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排序方式: 共有1281条查询结果,搜索用时 15 毫秒
81.
Alloy 617 (nickel based austenitic alloy) is a candidate structural material for next generation high temperature nuclear reactor. The secondary phases present in the Alloy 617 has been identified as TiN and M23C6 by optical microscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). Surface potentials of these phases have been evaluated by Scanning Kelvin Probe Force Microscope (SKPFM). SKPFM investigation showed higher surface potential of the secondary phases than that of the austenite matrix. The surface potential of the TiN was nobler than that of M23C6 indicating that these precipitates could act as cathodic sites during oxidation reaction. Difference in the local chemistry of these phases results in variation of the chemical potentials, which in turn could lead to enhanced oxidation at localized areas in the vicinity of the secondary phase precipitates that act as cathodic sites. 相似文献
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84.
Martin P. Harmer Raja K. Mishra Gareth Thomas 《Journal of the American Ceramic Society》1983,66(3):44-C-
( Ni,Zn)Fe2 O4 samples containing small amounts of Co were characterized in a transmission electron microscope to ascertain the micro structural changes accompanying low-temperature oxidation of the samples. Although no new features resulting from oxidation were observed, prominent surjace reduction occurred in the thin foil specimens. Formation and growth of Ni particles on the ferrite surface are explained using the heats of formation of the oxides.2 相似文献
85.
Mehmood Ammara Shi Peng Raja Muhammad Asif Zahoor Zameer Aneela Chaudhary Naveed Ishtiaq 《Neural computing & applications》2021,33(5):1479-1496
Neural Computing and Applications - This study presents a novel implementation of evolutionary heuristics through backtracking search optimization algorithm (BSA) for accurate, efficient and robust... 相似文献
86.
Mohammed Muhammad Zafran Raja Ng Zi Wei Putranto Aditya Kong Zong Yang Sunarso Jaka Aziz Muhammad Zein Sharif H. Giwangkara Jannata Butar Ivan 《Clean Technologies and Environmental Policy》2023,25(5):1551-1567
Clean Technologies and Environmental Policy - This study aims to propose a new process design, simulation, and techno-economic analysis of an integrated process plant that produces glucose and... 相似文献
87.
In cloud data centers, the consolidation of workload is one of the phases during which the available hosts are allocated tasks. This phenomenon ensures that the least possible number of hosts is used without compromise in meeting the Service Level Agreement (SLA). To consolidate the workloads, the hosts are segregated into three categories: normal hosts, under-loaded hosts, and overloaded hosts based on their utilization. It is to be noted that the identification of an extensively used host or underloaded host is challenging to accomplish. Threshold values were proposed in the literature to detect this scenario. The current study aims to improve the existing methods that choose the underloaded hosts, get rid of Virtual Machines (VMs) from them, and finally place them in some other hosts. The researcher proposes a Host Resource Utilization Aware (HRUAA) Algorithm to detect those underloaded and place its virtual machines on different hosts in a vibrant Cloud environment. The mechanism presented in this study is contrasted with existing mechanisms empirically. The results attained from the study establish that numerous hosts can be shut down, while at the same time, the user's workload requirement can also be met. The proposed method is energy-efficient in workload consolidation, saves cost and time, and leverages active hosts. 相似文献
88.
Jahed Armaghani Danial Shoib Raja Shahrom Nizam Shah Bin Raja Faizi Koohyar Rashid Ahmad Safuan A. 《Neural computing & applications》2017,28(2):391-405
Neural Computing and Applications - Rock-socketed piles are commonly used in foundations built in soft ground, and thus, their bearing capacity is a key issue of universal concern in research,... 相似文献
89.
Mahesh Raja Perumal Krishnan Balasubramaniam Kavitha Arunachalam 《Journal of Nondestructive Evaluation》2018,37(4):70
Understanding the scope and limitations of non-destructive testing procedure is essential for selecting the appropriate test parameters for material inspection. This paper presents the scope of material (\( \delta_{s} \)) and probe dependent (\( \delta_{t} \)) penetration depths for determining the optimal test frequency (\( f_{opt} ) \) for detection of sub surface defects in electrically thick conducting specimens. Numerical modelling is carried out for a pancake coil above an electrically thick aluminium plate, \( t/\delta_{t} \)?>?1, to study the influence of the EC probe and defect location (\( t_{df} \)) on the test frequency for near and deep sub surface defects. The study concludes that the optimal test frequency, \( f_{opt} \) for detection of deep sub surface defects (\( t_{df} /t \approx 1 \)) is determined by the probe dependent skin depth, \( \delta_{t} \), and the plate thickness is related to \( f_{opt} \) by, \( t \propto 1/\sqrt {f_{opt} } \). The numerical observations were experimentally validated for machined sub surface notches on a 10 mm thick (\( t \)) aluminium plate. 相似文献
90.
D. Raja Satish Fitsum Feyissa D. Ravi Kumar 《Materials and Manufacturing Processes》2017,32(12):1345-1352
Cryorolling is a severe plastic deformation (SPD) process used to obtain ultrafine-grained aluminum alloy sheets along with higher strength and hardness than in conventional cold rolling, but it results in poor formability. An alternative method to improve both strength and formability of cryorolled sheets by warm forming after cryorolling without any post-heat treatment is proposed in this work. The formability of cryorolled AA6061 Al alloy sheets in the warm working temperature range is characterized in terms of forming limit diagrams (FLDs) and limiting dome height (LDH). Strain distributions and thinning in biaxially stretched samples are studied. Hardness of the formed samples is correlated with ultimate tensile strength to estimate post-forming mechanical properties. The limit strains and LDH have been found to be higher than in the case of the conventional processing route (cold rolled, annealed and formed at room temperature), making this hybrid route capable of producing sheet metal parts of aluminum alloys with high strength and formability. In order to combine the advantages of enhanced formability and better post-forming strength than the conventional cold rolled and annealed sheets, warm forming at 250°C has been found to be suitable for this alloy in the temperature range that has been studied. 相似文献