The processing of semantic relatedness in the brain: Evidence from associative and categorical false recognition effects following transcranial direct current stimulation of the left anterior temporal lobe.

PubMed

Díez, Emiliano; Gómez-Ariza, Carlos J; Díez-Álamo, Antonio M; Alonso, María A; Fernandez, Angel

2017-08-01

A dominant view of the role of the anterior temporal lobe (ATL) in semantic memory is that it serves as an integration hub, specialized in the processing of semantic relatedness by way of mechanisms that bind together information from different brain areas to form coherent amodal representations of concepts. Two recent experiments, using brain stimulation techniques along with the Deese-Roediger-McDermott (DRM) paradigm, have found a consistent false memory reduction effect following stimulation of the ATL, pointing to the importance of the ATL in semantic/conceptual processing. To more precisely identify the specific process being involved, we conducted a DRM experiment in which transcranial direct current stimulation (anode/cathode/sham) was applied over the participants' left ATL during the study of lists of words that were associatively related to their non-presented critical words (e.g., rotten, worm, red, tree, liqueur, unripe, cake, food, eden, peel, for the critical item apple) or categorically related (e.g., pear, banana, peach, orange, cantaloupe, watermelon, strawberry, cherry, kiwi, plum, for the same critical item apple). The results showed that correct recognition was not affected by stimulation. However, an interaction between stimulation condition and type of relation for false memories was found, explained by a significant false recognition reduction effect in the anodal condition for associative lists that was not observed for categorical lists. Results are congruent with previous findings and, more importantly, they help to clarify the nature and locus of false memory reduction effects, suggesting a differential role of the left ATL, and providing critical evidence for understanding the creation of semantic relatedness-based memory illusions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Reduction in Force. [and] Teacher Burnout.

ERIC Educational Resources Information Center

Dialogue: A Review of Labor-Management Cooperation in Public Education, 1984

1984-01-01

"Dialogue" is a review of labor-management cooperation in public education, whose goal is to provide teachers, administrators, school boards, and labor relations practitioners with analyses of critical issues, information about current projects, reviews of relevant literature, and a variety of special features. Each issue is generally devoted to a…

CRITICAL EVALUATION OF THE EFFECTIVENESS OF SEWAGE SLUDGE DISINFECTION AND VECTOR ATTRACTION REDUCTION PROCESSES

EPA Science Inventory

What is the current state of management practices for biosolids production and application, and how can those be made more effective? How effective are Class B disinfection and vector attraction processes, and public access and harvesting restrictions at reducing the public's exp...

Numerical study on AC loss reduction of stacked HTS tapes by optimal design of flux diverter

NASA Astrophysics Data System (ADS)

Liu, Guole; Zhang, Guomin; Jing, Liwei; Yu, Hui

2017-12-01

High temperature superconducting (HTS) coils are key parts of many AC applications, such as generators, superconducting magnetic energy storage and transformers. AC loss reduction in HTS coils is essential for the commercialization of these HTS devices. Magnetic material is generally used as the flux diverter in an effort to reduce the AC loss in HTS coils. To achieve the greatest reduction in the AC loss of the coils, the flux diverter should be made of a material with low loss and high saturated magnetic density, and the optimization of the geometric size and location of the flux diverter is required. In this paper, we chose Ni-alloy as the flux diverter, which can be processed into a specific shape and size. The influence of the shape and location of the flux diverter on the AC loss characteristics of stacked (RE)BCO tapes is investigated by use of a finite element method. Taking both the AC loss of the (RE)BCO coils and the ferromagnetic loss of the flux diverter into account, the optimal geometry of the flux diverter is obtained. It is found that when the applied current is at half the value of the critical current, the total loss of the HTS stack with the optimal flux diverter is only 18% of the original loss of the HTS stack without the flux diverter. Besides, the effect of the flux diverter on the critical current of the (RE)BCO stack is investigated.

Consensus on context-specific strategies for reducing the stigma of human immunodeficiency virus/acquired immunodeficiency syndrome in Zambézia Province, Mozambique.

PubMed

Mukolo, Abraham; Torres, Isabel; Bechtel, Ruth M; Sidat, Mohsin; Vergara, Alfredo E

2013-01-01

Stigma has been implicated in poor outcomes of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) care. Reducing stigma is important for HIV prevention and long-term treatment success. Although stigma reduction interventions are conducted in Mozambique, little is known about the current nature of stigma and the efficacy and effectiveness of stigma reduction initiatives. We describe action research to generate consensus on critical characteristics of HIV stigma and anti-stigma interventions in Zambézia Province, Mozambique. Qualitative data gathering methods, including in-depth key-informant interviews, community interviews and consensus group sessions, were utilized. Delphi methods and the strategic options development analysis technique were used to synthesize qualitative data. Key findings are that stigma enacted by the general public might be declining in tandem with the HIV/AIDS epidemic in Mozambique, but there is likely excessive residual fear of HIV disease and community attitudes that sustain high levels of perceived stigma. HIV-positive women accessing maternal and child health services appear to shoulder a disproportionate burden of stigma. Unintentional biases among healthcare providers are currently the critical frontier of stigmatization, but there are few interventions designed to address them. Culturally sensitive psychotherapies are needed to address psychological distress associated with internalized stigma and these interventions should complement current supports for voluntary counseling and testing. While advantageous for defining stakeholder priorities for stigma reduction efforts, confirmatory quantitative studies of these consensus positions are needed before the launch of specific interventions.

A critical analysis of user satisfaction surveys in addiction services: opioid maintenance treatment as a representative case study.

PubMed

Trujols, Joan; Iraurgi, Ioseba; Oviedo-Joekes, Eugenia; Guàrdia-Olmos, Joan

2014-01-01

Satisfaction with services represents a key component of the user's perspective, and user satisfaction surveys are the most commonly used approach to evaluate the aforementioned perspective. The aim of this discursive paper is to provide a critical overview of user satisfaction surveys in addiction treatment and harm reduction services, with a particular focus on opioid maintenance treatment as a representative case. We carried out a selective critical review and analysis of the literature on user satisfaction surveys in addiction treatment and harm reduction services. Most studies that have reported results of satisfaction surveys have found that the great majority of users (virtually all, in many cases) are highly satisfied with the services received. However, when these results are compared to the findings of studies that use different methodologies to explore the patient's perspective, the results are not as consistent as might be expected. It is not uncommon to find that "highly satisfied" patients report significant problems when mixed-methods studies are conducted. To understand this apparent contradiction, we explored two distinct (though not mutually exclusive) lines of reasoning, one of which concerns conceptual aspects and the other, methodological questions. User satisfaction surveys, as currently designed and carried out in addiction treatment and harm reduction services, do not significantly help to improve service quality. Therefore, most of the enthusiasm and naiveté with which satisfaction surveys are currently performed and interpreted - and rarely acted on in the case of nonoptimal results - should be avoided. A truly participatory approach to program evaluation is urgently needed to reshape and transform patient satisfaction surveys.

Study on emission characteristics and reduction strategy of nitrous oxide during wastewater treatment by different processes.

PubMed

Sun, Shichang; Bao, Zhiyuan; Sun, Dezhi

2015-03-01

Given the inexorable increase in global wastewater treatment, increasing amounts of nitrous oxide are expected to be emitted from wastewater treatment plants and released to the atmosphere. It has become imperative to study the emission and control of nitrous oxide in the various wastewater treatment processes currently in use. In the present investigation, the emission characteristics and the factors affecting the release of nitrous oxide were studied via full- and pilot-scale experiments in anoxic-oxic, sequencing batch reactor and oxidation ditch processes. We propose an optimal treatment process and relative strategy for nitrous oxide reduction. Our results show that both the bio-nitrifying and bio-denitrifying treatment units in wastewater treatment plants are the predominant sites for nitrous oxide production in each process, while the aerated treatment units are the critical sources for nitrous oxide emission. Compared with the emission of nitrous oxide from the anoxic-oxic (1.37% of N-influent) and sequencing batch reactor (2.69% of N-influent) processes, much less nitrous oxide (0.25% of N-influent) is emitted from the oxidation ditch process, which we determined as the optimal wastewater treatment process for nitrous oxide reduction, given the current technologies. Nitrous oxide emissions differed with various operating parameters. Controlling the dissolved oxygen concentration at a proper level during nitrification and denitrification and enhancing the utilization rate of organic carbon in the influent for denitrification are the two critical methods for nitrous oxide reduction in the various processes considered.

The U.S. Department of Agriculture Automated Multiple-Pass Method accurately assesses sodium intakes

USDA-ARS?s Scientific Manuscript database

Accurate and practical methods to monitor sodium intake of the U.S. population are critical given current sodium reduction strategies. While the gold standard for estimating sodium intake is the 24 hour urine collection, few studies have used this biomarker to evaluate the accuracy of a dietary ins...

Particle and flow field holography: A critical survey

NASA Technical Reports Server (NTRS)

Trolinger, James D.

1987-01-01

A brief background is provided for the fields of particle and flow visualization holography. A summary of methods currently in use is given, followed by a discussion of more recent and unique applications. The problem of data reduction is discussed. A state of the art summary is then provided with a prognosis of the future of the field. Particle and flow visualization holography are characterized as powerful tools currently in wide use and with significant untapped potential.

Preparation, patterning, and properties of thin YBa2Cu3O(7-delta) films

NASA Astrophysics Data System (ADS)

de Vries, J. W. C.; Dam, B.; Heijman, M. G. J.; Stollman, G. M.; Gijs, M. A. M.

1988-05-01

High T(c) superconducting thin films were prepared on (100) SrTiO3 substrates by dc triode sputtering and subsequent annealing. In these films Hall-bar structures having a width down to 5 microns were patterned using a reactive ion-etching technique. Superconductivity above 77 K was observed. When compared with the original film there is only a small reduction in T(c). The critical current density determined by electrical measurements is substantially reduced. On the other hand, the critical current density in the bulk of the grains as measured by the torque on a film is not reduced by the patterning process. It is suggested that superconductor-normal metal-superconductor junctions between the grains account for this difference.

Reduction of low frequency ac losses in coaxial cables of type II superconductors by a steady bias current

NASA Astrophysics Data System (ADS)

LeBlanc, M. A. R.; Cameron, Daniel S. M.; LeBlanc, David; Meng, Jinglei

1996-01-01

Hysteresis losses, Wac, in the core of a monolithic coaxial cable carrying an alternating current of fixed amplitude Iac are predicted to trace a valley as a steady bias current Ibias is superimposed on Iac, when (a) the critical current density jc diminishes with increasing magnetic field H, and/or (b) a Meissner current IM or a surface barrier current ISB opposing flux entry play a role. The predicted Ibias,min where the valley minimum occurs and the value of Wac at the minima are displayed for various IM≥0 and ISB≥0 when jc=α (Bean) and jc=α/H (Kim approximation).

Estimating 'lost heart beats' rather than reductions in heart rate during the intubation of critically-ill children.

PubMed

Jones, Peter; Ovenden, Nick; Dauger, Stéphane; Peters, Mark J

2014-01-01

Reductions in heart rate occur frequently in children during critical care intubation and are currently considered the gold standard for haemodynamic instability. Our objective was to estimate loss of heart beats during intubation and compare this to reduction in heart rate alone whilst testing the impact of atropine pre-medication. Data were extracted from a prospective 2-year cohort study of intubation ECGs from critically ill children in PICU/Paediatric Transport. A three step algorithm was established to exclude variation in pre-intubation heart rate (using a 95%CI limit derived from pre-intubation heart rate variation of the children included), measure the heart rate over time and finally the estimate the numbers of lost beats. 333 intubations in children were eligible for inclusion of which 245 were available for analysis (74%). Intubations where the fall in heart rate was less than 50 bpm were accompanied almost exclusively by less than 25 lost beats (n = 175, median 0 [0-1]). When there was a reduction of >50 bpm there was a poor correlation with numbers of lost beats (n = 70, median 42 [15-83]). During intubation the median number of lost beats was 8 [1]-[32] when atropine was not used compared to 0 [0-0] when atropine was used (p<0.001). A reduction in heart rate during intubation of <50 bpm reliably predicted a minimal loss of beats. When the reduction in heart rate was >50 bpm the heart rate was poorly predictive of lost beats. A study looking at the relationship between lost beats and cardiac output needs to be performed. Atropine reduces both fall in heart rate and loss of beats. Similar area-under-the-curve methodology may be useful for estimating risk when biological parameters deviate outside normal range.

Consensus on context-specific strategies for reducing the stigma of human immunodeficiency virus/acquired immunodeficiency syndrome in Zambézia Province, Mozambique

PubMed Central

Mukolo, Abraham; Torres, Isabel; Bechtel, Ruth M.; Sidat, Mohsin; Vergara, Alfredo E.

2014-01-01

Stigma has been implicated in poor outcomes of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) care. Reducing stigma is important for HIV prevention and long-term treatment success. Although stigma reduction interventions are conducted in Mozambique, little is known about the current nature of stigma and the efficacy and effectiveness of stigma reduction initiatives. We describe action research to generate consensus on critical characteristics of HIV stigma and anti-stigma interventions in Zambézia Province, Mozambique. Qualitative data gathering methods, including indepth key-informant interviews, community interviews and consensus group sessions, were utilized. Delphi methods and the strategic options development analysis technique were used to synthesize qualitative data. Key findings are that stigma enacted by the general public might be declining in tandem with the HIV/AIDS epidemic in Mozambique, but there is likely excessive residual fear of HIV disease and community attitudes that sustain high levels of perceived stigma. HIV-positive women accessing maternal and child health services appear to shoulder a disproportionate burden of stigma. Unintentional biases among healthcare providers are currently the critical frontier of stigmatization, but there are few interventions designed to address them. Culturally sensitive psychotherapies are needed to address psychological distress associated with internalized stigma and these interventions should complement current supports for voluntary counseling and testing. While advantageous for defining stakeholder priorities for stigma reduction efforts, confirmatory quantitative studies of these consensus positions are needed before the launch of specific interventions. PMID:24527744

Animal Research on Nicotine Reduction: Current Evidence and Research Gaps.

PubMed

Smith, Tracy T; Rupprecht, Laura E; Denlinger-Apte, Rachel L; Weeks, Jillian J; Panas, Rachel S; Donny, Eric C; Sved, Alan F

2017-09-01

A mandated reduction in the nicotine content of cigarettes may improve public health by reducing the prevalence of smoking. Animal self-administration research is an important complement to clinical research on nicotine reduction. It can fill research gaps that may be difficult to address with clinical research, guide clinical researchers about variables that are likely to be important in their own research, and provide policy makers with converging evidence between clinical and preclinical studies about the potential impact of a nicotine reduction policy. Convergence between clinical and preclinical research is important, given the ease with which clinical trial participants can access nonstudy tobacco products in the current marketplace. Herein, we review contributions of preclinical animal research, with a focus on rodent self-administration, to the science of nicotine reduction. Throughout this review, we highlight areas where clinical and preclinical research converge and areas where the two differ. Preclinical research has provided data on many important topics such as the threshold for nicotine reinforcement, the likelihood of compensation, moderators of the impact of nicotine reduction, the impact of environmental stimuli on nicotine reduction, the impact of nonnicotine cigarette smoke constituents on nicotine reduction, and the impact of nicotine reduction on vulnerable populations. Special attention is paid to current research gaps including the dramatic rise in alternative tobacco products, including electronic nicotine delivery systems (ie, e-cigarettes). The evidence reviewed here will be critical for policy makers as well as clinical researchers interested in nicotine reduction. This review will provide policy makers and clinical researchers interested in nicotine reduction with an overview of the preclinical animal research conducted on nicotine reduction and the regulatory implications of that research. The review also highlights the utility of preclinical research for research questions related to nicotine reduction. © The Author 2017. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Introduction to Electrochemistry and the Use of Electrochemistry to Synthesize and Evaluate Catalysts for Water Oxidation and Reduction

ERIC Educational Resources Information Center

Hendel, Samuel J.; Young, Elizabeth R.

2016-01-01

Electrochemical analysis is an important skill to teach in chemistry curricula because it is a critical tool in current high-impact chemical research. Electrochemistry enables researchers to analyze a variety of systems extending from molecules to materials that encompass research themes ranging from clean energy to substrate activation in…

Influence of water vapor on the formation of pinning centers in YBa2Cu3O y upon low-temperature annealing

NASA Astrophysics Data System (ADS)

Bobylev, I. B.; Gerasimov, E. G.; Zyuzeva, N. A.

2017-08-01

The influence of the double heat treatment ( T = 300 and 930°C) on the critical parameters of highly textured YBa2Cu3O6.96 and YBa2Cu3O6.8 ceramics has been investigated. It has been shown that, upon low-temperature annealing in humid air, planar stacking faults are formed in these ceramics. These defects are partly retained after reduction annealing (at T = 930°C) and are efficient pinning centers in magnetic fields applied parallel and perpendicular to the c axis. Due to the absorption of water, the oxygen content is increased in the ceramics, which is accompanied by an increase in the critical temperature of superconducting transition up to 94 K for YBa2Cu3O6.96 and up to 90 K for YBa2Cu3O6.8. Optimal conditions of the double annealing have been established, after which the critical-current density increased to j c ≥ 104 A/cm2 in an external magnetic field of up to 6 T. The low-temperature treatment in the neutral atmosphere saturated by water vapors deteriorates the current-carrying capacity of the highly textured ceramics, which is connected with the disappearance of texture due to the copper reduction and the precipitation of impurity phases.

A critical analysis of user satisfaction surveys in addiction services: opioid maintenance treatment as a representative case study

PubMed Central

Trujols, Joan; Iraurgi, Ioseba; Oviedo-Joekes, Eugenia; Guàrdia-Olmos, Joan

2014-01-01

Background Satisfaction with services represents a key component of the user’s perspective, and user satisfaction surveys are the most commonly used approach to evaluate the aforementioned perspective. The aim of this discursive paper is to provide a critical overview of user satisfaction surveys in addiction treatment and harm reduction services, with a particular focus on opioid maintenance treatment as a representative case. Methods We carried out a selective critical review and analysis of the literature on user satisfaction surveys in addiction treatment and harm reduction services. Results Most studies that have reported results of satisfaction surveys have found that the great majority of users (virtually all, in many cases) are highly satisfied with the services received. However, when these results are compared to the findings of studies that use different methodologies to explore the patient’s perspective, the results are not as consistent as might be expected. It is not uncommon to find that “highly satisfied” patients report significant problems when mixed-methods studies are conducted. To understand this apparent contradiction, we explored two distinct (though not mutually exclusive) lines of reasoning, one of which concerns conceptual aspects and the other, methodological questions. Conclusion User satisfaction surveys, as currently designed and carried out in addiction treatment and harm reduction services, do not significantly help to improve service quality. Therefore, most of the enthusiasm and naiveté with which satisfaction surveys are currently performed and interpreted – and rarely acted on in the case of nonoptimal results – should be avoided. A truly participatory approach to program evaluation is urgently needed to reshape and transform patient satisfaction surveys. PMID:24482571

Reduced impedance and superconductivity of SnAgCu solder alloy at high frequency

NASA Astrophysics Data System (ADS)

Yao, Wei; Basaran, Cemal

2012-10-01

Skin effect of lead-free solder joints is investigated over a wide frequency band. Contrary to common believe that `effective impedance of solder alloys increases with frequency', resistance tends to saturate when frequency reaches a critical value, 10 MHz for SAC solder alloys. Negative surface impedance growth rate is observed when employs square waveform AC current loading at high current density. Further increased frequency causes a dramatic reduction of effective resistance. At 11 MHz with current density of 106 A/cm2, effective resistance of solder alloy drops to near zero value.

Subsurface oxide plays a critical role in CO2 activation by Cu(111) surfaces to form chemisorbed CO2, the first step in reduction of CO2.

PubMed

Favaro, Marco; Xiao, Hai; Cheng, Tao; Goddard, William A; Yano, Junko; Crumlin, Ethan J

2017-06-27

A national priority is to convert CO 2 into high-value chemical products such as liquid fuels. Because current electrocatalysts are not adequate, we aim to discover new catalysts by obtaining a detailed understanding of the initial steps of CO 2 electroreduction on copper surfaces, the best current catalysts. Using ambient pressure X-ray photoelectron spectroscopy interpreted with quantum mechanical prediction of the structures and free energies, we show that the presence of a thin suboxide structure below the copper surface is essential to bind the CO 2 in the physisorbed configuration at 298 K, and we show that this suboxide is essential for converting to the chemisorbed CO 2 in the presence of water as the first step toward CO 2 reduction products such as formate and CO. This optimum suboxide leads to both neutral and charged Cu surface sites, providing fresh insights into how to design improved carbon dioxide reduction catalysts.

Subsurface oxide plays a critical role in CO2 activation by Cu(111) surfaces to form chemisorbed CO2, the first step in reduction of CO2

PubMed Central

Favaro, Marco; Yano, Junko; Crumlin, Ethan J.

2017-01-01

A national priority is to convert CO2 into high-value chemical products such as liquid fuels. Because current electrocatalysts are not adequate, we aim to discover new catalysts by obtaining a detailed understanding of the initial steps of CO2 electroreduction on copper surfaces, the best current catalysts. Using ambient pressure X-ray photoelectron spectroscopy interpreted with quantum mechanical prediction of the structures and free energies, we show that the presence of a thin suboxide structure below the copper surface is essential to bind the CO2 in the physisorbed configuration at 298 K, and we show that this suboxide is essential for converting to the chemisorbed CO2 in the presence of water as the first step toward CO2 reduction products such as formate and CO. This optimum suboxide leads to both neutral and charged Cu surface sites, providing fresh insights into how to design improved carbon dioxide reduction catalysts. PMID:28607092

Reductions in Experienced Control and Depression in Psychiatric Inpatients: A Test of the Learned Helplessness Model

ERIC Educational Resources Information Center

Dinning, W. David; Evans, Ronald G.

1978-01-01

In critically reviewing learned helplessness literature, P. H. Blaney (1977) has noted that most of the current support for this model rests on studies that induce or reduce helplessness in college student Ss. This research, employing a psychiatric population, addressed two issues Blaney suggested as in need of clarification: (1) the role of…

Direct Electric Current Treatment under Physiologic Saline Conditions Kills Staphylococcus epidermidis Biofilms via Electrolytic Generation of Hypochlorous Acid

PubMed Central

Sandvik, Elizabeth L.; McLeod, Bruce R.; Parker, Albert E.; Stewart, Philip S.

2013-01-01

The purpose of this study was to investigate the mechanism by which a direct electrical current reduced the viability of Staphylococcus epidermidis biofilms in conjunction with ciprofloxacin at physiologic saline conditions meant to approximate those in an infected artificial joint. Biofilms grown in CDC biofilm reactors were exposed to current for 24 hours in 1/10th strength tryptic soy broth containing 9 g/L total NaCl. Dose-dependent log reductions up to 6.7 log10 CFU/cm2 were observed with the application of direct current at all four levels (0.7 to 1.8 mA/cm2) both in the presence and absence of ciprofloxacin. There were no significant differences in log reductions for wells with ciprofloxacin compared to those without at the same current levels. When current exposures were repeated without biofilm or organics in the medium, significant generation of free chlorine was measured. Free chlorine doses equivalent to the 24 hour endpoint concentration for each current level were shown to mimic killing achieved by current application. Current exposure (1.8 mA/cm2) in medium lacking chloride and amended with sulfate, nitrate, or phosphate as alternative electrolytes produced diminished kills of 3, 2, and 0 log reduction, respectively. Direct current also killed Pseudomonas aeruginosa biofilms when NaCl was present. Together these results indicate that electrolysis reactions generating hypochlorous acid from chloride are likely a main contributor to the efficacy of direct current application. A physiologically relevant NaCl concentration is thus a critical parameter in experimental design if direct current is to be investigated for in vivo medical applications. PMID:23390518

Direct electric current treatment under physiologic saline conditions kills Staphylococcus epidermidis biofilms via electrolytic generation of hypochlorous acid.

PubMed

Sandvik, Elizabeth L; McLeod, Bruce R; Parker, Albert E; Stewart, Philip S

2013-01-01

The purpose of this study was to investigate the mechanism by which a direct electrical current reduced the viability of Staphylococcus epidermidis biofilms in conjunction with ciprofloxacin at physiologic saline conditions meant to approximate those in an infected artificial joint. Biofilms grown in CDC biofilm reactors were exposed to current for 24 hours in 1/10(th) strength tryptic soy broth containing 9 g/L total NaCl. Dose-dependent log reductions up to 6.7 log(10) CFU/cm(2) were observed with the application of direct current at all four levels (0.7 to 1.8 mA/cm(2)) both in the presence and absence of ciprofloxacin. There were no significant differences in log reductions for wells with ciprofloxacin compared to those without at the same current levels. When current exposures were repeated without biofilm or organics in the medium, significant generation of free chlorine was measured. Free chlorine doses equivalent to the 24 hour endpoint concentration for each current level were shown to mimic killing achieved by current application. Current exposure (1.8 mA/cm(2)) in medium lacking chloride and amended with sulfate, nitrate, or phosphate as alternative electrolytes produced diminished kills of 3, 2, and 0 log reduction, respectively. Direct current also killed Pseudomonas aeruginosa biofilms when NaCl was present. Together these results indicate that electrolysis reactions generating hypochlorous acid from chloride are likely a main contributor to the efficacy of direct current application. A physiologically relevant NaCl concentration is thus a critical parameter in experimental design if direct current is to be investigated for in vivo medical applications.

Minimization of Ohmic Losses for Domain Wall Motion in a Ferromagnetic Nanowire

NASA Astrophysics Data System (ADS)

Tretiakov, O. A.; Liu, Y.; Abanov, Ar.

2010-11-01

We study current-induced domain-wall motion in a narrow ferromagnetic wire. We propose a way to move domain walls with a resonant time-dependent current which dramatically decreases the Ohmic losses in the wire and allows driving of the domain wall with higher speed without burning the wire. For any domain-wall velocity we find the time dependence of the current needed to minimize the Ohmic losses. Below a critical domain-wall velocity specified by the parameters of the wire the minimal Ohmic losses are achieved by dc current. Furthermore, we identify the wire parameters for which the losses reduction from its dc value is the most dramatic.

Critical Low-Noise Technologies Being Developed for Engine Noise Reduction Systems Subproject

NASA Technical Reports Server (NTRS)

Grady, Joseph E.; Civinskas, Kestutis C.

2004-01-01

NASA's previous Advanced Subsonic Technology (AST) Noise Reduction Program delivered the initial technologies for meeting a 10-year goal of a 10-dB reduction in total aircraft system noise. Technology Readiness Levels achieved for the engine-noise-reduction technologies ranged from 4 (rig scale) to 6 (engine demonstration). The current Quiet Aircraft Technology (QAT) project is building on those AST accomplishments to achieve the additional noise reduction needed to meet the Aerospace Technology Enterprise's 10-year goal, again validated through a combination of laboratory rig and engine demonstration tests. In order to meet the Aerospace Technology Enterprise goal for future aircraft of a 50- reduction in the perceived noise level, reductions of 4 dB are needed in both fan and jet noise. The primary objectives of the Engine Noise Reduction Systems (ENRS) subproject are, therefore, to develop technologies to reduce both fan and jet noise by 4 dB, to demonstrate these technologies in engine tests, and to develop and experimentally validate Computational Aero Acoustics (CAA) computer codes that will improve our ability to predict engine noise.

Ecological and geographical analysis of the distribution of the mountain tapir (Tapirus pinchaque) in Ecuador: importance of protected areas in future scenarios of global warming.

PubMed

Ortega-Andrade, H Mauricio; Prieto-Torres, David A; Gómez-Lora, Ignacio; Lizcano, Diego J

2015-01-01

In Ecuador, Tapirus pinchaque is considered to be critically endangered. Although the species has been registered in several localities, its geographic distribution remains unclear, and the effects of climate change and current land uses on this species are largely unknown. We modeled the ecological niche of T. pinchaque using MaxEnt, in order to assess its potential adaptation to present and future climate change scenarios. We evaluated the effects of habitat loss due by current land use, the ecosystem availability and importance of Ecuadorian System of Protected Areas into the models. The model of environmental suitability estimated an extent of occurrence for species of 21,729 km2 in all of Ecuador, mainly occurring along the corridor of the eastern Ecuadorian Andes. A total of 10 Andean ecosystems encompassed ~98% of the area defined by the model, with herbaceous paramo, northeastern Andean montane evergreen forest and northeastern Andes upper montane evergreen forest being the most representative. When considering the effect of habitat loss, a significant reduction in model area (~17%) occurred, and the effect of climate change represented a net reduction up to 37.86%. However, the synergistic effect of both climate change and habitat loss, given current land use practices, could represent a greater risk in the short-term, leading to a net reduction of 19.90 to 44.65% in T. pinchaque's potential distribution. Even under such a scenarios, several Protected Areas harbor a portion (~36 to 48%) of the potential distribution defined by the models. However, the central and southern populations are highly threatened by habitat loss and climate change. Based on these results and due to the restricted home range of T. pinchaque, its preference for upland forests and paramos, and its small estimated population size in the Andes, we suggest to maintaining its current status as Critically Endangered in Ecuador.

Ecological and Geographical Analysis of the Distribution of the Mountain Tapir (Tapirus pinchaque) in Ecuador: Importance of Protected Areas in Future Scenarios of Global Warming

PubMed Central

Ortega-Andrade, H. Mauricio; Prieto-Torres, David A.; Gómez-Lora, Ignacio; Lizcano, Diego J.

2015-01-01

In Ecuador, Tapirus pinchaque is considered to be critically endangered. Although the species has been registered in several localities, its geographic distribution remains unclear, and the effects of climate change and current land uses on this species are largely unknown. We modeled the ecological niche of T. pinchaque using MaxEnt, in order to assess its potential adaptation to present and future climate change scenarios. We evaluated the effects of habitat loss due by current land use, the ecosystem availability and importance of Ecuadorian System of Protected Areas into the models. The model of environmental suitability estimated an extent of occurrence for species of 21,729 km2 in all of Ecuador, mainly occurring along the corridor of the eastern Ecuadorian Andes. A total of 10 Andean ecosystems encompassed ~98% of the area defined by the model, with herbaceous paramo, northeastern Andean montane evergreen forest and northeastern Andes upper montane evergreen forest being the most representative. When considering the effect of habitat loss, a significant reduction in model area (~17%) occurred, and the effect of climate change represented a net reduction up to 37.86%. However, the synergistic effect of both climate change and habitat loss, given current land use practices, could represent a greater risk in the short-term, leading to a net reduction of 19.90 to 44.65% in T. pinchaque’s potential distribution. Even under such a scenarios, several Protected Areas harbor a portion (~36 to 48%) of the potential distribution defined by the models. However, the central and southern populations are highly threatened by habitat loss and climate change. Based on these results and due to the restricted home range of T. pinchaque, its preference for upland forests and paramos, and its small estimated population size in the Andes, we suggest to maintaining its current status as Critically Endangered in Ecuador. PMID:25798851

Enhancement of the in-field Jc of MgB2 via SiCl4 doping

NASA Astrophysics Data System (ADS)

Wang, Xiao-Lin; Dou, S. X.; Hossain, M. S. A.; Cheng, Z. X.; Liao, X. Z.; Ghorbani, S. R.; Yao, Q. W.; Kim, J. H.; Silver, T.

2010-06-01

We present the following results. (1) We introduce a doping source for MgB2 , liquid SiCl4 , which is free of C, to significantly enhance the irreversibility field (Hirr) , the upper critical field (Hc2) , and the critical current density (Jc) with a little reduction in the critical temperature (Tc) . (2) Although Si can not be incorporated into the crystal lattice, a significant reduction in the a -axis lattice parameter was found, to the same extent as for carbon doping. (3) Based on the first-principles calculation, it is found that it is reliable to estimate the C concentration just from the reduction in the a -lattice parameter for C-doped MgB2 polycrystalline samples that are prepared at high sintering temperatures, but not for those prepared at low sintering temperatures. Strain effects and magnesium deficiency might be reasons for the a -lattice reduction in non-C or some of the C-added MgB2 samples. (4) The SiCl4 -doped MgB2 shows much higher Jc with superior field dependence above 20 K compared to undoped MgB2 and MgB2 doped with various carbon sources. (5) We introduce a parameter, RHH (Hc2/Hirr) , which can clearly reflect the degree of flux-pinning enhancement, providing us with guidance for further enhancing Jc . (6) It was found that spatial variation in the charge-carrier mean free path is responsible for the flux-pinning mechanism in the SiCl4 treated MgB2 with large in-field Jc .

A novel eco-friendly technique for efficient control of lime water softening process.

PubMed

Ostovar, Mohamad; Amiri, Mohamad

2013-12-01

Lime softening is an established type of water treatment used for water softening. The performance of this process is highly dependent on lime dosage. Currently, lime dosage is adjusted manually based on chemical tests, aimed at maintaining the phenolphthalein (P) and total (M) alkalinities within a certain range (2 P - M > or = 5). In this paper, a critical study of the softening process has been presented. It has been shown that the current method is frequently incorrect. Furthermore, electrical conductivity (EC) has been introduced as a novel indicator for effectively characterizing the lime softening process.This novel technique has several advantages over the current alkalinities method. Because no chemical reagents are needed for titration, which is a simple test, there is a considerable reduction in test costs. Additionally, there is a reduction in the treated water hardness and generated sludge during the lime softening process. Therefore, it is highly eco-friendly, and is a very cost effective alternative technique for efficient control of the lime softening process.

Timing, predictors, and progress of third space fluid accumulation during preliminary phase fluid resuscitation in adult patients with dengue.

PubMed

Premaratna, R; Ragupathy, A; Miththinda, J K N D; de Silva, H J

2013-07-01

Fluid leakage remains the hallmark of dengue hemorrhagic fever (DHF). The applicability of currently recommended predictors of DHF for adults with dengue is questionable as these are based on studies conducted in children. One hundred and two adults with dengue were prospectively followed up to investigate whether home-based or hospital-based early phase fluid resuscitation has an impact on clinical and hematological parameters used for the diagnosis of early or critical phase fluid leakage. In the majority of subjects, third space fluid accumulation (TSFA) was detected on the fifth and sixth days of infection. The quantity and quality of fluids administered played no role in TSFA. A reduction in systolic blood pressure appeared to be more helpful than a reduction in pulse pressure in predicting fluid leakage. TSFA occurred with lower percentage rises in packed cell volume (PCV) than stated in the current recommendations. A rapid reduction in platelets, progressive reduction in white blood cells, percentage rises in Haemoglobin (Hb), and PCV, and rises in aspartate aminotransferase and alanine aminotransferase were observed in patients with TSFA and therefore with the development of severe illness. Clinicians should be aware of the limitations of currently recommended predictors of DHF in adult patients who are receiving fluid resuscitation. Copyright © 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

A Randomized Trial Comparing the Effect of Nicotine Versus Placebo Electronic Cigarettes on Smoking Reduction Among Young Adult Smokers.

PubMed

Tseng, Tuo-Yen; Ostroff, Jamie S; Campo, Alena; Gerard, Meghan; Kirchner, Thomas; Rotrosen, John; Shelley, Donna

2016-10-01

Electronic cigarette (EC) use is growing dramatically with use highest among young adults and current smokers. One of the most common reasons for using ECs is interest in quitting or reducing cigarettes per day (CPD); however there are few randomized controlled trials (RCT) on the effect of ECs on smoking abstinence and reduction. We conducted a two-arm; double-blind RCT. Subjects were randomized to receive 3-weeks of either disposable 4.5% nicotine EC (intervention) or placebo EC. The primary outcome was self-reported reduction of at least 50% in the number of CPDs smoked at week 3 (end of treatment) compared to baseline. Study subjects (n = 99) were young adult (21-35), current smokers (smoked ≥ 10 CPDs) living in NYC. Compared with baseline, a significant reduction in CPDs was observed at both study time periods (1 and 3 weeks) for intervention (P < .001) and placebo (P < .001) groups. Between-group analyses showed significantly fewer CPDs in the intervention group compared to the placebo group at week 3 (P = .03), but not at any other follow-up periods. The logistic regression analysis showed that using a greater number of ECs, treatment condition and higher baseline readiness to quit were significantly associated with achieving at least 50% reduction in CPDs at the end of treatment. A diverse young adult sample of current everyday smokers, who were not ready to quit, was able to reduce smoking with the help of ECs. Further study is needed to establish the role of both placebo and nicotine containing ECs in increasing both reduction and subsequent cessation. Despite the critical need for well-designed clinical trials on the effect of ECs on cessation and cigarette reduction, the majority of studies have been observational or noncomparative intervention designs. Only three RCTs studying ECs as a cessation or reduction intervention have been published, and none were conducted in the United States. The current study adds knowledge to current literature on the feasibility of using ECs to aid smoking reduction among young smokers in US urban populations. © The Author 2016. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Desensitization of chemical activation by auxiliary subunits: convergence of molecular determinants critical for augmenting KCNQ1 potassium channels.

PubMed

Gao, Zhaobing; Xiong, Qiaojie; Sun, Haiyan; Li, Min

2008-08-15

Chemical openers for KCNQ potassium channels are useful probes both for understanding channel gating and for developing therapeutics. The five KCNQ isoforms (KCNQ1 to KCNQ5, or Kv7.1 to Kv7.5) are differentially localized. Therefore, the molecular specificity of chemical openers is an important subject of investigation. Native KCNQ1 normally exists in complex with auxiliary subunits known as KCNE. In cardiac myocytes, the KCNQ1-KCNE1 (IsK or minK) channel is thought to underlie the I(Ks) current, a component critical for membrane repolarization during cardiac action potential. Hence, the molecular and pharmacological differences between KCNQ1 and KCNQ1-KCNE1 channels have been important topics. Zinc pyrithione (ZnPy) is a newly identified KCNQ channel opener, which potently activates KCNQ2, KCNQ4, and KCNQ5. However, the ZnPy effects on cardiac KCNQ1 potassium channels remain largely unknown. Here we show that ZnPy effectively augments the KCNQ1 current, exhibiting an increase in current amplitude, reduction of inactivation, and slowing of both activation and deactivation. Some of these are reminiscent of effects by KCNE1. In addition, neither the heteromultimeric KCNQ1-KCNE1 channels nor native I(Ks) current displayed any sensitivity to ZnPy, indicating that the static occupancy by a KCNE subunit desensitizes the reversible effects by a chemical opener. Site-directed mutagenesis of KCNQ1 reveals that residues critical for the potentiation effects by either ZnPy or KCNE are clustered together in the S6 region overlapping with the critical gating determinants. Thus, the convergence of potentiation effects and molecular determinants critical for both an auxiliary subunit and a chemical opener argue for a mechanistic overlap in causing potentiation.

Taking stock of decentralized disaster risk reduction in Indonesia

NASA Astrophysics Data System (ADS)

Grady, Anthony; Gersonius, Berry; Makarigakis, Alexandros

2016-09-01

The Sendai Framework, which outlines the global course on disaster risk reduction until 2030, places strong importance on the role of local government in disaster risk reduction. An aim of decentralization is to increase the influence and authority of local government in decision making. Yet, there is limited empirical evidence of the extent, character and effects of decentralization in current disaster risk reduction implementation, and of the barriers that are most critical to this. This paper evaluates decentralization in relation to disaster risk reduction in Indonesia, chosen for its recent actions to decentralize governance of DRR coupled with a high level of disaster risk. An analytical framework was developed to evaluate the various dimensions of decentralized disaster risk reduction, which necessitated the use of a desk study, semi-structured interviews and a gap analysis. Key barriers to implementation in Indonesia included: capacity gaps at lower institutional levels, low compliance with legislation, disconnected policies, issues in communication and coordination and inadequate resourcing. However, any of these barriers are not unique to disaster risk reduction, and similar barriers have been observed for decentralization in other developing countries in other public sectors.

Minimization of Ohmic losses for domain wall motion in ferromagnetic nanowires

NASA Astrophysics Data System (ADS)

Abanov, Artem; Tretiakov, Oleg; Liu, Yang

2011-03-01

We study current-induced domain-wall motion in a narrow ferromagnetic wire. We propose a way to move domain walls with a resonant time-dependent current which dramatically decreases the Ohmic losses in the wire and allows driving of the domain wall with higher speed without burning the wire. For any domain wall velocity we find the time-dependence of the current needed to minimize the Ohmic losses. Below a critical domain-wall velocity specified by the parameters of the wire the minimal Ohmic losses are achieved by dc current. Furthermore, we identify the wire parameters for which the losses reduction from its dc value is the most dramatic. This work was supported by the NSF Grant No. 0757992 and Welch Foundation (A-1678).

Subsurface oxide plays a critical role in CO 2 activation by Cu(111) surfaces to form chemisorbed CO 2, the first step in reduction of CO 2

DOE PAGES

Favaro, Marco; Xiao, Hai; Cheng, Tao; ...

2017-06-12

A national priority is to convert CO 2 into high-value chemical products such as liquid fuels. Because current electrocatalysts are not adequate, we aim to discover new catalysts by obtaining a detailed understanding of the initial steps of CO 2 electroreduction on copper surfaces, the best current catalysts. Using ambient pressure X-ray photoelectron spectroscopy interpreted with quantum mechanical prediction of the structures and free energies, we show that the presence of a thin suboxide structure below the copper surface is essential to bind the CO 2 in the physisorbed configuration at 298 K, and we show that this suboxide ismore » essential for converting to the chemisorbed CO 2 in the presence of water as the first step toward CO 2 reduction products such as formate and CO. This optimum suboxide leads to both neutral and charged Cu surface sites, providing fresh insights into how to design improved carbon dioxide reduction catalysts.« less

Pt thickness dependence of spin Hall effect switching of in-plane magnetized CoFeB free layers studied by differential planar Hall effect

NASA Astrophysics Data System (ADS)

Mihajlović, G.; Mosendz, O.; Wan, L.; Smith, N.; Choi, Y.; Wang, Y.; Katine, J. A.

2016-11-01

We introduce a differential planar Hall effect method that enables the experimental study of spin orbit torque switching of in-plane magnetized free layers in a simple Hall bar device geometry. Using this method, we study the Pt thickness dependence of switching currents and show that they decrease monotonically down to the minimum experimental thickness of ˜5 nm, while the critical current and power densities are very weakly thickness dependent, exhibiting the minimum values of Jc0 = 1.1 × 108 A/cm2 and ρJc0 2=0.6 ×1012 W/cm 3 at this minimum thickness. Our results suggest that a significant reduction of the critical parameters could be achieved by optimizing the free layer magnetics, which makes this technology a viable candidate for fast, high endurance and low-error rate applications such as cache memories.

Proximity-induced superconductivity in all-silicon superconductor /normal-metal junctions

NASA Astrophysics Data System (ADS)

Chiodi, F.; Duvauchelle, J.-E.; Marcenat, C.; Débarre, D.; Lefloch, F.

2017-07-01

We have realized laser-doped all-silicon superconducting (S)/normal metal (N) bilayers of tunable thickness and dopant concentration. We observed a strong reduction of the bilayers' critical temperature when increasing the normal metal thickness, a signature of the highly transparent S/N interface associated to the epitaxial sharp laser doping profile. We extracted the interface resistance by fitting with the linearized Usadel equations, demonstrating a reduction of 1 order of magnitude from previous superconductor/doped Si interfaces. In this well-controlled crystalline system we exploited the low-resistance S/N interfaces to elaborate all-silicon lateral SNS junctions with long-range proximity effect. Their dc transport properties, such as the critical and retrapping currents, could be well understood in the diffusive regime. Furthermore, this work led to the estimation of important parameters in ultradoped superconducting Si, such as the Fermi velocity, the coherence length, or the electron-phonon coupling constant, fundamental to conceive all-silicon superconducting electronics.

Elevated moisture stimulates carbon loss from mineral soils by releasing protected organic matter.

PubMed

Huang, Wenjuan; Hall, Steven J

2017-11-24

Moisture response functions for soil microbial carbon (C) mineralization remain a critical uncertainty for predicting ecosystem-climate feedbacks. Theory and models posit that C mineralization declines under elevated moisture and associated anaerobic conditions, leading to soil C accumulation. Yet, iron (Fe) reduction potentially releases protected C, providing an under-appreciated mechanism for C destabilization under elevated moisture. Here we incubate Mollisols from ecosystems under C 3 /C 4 plant rotations at moisture levels at and above field capacity over 5 months. Increased moisture and anaerobiosis initially suppress soil C mineralization, consistent with theory. However, after 25 days, elevated moisture stimulates cumulative gaseous C-loss as CO 2 and CH 4 to >150% of the control. Stable C isotopes show that mineralization of older C 3 -derived C released following Fe reduction dominates C losses. Counter to theory, elevated moisture may significantly accelerate C losses from mineral soils over weeks to months-a critical mechanistic deficiency of current Earth system models.

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

Posch, M.; Kaemaeri, J.; Forsius, M.

The main objectives of this study were to identify the regions in Fennoscandia where the critical loads of sulfur (S) and acidifying nitrogen (N) for lakes are exceeded and to investigate the consequences for deposition reductions, with special emphasis on the possible trade-offs between S and N deposition in order to achieve nonexceedance. In the steady-state model for calculating critical loads and their exceedances, all relevant processes acting as sinks for N and S are considered. The critical loads of N and S are interrelated (defining the so-called critical load function), and therefore a single critical load for one pollutantmore » cannot be defined without making assumptions about the other. Comparing the present N and S deposition with the critical function for each lake allows determination of the percentage of lakes in the different regions of Fennoscandia where: (1) S reductions alone can achieve nonexceedance. (2) N reductions alone are sufficient, and (3) both N and S reductions are required but to a certain degree interchangeable. Secondly, deposition reduction requirements were assessed by fixing the N deposition to the present level, in this way analyzing the reductions required for S, and by computing the percentage of lakes exceeded in Finland, Norway and Sweden for every possible percent deposition reduction in S and N, in this way showing the (relative) effectiveness of reducing S and/or N deposition. The results showed clear regional patterns in the S and N reduction requirements. In practically the whole of Finland and the northern parts of Scandinavia man-made acidification of surface waters could be avoided by reducing S deposition alone. In the southern parts of Sweden some reductions in N deposition are clearly needed in addition to those for S. In southern Norway strong reductions are required for both N and S deposition. 55 refs., 5 figs.« less

Reduction redux.

PubMed

Shapiro, Lawrence

2018-04-01

Putnam's criticisms of the identity theory attack a straw man. Fodor's criticisms of reduction attack a straw man. Properly interpreted, Nagel offered a conception of reduction that captures everything a physicalist could want. I update Nagel, introducing the idea of overlap, and show why multiple realization poses no challenge to reduction so construed. Copyright © 2017 Elsevier Ltd. All rights reserved.

An Analysis of Proposed and Current Regulations Concerning Lobbying Costs in Department of Defense Contracts.

DTIC Science & Technology

1984-06-01

a reduction in industry participation in the defense mobilization base, and a limiting of capital available for investment in producti- vity...FAR proposals, it appears that this stratgy has b-2n successful to a large degree. Thor,-, ar , how-vr, still areas where critics believe that further...appropriations. Lobbying includes but is not limited to personal discussions or conferences, advertising , sending tel- egrams, engaging in telephonic

Current practices of construction waste reduction through 3R practice among contractors in malaysia: Case study in penang

NASA Astrophysics Data System (ADS)

Ng, L. S.; Tan, L. W.; Seow, T. W.

2017-11-01

The effectiveness of the implementation of construction waste reduction through 3R reflects the sustainability in construction waste management. Weak implementation of construction waste reduction through 3R among contractors will lead to unsustainable construction waste management. Increase in construction waste on landfills is critical especially on islands where land is very limited for solid waste disposal. This aim of this paper is to investigate current practice of construction waste reduction through 3R practice among contractors in Penang, Malaysia. The findings reported herein is based on feedbacks from 143 construction contractors of grade CIDB G7, G6 and G5 in Penang and experts from Penang Local Authority, CIDB in Penang and its Headquarters, National Solid Waste Management Department, and Headquarters of Solid Waste and Public Cleansing Management Corporation. Interviews and questionnaire surveys have been found that 3R practice is not mandatory in construction waste management in Penang. Only 39.8% construction contractors practiced 3R in managing their waste. Therefore, 3R practices should be emphasized in construction industry. Reducing wastes through 3R practices in construction industry is a way forward towards sustainable construction waste management especially in expanding the lifetime of landfill.

The reduction of optimal heat treatment temperature and critical current density enhancement of ex situ processed MgB2 tapes using ball milled filling powder

NASA Astrophysics Data System (ADS)

Fujii, Hiroki; Iwanade, Akio; Kawada, Satoshi; Kitaguchi, Hitoshi

2018-01-01

The optimal heat treatment temperature (Topt) at which best performance in the critical current density (Jc) property at 4.2 K is obtained is influenced by the quality or reactivity of the filling powder in ex situ processed MgB2 tapes. Using a controlled fabrication process, the Topt decreases to 705-735 °C, which is lower than previously reported by more than 50 °C. The Topt decrease is effective to suppress both the decomposition of MgB2 and hence the formation of impurities such as MgB4, and the growth of crystallite size which decreases upper critical filed (Hc2). These bring about the Jc improvement and the Jc value at 4.2 K and 10 T reaches 250 A/mm2. The milling process also decreases the critical temperature (Tc) below 30 K. The milled powder is easily contaminated in air and thus, the Jc property of the contaminated tapes degrades severely. The contamination can raise the Topt by more than 50 °C, which is probably due to the increased sintering temperature required against contaminated surface layer around the grains acting as a barrier.

Critical current and flux dynamics in Ag-doped FeSe superconductor

NASA Astrophysics Data System (ADS)

Galluzzi, A.; Polichetti, M.; Buchkov, K.; Nazarova, E.; Mancusi, D.; Pace, S.

2017-02-01

The measurements of DC magnetization as a function of the temperature M(T), magnetic field M(H), and time M(t) have been performed in order to compare the superconducting and pinning properties of an undoped FeSe0.94 sample and a silver doped FeSe0.94 + 6 wt% Ag sample. The M(T) curves indicate an improvement of the superconducting critical temperature and a reduction of the non-superconducting phase Fe7Se8 due to the silver doping. This is confirmed by the field and temperature dependent critical current density Jc(H,T) extracted from the superconducting hysteresis loops at different temperatures within the Bean critical state model. Moreover, the combined analysis of the Jc(T) and of the pinning force Fp(H/Hirr) indicate that the pinning mechanisms in both samples can be described in the framework of the collective pinning theory. The U*(T, J) curves show a pinning crossover from an elastic creep regime of intermediate size flux bundles, for low temperatures, to a plastic creep regime at higher temperatures for both the samples. Finally, the vortex hopping attempt time has been evaluated for both samples and the results are comparable with the values reported in the literature for high Tc materials.

Cardiovascular Health Promotion in Children: Challenges and Opportunities for 2020 and Beyond: A Scientific Statement From the American Heart Association.

PubMed

Steinberger, Julia; Daniels, Stephen R; Hagberg, Nancy; Isasi, Carmen R; Kelly, Aaron S; Lloyd-Jones, Donald; Pate, Russell R; Pratt, Charlotte; Shay, Christina M; Towbin, Jeffrey A; Urbina, Elaine; Van Horn, Linda V; Zachariah, Justin P

2016-09-20

This document provides a pediatric-focused companion to "Defining and Setting National Goals for Cardiovascular Health Promotion and Disease Reduction: The American Heart Association's Strategic Impact Goal Through 2020 and Beyond," focused on cardiovascular health promotion and disease reduction in adults and children. The principles detailed in the document reflect the American Heart Association's new dynamic and proactive goal to promote cardiovascular health throughout the life course. The primary focus is on adult cardiovascular health and disease prevention, but critical to achievement of this goal is maintenance of ideal cardiovascular health from birth through childhood to young adulthood and beyond. Emphasis is placed on the fundamental principles and metrics that define cardiovascular health in children for the clinical or research setting, and a balanced and critical appraisal of the strengths and weaknesses of the cardiovascular health construct in children and adolescents is provided. Specifically, this document discusses 2 important factors: the promotion of ideal cardiovascular health in all children and the improvement of cardiovascular health metric scores in children currently classified as having poor or intermediate cardiovascular health. Other topics include the current status of cardiovascular health in US children, opportunities for the refinement of health metrics, improvement of health metric scores, and possibilities for promoting ideal cardiovascular health. Importantly, concerns about the suitability of using single thresholds to identify elevated cardiovascular risk throughout the childhood years and the limits of our current knowledge are noted, and suggestions for future directions and research are provided. © 2016 American Heart Association, Inc.

Economic viability and critical influencing factors assessment of black water and grey water source-separation sanitation system.

PubMed

Thibodeau, C; Monette, F; Glaus, M; Laflamme, C B

2011-01-01

The black water and grey water source-separation sanitation system aims at efficient use of energy (biogas), water and nutrients but currently lacks evidence of economic viability to be considered a credible alternative to the conventional system. This study intends to demonstrate economic viability, identify main cost contributors and assess critical influencing factors. A technico-economic model was built based on a new neighbourhood in a Canadian context. Three implementation scales of source-separation system are defined: 500, 5,000 and 50,000 inhabitants. The results show that the source-separation system is 33% to 118% more costly than the conventional system, with the larger cost differential obtained by lower source-separation system implementation scales. A sensitivity analysis demonstrates that vacuum toilet flow reduction from 1.0 to 0.25 L/flush decreases source-separation system cost between 23 and 27%. It also shows that high resource costs can be beneficial or unfavourable to the source-separation system depending on whether the vacuum toilet flow is low or normal. Therefore, the future of this configuration of the source-separation system lies mainly in vacuum toilet flow reduction or the introduction of new efficient effluent volume reduction processes (e.g. reverse osmosis).

System Analysis and Performance Benefits of an Optimized Rotorcraft Propulsion System

NASA Technical Reports Server (NTRS)

Bruckner, Robert J.

2007-01-01

The propulsion system of rotorcraft vehicles is the most critical system to the vehicle in terms of safety and performance. The propulsion system must provide both vertical lift and forward flight propulsion during the entire mission. Whereas propulsion is a critical element for all flight vehicles, it is particularly critical for rotorcraft due to their limited safe, un-powered landing capability. This unparalleled reliability requirement has led rotorcraft power plants down a certain evolutionary path in which the system looks and performs quite similarly to those of the 1960 s. By and large the advancements in rotorcraft propulsion have come in terms of safety and reliability and not in terms of performance. The concept of the optimized propulsion system is a means by which both reliability and performance can be improved for rotorcraft vehicles. The optimized rotorcraft propulsion system which couples an oil-free turboshaft engine to a highly loaded gearbox that provides axial load support for the power turbine can be designed with current laboratory proven technology. Such a system can provide up to 60% weight reduction of the propulsion system of rotorcraft vehicles. Several technical challenges are apparent at the conceptual design level and should be addressed with current research.

Bioremediation of waste under ocean acidification: Reviewing the role of Mytilus edulis.

PubMed

Broszeit, Stefanie; Hattam, Caroline; Beaumont, Nicola

2016-02-15

Waste bioremediation is a key regulating ecosystem service, removing wastes from ecosystems through storage, burial and recycling. The bivalve Mytilus edulis is an important contributor to this service, and is used in managing eutrophic waters. Studies show that they are affected by changes in pH due to ocean acidification, reducing their growth. This is forecasted to lead to reductions in M. edulis biomass of up to 50% by 2100. Growth reduction will negatively affect the filtering capacity of each individual, potentially leading to a decrease in bioremediation of waste. This paper critically reviews the current state of knowledge of bioremediation of waste carried out by M. edulis, and the current knowledge of the resultant effect of ocean acidification on this key service. We show that the effects of ocean acidification on waste bioremediation could be a major issue and pave the way for empirical studies of the topic. Copyright © 2016 Elsevier Ltd. All rights reserved.

Geometric and compositional factors on critical current density in YBa2Cu3O7‑δ films containing nanorods

NASA Astrophysics Data System (ADS)

Horide, Tomoya; Nagao, Sho; Izutsu, Ryosuke; Ishimaru, Manabu; Kita, Ryusuke; Matsumoto, Kaname

2018-06-01

Critical current density (J c) was investigated in YBa2Cu3O7‑δ films containing nanorods prepared with various nanorod materials, with variation of nanorod content, substrate temperature, and oxidization condition. Three types of compositional situation were realized: films containing strain induced oxygen vacancies; fully oxidized films containing cation compositional deviation; and oxygen deficient films. Normalized J c‑B behavior was determined via the matching field, which is a geometric factor, regardless of the compositional details. A J c‑critical temperature (T c) relation depending on distribution and fraction of compositional deviation (cation compositional deviation and strain induced oxygen vacancies) was found: the J c values decreased with decreasing T c due to the effect of T c on nanorod pinning strength in the fully oxidized films; J c decreased with decreasing oxygen pressure in the film cooling process after film deposition in spite of T c remaining almost the same, due to reduction of the effective area for current flow in the oxygen deficient films. Thus, a J c landscape based on geometric and compositional factors was obtained. The study highlights the importance of the J c‑T c analysis in the understanding of J c in YBa2Cu3O7‑δ films containing nanorods.

Kelp, cobbles, and currents: Biologic reduction of coarse grain entrainment stress

USGS Publications Warehouse

Masteller, Claire C; Finnegan, Noah J; Warrick, Jonathan; Miller, Ian M.

2015-01-01

Models quantifying the onset of sediment motion do not typically account for the effect of biotic processes because they are difficult to isolate and quantify in relation to physical processes. Here we investigate an example of the interaction of kelp (Order Laminariales) and coarse sediment transport in the coastal zone, where it is possible to directly quantify and test its effect. Kelp is ubiquitous along rocky coastlines and the impact on ecosystems has been well studied. We develop a physical model to explore the reduction in critical shear stress of large cobbles colonized by Nereocystis luetkeana, or bull kelp. Observations of coarse sediment motion at a site in the Strait of Juan de Fuca (northwest United States–Canada boundary channel) confirm the model prediction and show that kelp reduces the critical stress required for transport of a given grain size by as much as 92%, enabling annual coarse sediment transport rates comparable to those of fluvial systems. We demonstrate that biology is fundamental to the physical processes that shape the coastal zone in this setting.

Role of Fundamental Physics in Human Space Exploration

NASA Technical Reports Server (NTRS)

Turyshev, Slava

2004-01-01

This talk will discuss the critical role that fundamental physics research plays for the human space exploration. In particular, the currently available technologies can already provide significant radiation reduction, minimize bone loss, increase crew productivity and, thus, uniquely contribute to overall mission success. I will discuss how fundamental physics research and emerging technologies may not only further reduce the risks of space travel, but also increase the crew mobility, enhance safety and increase the value of space exploration in the near future.

Tolerance assays: measuring the unknown.

PubMed

Newell, Kenneth A; Larsen, Christian P

2006-06-15

Distinguishing transplant recipients who will benefit from a reduction in, or even the withdrawal of, immunosuppression from those who require intensive, lifelong immunosuppression will be dependent on developing strategies for immune monitoring. Currently, no assays have been shown to accurately predict the development or presence of donor-specific tolerance in humans after transplantation. In this overview we describe and discuss those assays that we believe may be useful for identifying tolerant transplant recipients. Validation of "tolerance" assays will be critical for the safe development of tolerance regimens in humans.

Development and validation of a risk model for identification of non-neutropenic, critically ill adult patients at high risk of invasive Candida infection: the Fungal Infection Risk Evaluation (FIRE) Study.

PubMed

Harrison, D; Muskett, H; Harvey, S; Grieve, R; Shahin, J; Patel, K; Sadique, Z; Allen, E; Dybowski, R; Jit, M; Edgeworth, J; Kibbler, C; Barnes, R; Soni, N; Rowan, K

2013-02-01

There is increasing evidence that invasive fungal disease (IFD) is more likely to occur in non-neutropenic patients in critical care units. A number of randomised controlled trials (RCTs) have evaluated antifungal prophylaxis in non-neutropenic, critically ill patients, demonstrating a reduction in the risk of proven IFD and suggesting a reduction in mortality. It is necessary to establish a method to identify and target antifungal prophylaxis at those patients at highest risk of IFD, who stand to benefit most from any antifungal prophylaxis strategy. To develop and validate risk models to identify non-neutropenic, critically ill adult patients at high risk of invasive Candida infection, who would benefit from antifungal prophylaxis, and to assess the cost-effectiveness of targeting antifungal prophylaxis to high-risk patients based on these models. Systematic review, prospective data collection, statistical modelling, economic decision modelling and value of information analysis. Ninety-six UK adult general critical care units. Consecutive admissions to participating critical care units. None. Invasive fungal disease, defined as a blood culture or sample from a normally sterile site showing yeast/mould cells in a microbiological or histopathological report. For statistical and economic modelling, the primary outcome was invasive Candida infection, defined as IFD-positive for Candida species. Systematic review: Thirteen articles exploring risk factors, risk models or clinical decision rules for IFD in critically ill adult patients were identified. Risk factors reported to be significantly associated with IFD were included in the final data set for the prospective data collection. Data were collected on 60,778 admissions between July 2009 and March 2011. Overall, 383 patients (0.6%) were admitted with or developed IFD. The majority of IFD patients (94%) were positive for Candida species. The most common site of infection was blood (55%). The incidence of IFD identified in unit was 4.7 cases per 1000 admissions, and for unit-acquired IFD was 3.2 cases per 1000 admissions. Statistical modelling: Risk models were developed at admission to the critical care unit, 24 hours and the end of calendar day 3. The risk model at admission had fair discrimination (c-index 0.705). Discrimination improved at 24 hours (c-index 0.823) and this was maintained at the end of calendar day 3 (c-index 0.835). There was a drop in model performance in the validation sample. Economic decision model: Irrespective of risk threshold, incremental quality-adjusted life-years of prophylaxis strategies compared with current practice were positive but small compared with the incremental costs. Incremental net benefits of each prophylaxis strategy compared with current practice were all negative. Cost-effectiveness acceptability curves showed that current practice was the strategy most likely to be cost-effective. Across all parameters in the decision model, results indicated that the value of further research for the whole population of interest might be high relative to the research costs. The results of the Fungal Infection Risk Evaluation (FIRE) Study, derived from a highly representative sample of adult general critical care units across the UK, indicated a low incidence of IFD among non-neutropenic, critically ill adult patients. IFD was associated with substantially higher mortality, more intensive organ support and longer length of stay. Risk modelling produced simple risk models that provided acceptable discrimination for identifying patients at 'high risk' of invasive Candida infection. Results of the economic model suggested that the current most cost-effective treatment strategy for prophylactic use of systemic antifungal agents among non-neutropenic, critically ill adult patients admitted to NHS adult general critical care units is a strategy of no risk assessment and no antifungal prophylaxis. Funding for this study was provided by the Health Technology Assessment programme of the National Institute for Health Research.

Reduction-Responsive Polymeric Micelles and Vesicles for Triggered Intracellular Drug Release

PubMed Central

Sun, Huanli; Cheng, Ru; Deng, Chao

2014-01-01

Abstract Significance: The therapeutic effects of current micellar and vesicular drug formulations are restricted by slow and inefficient drug release at the pathological site. The development of smart polymeric nanocarriers that release drugs upon arriving at the target site has received a tremendous amount of attention for cancer therapy. Recent Advances: Taking advantage of a high reducing potential in the tumor tissues and in particular inside the tumor cells, various reduction-sensitive polymeric micelles and vesicles have been designed and explored for triggered anticancer drug release. These reduction-responsive nanosystems have demonstrated several unique features, such as good stability under physiological conditions, fast response to intracellular reducing environment, triggering drug release right in the cytosol and cell nucleus, and significantly improved antitumor activity, compared to traditional reduction-insensitive counterparts. Critical Issues: Although reduction-sensitive micelles and polymersomes have accomplished rapid intracellular drug release and enhanced in vitro antitumor effect, their fate inside the cells including the mechanism, site, and rate of reduction reaction remains unclear. Moreover, the systemic fate and performance of reduction-sensitive polymeric drug formulations have to be investigated. Future Directions: Biophysical studies should be carried out to gain insight into the degradation and drug release behaviors of reduction-responsive nanocarriers inside the tumor cells. Furthermore, novel ligand-decorated reduction-sensitive nanoparticulate drug formulations should be designed and explored for targeted cancer therapy in vivo. Antioxid. Redox Signal. 21, 755–767. PMID:24279980

Cigarette Users’ Interest in Using or Switching to Electronic Nicotine Delivery Systems for Smokeless Tobacco for Harm Reduction, Cessation, or Novelty: A Cross-Sectional Survey of US Adults

PubMed Central

Haardoerfer, Regine; Escoffery, Cam; Zheng, Pinpin; Kegler, Michelle

2015-01-01

Introduction: We examined: (a) current (past 30-day) smokers’ interest in using or switching to electronic nicotine delivery systems (ENDS) or smokeless tobacco for various reasons; (b) correlates of interest in these products; and (c) subgroups of current smokers in relation to interest in these products. Methods: We conducted a cross-sectional survey assessing sociodemographics, tobacco use, interest in ENDS and smokeless tobacco among smokers, and knowledge about ENDS among 2,501US adults recruited through an online consumer panel. We oversampled tobacco users (36.7% current cigarette smokers), ethnic minorities, and southeastern US state residents. Results: On average, participants were more interested in ENDS than smokeless tobacco across all reasons provided. Additionally, they were less interested in either product because of their potential use in places prohibiting smoking or due to curiosity and more interested in reducing health risk or cigarette consumption or to aid in cessation. We documented high rates (27.9%) of misbeliefs about Food and Drug Administration approval of ENDS for cessation, particularly among current smokers (38.5%). Also, 27.2% of current smokers had talked with a health care provider about ENDS, with 18.0% reporting that their provider endorsed ENDS use for cessation. Furthermore, cluster analyses revealed 3 groups distinct in their interest in the products, sociodemographics, and smoking-related characteristics. Conclusions: This study highlights higher interest in ENDS versus smokeless tobacco and greater interest in both for harm reduction and cessation than due to novelty or smoking restrictions. Developing educational campaigns and informing practitioners about caveats around ENDS as cessation or harm reduction aids are critical. PMID:24951496

Thromboprophylaxis using combined intermittent pneumatic compression and pharmacologic prophylaxis versus pharmacologic prophylaxis alone in critically ill patients: study protocol for a randomized controlled trial.

