检索结果-南通市图书馆

Response of a slender cylindrical member under breaking wave impact

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2019年第2期31卷 345-357页

作者： manjula R. sannasiraj s.A Department of Civil Engineering National Institute of TechnologyTiruchirappalliIndia Department of Ocean Engineering Indian Institute of Technology MadrasChennaiIndia

A slender cylindrical member is the fundamental component of many coastal and offshore *** is essential to understand the action of breaking waves on structural members since,when these members are subjected to wave impact load,the structural damages and failures may be *** the present study,an experimental investigation has been carried out to measure the response of the slender vertical cylinder subjected to breaking wave *** measurements were made in order to estimate the total force acting on the *** empirical relation is established between total impact force and the wave steepness parameter which dictates the intensity of the *** rise time is an important parameter dictating the impact *** acceleration and strain measurements were made to evaluate the response of the *** has been derived from structure *** deflection due to the moderate plunging differs by two order more than severe plunging *** rate is another important consideration for the impact *** higher strain rate increases the resistance of the *** the breaking wave impact on the cylinder,the strain rate varies from 102 to 10-4.

关键词： Breaking wave impact acceleration slender vertical cylinder wave steepness strain rate strain

microstructural characteristics of thixoforged A356 alloy in mushy state

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

中国有色金属学会会刊：英文版 2010年第S3期20卷 781-787页

作者： s.TAHAmTAN A.FADAVI BOOsTANI Department of materials science and Engineering Isfahan University of Technology

Tensile properties of a thixoforged A356 alloy were measured and compared with those of rheocast and gravity cast alloys with the same *** the thixoforging process,A356 rheocast alloy produced by stirring method was reheated to 600 °C or 610 °C,held for 10 min,and then 50% deformation was ***,tensile properties and fracture surfaces of produced specimens were then *** obtained show that tensile strength,yield strength and elongation-to-failure of thixoforged samples formed at lower temperature are higher than those of samples formed at higher *** increasing temperature,in the case of thixoforged samples,tensile fracture path is changed from trans-primary alpha phase to inter-primary alpha *** observed in the tensile fracture path and improvement in the mechanical properties due to thixoforging process is attributed to microstructural changes as well as morphological aspects of silicon phase.

关键词： thixoforging rheocasting tensile properties hot working fracture surface

Intensification of photocatalytic decomposition of water by ultrasound

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2018年第4期27卷 1183-1188页

作者： Arvind singh A.s.K.sinha Department of Chemical Engineering and Technology Indian Institute of Technology (Banaras Hindu University)

Photocatalysis of water with and without ultrasound was studied using rGO supported Cds catalyst utilizing visible light. A higher hydrogen production was observed when ultrasound was used. This is attributed to a faster removal of bubbles of hydrogen from the surface of photocatalyst due to the mechanical energy associated with ultrasound overcoming surface tension. It has been further reported that the rate of hydrogen production decreased with time due to reversible deactivation of catalyst. This has been attributed to decrease in rate of hydrogen desorption with time.

关键词： Hydrogen Photocatalysis Ultrasound Kinetics

Nanoscale mass sensing based on vibration of single-layered graphene sheet in thermal environments

在线全文

学校读者我要写书评

暂无评论

Acta mechanica sinica 2014年第1期30卷 84-91页

作者： s.Ahmad Fazelzadeh Esmaeal Ghavanloo school of mechanical Engineering Shiraz University

Based on vibration analysis, single-layered graphene sheet （sLGs） with multiple attached nanoparticles is developed as nanoscale mass sensor in thermal environments. Graphene sensors are assumed to be in simplysupported configuration. Based on the nonlocal plate the- ory which incorporates size effects into the classical theory, closed-form expressions lot the frequencies and relative fre- quency shills of sLGs-based mass sensor are derived using the Galerkin method. The suggested model is justified by a good agreement between the results given by the present model and available data in literature. The effects of tem- perature difference, nonlocal parameter, the location of the nanoparticle and the number of nanoparticles on the relative frequency shift of the mass sensor are also elucidated. The obtained results show that the sensitivity of the sLGs- based mass sensor increases with increasing temperature difference.

关键词： Vibration - single-layered graphene sheet. Ther- mal environment - Nonlocal elasticity theory Relative frequency shift

Effect of Rare Earth and Transition metal Elements on the Glass Forming Ability of mechanical Alloyed Al–Tm–RE Based Amorphous Alloys

在线全文

学校读者我要写书评

暂无评论

Journal of materials science & Technology 2015年第11期31卷 1118-1124页

作者： Ram s.maurya Tapas Laha Department of metallurgical & materials Engineering Indian Institute of Technology Kharagpur

The present work aims to compare the amorphous phase forming ability of ternary and quaternary Al based alloys （Al86Ni8Y6, Al86GNi6Y6Co2, Al86NigLa6 and Al86Ni8Y45La15） synthesized via mechanical alloying by varying the composition, i.e. fully or partially replacing rare earth （RE） and transition metal （Tm） elements based on similar atomic radii and coordination number. X-ray diffraction and high resolution transmission electron microscopy study revealed that the amorphization process occurred through formation of various intermetallic phases and nanocrystalline FCC Al. Fully amorphous phase was obtained for the alloys not containing lanthanum, whereas the other alloys containing La showed partial amorphization with reappearance of intermetallic phases attributed to mechanical crystallization. Differential scanning calorimetry study confirmed better thermal stability with wider transformation temperature for the alloys without La.

