检索结果-南通市图书馆

MHD flow of a visco-elastic fluid through a porous medium between infinite parallel plates with time dependent suction

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2015年第5期27卷 738-747页

作者： BAAG S. AcHArYA M.r. DASH G.c. MISHrA S.r. Department of Physics College of Basic Science and HumanitiesOUAT Department of Mathematics ITER SOA University

This work provides a comprehensive theoretical analysis of MHD unsteady free convection viscoelastic fluid flow through a porous medium. The medium is treated as incompressible and optically transparent. The flow of the fluid is initiated by shearing action of the moving wall with time dependent suction. radiative heat flow is considered in temperature equation. The coupled nonlinear problem has been solved asymptotically. Approximate solutions have been obtained for the mean velocity, mean temperature using multi parameter perturbation technique. The originality of the present study is to investigate the effect of viscoelastic property of the fluid（Walters B？ model） on the flow and heat transfer phenomena when the flow is permeated through a porous medium with uniform porous matrix subject to transverse magnetic field and time dependent fluctuative suction at the boundary surface. The case of viscous flow has been discussed as a particular case on comparison with the result reported earlier and it is in good agreement. Flow reversal is indicated incase of viscoelastic fluid with high heat capacity in the presence of magnetic field. The higher cooling of the plate in case of viscoelastic flow also causes a flow reversal.

关键词： viscoelastic liquid porosity radiation parameter time dependent suction

Influence of Heat Treatment on the Bond coat cyclic Oxidation Behaviour in an Air-plasma-sprayed Thermal Barrier coating System

在线全文

学校读者我要写书评

暂无评论

材料热处理学报 2004年第05B期25卷 923-929页

作者： W.r.chen X.Wu B.r.Marple P.c.Patnaik Structures MaterialsandPropulsionLaboratoryInstituteforAerospaceResearchNationalResearchCouncilCanadaOttawaOntarioCanadaK1AOR6 IndustrialMaterialsInstitute NationalResearchCouncilCanadaBouchervilleQuebecCanadaJ4B6Y4

It is generally believed that a thermally grown oxide (TOO) layer of alumina provides enhanced protection to the metallic bond coat in thermal barrier coating (TBc) systems at elevated temperatures. However, in an air-plasma-sprayed (APS) TBc system with co-32Ni-21cr-8Al-0.5Y (wt%) bond coat, the TGO layer formed upon thermal exposure in air was predominantly chromia and spinels, which would not effectively protect the bond coat at above 1000°c. In addition, mixed oxides of chromia, spinel and nickel oxide formed heterogeneously between the ceramic coating and coNicrAlY bond coat, which would promote crack initiation and lead to premature TBc failure. A heat treatment in a low-pressure condition was applied to the as-sprayed TBc system, with the aim to produce an alumina layer as well as reduce the amount of detrimental oxides. The influence of this low-pressure oxidation treatment (LPOT) on the bond coat cyclic oxidation behaviour of the TBc system was also investigated.

关键词：热处理 TGO TBc 低压氧化周期性氧化 coNicrAlY合金

Protozoan colonization on artificial substrates in relation to water quality in a tropical Indian harbour

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2001年第2期13卷 143-147页

作者： V.r.Bharati r.N.Khan c.Kalavati A.V.raman Department of Zoology Andhra UniversityVisakhapatnam 530003India.

A field study was conducted to evaluate the protozoan colonization patterns on artificial substrates in relation to organic pollution within a tropical harbour. The composition of protozoans and their succession rates on artificial substrates(polyurethane foam units) were compared between two field stations(A and B), and their presence were considered with regards to the prevailing water quality conditions at the study sites. Altogether 44 genera of flagellates and ciliates were documented. The common genera of flagellates encountered included Monas, Polytoma, and chromalina. Among the ciliates, the predominant genera were Tetrahymena, Vorticella, Lagynophyra, and Heloiphyra. These groups exhibited characteristic successional patterns in relation to ambient water quality. At Station A, located close to the sewage outfall, the water quality parameters included poor Secchi disc transparency(0.48m), dissolved oxygen of 1.93 mg/ml, salinity of 18 psu, and temperature 31.3 ℃. Here, the nanoflagellates( spumella ) colonized first, followed by microcilliate( Tetrahymena ) and sessile form( Vorticella ). Station B, located on the seaward side, was characterized by relatively less stressed environmental conditions with transparency 1.85m and dissolved oxygen value of 6 04 mg/ml. Salinity of 27.27 psu, and mean temperature of 30 ℃ were recorded at “B'. At this station, the nanoflagellate Polytoma was first documented to colonize on the substrates, followed by microcilliate( Lagynophrya ) and suctorid( Heliophyra ). These findings support the use of protozoans as indicator species for evaluating the hazards posed by organic pollution to natural estuarine communities.

