension of the biopsychosocial model currently applied to our understanding and treatment of pain, and point to harnessing support from significant others as a potentially effective management strategy.

Softened Mechanical Properties of Graphene Induced by Electric Field.

PubMed

Huang, Peng; Guo, Dan; Xie, Guoxin; Li, Jian

2017-10-11

The understanding on the mechanical properties of graphene under the applications of physical fields is highly relevant to the reliability and lifetime of graphene-based nanodevices. In this work, we demonstrate that the application of electric field could soften the mechanical properties of graphene dramatically on the basis of the conductive AFM nanoindentation method. It has been found that the Young's modulus and fracture strength of graphene nanosheets suspended on the holes almost stay the same initially and then exhibit a sharp drop when the normalized electric field strength increases to be 0.18 ± 0.03 V/nm. The threshold voltage of graphene nanosheets before the onset of fracture under the fixed applied load increases with the thickness. Supported graphene nanosheets can sustain larger electric field under the same applied load than the suspended ones. The excessively regional Joule heating caused by the high electric current under the applied load is responsible for the electromechanical failure of graphene. These findings can provide a beneficial guideline for the electromechanical applications of graphene-based nanodevices.

Rigor Mortis: Statistical thoroughness in reporting and the making of truth.

PubMed

Tal, Aner

2016-02-01

Should a uniform checklist be adopted for methodological and statistical reporting? The current article discusses this notion, with particular attention to the use of old versus new statistics, and a consideration of the arguments brought up by Von Roten. The article argues that an overly exhaustive checklist that is uniformly applied to all submitted papers may be unsuitable for multidisciplinary work, and would further result in undue clutter and potentially distract reviewers from pertinent considerations in their evaluation of research articles. © The Author(s) 2015.

Rotational Alignment Altered by Source Position Correlations

NASA Technical Reports Server (NTRS)

Jacobs, Chris S.; Heflin, M. B.; Lanyi, G. E.; Sovers, O. J.; Steppe, J. A.

2010-01-01

In the construction of modern Celestial Reference Frames (CRFs) the overall rotational alignment is only weakly constrained by the data. Therefore, common practice has been to apply a 3-dimensional No-Net-Rotation (NNR) constraint in order to align an under-construction frame to the ICRF. We present evidence that correlations amongst source position parameters must be accounted for in order to properly align a CRF at the 5-10 (mu)as level of uncertainty found in current work. Failure to do so creates errors at the 10-40 (mu)as level.

Recycling of car tires by means of Waterjet technologies

NASA Astrophysics Data System (ADS)

Holka, Henryk; Jarzyna, Tomasz

2017-03-01

An increasing number of used car tires poses a threat to the environment. Therefore they need to be recycled. In this work a decomposition method that involves applying a stream of water at very high pressure (to 600MPa) is presented. This method is based on the authors' own patent from 2010 and the results have been provided from two year-long tests and calculations This study includes many diagrams, images and calculations that have been used to develop the discussed method which is competitive for currently used ones.

The built-in environment: the role of personality and physical activity.

PubMed

Rhodes, Ryan E

2006-04-01

Personality trait psychology has seen a reemergence in recent years, and researchers are beginning to apply personality models to understand health behavior habits. This review features recent research on personality correlates of physical activity (PA) and the integration of personality with PA-related social cognition. The current definition and status of general personality work is introduced followed by a review and discussion of the evidence for personality and PA relations. The review concludes with recommendations for personality-matched PA marketing and experimental and longitudinal designs.

A crunch on thermocompression flip chip bonding

NASA Astrophysics Data System (ADS)

Suppiah, Sarveshvaran; Ong, Nestor Rubio; Sauli, Zaliman; Sarukunaselan, Karunavani; Alcain, Jesselyn Barro; Mahmed, Norsuria; Retnasamy, Vithyacharan

2017-09-01

This study discussed the evolution and important findings, critical technical challenges, solutions and bonding equipment of flip chip thermo compression bonding (TCB). The bonding force, temperature and time were the key bonding parameters that need to be tweaked based on the researches done by others. TCB technology worked well with both pre-applied underfill and flux (still under development). Lower throughput coupled with higher processing costs was example of challenges in the TCB technology. The paper is concluded with a brief description of the current equipment used in thermo compression process.

Research on large equipment maintenance system in life cycle

NASA Astrophysics Data System (ADS)

Xu, Xiaowei; Wang, Hongxia; Liu, Zhenxing; Zhang, Nan

2017-06-01

In order to change the current disadvantages of traditional large equipment maintenance concept, this article plans to apply the technical method of prognostics and health management to optimize equipment maintenance strategy and develop large equipment maintenance system. Combined with the maintenance procedures of various phases in life cycle, it concluded the formulation methods of maintenance program and implement plans of maintenance work. In the meantime, it takes account into the example of the dredger power system of the Waterway Bureau to establish the auxiliary platform of ship maintenance system in life cycle.

Using the Personal Health Train for Automated and Privacy-Preserving Analytics on Vertically Partitioned Data.

PubMed

van Soest, Johan; Sun, Chang; Mussmann, Ole; Puts, Marco; van den Berg, Bob; Malic, Alexander; van Oppen, Claudia; Towend, David; Dekker, Andre; Dumontier, Michel

2018-01-01

Conventional data mining algorithms are unable to satisfy the current requirements on analyzing big data in some fields such as medicine, policy making, judicial, and tax records. However, applying diverse datasets from different institutes (both healthcare and non-healthcare related) can enrich information and insights. So far, analyzing this data in an automated, privacy-preserving manner does not exist to our knowledge. In this work, we propose an infrastructure, and proof-of-concept for privacy-preserving analytics on vertically partitioned data.

Optical diagnostics of the arc plasma using fast intensified CCD-spectrograph system

NASA Astrophysics Data System (ADS)

Pavelescu, Gabriela; Guillot, Stephane; Braic, Mariana T.; Hong, Dunpin; Pavelescu, D.; Fleurier, Claude; Braic, Viorel; Gherendi, F.; Dumitrescu, G.; Anghelita, P.; Bauchire, J. M.

2004-10-01

Spectroscopic diagnostics, using intensified high speed CCD camera, was applied to study the arc dynamics in low voltage circuit breakers, in vacuum and in air. Time-resolved emission spectroscopy of the vacuum arc plasma, generated during electrode separation, provided information about the interruption process. The investigations were focused on the partial unsuccessful interruption around current zero. Absorption spectroscopy, in a peculiar setup, was used in order to determine the metallic atoms densities in the interelectrode space of a low voltage circuit breaker, working in ambient air.

A Clinician-Centered Evaluation of the Usability of AHLTA and Automated Clinical Practice Guidelines at TAMC

DTIC Science & Technology

2011-03-31

evidence based medicine into clinical practice. It will decrease costs and enable multiple stakeholders to work in an open content/source environment to exchange clinical content, develop and test technology and explore processes in applied CDS. Design: Comparative study between the KMR infrastructure and capabilities developed as an open source, vendor agnostic solution for aCPG execution within AHLTA and the current DoD/MHS standard evaluating: H1: An open source, open standard KMR and Clinical Decision Support Engine can enable organizations to share domain

Individual to collaborative: guided group work and the role of teachers in junior secondary science classrooms

NASA Astrophysics Data System (ADS)

Fung, Dennis; Lui, Wai-mei

2016-05-01

This paper, through discussion of a teaching intervention at two secondary schools in Hong Kong, demonstrates the learning advancement brought about by group work and dissects the facilitating role of teachers in collaborative discussions. One-hundred and fifty-two Secondary Two (Grade 8) students were divided into three pedagogical groups, namely 'whole-class teaching', 'self-directed group work' and 'teacher-supported group work' groups, and engaged in peer-review, team debate, group presentation and reflection tasks related to a junior secondary science topic (i.e. current electricity). Pre- and post-tests were performed to evaluate students' scientific conceptions, alongside collected written responses and audio-recorded discussions. The results indicate that students achieved greater cognitive growth when they engaged in cooperative learning activities, the interactive and multi-sided argumentative nature of which is considered to apply particularly well to science education and Vygotsky's zone of proximal development framework. Group work learning is also found to be most effective when teachers play a role in navigating students during the joint construction of conceptual knowledge.

