bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental determination of optimal clamping torque for AB-PEM Fuel cell
Authors: Ul Hassan Noor , Kilic Murat , Okumus Emin , Tunaboylu Bahadir , Soydan Ali Murat 
Published: April 2016

<span lang="EN-GB">Polymer electrolyte Membrane (PEM) fuel cell is an electrochemical device producing electricity by the reaction of hydrogen and oxygen without combustion. PEM fuel cell stack is provided with an appropriate clamping torque to prevent leakage of reactant gases and to minimize the contact resistance between gas diffusion media (GDL) and bipolar plates. GDL porous structure and gas permeability is directly affected by the compaction pressure which, consequently, drastically change the fuel cell performance. Various efforts were made to determine the optimal compaction pressure and pressure distributions through simulations and experimentation. Lower compaction pressure results in increase of contact resistance and also chances of leakage. On the other hand, higher compaction pressure decreases the contact resistance but also narrows down the diffusion path for mass transfer from gas channels to the catalyst layers, consequently, lowering cell performance. The optimal cell performance is related to the gasket thickness and compression pressure on GDL. Every stack has a unique assembly pressure due to differences in fuel cell components material and stack design. Therefore, there is still need to determine the optimal torque value for getting the optimal cell performance. This study has been carried out in continuation of deve­lopment of Air breathing PEM fuel cell for small Unmanned Aerial Vehicle (UAV) application. Compaction pressure at minimum contact resistance was determined and clamping torque value was calcu­la­ted accordingly. Single cell performance tests were performed at five different clamping torque values i.e 0.5, 1.0, 1.5, 2.0 and 2.5 N m, for achieving optimal cell per­formance. Clamping pressure distribution tests were also performed at these torque values to verify uniform pressure distribution at optimal torque value. Experimental and theoretical results were compared for making inferences about optimal cell perfor­man­ce. A clamp­ing torque value of 1.5 N m was determined experimentally to be the best for getting optimal performance as well as uniform pressure distribution for this specific fuel cell.</span>
Electrochemical study of doped LiFePO4 as a cathode material for lithium-ion battery
Authors: Chekannikov Andrey , Novikova Svetlana , Kulova Tatiana , Skundin Alexander , Yaroslavtsev Andrey 
Published: April 2016

<p class="PaperAbstract"><span lang="EN-US">LiFe<sub>1-x</sub>VxPO<sub>4</sub>/C (x= 0.01, 0.03, 0.05, 0.1) composites had been obtained by sol-gel method and characterized with the use of the XRD-analysis, SEM and charge/discharge tests. The doping was shown to result in decrease of electrode polarization, and correspondingly in capacity increase at high C-rates.</span></p>
Perfil epidemiológico do idoso: experiência de uma unidade de saúde do Programa de Saúde da Família em Curitiba
Authors: Lobo Gilmar Leão 
Published: April 2016

Pesquisas demonstram a questão gerontológica como a urgência do amanhã. Sendo assim, buscou-se determinar o perfil dos idosos da comunidade de Vila Torres, no município de Curitiba, com o intuito de se constatar o quadro agravante em que os mesmos se encontram. Após preenchimento do termo de consentimento livre e esclarecido, efetuou-se a apuração de dados vitais dos pacientes em questão, por meio de antropometria, miniavaliação nutricional, mini exame do estado mental, teste físico e revisão do prontuário eletrônico do período de 1 ano anterior a essa pesquisa (o qual fornece informações acerca de número de consultas, diagnósticos, medicação e confirmação de dados) e, então,verificou-se que: a) 72% dos examinados apresentaram pressão arterial elevada com ou sem tratamento,estando 64% dos mesmos tanto com alterações sistólicas quanto diastólicas; b) as alterações da pressão arterial estão diretamente relacionadas a mudanças do estado mental (demência); c) há um percentual elevado de demência em normotensos que compõem a faixa etária de 70 a 74 anos (4 casos, dentre os avaliados); d) sendo desfavorecida a condição socioeconômica dos pacientes, o nível de alterações da nutrição é mais elevado. Por esse motivo, nenhum dos que se submeteu à avaliação apresentou estado nutricional adequado, estando 83% deles em risco nutricional e 17% desnutridos (perceptível apenas pela miniavaliação do quadro alimentar); e) há o predomínio de mulheres sobre homens em todas as idades. Sendo observados, em proporção ainda maior do que na literatura, o comprometimento nutricional e a doença hipertensiva descontrolada, urge abordar tanto o controle da pressão arterial quanto o estado nutricional dos idosos dessa comunidade, por meio de promoção, prevenção, proteção e recuperação da saúde dos mesmos, além de melhor programação de ações sobre suas causas e seus riscos e danos.
A produção científica em MFC e APS e sua importância estratégica para o SUS
Authors: Wagner Hamilton Lima 
Published: April 2016

