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Stretching and shearing contamination analysis for Liutex and other vortex identification methods

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Advances in Aerodynamics 2021年第1期3卷 166-185页

作者： Pushpa Shrestha Charles Nottage Yifei Yu oscar alvarez Chaoqun Liu Department of Mathematics The University of Texas at ArlingtonArlingtonTX 76019USA

The newly developed vortex-identification method,Liutex,has provided a new systematic description of the local fluid rotation,which includes scalar,vector,and tensor ***,the advantages of Liutex over the other widely used vortexidentification methods such as Q,Δ,λ2,andλci have not been *** traditional methods count on shearing and stretching as a part of vortex ***,in the real flow,shearing and stretching do not contribute to fluid *** this paper,the decomposition of the velocity gradient tensor is conducted in the Principal Coordinate for *** the contamination effects of stretching and shearing of the traditional methods are investigated and compared with the Liutex method in terms of mathematical analysis and numerical *** results show that the Liutex method is the only method that is not affected by either stretching or shear,as it represents only the local fluid rigid *** results provide supporting evidence that Liutex is the superior method over others.

关键词： Liutex Vorticity Vortex Omega method Transition flow Velocity gradient tensor Principal coordinate Principal tensor Liutex tensor decomposition

Enhancement of the benthic communities around an isolated island in the Antarctic Ocean

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Acta Oceanologica Sinica 2013年第6期32卷 47-55页

作者： José I Saiz Nuria Anadón Javier Cristobo oscar García-alvarez Gerardo García-Castrillo Eduardo López Cruz Palacín Jesús S Troncoso Ana Ramos Department of Zoology and Animal Cell Biology University of the Basque CountryBilbao 48080 Spain Department of Organisms and Systems Biology (Zoology) Rodrigo Uría s/n University of OviedoOviedo 33071 Spain Spanish Institute of Oceanography Gijón Oceanographic Centre Príncipe de Asturias 70bisGijón 33212 Spain Department of Zoology and Physical Anthropology University of Santiago de CompostelaSouth Campus Santiago de Compostela 15706 Spain Cantabrian Maritime Museum San Martín de Bajamar s/nSantander 39004 Spain Department of Biology Faculty of Sciences Autonomous University of MadridMadrid 28049 Spain Department of Animal Biology University of BarcelonaAvinguda Diagonal 645 Barcelona 08028 Spain Department of Ecology and Animal Biology Marine Sciences Faculty University of VigoVigo 36310 Spain Spanish Institute of Oceanography Subida a Radio Faro 50-52Vigo 36390 Spain

Insular marine biotas are often richer in faunal diversity than those from the open sea in the same geo- graphical region. The existence of particular island effects were tested under polar conditions by compar- ing infaunal benthic assemblages on Peter I Island with those of similar latitudes in the open ocean at the Bellingshausen Sea and also from the coast of the Antarctic Peninsula. Sampling was carried out aboard the R/V Hesperides during the expedition named BENTART-2003 from 24 January to 3 March 2003. Benthic samples were collected at 18 stations ranging from 90 to 2 044 m depth, using an USNEL-type box corer （BC） dredge. Representatives of 32 higher taxa of invertebrates were found. Univariate and multivariate analyses revealed various patterns in the data. First, significant differences in polychaete abundance were detected between the stations located in the open sea and the remaining sites （island plus mainland sites）. Bivalve abundances were also distinct between island and mainland sampling sites. Sediment columns taken from the island seafloor exhibited the highest rate of bioturbation by the infauna. These findings confirm the model that islands develop distinct assemblages characterized by the enhancement of the benthic commu- nities even in cold waters. Several abiotic factors were measured simultaneously at the seafloor and along the water column to investigate faunal distribution patterns. Significant correlations were found between the benthic assemblages and a combination of two environmental variables：＂island effect＂（measured as a categorical variable） and the redox state of sediments. Richer and more complex benthic assemblages were found in Peter I Island＇s sea bottom, whereas the more depauperate bottoms remained in the open sea.