关键词： Al-Tm-RE amorphous alloy mechanical alloying Glass forming ability microstructural transformation Intermetallics Glass transition temperature

Quantitative and spatially resolved detection of multiplexed microRNA from plant tissue via hybridization to hydrogel-bound DNA probes in nanoliter well arrays

在线全文

学校读者我要写书评

暂无评论

microsystems & Nanoengineering 2024年第5期10卷 331-343页

作者： Jennifer Fang Patrick s.Doyle Department of Chemical Engineering Massachusetts Institute of TechnologyCambridgeMAUSA

Understanding complex regulatory networks in plant systems requires elucidating the roles of various gene regulators under a spatial *** are key regulators that impart high information value through their tissue specificity and stability when using expression patterns for evaluating network ***,current techniques that utilize spatial multiplexing and quantitation of microRNA are limited to primarily mammalian ***,we present a method to spatially resolve and quantify multiple endogenous microRNA in situ using ethanol fixed,paraffin embedded model plant *** method utilizes target-specific microRNA capture along with universal ligating and labelling,all within functionalized hydrogel posts containing DNA probes in nanoliter well *** demonstrate the platform's multiplexing capabilities through analyzing three endogenous microRNA in Arabidopsis thaliana rosettes which provide useful answers to fundamental plant growth and development from the unique expression *** spatial tissue technique is also validated using non-spatial small RNA assays to demonstrate the versatility of the well array *** new platform expands the toolkit of spatial omics technologies for plants.

关键词： endogenous spatially utilize

Influence of soaking time in deep cryogenic treatment on the microstructure and mechanical properties of low-alloy medium-carbon HY-TUF steel

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

International Journal of minerals,metallurgy and materials 2016年第6期23卷 658-666页

作者： Ahmad Zare s.R.Hosseini Department of materials Engineering Maleke-ashtar University of Technology

The influence of soaking time in deep cryogenic treatment on the tensile and impact properties of low-alloy medium-carbon HY-TUF steel was investigated in this study. microstructural studies based on phase distribution mapping by electron backscatter diffraction show that the deep cryogenic process causes a decrease in the content of retained austenite and an increase in the volume fraction of η-carbide with increasing soaking time up to 48 h. The decrease in the content of retained austenite from ~1.23vol% to 0.48vol% suggests an isothermal martensitic transformation at 77 K. The η-type precipitates formed in deep cryogenic-treated martensite over 48 h have the Hirotsu and Nagakura orientation relation with the martensitic matrix. Furthermore, a high coherency between η-carbide and the martensitic matrix is observed by high-resolution transmission electron microscopy. The variations in macrohardness, yield strength, ultimate tensile strength, and ductility with soaking time in the deep cryogenic process show a peak/plateau trend.

关键词： low alloy steel medium carbon steel cryogenic treatment microstructure mechanical properties fractography

mean-Field model Beyond Boltzmann-Enskog Picture for Dense Gases

在线全文

学校读者我要写书评

暂无评论

Communications in Computational Physics 2011年第5期9卷 1106-1116页

作者： s.Ansumali Engineering mechanics Unit Jawaharlal Nehru Centre for Scientific Research560064 BangaloreIndia

This work proposes an extension to Boltzmann BGK equation for dense *** present model has an H-theorem and it allows choice of the Prandtl number as an independent parameter.I show that similar to Enskog equation this... 详细信息

关键词： microflows lattice Boltzmann method

Health implication among occupational exposed workers in a chromium alloy factory, Thailand

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 Environmental sciences 2004年第2期16卷 181-186页

作者： s. muttamara shing Tet Leong Research Lab supervisor Urban Environmental Engineering and Management Program School of EnvironmentResources and DevelopmentAsian Institute of Technology G.P.O. Box 4Klong LuangResearch Lab SupervisorUrban Environmental Engineering and Management Program School of EnvironmentResources and DevelopmentAsian Institute of Technology G.P.O. Box 4Klong Luang Pathumthani 12120 ThailandPathumthani 12120 Thailand

This study was conducted to assess the occupational exposure and its health impact on the chromium alloy workers. Environmental and biological monitoring, noise and audiometry measurements were done to evaluate the exposure levels in the factory. A total of 112 non-smoking workers were monitored from July 2001 to August 2002 The results showed that most of the chromium and lead exposures in the factory were below the ACGIH-TWA of 50 μg/m 3 for chromium(Ⅵ) and OsHA-PEL of 50 μg/m 3 for lead. The highest chromium(7 25±0 16 μg/m 3) and lead(14 50±0 29 μg/m 3) concentrations were measured in the vibro room. The results indicated that elevated concentrations of chromium and lead were found in both blood and urine samples especially in those areas which were characterized by poor ventilation. The metal contents in blood and urine samples were significantly correlated with airborne metal concentrations in the factory. The result demonstrated that blood and urinary levels among workers were associated with increasing age and duration of exposure. The background noise level of the factory ranged from 67 6 to 89 2 dBA and was frequently higher than the threshold limit value for noise(90 dBA). According to the audiometric test, the exposed workers showed signs of noise-induced hearing loss. Noise at work continued to be an important factor to hearing loss among exposed workers. In our statistical analysis, a significant hearing loss was established on age effect and year of exposure among the workforce.

关键词： chromium and lead exposure electroplating environmental and biological monitoring audiometry measurement