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Experimental study on behaviors of polypropylene fibrous concrete beams

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第7期8卷 1101-1109页

作者： SUJI d. NATESAN S. C. MUrUGESAN r. Sathyabama Institute of Science and Technology Chennai Tamil Nadu India VLB Janakiammal College of Engineering and Technology Coimbatore Tamil Nadu India Gojan School of Business and Technology Red Hills Chennai Tamil Nadu India

Synthetic fibers made from nylon or polypropylene have gained application when loose and woven into geo textile form although no information on the matrix’s mechanical performance is obtained so that more understanding of their structural contribution to resist cracking can be determined. This paper presents the results of an experimental investigation to determine the performance characteristics of concrete reinforced with a polypropylene structural fiber. In this investigation “Fiber mesh” brand of fibers manufactured by SL Concrete System, Tennessee, USA and marketed by M/S Millennium Building System, Inc., Ban-galore, India are used. The lengths of the fibers used were 24 mm. Fiber dosages used were 0.9, 1.8, 2.7 kg/m3. A total of three mixtures, one for each fiber dosage were made. A standard slump cone test was conducted on the fresh concrete mix with and without fibers to determine the workability of the mix. The test program included the evaluation of hardened concrete properties such as compressive, split tensile, modulus of rupture and flexural strengths. The increase in compressive strength is about 36.25%, 26.20%, and 23.75% respectively that of plain concrete. This increase in strength was directly proportional to amount of fibers present in the mix. The increase in flexural strength for Mixes I^III is about 21%, 16.6%, and 23% respectively that of plain concrete specimens. An experimental investigation was also made to study the behaviors of reinforced fibers concrete beams (with longitudinal reinforcements) under two-point loading. The deflection and crack patterns were also studied. The improvements in strength and ductility characteristics were discussed.

关键词： Fiber reinforcement Concrete Mechanical properties Polypropylene Fibre reinforced Concrete (PFrC)

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Getting physical with medical education:Exercise based virtual anatomy review classes for medical students

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World Journal of Methodology 2025年第1期15卷 20-25页

作者： Nadeesha r Samarasinghe Taniya S Nagpal Michele L Barbeau Charys M Martin division of General Surgery Faculty of MedicineUniversity of British ColumbiaVancouver V6T 1Z3BCCanada Faculty of Kinesiology Sport and RecreationUniversity of AlbertaEdmonton T6G 2R3ABCanada Anatomy and Cell Biology University of Western OntarioLondon N6A 3K7ONCanada department of Anatomy and Cell Biology Schulich School of Medicine and DentistryThe University of Western OntarioLondon N6A 3K7ONCanada

The benefits of regular physical activity are well ***,few studies have examined the effectiveness of integrating physical activity(PA)into curricula within a post-secondary *** investigate the incorporation of PA into medical curriculum,we developed a series of optional exercise-based review sessions designed to reinforce musculoskeletal(MSK)anatomy course *** synchronous sessions were co-taught by a group fitness instructor and an anatomy *** fitness instructor would lead students through both strength and yoga style exercises,while the anatomy instructor asked questions about relevant anatomical structures related to course material previously *** the sessions,participants were asked to evaluate the classes on their self-reported exam preparedness in improving MSK anatomy knowledge,PA levels,and mental *** participants completed surveys;a majority agreed that the classes increased understanding of MSK concepts(90.0%)and activity levels(97.7%).Many(70.0%)felt that the classes helped reduce *** majority of respondents(90.0%)agreed that the classes contributed to increased feelings of social ***,medical students saw benefit in PA based interventions to supplement MSK course *** with increasing activity levels and promoting health behaviours,integrating PA into medical curriculum may improve comprehension of learning material,alleviate stress and foster social connectivity among medical students.