关键词： Protozoan colonization on artificial substrates in relation to water quality in a tropical Indian harbour

Antimicrobial activity of cotton and silk fabric with herbal extract by micro encapsulation

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2010年第2期3卷 128-132页

作者： Saraswathi r Krishnan PN Dilip c Al Shifa college of Pharmacy KizhatturPerinthalmannaKerala679325India

Objective:To explore the antimicrobial activity of microcapsules encapsulated with mixture of herbs like neem,tulsi and turmeric,and its application on cellulosic fabric in the form of ***:The microcapsules were prepared from the mixture of herbs by plain diffusion method,a natural encapsulation technique with yeast and applied on cotton and silk fabric by pad-dry-cure *** microcapsules were fixed on cotton and silk fabric using the binder UF Silpure FBr-5(PA)B at 120℃.The antimicrobial activities of the finished fabric were assessed by using three types of bacteria including Staphylococcus aureus,Escherichia coli and ***:The results of antimicrobial activity from the tests including parallel streak method and disc diffusion method showed that activity of the mixture of herbs was very effective among the three types of bacteria selected,and the antimicrobial activity of prepared microcapsule against Pseudomonas was very ***:The herbal microcapsule treated fabric could be applied in the field of *** scanning electron microscope photographs ensure the fixing of the microcapsules firmly in the yarn structure of plain woven cotton and silk fabric.

关键词： Antimicrobial activity Herbs microencapsulation Ultra-fresh silpure

Investigating the use of an ionic liquid for rare earth mineral flotation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of rare Earths 2021年第7期39卷 866-874,I0004页

作者： r.Li c.Marion E.r.L.Espirtu r.Multani Xiaoqi Sun K.E.Waters Department of Mining and Materials Engineering McGill University3610 Rue University.MontrealQuebecH3A 0C5Canada Vale Ontario Operations(Base Metals)18 Rink St.Copper CliffOntario POM 1N0Canada Fujian Institute of research on the Structure of Matter Chinese Academy of Sciences155 Yangqiao Road WestFuzhou 350002China

common collectors for rare earth mineral(rEM) flotation,which include carboxylates and hydroxamates,face problems such as being non-selective and sensitive to impurity ions.A type of ionic liquid(IL),tetraethylammonium mono-(2-ethylhexyl)2-ethylhexyl phosphonate([N_(2222)][EHEHP]),has been investigated previously for rare earth elements(rEE) solvent extraction,and was proven to be selective and *** this work,[N_(2222)][EHEHP] was evaluated as a collector in bastnasite(a primary rEM source for rEE production) flotation for the first *** results were compared with quartz and hematite,two common gangue minerals in rEM *** potential measurements and Fouriertransform infrared spectroscopy(FT-Ir) were completed to investigate the surface chemical properties involved in the flotation of these minerals using this *** findings were compared with microflotation ***-Ir and zeta potential measurements suggest adsorption of the collector’s phosphonate group onto bastnäsite and hematite,likely through chemisorption;whereas for quartz,the minimum micro flotation recovery is likely due to no adsorption of IL on its *** flotation re sults show higher collectability of [N_(2222)] [EHEHP] for hematite than bastnasite,the latter only shows appreciable recovery at pH 5 with elevated dosage of IL(500 g/t).To achieve better separation,a two-stage flotation scheme was designed and evaluated by bench scale flotation on a synthetic mineral *** concentrates and tails were analyzed by magnetic separation,and it is found that bastnasite recovery over 90% with maximum upgrade ratio 1.7 can be achieved with elevated collector dosage.

关键词： Ionic liquid rare earth Bastnasite Flotation FT-Ir Zeta potential

Hepatocellular carcinoma recurrence after liver transplant:An Australian single-centre study

在线全文

学校读者我要写书评

暂无评论

World Journal of Transplantation 2025年第1期15卷 105-114页

作者： Matthew G Garas Luis calzadilla-Bertot Briohny W Smith Luc Delriviere Byron Jaques Lingjun Mou Leon A Adams Gerry c MacQuillan George Garas Gary P Jeffrey Michael c Wallace Medical School University of Western AustraliaNedlands 6009Western AustraliaAustralia Department of Hepatology Sir Charles Gairdner HospitalNedlands 6009Western AustraliaAustralia Department of Surgery Sir Charles Gairdner HospitalNedlands 6009Western AustraliaAustralia

BAcKGrOUND Hepatocellular carcinoma(Hcc)is a leading cause of cancer-related deaths *** transplantation(LT)offers the most effective *** recurrence is the strongest risk factor that decreases post-LT survival in patients transplanted for *** rate of Hcc recurrence is generally reported as 8%-20%in the *** predictors of Hcc have already been researched,however,to our knowledge there are no published studies on this topic using Australian *** To determine the rate and identify predictors of Hcc recurrence in a contemporary Western Australian LT *** We performed a retrospective cohort study of all liver transplants in patients with Hcc at Sir charles Gairdner Hospital between 2006 and *** was collected from various health record databases and included recipient demographics,serum biochemistry,radiology,operation notes,explant histopathology and details of *** survival of Hcc patients post-LT,stratified for recurrence,was calculated by Kaplan Meier *** and multivariate cox regression was used to determine predictors of Hcc recurrence *** Between 1/1/2006 and 12/31/2021,119 patients were transplanted with Hcc.8.4%of subjects developed recurrent Hcc after LT with median follow-up time of 5.4 *** median time to recurrence was 2.9 years±0.75 *** comparing baseline characteristics,a greater proportion of subjects with recurrence had common characteristics on explant histopathology,including>3 viable nodules(P=0.001),vascular invasion(P=0.003)and poorly differentiated Hcc(P=0.03).Unadjusted survival curves showed lower 1-year,3-year,5-year and 10-year survival rates in subjects with Hcc recurrence compared to those without Hcc recurrence(90%vs 92%,70%vs 88%,42%vs 80%,14%vs 76%,respectively;log rank PcONcLUSION Hcc recurrence was low at 8.4%in this contemporary Australian cohort,however it significantly impacted post-LT *** studies are requir