Foundations of DC plasma sources

NASA Astrophysics Data System (ADS)

Tomas Gudmundsson, Jon; Hecimovic, Ante

2017-12-01

A typical dc discharge is configured with the negative cathode at one end and a positive anode at the other end, separated by a gas filled gap, placed inside a long glass cylinder. A few hundred volts between the cathode and anode is required to maintain the discharge. The type of discharge that is formed between the two electrodes depends upon the pressure of the working gas, the nature of the working gas, the applied voltage and the geometry of the discharge. We discuss the current-voltage characteristics of the discharge as well as the distinct structure that develops in the glow discharge region. The dc glow discharge appears in the discharge current range from μA to mA at 0.5-300 Pa pressure. We discuss the various phenomena observed in the dc glow discharge, including the cathode region, the positive column, and striations. The dc glow discharge is maintained by the emission of secondary electrons from the cathode target due to the bombardment of ions. For decades, the dc glow discharge has been used as a sputter source. Then it is often operated as an obstructed abnormal glow discharge and the required applied voltage is in the range 2-5 kV. Typically, the cathode target (the material to be deposited) is connected to a negative voltage supply (dc or rf) and the substrate holder faces the target. The relatively high operating pressure, in the range from 2 to 4 Pa, high applied voltages, and the necessity to have a conductive target limit the application of dc glow discharge as a sputter source. In order to lower the discharge voltage and expand the operation pressure range, the lifetime of the electrons in target vicinity is increased through applying magnetic field, by adding permanent magnets behind the cathode target. This arrangement is coined the magnetron sputtering discharge. The various configurations of the magnetron sputtering discharge and its applications are described. Furthermore, the use of dc discharges for chemical analysis, the Penning discharge and the hollow cathode discharges and some of its applications are briefly discussed.

Localised electrochemical impedance measurements of a polymer electrolyte fuel cell using a reference electrode array to give cathode-specific measurements and examine membrane hydration dynamics

NASA Astrophysics Data System (ADS)

Engebretsen, Erik; Hinds, Gareth; Meyer, Quentin; Mason, Tom; Brightman, Edward; Castanheira, Luis; Shearing, Paul R.; Brett, Daniel J. L.

2018-04-01

Advances in bespoke diagnostic techniques for polymer electrolyte fuel cells continue to provide unique insight into the internal operation of these devices and lead to improved performance and durability. Localised measurements of current density have proven to be extremely useful in designing better fuel cells and identifying optimal operating strategies, with electrochemical impedance spectroscopy (EIS) now routinely used to deconvolute the various losses in fuel cells. Combining the two techniques provides another dimension of understanding, but until now each localised EIS has been based on 2-electrode measurements, composed of both the anode and cathode responses. This work shows that a reference electrode array can be used to give individual electrode-specific EIS responses, in this case the cathode is focused on to demonstrate the approach. In addition, membrane hydration dynamics are studied under current load steps from open circuit voltage. A three-stage process is identified associated with an initial rapid reduction in membrane resistance after 10 s of applying a current step, followed by a slower ramp to approximately steady state, which was achieved after ∼250 s. These results support previously published work that has looked at membrane swelling dynamics and reveal that membrane hydration/membrane resistance is highly heterogeneous.

Effects of Exposure to Welding Fume on Lung Function: Results from the German WELDOX Study.

PubMed

Lehnert, M; Hoffmeyer, F; Gawrych, K; Lotz, A; Heinze, E; Berresheim, H; Merget, R; Harth, V; Van Gelder, R; Hahn, J-U; Hartwig, A; Weiß, T; Pesch, B; Brüning, T

2015-01-01

The association between exposure to welding fume and chronic obstructive pulmonary disease (COPD) has been insufficiently clarified. In this study we assessed the influence of exposure to welding fume on lung function parameters. We investigated forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC, and expiratory flow rates in 219 welders. We measured current exposure to respirable particles and estimated a worker's lifetime exposure considering welding techniques, working conditions and protective measures at current and former workplaces. Multiple regression models were applied to estimate the influence of exposure to welding fume, age, and smoking on lung function. We additionally investigated the duration of working as a welder and the predominant welding technique. The findings were that age- and smoking-adjusted lung function parameters showed no decline with increasing duration, current exposure level, and lifetime exposure to welding fume. However, 15% of the welders had FEV1/FVC below the lower limit of normal, but we could not substantiate the presence of an association with the measures of exposure. Adverse effects of cigarette smoking were confirmed. In conclusion, the study did not support the notion of a possible detrimental effect of exposure to welding fume on lung function in welders.

A vacuum sealed high emission current and transmission efficiency carbon nanotube triode

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

Di, Yunsong; Jiangsu Key Laboratory of Optoelectronic Technology, Nanjing Normal University, Nanjing 210023; Wang, Qilong

A vacuum sealed carbon nanotubes (CNTs) triode with a concave and spoke-shaped Mo grid is presented. Due to the high aperture ratio of the grid, the emission current could be modulated at a relatively high electric field. Totally 75 mA emission current has been obtained from the CNTs cathode with the average applied field by the grid shifting from 8 to 13 V/μm. Whilst with the electron transmission efficiency of the grid over 56%, a remarkable high modulated current electron beam over 42 mA has been collected by the anode. Also contributed by the high aperture ration of the grid,more » desorbed gas molecules could flow away from the emission area rapidly when the triode has been operated at a relative high emission current, and finally collected by a vacion pump. The working pressure has been maintained at ∼1 × 10{sup −7} Torr, seldom spark phenomena occurred. Nearly perfect I-V curve and corresponding Fowler-Nordheim (FN) plot confirmed the accuracy of the measured data, and the emission current was long term stable and reproducible. Thusly, this kind of triode would be used as a high-power electron source.« less

Charge Exchange Contribution to the Decay of the Ring Current, Measured by Energetic Neutral Atoms (ENAs)

NASA Technical Reports Server (NTRS)

Jorgensen, A. M.; Henderson, M. G.; Roelof, E. C.; Reeves, G. D.; Spence, H. E.

2001-01-01

In this paper we calculate the contribution of charge exchange to the decay of the ring current. Past works have suggested that charge exchange of ring current protons is primarily responsible for the decay of the ring current during the late recovery phase, but there is still much debate about the fast decay of the early recovery phase. We use energetic neutral atom (ENA) measurements from Polar to calculate the total ENA energy escape. To get the total ENA escape we apply a forward modeling technique, and to estimate the total ring current energy escape we use the Dessler-Parker-Sckopke relationship. We find that during the late recovery phase of the March 10, 1998 storm ENAs with energies greater than 17.5 keV can account for 75% of the estimated energy loss from the ring current. During the fast recovery the measured ENAs can only account for a small portion of the total energy loss. We also find that the lifetime of the trapped ions is significantly shorter during the fast recovery phase than during the late recovery phase, suggesting that different processes are operating during the two phases.

An error reduction algorithm to improve lidar turbulence estimates for wind energy

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

Newman, Jennifer F.; Clifton, Andrew

Remote-sensing devices such as lidars are currently being investigated as alternatives to cup anemometers on meteorological towers for the measurement of wind speed and direction. Although lidars can measure mean wind speeds at heights spanning an entire turbine rotor disk and can be easily moved from one location to another, they measure different values of turbulence than an instrument on a tower. Current methods for improving lidar turbulence estimates include the use of analytical turbulence models and expensive scanning lidars. While these methods provide accurate results in a research setting, they cannot be easily applied to smaller, vertically profiling lidarsmore » in locations where high-resolution sonic anemometer data are not available. Thus, there is clearly a need for a turbulence error reduction model that is simpler and more easily applicable to lidars that are used in the wind energy industry. In this work, a new turbulence error reduction algorithm for lidars is described. The Lidar Turbulence Error Reduction Algorithm, L-TERRA, can be applied using only data from a stand-alone vertically profiling lidar and requires minimal training with meteorological tower data. The basis of L-TERRA is a series of physics-based corrections that are applied to the lidar data to mitigate errors from instrument noise, volume averaging, and variance contamination. These corrections are applied in conjunction with a trained machine-learning model to improve turbulence estimates from a vertically profiling WINDCUBE v2 lidar. The lessons learned from creating the L-TERRA model for a WINDCUBE v2 lidar can also be applied to other lidar devices. L-TERRA was tested on data from two sites in the Southern Plains region of the United States. The physics-based corrections in L-TERRA brought regression line slopes much closer to 1 at both sites and significantly reduced the sensitivity of lidar turbulence errors to atmospheric stability. The accuracy of machine-learning methods in L-TERRA was highly dependent on the input variables and training dataset used, suggesting that machine learning may not be the best technique for reducing lidar turbulence intensity (TI) error. Future work will include the use of a lidar simulator to better understand how different factors affect lidar turbulence error and to determine how these errors can be reduced using information from a stand-alone lidar.« less