关键词： Medical education Musculoskeletal Anatomy Exercise Online learning

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The role of net ecosystem productivity and of inventories in climate change research:the need for “net ecosystem productivity with harvest”,NEPH

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Forest Ecosystems 2021年第1期8卷 199-206页

作者： E.d.Schulze r.Valentini O.Bouriaud Max planck institute for biogeochemistry box 100164jenagermany department of forest environment and resources university of tuscia01100 viterboitaly Laboratoire d’inventaire forestier ignnancyfrance

Background:There is an urgent need for quantifying the terrestrial carbon sink in the context of global carbon ***,neither the flux measurements,nor the national wood balances fulfil this *** this discussion article we point at various shortcomings and necessary improvements of these approaches in order to achieve a true quantification of the carbon exchange of land ***:We discuss the necessity of incorporating all lateral fluxes,but mainly the export of biomass by harvest,into the flux balance and to recognize feedbacks between management and fluxes to make flux measurements compatible with *** the same time,we discuss the necessity that national reports of wood use need to fully recognize the use of wood for energy *** approaches of establishing an ecosystem carbon balance,fluxes and inventories,have ***:Including harvest and feedbacks by management appears to be the main requirement for the flux approach.A better quantification of wood use for bioenergy seems a real need for integrating the national wood balances into the global carbon cycle.

关键词： Terrestrial carbon sink Flux measurements Carbon inventories National wood balances

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Optimal placement of wind turbines within a wind farm considering multi-directional wind speed using two-stage genetic algorithm

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Frontiers in Energy 2021年第1期15卷 240-255页

作者： A.S.O.OGUNJUYIGBE T.r.AYOdELE O.d.BAMGBOJE Power Energy Machines and drives(PEMd)research Group Department of Electrical and Electronic EngineeringUniversity of IbadanNigeria

Most wind turbines within wind farms are set up to face a pre-determined wind ***,wind directions are intermittent in nature,leading to less electricity production *** paper proposes an algorithm to solve the wind farm layout optimization problem considering multi-angular(MA)wind direction with the aim of maximizing the total power generated on wind farms and minimizing the cost of installation.A twostage genetic algorithm(GA)equipped with complementary sampling and uniform crossover is used to evolve a MA layout that will yield optimal output regardless of the wind *** the first stage,the optimal wind turbine layouts for 8 different major wind directions were determined while the second stage allows each of the previously determined layouts to compete and inter-breed so as to evolve an optimal MA wind farm *** proposed MA wind farm layout is thereafter compared to other layouts whose turbines have focused site specific wind turbine *** results reveal that the proposed wind farm layout improves wind power production capacity with minimum cost of installation compared to the layouts with site specific wind turbine *** paper will find application at the planning stage of wind farm.

关键词： optimal placement wind turbines wind direction genetic algorithm wake effect

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Spatio-temporal variation and propagation direction of coal fire in Jharia Coalfield,India by satellite-based multi-temporal night-time land surface temperature imaging

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International Journal of Mining Science and Technology 2021年第5期31卷 765-778页

作者： Narendra Singh r.S.Chatterjee dheeraj Kumar d.C.Panigrahi department of Mining Engineering Indian Institute of Technology(Indian School of Mines)Dhanbad 826004India Geosciences department Indian Institute of Remote SensingDehradun 248001India

In this paper,the spatio-temporal variation and propagation direction of coal fire were studied in the Jharia Coalfield(JCF),India during 2006–2015 through satellite-based night-time land surface temperature(LST)*** LST was retrieved from Advanced Spaceborne Thermal Emission and reflection radiometer(ASTEr)night-time thermal-infrared data by a robust split-window algorithm based on scene-specific regression coefficients,band-specific hybrid emissivity,and night-time atmospheric *** LST-profile-based coal fire detection algorithm was formulated through statistical analysis of the LST values along multiple transects across diverse coal fire locations in the JCF in order to compute date-specific threshold temperatures for separating thermally-anomalous and background *** algorithm efficiently separates surface fire,subsurface fire,and thermally-anomalous transitional *** the observation period,it was noticed that the coal fire area increased significantly,which resulted from new coal fire at many places owing to extensive opencast-mining *** was observed that the fire propagation occurred primarily along the dip direction of the coal *** places,lateral-propagation of limited spatial extent was also observed along the strike direction possibly due to spatial continuity of the coal seams along ***,the opencast-mining activities carried out during 2009–2015 and the structurally weak planes facilitated the fire propagation.

