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Turbine passage Secondary Flow Dynamics and Endwall Heat Transfer Under Different Inflow Turbulence

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Journal of Harbin Institute of Technology(New Series) 2024年第3期31卷 51-62页

作者： Arjun K S Tide p S Biju N Division of Mechanical Engineering School of EngineeringCochin University of Science&TechnologyKalamassery 682022India

This study presents endwall hydrodynamics and heat transfer in a linear turbine cascade at Re 5×105 at low and high intensities of *** are numerically predicted using the standard SST model and Reθ-γtransition model as well as using the high-resolution LES *** major secondary flow components,comprising the horseshoe,corner,and passage vortices are recognized and the impact on heat or mass transfer is *** complicated behavior of turbine passage secondary flow generation and establishment are impacted by the perspective of boundary layer attributes and inflow *** passage vortex concerning the latest big leading-edge vane is generated by the enlargement of the circulation developed at the first instance adjacent to the pressure side becomes powerful and mixes with other vortex systems during its migration towards the suction *** study conclusions reveal that substantial enhancements are attained on the endwall surface,for the entire spanwise blade extension on the pressure surface,and in the highly 3-D region close to the endwall on the suction *** forecasted suction surface thermal exchange depicts great conformity with the measurement values and precisely reproduces the enhanced thermal exchange owing to the development and lateral distribution of the secondary flows along the midspan of the blade passage *** impacts of the different secondary flow structures on the endwall thermal exchange are described in depth.

关键词： turbine vane heat transfer endwall turbulence secondary flow

Optimum profiles of Endwall Contouring for Enhanced Net Heat Flux Reduction and Aerodynamic performance

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Journal of Harbin Institute of Technology(New Series) 2024年第2期31卷 80-92页

作者： Arjun K S Tide p S Biju N Division of Mechanical Engineering School of EngineeringCochin University of Science&TechnologyKalamassery 682022India

Successfully utilized non-axisymmetric endwalls to enhance turbine efficiencies(aerodynamic and turbine inlet temperatures)by controlling the characteristics of the secondary flow in a blade *** is accomplished by steady-state numerical hydrodynamics and deep knowledge of the field of *** of the interaction between mainstream and purge flow contributing supplementary losses in the stage,non-axisymmetric endwalls are highly susceptible to the inception of purge flow exit compared to the flat and any advantage rapidly *** conclusions reveal that the supreme endwall pattern could yield a lowering of the gross pressure loss at the design stage and is related to the size of the top-loss location being productively *** has led to diminished global thermal exchange lowered in the passage of the vane *** reverse flow adjacent to the suction side corner of the endwall is migrated farther from the vane surface,as the deviated pressure spread on the endwall accelerates the flow and progresses the reverse flow core still *** depleted association between the tornado-like vortex and the corner vortex adjacent to the suction side corner of the endwall is the dominant mechanism of control in the contoured end *** this publication,we show that the non-axisymmetric endwall contouring by selective numerical shape change method at most prominent locations is advantageous in lowering the thermal load in turbines to augment the net heat flux reduction as well as the aerodynamic performance using multi-objective optimization.

关键词： endwall contouring turbine vane heat transfer phantom cooling coolant injection net heat flux reduction aerodynamic performance

Workplace harassment faced by female Nepalese migrants working aboard

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Global Health Journal 2024年第3期8卷 128-132页

作者： padam p Simkhad Edwin van Teijlingen Manju Gurung Samjhana Bhujel Kalpana Gyawali Sharada p Wasti School of Human and Health Sciences University of HuddersfieldHuddersfieldHD13DHUnited Kingdom Centre for Midwifery and Women's Health Faculty of Health&Social SciencesBournemouth UniversityBournemouth BH88GPUnited Kingdom pourakhi Nepal Makhamali MargMaharajgunj Kathmandu 44600Nepal Green Tara Nepal BaluwatarKathmandu 44600Nepal Faculty of Education Tribhuvan UniversityKathmandu 44600Nepal School of Human Sciences Faculty of EducationHealth and Human SciencesGreenwich UniversityLondonSE109LSUnited Kingdom

