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61.
62.
One of the strategic activities of a firm is supplier segmentation, whereby a firm creates groups of suppliers to handle them differently. Existing literature provides several typologies of suppliers, each of which uses different dimensions/variables. In this paper, different typologies are combined by distinguishing two overarching dimensions, the capabilities and the willingness of suppliers to cooperate with a particular firm. These dimensions cover almost all the existing supplier segmentation criteria mentioned in existing literature. For each particular situation, these dimensions can be specified using a multi-criteria decision-making method. A methodology is proposed that includes a fuzzy Analytic Hierarchy Process (AHP) which uses fuzzy preference relations to incorporate the ambiguities and uncertainties that usually exist in human judgment. The proposed methodology is used to segment the suppliers of a broiler company. The result is a segmentation of suppliers based on two aggregated dimensions. Finally some strategies to handle different segments are discussed and concluding remarks and suggestions for future research are provided. 相似文献
63.
64.
Kobra?Hasanirokh Jafar?Azizi Arash?PhirouzniaEmail author Hakimeh?Mohammadpour 《The European Physical Journal B - Condensed Matter and Complex Systems》2014,87(4):95
In the current work, based on a semiclassical Boltzmann approach, we have investigatedthe influence of the Rashba spin-orbit coupling on spin-current of a single layer gappedgraphene. It was shown that the Rashba coupling plays a considerable role in thegeneration of the spin-current of vertical spins in mono-layer graphene. The behavior ofthe spin-current is determined by the density of impurities. It was also shown that thespin-current of the system could increase by increasing the Rashba coupling strength andband-gap of the graphene and the sign of the spin-current could be controlled by thedirection of the current-driving electric field. 相似文献
65.
Gegenbauer spectral method for time‐fractional convection–diffusion equations with variable coefficients 下载免费PDF全文
Mohammad Mahdi Izadkhah Jafar Saberi‐Nadjafi 《Mathematical Methods in the Applied Sciences》2015,38(15):3183-3194
In this paper, we study the numerical solution to time‐fractional partial differential equations with variable coefficients that involve temporal Caputo derivative. A spectral method based on Gegenbauer polynomials is taken for approximating the solution of the given time‐fractional partial differential equation in time and a collocation method in space. The suggested method reduces this type of equation to the solution of a linear algebraic system. Finally, some numerical examples are presented to illustrate the efficiency and accuracy of the proposed method. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
66.
Maryamalsadat Lajvardi Jafar Moghimi-Rad Iraj Hadi Anwar Gavili Taghi Dallali Isfahani Fatemeh Zabihi Jamshid Sabbaghzadeh 《Journal of magnetism and magnetic materials》2010,322(21):3508-3513
This paper reports an experimental work on the convective heat transfer of ferrofluid flowing through a heated copper tube in the laminar regime in the presence of magnetic field. Significant enhancement on the heat transfer of ferrofluid by applying various orders of magnetic field is observed in this experiment. Also in this experiment, the effect of magnetic nanoparticles concentrations and magnet position have been investigated. The main reason for the enhancement of heat transfer coefficient could be caused due to remarkable changes in thermophysical properties of ferrofluid under the influence of applied magnetic field. 相似文献
67.
Ali Nakhaei Pour Yahya Zamani Kheirolah Jafari Jozani Jafar Yeganeh Mehr 《Reaction Kinetics and Catalysis Letters》2005,86(1):157-162
Summary The effect of La2O3 and TiO2 on product selectivity, methane conversion and coke formation over NiO/MgO/ α -Al2O3 catalyst were studied in a simultaneous steam and CO2 reforming of methane to syngas. La2O3 and TiO2 were added to the catalyst via incipient wetness impregnation and bulk precipitation techniques and catalyst activity was tested in a fixed bed quartz reactor. Results reveal that although the addition of these oxides has no effect on the product selectivity and methane conversion, but can reduce coke formation on the surface of the catalysts as it can enhance the mobility of lattice oxygen anions. The results further show that the catalysts prepared by bulk precipitation technique decrease the coke formation more effectively. 相似文献
68.
The catalytic effect of manganese(II) on the oxidation of barium diphenylamine sulfonate (BDAS) with potassium bromate in sulfuric acid was studied. Progress of the reaction was monitored, spectrophotometrically, by measuring absorbance changes at 547.5 nm. A highly sensitive, selective and simple method was accordingly developed for the determination of trace amounts of Mn(II), with no need for a separation or pre‐concentration step. Effects of reaction time, concentration of reagents, temperature and ionic strength on the reaction rate were studied. In the optimized conditions, manganese could be determined in a range of 1 to 60 ng mL?1 with a detection limit of 0.2 ng mL?1. The proposed method was successfully applied to the determination of manganese in tea leaves. 相似文献
69.
Ahmad Shaabani Abbas Rahmati Masoumeh Sharifi Jafar Mogimi Rad Behnaz Aghaaliakbari Elham Farhangi Donald G. Lee 《Monatshefte für Chemie / Chemical Monthly》2007,138(7):649-651
Summary. The oxidation of arenes and sulfides by potassium permanganate was accomplished in good yields under solvent free and heterogeneous
conditions when manganese(II) sulfate is used as a solid support. After extraction of the organic products, the inorganic
products can be reoxidized to permanganate. This result is important because it provides an approach to oxidation reactions
that is, in theory, infinitely sustainable. 相似文献
70.
A novel isocyanide-based three-component reaction: synthesis of highly substituted 1,6-dihydropyrazine-2,3-dicarbonitrile derivatives 总被引:2,自引:0,他引:2
A novel multi-component synthesis of highly substituted 1,6-dihydropyrazine-2,3-dicarbonitrile derivatives starting from simple and readily available inputs is described. Thus, simply stirring an ethanol solution of 2,3-diaminomaleonitrile, a ketone, and an isocyanide in the presence of a catalytic amount of p-toluenesulfonic acid provided highly substituted 1,6-dihydropyrazine-2,3-dicarbonitrile derivatives in good to excellent yields at ambient temperature. 相似文献