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991.
The work is aimed at investigating the influence of trace additions of Tin (Sn) on the microstructure, mechanical properties and age-hardening behavior of Al–6.2%Cu–0.6%Mg alloy system. Al–6.2%Cu–0.6%Mg alloys containing varying weight percentages (from 0 to 0.1 wt.%) of Sn were prepared by casting technique. The mechanical properties and microstructure of these alloys were investigated in the as-cast as well as different heat treated conditions. The composition of the different phases present in the microstructure was determined by energy dispersive X-ray (EDS) analysis. The average grain size of the annealed alloy was found to be maximum with trace content of 0.06 wt.% Sn. The hardness and strength of the alloy increased but the ductility reduced with increase in Sn content up to 0.06 wt.%. Precipitation hardening behavior of the alloys was investigated by analyzing the aging time required to attain the peak hardness value. Addition of trace percentage of Sn was observed to have no significant influence on the peak ageing time of the investigated alloy system. 相似文献
992.
Basic morphological operations such as the erosion, dilation, opening, and closing often fail to detect various types of defects that may be present in woven fabric, mainly because of the heuristic selection of structuring element needed for these operations. In this paper, an artificial neural network (ANN) is utilized for the selection of structuring element, where ANN is trained by two pre‐assigned normalized numbers related to the warp and weft counts of the test fabric. The test gray fabric image is pre‐processed to remove noise and the interlaced grating structure of weft and warp and then converted to a binary image by thresholding. An intensity threshold value of the processed fabric image and the dimension of a sliding window needed for correlation operation are obtained from the trained ANN. Defects are detected after morphological reconstruction of the processed binary fabric image, where an ANN trained structuring element is used. The technique is tested on 317 samples for eight different types of defects in three types of plain woven fabrics from TILDA database and 92.8% success of detection is achieved. 相似文献
993.
Rajat Banerjee 《Bulletin of Materials Science》2001,24(2):157-160
Lithium-di-silicate glass ceramic (Li2O, SiO2) with uniformly oriented crystals was placed on a Vickers indentation with extrusion axis horizontally parallel to the base
axis. The material was rotated through 0°–90° and at each angle a 20 N load was applied to ascertain the crack path. It was
observed that the crack length decreases and the crack deviates from its original path with increasing angle. The deviation
of the crack was correlated with the component of the crack driving force and the theoretical strength of the aligned crystals
at different angles. 相似文献
994.
B. Banerjee 《热应力杂志》2013,36(3-4):285-292
In this paper nonlinear thermal behaviors of polygonal plates have been investigated following a new approach. A conformal mapping technique has been employed in the investigation. Numerical results obtained for different polygons are given in tables and compared with other known results. 相似文献
995.
This study examines the antecedents of strategic alliance formation in manufacturing firms in China, the alliance effect on innovation capability and dyadic quality performance, and how these two organisational capabilities are related to the supply chain performance of Chinese manufacturing enterprises in Shanghai. We perform a series of statistical techniques including logistic regression analysis, multivariate analysis of variance (MANOVA) and multiple regression analysis for assessing the hypothesised relationships. Our findings indicate that relational stability and effective communication are significant antecedent factors influencing strategic alliance formation among Chinese manufacturing enterprises. Such alliance formation is found to benefit innovation capability and dyadic quality performance, which are significant contributors to the supply chain performance of Chinese manufacturers. We provide important theoretical and practical implications on these antecedents and consequences of strategic alliance formation leading to supply chain performance in the Chinese manufacturing context. 相似文献
996.
In a multi-product, flexible manufacturing environment, line capacity of printed wiring board (PWB) assembly systems may need to be adjusted at the beginning of each aggregate planning period because of demand fluctuation over multiple periods. A model of production planning and equipment changeover scheduling at the aggregate level is developed. In the described model, three kinds of equipment changeover methods, i.e. adding machine, removing machine and transferring machine, are involved. Because the model is a large-scale integer programming problem, it cannot be solved directly. A solution approach is developed, which first solves a recursive linear programming problem to obtain a rough set of machines to be added and a rough set of machines to be removed for each machine line in each period, then applies a branch and bound heuristic to the rough sets to obtain near-optimal solutions to the equipment changeover scheduling problem. Computational studies show the financial benefit both on capital cost and equipment changeover costs. 相似文献
997.
Silicon nanowire is an important material for the potential use as a cold cathode, but there are some bottlenecks like oxidation of the surface during field emission thereby degradation of its performance. To compete with carbon based nanostructures in this field the performance of Si nanowires as field emitter should be improved. Here, we report a simple technique for the significant improvement of field emission properties of Si nanowires by ZnO nanoparticle coating. Boron-doped p-type Si wafers were chemically etched to synthesize vertically aligned silicon nanowires and they were coated with different thicknesses of ZnO layer by radio frequency magnetron sputtering technique. The nanostructured thin films were studied by X-ray photoelectron spectroscopy for compositional and valence states information while their morphological information was obtained by a field emission scanning electron microscope and a high resolution transmission electron microscope. The field assisted electron emission performance of Si nanowires significantly improved for the thickness optimized ZnO coating. The photoluminescence spectra showed a peak at ~558 nm assigned to surface defect states of ZnO and the field emission from Si nanowires coated with ZnO for different times were correlated with the surface defect structures. The mechanism of such improvement is also discussed. 相似文献
998.
Q. Wang Song Partha P. Banerjee Jaw-Jueh Liu Anjan K. Ghosh 《Journal of Modern Optics》2013,60(9):1977-1983
Abstract Using a novel transfer function approach, we investigate the nature of the diffracted Gaussian beam from a photorefractive hologram under the influence of noise. The signal-to-noise ratio and spatial fidelity are defined, and their dependence on fringe spacing, temperature and reading beam intensity are discussed. 相似文献
999.
Experimental investigations are reported for air–water two-phase flow through a 2.1-mm horizontal circular minichannel. Influence of inlet premixing on two-phase flow is established by constructing various T-junction geometries with cross-flow arrangement of air and water. Six different flow patterns are observed and flow pattern maps are developed. The developed flow pattern maps are then compared for different inlet designs. It is observed that the degree of premixing of the two fluids has significant effect on flow patterns, particularly for surface-tension-dominated regime. The results obtained from these experiments can provide guidelines for selection, design, and control of wide-ranging microfluidic applications. The flow pattern map established in the present study may facilitate prediction of flow regimes in pulsating heat pipes based on the inlet flow rates of the gas and liquid. 相似文献
1000.
Recent research on supply chain management has highlighted the importance of building strong customer–supplier relationships in order to gain competitive advantage. This paper examines the benefits of buyer–supplier partnerships over lot-for-lot, i.e. single setup single delivery (SSSD) systems and suggests two policies that the supplier can pursue in order to meet customers’ needs: (1) Single setup multiple delivery (SSMD), and (2) Multiple setup multiple delivery (MSMD). If its fixed setup cost is relatively high, the supplier would prefer to implement SSMD and produce an entire order with one setup. However, if the supplier can reduce the setup cost and the supplier's capacity is greater than the threshold level (P?=?2D), it is more beneficial for the supplier to implement the multiple setups and multiple deliveries (MSMD) policy, even though he pays more frequent setup costs since the savings in inventory holding costs is greater than the increased setup costs. In the latter case, setup reduction is realized by the knowledge and efficiency gained through frequent setup operations. To provide guidelines for the policy selection, we examine the interactions among variables, such as production capacity, learning rate, and holding costs for both parties. The paper also discusses the benefit sharing plan, which discusses according to the contribution (or sacrifice) each party made to the partnership efforts. 相似文献