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rheological behavior,microstructure and hardness of A356 aluminum alloy in semisolid state using backward extrusion process

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中国有色金属学会会刊：英文版 2010年第S3期20卷 906-910页

作者： S.A.SADOUGH m.r.rAHmANI v.POUYAFAr Center of Excellence in Termoelasticity Amir Kabir University of Technology Department of mechanical Engineering Islamic Azad University Science and Research Branch

The influence of temperature on the flow behavior and rheological characteristics of an A356 alloy in the semi-solid state was investigated using backward extrusion *** were performed at 5 temperatures and 4 different wall *** were determined using the force-displacement graphs obtained form back extrusion *** observed experimentally,at a constant temperature,the increase of shear rate results in the decrease of alloy viscosity *** the temperature increases the liquid fraction hence reduces the semi-solid alloy *** and image analyses show that,because of low forming speed,liquid has time to escape from solid phase forward the sample *** condition is the main reason for the segregation phenomenon seen in the base and *** hardness test on samples reveals that the hardness increases with the decrease of temperature and wall thickness.

关键词： aluminum alloy A356 backward extrusion semisolid forming rheology

Object-Based method Outperforms Per-Pixel method for Land Cover Classification in a Protected Area of the Brazilian Atlantic rainforest region

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Pedosphere 2013年第3期23卷 290-297页

作者： T.rITTL m.COOPEr r.J.HECK m.v.r.BALLESTEr Department of Soil Quality University of Wageningen Department of Soil Science University of So Paulo School of Environmental Sciences University of Guelph Center for Nuclear Energy in Agriculture (CENA) University of So Paulo

Conventional image classification based on pixels hinders the possibilities to obtain information contained in images, while modern object-based classification methods increase the acquisition of information about the object and the context in which it is inserted in the image. The objective of this study was to investigate the performance of different classification methods for land cover mapping in the vicinity of the Alto ribeira Tourist State Park, a Brazilian Atlantic rainforest area. Two classification methods were tested, including i） a hybrid per-pixel classification using the image processing software ErDAS Imagine version 9.1 and ii） an object-based classification using the software eCognition version 5. In the first method, six different classes were established, while in the second method, another two classes were established in addition to the six classes in the first method. Accuracy assessment of the classification results presented showed that the object-based classification with a Kappa index value of 0.8687 outperformed the per-pixel classification with a Kappa index value of 0.2224. Application of the user＇s knowledge during the object-based classification process achieved the desired quality; therefore, the use of inter-relationships between objects, superelasses, subclasses, and neighboring classes were critical to improving the efficiency of land cover classification.

关键词： accuracy assessment image classification Kappa index user's knowledge

microstructure and mechanical properties of friction welded carbon steel(EN24) and nickel-based superalloy(IN718)

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International Journal of minerals,metallurgy and materials 2021年第1期28卷 111-119页

作者： v.T.Gaikwad m.K.mishra v.D.Hiwarkar r.K.P.Singh Kalyani Centre for Technology and Innovation Bharat Forge LimitedPune 411036India Department of materials Engineering Defense Institute of Advance TechnologyPune 411025India

Continuous-drive rotary friction welding was performed to join cylindrical specimens of carbon steel(EN24) and nickel-based superalloy(IN718), and the microstructures of three distinct weld zones—the weld interface(WI)/thermo-mechanically affected zone(TmAZ),the heat-affected zone(HAZ), and the base metal—were *** joint was observed to be free of defects but featured uneven flash *** backscatter diffraction(EBSD) analysis showed substantial changes in high-angle grain boundaries, low-angle grain boundaries, and twin boundaries in the TmAZ and ***, significant refinement in grain size(2 –5 μm) was observed at the WI/TmAZ with reference to the base *** possible causes of these are *** microhardness profile across the welded joint shows variation in *** changes in hardness are ascribed to grain refinement, phase transformation, and the dissolution of strengthening *** tensile test results reveal that a joint efficiency of 100% can be achieved using this method.