关键词： Liver cancer recurrence Liver transplantation Hepatocellular carcinoma Predictors Post-transplant survival Australian data

Effect of Laser Welding on Properties of Dissimilar Joint of Al-Mg-Si and Al-Mn Aluminum Alloys

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2010年第3期26卷 276-282页

作者： c.c.chang c.P.chou S.N.Hsu G.Y.Hsiung J.r.chen Department of Mechanical Engineering National Chiao-Tung University National Synchrotron radiation research center Department of Biomedical Engineering and Environmental Sciences National Tsing-Hua University

This study discusses the welding properties for the components of an aluminum-alloy ultra-high vacuum chamber and beam position monitor （BPM）.The welding parameters include the modes of laser output （pulsed wave and continuous wave）,welding speed,shield gas flow,welding bead structure,and focusing *** results showed that the welding defect rate of the pulsed wave type was larger than that of the continuous wave *** crack in the welding bead reduced with decreasing welding *** fusion penetration of the welding bead was higher when the focusing distance was long enough to deepen into the welding *** morphology during the experimental process revealed the proper flow of shield *** adaptability design of the welding bead structure in the preceding processes had more effect on overall welding structure and morphology.

关键词： Laser welding Aluminum alloy Ultra-high vacuum Beam position monitor (BPM)

Microstructural Evolution of Infrared Brazed cP-Ti Using Ti-cu-Ni Brazes

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2011年第2期27卷 131-138页

作者： c.T.chang T.Y.Yeh r.K.Shiue c.S.chang Department of Mechanical Engineering National Hualien Industrial Vocational Senior High SchoolHualien 970TaiwanChina Department of Materials Science and Engineering National Taiwan UniversityTaipei 106TaiwanChina Engineered Materials Solutions 39 Perry AvenueMS 4-1AttleboroMA 02703-2410USA

Microstructural evolution of infrared vacuum brazed cP-Ti using two Ti-based braze alloys,Ti-15cu-15Ni and Ti-15cu-25Ni,has been *** infrared brazed joint consisted of eutectic Ti 2 cu/Ti 2 Ni intermetallic compounds and Ti-rich *** eutectic Ti 2 cu/Ti 2 Ni intermetallic compounds disappeared from the joint after being annealed at 900 c for 1 *** contrast,the depletion rate of both cu and Ni from the braze alloy into cP-Ti substrate at 750 c annealing was greatly decreased as compared with that annealed at 900 *** Ti 2 cu/Ti 2 Ni phases were observed even if the specimen was annealed at 750 c for 15 *** the Ni content of the Ti-15cu-25Ni braze alloy is much higher than that of the Ti-15cu-15Ni alloy,the amount of eutectic Ti 2 cu/Ti 2 Ni phases in Ti-15cu-25Ni brazed joint is more than that in Ti-15ci-15Ni brazed ***,similar microstructural evolution can be obtained from the infrared brazed joint annealed at various temperatures and/or time for both filler metals.

关键词： Infrared Brazing cP-Ti Ti-cu-Ni fillers Microstructure

Optimization algorithms and intelligent techniques on electrical discharge machining process

在线全文

学校读者我要写书评

暂无评论

International Journal of Modeling, Simulation, and Scientific computing 2021年第4期12卷 12-40页

作者： c.S.Shyn r.rajesh Noorul Islam centre for Higher Education Tamil Nadu India

Electrical Discharge Machining (EDM) is considered as the much traditional, adaptableand unconventional machining process that is proficient in generating complicated structures. Further, it is self-sufficient over the mechanical properties of workpiece materialsonly if it is conductive. The viability of the EDM process regarding the application typesmight get considerably improved with the constant enhancement in the personificationof numerical control and the metal removal efficacy. This survey intends to make a reviewof 65 papers related to the optimization and modeling of EDM process machining. Theanalysis is thus made with regards to the following factors like Al alloy composite in DieShrinking EDM, Optimization and Al metal matrix composites. Particularly, the hybridoptimization models in various papers are analyzed concerning their logic. Further, thealgorithmic and parametric analysis is also made with the contributed papers. Finally,the research gaps and challenges in this EDM processing are discussed, which wouldpave the way for efficient research works in this area.

关键词： Electric discharge machining aluminium alloy metal matrix composite neural network optimization