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菜籽油作为800kV高压直流换流变压器冷却液的数值模拟研究

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菜籽油作为800kV高压直流换流变压器冷却液的数值模拟研究

作者： gutierrez diaz edgardy miguel 华北电力大学(北京)

学位级别：硕士

电力变压器作为输配电系统中最为重要和昂贵的设备之一,其可靠性和稳定性一直是电力系统安全运行的关键所在。然而随着近年来高压直流输电（HVDC）技术被广泛应用于世界各地的电网体系中,高交直流电压对变压器内介电绝缘介质的性能提出... 详细信息

电力变压器作为输配电系统中最为重要和昂贵的设备之一,其可靠性和稳定性一直是电力系统安全运行的关键所在。然而随着近年来高压直流输电（HVDC）技术被广泛应用于世界各地的电网体系中,高交直流电压对变压器内介电绝缘介质的性能提出了新的特殊要求,其相关研究已逐渐成为电力领域的重点内容。目前大多数变压器主要以液体介质作为绝缘材料,其可有效防止设备内部短路,并保护变压器免受化学侵蚀,同时也能够在变压器通电工作阶段充当冷却剂,从而避免设备过热损坏。本文的主要工作是通过数值模拟手段评估菜籽油在高压直流换流变压器中的换热效果,并与传统的矿物油冷却液进行对比,综合分析菜籽油绝缘介质的冷却性能。论文首先基于上海向家坝工程富龙换流站换流变压器的技术数据,通过FLUENT模拟软件构建了换流变压器的二维截面物理模型,并给出了相关设计参数。在此基础上,采用计算流体力学（CFD）工具,对换流变压器投入运行和ODAF冷却系统运行两种工况下的设备内部对流换热过程进行了数值模拟,并分析计算得到界点时流道内的温度场和速度场。同时对比菜籽油和矿物油绝缘介质在两种工况下的温度响应情况,进而得到体系整体的冷却性能表现。研究结果表明,菜籽油由于导热系数较低,需要较长的时间从变压器的核心和绕组获得热量以达到热平衡。然而,当通道温度达到稳定之后,菜籽油和矿物油的平衡温度没有显著差异。因此在相同的加热功率条件下,菜籽油可以有效地替代矿物油作为变压器的绝缘冷却液。此外,菜籽油相比矿物油粘度更高,导致其流速较慢,使得油液能够顺畅进入冷却通道,并更早地从设备内部热源吸收热量。冷却效果的改善表明菜籽油作为变压器冷却液和电绝缘液的效果明显优于矿物油。

关键词：高压直流变压器菜籽油冷却液矿物油 CFD分析

Bull spermatozoa selected by thermotaxis exhibit high DNA integrity,specific head morphometry,and improve ICSI outcome

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Journal of Animal Science and Biotechnology 2023年第3期14卷 1001-1011页

作者： Sara Ruiz-diaz Rosane mazzarella Paula Navarrete-Lopez Raul Fernandez-Gonzalez Celia de Frutos maria maroto Claudia Cucala Paula Beltran-Brena marta Lombo Dimitrios Rizos Alfonso gutierrez-Adan Department of Animal Reproduction INIA-CSIC28040 MadridSpain mistral Fertility Clinics S.L Clinica TambreCalle Tambre828002 MadridSpain

Background Sperm migration by thermotaxis is a guidance mechanism that operates along the oviduct and it has proved to be a valid method for selecting spermatozoa with low DNA fragmentation(SDF)in mice,humans,and stallions.This study aimed to analyse if bull spermatozoa could be selected by thermotaxis and to assess their quality in terms of SDF as well as determine the presence of a specific sperm subpopulation based on sperm morphometry and assess their fertilizing capacity by ICSI.methods We used frozen-thawed sperm from 6 bulls and sperm selection by thermotaxis was performed with TALP medium supplemented with 25 mmol/L of HEPES and 5 mmol/L of caffeine.In these conditions,sperm selection was achieved,obtaining a net thermotaxis of 3.6%.Subsequently,we analysed the SDF of the migrated and not-migrated spermatozoa using the neutral COmET assay,and we evaluated the size of the sperm head using Hemacolor■ staining with motic Images Plus 3 software.Additionally,migrated and not-migrated spermatozoa by thermotaxis were used to fertilize bovine in vitro matured(IVm)oocytes by ICSI,a very inefficient procedure in cattle that is only successful when the oocyte is artificially activated.Results The results showed lower SDF(χ^(2),Pmeters(length and width,Pmeter and area,Pmatozoa migrated in comparison to those not-migrated.The distribution of sperm subpopulations structure varied between groups,highlighting cluster 2,characterized by spermatozoa with small head size,and high ellipticity and elongated heads,as the most abundant in the thermotaxis migrated group.When performed ICSI(without oocyte artificial activation)with the thermotactic sperm,the blastocyst rate was 32.2%±9.3%in the group microinjected with the thermotactic spermatozoa vs.8.3%±7.8%in the group of not-migrated sperm(χ^(2),Pm selection by thermotaxis has a much higher DNA integrity,small and elongated head size param