关键词： friction welding dissimilar metals EN24 IN718 microstructure mechanical properties

Enhancement of Distributed Generation by Using Custom Power Device

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Journal of Electronic Science and Technology 2015年第3期13卷 246-254页

作者： Kishor v.Bhadane m.S.Ballal r.m.moharil G.H.raisoni Institute of Engineering and managem Electrical Department VNIT.Nagpur and YCCE.Nagpur India

Wind energy （WE） has become immensely popular for distributed generation （DG）. This case presents the monitoring, modeling, control, and analysis of the two-level three-phase WE based DG system where the electric grid interfacing custom power device （CPD） is controlled to perform the smart exchanging of electric power as per the Indian grid code. WE is connected to DC link of CPD for the grid integration purpose. The CPD based distributed static compensator, i.e. the distributed static synchronous compensator （DSTATCOm）, is utilized for injecting the wind power to the point of common coupling （PCC） and also acts against the reactive power demand. The novel indirect current control scheme of DSTATCOm regulates the power import and export between the WE and the electric grid system. It also acts as a compensator and performs both the key features simultaneously. Hence, the penetration of additional generated WE power to the grid is increased by 20% to 25%. The burden of reactive power compensation from grid is reduced by DSTATCOm. The modeling and simulation are done in mATLAB. The results are validated and verified.

关键词： Custom power device distributed generation (DG) distributed static synchronous compensator (DSTATCOm) indirect current control scheme reactive power

Progressive Failure Evaluation of Composite Skin-Stiffener Joints Using Node to Surface Interactions and CZm

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Computer modeling in Engineering & Sciences 2018年第5期115卷 281-294页

作者： A.Sane P.m.Padole r.v.Uddanwadiker Department of mechanical Engineering Visvesvaraya National Institute of TechnologyNagpur440010India

T shaped skin-stiffener joint are one of the most commonly used structures in aerospace *** has been proven in various studies that these joints are susceptible to failure when loaded in pull out conditions however,in specific applications these joints undergo pull ***-lamination/de-bond nucleation and its growth is one of the most common failure mechanisms in a fiber reinforced composite *** growth takes place due to the induced interlaminar normal and shear stresses between different structural constituents when a load is *** this study,Finite Element Analysis has been performed using cohesive contact interactions on a composite T-joint to simulate the pull out test conditions.A simplified shell based model coupled with CZm is proposed,which can evaluate the failure initiation and progression accurately with lesser computational *** final failure occurred at a displacement of 4.71 mm at the computed failure load of 472.57 kgf for basic *** Failure load for the padded configuration is 672.8 kgf and corresponding displacement is 4.6 *** results obtained by the proposed numerical model are validated by experimental results and it is observed that predicted failure displacements and failure load calculated were correlating reasonably well with the experiment.

关键词： Carbon fiber composite FE analysis T-joint cohesive zone modeling node to surface interactions

Biochemical Factors Affecting the Quality of Products and the Technology of Processing Deep-Sea Fish, the Giant Grenadier Albatrossia pectoralis

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Journal of Ocean University of China 2020年第3期19卷 681-690页

作者： PIvNENKO T.N. KArPENKO Yu.v. KrASHCHENKO v.v. POZDNYAKOvA Yu.m. ESIPENKO r.v. Far Eastern State Technical Fisheries University Vladivostok 690087Russia

The composition of muscle tissues of a deep-sea species, the giant grenadier(Albatrossia pectoralis), and a mesopelagic species, the Alaska pollock(Theragra chalcogramma), are compared. Grenadier is proved to have a higher moisture content(91.7%) and lower protein(7.4%) and lipid(0.3%) contents. The factors responsible for the softening and moisture separation during processing of grenadier are identified. Contents of some fractions of non-protein nitrogenous components, including trimethylamine oxide(TmAO) and free amino acids, are clarified. The proportion of the main myofibrillar proteins myosin and actin, which is considered as an indicator of efficiency of structure formation in fish muscle tissue during processing, is almost 20% lower in giant grenadier than in pollock. The effects of endogenous protease, Са^2+-ATPase and transglutaminase on the processes of autolysis, denaturation, and possibility of myofibrillar proteins cross-linking were also studied. The proposed technology of getting a nutritionally balanced, gel-like, ready-to-use foodstuff from grenadier fillet includes its enrichment with pollock muscle tissue and supplementing with a binary structure-forming agent containing collagen and chitosan. Nutritional value of the products is assessed by the method of biological assay and by determining the denaturation changes of myofibrillar proteins. The modes of fine mincing and thermal processing, as well as the shelf-life of the finished product are justified. The developed technology of producing a ready-to-eat food from giant grenadier will allow a more efficient use of this underutilized resource.