PubMed

Arabi, Yaseen M; Alsolamy, Sami; Al-Dawood, Abdulaziz; Al-Omari, Awad; Al-Hameed, Fahad; Burns, Karen E A; Almaani, Mohammed; Lababidi, Hani; Al Bshabshe, Ali; Mehta, Sangeeta; Al-Aithan, Abdulsalam M; Mandourah, Yasser; Almekhlafi, Ghaleb; Finfer, Simon; Abdukahil, Sheryl Ann I; Afesh, Lara Y; Dbsawy, Maamoun; Sadat, Musharaf

2016-08-03

Venous thromboembolism (VTE) remains a common problem in critically ill patients. Pharmacologic prophylaxis is currently the standard of care based on high-level evidence from randomized controlled trials. However, limited evidence exists regarding the effectiveness of intermittent pneumatic compression (IPC) devices. The Pneumatic compREssion for preventing VENous Thromboembolism (PREVENT trial) aims to determine whether the adjunct use of IPC with pharmacologic prophylaxis compared to pharmacologic prophylaxis alone in critically ill patients reduces the risk of VTE. The PREVENT trial is a multicenter randomized controlled trial, which will recruit 2000 critically ill patients from over 20 hospitals in three countries. The primary outcome is the incidence of proximal lower extremity deep vein thrombosis (DVT) within 28 days after randomization. Radiologists interpreting the scans are blinded to intervention allocation, whereas the patients and caregivers are unblinded. The trial has 80 % power to detect a 3 % absolute risk reduction in proximal DVT from 7 to 4 %. The first patient was enrolled in July 2014. As of May 2015, a total of 650 patients have been enrolled from 13 centers in Saudi Arabia, Canada and Australia. The first interim analysis is anticipated in July 2016. We expect to complete recruitment by 2018. Clinicaltrials.gov: NCT02040103 (registered on 3 November 2013). Current controlled trials: ISRCTN44653506 (registered on 30 October 2013).

The MICRO-BOSS scheduling system: Current status and future efforts

NASA Technical Reports Server (NTRS)

Sadeh, Norman M.

1993-01-01

In this paper, a micro-opportunistic approach to factory scheduling was described that closely monitors the evolution of bottlenecks during the construction of the schedule, and continuously redirects search towards the bottleneck that appears to be most critical. This approach differs from earlier opportunistic approaches, as it does not require scheduling large resource subproblems or large job subproblems before revising the current scheduling strategy. This micro-opportunistic approach was implemented in the context of the MICRO-BOSS factory scheduling system. A study comparing MICRO-BOSS against a macro-opportunistic scheduler suggests that the additional flexibility of the micro-opportunistic approach to scheduling generally yields important reductions in both tardiness and inventory.

The Safety Course Design and Operations of Composite Overwrapped Pressure Vessels (COPV)

NASA Technical Reports Server (NTRS)

Saulsberry, Regor; Prosser, William

2015-01-01

Following a Commercial Launch Vehicle On-Pad COPV (Composite Overwrapped Pressure Vessels) failure, a request was received by the NESC (NASA Engineering and Safety Center) June 14, 2014. An assessment was approved July 10, 2014, to develop and assess the capability of scanning eddy current (EC) nondestructive evaluation (NDE) methods for mapping thickness and inspection for flaws. Current methods could not identify thickness reduction from necking and critical flaw detection was not possible with conventional dye penetrant (PT) methods, so sensitive EC scanning techniques were needed. Developmental methods existed, but had not been fully developed, nor had the requisite capability assessment (i.e., a POD (Probability of Detection) study) been performed.

MICROSCALE METABOLIC, REDOX AND ABIOTIC REACTIONS IN HANFORD 300 AREA SUBSURFACE SEDIMENTS

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

Beyenal, Haluk; McLEan, Jeff; Majors, Paul

2013-11-14

The Hanford 300 Area is a unique site due to periodic hydrologic influence of river water resulting in changes in groundwater elevation and flow direction. This area is also highly subject to uranium remobilization, the source of which is currently believed to be the region at the base of the vadose zone that is subject to period saturation due to the changes in the water levels in the Columbia River. We found that microbial processes and redox and abiotic reactions which operate at the microscale were critical to understanding factors controlling the macroscopic fate and transport of contaminants in themore » subsurface. The combined laboratory and field research showed how microscale conditions control uranium mobility and how biotic, abiotic and redox reactions relate to each other. Our findings extended the current knowledge to examine U(VI) reduction and immobilization using natural 300 Area communities as well as selected model organisms on redox-sensitive and redox-insensitive minerals. Using innovative techniques developed specifically to probe biogeochemical processes at the microscale, our research expanded our current understanding of the roles played by mineral surfaces, bacterial competition, and local biotic, abiotic and redox reaction rates on the reduction and immobilization of uranium.« less

Identifying the role of cytochromes upon the attachment, growth and detachment of Shewanella oneidensis MR-1 on hematite during dissimilatory iron reduction under natural- flow conditions

NASA Astrophysics Data System (ADS)

Mitchell, A. C.; Geesey, G. G.

2006-12-01

Current understanding of bacterial respiration by dissimilatory iron (Fe) reduction is based primarily on studies of closed systems using soluble Fe(III). However, natural environments likely to support Fe reduction are typically open systems and contain Fe(III) primarily in the form of crystalline (hydr)oxides. Mechanisms by which electrons are transported between bacteria and mineral terminal electron acceptors (TEAs) under open system conditions are still poorly understood. However, a number of cytochromes have been identified as potentially playing a critical role in the electron transport system of some Fe reducing bacteria. Experiments were performed using (i) omcA, (ii) mtrC, or (iii) omcA and mtrC cytochrome deficient mutants of the Fe-reducing bacteria, Shewanella oneidensis MR-1, in transparent-window flow- reactors containing hematite as the only TEA. These were operated under defined hydrodynamic and anaerobic conditions. Cells expressed green fluorescent protein (gfp), allowing real time measurement of cells at the mineral surface by epifluorescence microscopy. Cytochromes which play a critical role in the anaerobic growth of S. Oneidensis by Fe reduction under open system natural-flow conditions could then be identified. Differences in the accumulation, maximum density, detachment and total production of surface-associated cells growing on hematite surfaces were apparent between the mutants, and between the mutants and the wild-type. Mutants deficient in cytochromes grew to a lower max density by up to 2 orders of magnitude than the wild-type, and exhibited no reduced Fe in the reactor effluent or at the surface of the hematite at the conclusion of the experiment, as revealed by X-Ray photoelectron spectroscopy (XPS). Therefore omcA and / or mtrC cytochromes appear critical for electron shuttling and anaerobic growth of S. Oneidensis on hematite under natural-flow conditions.

Enhanced critical current in superconducting FeSe0.5Te0.5 films at all magnetic field orientations by scalable gold ion irradiation

NASA Astrophysics Data System (ADS)

Ozaki, Toshinori; Wu, Lijun; Zhang, Cheng; Si, Weidong; Jie, Qing; Li, Qiang

2018-07-01

The loss-less electrical current-carrying capability of type II superconductors, measured by the critical current density J c, can be increased by engineering desirable defects in superconductors to pin the magnetic vortices. Here, we demonstrate that such desirable defects can be created in superconducting FeSe0.5Te0.5 films by 6 MeV Au-ions irradiations that produce cluster-like defects with sizes of 10-15 nm over the entire film. The pristine FeSe0.5Te0.5 film exhibits a low anisotropy in the angular dependence of J c. A clear improvement in the J c is observed upon Au-ion irradiation for all field orientations at 4.2 K. Furthermore, a nearly 70% increase in J c is observed at a magnetic field of 9 T applied parallel to the crystallographic c-axis at 10 K with little reduction of the superconducting transition temperature T c. Our studies show that a dose of 1 × 1012 Au cm-2 irradiation at a few MeV is sufficient in order to provide a strong isotropic pinning defect landscape in iron-based superconducting films.

Intonation influences how children and adults interpret sarcasm.

PubMed

Glenwright, Melanie; Parackel, Jayanthi M; Cheung, Kristene R J; Nilsen, Elizabeth S

2014-03-01

Adults distinguish sarcasm from literal language according to intonation involving a reduction in fundamental frequency (F0). We examined whether children's and adults' interpretation of a sarcastic speaker's belief, attitude, and humor was affected by degree of F0 reduction by presenting five- to six-year-olds and adults with sarcastic and literal criticisms with a small, medium, or large mean F0 reduction. Children and adults were more accurate in attributing the speaker's belief and intent for sarcastic criticisms for large F0 reductions compared to small reductions. These results show that F0 reduction is a helpful cue to sarcasm interpretation for both children and adults.

Social Isolation During the Critical Period Reduces Synaptic and Intrinsic Excitability of a Subtype of Pyramidal Cell in Mouse Prefrontal Cortex.

PubMed

Yamamuro, Kazuhiko; Yoshino, Hiroki; Ogawa, Yoichi; Makinodan, Manabu; Toritsuka, Michihiro; Yamashita, Masayuki; Corfas, Gabriel; Kishimoto, Toshifumi

2018-03-01

Juvenile social experience is crucial for the functional development of forebrain regions, especially the prefrontal cortex (PFC). We previously reported that social isolation for 2 weeks after weaning induces prefrontal cortex dysfunction and hypomyelination. However, the effect of social isolation on physiological properties of PFC neuronal circuit remained unknown. Since hypomyelination due to isolation is prominent in deep-layer of medial PFC (mPFC), we focused on 2 types of Layer-5 pyramidal cells in the mPFC: prominent h-current (PH) cells and nonprominent h-current (non-PH) cells. We found that a 2-week social isolation after weaning leads to a specific deterioration in action potential properties and reduction in excitatory synaptic inputs in PH cells. The effects of social isolation on PH cells, which involve reduction in functional glutamatergic synapses and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/N-methyl-d-aspartate charge ratio, are specific to the 2 weeks after weaning and to the mPFC. We conclude that juvenile social experience plays crucial roles in the functional development in a subtype of Layer-5 pyramidal cells in the mPFC. Since these neurons project to subcortical structures, a deficit in social experience during the critical period may result in immature neural circuitry between mPFC and subcortical targets. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

A review of ADM1 extensions, applications, and analysis: 2002-2005.

PubMed

Batstone, D J; Keller, J; Steyer, J P

2006-01-01

Since publication of the Scientific and Technical Report (STR) describing the ADM1, the model has been extensively used, and analysed in both academic and practical applications. Adoption of the ADM1 in popular systems analysis tools such as the new wastewater benchmark (BSM2), and its use as a virtual industrial system can stimulate modelling of anaerobic processes by researchers and practitioners outside the core expertise of anaerobic processes. It has been used as a default structural element that allows researchers to concentrate on new extensions such as sulfate reduction, and new applications such as distributed parameter modelling of biofilms. The key limitations for anaerobic modelling originally identified in the STR were: (i) regulation of products from glucose fermentation, (ii) parameter values, and variability, and (iii) specific extensions. Parameter analysis has been widespread, and some detailed extensions have been developed (e.g., sulfate reduction). A verified extension that describes regulation of products from glucose fermentation is still limited, though there are promising fundamental approaches. This is a critical issue, given the current interest in renewable hydrogen production from carbohydrate-type waste. Critical analysis of the model has mainly focused on model structure reduction, hydrogen inhibition functions, and the default parameter set recommended in the STR. This default parameter set has largely been verified as a reasonable compromise, especially for wastewater sludge digestion. One criticism of note is that the ADM1 stoichiometry focuses on catabolism rather than anabolism. This means that inorganic carbon can be used unrealistically as a carbon source during some anabolic reactions. Advances and novel applications have also been made in the present issue, which focuses on the ADM1. These papers also explore a number of novel areas not originally envisaged in this review.

Some reflections on the understanding of the oxygen reduction reaction at Pt(111)

PubMed Central

Gómez-Marín, Ana M; Rizo, Ruben

2013-01-01

Summary The oxygen reduction reaction (ORR) is a pivotal process in electrochemistry. Unfortunately, after decades of intensive research, a fundamental knowledge about its reaction mechanism is still lacking. In this paper, a global and critical view on the most important experimental and theoretical results regarding the ORR on Pt(111) and its vicinal surfaces, in both acidic and alkaline media, is taken. Phenomena such as the ORR surface structure sensitivity and the lack of a reduction current at high potentials are discussed in the light of the surface oxidation and disordering processes and the possible relevance of the hydrogen peroxide reduction and oxidation reactions in the ORR mechanism. The necessity to build precise and realistic reaction models, which are deducted from reliable experimental results that need to be carefully taken under strict working conditions is shown. Therefore, progress in the understanding of this important reaction on a molecular level, and the choice of the right approach for the design of the electrocatalysts for fuel-cell cathodes is only possible through a cooperative approach between theory and experiments. PMID:24455454

Some reflections on the understanding of the oxygen reduction reaction at Pt(111).

PubMed

Gómez-Marín, Ana M; Rizo, Ruben; Feliu, Juan M

2013-12-27

The oxygen reduction reaction (ORR) is a pivotal process in electrochemistry. Unfortunately, after decades of intensive research, a fundamental knowledge about its reaction mechanism is still lacking. In this paper, a global and critical view on the most important experimental and theoretical results regarding the ORR on Pt(111) and its vicinal surfaces, in both acidic and alkaline media, is taken. Phenomena such as the ORR surface structure sensitivity and the lack of a reduction current at high potentials are discussed in the light of the surface oxidation and disordering processes and the possible relevance of the hydrogen peroxide reduction and oxidation reactions in the ORR mechanism. The necessity to build precise and realistic reaction models, which are deducted from reliable experimental results that need to be carefully taken under strict working conditions is shown. Therefore, progress in the understanding of this important reaction on a molecular level, and the choice of the right approach for the design of the electrocatalysts for fuel-cell cathodes is only possible through a cooperative approach between theory and experiments.

Effect of Chloride Anions on the Synthesis and Enhanced Catalytic Activity of Silver Nanocoral Electrodes for CO 2 Electroreduction

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

Hsieh, Yu-Chi; Senanayake, Sanjaya D.; Zhang, Yu

2015-09-04

Metallic silver (Ag) is known as an efficient electrocatalyst for the conversion of carbon dioxide (CO 2) to carbon monoxide (CO) in aqueous or nonaqueous electrolytes. However, polycrystalline silver electrocatalysts require significant overpotentials in order to achieve high selectivity toward CO 2 reduction, as compared to the side reaction of hydrogen evolution. Here we report a high-surface-area Ag nanocoral catalyst, fabricated by an oxidation–reduction method in the presence of chloride anions in an aqueous medium, for the electro-reduction of CO 2 to CO with a current efficiency of 95% at the low overpotential of 0.37 V and the current densitymore » of 2 mA cm –2. A lower limit of TOF of 0.4 s –1 and TON > 8.8 × 10 4 (over 72 h) was estimated for the Ag nanocoral catalyst at an overpotential of 0.49 V. The Ag nanocoral catalyst demonstrated a 32-fold enhancement in surface-area-normalized activity, at an overpotential of 0.49 V, as compared to Ag foil. We found that, in addition to the effect on nanomorphology, the adsorbed chloride anions play a critical role in the observed enhanced activity and selectivity of the Ag nanocoral electrocatalyst toward CO 2 reduction. Synchrotron X-ray photoelectron spectroscopy (XPS) studies along with a series of control experiments suggest that the chloride anions, remaining adsorbed on the catalyst surface under electrocatalytic conditions, can effectively inhibit the side reaction of hydrogen evolution and enhance the catalytic performance for CO 2 reduction.« less

Engine Conceptual Design Studies for a Hybrid Wing Body Aircraft

NASA Technical Reports Server (NTRS)

Tong, Michael T.; Jones, Scott M.; Haller, William J.; Handschuh, Robert F.

2009-01-01

Worldwide concerns of air quality and climate change have made environmental protection one of the most critical issues in aviation today. NASA's current Fundamental Aeronautics research program is directed at three generations of aircraft in the near, mid and far term, with initial operating capability around 2015, 2020, and 2030, respectively. Each generation has associated goals for fuel burn, NOx, noise, and field-length reductions relative to today's aircrafts. The research for the 2020 generation is directed at enabling a hybrid wing body (HWB) aircraft to meet NASA's aggressive technology goals. This paper presents the conceptual cycle and mechanical designs of the two engine concepts, podded and embedded systems, which were proposed for a HWB cargo freighter. They are expected to offer significant benefits in noise reductions without compromising the fuel burn.

Mindfulness-based stress reduction: an intervention to enhance the effectiveness of nurses' coping with work-related stress.

PubMed

Smith, Sarah A

2014-06-01

This critical literature review explored the current state of the science regarding mindfulness-based stress reduction (MBSR) as a potential intervention to improve the ability of nurses to effectively cope with stress. Literature sources include searches from EBSCOhost, Gale PowerSearch, ProQuest, PubMed Medline, Google Scholar, Online Journal of Issues in Nursing, and reference lists from relevant articles. Empirical evidence regarding utilizing MBSR with nurses and other healthcare professionals suggests several positive benefits including decreased stress, burnout, and anxiety; and increased empathy, focus, and mood. Nurse use of MBSR may be a key intervention to help improve nurses' ability to cope with stress and ultimately improve the quality of patient care provided. © 2014 NANDA International, Inc.

Ion beam deposition system for depositing low defect density extreme ultraviolet mask blanks

NASA Astrophysics Data System (ADS)

Jindal, V.; Kearney, P.; Sohn, J.; Harris-Jones, J.; John, A.; Godwin, M.; Antohe, A.; Teki, R.; Ma, A.; Goodwin, F.; Weaver, A.; Teora, P.

2012-03-01

Extreme ultraviolet lithography (EUVL) is the leading next-generation lithography (NGL) technology to succeed optical lithography at the 22 nm node and beyond. EUVL requires a low defect density reflective mask blank, which is considered to be one of the top two critical technology gaps for commercialization of the technology. At the SEMATECH Mask Blank Development Center (MBDC), research on defect reduction in EUV mask blanks is being pursued using the Veeco Nexus deposition tool. The defect performance of this tool is one of the factors limiting the availability of defect-free EUVL mask blanks. SEMATECH identified the key components in the ion beam deposition system that is currently impeding the reduction of defect density and the yield of EUV mask blanks. SEMATECH's current research is focused on in-house tool components to reduce their contributions to mask blank defects. SEMATECH is also working closely with the supplier to incorporate this learning into a next-generation deposition tool. This paper will describe requirements for the next-generation tool that are essential to realize low defect density EUV mask blanks. The goal of our work is to enable model-based predictions of defect performance and defect improvement for targeted process improvement and component learning to feed into the new deposition tool design. This paper will also highlight the defect reduction resulting from process improvements and the restrictions inherent in the current tool geometry and components that are an impediment to meeting HVM quality EUV mask blanks will be outlined.

Hot topics in parenteral nutrition. Current evidence and ongoing trials on the use of glutamine in critically-ill patients and patients undergoing surgery.

PubMed

Avenell, Alison

2009-08-01

The amino acid glutamine has numerous important roles including particularly antioxidant defence, immune function, the inflammatory response, acid-base balance and N economy. The present systematic review of randomised controlled trials of nutrition support with glutamine up to August 2008 has found that parenteral glutamine in critical illness is associated with a non-significant reduction in mortality (risk ratio 0.71 (95% CI 0.49, 1.03)) and may reduce infections. However, poor study quality and the possibility of publication bias mean that these results should be interpreted with caution. There is no evidence to suggest that glutamine is harmful in terms of organ failure and parenteral glutamine may reduce the development of organ failure.

Using Ada: The deeper challenges

NASA Technical Reports Server (NTRS)

Feinberg, David A.

1986-01-01

The Ada programming language and the associated Ada Programming Support Environment (APSE) and Ada Run Time Environment (ARTE) provide the potential for significant life-cycle cost reductions in computer software development and maintenance activities. The Ada programming language itself is standardized, trademarked, and controlled via formal validation procedures. Though compilers are not yet production-ready as most would desire, the technology for constructing them is sufficiently well known and understood that time and money should suffice to correct current deficiencies. The APSE and ARTE are, on the other hand, significantly newer issues within most software development and maintenance efforts. Currently, APSE and ARTE are highly dependent on differing implementer concepts, strategies, and market objectives. Complex and sophisticated mission-critical computing systems require the use of a complete Ada-based capability, not just the programming language itself; yet the range of APSE and ARTE features which must actually be utilized can vary significantly from one system to another. As a consequence, the need to understand, objectively evaluate, and select differing APSE and ARTE capabilities and features is critical to the effective use of Ada and the life-cycle efficiencies it is intended to promote. It is the selection, collection, and understanding of APSE and ARTE which provide the deeper challenges of using Ada for real-life mission-critical computing systems. Some of the current issues which must be clarified, often on a case-by-case basis, in order to successfully realize the full capabilities of Ada are discussed.

Reducing Size, Weight, and Power (SWaP) of Perception Systems in Small Autonomous Aerial Systems

NASA Technical Reports Server (NTRS)

Jones, Kennie H.; Gross, Jason

2014-01-01

The objectives are to examine recent trends in the reduction of size, weight, and power (SWaP) requirements of sensor systems for environmental perception and to explore new technology that may overcome limitations in current systems. Improving perception systems to facilitate situation awareness is critical in the move to introduce increasing autonomy in aerial systems. Whether the autonomy is in the current state-of-the-art of increasing automation or is enabling cognitive decisions that facilitate adaptive behavior, collection of environmental information and fusion of that information into knowledge that can direct actuation is imperative to decisions resulting in appropriate behavior. Artificial sensory systems such as cameras, radar, LIDAR, and acoustic sensors have been in use on aircraft for many years but, due to the large size and weight of the airplane and electrical power made available through powerful engines, the SWaP requirements of these sensors was inconsequential. With the proliferation of Remote Piloted Vehicles (RPV), the trend is in significant reduction in SWaP of the vehicles. This requires at least an equivalent reduction in SWaP for the sensory systems. A survey of some currently available sensor systems and changing technology will reveal the trend toward reduction of SWaP of these systems and will predict future reductions. A new technology will be introduced that provides an example of a desirable new trend. A new device replaces multiple conventional sensory devices facilitating synchronization, localization, altimetry, collision avoidance, terrain mapping, and data communication in a single integrated, small form-factor, extremely lightweight, and low power device that it is practical for integration into small autonomous vehicles and can facilitate cooperative behavior. The technology is based on Ultra WideBand (UWB) radio using short pulses of energy rather than continuous sine waves. The characteristics of UWB yield several desirable characteristics to facilitate integration of perception for autonomous activities. The capabilities of this device and its limitations will be assessed.

2010 Defense Industrial Base Critical Infrastructure Protection Conference (DIBCIP) Risk Reduction and Mitigation in the Defense Industrial Base

DTIC Science & Technology

2010-04-28

Base Critical Infrastructure Protection Conference (DIBCIP) “Risk Reduction & Mitigation in the Defense Industrial Base ” April 26-28, 2010...Philadelphia, PA Agenda Tuesday, April 27, 2010 Keynote Address: The Economic Crisis and Its Impact on the DIB: Defense Industrial Base Forecasts 2010...Ms. Nancy Pomerleau, Exercise Director, Partnership Outreach Division, DHS-IP DIB 2010 DIB CIP DEFENSE INDUSTRIAL BASE CRITICAL

Microfinance and HIV/AIDS Prevention: Assessing its Promise and Limitations

PubMed Central

Dworkin, Shari L.; Blankenship, Kim

2013-01-01

Researchers increasingly argue that poverty and gender inequality exacerbate the spread of HIV/AIDS and that economic empowerment can therefore assist in the prevention and mitigation of the disease, particularly for women. This paper critically evaluates such claims. First, we examine the promises and limits of integrated HIV/AIDS prevention and microfinance programs by examining the available evidence base. We then propose future research agendas and next steps that may help to clear current ambiguities about the potential for economic programs to contribute to HIV/AIDS risk reduction efforts. PMID:19294500

PubMed

Ströhle, Alexander; Löser, Christian; Behrendt, Isabel; Leitzmann, Claus; Hahn, Andreas

2018-02-01

Alternative diets (AD) differ from the current common mixed diet; AD are recommended as a permanent diet. These diets are based on ethical, philosophical and health promoting principles and lead to very different recommendations for food selection. Even within a particular AD there is usually a broad spectrum of versions, so that a general evaluation is only possible to a limited extent. This is also true for single AD. Vegetarian diets and partly paleo-diets have been investigated to a reasonable extent. Plant based diets are appropriate as permanent diets and offer health benefits as compared with currently practiced diets (risk reduction of cancers by 10-18% and of heart diseases by 30%; favorable effect on blood pressure and lipid profile; no risk reduction on cancer and total mortality). Vegan diets have to be critically assessed: they are linked to an increased risk of deficits for single nutrients (vitamin B 12 , iodine and as the case may be. calcium and long chain omega-3 fatty acids), if suitable supplements or fortified foods are not consumed. © Georg Thieme Verlag KG Stuttgart · New York.

Spin torque oscillator for microwave assisted magnetization reversal

NASA Astrophysics Data System (ADS)

Taniguchi, Tomohiro; Kubota, Hitoshi

2018-05-01

A theoretical study is given for the self-oscillation excited in a spin torque oscillator (STO) consisting of an in-plane magnetized free layer and a perpendicularly magnetized pinned layer in the presence of a perpendicular magnetic field. This type of STO is a potential candidate for a microwave source of microwave assisted magnetization reversal (MAMR). It is, however, found that the self-oscillation applicable to MAMR disappears when the perpendicular field is larger than a critical value, which is much smaller than a demagnetization field. This result provides a condition that the reversal field of a magnetic recording bit by MAMR in nanopillar structure should be smaller than the critical value. The analytical formulas of currents determining the critical field are obtained, which indicate that a material with a small damping is not preferable to acheive a wide range of the self-oscillation applicable to MAMR, although such a material is preferable from the viewpoint of the reduction of the power consumption.

[Hyperhydration and dialysis in acute kidney failure].

PubMed

Saner, Fuat H; Bienholz, Anja; Tyczynski, Bartosz; Kribben, Andreas; Feldkamp, Thorsten

2015-05-01

Despite the advances in critical care medicine, the hospital mortality in patients with acute kidney injury (AKI) requiring dialysis remains high. Depending on the underlying disease the in-house mortality is reported to be up to 80%. Several observational studies demonstrated an association between mortality and fluid overload. A primary mechanism of interest is that fluid overload causes tissue edema and subsequent reduction of perfusion, oxygenation and nutrient delivery. This results in further renal damage. In addition, fluid overload-related dilution within the extracellular space causes artificially low serum creatinine, which masks AKI diagnosis. As a consequence, renal protective management strategies are deferred, which further aggravates kidney injury. This aggravation of renal damage subsequently increases the mortality. This review discusses the role of fluid overload for outcomes in critically ill patients as described in the current literature and assesses criteria for the initiation of renal replacement therapy in this critically ill population. © Georg Thieme Verlag KG Stuttgart · New York.

Effect of hydrogen intercalation on the critical parameters of YBa2Cu3O y

NASA Astrophysics Data System (ADS)

Bobylev, I. B.; Gerasimov, E. G.; Zyuzeva, N. A.; Terent'ev, P. B.

2017-10-01

The effect of hydrogenation at T = 150 and 200°C on the electrophysical properties of highly textured YBa2Cu3O y ceramics with different oxygen content has been investigated. Like hydration, hydrogenation results in the deterioration of these properties. However, in samples with high oxygen contents ( y = 6.96) hydrogenated at T = 150°C after oxidation (400°C) or recovery annealing with subsequent oxidation, the critical current density and first critical field increase compared to the initial state. The improvement of the properties occurs mainly in a magnetic field applied perpendicularly to the c axis. As after hydration, this is connected with the formation of planar defects in the course of low-temperature annealing. In addition, in the process of the hydrogenation, the partial reduction of copper occurs with the formation of microinclusions of Cu2O and other products of chemical decomposition, which are extra pinning centers of magnetic vortices.

Microfluidic platform for studying the electrochemical reduction of carbon dioxide

NASA Astrophysics Data System (ADS)

Whipple, Devin Talmage

Diminishing supplies of conventional energy sources and growing concern over greenhouse gas emissions present significant challenges to supplying the world's rapidly increasing demand for energy. The electrochemical reduction of carbon dioxide has the potential to address many of these issues by providing a means of storing electricity in chemical form. Storing electrical energy as chemicals is beneficial for leveling the output of clean, but intermittent renewable energy sources such as wind and solar. Electrical energy stored as chemicals can also be used as carbon neutral fuels for portable applications allowing petroleum derived fuels in the transportation sector to be replaced by more environmentally friendly energy sources. However, to be a viable technology, the electrochemical reduction of carbon dioxide needs to have both high current densities and energetic efficiencies (Chapter 1). Although many researchers have studied the electrochemical reduction of CO2 including parameters such as catalysts, electrolytes and temperature, further investigation is needed to improve the understanding of this process and optimize the performance (Chapter 2). This dissertation reports the development and validation of a microfluidic reactor for the electrochemical reduction of CO2 (Chapter 3). The design uses a flowing liquid electrolyte instead of the typical polymer electrolyte membrane. In addition to other benefits, this flowing electrolyte gives the reactor great flexibility, allowing independent analysis of each electrode and the testing of a wide variety of conditions. In this work, the microfluidic reactor has been used in the following areas: • Comparison of different metal catalysts for the reduction of CO2 to formic acid and carbon monoxide (Chapter 4). • Investigation of the effects of the electrolyte pH on the reduction of CO2 to formic acid and carbon monoxide (Chapter 5). • Study of amine based electrolytes for lowering the overpotentials for CO2 reduction and suppressing undesirable hydrogen evolution (Chapter 6). • Investigation of the effects of reaction temperature on the Faradaic efficiency and current density for CO2 reduction on several catalysts (Chapter 7). These studies demonstrate the utility of this flexible reactor design and provide increased understanding of the electrochemical reduction of CO2 and the critical parameters for optimization of this process.

Diagram reduction in problem of critical dynamics of ferromagnets: 4-loop approximation

NASA Astrophysics Data System (ADS)

Adzhemyan, L. Ts; Ivanova, E. V.; Kompaniets, M. V.; Vorobyeva, S. Ye

2018-04-01

Within the framework of the renormalization group approach to the models of critical dynamics, we propose a method for a considerable reduction of the number of integrals needed to calculate the critical exponents. With this method we perform a calculation of the critical exponent z of model A at 4-loop level, where our method allows one to reduce the number of integrals from 66 to 17. The way of constructing the integrand in a Feynman representation of such diagrams is discussed. Integrals were estimated numerically with a sector decomposition technique.

Enhanced low-temperature critical current by reduction of stacking faults in REBCO coated conductors

NASA Astrophysics Data System (ADS)

Puichaud, A.-H.; Wimbush, S. C.; Knibbe, R.

2017-07-01

The effect of stacking faults (SF) on flux pinning and critical current (I c) in rare earth based coated conductors was investigated. The SF density in YBa2Cu3O7-δ (YBCO) films with and without Dy addition, produced by metal organic deposition, was modified by altering the oxygenation temperature. A detailed microstructural analysis of the coated conductors was performed by x-ray diffraction, scanning and transmission electron microscopy and energy dispersive spectroscopy, and the observed defect population was correlated with both the self-field and in-field I c. We report that the best self-field I c was obtained for samples having a low SF density, in spite of the SF being effective flux pinning defects at 77 K for magnetic fields applied within the ab plane. We also show that the SF have no observable flux pinning effect at low temperatures. This study demonstrates that for devices operated at low temperatures, the elimination of SF in the conductor wires is essential to attain higher I c.

Flux pinning and inhomogeneity in magnetic nanoparticle doped MgB2/Fe wires

NASA Astrophysics Data System (ADS)

Novosel, Nikolina; Pajić, Damir; Mustapić, Mislav; Babić, Emil; Shcherbakov, Andrey; Horvat, Joseph; Skoko, Željko; Zadro, Krešo

2010-06-01

The effects of magnetic nanoparticle doping on superconductivity of MgB2/Fe wires have been investigated. Fe2B and SiO2-coated Fe2B particles with average diameters 80 and 150 nm, respectively, were used as dopands. MgB2 wires with different nanoparticle contents (0, 3, 7.5, 12 wt.%) were sintered at temperature 750°C. The magnetoresistivity and critical current density Jc of wires were measured in the temperature range 2-40 K in magnetic field B <= 16 T. Both transport and magnetic Jc were determined. Superconducting transition temperature Tc of doped wires decreases quite rapidly with doping level (~ 0.5 K per wt.%). This results in the reduction of the irreversibility fields Birr(T) and critical current densities Jc(B,T) in doped samples (both at low (5 K) and high temperatures (20 K)). Common scaling of Jc(B,T) curves for doped and undoped wires indicates that the main mechanism of flux pinning is the same in both types of samples. Rather curved Kramer's plots for Jc of doped wires imply considerable inhomogeneity.

Sleep disturbances in the critically ill patients: role of delirium and sedative agents.

PubMed

Trompeo, A C; Vidi, Y; Locane, M D; Braghiroli, A; Mascia, L; Bosma, K; Ranieri, V M

2011-06-01

Impairment of sleep quality and quantity has been described in critically ill patients. Delirium, an organ dysfunction that affects outcome of the critically ill patients, is characterized by an acute onset of impaired cognitive function, visual hallucinations, delusions, and illusions. These symptoms resemble the hypnagogic hallucinations and wakeful dreams seen in patients with neurological degenerative disorders and suffering of disorders of rapid eye movement (REM) sleep. We assessed the characteristics of sleep disruption in a cohort of surgical critically ill patients examining the hypothesis that severe impairments of rapid eyes movement (REM) sleep are associated to delirium. Surgical patients admitted to the intensive care units of the San G. Battista Hospital (University of Turin) were enrolled. Once weaning was initiated, sleep was recorded for one night utilizing standard polysomnography. Clinical status, laboratory data on admission, co-morbidities and duration of mechanical ventilation were recorded. Patients were a priori classified as having a "severe REM reduction" or "REM reduction" if REM was higher or lower than 6% of the total sleep time (TST), respectively. Occurrence of delirium during intensive care unit (ICU) stay was identified by CAM-ICU twice a day. Multivariate forward stepwise logistic regression analysis was performed with sleep ("severe REM reduction" vs. "REM reduction") as the a priori dependent factor. REM sleep amounted to 44 (16-72) minutes [11 (8-55) % of the TST] in 14 patients ("REM reduction") and to 2.5 (0-36) minutes [1 (0-6) % of the TST] in the remaining 15 patients ("severe REM reduction") (P = 0.0004). SAPS II on admission was higher in " severely REM deprived" then in "REM deprived" patients. Delirium was present in 11 patients (73.3%) of the patients with "severe REM reduction" and lasted for a median of 3 (0-11) days before sleep assessment, while only one patient having "REM reduction" developed delirium that lasted for 1 day. The factors independently associated with a higher risk of developing "severe REM reduction" were delirium and daily dosage of lorazepam. The present study shows that while all critically ill patients present a profound fragmentation of sleep with a high frequency of arousals and awakenings and a reduction of REM sleep, a percentage of patients present an extremely severe reduction of REM sleep. Delirium and daily dosage of lorazepam are the factors independently associated to extremely severe REM sleep reduction.

Engine Conceptual Design Studies for a Hybrid Wing Body Aircraft

NASA Technical Reports Server (NTRS)

Tong, Michael T.; Jones, Scott M.; Haller, William J.; Handschuh, Robert F.

2009-01-01

Worldwide concerns of air quality and climate change have made environmental protection one of the most critical issues in aviation today. NASA s current Fundamental Aeronautics Research program is directed at three generations of aircraft in the near, mid and far term, with initial operating capability around 2015, 2020, and 2030, respectively. Each generation has associated goals for fuel burn, NOx, noise, and field-length reductions relative to today s aircrafts. The research for the 2020 generation is directed at enabling a hybrid wing body (HWB) aircraft to meet NASA s aggressive technology goals. This paper presents the conceptual cycle and mechanical designs of the two engine concepts, podded and embedded systems, which were proposed for a HWB cargo freighter. They are expected to offer significant benefits in noise reductions without compromising the fuel burn.

Health education in Cuba: a preface.

PubMed

Tesh, S

1986-01-01

Critics of health education policy in the United States fault it for ignoring the unequal ability of Americans to adopt more healthy behavior and for underestimating the social, economic, and political causes of disease. Many critics hypothesize that health education in a less bourgeois society would be more equitable and less individualistic. This article tests that hypothesis by analyzing the current Cuban health education program aimed at the reduction of chronic diseases. It argues that while the Cuban program appears to be every bit as individualistic as the North American program, theirs may not be comparable to ours because Cubans are less likely than Americans to reify the state. At least among supporters of the revolution, Cubans do not automatically make a conceptual distinction between the individual and the society. Discussions about responsibility for disease prevention take on new meaning in this light.

Fundamental study on the magnetic field control method using multiple HTS coils for Magnetic Drug Delivery System

NASA Astrophysics Data System (ADS)

Hirano, R.; Kim, S. B.; Nakagawa, T.; Tomisaka, Y.; Ueda, H.

2017-07-01

The magnetic drug delivery system (MDDS) is a key technology to reduce the side effects in the medical applications, and the magnetic force control is very important issue in MDDS. In this application, the strength of magnetic field and gradient required to MDDS devices are 54 mT and 5.5 T/m, respectively. We proposed the new magnetic force control system that consists of the multiple racetrack HTS magnets. We can control the magnetic field gradient along the longitudinal direction by the arrangement of the multiple racetrack HTS magnets and operating current of each magnet. When the racetrack HTS magnets were used, the critical current was reduced by the self-magnetic field. Therefore, the shape design of HTS magnet to reduce the magnet field into the surface of HTS tapes was required. Therefore, the electromagnetic analysis based on finite element method (FEM) was carried out to design and optimize the shape of multiple racetrack HTS magnet. We were able to suppress the reduction of critical current by placing the magnetic substance at upper and lower side of the HTS magnets. It was confirmed that obtained maximum values of magnetic field strength and field gradient were 33 mT and 0.18 T/m, respectively.

Enhanced critical current in superconducting FeSe 0.5 Te 0.5 films at all magnetic field orientations by scalable gold ion irradiation

DOE PAGES

Ozaki, Toshinori; Wu, Lijun; Zhang, Cheng; ...

2018-01-17

The loss-less electrical current-carrying capability of type II superconductors, measured by the critical current density J c, can be increased by engineering desirable defects in superconductors to pin the magnetic vortices. Here, we demonstrate that such desirable defects can be created in superconducting FeSe 0.5Te 0.5 films by 6 MeV Au-ions irradiations that produce cluster-like defects with sizes of 10–15 nm over the entire film. The pristine FeSe 0.5Te 0.5 film exhibits a low anisotropy in the angular dependence of J c. A clear improvement in the J c is observed upon Au-ion irradiation for all field orientations at 4.2more » K. Furthermore, a nearly 70% increase in J c is observed at a magnetic field of 9 T applied parallel to the crystallographic c-axis at 10 K with little reduction of the superconducting transition temperature T c. Our studies show that a dose of 1×10 12 Au cm –2 irradiation at a few MeV is sufficient in order to provide a strong isotropic pinning defect landscape in iron-based superconducting films.« less

Enhanced critical current in superconducting FeSe 0.5 Te 0.5 films at all magnetic field orientations by scalable gold ion irradiation

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

Ozaki, Toshinori; Wu, Lijun; Zhang, Cheng

The loss-less electrical current-carrying capability of type II superconductors, measured by the critical current density J c, can be increased by engineering desirable defects in superconductors to pin the magnetic vortices. Here, we demonstrate that such desirable defects can be created in superconducting FeSe 0.5Te 0.5 films by 6 MeV Au-ions irradiations that produce cluster-like defects with sizes of 10–15 nm over the entire film. The pristine FeSe 0.5Te 0.5 film exhibits a low anisotropy in the angular dependence of J c. A clear improvement in the J c is observed upon Au-ion irradiation for all field orientations at 4.2more » K. Furthermore, a nearly 70% increase in J c is observed at a magnetic field of 9 T applied parallel to the crystallographic c-axis at 10 K with little reduction of the superconducting transition temperature T c. Our studies show that a dose of 1×10 12 Au cm –2 irradiation at a few MeV is sufficient in order to provide a strong isotropic pinning defect landscape in iron-based superconducting films.« less

Recent Developments in Computed Tomography for Urolithiasis: Diagnosis and Characterization

PubMed Central

Mc Laughlin, P. D.; Crush, L.; Maher, M. M.; O'Connor, O. J.

2012-01-01

Objective. To critically evaluate the current literature in an effort to establish the current role of radiologic imaging, advances in computed tomography (CT) and standard film radiography in the diagnosis, and characterization of urinary tract calculi. Conclusion. CT has a valuable role when utilized prudently during surveillance of patients following endourological therapy. In this paper, we outline the basic principles relating to the effects of exposure to ionizing radiation as a result of CT scanning. We discuss the current developments in low-dose CT technology, which have resulted in significant reductions in CT radiation doses (to approximately one-third of what they were a decade ago) while preserving image quality. Finally, we will discuss an important recent development now commercially available on the latest generation of CT scanners, namely, dual energy imaging, which is showing promise in urinary tract imaging as a means of characterizing the composition of urinary tract calculi. PMID:22952473

Influence of Joule heating on current-induced domain wall depinning

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

Moretti, Simone, E-mail: simone.moretti@usal.es; Raposo, Victor; Martinez, Eduardo

2016-06-07

The domain wall depinning from a notch in a Permalloy nanostrip on top of a SiO{sub 2}/Si substrate is studied theoretically under application of static magnetic fields and the injection of short current pulses. The influence of Joule heating on current-induced domain wall depinning is explored self-consistently by coupling the magnetization dynamics in the ferromagnetic strip to the heat transport throughout the system. Our results indicate that Joule heating plays a remarkable role in these processes, resulting in a reduction in the critical depinning field and/or in a temporary destruction of the ferromagnetic order for typically injected current pulses. Inmore » agreement with experimental observations, similar pinning-depinning phase diagrams can be deduced for both current polarities when the Joule heating is taken into account. These observations, which are incompatible with the sole contribution of spin transfer torques, provide a deeper understanding of the physics underlying these processes and establish the real scope of the spin transfer torque. They are also relevant for technological applications based on current-induced domain-wall motion along soft strips.« less

Anaemia only causes a small reduction in the upper critical temperature of sea bass: is oxygen delivery the limiting factor for tolerance of acute warming in fishes?

PubMed

Wang, Tobias; Lefevre, Sjannie; Iversen, Nina K; Findorf, Inge; Buchanan, Rasmus; McKenzie, David J

2014-12-15

To address how the capacity for oxygen transport influences tolerance of acute warming in fishes, we investigated whether a reduction in haematocrit, by means of intra-peritoneal injection of the haemolytic agent phenylhydrazine, lowered the upper critical temperature of sea bass. A reduction in haematocrit from 42±2% to 20±3% (mean ± s.e.m.) caused a significant but minor reduction in upper critical temperature, from 35.8±0.1 to 35.1±0.2°C, with no correlation between individual values for haematocrit and upper thermal limit. Anaemia did not influence the rise in oxygen uptake between 25 and 33°C, because the anaemic fish were able to compensate for reduced blood oxygen carrying capacity with a significant increase in cardiac output. Therefore, in sea bass the upper critical temperature, at which they lost equilibrium, was not determined by an inability of the cardio-respiratory system to meet the thermal acceleration of metabolic demands. © 2014. Published by The Company of Biologists Ltd.

Cigarette users' interest in using or switching to electronic nicotine delivery systems for smokeless tobacco for harm reduction, cessation, or novelty: a cross-sectional survey of US adults.

PubMed

Berg, Carla J; Haardoerfer, Regine; Escoffery, Cam; Zheng, Pinpin; Kegler, Michelle

2015-02-01

We examined: (a) current (past 30-day) smokers' interest in using or switching to electronic nicotine delivery systems (ENDS) or smokeless tobacco for various reasons; (b) correlates of interest in these products; and (c) subgroups of current smokers in relation to interest in these products. We conducted a cross-sectional survey assessing sociodemographics, tobacco use, interest in ENDS and smokeless tobacco among smokers, and knowledge about ENDS among 2,501 US adults recruited through an online consumer panel. We oversampled tobacco users (36.7% current cigarette smokers), ethnic minorities, and southeastern US state residents. On average, participants were more interested in ENDS than smokeless tobacco across all reasons provided. Additionally, they were less interested in either product because of their potential use in places prohibiting smoking or due to curiosity and more interested in reducing health risk or cigarette consumption or to aid in cessation. We documented high rates (27.9%) of misbeliefs about Food and Drug Administration approval of ENDS for cessation, particularly among current smokers (38.5%). Also, 27.2% of current smokers had talked with a health care provider about ENDS, with 18.0% reporting that their provider endorsed ENDS use for cessation. Furthermore, cluster analyses revealed 3 groups distinct in their interest in the products, sociodemographics, and smoking-related characteristics. This study highlights higher interest in ENDS versus smokeless tobacco and greater interest in both for harm reduction and cessation than due to novelty or smoking restrictions. Developing educational campaigns and informing practitioners about caveats around ENDS as cessation or harm reduction aids are critical. © The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A YAC contig encompassing the Treacher Collins syndrome critical region at 5q31. 3-32

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

Dixon, J.; Gladwin, A.J.; Perveen, R.

Treacher Collins syndrome (TCOF1) is an autosomal dominant disorder of craniofacial development the features of which include conductive hearing loss and cleft palate. Previous studies have localized the TCOF1 locus between D5S519 (proximal) and SPARC (distal), a region of 22 centirays as estimated by radiation hybrid mapping. In the current investigation the authors have created a contig across the TCOF1 critical region, using YAC clones. Isolation of a novel short tandem repeat polymorphism corresponding to the end of one of the YACs has allowed reduction of the size of the critical region to [approximately] 840 kb, which has been coveredmore » with three nonchimeric YACs. Restriction mapping has revealed that the region contains a high density of clustered rare-cutter restriction sites, suggesting that it may contain a number of different genes. The results of the present investigation have further allowed confirmation that the RPS14 locus lies proximal to the critical region and can thereby be excluded from a role in the pathogenesis of TCOF1, while ANX6 lies within the TCOF1 critical region and remains a potential candidate for the mutated gene. 26 refs., 4 figs., 1 tab.« less

Oxygen in the critically ill: friend or foe?

PubMed

Damiani, Elisa; Donati, Abele; Girardis, Massimo

2018-04-01

To examine the potential harmful effects of hyperoxia and summarize the results of most recent clinical studies evaluating oxygen therapy in critically ill patients. Excessive oxygen supplementation may have detrimental pulmonary and systemic effects because of enhanced oxidative stress and inflammation. Hyperoxia-induced lung injury includes altered surfactant protein composition, reduced mucociliary clearance and histological damage, resulting in atelectasis, reduced lung compliance and increased risk of infections. Hyperoxemia causes vasoconstriction, reduction in coronary blood flow and cardiac output and may alter microvascular perfusion. Observational studies showed a close relationship between hyperoxemia and increased mortality in several subsets of critically ill patients. In absence of hypoxemia, the routine use of oxygen therapy in patients with myocardial infarction, stroke, traumatic brain injury, cardiac arrest and sepsis, showed no benefit but rather it seems to be harmful. In patients admitted to intensive care unit, a conservative oxygen therapy aimed to maintain arterial oxygenation within physiological range has been proved to be well tolerated and may improve outcome. Liberal O2 use and unnecessary hyperoxia may be detrimental in critically ill patients. The current evidence supports the use of a conservative strategy in O2 therapy to avoid patient exposure to unnecessary hyperoxemia.

A Market Model for Evaluating Technologies That Impact Critical-Material Intensity

NASA Astrophysics Data System (ADS)

Iyer, Ananth V.; Vedantam, Aditya

2016-07-01

A recent Critical Materials Strategy report highlighted the supply chain risk associated with neodymium and dysprosium, which are used in the manufacturing of neodymium-iron-boron permanent magnets (PM). In response, the Critical Materials Institute is developing innovative strategies to increase and diversify primary production, develop substitutes, reduce material intensity and recycle critical materials. Our goal in this paper is to propose an economic model to quantify the impact of one of these strategies, material intensity reduction. Technologies that reduce material intensity impact the economics of magnet manufacturing in multiple ways because of: (1) the lower quantity of critical material required per unit PM, (2) more efficient use of limited supply, and (3) the potential impact on manufacturing cost. However, the net benefit of these technologies to a magnet manufacturer is an outcome of an internal production decision subject to market demand characteristics, availability and resource constraints. Our contribution in this paper shows how a manufacturer's production economics moves from a region of being supply-constrained, to a region enabling the market optimal production quantity, to a region being constrained by resources other than critical materials, as the critical material intensity changes. Key insights for engineers and material scientists are: (1) material intensity reduction can have a significant market impact, (2) benefits to manufacturers are non-linear in the material intensity reduction, (3) there exists a threshold value for material intensity reduction that can be calculated for any target PM application, and (4) there is value for new intellectual property (IP) when existing manufacturing technology is IP-protected.

Polymer-surfactant complex formation and its effect on turbulent wall shear stress.

PubMed

Suksamranchit, Siriluck; Sirivat, Anuvat; Jamieson, Alexander M

2006-02-01

Turbulent drag reduction in Couette flow was investigated in terms of a decrease in wall shear stress for aqueous solutions of a nonionic polymer, poly(ethylene oxide) (PEO), a cationic surfactant, hexadecyltrimethylammonium chloride (HTAC), and their mixtures. Consistent with literature data, drag reduction was observed for PEO solutions above a critical molecular weight, 0.91 x 10(5) < Mc < 3.04 x 10(5) g/mol. Maximum drag reduction occurred at an optimum concentration, c(PEO)*, which scales inversely with molecular weight, and the % maximum drag reduction increases with molecular weight. For aqueous HTAC solutions, wall shear stress decreased with increasing HTAC concentration and leveled off at an optimum concentration, c(HTAC)*, comparable to the critical micelle concentration. For HTAC/PEO mixtures, the critical PEO molecular weight for drag reduction decreases, interpreted as due to an increase in hydrodynamic volume because of binding of HTAC micelles to PEO. Consistent with this interpretation, at fixed PEO concentration, maximum drag reduction was observed at an optimum HTAC concentration, c(HTAC/PEO)*, comparable to the maximum binding concentration, MBC. Also, with HTAC concentration fixed at the MBC, the optimum PEO concentration for drag reduction, c(PEO/HTAC)*, decreases relative to that, c(PEO)*, in the absence of HTAC.

Complementary and alternative exercise for fibromyalgia: a meta-analysis.

PubMed

Mist, Scott David; Firestone, Kari A; Jones, Kim Dupree

2013-01-01

Complementary and alternative medicine includes a number of exercise modalities, such as tai chi, qigong, yoga, and a variety of lesser-known movement therapies. A meta-analysis of the current literature was conducted estimating the effect size of the different modalities, study quality and bias, and adverse events. The level of research has been moderately weak to date, but most studies report a medium-to-high effect size in pain reduction. Given the lack of adverse events, there is little risk in recommending these modalities as a critical component in a multimodal treatment plan, which is often required for fibromyalgia management.

Surface Ligand Promotion of Carbon Dioxide Reduction through Stabilizing Chemisorbed Reactive Intermediates.

PubMed

Wang, Zhijiang; Wu, Lina; Sun, Kun; Chen, Ting; Jiang, Zhaohua; Cheng, Tao; Goddard, William A

2018-05-23

We have explored functionalizing metal catalysts with surface ligands as an approach to facilitate electrochemical carbon dioxide reduction reaction (CO 2 RR). To provide a molecular level understanding of the mechanism by which this enhancement occurs, we combine in situ spectroscopy analysis with an interpretation based on quantum mechanics (QM) calculations. We find that a surface ligand can play a critical role in stabilizing the chemisorbed CO 2 , which facilitates CO 2 activation and leads to a 0.3 V decrease in the overpotential for carbon monoxide (CO) formation. Moreover, the presence of the surface ligand leads to nearly exclusive CO production. At -0.6 V (versus reversible hydrogen electrode, RHE), CO is the only significant product with a faradic efficiency of 93% and a current density of 1.9 mA cm -2 . This improvement corresponds to 53-fold enhancement in turnover frequency compared with the Ag nanoparticles (NPs) without surface ligands.

Orthopaedic traumatology: fundamental principles and current controversies for the acute care surgeon

PubMed Central

Pharaon, Shad K; Schoch, Shawn; Marchand, Lucas; Mirza, Amer

2018-01-01

Multiply injured patients with fractures are co-managed by acute care surgeons and orthopaedic surgeons. In most centers, orthopaedic surgeons definitively manage fractures, but preliminary management, including washouts, splinting, reductions, and external fixations, may be performed by selected acute care surgeons. The acute care surgeon should have a working knowledge of orthopaedic terminology to communicate with colleagues effectively. They should have an understanding of the composition of bone, periosteum, and cartilage, and their reaction when there is an injury. Fractures are usually fixed urgently, but some multiply injured patients are better served with a damage control strategy. Extremity compartment syndrome should be suspected in all critically injured patients with or without fractures and a low threshold for compartment pressure measurements or empiric fasciotomy maintained. Acute care surgeons performing rib fracture fixation and other chest wall injury reconstructions should follow the principles of open fracture reduction and stabilization. PMID:29766123

Orthopaedic traumatology: fundamental principles and current controversies for the acute care surgeon.

PubMed

Pharaon, Shad K; Schoch, Shawn; Marchand, Lucas; Mirza, Amer; Mayberry, John

2018-01-01

Multiply injured patients with fractures are co-managed by acute care surgeons and orthopaedic surgeons. In most centers, orthopaedic surgeons definitively manage fractures, but preliminary management, including washouts, splinting, reductions, and external fixations, may be performed by selected acute care surgeons. The acute care surgeon should have a working knowledge of orthopaedic terminology to communicate with colleagues effectively. They should have an understanding of the composition of bone, periosteum, and cartilage, and their reaction when there is an injury. Fractures are usually fixed urgently, but some multiply injured patients are better served with a damage control strategy. Extremity compartment syndrome should be suspected in all critically injured patients with or without fractures and a low threshold for compartment pressure measurements or empiric fasciotomy maintained. Acute care surgeons performing rib fracture fixation and other chest wall injury reconstructions should follow the principles of open fracture reduction and stabilization.

Sizing Single Cantilever Beam Specimens for Characterizing Facesheet/Core Peel Debonding in Sandwich Structure

NASA Technical Reports Server (NTRS)

Ratcliffe, James G.

2010-01-01

This paper details part of an effort focused on the development of a standardized facesheet/core peel debonding test procedure. The purpose of the test is to characterize facesheet/core peel in sandwich structure, accomplished through the measurement of the critical strain energy release rate associated with the debonding process. The specific test method selected for the standardized test procedure utilizes a single cantilever beam (SCB) specimen configuration. The objective of the current work is to develop a method for establishing SCB specimen dimensions. This is achieved by imposing specific limitations on specimen dimensions, with the objectives of promoting a linear elastic specimen response, and simplifying the data reduction method required for computing the critical strain energy release rate associated with debonding. The sizing method is also designed to be suitable for incorporation into a standardized test protocol. Preliminary application of the resulting sizing method yields practical specimen dimensions.

New perspectives for advanced automobile diesel engines

NASA Technical Reports Server (NTRS)

Tozzi, L.; Sekar, R.; Kamo, R.; Wood, J. C.

1983-01-01

Computer simulation results are presented for advanced automobile diesel engine performance. Four critical factors for performance enhancement were identified: (1) part load preheating and exhaust gas energy recovery, (2) fast heat release combustion process, (3) reduction in friction, and (4) air handling system efficiency. Four different technology levels were considered in the analysis. Simulation results are compared in terms of brake specific fuel consumption and vehicle fuel economy in km/liter (miles per gallon). Major critical performance sensitivity areas are: (1) combustion process, (2) expander and compressor efficiency, and (3) part load preheating and compound system. When compared to the state of the art direct injection, cooled, automobile diesel engine, the advanced adiabatic compound engine concept showed the unique potential of doubling the fuel economy. Other important performance criteria such as acceleration, emissions, reliability, durability and multifuel capability are comparable to or better than current passenger car diesel engines.

Psychological science's contributions to a sustainable environment: extending our reach to a grand challenge of society.

PubMed

Kazdin, Alan E

2009-01-01

Climate change and degradation of the environment are global problems associated with many other challenges (e.g., population increases, reduction of glaciers, and loss of critical habitats). Psychological science can play a critical role in addressing these problems by fostering a sustainable environment. Multiple strategies for fostering a sustainable environment could draw from the diversity of topics and areas of specialization within psychology. Psychological research on fostering environmentally sustainable behaviors is rather well developed, as illustrated by interventions focusing on education of the public, message framing, feedback, decision making, the media, incentives and disincentives, and social marketing. Other sciences and professions as well as religion and ethics are actively involved in fostering a sustainable environment. Psychology ought to be more involved directly, systematically, and visibly to draw on our current knowledge and to have palpable impact. We would serve the world very well and in the process our discipline and profession.

Core Noise Reduction

NASA Technical Reports Server (NTRS)

Hultgren, Lennart S.

2011-01-01

This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015, 2020, and 2025 timeframes; turbofan design trends and their aeroacoustic implications; the emerging importance of core noise and its relevance to the SFW Reduce-Perceived-Noise Technical Challenge; and the current research activities in the core noise area. Recent work1 on the turbine-transmission loss of combustor noise is briefly described, two2,3 new NRA efforts in the core-noise area are outlined, and an effort to develop CMC-based acoustic liners for broadband noise reduction suitable for turbofan-core application is delineated. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic. The Subsonic Fixed Wing Project's Reduce-Perceived-Noise Technical Challenge aims to develop concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries.

Dissimilatory Reduction of Extracellular Electron Acceptors in Anaerobic Respiration

PubMed Central

Richter, Katrin; Schicklberger, Marcus

2012-01-01

An extension of the respiratory chain to the cell surface is necessary to reduce extracellular electron acceptors like ferric iron or manganese oxides. In the past few years, more and more compounds were revealed to be reduced at the surface of the outer membrane of Gram-negative bacteria, and the list does not seem to have an end so far. Shewanella as well as Geobacter strains are model organisms to discover the biochemistry that enables the dissimilatory reduction of extracellular electron acceptors. In both cases, c-type cytochromes are essential electron-transferring proteins. They make the journey of respiratory electrons from the cytoplasmic membrane through periplasm and over the outer membrane possible. Outer membrane cytochromes have the ability to catalyze the last step of the respiratory chains. Still, recent discoveries provided evidence that they are accompanied by further factors that allow or at least facilitate extracellular reduction. This review gives a condensed overview of our current knowledge of extracellular respiration, highlights recent discoveries, and discusses critically the influence of different strategies for terminal electron transfer reactions. PMID:22179232

How to simulate pedestrian behaviors in seismic evacuation for vulnerability reduction of existing buildings

NASA Astrophysics Data System (ADS)

Quagliarini, Enrico; Bernardini, Gabriele; D'Orazio, Marco

2017-07-01

Understanding and representing how individuals behave in earthquake emergencies would be essentially to assess the impact of vulnerability reduction strategies on existing buildings in seismic areas. In fact, interactions between individuals and the scenario (modified by the earthquake occurrence) are really important in order to understand the possible additional risks for people, especially during the evacuation phase. The current approach is based on "qualitative" aspects, in order to define best practice guidelines for Civil Protection and populations. On the contrary, a "quantitative" description of human response and evacuation motion in similar conditions is urgently needed. Hence, this work defines the rules for pedestrians' earthquake evacuation in urban scenarios, by taking advantages of previous results of real-world evacuation analyses. In particular, motion laws for pedestrians is defined by modifying the Social Force model equation. The proposed model could be used for evaluating individuals' evacuation process and so for defining operative strategies for interferences reduction in critical urban fabric parts (e.g.: interventions on particular buildings, evacuation strategies definition, city parts projects).

The role of occupational and physiotherapy in multi-modal approach to tackling delirium in the intensive care

PubMed Central

Chee, Nigel

2017-01-01

The presence of delirium within critical care remains a long-standing challenge for patients and clinicians alike. A myriad of pre-disposing and precipitating factors lead to this patient cohort being high risk for developing delirium during their critical care stay. Until now, non-pharmacological management of these patients usually encompasses a ‘bundle’ of principles to reduce delirium days. These bundles have limited focus on the entire multi-disciplinary team (including occupational therapists and physiotherapists) who could assist with the reduction of delirium. The purpose of this analysis is to review the current literature and develop a mnemonic, which may help facilitate collaborative working for patients with delirium. Electronic databases were searched for non-pharmacological managements of delirium within intensive care settings, after 2006. Critical appraisal using Critical Appraisal Skills Programme methodology was completed by the author. Multi-intervention approaches and bundles are successful at reducing delirium days, and in some cases, reducing hospital length of stay. The key components of these bundles include spontaneous breathing trials, daily sedation holds, addressing pain relief, early mobilisation and to a small extent normalisation of a daily routine. There is limited research into the role of therapy within this patient group, but there is a role for cognitive therapy, functional tasks, and a greater rehab emphasis within other patient populations such as stroke and elderly care. The critical care population have similar rehabilitation needs to these groups, and therefore would benefit from similar treatment plans. Critical care patients with delirium may benefit from a range of additional therapeutic activities to reduce the duration of delirium. The D.E.L.I.R.I.U.M mnemonic has been developed to encompass all the key elements of current delirium research in a simplistic memorable fashion. Further work is needed to trial the usefulness of the mnemonic in clinical practice to enable the entire multi-disciplinary team work collaboratively to reduce delirium with the intensive care. PMID:29123562

Evaluation of oxygen reduction activity by the thin-film rotating disk electrode methodology: The effects of potentiodynamic parameters

DOE PAGES

Chen, Guangyu; Li, Meng; Kuttiyiel, Kurian A.; ...

2016-04-11

Here, an accurate and efficient assessment of activity is critical for the research and development of electrocatalysts for oxygen reduction reaction (ORR). Currently, the methodology combining the thin-film rotating disk electrode (TF-RDE) and potentiodynamic polarization is the most commonly used to pre-evaluate ORR activity, acquire kinetic data (i.e., kinetic current, Tafel slope, etc.), and gain understanding of the ORR mechanism. However, it is often neglected that appropriate potentiodynamic parameters have to be chosen to obtain reliable results. We first evaluate the potentiodynamic and potentiostatic polarization measurements with TF-RDE to examine the ORR activity of Pt nanoelectrocatalyst. Furthermore, our results demonstratemore » that besides depending on the nature of electrocatalyst, the apparent ORR kinetics also strongly depends on the associated potentiodynamic parameters, such as scan rate and scan region, which have a great effect on the coverage of adsorbed OH ad/O ad on Pt surface, thereby affecting the ORR activities of both nanosized and bulk Pt. However, the apparent Tafel slopes remained nearly the same, indicating that the ORR mechanism in all the measurements was not affected by different potentiodynamic parameters.« less

Implementing critical pathways and a multidisciplinary team approach to cardiovascular disease management.

PubMed

Peterson, Eric D; Albert, Nancy M; Amin, Alpesh; Patterson, J Herbert; Fonarow, Gregg C

2008-09-08

According to several medical registries, there is a need to improve the care of post-myocardial infarction (MI) patients, especially those with left ventricular dysfunction (LVD) and heart failure. This can potentially be achieved by implementing disease management programs, which include critical pathways, patient education, and multidisciplinary hospital teams. Currently, algorithms for critical pathways, including discharge processes, are lacking for post-MI LVD patients. Such schemes can increase the use of evidence-based medicines proved to reduce mortality. Educational programs are aimed at increasing patients' awareness of their condition, promoting medication compliance, and encouraging the adoption of healthy behaviors; such programs have been shown to be effective in improving outcomes of post-MI LVD patients. Reductions in all-cause hospitalizations and medical costs as well as improved survival rates have been observed when a multidisciplinary team (a nurse, a pharmacist, and a hospitalist) is engaged in patient care. In addition, the use of the "pay for performance" method, which can be advantageous for patients, physicians, and hospitals, may potentially improve the care of post-MI patients with LVD.

Lean spacecraft avionics trade study

NASA Technical Reports Server (NTRS)

Main, John A.

1994-01-01

Spacecraft design is generally an exercise in design trade-offs: fuel vs. weight, power vs. solar cell area, radiation exposure vs. shield weight, etc. Proper analysis of these trades is critical in the development of lightweight, efficient, 'lean' satellites. The modification of the launch plans for the Magnetosphere Imager (MI) to a Taurus launcher from the much more powerful Delta has forced a reduction in spacecraft weight availability into the mission orbit from 1300 kg to less than 500 kg. With weight now a driving factor it is imperative that the satellite design be extremely efficient and lean. The accuracy of engineering trades now takes on an added importance. An understanding of spacecraft subsystem interactions is critical in the development of a good spacecraft design, yet it is a challenge to define these interactions while the design is immature. This is currently an issue in the development of the preliminary design of the MI. The interaction and interfaces between this spacecraft and the instruments it carries are currently unclear since the mission instruments are still under development. It is imperative, however, to define these interfaces so that avionics requirements ideally suited to the mission's needs can be determined.

High quantum efficiency and low dark count rate in multi-layer superconducting nanowire single-photon detectors

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

Jafari Salim, A., E-mail: ajafaris@uwaterloo.ca; Eftekharian, A.; University of Waterloo, Waterloo, Ontario N2L 3G1

In this paper, we theoretically show that a multi-layer superconducting nanowire single-photon detector (SNSPD) is capable of approaching characteristics of an ideal SNSPD in terms of the quantum efficiency, dark count, and band-width. A multi-layer structure improves the performance in two ways. First, the potential barrier for thermally activated vortex crossing, which is the major source of dark counts and the reduction of the critical current in SNSPDs is elevated. In a multi-layer SNSPD, a vortex is made of 2D-pancake vortices that form a stack. It will be shown that the stack of pancake vortices effectively experiences a larger potentialmore » barrier compared to a vortex in a single-layer SNSPD. This leads to an increase in the experimental critical current as well as significant decrease in the dark count rate. In consequence, an increase in the quantum efficiency for photons of the same energy or an increase in the sensitivity to photons of lower energy is achieved. Second, a multi-layer structure improves the efficiency of single-photon absorption by increasing the effective optical thickness without compromising the single-photon sensitivity.« less

ERG voltage-gated K+ channels regulate excitability and discharge dynamics of the medial vestibular nucleus neurones

PubMed Central

Pessia, Mauro; Servettini, Ilenio; Panichi, Roberto; Guasti, Leonardo; Grassi, Silvarosa; Arcangeli, Annarosa; Wanke, Enzo; Pettorossi, Vito Enrico

2008-01-01

The discharge properties of the medial vestibular nucleus neurones (MVNn) critically depend on the activity of several ion channel types. In this study we show, immunohistochemically, that the voltage-gated K+ channels ERG1A, ERG1B, ERG2 and ERG3 are highly expressed within the vestibular nuclei of P10 and P60 mice. The role played by these channels in the spike-generating mechanisms of the MVNn and in temporal information processing was investigated electrophysiologically from mouse brain slices, in vitro, by analysing the spontaneous discharge and the response to square-, ramp- and sinusoid-like intracellular DC current injections in extracellular and whole-cell patch-clamp studies. We show that more than half of the recorded MVNn were responsive to ERG channel block (WAY-123,398, E4031), displaying an increase in spontaneous activity and discharge irregularity. The response to step and ramp current injection was also modified by ERG block showing a reduction of first spike latency, enhancement of discharge rate and reduction of the slow spike-frequency adaptation process. ERG channels influence the interspike slope without affecting the spike shape. Moreover, in response to sinusoid-like current, ERG channel block caused frequency-dependent gain enhancement and phase-lead shift. Taken together, the data demonstrate that ERG channels control the excitability of MVNn, their discharge regularity and probably their resonance properties. PMID:18718985

ERG voltage-gated K+ channels regulate excitability and discharge dynamics of the medial vestibular nucleus neurones.