An error reduction algorithm to improve lidar turbulence estimates for wind energy

DOE PAGES

Newman, Jennifer F.; Clifton, Andrew

2017-02-10

Remote-sensing devices such as lidars are currently being investigated as alternatives to cup anemometers on meteorological towers for the measurement of wind speed and direction. Although lidars can measure mean wind speeds at heights spanning an entire turbine rotor disk and can be easily moved from one location to another, they measure different values of turbulence than an instrument on a tower. Current methods for improving lidar turbulence estimates include the use of analytical turbulence models and expensive scanning lidars. While these methods provide accurate results in a research setting, they cannot be easily applied to smaller, vertically profiling lidarsmore » in locations where high-resolution sonic anemometer data are not available. Thus, there is clearly a need for a turbulence error reduction model that is simpler and more easily applicable to lidars that are used in the wind energy industry. In this work, a new turbulence error reduction algorithm for lidars is described. The Lidar Turbulence Error Reduction Algorithm, L-TERRA, can be applied using only data from a stand-alone vertically profiling lidar and requires minimal training with meteorological tower data. The basis of L-TERRA is a series of physics-based corrections that are applied to the lidar data to mitigate errors from instrument noise, volume averaging, and variance contamination. These corrections are applied in conjunction with a trained machine-learning model to improve turbulence estimates from a vertically profiling WINDCUBE v2 lidar. The lessons learned from creating the L-TERRA model for a WINDCUBE v2 lidar can also be applied to other lidar devices. L-TERRA was tested on data from two sites in the Southern Plains region of the United States. The physics-based corrections in L-TERRA brought regression line slopes much closer to 1 at both sites and significantly reduced the sensitivity of lidar turbulence errors to atmospheric stability. The accuracy of machine-learning methods in L-TERRA was highly dependent on the input variables and training dataset used, suggesting that machine learning may not be the best technique for reducing lidar turbulence intensity (TI) error. Future work will include the use of a lidar simulator to better understand how different factors affect lidar turbulence error and to determine how these errors can be reduced using information from a stand-alone lidar.« less

Simulation of leakage current measurement on medical devices using helmholtz coil configuration with different current flow

NASA Astrophysics Data System (ADS)

Sutanto, E.; Chandra, F.; Dinata, R.

2017-05-01

Leakage current measurement which can follow IEC standard for medical device is one of many challenges to be answered. The IEC 60601-1 has defined that the limit for a leakage current for Medical Device can be as low as 10 µA and as high as 500 µA, depending on which type of contact (applied part) connected to the patient. Most people are using ELCB (Earth-leakage circuit breaker) for safety purpose as this is the most common and available safety device in market. One type of ELCB devices is RCD (Residual Current Device) and this RCD type can measure the leakage current directly. This work will show the possibility on how Helmholtz Coil Configuration can be made to be like the RCD. The possibility is explored by comparing the magnetic field formula from each device, then it proceeds with a simulation using software EJS (Easy Java Simulation). The simulation will make sure the concept of magnetic field current cancellation follows the RCD concept. Finally, the possibility of increasing the measurement’s sensitivity is also analyzed. The sensitivity is needed to see the possibility on reaching the minimum leakage current limit defined by IEC, 0.01mA.

Application of Weighted Gene Co-expression Network Analysis for Data from Paired Design.

PubMed

Li, Jianqiang; Zhou, Doudou; Qiu, Weiliang; Shi, Yuliang; Yang, Ji-Jiang; Chen, Shi; Wang, Qing; Pan, Hui

2018-01-12

Investigating how genes jointly affect complex human diseases is important, yet challenging. The network approach (e.g., weighted gene co-expression network analysis (WGCNA)) is a powerful tool. However, genomic data usually contain substantial batch effects, which could mask true genomic signals. Paired design is a powerful tool that can reduce batch effects. However, it is currently unclear how to appropriately apply WGCNA to genomic data from paired design. In this paper, we modified the current WGCNA pipeline to analyse high-throughput genomic data from paired design. We illustrated the modified WGCNA pipeline by analysing the miRNA dataset provided by Shiah et al. (2014), which contains forty oral squamous cell carcinoma (OSCC) specimens and their matched non-tumourous epithelial counterparts. OSCC is the sixth most common cancer worldwide. The modified WGCNA pipeline identified two sets of novel miRNAs associated with OSCC, in addition to the existing miRNAs reported by Shiah et al. (2014). Thus, this work will be of great interest to readers of various scientific disciplines, in particular, genetic and genomic scientists as well as medical scientists working on cancer.

Applying a laser-induced incandescence (LII) diagnostic to monitor nanoparticle synthesis in an atmospheric plasma, in situ

NASA Astrophysics Data System (ADS)

Yatom, Shurik; Mitrani, James; Yeh, Yao-Wen; Shneider, Mikhail; Stratton, Brentley; Raitses, Yevgeny

2016-09-01

A DC arc discharge with a consumed graphite anode is commonly used for synthesis of carbon nanoparticles, including carbon nanotubes (CNTs) and graphene flakes. The graphite electrode is physically vaporized by high currents (20-60 A) in a buffer gas at 100-600 torr, leading to nanoparticle synthesis in a low temperature (>1 eV), plasma. Utilizing arc plasma synthesis technique has resulted in the synthesis of higher quality nanomaterials. However, the formation of nanoparticles in arc discharge plasmas is poorly understood. A particularly interesting question is where in the arc the nanoparticles nucleate and grow. In our current work we show the results of studying the formation of carbon nanotubes in an arc discharge, in situ, using laser-induced incandescence (LII). The results of LII are discussed in combination with ex situ measurements of the synthesized nanoparticles and modeling, to provide an insight into the physics behind nanoparticle synthesis in plasma. This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.

a High-Level Technique for Estimation and Optimization of Leakage Power for Full Adder

NASA Astrophysics Data System (ADS)

Shrivas, Jayram; Akashe, Shyam; Tiwari, Nitesh

2013-06-01

Optimization of power is a very important issue in low-voltage and low-power application. In this paper, we have proposed power gating technique to reduce leakage current and leakage power of one-bit full adder. In this power gating technique, we use two sleep transistors i.e., PMOS and NMOS. PMOS sleep transistor is inserted between power supply and pull up network. And NMOS sleep transistor is inserted between pull down network and ground terminal. These sleep transistors (PMOS and NMOS) are turned on when the circuit is working in active mode. And sleep transistors (PMOS and NMOS) are turned off when circuit is working in standby mode. We have simulated one-bit full adder and compared with the power gating technique using cadence virtuoso tool in 45 nm technology at 0.7 V at 27°C. By applying this technique, we have reduced leakage current from 2.935 pA to 1.905 pA and leakage power from 25.04μw to 9.233μw. By using this technique, we have reduced leakage power up to 63.12%.

Role of interference in the photosynthetic heat engine

NASA Astrophysics Data System (ADS)

Xu, Y. Y.; Liu, J.

2014-11-01

The observation of quantum coherence in pigment-protein complexes has attracted considerable interest. One such endeavor entails applying a quantum heat engine to model the photosynthetic reaction center, but the definition of work used is inconsistent with that defined in quantum thermodynamics. Using the definition of work proposed in Weimer et al. [Europhys. Lett. 83, 30008 (2008), 10.1209/0295-5075/83/30008], we investigated two proposals for enhancing the performance of the photosynthetic reaction center. In proposal A, which is similar to that in Dorfman et al. [Proc. Natl. Acad. Sci. USA 110, 2746 (2013), 10.1073/pnas.1212666110], we found that the power and current-voltage characteristic of the heat engine can be increased by Fano interference but the efficiency cannot. In proposal B, which is similar to that in Creatore et al. [Phys. Rev. Lett. 111, 253601 (2013), 10.1103/PhysRevLett.111.253601], we found that the mechanism of strengthening the performance of the heat engine is invalid; i.e., the dipole-dipole interaction between two electron donors could not increase the power, efficiency, or current-voltage characteristic.