Dia a dia cresce a penetração da Medicina de Família e Comunidade, e com isto a produção científica dos médicos e profissionais que militam dentro da Atenção Primária à Saúde (APS). É deste trabalho e produção que a Revista Brasileira de Medicina de Família e Comunidade (RBMFC) se alimenta e cresce. Neste editorial queremos agradecer aos autores que tem contribuído para que esta nova revista se torne viável, e brevemente possa estar pleiteando a sua indexação as bases de dados nacionais e internacionais. Dentro desta meta é que as normas de publicação da revista têm se adequado, buscando obter o padrão necessário para a indexação. Para isto precisamos de um volume de artigos que estejam adequados às normas de publicação científica, que sejam inéditos e de boa qualidade. A regularidade das contribuições, o cumprimento dos prazos e o rigor editorial exigirão o esforço e a dedicação de todos nós, de forma a demonstrar que a MFC é uma especialidade inserida na atual produção de conhecimento na área da APS com padrão de excelência nacional e internacional. Surge agora um desafio a ser levado a todos os profissionais envolvidos . demonstrar o impacto da APS na construção do Sistema Único de Saúde (SUS) e seus resultados junto a população brasileira. É fundamental que os autores demonstrem como o trabalho dentro da filosofia da APS . eixo estruturante do SUS, e contraponto ao modelo hospitalocêntrico vigente, cria condições para a validação das ações desenvolvidas pelos governos brasileiros nos últimos anos. É fundamental que não ignoremos a reação dos que defendem modelo há pouco vigente, baseado nas especialidades focais e nos serviços hospitalares. Experimentamos, por muito tempo, pouco valor à APS, uma discreta condescendência e quase nenhum apoio aos profissionais que tentaram desenvolver um trabalho voltado aos problemas e as necessidades das comunidades. Em um momento seguinte, a MFC e a APS foram colocadas como proposta de atenção de baixo custo à população de baixa renda, demonstrando-se a falta de compreensão da força e da importância da especialidade horizontal . que é a MFC . e da proposta da APS como reestruturantes do sistema. No momento atual busca-se discutir o mercado de trabalho e alega-se uma maior efetividade das especialidades focais em relação à especialidade horizontal. É neste contexto que se insere a produção científica dos MFC e dos profissionais envolvidos em APS, como forma de demonstrar o impacto de nossas ações e a Sociedade Brasileira de Medicina de Família e Comunidade, através da RBMFC, deve reiterar quão importantes e definitivos somos para melhorar o acesso, a resolutividade e a satisfação da população. Neste editorial conclamamos a todos os nossos leitores e colaboradores a focarem suas pesquisas na busca de demonstrar os resultados das ações da MFC e da APS para consolidação do SUS e da especialidade como modelo de saúde que melhor atende as necessidades da população.
Doença de Lyme: diagnóstico e tratamento
Authors: Maluf Junior Ivan , Zahdi Mariana Ribas , Bonalumi Filho Aguinaldo , Cruz Cristina Rodrigues 
Published: April 2016

A doença de Lyme é uma infecção bacteriana sistêmica causada pela espiroqueta Borrelia burgdoferi e transmitida por carrapatos do gênero Ixodes e Amblyomma. Ela é doença endêmica em áreas de animais silvestres, carrapatos e florestas, sendo pouco relatada no Brasil. É a patologia mais comum transmitida por carrapatos. As manifestações clínicas iniciam-se com aparecimento de eritema migratório no local da picada, seguido de sintomas semelhantes ao da gripe. Com a evolução da doença, pode ocorrer acometimento dos sistemas nervoso central, cardiovascular, ocular e articulações.Odiagnóstico é feito pelas características clínicas, dados epidemiológicos e exames laboratoriais; já o tratamento é realizado com administração de antibióticos conforme o estágio da doença.
Major disruption of D″ beneath Alaska
Authors: Sun Daoyuan , Helmberger Don , Miller Meghan S. , Jackson Jennifer M. 
Published: April 2016