关键词： ART Bovine Sperm morphometry Sperm selection Thermotaxis

Performance and calibration of quark/gluon-jet taggers using 140 fb^(-1) of pp collisions at √s=13 TeV with the ATLAS detector

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Chinese Physics C 2024年第2期48卷 1-25页

作者： G. Aad B. Abbott K. Abeling N.J. Abicht S.H. Abidi A. Aboulhorma H. Abramowicz H. Abreu Y. Abulaiti B.S. Acharya C. Adam Bourdarios L. Adamczyk S.V. Addepalli m.J. Addison J. Adelman A. Adiguzel T. Adye A.A. Affolder Y. Afik m.N. Agaras J. Agarwala A. Aggarwal C. Agheorghiesei A. Ahmad F. Ahmadov W.S. Ahmed S. Ahuja X. Ai G. Aielli A. Aikot m. Ait Tamlihat B. Aitbenchikh I. Aizenberg m. Akbiyik T.P.A. Åkesson A.V. Akimov D. Akiyama N.N. Akolkar K. Al Khoury G.L. Alberghi J. Albert P. Albicocco G.L. Albouy S. Alderweireldt m. Aleksa I.N. Aleksandrov C. Alexa T. Alexopoulos F. Alfonsi m. Algren m. Alhroob B. Ali H.m.J. Ali S. Ali S.W. Alibocus m. Aliev G. Alimonti W. Alkakhi C. Allaire B.m.m. Allbrooke J.F. Allen C.A. Allendes Flores P.P. Allport A. Aloisio F. Alonso C. Alpigiani m. Alvarez Estevez A. Alvarez Fernandez m. Alves Cardoso m.G. Alviggi m. Aly Y. Amaral Coutinho A. Ambler C. Amelung m. Amerl C.G. Ames D. Amidei S.P. Amor Dos Santos K.R. Amos V. Ananiev C. Anastopoulos T. Andeen J.K. Anders S.Y. Andrean A. Andreazza S. Angelidakis A. Angerami A.V. Anisenkov A. Annovi C. Antel m.T. Anthony E. Antipov m. Antonelli F. Anulli m. Aoki T. Aoki J.A. Aparisi Pozo m.A. Aparo L. Aperio Bella C. Appelt A. Apyan N. Aranzabal S.J. Arbiol Val C. Arcangeletti A.T.H. Arce E. Arena J-F. Arguin S. Argyropoulos J.-H. Arling O. Arnaez H. Arnold G. Artoni H. Asada K. Asai S. Asai N.A. Asbah J. Assahsah K. Assamagan R. Astalos S. Atashi R.J. Atkin m. Atkinson H. Atmani P.A. Atmasiddha K. Augsten S. Auricchio A.D. Auriol V.A. Austrup G. Avolio K. Axiotis G. Azuelos D. Babal H. Bachacou K. Bachas A. Bachiu F. Backman A. Badea P. Bagnaia m. Bahmani A.J. Bailey V.R. Bailey J.T. Baines L. Baines O.K. Baker E. Bakos D. Bakshi Gupta V. Balakrishnan R. Balasubramanian E.m. Baldin P. Balek E. Ballabene F. Balli L.m. Baltes W.K. Balunas J. Balz E. Banas m. Bandieramonte A. Bandyopadhyay S. Bansal L. Barak m. Barakat E.L. Barberio D. Barberis m. Barbero m.Z. Barel K.N. Barends T. Barillari m-S. Barisits T. Barklow P. Baron D.A. Baron mo The ATLAS Collaboration

The identification of jets originating from quarks and gluons,often referred to as quark/gluon tagging,plays an important role in various analyses performed at the Large Hadron Collider,as Standard model measurements and searches for new particles decaying to quarks often rely on suppressing a large gluon-induced background.This paper describes the measurement of the efficiencies of quark/gluon taggers developed within the ATLAS Collaboration,using √s=13 TeV proton–proton collision data with an integrated luminosity of 140 fb^(-1) collected by the ATLAS experiment.Two taggers with high performances in rejecting jets from gluon over jets from quarks are studied:one tagger is based on requirements on the number of inner-detector tracks associated with the jet,and the other combines several jet substructure observables using a boosted decision tree.A method is established to determine the quark/gluon fraction in data,by using quark/gluon-enriched subsamples defined by the jet pseudorapidity.Differences in tagging efficiency between data and simulation are provided for jets with transverse momentum between 500 GeV and 2 TeV and for multiple tagger working points.