PubMed

Pessia, Mauro; Servettini, Ilenio; Panichi, Roberto; Guasti, Leonardo; Grassi, Silvarosa; Arcangeli, Annarosa; Wanke, Enzo; Pettorossi, Vito Enrico

2008-10-15

The discharge properties of the medial vestibular nucleus neurones (MVNn) critically depend on the activity of several ion channel types. In this study we show, immunohistochemically, that the voltage-gated K(+) channels ERG1A, ERG1B, ERG2 and ERG3 are highly expressed within the vestibular nuclei of P10 and P60 mice. The role played by these channels in the spike-generating mechanisms of the MVNn and in temporal information processing was investigated electrophysiologically from mouse brain slices, in vitro, by analysing the spontaneous discharge and the response to square-, ramp- and sinusoid-like intracellular DC current injections in extracellular and whole-cell patch-clamp studies. We show that more than half of the recorded MVNn were responsive to ERG channel block (WAY-123,398, E4031), displaying an increase in spontaneous activity and discharge irregularity. The response to step and ramp current injection was also modified by ERG block showing a reduction of first spike latency, enhancement of discharge rate and reduction of the slow spike-frequency adaptation process. ERG channels influence the interspike slope without affecting the spike shape. Moreover, in response to sinusoid-like current, ERG channel block caused frequency-dependent gain enhancement and phase-lead shift. Taken together, the data demonstrate that ERG channels control the excitability of MVNn, their discharge regularity and probably their resonance properties.

Overview of ASDEX Upgrade results

DOE PAGES

Aguiam, D.

2017-06-28

Here, the ASDEX Upgrade (AUG) programme is directed towards physics input to critical elements of the ITER design and the preparation of ITER operation, as well as addressing physics issues for a future DEMO design. Since 2015, AUG is equipped with a new pair of 3-strap ICRF antennas, which were designed for a reduction of tungsten release during ICRF operation. As predicted, a factor two reduction on the ICRF-induced W plasma content could be achieved by the reduction of the sheath voltage at the antenna limiters via the compensation of the image currents of the central and side straps in the antenna frame. There are two main operational scenario lines in AUG. Experiments with low collisionality, which comprise current drive, ELM mitigation/suppression and fast ion physics, are mainly done with freshly boronized walls to reduce the tungsten influx at these high edge temperature conditions. Full ELM suppression and non-inductive operation up to a plasma current ofmore » $${{I}_{\\text{p}}}=0.8$$ MA could be obtained at low plasma density. Plasma exhaust is studied under conditions of high neutral divertor pressure and separatrix electron density, where a fresh boronization is not required. Substantial progress could be achieved for the understanding of the confinement degradation by strong D puffing and the improvement with nitrogen or carbon seeding. Inward/outward shifts of the electron density profile relative to the temperature profile effect the edge stability via the pressure profile changes and lead to improved/decreased pedestal performance. Seeding and D gas puffing are found to effect the core fueling via changes in a region of high density on the high field side (HFSHD).« less

Efficient Conversion of CO 2 to CO Using Tin and Other Inexpensive and Easily Prepared Post-Transition Metal Catalysts

DOE PAGES

Medina-Ramos, Jonnathan; Pupillo, Rachel C.; Keane, Thomas P.; ...

2015-02-19

The development of affordable electrocatalysts that can drive the reduction of CO 2 to CO with high selectivity, efficiency, and large current densities is a critical step on the path to production of liquid carbon-based fuels. In this work, we show that inexpensive triflate salts of Sn 2+, Pb 2+, Bi 3+, and Sb 3+ can be used as precursors for the electrodeposition of CO 2 reduction cathode materials from MeCN solutions, providing a general and facile electrodeposition strategy, which streamlines catalyst synthesis. The ability of these four platforms to drive the formation of CO from CO 2 in themore » presence of [BMIM]OTf was probed. The electrochemically prepared Sn and Bi catalysts proved to be highly active, selective, and robust platforms for CO evolution, with partial current densities of j CO = 5-8 mA/cm 2 at applied overpotentials of η < 250 mV. By contrast, the electrodeposited Pb and Sb catalysts do not promote rapid CO generation with the same level of selectivity. The Pb material is only ~10% as active as the Sn and Bi systems at an applied potential of E = -1.95 V and is rapidly passivated during catalysis. The Sb-comprised cathode material shows no activity for conversion of CO 2 to CO under analogous conditions. When taken together, this work demonstrates that 1,3-dialkylimidazoliums can promote CO production, but only when used in combination with an appropriately chosen electrocatalyst material. More broadly, these results suggest that the interactions between CO 2, the imidazolium promoter, and the cathode surface are all critical to the observed catalysis.« less

Critical Nuclei Size, Rate, and Activation Energy of H2 Gas Nucleation.

PubMed

German, Sean R; Edwards, Martin A; Ren, Hang; White, Henry S

2018-03-21

Electrochemical measurements of the nucleation rate of individual H 2 bubbles at the surface of Pt nanoelectrodes (radius = 7-41 nm) are used to determine the critical size and geometry of H 2 nuclei leading to stable bubbles. Precise knowledge of the H 2 concentration at the electrode surface, C H 2 surf , is obtained by controlled current reduction of H + in a H 2 SO 4 solution. Induction times of single-bubble nucleation events are measured by stepping the current, to control C H 2 surf , while monitoring the voltage. We find that gas nucleation follows a first-order rate process; a bubble spontaneously nucleates after a stochastic time delay, as indicated by a sudden voltage spike that results from impeded transport of H + to the electrode. Hundreds of individual induction times, at different applied currents and using different Pt nanoelectrodes, are used to characterize the kinetics of phase nucleation. The rate of bubble nucleation increases by four orders of magnitude (0.3-2000 s -1 ) over a very small relative change in C H 2 surf (0.21-0.26 M, corresponding to a ∼0.025 V increase in driving force). Classical nucleation theory yields thermodynamic radii of curvature for critical nuclei of 4.4 to 5.3 nm, corresponding to internal pressures of 330 to 270 atm, and activation energies for nuclei formation of 14 to 26 kT, respectively. The dependence of nucleation rate on H 2 concentration indicates that nucleation occurs by a heterogeneous mechanism, where the nuclei have a contact angle of ∼150° with the electrode surface and contain between 35 and 55 H 2 molecules.

Smart Solution Chemistry to Sn-Containing Intermetallic Compounds through a Self-Disproportionation Process.

PubMed

Zhang, Yuelan; Li, Liping; Li, Qi; Fan, Jianming; Zheng, Jing; Li, Guangshe

2016-09-26

Developing new methods to synthesize intermetallics is one of the most critical issues for the discovery and application of multifunctional metal materials; however, the synthesis of Sn-containing intermetallics is challenging. In this work, we demonstrated for the first time that a self-disproportionation-induced in situ process produces cavernous Sn-Cu intermetallics (Cu3 Sn and Cu6 Sn5 ). The successful synthesis is realized by introducing inorganic metal salts (SnCl2 ⋅2 H2 O) to NaOH aqueous solution to form an intermediate product of reductant (Na2 SnO2 ) and by employing steam pressures that enhance the reduction ability. Distinct from the traditional in situ reduction, the current reduction process avoided the uncontrolled phase composition and excessive use of organic regents. An insight into the mechanism was revealed for the Sn-Cu case. Moreover, this method could be extended to other Sn-containing materials (Sn-Co, Sn-Ni). All these intermetallics were attempted in the catalytic effect on thermal decompositions of ammonium perchlorate. It is demonstrated that Cu3 Sn showed an outstanding catalytic performance. The superior property might be primarily originated from the intrinsic chemical compositions and cavernous morphology as well. We supposed that this smart solution reduction methodology reported here would provide a new recognition for the reduction reaction, and its modified strategy may be applied to the synthesis of other metals, intermetallics as well as some unknown materials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Prevention of Overweight and Obesity: How Effective is the Current Public Health Approach

PubMed Central

Chan, Ruth S.M; Woo, Jean

2010-01-01

Obesity is a public health problem that has become epidemic worldwide. Substantial literature has emerged to show that overweight and obesity are major causes of co-morbidities, including type II diabetes, cardiovascular diseases, various cancers and other health problems, which can lead to further morbidity and mortality. The related health care costs are also substantial. Therefore, a public health approach to develop population-based strategies for the prevention of excess weight gain is of great importance. However, public health intervention programs have had limited success in tackling the rising prevalence of obesity. This paper reviews the definition of overweight and obesity and the variations with age and ethnicity; health consequences and factors contributing to the development of obesity; and critically reviews the effectiveness of current public health strategies for risk factor reduction and obesity prevention. PMID:20617002

Research on Soft Reduction Amount Distribution to Eliminate Typical Inter-dendritic Crack in Continuous Casting Slab of X70 Pipeline Steel by Numerical Model

NASA Astrophysics Data System (ADS)

Liu, Ke; Wang, Chang; Liu, Guo-liang; Ding, Ning; Sun, Qi-song; Tian, Zhi-hong

2017-04-01

To investigate the formation of one kind of typical inter-dendritic crack around triple point region in continuous casting(CC) slab during the operation of soft reduction, fully coupled 3D thermo-mechanical finite element models was developed, also plant trials were carried out in a domestic continuous casting machine. Three possible types of soft reduction amount distribution (SRAD) in the soft reduction region were analyzed. The relationship between the typical inter-dendritic cracks and soft reduction conditions is presented and demonstrated in production practice. Considering the critical strain of internal crack formation, a critical tolerance for the soft reduction amount distribution and related casing parameters have been proposed for better contribution of soft reduction to the internal quality of slabs. The typical inter-dendritic crack around the triple point region had been eliminated effectively through the application of proposed suggestions for continuous casting of X70 pipeline steel in industrial practice.

Reductions in the Cardiac Transient Outward K+ Current Ito Caused by Chronic β-Adrenergic Receptor Stimulation Are Partly Rescued by Inhibition of Nuclear Factor κB.

PubMed

Panama, Brian K; Korogyi, Adam S; Aschar-Sobbi, Roozbeh; Oh, Yena; Gray, Charles B B; Gang, Hongying; Brown, Joan Heller; Kirshenbaum, Lorrie A; Backx, Peter H

2016-02-19

The fast transient outward potassium current (Ito,f) plays a critical role in the electrical and contractile properties of the myocardium. Ito,f channels are formed by the co-assembly of the pore-forming α-subunits, Kv4.2 and Kv4.3, together with the accessory β-subunit KChIP2. Reductions of Ito,f are common in the diseased heart, which is also associated with enhanced stimulation of β-adrenergic receptors (β-ARs). We used cultured neonatal rat ventricular myocytes to examine how chronic β-AR stimulation decreases Ito,f. To determine which downstream pathways mediate these Ito,f changes, adenoviral infections were used to inhibit CaMKIIδc, CaMKIIδb, calcineurin, or nuclear factor κB (NF-κB). We observed that chronic β-AR stimulation with isoproterenol (ISO) for 48 h reduced Ito,f along with mRNA expression of all three of its subunits (Kv4.2, Kv4.3, and KChIP2). Inhibiting either CaMKIIδc nor CaMKIIδb did not prevent the ISO-mediated Ito,f reductions, even though CaMKIIδc and CaMKIIδb clearly regulated Ito,f and the mRNA expression of its subunits. Likewise, calcineurin inhibition did not prevent the Ito,f reductions induced by β-AR stimulation despite strongly modulating Ito,f and subunit mRNA expression. In contrast, NF-κB inhibition partly rescued the ISO-mediated Ito,f reductions in association with restoration of KChIP2 mRNA expression. Consistent with these observations, KChIP2 promoter activity was reduced by p65 as well as β-AR stimulation. In conclusion, NF-κB, and not CaMKIIδ or calcineurin, partly mediates the Ito,f reductions induced by chronic β-AR stimulation. Both mRNA and KChIP2 promoter data suggest that the ISO-induced Ito,f reductions are, in part, mediated through reduced KChIP2 transcription caused by NF-κB activation. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Critical current and electric transport properties of superconducting epitaxial Nb(Ti)N submicron structures

NASA Astrophysics Data System (ADS)

Klimov, A.; Słysz, W.; Guziewicz, M.; Kolkovsky, V.; Wegrzecki, M.; Bar, J.; Marchewka, M.; Seredyński, B.

2016-12-01

Critical current and current-voltage characteristics of epitaxial Nb(Ti)N submicron ultrathin structures were measured as function of temperature. For 700-nm-wide bridge we found current-driven vortex de-pinning at low temperatures and thermally activated flux flow closer to the transition temperature, as the limiting factors for the critical current density. For 100-nm-wide meander we observed combination of phase-slip activation and vortex-anti-vortex pair (VAP) thermal excitation. Our Nb(Ti)N meander structure demonstrates high de-pairing critical current densities 107 A/cm2 at low temperatures, but the critical currents are much smaller due to presence of the local constrictions.

Two-slot coiled coaxial cable resonator: reaching critical coupling at a reduced number of coils.

PubMed

Hefferman, Gerald; Chen, Zhen; Wei, Tao

2014-11-01

This paper reports the experimental demonstration of a coiled coaxial cable resonator capable of meeting the critical coupling condition using a reduced number of coils relative to previously reported coiled resonators. By introducing a second slot along the length of the device, a two-slot coiled coaxial cable resonator was fabricated and critical coupling observed at 22 turns. An additional device with one-slot, but otherwise identically constructed, was also fabricated. After 44 turns, the one-slot device had yet to reach critical coupling. An ultrahigh signal-to-noise ratio (greater than 70 dB) was observed at critical coupling of the two-slot device. This reduction in number of slots necessary to reach critical coupling, and the corresponding reduction of physical length of the device, makes this demonstration of the control of critical coupling a potentially important step towards the successful application of coiled coaxial cable resonators to microwave communication and robust sensing applications.

The Healthy Eating Agenda in Australia. Is Salt a Priority for Manufacturers?

PubMed Central

Nichols, Tyler; Yam, Chrystal

2017-01-01

Many nation states have endorsed and acted on the World Health Organization’s target of a 30% reduction in global salt consumption by 2025. In Australia, new government-led voluntary measures were initiated in 2009, consisting of public–private partnerships, front-of-pack labelling, and food reformulation targets (which include reduced salt). How Australia’s private sector has responded to this healthy eating agenda has been investigated in a limited way, particularly with regards to manufacturers which produce processed foods considered significant sources of sodium. In this study we asked: have Australia’s largest food manufacturers made “…positive (nutrition) changes to their product portfolios” as disclosed in their public policies, priorities, and communications? And, is salt reduction a priority for processed food manufacturers? A systematic search and critical content-analysis of grey literature published by food manufacturers was conducted. The results suggest half of the sample publically describe some salt reduction activities but the scale and efficacy of these changes is unclear from the available literature. The Australian Government’s Healthy Food Partnership could capitalise on current documented activities in salt reduction, and implement a more comprehensive healthy eating agenda moving forward. In light of the increasing rates of hypertension, population salt consumption and diet-related disease, more could be done. PMID:28809812

The impact of uncertainty on optimal emission policies

NASA Astrophysics Data System (ADS)

Botta, Nicola; Jansson, Patrik; Ionescu, Cezar

2018-05-01

We apply a computational framework for specifying and solving sequential decision problems to study the impact of three kinds of uncertainties on optimal emission policies in a stylized sequential emission problem.We find that uncertainties about the implementability of decisions on emission reductions (or increases) have a greater impact on optimal policies than uncertainties about the availability of effective emission reduction technologies and uncertainties about the implications of trespassing critical cumulated emission thresholds. The results show that uncertainties about the implementability of decisions on emission reductions (or increases) call for more precautionary policies. In other words, delaying emission reductions to the point in time when effective technologies will become available is suboptimal when these uncertainties are accounted for rigorously. By contrast, uncertainties about the implications of exceeding critical cumulated emission thresholds tend to make early emission reductions less rewarding.

Both differences in encoding processes and monitoring at retrieval reduce false alarms when distinctive information is studied.

PubMed

Hanczakowski, Maciej; Mazzoni, Giuliana

2011-04-01

A reduction in false alarms to critical lures is observed in the DRM paradigm (Roediger & McDermott, 1995) when distinctive information is presented at encoding. Two mechanisms have been proposed to account for this reduction. According to the monitoring theory (e.g., the distinctiveness heuristic), lack of diagnostic recollection serves as a basis for discarding non-presented lures. According to the encoding theory, presenting distinctive information at study leads to impoverished relational processing, which results in a reduction in memorial information elicited by critical lures. In the present study a condition was created in which the use of the distinctiveness heuristic was precluded by associating, within the same study, lures with distinctive information in a context different from the study session. Under that condition reduction in false alarms to distinctive critical lures was still observed. This result supports the predictions of the encoding theory. However, when in the same study the use of the distinctiveness heuristic was not precluded, reductions in false alarms to unrelated lures were also observed when distinctive information was presented at study, indicating that both mechanisms are likely to contribute to the rejection of false memories.

The MICRO-BOSS scheduling system: Current status and future efforts

NASA Technical Reports Server (NTRS)

Sadeh, Norman M.

1992-01-01

In this paper, a micro-opportunistic approach to factory scheduling was described that closely monitors the evolution of bottlenecks during the construction of the schedule and continuously redirects search towards the bottleneck that appears to be most critical. This approach differs from earlier opportunistic approaches, as it does not require scheduling large resource subproblems or large job subproblems before revising the current scheduling strategy. This micro-opportunistic approach was implemented in the context of the MICRO-BOSS factory scheduling system. A study comparing MICRO-BOSS against a macro-opportunistic scheduler suggests that the additional flexibility of the micro-opportunistic approach to scheduling generally yields important reductions in both tardiness and inventory. Current research efforts include: adaptation of MICRO-BOSS to deal with sequence-dependent setups and development of micro-opportunistic reactive scheduling techniques that will enable the system to patch the schedule in the presence of contingencies such as machine breakdowns, raw materials arriving late, job cancellations, etc.

NASA's In Space Manufacturing Initiatives: Conquering the Challenges of In-Space Manufacturing

NASA Technical Reports Server (NTRS)

Clinton, R. G., Jr.

2017-01-01

Current maintenance logistics strategy will not be effective for deep space exploration missions. ISM (In Space Manufacturing) offers the potential to: Significantly reduce maintenance logistics mass requirements; Enable the use of recycled materials and in-situ resources for more dramatic reductions in mass requirements; Enable flexibility, giving systems a broad capability to adapt to unanticipated circumstances; Mitigate risks that are not covered by current approaches to maintainability. Multiple projects are underway currently to develop and validate these capabilities for infusion into ISM exploration systems. ISS is a critical testbed for demonstrating ISM technologies, proving out these capabilities, and performing operational validation of deep space ISM applications. Developing and testing FabLab is a major milestone for springboard to DSG/Cis-lunar Space applications. ISM is a necessary paradigm shift in space operations – design for repair culture must be embraced. ISM team needs to be working with exploration system designers now to identify high-value application areas and influence design.

Physical pretreatment – woody biomass size reduction – for forest biorefinery

Treesearch

J.Y. Zhu

2011-01-01

Physical pretreatment of woody biomass or wood size reduction is a prerequisite step for further chemical or biochemical processing in forest biorefinery. However, wood size reduction is very energy intensive which differentiates woody biomass from herbaceous biomass for biorefinery. This chapter discusses several critical issues related to wood size reduction: (1)...

Chemoselective catalytic conversion of glycerol as a biorenewable source to valuable commodity chemicals.

PubMed

Zhou, Chun-Hui Clayton; Beltramini, Jorge N; Fan, Yong-Xian; Lu, G Q Max

2008-03-01

New opportunities for the conversion of glycerol into value-added chemicals have emerged in recent years as a result of glycerol's unique structure, properties, bioavailability, and renewability. Glycerol is currently produced in large amounts during the transesterification of fatty acids into biodiesel and as such represents a useful by-product. This paper provides a comprehensive review and critical analysis on the different reaction pathways for catalytic conversion of glycerol into commodity chemicals, including selective oxidation, selective hydrogenolysis, selective dehydration, pyrolysis and gasification, steam reforming, thermal reduction into syngas, selective transesterification, selective etherification, oligomerization and polymerization, and conversion of glycerol into glycerol carbonate.

Complementary and alternative exercise for fibromyalgia: a meta-analysis

PubMed Central

Mist, Scott David; Firestone, Kari A; Jones, Kim Dupree

2013-01-01

Complementary and alternative medicine includes a number of exercise modalities, such as tai chi, qigong, yoga, and a variety of lesser-known movement therapies. A meta-analysis of the current literature was conducted estimating the effect size of the different modalities, study quality and bias, and adverse events. The level of research has been moderately weak to date, but most studies report a medium-to-high effect size in pain reduction. Given the lack of adverse events, there is little risk in recommending these modalities as a critical component in a multimodal treatment plan, which is often required for fibromyalgia management. PMID:23569397

Ozone dose-response relationships for spring oilseed rape and broccoli

NASA Astrophysics Data System (ADS)

De Bock, Maarten; Op de Beeck, Maarten; De Temmerman, Ludwig; Guisez, Yves; Ceulemans, Reinhart; Vandermeiren, Karine

2011-03-01

Tropospheric ozone is an important air pollutant with known detrimental effects for several crops. Ozone effects on seed yield, oil percentage, oil yield and 1000 seed weight were examined for spring oilseed rape ( Brassica napus cv. Ability). For broccoli ( Brassica oleracea L. cv. Italica cv. Monaco) the effects on fresh marketable weight and total dry weight were studied. Current ozone levels were compared with an increase of 20 and 40 ppb during 8 h per day, over the entire growing season. Oilseed rape seed yield was negatively correlated with ozone dose indices calculated from emergence until harvest. This resulted in an R2 of 0.24 and 0.26 ( p < 0.001) for the accumulated hourly O 3 exposure over a threshold of 40 ppb (AOT40) and the phytotoxic ozone dose above a threshold of 6 nmol m -2 s -1 (POD 6) respectively. Estimated critical levels, above which 5% yield reduction is expected, were 3.7 ppm h and 4.4 mmol m -2 respectively. Our results also confirm that a threshold value of 6 nmol s -1 m -2 projected leaf area, as recommended for agricultural crops (UNECE, Mills, 2004), can indeed be applied for spring oilseed rape. The reduction of oilseed rape yield showed the highest correlation with the ozone uptake during the vegetative growth stage: when only the first 47 days after emergence were used to calculate POD 6, R2 values increased up to 0.476 or even 0.545 when the first 23 days were excluded. The highest ozone treatments, corresponding to the future ambient level by 2100 (IPCC, Meehl et al., 2007), led to a reduction of approximately 30% in oilseed rape seed yield in comparison to the current ozone concentrations. Oil percentage was also significantly reduced in response to ozone ( p < 0.001). As a consequence oil yield was even more severely affected by elevated ozone exposure compared to seed yield: critical levels for oil yield dropped to 3.2 ppm h and 3.9 mmol m -2. For broccoli the applied ozone doses had no effect on yield.

Spin Transfer Torque in Graphene

NASA Astrophysics Data System (ADS)

Lin, Chia-Ching; Chen, Zhihong

2014-03-01

Graphene is an idea channel material for spin transport due to its long spin diffusion length. To develop graphene based spin logic, it is important to demonstrate spin transfer torque in graphene. Here, we report the experimental measurement of spin transfer torque in graphene nonlocal spin valve devices. Assisted by a small external in-plane magnetic field, the magnetization reversal of the receiving magnet is induced by pure spin diffusion currents from the injector magnet. The magnetization switching is reversible between parallel and antiparallel configurations by controlling the polarity of the applied charged currents. Current induced heating and Oersted field from the nonlocal charge flow have also been excluded in this study. Next, we further enhance the spin angular momentum absorption at the interface of the receiving magnet and graphene channel by removing the tunneling barrier in the receiving magnet. The device with a tunneling barrier only at the injector magnet shows a comparable nonlocal spin valve signal but lower electrical noise. Moreover, in the same preset condition, the critical charge current density for spin torque in the single tunneling barrier device shows a substantial reduction if compared to the double tunneling barrier device.

Experimental Analysis of Critical Current and Alternating Current Losses of High-Temperature Superconductor Tape with Resin and Gallium-Indium-Tin

PubMed Central

Sun, Yajie; Zhang, Huiming; Meng, Yuanzhu

2018-01-01

This paper experimentally analyzes the critical current degradation and AC (alternating current) losses of second-generation (2G) high-temperature superconductor (HTS) tape during the impregnation process. Two impregnation materials were utilized: Gallium-Indium-Tin (GaInSn), and an epoxy resin, Araldite. The critical current of the impregnation materials was measured after different thermal cycles and compared with the tape with no impregnation process. The experimental results show that the critical current of Yttrium Barium Copper Oxide (YBCO) short samples varies between differently impregnated materials. The resin, Araldite, degraded the critical current; however, the GaInSn showed no degradation. Two degradation patterns with Araldite were identified due to the impregnation process, and the corresponding causes were analyzed. We further measured the AC losses of tapes impregnated with liquid metal at different frequencies, up to 600 Hz. Based on the experimental results, GaInSn liquid metal should be the most suitable impregnation material in terms of critical current degradation. PMID:29642490

Experimental Analysis of Critical Current and Alternating Current Losses of High-Temperature Superconductor Tape with Resin and Gallium-Indium-Tin.

PubMed

Yu, Dongmin; Sun, Yajie; Zhang, Huiming; Meng, Yuanzhu; Liu, Huanan

2018-04-08

This paper experimentally analyzes the critical current degradation and AC (alternating current) losses of second-generation (2G) high-temperature superconductor (HTS) tape during the impregnation process. Two impregnation materials were utilized: Gallium-Indium-Tin (GaInSn), and an epoxy resin, Araldite. The critical current of the impregnation materials was measured after different thermal cycles and compared with the tape with no impregnation process. The experimental results show that the critical current of Yttrium Barium Copper Oxide (YBCO) short samples varies between differently impregnated materials. The resin, Araldite, degraded the critical current; however, the GaInSn showed no degradation. Two degradation patterns with Araldite were identified due to the impregnation process, and the corresponding causes were analyzed. We further measured the AC losses of tapes impregnated with liquid metal at different frequencies, up to 600 Hz. Based on the experimental results, GaInSn liquid metal should be the most suitable impregnation material in terms of critical current degradation.

The effectiveness of noninvasive interventions for musculoskeletal thoracic spine and chest wall pain: a systematic review by the Ontario Protocol for Traffic Injury Management (OPTIMa) collaboration.

PubMed

Southerst, Danielle; Marchand, Andrée-Anne; Côté, Pierre; Shearer, Heather M; Wong, Jessica J; Varatharajan, Sharanya; Randhawa, Kristi; Sutton, Deborah; Yu, Hainan; Gross, Douglas P; Jacobs, Craig; Goldgrub, Rachel; Stupar, Maja; Mior, Silvano; Carroll, Linda J; Taylor-Vaisey, Anne

2015-09-01

The purpose of this study was to critically appraise and synthesize evidence on the effectiveness of noninvasive interventions, excluding pharmacological treatments, for musculoskeletal thoracic pain. Randomized controlled trials (RCTs), cohort studies, and case-control studies evaluating the effectiveness of noninvasive interventions were eligible. We searched MEDLINE, EMBASE, PsycINFO, and the Cochrane Central Register of Controlled Trials accessed through Ovid Technologies, Inc, and CINAHL Plus with Full Text accessed through EBSCOhost from 1990 to 2015. Our search strategies combined controlled vocabulary relevant to each database (eg, MeSH for MEDLINE) and text words relevant to our research question and the inclusion criteria. Random pairs of independent reviewers screened studies for relevance and critically appraised relevant studies using the Scottish Intercollegiate Guidelines Network criteria. Studies with a low risk of bias were synthesized following best evidence synthesis principles. We screened 6988 articles and critically appraised 2 studies. Both studies had a low risk of bias and were included in our synthesis. One RCT compared thoracic spinal manipulation, needle acupuncture, and placebo electrotherapy for recent thoracic spine pain. There were statistically significant but clinically nonimportant short-term reductions in pain favoring manipulation. There were no differences between acupuncture and placebo electrotherapy. Another RCT compared a multimodal program of care and a session of education for recent musculoskeletal chest wall pain. The multimodal care resulted in statistically significant but clinically nonimportant short-term reductions in pain over education. However, participants receiving multimodal care were more likely to report important improvements in chest pain. Quality evidence on the management of musculoskeletal thoracic pain is sparse. The current evidence suggests that compared to placebo, spinal manipulation is associated with a small and clinically nonimportant reduction in pain intensity and that acupuncture leads to similar outcomes as placebo. Furthermore, a multimodal program of care (ie, manual therapy, soft tissue therapy, exercises, heat/ice, and advice) and a single education session lead to similar pain reduction for recent-onset musculoskeletal chest wall pain. However, patients who receive multimodal care are more likely to report pain improvements. Copyright © 2015 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

Critical currents of Nb sub 3 Sn wires for the US-DPC coil

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

Takayasu, M.; Gung, C.Y.; Steeves, M.M.

1991-03-01

This paper evaluates the critical current of titanium-alloyed internal-tin, jelly-roll Nb{sub 3}Sn wire for use in the US-DPC coil. It was confirmed from 14 randomly-selected samples that the critical-current values were uniform and consistent: the non-copper critical-current density was approximately 700 A/mm{sup 2} at 10 T and 4.2 K in agreement with expectations. A 27-strand cable-in-conduit conductor (CICC) using the low-thermal-coefficient-of-expansion superalloy Incoloy 905 yielded a critical current 5--7% below the average value of the single-strand data.

Preventing preterm births: trends and potential reductions with current interventionsin 39 very high human development index countries

PubMed Central

Chang, Hannah H.; Larson, Jim; Blencowe, Hannah; Spong, Catherine Y.; Howson, Christopher P.; Cairns-Smith, Sarah; Lackritz, Eve M.; Lee, Shoo K.; Mason, Elizabeth; Serazin, Andrew C.; Walani, Salimah; Simpson, Joe Leigh; Lawn, Joy E.

2013-01-01

Summary Background Each year,1.1 million babies die from prematurity, andmany survivors are disabled. Worldwide, 15 million babies are preterm(<37 weeks’ gestation),withtwo decades of increasing ratesinalmost all countries with reliable data. Improved care of babies has reduced mortality in high-income countries, although effective interventions have yet to be scaled-up in most low-income countries. A 50% reduction goal for preterm-specific mortality by 2025 has been set in the “Born Too Soon” report. However, for preterm birth prevention,understanding of drivers and potential impact of preventive interventions is limited. We examine trends and estimate the potential reduction in preterm birthsforvery high human development index (VHHDI) countries if current evidence-based interventions were widely implemented. This analysis is to inform a “Born Too Soon” rate reduction target. Methods Countries were assessed for inclusion based on availability and quality ofpreterm prevalence data (2000-2010), and trend analyses with projections undertaken. We analysed drivers of rate increases in the USA, 1998-2004. For 39 VHHDI countrieswith >10,000 births, country-by-country analyses were performed based on target population, incremental coverage increase,and intervention efficacy. Cost savings were estimated based on reported costs for preterm care in the USAadjusted usingWorld Bank purchasing power parity. Findings From 2010, even if all VHHDI countries achieved annual preterm birth rate reductions of the best performers, (Sweden and Netherlands), 2000-2010 or 2005-2010(Lithuania, Estonia)), rates would experience a relative reduction of<5% by 2015 on average across the 39 countries.Our analysis of preterm birth rise 1998-2004 in USA suggests half the change is unexplained, but important drivers includeinductions/cesareandelivery and ART.For all 39 VHHDI countries, five interventionsmodeling at high coveragepredicted 5%preterm birth rate relative reduction from 9.59 to 9.07% of live births:smoking cessation (0.01 rate reduction), decreasing multiple embryo transfers during assisted reproductive technologies (0.06), cervical cerclage (0.15), progesterone supplementation (0.01), and reduction of non-medically indicated labour induction or caesarean delivery (0.29).These translate to 58,000 preterm births averted and total annual economic cost savings of ~US$ 3 billion. Interpretation Even with optimal coverage of current interventions, many being complex to implement, the estimated potential reduction in preterm birth is tiny. Hence we recommenda conservative target of 5% preterm birth rate relative reductionby 2015. Our findings highlight the urgent need for discovery research into underlying mechanisms of preterm birth, and developmentof innovative interventions. Furthermore, the highest preterm birth rates occur in low-income settings where the causes of prematurity may differand have simpler solutions, such as birth spacing and treatment of infections in pregnancy. Urgent focus on these settings also is critical to reduce preterm births worldwide. PMID:23158883

An aging effect and its origin in GdBCO thin films

NASA Astrophysics Data System (ADS)

Schlesier, K.; Huhtinen, H.; Granroth, S.; Paturi, P.

2010-06-01

An aging effect investigation was made for GdBa2Cu3O7 (GdBCO) thin films grown on SrTiO3 (001) substrates with pulsed laser deposition (PLD) method from nanograined targets. The films were cut into two pieces where one piece was coated with gold cap layer while the other was left without coating. Both pieces were kept in ambient air during the half year measurement period. Magnetization measurements as well as phase purity, lattice parameter, oxygen effect and depth structure determination with x-ray diffraction (XRD) were made in one month interval. For structure and oxygen content, x-ray photoelectron spectroscopy measurements (XPS) were done in the beginning and in the end of the period. A reduction of the critical temperature and the critical current density, Jc, was found in the gold coated GdBCO film in ambient air in course of time. A smaller decrease of Jc was detected in uncoated GdBCO. No development of impurity phase, increase of a-orientation or reduction of the pinning structure was detected in uncoated GdBCO. However, a small development of impurity phase was found in gold coated GdBCO. The diminution of Tc and Jc is concluded to originate from oxygen release. No such a phenomenon was found in YBa2Cu3O7. We conclude that gold is not a proper cap layer at least for some applications.

Towards real-time risk mitigation for NPP in Switzerland: the potential role of EEW and OEF.

NASA Astrophysics Data System (ADS)

Cauzzi, Carlo; Wiemer, Stefan; Behr, Yannik; Clinton, John; Renault, Philippe; Le Guenan, Thomas; Douglas, John; Woessner, Jochen; Biro, Yesim; Caprio, Marta; Cua, Georgia

2014-05-01

Spurred by the research activities being carried out within the EC-funded project REAKT (Strategies and Tools for Real Time Earthquake Risk Reduction, FP7, contract no. 282862, 2011-2014, www.reaktproject.eu), we present herein the key elements to understanding the potential benefits of routinely using Earthquake Early Warning and Operational Earthquake Forecasting methods to mitigate the seismic risk at NPP in Switzerland. The advantages of using the aforementioned real-time risk reduction tools are critically discussed based on the limitations of the current scientific knowledge and technology, as well as on the costs associated to both system maintenance and machine- or human-triggered actions following an alert. Basic inputs to this discussion are, amongst others: a) the performances of the Swiss seismic network (http://www.seismo.ethz.ch/monitor, where SeisComP3 is used as earthquake monitoring software) and the selected EEW algorithm (the Virtual Seismologist, VS, http://www.seiscomp3.org/doc/seattle/2013.200/apps/vs.html), in terms of correct detections, false alerts, and missed events; b) the reliability of time-dependent hazard scenarios for the region of interest; c) a careful assessment of the frequency of occurrence of critical warnings based on the local and regional seismicity; d) the identification of the mitigation actions and their benefits and costs for the stakeholders.

Singular reduction of resonant Hamiltonians

NASA Astrophysics Data System (ADS)

Meyer, Kenneth R.; Palacián, Jesús F.; Yanguas, Patricia

2018-06-01

We investigate the dynamics of resonant Hamiltonians with n degrees of freedom to which we attach a small perturbation. Our study is based on the geometric interpretation of singular reduction theory. The flow of the Hamiltonian vector field is reconstructed from the cross sections corresponding to an approximation of this vector field in an energy surface. This approximate system is also built using normal forms and applying reduction theory obtaining the reduced Hamiltonian that is defined on the orbit space. Generically, the reduction is of singular character and we classify the singularities in the orbit space, getting three different types of singular points. A critical point of the reduced Hamiltonian corresponds to a family of periodic solutions in the full system whose characteristic multipliers are approximated accordingly to the nature of the critical point.

Ozone depletion following future volcanic eruptions

NASA Astrophysics Data System (ADS)

Eric Klobas, J.; Wilmouth, David M.; Weisenstein, Debra K.; Anderson, James G.; Salawitch, Ross J.

2017-07-01

While explosive volcanic eruptions cause ozone loss in the current atmosphere due to an enhancement in the availability of reactive chlorine following the stratospheric injection of sulfur, future eruptions are expected to increase total column ozone as halogen loading approaches preindustrial levels. The timing of this shift in the impact of major volcanic eruptions on the thickness of the ozone layer is poorly known. Modeling four possible climate futures, we show that scenarios with the smallest increase in greenhouse gas concentrations lead to the greatest risk to ozone from heterogeneous chemical processing following future eruptions. We also show that the presence in the stratosphere of bromine from natural, very short-lived biogenic compounds is critically important for determining whether future eruptions will lead to ozone depletion. If volcanic eruptions inject hydrogen halides into the stratosphere, an effect not considered in current ozone assessments, potentially profound reductions in column ozone would result.

Selective detection of vapor phase hydrogen peroxide with phthalocyanine chemiresistors.

PubMed

Bohrer, Forest I; Colesniuc, Corneliu N; Park, Jeongwon; Schuller, Ivan K; Kummel, Andrew C; Trogler, William C

2008-03-26

The use of hydrogen peroxide as a precursor to improvised explosives has made its detection a topic of critical importance. Chemiresistor arrays comprised of 50 nm thick films of metallophthalocyanines (MPcs) are redox selective vapor sensors of hydrogen peroxide. Hydrogen peroxide is shown to decrease currents in cobalt phthalocyanine sensors while it increases currents in nickel, copper, and metal-free phthalocyanine sensors; oxidation and reduction of hydrogen peroxide via catalysis at the phthalocyanine surface are consistent with the pattern of sensor responses. This represents the first example of MPc vapor sensors being oxidized and reduced by the same analyte by varying the metal center. Consequently, differential analysis by redox contrast with catalytic amplification using a small array of sensors may be used to uniquely identify peroxide vapors. Metallophthalocyanine chemiresistors represent an improvement over existing peroxide vapor detection technologies in durability and selectivity in a greatly decreased package size.

Dietary fats and cardiovascular health: a summary of the scientific evidence and current debate.

PubMed

Fattore, Elena; Massa, Elena

2018-04-04

This narrative review summarises the main studies of the role of the different fatty acids in coronary heart disease (CHD) and cardiovascular disease (CVD) risk and the current scientific debate on dietary recommendations. Reduction and substitution of the saturated fatty acids (SFAs) with the polyunsaturated fatty acids (PUFAs) are still the main dietary recommendation to prevent CHD and CVD. In the last few years, however, the strength of the scientific evidence underlying this dietary advice has been questioned. Recent investigations reappraise the previously declared deleterious role of the SFAs and reduce the positive role of PUFAs, mainly the omega-6, whereas the role of monounsaturated fatty acids (MUFAs) remains unclear. In contrast, the negative effects of trans fatty acids (TFAs) seem stronger than previously thought. Finally, criticisms have emerged from a dietary recommendation approach focussed on individual components rather than on wide food items and eating habits.

40 CFR 430.24 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2012 CFR

2012-07-01

... new technology components or process modifications and identifying critical path relationships within... degree of effluent reduction attainable by the application of best available technology economically... effluent reduction attainable by the application of best available technology economically achievable (BAT...

Effect of tailored on-road driving lessons on driving safety in older adults: A randomised controlled trial.

PubMed

Anstey, Kaarin J; Eramudugolla, Ranmalee; Kiely, Kim M; Price, Jasmine

2018-06-01

We evaluated the effectiveness of individually tailored driving lessons compared with a road rules refresher course for improving older driver safety. Two arm parallel randomised controlled trial, involving current drivers aged 65 and older (Mean age 72.0, 47.4% male) residing in Canberra, Australia. The intervention group (n = 28) received a two-hour class-based road rules refresher course, and two one-hour driving lessons tailored to improve poor driving skills and habits identified in a baseline on-road assessment. The control group (n = 29) received the road rules refresher course only. Tests of cognitive performance, and on-road driving were conducted at baseline and at 12-weeks. Main outcome measure was the Driver safety rating (DSR) on the on-road driving test. The number of Critical Errors made during the on-road was also recorded. 55 drivers completed the trial (intervention group: 27, control group: 28). Both groups showed reduction in dangerous/hazardous driver errors that required instructor intervention. From baseline to follow-up there was a greater reduction in the number of critical errors made by the intervention group relative to the control group (IRR = 0.53, SE = 0.1, p = .008). The intervention group improved on the DSR more than the control group (intervention mean change = 1.07 SD = 2.00, control group mean change = 0.32 SD = 1.61). The intervention group had 64% remediation of unsafe driving, where drivers who achieved a score of 'fail' at baseline, 'passed' at follow-up. The control group had 25% remediation. Tailored driving lessons reduced the critical driving errors made by older adults. Longer term follow-up and larger trials are required. Copyright © 2018 Elsevier Ltd. All rights reserved.

Rituximab biosimilars.

PubMed

Vital, Edward M; Kay, Jonathan; Emery, Paul

2013-07-01

Rituximab is a monoclonal antibody targeting CD20, used to treat B cell malignancies and B cell-mediated autoimmune diseases. Rituximab has the largest market of any monoclonal antibody therapeutic. Its patent will expire within the next few years and several manufacturers have already produced or are developing rituximab biosimilars that aim to match the innovator rituximab as closely as possible. In this review, we discuss key factors that determine the efficacy of rituximab therapy, potential technical challenges in the manufacture and evaluation of biosimilars, regulatory considerations regarding the review and approval of biosimilars, and the current status of biosimilar rituximab development by various manufacturers. Due to the nature of the topic, literature searches included conference abstracts, regulatory and industry websites as well as peer reviewed literature. Cost is a key limitation of current biologics usage and there is a political impetus to the licensing of biosimilars. Concerns regarding potential dissimilarities of biosimilars are legitimate, but surmountable with techniques for in vitro, in vivo and clinical testing and more clearly defined regulatory requirements. These should provide reassurance to prescribers. However, the cost of manufacturing and licensing a biosimilar remains high and the reduction in cost may be more limited than for a non-biologic small molecule drug and its generic version. This cost reduction will be critical to the impact and use of rituximab biosimilars.

Enhanced quench propagation in 2G-HTS coils co-wound with stainless steel or anodised aluminium tapes

NASA Astrophysics Data System (ADS)

Núñez-Chico, A. B.; Martínez, E.; Angurel, L. A.; Navarro, R.

2016-08-01

Early quench detection and thermal stability of superconducting coils are of great relevance for practical applications. Magnets made with second generation high temperature superconducting (2G-HTS) tapes present low quench propagation velocities and therefore slow voltage development and high local temperature rises, which may cause irreversible damage. Since quench propagation depends on the anisotropy of the thermal conductivity, this may be used to achieve an improvement of the thermal stability and robustness of 2G-HTS coils. On pancake type coils, the thermal conductivity along the tapes (coil’s azimuthal direction) is mostly fixed by the 2G-HTS tape characteristics, so that the reduction of anisotropy relies on the improvement of the radial thermal conductivity, which depends on the used materials between superconducting tapes, as well as on the winding and impregnation processes. In this contribution, we have explored two possibilities for such anisotropy reduction: by using anodised aluminium or stainless steel tapes co-wound with the 2G-HTS tapes. For all the analysed coils, critical current distribution, minimum quench energy values and both tangential and radial quench propagation velocities at different temperatures and currents are reported and compared with the results of similar coils co-wound with polyimide (Kapton®) tapes.

Seven Types of Ambiguity in Evaluating the Impact of Humanities Provision in Undergraduate Medicine Curricula.

PubMed

Bleakley, Alan

2015-12-01

Inclusion of the humanities in undergraduate medicine curricula remains controversial. Skeptics have placed the burden of proof of effectiveness upon the shoulders of advocates, but this may lead to pursuing measurement of the immeasurable, deflecting attention away from the more pressing task of defining what we mean by the humanities in medicine. While humanities input can offer a fundamental critical counterweight to a potentially reductive biomedical science education, a new wave of thinking suggests that the kinds of arts and humanities currently used in medical education are neither radical nor critical enough to have a deep effect on students' learning and may need to be reformulated. The humanities can certainly educate for tolerance of ambiguity as a basis to learning democratic habits for contemporary team-based clinical work. William Empson's 'seven types of ambiguity' model for analyzing poetry is transposed to medical education to: (a) formulate seven values proffered by the humanities for improving medical education; (b) offer seven ways of measuring impact of medical humanities provision, thereby reducing ambiguity; and (c) --as a counterweight to (b) - celebrate seven types of ambiguity in contemporary medical humanities that critically reconsider issues of proof of impact.

Progressing in cable-in-conduit for fusion magnets: from ITER to low cost, high performance DEMO

NASA Astrophysics Data System (ADS)

Uglietti, D.; Sedlak, K.; Wesche, R.; Bruzzone, P.; Muzzi, L.; della Corte, A.

2018-05-01

The performance of ITER toroidal field (TF) conductors still have a significant margin for improvement because the effective strain between ‑0.62% and ‑0.95% limits the strands’ critical current between 15% and 45% of the maximum achievable. Prototype Nb3Sn cable-in-conduit conductors have been designed, manufactured and tested in the frame of the EUROfusion DEMO activities. In these conductors the effective strain has shown a clear improvement with respect to the ITER conductors, reaching values between ‑0.55% and ‑0.28%, resulting in a strand critical current which is two to three times higher than in ITER conductors. In terms of the amount of Nb3Sn strand required for the construction of the DEMO TF magnet system, such improvement may lead to a reduction of at least a factor of two with respect to a similar magnet built with ITER type conductors; a further saving of Nb3Sn is possible if graded conductors/windings are employed. In the best case the DEMO TF magnet could require fewer Nb3Sn strands than the ITER one, despite the larger size of DEMO. Moreover high performance conductors could be operated at higher fields than ITER TF conductors, enabling the construction of low cost, compact, high field tokamaks.

A systematic review and critical appraisal of qualitative metasynthetic practice in public health to develop a taxonomy of operations of reciprocal translation.

PubMed

Melendez-Torres, G J; Grant, Sean; Bonell, Chris

2015-12-01

Reciprocal translation, the understanding of one study's findings in terms of another's, is the foundation of most qualitative metasynthetic methods. In light of the proliferation of metasynthesis methods, the current review sought to create a taxonomy of operations of reciprocal translation using recently published qualitative metasyntheses. On 19 August 2013, MEDLINE, Embase and PsycINFO were searched. Included articles were full reports of metasyntheses of qualitative studies published in 2012 in English-language peer-reviewed journals. Two reviewers, working independently, screened records, assessed full texts for inclusion and extracted data on methods from each included metasynthesis. Systematic review methods used were summarised, and metasynthetic methods were inductively analysed to develop the taxonomy. Of 61 included metasyntheses, 21 (34%) reported fully replicable search strategies and 51 (84%) critically appraised included studies. Based on methods in these metasyntheses, we developed a taxonomy of reciprocal translation with four overlapping categories: visual representation; key paper integration; data reduction and thematic extraction; and line-by-line coding. This systematic review presents an update on methods and reporting currently used in qualitative metasynthesis. It also goes beyond the proliferation of approaches to offer a parsimonious approach to understanding how reciprocal translations are accomplished across metasynthetis methods. Copyright © 2015 John Wiley & Sons, Ltd.

Bandgap narrowing and emitter efficiency in heavily doped emitter structures revisited

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

Van Vliet, C.M.

The developments of heavy doping effects and of bandgap narrowing concepts (BGN) during the last two decades are critically discussed. The differences between the real bandgap reduction [Delta]E[sub g] and the apparent electrical bandgap reduction [Delta]G are once more set forth, showing the precise meaning of the density-of-states and degeneracy contributions to [Delta]G. From these concepts, previously elaborated by Marshak and Van Vilet and by Lundstrom et al., the authors indicated before that for negligible recombination the minority-carrier emitter current (J[sub pe]) is given by a Merten-type result. In this paper they show that in the presence of surface andmore » (or) bulk recombination (Auger and SRH) the result of Selvakumar and Roulston is recovered; however, the electrical field in the emitter and the effective intrinsic density of carriers are not those used by these authors but, on the contrary, these quantities are given by the detailed expressions of their previous work.« less

Hybrid CFx–Ag2V4O11 as a high-energy, power density cathode for application in an underwater acoustic microtransmitter

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

Meduri, Praveen; Chen, Honghao; Chen, Xilin

2011-12-01

This study demonstrates the excellent electrochemical performance of the hybrid carbon fluoride(CFx)/silver vanadium oxide(SVO)/graphene(G) cathode and its potential utilization in Acoustic Telemetry System Transmitter (ATST). The impedance increase issue caused by LiF formation from CFx is effectively addressed by the deposition of conductive silver metal from the reduction of SVO aided by the coexistence of graphene additive thus a prolonged operation voltage is observed with enhanced electronic conductivity throughout the whole discharge process. In particular, the hybrid shows capacity retention of {approx}462 mAhg-1 at 5C rate and 661 mAhg-1 at 1C rate. The peak current delivered from the as-designed hybridmore » cathode is improved compared with that of commercial Zn/Ag2O batteries suggesting the possibility of the further reduction on the size/weight of the micro batteries which is critical for the transmitters.« less

U.S. Army PEM fuel cell programs

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

Patil, A.S.; Jacobs, R.

The United States Army has identified the need for lightweight power sources to provide the individual soldier with continuous power for extended periods without resupply. Due to the high cost of primary batteries and the high weight of rechargeable batteries, fuel cell technology is being developed to provide a power source for the individual soldier, sensors, communications equipment and other various applications in the Army. Current programs are in the tech base area and will demonstrate Proton Exchange Membrane (PEM) Fuel Cell Power Sources with low weight and high energy densities. Fuel Cell Power Sources underwent user evaluations in 1996more » that showed a power source weight reduction of 75%. The quiet operation along with the ability to refuel much like an engine was well accepted by the user and numerous applications were investigated. These programs are now aimed at further weight reduction for applications that are weight critical; system integration that will demonstrate a viable military power source; refining the user requirements; and planning for a transition to engineering development.« less

Critical Current of Superconducting Rutherford Cable in High Magnetic Fields with Transverse Pressure

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

Dietderich, D.R.; Scanlan, R.M.; Walsh, R.P.

For high energy physics applications superconducting cables are subjected to large stresses and high magnetic fields during service. It is essential to know how these cables perform in these operating conditions. A loading fixture capable of applying loads of up to 700 kN has been developed by NHMFL for LBNL. This fixture permits uniform loading of straight cables over a 122 mm length in a split-pair solenoid in fields up to 12 T at 4.2 K. The first results from this system for Rutherford cables of internal-tin and modified jelly roll strand of Nb{sub 3}Sn produced by IGC and TWCmore » showed that little permanent degradation occurs up to 210 MPa. However, the cable made from internal-tin strand showed a 40% reduction in K{sub c} at 11T and 210 MPa while a dable made from modified jelly roll material showed only a 15% reduction in I{sub c} at 11T and 185 MPa.« less

Frog virus 3 ORF 53R, a putative myristoylated membrane protein, is essential for virus replication in vitro

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

Whitley, Dexter S.; Yu, Kwang; Sample, Robert C.

2010-09-30

Although previous work identified 12 complementation groups with possible roles in virus assembly, currently only one frog virus 3 protein, the major capsid protein (MCP), has been linked with virion formation. To identify other proteins required for assembly, we used an antisense morpholino oligonucleotide to target 53R, a putative myristoylated membrane protein, and showed that treatment resulted in marked reductions in 53R levels and a 60% drop in virus titers. Immunofluorescence assays confirmed knock down and showed that 53R was found primarily within viral assembly sites, whereas transmission electron microscopy detected fewer mature virions and, in some cells, dense granularmore » bodies that may represent unencapsidated DNA-protein complexes. Treatment with a myristoylation inhibitor (2-hydroxymyristic acid) resulted in an 80% reduction in viral titers. Collectively, these data indicate that 53R is an essential viral protein that is required for replication in vitro and suggest it plays a critical role in virion formation.« less

Radiation Hardness Assurance (RHA): Challenges and New Considerations

NASA Technical Reports Server (NTRS)

Campola, Michael J.

2017-01-01

Use of commercial-off-the-shelf (COTS) components and emerging technologies often require space flight missions to accept elevated risk. The Radiation Hardness Assurance (RHA) flow includes environment definition, hazard evaluation, requirements definition, evaluation of design, and design trades to accommodate and mitigate the risk a project or program takes. Depending on the mission profile and environment, different missions may not necessarily benefit from the same risk reduction efforts or cost reduction attempts. While this poses challenges for the radiation engineer, it also presents opportunities to tailor the RHA flow to minimize risk based on the environment or design criticality while remaining within budget. This presentation will focus on an approach to RHA amidst the present challenges, using the same RHA flow as in the past, with examples from recent radiation test results. The current challenges and the types of risk will be identified. How these risks drive requirements development and realization will be explained with examples of device results and data for single event effects (SEE) and in one case total ionizing dose (TID).

Turning readmission reduction policies into results: some lessons from a multistate initiative to reduce readmissions.

PubMed

Mittler, Jessica N; O'Hora, Jennifer L; Harvey, Jillian B; Press, Matthew J; Volpp, Kevin G; Scanlon, Dennis P

2013-08-01

Efforts are under way nationally to reduce avoidable hospital readmissions by changing payments to hospitals, but it is unclear how well or how quickly these policy changes will produce widespread reductions in hospital readmissions. To examine some of the challenges to implementing such approaches, the authors analyzed the early experiences of 3 statewide programs to reduce preventable readmissions that began in 2009. Based on interviews with program participants in 2011, the authors identified 3 key obstacles to progress: the difficulty of developing collaborative relationships across care settings, gaps in evidence for effective interventions, and deficits in quality improvement capabilities among some organizations. These findings underscore the uncertainty of success of current readmissions policies and suggest that immediate improvement in readmission rates through a change in reimbursement may be unlikely unless these other obstacles are addressed expeditiously. In particular, cultivation of productive collaboration across care settings will be critical because these kinds of relationships are not well established or naturally occurring in most communities.

Oxygen Vacancies in ZnO Nanosheets Enhance CO2 Electrochemical Reduction to CO.

PubMed

Geng, Zhigang; Kong, Xiangdong; Chen, Weiwei; Su, Hongyang; Liu, Yan; Cai, Fan; Wang, Guoxiong; Zeng, Jie

2018-05-22

As electron transfer to CO 2 is generally considered to be the critical step during the activation of CO 2 , it is important to develop approaches to engineer the electronic properties of catalysts to improve their performance in CO 2 electrochemical reduction. Herein, we developed an efficient strategy to facilitate CO 2 activation by introducing oxygen vacancies into electrocatalysts with electronic-rich surface. ZnO nanosheets rich in oxygen vacancies exhibited a current density of -16.1 mA cm -2 with a Faradaic efficiency of 83 % for CO production. Based on density functional theory (DFT) calculations, the introduction of oxygen vacancies increased the charge density of ZnO around the valence band maximum, resulting in the enhanced activation of CO 2 . Mechanistic studies further revealed that the enhancement of CO production by introducing oxygen vacancies into ZnO nanosheets originated from the increased binding strength of CO 2 and the eased CO 2 activation. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mastitis treatment-Reduction in antibiotic usage in dairy cows.

PubMed

Krömker, V; Leimbach, S

2017-08-01

Animal-friendly, economical, resource-saving milk production provides the basis for sustained consumer acceptance. Bovine mastitis plays a decisive role in the dairy industry-disturbing animal health and welfare and causing considerable economic losses on the other hand. Currently, antimicrobial treatment is indispensable to keep bovine udder health, animal welfare and economic aspects in balance. On the contrary, emergence and spread of antimicrobial resistance (AMR) is an urgent matter of particular public interest, and as a consequence, antimicrobial usage (AMU) in production livestock is a critically discussed subject. In urgent need of future reduction in AMU in the dairy industry, this review article describes and discusses possible approaches promising prompt implementation, including therapeutical alternatives as well as pro- and metaphylactic concepts such as the implementation of evidence-based mastitis therapy concepts and selective dry cow treatment (sDCT), in search of the most effective and contemporary methods for decreasing AMU and AMR in dairy production. © 2017 Blackwell Verlag GmbH.

Some advanced parametric methods for assessing waveform distortion in a smart grid with renewable generation

NASA Astrophysics Data System (ADS)

Alfieri, Luisa

2015-12-01

Power quality (PQ) disturbances are becoming an important issue in smart grids (SGs) due to the significant economic consequences that they can generate on sensible loads. However, SGs include several distributed energy resources (DERs) that can be interconnected to the grid with static converters, which lead to a reduction of the PQ levels. Among DERs, wind turbines and photovoltaic systems are expected to be used extensively due to the forecasted reduction in investment costs and other economic incentives. These systems can introduce significant time-varying voltage and current waveform distortions that require advanced spectral analysis methods to be used. This paper provides an application of advanced parametric methods for assessing waveform distortions in SGs with dispersed generation. In particular, the Standard International Electrotechnical Committee (IEC) method, some parametric methods (such as Prony and Estimation of Signal Parameters by Rotational Invariance Technique (ESPRIT)), and some hybrid methods are critically compared on the basis of their accuracy and the computational effort required.

Defective Carbon-Based Materials for the Electrochemical Synthesis of Hydrogen Peroxide

DOE PAGES

Chen, Shucheng; Chen, Zhihua; Siahrostami, Samira; ...

2017-10-30

Hydrogen peroxide (H 2O 2), an important industrial chemical, is currently produced through an energy-intensive anthraquinone process that is limited to large-scale facilities. Small-scale decentralized electrochemical production of H 2O 2 via a two-electron oxygen reduction reaction (ORR) offers unique opportunities for sanitization applications and the purification of drinking water. The development of inexpensive, efficient, and selective catalysts for this reaction remains a challenge. Here in this paper, we examine two different porous carbon-based electrocatalysts and show that they exhibit high selectivity for H 2O 2 under alkaline conditions. By rationally varying synthetic methods, we explore the effect of poremore » size on electrocatalytic performance. Furthermore, by means of density functional calculations, we point out the critical role of carbon defects. Our theory results show that the majority of defects in graphene are naturally selective for the two-electron reduction of O 2 to H 2O 2, and we identify the types of defects with high activity.« less

Simple-Cubic Carbon Frameworks with Atomically Dispersed Iron Dopants toward High-Efficiency Oxygen Reduction.

PubMed

Wang, Biwei; Wang, Xinxia; Zou, Jinxiang; Yan, Yancui; Xie, Songhai; Hu, Guangzhi; Li, Yanguang; Dong, Angang

2017-03-08

Iron and nitrogen codoped carbons (Fe-N-C) have attracted increasingly greater attention as electrocatalysts for oxygen reduction reaction (ORR). Although challenging, the synthesis of Fe-N-C catalysts with highly dispersed and fully exposed active sites is of critical importance for improving the ORR activity. Here, we report a new type of graphitic Fe-N-C catalysts featuring numerous Fe single atoms anchored on a three-dimensional simple-cubic carbon framework. The Fe-N-C catalyst, derived from self-assembled Fe 3 O 4 nanocube superlattices, was prepared by in situ ligand carbonization followed by acid etching and ammonia activation. Benefiting from its homogeneously dispersed and fully accessible active sites, highly graphitic nature, and enhanced mass transport, our Fe-N-C catalyst outperformed Pt/C and many previously reported Fe-N-C catalysts for ORR. Furthermore, when used for constructing the cathode for zinc-air batteries, our Fe-N-C catalyst exhibited current and power densities comparable to those of the state-of-the-art Pt/C catalyst.

Approach to traumatic hand injuries for primary care physicians.

PubMed

Cheung, Kevin; Hatchell, Alexandra; Thoma, Achilleas

2013-06-01

To review the initial management of common traumatic hand injuries seen by primary care physicians. Current clinical evidence and literature identified through MEDLINE electronic database searches was reviewed. Expert opinion was used to supplement recommendations for areas with little evidence. Primary care physicians must routinely manage patients with acute traumatic hand injuries. In the context of a clinical case, we review the assessment, diagnosis, and initial management of common traumatic hand injuries. The presentation and management of nail bed injuries, fingertip amputations, mallet fingers, hand fractures, tendon lacerations, bite injuries, and infectious tenosynovitis will also be discussed. The principles of managing traumatic hand injuries involve the reduction and immobilization of fractures, obtaining post-reduction x-ray scans, obtaining soft tissue coverage, preventing and treating infection, and ensuring tetanus prophylaxis. Proper assessment and management of traumatic hand injuries is essential to prevent substantial long-term morbidity in this generally otherwise healthy population. Early recognition of injuries that require urgent or emergent referral to a hand surgeon is critical.

Apparatus and method for measuring critical current properties of a coated conductor

DOEpatents

Mueller, Fred M [Los Alamos, NM; Haenisch, Jens [Dresden, DE

2012-07-24

The transverse critical-current uniformity in a superconducting tape was determined using a magnetic knife apparatus. A critical current I.sub.c distribution and transverse critical current density J.sub.c distribution in YBCO coated conductors was measured nondestructively with high resolution using a magnetic knife apparatus. The method utilizes the strong depression of J.sub.c in applied magnetic fields. A narrow region of low, including zero, magnetic field in a surrounding higher field is moved transversely across a sample of coated conductor. This reveals the critical current density distribution. A Fourier series inversion process was used to determine the transverse J.sub.c distribution in the sample.

Soil mechanics: breaking ground.

PubMed

Einav, Itai

2007-12-15

In soil mechanics, student's models are classified as simple models that teach us unexplained elements of behaviour; an example is the Cam clay constitutive models of critical state soil mechanics (CSSM). 'Engineer's models' are models that elaborate the theory to fit more behavioural trends; this is usually done by adding fitting parameters to the student's models. Can currently unexplained behavioural trends of soil be explained without adding fitting parameters to CSSM models, by developing alternative student's models based on modern theories?Here I apply an alternative theory to CSSM, called 'breakage mechanics', and develop a simple student's model for sand. Its unique and distinctive feature is the use of an energy balance equation that connects grain size reduction to consumption of energy, which enables us to predict how grain size distribution (gsd) evolves-an unprecedented capability in constitutive modelling. With only four parameters, the model is physically clarifying what CSSM cannot for sand: the dependency of yielding and critical state on the initial gsd and void ratio.

Additive-manufactured sandwich lattice structures: A numerical and experimental investigation

NASA Astrophysics Data System (ADS)

Fergani, Omar; Tronvoll, Sigmund; Brøtan, Vegard; Welo, Torgeir; Sørby, Knut

2017-10-01

The utilization of additive-manufactured lattice structures in engineered products is becoming more and more common as the competitiveness of AM as a production technology has increased during the past several years. Lattice structures may enable important weight reductions as well as open opportunities to build products with customized functional properties, thanks to the flexibility of AM for producing complex geometrical configurations. One of the most critical aspects related to taking AM into new application areas—such as safety critical products—is currently the limited understanding of the mechanical behavior of sandwich-based lattice structure mechanical under static and dynamic loading. In this study, we evaluate manufacturability of lattice structures and the impact of AM processing parameters on the structural behavior of this type of sandwich structures. For this purpose, we conducted static compression testing for a variety of geometry and manufacturing parameters. Further, the study discusses a numerical model capable of predicting the behavior of different lattice structure. A reasonably good correlation between the experimental and numerical results was observed.

40 CFR 440.52 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available (BPT). 440.52 Section 440.52 Protection of Environment ENVIRONMENTAL... reduction attainable by the application of the best practicable control technology currently available (BPT... effluent reduction attainable after application of the best practicable control technology currently...

40 CFR 440.52 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... technology currently available (BPT). 440.52 Section 440.52 Protection of Environment ENVIRONMENTAL... reduction attainable by the application of the best practicable control technology currently available (BPT... effluent reduction attainable after application of the best practicable control technology currently...

Decreases in perceived maternal criticism predict improvement in subthreshold psychotic symptoms in a randomized trial of family-focused therapy for individuals at clinical high risk for psychosis.

PubMed

O'Brien, Mary P; Miklowitz, David J; Cannon, Tyrone D

2015-12-01

Perceived criticism (PC) is a measure of how much criticism from 1 family member "gets through" to another. PC ratings have been found to predict the course of psychotic disorders, but questions remain regarding whether psychosocial treatment can effectively decrease PC, and whether reductions in PC predict symptom improvement. In a sample of individuals at high risk for psychosis, we examined a) whether Family Focused Therapy for Clinical High-Risk (FFT-CHR), an 18-session intervention that consists of psychoeducation and training in communication and problem solving, brought about greater reductions in perceived maternal criticism, compared to a 3-session family psychoeducational intervention; and b) whether reductions in PC from baseline to 6-month reassessment predicted decreases in subthreshold positive symptoms of psychosis at 12-month follow-up. This study was conducted within a randomized controlled trial across 8 sites. The perceived criticism scale was completed by 90 families prior to treatment and by 41 families at 6-month reassessment. Evaluators, blind to treatment condition, rated subthreshold symptoms of psychosis at baseline, 6- and 12-month assessments. Perceived maternal criticism decreased from pre- to posttreatment for both treatment groups, and this change in criticism predicted decreases in subthreshold positive symptoms at 12-month follow-up. This study offers evidence that participation in structured family treatment is associated with improvement in perceptions of the family environment. Further, a brief measure of perceived criticism may be useful in predicting the future course of attenuated symptoms of psychosis for CHR youth. (c) 2015 APA, all rights reserved).

Hospital economics of primary total knee arthroplasty at a teaching hospital.

PubMed

Healy, William L; Rana, Adam J; Iorio, Richard

2011-01-01

The hospital cost of total knee arthroplasty (TKA) in the United States is a major growing expense for the Centers for Medicare & Medicaid Services (CMS). Many hospitals are unable to deliver TKA with profitable or breakeven economics under the current Diagnosis-Related Group (DRG) hospital reimbursement system. The purposes of the current study were to (1) determine revenue, expenses, and profitability (loss) for TKA for all patients and for different payors; (2) define changes in utilization and unit costs associated with this operation; and (3) describe TKA cost control strategies to provide insight for hospitals to improve their economic results for TKA. From 1991 to 2009, Lahey Clinic converted a $2172 loss per case on primary TKA in 1991 to a $2986 profit per case in 2008. The improved economics was associated with decreasing revenue in inflation-adjusted dollars and implementation of hospital cost control programs that reduced hospital expenses for TKA. Reduction of hospital length of stay and reduction of knee implant costs were the major drivers of hospital expense reduction. During the last 25 years, our economic experience with TKA is concerning. Hospital revenues have lagged behind inflation, hospital expenses have been reduced, and our institution is earning a profit. However, the margin for TKA is decreasing and Managed Medicare patients do not generate a profit. The erosion of hospital revenue for TKA will become a critical issue if it leads to economic losses for hospitals or reduced access to TKA. Level III, Economic and Decision Analyses. See Guidelines for Authors for a complete description of levels of evidence.