AbstractD″ represents one of the most dramatic thermal and compositional layers within our planet. In particular, global tomographic models display relatively fast patches at the base of the mantle along the circum‐Pacific which are generally attributed to slab debris. Such distinct patches interact with the bridgmanite (Br) to post‐bridgmanite (PBr) phase boundary to generate particularly strong heterogeneity at their edges. Most seismic observations for the D″ come from the lower mantle S wave triplication (Scd). Here we exploit the USArray waveform data to examine one of these sharp transitions in structure beneath Alaska. From west to east beneath Alaska, we observed three different characteristics in D″: (1) the western region with a strong Scd, requiring a sharp δVs = 2.5% increase; (2) the middle region with no clear Scd phases, indicating a lack of D″ (or thin Br‐PBr layer); and (3) the eastern region with strong Scd phase, requiring a gradient increase in δVs. To explain such strong lateral variation in the velocity structure, chemical variations must be involved. We suggest that the western region represents relatively normal mantle. In contrast, the eastern region is influenced by a relic slab that has subducted down to the lowermost mantle. In the middle region, we infer an upwelling structure that disrupts the Br‐PBr phase boundary. Such an interpretation is based upon a distinct pattern of travel time delays, waveform distortions, and amplitude patterns that reveal a circular‐shaped anomaly about 5° across which can be modeled synthetically as a plume‐like structure rising about 400 km high with a shear velocity reduction of ~5%, similar to geodynamic modeling predictions of upwellings.
Basin mass dynamic changes in China from GRACE based on a multibasin inversion method
Authors: Yi Shuang , Wang Qiuyu , Sun Wenke 
Published: April 2016

AbstractComplex landforms, miscellaneous climates, and enormous populations have influenced various geophysical phenomena in China, which range from water depletion in the underground to retreating glaciers on high mountains and have attracted abundant scientific interest. This paper, which utilizes gravity observations during 2003–2014 from the Gravity Recovery and Climate Experiment (GRACE), intends to comprehensively estimate the mass status in 16 drainage basins in the region. We propose a multibasin inversion method that features resistance to stripe noise and an ability to alleviate signal attenuation from the truncation and smoothing of GRACE data. The results show both positive and negative trends. Tremendous mass accumulation has occurred from the Tibetan Plateau (12.1 ± 0.6 Gt/yr) to the Yangtze River (7.7 ± 1.3 Gt/yr) and southeastern coastal areas, which is suggested to involve an increase in the groundwater storage, lake and reservoir water volume, and the flow of materials from tectonic processes. Additionally, mass loss has occurred in the Huang‐Huai‐Hai‐Liao River Basin (−10.2 ± 0.9 Gt/yr), the Brahmaputra‐Nujiang‐Lancang River Basin (−15.0 ± 1.1 Gt/yr), and Tienshan Mountain (−4.1 ± 0.3 Gt/yr), a result of groundwater pumping and glacier melting. Areas with groundwater depletion are consistent with the distribution of cities with land subsidence in North China. We find that intensified precipitation can alter the local water supply and that GRACE can adequately capture these dynamics, which could be instructive for China's South‐to‐North Water Diversion hydrologic project.
Summertime surface O3 behavior and deposition to tundra in the Alaskan Arctic
Authors: Van Dam Brie , Helmig Detlev , Doskey Paul V. , Oltmans Samuel J. 
Published: April 2016

AbstractAtmospheric turbulence quantities, boundary layer ozone (O3) levels, and O3 deposition to the tundra surface were investigated at Toolik Lake, AK, during the 2011 summer season. Beginning immediately after snowmelt, a diurnal cycle of O3 in the atmospheric surface layer developed with daytime O3 maxima, and minima during low‐light hours, resulting in a mean amplitude of 13 ppbv. This diurnal O3 cycle is far larger than observed at other high Arctic locations during the snow‐free season. During the snow‐free months of June, July, and August, O3 deposition velocities were ∼3 to 5 times faster than during May, when snow covered the ground most of the month. The overall mean O3 deposition velocity between June and August was 0.10 cm s−1. The month of June had the highest diurnal variation, with a median O3 deposition velocity of 0.2 cm s−1 during the daytime and 0.08 cm s−1 during low‐light conditions. These values are slightly lower than previously reported summertime deposition velocities in northern latitudes over tundra or fen. O3 loss during low‐light periods was attributed to a combination of surface deposition to the tundra and stable boundary layer conditions. We also hypothesize that emissions of reactive biogenic volatile organic compounds into the shallow boundary layer may contribute to nighttime O3 loss.
Lidar remote sensing of cloud formation caused by low‐level jets
Authors: Su Jia , Felton Melvin , Lei Liqiao , McCormick M. Patrick , Delgado Ruben , St. Pé Alexandra 
Published: April 2016

