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Variational Formulations Yielding High-Order Finite-Element Solutions in Smooth Domains without Curved Elements

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Journal of Applied Mathematics and Physics 2017年第11期5卷 2127-2139页

作者： vitoriano ruas Sorbonne Universités UPMC Univ Paris 06 & CNRS UMR 7190 IJRDA Paris France CNRS UMR 7190 Institut Jean Le Rond d’Alembert Paris France CNPq Research Grant Holder PUC-Rio Rio de Janeiro Brazil

One of the reasons for the great success of the finite element method is its versatility to deal with different types of geometries. This is particularly true of problems posed in curved domains. Nevertheless it is well-known that, for standard variational formulations, the optimal approximation properties known to hold for polytopic domains are lost, if meshes consisting of ordinary elements are still used in the case of curved domains. That is why method’s isoparametric version for meshes consisting of curved triangles or tetrahedra has been widely employed, especially in case Dirichlet boundary conditions are prescribed all over a curved boundary. However, besides geometric inconveniences, the isoparametric technique helplessly requires the manipulation of rational functions and the use of numerical integration. In this work we consider a simple alternative that bypasses these drawbacks, without eroding qualitative approximation properties. More specifically we work with a variational formulation leading to high order finite element methods based only on polynomial algebra, since they do not require the use of curved elements. Application of the new approach to Lagrange methods of arbitrary order illustrates its potential to take the best advantage of finite-element discretizations in the solution of wide classes of problems posed in curved domains.

关键词： Curved Domain Dirichlet Finite Elements Interpolated Boundary Condition Polynomial Algebra

Finite Element Solution of a Stream Function-Vorticity System and Its Application to the Navier Stokes Equations

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Applied Mathematics 2013年第1期4卷 257-262页

作者： Fattehallah Ghadi vitoriano ruas Mohamed Wakrim Equipe Modélisation Mathématique et Simulation Faculté des Sciences Université Ibn Zohr Agadir Maroc Institut Jean Rond d’Alembert/CNRS UPMC Université Paris France

The finite element solution of a generalized Stokes system in terms of the flow variables stream function and vorticity is studied. This system results from a time discretization of the time-dependent Stokes system in stream function-vorticity formulation, or yet by the application of the characteristics method to solve the Navier-Stokes equations in the same representation. Numerical results presented for both cases illustrate the good behaviour of the adopted approach.

关键词： Characteristics Method Navier-Stokes Stream Function Vorticity

Driving the sodium-oxygen battery chemistry towards the efficient formation of discharge products: The importance of sodium superoxide quantification

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Journal of Energy Chemistry 2022年第5期31卷 709-720页

作者： Marina Enterría Marine Reynaud Juan Ignacio Paredes Lidia Medinilla Reza Younesi Nagore Ortiz-vitoriano Centre for Cooperative Research on Alternative Energies(CIC energiGUNE) Basque Research and Technology Alliance(BRTA)Vitoria-Gasteiz 01510Spain Instituto de Ciencia y Tecnología del Carbono INCAR-CSICC/Francisco Pintado Fe 26Oviedo 33011Spain Ångström Advanced Battery Centre(ÅABC) Department of Chemistry-Ångström LaboratoryUppsala UniversityUppsala SE-75121Sweden Ikerbasque Basque Foundation for ScienceBilbao 48013Spain

Sodium-oxygen batteries(SOBs) have the potential to provide energy densities higher than the state-ofthe-art Li-ion batteries. However, controlling the formation of sodium superoxide(NaO_(2)) as the sole discharge product on the cathode side is crucial to achieve durable and efficient SOBs. In this work, the discharge efficiency of two graphene-based cathodes was evaluated and compared with that of a commercial gas diffusion layer. The discharge products formed at the surface of these cathodes in a glyme-based electrolyte were carefully studied using a range of characterization techniques. NaO_(2) was detected as the main discharge product regardless of the specific cathode material while small amounts of Na_(2)O_(2).2H_(2)O and carbonate-like side-products were detected by X-ray diffraction as well as by Raman and infrared spectroscopies. This work leverages the use of X-ray diffraction to determine the actual yield of NaO_(2)which is usually overlooked in this type of batteries. Thus, the proper quantification of the superoxide formed on the cathode surface is widely underestimated;even though is crucial for determining the efficiency of the battery while eliminating the parasitic chemistry in SOBs. Here, we develop an ex-situ analysis method to determine the amount of NaO_(2) generated upon discharge in SOBs by transmission X-ray diffraction and quantitative Rietveld analysis. This work unveils that the yield of NaO_(2) depends on the depth of discharge where high capacities lead to very low discharge efficiency, regardless of the used cathode. We anticipate that the methodology developed herein will provide a convenient diagnosis tool in future efforts to optimize the performance of the different cell components in SOBs.