Future Directions in Research on Racism-Related Stress and Racial-Ethnic Protective Factors for Black Youth.

PubMed

Jones, Shawn C T; Neblett, Enrique W

2017-01-01

Research on racism-related stress and racial-ethnic protective factors represents an important enterprise for optimizing the mental health of African American and other racial and ethnic minority youth. However, there has been a relative dearth of work on these factors in the clinical psychology research literature, and more work is needed in outlets such as these. To this end, the current article adopts a developmental psychopathology framework and uses recent empirical findings to outline our current understanding of racism-related stress and racial-ethnic protective factors (i.e., racial identity, racial socialization, Africentric worldview) for African American youth. We then provide nine recommendations-across basic, applied, and broader/cross-cutting research lines-that we prioritize as essential to advancing the future scientific investigation of this crucial research agenda. Within and across these recommendations, we issue a charge to researchers and clinicians alike, with the ultimate goal of alleviating the negative mental health impact that racism-related stress can have on the well-being and mental health of African American and other racial and ethnic minority youth.

Establishing national priorities for Australian occupational health and safety research.

PubMed

Smith, Derek R

2010-01-01

This study aimed to identify current and emerging issues relevant to Occupational Health & Safety (OHS) research in Australia, and to formulate strategic research directions and strategies for the future. A national research forum was held which included leading OHS academics, employer and employee representative groups, as well as executives from state (New South Wales) and national (Safe Work Australia) representative bodies. A modified Delphi technique was used for collecting data in three phases. When ranked according to group consensus, the top three priorities for future OHS research in Australia were identified as being psychosocial and soft tissue injury hazards, work/life issues, and the impact of multiple, long-term exposures. Strategies to enhance collaboration despite limited research funding included the need to focus on complementary skills, to make the best use of Safe Work Australia's role (particularly to link with strategic and operational plans), and to foster closer engagement with research communities. While certain research priorities appear to be similar to those of other countries, the current study did identify some unique characteristics within an Australian context. High quality investigations of these issues should now be considered, in conjunction with greater cooperation between governments, regulators, employers and employee groups for the more effective facilitation of applied OHS research in the coming years.

Measuring the impact of the advanced practitioner role: a practical approach.

PubMed

Neville, Lillian; Swift, Juliette

2012-04-01

This paper aims to illuminate difficulties in evaluating the advanced practitioner role and to offer a practical solution. The advanced practice role has been part of the workforce strategy in the Northwest of England since 2005. However capturing hard evidence of the impact of this role has been problematic. Current restrictions on resources require the provision of evidence of the value of roles and services. Critical analysis of literature has identified challenges in evaluating the advanced practice role. The case study design takes account of current policy initiatives, notably QIPP. There is no common approach to evaluating the role of advanced practitioners. The case study has the potential to be a useful tool to organise evidence of the impact of advanced practitioner roles. Advanced practitioners need to have appropriate knowledge and skills to provide evidence of the impact of their role. There is potential for this work to be applied to other roles across the NHS. Managers need to work in partnership with workforce planners and educationalists to support advanced practitioners to utilise their skills in methods of providing evidence that they do work of value. Clear strategic direction for advanced practitioners is advised as part of the workforce strategy. © 2012 Blackwell Publishing Ltd.

Enacting Firm, Fair and Friendly Practice: A Model for Strengths-Based Child Protection Relationships?

PubMed

Oliver, Carolyn; Charles, Grant

2016-06-01

Strengths-based solution-focused approaches are gaining ground in statutory child protection work, but few studies have asked front line practitioners how they navigate the complex worker-client relationships such approaches require. This paper describes one component of a mixed-methods study in a large Canadian statutory child protection agency in which 225 workers described how they applied the ideas of strengths-based practice in their daily work. Interviews with twenty-four practitioners were analysed using an interpretive description approach. Only four interviewees appeared to successfully enact a version of strengths-based practice that closely mirrored those described by key strengths-based child protection theorists and was fully congruent with their mandated role. They described navigating a shifting balance of collaboration and authority in worker-client relationships based on transparency, impartial judgement, attentiveness to the worker-client interaction and the value that clients were fellow human beings. Their accounts extend current conceptualisations of the worker-client relationship in strengths-based child protection work and are congruent with current understandings of effective mandated relationships. They provide what may be a useful model to help workers understand and navigate relationships in which they must reconcile their own authority and expertise with genuine support for the authority and expertise of their clients.

USGS River Ecosystem Modeling: Where Are We, How Did We Get Here, and Where Are We Going?

USGS Publications Warehouse

Hanson, Leanne; Schrock, Robin; Waddle, Terry; Duda, Jeffrey J.; Lellis, Bill

2009-01-01

This report developed as an outcome of the USGS River Ecosystem Modeling Work Group, convened on February 11, 2008 as a preconference session to the second USGS Modeling Conference in Orange Beach, Ala. Work Group participants gained an understanding of the types of models currently being applied to river ecosystem studies within the USGS, learned how model outputs are being used by a Federal land management agency, and developed recommendations for advancing the state of the art in river ecosystem modeling within the USGS. During a break-out session, participants restated many of the recommendations developed at the first USGS Modeling Conference in 2006 and in previous USGS needs assessments. All Work Group recommendations require organization and coordination across USGS disciplines and regions, and include (1) enhancing communications, (2) increasing efficiency through better use of current human and technologic resources, and (3) providing a national infrastructure for river ecosystem modeling resources, making it easier to integrate modeling efforts. By implementing these recommendations, the USGS will benefit from enhanced multi-disciplinary, integrated models for river ecosystems that provide valuable risk assessment and decision support tools for adaptive management of natural and managed riverine ecosystems. These tools generate key information that resource managers need and can use in making decisions about river ecosystem resources.

Configurations of power relations in the Brazilian emergency care system: analyzing a context of visible practices.

PubMed

Velloso, Isabela; Ceci, Christine; Alves, Marilia

2013-09-01

In this paper, we make explicit the changing configurations of power relations that currently characterize the Brazilian Emergency Care System (SAMU) team in Belo Horizonte, Brazil. The SAMU is a recent innovation in Brazilian healthcare service delivery. A qualitative case study methodology was used to explore SAMU's current organizational arrangements, specifically the power relations that have developed and that demonstrate internal team struggles over space and defense of particular occupational interests. The argument advanced in this paper is that these professionals are developing their work in conditions of exposure, that is, they are always being observed by someone, and that such observational exposure provides the conditions whereby everyday emergency care practices are enacted such that practice is shaped by, as well as shapes, particular, yet recognizable power relationships. Data were collected through the observation of the SAMU's work processes and through semi-structured interviews. Research materials were analyzed using discourse analysis. In the emergency care process of work, visibility is actually embedded in the disciplinary context and can thus be analyzed as a technique applied to produce disciplined individuals through the simple mechanisms elaborated by Foucault such as hierarchical surveillance, normalizing judgment, and the examination. © 2012 John Wiley & Sons Ltd.

Ovsiankina's Great Relief: How Supplemental Work during the Weekend May Contribute to Recovery in the Face of Unfinished Tasks.

PubMed

Weigelt, Oliver; Syrek, Christine J

2017-12-20

Unfinished tasks have been identified as a significant job stressor that impairs employee recovery after work. Classic experimental research by Ovsiankina has shown that people tend to resume yet unfinished tasks to satisfy their need for closure. We apply this notion to current working life and examine supplemental work after hours as a means to achieve peace of mind. We investigate how progress towards goal accomplishment through supplemental work may facilitate recovery in terms of psychological detachment, relaxation, autonomy, and mastery experiences. We conducted a week-level diary study among 83 employees over a period of 14 consecutive weeks, which yielded 575 observations in total and 214 matched observations of unfinished tasks, supplemental work during the weekend, progress, and recovery experiences. Unfinished tasks were assessed on Friday. Supplemental work and recovery experiences were assessed on Monday. Multilevel modeling analyses provide evidence that unfinished tasks at the end of the work week are associated with lower levels of detachment at the intraindividual level, tend to relate to lower relaxation, but are unrelated to autonomy and mastery. Progress towards finishing tasks during the weekend alleviates the detrimental effects of unfinished tasks on both kinds of recovery experiences. Supplemental work is negatively linked to detachment, but largely unrelated to the other recovery experiences.