关键词： Antarctica Bellingshausen Sea benthos Peter I Island PRIMER

Proline and Oxidative Metabolism in Young Pecan Trees Associated with Sulphate Accumulation

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Phyton-International Journal of Experimental Botany 2022年第6期91卷 1141-1152页

作者： Dalila Jacqueline Escudero-Almanza oscar Cruz-alvarez Ofelia Adriana Hernández-Rodríguez Juan Luis Jacobo-Cuellar Esteban Sánchez-Chávez Pablo Preciado-Rángel Dámaris Leopoldina Ojeda-Barrios Facultad de Ciencias Agrotecnológicas Universidad Autónoma de ChihuahuaChihuahua31350México Centro de Investigación en Alimentación y Desarrollo A.C.Delicias33088México InstitutoTecnologico Nacional de México-Instituto Tecnológico de Torreón Coahuila27170México

Pecan[Carya illinoinensis(Wangenh.)***.]is a deciduous tree whose fruits(nuts)are of high economic value and offer excellent nutritional ***,soils high in sulphates can limit its growth and *** with 5-year-old trees of‘Western Schley’pecan grown in soils high in sulphates,the levels of proline and oxidative metabolism were recorded in the *** showed that different levels of visible leaflet damage(‘sufficiency’,‘low’,‘moderate’or‘severe’)were associated with different levels of leaflet sulphates(mg kg^(−1)):‘sufficiency’(≤40),‘low’(41–60),‘moderate’(61–80)and‘severe’(80–100).‘Severe’sulphate damage was associated with significant reductions in chlorophyll(TChl)(17.04μg g^(−1)),relative water content(RWC)(50%)and leaf area(LA),and with increases in the concentrations of total carotenoids(TC)and proline(Prl).Increases were also observed in the activities of the oxidative metabolism enzymes:superoxide dismutase(SOD)(1.82 units min^(−1) g^(−1)),catalase(CAT)(2.86μmol H_(2)O_(2) min^(−1) g^(−1))and antioxidant capacity(AC)(87%DPPH inhibition).However,guaiacol peroxidase(GP)showed a reduction(2.97 nmol GSH min^(−1) g^(−1)).An inverse relationship was found between the sulphate concentration in the leaflets with respect to the evaluated parameters of TChl,TC,RWC,LA,AC,and *** synthesis and antioxidant enzymatic activity indicate salt stress in pecan leaflets in orchards irrigated with deep-well water high in sulphates.

关键词： Carya illinoinensis catalase guaiacol peroxidase salt stress photosynthetic pigments superoxide dismutase

Correction to: Stretching and shearing contamination analysis for Liutex and other vortex identification methods

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Advances in Aerodynamics 2021年第1期3卷 227-227页

作者： Pushpa Shrestha Charles Nottage Yifei Yu oscar alvarez Chaoqun Liu Department of Mathematics The University of Texas at ArlingtonArlingtonTX 76019USA

Correction to:Adv Aerodyn 3,8(2021)https://***/10.1186/s42774-020-00060-9 After publication of this article[1],it is noticed letter‘a’is missing from the below sentence in section 6.2‘Adding stretching components’... 详细信息

关键词： stretching shearing

Superplasticity of a friction stir processed overaged WE54 magnesium alloy

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Journal of Magnesium and Alloys 2022年第11期10卷 3156-3166页

作者： oscar A.Ruano Marta alvarez-Leal Alberto Orozco-Caballero Fernando Carreño Physical Metallurgy Department CENIM-CSICAv.Gregorio del Amo 828040 MadridSpain Department of R&D and programmes Technology Centre of Metal-Mechanical and Transport(CETEMET).Avda.1°de Mayos/n.LinaresJaén2370Spain Department of Mechanical Engineering Chemistry and Industrial DesignPolytechnic University of MadridRonda de Valencia 328012MadridSpain