关键词： Na-O_(2)batteries Graphene Transmission X-Ray diffraction Rietveld refinement Na-O_(2)quantification Parasitic chemistry Cathode design

Generalisation,symbol specification and map evaluation:feedback from research done at COGIT laboratory,IGN France

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International Journal of Digital Earth 2011年第S01期4卷 25-41页

作者： C.Duchenea S.Christophe A.ruas COGIT Laboratory Institut Geographique NationalSaint-MandeFrance Laboratory of Informatics Grenoble(LIG) J.Fourier UniversityGrenobleFrance

This paper presents an overview of research studies made at the COGIT laboratory of IGN France in the fields of generalisation and symbol specification,particularly considering evaluation *** then discusses how generalisation and symbol specification *** it explores some possible adaptations of the presented works in generalisation and symbol specification to cartography in the context of crisis management.

关键词： automated cartography generalisation evaluation semiotics symbol specification

Acute Effects of Stretching on Flexibility and Performance:A Narrative Review

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Journal of Science in Sport and Exercise 2019年第1期1卷 29-37页

作者： Camila D.Lima Cassio V.ruas David G.Behm Lee E.Brown School of Human Kinetics and Recreation Memorial University of NewfoundlandSt.John’sCanada Centre for Exercise and Sports Science Research(CESSR) School of Medical and Health SciencesEdith Cowan UniversityJoondalupAustralia Department of Kinesiology California State UniversityFullerton7178 Loysburg StreetNavarreFL 32566USA

Passive and active stretching techniques have been shown to increase both chronic and acute range of motion(ROM).Acute ROM improvements can be countered by decreases in muscle performance,primarily after prolonged static stretching(SS)and proprioceptive neuromuscular facilitation(PNF)techniques when not incorporated into a full warm up *** contrast,ballistic stretching and dynamic stretching techniques typically induce either an increase or no change in muscular force and *** review explores studies that have investigated stretching responses on ROM,muscle functionality and ***,the literature demonstrates that prolonged acute SS and PNF stretching can elicit the greatest changes in flexibility,but without additional dynamic activities(*** warm up)can induce neuromuscular force and power output impairments,while increasing ROM and some sports specific *** response to stretching may be determined by the manipulation of confounding variables such as duration,population,volume,test specificity and *** increased dosage of some of these variables during stretching in isolation,augments ROM increases while attenuating muscle force output,except for stretching intensity which may lead to similar *** with high flexibility may have positive effects from stretching when tested on their sport specific performance,while general population may suffer greater negative *** control-ling these variables during stretching protocols may lead to misleading information regarding its effects on muscle performance.

关键词： Passive stretching Active stretching Range of motion Performance

Intestinal microbiota in health and disease: Role of bifidobacteria in gut homeostasis

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World Journal of Gastroenterology 2014年第41期20卷 15163-15176页

作者： Rafael Tojo Adolfo Suárez Marta G Clemente Clara G de los Reyes-Gavilán Abelardo Margolles Miguel Gueimonde Patricia ruas-Madiedo Gastroenterology Department Hospital de Cabue?es Gastroenterology Department Hospital Universitario Central de Asturias (HUCA) Respiratory Department Hospital Universitario Central de Asturias (HUCA) Department of Microbiology and Biochemistry of Dairy Products Instituto de Productos Lácteos de Asturias-Consejo Superior de Investigaciones Científicas (IPLA-CSIC)