Magnetic Field Sensors Based on Giant Magnetoresistance (GMR) Technology: Applications in Electrical Current Sensing

PubMed Central

Reig, Candid; Cubells-Beltran, María-Dolores; Muñoz, Diego Ramírez

2009-01-01

The 2007 Nobel Prize in Physics can be understood as a global recognition to the rapid development of the Giant Magnetoresistance (GMR), from both the physics and engineering points of view. Behind the utilization of GMR structures as read heads for massive storage magnetic hard disks, important applications as solid state magnetic sensors have emerged. Low cost, compatibility with standard CMOS technologies and high sensitivity are common advantages of these sensors. This way, they have been successfully applied in a lot different environments. In this work, we are trying to collect the Spanish contributions to the progress of the research related to the GMR based sensors covering, among other subjects, the applications, the sensor design, the modelling and the electronic interfaces, focusing on electrical current sensing applications. PMID:22408486

Low Frequency Flats for Imaging Cameras on the Hubble Space Telescope

NASA Astrophysics Data System (ADS)

Kossakowski, Diana; Avila, Roberto J.; Borncamp, David; Grogin, Norman A.

2017-01-01

We created a revamped Low Frequency Flat (L-Flat) algorithm for the Hubble Space Telescope (HST) and all of its imaging cameras. The current program that makes these calibration files does not compile on modern computer systems and it requires translation to Python. We took the opportunity to explore various methods that reduce the scatter of photometric observations using chi-squared optimizers along with Markov Chain Monte Carlo (MCMC). We created simulations to validate the algorithms and then worked with the UV photometry of the globular cluster NGC6681 to update the calibration files for the Advanced Camera for Surveys (ACS) and Solar Blind Channel (SBC). The new software was made for general usage and therefore can be applied to any of the current imaging cameras on HST.

[Artificial intelligence--the knowledge base applied to nephrology].

PubMed

Sancipriano, G P

2005-01-01

The idea that efficacy efficiency, and quality in medicine could not be reached without sorting the huge knowledge of medical and nursing science is very common. Engineers and computer scientists have developed medical software with great prospects for success, but currently these software applications are not so useful in clinical practice. The medical doctor and the trained nurse live the 'information age' in many daily activities, but the main benefits are not so widespread in working activities. Artificial intelligence and, particularly, export systems charm health staff because of their potential. The first part of this paper summarizes the characteristics of 'weak artificial intelligence' and of expert systems important in clinical practice. The second part discusses medical doctors' requirements and the current nephrologic knowledge bases available for artificial intelligence development.

A Numerical Investigation of the Effect of Thermoelectromagnetic Convection (TEMC) on the Bridgman Growth of Ge(1-x)Si(x)

NASA Technical Reports Server (NTRS)

Yesilyurt, Serhat; Vujisic, Ljubomir; Motakef, Shariar; Szofran, F. R.; Volz, Martin P.

1998-01-01

Thermoelectric currents at the growth interface of GeSi during Bridgman growth are shown to promote convection when a low intensity axial magnetic field is applied. TEMC, typically, is characterized by a meridional flow driven by the rotation of the fluid; meridional convection alters composition of the melt, and shape of the growth interface substantially. TEMC effect is more important in micro-gravity environment than the terrestrial one, and can be used to control convection during the growth of GeSi. In this work, coupled thermo-solutal flow equations (energy, scalar transport, momentum and mass) are solved in tandem with Maxwell's equations to compute the thermo-solutat flow field, electric currents, and the growth-interface shape.

Direct EIT reconstructions of complex admittivities on a chest-shaped domain in 2-D.

PubMed

Hamilton, Sarah J; Mueller, Jennifer L

2013-04-01

Electrical impedance tomography (EIT) is a medical imaging technique in which current is applied on electrodes on the surface of the body, the resulting voltage is measured, and an inverse problem is solved to recover the conductivity and/or permittivity in the interior. Images are then formed from the reconstructed conductivity and permittivity distributions. In the 2-D geometry, EIT is clinically useful for chest imaging. In this work, an implementation of a D-bar method for complex admittivities on a general 2-D domain is presented. In particular, reconstructions are computed on a chest-shaped domain for several realistic phantoms including a simulated pneumothorax, hyperinflation, and pleural effusion. The method demonstrates robustness in the presence of noise. Reconstructions from trigonometric and pairwise current injection patterns are included.

Electrochemical measurements on a droplet using gold microelectrodes

NASA Astrophysics Data System (ADS)

Jenabi, Amin; Souri, Asma; Rastkhadiv, Ali

2016-03-01

Facile methods of ion recognition are important for the fabrication of electronic tongue systems. In this work, we demonstrate performing pulsed conductometry on microliter electrolyte droplets dropped on gold microelectrodes vapor deposited on soda lime glass slides. A droplet is dropped between two microelectrodes when a voltage waveform from a preprogramed power supply is applied on them. The temporal variation of the electric current passing through the droplet is recorded, digitized and stored. The obtained data are compared with the database formed out of the previous experiences for the classification of the sample electrolytes. It is shown that the shape of the voltage waveform is the important parameter of the process. We devised a method for the optimization of the voltage waveform profile for obtaining the maximum of discriminating information from the recorded current variations.

The evolution and future of diversity at work.

PubMed

Roberson, Quinetta; Ryan, Ann Marie; Ragins, Belle Rose

2017-03-01

This article examines the evolution of diversity in the Journal of Applied Psychology. To begin, we explore foundations of the concept of diversity, including its appearance in both applied contexts and the scholarly literature. We then review the literature on diversity, including the development of its conceptualization and operationalizations over time, in the Journal and in the field of applied psychological science at large. We also examine the processes underlying the effects of diversity, and specific outcomes of diversity in organizations. To conclude, we offer a future research agenda that highlights diversity-related topics and issues important for advancing an understanding of diversity and moving the field forward, especially within the Journal. This work makes several contributions to research on diversity in organizations. First, we provide a lens for examining change in the study of diversity over time as well as a critical examination of the benefits and challenges associated with these changes. Second, we review the underlying mechanisms and key contextual influences on diversity effects in organizations. Third, our review examines the explanatory power of current diversity research and then uses this to develop a research agenda. By organizing the broad body of literature that exists on diversity, our article offers a sharp picture of what gaps in knowledge exist and where future research should focus. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

White blood cell counting analysis of blood smear images using various segmentation strategies

NASA Astrophysics Data System (ADS)

Safuan, Syadia Nabilah Mohd; Tomari, Razali; Zakaria, Wan Nurshazwani Wan; Othman, Nurmiza

2017-09-01

In white blood cell (WBC) diagnosis, the most crucial measurement parameter is the WBC counting. Such information is widely used to evaluate the effectiveness of cancer therapy and to diagnose several hidden infection within human body. The current practice of manual WBC counting is laborious and a very subjective assessment which leads to the invention of computer aided system (CAS) with rigorous image processing solution. In the CAS counting work, segmentation is the crucial step to ensure the accuracy of the counted cell. The optimal segmentation strategy that can work under various blood smeared image acquisition conditions is remain a great challenge. In this paper, a comparison between different segmentation methods based on color space analysis to get the best counting outcome is elaborated. Initially, color space correction is applied to the original blood smeared image to standardize the image color intensity level. Next, white blood cell segmentation is performed by using combination of several color analysis subtraction which are RGB, CMYK and HSV, and Otsu thresholding. Noises and unwanted regions that present after the segmentation process is eliminated by applying a combination of morphological and Connected Component Labelling (CCL) filter. Eventually, Circle Hough Transform (CHT) method is applied to the segmented image to estimate the number of WBC including the one under the clump region. From the experiment, it is found that G-S yields the best performance.

Process for applying control variables having fractal structures

DOEpatents

Bullock, IV, Jonathan S.; Lawson, Roger L.

1996-01-01

A process and apparatus for the application of a control variable having a fractal structure to a body or process. The process of the present invention comprises the steps of generating a control variable having a fractal structure and applying the control variable to a body or process reacting in accordance with the control variable. The process is applicable to electroforming where first, second and successive pulsed-currents are applied to cause the deposition of material onto a substrate, such that the first pulsed-current, the second pulsed-current, and successive pulsed currents form a fractal pulsed-current waveform.

Process for applying control variables having fractal structures

DOEpatents

Bullock, J.S. IV; Lawson, R.L.

