A new multi-objective stochastic model for a forward/reverse logistic network design with responsiveness and quality level

Logistic network design has an important and strategic platform in an efficient and effective supply chain management, and usually involves multiple and conflicting goals, such as cost/profit, resource balance, customer responsiveness, quality, and the like. Besides, due to the implementation of government legislation, environmental concern, social responsibility and customer awareness, companies have been forced by customers not only to supply environmentally amicable products but also to be responsible for the returned products. Hence, this paper presents a stochastic multi-objective model for forward/reverse logistic network design under a uncertain environment including three echelons in forward direction (i.e., suppliers, plants, and distribution centers) and two echelons in backward direction (i.e., collection centers and disposal centers). We demonstrate a method to evaluate the systematic supply chain configuration maximizing the profit, customer responsiveness, and quality as objectives of the logistic network. The set of Pareto optimal solutions is obtained and also financial risk relevant to them is computed in order to show the tradeoff between objectives. The results give important insight for fostering the decision making process.     

First principles study on spin and orbital magnetism in CuFeSb and CuCoSb alloys with C1b structure

In this work the effect of spin–orbit coupling and orbital polarization (OP) corrections on the spin and orbital magnetism of two half-Heusler alloys (CuFeSb and CuCoSb) is investigated by means of local spin density calculations. It is demonstrated that OP corrections predict large orbital moments for Fe and Co individual atoms in the considered compounds. It is found that the Heusler alloys with C1_b structure are potential candidates to show large orbital magnetism.     

The first report of [2+2] ketene–imine cycloaddition reactions (Staudinger) on carbon nanotubes

Several new carbon nanotube-functionalized β-lactams have been synthesized from chiral imines derived from β-d-glucopyranosylamine and a ketene from carbon nanotube-based oxyacetic acid via a [2+2] cycloaddition reaction. The cycloadducts were characterized by thermogravimetric analysis, Raman spectrometry, IR, and N₂ adsorption processes.     

Comment on: “Theoretical calculation of turn-on delay time of VCSEL and effect of carriers recombination” [Opt. Laser Technol. 39 (2007) 997–1001]

Zhang et al. [Opt. Laser Technol. 39 (2007) 997–1001], through theoretical calculation, have shown that the turn-on time delay can be reduced by increasing any of the non-radiative (A_nr), radiative (B), and/or Auger recombination (C) coefficients at a constant injection current over threshold current. Here, we explain that the results presented by that paper are incorrect and the turn-on time delay increases by increasing any of the carrier recombination rate coefficients.     

A novel signal extraction approach for filtering and forecasting noisy exponential series

The coefficients of Linear Recurrent Relations (LRR) play a pivotal role in many forecasting techniques. Precise and closed form of the LRR coefficients enables one to achieve more accurate forecasts. On account to the fact that, in real-world situations, a time series data is contaminated with noise, extracting the noiseless series is of great importance. This paper seeks to obtain a closed form, with less noise level, of LRR coefficients for noisy exponential time series. Improving the filtering performance through employing noiseless eigenvectors of the covariance matrix is another novelty of this study. Our simulation results confirm that the proposed approach enhances filtering and forecasting results.     

Magnetic and structural studies on CoFe2O4 nanoparticles synthesized by co-precipitation,normal micelles and reverse micelles methods

Cobalt ferrite nanoparticles were synthesized by the chemical co-precipitation, normal micelles and reverse micelles methods of iron and cobalt chlorides. X-ray diffraction analysis, Fourier Transform Infrared (FTIR) and Vibrating Sample Magnetometer were carried out at room temperature to study the structural and magnetic properties. X-ray patterns revealed the production of a broad single cubic phase with the average particle sizes of ∼12 nm, 5 nm and 8 nm for co-precipitation, normal micelles and reverse micelles methods, respectively. The FTIR measurements between 400 and 4000 cm⁻¹ confirmed the intrinsic cation vibrations of spinel structure for each one of the three methods. Moreover, the average particle sizes were lower than the single domain size (128 nm) and higher than the super-paramagnetic size (2–3 nm) at room temperature. The results revealed that the magnetic properties depend on the particle size and cation distribution, whereas the role of particle size is more significant.