Critical Propulsion and Noise reduction Technologies for Future Commercial Subsonic Engines. Area of Interest 14.3: Separate Flow Exhaust System Noise

NASA Technical Reports Server (NTRS)

Janardan, B. A.; Hoff, G. E.; Barter, J. W.; Brausch, J. F.; Gliebe, P. R.; Coffin, R. S.; Martens, S.; Delaney, B. R.; Dalton, W. N.; Mengle, V. G.

2000-01-01

This presentation discusses: Project Objectives, Approach and Goal; Baseline Nozzles and Test Cycle Definition; Repeatability and Baseline Nozzle Results; Noise Reduction Concepts; Noise Reduction Tests Configurations of BPR=5 Internal Plug Nozzle adn Acoustic Results; Noise Reduction Test Configurations of BPR=5 External Plug Nozzle and Acoustic Results; and Noise Reduction Tests Configurations of BPR=8 External Plug Nozzle and Acoustic Results.

A case study evaluation of a Critical Care Information System adoption using the socio-technical and fit approach.

PubMed

Yusof, Maryati Mohd

2015-07-01

Clinical information systems have long been used in intensive care units but reports on their adoption and benefits are limited. This study evaluated a Critical Care Information System implementation. A case study summative evaluation was conducted, employing observation, interview, and document analysis in operating theatres and 16-bed adult intensive care units in a 400-bed Malaysian tertiary referral centre from the perspectives of users (nurses and physicians), management, and information technology staff. System implementation, factors influencing adoption, fit between these factors, and the impact of the Critical Care Information System were evaluated after eight months of operation. Positive influences on system adoption were associated with technical factors, including system ease of use, usefulness, and information relevancy; human factors, particularly user attitude; and organisational factors, namely clinical process-technology alignment and champions. Organisational factors such as planning, project management, training, technology support, turnover rate, clinical workload, and communication were barriers to system implementation and use. Recommendations to improve the current system problems were discussed. Most nursing staff positively perceived the system's reduction of documentation and data access time, giving them more time with patients. System acceptance varied among doctors. System use also had positive impacts on timesaving, data quality, and clinical workflow. Critical Care Information Systems is crucial and has great potentials in enhancing and delivering critical care. However, the case study findings showed that the system faced complex challenges and was underutilised despite its potential. The role of socio-technical factors and their fit in realizing the potential of Critical Care Information Systems requires continuous, in-depth evaluation and stakeholder understanding and acknowledgement. The comprehensive and specific evaluation measures of the Human-Organisation-Technology Fit framework can flexibly evaluate Critical Care Information Systems. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Study of the inhomogeneity of critical current under in-situ tensile stress for YBCO tape

NASA Astrophysics Data System (ADS)

Zhu, Y. P.; Chen, W.; Zhang, H. Y.; Liu, L. Y.; Pan, X. F.; Yang, X. S.; Zhao, Y.

2018-07-01

A Hall sensor system was used to measure the local critical current of YBCO tape with high spatial resolution under in-situ tensile stress. The hot spot generation and minimum quench energy of YBCO tape, which depended on the local critical current, was calculated through the thermoelectric coupling model. With the increase in tensile stress, the cracks which have different dimensions and critical current degradation arose more frequently and lowered the thermal stability of the YBCO tape.

Ecological Engineering Practices for the Reduction of Excess Nitrogen in Human-Influenced Landscapes: A Guide for Watershed Managers

NASA Astrophysics Data System (ADS)

Passeport, Elodie; Vidon, Philippe; Forshay, Kenneth J.; Harris, Lora; Kaushal, Sujay S.; Kellogg, Dorothy Q.; Lazar, Julia; Mayer, Paul; Stander, Emilie K.

2013-02-01

Excess nitrogen (N) in freshwater systems, estuaries, and coastal areas has well-documented deleterious effects on ecosystems. Ecological engineering practices (EEPs) may be effective at decreasing nonpoint source N leaching to surface and groundwater. However, few studies have synthesized current knowledge about the functioning principles, performance, and cost of common EEPs used to mitigate N pollution at the watershed scale. Our review describes seven EEPs known to decrease N to help watershed managers select the most effective techniques from among the following approaches: advanced-treatment septic systems, low-impact development (LID) structures, permeable reactive barriers, treatment wetlands, riparian buffers, artificial lakes and reservoirs, and stream restoration. Our results show a broad range of N-removal effectiveness but suggest that all techniques could be optimized for N removal by promoting and sustaining conditions conducive to biological transformations (e.g., denitrification). Generally, N-removal efficiency is particularly affected by hydraulic residence time, organic carbon availability, and establishment of anaerobic conditions. There remains a critical need for systematic empirical studies documenting N-removal efficiency among EEPs and potential environmental and economic tradeoffs associated with the widespread use of these techniques. Under current trajectories of N inputs, land use, and climate change, ecological engineering alone may be insufficient to manage N in many watersheds, suggesting that N-pollution source prevention remains a critical need. Improved understanding of N-removal effectiveness and modeling efforts will be critical in building decision support tools to help guide the selection and application of best EEPs for N management.

Accelerated Testing of UH-60 Viscous Bearings for Degraded Grease Fault

NASA Technical Reports Server (NTRS)

Dykas, Brian; Hood, Adrian; Krantz, Timothy; Klemmer, Marko

2015-01-01

An accelerated aging investigation of critical aviation bearings lubricated with MIL-PRF- 81322 grease was conducted to derive an understanding of the mechanisms of grease degradation and loss of lubrication over time. The current study focuses on UH-60 Black Hawk viscous damper bearings supporting the tail rotor driveshaft, which were subjected to more than 5800 hours of testing in a heated environment to accelerate the deterioration of the grease. The mechanism of grease degradation is a reduction in the oil/thickener ratio rather than the expected chemical degradation of grease constituents. Over the course of testing, vibration and temperature monitoring of bearings was conducted and trends for failing bearings are presented.

Development of Carbon Dioxide Removal Systems for NASA's Deep Space Human Exploration Missions 2016-2017

NASA Technical Reports Server (NTRS)

Knox, James C.

2017-01-01

NASA has embarked on an endeavor that will enable humans to explore deep space, with the ultimate goal of sending humans to Mars. This journey will require significant developments in a wide range of technical areas, as resupply is unavailable in the Mars transit phase and early return is not possible. Additionally, mass, power, volume, and other resources must be minimized for all subsystems to reduce propulsion needs. Among the critical areas identified for development are life support systems, which will require increases in reliability and reductions in resources. This paper discusses current and planned developments in the area of carbon dioxide removal to support crewed Mars-class missions.

Reusable rocket engine turbopump condition monitoring

NASA Technical Reports Server (NTRS)

Hampson, M. E.; Barkhoudarian, S.

1985-01-01

Significant improvements in engine readiness with attendant reductions in maintenance costs and turnaround times can be achieved with an engine condition monitoring system (CMS). The CMS provides real time health status of critical engine components, without disassembly, through component monitoring with advanced sensor technologies. Three technologies were selected to monitor the rotor bearings and turbine blades: the isotope wear detector and fiber optic deflectometer (bearings), and the fiber optic pyrometer (blades). Signal processing algorithms were evaluated and ranked for their utility in providing useful component health data to unskilled maintenance personnel. Design modifications to current configuration Space Shuttle Main Engine (SSME) high pressure turbopumps and the MK48-F turbopump were developed to incorporate the sensors.

Joint Research on Scatterometry and AFM Wafer Metrology

NASA Astrophysics Data System (ADS)

Bodermann, Bernd; Buhr, Egbert; Danzebrink, Hans-Ulrich; Bär, Markus; Scholze, Frank; Krumrey, Michael; Wurm, Matthias; Klapetek, Petr; Hansen, Poul-Erik; Korpelainen, Virpi; van Veghel, Marijn; Yacoot, Andrew; Siitonen, Samuli; El Gawhary, Omar; Burger, Sven; Saastamoinen, Toni

2011-11-01

Supported by the European Commission and EURAMET, a consortium of 10 participants from national metrology institutes, universities and companies has started a joint research project with the aim of overcoming current challenges in optical scatterometry for traceable linewidth metrology. Both experimental and modelling methods will be enhanced and different methods will be compared with each other and with specially adapted atomic force microscopy (AFM) and scanning electron microscopy (SEM) measurement systems in measurement comparisons. Additionally novel methods for sophisticated data analysis will be developed and investigated to reach significant reductions of the measurement uncertainties in critical dimension (CD) metrology. One final goal will be the realisation of a wafer based reference standard material for calibration of scatterometers.

A hypothesis for delayed dynamic earthquake triggering

USGS Publications Warehouse

Parsons, T.

2005-01-01

It's uncertain whether more near-field earthquakes are triggered by static or dynamic stress changes. This ratio matters because static earthquake interactions are increasingly incorporated into probabilistic forecasts. Recent studies were unable to demonstrate all predictions from the static-stress-change hypothesis, particularly seismicity rate reductions. However, current dynamic stress change hypotheses do not explain delayed earthquake triggering and Omori's law. Here I show numerically that if seismic waves can alter some frictional contacts in neighboring fault zones, then dynamic triggering might cause delayed triggering and an Omori-law response. The hypothesis depends on faults following a rate/state friction law, and on seismic waves changing the mean critical slip distance (Dc) at nucleation zones.

Aircraft interior noise reduction by alternate resonance tuning

NASA Technical Reports Server (NTRS)

Bliss, Donald B.; Gottwald, James A.; Gustaveson, Mark B.; Burton, James R., III

1988-01-01

Model problem development and analysis continues with the Alternate Resonance Tuning (ART) concept. The various topics described are presently at different stages of completion: investigation of the effectiveness of the ART concept under an external propagating pressure field associated with propeller passage by the fuselage; analysis of ART performance with a double panel wall mounted in a flexible frame model; development of a data fitting scheme using a branch analysis with a Newton-Raphson scheme in multiple dimensions to determine values of critical parameters in the actual experimental apparatus; and investigation of the ART effect with real panels as opposed to the spring-mass-damper systems currently used in much of the theory.

Cryogenic homogenization and sampling of heterogeneous multi-phase feedstock

DOEpatents

Doyle, Glenn Michael; Ideker, Virgene Linda; Siegwarth, James David

2002-01-01

An apparatus and process for producing a homogeneous analytical sample from a heterogenous feedstock by: providing the mixed feedstock, reducing the temperature of the feedstock to a temperature below a critical temperature, reducing the size of the feedstock components, blending the reduced size feedstock to form a homogeneous mixture; and obtaining a representative sample of the homogeneous mixture. The size reduction and blending steps are performed at temperatures below the critical temperature in order to retain organic compounds in the form of solvents, oils, or liquids that may be adsorbed onto or absorbed into the solid components of the mixture, while also improving the efficiency of the size reduction. Preferably, the critical temperature is less than 77 K (-196.degree. C.). Further, with the process of this invention the representative sample may be maintained below the critical temperature until being analyzed.

Kiloampere, Variable-Temperature, Critical-Current Measurements of High-Field Superconductors

PubMed Central

Goodrich, LF; Cheggour, N; Stauffer, TC; Filla, BJ; Lu, XF

2013-01-01

We review variable-temperature, transport critical-current (Ic) measurements made on commercial superconductors over a range of critical currents from less than 0.1 A to about 1 kA. We have developed and used a number of systems to make these measurements over the last 15 years. Two exemplary variable-temperature systems with coil sample geometries will be described: a probe that is only variable-temperature and a probe that is variable-temperature and variable-strain. The most significant challenge for these measurements is temperature stability, since large amounts of heat can be generated by the flow of high current through the resistive sample fixture. Therefore, a significant portion of this review is focused on the reduction of temperature errors to less than ±0.05 K in such measurements. A key feature of our system is a pre-regulator that converts a flow of liquid helium to gas and heats the gas to a temperature close to the target sample temperature. The pre-regulator is not in close proximity to the sample and it is controlled independently of the sample temperature. This allows us to independently control the total cooling power, and thereby fine tune the sample cooling power at any sample temperature. The same general temperature-control philosophy is used in all of our variable-temperature systems, but the addition of another variable, such as strain, forces compromises in design and results in some differences in operation and protocol. These aspects are analyzed to assess the extent to which the protocols for our systems might be generalized to other systems at other laboratories. Our approach to variable-temperature measurements is also placed in the general context of measurement-system design, and the perceived advantages and disadvantages of design choices are presented. To verify the accuracy of the variable-temperature measurements, we compared critical-current values obtained on a specimen immersed in liquid helium (“liquid” or Ic liq) at 5 K to those measured on the same specimen in flowing helium gas (“gas” or Ic gas) at the same temperature. These comparisons indicate the temperature control is effective over the superconducting wire length between the voltage taps, and this condition is valid for all types of sample investigated, including Nb-Ti, Nb3Sn, and MgB2 wires. The liquid/gas comparisons are used to study the variable-temperature measurement protocol that was necessary to obtain the “correct” critical current, which was assumed to be the Ic liq. We also calibrated the magnetoresistance effect of resistive thermometers for temperatures from 4 K to 35 K and magnetic fields from 0 T to 16 T. This calibration reduces systematic errors in the variable-temperature data, but it does not affect the liquid/gas comparison since the same thermometers are used in both cases. PMID:26401435

Cognitive workload reduction in hospital information systems : Decision support for order set optimization.

PubMed

Gartner, Daniel; Zhang, Yiye; Padman, Rema

2018-06-01

Order sets are a critical component in hospital information systems that are expected to substantially reduce physicians' physical and cognitive workload and improve patient safety. Order sets represent time interval-clustered order items, such as medications prescribed at hospital admission, that are administered to patients during their hospital stay. In this paper, we develop a mathematical programming model and an exact and a heuristic solution procedure with the objective of minimizing physicians' cognitive workload associated with prescribing order sets. Furthermore, we provide structural insights into the problem which lead us to a valid lower bound on the order set size. In a case study using order data on Asthma patients with moderate complexity from a major pediatric hospital, we compare the hospital's current solution with the exact and heuristic solutions on a variety of performance metrics. Our computational results confirm our lower bound and reveal that using a time interval decomposition approach substantially reduces computation times for the mathematical program, as does a K -means clustering based decomposition approach which, however, does not guarantee optimality because it violates the lower bound. The results of comparing the mathematical program with the current order set configuration in the hospital indicates that cognitive workload can be reduced by about 20.2% by allowing 1 to 5 order sets, respectively. The comparison of the K -means based decomposition with the hospital's current configuration reveals a cognitive workload reduction of about 19.5%, also by allowing 1 to 5 order sets, respectively. We finally provide a decision support system to help practitioners analyze the current order set configuration, the results of the mathematical program and the heuristic approach.

[Bio-electrochemical effect on hydrogenotrophic sulfate reduction stimulated by electrical field in the presence of H2 under atmospheric pressure].

PubMed

Xu, Hui-Wei; Zhang, Xu; Yang, Shan-Shan; Li, Guang-He

2009-07-15

Microbial sulfate reduction rate is limited with H2 as electron donor. In order to improve hydrogenotrophic sulfate reduction under normal atmospheric H2 pressure, a bio-electrochemical system with direct current was designed and performed in this study. Results indicates that sulfate reduction rate (SRR) increases with the augment of current intensity under lower current intensity (I < or = 1.50 mA). When optimum current intensity of 1.50 mA is applied, the SRR is 1.7 to 2.1 times higher than that of the control reactor. The synergistic effect of electrochemistry and microbiology on sulfate reduction varies at different current intensity. Under the condition of I < or = 1.50 mA, the most probable mechanism of SRR increase is that electric or magnetic field stimulates the proliferation of sulfate-reducing bacteria (SRB) and the activity of the enzymes. When I is higher than 1.50 mA, the activity of SRB is inhibited, resulting in lower reduction rate compared with that at lower current. If controlling the cathode potential lower than -0.69 V and H2 partial pressure 1.01 x 10(5) Pa, electro-catalytic sulfate reduction process takes place with H2 as reductant in this bio-electrochemical system. However, the overall reduction rate is still lower than that when I = 1.50 mA is applied, and additionally the energy consumption is much higher. Therefore, electric field of low intensity can enhance hydrogenotrophic sulfate reduction in the presence of H2 under atmospheric pressure.

40 CFR 430.112 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... effluent reduction attainable by the application of the best practicable control technology currently... reduction attainable by the application of the best practicable control technology currently available (BPT...

40 CFR 430.112 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2011 CFR

2011-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... effluent reduction attainable by the application of the best practicable control technology currently... reduction attainable by the application of the best practicable control technology currently available (BPT...

Vanishing characteristic speeds and critical dispersive points in nonlinear interfacial wave problems

NASA Astrophysics Data System (ADS)

Ratliff, Daniel J.

2017-11-01

Criticality plays a central role in the study of reductions and stability of hydrodynamical systems. At critical points, it is often the case that nonlinear reductions with dispersion arise to govern solution behavior. By considering when such models become bidirectional and lose their initial dispersive properties, it will be shown that higher order dispersive models may be supported in hydrodynamical systems. Precisely, this equation is a two-way Boussinesq equation with sixth order dispersion. The case of two layered shallow water is considered to illustrate this, and it is reasoned why such an environment is natural for such a system to emerge. Further, it is demonstrated that the regions in the parameter space for nontrivial flow, which admit this reduction, are vast and in fact form a continuum. The reduced model is then numerically simulated to illustrate how the two-way and higher dispersive properties suggest more exotic families of solitary wave solutions can emerge in stratified flows.

78 FR 4042 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-18

... provides an option for a high frequency eddy current inspection for cracking of the critical fastener holes... for a high frequency eddy current inspection for cracking of the critical fastener holes, and repair..., August 9, 2007)), do a high frequency eddy current (HFEC) inspection for cracking of the four critical...

Naval electrochemical corrosion reducer

DOEpatents

Clark, Howard L.

1991-10-01

A corrosion reducer for use with ships having a hull, a propeller mounted a propeller shaft and extending through the hull, bearings supporting the shaft, at least one thrust bearing and one seal. The improvement includes a current collector and a current reduction assembly for reducing the voltage between the hull and shaft in order to reduce corrosion due to electrolytic action. The current reduction assembly includes an electrical contact, the current collector, and the hull. The current reduction assembly further includes a device for sensing and measuring the voltage between the hull and the shaft and a device for applying a reverse voltage between the hull and the shaft so that the resulting voltage differential is from 0 to 0.05 volts. The current reduction assembly further includes a differential amplifier having a voltage differential between the hull and the shaft. The current reduction assembly further includes an amplifier and a power output circuit receiving signals from the differential amplifier and being supplied by at least one current supply. The current selector includes a brush assembly in contact with a slip ring over the shaft so that its potential may be applied to the differential amplifier.

Advanced development of TFA-MOD coated conductors

NASA Astrophysics Data System (ADS)

Rupich, M. W.; Li, X.; Sathyamurthy, S.; Thieme, C.; Fleshler, S.

2011-11-01

American Superconductor is manufacturing 2G wire for initial commercial applications. The 2G wire properties satisfy the requirements for these initial projects; however, improvements in the critical current, field performance and cost are required to address the broad range of potential commercial and military applications. In order to meet the anticipated the performance and cost requirements, AMSC's R&D effort is focused on two major areas: (1) higher critical current and (2) enhanced flux pinning. AMSC's current 2G production wire, designed around a 0.8 μm thick YBCO layer deposited by a Metal Organic Deposition (MOD) process, carries a critical current in the range of 200-300 A/cm-w (77 K, sf). Achieving higher critical current requires increasing the thickness of the YBCO layer. This paper describes recent progress at AMSC on increasing the critical current of MOD-YBCO films using processes compatible with low-cost, high-rate manufacturing.

Evaluation of stabilization techniques for ion implant processing

NASA Astrophysics Data System (ADS)

Ross, Matthew F.; Wong, Selmer S.; Minter, Jason P.; Marlowe, Trey; Narcy, Mark E.; Livesay, William R.

1999-06-01

With the integration of high current ion implant processing into volume CMOS manufacturing, the need for photoresist stabilization to achieve a stable ion implant process is critical. This study compares electron beam stabilization, a non-thermal process, with more traditional thermal stabilization techniques such as hot plate baking and vacuum oven processing. The electron beam processing is carried out in a flood exposure system with no active heating of the wafer. These stabilization techniques are applied to typical ion implant processes that might be found in a CMOS production process flow. The stabilization processes are applied to a 1.1 micrometers thick PFI-38A i-line photoresist film prior to ion implant processing. Post stabilization CD variation is detailed with respect to wall slope and feature integrity. SEM photographs detail the effects of the stabilization technique on photoresist features. The thermal stability of the photoresist is shown for different levels of stabilization and post stabilization thermal cycling. Thermal flow stability of the photoresist is detailed via SEM photographs. A significant improvement in thermal stability is achieved with the electron beam process, such that photoresist features are stable to temperatures in excess of 200 degrees C. Ion implant processing parameters are evaluated and compared for the different stabilization methods. Ion implant system end-station chamber pressure is detailed as a function of ion implant process and stabilization condition. The ion implant process conditions are detailed for varying factors such as ion current, energy, and total dose. A reduction in the ion implant systems end-station chamber pressure is achieved with the electron beam stabilization process over the other techniques considered. This reduction in end-station chamber pressure is shown to provide a reduction in total process time for a given ion implant dose. Improvements in the ion implant process are detailed across several combinations of current and energy.

Restoration of dimensional reduction in the random-field Ising model at five dimensions

NASA Astrophysics Data System (ADS)

Fytas, Nikolaos G.; Martín-Mayor, Víctor; Picco, Marco; Sourlas, Nicolas

2017-04-01

The random-field Ising model is one of the few disordered systems where the perturbative renormalization group can be carried out to all orders of perturbation theory. This analysis predicts dimensional reduction, i.e., that the critical properties of the random-field Ising model in D dimensions are identical to those of the pure Ising ferromagnet in D -2 dimensions. It is well known that dimensional reduction is not true in three dimensions, thus invalidating the perturbative renormalization group prediction. Here, we report high-precision numerical simulations of the 5D random-field Ising model at zero temperature. We illustrate universality by comparing different probability distributions for the random fields. We compute all the relevant critical exponents (including the critical slowing down exponent for the ground-state finding algorithm), as well as several other renormalization-group invariants. The estimated values of the critical exponents of the 5D random-field Ising model are statistically compatible to those of the pure 3D Ising ferromagnet. These results support the restoration of dimensional reduction at D =5 . We thus conclude that the failure of the perturbative renormalization group is a low-dimensional phenomenon. We close our contribution by comparing universal quantities for the random-field problem at dimensions 3 ≤D <6 to their values in the pure Ising model at D -2 dimensions, and we provide a clear verification of the Rushbrooke equality at all studied dimensions.

Restoration of dimensional reduction in the random-field Ising model at five dimensions.

PubMed

Fytas, Nikolaos G; Martín-Mayor, Víctor; Picco, Marco; Sourlas, Nicolas

2017-04-01

The random-field Ising model is one of the few disordered systems where the perturbative renormalization group can be carried out to all orders of perturbation theory. This analysis predicts dimensional reduction, i.e., that the critical properties of the random-field Ising model in D dimensions are identical to those of the pure Ising ferromagnet in D-2 dimensions. It is well known that dimensional reduction is not true in three dimensions, thus invalidating the perturbative renormalization group prediction. Here, we report high-precision numerical simulations of the 5D random-field Ising model at zero temperature. We illustrate universality by comparing different probability distributions for the random fields. We compute all the relevant critical exponents (including the critical slowing down exponent for the ground-state finding algorithm), as well as several other renormalization-group invariants. The estimated values of the critical exponents of the 5D random-field Ising model are statistically compatible to those of the pure 3D Ising ferromagnet. These results support the restoration of dimensional reduction at D=5. We thus conclude that the failure of the perturbative renormalization group is a low-dimensional phenomenon. We close our contribution by comparing universal quantities for the random-field problem at dimensions 3≤D<6 to their values in the pure Ising model at D-2 dimensions, and we provide a clear verification of the Rushbrooke equality at all studied dimensions.

Ontario's Poverty Reduction Strategy: A Critical Discourse Analysis.

PubMed

Benbow, Sarah; Gorlick, Carolyne; Forchuk, Cheryl; Ward-Griffin, Catherine; Berman, Helene

2016-01-01

This article overviews the second phase of a two-phase study which examined experiences of health and social exclusion among mothers experiencing homelessness in Ontario, Canada. A critical discourse analysis was employed to analyze the policy document, Realizing Our Potential: Ontario's Poverty Reduction Strategy, 2014-2019. In nursing, analysis of policy is an emerging form of scholarship, one that draws attention to the macro levels influencing health and health promotion, such as the social determinants of health, and the policies that impact them. The clear neo-liberal underpinnings, within the strategy, with a focus on productivity and labor market participation leave little room for an understanding of poverty reduction from a human rights perspective. Further, gender-neutrality rendered the poverty experienced by women, and mothers, invisible. Notably, there were a lack of deadlines, target dates, and thorough action and evaluation plans. Such absence troubles whether poverty reduction is truly a priority for the government, and society as a whole.

NASA Astrophysics Data System (ADS)

Nishimura, A.; Takeuchi, T.; Nishijima, S.; Ochiai, K.; Nishijima, G.; Watanabe, K.; Shikama, T.

2010-04-01

To investigate the effect of neutron irradiation on superconducting properties, a collaboration network was established among superconducting material engineering and neutronics fields. Within the framework, irradiation test of Nb3Sn and Nb3Al wires by 14 MeV fusion neutron was planned and carried out at Fusion Neutronics Source in Japan Atomic Energy Agency. After the irradiation, critical current and critical magnetic field were measured with 28 T hybrid magnet at Institute for Metals Research in Tohoku University. The irradiation to 3.52×1020 n/m2 showed a slight increase of the critical current of the Nb3Sn wire, and the irradiation to 1.78×1021 n/m2 made the critical current appreciably larger. Regarding the critical magnetic field, no clear change was observed. In the case of Nb3Al wire, a sample irradiated to 1.78×1021 n/m2 showed no increase of the critical current below 200 A which was the limit of the power supply. As for the critical magnetic field, there was no clear improvement similar to the Nb3Sn wire. The increase of the critical current would be caused by knock-on effect of the fast neutron.

Research and Development Project Summaries, October 1991

DTIC Science & Technology

1991-10-01

delivery methods, training cost reduction, demonstration of technology’ effectiveness, and the reduction of acquisition risk . The majority of the work...demonstrations, risk reduction developments, and cost-effectiveness investigations in simulator and training technologzv. This advanced development program is a...systems. The program is organized around specific demonstration tasks that target critical technical risks that confront future weapons system

Enhancing critical current density of cuprate superconductors

DOEpatents

Chaudhari, Praveen

2015-06-16

The present invention concerns the enhancement of critical current densities in cuprate superconductors. Such enhancement of critical current densities include using wave function symmetry and restricting movement of Abrikosov (A) vortices, Josephson (J) vortices, or Abrikosov-Josephson (A-J) vortices by using the half integer vortices associated with d-wave symmetry present in the grain boundary.

Type 2 diabetes in the sultanate of Oman.

PubMed

Al-Shookri, A; Khor, G L; Chan, Y M; Loke, S C; Al-Maskari, M

2011-04-01

During the past four decades, Oman has undergone a rapid socioe-conomic and epidemiological transition leading to a substantial reduction in the prevalence of various communicable diseases, including vaccine-preventable diseases. Health care planning together with the commitment of policy makers has been a critical factor in this reduction. However, with rapid social and economic growth, lifestyle-related non communicable diseases have emerged as new health challenges to the country. Diabetes and obesity are leading risks posed by the chronic diseases. The burden of diabetes has increased sharply in Oman over the last decade, rising from 8.3% in 1991 to 11.6% in 2000 among adults aged 20 years and older. The World Health Organization (WHO) predicted an increase of 190% in the number of subjects living with diabetes in Oman over the next 20 years, rising from 75,000 in 2000 to 217,000 in 2025. There is a lack of awareness of the major risk factors for diabetes mellitus in the Omani population generally. As education is often the most significant predictor of knowledge regarding risk factors, complications and the prevention of diabetes, health promotion in Oman is deemed critical, along with other prevention and control measures. Suitable prevention strategies for reducing the prevalence of diabetes in Oman are discussed. Recommendations are made for reforms in the current health care system; otherwise, diabetes will constitute a major drain on Oman's human and financial resources, threatening the advances in health and longevity achieved over the past decades.

Design, Development, Pre-Testing and Preparation for Full Scale Cold Testing of a System for Field Remediation of Vertical Pipe Units at the Hanford Site 618-10 Burial Grounds -12495

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

Halliwell, Stephen

2012-07-01

At the Hanford site, in the 1950's and 60's, radioactive waste materials, including Transuranic (TRU) wastes from a number of laboratories were stored in vertical pipe units (VPUs) in what are now the 618-10 and 618-11 burial grounds. Although the current physical condition of the VPUs is unknown, initial R and D studies had shown that in-ground size reduction and stabilization of VPU contents was feasible. This paper describes the R and D work and testing activities to validate the concept of in-ground size reduction and stabilization of VPU contents, and the design and pre-testing of major plant items andmore » augering systems on full size simulated VPUs. The paper also describes the full size prototype equipment which will be used in full size cold testing of simulated VPUs off the Hanford site, to prove the equipment, develop operating procedures, and train operators prior to deployment on site. Safe and effective field remediation, removal and disposal of the VPUs in the 600 area are critical to the success of the River Corridor Closure Contract at the U.S. Department of Energy's Hanford Site. Safe and effective field remediation, removal and disposal of the VPUs in the 600 area are critical to the success of the River Corridor Closure Contract at the U.S. Department of Energy's Hanford Site. (authors)« less

Role of the Excitability Brake Potassium Current IKD in Cold Allodynia Induced by Chronic Peripheral Nerve Injury.

PubMed

González, Alejandro; Ugarte, Gonzalo; Restrepo, Carlos; Herrera, Gaspar; Piña, Ricardo; Gómez-Sánchez, José Antonio; Pertusa, María; Orio, Patricio; Madrid, Rodolfo

2017-03-22

Cold allodynia is a common symptom of neuropathic and inflammatory pain following peripheral nerve injury. The mechanisms underlying this disabling sensory alteration are not entirely understood. In primary somatosensory neurons, cold sensitivity is mainly determined by a functional counterbalance between cold-activated TRPM8 channels and Shaker-like Kv1.1-1.2 channels underlying the excitability brake current I KD Here we studied the role of I KD in damage-triggered painful hypersensitivity to innocuous cold. We found that cold allodynia induced by chronic constriction injury (CCI) of the sciatic nerve in mice, was related to both an increase in the proportion of cold-sensitive neurons (CSNs) in DRGs contributing to the sciatic nerve, and a decrease in their cold temperature threshold. I KD density was reduced in high-threshold CSNs from CCI mice compared with sham animals, with no differences in cold-induced TRPM8-dependent current density. The electrophysiological properties and neurochemical profile of CSNs revealed an increase of nociceptive-like phenotype among neurons from CCI animals compared with sham mice. These results were validated using a mathematical model of CSNs, including I KD and TRPM8, showing that a reduction in I KD current density shifts the thermal threshold to higher temperatures and that the reduction of this current induces cold sensitivity in former cold-insensitive neurons expressing low levels of TRPM8-like current. Together, our results suggest that cold allodynia is largely due to a functional downregulation of I KD in both high-threshold CSNs and in a subpopulation of polymodal nociceptors expressing TRPM8, providing a general molecular and neural mechanism for this sensory alteration. SIGNIFICANCE STATEMENT This paper unveils the critical role of the brake potassium current I KD in damage-triggered cold allodynia. Using a well-known form of nerve injury and combining behavioral analysis, calcium imaging, patch clamping, and pharmacological tools, validated by mathematical modeling, we determined that the functional expression of I KD is reduced in sensory neurons in response to peripheral nerve damage. This downregulation not only enhances cold sensitivity of high-threshold cold thermoreceptors signaling cold discomfort, but it also transforms a subpopulation of polymodal nociceptors signaling pain into neurons activated by mild temperature drops. Our results suggest that cold allodynia is linked to a reduction of I KD in both high-threshold cold thermoreceptors and nociceptors expressing TRPM8, providing a general model for this form of cold-induced pain. Copyright © 2017 the authors 0270-6474/17/373109-18$15.00/0.

Enhancing superconducting critical current by randomness

NASA Astrophysics Data System (ADS)

Wang, Y. L.; Thoutam, L. R.; Xiao, Z. L.; Shen, B.; Pearson, J. E.; Divan, R.; Ocola, L. E.; Crabtree, G. W.; Kwok, W. K.

2016-01-01

The key ingredient of high critical currents in a type-II superconductor is defect sites that pin vortices. Contrary to earlier understanding on nanopatterned artificial pinning, here we show unequivocally the advantages of a random pinscape over an ordered array in a wide magnetic field range. We reveal that the better performance of a random pinscape is due to the variation of its local density of pinning sites (LDOPS), which mitigates the motion of vortices. This is confirmed by achieving even higher enhancement of the critical current through a conformally mapped random pinscape, where the distribution of the LDOPS is further enlarged. The demonstrated key role of LDOPS in enhancing superconducting critical currents gets at the heart of random versus commensurate pinning. Our findings highlight the importance of random pinscapes in enhancing the superconducting critical currents of applied superconductors.

Reducing pesticide use while preserving crop productivity and profitability on arable farms.

PubMed

Lechenet, Martin; Dessaint, Fabrice; Py, Guillaume; Makowski, David; Munier-Jolain, Nicolas

2017-03-01

Achieving sustainable crop production while feeding an increasing world population is one of the most ambitious challenges of this century 1 . Meeting this challenge will necessarily imply a drastic reduction of adverse environmental effects arising from agricultural activities 2 . The reduction of pesticide use is one of the critical drivers to preserve the environment and human health. Pesticide use could be reduced through the adoption of new production strategies 3-5 ; however, whether substantial reductions of pesticide use are possible without impacting crop productivity and profitability is debatable 6-17 . Here, we demonstrated that low pesticide use rarely decreases productivity and profitability in arable farms. We analysed the potential conflicts between pesticide use and productivity or profitability with data from 946 non-organic arable commercial farms showing contrasting levels of pesticide use and covering a wide range of production situations in France. We failed to detect any conflict between low pesticide use and both high productivity and high profitability in 77% of the farms. We estimated that total pesticide use could be reduced by 42% without any negative effects on both productivity and profitability in 59% of farms from our national network. This corresponded to an average reduction of 37, 47 and 60% of herbicide, fungicide and insecticide use, respectively. The potential for reducing pesticide use appeared higher in farms with currently high pesticide use than in farms with low pesticide use. Our results demonstrate that pesticide reduction is already accessible to farmers in most production situations. This would imply profound changes in market organization and trade balance.

Stakeholder discussion to reduce population-wide sodium intake and decrease sodium in the food supply: a conference report from the American Heart Association Sodium Conference 2013 Planning Group.

PubMed

Antman, Elliott M; Appel, Lawrence J; Balentine, Douglas; Johnson, Rachel K; Steffen, Lyn M; Miller, Emily Ann; Pappas, Antigoni; Stitzel, Kimberly F; Vafiadis, Dorothea K; Whitsel, Laurie

2014-06-24

A 2-day interactive forum was convened to discuss the current status and future implications of reducing sodium in the food supply and to identify opportunities for stakeholder collaboration. Participants included 128 stakeholders engaged in food research and development, food manufacturing and retail, restaurant and food service operations, regulatory and legislative activities, public health initiatives, healthcare, academia and scientific research, and data monitoring and surveillance. Presentation topics included scientific evidence for sodium reduction and public health policy recommendations; consumer sodium intakes, attitudes, and behaviors; food technologies and solutions for sodium reduction and sensory implications; experiences of the food and dining industries; and translation and implementation of sodium intake recommendations. Facilitated breakout sessions were conducted to allow for sharing of current practices, insights, and expertise. A well-established body of scientific research shows that there is a strong relationship between excess sodium intake and high blood pressure and other adverse health outcomes. With Americans getting >75% of their sodium from processed and restaurant food, this evidence creates mounting pressure for less sodium in the food supply. The reduction of sodium in the food supply is a complex issue that involves multiple stakeholders. The success of new technological approaches for reducing sodium will depend on product availability, health effects (both intended and unintended), research and development investments, quality and taste of reformulated foods, supply chain management, operational modifications, consumer acceptance, and cost. The conference facilitated an exchange of ideas and set the stage for potential collaboration opportunities among stakeholders with mutual interest in reducing sodium in the food supply and in Americans' diets. Population-wide sodium reduction remains a critically important component of public health efforts to promote cardiovascular health and prevent cardiovascular disease and will remain a priority for the American Heart Association. © 2014 American Heart Association, Inc.

Development of a Deterministic Ethernet Building blocks for Space Applications

NASA Astrophysics Data System (ADS)

Fidi, C.; Jakovljevic, Mirko

2015-09-01

The benefits of using commercially based networking standards and protocols have been widely discussed and are expected to include reduction in overall mission cost, shortened integration and test (I&T) schedules, increased operations flexibility, and hardware and software upgradeability/scalability with developments ongoing in the commercial world. The deterministic Ethernet technology TTEthernet [1] diploid on the NASA Orion spacecraft has demonstrated the use of the TTEthernet technology for a safety critical human space flight application during the Exploration Flight Test 1 (EFT-1). The TTEthernet technology used within the NASA Orion program has been matured for the use within this mission but did not lead to a broader use in space applications or an international space standard. Therefore TTTech has developed a new version which allows to scale the technology for different applications not only the high end missions allowing to decrease the size of the building blocks leading to a reduction of size weight and power enabling the use in smaller applications. TTTech is currently developing a full space products offering for its TTEthernet technology to allow the use in different space applications not restricted to launchers and human spaceflight. A broad space market assessment and the current ESA TRP7594 lead to the development of a space grade TTEthernet controller ASIC based on the ESA qualified Atmel AT1C8RHA95 process [2]. In this paper we will describe our current TTEthernet controller development towards a space qualified network component allowing future spacecrafts to operate in significant radiation environments while using a single onboard network for reliable commanding and data transfer.

Magnetic Field Dependence of the Critical Current in S-N Bilayer Thin Films

NASA Technical Reports Server (NTRS)

Sadleir, John E.; Lee, Sang-Jun; Smith, Stephen James; Bandler, Simon; Chervenak, James; Kilbourne, Caroline A.; Finkbeiner, Fred M.; Porter, Frederick S.; Kelley, Richard L.; Adams, Joseph S.;

75 FR 67366 - Agency Forms Undergoing Paperwork Reduction Act Review

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-02

... U.S. and to characterize resistant isolates. Monitoring antibiotic susceptibility is critical since Neisseria gonorrhoeae has demonstrated the consistent ability to gain antibiotic resistance. GISP provides critical surveillance for antimicrobial resistance, allowing for informed treatment recommendations. This...

Quantitative assessment of resilience of a water supply system under rainfall reduction due to climate change

NASA Astrophysics Data System (ADS)

Amarasinghe, Pradeep; Liu, An; Egodawatta, Prasanna; Barnes, Paul; McGree, James; Goonetilleke, Ashantha

2016-09-01

A water supply system can be impacted by rainfall reduction due to climate change, thereby reducing its supply potential. This highlights the need to understand the system resilience, which refers to the ability to maintain service under various pressures (or disruptions). Currently, the concept of resilience has not yet been widely applied in managing water supply systems. This paper proposed three technical resilience indictors to assess the resilience of a water supply system. A case study analysis was undertaken of the Water Grid system of Queensland State, Australia, to showcase how the proposed indicators can be applied to assess resilience. The research outcomes confirmed that the use of resilience indicators is capable of identifying critical conditions in relation to the water supply system operation, such as the maximum allowable rainfall reduction for the system to maintain its operation without failure. Additionally, resilience indicators also provided useful insight regarding the sensitivity of the water supply system to a changing rainfall pattern in the context of climate change, which represents the system's stability when experiencing pressure. The study outcomes will help in the quantitative assessment of resilience and provide improved guidance to system operators to enhance the efficiency and reliability of a water supply system.

Product lifetime, energy efficiency and climate change: A case study of air conditioners in Japan.

PubMed

Nishijima, Daisuke

2016-10-01

This study proposed a modelling technique for estimating life-cycle CO2 emissions of durable goods by considering changes in product lifetime and energy efficiency. The stock and flow of durable goods was modelled by Weibull lifetime distributions and the trend in annual energy efficiency (i.e., annual electricity consumption) of an "average" durable good was formulated as a reverse logistic curve including a technologically critical value (i.e., limit energy efficiency) with respect to time. I found that when the average product lifetime is reduced, there is a trade-off between the reduction in emissions during product use (use phase), due to the additional purchases of new, more energy-efficient air conditioners, and the increase in emissions arising from the additional production of new air conditioners stimulated by the reduction of the average product lifetime. A scenario analysis focused on residential air conditioners in Japan during 1972-2013 showed that for a reduction of average lifetime of 1 year, if the air conditioner energy efficiency limit can be improved by 1.4% from the estimated current efficiency level, then CO2 emissions can be reduced by approximately the same amount as for an extension of average product lifetime of 1 year. Copyright © 2016 Elsevier Ltd. All rights reserved.

Safety and efficacy of physical restraints for the elderly. Review of the evidence.

PubMed Central

Frank, C.; Hodgetts, G.; Puxty, J.

1996-01-01

OBJECTIVE: To critically review evidence on the safety and efficacy of physical restraints for the elderly and to provide family physicians with guidelines for rational use of restraints. DATA SOURCES: Articles cited on MEDLINE (from 1989 to November 1994) and Cinahl (from 1982 to 1994) under the MeSH heading "physical restraints." STUDY SELECTION: Articles that specifically dealt with the safety and efficacy of restraints and current patterns of use, including prevalence, risk factors, and indications, were selected. Eight original research articles were identified and critically appraised. DATA EXTRACTION: Data extracted concerned the negative sequelae of restraints and the association between restraint use and fall and injury rates. General data about current patterns of restraint use were related to safety and efficacy findings. DATA SYNTHESIS: No randomized, controlled trials of physical restraint use were found in the literature. A variety of study design, including retrospective chart review, prospective cohort studies, and case reports, found little evidence that restraints prevent injury. Some evidence suggested that restraints might increase risk of falls and injury. Restraint-reduction programs have not been shown to increase fall or injury rates. Numerous case reports document injuries or deaths resulting from restraint use or misuse. CONCLUSIONS: Although current evidence does not support the belief that restraints prevent falls and injuries and questions their safety, further prospective and controlled studies are needed to clarify these issues. Information from review and research articles was synthesized in this paper to produce guidelines for the safe and rational use of restraints. PMID:8969858

Whole-Brain Source-Reconstructed MEG-Data Reveal Reduced Long-Range Synchronization in Chronic Schizophrenia.

PubMed

Hirvonen, Jonni; Wibral, Michael; Palva, J Matias; Singer, Wolf; Uhlhaas, Peter; Palva, Satu

2017-01-01

Current theories of schizophrenia (ScZ) posit that the symptoms and cognitive dysfunctions arise from a dysconnection syndrome. However, studies that have examined this hypothesis with physiological data at realistic time scales are so far scarce. The current study employed a state-of-the-art approach using Magnetoencephalography (MEG) to test alterations in large-scale phase synchronization in a sample of n = 16 chronic ScZ patients, 10 males and n = 19 healthy participants, 10 males, during a perceptual closure task. We identified large-scale networks from source reconstructed MEG data using data-driven analyses of neuronal synchronization. Oscillation amplitudes and interareal phase-synchronization in the 3-120 Hz frequency range were estimated for 400 cortical parcels and correlated with clinical symptoms and neuropsychological scores. ScZ patients were characterized by a reduction in γ-band (30-120 Hz) oscillation amplitudes that was accompanied by a pronounced deficit in large-scale synchronization at γ-band frequencies. Synchronization was reduced within visual regions as well as between visual and frontal cortex and the reduction of synchronization correlated with elevated clinical disorganization. Accordingly, these data highlight that ScZ is associated with a profound disruption of transient synchronization, providing critical support for the notion that core aspect of the pathophysiology arises from an impairment in coordination of distributed neural activity.

How can research on anthropogenic greenhouse gas flux quantification be better aligned with US climate change policy needs?

NASA Astrophysics Data System (ADS)

Gurney, K. R.

2014-12-01

Scientific research on quantification of anthropogenic greenhouse gas emissions at national and sub-national scales within the US has advanced considerably in the last decade. Large investment has been made in building systems capable of observing greenhouse gases in the atmosphere at multiple scales, measuring direct anthropogenic fluxes near sources and modeling the linkages between fluxes and observed concentrations. Much of this research has been focused at improving the "verification" component of "monitoring, reporting, and verification" and indeed, has achieved successes in recent years. However, there are opportunities for ongoing scientific research to contribute critical new information to policymakers. In order to realize this contribution, additional but complementary, research foci must be emphasized. Examples include more focus on anthropogenic emission drivers, quantification at scales relevant to human decision-making, and exploration of cost versus uncertainty in observing/modeling systems. I will review what I think are the opportunities to better align scientific research with current and emerging US climate change policymaking. I will then explore a few examples of where expansion or alteration of greenhouse gas flux quantification research focus could better align with current and emerging US climate change policymaking such as embodied in the proposed EPA rule aimed at reducing emissions from US power plants, California's ongoing emissions reduction policymaking and aspirational emission reduction efforts in multiple US cities.

Whole-Brain Source-Reconstructed MEG-Data Reveal Reduced Long-Range Synchronization in Chronic Schizophrenia

PubMed Central

Hirvonen, Jonni; Palva, J. Matias; Singer, Wolf; Uhlhaas, Peter

2017-01-01

Abstract Current theories of schizophrenia (ScZ) posit that the symptoms and cognitive dysfunctions arise from a dysconnection syndrome. However, studies that have examined this hypothesis with physiological data at realistic time scales are so far scarce. The current study employed a state-of-the-art approach using Magnetoencephalography (MEG) to test alterations in large-scale phase synchronization in a sample of n = 16 chronic ScZ patients, 10 males and n = 19 healthy participants, 10 males, during a perceptual closure task. We identified large-scale networks from source reconstructed MEG data using data-driven analyses of neuronal synchronization. Oscillation amplitudes and interareal phase-synchronization in the 3–120 Hz frequency range were estimated for 400 cortical parcels and correlated with clinical symptoms and neuropsychological scores. ScZ patients were characterized by a reduction in γ-band (30–120 Hz) oscillation amplitudes that was accompanied by a pronounced deficit in large-scale synchronization at γ-band frequencies. Synchronization was reduced within visual regions as well as between visual and frontal cortex and the reduction of synchronization correlated with elevated clinical disorganization. Accordingly, these data highlight that ScZ is associated with a profound disruption of transient synchronization, providing critical support for the notion that core aspect of the pathophysiology arises from an impairment in coordination of distributed neural activity. PMID:29085902

Simulation of the cabling process for Rutherford cables: An advanced finite element model

NASA Astrophysics Data System (ADS)

Cabanes, J.; Garlasche, M.; Bordini, B.; Dallocchio, A.

2016-12-01

In all existing large particle accelerators (Tevatron, HERA, RHIC, LHC) the main superconducting magnets are based on Rutherford cables, which are characterized by having: strands fully transposed with respect to the magnetic field, a significant compaction that assures a large engineering critical current density and a geometry that allows efficient winding of the coils. The Nb3Sn magnets developed in the framework of the HL-LHC project for improving the luminosity of the Large Hadron Collider (LHC) are also based on Rutherford cables. Due to the characteristics of Nb3Sn wires, the cabling process has become a crucial step in the magnet manufacturing. During cabling the wires experience large plastic deformations that strongly modify the geometrical dimensions of the sub-elements constituting the superconducting strand. These deformations are particularly severe on the cable edges and can result in a significant reduction of the cable critical current as well as of the Residual Resistivity Ratio (RRR) of the stabilizing copper. In order to understand the main parameters that rule the cabling process and their impact on the cable performance, CERN has developed a 3D Finite Element (FE) model based on the LS-Dyna® software that simulates the whole cabling process. In the paper the model is presented together with a comparison between experimental and numerical results for a copper cable produced at CERN.

Enhancement in transport critical current density of ex situ PIT Ag/(Ba, K)Fe2As2 tapes achieved by applying a combined process of flat rolling and uniaxial pressing

NASA Astrophysics Data System (ADS)

Togano, Kazumasa; Gao, Zhaoshun; Matsumoto, Akiyoshi; Kumakura, Hiroaki

2013-11-01

We report that the transport critical current density Jc of ex situ powder-in-tube (PIT) processed (Ba, K)Fe2As2 (Ba-122) tapes can be significantly enhanced by applying uniaxial cold pressing at the final stage of deformation. The tapes were prepared by packing high quality precursor powder into a Ag tube, cycles of rolling and intermediate annealing, and pressing followed by the final heat treatment for sintering. The Jc values in applied magnetic fields were increased by almost one order of magnitude compared to the tapes processed without pressing, exceeding 104 A cm-2 at 4.2 K. We achieved the highest Jc (at 4.2 K and 10 T) of 2.1×104 A cm-2 among PIT-processed Fe-based wires and tapes reported so far. The Jc-H curves measured at higher temperatures maintain small field dependence up to around 20 K, suggesting that these tapes are promising for applications at higher temperatures as well as at liquid helium temperature. The microstructure investigations reveal that there are two possible causes of the large Jc enhancement by pressing: one is densification and the other is the change of crack structure. Optimization of processing parameters such as the reduction ratio of rolling and pressing is expected to yield further Jc enhancement.

Dynamics of cosmic strings with higher-dimensional windings

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

Yamauchi, Daisuke; Lake, Matthew J.; Thailand Center of Excellence in Physics, Ministry of Education,Bangkok 10400

2015-06-11

We consider F-strings with arbitrary configurations in the Minkowski directions of a higher-dimensional spacetime, which also wrap and spin around S{sup 1} subcycles of constant radius in an arbitrary internal manifold, and determine the relation between the higher-dimensional and the effective four-dimensional quantities that govern the string dynamics. We show that, for any such configuration, the motion of the windings in the compact space may render the string effectively tensionless from a four-dimensional perspective, so that it remains static with respect to the large dimensions. Such a critical configuration occurs when (locally) exactly half the square of the string lengthmore » lies in the large dimensions and half lies in the compact space. The critical solution is then seen to arise as a special case, in which the wavelength of the windings is equal to their circumference. As examples, long straight strings and circular loops are considered in detail, and the solutions to the equations of motion that satisfy the tensionless condition are presented. These solutions are then generalized to planar loops and arbitrary three-dimensional configurations. Under the process of dimensional reduction, in which higher-dimensional motion is equivalent to an effective worldsheet current (giving rise to a conserved charge), this phenomenon may be seen as the analogue of the tensionless condition which arises for superconducting and chiral-current carrying cosmic strings.« less

Dynamics of cosmic strings with higher-dimensional windings

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

Yamauchi, Daisuke; Lake, Matthew J., E-mail: yamauchi@resceu.s.u-tokyo.ac.jp, E-mail: matthewj@nu.ac.th

2015-06-01

We consider F-strings with arbitrary configurations in the Minkowski directions of a higher-dimensional spacetime, which also wrap and spin around S{sup 1} subcycles of constant radius in an arbitrary internal manifold, and determine the relation between the higher-dimensional and the effective four-dimensional quantities that govern the string dynamics. We show that, for any such configuration, the motion of the windings in the compact space may render the string effectively tensionless from a four-dimensional perspective, so that it remains static with respect to the large dimensions. Such a critical configuration occurs when (locally) exactly half the square of the string lengthmore » lies in the large dimensions and half lies in the compact space. The critical solution is then seen to arise as a special case, in which the wavelength of the windings is equal to their circumference. As examples, long straight strings and circular loops are considered in detail, and the solutions to the equations of motion that satisfy the tensionless condition are presented. These solutions are then generalized to planar loops and arbitrary three-dimensional configurations. Under the process of dimensional reduction, in which higher-dimensional motion is equivalent to an effective worldsheet current (giving rise to a conserved charge), this phenomenon may be seen as the analogue of the tensionless condition which arises for superconducting and chiral-current carrying cosmic strings.« less

Reduction of across-wafer CDU via constrained optimization of a multichannel PEB plate controller based on in-situ measurements of thermal time constants

NASA Astrophysics Data System (ADS)

Tiffany, Jason E.; Cohen, Barney M.

2004-05-01

As line widths approach 90nm node in volume production, post exposure bake (PEB) uniformity becomes a much larger component of the across wafer critical dimension uniformity (CDU). In production, the need for PEB plate matching has led to novel solutions such as plate specific dose offsets. This type of correction does not help across wafer CDU. Due to unequal activation energies of the critical PEB processes, any thermal history difference can result in a corresponding CD variation. The rise time of the resist to the target temperature has been shown to affect CD, with the most critical time being the first 5-7 seconds. A typical PEB plate has multi-zone thermal control with one thermal sensor per zone. The current practice is to setup each plate to match the steady-state target temperature, ignoring any dynamic performance. Using an in-situ wireless RTD wafer, it is possible to characterize the dynamic performance, or time constant, of each RTD location on the sensing wafer. Constrained by the zone structure of the PEB plate, the proportional, integral and derivative (PID) settings of each controller channel could be optimized to reduce the variations in rise time across the RTD wafer, thereby reducing the PEB component of across wafer CDU.

Development of Novel Methods for the Reduction of Noise and Weight in Helicopter Transmissions

NASA Technical Reports Server (NTRS)

Dimofte, Florin; Keith, Theo G., Jr.

2003-01-01

Over the 70-year evolution of the helicopter, man's understanding of vibration control has greatly increased. However, in spite of the increased performance, the extent of helicopter vibration problems has not significantly diminished. Crew vibration and noise remains important factors in the design of all current helicopters. With more complex and critical demands being placed on aircrews, it is essential that vibration and noise not impair their performance. A major source of helicopter cabin noise (which has been measured at a sound pressure level of over 100 dB) is the gearbox. Reduction of this noise has been a goal of NASA and the U.S. Army. Gear mesh noise is typically in the frequency range of 1000 to 3000 Hz, a range important for speech. A requirement for U.S. Army/NASA Advanced Rotorcraft Transmission project has been a 10-dB reduction compared to current designs. A combined analytical/experimental effort has been underway, since the end of the 80's, to study effects of design parameters on noise production. The noise generated by the gear mesh can be transmitted to the surrounding media through the bearings that support the gear shaft. Therefore, the use of fluid film bearings instead of rolling element bearings could reduce the transmission noise by 10 dB. In addition, the fluid film bearings that support the gear shaft can change the dynamics of the gear assembly by providing damping to the system and by being softer than rolling element bearings. Wave bearings can attenuate, and filter, the noise generated by a machine component due to the dynamic stiffness and damping coefficients. The attenuation ratio could be as large as 35-40 dB. The noise components at higher frequencies than a synchronous frequency can be almost eliminated.

The Longterm Effects of Climate Change in European Shrubland Ecosystems

NASA Astrophysics Data System (ADS)

Emmett, B.; Sowerby, A.; Smith, A.; EU Increase-infrastructure Project Team

2011-12-01

Shrublands constitute significant and important parts of European landscapes providing a large number of important ecosystem services. Biogeochemical cycles in these ecosystems have gained little attention relative to forests and grassland systems. As climate change progresses the potential feedback from the biosphere to the atmosphere through changes in above and below-ground structure and functioning will become increasingly important. A series of replicate long term climate change experiments have been running for ca. 10 years in contrasting shrubland types across Europe to quantify; (a) the potential changes in carbon sequestration, GHG emissions and nutrient cycling, (b) the links to above and below-ground biodiversity, and (c) implications for water quality, in response to warming and repeated summer drought. Results indicate a relatively high rate of below-ground carbon allocation compared to forest systems and the importance of modifying factors such as past and current management, atmospheric deposition and soil type in determining resilience to change. Unexpectedly, sustained reduction in soil moisture over winter (between drought periods and despite major winter rainfall) was observed in the repeated summer drought treatment, along with a reduction in the maximum water-holding capacity attained. The persistent reduction in soil moisture throughout the year resulted in a year-round increase in soil respiration flux, a response that accelerated over time to 40% above control levels in the hydric, organic-rich UK system. As above-ground biomass, litter production and diversity was remarkably stable, changes in soil fungal communities and soil physical structure appear to be critical in driving changes in soil carbon fluxes in this organic-rich site. Current ecosystem models may under-estimate potential changes in carbon loss in response to climate change if changes in soil biological and physical properties are not included.

Core Noise: Overview of Upcoming LDI Combustor Test

NASA Technical Reports Server (NTRS)

Hultgren, Lennart S.

2012-01-01

This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Fixed Wing Project. The presentation covers: the emerging importance of core noise due to turbofan design trends and its relevance to the NASA N+3 noise-reduction goal; the core noise components and the rationale for the current emphasis on combustor noise; and the current and planned research activities in the combustor-noise area. Two NASA-sponsored research programs, with particular emphasis on indirect combustor noise, "Acoustic Database for Core Noise Sources", Honeywell Aerospace (NNC11TA40T) and "Measurement and Modeling of Entropic Noise Sources in a Single-Stage Low-Pressure Turbine", U. Illinois/U. Notre Dame (NNX11AI74A) are briefly described. Recent progress in the development of CMC-based acoustic liners for broadband noise reduction suitable for turbofan-core application is outlined. Combustor-design trends and the potential impacts on combustor acoustics are discussed. A NASA GRC developed nine-point lean-direct-injection (LDI) fuel injector is briefly described. The modification of an upcoming thermo-acoustic instability evaluation of the GRC injector in a combustor rig to also provide acoustic information relevant to community noise is presented. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic. The Quiet Performance Research Theme of the Fixed Wing Project aims to develop concepts and technologies to dramatically reduce the perceived community noise attributable to aircraft with minimal impact on weight and performance.

Integrating risk assessment and life cycle assessment: a case study of insulation.

PubMed

Nishioka, Yurika; Levy, Jonathan I; Norris, Gregory A; Wilson, Andrew; Hofstetter, Patrick; Spengler, John D

2002-10-01

Increasing residential insulation can decrease energy consumption and provide public health benefits, given changes in emissions from fuel combustion, but also has cost implications and ancillary risks and benefits. Risk assessment or life cycle assessment can be used to calculate the net impacts and determine whether more stringent energy codes or other conservation policies would be warranted, but few analyses have combined the critical elements of both methodologies In this article, we present the first portion of a combined analysis, with the goal of estimating the net public health impacts of increasing residential insulation for new housing from current practice to the latest International Energy Conservation Code (IECC 2000). We model state-by-state residential energy savings and evaluate particulate matter less than 2.5 microm in diameter (PM2.5), NOx, and SO2 emission reductions. We use past dispersion modeling results to estimate reductions in exposure, and we apply concentration-response functions for premature mortality and selected morbidity outcomes using current epidemiological knowledge of effects of PM2.5 (primary and secondary). We find that an insulation policy shift would save 3 x 10(14) British thermal units or BTU (3 x 10(17) J) over a 10-year period, resulting in reduced emissions of 1,000 tons of PM2.5, 30,000 tons of NOx, and 40,000 tons of SO2. These emission reductions yield an estimated 60 fewer fatalities during this period, with the geographic distribution of health benefits differing from the distribution of energy savings because of differences in energy sources, population patterns, and meteorology. We discuss the methodology to be used to integrate life cycle calculations, which can ultimately yield estimates that can be compared with costs to determine the influence of external costs on benefit-cost calculations.

Electrochemical Generation of a Hydrogen Bubble at a Recessed Platinum Nanopore Electrode.

PubMed

Chen, Qianjin; Luo, Long; White, Henry S

2015-04-21

We report the electrochemical generation of a single hydrogen bubble within the cavity of a recessed Pt nanopore electrode. The recessed Pt electrode is a conical pore in glass that contains a micrometer-scale Pt disk (1-10 μm radius) at the nanopore base and a nanometer-scale orifice (10-100 nm radius) that restricts diffusion of electroactive molecules and dissolved gas between the nanopore cavity and bulk solution. The formation of a H2 bubble at the Pt disk electrode in voltammetric experiments results from the reduction of H(+) in a 0.25 M H2SO4 solution; the liquid-to-gas phase transformation is indicated in the voltammetric response by a precipitous decrease in the cathodic current due to rapid bubble nucleation and growth within the nanopore cavity. Finite element simulations of the concentration distribution of dissolved H2 within the nanopore cavity, as a function of the H(+) reduction current, indicate that H2 bubble nucleation at the recessed Pt electrode surface occurs at a critical supersaturation concentration of ∼0.22 M, in agreement with the value previously obtained at (nonrecessed) Pt disk electrodes (∼0.25 M). Because the nanopore orifice limits the diffusion of H2 out of the nanopore cavity, an anodic peak corresponding to the oxidation of gaseous and dissolved H2 trapped in the recessed cavity is readily observed on the reverse voltammetric scan. Integration of the charge associated with the H2 oxidation peak is found to approach that of the H(+) reduction peak at high scan rates, confirming the assignment of the anodic peak to H2 oxidation. Preliminary results for the electrochemical generation of O2 bubbles from water oxidation at a recessed nanopore electrode are consistent with the electrogeneration of H2 bubbles.

Effect of hexagonal patterned arrays and defect geometry on the critical current of superconducting films

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

Sadovskyy, I. A.; Wang, Y. L.; Xiao, Z. -L.

Understanding the effect of pinning on the vortex dynamics in superconductors is a key factor towards controlling critical current values. Large-scale simulations of vortex dynamics can provide a rational approach to achieve this goal. Here, we use the time-dependent Ginzburg-Landau equations to study thin superconducting films with artificially created pinning centers arranged periodically in hexagonal lattices. We calculate the critical current density for various geometries of the pinning centers—varying their size, strength, and density. Furthermore, we shed light upon the influence of pattern distortion on the magnetic-field-dependent critical current. We compare our result directly with available experimental measurements on patternedmore » molybdenum-germanium films, obtaining good agreement. In conclusion, our results give important systematic insights into the mechanisms of pinning in these artificial pinning landscapes and open a path for tailoring superconducting films with desired critical current behavior.« less

Effect of hexagonal patterned arrays and defect geometry on the critical current of superconducting films

NASA Astrophysics Data System (ADS)

Sadovskyy, I. A.; Wang, Y. L.; Xiao, Z.-L.; Kwok, W.-K.; Glatz, A.

2017-02-01

Understanding the effect of pinning on the vortex dynamics in superconductors is a key factor towards controlling critical current values. Large-scale simulations of vortex dynamics can provide a rational approach to achieve this goal. Here, we use the time-dependent Ginzburg-Landau equations to study thin superconducting films with artificially created pinning centers arranged periodically in hexagonal lattices. We calculate the critical current density for various geometries of the pinning centers—varying their size, strength, and density. Furthermore, we shed light upon the influence of pattern distortion on the magnetic-field-dependent critical current. We compare our result directly with available experimental measurements on patterned molybdenum-germanium films, obtaining good agreement. Our results give important systematic insights into the mechanisms of pinning in these artificial pinning landscapes and open a path for tailoring superconducting films with desired critical current behavior.

Effect of hexagonal patterned arrays and defect geometry on the critical current of superconducting films

NASA Astrophysics Data System (ADS)

Sadovskyy, Ivan; Wang, Yonglei; Xiao, Zhili; Kwok, Wai-Kwong; Glatz, Andreas

Understanding the effect of pinning on the vortex dynamics in superconductors is a key factor towards controlling critical current values. Large-scale simulations of vortex dynamics can provide a rational approach to achieve this goal. Here, we use the time-dependent Ginzburg-Landau equations to study thin superconducting films with artificially created pinning centers arranged periodically in hexagonal lattices. We calculate the critical current density for various geometries of the pinning centers - varying their size, strength, and density. Furthermore, we shed light upon the influence of pattern distortion on the magnetic field dependent critical current. We compare our result directly with available experimental measurements on patterned molybdenum-germanium films, obtaining good agreement. Our results give important systematic insights into the mechanisms of pinning in these artificial pinning landscapes and open a path for tailoring superconducting films with desired critical current behavior.

Effect of hexagonal patterned arrays and defect geometry on the critical current of superconducting films

DOE PAGES

Sadovskyy, I. A.; Wang, Y. L.; Xiao, Z. -L.; ...

2017-02-07

Understanding the effect of pinning on the vortex dynamics in superconductors is a key factor towards controlling critical current values. Large-scale simulations of vortex dynamics can provide a rational approach to achieve this goal. Here, we use the time-dependent Ginzburg-Landau equations to study thin superconducting films with artificially created pinning centers arranged periodically in hexagonal lattices. We calculate the critical current density for various geometries of the pinning centers—varying their size, strength, and density. Furthermore, we shed light upon the influence of pattern distortion on the magnetic-field-dependent critical current. We compare our result directly with available experimental measurements on patternedmore » molybdenum-germanium films, obtaining good agreement. In conclusion, our results give important systematic insights into the mechanisms of pinning in these artificial pinning landscapes and open a path for tailoring superconducting films with desired critical current behavior.« less

Memory characteristics of ring-shaped ceramic superconductors

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

Takeoka, A.; Hasunuma, M.; Sakaiya, S.

1989-03-01

For the practical application of ceramic superconductors, the authors investigated the residual magnetic field characteristics of ring-shaped ceramic superconductors in a Y-Ba-Cu-O system with high Tc. The residual magnetic field of a ring with asymmetric current paths, supplied by external currents, appeared when one of the branch currents was above the critical current. The residual magnetic field saturated when both brach currents exceeded the critical current of the ring and showed hysteresis-like characteristics. The saturated magnetic field is subject to the critical current of the ring. A superconducting ring with asymmetric current paths suggests a simple and quite new persistent-currentmore » type memory device.« less

Efficiency and Accuracy in Thermal Simulation of Powder Bed Fusion of Bulk Metallic Glass

NASA Astrophysics Data System (ADS)

Lindwall, J.; Malmelöv, A.; Lundbäck, A.; Lindgren, L.-E.

2018-05-01

Additive manufacturing by powder bed fusion processes can be utilized to create bulk metallic glass as the process yields considerably high cooling rates. However, there is a risk that reheated material set in layers may become devitrified, i.e., crystallize. Therefore, it is advantageous to simulate the process to fully comprehend it and design it to avoid the aforementioned risk. However, a detailed simulation is computationally demanding. It is necessary to increase the computational speed while maintaining accuracy of the computed temperature field in critical regions. The current study evaluates a few approaches based on temporal reduction to achieve this. It is found that the evaluated approaches save a lot of time and accurately predict the temperature history.

A perspective on the current issues in the DSM-5 classification of personality disorders.

