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Do black-furred animals compensate for high solar absorption with smaller hairs？ A test with a polymorphic squirrel species

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Current Zoology 2011年第6期57卷 731-736页

作者： Melanie A. FRATTO Andrew K. davis Odum School of Ecology The University of Georgia Athens GA USA 30602

In polymorphic mammalian species that display multiple color forms, those with dark, or melanic pelage would be prone to overheating, especially if they live in warm climates, because their fur absorbs solar energy at a higher rate. however, experimental studies indicate that certain physical properties of fur of dark individuals appear to prevent, or minimize heat stress, although it is not clear what properties do so. here, we tested the possibility that black-furred individuals simply have shorter or thinner hair fibers, which would create a lighter （in terms of weight） coat or one that allows greater air flow for evaporative coo- ling. We examined museum specimens of eastern fox squirrels Sciurus niger, a species native to the United States and one that displays brown, grey or all-black pelage color, and used image analysis procedures to quantify hairs from the dorsal surface and tail. From examination of 43 specimens （19 brown, 9 black and 15 grey）, and 1,720 hairs, we found no significant difference in hair lengths across color morphs, but significant differences in hair fiber widths. Black squirrels had thinner body hairs than other forms （7% thinner）, but thicker tail hairs （9% thicker） than the others. Given that the dorsal surface would be directly exposed to solar radiation, we interpret this to be an adaptation to prevent heat stress during the day. The thicker tail hairs may be an adapta- tion for nighttime thermoregulation, since squirrels sleep with their tails wrapped around their bodies. These results add to a growing literature body of the functional significance of mammalian pelage [Current Zoology 57 （6）： 731-736, 2011].

关键词： polymorphism Melanism Fox squirrels Sciurus niger heat stress hair morphology

Regulation of protein degradation pathways by amino acids and insulin in skeletal muscle of neonatal pigs

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Journal of Animal Science and Biotechnology 2014年第3期5卷 299-309页

作者： Agus Suryawan Teresa A davis United States Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center Department of PediatricsBaylor College of Medicine

Background： The rapid gain in lean mass in neonates requires greater rates of protein synthesis than degradation. We previously delineated the molecular mechanisms by which insulin and amino acids, especially leucine, modulate skeletal muscle protein synthesis and how this changes with development. In the current study, we identified mechanisms involved in protein degradation regulation. In experiment 1,6- and 26-d-old pigs were studied during 1） euinsulinemic-euglycemic-euaminoacidemic, 2） euinsulinemic-euglycemiohyperaminoacidemic, and 3） hyperinsulinemic-euglycemic-euaminoacidemic clamps for 2 h. In experiment 2, 5-d-old pigs were studied during 1） euinsulinemic-euglycemic-euaminoacidemic-euleucinemic, 2） euinsulinemic-euglycemic-hypoaminoacidemic- hyperleucinemic, and 3） euinsulinemic-euglycemic-euaminoacidemic-hyperleucinemic clamps for 24 h. We determined in muscle indices of ubiquitin-proteasome, i.e., atrogin-1 （MAFbx） and muscle RING-finger protein-1 （MuRF1） and autophagy-lysosome systems, i.e., unc51-1ike kinase 1 （UKL1）, microtubule-associated protein light chain 3 （LC3）, and lysosomal-associated membrane protein 2 （Lamp-2）. For comparison, we measured ribosomal protein 56 （rpS6） and eukaryotic initiation factor 4E （elF4E） activation, components of translation initiation. Results： Abundance of atrogin-1, but not MuRF1, was greater in 26- than 6-d-old pigs and was not affected by insulin, amino acids, or leucine. Abundance of ULK1 and LC3 was higher in younger pigs and not affected by treatment. The LC3-11/LC3-1 ratio was reduced and ULK1 phosphorylation increased by insulin, amino acids, and leucine. These responses were more profound in younger pigs. Abundance of Lamp-2 was not affected by treatment or development. Abundance of elF4E, but not rpS6, was higher in 6- than 26-d-old-pigs but unaffected by treatment. phosphorylation of elF4E was not affected by treatment, however, insulin, amino acids, and leucine stimulated rpS6 phosphorylation, and the resp

关键词： Amino acids Autophagy Insulin Leucine Muscle Neonate protein degradation protein synthesis,Swine Ubiquitin

