A multiobjective model of wholesaler-retailers' problem via genetic algorithm

In the existing literature, most of the purchasing models were developed only for retailers problem ignoring the constraint of storage capacity of retailers shop/showroom. In this paper, we have developed a deterministic model of wholesaler-retailers' problem of single product. The storage capacity of wholesaler's warehouse/showroom and retailers' showroom/shop are assumed to be finite. The items are transported from wholesaler's warehouse to retailers' Own Warehouse (OW) in a lot. The customer's demand is assumed to be displayed inventory level dependent. Demands are met from OW and that spaces of OW will immediately be filled by shifting the same amount from the Rented Warehouse (RW) till the RW is empty. The time duration between selling from OW and filling up its space by new ones from RW is negligible. According to relative size of the retailers' existing (own) warehouse capacity and the demand factors, different scenarios are identified. Our objectives are to optimize the cost functions of wholesaler and two retailers separately. To solve this problem, a real coded Genetic Algorithm (GA) with roulette wheel selection/reproduction, whole arithmetic crossover and non-uniform mutation is developed. Finally a numerical example is presented to illustrate the results for different scenarios. To compare the results of GA, Generalised Reduced Gradient Method has been used for the problem. Also, a sensitivity analysis has been performed to study the variations of the optimal average cost with respect to the different parameters.     

Intramolecular Heck Reaction on Bromobenzyloxy-Substituted Chromenes: Formation of Chelated Ketones

Heck reaction on 2-bromobenzyloxy-substituted 4H-chromene derivatives using Pd(OAc)₂ in Aliquat 336 and N,N-dimethylformamide mixture leads to intramolecular heteroannulation along with hydrolysis, affording chelated 6H-benzo[c]chromen-2-yl ketones. The method offers Pd(0)-catalysis and regioselectivity in product formation.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

Kinetics and Mechanism of the Oxidation of Some Aldoses by Cerium(IV)

Abstract

The kinetics of oxidation of some aldoses by cerium(IV) have been studied spectrophotometrically in sulphuric acid medium. The reactions are second order; first order with respect to both cerium(IV) and aldose concentration. The reaction rate decreases with increase in sulphuric acid concentration. The mechanisms for the reactions are discussed.     

Pd–Cl cleavage of dichloro-[1-alkyl-2-(naphthylazo)imidazole]palladium(II) complexes by picolinic acid: Kinetic and mechanistic studies

Picolinic acid (picH) reacts with [Pd(α-/β-NaiR)Cl₂] [α-/β-NaiR = 1-alkyl-2-(naphthyl-α-/β-azo)imidazole] in acetonitrile (MeCN) medium to give [Pd(α-/β-NaiR)(pic)](ClO₄). The products are characterized by spectroscopic techniques (FT-IR, UV–Vis, NMR). The reaction kinetics show first order dependence of rate on each of the concentration of Pd(II) complex and picH. Addition of LiCl to the reaction decreases the rate of reaction and has proved the cleavage of Pd–Cl bond at the rate-determining step. Thermodynamic parameters (Δ^‡H° and Δ^‡S°) are determined from variable temperature kinetic studies. The magnitude of the second order rate constant, k₂ increases as in the order: Pd(NaiEt)Cl₂ < Pd(NaiMe)Cl₂ <  Pd(NaiBz)Cl₂ as well as Pd(β-NaiR)Cl₂ <  Pd(α-NaiR)Cl₂.     

Development of a honeycomb gas proportional counter array for photon multiplicity measurements in high multiplicity environment

A novel gas-based detector using large arrays of honeycomb cells has been developed and tested for use as a pre-shower photon multiplicity detector (PMD) for STAR and ALICE experiments. The appropriate cell design was arrived at using GARFIELD simulations. Prototype chambers with cell dimensions corresponding to STAR and ALICE were fabricated and tested at CERN PS and SPS. The charged particle detection efficiency and the pre-shower characteristics have been studied using pion and electron beams.     

Nuclear motion on the orbitally degenerate electronic ground state of fully deuterated triatomic hydrogen

Nuclear motion in the vicinity of conical intersections of the degenerate electronic ground state of fully deuterated triatomic hydrogen, D(3), is investigated with the aid of a time-dependent wavepacket approach in hyperspherical coordinates. Vibronic energy level spectra and the eigenfunctions are examined by including, for example, (1) geometric phase (GP) correction, (2) diagonal Born-Huang (BH) correction, and (3) both GP and BH corrections to the Born-Oppenheimer adiabatic Hamiltonian and finally by considering the nonadiabatic coupling between the two electronic surfaces explicitly. It emerges from this study that inclusion of both the GP and BH corrections is insufficient to explain the spectral features observed in the experiment. The latter are recovered by considering the complete two-states coupled Hamiltonian only. This study shows that both the GP and BH corrections constitute a minor part of the surface coupling effects, in particular, on the dynamics of the upper adiabatic sheet. Most importantly, we add that the experimental signature of the GP effect appears only in the observed shift of the eigenlevels of the electronic state when compared to those obtained from a completely Born-Oppenheimer Hamiltonian. The detail fine structure of the observed band of the electronic state is shaped by the off-diagonal derivative coupling elements of the nonadiabatic coupling operator.     

STM and XPS investigations of bismuth islands on HOPG

The growth of bismuth thin films on highly oriented pyrolitic graphite (HOPG) was studied using ultra high vacuum (UHV) scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The locations of the main XPS peaks, and also the plasmon energy, are in good agreement with results recorded on bulk bismuth. The shape of the Bi 4f doublet, as well as the well developed Fermi edge, indicates the metallic character of the deposited film. One of the observed shoulders is identified with a quantum-well subband characteristic of thin bismuth films. There is no evidence for the existence of Bi–C bonds, consistent with weak bonding between the Bi islands and the HOPG. The height of the islands and their crystallographic orientation were investigated as a function of surface coverage. The Bi islands grow with the (110) plane parallel to the substrate. The observed heights (3, 5, 7, 9 ML) indicate that the preferred crystal structure involves paired layers on an intermediate mono-atomic Bi layer. There is evidence both for and against the Black Phosphorus like allotrope, and the nature of both the layer pairing and the intermediate layer are yet to be resolved. The islands exhibit stripes oriented along the $<1\overline{1}0>$ axis of the Bi crystal, which is a fast growth direction due to the existence of strongly bonded zig-zag chains of atoms. The surface unit cell and the parameters of the rhombohedral bulk unit cell are estimated based on atomic resolution images. In the case of 2 ML stripes on top of a 5 ML base, the expansion of the outer atomic rows was estimated at 27%. Asymmetries in the growth of the islands are observed. Based on low coverage depositions at reduced substrate temperatures, it is proposed that there is a second fast growth direction corresponding to preferential attachment of atoms to one of the faces of the asymmetric, rhombic cross-section of the (110) crystal.