PubMed

Guelfi, Julien D

2013-06-01

David Kupfer chaired the DSM-5 Task Force, and Andrew Skodol the working group, on personality disorders. Various initial propositions were posted on the Internet in 2010 for comment and discussion: new general definition, new criteria, new diagnostic procedures, reduction in the number of categories, and dimensional representation. Following numerous criticisms, the Task Force's final decisions were made public on December 1, 2012. Personality disorders now figure alongside other mental disorders, because of the deletion of Axis II. The methodology concerning personality traits is in a third section to promote new studies. The new proposed hybrid system has not, to date, proven better than the categories of the DSM-IV. These various decisions are commented upon.

[Air rescue: current significance and practical issues].

PubMed

Schellhaaß, A; Popp, E

2014-12-01

Germany has a nationwide and powerful helicopter emergency medical services system (HEMS), which executes primary rescue missions and interhospital transfer of intensive care patients. In recent years the range of HEMS missions has become modified due to demographic changes and structural changes in the healthcare system. Furthermore, the number of HEMS missions is steadily increasing. If reasonably used air rescue contributes to desired reductions in overall preclinical time. Moreover, it facilitates prompt transport of patients to a hospital suitable for definitive medical care and treatment can be initiated earlier which is a particular advantage for severely injured and critically ill patients. Because of complex challenges during air rescue missions the qualifications of the HEMS personnel have to be considerably higher in comparison with ground based emergency medical services.

The Marshall Islands Data Management Program

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

Stoker, A.C.; Conrado, C.L.

1995-09-01

This report is a resource document of the methods and procedures used currently in the Data Management Program of the Marshall Islands Dose Assessment and Radioecology Project. Since 1973, over 60,000 environmental samples have been collected. Our program includes relational database design, programming and maintenance; sample and information management; sample tracking; quality control; and data entry, evaluation and reduction. The usefulness of scientific databases involves careful planning in order to fulfill the requirements of any large research program. Compilation of scientific results requires consolidation of information from several databases, and incorporation of new information as it is generated. The successmore » in combining and organizing all radionuclide analysis, sample information and statistical results into a readily accessible form, is critical to our project.« less

Teachers' Perspectives on Preventing Suicide in Children and Adolescents in Schools: A Qualitative Study.

PubMed

Ross, Victoria; Kõlves, Kairi; De Leo, Diego

2017-07-03

Given the important role teachers play as gatekeepers in school suicide prevention, this study explored teachers' perspectives on what should be done to improve current suicide prevention efforts. The study, in Queensland, Australia, was part of a large-scale survey examining teachers' knowledge, attitudes and experience of suicidality. One hundred and fifteen teachers responded to an online survey question regarding their views on the requirements for school suicide prevention. Qualitative analysis identified five themes from teachers' responses: awareness and stigma reduction, support services for students, education and training, bullying and the role of social media. The results of this study provide some profound insights into teachers' perspectives on suicide and highlight the critical need for improved suicide prevention efforts in schools.

A perspective on the current issues in the DSM-5 classification of personality disorders

PubMed Central

Guelfi, Julien D.

2013-01-01

David Kupfer chaired the DSM-5 Task Force, and Andrew Skodol the working group, on personality disorders. Various initial propositions were posted on the Internet in 2010 for comment and discussion: new general definition, new criteria, new diagnostic procedures, reduction in the number of categories, and dimensional representation. Following numerous criticisms, the Task Force's final decisions were made public on December 1, 2012. Personality disorders now figure alongside other mental disorders, because of the deletion of Axis II. The methodology concerning personality traits is in a third section to promote new studies. The new proposed hybrid system has not, to date, proven better than the categories of the DSM-IV. These various decisions are commented upon. PMID:24174887

Temperature dependent DC characterization of InAlN/(AlN)/GaN HEMT for improved reliability

NASA Astrophysics Data System (ADS)

Takhar, K.; Gomes, U. P.; Ranjan, K.; Rathi, S.; Biswas, D.

2015-02-01

InxAl1-xN/AlN/GaN HEMT device performance is analysed at various temperatures with the help of physics based 2-D simulation using commercially available BLAZE and GIGA modules from SILVACO. Various material parameters viz. band-gap, low field mobility, density of states, velocity saturation, and substrate thermal conductivity are considered as critical parameters for predicting temperature effect in InxAl1-xN/AlN/GaN HEMT. Reduction in drain current and transconductance has been observed due to the decrease of 2-DEG mobility and effective electron velocity with the increase in temperature. Degradation in cut-off frequency follows the transconductance profile as variation in gate-source/gate-drain capacitances observed very small.

Effects of dividing attention during encoding on perceptual priming of unfamiliar visual objects.

PubMed

Soldan, Anja; Mangels, Jennifer A; Cooper, Lynn A

2008-11-01

According to the distractor-selection hypothesis (Mulligan, 2003), dividing attention during encoding reduces perceptual priming when responses to non-critical (i.e., distractor) stimuli are selected frequently and simultaneously with critical stimulus encoding. Because direct support for this hypothesis comes exclusively from studies using familiar word stimuli, the present study tested whether the predictions of the distractor-selection hypothesis extend to perceptual priming of unfamiliar visual objects using the possible/impossible object decision test. Consistent with the distractor-selection hypothesis, Experiments 1 and 2 found no reduction in priming when the non-critical stimuli were presented infrequently and non-synchronously with the critical target stimuli, even though explicit recognition memory was reduced. In Experiment 3, non-critical stimuli were presented frequently and simultaneously during encoding of critical stimuli; however, no decrement in priming was detected, even when encoding time was reduced. These results suggest that priming in the possible/impossible object decision test is relatively immune to reductions in central attention and that not all aspects of the distractor-selection hypothesis generalise to priming of unfamiliar visual objects. Implications for theoretical models of object decision priming are discussed.

Effects of dividing attention during encoding on perceptual priming of unfamiliar visual objects

PubMed Central

Soldan, Anja; Mangels, Jennifer A.; Cooper, Lynn A.

2008-01-01

According to the distractor-selection hypothesis (Mulligan, 2003), dividing attention during encoding reduces perceptual priming when responses to non-critical (i.e., distractor) stimuli are selected frequently and simultaneously with critical stimulus encoding. Because direct support for this hypothesis comes exclusively from studies using familiar word stimuli, the present study tested whether the predictions of the distractor-selection hypothesis extend to perceptual priming of unfamiliar visual objects using the possible/impossible object-decision test. Consistent with the distractor-selection hypothesis, Experiments 1 and 2 found no reduction in priming when the non-critical stimuli were presented infrequently and non-synchronously with the critical target stimuli, even though explicit recognition memory was reduced. In Experiment 3, non-critical stimuli were presented frequently and simultaneously during encoding of critical stimuli; however, no decrement in priming was detected, even when encoding time was reduced. These results suggest that priming in the possible/impossible object-decision test is relatively immune to reductions in central attention and that not all aspects of the distractor-selection hypothesis generalize to priming of unfamiliar visual objects. Implications for theoretical models of object-decision priming are discussed. PMID:18821167

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

Kimmel, Gregory; Sadovskyy, Ivan A.; Glatz, Andreas

For many technological applications of superconductors the performance of a material is determined by the highest current it can carry losslessly-the critical current. In turn, the critical current can be controlled by adding nonsuperconducting defects in the superconductor matrix. Here we report on systematic comparison of different local and global optimization strategies to predict optimal structures of pinning centers leading to the highest possible critical currents. We demonstrate performance of these methods for a superconductor with randomly placed spherical, elliptical, and columnar defects.

Interim glycol flowsheet reduction/oxidation (redox) model for the Defense Waste Processing Facility (DWPF)

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

Jantzen, C. M.; Williams, M. S.; Zamecnik, J. R.

Control of the REDuction/OXidation (REDOX) state of glasses containing high concentrations of transition metals, such as High Level Waste (HLW) glasses, is critical in order to eliminate processing difficulties caused by overly reduced or overly oxidized melts. Operation of a HLW melter at Fe +2/ΣFe ratios of between 0.09 and 0.33, a range which is not overly oxidizing or overly reducing, helps retain radionuclides in the melt, i.e. long-lived radioactive 99Tc species in the less volatile reduced Tc 4+ state, 104Ru in the melt as reduced Ru +4 state as insoluble RuO 2, and hazardous volatile Cr 6+ in themore » less soluble and less volatile Cr +3 state in the glass. The melter REDOX control balances the oxidants and reductants from the feed and from processing additives such as antifoam. Currently, the Defense Waste Processing Facility (DWPF) is running a formic acid-nitric acid (FN) flowsheet where formic acid is the main reductant and nitric acid is the main oxidant. During decomposition formate and formic acid releases H 2 gas which requires close control of the melter vapor space flammability. A switch to a nitric acid-glycolic acid (GN) flowsheet is desired as the glycolic acid flowsheet releases considerably less H 2 gas upon decomposition. This would greatly simplify DWPF processing. Development of an EE term for glycolic acid in the GN flowsheet is documented in this study.« less

Theory of flux cutting and flux transport at the critical current of a type-II superconducting cylindrical wire

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

Clem, John R

2011-02-17

I introduce a critical-state theory incorporating both flux cutting and flux transport to calculate the magnetic-field and current-density distributions inside a type-II superconducting cylinder at its critical current in a longitudinal applied magnetic field. The theory is an extension of the elliptic critical-state model introduced by Romero-Salazar and Pérez-Rodríguez. The vortex dynamics depend in detail on two nonlinear effective resistivities for flux cutting (ρ{sub ∥}) and flux flow (ρ{sub ⊥}), and their ratio r=ρ{sub ∥}/ρ{sub ⊥}. When r<1, the low relative efficiency of flux cutting in reducing the magnitude of the internal magnetic-flux density leads to a paramagnetic longitudinal magneticmore » moment. As a model for understanding the experimentally observed interrelationship between the critical currents for flux cutting and depinning, I calculate the forces on a helical vortex arc stretched between two pinning centers when the vortex is subjected to a current density of arbitrary angle Φ. Simultaneous initiation of flux cutting and flux transport occurs at the critical current density J{sub c}(Φ) that makes the vortex arc unstable.« less

Theory of flux cutting and flux transport at the critical current of a type-II superconducting cylindrical wire

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

Clem, John R.

2011-02-17

I introduce a critical-state theory incorporating both flux cutting and flux transport to calculate the magnetic-field and current-density distributions inside a type-II superconducting cylinder at its critical current in a longitudinal applied magnetic field. The theory is an extension of the elliptic critical-state model introduced by Romero-Salazar and Perez-Rodriguez. The vortex dynamics depend in detail on two nonlinear effective resistivities for flux cutting ({rho}{parallel}) and flux flow ({rho}{perpendicular}), and their ratio r = {rho}{parallel}/{rho}{perpendicular}. When r < 1, the low relative efficiency of flux cutting in reducing the magnitude of the internal magnetic-flux density leads to a paramagnetic longitudinal magneticmore » moment. As a model for understanding the experimentally observed interrelationship between the critical currents for flux cutting and depinning, I calculate the forces on a helical vortex arc stretched between two pinning centers when the vortex is subjected to a current density of arbitrary angle {phi}. Simultaneous initiation of flux cutting and flux transport occurs at the critical current density J{sub c}({phi}) that makes the vortex arc unstable.« less

Theory of flux cutting and flux transport at the critical current of a type-II superconducting cylindrical wire

NASA Astrophysics Data System (ADS)

Clem, John R.

2011-06-01

I introduce a critical-state theory incorporating both flux cutting and flux transport to calculate the magnetic-field and current-density distributions inside a type-II superconducting cylinder at its critical current in a longitudinal applied magnetic field. The theory is an extension of the elliptic critical-state model introduced by Romero-Salazar and Pérez-Rodríguez. The vortex dynamics depend in detail on two nonlinear effective resistivities for flux cutting (ρ∥) and flux flow (ρ⊥), and their ratio r=ρ∥/ρ⊥. When r<1, the low relative efficiency of flux cutting in reducing the magnitude of the internal magnetic-flux density leads to a paramagnetic longitudinal magnetic moment. As a model for understanding the experimentally observed interrelationship between the critical currents for flux cutting and depinning, I calculate the forces on a helical vortex arc stretched between two pinning centers when the vortex is subjected to a current density of arbitrary angle ϕ. Simultaneous initiation of flux cutting and flux transport occurs at the critical current density Jc(ϕ) that makes the vortex arc unstable.

Microalgae as feedstock for biodiesel production under ultrasound treatment - A review.

PubMed

Sivaramakrishnan, Ramachandran; Incharoensakdi, Aran

2018-02-01

The application of ultrasound in biodiesel production has recently emerged as a novel technology. Ultrasound treatment enhances the mass transfer characteristics leading to the increased reaction rate with short reaction time and potentially reduces the production cost. In this review, application of ultrasound-assisted biodiesel production using acid, base and enzyme catalysts is presented. A critical assessment of the current status of ultrasound in biodiesel production was discussed with the emphasis on using ultrasound for efficient microalgae biodiesel production. The ultrasound in the biodiesel production enhances the emulsification of immiscible liquid reactant by microturbulence generated by cavitation bubbles. The major benefit of the ultrasound-assisted biodiesel production is a reduction in reaction time. Several different methods have been discussed to improve the biodiesel production. Overall, this review focuses on the current understanding of the application of ultrasound in biodiesel production from microalgae and to provide insights into future developments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microbial β-etherases and glutathione lyases for lignin valorisation in biorefineries: current state and future perspectives.

PubMed

Husarcíková, Jana; Voß, Hauke; Domínguez de María, Pablo; Schallmey, Anett

2018-05-04

Lignin is the major aromatic biopolymer in nature, and it is considered a valuable feedstock for the future supply of aromatics. Hence, its valorisation in biorefineries is of high importance, and various chemical and enzymatic approaches for lignin depolymerisation have been reported. Among the enzymes known to act on lignin, β-etherases offer the possibility for a selective cleavage of the β-O-4 aryl ether bonds present in lignin. These enzymes, together with glutathione lyases, catalyse a reductive, glutathione-dependent ether bond cleavage displaying high stereospecificity. β-Etherases and glutathione lyases both belong to the superfamily of glutathione transferases, and several structures have been solved recently. Additionally, different approaches for their application in lignin valorisation have been reported in the last years. This review gives an overview on the current knowledge on β-etherases and glutathione lyases, their biochemical and structural features, and critically discusses their potential for application in biorefineries.

Feminist self-defense and resistance training for college students: a critical review and recommendations for the future.

PubMed

Gidycz, Christine A; Dardis, Christina M

2014-10-01

There remains resistance to feminist self-defense and resistance training programming for women, despite (a) documented effectiveness of rape resistance strategies in avoiding rape, (b) consistently high rates of sexual victimization on college campuses, and (c) limited evidence of lasting change in sexual assault perpetration reduction within existing men's prevention programs. The current article seeks to discuss (1) the rationale for feminist self-defense and resistance training for women, (2) key components of feminist self-defense and resistance training, (3) barriers to its implementation, (4) outcomes of self-defense and resistance training programming, and (5) recommendations for future work. Such suggestions include increasing funding for large-scale self-defense and rape resistance outcome research to examine program effectiveness. Specifically, outcome research that examines the role of contextual factors (e.g., alcohol use) and women's victimization histories is needed. Finally, self-defense training and resistance training should be combined with bystander intervention and men's programs with the goal of providing synergistic effects on rape reduction. © The Author(s) 2014.

Reduced Graphene Oxides: Influence of the Reduction Method on the Electrocatalytic Effect towards Nucleic Acid Oxidation

PubMed Central

Báez, Daniela F.; Pardo, Helena; Laborda, Ignacio; Marco, José F.; Yáñez, Claudia; Bollo, Soledad

2017-01-01

For the first time a critical analysis of the influence that four different graphene oxide reduction methods have on the electrochemical properties of the resulting reduced graphene oxides (RGOs) is reported. Starting from the same graphene oxide, chemical (CRGO), hydrothermal (hTRGO), electrochemical (ERGO), and thermal (TRGO) reduced graphene oxide were produced. The materials were fully characterized and the topography and electroactivity of the resulting glassy carbon modified electrodes were also evaluated. An oligonucleotide molecule was used as a model of DNA electrochemical biosensing. The results allow for the conclusion that TRGO produced the RGOs with the best electrochemical performance for oligonucleotide electroanalysis. A clear shift in the guanine oxidation peak potential to lower values (~0.100 V) and an almost two-fold increase in the current intensity were observed compared with the other RGOs. The electrocatalytic effect has a multifactorial explanation because the TRGO was the material that presented a higher polydispersity and lower sheet size, thus exposing a larger quantity of defects to the electrode surface, which produces larger physical and electrochemical areas. PMID:28677654

FY2016 Propulsion Materials Annual Progress Report

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

None, None

The Propulsion Materials Program actively supports the energy security and reduction of greenhouse emissions goals of VTO by investigating and identifying the materials properties that are most essential for continued development of cost-effective, highly efficient, and environmentally friendly next-generation heavy and light-duty powertrains. The technical approaches available to enhance propulsion systems focus on improvements in both vehicle efficiency and fuel substitution, both of which must overcome the performance limitations of the materials currently in use. Propulsion Materials Program activities work with national laboratories, industry experts, and VTO powertrain systems (e.g., Advanced Combustion Engines and Fuels) teams to develop strategies thatmore » overcome materials limitations in future powertrain performance. The technical maturity of the portfolio of funded projects ranges from basic science to subsystem prototype validation. Projects within a Propulsion Materials Program activity address materials concerns that directly impact critical technology barriers within each of the above programs, including barriers that impact fuel efficiency, thermal management, emissions reduction, improved reliability, and reduced manufacturing costs. The program engages only the barriers that result from material property limitations and represent fundamental, high-risk materials issues.« less

Optimal Ge/SiGe nanofin geometries for hole mobility enhancement: Technology limit from atomic simulations

NASA Astrophysics Data System (ADS)

Vedula, Ravi Pramod; Mehrotra, Saumitra; Kubis, Tillmann; Povolotskyi, Michael; Klimeck, Gerhard; Strachan, Alejandro

2015-05-01

We use first principles simulations to engineer Ge nanofins for maximum hole mobility by controlling strain tri-axially through nano-patterning. Large-scale molecular dynamics predict fully relaxed, atomic structures for experimentally achievable nanofins, and orthogonal tight binding is used to obtain the corresponding electronic structure. Hole transport properties are then obtained via a linearized Boltzmann formalism. This approach explicitly accounts for free surfaces and associated strain relaxation as well as strain gradients which are critical for quantitative predictions in nanoscale structures. We show that the transverse strain relaxation resulting from the reduction in the aspect ratio of the fins leads to a significant enhancement in phonon limited hole mobility (7× over unstrained, bulk Ge, and 3.5× over biaxially strained Ge). Maximum enhancement is achieved by reducing the width to be approximately 1.5 times the height and further reduction in width does not result in additional gains. These results indicate significant room for improvement over current-generation Ge nanofins, provide geometrical guidelines to design optimized geometries and insight into the physics behind the significant mobility enhancement.

R3D: Reduction Package for Integral Field Spectroscopy

NASA Astrophysics Data System (ADS)

Sánchez, Sebastián. F.

2011-06-01

R3D was developed to reduce fiber-based integral field spectroscopy (IFS) data. The package comprises a set of command-line routines adapted for each of these steps, suitable for creating pipelines. The routines have been tested against simulations, and against real data from various integral field spectrographs (PMAS, PPAK, GMOS, VIMOS and INTEGRAL). Particular attention is paid to the treatment of cross-talk. R3D unifies the reduction techniques for the different IFS instruments to a single one, in order to allow the general public to reduce different instruments data in an homogeneus, consistent and simple way. Although still in its prototyping phase, it has been proved to be useful to reduce PMAS (both in the Larr and the PPAK modes), VIMOS and INTEGRAL data. The current version has been coded in Perl, using PDL, in order to speed-up the algorithm testing phase. Most of the time critical algorithms have been translated to C[float=][/float], and it is our intention to translate all of them. However, even in this phase R3D is fast enough to produce valuable science frames in reasonable time.

Combined theoretical and experimental analysis of processes determining cathode performance in solid oxide fuel cells.

PubMed

Kuklja, M M; Kotomin, E A; Merkle, R; Mastrikov, Yu A; Maier, J

2013-04-21

Solid oxide fuel cells (SOFC) are under intensive investigation since the 1980's as these devices open the way for ecologically clean direct conversion of the chemical energy into electricity, avoiding the efficiency limitation by Carnot's cycle for thermochemical conversion. However, the practical development of SOFC faces a number of unresolved fundamental problems, in particular concerning the kinetics of the electrode reactions, especially oxygen reduction reaction. We review recent experimental and theoretical achievements in the current understanding of the cathode performance by exploring and comparing mostly three materials: (La,Sr)MnO3 (LSM), (La,Sr)(Co,Fe)O3 (LSCF) and (Ba,Sr)(Co,Fe)O3 (BSCF). Special attention is paid to a critical evaluation of advantages and disadvantages of BSCF, which shows the best cathode kinetics known so far for oxides. We demonstrate that it is the combined experimental and theoretical analysis of all major elementary steps of the oxygen reduction reaction which allows us to predict the rate determining steps for a given material under specific operational conditions and thus control and improve SOFC performance.

Double disordered YBCO coated conductors of industrial scale: high currents in high magnetic field

NASA Astrophysics Data System (ADS)

Abraimov, D.; Ballarino, A.; Barth, C.; Bottura, L.; Dietrich, R.; Francis, A.; Jaroszynski, J.; Majkic, G. S.; McCallister, J.; Polyanskii, A.; Rossi, L.; Rutt, A.; Santos, M.; Schlenga, K.; Selvamanickam, V.; Senatore, C.; Usoskin, A.; Viouchkov, Y. L.

2015-11-01

A significant increase of critical current in high magnetic field, up to 31 T, was recorded in long tapes manufactured by employing a double-disorder route. In a double-disordered high-temperature superconductor (HTS), a superimposing of intrinsic and extrinsic disorder takes place in a way that (i) the intrinsic disorder is caused by local stoichiometry deviations that lead to defects of crystallinity that serve as pining centers in the YBa2Cu3O x-δ matrix and (ii) the extrinsic disorder is introduced via embedded atoms or particles of foreign material (e.g. barium zirconate), which create a set of lattice defects. We analyzed possible technological reasons for this current gain. The properties of these tapes over a wider field-temperature range as well as field anisotropy were also studied. Record values of critical current as high as 309 A at 31 T, 500 A at 18 Tm and 1200 A at 5 T were found in 4 mm wide tape at 4.2 K and B perpendicular to tape surface. HTS layers were processed in medium-scale equipment that allows a maximum batch length of 250 m while 22 m long batches were provided for investigation. Abnormally high ratios (up to 10) of critical current density measured at 4.2 K, 19 T to critical current density measured at 77 K, self-field were observed in tapes with the highest in-field critical current. Anisotropy of the critical current as well as angular dependences of n and α values were investigated. The temperature dependence of critical current is presented for temperatures between 4.2 and 40 K. Prospects for the suppression of the dog-bone effect by Cu plating and upscale of processing chain to >500 m piece length are discussed.

Information Technology and Community Restoration Studies/Task 1: Information Technology

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

Upton, Jaki F.; Lesperance, Ann M.; Stein, Steven L.

2009-11-19

Executive Summary The Interagency Biological Restoration Demonstration—a program jointly funded by the Department of Defense's Defense Threat Reduction Agency and the Department of Homeland Security's (DHS's) Science and Technology Directorate—is developing policies, methods, plans, and applied technologies to restore large urban areas, critical infrastructures, and Department of Defense installations following the intentional release of a biological agent (anthrax) by terrorists. There is a perception that there should be a common system that can share information both vertically and horizontally amongst participating organizations as well as support analyses. A key question is: "How far away from this are we?" As partmore » of this program, Pacific Northwest National Laboratory conducted research to identify the current information technology tools that would be used by organizations in the greater Seattle urban area in such a scenario, to define criteria for use in evaluating information technology tools, and to identify current gaps. Researchers interviewed 28 individuals representing 25 agencies in civilian and military organizations to identify the tools they currently use to capture data needed to support operations and decision making. The organizations can be grouped into five broad categories: defense (Department of Defense), environmental/ecological (Environmental Protection Agency/Ecology), public health and medical services, emergency management, and critical infrastructure. The types of information that would be communicated in a biological terrorism incident include critical infrastructure and resource status, safety and protection information, laboratory test results, and general emergency information. The most commonly used tools are WebEOC (web-enabled crisis information management systems with real-time information sharing), mass notification software, resource tracking software, and NW WARN (web-based information to protect critical infrastructure systems). It appears that the current information management tools are used primarily for information gathering and sharing—not decision making. Respondents identified the following criteria for a future software system. It is easy to learn, updates information in real time, works with all agencies, is secure, uses a visualization or geographic information system feature, enables varying permission levels, flows information from one stage to another, works with other databases, feeds decision support tools, is compliant with appropriate standards, and is reasonably priced. Current tools have security issues, lack visual/mapping functions and critical infrastructure status, and do not integrate with other tools. It is clear that there is a need for an integrated, common operating system. The system would need to be accessible by all the organizations that would have a role in managing an anthrax incident to enable regional decision making. The most useful tool would feature a GIS visualization that would allow for a common operating picture that is updated in real time. To capitalize on information gained from the interviews, the following activities are recommended: • Rate emergency management decision tools against the criteria specified by the interviewees. • Identify and analyze other current activities focused on information sharing in the greater Seattle urban area. • Identify and analyze information sharing systems/tools used in other regions.« less

Assessment of critical-fluid extractions in the process industries

NASA Technical Reports Server (NTRS)

1982-01-01

The potential for critical-fluid extraction as a separation process for improving the productive use of energy in the process industries is assessed. Critical-fluid extraction involves the use of fluids, normally gaseous at ambient conditions, as extraction solvents at temperatures and pressures around the critical point. Equilibrium and kinetic properties in this regime are very favorable for solvent applications, and generally allow major reductions in the energy requirements for separating and purifying chemical component of a mixture.

5 CFR 432.103 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... performance above “unacceptable” in the critical element(s) at issue. (b) Critical element means a work... to the work. (h) Unacceptable performance means performance of an employee that fails to meet... Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERFORMANCE BASED REDUCTION IN...

The nociceptive and anti-nociceptive effects of bee venom injection and therapy: A double-edged sword

PubMed Central

Chen, Jun; Lariviere, William R.

2010-01-01

Bee venom injection as a therapy, like many other complementary and alternative medicine approaches, has been used for thousands of years to attempt to alleviate a range of diseases including arthritis. More recently, additional theraupeutic goals have been added to the list of diseases making this a critical time to evaluate the evidence for the beneficial and adverse effects of bee venom injection. Although reports of pain reduction (analgesic and antinociceptive) and anti-inflammatory effects of bee venom injection are accumulating in the literature, it is common knowledge that bee venom stings are painful and produce inflammation. In addition, a significant number of studies have been performed in the past decade highlighting that injection of bee venom and components of bee venom produce significant signs of pain or nociception, inflammation and many effects at multiple levels of immediate, acute and prolonged pain processes. This report reviews the extensive new data regarding the deleterious effects of bee venom injection in people and animals, our current understanding of the responsible underlying mechanisms and critical venom components, and provides a critical evaluation of reports of the beneficial effects of bee venom injection in people and animals and the proposed underlying mechanisms. Although further studies are required to make firm conclusions, therapeutic bee venom injection may be beneficial for some patients, but may also be harmful. This report highlights key patterns of results, critical shortcomings, and essential areas requiring further study. PMID:20558236

Soy and Gut Microbiota: Interaction and Implication for Human Health.

PubMed

Huang, Haiqiu; Krishnan, Hari B; Pham, Quynhchi; Yu, Liangli Lucy; Wang, Thomas T Y

2016-11-23

Soy (Glycine max) is a major commodity in the United States, and soy foods are gaining popularity due to their reported health-promoting effects. In the past two decades, soy and soy bioactive components have been studied for their health-promoting/disease-preventing activities and potential mechanisms of action. Recent studies have identified gut microbiota as an important component in the human body ecosystem and possibly a critical modulator of human health. Soy foods' interaction with the gut microbiota may critically influence many aspects of human development, physiology, immunity, and nutrition at different stages of life. This review summarizes current knowledge on the effects of soy foods and soy components on gut microbiota population and composition. It was found, although results vary in different studies, in general, both animal and human studies have shown that consumption of soy foods can increase the levels of bifidobacteria and lactobacilli and alter the ratio between Firmicutes and Bacteroidetes. These changes in microbiota are consistent with reported reductions in pathogenic bacteria populations in the gut, thereby lowering the risk of diseases and leading to beneficial effects on human health.

Eight-Channel AC Magnetosusceptometer of Magnetic Nanoparticles for High-Throughput and Ultra-High-Sensitivity Immunoassay

PubMed Central

Chieh, Jen-Jie; Wei, Wen-Chun; Chen, Hsin-Hsein; Lee, Yen-Fu; Lin, Feng-Chun; Chiang, Ming-Hsien; Chiu, Ming-Jang; Horng, Herng-Er; Yang, Shieh-Yueh

2018-01-01

An alternating-current magnetosusceptometer of antibody-functionalized magnetic nanoparticles (MNPs) was developed for immunomagnetic reduction (IMR). A high-sensitivity, high-critical-temperature superconducting quantum interference device was used in the magnetosusceptometer. Minute levels of biomarkers of early-stage neurodegeneration diseases were detectable in serum, but measuring each biomarker required approximately 4 h. Hence, an eight-channel platform was developed in this study to fit minimal screening requirements for Alzheimer’s disease. Two consistent results were measured for three biomarkers, namely Aβ40, Aβ42, and tau protein, per human specimen. This paper presents the instrument configuration as well as critical characteristics, such as the low noise level variations among channels, a high signal-to-noise ratio, and the coefficient of variation for the biomarkers’ IMR values. The instrument’s ultrahigh sensitivity levels for the three biomarkers and the substantially shorter total measurement time in comparison with the previous single- and four-channels platforms were also demonstrated in this study. Thus, the eight-channel instrument may serve as a powerful tool for clinical high-throughput screening of Alzheimer’s disease. PMID:29601532

The Effect of Carbonaceous Reductant Selection on Chromite Pre-reduction

NASA Astrophysics Data System (ADS)

Kleynhans, E. L. J.; Beukes, J. P.; Van Zyl, P. G.; Bunt, J. R.; Nkosi, N. S. B.; Venter, M.

2017-04-01

Ferrochrome (FeCr) production is an energy-intensive process. Currently, the pelletized chromite pre-reduction process, also referred to as solid-state reduction of chromite, is most likely the FeCr production process with the lowest specific electricity consumption, i.e., MWh/t FeCr produced. In this study, the effects of carbonaceous reductant selection on chromite pre-reduction and cured pellet strength were investigated. Multiple linear regression analysis was employed to evaluate the effect of reductant characteristics on the aforementioned two parameters. This yielded mathematical solutions that can be used by FeCr producers to select reductants more optimally in future. Additionally, the results indicated that hydrogen (H)- (24 pct) and volatile content (45.8 pct) were the most significant contributors for predicting variance in pre-reduction and compressive strength, respectively. The role of H within this context is postulated to be linked to the ability of a reductant to release H that can induce reduction. Therefore, contrary to the current operational selection criteria, the authors believe that thermally untreated reductants ( e.g., anthracite, as opposed to coke or char), with volatile contents close to the currently applied specification (to ensure pellet strength), would be optimal, since it would maximize H content that would enhance pre-reduction.

Emerging Community Noise Reduction Approaches

NASA Technical Reports Server (NTRS)

Envia, Edmane

2012-01-01

An overview of the current NASA research portfolio in the area of aircraft noise reduction is presented. The emphasis of the research described herein is on meeting the aggressive near- and mid-term national goals for reducing aircraft noise emissions, which NASA internal studies have shown to be feasible using noise reduction technologies currently being developed in-house or in partnership with NASA s industry and academic partners. While NASA has an active research effort in airframe noise reduction, this overview focuses on propulsion noise reduction only.

40 CFR 415.432 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available (BPT). 415.432 Section 415.432 Protection of Environment ENVIRONMENTAL... degree of effluent reduction attainable by the application of the best practicable control technology... effluent reduction attainable by the application of the best practicable control technology currently...

40 CFR 418.72 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available. 418.72 Section 418.72 Protection of Environment ENVIRONMENTAL PROTECTION... degree of effluent reduction attainable by the application of the best practicable control technology... reduction attainable by the application of the best practicable control technology currently available (BPT...

40 CFR 415.272 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available (BPT). 415.272 Section 415.272 Protection of Environment ENVIRONMENTAL... degree of effluent reduction attainable by the application of the best practicable control technology... effluent reduction attainable by the application of the best practicable control technology currently...

40 CFR 415.292 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available (BPT). 415.292 Section 415.292 Protection of Environment ENVIRONMENTAL... degree of effluent reduction attainable by the application of the best practicable control technology... effluent reduction attainable by the application of the best practicable control technology currently...

40 CFR 440.72 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2014 CFR

2014-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... attainable by the application of the best practicable control technology currently available (BPT). Except as... reduction attainable by the application of the best practicable control technology currently available (BPT...

40 CFR 440.12 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2014 CFR

2014-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... by the application of the best practicable control technology currently available (BPT). Except as... reduction attainable after application of the best practicable control technology currently available (BPT...

40 CFR 440.62 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2012 CFR

2012-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... attainable by the application of the best practicable control technology currently available (BPT). Except as... reduction attainable by the application of the best practicable control technology currently available (BPT...

40 CFR 440.12 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2013 CFR

2013-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... by the application of the best practicable control technology currently available (BPT). Except as... reduction attainable after application of the best practicable control technology currently available (BPT...

40 CFR 440.42 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2014 CFR

2014-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... attainable by the application of the best practicable control technology currently available (BPT). Except as... reduction attainable after application of the best practicable control technology currently available (BPT...

40 CFR 440.72 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2013 CFR

2013-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... attainable by the application of the best practicable control technology currently available (BPT). Except as... reduction attainable by the application of the best practicable control technology currently available (BPT...

40 CFR 440.42 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2012 CFR

2012-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... attainable by the application of the best practicable control technology currently available (BPT). Except as... reduction attainable after application of the best practicable control technology currently available (BPT...

40 CFR 440.62 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2014 CFR

2014-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... attainable by the application of the best practicable control technology currently available (BPT). Except as... reduction attainable by the application of the best practicable control technology currently available (BPT...

40 CFR 440.12 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2012 CFR

2012-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... by the application of the best practicable control technology currently available (BPT). Except as... reduction attainable after application of the best practicable control technology currently available (BPT...

40 CFR 440.72 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2012 CFR

2012-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... attainable by the application of the best practicable control technology currently available (BPT). Except as... reduction attainable by the application of the best practicable control technology currently available (BPT...

40 CFR 440.42 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2013 CFR

2013-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... attainable by the application of the best practicable control technology currently available (BPT). Except as... reduction attainable after application of the best practicable control technology currently available (BPT...

40 CFR 440.62 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2013 CFR

2013-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... attainable by the application of the best practicable control technology currently available (BPT). Except as... reduction attainable by the application of the best practicable control technology currently available (BPT...

Vortices in high-performance high-temperature superconductors

DOE PAGES

Kwok, Wai-Kwong; Welp, Ulrich; Glatz, Andreas; ...

2016-09-21

The behavior of vortex matter in high-temperature superconductors (HTS) controls the entire electromagnetic response of the material, including its current carrying capacity. In this paper, we review the basic concepts of vortex pinning and its application to a complex mixed pinning landscape to enhance the critical current and to reduce its anisotropy. We focus on recent scientific advances that have resulted in large enhancements of the in-field critical current in state-of-the-art second generation (2G) YBCO coated conductors and on the prospect of an isotropic, high-critical current superconductor in the iron-based superconductors. Finally, we discuss an emerging new paradigm of criticalmore » current by design—a drive to achieve a quantitative correlation between the observed critical current density and mesoscale mixed pinning landscapes by using realistic input parameters in an innovative and powerful large-scale time dependent Ginzburg–Landau approach to simulating vortex dynamics.« less

Superconducting magnetic coil

DOEpatents

Aized, Dawood; Schwall, Robert E.

1999-06-22

A superconducting magnetic coil includes a plurality of sections positioned axially along the longitudinal axis of the coil, each section being formed of an anisotropic high temperature superconductor material wound about a longitudinal axis of the coil and having an associated critical current value that is dependent on the orientation of the magnetic field of the coil. The cross section of the superconductor, or the type of superconductor material, at sections along the axial and radial axes of the coil are changed to provide an increased critical current at those regions where the magnetic field is oriented more perpendicularly to the conductor plane, to thereby increase the critical current at these regions and to maintain an overall higher critical current of the coil.

Superconducting magnetic coil

DOEpatents

Aized, Dawood; Schwall, Robert E.

1996-06-11

A superconducting magnetic coil includes a plurality of sections positioned axially along the longitudinal axis of the coil, each section being formed of an anisotropic high temperature superconductor material wound about a longitudinal axis of the coil and having an associated critical current value that is dependent on the orientation of the magnetic field of the coil. The cross section of the superconductor, or the type of superconductor material, at sections along the axial and radial axes of the coil are changed to provide an increased critical current at those regions where the magnetic field is oriented more perpendicularly to the conductor plane, to thereby increase the critical current at these regions and to maintain an overall higher critical current of the coil.

Method for determining transport critical current densities and flux penetration depth in bulk superconductors

NASA Technical Reports Server (NTRS)

Israelsson, Ulf E. (Inventor); Strayer, Donald M. (Inventor)

1992-01-01

A contact-less method for determining transport critical current density and flux penetration depth in bulk superconductor material. A compressor having a hollow interior and a plunger for selectively reducing the free space area for distribution of the magnetic flux therein are formed of superconductor material. Analytical relationships, based upon the critical state model, Maxwell's equations and geometrical relationships define transport critical current density and flux penetration depth in terms of the initial trapped magnetic flux density and the ratio between initial and final magnetic flux densities whereby data may be reliably determined by means of the simple test apparatus for evaluating the current density and flux penetration depth.

Action Potential Broadening in Capsaicin-Sensitive DRG Neurons from Frequency-Dependent Reduction of Kv3 Current

PubMed Central

Liu, Pin W.; Blair, Nathaniel T.

2017-01-01

Action potential (AP) shape is a key determinant of cellular electrophysiological behavior. We found that in small-diameter, capsaicin-sensitive dorsal root ganglia neurons corresponding to nociceptors (from rats of either sex), stimulation at frequencies as low as 1 Hz produced progressive broadening of the APs. Stimulation at 10 Hz for 3 s resulted in an increase in AP width by an average of 76 ± 7% at 22°C and by 38 ± 3% at 35°C. AP clamp experiments showed that spike broadening results from frequency-dependent reduction of potassium current during spike repolarization. The major current responsible for frequency-dependent reduction of overall spike-repolarizing potassium current was identified as Kv3 current by its sensitivity to low concentrations of 4-aminopyridine (IC50 <100 μm) and block by the peptide inhibitor blood depressing substance I (BDS-I). There was a small component of Kv1-mediated current during AP repolarization, but this current did not show frequency-dependent reduction. In a small fraction of cells, there was a component of calcium-dependent potassium current that showed frequency-dependent reduction, but the contribution to overall potassium current reduction was almost always much smaller than that of Kv3-mediated current. These results show that Kv3 channels make a major contribution to spike repolarization in small-diameter DRG neurons and undergo frequency-dependent reduction, leading to spike broadening at moderate firing frequencies. Spike broadening from frequency-dependent reduction in Kv3 current could mitigate the frequency-dependent decreases in conduction velocity typical of C-fiber axons. SIGNIFICANCE STATEMENT Small-diameter dorsal root ganglia (DRG) neurons mediating nociception and other sensory modalities express many types of potassium channels, but how they combine to control firing patterns and conduction is not well understood. We found that action potentials of small-diameter rat DRG neurons showed spike broadening at frequencies as low as 1 Hz and that spike broadening resulted predominantly from frequency-dependent inactivation of Kv3 channels. Spike width helps to control transmitter release, conduction velocity, and firing patterns and understanding the role of particular potassium channels can help to guide new pharmacological strategies for targeting pain-sensing neurons selectively. PMID:28877968

Action Potential Broadening in Capsaicin-Sensitive DRG Neurons from Frequency-Dependent Reduction of Kv3 Current.

PubMed

Liu, Pin W; Blair, Nathaniel T; Bean, Bruce P

2017-10-04

Action potential (AP) shape is a key determinant of cellular electrophysiological behavior. We found that in small-diameter, capsaicin-sensitive dorsal root ganglia neurons corresponding to nociceptors (from rats of either sex), stimulation at frequencies as low as 1 Hz produced progressive broadening of the APs. Stimulation at 10 Hz for 3 s resulted in an increase in AP width by an average of 76 ± 7% at 22°C and by 38 ± 3% at 35°C. AP clamp experiments showed that spike broadening results from frequency-dependent reduction of potassium current during spike repolarization. The major current responsible for frequency-dependent reduction of overall spike-repolarizing potassium current was identified as Kv3 current by its sensitivity to low concentrations of 4-aminopyridine (IC 50 <100 μm) and block by the peptide inhibitor blood depressing substance I (BDS-I). There was a small component of Kv1-mediated current during AP repolarization, but this current did not show frequency-dependent reduction. In a small fraction of cells, there was a component of calcium-dependent potassium current that showed frequency-dependent reduction, but the contribution to overall potassium current reduction was almost always much smaller than that of Kv3-mediated current. These results show that Kv3 channels make a major contribution to spike repolarization in small-diameter DRG neurons and undergo frequency-dependent reduction, leading to spike broadening at moderate firing frequencies. Spike broadening from frequency-dependent reduction in Kv3 current could mitigate the frequency-dependent decreases in conduction velocity typical of C-fiber axons. SIGNIFICANCE STATEMENT Small-diameter dorsal root ganglia (DRG) neurons mediating nociception and other sensory modalities express many types of potassium channels, but how they combine to control firing patterns and conduction is not well understood. We found that action potentials of small-diameter rat DRG neurons showed spike broadening at frequencies as low as 1 Hz and that spike broadening resulted predominantly from frequency-dependent inactivation of Kv3 channels. Spike width helps to control transmitter release, conduction velocity, and firing patterns and understanding the role of particular potassium channels can help to guide new pharmacological strategies for targeting pain-sensing neurons selectively. Copyright © 2017 the authors 0270-6474/17/379705-10$15.00/0.

The transverse stress effect on the critical current of jelly-roll multifilamentary Nb sub 3 Al wires

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

Zeritis, D.; Iwasa, Y.; Ando, T.

This paper reports on experiments conducted to determine the effect of transverse compressive stress (TCS) on the critical current of jelly-roll multifilamentary Nb{sub 3}Al wire (0.8-mm dia.) for magnetic flux densities up to 12 T. For comparison, identical experiments were performed for bronze-process Ti-alloyed multifilamentary Nb{sub 3}Sn wire (1.0-mm dia.). Although the unstressed critical current density of Nb{sub 3}Al was inferior to that of (NbTi){sub 3}Sn at high fields, under applied TCS Nb{sub 3}Al exhibited less critical current degradation than (NbTi){sub 3}Sn. For example, at 12 T and 150 MPa, TCS-induced critical current degradation was approximately 20% for Nb{sub 3}Al,more » whereas it was approximately 65% for (NbTi){sub 3}Sn. There is optimism that Nb{sub 3}Al will evolve into a useful superconductor for large-scale, high-field applications.« less

Crack problem in superconducting cylinder with exponential distribution of critical-current density

NASA Astrophysics Data System (ADS)

Zhao, Yufeng; Xu, Chi; Shi, Liang

2018-04-01

The general problem of a center crack in a long cylindrical superconductor with inhomogeneous critical-current distribution is studied based on the extended Bean model for zero-field cooling (ZFC) and field cooling (FC) magnetization processes, in which the inhomogeneous parameter η is introduced for characterizing the critical-current density distribution in inhomogeneous superconductor. The effect of the inhomogeneous parameter η on both the magnetic field distribution and the variations of the normalized stress intensity factors is also obtained based on the plane strain approach and J-integral theory. The numerical results indicate that the exponential distribution of critical-current density will lead a larger trapped field inside the inhomogeneous superconductor and cause the center of the cylinder to fracture more easily. In addition, it is worth pointing out that the nonlinear field distribution is unique to the Bean model by comparing the curve shapes of the magnetization loop with homogeneous and inhomogeneous critical-current distribution.

Effect of fatigue loading on critical current in stainless steel-laminated DI-BSCCO superconducting composite tape

NASA Astrophysics Data System (ADS)

Hojo, M.; Osawa, K.; Adachi, T.; Inoue, Y.; Osamura, K.; Ochiai, S.; Ayai, N.; Hayashi, K.

2010-11-01

Tensile strain tolerance of the critical current in (Bi,Pb)2Sr2Ca2Cu3Ox (Bi2223) composite superconductor is dramatically improved when the tape is laminated with stainless steel. For practical applications, it is important to understand whether this reinforcement by lamination is effective under fatigue loading. In the present study, we carried out fatigue tests in LN2 and measured the critical current at the specific fatigue cycles to clarify the strain tolerance of the critical current in stainless steel-laminated drastically innovative Bi2223 (DI-BSCCO®) tapes. The fatigue tests were carried out using a computer-controlled 10 kN servo-hydraulic fatigue testing machine with a load cell capacity of 2.5 kN. Tests under static loading showed that the irreversible stress at which the critical current is reduced by 1% from the original value (tensile stress at Ic/Ic0 = 0.99) was 315 MPa when measured at unloading state. The present fatigue tests results indicated that the critical current was maintained at over 98% of the original value at unloading state after stress cycles of 106 when the static irreversible stress was selected as the maximum stress under fatigue loading. Thus, laminated DI-BSCCO tapes showed excellent mechanical properties even under fatigue loading.

Apparatus and method for critical current measurements

DOEpatents

Martin, Joe A.; Dye, Robert C.

1992-01-01

An apparatus for the measurement of the critical current of a superconductive sample, e.g., a clad superconductive sample, the apparatus including a conductive coil, a means for maintaining the coil in proximity to a superconductive sample, an electrical connection means for passing a low amplitude alternating current through the coil, a cooling means for maintaining the superconductive sample at a preselected temperature, a means for passing a current through the superconductive sample, and, a means for monitoring reactance of the coil, is disclosed, together with a process of measuring the critical current of a superconductive material, e.g., a clad superconductive material, by placing a superconductive material into the vicinity of the conductive coil of such an apparatus, cooling the superconductive material to a preselected temperature, passing a low amplitude alternating current through the coil, the alternating current capable of generating a magnetic field sufficient to penetrate, e.g., any cladding, and to induce eddy currents in the superconductive material, passing a steadily increasing current through the superconductive material, the current characterized as having a different frequency than the alternating current, and, monitoring the reactance of the coil with a phase sensitive detector as the current passed through the superconductive material is steadily increased whereby critical current of the superconductive material can be observed as the point whereat a component of impedance deviates.

Critical Synergistic Concentration of Lecithin Phospholipids Improves the Antimicrobial Activity of Eugenol against Escherichia coli

PubMed Central

Zhang, Haoshu; Dudley, Edward G.

2017-01-01

ABSTRACT In this study, the effect of individual lecithin phospholipids on the antimicrobial properties of eugenol against Escherichia coli C600 was investigated. We tested five major phospholipids common in soy or egg lecithin (1,2-dihexadecanoyl-sn-glycero-3-phosphocholine [DPPC], 1,2-dioctadecanoyl-sn-glycero-3-phosphocholine [DSPC], 1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine [DPPE], 1,2-dihexadecanoyl-sn-glycero-3-phosphate [sodium salt] [DPPA], and 1,2-dihexadecanoyl-sn-glycero-3-phospho-l-serine [DPPS]) and one synthetic cationic phospholipid (1,2-dioctadecanoyl-sn-glycero-3-ethylphosphocholine [18:0 EPC]). Among the six phospholipids, DPPC, DSPC, DPPE, DPPA, and the cationic 18:0 EPC showed critical synergistic concentrations that significantly improved the inactivation effect of eugenol against E. coli after 30 min of exposure. At the critical synergistic concentration, an additional ca. 0.4 to 1.9 log reduction (ca. 0.66 to 2.17 log CFU/ml reduction) in the microbial population was observed compared to eugenol-only (control) treatments (ca. 0.25 log reduction). In all cases, increasing the phospholipid amount above the critical synergistic concentration (which was different for each phospholipid) resulted in antimicrobial properties similar to those seen with the eugenol-only (control) treatments. DPPS did not affect the antimicrobial properties of eugenol at the tested concentrations. The critical synergistic concentration of phospholipids was correlated with their critical micelle concentrations (CMC). IMPORTANCE Essential oils (EOs) are naturally occurring antimicrobials, with limited use in food due to their hydrophobicity and strong aroma. Lecithin is used as a natural emulsifier to stabilize EOs in aqueous systems. We previously demonstrated that, within a narrow critical-concentration window, lecithin can synergistically enhance the antimicrobial properties of eugenol. Since lecithin is a mixture of different phospholipids, we aimed to identify which phospholipids are crucial for the observed synergistic effect. This research studied the bioactivity of lecithin phospholipids, contributing to a rational design in using lecithin to effectively control foodborne pathogens in foods. PMID:28842540

Analysis of Proportional Integral and Optimized Proportional Integral Controllers for Resistance Spot Welding System (RSWS) - A Performance Perspective

NASA Astrophysics Data System (ADS)

Rama Subbanna, S.; Suryakalavathi, M., Dr.

2017-08-01

This paper is an attempt to accomplish a performance analysis of the different control techniques on spikes reduction method applied on the medium frequency transformer based DC spot welding system. Spike reduction is an important factor to be considered while spot welding systems are concerned. During normal RSWS operation welding transformer’s magnetic core can become saturated due to the unbalanced resistances of both transformer secondary windings and different characteristics of output rectifier diodes, which causes current spikes and over-current protection switch-off of the entire system. The current control technique is a piecewise linear control technique that is inspired from the DC-DC converter control algorithms to register a novel spike reduction method in the MFDC spot welding applications. Two controllers that were used for the spike reduction portion of the overall applications involve the traditional PI controller and Optimized PI controller. Care is taken such that the current control technique would maintain a reduced spikes in the primary current of the transformer while it reduces the Total Harmonic Distortion. The performance parameter that is involved in the spikes reduction technique is the THD, Percentage of current spike reduction for both techniques. Matlab/SimulinkTM based simulation is carried out for the MFDC RSWS with KW and results are tabulated for the PI and Optimized PI controllers and a tradeoff analysis is carried out.

40 CFR 430.112 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2014 CFR

2014-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... technology currently available (BPT). Except as provided in 40 CFR 125.30 through 125.32, any existing point... effluent reduction attainable by the application of the best practicable control technology currently...

40 CFR 430.112 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2012 CFR

2012-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... technology currently available (BPT). Except as provided in 40 CFR 125.30 through 125.32, any existing point... effluent reduction attainable by the application of the best practicable control technology currently...

40 CFR 430.112 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2013 CFR

2013-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... technology currently available (BPT). Except as provided in 40 CFR 125.30 through 125.32, any existing point... effluent reduction attainable by the application of the best practicable control technology currently...

Health and vulnerability to poverty in Ghana: evidence from the Ghana Living Standards Survey Round 5

PubMed Central

2012-01-01

Background An understanding of the complex relationship between health status and welfare is crucial for critical policy interventions. However, the focus of most policies in developing regions has been on current welfare to the neglect of forward-looking welfare analysis. The absence of adequate research in the area of future poverty or vulnerability to poverty has also contributed to the focus on current welfare. The objectives of this study were to estimate vulnerability to poverty among households in Ghana and examine the relationship between health status and vulnerability to poverty. Method The study used cross section data from the Fifth Round of the Ghana Living Standards Survey (GLSS 5) with a nationally representative sample of 8,687 households from all administrative regions in Ghana. A three-step Feasible Generalized Least Squares (FGLS) estimation procedure was employed to estimate vulnerability to poverty and to model the effect of health status on expected future consumption and variations in future consumption. Vulnerability to poverty estimates were also examined against various household characteristics. Results Using an upper poverty line, the estimates of vulnerability show that about 56% of households in Ghana are vulnerable to poverty in the future and this is higher than the currently observed poverty level of about 29%. Households with ill members were vulnerable to poverty. Moreover, households with poor hygiene conditions were also vulnerable to future poverty. The vulnerability to poverty estimates were, however, sensitive to the poverty line used and varied with household characteristics. Conclusion The results imply that policies directed towards poverty reduction need to take into account the vulnerability of households to future poverty. Also, hygienic conditions and health status of households need not be overlooked in poverty reduction strategies. PMID:22827954

Metal based gas diffusion layers for enhanced fuel cell performance at high current densities

NASA Astrophysics Data System (ADS)

Hussain, Nabeel; Van Steen, Eric; Tanaka, Shiro; Levecque, Pieter

2017-01-01

The gas diffusion layer strongly influences the performance and durability of polymer electrolyte fuel cells. A major drawback of current carbon fiber based GDLs is the non-controlled variation in porosity resulting in a random micro-structure. Moreover, when subjected to compression these materials show significant reduction in porosity and permeability leading to water management problems and mass transfer losses within the fuel cell. This study investigated the use of uniform perforated metal sheets as GDLs in conjunction with microchannel flowfields. A metal sheet design with a pitch of 110 μm and a hole diameter of 60 μm in combination with an MPL showed superior performance in the high current density region compared to a commercially available carbon paper based GDL in a single cell environment. Fuel cell testing with different oxidants (air, heliox and oxygen) indicate that the metal sheet offers both superior diffusion and reduced flooding in comparison to the carbon based GDL. The presence of the MPL has been found to be critical to the functionality of the metal sheet suggesting that the MPL design may represent an important optimisation parameter for further improvements in performance.

Microstructural analysis of mass transport phenomena in gas diffusion media for high current density operation in PEM fuel cells

NASA Astrophysics Data System (ADS)

Kotaka, Toshikazu; Tabuchi, Yuichiro; Mukherjee, Partha P.

2015-04-01

Cost reduction is a key issue for commercialization of fuel cell electric vehicles (FCEV). High current density operation is a solution pathway. In order to realize high current density operation, it is necessary to reduce mass transport resistance in the gas diffusion media commonly consisted of gas diffusion layer (GDL) and micro porous layer (MPL). However, fundamental understanding of the underlying mass transport phenomena in the porous components is not only critical but also not fully understood yet due to the inherent microstructural complexity. In this study, a comprehensive analysis of electron and oxygen transport in the GDL and MPL is conducted experimentally and numerically with three-dimensional (3D) microstructural data to reveal the structure-transport relationship. The results reveal that the mass transport in the GDL is strongly dependent on the local microstructural variations, such as local pore/solid volume fractions and connectivity. However, especially in the case of the electrical conductivity of MPL, the contact resistance between carbon particles is the dominant factor. This suggests that reducing the contact resistance between carbon particles and/or the number of contact points along the transport pathway can improve the electrical conductivity of MPL.

Assessing Ecosystem Service Provision Under Climate Change to Support Conservation and Development Planning in Myanmar

NASA Technical Reports Server (NTRS)

Mandle, Lisa; Wolny, Stacie; Bhagabati, Nirmal; Helsingen, Hanna; Hamel, Perrine; Bartlett, Ryan; Dixon, Adam; Horton, Radley M.; Lesk, Corey; Manley, Danielle;

Mission Systems Open Architecture Science and Technology (MOAST) program

NASA Astrophysics Data System (ADS)

Littlejohn, Kenneth; Rajabian-Schwart, Vahid; Kovach, Nicholas; Satterthwaite, Charles P.

2017-04-01

The Mission Systems Open Architecture Science and Technology (MOAST) program is an AFRL effort that is developing and demonstrating Open System Architecture (OSA) component prototypes, along with methods and tools, to strategically evolve current OSA standards and technical approaches, promote affordable capability evolution, reduce integration risk, and address emerging challenges [1]. Within the context of open architectures, the program is conducting advanced research and concept development in the following areas: (1) Evolution of standards; (2) Cyber-Resiliency; (3) Emerging Concepts and Technologies; (4) Risk Reduction Studies and Experimentation; and (5) Advanced Technology Demonstrations. Current research includes the development of methods, tools, and techniques to characterize the performance of OMS data interconnection methods for representative mission system applications. Of particular interest are the OMS Critical Abstraction Layer (CAL), the Avionics Service Bus (ASB), and the Bulk Data Transfer interconnects, as well as to develop and demonstrate cybersecurity countermeasures techniques to detect and mitigate cyberattacks against open architecture based mission systems and ensure continued mission operations. Focus is on cybersecurity techniques that augment traditional cybersecurity controls and those currently defined within the Open Mission System and UCI standards. AFRL is also developing code generation tools and simulation tools to support evaluation and experimentation of OSA-compliant implementations.

Microstructural and crystallographic imperfections of MgB2 superconducting wire and their correlation with the critical current density

NASA Astrophysics Data System (ADS)

Shahabuddin, Mohammed; Alzayed, Nasser S.; Oh, Sangjun; Choi, Seyong; Maeda, Minoru; Hata, Satoshi; Shimada, Yusuke; Hossain, Md Shahriar Al; Kim, Jung Ho

2014-01-01

A comprehensive study of the effects of structural imperfections in MgB2 superconducting wire has been conducted. As the sintering temperature becomes lower, the structural imperfections of the MgB2 material are increased, as reflected by detailed X-ray refinement and the normal state resistivity. The crystalline imperfections, caused by lattice disorder, directly affect the impurity scattering between the π and σ bands of MgB2, resulting in a larger upper critical field. In addition, low sintering temperature keeps the grain size small, which leads to a strong enhancement of pinning, and thereby, enhanced critical current density. Owing to both the impurity scattering and the grain boundary pinning, the critical current density, irreversibility field, and upper critical field are enhanced. Residual voids or porosities obviously remain in the MgB2, however, even at low sintering temperature, and thus block current transport paths.

Dependency and Self-Criticism in Treatments for Depression

PubMed Central

Chui, Harold; Zilcha-Mano, Sigal; Dinger, Ulrike; Barrett, Marna S.; Barber, Jacques P.

2016-01-01

Dependency and self-criticism are vulnerability factors for depression. How these personality factors change with treatment for depression, and how they relate to symptom change across different types of treatment require further research. In addition, cultural differences that interact with the dependency/self-criticism-depression relation remain under-investigated. One hundred and forty-nine adults with major depression were randomly assigned to receive active medication (MED; n = 50), supportive-expressive therapy (SET; n = 49), or placebo pill (PBO; n = 50). Participants completed the Depressive Experiences Questionnaire (DEQ; Blatt, D'Afflitti, & Quinlan, 1976) before and after treatment, and were administered the Hamilton Rating Scale for Depression (Hamilton, 1967) throughout the course of treatment. Self-criticism as measured on the DEQ decreased with treatment similarly across conditions. DEQ Dependency decreased in MED but remained unchanged in SET and PBO. Higher initial dependency, but not higher initial self-criticism, predicted poor treatment response across conditions. Greater reduction in self-criticism was associated with greater reduction in depressive symptoms, but the effect was weaker for racial minorities (vs. White). Increase in connectedness, an adaptive form of dependency, was associated with symptom improvement in SET but not MED. Hence, different pathways of change seem to be implicated in the treatment of depression depending on culture and type of intervention. Implications for future research are discussed. PMID:26866638

40 CFR 436.32 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... technology currently available. 436.32 Section 436.32 Protection of Environment ENVIRONMENTAL PROTECTION... effluent reduction attainable by the application of the best practicable control technology currently... of the best practicable control technology currently available (BPT): (1) Discharges of process...

40 CFR 436.22 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available. 436.22 Section 436.22 Protection of Environment ENVIRONMENTAL PROTECTION... reduction attainable by the application of the best practicable control technology currently available. (a... best practicable control technology currently available (BPT): (1) Discharges of process generated...

40 CFR 436.22 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... technology currently available. 436.22 Section 436.22 Protection of Environment ENVIRONMENTAL PROTECTION... reduction attainable by the application of the best practicable control technology currently available. (a... best practicable control technology currently available (BPT): (1) Discharges of process generated...

Influence of field dependent critical current density on flux profiles in high Tc superconductors

NASA Technical Reports Server (NTRS)

Takacs, S.

1990-01-01

The field distribution for superconducting cylinders and slabs with field dependent critical current densities in combined DC and AC magnetic fields and the corresponding magnetic fluxes are calculated. It is shown that all features of experimental magnetic-field profile measurements can be explained in the framework of field dependent critical current density. Even the quantitative agreement between the experimental and theoretical results using Kim's model is very good.

Intermittent Theta-Burst Transcranial Magnetic Stimulation Alters Electrical Properties of Fast-Spiking Neocortical Interneurons in an Age-Dependent Fashion

PubMed Central

Hoppenrath, Kathrin; Härtig, Wolfgang; Funke, Klaus

2016-01-01

Modulation of human cortical excitability by repetitive transcranial magnetic stimulation (rTMS) appears to be in part related to changed activity of inhibitory systems. Our own studies showed that intermittent theta-burst stimulation (iTBS) applied via rTMS to rat cortex primarily affects the parvalbumin-expressing (PV) fast-spiking interneurons (FSIs), evident via a strongly reduced PV expression. We further found the iTBS effect on PV to be age-dependent since no reduction in PV could be induced before the perineuronal nets (PNNs) of FSIs start to grow around postnatal day (PD) 30. To elucidate possible iTBS-induced changes in the electrical properties of FSIs and cortical network activity during cortical critical period, we performed ex vivo—in vitro whole-cell patch clamp recordings from pre-labeled FSIs in the current study. FSIs of verum iTBS-treated rats displayed a higher excitability than sham-treated controls at PD29–38, evident as higher rates of induced action potential firing at low current injections (100–200 pA) and a more depolarized resting membrane potential. This effect was absent in younger (PD26–28) and older animals (PD40–62). Slices of verum iTBS-treated rats further showed higher rates of spontaneous excitatory postsynaptic currents (sEPSCs). Based on these and previous findings we conclude that FSIs are particularly sensitive to TBS during early cortical development, when FSIs show an activity-driven step of maturation which is paralleled by intense growth of the PNNs and subsequent closure of the cortical critical period. Although to be proven further, rTMS may be a possible early intervention to compensate for hypo-activity related mal-development of cortical neuronal circuits. PMID:27065812

Intermittent Theta-Burst Transcranial Magnetic Stimulation Alters Electrical Properties of Fast-Spiking Neocortical Interneurons in an Age-Dependent Fashion.

PubMed

Hoppenrath, Kathrin; Härtig, Wolfgang; Funke, Klaus

2016-01-01

Modulation of human cortical excitability by repetitive transcranial magnetic stimulation (rTMS) appears to be in part related to changed activity of inhibitory systems. Our own studies showed that intermittent theta-burst stimulation (iTBS) applied via rTMS to rat cortex primarily affects the parvalbumin-expressing (PV) fast-spiking interneurons (FSIs), evident via a strongly reduced PV expression. We further found the iTBS effect on PV to be age-dependent since no reduction in PV could be induced before the perineuronal nets (PNNs) of FSIs start to grow around postnatal day (PD) 30. To elucidate possible iTBS-induced changes in the electrical properties of FSIs and cortical network activity during cortical critical period, we performed ex vivo-in vitro whole-cell patch clamp recordings from pre-labeled FSIs in the current study. FSIs of verum iTBS-treated rats displayed a higher excitability than sham-treated controls at PD29-38, evident as higher rates of induced action potential firing at low current injections (100-200 pA) and a more depolarized resting membrane potential. This effect was absent in younger (PD26-28) and older animals (PD40-62). Slices of verum iTBS-treated rats further showed higher rates of spontaneous excitatory postsynaptic currents (sEPSCs). Based on these and previous findings we conclude that FSIs are particularly sensitive to TBS during early cortical development, when FSIs show an activity-driven step of maturation which is paralleled by intense growth of the PNNs and subsequent closure of the cortical critical period. Although to be proven further, rTMS may be a possible early intervention to compensate for hypo-activity related mal-development of cortical neuronal circuits.

COMPUTATIONAL MODELING OF CATHODIC LIMITATIONS ON LOCALIZED CORROSION OF WETTED SS 316L, AT ROOM TEMPERATURE

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

F. Cui; F.J. Presuel-Moreno; R.G. Kelly

2005-10-13

The ability of a SS316L surface wetted with a thin electrolyte layer to serve as an effective cathode for an active localized corrosion site was studied computationally. The dependence of the total net cathodic current, I{sub net}, supplied at the repassivation potential E{sub rp} (of the anodic crevice) on relevant physical parameters including water layer thickness (WL), chloride concentration ([Cl{sup -}]) and length of cathode (Lc) were investigated using a three-level, full factorial design. The effects of kinetic parameters including the exchange current density (i{sub o,c}) and Tafel slope ({beta}{sub c}) of oxygen reduction, the anodic passive current density (i{submore » p}) (on the cathodic surface), and E{sub rp} were studied as well using three-level full factorial designs of [Cl{sup -}] and Lc with a fixed WL of 25 {micro}m. The study found that all the three parameters WL, [Cl{sup -}] and Lc as well as the interactions of Lc x WL and Lc x [Cl{sup -}] had significant impact on I{sub net}. A five-factor regression equation was obtained which fits the computation results reasonably well, but demonstrated that interactions are more complicated than can be explained with a simple linear model. Significant effects on I{sub net} were found upon varying either i{sub o,c}, {beta}{sub c}, or E{sub rp}, whereas i{sub p} in the studied range was found to have little impact. It was observed that I{sub net} asymptotically approached maximum values (I{sub max}) when Lc increased to critical minimum values. I{sub max} can be used to determine the stability of coupled localized corrosion and the critical Lc provides important information for experimental design and corrosion protection.« less

Superconducting magnetic coil

DOEpatents

Aized, D.; Schwall, R.E.

1999-06-22

A superconducting magnetic coil includes a plurality of sections positioned axially along the longitudinal axis of the coil, each section being formed of an anisotropic high temperature superconductor material wound about a longitudinal axis of the coil and having an associated critical current value that is dependent on the orientation of the magnetic field of the coil. The cross section of the superconductor, or the type of superconductor material, at sections along the axial and radial axes of the coil are changed to provide an increased critical current at those regions where the magnetic field is oriented more perpendicularly to the conductor plane, to thereby increase the critical current at these regions and to maintain an overall higher critical current of the coil. 15 figs.

Respondent Techniques for Reduction of Emotions Limiting School Adjustment: A Quantitative Review and Methodological Critique.

ERIC Educational Resources Information Center

Misra, Anjali; Schloss, Patrick J.

1989-01-01

The critical analysis of 23 studies using respondent techniques for the reduction of excessive emotional reactions in school children focuses on research design, dependent variables, independent variables, component analysis, and demonstrations of generalization and maintenance. Results indicate widespread methodological flaws that limit the…

The Critical Events Interview Manual.