关键词： ATLAS JET QUARK GLUON TAGGING

Unilateral Impact of Altered Loading by Changing Teeth Height on the TmJ Fibrocartilage: Disc and Condyle of Wistar Rats

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microscopy Research 2016年第2期4卷 20-31页

作者： Roxanne m. Olvera-Farias Jose Raymundo Cruz-Perez Rogelio Salinas-gutierrez Jose Antonio Guerrero-diaz de Leon Juan B. Kouri-Flores Raul Rosales-Ibañez David masuoka Ito Alma Lilian Guerrero Barrera Departamento de morfología Universidad Autónoma de Aguascalientes Aguascalientes México Departamento de Infectómica y Patogénesis molecular CINVESTAV-IPN Mexico City Mexico Departamento de Estadística Universidad Autónoma de Aguascalientes Aguascalientes México Departamento de Estomatología Universidad Autónoma de San Luis Potosí San Luis Potosi México Departamento de Estomatología Universidad Autónoma de Aguascalientes Aguascalientes México Laboratorio de Biología Celular y Tisular Departamento de Morfología Universidad Autónoma de Aguascalientes Aguascalientes México

Temporomandibular joint (TmJ) is sensitive to loading and mechanical stress that provokes morphological changes produced by the impact in the occlusal plane. Here, this impact is evaluated in TmJ articular disc and articular cartilage using an in vivo model of unilateral occlusal plane impact and by analysis of serial tissue sections stained with Hematoxylin-Eosin (H-E) or with masson trichrome technique. Thus, six groups of 5 Wistar rats (200 - 250 g) are subjected to biomechanical dental stimulation by placing unilateral resin occlusal interference, or unilateral tooth wear made by upper left molars artificial mechanical devastation (1 control and 2 experimental groups for each treatment). Each treatment is evaluated two times at 1 and 15 days post-treatment. By H-E staining, control groups show chondrocytes arrangement as several cord cell groups in comparison with the experimental groups, which show an arrangement in one cord cell along of articular disc. However, this yields no significant difference (p mber between control and experimental groups. In contrast, in articular cartilage chondrocytes are random distributed along the superficial zone in control groups, while in experimental groups cell-free regions are observed in superficial zone. An image Blue hue analysis for trichrome stain is performed to quantify collagen;this shows a significant collagen decrease (p most all experimental groups compared with the controls. A degenerative process biomechanically induced by unilateral occlusal plane modification, causes cell and tissue changes on the TmJ structures that remain the degenerative changes observed in early osteoarthritis.

关键词： Articular Disc Articular Cartilage Dental Occlusion Collagen Temporomandibular Joint

Studying Some Brain and Ovarian morphological Traits in Diaglena spatulata Female Frogs Thriving in Conserved and Perturbed Habitats:A Preliminary Report and Its Implications for Amphibian Survival and Continuity

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Advances in Bioscience and Biotechnology 2014年第9期5卷 740-747页

作者： Esperanza melendez-Herrera Bryan Victor Phillips-Farfan Fany Edith Bucio-Pina Noemi Ramirez-Arres Gabriel gutierrez-Ospina Ireri Suazo-Ortuno Javier Alvarado-diaz Alma Lilia Fuentes-Farias Laboratorio de Ecofisiologia Animal Departamento de ZoologiaInstituto de Investigaciones sobre los Recursos NaturalesUniversidad Michoacana de San Nicolas de HidalgoMoreliaMéxico Laboratorio de Nutricion Experimental Instituto Nacional de PediatriaSecretaria de SaludMexico Distrito FederalMexico Laboratorio de Biologia de Sistemas Departamento de Biologia Celular y FisiologiaInstituto de Investigaciones BiomedicasCoordinacion de Psicobiologia y NeurocienciasFacultad de PsicologiaUniversidad Nacional Autonoma de MexicoMexico Distrito FederalMexico Laboratorio de Ecologia Departamento de ZoologiaInstituto de Investigaciones sobre los Recursos NaturalesUniversidad Michoacana de San Nicolas de HidalgoMoreliaMexico Laboratorio de Herpetologia Departamento de ZoologiaInstituto de Investigaciones sobre los Recursos NaturalesUniversidad Michoacana de San Nicolas de HidalgoMoreliaMexico

Amphibians are thought to be highly susceptible to perturbed environments. However, recent studies show that many of them are successful inhabitants of disturbed, fragmented habitats. The source of this resilience is yet unclear, but it may be the byproduct of having a robust phenotype and/or the result of phenotypic plasticity. We then assessed the contribution of each by evaluating cytological features of two brain nuclei that modulate reproductive behavior and of the ovary, using female specimens of the frog Diaglena spatulata prospering in conserved and disturbed areas of a tropical dry forest. Our results in the brain show that the medial amygdala, but not the preoptic area, had a reduced size in frogs collected in disturbed forests compared to specimens collected in conserved forests. Both brain nuclei displayed, however, neurons with a reduced size in frogs captured in disturbed forest patches. In contrast, ovarian cytological features were similar between groups. Our preliminary results lead us to propose that Diaglena spatulata female specimens might combine robust ovary and plastic brain’s phenotypic traits to confront disturbed environments. This, however, is still a working hypothetical framework that needs to be experimentally confirmed.

关键词： Amphibians Reproductive Traits Amygdala medial Preoptic Area Ovary