The coarse-grained WE54 magnesium alloy was heat treated in order to have minimum hardness minimizing the effects of precipitates and solid solution. Friction stir processing(FSP) was applied in severe conditions to obtain fine, equiaxed and highly misoriented grains, with grain sizes even less than 1 μm. The high severity of processing demonstrated to have a strong impact in the microstructure. Consequently,the processed materials exhibited excellent superplasticity at the high strain rate 10^(-2)s^(-1), and temperatures between 300 and 400 ℃. The maximum tensile superplastic elongation of 756% was achieved at 400 ℃ thanks to the operation of grain boundary sliding mechanism(GBS). Besides the new data obtained through tensile testing, the paper deals with a transcendental question regarding the large differences in strain rate values at a given stress in the superplastic regime at maximum elongation compared to other magnesium-based alloys. With this is mind, 19 magnesium alloys from 22 different investigations were analyzed to give some light to this behavior that never was treated before. It is proposed that this behavior has to be attributed to the accommodation process, necessary for GBS to occur, which is hindered by reinforcing solutes.

关键词： WE54 magnesium alloy Friction stir processing Processing severity Superplasticity Grain boundary sliding Solutes

Introduction to 3D reconstruction of macromolecules using single particle electron microscopy

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Acta Pharmacologica Sinica 2005年第10期26卷 1153-1164页

作者： oscar LLORCA Centro de lnvestigaciones Biológicas Consejo Superior de Investigaciones Científicas Ramiro de Maeztu 9 Campus Universidad Complutense 28040 Madrid Spain

Single-particle electron microscopy has now reached maturity, becoming a commonly used method in the examination of macromolecular structure. Using a small amount of purified protein, isolated molecules are observed under the electron microscope and the data collected can be averaged into a 3D reconstruction. Single-particle electron microscopy is an appropriate tool for the analysis of proteins that can only be obtained in modest quantities, like many of the large complexes currently of interest in biomedicine. Whilst the use of electron microscopy expands, new methods are being developed and improved to deal with further challenges, such as reaching higher resolutions and the combination of informa tion at different levels of structural detail. More importantly, present methodology is still not robust enough when studying certain "tricky" proteins like those displaying extensive conformational flexibility and a great deal of user expertise is required, posing a threat to the consistency of the final structure. This mini review describes a brief outline of the methods currently used in the 3D analysis of macromolecules using single-particle electron microscopy, intended for those first approaching this field. A summary of methods, techniques, software, and some recent work is presented. The spectacular improvements to the technique in recent years, its advantages and limitations compared to other structural methods, and its future developments are discussed.

关键词： single particle electron microscopy 3D reconstruction cryoelectron microscopy image processing DNA-PK

Lessons from International Students’ Reaction to the 2011 Great East Japan Earthquake:The Case of the School of Engineering at Tohoku University

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International Journal of Disaster Risk Science 2013年第3期4卷 137-149页

作者： oscar A.Gómez Graduate School of Global Studies Doshisha UniversityKyoto 602-0898Japan

The objective of this study is to document the reaction of international students to the 11 March 2011 emergency in order to inform and improve disaster management strategies, both public and institutional. The study is based mainly on a questionnaire survey carried out in August 2011 and follow-up interviews with students and other stakeholders. It describes the background of Tohoku University’s School of Engineering and covers six different stages in the evolution of the emergency:(1) immediate response;(2) taking shelter in Sendai;(3) life in the city during the aftermath;(4) sheltering outside Sendai;(5) coming back;plus(6) an overview of the experience. Major findings include: the process of evacuation and safety confirmation was successful, yet the subsequent phases(2 and 3) went on mostly unmanaged;students relied mostly on secondary sources of information to make decisions, mainly family and friends of the same nationality, most of whom probably were not better informed than the students themselves. Based on the findings, suggestions for future disaster planning are advanced, as well as a discussion on the challenges of information provision during crisis.