ERIC Educational Resources Information Center

Avery, Donna M.; Taubert, Alexis

This guide for counselors describes the Critical Events Interview (CEI), a new counseling technique designed to be used with women in transition. The concept of critical events and their influence on adult development is described and the history and current status of the CEI are reviewed, along with current results of CEI evaluations and…

Harm reduction in name, but not substance: a comparative analysis of current Canadian provincial and territorial policy frameworks.

PubMed

Hyshka, Elaine; Anderson-Baron, Jalene; Karekezi, Kamagaju; Belle-Isle, Lynne; Elliott, Richard; Pauly, Bernie; Strike, Carol; Asbridge, Mark; Dell, Colleen; McBride, Keely; Hathaway, Andrew; Wild, T Cameron

2017-07-26

In Canada, funding, administration, and delivery of health services-including those targeting people who use drugs-are primarily the responsibility of the provinces and territories. Access to harm reduction services varies across jurisdictions, possibly reflecting differences in provincial and territorial policy commitments. We examined the quality of current provincial and territorial harm reduction policies in Canada, relative to how well official documents reflect internationally recognized principles and attributes of a harm reduction approach. We employed an iterative search and screening process to generate a corpus of 54 provincial and territorial harm reduction policy documents that were current to the end of 2015. Documents were content-analyzed using a deductive coding framework comprised of 17 indicators that assessed the quality of policies relative to how well they described key population and program aspects of a harm reduction approach. Only two jurisdictions had current provincial-level, stand-alone harm reduction policies; all other documents were focused on either substance use, addiction and/or mental health, or sexually transmitted and/or blood-borne infections. Policies rarely named specific harm reduction interventions and more frequently referred to generic harm reduction programs or services. Only one document met all 17 indicators. Very few documents acknowledged that stigma and discrimination are issues faced by people who use drugs, that not all substance use is problematic, or that people who use drugs are legitimate participants in policymaking. A minority of documents recognized that abstaining from substance use is not required to receive services. Just over a quarter addressed the risk of drug overdose, and even fewer acknowledged the need to apply harm reduction approaches to an array of drugs and modes of use. Current provincial and territorial policies offer few robust characterizations of harm reduction or go beyond rhetorical or generic support for the approach. By endorsing harm reduction in name, but not in substance, provincial and territorial policies may communicate to diverse stakeholders a general lack of support for key aspects of the approach, potentially challenging efforts to expand harm reduction services.

The Oedipus Films: A Review

ERIC Educational Resources Information Center

Clarke, Howard

1965-01-01

A critical review of Bernard Knox's literary analysis of Sophocles'"Oedipus the King" in a four-lesson film series is offered largely as a "warning" to high school teachers. Central to the criticism is the author's belief that Professor Knox has imposed a reductive and marginal interpretation on the play which tends to obscure…

Decompression Sickness During Simulated Low Pressure Exposure is Increased with Mild Ambulation Exercise

NASA Technical Reports Server (NTRS)

Pollock, N. W.; Natoli, M. J.; Martina, S. D.; Conkin, J.; Wessel, J. H., III; Gernhardt, M. L.

2016-01-01

Musculoskeletal activity accelerates inert gas elimination during oxygen breathing prior to decompression (prebreathe), but may also promote bubble formation (nucleation) and increase the risk of decompression sickness (DCS). The timing, pattern and intensity of musculoskeletal activity are likely critical to the net effect. The NASA Prebreathe Reduction Program (PRP) combined oxygen prebreathe and exercise preceding a 4.3 psia exposure in non-ambulatory subjects (a microgravity analog) to produce two protocols now used by astronauts preparing for extravehicular activity - one employing cycling and non-cycling exercise (CEVIS: 'cycle ergometer vibration isolation system') and one relying on non-cycling exercise only (ISLE: 'in-suit light exercise'). Current efforts investigate whether light exercise normal to 1 G environments increases the risk of DCS over microgravity simulation.

Compartment syndromes

NASA Technical Reports Server (NTRS)

Mubarak, S. J.; Pedowitz, R. A.; Hargens, A. R.

1989-01-01

The compartment syndrome is defined as a condition in which high pressure within a closed fascial space (muscle compartment) reduces capillary blood perfusion below the level necessary for tissue viability'. This condition occurs in acute and chronic (exertional) forms, and may be secondary to a variety of causes. The end-result of an extended period of elevated intramuscular pressure may be the development of irreversible tissue injury and Volkmann's contracture. The goal of treatment of the compartment syndrome is the reduction of intracompartmental pressure thus facilitating reperfusion of ischaemic tissue and this goal may be achieved by decompressive fasciotomy. Controversy exists regarding the critical pressure-time thresholds for surgical decompression and the optimal diagnostic methods of measuring intracompartmental pressures. This paper will update and review some current knowledge regarding the pathophysiology, aetiology, diagnosis, and treatment of the acute compartment syndrome.

Entanglement of solid vortex matter: a boomerang-shaped reduction forced by disorder in interlayer phase coherence in Bi2Sr2CaCu2O8+y.

PubMed

Kato, T; Shibauchi, T; Matsuda, Y; Thompson, J R; Krusin-Elbaum, L

2008-07-11

We present evidence for entangled solid vortex matter in a glassy state in a layered superconductor Bi2Sr2CaCu2O8+y containing randomly splayed linear defects. The interlayer phase coherence--probed by the Josephson plasma resonance--is enhanced at high temperatures, reflecting the recoupling of vortex liquid by the defects. At low temperatures in the vortex solid state, the interlayer coherence follows a boomerang-shaped reentrant temperature path with an unusual low-field decrease in coherence, indicative of meandering vortices. We uncover a distinct temperature scaling between in-plane and out-of-plane critical currents with opposing dependencies on field and time, consistent with the theoretically proposed "splayed-glass" state.

Overcoming the electroluminescence efficiency limitations of perovskite light-emitting diodes

NASA Astrophysics Data System (ADS)

Cho, Himchan; Jeong, Su-Hun; Park, Min-Ho; Kim, Young-Hoon; Wolf, Christoph; Lee, Chang-Lyoul; Heo, Jin Hyuck; Sadhanala, Aditya; Myoung, NoSoung; Yoo, Seunghyup; Im, Sang Hyuk; Friend, Richard H.; Lee, Tae-Woo

2015-12-01

Organic-inorganic hybrid perovskites are emerging low-cost emitters with very high color purity, but their low luminescent efficiency is a critical drawback. We boosted the current efficiency (CE) of perovskite light-emitting diodes with a simple bilayer structure to 42.9 candela per ampere, similar to the CE of phosphorescent organic light-emitting diodes, with two modifications: We prevented the formation of metallic lead (Pb) atoms that cause strong exciton quenching through a small increase in methylammonium bromide (MABr) molar proportion, and we spatially confined the exciton in uniform MAPbBr3 nanograins (average diameter = 99.7 nanometers) formed by a nanocrystal pinning process and concomitant reduction of exciton diffusion length to 67 nanometers. These changes caused substantial increases in steady-state photoluminescence intensity and efficiency of MAPbBr3 nanograin layers.

SEMATECH produces defect-free EUV mask blanks: defect yield and immediate challenges

NASA Astrophysics Data System (ADS)

Antohe, Alin O.; Balachandran, Dave; He, Long; Kearney, Patrick; Karumuri, Anil; Goodwin, Frank; Cummings, Kevin

2015-03-01

Availability of defect-free reflective mask has been one of the most critical challenges to extreme ultraviolet lithography (EUVL). To mitigate the risk, significant progress has been made on defect detection, pattern shifting, and defect repair. Clearly such mitigation strategies are based on the assumption that defect counts and sizes from incoming mask blanks must be below practical levels depending on mask specifics. The leading industry consensus for early mask product development is that there should be no defects greater than 80 nm in the quality area, 132 mm x 132 mm. In addition less than 10 defects smaller than 80 nm may be mitigable. SEMATECH has been focused on EUV mask blank defect reduction using Veeco Nexus TM IBD platform, the industry standard for mask blank production, and assessing if IBD technology can be evolved to a manufacturing solution. SEMATECH has recently announced a breakthrough reduction of defects in the mask blank deposition process resulting in the production of two defect-free EUV mask blanks at 54 nm inspection sensitivity (SiO2 equivalent). This paper will discuss the dramatic reduction of baseline EUV mask blank defects, review the current deposition process run and compare results with previous process runs. Likely causes of remaining defects will be discussed based on analyses as characterized by their compositions and whether defects are embedded in the multilayer stack or non-embedded.

[Changes in self-referent emotions during inpatient psychotherapy: the role of mindfulness and acceptance].

PubMed

Mitmansgruber, Horst; Beck, Thomas N; Grubinger, Thomas; Schüssler, Gerhard; Dahlbender, Reiner W

2012-01-01

Current theoretical and clinical approaches conceive the avoidance and acceptance of emotions as critical factors in the maintenance and alleviation of psychological problems. This study investigates the role of mindfulness, experiential avoidance (EA), and positive and negative meta-emotions (emotional reactions towards the emotional self) on the symptoms and psychological well-being of inpatients. Changes of mindfulness measured during a 6-week stay at a psychosomatic clinic were explored in a sample of 293 inpatients with diverse psychological problems. Multivariate analyses were performed to determine the predictive power of mindfulness and acceptance on symptoms and psychological well-being. Staying on an inpatient ward was associated with reductions in EA and negative meta-emotions as well as improvements in mindful awareness and positive meta-emotions, i.e., participants reported greater acceptance of their own emotional reactions. These aspects were associated with a reduction in symptom severity and greater psychological well-being. A differentiation of meta-emotions allowed the meaningful identification of possible processes of change. Anger and contempt seem to have distinctive functions in self-regulation. Reducing the amount of contempt/shame for one's own emotions and generating greater interest were associated with symptom reduction and greater psychological well-being. Self-compassion was negatively associated with symptoms, though it had no association with psychological well-being. The theoretical implications are discussed.

40 CFR 418.62 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available. 418.62 Section 418.62 Protection of Environment ENVIRONMENTAL PROTECTION... effluent reduction attainable by the application of the best practicable control technology currently... attainable by the application of the best practicable control technology currently available (BPT): There...

40 CFR 436.322 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available. 436.322 Section 436.322 Protection of Environment ENVIRONMENTAL PROTECTION... reduction attainable by the application of the best practicable control technology currently available... application of the best practicable control technology currently available (BPT): For operations not employing...

40 CFR 436.112 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available. 436.112 Section 436.112 Protection of Environment ENVIRONMENTAL PROTECTION... reduction attainable by the application of the best practicable control technology currently available... application of the best practicable control technology currently available (BPT): For operations not employing...

40 CFR 436.102 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available. 436.102 Section 436.102 Protection of Environment ENVIRONMENTAL PROTECTION... reduction attainable by the application of the best practicable control technology currently available... application of the best practicable control technology currently available (BPT): For operations not employing...

40 CFR 424.52 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... practicable control technology currently available (BPT): There shall be no discharge of process waste water... technology currently available. 424.52 Section 424.52 Protection of Environment ENVIRONMENTAL PROTECTION... effluent reduction attainable by the application of the best practicable control technology currently...

40 CFR 420.22 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available (BPT). 420.22 Section 420.22 Protection of Environment ENVIRONMENTAL... reduction attainable by the application of the best practicable control technology currently available (BPT... attainable by the application of the best practicable control technology currently available (BPT). (a...

40 CFR 436.182 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... technology currently available. 436.182 Section 436.182 Protection of Environment ENVIRONMENTAL PROTECTION... reduction attainable by the application of the best practicable control technology currently available. (a... practicable control technology currently available (BPT): (1) Discharges of process generated waste water and...

40 CFR 436.182 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available. 436.182 Section 436.182 Protection of Environment ENVIRONMENTAL PROTECTION... reduction attainable by the application of the best practicable control technology currently available. (a... practicable control technology currently available (BPT): (1) Discharges of process generated waste water and...

Radio-Frequency-Based NH3-Selective Catalytic Reduction Catalyst Control: Studies on Temperature Dependency and Humidity Influences

PubMed Central

Dietrich, Markus; Hagen, Gunter; Reitmeier, Willibald; Burger, Katharina; Hien, Markus; Grass, Philippe; Kubinski, David; Visser, Jaco; Moos, Ralf

2017-01-01

The upcoming more stringent automotive emission legislations and current developments have promoted new technologies for more precise and reliable catalyst control. For this purpose, radio-frequency-based (RF) catalyst state determination offers the only approach for directly measuring the NH3 loading on selective catalytic reduction (SCR) catalysts and the state of other catalysts and filter systems. Recently, the ability of this technique to directly control the urea dosing on a current NH3 storing zeolite catalyst has been demonstrated on an engine dynamometer for the first time and this paper continues that work. Therefore, a well-known serial-type and zeolite-based SCR catalyst (Cu-SSZ-13) was investigated under deliberately chosen high space velocities. At first, the full functionality of the RF system with Cu-SSZ-13 as sample was tested successfully. By direct RF-based NH3 storage control, the influence of the storage degree on the catalyst performance, i.e., on NOx conversion and NH3 slip, was investigated in a temperature range between 250 and 400 °C. For each operation point, an ideal and a critical NH3 storage degree was found and analyzed in the whole temperature range. Based on the data of all experimental runs, temperature dependent calibration functions were developed as a basis for upcoming tests under transient conditions. Additionally, the influence of exhaust humidity was observed with special focus on cold start water and its effects to the RF signals. PMID:28704929

An experimental study of the influence of stress history on fault slip during injection of supercritical CO2

NASA Astrophysics Data System (ADS)

Cuss, Robert J.; Wiseall, Andrew C.; Tamayo-Mas, Elena; Harrington, Jon F.

2018-04-01

The injection of super-critical CO2 into a depleted reservoir will alter the pore pressure of the basin, which if sufficiently perturbed could result in fault slip. Therefore, knowledge of the acceptable pressure limits is required in order to maintain fault stability. A two-part laboratory study was conducted on fully saturated kaolinite fault gouge to investigate this issue. Previously, we showed that fault slip occurred once pore-pressure within the gouge was sufficient to overcome the normal stress acting on the fault. For kaolinite, this behaviour occurred at a pressure similar to the yield stress. The current study shows that following a slow-reduction in the maximum principal stress, as would be expected through changes in effective stress, the reactivation pressure shows a stress memory. Consequently, the pressure necessary to initiate fault slip is similar to that required at the maximum stress encountered. Therefore, fault slip is at least partially controlled by the previous maximum stress and not the current stress state. During the slow reduction in normal stress, the flow characteristics of the fault remain unchanged until pore-pressure exceeds shear stress and does not increase significantly until it exceeds normal stress. This results in fault slip, which slows the rate of flow increase as shear is an effective self-sealing mechanism. These observations lead to the conclusion that stress history is a vital parameter when considering fault stability.

Impact of antipsychotic medication on transcranial direct current stimulation (tDCS) effects in schizophrenia patients.

PubMed

Agarwal, Sri Mahavir; Bose, Anushree; Shivakumar, Venkataram; Narayanaswamy, Janardhanan C; Chhabra, Harleen; Kalmady, Sunil V; Varambally, Shivarama; Nitsche, Michael A; Venkatasubramanian, Ganesan; Gangadhar, Bangalore N

2016-01-30

Transcranial direct current stimulation (tDCS) has generated interest as a treatment modality for schizophrenia. Dopamine, a critical pathogenetic link in schizophrenia, is also known to influence tDCS effects. We evaluated the influence of antipsychotic drug type (as defined by dopamine D2 receptor affinity) on the impact of tDCS in schizophrenia. DSM-IV-TR-diagnosed schizophrenia patients [N=36] with persistent auditory hallucinations despite adequate antipsychotic treatment were administered add-on tDCS. Patients were divided into three groups based on the antipsychotic's affinity to D2 receptors. An auditory hallucinations score (AHS) was measured using the auditory hallucinations subscale of the Psychotic Symptom Rating Scales (PSYRATS). Add-on tDCS resulted in a significant reduction inAHS. Antipsychotic drug type had a significant effect on AHS reduction. Patients treated with high affinity antipsychotics showed significantly lesser improvement compared to patients on low affinity antipsychotics or a mixture of the two. Furthermore, a significant sex-by-group interaction occurred; type of medication had an impact on tDCS effects only in women. Improvement differences could be due to the larger availability of the dopamine receptor system in patients taking antipsychotics with low D2 affinity. Sex-specific differences suggest potential estrogen-mediated effects. This study reports a first-time observation on the clinical utility of antipsychotic drug type in predicting tDCS effects in schizophrenia. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Radio-Frequency-Based NH₃-Selective Catalytic Reduction Catalyst Control: Studies on Temperature Dependency and Humidity Influences.

PubMed

Dietrich, Markus; Hagen, Gunter; Reitmeier, Willibald; Burger, Katharina; Hien, Markus; Grass, Philippe; Kubinski, David; Visser, Jaco; Moos, Ralf

2017-07-12

The upcoming more stringent automotive emission legislations and current developments have promoted new technologies for more precise and reliable catalyst control. For this purpose, radio-frequency-based (RF) catalyst state determination offers the only approach for directly measuring the NH₃ loading on selective catalytic reduction (SCR) catalysts and the state of other catalysts and filter systems. Recently, the ability of this technique to directly control the urea dosing on a current NH₃ storing zeolite catalyst has been demonstrated on an engine dynamometer for the first time and this paper continues that work. Therefore, a well-known serial-type and zeolite-based SCR catalyst (Cu-SSZ-13) was investigated under deliberately chosen high space velocities. At first, the full functionality of the RF system with Cu-SSZ-13 as sample was tested successfully. By direct RF-based NH₃ storage control, the influence of the storage degree on the catalyst performance, i.e., on NO x conversion and NH₃ slip, was investigated in a temperature range between 250 and 400 °C. For each operation point, an ideal and a critical NH₃ storage degree was found and analyzed in the whole temperature range. Based on the data of all experimental runs, temperature dependent calibration functions were developed as a basis for upcoming tests under transient conditions. Additionally, the influence of exhaust humidity was observed with special focus on cold start water and its effects to the RF signals.

A Needs Assessment of Brain Death Education in Pediatric Critical Care Medicine Fellowships.

PubMed

Ausmus, Andrew M; Simpson, Pippa M; Zhang, Liyun; Petersen, Tara L

2018-04-12

To assess the current training in brain death examination provided during pediatric critical care medicine fellowship. Internet-based survey. United States pediatric critical care medicine fellowship programs. Sixty-four pediatric critical care medicine fellowship program directors and 230 current pediatric critical care medicine fellows/recent graduates were invited to participate. Participants were asked demographic questions related to their fellowship programs, training currently provided at their fellowship programs, previous experience with brain death examinations (fellows/graduates), and perceptions regarding the adequacy of current training. Twenty-nine program directors (45%) and 91 current fellows/graduates (40%) responded. Third-year fellows reported having performed a median of five examinations (interquartile range, 3-6). On a five-point Likert scale, 93% of program directors responded they "agree" or "strongly agree" that their fellows receive enough instruction on performing brain death examinations compared with 67% of fellows and graduates (p = 0.007). The responses were similar when asked about opportunity to practice brain death examinations (90% vs 54%; p < 0.001). In a regression tree analysis, number of brain death examinations performed was the strongest predictor of trainee satisfaction. Both fellows and program directors preferred bedside demonstration or simulation as educational modalities to add to the fellowship curriculum. Pediatric critical care medicine fellows overall perform relatively few brain death examinations during their training. Pediatric critical care medicine fellows and program directors disagree in their perceptions of the current training in brain death examination, with fellows perceiving a need for increased training. Both program directors and fellows prefer additional training using bedside demonstration or simulation. Since clinical exposure to brain death examinations is variable, adding simulated brain death examinations to the pediatric critical care medicine fellowship curriculum could help standardize the experience.

Use of a patient hand hygiene protocol to reduce hospital-acquired infections and improve nurses' hand washing.

PubMed

Fox, Cherie; Wavra, Teresa; Drake, Diane Ash; Mulligan, Debbie; Bennett, Yvonne Pacheco; Nelson, Carla; Kirkwood, Peggy; Jones, Louise; Bader, Mary Kay

2015-05-01

Critically ill patients are at marked risk of hospital-acquired infections, which increase patients' morbidity and mortality. Registered nurses are the main health care providers of physical care, including hygiene to reduce and prevent hospital-acquired infections, for hospitalized critically ill patients. To investigate a new patient hand hygiene protocol designed to reduce hospital-acquired infection rates and improve nurses' hand-washing compliance in an intensive care unit. A preexperimental study design was used to compare 12-month rates of 2 common hospital-acquired infections, central catheter-associated bloodstream infection and catheter-associated urinary tract infection, and nurses' hand-washing compliance measured before and during use of the protocol. Reductions in 12-month infection rates were reported for both types of infections, but neither reduction was statistically significant. Mean 12-month nurse hand-washing compliance also improved, but not significantly. A hand hygiene protocol for patients in the intensive care unit was associated with reductions in hospital-acquired infections and improvements in nurses' hand-washing compliance. Prevention of such infections requires continuous quality improvement efforts to monitor lasting effectiveness as well as investigation of strategies to eliminate these infections. ©2015 American Association of Critical-Care Nurses.

Using probabilistic terrorism risk modeling for regulatory benefit-cost analysis: application to the Western hemisphere travel initiative in the land environment.

PubMed

Willis, Henry H; LaTourrette, Tom

2008-04-01

This article presents a framework for using probabilistic terrorism risk modeling in regulatory analysis. We demonstrate the framework with an example application involving a regulation under consideration, the Western Hemisphere Travel Initiative for the Land Environment, (WHTI-L). First, we estimate annualized loss from terrorist attacks with the Risk Management Solutions (RMS) Probabilistic Terrorism Model. We then estimate the critical risk reduction, which is the risk-reducing effectiveness of WHTI-L needed for its benefit, in terms of reduced terrorism loss in the United States, to exceed its cost. Our analysis indicates that the critical risk reduction depends strongly not only on uncertainties in the terrorism risk level, but also on uncertainty in the cost of regulation and how casualties are monetized. For a terrorism risk level based on the RMS standard risk estimate, the baseline regulatory cost estimate for WHTI-L, and a range of casualty cost estimates based on the willingness-to-pay approach, our estimate for the expected annualized loss from terrorism ranges from $2.7 billion to $5.2 billion. For this range in annualized loss, the critical risk reduction for WHTI-L ranges from 7% to 13%. Basing results on a lower risk level that results in halving the annualized terrorism loss would double the critical risk reduction (14-26%), and basing the results on a higher risk level that results in a doubling of the annualized terrorism loss would cut the critical risk reduction in half (3.5-6.6%). Ideally, decisions about terrorism security regulations and policies would be informed by true benefit-cost analyses in which the estimated benefits are compared to costs. Such analyses for terrorism security efforts face substantial impediments stemming from the great uncertainty in the terrorist threat and the very low recurrence interval for large attacks. Several approaches can be used to estimate how a terrorism security program or regulation reduces the distribution of risks it is intended to manage. But, continued research to develop additional tools and data is necessary to support application of these approaches. These include refinement of models and simulations, engagement of subject matter experts, implementation of program evaluation, and estimating the costs of casualties from terrorism events.

Decreasing the overall environmental impact of the Dutch diet: how to find healthy and sustainable diets with limited changes.

PubMed

Kramer, Gerard Fh; Tyszler, Marcelo; Veer, Pieter Van't; Blonk, Hans

2017-06-01

To find diets optimised on nutrition and environmental impact close to the current Dutch diet and to identify the most effective and acceptable options for mitigating environmental impact. Linear programming was used to optimise diets of Dutch men and women aged 9-69 years, divided into ten age-gender groups. The analysis included nutrient composition, a metric for popularity and life cycle assessments of 207 food products. Greenhouse gas emissions, fossil energy use and land occupation were used to calculate a weighted score for the overall environmental impact. Optimised diets were solutions that minimised changes to the current diet while satisfying all nutritional constraints, with stepwise reductions in environmental impact. The Netherlands. Dutch children and adults aged 9-69 years. Meat was always reduced. Vegetable, fruit and dairy contents remained similar, while bread, fatty fish and legumes increased. The extent of changes depended on age and gender. Beverages were not heavily reduced. Nutrients critical for the outcome were α-linoleic acid, retinol, Ca, Na, Se, dietary fibre, SFA, thiamin and Fe (women of childbearing age). Total protein, essential amino acids and carbohydrates were not critical. Reducing meat is the most effective option for lowering the environmental impact of diets in all age-gender groups. Reducing alcoholic and non-alcoholic beverages is another option. Leaving out fish and dairy products are not. The differences in nutritional requirements related to age and gender have a significant effect on the composition of the optimised diets.

A graphite based STT-RAM cell with reduction in switching current

NASA Astrophysics Data System (ADS)

Varghani, Ali; Peiravi, Ali

2015-10-01

Spin Transfer Torque Random Access Memory (STT-RAM) is a serious candidate for "universal memory" because of its non-volatility, fast access time, high density, good scalability, high endurance and relatively low power dissipation. However, problems with low write speed and large write current are important existing challenges in STT-RAM design and there is a tradeoff between them and data retention time. In this study, a novel STT-RAM cell structure which uses perfect graphite based Magnetic Tunnel Junction (MTJ) is proposed. First, the cross-section of the structure is selected to be an ellipse of 45 nm and 180 nm dimensions and a six-layer graphite is used as tunnel barrier. By passing a lateral current with a short pulse width (before applying STT current and independent of it) through four middle graphene layers of the tunnel barrier, a 27% reduction in the amplitude of the switching current (for fast switching time of 2 ns) or a 58% reduction in its pulse width is achieved without any reduction in data retention time. Finally, the effect of downscaling of technology on the proposed structure is evaluated. A reduction of 31.6% and 9% in switching current is achieved for 90 and 22 nm cell width respectively by passing sufficient current (100 μA with 0.1 ns pulse width) through the tunnel barrier. Simulations are done using Object Oriented Micro Magnetic Framework (OOMMF).

Thyroid hormone is required for pruning, functioning and long-term maintenance of afferent inner hair cell synapses

PubMed Central

Sundaresan, Srividya; Kong, Jee-Hyun; Fang, Qing; Salles, Felipe T.; Wangsawihardja, Felix; Ricci, Anthony J.; Mustapha, Mirna

2016-01-01

Functional maturation of afferent synaptic connections to inner hair cells (IHCs) involves pruning of excess synapses formed during development, as well as the strengthening and survival of the retained synapses. These events take place during the thyroid hormone (TH)-critical period of cochlear development, which is in the perinatal period for mice and in the third trimester for humans. Here, we used the hypothyroid Snell dwarf mouse (Pit1dw) as a model to study the role of TH in afferent type I synaptic refinement and functional maturation. We observed defects in afferent synaptic pruning and delays in calcium channel clustering in the IHCs of Pit1dw mice. Nevertheless, calcium currents and capacitance reached near normal levels in Pit1dw IHCs by the age of onset of hearing, despite the excess number of retained synapses. We restored normal synaptic pruning in Pit1dw IHCs by supplementing with TH from postnatal day (P)3 to P8, establishing this window as being critical for TH action on this process. Afferent terminals of older Pit1dw IHCs showed evidence of excitotoxic damage accompanied by a concomitant reduction in the levels of the glial glutamate transporter, GLAST. Our results indicate that a lack of TH during a critical period of inner ear development causes defects in pruning and long-term homeostatic maintenance of afferent synapses. PMID:26386265

Striving for Optimum Noise-Decreasing Strategies in Critical Care: Initial Measurements and Observations.

PubMed

Disher, Timothy C; Benoit, Britney; Inglis, Darlene; Burgess, Stacy A; Ellsmere, Barbara; Hewitt, Brenda E; Bishop, Tanya M; Sheppard, Christopher L; Jangaard, Krista A; Morrison, Gavin C; Campbell-Yeo, Marsha L

To identify baseline sound levels, patterns of sound levels, and potential barriers and facilitators to sound level reduction. The study setting was neonatal and pediatric intensive care units in a tertiary care hospital. Participants were staff in both units and parents of currently hospitalized children or infants. One 24-hour sound measurements and one 4-hour sound measurement linked to observed sound events were conducted in each area of the center's neonatal intensive care unit. Two of each measurement type were conducted in the pediatric intensive care unit. Focus groups were conducted with parents and staff. Transcripts were analyzed with descriptive content analysis and themes were compared against results from quantitative measurements. Sound levels exceeded recommended standards at nearly every time point. The most common code was related to talking. Themes from focus groups included the critical care context and sound levels, effects of sound levels, and reducing sound levels-the way forward. Results are consistent with work conducted in other critical care environments. Staff and families realize that high sound levels can be a problem, but feel that the culture and context are not supportive of a quiet care space. High levels of ambient sound suggest that the largest changes in sound levels are likely to come from design and equipment purchase decisions. L10 and Lmax appear to be the best outcomes for measurement of behavioral interventions.

Exploration Life Support Critical Questions for Future Human Space Missions

NASA Technical Reports Server (NTRS)

Kwert, Michael K.; Barta, Daniel J.; McQuillan, Jeff

2010-01-01

Exploration Life Support (ELS) is a current project under NASA's Exploration Systems Mission Directorate. The ELS Project plans, coordinates and implements the development of advanced life support technologies for human exploration missions in space. Recent work has focused on closed loop atmosphere and water systems for long duration missions, including habitats and pressurized rovers. But, what are the critical questions facing life support system developers for these and other future human missions? This paper explores those questions and how progress in the development of ELS technologies can help answer them. The ELS Project includes the following Elements: Atmosphere Revitalization Systems, Water Recovery Systems, Waste Management Systems, Habitation Engineering, Systems Integration, Modeling and Analysis, and Validation and Testing, which includes the Sub-Elements Flight Experiments and Integrated Testing. Systems engineering analysis by ELS seeks to optimize overall mission architectures by considering all the internal and external interfaces of the life support system and the potential for reduction or reuse of commodities. In particular, various sources and sinks of water and oxygen are considered along with the implications on loop closure and the resulting launch mass requirements. Systems analysis will be validated through the data gathered from integrated testing, which will demonstrate the interfaces of a closed loop life support system. By applying a systematic process for defining, sorting and answering critical life support questions, the ELS project is preparing for a variety of future human space missions

Gender, smoking and tobacco reduction and cessation: a scoping review.

PubMed

Bottorff, Joan L; Haines-Saah, Rebecca; Kelly, Mary T; Oliffe, John L; Torchalla, Iris; Poole, Nancy; Greaves, Lorraine; Robinson, Carole A; Ensom, Mary H H; Okoli, Chizimuzo T C; Phillips, J Craig

2014-12-12

Considerations of how gender-related factors influence smoking first appeared over 20 years ago in the work of critical and feminist scholars. This scholarship highlighted the need to consider the social and cultural context of women's tobacco use and the relationships between smoking and gender inequity. Parallel research on men's smoking and masculinities has only recently emerged with some attention being given to gender influences on men's tobacco use. Since that time, a multidisciplinary literature addressing women and men's tobacco use has spanned the social, psychological and medical sciences. To incorporate these gender-related factors into tobacco reduction and cessation interventions, our research team identified the need to clarify the current theoretical and methodological interpretations of gender within the context of tobacco research. To address this need a scoping review of the published literature was conducted focussing on tobacco reduction and cessation from the perspective of three aspects of gender: gender roles, gender identities, and gender relations. Findings of the review indicate that there is a need for greater clarity on how researchers define and conceptualize gender and its significance for tobacco control. Patterns and anomalies in the literature are described to guide the future development of interventions that are gender-sensitive and gender-specific. Three principles for including gender-related factors in tobacco reduction and cessation interventions were identified: a) the need to build upon solid conceptualizations of gender, b) the importance of including components that comprehensively address gender-related influences, and c) the importance of promoting gender equity and healthy gender norms, roles and relations.

Forecasting Medicaid Expenditures for Antipsychotic Medications.

PubMed

Slade, Eric P; Simoni-Wastila, Linda

2015-07-01

The ongoing transition from use of mostly branded to mostly generic second-generation antipsychotic medications could bring about a substantial reduction in Medicaid expenditures for antipsychotic medications, a change with critical implications for formulary restrictions on second-generation antipsychotics in Medicaid. This study provided a forecast of the impact of generics on Medicaid expenditures for antipsychotic medications. Quarterly (N=816) state-level aggregate data on outpatient antipsychotic prescriptions in Medicaid between 2008 and 2011 were drawn from the Medicaid state drug utilization database. Annual numbers of prescriptions, expenditures, and cost per prescription were constructed for each antipsychotic medication. Forecasts of antipsychotic expenditures in calendar years 2016 and 2019 were developed on the basis of the estimated percentage reduction in Medicaid expenditures for risperidone, the only second-generation antipsychotic available generically throughout the study period. Two models of savings from generic risperidone use were estimated, one based on constant risperidone prices and the other based on variable risperidone prices. The sensitivity of the expenditure forecast to expected changes in Medicaid enrollment was also examined. In the main model, annual Medicaid expenditures for antipsychotics were forecasted to decrease by $1,794 million (48.8%) by 2016 and by $2,814 million (76.5%) by 2019. Adjustment for variable prices of branded medications and changes in Medicaid enrollment only moderately affected the magnitude of these reductions. Within five years, antipsychotic expenditures in Medicaid may decline to less than half their current levels. Such a spending reduction warrants a reassessment of the continued necessity of formulary restrictions for second-generation antipsychotics in Medicaid.

Aerosol pH buffering in the southeastern US: Fine particles remain highly acidic despite large reductions in sulfate

NASA Astrophysics Data System (ADS)

Weber, R. J.; Guo, H.; Russell, A. G.; Nenes, A.

2015-12-01

pH is a critical aerosol property that impacts many atmospheric processes, including biogenic secondary organic aerosol formation, gas-particle phase partitioning, and mineral dust or redox metal mobilization. Particle pH has also been linked to adverse health effects. Using a comprehensive data set from the Southern Oxidant and Aerosol Study (SOAS) as the basis for thermodynamic modeling, we have shown that particles are currently highly acidic in the southeastern US, with pH between 0 and 2. Sulfate and ammonium are the main acid-base components that determine particle pH in this region, however they have different sources and their concentrations are changing. Over 15 years of network data show that sulfur dioxide emission reductions have resulted in a roughly 70 percent decrease in sulfate, whereas ammonia emissions, mainly link to agricultural activities, have been largely steady, as have gas phase ammonia concentrations. This has led to the view that particles are becoming more neutralized. However, sensitivity analysis, based on thermodynamic modeling, to changing sulfate concentrations indicates that particles have remained highly acidic over the past decade, despite the large reductions in sulfate. Furthermore, anticipated continued reductions of sulfate and relatively constant ammonia emissions into the future will not significantly change particle pH until sulfate drops to clean continental background levels. The result reshapes our expectation of future particle pH and implies that atmospheric processes and adverse health effects linked to particle acidity will remain unchanged for some time into the future.

Enhancing superconducting critical current by randomness

DOE PAGES

Wang, Y. L.; Thoutam, L. R.; Xiao, Z. L.; ...

2016-01-11

The key ingredient of high critical currents in a type-II superconductor is defect sites that pin vortices. Here, we demonstrate that a random pinscape, an overlooked pinning system in nanopatterned superconductors, can lead to a substantially larger critical current enhancement at high magnetic fields than an ordered array of vortex pin sites. We reveal that the better performance of a random pinscape is due to the variation of the local density of its pinning sites, which mitigates the motion of vortices. This is confirmed by achieving even higher enhancement of the critical current through a conformally mapped random pinscape, wheremore » the distribution of the local density of pinning sites is further enlarged. Our findings highlight the potential of random pinscapes in enhancing the superconducting critical currents of applied superconductors in which random pin sites of nanoscale defects emerging in the materials synthesis process or through ex-situ irradiation are the only practical choice for large-scale production. Our results may also stimulate research on effects of a random pinscape in other complementary systems such as colloidal crystals, Bose-Einstein condensates, and Luttinger liquids.« less

Design and test of current limiting modules using YBCO-coated conductors

NASA Astrophysics Data System (ADS)

Schmidt, W.; Gamble, B.; Kraemer, H.-P.; Madura, D.; Otto, A.; Romanosky, W.

2010-01-01

Within the cooperation between American Superconductor Corporation (AMSC) and Siemens Corporate Technology we have investigated the fault current limiting performance of YBCO-coated conductors (also called second-generation or 2G HTS wires) stabilized with stainless steel laminates. Design rules for the length and width of the wire depending on utility grid requirements have been established. Bifilar coils have been manufactured and tested with a typical limitation period of 50 ms under stepwise increasing voltage loads to determine the maximum temperature the wires can withstand without degradation. Coils have been assembled into limiter modules demonstrating uniform tripping of the individual coils and recovery within seconds. At present this cooperation is proceeding within a joint project funded by the US Department of Energy (DOE) that encompasses the design, construction and testing of a 115 kV FCL for power transmission within a time frame of 4-5 years, and additional partners. Besides AMSC and Siemens, Nexans contributes the high voltage terminations and Los Alamos National Lab investigates the ac losses. Installation and testing are planned for a Southern California Edison substation. The module planned for the transmission voltage application consists of 63 horizontally arranged coils connected in parallel and series to account for a rated current of 1.2 kArms and voltage of 31 kVrms plus margins. The rated voltage of the module is considerably lower than the line to ground voltage in the 115 kV grid owing to our shunted limiter concept. The shunt reactor connected in parallel to the module outside the cryostat allows for adjustment of the limited current and reduces voltage drop across the module in case of a fault. The fault current reduction ratio is 42% for our present design. A subscale module comprising six full-size coils has been assembled and tested recently to validate the coil performance and coil winding technique. The module had a critical current of 425 ADC and a nominal power of 2.52 MV A at 77 K. A complete series of tests with applied voltage up to 8.4 kVrms, prospective short circuit current up to 26.6 kArms and variation of phase angle at initiation of the fault has been performed. After more than 40 switching tests the critical current of the module remained unchanged, indicating that no degradation of the wire occurred.

Wet particle source identification and reduction using a new filter cleaning process

NASA Astrophysics Data System (ADS)

Umeda, Toru; Morita, Akihiko; Shimizu, Hideki; Tsuzuki, Shuichi

2014-03-01

Wet particle reduction during filter installation and start-up aligns closely with initiatives to reduce both chemical consumption and preventative maintenance time. The present study focuses on the effects of filter materials cleanliness on wet particle defectivity through evaluation of filters that have been treated with a new enhanced cleaning process focused on organic compounds reduction. Little difference in filter performance is observed between the two filter types at a size detection threshold of 60 nm, while clear differences are observed at that of 26 nm. It can be suggested that organic compounds can be identified as a potential source of wet particles. Pall recommends filters that have been treated with the special cleaning process for applications with a critical defect size of less than 60 nm. Standard filter products are capable to satisfy wet particle defect performance criteria in less critical lithography applications.

Generate an Optimum Lightweight Legs Structure Design Based on Critical Posture in A-FLoW Humanoid Robot

NASA Astrophysics Data System (ADS)

Luthfi, A.; Subhan, K. A.; Eko H, B.; Sanggar, D. R.; Pramadihanto, D.

2018-04-01

Lightweight construction and energy efficiency play an important role in humanoid robot development. The application of computer-aided engineering (CAE) in the development process is one of the possibilities to achieve the appropriate reduction of the weight. This paper describes a method to generate an optimum lightweight legs structure design based on critical posture during walking locomotion in A-FLoW Humanoid robot.The criticalposture can be obtained from the highest forces and moments in each joint of the robot body during walking locomotion. From the finite element analysis (FEA) result can be realized leg structure design of A-FLoW humanoid robot with a maximum displacement value of 0.05 mmand weight reduction about 0.598 Kg from the thigh structure and a maximum displacement value of 0,13 mmand weight reduction about 0.57 kg from the shin structure.

Benchmarking on Tsunami Currents with ComMIT

NASA Astrophysics Data System (ADS)

Sharghi vand, N.; Kanoglu, U.

2015-12-01

There were no standards for the validation and verification of tsunami numerical models before 2004 Indian Ocean tsunami. Even, number of numerical models has been used for inundation mapping effort, evaluation of critical structures, etc. without validation and verification. After 2004, NOAA Center for Tsunami Research (NCTR) established standards for the validation and verification of tsunami numerical models (Synolakis et al. 2008 Pure Appl. Geophys. 165, 2197-2228), which will be used evaluation of critical structures such as nuclear power plants against tsunami attack. NCTR presented analytical, experimental and field benchmark problems aimed to estimate maximum runup and accepted widely by the community. Recently, benchmark problems were suggested by the US National Tsunami Hazard Mitigation Program Mapping & Modeling Benchmarking Workshop: Tsunami Currents on February 9-10, 2015 at Portland, Oregon, USA (http://nws.weather.gov/nthmp/index.html). These benchmark problems concentrated toward validation and verification of tsunami numerical models on tsunami currents. Three of the benchmark problems were: current measurement of the Japan 2011 tsunami in Hilo Harbor, Hawaii, USA and in Tauranga Harbor, New Zealand, and single long-period wave propagating onto a small-scale experimental model of the town of Seaside, Oregon, USA. These benchmark problems were implemented in the Community Modeling Interface for Tsunamis (ComMIT) (Titov et al. 2011 Pure Appl. Geophys. 168, 2121-2131), which is a user-friendly interface to the validated and verified Method of Splitting Tsunami (MOST) (Titov and Synolakis 1995 J. Waterw. Port Coastal Ocean Eng. 121, 308-316) model and is developed by NCTR. The modeling results are compared with the required benchmark data, providing good agreements and results are discussed. Acknowledgment: The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no 603839 (Project ASTARTE - Assessment, Strategy and Risk Reduction for Tsunamis in Europe)

Solutions for Critical Raw Materials under Extreme Conditions: A Review

PubMed Central

Grilli, Maria Luisa; Bellezze, Tiziano; Gamsjäger, Ernst; Rinaldi, Antonio; Novak, Pavel; Balos, Sebastian; Piticescu, Radu Robert; Ruello, Maria Letizia

2017-01-01

In Europe, many technologies with high socio-economic benefits face materials requirements that are often affected by demand-supply disruption. This paper offers an overview of critical raw materials in high value alloys and metal-matrix composites used in critical applications, such as energy, transportation and machinery manufacturing associated with extreme working conditions in terms of temperature, loading, friction, wear and corrosion. The goal is to provide perspectives about the reduction and/or substitution of selected critical raw materials: Co, W, Cr, Nb and Mg. PMID:28772645

Influence of ageing on glass and resin bonding of dental glass-ceramic veneer adhesion to zirconia: A fracture mechanics analysis and interpretation.

PubMed

Swain, M V; Gee, C; Li, K C

2018-04-26

Adhesion plays a major role in the bonding of dental materials. In this study the adhesion of two glass-ceramic systems (IPS e.max and VITABLOCS) to a zirconia sintered substrate using a glass (for IPS e.max) and resin (VITABLOCS) before and after exposure to ageing for 14 days in distilled water at 37 °C are compared using two interfacial fracture mechanics tests, the 3 point bend Schwickerath (Kosyfaki and Swain, 2014; Schneider and Swain, 2015) and 4 point bend (Charalambides et al., 1989) approaches. Both tests result in stable crack extension from which the strain energy release rate (G, N/m or J/m 2 ) can be determined. In the case of the 3 PB test the Work of Fracture was also determined. In addition, the Schwickerath test enables determination of the critical stress for the onset of cracking to occur, which forms the basis of the ISO (ISO9693-2:2016) adhesion test for porcelain ceramic adhesion to zirconia. For the aged samples there was a significant reduction in the resin-bonded strengths (Schwickerath) and strain energy release rate (both 3 and 4 PB tests), which was not evident for the glass bonded specimens. Critical examination of the force-displacement curves showed that ageing of the resin resulted in a major change in the form of the curves, which may be interpreted in terms of a reduction in the critical stress to initiate cracking and also in the development of an R-curve. The extent of the reduction in strain energy release rate following ageing was greater for the Schwickerath test than the Charalambides test. The results are discussed in terms of; the basic mechanics of these two tests, the deterioration of the resin bonding following moisture exposure and the different dimensions of the specimens. These in-vitro results raise concerns regarding resin bonding to zirconia. The present study uses a novel approach to investigate the role of ageing or environmental degradation on the adhesive bonding of two dental ceramics to zirconia. This continues to be a major clinical problem but current approaches, till now, have relied upon a myriad of strength based tests to quantify the extent of environmental degradation with time. In this paper we use two fracture mechanics approaches, based upon simple 3 and 4 point bend testing procedures that enable stable debonding crack extension to occur. The paper provides a more critical approach to evaluate the role of environmental degradation of adhesion for dental materials. Copyright © 2018. Published by Elsevier Ltd.

DOE Light Truck Clean Diesel (LTCD) Program Final Caterpillar Public Report Light Truck Clean Diesel Program

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

Eric Fluga

The US Department of Energy and Caterpillar entered a Cooperative Agreement to develop compression ignition engine technology suitable for the light truck/SUV market. Caterpillar, in collaboration with a suitable commercialization partner, developed a new Compression Ignition Direct Injection (CIDI) engine technology to dramatically improve the emissions and performance of light truck engines. The overall program objective was to demonstrate engine prototypes by 2004, with an order of magnitude emission reduction while meeting challenging fuel consumption goals. Program emphasis was placed on developing and incorporating cutting edge technologies that could remove the current impediments to commercialization of CIDI power sources inmore » light truck applications. The major obstacle to commercialization is emissions regulations with secondary concerns of driveability and NVH (noise, vibration and harshness). The target emissions levels were 0.05 g/mile NOx and 0.01 g/mile PM to be compliant with the EPA Tier 2 fleet average requirements of 0.07 g/mile and the CARB LEV 2 of 0.05 g/mile for NOx, both have a PM requirement of 0.01 g/mile. The program team developed a combustion process that fundamentally shifted the classic NOx vs. PM behavior of CIDI engines. The NOx vs. PM shift was accomplished with a form of Homogeneous Charge Compression Ignition (HCCI). The HCCI concept centers on appropriate mixing of air and fuel in the compression process and controlling the inception and rate of combustion through various means such as variable valve timing, inlet charge temperature and pressure control. Caterpillar has adapted an existing Caterpillar design of a single injector that: (1) creates the appropriate fuel and air mixture for HCCI, (2) is capable of a more conventional injection to overcome the low power density problems of current HCCI implementations, (3) provides a mixed mode where both the HCCI and conventional combustion are functioning in the same combustion cycle. Figure 1 illustrates the mixed mode injection system. Under the LTCD program Caterpillar developed a mixed mode injector for a multi-cylinder engine system. The mixed mode injection system represents a critical enabling technology for the implementation of HCCI. In addition, Caterpillar implemented variable valve system technology and air system technology on the multi-cylinder engine platform. The valve and air system technology were critical to system control. Caterpillar developed the combustion system to achieve a 93% reduction in NOx emissions. The resulting NOx emissions were 0.12 gm/mile NOx. The demonstrated emissions level meets the stringent Tier 2 Bin 8 requirement without NOx aftertreatment! However, combustion development alone was not adequate to meet the program goal of 0.05gm/mile NOx. To meet the program goals, an additional 60% NOx reduction technology will be required. Caterpillar evaluated a number of NOx reduction technologies to quantify and understand the NOx reduction potential and system performance implications. The NOx adsorber was the most attractive NOx aftertreatment option based on fuel consumption and NOx reduction potential. In spite of the breakthrough technology development conducted under the LTCD program there remains many significant challenges associated with the technology configuration. For HCCI, additional effort is needed to develop a robust control strategy, reduce the hydrocarbon emissions at light load condition, and develop a more production viable fuel system. Furthermore, the NOx adsorber suffers from cost, packaging, and durability challenges that must be addressed.« less

Optimizing C–C Coupling on Oxide-Derived Copper Catalysts for Electrochemical CO 2 Reduction

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

Lum, Yanwei; Yue, Binbin; Lobaccaro, Peter

Here, copper electrodes, prepared by reduction of oxidized metallic copper, have been reported to exhibit higher activity for the electrochemical reduction of CO 2 and better selectivity toward C 2 and C 3 (C 2+) products than metallic copper that has not been preoxidized. We report here an investigation of the effects of four different preparations of oxide-derived electrocatalysts on their activity and selectivity for CO 2 reduction, with particular attention given to the selectivity to C 2+ products. All catalysts were tested for CO 2 reduction in 0.1 M KHCO 3 and 0.1 M CsHCO 3 at applied voltagesmore » in the range from –0.7 to –1.0 V vs RHE. The best performing oxide-derived catalysts show up to ~70% selectivity to C 2+ products and only ~3% selectivity to C 1 products at –1.0 V vs RHE when CsHCO 3 is used as the electrolyte. In contrast, the selectivity to C 2+ products decreases to ~56% for the same catalysts tested in KHCO 3. By studying all catalysts under identical conditions, the key factors affecting product selectivity could be discerned. These efforts reveal that the surface area of the oxide-derived layer is a critical parameter affecting selectivity. A high selectivity to C 2+ products is attained at an overpotential of –1 V vs RHE by operating at a current density sufficiently high to achieve a moderately high pH near the catalyst surface but not so high as to cause a significant reduction in the local concentration of CO 2. On the basis of recent theoretical studies, a high pH suppresses the formation of C 1 relative to C 2+ products. At the same time, however, a high local CO 2 concentration is necessary for the formation of C 2+ products.« less

Optimizing C–C Coupling on Oxide-Derived Copper Catalysts for Electrochemical CO 2 Reduction

DOE PAGES

Lum, Yanwei; Yue, Binbin; Lobaccaro, Peter; ...

2017-07-06

Here, copper electrodes, prepared by reduction of oxidized metallic copper, have been reported to exhibit higher activity for the electrochemical reduction of CO 2 and better selectivity toward C 2 and C 3 (C 2+) products than metallic copper that has not been preoxidized. We report here an investigation of the effects of four different preparations of oxide-derived electrocatalysts on their activity and selectivity for CO 2 reduction, with particular attention given to the selectivity to C 2+ products. All catalysts were tested for CO 2 reduction in 0.1 M KHCO 3 and 0.1 M CsHCO 3 at applied voltagesmore » in the range from –0.7 to –1.0 V vs RHE. The best performing oxide-derived catalysts show up to ~70% selectivity to C 2+ products and only ~3% selectivity to C 1 products at –1.0 V vs RHE when CsHCO 3 is used as the electrolyte. In contrast, the selectivity to C 2+ products decreases to ~56% for the same catalysts tested in KHCO 3. By studying all catalysts under identical conditions, the key factors affecting product selectivity could be discerned. These efforts reveal that the surface area of the oxide-derived layer is a critical parameter affecting selectivity. A high selectivity to C 2+ products is attained at an overpotential of –1 V vs RHE by operating at a current density sufficiently high to achieve a moderately high pH near the catalyst surface but not so high as to cause a significant reduction in the local concentration of CO 2. On the basis of recent theoretical studies, a high pH suppresses the formation of C 1 relative to C 2+ products. At the same time, however, a high local CO 2 concentration is necessary for the formation of C 2+ products.« less

Criticality safety evaluation for the Advanced Test Reactor enhanced low enriched uranium fuel elements

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

Montierth, Leland M.

2016-07-19

The Global Threat Reduction Initiative (GTRI) convert program is developing a high uranium density fuel based on a low enriched uranium (LEU) uranium-molybdenum alloy. Testing of prototypic GTRI fuel elements is necessary to demonstrate integrated fuel performance behavior and scale-up of fabrication techniques. GTRI Enhanced LEU Fuel (ELF) elements based on the ATR-Standard Size elements (all plates fueled) are to be fabricated for testing in the Advanced Test Reactor (ATR). While a specific ELF element design will eventually be provided for detailed analyses and in-core testing, this criticality safety evaluation (CSE) is intended to evaluate a hypothetical ELF element designmore » for criticality safety purposes. Existing criticality analyses have analyzed Standard (HEU) ATR elements from which controls have been derived. This CSE documents analysis that determines the reactivity of the hypothetical ELF fuel elements relative to HEU ATR elements and whether the existing HEU ATR element controls bound the ELF element. The initial calculations presented in this CSE analyzed the original ELF design, now referred to as Mod 0.1. In addition, as part of a fuel meat thickness optimization effort for reactor performance, other designs have been evaluated. As of early 2014 the most current conceptual designs are Mk1A and Mk1B, that were previously referred to as conceptual designs Mod 0.10 and Mod 0.11, respectively. Revision 1 evaluates the reactivity of the ATR HEU Mark IV elements for a comparison with the Mark VII elements.« less

40 CFR 415.352 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available (BPT). 415.352 Section 415.352 Protection of Environment ENVIRONMENTAL... technology currently available (BPT). Except as provided in 40 CFR 125.30 through 125.32, any existing point... effluent reduction attainable by the application of the best practicable control technology currently...

40 CFR 415.382 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available (BPT). 415.382 Section 415.382 Protection of Environment ENVIRONMENTAL... technology currently available (BPT). Except as provided in 40 CFR 125.30 through 125.32, any existing point... effluent reduction attainable by the application of the best practicable control technology currently...

40 CFR 415.122 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available (BPT). 415.122 Section 415.122 Protection of Environment ENVIRONMENTAL... technology currently available (BPT). Except as provided in 40 CFR 125.30 through 125.32, any existing point... effluent reduction attainable by the application of the best practicable control technology currently...

40 CFR 415.412 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available (BPT). 415.412 Section 415.412 Protection of Environment ENVIRONMENTAL... technology currently available (BPT). Except as provided in 40 CFR 125.30 through 125.32, any existing point... effluent reduction attainable by the application of the best practicable control technology currently...

40 CFR 415.442 - Effluent limitations quidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available (BPT). 415.442 Section 415.442 Protection of Environment ENVIRONMENTAL... technology currently available (BPT). Except as provided in 40 CFR 125.30 through 125.32, any existing point... effluent reduction attainable by the application of the best practicable control technology currently...

40 CFR 415.112 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available (BPT). 415.112 Section 415.112 Protection of Environment ENVIRONMENTAL... technology currently available (BPT). Except as provided in 40 CFR 125.30 through 125.32, any existing point... effluent reduction attainable by the application of the best practicable control technology currently...

40 CFR 415.312 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available (BPT). 415.312 Section 415.312 Protection of Environment ENVIRONMENTAL... technology currently available (BPT). Except as provided in 40 CFR 125.30 through 125.32, any existing point... effluent reduction attainable by the application of the best practicable control technology currently...

40 CFR 415.142 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available (BPT). 415.142 Section 415.142 Protection of Environment ENVIRONMENTAL... technology currently available (BPT). Except as provided in 40 CFR 125.30 through 125.32, any existing point... effluent reduction attainable by the application of the best practicable control technology currently...

40 CFR 415.632 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available (BPT). 415.632 Section 415.632 Protection of Environment ENVIRONMENTAL... technology currently available (BPT). Except as provided in 40 CFR 125.30 through 125.32, any existing point... effluent reduction attainable by the application of the best practicable control technology currently...

40 CFR 415.32 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available (BPT). 415.32 Section 415.32 Protection of Environment ENVIRONMENTAL... technology currently available (BPT). Except as provided in 40 CFR 125.30 through 125.32, any existing point... effluent reduction attainable by the application of the best practicable control technology currently...

40 CFR 415.402 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available (BPT). 415.402 Section 415.402 Protection of Environment ENVIRONMENTAL... technology currently available (BPT). Except as provided in 40 CFR 125.30 through 125.32, any existing point... effluent reduction attainable by the application of the best practicable control technology currently...

40 CFR 415.602 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available (BPT). 415.602 Section 415.602 Protection of Environment ENVIRONMENTAL... technology currently available (BPT). Except as provided in 40 CFR 125.30 through 125.32, any existing point... effluent reduction attainable by the application of the best practicable control technology currently...

Assessing the cost of fuel reduction treatments: a critical review

Treesearch

Bob Rummer

2008-01-01

The basic costs of the operations for implementing fuel reduction treatments are used to evaluate treatment effectiveness, select among alternatives, estimate total project costs, and build national program strategies. However, a review of the literature indicates that there is questionable basis for many of the general estimates used to date. Different approaches to...

High purity, low dislocation GaAs single crystals

NASA Technical Reports Server (NTRS)

Chen, R. T.; Holmes, D. E.; Kirkpatrick, C. G.

1983-01-01

Liquid encapsulated Czochralski crystal growth techniques for producing undoped, high resistivity, low dislocation material suitable for device applications is described. Technique development resulted in reduction of dislocation densities in 3 inch GaAs crystals. Control over the melt stoichiometry was determined to be of critical importance for the reduction of twinning and polycrystallinity during growth.

78 FR 22625 - Endangered and Threatened Wildlife and Plants; Revised Designation of Critical Habitat for Allium...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-16

... grassland, open coastal sage scrub, and cismontane juniper woodlands, due to urban development, agricultural... from urban development or destruction to maintain integrity of clay soils, (2) Reduction of land conversion to agricultural uses and reduction of disking or dryland farming to maintain native habitats, (3...

Cost Reduction and Value of Money.

ERIC Educational Resources Information Center

Kedney, Bob; Davies, Trefor

1995-01-01

This report is designed to assist newly independent colleges in the United Kingdom to examine expenditures objectively and critically in order to promote the most effective use of all funds and resources. Chapter 1 looks at: the rationale for cost reduction; the importance of scanning the operating environment as part of developing an overall…

Dissecting Choral Speech: Properties of the Accompanist Critical to Stuttering Reduction

ERIC Educational Resources Information Center

Kiefte, Michael; Armson, Joy

2008-01-01

The effects of choral speech and altered auditory feedback (AAF) on stuttering frequency were compared to identify those properties of choral speech that make it a more effective condition for stuttering reduction. Seventeen adults who stutter (AWS) participated in an experiment consisting of special choral speech conditions that were manipulated…

Values-Based Business Education for Empowerment, Self-Reliance and Poverty Reduction in Nigeria

ERIC Educational Resources Information Center

Umoru, Titus Amodu

2013-01-01

This study centered on values-based business education for empowerment, self-reliance and poverty reduction in Nigeria. The study identified 30 critical values business education students need to possess. 192 questionnaire items were constructed after careful review of literature (Njoku, 2007 and Living Values Education, 2013) and administered…

Development of a 10 m quasi-isotropic strand assembled from 2G wires

NASA Astrophysics Data System (ADS)

Kan, Changtao; Wang, Yinshun; Hou, Yanbing; Li, Yan; Zhang, Han; Fu, Yu; Jiang, Zhe

2018-03-01

Quasi-isotropic strands made of second generation (2G) high temperature superconducting (HTS) wires are attractive to applications of high-field magnets at low temperatures and power transmission cables at liquid nitrogen temperature in virtue of their high current carrying capability and well mechanical property. In this contribution, a 10 m length quasi-isotropic strand is manufactured and successfully tested in liquid nitrogen to verify the feasibility of an industrial scale production of the strand by the existing cabling technologies. The strand with copper sheath consists of 72 symmetrically assembled 2G wires. The uniformity of critical properties of long quasi-isotropic strands, including critical current and n-value, is very important for their using. Critical currents as well as n-values of the strand are measured every 1 m respectively and compared with the simulation results. Critical current and n-value of the strand are calculated basing on the self-consistent model solved by the finite element method (FEM). Effects of self-field on the critical current and n-value distributions in wires of the strand are analyzed in detail. The simulation results show good agreement with the experimental data and the 10 m quasi-isotropic strand has good critical properties uniformity.

Embers of Hope: In Search of a Meaningful Critical Pedagogy

ERIC Educational Resources Information Center

Ayers, William; Michie, Gregory; Rome, Amy

2004-01-01

Critical pedagogy. Whatever insurgent energy once pulsed through those words--giving them life and investing them with power and possibility--has been largely lost, their meaning sapped away with overuse and misuse, reduction and dogmatic application. Yesterday's iconoclasts are often today's icons, and every revolution, large or small, finds a…

Ultramicroelectrode Studies of Self-Terminated Nickel Electrodeposition and Nickel Hydroxide Formation upon Water Reduction.

PubMed

Ritzert, Nicole L; Moffat, Thomas P

2016-12-08

The interaction between electrodeposition of Ni and electrolyte breakdown, namely the hydrogen evolution reaction (HER) via H 3 O + and H 2 O reduction, was investigated under well-defined mass transport conditions using ultramicroelectrodes (UME's) coupled with optical imaging, generation/collection scanning electrochemical microscopy (G/C-SECM), and preliminary microscale pH measurements. For 5 mmol/L NiCl 2 + 0.1 mol/L NaCl, pH 3.0, electrolytes, the voltammetric current at modest overpotentials, i.e. , between -0.6 V and -1.4 V vs. Ag/AgCl, was distributed between metal deposition and H 3 O + reduction, with both reactions reaching mass transport limited current values. At more negative potentials, an unusual sharp current spike appeared upon the onset of H 2 O reduction that was accompanied by a transient increase in H 2 production. The peak potential of the current spike was a function of both [Ni(H 2 O) 6 ] 2+ (aq) concentration and pH. The sharp rise in current was ascribed to the onset of autocatalytic H 2 O reduction, where electrochemically generated OH - species induce heterogeneous nucleation of Ni(OH) 2(ads) islands, the perimeter of which is reportedly active for H 2 O reduction. As the layer coalesces, further metal deposition is quenched while H 2 O reduction continues albeit at a decreased rate as fewer of the most reactive sites, e.g. , Ni/Ni(OH) 2 island edges, are available. At potentials below -1.5 V vs. Ag/AgCl, H 2 O reduction is accelerated, leading to homogeneous precipitation of bulk Ni(OH) 2 · x H 2 O within the nearly hemispherical diffusion layer of the UME.

Using learning curves on energy-efficient technologies to estimate future energy savings and emission reduction potentials in the U.S. iron and steel industry

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

Karali, Nihan; Park, Won Young; McNeil, Michael A.

Increasing concerns on non-sustainable energy use and climate change spur a growing research interest in energy efficiency potentials in various critical areas such as industrial production. This paper focuses on learning curve aspects of energy efficiency measures in the U.S iron and steel sector. A number of early-stage efficient technologies (i.e., emerging or demonstration technologies) are technically feasible and have the potential to make a significant contribution to energy saving and CO 2 emissions reduction, but fall short economically to be included. However, they may also have the cost effective potential for significant cost reduction and/or performance improvement in themore » future under learning effects such as ‘learning-by-doing’. The investigation is carried out using ISEEM, a technology oriented, linear optimization model. We investigated how steel demand is balanced with/without the availability learning curve, compared to a Reference scenario. The retrofit (or investment in some cases) costs of energy efficient technologies decline in the scenario where learning curve is applied. The analysis also addresses market penetration of energy efficient technologies, energy saving, and CO 2 emissions in the U.S. iron and steel sector with/without learning impact. Accordingly, the study helps those who use energy models better manage the price barriers preventing unrealistic diffusion of energy-efficiency technologies, better understand the market and learning system involved, predict future achievable learning rates more accurately, and project future savings via energy-efficiency technologies with presence of learning. We conclude from our analysis that, most of the existing energy efficiency technologies that are currently used in the U.S. iron and steel sector are cost effective. Penetration levels increases through the years, even though there is no price reduction. However, demonstration technologies are not economically feasible in the U.S. iron and steel sector with the current cost structure. In contrast, some of the demonstration technologies are adapted in the mid-term and their penetration levels increase as the prices go down with learning curve. We also observe large penetration of 225kg pulverized coal injection with the presence of learning.« less

Learning to not know: results of a program for ancillary cost reduction in surgical critical care.

PubMed

Barie, P S; Hydo, L J

1996-10-01

Compelling internal and external influences are stimulating global re-evaluations of care standards for efficacy and cost. Critical care uses huge amounts of resources despite widespread shortages of beds and nurses. This study tested the hypothesis that ancillary expenditures can be decreased without compromising care. Costs for laboratory tests, radiographs, blood products, nutritional supplements, and drugs were compared prospectively for all surgical intensive care unit care for two 4-month periods (January 1 to April 30, 1994 and January 1 to April 30, 1995) at a urban university center. A systematic, multidisciplinary cost-reduction program began May 1, 1994, with emphasis on laboratory and radiographic testing and procedures, and blood product, nutritional, and drug therapies. Cohorts were compared by age, Acute Physiology and Chronic Health Evaluation (APACHE) II and III admission scores, and case mix. Outcome variables were hospital mortality, days in the intensive care unit and hospital, the development of multiple organ dysfunction syndrome, and expenditures. Cost data were taken weekly from the hospital's clinical information system. No new equipment was introduced during the study period except for pumps for patient-controlled analgesia, and there were no new critical pathways or other patient care guidelines. Case mix and all noncost variables were identical. Overall costs were reduced by 29% when normalized by the number of patient-days in each period. Laboratory testing was reduced in frequency by 24 to 32%, and cost by 26 to 28%. Comparable reductions in the cost of blood products (32%) were exceeded by the reductions in expenditures for nutritional supplements (49%) and pharmaceuticals (45%) (all, p < 0.01 or less). Modestly increased (2%) x-ray charges in 1995 were owing entirely to insertion of prophylactic inferior vena cava filters (each, $2,800, n = 5) and computed tomography scans for sinusitis (each, $350, n = 5), although the 7% reduction in portable chest radiographs that was achieved did not meet expectations. Substantial reductions in physician-ordered ancillary expenditures are possible without compromising the standard of care of critically ill patients, or the support of an elaborate framework of defined care plans. With additional experience, incremental savings may accrue from refinement of successful strategies and new approaches to intractable problems.

Chromium Stable Isotope Fractionation - An Indicator of Hexavalent Chromium Reduction.

NASA Astrophysics Data System (ADS)

Ellis, A.; Johnson, T. M.; Bullen, T. D.

2001-12-01

Chromium is a common anthropogenic contaminant in surface water and ground water, and is also of interest in oceanography. It is redox-active; the two common valences in natural waters are Cr(VI), which is highly soluble and toxic, and Cr(III), which is relatively insoluble. Redox reactions thus control Cr mobility in aqueous solutions, and reduction of Cr(VI) to Cr(III) is the most important reaction controlling attenuation of Cr in groundwater. Our results show that Cr(VI) reduction favors the lighter isotopes and leads to enrichment of heavier isotopes in the remaining Cr(VI). Cr isotope measurements thus show great promise as indicators of Cr(VI) reduction. We report here the first measurements of the magnitude of Cr isotope fractionation during Cr(VI) reduction and variations in δ 53Cr values obtained from three contaminated sites. Experiments were conducted to measure Cr isotope fractionation during Cr(VI) reduction by suspensions of magnetite and unamended sediments from a local pond, Urbana, IL and San Francisco Estuary near Martinez, CA. Suspensions were incubated anaerobically with constant shaking, and complete Cr(VI) reduction occurred within a few days. Cr(VI) from intermediate time points in the experiments was purified via ion exchange and 53Cr/52Cr ratios were measured via TIMS with a double isotope spike. The instantaneous per mil fractionation, ɛ , was calculated assuming a Rayleigh fractionation model. The ɛ for Cr(VI) reduction on magnetite surfaces yielded a fractionation of -3.5 ‰ . The ɛ values for the pond and estuary sediments were -3.5 ‰ and -3.3 ‰ respectively. The size of this Cr isotope fractionation is encouraging, as current precision is 0.2 \\permil. δ 53Cr values in dissolved Cr(VI) from three contaminated sites range from 1.1 ‰ to 5.8 ‰ , suggesting that Cr(VI) reduction has occurred and has induced isotopic fractionation in these settings. δ 53Cr values measured from Cr(VI) in plating baths show little or no fractionation during plating operations during up to 5 years of use. These results demonstrate that Cr stable isotope analyses should be a highly practical indicator of the critical chromate reduction reaction, and an otherwise useful geologic and oceanographic tool.