Background:Nepal has a long history of labour migration over the *** can experience a range of problems in their destination countries,and women are more at risk than *** paper is the first to explore the problems faced by Nepalese women migrants while working ***:This study was conducted among 1,889 women who were registered as migrant returnees at an organisation called pourakhi *** study extracted and analysed data from a non-governmental organisation that supports returning female migrant workers in ***:Around half(43.1%)of the women were 35 or older,30.9%were illiterate,and 63.6%were in their first overseas *** than one-third(38.5%)had self-reported workplace *** violence was the most prevalent(68%),followed by verbal abuse(37.5%),mental stress(29.7%),and sexual abuse(14.1%).Women who were illiterate(adjusted odds ratio[AOR]1.25,95%confidence interval[CI):1.01 to 1.55),unmarried(AOR 1.27,95%CI:1.05 to 1.56),worked abroad twice or more(AOR 1.35,95%CI:1.10 to 1.66),changed their place of work(AOR 2.38,95%CI:1.42 to 4.01),lived without documents(AOR 1.24,95%CI:1.03 to 1.50),worked as domestics(AOR 3.56,95%CI:2.03 to 6.23),worked in other than Gulf Cooperation Council countries(AOR 1.45,95%CI:1.06 to 1.99),women who did not have a fixed salary(AOR 1.64,95%CI:1.28 to 2.10)and did not receive salary(AOR 3.71,95%CI:2.88 to 4.77)were more likely to be harassed at ***:Our findings suggest that the host governments should introduce and enforce policies protecting women in the *** women should be provided with better information about health risks and hazards as well as how to improve preventive measures in destination countries to reduce workplace harassment.

关键词： Health problems Migration Exploitation Middle East South Asia

Broadband nonreciprocal thermal emissivity and absorptivity

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Light(Science & Applications) 2024年第9期13卷 1820-1827页

作者： Komron J.Shayegan Jae S.Hwang Bo Zhao Aaswath p.Raman Harry A.Atwater Thomas J.Watson Laboratory of Applied physics California Institute of TechnologyPasadenaCAUSA Department of Electrical Engineering California Institute of TechnologyPasadenaCAUSA Department of Materials Science and Engineering University of CaliforniaLos AngelesLos AngelesCAUSA Department of Mechanical Engineering University of HoustonHoustonTXUSA

A body that violates Kirchhoff’s law of thermal radiation exhibits an inequality in its spectral directional absorptivity and *** such an inequality is of fundamental interest as well as a prerequisite for achieving thermodynamic limits in photonic energy conversion1 and radiative *** far,inequalities in the spectral directional emissivity and absorptivity have been limited to narrow spectral resonances3,or wavelengths well beyond the infrared *** the gap from basic demonstrations to practical applications requires control over a broad spectral range of the unequal spectral directional absorptivity and *** this work,we demonstrate broadband nonreciprocal thermal emissivity and absorptivity by measuring the thermal emissivity and absorptivity of gradient epsilon-near-zero InAs layers of subwavelength thicknesses(50 nm and 150 nm)with an external magnetic *** effect occurs in a spectral range(12.5–16μm)that overlaps with the infrared transparency window and is observed at moderate(1 T)magnetic fields.

关键词： field. reciprocal thermal

Explainable artificial intelligence models for mineral prospectivity mapping

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Science China Earth Sciences 2024年第9期67卷 2864-2875页

作者： Renguang ZUO Qiuming CHENG Ying XU Fanfan YANG Yihui XIONG Ziye WANG Oliver p.KREUZER State Key Laboratory of Geological processes and Mineral Resources China University of GeosciencesWuhan 430074China School of Earth Sciences and Engineering Sun Yat-sen UniversityZhuhai 519000China Corporate Geoscience Group(CGSG) PO Box 5128 Rockingham BeachWA 6969Australia Economic Geology Research Centre(EGRU) College of Science and EngineeringJames Cook UniversityTownsvilleQLD 4811Australia

Mineral prospectivity mapping(MpM)is designed to reduce the exploration search space by combining and analyzing geological prospecting big *** geological big data are too large and complex for humans to effectively handle and *** intelligence(AI)algorithms,which are powerful tools for mining nonlinear mineralization patterns in big data obtained from mineral exploration,have demonstrated excellent performance in ***,AI-driven MpM faces several challenges,including difficult interpretability,poor generalizability,and physical *** this study,based on previous studies,we devised a novel workflow that aims to constructing more transparent and explainable artificial intelligence(XAI)models for MpM by embedding domain knowledge throughout the AI-driven MpM,from input data to model design and model *** newly proposed approach provides strong geological and conceptual leads that guide the entire AI-driven MpM model training process,thereby improving model interpretability and ***,the development of XAI models for MpM is capable of embedding prior and expert knowledge throughout the modeling process,presenting a valuable and promising area for future research designed to improve MpM.