1996-01-23

A process and apparatus are disclosed for the application of a control variable having a fractal structure to a body or process. The process of the present invention comprises the steps of generating a control variable having a fractal structure and applying the control variable to a body or process reacting in accordance with the control variable. The process is applicable to electroforming where first, second and successive pulsed-currents are applied to cause the deposition of material onto a substrate, such that the first pulsed-current, the second pulsed-current, and successive pulsed currents form a fractal pulsed-current waveform. 3 figs.

Electromechanical actuator with controllable motion, fast response rate, and high-frequency resonance based on graphene and polydiacetylene.

PubMed

Liang, Jiajie; Huang, Lu; Li, Na; Huang, Yi; Wu, Yingpeng; Fang, Shaoli; Oh, Jiyoung; Kozlov, Mikhail; Ma, Yanfeng; Li, Feifei; Baughman, Ray; Chen, Yongsheng

2012-05-22

Although widely investigated, novel electromechanical actuators with high overall actuation performance are still in urgent need for various practical and scientific applications, such as robots, prosthetic devices, sensor switches, and sonar projectors. In this work, combining the properties of unique environmental perturbations-actuated deformational isomerization of polydiacetylene (PDA) and the outstanding intrinsic features of graphene together for the first time, we design and fabricate an electromechanical bimorph actuator composed of a layer of PDA crystal and a layer of flexible graphene paper through a simple yet versatile solution approach. Under low applied direct current (dc), the graphene-PDA bimorph actuator with strong mechanical strength can generate large actuation motion (curvature is about 0.37 cm(-1) under a current density of 0.74 A/mm(2)) and produce high actuation stress (more than 160 MPa/g under an applied dc of only 0.29 A/mm(2)). When applying alternating current (ac), this actuator can display reversible swing behavior with long cycle life under high frequencies even up to 200 Hz; significantly, while the frequency and the value of applied ac and the state of the actuators reach an appropriate value, the graphene-PDA actuator can produce a strong resonance and the swing amplitude will jump to a peak value. Moreover, this stable graphene-PDA actuator also demonstrates rapidly and partially reversible electrochromatic phenomenon when applying an ac. Two mechanisms-the dominant one, electric-induced deformation, and a secondary one, thermal-induced expansion of PDA-are proposed to contribute to these interesting actuation performances of the graphene-PDA actuators. On the basis of these results, a mini-robot with controllable direction of motion based on the graphene-PDA actuator is designed to illustrate the great potential of our discoveries for practical use. Combining the unique actuation mechanism and many outstanding properties of graphene and PDA, this novel kind of graphene-PDA actuator exhibits compelling advantages to traditional electromechanical actuation technology and may provide a new avenue for actuation applications.

Conductance of Ion Channels - Theory vs. Experiment

NASA Technical Reports Server (NTRS)

Pohorille, Andrew; Wilson, Michael; Mijajlovic, Milan

2013-01-01

Transmembrane ion channels mediate a number of essential physiological processes in a cell ranging from regulating osmotic pressure to transmission of neural signals. Kinetics and selectivity of ion transport is of critical importance to a cell and, not surprisingly, it is a subject of numerous experimental and theoretical studies. In this presentation we will analyze in detail computer simulations of two simple channels from fungi - antiamoebin and trichotoxin. Each of these channels is made of an alpha-helical bundle of small, nongenomically synthesized peptides containing a number of rare amino acids and exhibits strong antimicrobial activity. We will focus on calculating ionic conductance defined as the ratio of ionic current through the channel to applied voltage. From molecular dynamics simulations, conductance can be calculated in at least two ways, each involving different approximations. Specifically, the current, given as the number of charges transferred through the channel per unit of time, can be obtained from the number of events in which ions cross the channel during the simulation. This method works well for large currents (high conductance values and/or applied voltages). If the number of crossing events is small, reliable estimates of current are difficult to achieve. Alternatively, conductance can be estimated assuming that ion transport can be well approximated as diffusion in the external potential given by the free energy profile. Then, the current can be calculated by solving the one-dimensional diffusion equation in this external potential and applied voltage (the generalized Nernst-Planck equation). To do so three ingredients are needed: the free energy profile, the position-dependent diffusion coefficient and the diffusive flux of ions into the channel. All these quantities can be obtained from molecular dynamics simulations. An important advantage of this method is that it can be used equally well to estimating large and small currents. In addition, once the free energy profile becomes available the full current-voltage dependence can be readily obtained. For both channels we carried out calculations using both approaches. We also tested the main assumptions underlying the diffusive model, such as uncorrelated nature of individual crossing events and Fickian diffusion. The accuracy and consistency of different methods will be discussed. Finally we will discuss how comparisons between calculated and measured ionic conductance and selectivity of transport can be used for determining structural models of the channels.

Task-Driven Tube Current Modulation and Regularization Design in Computed Tomography with Penalized-Likelihood Reconstruction.

PubMed

Gang, G J; Siewerdsen, J H; Stayman, J W

2016-02-01

This work applies task-driven optimization to design CT tube current modulation and directional regularization in penalized-likelihood (PL) reconstruction. The relative performance of modulation schemes commonly adopted for filtered-backprojection (FBP) reconstruction were also evaluated for PL in comparison. We adopt a task-driven imaging framework that utilizes a patient-specific anatomical model and information of the imaging task to optimize imaging performance in terms of detectability index ( d' ). This framework leverages a theoretical model based on implicit function theorem and Fourier approximations to predict local spatial resolution and noise characteristics of PL reconstruction as a function of the imaging parameters to be optimized. Tube current modulation was parameterized as a linear combination of Gaussian basis functions, and regularization was based on the design of (directional) pairwise penalty weights for the 8 in-plane neighboring voxels. Detectability was optimized using a covariance matrix adaptation evolutionary strategy algorithm. Task-driven designs were compared to conventional tube current modulation strategies for a Gaussian detection task in an abdomen phantom. The task-driven design yielded the best performance, improving d' by ~20% over an unmodulated acquisition. Contrary to FBP, PL reconstruction using automatic exposure control and modulation based on minimum variance (in FBP) performed worse than the unmodulated case, decreasing d' by 16% and 9%, respectively. This work shows that conventional tube current modulation schemes suitable for FBP can be suboptimal for PL reconstruction. Thus, the proposed task-driven optimization provides additional opportunities for improved imaging performance and dose reduction beyond that achievable with conventional acquisition and reconstruction.

Human Subjects Research and the Physics Classroom

NASA Astrophysics Data System (ADS)

Kubitskey, Beth W.; Thomsen, Marshall

2012-09-01

Physics Education Research is a form of social science research in that it uses human subjects. As physicists we need to be aware of the ethical and legal ramifications of performing this research, taking into account the fundamental differences between working with substances and working with people. For several decades, the federal government has regulated research involving human subjects. With current procedures, a proposal soliciting federal funds for a research project involving human subjects will be flagged by the applicants institution and checked for compliance with appropriate regulations. However, there is a large body of Physics Education Research that is not federally funded and thus may not be flagged. Nevertheless, there are ethical standards that apply to this research. This paper outlines the preliminary considerations for conducting such research.

Review of homogeneous charge compression ignition (HCCI) combustion engines and exhaust gas recirculation (EGR) effects on HCCI

NASA Astrophysics Data System (ADS)

Akma Tuan Kamaruddin, Tengku Nordayana; Wahid, Mazlan Abdul; Sies, Mohsin Mohd

2012-06-01

This paper describes the development in ICE which leads to the new advanced combustion mode named Homogeneous Charge Compression Ignition (HCCI). It explains regarding the theory and working principle of HCCI plus the difference of the process in gasoline and diesel fuelled engines. Many of pioneer and recent research works are discussed to get the current state of art about HCCI. It gives a better indication on the potential of this method in improving the fuel efficiency and emission produced by the vehicles' engine. Apart from the advantages, the challenges and future trend of this technology are also included. HCCI is applying few types of control strategy in producing the optimum performance. This paper looks into Exhaust Gas Recirculation (EGR) as one of the control strategies.

Galaxy formation through hierarchical clustering

NASA Astrophysics Data System (ADS)

White, Simon D. M.; Frenk, Carlos S.