Reviews on current carbon emission reduction technologies and projects and their feasibilities on ships

NASA Astrophysics Data System (ADS)

Wang, Haibin; Zhou, Peilin; Wang, Zhongcheng

2017-06-01

Concern about global climate change is growing, and many projects and researchers are committed to reducing greenhouse gases from all possible sources. International Maritime (IMO) has set a target of 20% CO2 reduction from shipping by 2020 and also presented a series of carbon emission reduction methods, which are known as Energy Efficiency Design Index (EEDI) and Energy Efficiency Operation Indicator (EEOI). Reviews on carbon emission reduction from all industries indicate that, Carbon Capture and Storage (CCS) is an excellent solution to global warming. In this paper, a comprehensive literature review of EEDI and EEOI and CCS is conducted and involves reviewing current policies, introducing common technologies, and considering their feasibilities for marine activities, mainly shipping. Current projects are also presented in this paper, thereby illustrating that carbon emission reduction has been the subject of attention from all over the world. Two case ship studies indicate the economic feasibility of carbon emission reduction and provide a guide for CCS system application and practical installation on ships.

Dark Current Reduction of IR Detectors

DTIC Science & Technology

2017-10-19

demonstrating a novel dark current reduction approach for dense infrared detector arrays. This technique is based on the diffusion control junction (DCJ...fabricate and test detector arrays with and without DCJs on the same wafer and demonstrate the effectiveness of the DCJ approach in reducing dark current...subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE

Higher Education: A Critical Business.

ERIC Educational Resources Information Center

Barnett, Ronald

Current concepts of critical thinking need to be reconstrued into the much broader concept of "critical being" and applied to higher education. Under this construct, critical persons (students) become more than just critical thinkers; they engage critically with the world and with themselves; they not only reflect critically on…

Magnetic field oscillations of the critical current in long ballistic graphene Josephson junctions

NASA Astrophysics Data System (ADS)

Rakyta, Péter; Kormányos, Andor; Cserti, József

2016-06-01

We study the Josephson current in long ballistic superconductor-monolayer graphene-superconductor junctions. As a first step, we have developed an efficient computational approach to calculate the Josephson current in tight-binding systems. This approach can be particularly useful in the long-junction limit, which has hitherto attracted less theoretical interest but has recently become experimentally relevant. We use this computational approach to study the dependence of the critical current on the junction geometry, doping level, and an applied perpendicular magnetic field B . In zero magnetic field we find a good qualitative agreement with the recent experiment of M. Ben Shalom et al. [Nat. Phys. 12, 318 (2016), 10.1038/nphys3592] for the length dependence of the critical current. For highly doped samples our numerical calculations show a broad agreement with the results of the quasiclassical formalism. In this case the critical current exhibits Fraunhofer-like oscillations as a function of B . However, for lower doping levels, where the cyclotron orbit becomes comparable to the characteristic geometrical length scales of the system, deviations from the results of the quasiclassical formalism appear. We argue that due to the exceptional tunability and long mean free path of graphene systems a new regime can be explored where geometrical and dynamical effects are equally important to understand the magnetic field dependence of the critical current.

Dependency and self-criticism in treatments for depression.

PubMed

Chui, Harold; Zilcha-Mano, Sigal; Dinger, Ulrike; Barrett, Marna S; Barber, Jacques P

2016-07-01

Dependency and self-criticism are vulnerability factors for depression. How these personality factors change with treatment for depression and how they relate to symptom change across different types of treatment require further research. In addition, cultural differences that interact with the dependency/self-criticism-depression relation remain underinvestigated. We randomly assigned 149 adults with major depression to receive active medication (MED; n = 50), supportive-expressive therapy (SET; n = 49), or placebo pill (PBO; n = 50). Participants completed the Depressive Experiences Questionnaire (DEQ; Blatt, D'Afflitti, & Quinlan, 1976) before and after treatment and completed the Hamilton Rating Scale for Depression (Hamilton, 1967) throughout the course of treatment. Self-criticism as measured on the DEQ decreased with treatment similarly across conditions. DEQ Dependency decreased in MED but remained unchanged in SET and PBO. Higher initial dependency, but not higher initial self-criticism, predicted poor treatment response across conditions. Greater reduction in self-criticism was associated with greater reduction in depressive symptoms, but the effect was weaker for racial minorities (vs. White). Increase in connectedness, an adaptive form of dependency, was associated with symptom improvement in SET but not MED. Hence, different pathways of change seem to be implicated in the treatment of depression depending on culture and type of intervention. Implications for future research are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Critical Decay Index at the Onset of Solar Eruptions

NASA Astrophysics Data System (ADS)

Zuccarello, F. P.; Aulanier, G.; Gilchrist, S. A.

2015-12-01

Magnetic flux ropes are topological structures consisting of twisted magnetic field lines that globally wrap around an axis. The torus instability model predicts that a magnetic flux rope of major radius R undergoes an eruption when its axis reaches a location where the decay index -d({ln}{B}{ex})/d({ln}R) of the ambient magnetic field Bex is larger than a critical value. In the current-wire model, the critical value depends on the thickness and time evolution of the current channel. We use magnetohydrodynamic simulations to investigate whether the critical value of the decay index at the onset of the eruption is affected by the magnetic flux rope’s internal current profile and/or by the particular pre-eruptive photospheric dynamics. The evolution of an asymmetric, bipolar active region is driven by applying different classes of photospheric motions. We find that the critical value of the decay index at the onset of the eruption is not significantly affected by either the pre-erupitve photospheric evolution of the active region or the resulting different magnetic flux ropes. As in the case of the current-wire model, we find that there is a “critical range” [1.3-1.5], rather than a “critical value” for the onset of the torus instability. This range is in good agreement with the predictions of the current-wire model, despite the inclusion of line-tying effects and the occurrence of tether-cutting magnetic reconnection.

A Cryogenic Dc-Dc Power Converter for a 100 kW Synchronous HTS Generator at Liquid Nitrogen Temperatures

NASA Astrophysics Data System (ADS)

Bailey, Wendell; Wen, Hauming; Yang, Yifeng; Forsyth, Andrew; Jia, Chungjiang

A dc-dc converter has been developed for retrofitting inside the vacuum space of the HTS rotor of a synchronous generator. The heavy copper sections of the current leads used for energising the HTS field winding were replaced by cryogenic power electronics; consisting of the converter and a rotor control unit. The converter board was designed using an H-bridge configuration with two 5A rated wires connecting the cryogenic boards to the stator control board located on the outside of the generator and drawing power from a (5A, 50 V) dc power source. The robustness of converter board was well demonstrated when it was powered up from a cold start at 82K. When charging the field winding with moderate currents (30A), the heat in-leak to the 'cold' rotor core was only 2W. It continued to function down to 74K, surviving several quenches. However, the quench protection function failed when injecting 75A into the field winding, resulting in the burn out of one of the DC-link capacitors. The magnitudes of the critical currents measured with the original current leads were compared to the quench currents, which was defined as the current which triggered quench protection protocol. The difference between the two currents was rather large, (∼20A). However, additional measurements using a single HTS coil in liquid nitrogen found that this reduction should not be so dramatic and in the region of 4A. Our conclusions identified the converter's switching voltage and its operating frequency as two parameters, which could have contributed to lowering the quench current. Magnetic fields and eddy currents are expected to be more prominent the field winding and its impact on the converter also need further investigation.

Joint carbon footprint assessment and data envelopment analysis for the reduction of greenhouse gas emissions in agriculture production.

PubMed

Rebolledo-Leiva, Ricardo; Angulo-Meza, Lidia; Iriarte, Alfredo; González-Araya, Marcela C

2017-09-01

Operations management tools are critical in the process of evaluating and implementing action towards a low carbon production. Currently, a sustainable production implies both an efficient resource use and the obligation to meet targets for reducing greenhouse gas (GHG) emissions. The carbon footprint (CF) tool allows estimating the overall amount of GHG emissions associated with a product or activity throughout its life cycle. In this paper, we propose a four-step method for a joint use of CF assessment and Data Envelopment Analysis (DEA). Following the eco-efficiency definition, which is the delivery of goods using fewer resources and with decreasing environmental impact, we use an output oriented DEA model to maximize production and reduce CF, taking into account simultaneously the economic and ecological perspectives. In another step, we stablish targets for the contributing CF factors in order to achieve CF reduction. The proposed method was applied to assess the eco-efficiency of five organic blueberry orchards throughout three growing seasons. The results show that this method is a practical tool for determining eco-efficiency and reducing GHG emissions. Copyright © 2017 Elsevier B.V. All rights reserved.

FY2014 Propulsion Materials R&D Annual Progress Report

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

None

The Propulsion Materials Program actively supports the energy security and reduction of greenhouse emissions goals of VTO by investigating and identifying the materials properties that are most essential for continued development of cost-effective, highly efficient, and environmentally friendly next-generation heavy and light-duty powertrains. The technical approaches available to enhance propulsion systems focus on improvements in both vehicle efficiency and fuel substitution, both of which must overcome the performance limitations of the materials currently in use. Propulsion Materials Program activities work with national laboratories, industry experts, and VTO powertrain systems (e.g., Advanced Combustion Engines [ACE], Advanced Power Electronics and Electrical Machinesmore » [APEEM], and fuels) teams to develop strategies that overcome materials limitations in future powertrain performance. The technical maturity of the portfolio of funded projects ranges from basic science to subsystem prototype validation. Projects within a Propulsion Materials Program activity address materials concerns that directly impact critical technology barriers within each of the above programs, including barriers that impact fuel efficiency, thermal management, emissions reduction, improved reliability, and reduced manufacturing costs. The program engages only the barriers that result from material property limitations and represent fundamental, high-risk materials issues.« less

FY2015 Propulsion Materials Annual Report

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

None, None

The Propulsion Materials Program actively supports the energy security and reduction of greenhouse emissions goals of VTO by investigating and identifying the materials properties that are most essential for continued development of cost-effective, highly efficient, and environmentally friendly next-generation heavy and light-duty powertrains. The technical approaches available to enhance propulsion systems focus on improvements in both vehicle efficiency and fuel substitution, both of which must overcome the performance limitations of the materials currently in use. Propulsion Materials Program activities work with national laboratories, industry experts, and VTO powertrain systems (e.g., Advanced Combustion Engines [ACE], Advanced Power Electronics and Electrical Machinesmore » [APEEM], and fuels) teams to develop strategies that overcome materials limitations in future powertrain performance. The technical maturity of the portfolio of funded projects ranges from basic science to subsystem prototype validation. Projects within a Propulsion Materials Program activity address materials concerns that directly impact critical technology barriers within each of the above programs, including barriers that impact fuel efficiency, thermal management, emissions reduction, improved reliability, and reduced manufacturing costs. The program engages only the barriers that result from material property limitations and represent fundamental, high-risk materials issues.« less

Characterization of Heat Melt Compactor (HMC) Product Water

NASA Technical Reports Server (NTRS)

Harris, Linden; Wignarajah, Kanapathipi; Alba, Richard Gilbert; Pace, Gregory S.; Fisher, John W.

2013-01-01

The Heat Melt Compactor (HMC) is designed to sterilize and process wastes produced during space missions. Benefits of the HMC include reduction of biohazards to the crew, reduction in volume of wastes that would otherwise require storage, production of radiation shielding tiles, and recovery of water and other resources. Water reuse is critical onboard spacecrafts; it reduces the need for resupply missions and saves valuable storage space. The main sources of water in HMC batches are food, beverages, shampoo, disinfecting wipes, toothpaste, and diapers. Water reclaimed by the HMC was analyzed for concentrations of Na+, NH4+, K+, Mg2+, Ca2+, Cl-­-, NO2-­-, Br-­-, NO3-­-, PO43-­-, SO42-­-, total organic carbon (TOC), total inorganic carbon (TIC), % total solids, and pH. The data are discussed in relation to the current water input characteristics established for the International Space Station Water Processor Assembly system. Batches with higher than average amounts of food produced HMC product water with higher sulfate content, and batches with higher proportions of disinfectant wipes and food yielded HMC product water with higher ammonium concentration. We also compared theoretical chemical composition of HMC product water based on food labels and literature values to experimental results.

Mass and charge transport relevant to the formation of toroidal lithium peroxide nanoparticles in an aprotic lithium-oxygen battery: An experimental and theoretical modeling study

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

Luo, Xiangyi; Amine, Rachid; Lau, Kah Chun

2017-05-26

The discharge and charge mechanisms of rechargeable Li-O-2 batteries have been the subject of extensive investigation recently. However, they are not fully understood yet. Here we report a systematic study of the morphological transition of Li2O2 from a single crystalline structure to a toroid like particle during the discharge-charge cycle, with the help of a theoretical model to explain the evolution of the Li2O2 at different stages of this process. The model suggests that the transition starts in the first monolayer of Li2O2, and is subsequently followed by a transition from particle growth to film growth if the applied currentmore » exceeds the exchange current for the oxygen reduction reaction in a Li-O-2 cell. Furthermore, a sustainable mass transport of the diffusive active species (e.g., O-2 and Li+) and evolution of the underlying interfaces are critical to dictate desirable oxygen reduction (discharge) and evolution (charge) reactions in the porous carbon electrode of a Li-O-2 cell.« less

Linking assumptions in amblyopia

PubMed Central

LEVI, DENNIS M.

2017-01-01

Over the last 35 years or so, there has been substantial progress in revealing and characterizing the many interesting and sometimes mysterious sensory abnormalities that accompany amblyopia. A goal of many of the studies has been to try to make the link between the sensory losses and the underlying neural losses, resulting in several hypotheses about the site, nature, and cause of amblyopia. This article reviews some of these hypotheses, and the assumptions that link the sensory losses to specific physiological alterations in the brain. Despite intensive study, it turns out to be quite difficult to make a simple linking hypothesis, at least at the level of single neurons, and the locus of the sensory loss remains elusive. It is now clear that the simplest notion—that reduced contrast sensitivity of neurons in cortical area V1 explains the reduction in contrast sensitivity—is too simplistic. Considerations of noise, noise correlations, pooling, and the weighting of information also play a critically important role in making perceptual decisions, and our current models of amblyopia do not adequately take these into account. Indeed, although the reduction of contrast sensitivity is generally considered to reflect “early” neural changes, it seems plausible that it reflects changes at many stages of visual processing. PMID:23879956

NASA's Orbital Space Plane Risk Reduction Strategy

NASA Technical Reports Server (NTRS)

Dumbacher, Dan

2003-01-01

This paper documents the transformation of NASA s Space Launch Initiative (SLI) Second Generation Reusable Launch Vehicle Program under the revised Integrated Space Transportation Plan, announced November 2002. Outlining the technology development approach followed by the original SLI, this paper gives insight into the current risk-reduction strategy that will enable confident development of the Nation s first orbital space plane (OSP). The OSP will perform an astronaut and contingency cargo transportation function, with an early crew rescue capability, thus enabling increased crew size and enhanced science operations aboard the International Space Station. The OSP design chosen for full-scale development will take advantage of the latest innovations American industry has to offer. The OSP Program identifies critical technologies that must be advanced to field a safe, reliable, affordable space transportation system for U.S. access to the Station and low-Earth orbit. OSP flight demonstrators will test crew safety features, validate autonomous operations, and mature thermal protection systems. Additional enabling technologies may be identified during the OSP design process as part of an overall risk-management strategy. The OSP Program uses a comprehensive and evolutionary systems acquisition approach, while applying appropriate lessons learned.

Eddy current technique for predicting burst pressure

DOEpatents

Petri, Mark C.; Kupperman, David S.; Morman, James A.; Reifman, Jaques; Wei, Thomas Y. C.

2003-01-01

A signal processing technique which correlates eddy current inspection data from a tube having a critical tubing defect with a range of predicted burst pressures for the tube is provided. The method can directly correlate the raw eddy current inspection data representing the critical tubing defect with the range of burst pressures using a regression technique, preferably an artificial neural network. Alternatively, the technique deconvolves the raw eddy current inspection data into a set of undistorted signals, each of which represents a separate defect of the tube. The undistorted defect signal which represents the critical tubing defect is related to a range of burst pressures utilizing a regression technique.

A Qualitative Study of the Development of Health Literacy Capacities of Participants Attending a Community-Based Cardiovascular Health Programme.

PubMed

McKenna, Verna B; Sixsmith, Jane; Barry, Margaret M

2018-06-02

Health literacy is a critical determinant of health, which can empower individuals and lead to engagement in collective health promotion action and is also a crucial component in the self-management of illness. The current study moves beyond a focus on functional health literacy and presents findings from a longitudinal qualitative (LQ) study consisting of three phases. This paper presents findings from the second phase of the study, which assessed the development of health literacy capacities of individuals attending a structured cardiovascular risk reduction programme in Ireland. The study objectives were to: explore perceptions of changes in interactions and information exchange within health consultations; identify the facilitators associated with changes in health literacy capacities; assess developments in engagement with broader contexts for health literacy capacities. A LQ study design was undertaken, which employed repeat interview methodology with 19 participants (aged 36⁻76 years) 12 weeks after beginning a structured cardiovascular risk reduction programme. Health literacy levels were assessed using the HLS-EU 47 item instrument in phase 1 (68% limited health literacy (HL), 32% adequate health literacy). A semi-structured interview guide, (informed by Sørensen's conceptual model of health literacy), was used to explore the development of health literacy and to identify changes in knowledge, attitudes and experiences over time. Thematic analysis was used, informed by aspects of Saldaña's framework for longitudinal qualitative data analysis. All participants reported having acquired increased understanding of issues relevant to their health and self-care. Participants described health literacy capacities that incorporate aspects of all levels of health literacy (functional, interactive and critical). Core themes were identified corresponding to changes in these levels: re-engagement with health information and increased understanding of risk and protective factors (changes in functional health literacy); changes in interactions with healthcare providers (HCP) (changes in interactive health literacy); enhanced psychological insights and understanding the broader determinants of health (changes in critical health literacy). Findings support the development of health literacy capacities across the functional, interactive and critical health literacy domains. Participants are capable of locating responsibility for health beyond the individual level and are making sense of knowledge within their own social contexts. Individuals, regardless of their initial health literacy levels, are capable of engaging with broader issues that can impact on their health and can be supported to develop these critical health literacy capacities.

Theory for substorms triggered by sudden reductions in convection

NASA Technical Reports Server (NTRS)

Lyons, L. R.

1996-01-01

Many substorm expansions are triggered by interplanetary magnetic field changes that reduce magnetospheric convection. This suggests that expansion onsets are a result of a reduction in the large-scale electric field imparted to the magnetosphere from the solar wind. Such a reduction disrupts the inward motion and energization of plasma sheet particles that occur during the growth phase. It is proposed that the resulting magnetic drift of particles and a large dawn to dusk gradient in the ion energies leads to a longitudinally localized reduction in the plasma pressure, and thus, to the current wedge formation. This theory accounts for the rapid development of the expansion phase relative to growth phase, the magnitude of the wedge currents, the speeds of tailward and westward expansion of the current reduction region in the equatorial plane, and the speeds of the poleward and westward motion of active aurora in the ionosphere.

Mission definition study for a VLBI station utilizing the Space Shuttle

NASA Technical Reports Server (NTRS)

Burke, B. F.

1982-01-01

The uses of the Space Shuttle transportation system for orbiting VeryLong-Baseline Interferometry (OVLBI) were examined, both with respect to technical feasibility and its scientific possibilities. The study consisted of a critical look at the adaptability of current technology to an orbiting environment, the suitability of current data reduction facilities for the new technique, and a review of the new science that is made possible by using the Space Shuttle as a moving platform for a VLBI terminal in space. The conclusions are positive in all respects: no technological deficiencies exist that would need remedy, the data processing problem can be handled easily by straightforward adaptations of existing systems, and there is a significant new research frontier to be explored, with the Space Shuttle providing the first step. The VLBI technique utilizes the great frequency stability of modern atomic time standards, the power of integrated circuitry to perform real-time signal conditioning, and the ability of magnetic tape recorders to provide essentially error-free data recording, all of which combine to permit the realization of radio interferometry at arbitrarily large baselines.

In situ fabrication of green reduced graphene-based biocompatible anode for efficient energy recycle.

PubMed

Cheng, Ying; Mallavarapu, Megharaj; Naidu, Ravi; Chen, Zuliang

2018-02-01

Improving the anode configuration to enhance biocompatibility and accelerate electron shuttling is critical for efficient energy recovery in microbial fuel cells (MFCs). In this paper, green reduced graphene nanocomposite was successfully coated using layer-by-layer assembly technique onto carbon brush anode. The modified anode achieved a 3.2-fold higher power density of 33.7 W m -3 at a current density of 69.4 A m -3 with a 75% shorter start period. As revealed in the characterization, the green synthesized nanocomposite film affords larger surface roughness for microbial colonization. Besides, gold nanoparticles, which anchored on graphene sheets, promise the relatively high electroactive sites and facilitate electron transfer from electricigens to the anode. The reduction-oxidation peaks in cyclic voltammograms indicated the mechanism of surface cytochromes facilitated current generation while the electrochemical impedance spectroscopy confirmed the enhanced electron transfer from surface cytochrome to electrode. The green synthesis process has the potential to generate a high performing anode in further applications of MFCs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Preliminary Human-in-the-Loop Assessment of Procedures for Very-Closely-Spaced Parallel Runways

NASA Technical Reports Server (NTRS)

Verma, Savita; Lozito, Sandra C.; Ballinger, Deborah S.; Trot, Greg; Hardy, Gordon H.; Panda, Ramesh C.; Lehmer, Ronald D.; Kozon, Thomas E.

2010-01-01

Demand in the future air transportation system concept is expected to double or triple by 2025 [1]. Increasing airport arrival rates will help meet the growing demand that could be met with additional runways but the expansion airports is met with environmental challenges for the surrounding communities when using current standards and procedures. Therefore, changes to airport operations can improve airport capacity without adding runways. Building additional runways between current ones, or moving them closer, is a potential solution to meeting the increasing demand, as addressed by the Terminal Area Capacity Enhancing Concept (TACEC). TACEC requires robust technologies and procedures that need to be tested such that operations are not compromised under instrument meteorological conditions. The reduction of runway spacing for independent simultaneous operations dramatically exacerbates the criticality of wake vortex incursion and the calculation of a safe and proper breakout maneuver. The study presented here developed guidelines for such operations by performing a real-time, human-in-the-loop simulation using precision navigation, autopilot-flown approaches, with the pilot monitoring aircraft spacing and the wake vortex safe zone during the approach.

Pain, physical dependence and pseudoaddiction: redefining addiction for 'nice' people?

PubMed

Bell, Kirsten; Salmon, Amy

2009-03-01

The undertreatment of pain has increasingly been framed as both a public health problem and a human rights issue. The application of rights-based discourses to the field of pain management has provided an important means of critiquing "opiophobia" amongst healthcare professionals and challenging current criminal-legal and regulatory sanctions on the distribution of opiate medications. This movement would therefore appear to align with harm reduction advocacy and longstanding criticisms of international drug policies. However, discourses on pain management rest on moral as well as medical assumptions about who has pain and who needs drugs. In this paper, we critically examine discourses on pain management and addiction exemplified in academic and clinical literature produced by and for physicians providing guidance on the provision of opiates for the relief of chronic pain. Our analysis reveals that discourses on pain management and the right to pain relief reify distinctions between the 'deserving pain patient' and the 'undeserving addict', serving both to further stigmatise people labelled as 'addicts' and delegitimise claims to pain they might voice. Present efforts to secure access to pain relief as a human right are likely to undermine, rather than advance, the rights of so-called 'drug addicts'.

Progress in Tandem Solar Cells Based on Hybrid Organic-Inorganic Perovskites

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

Chen, Bo; Zheng, Xiaopeng; Bai, Yang

Owing to their high efficiency, low-cost solution-processability, and tunable bandgap, perovskite solar cells (PSCs) made of hybrid organic-inorganic perovskite (HOIP) thin films are promising top-cell candidates for integration with bottom-cells based on Si or other low-bandgap solar-cell materials to boost the power conversion efficiency (PCE) beyond the Shockley-Quiesser (S-Q) limit. In this review, recent progress in such tandem solar cells based on the emerging PSCs is summarized and reviewed critically. Notable achievements for different tandem solar cell configurations including mechanically-stacked, optical coupling, and monolithically-integrated with PSCs as top-cells are described in detail. Highly-efficient semitransparent PSC top-cells with high transmittance inmore » near-infrared (NIR) region are critical for tandem solar cells. Different types of transparent electrodes with high transmittance and low sheet-resistance for PSCs are reviewed, which presents a grand challenge for PSCs. The strategies to obtain wide-bandgap PSCs with good photo-stability are discussed. In conclusion, the PCE reduction due to reflection loss, parasitic absorption, electrical loss, and current mismatch are analyzed to provide better understanding of the performance of PSC-based tandem solar cells.« less

Progress in Tandem Solar Cells Based on Hybrid Organic-Inorganic Perovskites

DOE PAGES

Chen, Bo; Zheng, Xiaopeng; Bai, Yang; ...

2017-03-06

Owing to their high efficiency, low-cost solution-processability, and tunable bandgap, perovskite solar cells (PSCs) made of hybrid organic-inorganic perovskite (HOIP) thin films are promising top-cell candidates for integration with bottom-cells based on Si or other low-bandgap solar-cell materials to boost the power conversion efficiency (PCE) beyond the Shockley-Quiesser (S-Q) limit. In this review, recent progress in such tandem solar cells based on the emerging PSCs is summarized and reviewed critically. Notable achievements for different tandem solar cell configurations including mechanically-stacked, optical coupling, and monolithically-integrated with PSCs as top-cells are described in detail. Highly-efficient semitransparent PSC top-cells with high transmittance inmore » near-infrared (NIR) region are critical for tandem solar cells. Different types of transparent electrodes with high transmittance and low sheet-resistance for PSCs are reviewed, which presents a grand challenge for PSCs. The strategies to obtain wide-bandgap PSCs with good photo-stability are discussed. In conclusion, the PCE reduction due to reflection loss, parasitic absorption, electrical loss, and current mismatch are analyzed to provide better understanding of the performance of PSC-based tandem solar cells.« less

The use of lorcaserin in the management of obesity: a critical appraisal

PubMed Central

Bai, Bo; Wang, Yu

2011-01-01

Obesity is a chronic disease with a high prevalence in both developed and developing countries. Effective management of this worldwide epidemic will have a significant impact on the health care system globally. Lifestyle interventions, such as restricting calorie consumption and increasing physical activity, remain a major component of weight-reduction programs. The development of pharmacotherapy for the management of obesity is still at the infancy stage. Side effects have been the key issue for anti-obesity drugs previously withdrawn from the market. The focus of this review, lorcaserin, is a selective serotonin receptor agonist that is currently undergoing Phase III evaluations. The efficacy of this drug in reducing body weight and improving metabolic parameters of obese patients has been demonstrated in two recent clinical trials. The available evidence indicates that this drug does not show unwanted effects on heart valves or pulmonary artery pressure, and the treatment improves the risk factors for type 2 diabetes and cardiovascular diseases. Despite these promising results, additional experimental and clinical studies are critical for the approval of lorcaserin as a new anti-obesity monodrug therapy by the US Food and Drug Administration. PMID:21267355

The use of lorcaserin in the management of obesity: a critical appraisal.

PubMed

Bai, Bo; Wang, Yu

2010-12-20

Obesity is a chronic disease with a high prevalence in both developed and developing countries. Effective management of this worldwide epidemic will have a significant impact on the health care system globally. Lifestyle interventions, such as restricting calorie consumption and increasing physical activity, remain a major component of weight-reduction programs. The development of pharmacotherapy for the management of obesity is still at the infancy stage. Side effects have been the key issue for anti-obesity drugs previously withdrawn from the market. The focus of this review, lorcaserin, is a selective serotonin receptor agonist that is currently undergoing Phase III evaluations. The efficacy of this drug in reducing body weight and improving metabolic parameters of obese patients has been demonstrated in two recent clinical trials. The available evidence indicates that this drug does not show unwanted effects on heart valves or pulmonary artery pressure, and the treatment improves the risk factors for type 2 diabetes and cardiovascular diseases. Despite these promising results, additional experimental and clinical studies are critical for the approval of lorcaserin as a new anti-obesity monodrug therapy by the US Food and Drug Administration.

The global context for public health nutrition taxation.

PubMed

Thow, Anne Marie; Heywood, Peter; Leeder, Stephen; Burns, Lee

2011-01-01

To assess critically the scope for public health nutrition taxation within the framework of the global tax reform agenda. Review of the tax policy literature for global policy priorities relevant to public health nutrition taxation; critical analysis of proposals for public health nutrition taxation judged against the global agenda for tax reform. The global tax reform agenda shapes decisions of tax policy makers in all countries. By understanding this agenda, public health nutritionists can make feasible taxation proposals and thus improve the development, uptake and implementation of recommendations for nutrition-related taxation. The priorities of the global tax reform agenda relevant to public health nutrition taxation are streamlining of taxes, adoption of value-added tax (VAT), minimisation of excise taxes (except to correct for externalities) and removal of import taxes in line with trade liberalisation policies. Proposals consistent with the global tax reform agenda have included excise taxes, extension of VAT to currently exempted (unhealthy) foods and tariff reductions for healthy foods. Proposals for public health nutrition taxation should (i) use existing types and rates of taxes where possible, (ii) use excise taxes that specifically address externalities, (iii) avoid differential VAT on foods and (iv) use import taxes in ways that comply with trade liberalisation priorities.

CREB and FoxO1: two transcription factors for the regulation of hepatic gluconeogenesis

PubMed Central

Oh, Kyoung-Jin; Han, Hye-Sook; Kim, Min-Jung; Koo, Seung-Hoi

2013-01-01

Liver plays a major role in maintaining glucose homeostasis in mammals. Under fasting conditions, hepatic glucose production is critical as a source of fuel to maintain the basic functions in other tissues, including skeletal muscle, red blood cells, and the brain. Fasting hormones glucagon and cortisol play major roles during the process, in part by activating the transcription of key enzyme genes in the gluconeogenesis such as phosphoenol pyruvate carboxykinase (PEPCK) and glucose 6 phosphatase catalytic subunit (G6Pase). Conversely, gluconeogenic transcription is repressed by pancreatic insulin under feeding conditions, which effectively inhibits transcriptional activator complexes by either promoting post-translational modifications or activating transcriptional inhibitors in the liver, resulting in the reduction of hepatic glucose output. The transcriptional regulatory machineries have been highlighted as targets for type 2 diabetes drugs to control glycemia, so understanding of the complex regulatory mechanisms for transcription circuits for hepatic gluconeogenesis is critical in the potential development of therapeutic tools for the treatment of this disease. In this review, the current understanding regarding the roles of two key transcriptional activators, CREB and FoxO1, in the regulation of hepatic gluconeogenic program is discussed. [BMB Reports 2013; 46(12): 567-574] PMID:24238363

Drug Loading Capacity of Environmentally Sensitive Polymeric Microgels

NASA Astrophysics Data System (ADS)

McDonough, Ryan; Streletzky, Kiril; Bayachou, Mekki; Peiris, Pubudu

2009-10-01

Microgel nanoparticles consisting of cross-linked polymer hydroxypropyl cellulose chains have a temperature dependent volume phase transition, prompting the use of microgels for controlled drug transport. Drug particles aggregate in the slightly hydrophobic interior of microgels. Microgels are stored in equilibrium until the critical temperature (Tv) is reached and the volume phase transition limits available space, thus expelling the drugs. Our study was designed to test this property of microgels using amperometric electrochemical methods. A critical assumption was that small molecules inside microgels would not interact via diffusion with the electrode surface and thus total current would be decreased across the electrodes in a microgel sample. A room temperature (Troom) flow amperometric measurement comparing microgel/tylenol solution with control tylenol samples yielded about 20% tylenol concentration reduction of the microgel sample. Results from the steady state electrochemical experiment confirm the presence of about 20% tylenol concentration drop of the microgel sample compared to control sample at Troom. Using the steady-state experiment with a cyclic temperature ramp from Troom to beyond Tv showed that the tylenol concentration change between the temperature extremes was greater for the microgel solution than for the control solution.

Low Dose MDCT with Tube Current Modulation: Role in Detection of Urolithiasis and Patient Effective Dose Reduction

PubMed Central

Kakkar, Chandan; Sripathi, Smiti; Parakh, Anushri; Shrivastav, Rajendra

2016-01-01

Introduction Urolithiasis is one of the major, recurring problem in young individuals and CT being the commonest diagnostic modality used. In order to reduce the radiation dose to the patient who are young and as stone formation is a recurring process; one of the simplest way would be, low dose CT along with tube current modulation. Aim Aim of this study was to compare the sensitivity and specificity of low dose (70mAs) with standard dose (250mAs) protocol in detecting urolithiasis and to define the tube current and mean effective patient dose by these protocols. Materials and Methods A prospective study was conducted in 200 patients over a period of 2 years with acute flank pain presentation. CT was performed in 100 cases with standard dose and another 100 with low dose protocol using tube current modulation. Sensitivity and specificity for calculus detection, percentage reduction of dose and tube current with low dose protocol was calculated. Results Urolithiasis was detected in 138 patients, 67 were examined by high dose and 71 were by low dose protocol. Sensitivity and Specificity of low dose protocol was 97.1% and 96.4% with similar results found in high BMI patients. Tube current modulation resulted in reduction of effective tube current by 12.17%. The mean effective patient dose for standard dose was 10.33 mSv whereas 2.92 mSv for low dose with 51.13–53.8% reduction in low dose protocol. Conclusion The study has reinforced that low-dose CT with tube current modulation is appropriate for diagnosis of urolithiasis with significant reduction in tube current and patient effective dose. PMID:27437322

Low Dose MDCT with Tube Current Modulation: Role in Detection of Urolithiasis and Patient Effective Dose Reduction.

PubMed

Koteshwar, Prakashini; Kakkar, Chandan; Sripathi, Smiti; Parakh, Anushri; Shrivastav, Rajendra

2016-05-01

Urolithiasis is one of the major, recurring problem in young individuals and CT being the commonest diagnostic modality used. In order to reduce the radiation dose to the patient who are young and as stone formation is a recurring process; one of the simplest way would be, low dose CT along with tube current modulation. Aim of this study was to compare the sensitivity and specificity of low dose (70mAs) with standard dose (250mAs) protocol in detecting urolithiasis and to define the tube current and mean effective patient dose by these protocols. A prospective study was conducted in 200 patients over a period of 2 years with acute flank pain presentation. CT was performed in 100 cases with standard dose and another 100 with low dose protocol using tube current modulation. Sensitivity and specificity for calculus detection, percentage reduction of dose and tube current with low dose protocol was calculated. Urolithiasis was detected in 138 patients, 67 were examined by high dose and 71 were by low dose protocol. Sensitivity and Specificity of low dose protocol was 97.1% and 96.4% with similar results found in high BMI patients. Tube current modulation resulted in reduction of effective tube current by 12.17%. The mean effective patient dose for standard dose was 10.33 mSv whereas 2.92 mSv for low dose with 51.13-53.8% reduction in low dose protocol. The study has reinforced that low-dose CT with tube current modulation is appropriate for diagnosis of urolithiasis with significant reduction in tube current and patient effective dose.

Effects of temperature and gas-liquid mass transfer on the operation of small electrochemical cells for the quantitative evaluation of CO2 reduction electrocatalysts.

PubMed

Lobaccaro, Peter; Singh, Meenesh R; Clark, Ezra Lee; Kwon, Youngkook; Bell, Alexis T; Ager, Joel W

2016-09-29

In the last few years, there has been increased interest in electrochemical CO 2 reduction (CO2R). Many experimental studies employ a membrane separated, electrochemical cell with a mini H-cell geometry to characterize CO2R catalysts in aqueous solution. This type of electrochemical cell is a mini-chemical reactor and it is important to monitor the reaction conditions within the reactor to ensure that they are constant throughout the study. We show that operating cells with high catalyst surface area to electrolyte volume ratios (S/V) at high current densities can have subtle consequences due to the complexity of the physical phenomena taking place on electrode surfaces during CO2R, particularly as they relate to the cell temperature and bulk electrolyte CO 2 concentration. Both effects were evaluated quantitatively in high S/V cells using Cu electrodes and a bicarbonate buffer electrolyte. Electrolyte temperature is a function of the current/total voltage passed through the cell and the cell geometry. Even at a very high current density, 20 mA cm -2 , the temperature increase was less than 4 °C and a decrease of <10% in the dissolved CO 2 concentration is predicted. In contrast, limits on the CO 2 gas-liquid mass transfer into the cells produce much larger effects. By using the pH in the cell to measure the CO 2 concentration, significant undersaturation of CO 2 is observed in the bulk electrolyte, even at more modest current densities of 10 mA cm -2 . Undersaturation of CO 2 produces large changes in the faradaic efficiency observed on Cu electrodes, with H 2 production becoming increasingly favored. We show that the size of the CO 2 bubbles being introduced into the cell is critical for maintaining the equilibrium CO 2 concentration in the electrolyte, and we have designed a high S/V cell that is able to maintain the near-equilibrium CO 2 concentration at current densities up to 15 mA cm -2 .

Effects of temperature and gas–liquid mass transfer on the operation of small electrochemical cells for the quantitative evaluation of CO 2 reduction electrocatalysts

DOE PAGES

Lobaccaro, Peter; Singh, Meenesh R.; Clark, Ezra Lee; ...

2016-09-06

In the last few years, there has been increased interest in electrochemical CO 2 reduction (CO2R). Many experimental studies employ a membrane separated, electrochemical cell with a mini H-cell geometry to characterize CO2R catalysts in aqueous solution. This type of electrochemical cell is a mini-chemical reactor and it is important to monitor the reaction conditions within the reactor to ensure that they are constant throughout the study. Here we show that operating cells with high catalyst surface area to electrolyte volume ratios (S/V) at high current densities can have subtle consequences due to the complexity of the physical phenomena takingmore » place on electrode surfaces during CO2R, particularly as they relate to the cell temperature and bulk electrolyte CO 2 concentration. Both effects were evaluated quantitatively in high S/V cells using Cu electrodes and a bicarbonate buffer electrolyte. Electrolyte temperature is a function of the current/total voltage passed through the cell and the cell geometry. Even at a very high current density, 20 mA cm -2 , the temperature increase was less than 4 °C and a decrease of < 10% in the dissolved CO 2 concentration is predicted. In contrast, limits on the CO 2 gas-liquid mass transfer into the cells produce much larger effects. By using the pH in the cell to measure the CO 2 concentration, significant undersaturation of CO 2 is observed in the bulk electrolyte, even at more modest current densities of 10 mA cm -2 . Undersaturation of CO 2 produces large changes in the faradaic efficiency observed on Cu electrodes, with H 2 production becoming increasingly favored. Finally, we show that the size of the CO 2 bubbles being introduced into the cell is critical for maintaining the equilibrium CO 2 concentration in the electrolyte, and we have designed a high S/V cell that is able to maintain the near-equilibrium CO 2 concentration at current densities up to 15 mA cm -2.« less

Effects of temperature and gas–liquid mass transfer on the operation of small electrochemical cells for the quantitative evaluation of CO 2 reduction electrocatalysts

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

Lobaccaro, Peter; Singh, Meenesh R.; Clark, Ezra Lee

In the last few years, there has been increased interest in electrochemical CO 2 reduction (CO2R). Many experimental studies employ a membrane separated, electrochemical cell with a mini H-cell geometry to characterize CO2R catalysts in aqueous solution. This type of electrochemical cell is a mini-chemical reactor and it is important to monitor the reaction conditions within the reactor to ensure that they are constant throughout the study. Here we show that operating cells with high catalyst surface area to electrolyte volume ratios (S/V) at high current densities can have subtle consequences due to the complexity of the physical phenomena takingmore » place on electrode surfaces during CO2R, particularly as they relate to the cell temperature and bulk electrolyte CO 2 concentration. Both effects were evaluated quantitatively in high S/V cells using Cu electrodes and a bicarbonate buffer electrolyte. Electrolyte temperature is a function of the current/total voltage passed through the cell and the cell geometry. Even at a very high current density, 20 mA cm -2 , the temperature increase was less than 4 °C and a decrease of < 10% in the dissolved CO 2 concentration is predicted. In contrast, limits on the CO 2 gas-liquid mass transfer into the cells produce much larger effects. By using the pH in the cell to measure the CO 2 concentration, significant undersaturation of CO 2 is observed in the bulk electrolyte, even at more modest current densities of 10 mA cm -2 . Undersaturation of CO 2 produces large changes in the faradaic efficiency observed on Cu electrodes, with H 2 production becoming increasingly favored. Finally, we show that the size of the CO 2 bubbles being introduced into the cell is critical for maintaining the equilibrium CO 2 concentration in the electrolyte, and we have designed a high S/V cell that is able to maintain the near-equilibrium CO 2 concentration at current densities up to 15 mA cm -2.« less

Hypothesis: Normalisation of cytokine dysbalance explains the favourable effects of strict glucose regulation in the critically ill.

PubMed

Pickkers, P; Hoedemaekers, A; Netea, M G; de Galan, B E; Smits, P; van der Hoeven, J G; van Deuren, M

2004-05-01

Recent trials investigating the effects of strict glucose regulation in critically ill patients have shown impressive reductions in morbidity and mortality. Although the literature focuses on the possible toxic effects of high blood glucose levels, the underlying mechanism for this improvement is unclear. We hypothesise that strict glucose regulation results in modulation of cytokine production, leading to a shift towards a more anti-inflammatory pattern. This shift in the cytokine balance accounts for the reduction in morbidity and mortality. To support our hypothesis, effects of glucose and insulin on cytokine release and effects of glucose, insulin, and cytokines on host defence, cardiac function and coagulation will be reviewed.

Heterogeneous selenite reduction by zero valent iron steel wool.

PubMed

Li, Ziyan; Huang, Donglin; McDonald, Louis M

2017-02-01

Mine drainage from the low-sulfur surface coal mines in southern West Virginia, USA, is circumneutral (pH > 6) but contains elevated selenium (Se) concentrations. Removal of selenite ions from aqueous solutions under anoxic condition at pH 6-8.5 by zero valent iron steel wool (ZVI-SW) was investigated in bench-scale kinetic experiments using wet chemical, microscopic and spectroscopic techniques (X-ray photoelectron spectroscopy). ZVI-SW could effectively and efficiently remove Se IV from solution with pH 6-8.5. A two-step removal mechanism was identified for Se IV reduction by ZVI-SW. The proposed mechanism was electrochemical reduction of Se IV by Fe 0 in an initial lag stage, followed by a faster heterogeneous reduction, mediated by an Fe II -bearing phase (hydroxide or green rust). Solution pH was a critical factor for the kinetic rate in the lag stage (0.33 h -1 for pH > 8 and 0.10 h -1 for pH 6-8). The length of lag stage was 20-30 min as determined by the time for dissolved Fe II concentration to reach 0.30 ± 0.04 mg L -1 which was critical for induction of the faster stage. About 65% of the initial Se IV was reduced to Se 0 , the primary reductive product in both stages.

Nagel on reduction.

PubMed

Sarkar, Sahotra

2015-10-01

This paper attempts a critical reappraisal of Nagel's (1961, 1970) model of reduction taking into account both traditional criticisms and recent defenses. This model treats reduction as a type of explanation in which a reduced theory is explained by a reducing theory after their relevant representational items have been suitably connected. In accordance with the deductive-nomological model, the explanation is supposed to consist of a logical deduction. Nagel was a pluralist about both the logical form of the connections between the reduced and reducing theories (which could be conditionals or biconditionals) and their epistemological status (as analytic connections, conventions, or synthetic claims). This paper defends Nagel's pluralism on both counts and, in the process, argues that the multiple realizability objection to reductionism is misplaced. It also argues that the Nagel model correctly characterizes reduction as a type of explanation. However, it notes that logical deduction must be replaced by a broader class of inferential techniques that allow for different types of approximation. Whereas Nagel (1970), in contrast to his earlier position (1961), recognized the relevance of approximation, he did not realize its full import for the model. Throughout the paper two case studies are used to illustrate the arguments: the putative reduction of classical thermodynamics to the kinetic theory of matter and that of classical genetics to molecular biology. Copyright © 2015. Published by Elsevier Ltd.

The potential for iron reduction in upland soils in Calhoun Critical Zone Observatory

NASA Astrophysics Data System (ADS)

Thompson, A.; Chen, C.; Noor, N.; Hodges, C. A.; Barcellos, D.; Richter, D. D., Jr.

2017-12-01

Fe redox cycling plays an important role in organic matter preservation and degradation, and the fate of nutrients and contaminants. Despite its importance, Fe redox cycling in non-flooded upland soils has been underappreciated, although many upland terrestrial ecosystems have episodes of low redox events and an abundance of anoxic microsites. Soil Fe reduction is generally constrained by C availability, the reactivity of Fe(III) oxyhydroxides, and the abundance of Fe reducing bacteria. The goal of this study was to determine the potential for Fe reduction in upland soils under varying land-uses (Hardwood, Pine and Cultivated soils) from Calhoun Critical Zone Observatory. Fresh field soils from multiple depths were incubated in the lab without amendments under anoxic conditions for 3 weeks to determine the native potential for soil Fe reduction and to assess the limiting factors, the soils were amended with factorial mixtures of the following: (1) organic substrates (glucose and alanine); (2) bioavailable Fe (ferrihydrite); and (3) Fe reducing bacteria (Shewanella oneidensis strain MR-1). Results showed that Fe reduction potential generally decreased with soil depth. Fe reduction potential is very minimal below 1m of soil profile. The availability of Fe(III) minerals did not constrain pine and hardwood soil Fe reduction potential. Fe(III) availability only slightly limited the potential for Fe reduction the cultivated soils, which have the lowest extractable Fe by ascorbate-citrate. Labile C constrained Fe reduction in the hardwood and cultivated soils, but not in the pine soils, which had the highest extractable C by K2SO4. In addition, we found the more energetic C source (glucose) facilitated more Fe reduction in the subsurface soil than did Alanine. Finally, the abundance of Fe-reducing bacteria limited Fe reduction potential in almost all of these soils, particularly the pine soils.

A Comparison of QEIA and Non-QEIA Schools: Implications of Class Size Reduction

ERIC Educational Resources Information Center

Platt, Louise Carolyn Sater

2013-01-01

The purpose of this research study is to compare student achievement changes between matched QEIA and non-QEIA schools in an effort to infer effects of the most significant feature of QEIA funding, class size reduction. The study addressed the critical question--are there demonstrated, significant differences in student achievement gains between…

Correlations between critical current density, j(sub c), critical temperature, T(sub c),and structural quality of Y1B2Cu3O(7-x) thin superconducting films

NASA Technical Reports Server (NTRS)

Chrzanowski, J.; Xing, W. B.; Atlan, D.; Irwin, J. C.; Heinrich, B.; Cragg, R. A.; Zhou, H.; Angus, V.; Habib, F.; Fife, A. A.

1995-01-01

Correlations between critical current density (j(sub c)) critical temperature (T(sub c)) and the density of edge dislocations and nonuniform strain have been observed in YBCO thin films deposited by pulsed laser ablation on (001) LaAlO3 single crystals. Distinct maxima in j(sub c) as a function of the linewidths of the (00 l) Bragg reflections and as a function of the mosaic spread have been found in the epitaxial films. These maxima in j(sub c) indicate that the magnetic flux lines, in films of structural quality approachingthat of single crystals, are insufficiently pinned which results in a decreased critical current density. T(sub c) increased monotonically with improving crystalline quality and approached a value characteristic of a pure single crystal. A strong correlation between j(sub c) and the density of edge dislocations ND was found. At the maximum of the critical current density the density of edge dislocations was estimated to be N(sub D) approximately 1-2 x 10(exp 9)/sq cm.

Critical Synergistic Concentration of Lecithin Phospholipids Improves the Antimicrobial Activity of Eugenol against Escherichia coli.

PubMed

Zhang, Haoshu; Dudley, Edward G; Harte, Federico

2017-11-01

In this study, the effect of individual lecithin phospholipids on the antimicrobial properties of eugenol against Escherichia coli C600 was investigated. We tested five major phospholipids common in soy or egg lecithin (1,2-dihexadecanoyl-sn-glycero-3-phosphocholine [DPPC], 1,2-dioctadecanoyl-sn-glycero-3-phosphocholine [DSPC], 1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine [DPPE], 1,2-dihexadecanoyl-sn-glycero-3-phosphate [sodium salt] [DPPA], and 1,2-dihexadecanoyl-sn-glycero-3-phospho-l-serine [DPPS]) and one synthetic cationic phospholipid (1,2-dioctadecanoyl-sn-glycero-3-ethylphosphocholine [18:0 EPC]). Among the six phospholipids, DPPC, DSPC, DPPE, DPPA, and the cationic 18:0 EPC showed critical synergistic concentrations that significantly improved the inactivation effect of eugenol against E. coli after 30 min of exposure. At the critical synergistic concentration, an additional ca. 0.4 to 1.9 log reduction (ca. 0.66 to 2.17 log CFU/ml reduction) in the microbial population was observed compared to eugenol-only (control) treatments (ca. 0.25 log reduction). In all cases, increasing the phospholipid amount above the critical synergistic concentration (which was different for each phospholipid) resulted in antimicrobial properties similar to those seen with the eugenol-only (control) treatments. DPPS did not affect the antimicrobial properties of eugenol at the tested concentrations. The critical synergistic concentration of phospholipids was correlated with their critical micelle concentrations (CMC). IMPORTANCE Essential oils (EOs) are naturally occurring antimicrobials, with limited use in food due to their hydrophobicity and strong aroma. Lecithin is used as a natural emulsifier to stabilize EOs in aqueous systems. We previously demonstrated that, within a narrow critical-concentration window, lecithin can synergistically enhance the antimicrobial properties of eugenol. Since lecithin is a mixture of different phospholipids, we aimed to identify which phospholipids are crucial for the observed synergistic effect. This research studied the bioactivity of lecithin phospholipids, contributing to a rational design in using lecithin to effectively control foodborne pathogens in foods. Copyright © 2017 American Society for Microbiology.

Superconducting nanowire networks formed on nanoporous membrane substrates

NASA Astrophysics Data System (ADS)

Luo, Qiong

Introducing a regular array of holes into superconducting thin films has been actively pursued to stabilize and pin the vortex lattice against external driving forces, enabling higher current capabilities. If the width of the sections between neighboring holes is comparable to the superconducting coherence length, the circulation of the Cooper pairs in around the holes in the presence of a magnetic field can also produce the Little-Parks effect, i.e. periodic oscillation of the critical temperature. These two mechanisms, commensurate vortex pinning enhancement by the hole-array and the critical temperature oscillations of a wire network due to Little-Parks effect can induce similar experimental observations such as magnetoresistance oscillation and enhancement of the critical current at specific magnetic fields. This dissertation work investigates the effect of a hole-array on the properties of superconducting films deposited onto nanoporous substrates. Experiments on anisotropies of the critical temperature for niobium films on anodic aluminum oxide membrane substrates containing a regular hole-array reveal that the critical temperature exhibits two strong anisotropic effects: Little-Parks oscillations whose period varies with field direction superimposed on a smooth background arising from one dimensional confinement by the finite lateral space between neighboring holes. The two components of the anisotropy are intrinsically linked and appear in concert. That is, the hole-array changes the dimensionality of a two-dimensional (2D) film to a network of 1D nanowire network. Network of superconducting nanowires with transverse dimensions as small as few nanometers were achieved by coating molybdenum germanium (MoGe) layer onto commercially available filtration membranes which have extremely dense nanopores. The magnetoresistance, magnetic field dependence of the critical temperature and the anisotropies of the synthesized MoGe nanowire networks can be consistently attributed to thermal phase slips and Little-Parks effect, revealing new phenomena at extreme conditions. This research significantly advanced our understanding on confinement effects in superconductors. Since AAO membranes of large area can be fabricated easily and filtration membranes are commercially available, the developed fabrication approach provides an alternative but more accessible templating method to achieve samples for exploring phenomena in superconductors with transverse dimensions down to few nanometers. This research also sets limitations on efforts to pursue high commensurate vortex pinning fields by increasing the density of holes in a perforated film: a reduction in the width of superconducting section between neighboring holes can turn a 2D film into a network of 1D nanowires which dissipate energy when conducting electricity due to thermal and possibly also quantum phase slippages, eliminating the desired pinning effect of the introduced hole.

Are the second-generation antipsychotics cost-effective? A critical review on the background of different health systems.

PubMed

Hamann, J; Leucht, S; Kissling, W

2003-01-01

Despite clinical advantages over conventional compounds, second-generation antipsychotics are prescribed less frequently in some European countries than in the United States because of their higher acquisition price and the current cost-containment strategies of many European health systems. This has been criticized on the grounds that the higher acquisition costs of the new antipsychotics might be more than outweighed by savings in other fields, e. g., through a reduction in rehospitalizations or indirect costs. In order to create an empirical basis for this discussion, a review of the results of pharmacoeconomic studies (mostly cost-effectiveness studies) comparing second-generation with conventional antipsychotics was undertaken. Of the 35 studies identified, most report at least cost-neutrality of the new antipsychotics (in many cases clozapine) that is due to reductions in hospitalization costs. These results cannot be generalized, however, because of methodological shortcomings such as small patient samples and study designs with low validity, and especially because of a lack of studies performed outside the U.S. It is shown that results from studies in the U.S. cannot be generalized to other health systems in Europe or in developing countries. Furthermore, only a few findings on newer second-generation antipsychotics other than clozapine are reported, and no study investigated indirect costs, which play a major role because of the early onset and chronicity of schizophrenia. Until now, there has been no sufficient evidence for the superior cost-effectiveness of atypical antipsychotics in European countries. Considering the importance of this topic for health politics, more cost-effectiveness studies in European countries are urgently needed. But even if economic superiority of the second-generation antipsychotics cannot be demonstrated in such studies, their use is nevertheless indicated with respect to patient's well-being.

[Treatment of acrylate wastewater by electrocatalytic reduction process].

PubMed

Yu, Li-Na; Song, Yu-Dong; Zhou, Yue-Xi; Zhu, Shu-Quan; Zheng, Sheng-Zhi; Ll, Si-Min

2011-10-01

High-concentration acrylate wastewater was treated by an electrocatalytic reduction process. The effects of the cation exchange membrane (CEM) and cathode materials on acrylate reduction were investigated. It indicated that the acrylate could be reduced to propionate acid efficiently by the electrocatalytic reduction process. The addition of CEM to separator with the cathode and anode could significantly improve current efficiency. The cathode materials had significant effect on the reduction of acrylate. The current efficiency by Pd/Nickel foam, was greater than 90%, while those by nickel foam, the carbon fibers and the stainless steel decreased successively. Toxicity of the wastewater decreased considerably and methane production rate in the biochemical methane potential (BMP) test increased greatly after the electrocatalytic reduction process.

Psychological Science's Contributions to a Sustainable Environment: Extending Our Reach to a Grand Challenge of Society

ERIC Educational Resources Information Center

Kazdin, Alan E.

2009-01-01

Climate change and degradation of the environment are global problems associated with many other challenges (e.g., population increases, reduction of glaciers, and loss of critical habitats). Psychological science can play a critical role in addressing these problems by fostering a sustainable environment. Multiple strategies for fostering a…

Len Barton, Critical Education and the Problem of "Decentered Unities"

ERIC Educational Resources Information Center

Apple, Michael W.

2010-01-01

In the process of discussing the significant contributions that Len Barton has made to the sociology of education and to disability studies, I argue that a good deal of critical analyses of power and inequality in education are impoverished by some of their essentialist and reductive tendencies. I use an example taken from disability rights to…

Effects of Proactive and Prosocial Behaviors on Critical Incidents of Schoolers from Lima

ERIC Educational Resources Information Center

Holguin Alvarez, Jhon A.

2017-01-01

The study focuses on the theoretical approaches of proactive and prosocial behavior of Covey (1996), Xifra (2009) and Roche-Olivar (2004), with the objective of analyzing the significant differences in the reduction of critical incidents in students from public and private schools in the district of San Juan de Lurigancho. To this end, two…

Critical care of tropical disease in low income countries: Report from the Task Force on Tropical Diseases by the World Federation of Societies of Intensive and Critical Care Medicine.

PubMed

Baker, Tim; Khalid, Karima; Acicbe, Ozlem; McGloughlin, Steve; Amin, Pravin

2017-12-01

Tropical disease results in a great burden of critical illness. The same life-saving and supportive therapies to maintain vital organ functions that comprise critical care are required by these patients as for all other diseases. In low income countries, the little available data points towards high mortality rates and big challenges in the provision of critical care. Improving critical care in low income countries requires a focus on hospital design, training, triage, monitoring & treatment modifications, the basic principles of critical care, hygiene and the involvement of multi-disciplinary teams. As a large proportion of critical illness from tropical disease is in low income countries, the impact and reductions in mortality rates of improved critical care in such settings could be substantial. Copyright © 2017. Published by Elsevier Inc.

Antidepressant Efficacy of the Antimuscarinic Drug Scopolamine

PubMed Central

Furey, Maura L.; Drevets, Wayne C.

2010-01-01

Context The need for improved therapeutic agents that more quickly and effectively treat depression is critical. In a pilot study we evaluated the role of the cholinergic system in cognitive symptoms of depression and unexpectedly observed rapid reductions in depression severity following the administration of the antimuscarinic drug scopolamine hydrobromide (4 μg/kg intravenously) compared with placebo (P=.002). Subsequently a clinical trial was designed to assess more specifically the antidepressant efficacy of scopolamine. Objective To evaluate scopolamine as a potential antidepressant agent. Design Two studies were conducted: a double-blind, placebo-controlled, dose-finding study followed by a double-blind, placebo-controlled, crossover clinical trial. Setting The National Institute of Mental Health. Patients Currently depressed outpatients aged 18 to 50 years meeting DSM-IV criteria for recurrent major depressive disorder or bipolar disorder. Of 39 eligible patients, 19 were randomized and 18 completed the trial. Interventions Multiple sessions including intravenous infusions of placebo or scopolamine hydrobromide (4 μg/kg). Individuals were randomized to a placebo/ scopolamine or scopolamine/placebo sequence (series of 3 placebo sessions and series of 3 scopolamine sessions). Sessions occurred 3 to 5 days apart. Main Outcome Measures Psychiatric evaluations using the Montgomery-Asberg Depression Rating Scale and the Hamilton Anxiety Rating Scale were performed to assess antidepressant and antianxiety responses to scopolamine. Results The placebo/scopolamine group showed no significant change during placebo infusion vs baseline; reductions in depression and anxiety rating scale scores (P<.001 for both) were observed after the administration of scopolamine compared with placebo. The scopolamine/placebo group also showed reductions in depression and anxiety rating scale scores (P<.001 for both) after the administration of scopolamine, relative to baseline, and these effects persisted as they received placebo. In both groups, improvement was significant at the first evaluation after scopolamine administration (P≤.002). Conclusion Rapid, robust antidepressant responses to the antimuscarinic scopolamine occurred in currently depressed patients who predominantly had poor prognoses. PMID:17015814

Academia Sinica, TW E-science to Assistant Seismic Observations for Earthquake Research, Monitor and Hazard Reduction Surrounding the South China Sea

NASA Astrophysics Data System (ADS)

Huang, Bor-Shouh; Liu, Chun-Chi; Yen, Eric; Liang, Wen-Tzong; Lin, Simon C.; Huang, Win-Gee; Lee, Shiann-Jong; Chen, Hsin-Yen

Experience from the 1994 giant Sumatra earthquake, seismic and tsunami hazard have been considered as important issues in the South China Sea and its surrounding region, and attracted many seismologist's interesting. Currently, more than 25 broadband seismic instruments are currently operated by Institute of Earth Sciences, Academia Sinica in northern Vietnam to study the geodynamic evolution of the Red river fracture zone and rearranged to distribute to southern Vietnam recently to study the geodynamic evolution and its deep structures of the South China Sea. Similar stations are planned to deploy in Philippines in near future. In planning, some high quality stations may be as permanent stations and added continuous GPS observations, and instruments to be maintained and operated by several cooperation institutes, for instance, Institute of Geophysics, Vietnamese Acadamy of Sciences and Technology in Vietnam and Philippine Institute of Volcanology and Seismology in Philippines. Finally, those stations will be planed to upgrade as real time transmission stations for earthquake monitoring and tsunami warning. However, high speed data transfer within different agencies is always a critical issue for successful network operation. By taking advantage of both EGEE and EUAsiaGrid e-Infrastructure, Academia Sinica Grid Computing Centre coordinates researchers from various Asian countries to construct a platform to high performance data transfer for huge parallel computation. Efforts from this data service and a newly build earthquake data centre for data management may greatly improve seismic network performance. Implementation of Grid infrastructure and e-science issues in this region may assistant development of earthquake research, monitor and natural hazard reduction. In the near future, we will search for new cooperation continually from the surrounding countries of the South China Sea to install new seismic stations to construct a complete seismic network of the South China Sea and encourage studies for earthquake sciences and natural hazard reductions.

Utilization of volume correlation filters for underwater mine identification in LIDAR imagery

NASA Astrophysics Data System (ADS)

Walls, Bradley

2008-04-01

Underwater mine identification persists as a critical technology pursued aggressively by the Navy for fleet protection. As such, new and improved techniques must continue to be developed in order to provide measurable increases in mine identification performance and noticeable reductions in false alarm rates. In this paper we show how recent advances in the Volume Correlation Filter (VCF) developed for ground based LIDAR systems can be adapted to identify targets in underwater LIDAR imagery. Current automated target recognition (ATR) algorithms for underwater mine identification employ spatial based three-dimensional (3D) shape fitting of models to LIDAR data to identify common mine shapes consisting of the box, cylinder, hemisphere, truncated cone, wedge, and annulus. VCFs provide a promising alternative to these spatial techniques by correlating 3D models against the 3D rendered LIDAR data.

Reducing economic risk in areally anisotropic formations with multiple-lateral horizontal wells

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

Smith, J.; Economides, M.J.; Frick, T.P.

1995-12-31

Well orientation is critical to horizontal well performance in areally anisotropic reservoirs. A horizontal well, drilled normal to the direction of maximum permeability, will have higher productivity than one drilled in any other arbitrary direction. Currently, horizontal permeability magnitudes and even indications of direction are rarely measured in the field. Based on well performance modeling and economic evaluation, this study attempts to determine the relative attractiveness of horizontal wells with multiple-laterals. The work exposes the economic risk in ignoring horizontal permeability magnitudes and directions and demonstrates the importance of adequate reservoir testing. A new rationalization for multiple-lateral horizontal wells ismore » the reduction of the economic risk associated with poor reservoir characterization in areally anisotropic formations while increasing the incremental net present value (NPV) over single-horizontal wells.« less

Particulate matter air pollution in Europe in a +2 °C warming world

NASA Astrophysics Data System (ADS)

Lacressonnière, Gwendoline; Watson, Laura; Gauss, Michael; Engardt, Magnuz; Andersson, Camilla; Beekmann, Matthias; Colette, Augustin; Foret, Gilles; Josse, Béatrice; Marécal, Virginie; Nyiri, Agnes; Siour, Guillaume; Sobolowski, Stefan; Vautard, Robert

2017-04-01

In the framework of the IMPACT2C project, we have evaluated the future European particulate matter concentrations under the influence of climate change and anthropogenic emission reductions. To do so, 30-year simulations for present and future scenarios were performed with an ensemble of four regional Chemical Transport Models. +2 °C scenarios were issued from different regional climate simulations belonging to the CORDEX experiment (RCP4.5 scenario). Comparing present day simulations to observations shows that these simulations meet the requested quality criteria even if some biases do exist. Also, we showed that using regional climate models instead of meteorological reanalysis was not critical for the quality of our simulations. Present day as well as future scenarios show the large variability between models associated with different meteorology and process parameterizations. Future projections of PM concentrations show a large reduction of PM10 and PM2.5 concentrations in a +2 °C climate over the European continent (especially over Benelux), which can be mostly attributed to emission reduction policies. Under a current legislation scenario, annual PM10 could be reduced by between 1.8 and 2.9 μg m-3 (14.1-20.4%). If maximum technologically feasible emission reductions were implemented, further reductions of 1.4-1.9 μg m-3 (18.6-20.9%) are highlighted. Changes due to a +2 °C warming, in isolation from emission changes, are in general much weaker (-1.1 to +0.4 μg m-3,-0.3 to +5.1% for annual PM10 averaged over the European domain). Even if large differences exist between models, we have determined that the decrease of PM over Europe associated with emission reduction is a robust result. The patterns of PM changes resulting from climate change (for example the increase of PM over Spain and southern France and the decrease of PM10 over eastern Europe) are also robustly predicted even if its amplitude remains weak compared to changes associated with emission reductions.

Excess current experiment on YBCO tape conductor with metal stabilized layer

NASA Astrophysics Data System (ADS)

Tasaki, Kenji; Yazawa, Takashi; Ono, Michitaka; Kuriyama, Toru

2006-06-01

Excess current experiments were performed using YBCO tape conductors with a metal stabilized layer on the superconducting layer. The purpose of this research is to obtain the stable criteria of energy dissipation when YBCO tape is forced to flow excess current higher than its critical current. This situation should be considered in power applications. In the experiments short-length samples were immersed in liquid nitrogen and several cycles of 50Hz sinusoidal current were supplied to the samples by an induction voltage regulator. The critical current of the samples was about 110 A. With pulse length as long as 60 ms, YBCO tapes were able to be energized up to twelve times as the critical current without electrical or mechanical deformation. Prior to the excess current experiments, temperature dependency of resistance of the sample was measured so that the temperature rise was estimated by the generated resistance. It is found that YBCO tapes with a copper stabilized layer can be transiently heated to over 400K without degradation.

Ceruloplasmin copper induces oxidant damage by a redox process utilizing cell-derived superoxide as reductant

NASA Technical Reports Server (NTRS)

Mukhopadhyay, C. K.; Fox, P. L.