关键词： Artificial intelligence Mineral prospectivity mapping Geological prospecting big data Domain knowledge Interpretability

HI in High Gas-phase Metallicity Dwarf Galaxy WISEA J230615.06+143927.9

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Research in Astronomy and Astrophysics 2024年第1期24卷 292-299页

作者： Yan Guo C.Sengupta T.C.Scott p.Lagos Y.Luo purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China Institute of Astrophysics and Space Sciences(IA porto) Rua das Estrelas4150-762PortoPortugal

We present resolved Giant Metrewave Radio Telescope H I observations of the high gas-phase metallicity dwarf galaxy WISEA J230615.06+143927.9(z = 0.005)(hereafter J2306) and investigate whether it could be a Tidal Dwarf Galaxy(TDG) candidate. TDGs are observed to have higher metallicities than normal dwarfs. J2306 has an unusual combination of a blue g-r color of 0.23 mag, irregular optical morphology and high-metallicity(12 +log(O/H) = 8.68 ± 0.14), making it an interesting galaxy to study in more detail. We find J2306 to be an H I rich galaxy with a large extended, unperturbed rotating H I disk. Using our H I data we estimated its dynamical mass and found the galaxy to be dark matter(DM) dominated within its H I radius. The quantity of DM, inferred from its dynamical mass, appears to rule out J2306 as an evolved TDG. A wide area environment search reveals J2306 to be isolated from any larger galaxies which could have been the source of its high gas metallicity. Additionally, the H I morphology and kinematics of the galaxy show no indication of a recent merger to explain the *** detailed optical spectroscopic observations of J2306 might provide an answer to how a seemingly ordinary irregular dwarf galaxy achieved such a high level of metal enrichment.

关键词： galaxies:abundances galaxies:dwarf galaxies:irregular radio lines:galaxies radio lines:ISM

Diet and monensin influence the temporal dynamics of the rumen microbiome in stocker and finishing cattle

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Journal of Animal Science and Biotechnology 2024年第2期15卷 733-748页

作者： Jianmin Chai Caleb p.Weiss paul A.Beck Wei Zhao Ying Li Jiangchao Zhao Guangdong provincial Key Laboratory of Animal Molecular Design and precise Breeding College of Life Science and EngineeringFoshan UniversityFoshanChina Division of Agriculture Department of Animal ScienceUniversity of ArkansasFayettevilleARUSA Department of Animal and Food Sciences Oklahoma State UniversityStillwaterOKUSA Institute of Feed Research of Chinese Academy of Agricultural Sciences Key Laboratory of Feed Biotechnology of the Ministry of Agriculture and Rural AffairsBeijing 100193China

Background Stocker cattle diet and management influence beef cattle performance during the finishing stage,but knowledge of the dynamics of the rumen microbiome associated with the host are lacking.A longitudinal study was conducted to determine how the feeding strategy from the stocker to the finishing stages of production affects the temporal dynamics of rumen *** the stocker phase,either dry hay or wheat pasture were provided,and three levels of monensin were *** calves were then transported to a feedlot and received similar finishing diets with or without *** microbial samples were collected on d 0,28,85 during the stocker stage(S0,S28 and S85)and d 0,14,28,56,30 d before slaughter and the end of the trial during the finishing stage(F0,F14,F28,F56,pre-Ba,and Final).The V4 region of the bacterial 16S rRNA gene of 263 rumen samples was *** Higher alpha diversity,including the number of observed bacterial features and the Shannon index,was observed in the stocker phase compared to the finishing *** bacterial amplicon sequence variants(ASVs)differentiating different sampling time points were *** treatments during the stocker stage temporally impact the dynamics of rumen *** example,shared bacteria,including Bacteroidales(ASV19)and Streptococcus infantarius(ASV94),were significantly higher in hay rumen on S28,S85,and F0,while Bacteroidaceae(ASV11)and Limivicinus(ASV15)were more abundant in *** affected rumen microbial composition at a specific *** to feedlot significantly influenced microbiome structure and diversity in hay-fed *** taxa associated with body weight were classified,and core microbiotas interacted with each other during the *** In summary,the temporal dynamics of the rumen microbiome in cattle at the stocker and finishing stage are influenced by multiple factors of the feeding *** at the stocker phase may t