1991-09-01

Analytic methods for studying the formation of galaxies by gas condensation within massive dark halos are presented. The present scheme applies to cosmogonies where structure grows through hierarchical clustering of a mixture of gas and dissipationless dark matter. The simplest models consistent with the current understanding of N-body work on dissipationless clustering, and that of numerical and analytic work on gas evolution and cooling are adopted. Standard models for the evolution of the stellar population are also employed, and new models for the way star formation heats and enriches the surrounding gas are constructed. Detailed results are presented for a cold dark matter universe with Omega = 1 and H(0) = 50 km/s/Mpc, but the present methods are applicable to other models. The present luminosity functions contain significantly more faint galaxies than are observed.

Evaluation of a LiF:Mg,Ti thermoluminescent ring dosimeter according to the IEC 62387:2012 Standards

NASA Astrophysics Data System (ADS)

Oliveira, Edyelle L. B.; de Barros, Vinícius S. M.; Asfora, Viviane K.; Khoury, Helen J.

2018-03-01

This work shows results of type testing of a ring radiation dosimeter system under IEC 62387:2012. The personal dosimeter investigated in this work consists of a commercial one element plastic ring which contains an LiF:Mg,Ti thermoluminescent pellet. By applying requirements for statistical fluctuations and linearity, a minimum measurable dose in Hp(0.07) was established. Energy and angular dependence aided in determining energy correction factors and fading requirements were used to select the most appropriate preheat scheme. Type testing of passive radiation monitors was performed in the Radiation Metrology Laboratory (LMRI-DEN/UFPE) of the Federal University of Pernambuco and is a major step in Brazil for the independent evaluation of these dosimeters, currently not available in the country.

Model-based reasoning in SSF ECLSS

NASA Technical Reports Server (NTRS)

Miller, J. K.; Williams, George P. W., Jr.

1992-01-01

The interacting processes and reconfigurable subsystems of the Space Station Freedom Environmental Control and Life Support System (ECLSS) present a tremendous technical challenge to Freedom's crew and ground support. ECLSS operation and problem analysis is time-consuming for crew members and difficult for current computerized control, monitoring, and diagnostic software. These challenges can be at least partially mitigated by the use of advanced techniques such as Model-Based Reasoning (MBR). This paper will provide an overview of MBR as it is being applied to Space Station Freedom ECLSS. It will report on work being done to produce intelligent systems to help design, control, monitor, and diagnose Freedom's ECLSS. Specifically, work on predictive monitoring, diagnosability, and diagnosis, with emphasis on the automated diagnosis of the regenerative water recovery and air revitalization processes will be discussed.

Effective Crack Detection in Railway Axles Using Vibration Signals and WPT Energy.

PubMed

Gómez, María Jesús; Corral, Eduardo; Castejón, Cristina; García-Prada, Juan Carlos

2018-05-17

Crack detection for railway axles is key to avoiding catastrophic accidents. Currently, non-destructive testing is used for that purpose. The present work applies vibration signal analysis to diagnose cracks in real railway axles installed on a real Y21 bogie working on a rig. Vibration signals were obtained from two wheelsets with cracks at the middle section of the axle with depths from 5.7 to 15 mm, at several conditions of load and speed. Vibration signals were processed by means of wavelet packet transform energy. Energies obtained were used to train an artificial neural network, with reliable diagnosis results. The success rate of 5.7 mm defects was 96.27%, and the reliability in detecting larger defects reached almost 100%, with a false alarm ratio lower than 5.5%.

Proximity and touch sensing using deformable ionic conductors (Conference Presentation)

NASA Astrophysics Data System (ADS)

Madden, John D. W.; Dobashi, Yuta; Sarwar, Mirza S.; Preston, Eden C.; Wyss, Justin K. M.; Woehling, Vincent; Nguyen, Tran-Minh-Giao; Plesse, Cedric; Vidal, Frédéric; Naficy, Sina; Spinks, Geoffrey M.

2017-04-01

There is increasing interest in creating bendable and stretchable electronic interfaces that can be worn or applied to virtually any surface. The electroactive polymer community is well placed to add value by incorporating sensors and actuators. Recent work has demonstrated transparent dielectric elastomer actuation as well as pressure, stretch or touch sensing. Here we present two alternative forms of sensing. The first uses ionically conductive and stretchable gels as electrodes in capacitive sensors that detect finger proximity. In this case the finger acts as a third electrode, reducing capacitance between the two gel electrodes as it approaches, which can be detected even during bending and stretching. Very light finger touch is readily detected even during deformation of the substrate. Lateral resolution is achieved by creating a sensor array. In the second approach, electrodes placed beneath a salt containing gel are able to detect ion currents generated by the deformation of the gel. In this approach, applied pressure results in ion currents that create a potential difference around the point of contact, leading to a voltage and current in the electrodes without any need for input electrical energy. The mechanism may be related to effects seen in ionomeric polymer metal composites (IPMCs), but with the response in plane rather than through the thickness of the film. Ultimately, these ionically conductive materials that can also be transparent and actuate, have the potential to be used in wearable devices.

New Gas Polarographic Hydrogen Sensor

NASA Technical Reports Server (NTRS)

Dominguez, Jesus A.; Barile, Ron

2004-01-01

Polarography is the measurement of the current that flows in solution as a function of an applied voltage. The actual form of the observed polarographic current depends upon the manner in which the voltage is applied and on the characteristics of the working electrode. The new gas polarographic H2 sensor shows a current level increment with concentration of the gaseous H2 similar to those relating to metal ions in liquid electrolytes in well-known polarography. This phenomenon is caused by the fact that the diffusion of the gaseous H2 through a gas diffusion hole built in the sensor is a rate-determining step in the gaseous-hydrogen sensing mechanism. The diffusion hole artificially limits the diffusion of the gaseous H2 toward the electrode located at the sensor cavity. This gas polarographic H2 sensor. is actually an electrochemical-pumping cell since the gaseous H2 is in fact pumped via the electrochemical driving force generated between the electrodes. Gaseous H2 enters the diffusion hole and reaches the first electrode (anode) located in the sensor cavity to be transformed into an H+ ions or protons; H+ ions pass through the electrolyte and reach the second electrode (cathode) to be reformed to gaseous H2. Gas polarographic 02 sensors are commercially available; a gas polarographic 02 sensor was used to prove the feasibility of building a new gas polarographic H2 sensor.

H2 Detection via Polarography

NASA Technical Reports Server (NTRS)

Dominquez, Jesus; Barile, Ron

2006-01-01

Polarography is the measurement of the current that flows in solution as a function of an applied voltage. The actual form of the observed polarographic current depends upon the manner in which the voltage is applied and on the characteristics of the working electrode. The new gas polarographic H2 sensor shows a current level increment with concentration of the gaseous H2 similar to those relating to metal ions in liquid electrolytes in well-known polarography. This phenomenon is caused by the fact that the diffusion of the gaseous H2 through a gas diffusion hole built in the sensor is a rate-determining step in the gaseous-hydrogen sensing mechanism. The diffusion hole artificially limits the diffusion of the gaseous H2 toward the electrode located at the sensor cavity. This gas polarographic H2 sensor is actually an electrochemical-pumping cell since the gaseous H2 is in fact pumped via the electrochemical driving force generated between the electrodes. Gaseous H2 enters the diffusion hole and reaches the first electrode (anode) located in the sensor cavity to be transformed into an H ions or protons; H ions pass through the electrolyte and reach the second electrode (cathode) to be reformed to gaseous H2. Gas polarographic O2 sensors are commercially available; a gas polarographic O2 sensor was used to prove the feasibility of building a new gas polarographic H2 sensor.

Leonardo da Vinci's foot: historical evidence of concept.

PubMed

Jastifer, James R; Toledo-Pereyra, Luis H

2012-10-01

Leonardo da Vinci (1452-1519), world-renowned Italian renaissance master, is known for his contributions to, and broad interests in science and art. The objective of this work is to demonstrate the extent of his science by applying the use of his concepts to current models of foot and ankle mechanics. The art and science of Leonardo Da Vinci were extensively analyzed by reviewing his original drawings and hand written notebooks as well as their English translation. Current medical journals including the topics of foot, ankle, and biomechanics were reviewed for modern evidence and application of his concepts. The library of Michigan State University and the electronic library of the Royal Library at Windsor Castle were extensively utilized. From the depths of Santa Maria Nuova Hospital in Florence and Santo Spirito Hospital in Rome, through his commentary and anatomical drawings of around 30 cadaver dissections he performed, Leonardo da Vinci expressed his concept of foot and ankle anatomy and mechanics. He laid forth concepts, which vary little from current theories including those of proportion, statics and joint stability, sesamoid biomechanics, and structural support of the foot. Leonardo da Vinci, by combining an interest in anatomy and a gift of genius and artistic ability laid a foundation of foot and ankle anatomy and mechanics that have been applied in modern clinical sciences. Leonardo in this way made important contributions to the practice of foot and ankle orthopedics.