Vaccine-associated myocarditis:a case report and summary of the literature

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World Journal of Emergency Medicine 2022年第6期13卷 485-487页

作者： Joshua davis Lauren Jennings University of Kansas School of Medicine Wichita 67214USA Vituity Wichita 67214USA American Red Cross in hazelwood Missouri 63042USA

Dear editor,Myocarditis is a known complication of vaccines for COVID-19,particularly mRNA *** it is rare,the exact incidence of vaccine-associated myocarditis is *** of personal choice in vaccination decisions often cite the risk of myocarditis as a reason one might choose not to receive the COVID-19 ***,we describe a case of focal myocarditis associated with the pfizer-BioNTech COVID-19 vaccine and review the literature on the incidence and risk of COVID-19 vaccine-associated myocarditis.

关键词： myocarditis vaccine pfizer

AITEB - An European Research project on Aero-thermodynamics of Turbine Endwalls and Blades

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Journal of Thermal Science 2004年第2期13卷 97-108页

作者： F. hASELBACh h.-p. SChIFFER Rolls-Royce Deutschland Turbines Eschenweg 11 15827 Dahlewitz GermanyRolls-Royce Deutschland Turbines Eschenweg 11 15827 Dahlewitz Germany

The paper delivers an overview on the European research project AITEB - Aerothermal Investigations on Turbine Endwalls and Blades, which started in year 2000 in the course of the 5. Framework programme (GROWTh). The aim is to submit an integrated technology and design tool package for the advanced, aerothermal highly loaded design of turbines, especially: Experimental/numerical investigation on heat transfer and film-cooling in separated flow for highly loaded blades including advanced trailing edge cooling heat transfer/ improved cooling of turbine endwalls: Experimental/numerical work on cooling of turbine endwalls, shrouds and recessed blade tips. Optimised CFD-process (drawing-grid-modelling-postprocessing-risk assessment) in order to derive the 'best practice' to use CFD as a time effective tool. After most of the project life, an overview on the project is delivered. Experimental results of test series at various test sites are compared to numerical simulations of the industrial and university partners.

关键词： turbines aerothermal endwalls blades cooling-technology experiment CFD.

performance enhancement of water bath heater at natural gas city gate station using twisted tubes

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Chinese Journal of Chemical Engineering 2020年第1期28卷 165-179页

作者： p.Soleimani M.Khoshvaght-Aliabadi h.Rashidi h.Bahmanpour Department of Chemical Engineering Shahrood BranchIslamic Azad UniversityShahroodIran Department of Environment Shahrood BranchIslamic Azad UniversityShahroodIran

Natural gas is transported from producing regions to consumption regions by using transmission pipelines at high pressures. At consumption regions, the pressure of natural gas is reduced in city gate stations(CGSs). Before the pressure reduction process, the temperature of natural gas is increased usually by using a water bath heater,which burns natural gas as fuel, to protect against freezing of natural gas. These types of heat exchangers have a low efficiency and consume a lot of fuel to generate the required heat. In the current study, the twisted configuration of the heating coil is proposed and investigated to enhance the heat transfer through a water bath heater with a nominal capacity of 1000 m^3·h^-1. Firstly, the implementation procedure is validated with data collected from the CGS of Qaleh-Jiq(located in Golestan province of Iran). A very good agreement is achieved between the obtained results and the real data. Then, three different twist ratios are considered to examine the twisting effects. The proposed technique is evaluated in the terms of velocity, temperature, and pressure variations, and the results are compared with the conventional case, i.e. straight configuration. It is found that both the heat transfer rate and the pressure drop augment as the twist ratio is raised. Finally, it is concluded that the twisted tubes can reduce the length of the gas coil by about 12.5% for the model with low twist ratio, 18.75% for the model with medium twist ratio, and 25% for the model with high twist ratio as compared to the straight configuration.

