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排序方式: 共有2449条查询结果,搜索用时 31 毫秒
51.
52.
Conti-Ramsden MG Asghar HM Hussain SN Roberts EP Brown NW 《Water science and technology》2012,66(9):1849-1855
The removal of the mercaptan, 1-methyl-1-propanethiol, from aqueous solutions using a non-porous, electrically conducting carbon-based adsorbent (Nyex 1000) was investigated. The adsorption process was found to be rapid (equilibrium capacity achieved within 5 minutes) with low adsorptive capacity (of the order of 0.4 mg g(-1)) when compared with activated carbon. Electrochemical regeneration of the Nyex 1000 in a simple divided electrochemical cell within a sequential batch treatment unit restored 100% of the adsorbent's adsorptive capacity using treatment times as low as 20 minutes by passing a current of 0.5 A. The sorptive characteristics of a Nyex-water slurry were also modelled and investigated both in a bubble column and in a continuous adsorption-regeneration treatment system. It was demonstrated that the continuous removal-destruction system could achieve a step reduction in challenge gas concentration of approximately 75% for a period of 35 minutes with a current of 5 Amps. This was attributed to mass transfer enhanced by a combination of adsorption and chemical reaction with free chlorine species generated in the electrochemical process. 相似文献
53.
Hussain Shareef Azah Mohamed Saifunizam Abd. Khalid Mohd Wazir Mustafa 《中南工业大学学报(英文版)》2012,19(1):179-186
A multivariable regression (MVR) approach is proposed to identify the real power transfer between generators and loads. Based
on solved load flow results, it first uses modified nodal equation method (MNE) to determine real power contribution from
each generator to loads. Then, the results of MNE method and load flow information are utilized to determine suitable regression
coefficients using MVR model to estimate the power transfer. The 25-bus equivalent system of south Malaysia is utilized as
a test system to illustrate the effectiveness of the MVR output compared to that of the MNE method. The error of the estimate
of MVR method ranges from 0.001 4 to 0.007 9. Furthermore, when compared to MNE method, MVR method computes generator contribution
to loads within 26.40 ms whereas the MNE method takes 360 ms for the calculation of same real power transfer allocation. Therefore,
MVR method is more suitable for real time power transfer allocation. 相似文献
54.
Omar K. Hussain Tharam Dillon Farookh Khadeer Hussain Elizabeth Chang 《Journal of Intelligent Manufacturing》2012,23(6):2069-2084
In Demand-driven Production with Just-in-Time inputs, there are several sources of uncertainty which impact on the manufacturer??s ability to meet the required customer??s demand within the given time frame. This can result in a loss of revenue and customers, which will have undesirable impacts on the financial aspects and on the viability of the manufacturer. Hence, a key concern for manufacturers in just-in-time production is to determine whether they can meet a specific level of demand within a given time frame, to meet the customers?? orders and also to achieve the required revenue target for that period of time. In this paper, we propose a methodology by which a manufacturer can ascertain the probability of not meeting the required demand within a given period by considering the uncertainties in the availability of production units and raw materials, and the loss of financial revenue that it would experience as a result. 相似文献
55.
This paper reports on the affect of lead content on the absorption and emission spectra of the Ho3+ ion doped lead-zinc-borate glasses in the composition (mol%) of (20 − x)PbO-20ZnO-(59 + x)B2O3-1.0Ho2O3 where x = 0, 5,10,15 of PbO content with λexc = 405 nm. The experimental absorption band energies have satisfactorily been correlated with the theoretical results with an r.m.s deviation of zero with the following correction factors obtained by a least square fit analysis: ΔE1 = 348.495936 cm− 1, ΔE2 = 1.436043 cm− 1, ΔE3 = 46.481575 cm− 1, Δξ4f = − 28.512979 cm− 1, Δα = 55.508936 cm− 1, Δβ = − 1394.339908 cm− 1 and Δγ = 1208.424336 cm− 1. By applying the Judd-Ofelt intensity parameter Ω2 has been found to be linearly decreasing with the PbO content from 5 to 10 mol% and then increasing. And also radiative (A, AT, β, τr) characteristic factors of the luminescent transitions (5I8 ← 5F3,4,5 and 5S2) of the glasses have been evaluated. Stimulated emission cross-sections (σpE) of the measured emission transitions of holmium glasses have also been computed. 相似文献
56.