关键词： disaster mostly Great

Polygeneration Study of Low-to-Medium Enthalpy Geothermal Reservoirs in Mexico

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Journal of Thermal Science 2021年第3期30卷 1077-1087页

作者： CHÁVEZ oscar GODÍNEZ Francisco Tecnológico Nacional de México/I.T.Chihuahua.Av.Tecnológico 2909 C.P.31310ChihuahuaChihuahuaMéxico Instituto de Ingeniería Universidad Nacional Autónoma de MéxicoUNAMC.U.Ciudad de MéxicoC.P.04510México Polo Universitario de Tecnología Avanzada Universidad Nacional Autónoma de MéxicoVía de la Innovación No.410Autopista Monterrey-Aeropuertokm.10 PIITC.P.66629Apodaca Nuevo LeónMéxico

This study combines the thermodynamic analysis of a polygeneration system along with the numerical modelling of the thermal behavior of geothermal reservoirs in Mexico to exploit their *** reservoir was modeled as a porous medium assuming a five-spot well configuration and local thermal *** heat conduction-convection along with the Laplace equations were solved to compute temperature distributions,the useful life and the optimum distance between injection-extraction *** predicted temperature and pressure of the geothermal fluid at the outlet of the reservoir were exploited in the polygeneration system consisting of:(1)a Rankine cycle,(2)an absorption refrigeration cycle,and(3)a heat *** developed approach allows calculating both the optimal distance between injection-extraction wells and the global(utilization)efficiency of six arrangements(each composed by a reservoir connected to a polygeneration system)by assuming that reservoirs have a lifespan of 30 *** also show that:(a)due to the low efficiency of the Rankine cycle,very little thermal energy is converted into electrical one;(b)not only the temperature and the size are important when evaluating the power production performance of reservoirs,but also the permeability plays a fundamental role;(c)the first law efficiency of the polygeneration system ranges from 41.9%to 43.7%;(d)the utilization efficiency of the six arrangements lies in the range between 25.8%and 31%.

关键词： polygeneration system geothermal reservoir local thermal equilibrium low-to-medium enthalpy

Bile-acid-induced cell injury and protection

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World Journal of Gastroenterology 2009年第14期15卷 1677-1689页

作者： Maria J Perez oscar Briz Research Unit University Hospital of Salamanca Laboratory of Experimental Hepatology and Drug Targeting CIBERehd University of Salamanca E.D. 129 37007 Salamanca Spain

Several studies have characterized the cellular and molecular mechanisms of hepatocyte injury caused by the retention of hydrophobic bile acids （BAs） in cholestatic diseases. BAs may disrupt cell membranes through their detergent action on lipid components and can promote the generation of reactive oxygen species that, in turn, oxidatively modify lipids, proteins, and nucleic acids, and eventually cause hepatocyte necrosis and apoptosis. Several pathways are involved in triggering hepatocyte apoptosis. Toxic BAs can activate hepatocyte death receptors directly and induce oxidative damage, thereby causing mitochondrial dysfunction, and induce endoplasmic reticulum stress. When these compounds are taken up and accumulate inside biliary cells, they can also cause apoptosis. Regarding extrahepatic tissues, the accumulation of BAs in the systemic circulation may contribute to endothelial injury in the kidney and lungs. In gastrointestinal cells, BAs may behave as cancer promoters through an indirect mechanism involving oxidative stress and DNA damage, as well as acting as selection agents for apoptosis-resistant cells. The accumulation of BAs may have also deleterious effects on placental and fetal cells. However, other BAs, such as ursodeoxycholic acid, have been shown to modulate BA-induced injury in hepatocytes. The major beneficial effects of treatment with ursodeoxycholic acid are protection against cytotoxicity due to more toxic BAs; the stimulation of hepatobiliary secretion; antioxidant activity, due in part to an enhancement in glutathione levels; and the inhibition of liver cell apoptosis. Other natural BAs or their derivatives, such as cholyI-N- methylglycine or pharmacological properties. cholylsarcosine, interest owing have also aroused to their protective

关键词： Apoptosis Cholestasis Liver Necrosis Oxidative stress Ursodeoxycholic acid