关键词： Satellite-based night-time imaging Land surface temperature Coal fire Spatio-temporal variation Propagation direction Jharia Coalfield

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Effect of austenitization temperature on microstructure and mechanical properties of low-carbon-equivalent carbidic austempered ductile iron

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International Journal of Minerals,Metallurgy and Materials 2018年第7期25卷 770-778页

作者： vinayak dakre d.r.peshwe s.u.pathak ajay likhite department of Metallurgical ＆ Materials Engineering Visvesvaraya National Institute of TechnologyNagpur 440010India

The wear resistances of austempered ductile iron （AdI） were improved through intxoduction of a new phase （carbide） into the ma- txix by addition of chromium. In the present investigation, low-caxbon-equivalent ductile iron （LCEdI）（CE = 3.06%, and CE represents cax- bon-equivalent） with 2.42% chromium was selected. LCEdI was austeintized at two difl＇erent temperatures （900 and 975~C） a^ld soaked for 1 h and then quenched in a salt bath at 325~C for 0 to 10 h. Samples were analyzed using optical microscopy and X-ray diffraction. Wear tests were carded out on a pin-on-disk-type machine. The efl＇ect of austenization temperature on the wear resistance, impact strength, and the mi- crostructure was evaluated. A stxucture-property correlation based on the observations is established.

关键词： low carbon equivalent ductile iron (LCEdI) caxbidic austempered ductile iron (CAdI) wear test austenitization temperature impact strength

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Land use and land cover changes over a century (1914 2007) in the Neyyar river Basin, Kerala: a remote sensing and GIS approach

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International Journal of digital Earth 2011年第3期4卷 258-270页

作者： r.V.Sheeja Sabu Joseph d.S.Jaya r.S.Baiju Kerala State remote Sensing and Environment Centre VikasbhavanThiruvananthapuram 695033KeralaIndia department of Environmental Sciences University of KeralaKariyavattomThiruvananthapuramKeralaIndia Centre for Earth Science Studies(CESS) ThiruvananthapuramKeralaIndia

Land use and land cover change,perhaps the most significant anthropogenic disturbance to the environment,mainly due to rapid urbanization/industrialization and large scale agricultural *** this paper,an attempt has been made to appraise land use/land cover changes over a century(19142007)in the Neyyar river Basin(L56 km;Area483.4 km2)in southern Keralaa biodiversity hot spot in Peninsular *** this study,digital remote sensing data of the Indian remote Sensing satellite series I-d(LISS III,20062007)on 1:50,000 scale,Survey of India(SOI)toposheet of 1914(1:63,360)and 1967(1:50,000)have been utilized to map various land use/land cover *** of different periods have been registered and resampled to similar geographic coordinates using ErdAS Imagine *** most notable changes include decreases in areas of paddy cultivation,mixed crops,scrub lands and evergreen forests,and increases in built-up areas,rubber plantations,dense mixed forests,and water ***,large scale exploitation of flood plain mud and river sand have reached menacing proportions leading to bank caving and cut offs at channel *** of land and water resources forms an important aspect of ecosystem management in the basin.

关键词： remote sensing GIS land use/land cover Neyyar basin Kerala

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3d tomographic analysis of equatorial plasma bubble using GNSS-TEC data from Indonesian GNSS Network

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Earth and Planetary Physics 2025年第1期9卷 127-136页

作者： Ihsan Naufal Muafiry Prayitno Abadi Teguh N.Pratama dyah r.Martiningrum Sri Ekawati Yuandhika GWismaya Febrylian FChabibi Gatot HPramono research Center for Climate and Atmosphere Indonesian National Research and Innovation Agency(BRIN)BandungIndonesia Indonesian Geospatial Information Agency(BIG) JakartaIndonesia dept.of Physics Faculty of ScienceUniversiti Teknologi MalaysiaJohor BahruMalaysia dept.Earth Planet Sci. Hokkaido UniversitySapporoJapan School of Electrical Engineering Telkom UniversityBandungIndonesia

Equatorial Plasma Bubbles(EPBs)are ionospheric irregularities that take place near the magnetic *** most commonly occur after sunset during the equinox months,although they can also be observed during other *** phenomenon significantly disrupts radio wave signals essential to communication and navigation *** national network of Global Navigation Satellite System(GNSS)receivers in Indonesia(>30°longitudinal range)provides an opportunity for detailed EPB *** explore this,we conducted preliminary 3d tomography of total electron content(TEC)data captured by GNSS receivers following a geomagnetic storm on december 3,2023,when at least four EPB clusters occurred in the Southeast Asian *** and extracted TEC depletion with a 120-minute running average were then used as inputs for a 3d tomography *** 2d spatial distribution consistently captured the four EPB clusters over *** tomography results were validated through a classical checkerboard test and comparisons with other ionospheric data sources,such as the Global Ionospheric Map(GIM)and International reference Ionosphere(IrI)*** of the results demonstrates the capability of the Indonesian GNSS network to measure peak ionospheric *** findings highlight the potential for future three-dimensional research of plasma bubbles in low-latitude regions using existing GNSS networks,with extensive longitudinal coverage.