AbstractIn May 2014, the East Hampton Roads Aerosol Flux campaign was conducted at Hampton University to examine small‐scale aerosol transport using aerosol, Raman, and Doppler lidars and rawindsonde launches. We present the results of analyses performed on these high‐resolution planetary boundary layer and lower atmospheric measurements, with a focus on the low‐level jets (LLJs) that form in this region during spring and summer. We present a detailed case study of a LLJ lasting from evening of 20 May to morning of 21 May using vertical profiles of aerosol backscatter, wind speed and direction, water vapor mixing ratio, temperature, and turbulence structure. We show with higher resolution than in previous studies that enhanced nighttime turbulence triggered by LLJs can cause the aerosol and water vapor content of the boundary layer to be transported vertically and form a well‐mixed region containing the cloud condensation nuclei that are necessary for cloud formation.
Hydrogen and chlorine abundances in the Kimberley formation of Gale crater measured by the DAN instrument on board the Mars Science Laboratory Curiosity rover
Authors: Litvak M. L. , Mitrofanov I. G. , Hardgrove C. , Stack K. M. , Sanin A. B. , Lisov D. , Boynton W. V. , Fedosov F. , Golovin D. , Harshman K. , Jun I. , Kozyrev A. S. , Kuzmin R. O. , Malakhov A. , Milliken R. , Mischna M. , Moersch J. , Mokrousov M. , Nikiforov S. , Starr R. , Tate C. , Tret'yakov V. I. , Vostrukhin A. 
Published: April 2016

AbstractThe Dynamic Albedo of Neutron (DAN) instrument on board the Mars Science Laboratory Curiosity rover acquired a series of measurements as part of an observational campaign of the Kimberley area in Gale crater. These observations were planned to assess the variability of bulk hydrogen and neutron‐absorbing elements, characterized as chlorine‐equivalent concentration, in the geologic members of the Kimberley formation and in surface materials exposed throughout the area. During the traverse of the Kimberley area, Curiosity drove primarily over the “Smooth Hummocky” unit, a unit composed primarily of sand and loose rocks, with occasional stops at bedrock of the Kimberley formation. During the Kimberley campaign, DAN detected ranges of water equivalent hydrogen (WEH) and chlorine‐equivalent concentrations of 1.5–2.5 wt % and 0.6–2 wt %, respectively. Results show that as the traverse progressed, DAN observed an overall decrease in both WEH and chlorine‐equivalent concentration measured over the sand and loose rocks of the Smooth Hummocky unit. DAN measurements of WEH and chlorine‐equivalent concentrations in the well‐exposed sedimentary bedrock of the Kimberley formation show fluctuations with stratigraphic position. The Kimberley campaign also provided an opportunity to compare measurements from DAN with those from the Sample Analysis at Mars (SAM) and the Alpha‐Particle X‐ray Spectrometer (APXS) instruments. DAN measurements obtained near the Windjana drill location show a WEH concentration of ~1.5 wt %, consistent with the concentration of low‐temperature absorbed water measured by SAM for the Windjana drill sample. A comparison between DAN chlorine‐equivalent concentrations measured throughout the Kimberley area and APXS observations of corresponding local surface targets and drill fines shows general agreement between the two instruments.
A dense medium electromagnetic scattering model for the InSAR correlation of snow
Authors: Lei Yang , Siqueira Paul , Treuhaft Robert 
Published: April 2016