Genetic algorithms are applied to an important, but little investigated, network design problem, that of reconfiguring the topology and link capacities of an operational network to adapt to changes in its operating conditions. These conditions include: which nodes and links are unavailable; the traffic patterns; and the quality of service (QoS) requirements and priorities of different users and applications. Dynamic reconfiguration is possible in networks that contain links whose endpoints can be easily changed, such as satellite channels, terrestrial wireless connections, and certain types of optical connections. We report preliminary results that demonstrate the feasibility of performing genetic search quickly enough for online adaptation. 相似文献
57.
Optimization of abrasive water jet cutting of ductile materials 总被引:1,自引:0,他引:1
Full factorial design of experiments was developed in order to investigate the effects of jet pressure, abrasive mixing rate, cutting feed, and plate thickness upon three response variables, surface finish of cutting wear zone, percentage proportion of striation free area, and maximum width of cut. The set of sixteen experiments was performed on each of the following two ductile materials: AISI 4340 (high strength low alloy steel, hardened to 49HRc) and Aluminum 2219. Analysis of Variance (ANOVA) was performed on experimental data in order to determine the significance of effects of different parameters on the performance measures. It was found that cutting feed and thickness were highly influential parameters, while abrasive mixing rate is influential upon surface roughness only. Strong interaction was found between jet pressure and workpiece material. Multi-criteria numerical optimization was performed in order to simultaneously maximize/minimize different combinations of performance measures. 相似文献
58.
59.
Giulia Cancian Gianluca Tozzi Amirul Ashraf Bin Hussain Arianna De Mori Marta Roldo 《Journal of materials science. Materials in medicine》2016,27(8):126
Age related bone diseases such as osteoporosis are considered among the main causes of reduced bone mechanical stability and bone fractures. In order to restore both biological and mechanical function of diseased/fractured bones, novel bioactive scaffolds that mimic the bone structure are constantly under development in tissue engineering applications. Among the possible candidates, chitosan-based thermosensitive hydrogel scaffolds represent ideal systems due to their biocompatibility, biodegradability, enhanced antibacterial properties, promotion of osteoblast formation and ease of injection, which makes them suitable for less invasive surgical procedures. As a main drawback, these chitosan systems present poor mechanical performance that could not support load-bearing applications. In order to produce more mechanically-competent biomaterials, the combined addition of hydroxyapatite and carbon nanotubes (CNTs) is proposed in this study. Specifically, the aim of this work is to develop thermosensitive chitosan hydrogels containing stabilised single-walled and multi-walled CNTs, where their effect on the mechanical/physiochemical properties, calcium deposition patterns and ability to provide a platform for the controlled release of protein drugs was investigated. It was found that the addition of CNTs had a significant effect on the sol–gel transition time and significantly increased the resistance to compression for the hydrogels. Moreover, in vitro calcification studies revealed that CNTs played a major role in the spatial arrangements of newly formed calcium deposits in the composite materials studied, suggesting that they may have a role in the way the repair of fragile and/or fractured bones occurs in vivo. 相似文献
60.
A. Laref M. Alsagri Z. Hussain S. Laref F. Tawfik S. J. Luo 《Journal of Materials Science》2017,52(12):7039-7057
Employing systematic first-principle calculations to the family of tellurium II–VI compounds such as Hg- and Zn-based semiconductors and their related Zn1?x Hg x Te ternary alloys, we have simulated the electronic and optical characteristics incorporating the spin–orbit coupling effect. The salient features such as the band gaps and the optical spectra with a satisfactory adequate approach are computed with the so-called modified Becke–Johnson exchange correlation potential as implemented in the full-potential linearized augmented plane-wave scheme. The theoretical finding surmises that a topological insulating state may be caused with 25% of Zn concentration incorporated in HgTe material. Intriguingly, a band gap is conclusively developed near 0.25 eV in Zn0.25Hg0.75Te alloy. The relevant components like the band structure, optical response functions such as the real and imaginary parts of dielectric function, spectral dependence of optical conductivity, reflectivity spectrum, refractive index, electron energy loss function, and absorption coefficient are established for the bulk Zn1?x Hg x Te ternary alloys, while Zn composition spans in the range 0–1. The overall accordance between our results and other theoretical reports as well as experimental realization is fairly good. We infer that the current work may be beneficial for optical emitters/converters in solar cell devices applications. 相似文献