关键词： EPB Indonesian GNSS Network 3d tomography

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Tensile Properties and Fusion Zone Hardening for GMAW and MIEA Welds of a 7075-T651 Aluminum Alloy

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Acta Metallurgica Sinica(English Letters) 2014年第4期27卷 694-704页

作者： N.Alatorre r.r.Ambriz B.Noureddine A.Amrouche A.Talha d.Jaramillo Instituto Politcnico Nacional CIITEC-IPN Cerrada de Cecati S/N Col.Sta.CatarinaC.P 02250 AzcapotzalcoDFMexico Universit Lille Nord de France 59000 LilleFrance Universit Lille 1 LML59650 Villeneuve d’AscqFrance Laboratoire de Gnie Civil et ge'o-Environnement LGCgE EA 4515Facult des Sciences Appliques FSA BthuneUniversit d’ArtoisArrasFrance Ecole des Hautes Etudes d’Ingnieur (HEI) 13 rue de Toul59046 LilleFrance

Tensile and hardness values for 7075-T651 aluminum alloy in the as welded and post weld heat treated conditions（solubilization and artificial aging-T6）,obtained using GMAW and modified indirect electric arc（MIEA）welding processes are *** showed that the base material along rolling direction exhibited a tensile strength of around 600 MPa and elongation of 11%.For the as welded condition,tensile strength was 260 MPa and elongation percent of 3%.This behavior was attributed to brittleness induced by the microstructural characteristics of the welded alloys,as well as high *** profiles along the welds were obtained and different welded zones were identified.A soft zone（＊100 HV0.1） in the heat affected zone for GMAW and MIEA was observed,the minimum hardness corresponding to weld metal（＊85 and ＊96 HV0.1for GMAW and MIEA,respectively）.The high dilution between filler and base metal during welding in MIEA allows to the Zn and Cu to flow from the base metal into the weld metal,inducing hardening by solution and subsequent artificial *** this regard,the hardness of the weld metal for MIEA increases by 56%,while the tensile strength reaches a value close to 400 *** GMAW,non-favorable hardening effect was observed for the weld metal after solution and artificial aging.

关键词： Welding 7075-T651 dilution fraction Tensile properties Fusion zone hardening

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Effect of samarium doping on structural, optical and magnetic properties of vertically aligned ZnO nanorod arrays

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Journal of rare Earths 2017年第10期35卷 1002-1007页

作者： d.ranjith Kumar K.S.ranjith L.r.Nivedita r.T.rajendra Kumar department of Nanoscience and Technology Bharathiar University Coimbatore India Advanced Materials and devices Laboratory (AMdL) Department of Physics Bharathiar University Coimbatore India

Samarium doped vertically aligned one dimensional ZnO nanorod（Nr） arrays were grown by vapor phase transport（VPT） method through vapor solid（VS） growth process. Influence of different concentrations（0% to 8%） of Sm（all Sm contents in the paper are in mass fraction） on the ZnO Nr arrays were investigated by X-ray diffraction（Xrd）, field emission scanning electron microscopy（FESEM）, photoluminescence（PL）, raman spectroscopy and vibrating sample magnetometry（VSM） techniques, respectively. X-ray diffraction studies revealed that the ZnO Nr arrays were perfectly oriented along（002） crystallographic orientation with wurtzite crystal structure. Photoluminescence results showed an increase in oxygen vacancies due to increase in Sm doping. M-H curves revealed enhanced ferromagnetic behavior, and the magnetic moment values were 0.45, 0.363, 1.694, 3.613 and 2.197 emu/cm^3 for（0–8%） Sm doped ZnO Nr arrays respectively. The curve revealed that paramagnetic behavior was observed for undoped ZnO Nr arrays and on increasing the Sm dopant to 4%, paramagnetic switched to ferromagnetic behavior.

关键词： Sm doped ZnO room temperature ferromagnetism(rTFM) defects rare earths

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