The pool of microbes inhabiting our body is known as “microbiota” and their collective genomes as “microbiome”. The colon is the most densely populated organ in the human body, although other parts, such as the skin, vaginal mucosa, or respiratory tract, also harbour specific microbiota. This microbial community regulates some important metabolic and physiological functions of the host, and drives the maturation of the immune system in early life, contributing to its homeostasis during life. Alterations of the intestinal microbiota can occur by changes in composition (dysbiosis), function, or microbiota-host interactions and they can be directly correlated with several diseases. The only disease in which a clear causal role of a dysbiotic microbiota has been demonstrated is the case of Clostridium difficile infections. Nonetheless, alterations in composition and function of the microbiota have been associated with several gastrointestinal diseases (inflammatory bowel disease, colorectal cancer, or irritable bowel syndrome), as well as extra-intestinal pathologies, such as those affecting the liver, or the respiratory tract (e.g., allergy, bronchial asthma, and cystic fibrosis), among others. Species of Bifidobacterium genus are the normal inhabitants of a healthy human gut and alterations in number and composition of their populations is one of the most frequent features present in these diseases. The use of probiotics, including bifidobacteria strains, in preventive medicine to maintain a healthy intestinal function is well documented. Probiotics are also proposed as therapeutic agents for gastrointestinal disorders and other pathologies. The World Gastroenterology Organization recently published potential clinical applications for several probiotic formulations, in which species of lactobacilli are predominant. This review is focused on probiotic preparations containing Bifidobacterium strains, alone or in combination with other bac

关键词： Intestinal microbiota Bifidobacterium Probiotics Dysbiosis Inflammatory bowel disease Irritable bowel syndrome Colorectal cancer Liver disease Respiratory disease Functional foods

Decoding the Signaling Network for Abscisic Acid and Gibberellins:an Approach That Integrates Bioinformatics and Experimental Biology

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Decoding the Signaling Network for Abscisic Acid and Gibbere...

Genetic Distance Estimated by RAPD Markers and Performance of Topcross Hybrids in Popcorn

第二届植物分子育种国际会议

作者： C.Ross P.ruas Department of Biological Sciences University of NevadaLas VegasNevada89154USA

Seeds comprise 0% of the human diet, while cereals such as rice and wheat comprise 52.5% of the world diet (***/es/ess/chartroom/***). To meet the needs in food of the rapidly growing world population, crop breeders have put a tremendous amount of effort to improving the yield and quality of crops. However, drastic yield losses of cereal crops still result from preharvest sprouting and abiotic stresses (unfavorable environmental conditions).

关键词： Rice Biotechnology Bioinformatics Comparative Genomics Abscisic acid Gibberellins Signaling Perharvest-sprouting Germination Dormancy Stresses WRKY Transcription factors

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American Journal of Plant Sciences 2012年第12期3卷 1666-1673页

作者： Silvia Graciele Hülse de Souza Valéria Carpentieri-Pípolo Deoclécio Domingos Garbúglio Nelson da Silva Fonseca Júnior Claudete de Fátima ruas Paulo Maurício ruas Laboratory of Molecular Biology Universidade ParanaenseUmuaramaBrazil Agronomy Department Universidade Estadual de LondrinaLondrinaBrazil Instituto Agronomico do Paraná LondrinaBrazil Biology Department Universidade Estadual de LondrinaLondrinaBrazil

The purpose of this study was to investigate the diversity of 14 popcorn populations and a broad genetic base tester using molecular RAPD markers and to estimate the correlation between the genetic distances and the performance of top-cross hybrids. For the evaluation of populations and hybrids resulting from topcrosses, the reduced model of Gardner was used. A genetic distance matrix was generated based on RAPD markers by Jaccard coefficient, and a dendrogram was constructed. In general, topcrosses performed better than the populations per se and evidenced heterosis occurrence in topcrosses. The trait grain weight is influenced by additive as much as by dominance effects. Genetic associations separated the populations in three groups, and RAPD showed to be a useful tool to determine the extension of genetic diversity in popcorn populations and to place genotypes in distinct heterotic groups. Correlations between genetic divergences, detected by RAPD, and the means observed in the topcross crosses were positive and non-significant for expansion volume, plant height, and female flowering, and were negative for grain weight.

关键词： Zea mays L. Heterotic Groups Molecular Markers Testers Expansion Volume Yield

Investigating the role of TPC2-mediated Ca2+ signaling during the development of slow muscle cells and primary motor neurons in zebrafish

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Investigating the role of TPC2-mediated Ca2+ signaling durin...