关键词： Natural gas city gate station Water bath heater heat transfer enhancement Twisted tube

Crack initiation stress and strain of jointed rock containing multi-cracks under uniaxial compressive loading: A particle flow code approach

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Journal of Central South University 2015年第2期22卷 638-645页

作者：范祥 KULATILAKE p.h.S W 陈新曹平 School of Resources and Safety Engineering Central South University Rock Mass Modeling and Computational Rock Mechanics Laboratories University of Arizona School of Mechanics and Civil Engineering China University of Mining and Technology (Beijing)

The ratio of crack initiation stress to the uniaxial compressive strength(SCI,B/SUC,B) and the ratio of axial strain at the crack initiation stress to the axial strain at the uniaxial compressive strength(B,UCB,CI,A,A/SSSS) were studied by performing numerical stress analysis on blocks having multi flaws at close spacing's under uniaxial loading using pFC3 D. The following findings are obtained: SCI,B/SUC,B has an average value of about 0.5 with a variability of ± 0.1. This range agrees quite well with the values obtained by former research. For joint inclination angle, β=90°,B,UCB,CI,A,A/SSSS is found to be around 0.48 irrespective of the value of joint continuity factor, k. No particular relation is found betweenB,UCB,CI,A,A/SSSS and β; however, the average B,UCB,CI,A,A/SSSS seems to slightly decrease with increasing k. The variability ofB,UCB,CI,A,A/SSSS is found to increase with *** on the cases studied in this work,B,UCB,CI,A,A/SSSS ranges between 0.3 and 0.5. This range is quite close to the range of 0.4to 0.6 obtained for SCI,B/SUC,B. The highest variability of ± 0.12 forB,UCB,CI,A,A/SSSS is obtained for k=0.8. For the remaining k values the variability ofB,UCB,CI,A,A/SSSS can be expressed within ± 0.05. This finding is very similar to the finding obtained for the variability of SCI,B/SUC,B.

关键词： jointed rock multi flaws uniaxial loading pFC3D model crack initiation stress(SCI B) axial strain at crack initiation

EFFECTS OF CARBON CONTENT AND ROLLING pROCESSING ON RETAINED AUSTENITE FOR hOT-ROLLED TRIp STEELS

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Acta Metallurgica Sinica(English Letters) 2002年第5期15卷 439-447页

作者： Y. Chen, X. Chen, Z.X. Yuan, B.F. Xu, A.M. Guo, p.h. Li and S.K. puWuhan University of Science and Technology, Wuhan 430081, ChinaTechnical Center of Wuhan Iron and Steel Co., Wuhan 430080, China Wuhan University of Science and Technology Technical Center of Wuhan Iron and Steel Co.

The effects of finishing rolling temperature and coiling temperature on retained austen-ite were studied for hot-rolled transformation induced plasticity (TRIp) steels with different carbon content. The experimental results showed that an appropriate volume fraction of retained austenite from 6% to 11% could be obtained according to the different carbon content less than 0.20% by controlled finishing rolling and coiling for the hot-rolled TRIp steels. It can be concluded that carbon content has a significant effect on the fraction of retained austenite and coiling processing plays stronger role on retaining austenite than fishing rolling processing.

关键词： TRIp steel carbon content retained austenite

Experimental studies and phase field modeling of microstructure evolution during solidification with electromagnetic stirring

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中国有色金属学会会刊：英文版 2010年第S3期20卷 774-780页

作者： p.GERALD TENNYSON p.KUMAR h.LAKShMI G.phANIKUMAR p.DUTTA Department of Metallurgical and Materials Engineering Indian Institute of Technology National Facility for Semisolid Forming Department of Mechanical EngineeringIndian Institute of Science

Thixocasting requires manufacturing of billets with non-dendritic *** alloy A356 billets were produced by rheocasting in a mould placed inside a linear electromagnetic *** heat treatment was used to produce a transition from rosette to globular *** current and the duration of stirring were explored as control *** induction heating of the billet during stirring was quantified using experimentally determined thermal *** effect of processing parameters on the dendrite fragmentation was *** computational modeling of the process was performed using phase-field modeling of alloy solidification in order to gain insight into the process of morphological changes of a solid during this process.A non-isothermal alloy solidification model was used for *** morphological evolution under such imposed thermal cycles was simulated and compared with experimentally determined *** scaling using the thermosolutal diffusion distances was used to overcome computational difficulties in quantitative comparison at system *** results were interpreted in the light of existing theories of microstructure refinement and globularisation.

关键词： electromagnetic stirring non-dendritic phase field modeling microstructure

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