1998-01-01

Oxidative damage by transition metals bound to proteins may be an important pathogenic mechanism. Ceruloplasmin (Cp) is a Cu-containing plasma protein thought to be involved in oxidative modification of lipoproteins. We have previously shown that Cp increased cell-mediated low-density lipoprotein (LDL) oxidation by a process requiring cell-derived superoxide, but the underlying chemical mechanism(s) is (are) unknown. We now show that superoxide reduction of Cp Cu is a critical reaction in cellular LDL oxidation. By bathocuproine disulfonate (BCS) binding and by superoxide utilization, we showed that exogenous superoxide reduces a single Cp Cu atom, the same Cu required for LDL oxidation. The Cu atom remained bound to Cp during the redox cycle. Three avenues of evidence showed that vascular cells reduce Cp Cu by a superoxide-dependent process. The 2-fold higher rate of Cp Cu reduction by smooth muscle cells (SMC) compared to endothelial cells (EC) was consistent with their relative rates of superoxide release. Furthermore, Cp Cu reduction by cells was blocked by Cu,Zn superoxide dismutase (SOD1). Finally, the level of superoxide produced by EC and SMC was sufficient to cause the amount of Cu reduction observed. An important role of Cp Cu reduction in LDL oxidation was suggested by results showing that SOD1 inhibited Cp Cu reduction and LDL oxidation by SMC with equal potency, while tumor necrosis factor-alpha stimulated both processes. In summary, these results show that superoxide is a critical cellular reductant of divalent transition metals involved in oxidation, and that protein-bound Cu is a substrate for this reaction. The role of these mechanisms in oxidative processes in vivo has yet to be defined.

Therapeutic use of dolls for people living with dementia: A critical review of the literature.

PubMed

Mitchell, Gary; McCormack, Brendan; McCance, Tanya

2016-09-01

There are a number of therapies currently available to assist healthcare professionals and carers with non-pharmacological treatment for people living with dementia. One such therapy that has been growing in clinical practice is doll therapy. Providing dolls to some people living with dementia has the potential to enhance personal well-being through increased levels of communication and engagement with others. Despite its potential for benefits, the practice is currently under-developed in healthcare literature, probably due to varied ethical interpretations of its practice. To undertake a critical review of the published literature on doll therapy, using the Critical Appraisal Skills Programme Checklist (CASP) tool, in order to determine the potential benefits and challenges of this therapy for people living with dementia. A comprehensive literature search, incorporating the CINAHL, Medline, Embase, PubMed, Joanna Briggs, Cochrane Library and PsycINFO data bases, was conducted. Despite many commentaries and anecdotal accounts of the practice, this review identified only 11 empirical studies that were eligible. The majority of studies found that the use of dolls could be therapeutic for some people living with dementia by reporting increased levels of engagement, communication and reduction in episodes of distress. Some studies identified limitations to the therapy including; confusion over the ownership of the doll and healthcare professional uncertainty about issues pertaining to autonomy. According to this review, doll therapy has the potential to increase the well-being of some people living with dementia. This review illuminates that some healthcare professionals feel uncomfortable about its use in clinical practice. The operationalisation of doll therapy in clinical practice has been shown to be inconsistent with different approaches to the practice being advocated. This highlights the need for further empirical research to identify best practice and education to increase awareness in both healthcare professional and carer populations. © The Author(s) 2014.

Mass-Producible 2D-MoS2-Impregnated Screen-Printed Electrodes That Demonstrate Efficient Electrocatalysis toward the Oxygen Reduction Reaction.

PubMed

Rowley-Neale, Samuel J; Smith, Graham C; Banks, Craig E

2017-07-12

Two-dimensional molybdenum disulfide (2D-MoS 2 ) screen-printed electrodes (2D-MoS 2 -SPEs) have been designed, fabricated, and evaluated toward the electrochemical oxygen reduction reaction (ORR) within acidic aqueous media. A screen-printable ink has been developed that allows for the tailoring of the 2D-MoS 2 content/mass used in the fabrication of the 2D-MoS 2 -SPEs, which critically affects the observed ORR performance. In comparison to the graphite SPEs (G-SPEs), the 2D-MoS 2 -SPEs are shown to exhibit an electrocatalytic behavior toward the ORR which is found, critically, to be reliant upon the percentage mass incorporation of 2D-MoS 2 in the 2D-MoS 2 -SPEs; a greater percentage mass of 2D-MoS 2 incorporated into the 2D-MoS 2 -SPEs results in a significantly less electronegative ORR onset potential and a greater signal output (current density). Using optimally fabricated 2D-MoS 2 -SPEs, an ORR onset and a peak current of approximately +0.16 V [vs saturated calomel electrode (SCE)] and -1.62 mA cm -2 , respectively, are observed, which exceeds the -0.53 V (vs SCE) and -635 μA cm -2 performance of unmodified G-SPEs, indicating an electrocatalytic response toward the ORR utilizing the 2D-MoS 2 -SPEs. An investigation of the underlying electrochemical reaction mechanism of the ORR within acidic aqueous solutions reveals that the reaction proceeds via a direct four-electron process for all of the 2D-MoS 2 -SPE variants studied herein, where oxygen is electrochemically favorably reduced to water. The fabricated 2D-MoS 2 -SPEs are found to exhibit no degradation in the observed achievable current over the course of 1000 repeat scans. The production of such inks and the resultant mass-producible 2D-MoS 2 -SPEs mitigates the need to modify post hoc an electrode via the drop-casting technique that has been previously shown to result in a loss of achievable current over the course of 1000 repeat scans. The 2D-MoS 2 -SPEs designed, fabricated, and tested herein could have commercial viability as electrocatalytic fuel cell electrodes because of being economical as a result of their scales of economy and inherent tailorability. The technique utilized herein to produce the 2D-MoS 2 -SPEs could be adapted for the incorporation of different 2D nanomaterials, resulting in SPEs with the inherent advantages identified above.

Stability and chaotification of vibration isolation floating raft systems with time-delayed feedback control.

PubMed

Li, Y L; Xu, D L; Fu, Y M; Zhou, J X

2011-09-01

This paper presents a systematic study on the stability of a two-dimensional vibration isolation floating raft system with a time-delayed feedback control. Based on the generalized Sturm criterion, the critical control gain for the delay-independent stability region and critical time delays for the stability switches are derived. The critical conditions can provide a theoretical guidance of chaotification design for line spectra reduction. Numerical simulations verify the correctness of the approach. Bifurcation analyses reveal that chaotification is more likely to occur in unstable region defined by these critical conditions, and the stiffness of the floating raft and mass ratio are the sensitive parameters to reduce critical control gain.

The influence of winding direction of two-layer HTS DC cable on the critical current

NASA Astrophysics Data System (ADS)

Vyatkin, V. S.; Kashiwagi, K.; Ivanov, Y. V.; Otabe, E. S.; Yamaguchi, S.

2017-09-01

The design of twist pitch and direction of winding in multilayer HTS coaxial cable is important. For HTS AC transmitting cables, the main condition of twist pitch is the balance of inductances of each layer for providing the current balance between layers. In this work, the finite element method analysis for the coaxial cables with both same and opposite directions winding is used to calculate magnetic field distribution, and critical current of the cable is estimated. It was found that the critical current of the cable with same direction winding is about 10 percent higher than that in the case of the cable with the opposite direction winding.

Critical Education, Critical Pedagogies, Marxist Education in the United States

ERIC Educational Resources Information Center

Foley, Jean Ann; Morris, Doug; Gounari, Panayota; Agostinone-Wilson, Faith

2015-01-01

As critical pedagogy becomes more mainstream on the educational landscape in the United States, it is important to revisit the original tenets of critical pedagogy and explore their current manifestations. Since the beginning of "criticalism" from the theoretical/foundational work of the Frankfurt School of Critical Social Theory,…

Critical current studies of a HTS rectangular coil

NASA Astrophysics Data System (ADS)

Zhong, Z.; Chudy, M.; Ruiz, H. S.; Zhang, X.; Coombs, T.

2017-05-01

Nowadays, superconducting high field magnets are used in numerous applications due to their superior properties. High temperature superconductors (HTS) are usually used for production of circular pancake or racetrack coils. However different geometries of HTS coils might be required for some specific applications. In this study, the HTS coil wound on a rectangular frame was fully characterized in homogeneous DC background field. The study contains measurements of critical current angular dependencies. The critical current of the entire coil and two selected strands under different magnitudes and orientations of external magnetic fields are measured. The critical regions of the coil in different angular regimes are determined. This study brings better understanding of the in- field performance of HTS coils wound on frames with right-angles.

Spatial characterization of the edge barrier in wide superconducting films

NASA Astrophysics Data System (ADS)

Sivakov, A. G.; Turutanov, O. G.; Kolinko, A. E.; Pokhila, A. S.

2018-03-01

The current-induced destruction of superconductivity is discussed in wide superconducting thin films, whose width is greater than the magnetic field penetration depth, in weak magnetic fields. Particular attention is paid to the role of the boundary potential barrier (the Bin-Livingston barrier) in critical state formation and detection of the edge responsible for this critical state with different mutual orientations of external perpendicular magnetic field and transport current. Critical and resistive states of the film were visualized using the space-resolving low-temperature laser scanning microscopy (LTLSM) method, which enables detection of critical current-determining areas on the film edges. Based on these observations, a simple technique was developed for investigation of the critical state separately at each film edge, and for the estimation of residual magnetic fields in cryostats. The proposed method only requires recording of the current-voltage characteristics of the film in a weak magnetic field, thus circumventing the need for complex LTLSM techniques. Information thus obtained is particularly important for interpretation of studies of superconducting film single-photon light emission detectors.

Individualised care for women with assisted conception pregnancies and midwifery practice implications: An analysis of the existing research and current practice.

PubMed

Younger, Mimi; Hollins-Martin, Caroline; Choucri, Lesley

2015-02-01

the aim is to explore the psychosocial needs of women who are pregnant after assisted conception, specifically in vitro Fertilisation and whether their needs are being addressed within the current maternity care service. critical review of the literature using a narrative approach. 15 papers were identified. These included both qualitative and quantitative studies, literature reviews and surveys. The findings of this limited narrative review imply that women who undergo assistive reproductive techniques to achieve pregnancy have higher levels of anxiety in pregnancy and may have some difficulties in the transition to parenthood leading to perinatal morbidity. It appears that for this group of women it is important that their history in achieving pregnancy is known to the care providers, to enable the alleviation of some of the anxieties they face. Various aspects of antenatal care have been identified as possible areas which if addressed may reduce these levels of anxiety leading to a reduction in perinatal morbidity. currently, there is insufficient evidence to suggest that providing specialist midwifery care reduces morbidity in these women. However, maternity service providers should consider offering additional antenatal and postnatal services to meet the needs of this group in advance of further research in this area. Copyright © 2014 Elsevier Ltd. All rights reserved.

Glaucoma –state of the art and perspectives on treatment

PubMed Central

Wójcik-Gryciuk, Anna; Skup, Małgorzata; Waleszczyk, Wioletta J.

2015-01-01

Glaucoma is a chronic optic neuropathy characterized by progressive damage to the optic nerve, death of retinal ganglion cells and ultimately visual field loss. It is one of the leading causes of irreversible loss of vision worldwide. The most important trigger of glaucomatous damage is elevated eye pressure, and the current standard approach in glaucoma therapy is reduction of intraocular pressure (IOP). However, despite the use of effective medications or surgical treatment leading to lowering of IOP, progression of glaucomatous changes and loss of vision among patients with glaucoma is common. Therefore, it is critical to prevent vision loss through additional treatment. To implement such treatment(s), it is imperative to identify pathophysiological changes in glaucoma and develop therapeutic methods taking into account neuroprotection. Currently, there is no method of neuroprotection with long-term proven effectiveness in the treatment of glaucoma. Among the most promising molecules shown to protect the retina and optic nerve are neurotrophic factors. Thus, the current focus is on the development of safe and non-invasive methods for the long-term elevation of the intraocular level of neurotrophins through advanced gene therapy and topical eye treatment and on the search for selective agonists of neurotrophin receptors affording more efficient neuroprotection. PMID:26684267

Assessing ecosystem service provision under climate change to support conservation and development planning in Myanmar

PubMed Central

Wolny, Stacie; Bhagabati, Nirmal; Helsingen, Hanna; Hamel, Perrine; Bartlett, Ryan; Dixon, Adam; Horton, Radley; Lesk, Corey; Manley, Danielle; De Mel, Manishka; Bader, Daniel; Nay Won Myint, Sai; Myint, Win; Su Mon, Myat

2017-01-01

Inclusion of ecosystem services (ES) information into national-scale development and climate adaptation planning has yet to become common practice, despite demand from decision makers. Identifying where ES originate and to whom the benefits flow–under current and future climate conditions–is especially critical in rapidly developing countries, where the risk of ES loss is high. Here, using Myanmar as a case study, we assess where and how ecosystems provide key benefits to the country’s people and infrastructure. We model the supply of and demand for sediment retention, dry-season baseflows, flood risk reduction and coastal storm protection from multiple beneficiaries. We find that locations currently providing the greatest amount of services are likely to remain important under the range of climate conditions considered, demonstrating their importance in planning for climate resilience. Overlap between priority areas for ES provision and biodiversity conservation is higher than expected by chance overall, but the areas important for multiple ES are underrepresented in currently designated protected areas and Key Biodiversity Areas. Our results are contributing to development planning in Myanmar, and our approach could be extended to other contexts where there is demand for national-scale natural capital information to shape development plans and policies. PMID:28934282

Toward a new generation of therapeutics: artificial cell targeted delivery of live cells for therapy.

PubMed

Prakash, Satya; Martoni, Christopher

2006-01-01

Scientific evidence in the prevention and treatment of various disorders is accumulating regarding probiotics. The health benefits supported by adequate clinical data include increased resistance to infectious disease, decreased duration of diarrhea, management of inflammatory bowel disease, reduction of serum cholesterol, prevention of allergy, modulation of cytokine gene expression, and suppression of carcinogen production. Recent ventures in metabolic engineering and heterologous protein expression have enhanced the enzymatic and immunomodulatory effects of probiotics and, with time, may allow more active intervention among critical care patients. In addition, a number of approaches are currently being explored, including the physical and chemical protection of cells, to increase probiotic viability and its health benefits. Traditional immobilization of probiotics in gel matrices, most notably calcium alginate and kappa-carrageenan, has frequently been employed, with noted improvements in viability during freezing and storage. Conflicting reports exist, however, on the protection offered by immobilization from harsh physiologic environments. An alternative approach, microencapsulation in "artificial cells," builds on immobilization technologies by combining enhanced mechanical stability of the capsule membrane with improved mass transport, increased cell loading, and greater control of parameters. This review summarizes the current clinical status of probiotics, examines the promises and challenges of current immobilization technologies, and presents the concept of artificial cells for effective delivery of therapeutic bacterial cells.

Environmental implication of electric vehicles in China.

PubMed

Huo, Hong; Zhang, Qiang; Wang, Michael Q; Streets, David G; He, Kebin

2010-07-01

Today, electric vehicles (EVs) are being proposed in China as one of the potential options to address the dramatically increasing energy demand from on-road transport. However, the mass use of EVs could involve multiple environmental issues, because EVs use electricity that is generated primarily from coal in China. We examined the fuel-cycle CO(2), SO(2), and NO(x) emissions of EVs in China in both current (2008) and future (2030) periods and compared them with those of conventional gasoline vehicles and gasoline hybrids. EVs do not promise much benefit in reducing CO(2) emissions currently, but greater CO(2) reduction could be expected in future if coal combustion technologies improve and the share of nonfossil electricity increases significantly. EVs could increase SO(2) emissions by 3-10 times and also double NO(x) emissions compared to gasoline vehicles if charged using the current electricity grid. In the future, EVs would be able to reach the NO(x) emission level of gasoline vehicles with advanced emission control devices equipped in thermal power plants but still increase SO(2). EVs do represent an effective solution to issues in China such as oil shortage, but critical policy support is urgently needed to address the environmental issues caused by the use of EVs to make EVs competitive with other vehicle alternatives.

An optimized low-power voltage controlled oscillator

NASA Astrophysics Data System (ADS)

Shah, Kriyang; Le, Hai Phuong; Singh, Jugdutt

2007-01-01

This paper presents an optimised low-power low-phase-noise Voltage Controlled Oscillator (VCO) for Bluetooth wireless applications. The system level design issues and tradeoffs related to Direct Conversion Receiver (DCR) and Low Intermediate Frequency (IF) architecture for Bluetooth are discussed. Subsequently, for a low IF architecture, the critical VCO performance parameters are derived from system specifications. The VCO presented in the paper is optimised by implementing a novel biasing circuit that employs two current mirrors, one at the top and the other one at the bottom of the cross-coupled complementary VCO, to give the exact replica of the current in both the arms of current mirror circuit. This approach, therefore, significantly reduces the system power consumption as well as improves the system performance. Results show that, the VCO consumes only 281μW of power at 2V supply. Its phase noise performance are -115dBc/Hz, -130dBc/Hz and -141dBc/Hz at the offset frequency of 1MHz, 3MHz and 5MHz respectively. Results indicate that 31% reduction in power consumption is achieved as compared to the traditional VCO design. These characteristics make the designed VCO a better candidate for Bluetooth wireless application where power consumption is the major issue.

Transcranial Electrical Currents to Probe EEG Brain Rhythms and Memory Consolidation during Sleep in Humans

PubMed Central

Marshall, Lisa; Kirov, Roumen; Brade, Julian; Mölle, Matthias; Born, Jan

2011-01-01

Previously the application of a weak electric anodal current oscillating with a frequency of the sleep slow oscillation (∼0.75 Hz) during non-rapid eye movement sleep (NonREM) sleep boosted endogenous slow oscillation activity and enhanced sleep-associated memory consolidation. The slow oscillations occurring during NonREM sleep and theta oscillations present during REM sleep have been considered of critical relevance for memory formation. Here transcranial direct current stimulation (tDCS) oscillating at 5 Hz, i.e., within the theta frequency range (theta-tDCS) is applied during NonREM and REM sleep. Theta-tDCS during NonREM sleep produced a global decrease in slow oscillatory activity conjoint with a local reduction of frontal slow EEG spindle power (8–12 Hz) and a decrement in consolidation of declarative memory, underlining the relevance of these cortical oscillations for sleep-dependent memory consolidation. In contrast, during REM sleep theta-tDCS appears to increase global gamma (25–45 Hz) activity, indicating a clear brain state-dependency of theta-tDCS. More generally, results demonstrate the suitability of oscillating-tDCS as a tool to analyze functions of endogenous EEG rhythms and underlying endogenous electric fields as well as the interactions between EEG rhythms of different frequencies. PMID:21340034

A Multidisciplinary, Science-Based Approach to the Economics of Climate Change

PubMed Central

Carlin, Alan

2011-01-01

Economic analyses of environmental mitigation and other interdisciplinary public policy issues can be much more useful if they critically examine what other disciplines have to say, insist on using the most relevant observational data and the scientific method, and examine lower cost alternatives to the change proposed. These general principles are illustrated by applying them to the case of climate change mitigation, one of the most interdisciplinary of public policy issues. The analysis shows how use of these principles leads to quite different conclusions than those of most previous such economic analyses, as follows: The economic benefits of reducing CO2 emissions may be about two orders of magnitude less than those estimated by most economists because the climate sensitivity factor (CSF) is much lower than assumed by the United Nations because feedback is negative rather than positive and the effects of CO2 emissions reductions on atmospheric CO2 appear to be short rather than long lasting.The costs of CO2 emissions reductions are very much higher than usually estimated because of technological and implementation problems recently identified.Geoengineering such as solar radiation management is a controversial alternative to CO2 emissions reductions that offers opportunities to greatly decrease these large costs, change global temperatures with far greater assurance of success, and eliminate the possibility of low probability, high consequence risks of rising temperatures, but has been largely ignored by economists.CO2 emissions reductions are economically unattractive since the very modest benefits remaining after the corrections for the above effects are quite unlikely to economically justify the much higher costs unless much lower cost geoengineering is used.The risk of catastrophic anthropogenic global warming appears to be so low that it is not currently worth doing anything to try to control it, including geoengineering. PMID:21695026

Determining the N and O isotope effects of microbial nitrite reduction: the global N cycle implications of an enzyme-dependent isotope effect

NASA Astrophysics Data System (ADS)

Martin, T. S.; Casciotti, K. L.

2014-12-01

The marine nitrogen (N) cycle is a dynamic system of critical importance, since nitrogen is the limiting nutrient in over half of the world's oceans. Denitrification and anammox, the main N loss processes from the ocean, have different effects on carbon cycling and greenhouse gas emission. Understanding the balance between the two processes is vital to understanding the role of the N cycle in global climate change. One approach for investigating these processes is by using stable isotope analysis to estimate the relative magnitudes of N fluxes, particularly for biologically mediated processes. In order to make the most of the currently available isotope analysis techniques, it is necessary to know the isotope effects for each processes occurring in the environment. Nitrite reduction is an important step in denitrification. Previous work had begun to explore the N isotope effects for nitrite reduction, but no oxygen (O) isotope effect has been measured. Additionally, no consideration has been given to the type of nitrite reductase carrying out the reaction. There are two main types of respiratory nitrite reductase, one that is Cu-based and another that is Fe-based. We performed batch culture experiments with denitrifier strains possessing either a Cu-type or Fe-type nitrite reductase. Both N and O isotope effects for nitrite reduction were determined for each of these experiments by measuring the NO2- concentration, as well as the N and O isotopes of nitrite and applying a Rayleigh fractionation model. Both the N and O isotope effects were found to be significantly different between the two types of enzymes. This enzyme-linked difference in isotope effects emphasizes the importance of microbial community composition within the global N cycle.

Understanding Selectivity for the Electrochemical Reduction of Carbon Dioxide to Formic Acid and Carbon Monoxide on Metal Electrodes

DOE PAGES

Feaster, Jeremy T.; Shi, Chuan; Cave, Etosha R.; ...

2017-06-22

Increases in energy demand and in chemical production, together with the rise in CO 2 levels in the atmosphere, motivate the development of renewable energy sources. Electrochemical CO 2 reduction to fuels and chemicals is an appealing alternative to traditional pathways to fuels and chemicals due to its intrinsic ability to couple to solar and wind energy sources. Formate (HCOO –) is a key chemical for many industries; however, greater understanding is needed regarding the mechanism and key intermediates for HCOO – production. This work reports a joint experimental and theoretical investigation of the electrochemical reduction of CO 2 tomore » HCOO – on polycrystalline Sn surfaces, which have been identified as promising catalysts for selectively producing HCOO –. Our results show that Sn electrodes produce HCOO –, carbon monoxide (CO), and hydrogen (H 2) across a range of potentials and that HCOO – production becomes favored at potentials more negative than –0.8 V vs RHE, reaching a maximum Faradaic efficiency of 70% at –0.9 V vs RHE. Scaling relations for Sn and other transition metals are examined using experimental current densities and density functional theory (DFT) binding energies. While *COOH was determined to be the key intermediate for CO production on metal surfaces, we suggest that it is unlikely to be the primary intermediate for HCOO – production. Instead, *OCHO is suggested to be the key intermediate for the CO 2RR to HCOO – transformation, and Sn’s optimal *OCHO binding energy supports its high selectivity for HCOO –. Lastly, these results suggest that oxygen-bound intermediates are critical to understand the mechanism of CO 2 reduction to HCOO – on metal surfaces.« less

Understanding Selectivity for the Electrochemical Reduction of Carbon Dioxide to Formic Acid and Carbon Monoxide on Metal Electrodes

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

Feaster, Jeremy T.; Shi, Chuan; Cave, Etosha R.

Increases in energy demand and in chemical production, together with the rise in CO 2 levels in the atmosphere, motivate the development of renewable energy sources. Electrochemical CO 2 reduction to fuels and chemicals is an appealing alternative to traditional pathways to fuels and chemicals due to its intrinsic ability to couple to solar and wind energy sources. Formate (HCOO –) is a key chemical for many industries; however, greater understanding is needed regarding the mechanism and key intermediates for HCOO – production. This work reports a joint experimental and theoretical investigation of the electrochemical reduction of CO 2 tomore » HCOO – on polycrystalline Sn surfaces, which have been identified as promising catalysts for selectively producing HCOO –. Our results show that Sn electrodes produce HCOO –, carbon monoxide (CO), and hydrogen (H 2) across a range of potentials and that HCOO – production becomes favored at potentials more negative than –0.8 V vs RHE, reaching a maximum Faradaic efficiency of 70% at –0.9 V vs RHE. Scaling relations for Sn and other transition metals are examined using experimental current densities and density functional theory (DFT) binding energies. While *COOH was determined to be the key intermediate for CO production on metal surfaces, we suggest that it is unlikely to be the primary intermediate for HCOO – production. Instead, *OCHO is suggested to be the key intermediate for the CO 2RR to HCOO – transformation, and Sn’s optimal *OCHO binding energy supports its high selectivity for HCOO –. Lastly, these results suggest that oxygen-bound intermediates are critical to understand the mechanism of CO 2 reduction to HCOO – on metal surfaces.« less

Mechanism of oxygen reduction reaction on Pt(111) in alkaline solution: Importance of chemisorbed water on surface

DOE PAGES

Liu, Shizhong; White, Michael G.; Liu, Ping

2016-06-30

Here, we report a detailed mechanistic study of the oxygen reduction reaction (ORR) on Pt(111) in alkaline solution, combining density functional theory and kinetic Monte Carlo simulations. A complex reaction network including four possible pathways via either 2e – or 4e – transfer is established and is able to reproduce the experimental measured polarization curve at both low- and high-potential regions. Our results show that it is essential to account for solvation by water and the dynamic coverage of *OH to describe the reaction kinetics well. In addition, a chemisorbed water (*H 2O)-mediated mechanism including 4e – transfers is identified,more » where the reduction steps via *H 2O on the surface are potential-independent and only the final removal of *OH from the surface in the form of OH –(aq) contributes to the current. For the ORR in alkaline solutions, such a mechanism is more competitive than the associative and dissociative mechanisms typically used to describe the ORR in acid solution. Finally, *OH and **O 2 intermediates are found to be critically important for tuning the ORR activity of Pt in alkaline solution. To enhance the activity, the binding of Pt should be tuned in such a way that *OH binding is weak enough to release more surface sites under working conditions, while **O 2 binding is strong enough to enable the ORR via the 4e – transfer mechanism.« less

New barrierless copper-alloy film for future applications

NASA Astrophysics Data System (ADS)

Lin, Chon-Hsin Lin

2015-09-01

Since Cu metallization results in a conductivity and an electromigration resistance greater than those of Al, it has become popular for making Si-based interconnects for numerous devices in the field of microelectronics. Following the current trend of miniaturization required for most electronic components, there is a greater need for further size reduction in Si-based devices. The most critical side effect of size reduction is the increase in electronic scattering and resistivity when the barrier-layer thickness is further reduced. To explore advanced Cu-metallization methods and to develop a more economical manufacturing process for Cu-alloy films, the development of Cu materials having better quality and higher thermal stability becomes imperative for the metallization and annealing processes. For this purpose, we first fabricated Cu(GeNx) films and examined their thermal stability and electrical reliability after either cyclic or isothermal annealing. The excellent thermal and electrical properties make these new Cu-alloy films highly promising for applications that require more reliable and inexpensive copper interconnects. In this study, we fabricated Cu alloy films by doping a minute amount of Ge or GeNx, respectively, into the Cu films via barrierless Cu metallization, an inexpensive manufacturing method. Using these newly fabricated alloy films, we were able to eliminate or at least substantially reduce the detrimental interaction between the alloy and the barrierless Si substrate. The Cu(GeNx) films also exhibited high thermal stability, low resistivity and leakage current, and long time-dependent dielectric breakdown (TDDB) lifetimes, making such novel films a candidate for high-quality, economical, and more reliable Cu interconnects.

Lead poisoning and the deceptive recovery of the critically endangered California condor

PubMed Central

Finkelstein, Myra E.; Doak, Daniel F.; George, Daniel; Burnett, Joe; Brandt, Joseph; Church, Molly; Grantham, Jesse; Smith, Donald R.

2012-01-01

Endangered species recovery programs seek to restore populations to self-sustaining levels. Nonetheless, many recovering species require continuing management to compensate for persistent threats in their environment. Judging true recovery in the face of this management is often difficult, impeding thorough analysis of the success of conservation programs. We illustrate these challenges with a multidisciplinary study of one of the world’s rarest birds—the California condor (Gymnogyps californianus). California condors were brought to the brink of extinction, in part, because of lead poisoning, and lead poisoning remains a significant threat today. We evaluated individual lead-related health effects, the efficacy of current efforts to prevent lead-caused deaths, and the consequences of any reduction in currently intensive management actions. Our results show that condors in California remain chronically exposed to harmful levels of lead; 30% of the annual blood samples collected from condors indicate lead exposure (blood lead ≥ 200 ng/mL) that causes significant subclinical health effects, measured as >60% inhibition of the heme biosynthetic enzyme δ-aminolevulinic acid dehydratase. Furthermore, each year, ∼20% of free-flying birds have blood lead levels (≥450 ng/mL) that indicate the need for clinical intervention to avert morbidity and mortality. Lead isotopic analysis shows that lead-based ammunition is the principle source of lead poisoning in condors. Finally, population models based on condor demographic data show that the condor’s apparent recovery is solely because of intensive ongoing management, with the only hope of achieving true recovery dependent on the elimination or substantial reduction of lead poisoning rates. PMID:22733770

The Effect of a Reduction in Microbial Diversity on Greenhouse Gas Production in Alaskan Tundra Soils.

NASA Astrophysics Data System (ADS)

Wagner, R.; Oechel, W. C.; Lipson, D.

2017-12-01

Atmospheric methane accounts for 20% of the warming potential of all greenhouse gases, has increased by 150% since pre-industrial times, and has the potential to double again over the next century. Microbially mediated CH4 emissions from natural wetlands represent the highest uncertainty in relative contributions to atmospheric CH4 levels of all CH4 sources, with Arctic wetlands currently experiencing twice the rate of warming as the rest of the planet. Notwithstanding the central role that the soil microbial community plays, and the high uncertainty in CH4 emissions from this ecosystem, surprisingly little research has been done to directly connect the microbial community structure to methane production rates. This is especially disconcerting given that most current CH4 emission models completely neglect microbial characteristics, despite the fact that the soil microbial community is predicted to be heavily impacted by a changing climate. Here, the effect of an artificial reduction in soil microbial α-diversity was investigated with regard to methane production and respiration rates. The microbial community was serially diluted followed by re-inoculation of sterilized Arctic soils in a mesocosm experiment. Methane production and respiration rates were measured, metagenomic sequencing was performed to determine microbial community diversity measures, and the effect of the oxidation state of iron was investigated. Preliminary results indicate that microbial communities with reduced α-diversity have lowered respiration rates in these soils. Analyses are ongoing and are expected to provide critical observations linking the role of soil microbial community diversity and greenhouse gas production in Arctic tundra ecosystems.

Lead poisoning and the deceptive recovery of the critically endangered California condor.

PubMed

Finkelstein, Myra E; Doak, Daniel F; George, Daniel; Burnett, Joe; Brandt, Joseph; Church, Molly; Grantham, Jesse; Smith, Donald R

2012-07-10

Endangered species recovery programs seek to restore populations to self-sustaining levels. Nonetheless, many recovering species require continuing management to compensate for persistent threats in their environment. Judging true recovery in the face of this management is often difficult, impeding thorough analysis of the success of conservation programs. We illustrate these challenges with a multidisciplinary study of one of the world's rarest birds-the California condor (Gymnogyps californianus). California condors were brought to the brink of extinction, in part, because of lead poisoning, and lead poisoning remains a significant threat today. We evaluated individual lead-related health effects, the efficacy of current efforts to prevent lead-caused deaths, and the consequences of any reduction in currently intensive management actions. Our results show that condors in California remain chronically exposed to harmful levels of lead; 30% of the annual blood samples collected from condors indicate lead exposure (blood lead ≥ 200 ng/mL) that causes significant subclinical health effects, measured as >60% inhibition of the heme biosynthetic enzyme δ-aminolevulinic acid dehydratase. Furthermore, each year, ∼20% of free-flying birds have blood lead levels (≥450 ng/mL) that indicate the need for clinical intervention to avert morbidity and mortality. Lead isotopic analysis shows that lead-based ammunition is the principle source of lead poisoning in condors. Finally, population models based on condor demographic data show that the condor's apparent recovery is solely because of intensive ongoing management, with the only hope of achieving true recovery dependent on the elimination or substantial reduction of lead poisoning rates.

Navy Nurse Corps manpower management model.

PubMed

Kinstler, Daniel P; Johnson, Raymond W; Richter, Anke; Kocher, Kathryn

2008-01-01

The Navy Nurse Corps is part of a team of professionals that provides high quality, economical health care to approximately 700,000 active duty Navy and Marine Corps members, as well as 2.6 million retired and family members. Navy Nurse Corps manpower management efficiency is critical to providing this care. This paper aims to focus on manpower planning in the Navy Nurse Corps. The Nurse Corps manages personnel primarily through the recruitment process, drawing on multiple hiring sources. Promotion rates at the lowest two ranks are mandated, but not at the higher ranks. Retention rates vary across pay grades. Using these promotion and attrition rates, a Markov model was constructed to model the personnel flow of junior nurse corps officers. Hiring sources were shown to have a statistically significant effect on promotion and retention rates. However, these effects were not found to be practically significant in the Markov model. Only small improvements in rank imbalances are possible given current recruiting guidelines. Allowing greater flexibility in recruiting practices, fewer recruits would generate a 25 percent reduction in rank imbalances, but result in understaffing. Recruiting different ranks at entry would generate a 65 percent reduction in rank imbalances without understaffing issues. Policies adjusting promotion and retention rates are more powerful in controlling personnel flows than adjusting hiring sources. These policies are the only means for addressing the fundamental sources of rank imbalances in the Navy Nurse Corps arising from current manpower guidelines. The paper shows that modeling to improve manpower management may enable the Navy Nurse Corps to more efficiently fulfill its mandate for high-quality healthcare.

Poverty reduction and equity benefits of introducing or scaling up measles, rotavirus and pneumococcal vaccines in low-income and middle-income countries: a modelling study.

PubMed

Riumallo-Herl, Carlos; Chang, Angela Y; Clark, Samantha; Constenla, Dagna; Clark, Andrew; Brenzel, Logan; Verguet, Stéphane

2018-01-01

Beyond their impact on health, vaccines can lead to large economic benefits. While most economic evaluations of vaccines have focused on the health impact of vaccines at a national scale, it is critical to understand how their impact is distributed along population subgroups. We build a financial risk protection model to evaluate the impact of immunisation against measles, severe pneumococcal disease and severe rotavirus for birth cohorts vaccinated over 2016-2030 for three scenarios in 41 Gavi-eligible countries: no immunisation, current immunisation coverage forecasts and the current immunisation coverage enhanced with funding support. We distribute modelled disease cases per socioeconomic group and derive the number of cases of: (1) catastrophic health costs (CHCs) and (2) medical impoverishment. In the absence of any vaccine coverage, the number of CHC cases attributable to measles, severe pneumococcal disease and severe rotavirus would be approximately 18.9 million, 6.6 million and 2.2 million, respectively. Expanding vaccine coverage would reduce this number by up to 90%, 30% and 40% in each case. More importantly, we find a higher share of CHC incidence among the poorest quintiles who consequently benefit more from vaccine expansion. Our findings contribute to the understanding of how vaccines can have a broad economic impact. In particular, we find that immunisation programmes can reduce the proportion of households facing catastrophic payments from out-of-pocket health expenses, mainly in lower socioeconomic groups. Thus, vaccines could have an important role in poverty reduction.

Epitaxy versus oriented heterogeneous nucleation of organic crystals on ionic substrates

NASA Astrophysics Data System (ADS)

Sarma, K. R.; Shlichta, P. J.; Wilcox, W. R.; Lefever, R. A.

1997-04-01

It is plausible to assume that epitaxy is a special case of heterogeneous nucleation in which a restrictive crystallographic relationship exists between substrate and deposit orientations. This would mean that epitaxial substrates should always induce a perceptible reduction in the critical supercooling for nucleation of the deposit. To test this hypothesis, the critical supercoolings of six organic compounds were measured on glass and 11 single-crystal cleaved substrates including (0001) graphite, (001) mica, (111) BaF 2, SrF 2, and CaF 2, and (100) KCl, KBr, KI, NaCl, NaF, and LiF. Reductions in supercooling (with reference to glass substrates) were checked many times for repeatability and reproducibility and shown in almost all cases to have a standard deviation of 1 C or less. Acetanilide, benzoic acid, and p-bromochlorobenzene showed a wide range of supercooling reductions and were oriented on all crystalline substrates. Naphthalene and p-dibromobenzene showed only slight supercooling reductions but were oriented on all substrates, including glass. Benzil showed strong supercooling reductions only for mica and KI but was oriented not only in these cases but also with KI, BaF 2, CaF 2, and graphite. There was little correlation between degree of lattice match and either supercooling reduction or degree of preferred orientation. These results suggest that, for the systems and geometry studied, forces such as molecular dipole binding and growth anisotropy had a stronger effect than lattice match.

Effects of soil oxidation-reduction conditions on internal oxygen transport, root aeration, and growth of wetland plants

Treesearch

S.R. Pezeshki; R.D. DeLaune

2000-01-01

Characterization of hydric soils and the relationship between soil oxidation-reduction processes and wetland plant distribution are critical to the identification and delineation of wetlands and to our understanding of soil processes and plant functioning in wetland ecosystems. However, the information on the relationship between flood response of wetland plants and...

SparseCT: interrupted-beam acquisition and sparse reconstruction for radiation dose reduction

NASA Astrophysics Data System (ADS)

Koesters, Thomas; Knoll, Florian; Sodickson, Aaron; Sodickson, Daniel K.; Otazo, Ricardo

2017-03-01

State-of-the-art low-dose CT methods reduce the x-ray tube current and use iterative reconstruction methods to denoise the resulting images. However, due to compromises between denoising and image quality, only moderate dose reductions up to 30-40% are accepted in clinical practice. An alternative approach is to reduce the number of x-ray projections and use compressed sensing to reconstruct the full-tube-current undersampled data. This idea was recognized in the early days of compressed sensing and proposals for CT dose reduction appeared soon afterwards. However, no practical means of undersampling has yet been demonstrated in the challenging environment of a rapidly rotating CT gantry. In this work, we propose a moving multislit collimator as a practical incoherent undersampling scheme for compressed sensing CT and evaluate its application for radiation dose reduction. The proposed collimator is composed of narrow slits and moves linearly along the slice dimension (z), to interrupt the incident beam in different slices for each x-ray tube angle (θ). The reduced projection dataset is then reconstructed using a sparse approach, where 3D image gradients are employed to enforce sparsity. The effects of the collimator slits on the beam profile were measured and represented as a continuous slice profile. SparseCT was tested using retrospective undersampling and compared against commercial current-reduction techniques on phantoms and in vivo studies. Initial results suggest that SparseCT may enable higher performance than current-reduction, particularly for high dose reduction factors.

Regional drought-induced reduction in the biomass carbon sink of Canada's boreal forests.

PubMed

Ma, Zhihai; Peng, Changhui; Zhu, Qiuan; Chen, Huai; Yu, Guirui; Li, Weizhong; Zhou, Xiaolu; Wang, Weifeng; Zhang, Wenhua

2012-02-14

The boreal forests, identified as a critical "tipping element" of the Earth's climate system, play a critical role in the global carbon budget. Recent findings have suggested that terrestrial carbon sinks in northern high-latitude regions are weakening, but there has been little observational evidence to support the idea of a reduction of carbon sinks in northern terrestrial ecosystems. Here, we estimated changes in the biomass carbon sink of natural stands throughout Canada's boreal forests using data from long-term forest permanent sampling plots. We found that in recent decades, the rate of biomass change decreased significantly in western Canada (Alberta, Saskatchewan, and Manitoba), but there was no significant trend for eastern Canada (Ontario and Quebec). Our results revealed that recent climate change, and especially drought-induced water stress, is the dominant cause of the observed reduction in the biomass carbon sink, suggesting that western Canada's boreal forests may become net carbon sources if the climate change-induced droughts continue to intensify.

40 CFR 467.42 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology currently available. [Reserved] 467.42 Section 467.42 Protection of Environment ENVIRONMENTAL PROTECTION... application of the best practicable control technology currently available. [Reserved] ...

Forecasting the viability of sea turtle eggs in a warming world.

PubMed

Pike, David A

2014-01-01

Animals living in tropical regions may be at increased risk from climate change because current temperatures at these locations already approach critical physiological thresholds. Relatively small temperature increases could cause animals to exceed these thresholds more often, resulting in substantial fitness costs or even death. Oviparous species could be especially vulnerable because the maximum thermal tolerances of incubating embryos is often lower than adult counterparts, and in many species mothers abandon the eggs after oviposition, rendering them immobile and thus unable to avoid extreme temperatures. As a consequence, the effects of climate change might become evident earlier and be more devastating for hatchling production in the tropics. Loggerhead sea turtles (Caretta caretta) have the widest nesting range of any living reptile, spanning temperate to tropical latitudes in both hemispheres. Currently, loggerhead sea turtle populations in the tropics produce nearly 30% fewer hatchlings per nest than temperate populations. Strong correlations between empirical hatching success and habitat quality allowed global predictions of the spatiotemporal impacts of climate change on this fitness trait. Under climate change, many sea turtle populations nesting in tropical environments are predicted to experience severe reductions in hatchling production, whereas hatching success in many temperate populations could remain unchanged or even increase with rising temperatures. Some populations could show very complex responses to climate change, with higher relative hatchling production as temperatures begin to increase, followed by declines as critical physiological thresholds are exceeded more frequently. Predicting when, where, and how climate change could impact the reproductive output of local populations is crucial for anticipating how a warming world will influence population size, growth, and stability.

Weakest students benefit most from a customized educational experience for Generation Y students.

PubMed

Nalliah, Romesh P; Allareddy, Veerasathpurush

2014-01-01

Most current dental students were born in the 1980s and 1990s and are defined as Generation Y (Gen Y). The authors developed a customized educational experience that brought together some characteristics of Gen Y and the objective of this educational experience was to develop the critical thinking skills of Gen Y students. The objective of the current study is to evaluate outcomes from pre-session and post-session tests. Additionally, we wanted to integrate aspects of team-based learning, self-directed learning and peer-to-peer teaching as a means of reducing the need for intense faculty supervision but maintain positive educational outcomes. Single bitewing x-ray was displayed and informal class discussion was facilitated by a Senior Tutor. A list of questions and concepts that needed to be understood more clearly was made. Student groups self allocated research tasks to members. After conducting research, students presented to class and faculty facilitated discussions aiming to foster critical thinking and identify what information needed to be more thoroughly understood. Pre-session and post-session tests were conducted and compared. Students who scored below 85% in their pre-session test improved their score in the post-session test by a mean of 9.5 points (p = 0.02). Those who scored above 95% in their pre-session test scored less in the post-session test (mean reduction of 6.31 points, p = 0.001). Findings from this study demonstrate that the weakest students in the class (those who scored below 85% correct in the pre-session test) benefitted most from this unique educational experience.

Evaluation of variability and quality control procedures for a receptor-binding assay for paralytic shellfish poisoning toxins.

PubMed

Ruberu, S R; Langlois, G W; Masuda, M; Perera, S Kusum

2012-01-01

The receptor-binding assay (RBA) method for determining saxatoxin (STX) and its numerous analogues, which cause paralytic shellfish poisoning (PSP) in humans, was evaluated in a single laboratory study. Each step of the assay preparation procedure including the performance of the multi-detector TopCount® instrument was evaluated for its contribution to method variability. The overall inherent RBA variability was determined to be 17%. Variability within the 12 detectors was observed; however, there was no reproducible pattern in detector performance. This observed variability among detectors could be attributed to other factors, such as pipetting errors. In an attempt to reduce the number of plates rejected due to excessive variability in the method's quality control parameters, a statistical approach was evaluated using either Grubbs' test or the Student's t-test for rejecting outliers in the measurement of triplicate wells. This approach improved the ratio of accepted versus rejected plates, saving cost and time for rerunning the assay. However, the potential reduction in accuracy and the lack of improvement in precision suggests caution when using this approach. The current study has recommended an alternate quality control procedure for accepting or rejecting plates in place of the criteria currently used in the published assay, or the alternative of outlier testing. The recommended procedure involves the development of control charts to monitor the critical parameters identified in the published method (QC sample, EC₅₀, slope of calibration curve), with the addition of a fourth critical parameter which is the top value (100% binding) of the calibration curve.

Breaking Computational Barriers: Real-time Analysis and Optimization with Large-scale Nonlinear Models via Model Reduction

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

Carlberg, Kevin Thomas; Drohmann, Martin; Tuminaro, Raymond S.

2014-10-01

Model reduction for dynamical systems is a promising approach for reducing the computational cost of large-scale physics-based simulations to enable high-fidelity models to be used in many- query (e.g., Bayesian inference) and near-real-time (e.g., fast-turnaround simulation) contexts. While model reduction works well for specialized problems such as linear time-invariant systems, it is much more difficult to obtain accurate, stable, and efficient reduced-order models (ROMs) for systems with general nonlinearities. This report describes several advances that enable nonlinear reduced-order models (ROMs) to be deployed in a variety of time-critical settings. First, we present an error bound for the Gauss-Newton with Approximatedmore » Tensors (GNAT) nonlinear model reduction technique. This bound allows the state-space error for the GNAT method to be quantified when applied with the backward Euler time-integration scheme. Second, we present a methodology for preserving classical Lagrangian structure in nonlinear model reduction. This technique guarantees that important properties--such as energy conservation and symplectic time-evolution maps--are preserved when performing model reduction for models described by a Lagrangian formalism (e.g., molecular dynamics, structural dynamics). Third, we present a novel technique for decreasing the temporal complexity --defined as the number of Newton-like iterations performed over the course of the simulation--by exploiting time-domain data. Fourth, we describe a novel method for refining projection-based reduced-order models a posteriori using a goal-oriented framework similar to mesh-adaptive h -refinement in finite elements. The technique allows the ROM to generate arbitrarily accurate solutions, thereby providing the ROM with a 'failsafe' mechanism in the event of insufficient training data. Finally, we present the reduced-order model error surrogate (ROMES) method for statistically quantifying reduced- order-model errors. This enables ROMs to be rigorously incorporated in uncertainty-quantification settings, as the error model can be treated as a source of epistemic uncertainty. This work was completed as part of a Truman Fellowship appointment. We note that much additional work was performed as part of the Fellowship. One salient project is the development of the Trilinos-based model-reduction software module Razor , which is currently bundled with the Albany PDE code and currently allows nonlinear reduced-order models to be constructed for any application supported in Albany. Other important projects include the following: 1. ROMES-equipped ROMs for Bayesian inference: K. Carlberg, M. Drohmann, F. Lu (Lawrence Berkeley National Laboratory), M. Morzfeld (Lawrence Berkeley National Laboratory). 2. ROM-enabled Krylov-subspace recycling: K. Carlberg, V. Forstall (University of Maryland), P. Tsuji, R. Tuminaro. 3. A pseudo balanced POD method using only dual snapshots: K. Carlberg, M. Sarovar. 4. An analysis of discrete v. continuous optimality in nonlinear model reduction: K. Carlberg, M. Barone, H. Antil (George Mason University). Journal articles for these projects are in progress at the time of this writing.« less

Can You Hear That Peak? Utilization of Auditory and Visual Feedback at Peak Limb Velocity.

PubMed

Loria, Tristan; de Grosbois, John; Tremblay, Luc

2016-09-01

At rest, the central nervous system combines and integrates multisensory cues to yield an optimal percept. When engaging in action, the relative weighing of sensory modalities has been shown to be altered. Because the timing of peak velocity is the critical moment in some goal-directed movements (e.g., overarm throwing), the current study sought to test whether visual and auditory cues are optimally integrated at that specific kinematic marker when it is the critical part of the trajectory. Participants performed an upper-limb movement in which they were required to reach their peak limb velocity when the right index finger intersected a virtual target (i.e., a flinging movement). Brief auditory, visual, or audiovisual feedback (i.e., 20 ms in duration) was provided to participants at peak limb velocity. Performance was assessed primarily through the resultant position of peak limb velocity and the variability of that position. Relative to when no feedback was provided, auditory feedback significantly reduced the resultant endpoint variability of the finger position at peak limb velocity. However, no such reductions were found for the visual or audiovisual feedback conditions. Further, providing both auditory and visual cues concurrently also failed to yield the theoretically predicted improvements in endpoint variability. Overall, the central nervous system can make significant use of an auditory cue but may not optimally integrate a visual and auditory cue at peak limb velocity, when peak velocity is the critical part of the trajectory.

Evaluation of a steady-state test of foam stability

NASA Astrophysics Data System (ADS)

Hutzler, Stefan; Lösch, Dörte; Carey, Enda; Weaire, Denis; Hloucha, Matthias; Stubenrauch, Cosima

2011-02-01

We have evaluated a steady-state test of foam stability, based on the steady-state height of a foam produced by a constant velocity of gas flow. This test is mentioned in the book by Bikerman [Foams, Springer, Berlin, 1973] and an elementary theory was developed for it by Verbist et al. [J. Phys. Condens. Matter 8 (1996) p. 3715]. For the study, we used an aqueous solution of the cationic surfactant dodecyl trimethylammonium bromide, C12TAB, at a concentration of two times the critical micelle concentration (2 cmc). During foam generation, bubbles collapse at the top of the column which, in turn, eventually counterbalances the rate of bubble production at the bottom. The resulting balance can be described mathematically by an appropriate solution of the foam drainage equation under specified boundary conditions. Our experimental findings are in agreement with the theoretical predictions of a diverging foam height at a critical gas velocity and a finite foam height in the limit of zero velocity. We identify a critical liquid fraction below which a foam is unstable as an important parameter for characterizing foam stability. Furthermore, we deduce an effective viscosity of the liquid which flows through the foam. Currently unexplained are two experimental observations, namely sudden changes of the steady-state foam height in experiments that run over several hours and a reduction in foam height once an overflow of the foam from the containing vessel has occurred.

Reminiscence and adaptation to critical life events in older adults with mild to moderate depressive symptoms.

PubMed

Korte, Jojanneke; Bohlmeijer, Ernst T; Westerhof, Gerben J; Pot, Anne Margriet; Pot, Anne M

2011-07-01

The role of reminiscence as a way of adapting to critical life events and chronic medical conditions was investigated in older adults with mild to moderate depressive symptoms. Reminiscence is the (non)volitional act or process of recollecting memories of one's self in the past. 171 Dutch older adults with a mean age of 64 years (SD = 7.4) participated in this study. All of them had mild to moderate depressive symptoms. Participants completed measures on critical life events, chronic medical conditions, depressive symptoms, symptoms of anxiety and satisfaction with life. The reminiscence functions included were: identity, problem solving, bitterness revival and boredom reduction. Critical life events were positively correlated with identity and problem solving. Bitterness revival and boredom reduction were both positively correlated with depressive and anxiety symptoms, and negatively to satisfaction with life. Problem solving had a negative relation with anxiety symptoms. When all the reminiscence functions were included, problem solving was uniquely associated with symptoms of anxiety, and bitterness revival was uniquely associated with depressive symptoms and satisfaction with life. Interestingly, problem solving mediated the relation of critical life events with anxiety. This study corroborates the theory that reminiscence plays a role in coping with critical life events, and thereby maintaining mental health. Furthermore, it is recommended that therapists focus on techniques which reduce bitterness revival in people with depressive symptoms, and focus on problem-solving reminiscences among people with anxiety symptoms.

Effects of spatial gradients in thermophysical properties on the topology of turbulence in heated channel flow of supercritical fluids

NASA Astrophysics Data System (ADS)

Azih, Chukwudi; Yaras, Metin I.

2018-01-01

The current literature suggests that large spatial gradients of thermophysical properties, which occur in the vicinity of the pseudo-critical thermodynamic state, may result in significant variations in forced-convection heat transfer rates. Specifically, these property gradients induce inertia- and buoyancy-driven phenomena that may enhance or deteriorate the turbulence-dominated heat convection process. Through direct numerical simulations, the present study investigates the role of coherent flow structures in channel geometries for non-buoyant and buoyant flows of supercritical water, with buoyant configurations involving wall-normal oriented gravitational acceleration and downstream-oriented gravitational acceleration. This sequence of simulations enables the evaluation of the relative contributions of inertial and buoyancy phenomena to heat transfer variations. In these simulations, the state of the working fluid is in the vicinity of the pseudo-critical point. The uniform wall heat flux and the channel mass flux are specified such that the heat to mass flux ratio is 3 kJ/kg, with an inflow Reynolds number of 12 000 based on the channel hydraulic diameter, the area-averaged inflow velocity, and fluid properties evaluated at the bulk temperature and pressure of the inflow plane. In the absence of buoyancy forces, notable reductions in the density and viscosity in close proximity of the heated wall are observed to promote generation of small-scale vortices, with resultant breakdown into smaller scales as they interact with preexisting larger near-wall vortices. This interaction results in a reduction in the overall thermal mixing at particular wall-normal regions of the channel. Under the influence of wall-normal gravitational acceleration, the wall-normal density gradients are noted to enhance ejection motions due to baroclinic vorticity generation on the lower wall, thus providing additional wall-normal thermal mixing. Along the upper wall, the same mechanism generates streamwise vorticity of the opposing sense of rotation in the close vicinity to the respective legs of the hairpin vortices causing a net reduction in thermal mixing. Finally, in the case of downstream-oriented gravitational acceleration, baroclinic vorticity generation as per spanwise density gradients causes additional wall-normal thermal mixing by promoting larger-scale ejection and sweep motions.

Glucagon-Like Peptide 1 and Its Analogs Act in the Dorsal Raphe and Modulate Central Serotonin to Reduce Appetite and Body Weight.

PubMed

Anderberg, Rozita H; Richard, Jennifer E; Eerola, Kim; López-Ferreras, Lorena; Banke, Elin; Hansson, Caroline; Nissbrandt, Hans; Berqquist, Filip; Gribble, Fiona M; Reimann, Frank; Wernstedt Asterholm, Ingrid; Lamy, Christophe M; Skibicka, Karolina P

2017-04-01

Glucagon-like peptide 1 (GLP-1) and serotonin play critical roles in energy balance regulation. Both systems are exploited clinically as antiobesity strategies. Surprisingly, whether they interact in order to regulate energy balance is poorly understood. Here we investigated mechanisms by which GLP-1 and serotonin interact at the level of the central nervous system. Serotonin depletion impaired the ability of exendin-4, a clinically used GLP-1 analog, to reduce body weight in rats, suggesting that serotonin is a critical mediator of the energy balance impact of GLP-1 receptor (GLP-1R) activation. Serotonin turnover and expression of 5-hydroxytryptamine (5-HT) 2A (5-HT 2A ) and 5-HT 2C serotonin receptors in the hypothalamus were altered by GLP-1R activation. We demonstrate that the 5-HT 2A , but surprisingly not the 5-HT 2C , receptor is critical for weight loss, anorexia, and fat mass reduction induced by central GLP-1R activation. Importantly, central 5-HT 2A receptors are also required for peripherally injected liraglutide to reduce feeding and weight. Dorsal raphe (DR) harbors cell bodies of serotonin-producing neurons that supply serotonin to the hypothalamic nuclei. We show that GLP-1R stimulation in DR is sufficient to induce hypophagia and increase the electrical activity of the DR serotonin neurons. Finally, our results disassociate brain metabolic and emotionality pathways impacted by GLP-1R activation. This study identifies serotonin as a new critical neural substrate for GLP-1 impact on energy homeostasis and expands the current map of brain areas impacted by GLP-1R activation. © 2017 by the American Diabetes Association.

Evaluation of cardiovascular risks of spaceflight does not support the NASA bioastronautics critical path roadmap.

PubMed

Convertino, Victor A; Cooke, William H

2005-09-01

Occurrence of serious cardiac dysrhythmias and diminished cardiac and vascular function are the primary cardiovascular risks of spaceflight identified in the 2005 NASA Bioastronautics Critical Path Roadmap. A review of the literature was conducted on experimental results and observational data obtained from spaceflight and relevant ground simulation studies that addressed occurrence of cardiac dysrhythmias, cardiac contractile and vascular function, manifestation of asymptomatic cardiovascular disease, orthostatic intolerance, and response to exercise stress. Based on data from astronauts who have flown in space, there is no compelling experimental evidence to support significant occurrence of cardiac dysrhythmias, manifestation of asymptomatic cardiovascular disease, or reduction in myocardial contractile function. Although there are post-spaceflight data that demonstrate lower peripheral resistance in astronauts who become presyncopal compared with non-presyncopal astronauts, it is not clear that these differences are the result of decreased vascular function. However, the evidence of postflight orthostatic intolerance and reduced exercise capacity is well substantiated by both spaceflight and ground experiments. Although attenuation of baroreflex function(s) may contribute to postflight orthostatic instability, a primary mechanism of orthostatic intolerance and reduced exercise capacity is reduced end-diastolic and stroke volume associated with lower blood volumes and consequent cardiac remodeling. Data from the literature on the current population of astronauts support the notion that the primary cardiovascular risks of spaceflight are compromised hemodynamic responses to central hypovolemia resulting in reduced orthostatic tolerance and exercise capacity rather than occurrence of cardiac dysrhythmias, reduced cardiac contractile and vascular function, or manifestation of asymptomatic cardiovascular disease. These observations warrant a critical review and revision of the 2005 Bioastronautics Critical Path Roadmap.

Dynamics of aerospace vehicles

NASA Technical Reports Server (NTRS)

Schmidt, David K.

1991-01-01

The focus of this research was to address the modeling, including model reduction, of flexible aerospace vehicles, with special emphasis on models used in dynamic analysis and/or guidance and control system design. In the modeling, it is critical that the key aspects of the system being modeled be captured in the model. In this work, therefore, aspects of the vehicle dynamics critical to control design were important. In this regard, fundamental contributions were made in the areas of stability robustness analysis techniques, model reduction techniques, and literal approximations for key dynamic characteristics of flexible vehicles. All these areas are related. In the development of a model, approximations are always involved, so control systems designed using these models must be robust against uncertainties in these models.

Global Perspectives On Pediatric Cardiac Critical Care.

PubMed

Penny, Daniel J

2016-08-01

The objectives of this review are to discuss the global epidemiology of cardiovascular disease, emphasizing congenital heart disease; to discuss the concept of epidemiologic transition and its role in studying the evolving epidemiology of disease; and to assess and address the global burden of congenital heart disease including its prevention and treatment. MEDLINE and PubMed. Despite impressive reductions in mortality from congenital and acquired cardiovascular disease in high-income countries, these reductions have not been observed on a global scale. It will be necessary to continue our attempts to extend rational programs of care to middle- and low-income countries based on community empowerment, economics, and population health. The specialist in pediatric cardiac critical care can be a central driver of these programs.

Assessing Students' Critical Thinking Performance: Urging for Measurements Using Multi-Response Format

ERIC Educational Resources Information Center

Ku, Kelly Y. L.

2009-01-01

The current paper discusses ambiguities in critical thinking assessment. The paper first reviews the components of critical thinking. It then discusses the features and issues of commonly used critical thinking tests and to what extend they are made compatible to the conceptualization of critical thinking. The paper argues that critical thinking…

On-line and real-time diagnosis method for proton membrane fuel cell (PEMFC) stack by the superposition principle

NASA Astrophysics Data System (ADS)

Lee, Young-Hyun; Kim, Jonghyeon; Yoo, Seungyeol

2016-09-01

The critical cell voltage drop in a stack can be followed by stack defect. A method of detecting defective cell is the cell voltage monitoring. The other methods are based on the nonlinear frequency response. In this paper, the superposition principle for the diagnosis of PEMFC stack is introduced. If critical cell voltage drops exist, the stack behaves as a nonlinear system. This nonlinearity can explicitly appear in the ohmic overpotential region of a voltage-current curve. To detect the critical cell voltage drop, a stack is excited by two input direct test-currents which have smaller amplitude than an operating stack current and have an equal distance value from the operating current. If the difference between one voltage excited by a test current and the voltage excited by a load current is not equal to the difference between the other voltage response and the voltage excited by the load current, the stack system acts as a nonlinear system. This means that there is a critical cell voltage drop. The deviation from the value zero of the difference reflects the grade of the system nonlinearity. A simulation model for the stack diagnosis is developed based on the SPP, and experimentally validated.

40 CFR 427.102 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology currently available. 427.102 Section 427.102 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Vapor... reduction attainable by the application of the best practicable control technology currently available...

40 CFR 436.182 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... technology currently available. 436.182 Section 436.182 Protection of Environment ENVIRONMENTAL PROTECTION... degree of effluent reduction attainable by the application of the best practicable control technology... best practicable control technology currently available (BPT): (1) Discharges of process generated...

40 CFR 436.182 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... technology currently available. 436.182 Section 436.182 Protection of Environment ENVIRONMENTAL PROTECTION... degree of effluent reduction attainable by the application of the best practicable control technology... best practicable control technology currently available (BPT): (1) Discharges of process generated...

40 CFR 436.182 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... technology currently available. 436.182 Section 436.182 Protection of Environment ENVIRONMENTAL PROTECTION... degree of effluent reduction attainable by the application of the best practicable control technology... best practicable control technology currently available (BPT): (1) Discharges of process generated...

Effects of high-energy proton irradiation on the superconducting properties of Fe(Se,Te) thin films

NASA Astrophysics Data System (ADS)

Sylva, G.; Bellingeri, E.; Ferdeghini, C.; Martinelli, A.; Pallecchi, I.; Pellegrino, L.; Putti, M.; Ghigo, G.; Gozzelino, L.; Torsello, D.; Grimaldi, G.; Leo, A.; Nigro, A.; Braccini, V.

2018-05-01

In this paper we explore the effects of 3.5 MeV proton irradiation on Fe(Se,Te) thin films grown on CaF2. In particular, we carry out an experimental investigation with different irradiation fluences up to 7.30 · 1016 cm‑2 and different proton implantation depths, in order to clarify whether and to what extent the critical current is enhanced or suppressed, what are the effects of irradiation on the critical temperature, resistivity, and critical magnetic fields, and finally what is the role played by the substrate in this context. We find that the effect of irradiation on superconducting properties is generally small compared to the case of other iron-based superconductors. The irradiation effect is more evident on the critical current density Jc, while it is minor on the transition temperature Tc, normal state resistivity ρ, and on the upper critical field Hc2 up to the highest fluences explored in this work. In more detail, our analysis shows that when protons implant in the substrate far from the superconducting film, the critical current can be enhanced up to 50% of the pristine value at 7 T and 12 K; meanwhile, there is no appreciable effect on critical temperature and critical fields together with a slight decrease in resistivity. On the contrary, when the implantation layer is closer to the film–substrate interface, both critical current and temperature show a decrease accompanied by an enhancement of the resistivity and lattice strain. This result evidences that possible modifications induced by irradiation in the substrate may affect the superconducting properties of the film via lattice strain. The robustness of the Fe(Se,Te) system to irradiation-induced damage makes it a promising compound for the fabrication of magnets in high-energy accelerators.

Criticality and turbulence in a resistive magnetohydrodynamic current sheet

NASA Astrophysics Data System (ADS)

Klimas, Alexander J.; Uritsky, Vadim M.

2017-02-01

Scaling properties of a two-dimensional (2d) plasma physical current-sheet simulation model involving a full set of magnetohydrodynamic (MHD) equations with current-dependent resistivity are investigated. The current sheet supports a spatial magnetic field reversal that is forced through loading of magnetic flux containing plasma at boundaries of the simulation domain. A balance is reached between loading and annihilation of the magnetic flux through reconnection at the current sheet; the transport of magnetic flux from boundaries to current sheet is realized in the form of spatiotemporal avalanches exhibiting power-law statistics of lifetimes and sizes. We identify this dynamics as self-organized criticality (SOC) by verifying an extended set of scaling laws related to both global and local properties of the current sheet (critical susceptibility, finite-size scaling of probability distributions, geometric exponents). The critical exponents obtained from this analysis suggest that the model operates in a slowly driven SOC state similar to the mean-field state of the directed stochastic sandpile model. We also investigate multiscale correlations in the velocity field and find them numerically indistinguishable from certain intermittent turbulence (IT) theories. The results provide clues on physical conditions for SOC behavior in a broad class of plasma systems with propagating instabilities, and suggest that SOC and IT may coexist in driven current sheets which occur ubiquitously in astrophysical and space plasmas.

Criticality and turbulence in a resistive magnetohydrodynamic current sheet.

PubMed

Klimas, Alexander J; Uritsky, Vadim M

2017-02-01

Scaling properties of a two-dimensional (2d) plasma physical current-sheet simulation model involving a full set of magnetohydrodynamic (MHD) equations with current-dependent resistivity are investigated. The current sheet supports a spatial magnetic field reversal that is forced through loading of magnetic flux containing plasma at boundaries of the simulation domain. A balance is reached between loading and annihilation of the magnetic flux through reconnection at the current sheet; the transport of magnetic flux from boundaries to current sheet is realized in the form of spatiotemporal avalanches exhibiting power-law statistics of lifetimes and sizes. We identify this dynamics as self-organized criticality (SOC) by verifying an extended set of scaling laws related to both global and local properties of the current sheet (critical susceptibility, finite-size scaling of probability distributions, geometric exponents). The critical exponents obtained from this analysis suggest that the model operates in a slowly driven SOC state similar to the mean-field state of the directed stochastic sandpile model. We also investigate multiscale correlations in the velocity field and find them numerically indistinguishable from certain intermittent turbulence (IT) theories. The results provide clues on physical conditions for SOC behavior in a broad class of plasma systems with propagating instabilities, and suggest that SOC and IT may coexist in driven current sheets which occur ubiquitously in astrophysical and space plasmas.

Mapping the current–current correlation function near a quantum critical point

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

Prodan, Emil, E-mail: prodan@yu.edu; Bellissard, Jean

2016-05-15

The current–current correlation function is a useful concept in the theory of electron transport in homogeneous solids. The finite-temperature conductivity tensor as well as Anderson’s localization length can be computed entirely from this correlation function. Based on the critical behavior of these two physical quantities near the plateau–insulator or plateau–plateau transitions in the integer quantum Hall effect, we derive an asymptotic formula for the current–current correlation function, which enables us to make several theoretical predictions about its generic behavior. For the disordered Hofstadter model, we employ numerical simulations to map the current–current correlation function, obtain its asymptotic form near amore » critical point and confirm the theoretical predictions.« less

Significant long-term reduction in n-channel MESFET subthreshold leakage using ammonium-sulfide surface treated gates

NASA Technical Reports Server (NTRS)

Neudeck, P. G.; Carpenter, M. S.; Melloch, Michael R.; Cooper, James A., Jr.

1991-01-01

Ammonium-sulfide (NH4)2S treated gates have been employed in the fabrication of GaAs MESFETs that exhibit a remarkable reduction in subthreshold leakage current. A greater than 100-fold reduction in drain current minimum is observed due to a decrease in Schottky gate leakage. The electrical characteristics have remained stable for over a year during undesiccated storage at room temperature, despite the absence of passivation layers.