关键词： Beef cattle Diet Feedlot phase Monensin Next-generation sequencing Rumen microbiota Stocker

Taurine: a promising nutraceutic in the prevention of retinal degeneration

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Neural Regeneration Research 2024年第3期19卷 606-610页

作者： Diego García-Ayuso Johnny Di pierdomenico Ana Martínez-Vacas Manuel Vidal-Sanz Serge picaud María pVillegas-pérez Grupo de Investigación Oftalmología Experimental Departamento de OftalmologíaOptometríaOtorrinolaringología y Anatomía PatológicaFacultad de MedicinaUniversidad de MurciaInstituto Murciano de Investigación Biosanitaria(IMIB)Campus de Ciencias de la SaludMurciaEspaña Sorbonne Université INSERMCNRSInstitut de la VisionParisFrance

Taurine is considered a non-essential amino acid because it is synthesized by most ***,dietary intake of taurine may be necessary to achieve the physiological levels required for the development,maintenance,and function of certain *** may be especially important for the *** concentration of taurine in the retina is higher than that in any other tissue in the body and taurine deficiency causes retinal oxidative stress,apoptosis,and degeneration of photoreceptors and retinal ganglion *** plasma taurine levels may also underlie retinal degeneration in humans and therefore,taurine administration could exert retinal neuroprotective *** has antioxidant,anti-apoptotic,immunomodulatory,and calcium homeostasis-regulatory *** review summarizes the role of taurine in retinal health and disease,where it appears that taurine may be a promising nutraceutical.

关键词： amino acid anti-inflammatory antioxidant gamma-aminobutyric acid nutraceutical photoreceptor degeneration retina retinitis pigmentosa taurine

Wildfire severity alters soil microbial exoenzyme production and fungal abundances in the southern Appalachian Mountains

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pedosphere 2024年第5期34卷 865-878页

作者： Megan L.SCHILL Richard BAIRD Shawn p.BROWN Allison M.VEACH Department of Integrative Biology University of Texas at San Antonio Biochemistry Molecular Biology Entomology and Plant Pathology Department Mississippi State University Department of Biological Sciences The University of Memphis

Climate change has increased drought frequency and duration that are exacerbated by increased temperatures globally. This effect has, and will continue,to increase fire occurrence across many regions of North America. In the southern Appalachian Mountains, wildfires with high burn severity occurred in 2016due to increased drought and human activity. To investigate the effects of burn severity on soil physicochemical properties, microbial extracellular enzyme production, and microbial abundances in a temperate region, surface soils (0–15 cm) were collected from two sites (the Great Smoky Mountains National park in Tennessee and the Nantahala National Forest in North Carolina, USA) spanning lightly, moderately, and severely burned areas, accompanied by adjacent unburned locations that act as controls. The soil samples were collected at three time points between 2017 and 2019 (i.e., 0.5, 1, and 2.5 years post-fire)among burn severity plots. Total hydrolytic enzyme production varied over time, with severe burn plots having significantly lower enzyme production at 2.5years post-fire. Individual enzymes varied among burn severities and across time post-fire. Light burn plots showed greater carbon-specific (β-glucosidase and β-xylosidase) and phosphorus-specific (acid phosphatase) enzyme activities at 0.5 years post-fire, but this effect was transient. At 2.5 years post-fire, theβ-xylosidase and acid phosphatase activities were lower in severe or moderate burn plots relative to the controls. In contrast, the activity of nitrogen-specific enzyme leucyl aminopeptidase was the lowest in severe burn plots at 0.5 years post-fire, but was the lowest in light burn plots at 2.5 years post-fire. The fungi:bacteria ratio declined with burn severity, indicating that fungi are sensitive or less resilient to high burn severity during recovery. These results suggest that wildfires alter trajectories for soil microbial structure and function within a 2.5-year timeframe, which potentially

关键词： 16S carbon ITS nitrogen phosphorous