Computational Interpretation of the Relation Between Electric Field and the Applied Current for Cathodic Protection Under Different Conductivity Environments

NASA Astrophysics Data System (ADS)

Kim, Yong-Sang; Ko, Sang-Jin; Lee, Sangkyu; Kim, Jung-Gu

2018-03-01

An interpretation of the relation between the electric field and the applied current for cathodic protection is investigated using a boundary element method simulation. Also, a conductivity-difference environment is set for the interface influence. The variation of the potential distribution is increased with the increase of the applied current and the conductivity difference due to the rejection of the current at the interface. In the case of the electric field, the tendencies of the increasing rate and the applied currents are similar, but the interface influence is different according to the directional component and field type (decrease of E z and increases of E x and E y) due to the directional difference between the electric fields. Also, the change tendencies of the electric fields versus the applied current plots are affected by the polarization curve tendency regarding the polarization type (activation and concentration polarizations in the oxygen-reduction and hydrogen-reduction reactions). This study shows that the underwater electric signature is determined by the polarization behavior of the materials.

Methods for Increasing the Material Resistance of the Mulching Tool Body Against its Deformation in Operation

NASA Astrophysics Data System (ADS)

Ľuptáčiková, Veronika; Ťavodová, Miroslava

2017-12-01

Instruments working in the cultivation of forest areas, for example under the guidance of high stress, are exposed to factors of heterogeneous environment which are soil, wood, various types of rocks, sometimes waste - metal, plastics or glass as well. The mulching tool body, the forging, deforms and worsens rapidly after loss of the WC toe-caps. Currently used tools have a non-heat-treated body material with a ferritic-pearlitic structure that has low abrasion resistance. One of the possibilities is to heat the tool body. Another possibility is to apply suitable welds to exposed areas. By correctly selecting the thermal mode of the tool material or by applying the welded material to the exposed body part of the tool, we can ensure that the tool's operating time is increased.

Monitoring the fracture behavior of metal matrix composites by combined NDE methodologies

NASA Astrophysics Data System (ADS)

Kordatos, E. Z.; Exarchos, D. A.; Mpalaskas, A. C.; Matikas, T. E.

2015-03-01

Current work deals with the non-destructive evaluation (NDE) of the fatigue behavior of metal matrix composites (MMCs) materials using Infrared Thermography (IRT) and Acoustic Emission (AE). AE monitoring was employed to record a wide spectrum of cracking events enabling the characterization of the severity of fracture in relation to the applied load. IR thermography as a non-destructive, real-time and non-contact technique, allows the detection of heat waves generated by the thermo-mechanical coupling during mechanical loading of the sample. In this study an IR methodology, based on the monitoring of the intrinsically dissipated energy, was applied for the determination of the fatigue limit of A359/SiCp composites. The thermographic monitoring is in agreement with the AE results enabling the reliable monitoring of the MMCs' fatigue behavior.

Logit-normal mixed model for Indian monsoon precipitation

NASA Astrophysics Data System (ADS)

Dietz, L. R.; Chatterjee, S.

2014-09-01

Describing the nature and variability of Indian monsoon precipitation is a topic of much debate in the current literature. We suggest the use of a generalized linear mixed model (GLMM), specifically, the logit-normal mixed model, to describe the underlying structure of this complex climatic event. Four GLMM algorithms are described and simulations are performed to vet these algorithms before applying them to the Indian precipitation data. The logit-normal model was applied to light, moderate, and extreme rainfall. Findings indicated that physical constructs were preserved by the models, and random effects were significant in many cases. We also found GLMM estimation methods were sensitive to tuning parameters and assumptions and therefore, recommend use of multiple methods in applications. This work provides a novel use of GLMM and promotes its addition to the gamut of tools for analysis in studying climate phenomena.

Space operations and the human factor

NASA Astrophysics Data System (ADS)

Brody, Adam R.

1993-10-01

Although space flight does not put the public at high risk, billions of dollars in hardware are destroyed and the space program halted when an accident occurs. Researchers are therefore applying human-factors techniques similar to those used in the aircraft industry, albeit at a greatly reduced level, to the spacecraft environment. The intent is to reduce the likelihood of catastrophic failure. To increase safety and efficiency, space human factors researchers have simulated spacecraft docking and extravehicular activity rescue. Engineers have also studied EVA suit mobility and aids. Other basic human-factors issues that have been applied to the space environment include antropometry, biomechanics, and ergonomics. Workstation design, workload, and task analysis currently receive much attention, as do habitability and other aspects of confined environments. Much work also focuses on individual payloads, as each presents its own complexities.

Analysis and determination the efficiency of the European health systems.

PubMed

Del Rocío Moreno-Enguix, María; Gómez-Gallego, Juan Cándido; Gómez Gallego, María

2018-01-01

The current economic crisis has increased the interest in analyzing the efficiency of health care systems, as their funding is a very important part of the budgets for different countries. In this work determines the efficiency in the health services in European countries applying data envelopment analysis. In addition, the combined application of data envelopment analysis methods and ACP can provide an evaluation of the efficiency with respect to differently oriented productive health systems in the different countries. The results show that models with a lower level of efficiency are those whose input is beds, followed by the models whose input is physicians. Finally, we apply the AD to select a few simple indicators that facilitate control of the level of operational efficiency of a health system. Copyright © 2017 John Wiley & Sons, Ltd.

System and Method for Obtaining Simultaneous Levitation and Rotation of a Ferromagnetic Object

NASA Astrophysics Data System (ADS)

Banerjee, Subrata; Sarkar, Mrinal Kanti; Ghosh, Arnab

2017-02-01

In this work a practical demonstration for simultaneous levitation and rotation for a ferromagnetic cylindrical object is presented. A hollow steel cylinder has been arranged to remain suspended stably under I-core electromagnet utilizing dc attraction type levitation principle and then arranged to rotate the levitated object around 1000 rpm speed based on eddy current based energy meter principle. Since the object is to be rotating during levitated condition the device will be frictionless, energy-efficient and robust. This technology may be applied to frictionless energy meter, wind turbine, machine tool applications, precision instruments and many other devices where easy energy-efficient stable rotation will be required. The cascade lead compensation control scheme has been applied for stabilization of unstable levitation system. The proposed device is successfully tested in the laboratory and experimental results have been produced.

Cyanobacteria Assessment Network (CyAN) - 2017 NASA ...

EPA Pesticide Factsheets

Presentation on the Cyanobacteria Assessment Network (CYAN) and how is supports the environmental management and public use of the U.S. lakes and estuaries by providing a capability of detecting and quantifying algal blooms and related water quality using satellite data records. To be presented to the NASA Science Mission Directorate Earth Science Division Applied Sciences Program at the NASA Water Resources PI Meeting. The meeting had over 65 attendees, including currently funded PIs, participants from Western States Water Council, UCAR, California Department of Water Resources, and Navajo Nation. Some highlights from the meeting included discussions around impact assessment, with a session moderated by VALUABLES as well as a water manager needs panel, lead by WWAO. Each PI presentation also included lessons learned about how to work in applied sciences, ensure partner engagement, and pave the path towards transition.

Supersonic reacting internal flowfields

NASA Astrophysics Data System (ADS)

Drummond, J. P.

The national program to develop a trans-atmospheric vehicle has kindled a renewed interest in the modeling of supersonic reacting flows. A supersonic combustion ramjet, or scramjet, has been proposed to provide the propulsion system for this vehicle. The development of computational techniques for modeling supersonic reacting flowfields, and the application of these techniques to an increasingly difficult set of combustion problems are studied. Since the scramjet problem has been largely responsible for motivating this computational work, a brief history is given of hypersonic vehicles and their propulsion systems. A discussion is also given of some early modeling efforts applied to high speed reacting flows. Current activities to develop accurate and efficient algorithms and improved physical models for modeling supersonic combustion is then discussed. Some new problems where computer codes based on these algorithms and models are being applied are described.