关键词： giant grenadier Alaska pollock myosin actin proteases ATPase transglutaminase softening structure formation ready-to-eat foodstuffs

Heavy metal stress induced hyperglycemia in blue swimmer crab, Portunus pelagicus

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Acta Oceanologica Sinica 2018年第5期37卷 47-53页

作者： SArAvANAN r. SUGUmAr v. BEEmA mAHIN m.I. Department of Oceanography and Coastal Area Studies Alagappa UniversityThondi Campus

The study was to find out the effect of cadmium and mercury on levels of hemolymph glucose, crustacean hyperglycemic hormone（CHH） and hepatopancreas glycogen in the blue swimmer crab Portunus pelagicus. The experiments were performed in both intact and eyestalk ablated crabs. Quantification of CHH was done by the indirect ELISA with the aid of primary anti-Carcinus maenas-CHH antibody. Higher glucose concentration was observed on exposure to 8×10^–6 of cadmium（（825.6±5.42） μg/m L） and 6×10^–6 of mercury（（90.5±6.25） μg/m L）after 48 h and 24 h respectively. Higher level of hemolymph glucose was observed in eyestalk intact crabs on exposure to cadmium and mercury than eyestalk ablated crabs. Decrease in the levels of CHH was observed in both eyestalk intact and ablated crabs on heavy metal exposure. Decline of the hepatopancreas glycogen level was also witnessed with the exposure to heavy metal, which validated its utilization in the production of glucose. Thus this study brings to light, the variations in hemolymph glucose, CHH and hepatopancreas glycogen on heavy metal stress. These carbohydrate metabolites can be used as biomarkers in assessing heavy metal contamination in water bodies.

关键词： crustacean hyperglycemic hormone cadmium mercury decapod crustaceans blue swimmer crab

A precise solution for prediction of fiber-reinforced concrete behavior under flexure

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第7期12卷 495-502页

作者： r.AHmADI P.GHODDOUSI m.SHArIFI v.mojarrad BAHrEH Building and House research Center Tehran 13145-1996Iran Department of Civil Engineering Iran University of Science and TechnologyTehran 16846-13114Iran Department of Civil Engineering Sharif University of TechnologyTehran 11365-11155Iran

This paper presents a precise solution to predict the behavior of steel fiber reinforced concrete(SFrC) under the four point bending test(FPBT).All the force components at the beam section(before and after cracking) are formulated by applying these assumptions:a realistic stress-strain model is used for concrete behavior in compression,a linear response is considered for the uncracked tension region in a concrete constitutive model,and an exponential relationship is proposed as a stress-crack opening in the crack region which requires two *** the moment capacity of the critical cracked section is calculated by using these forces and satisfying equilibrium law at the *** studies are done on the behavior of SFrC to assess the sensitivity of the ***,this solution is validated with some existing experimental *** result shows the proposed solution is able to estimate the behavior of SFrC under FPBT.

关键词： Steel fiber reinforced concrete(SFrC) Flexure Stress-crack opening Four point bending test(FPBT)

Calculation of Surface Energy of metals and Alloys by theElectron Density Functional method

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Journal of materials Science & Technology 1998年第4期14卷 320-322页

作者： Kuznetsov, v.m. Kadyrov, r.I. rudenskii, G.E. Institute of Strength Physics and material Science Russian Academy of Sciences Siberian Branch 634048 Tomsk Academicheskii av. 2/1 Russian Federation

The surface energy of (100), (110), (111) surfaces in Ni, Al and ordered alloys NiAl and Ni//3Al has been calculated within the framework of methodology based upon the electron density functional method. The results of calculations are in good agreement with the known for pure metals experimental data and in case of Ni//3Al alloy. There is also a good agreement with the results obtained by calculation using the embedded atom method. The investigation has been carried out in this work to show that the surface energy sigma of alloys can not be interpreted as an averaged concentration sigma of pure metals. For NiAl, the obtained results reveal considerable distinctions in anisotropy of sigma in comparison to the anisotropy of surface energy in pure metals. (Edited author abstract) 8 refs.

关键词： Aluminum