AbstractSnow characteristics, such as snow water equivalent (SWE) and snow grain size, are important characteristics for the monitoring of the global hydrological cycle and as indicators of climate change. This paper derives an interferometric synthetic aperture radar (InSAR) scattering model for dense media, such as snow, which takes into account multiple scattering effects through the Quasi‐Crystalline Approximation. The result of this derivation is a simplified version of the InSAR correlation model derived for relating the InSAR correlation measurements to the snowpack characteristics of grain size, volume fraction, and layer depth as well as those aspects of the volume‐ground interaction that affects the interferometric observation (i.e., the surface topography and the ratio of ground‐to‐volume scattering). Based on the model, the sensitivity of the InSAR correlation measurements to the snow characteristics is explored by simulation. Through this process, it is shown that Ka‐band InSAR phase has a good sensitivity to snow grain size and volume fraction, while for lower frequency signals (Ku‐band to L‐band), the InSAR correlation magnitude and phase have a sensitivity to snow depth. Since the formulation depends, in part, on the pair distribution function, three functional forms of the pair distribution function are implemented and their effects on InSAR phase measurements compared. The InSAR scattering model described in this paper is intended to be an observational prototype for future Ka‐band and L‐band InSAR missions, such as NASA's Surface Water and Ocean Topography and NASA‐ISRO Synthetic Aperture Radar missions, planned for launch in the 2020–2021 time frame. This formulation also enables further investigation of the InSAR‐based snow retrieval approaches.
A new view for the geodynamics of Ecuador: Implication in seismogenic source definition and seismic hazard assessment
Authors: Yepes Hugo , Audin Laurence , Alvarado Alexandra , Beauval Céline , Aguilar Jorge , Font Yvonne , Cotton Fabrice 
Published: April 2016

AbstractA new view of Ecuador's complex geodynamics has been developed in the course of modeling seismic source zones for probabilistic seismic hazard analysis. This study focuses on two aspects of the plates' interaction at a continental scale: (a) age‐related differences in rheology between Farallon and Nazca plates—marked by the Grijalva rifted margin and its inland projection—as they subduct underneath central Ecuador, and (b) the rapidly changing convergence obliquity resulting from the convex shape of the South American northwestern continental margin. Both conditions satisfactorily explain several characteristics of the observed seismicity and of the interseismic coupling. Intermediate‐depth seismicity reveals a severe flexure in the Farallon slab as it dips and contorts at depth, originating the El Puyo seismic cluster. The two slabs position and geometry below continental Ecuador also correlate with surface expressions observable in the local and regional geology and tectonics. The interseismic coupling is weak and shallow south of the Grijalva rifted margin and increases northward, with a heterogeneous pattern locally associated to the Carnegie ridge subduction. High convergence obliquity is responsible for the North Andean Block northeastward movement along localized fault systems. The Cosanga and Pallatanga fault segments of the North Andean Block‐South American boundary concentrate most of the seismic moment release in continental Ecuador. Other inner block faults located along the western border of the inter‐Andean Depression also show a high rate of moderate‐size earthquake production. Finally, a total of 19 seismic source zones were modeled in accordance with the proposed geodynamic and neotectonic scheme.
Large‐scale variation in boreal and temperate forest carbon turnover rate related to climate
Authors: Thurner Martin , Beer Christian , Carvalhais Nuno , Forkel Matthias , Santoro Maurizio , Tum Markus , Schmullius Christiane 
Published: April 2016

AbstractVegetation carbon turnover processes in forest ecosystems and their dominant drivers are far from being understood at a broader scale. Many of these turnover processes act on long timescales and include a lateral dimension and thus can hardly be investigated by plot‐level studies alone. Making use of remote sensing‐based products of net primary production (NPP) and biomass, here we show that spatial gradients of carbon turnover rate (k) in Northern Hemisphere boreal and temperate forests are explained by different climate‐related processes depending on the ecosystem. k is related to frost damage effects and the trade‐off between growth and frost adaptation in boreal forests, while drought stress and climate effects on insects and pathogens can explain an elevated k in temperate forests. By identifying relevant processes underlying broadscale patterns in k, we provide the basis for a detailed exploration of these mechanisms in field studies, and ultimately the improvement of their representations in global vegetation models (GVMs).
On the temperature dependence of oceanic export efficiency
Authors: Cael B. B. , Follows Michael J. 
Published: April 2016

AbstractQuantifying the fraction of primary production exported from the euphotic layer (termed the export efficiency ef) is a complicated matter. Studies have suggested empirical relationships with temperature which offer attractive potential for parameterization. Here we develop what is arguably the simplest mechanistic model relating the two, using established thermodynamic dependencies for primary production and respiration. It results in a single‐parameter curve that constrains the envelope of possible efficiencies, capturing the upper bounds of several ef‐T data sets. The approach provides a useful theoretical constraint on this relationship and extracts the variability in ef due to temperature but does not idealize out the remaining variability which evinces the substantial complexity of the system in question.