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Chain Consisting (chain + consisting)
Selected AbstractsChannel Strategies and Stocking Policies in Uncapacitated and Capacitated Supply Chains,DECISION SCIENCES, Issue 2 2002Jayashree Mahajan ABSTRACT A supply chain consisting of a single supplier distributing two independent products through multiple retailers is analyzed in this paper. The supplier needs to incentivize its retailers to adopt stocking policies that are mutually advantageous and that result in the optimal level of market coverage. The focus is on determining the optimal stocking policies for retailers and the resulting distribution strategy given that the supplier has either unlimited or limited capacity. The results provide insights on the optimal distribution strategy and stocking policies for the supply chain. In general, the paper shows that it is optimal for the supplier to use an intensive distribution strategy (i.e., the products are stocked by all retailers). Selective or exclusive strategies are optimal only when retailers are risk averse, stocking synergies exist, and there are differences in demand or supply uncertainties across products. The analysis also shows that retailers hold larger stocks of a product which generates higher supplier margins but only when the supplier has unlimited capacity. If the supplier has limited capacity, then their margins have no effect on retailers' stocking decisions. Contrary to conventional wisdom, retailers hold larger stocks of a product that has less demand uncertainty as compared to one that has more demand uncertainty. [source] Donor,Acceptor-Substituted Oligo(1,4-phenylene)sHELVETICA CHIMICA ACTA, Issue 6 2009Soungkyoo Kim Abstract Oligo(para -phenylene)s (DAOPPs) 2a,2d (n=1,4) with terminal donor,acceptor substitution (D=C6H13O, A=NO2) were prepared by applying Suzuki cross-couplings for chain extension and end capping. The push,pull effect induces short-reaching polarizations of the chain consisting of conjugated but twisted benzene rings, which was studied by NMR measurements. Electron excitation from the ground-state S0 to the more planar first-excited singlet state S1 is combined with a strong intramolecular charge transfer (ICT), which is documented by the red shift of the long-wavelength absorption (charge-transfer band) for short chains (one or two repeat units, n,=,1 or 2). The opposite influence of decreasing ICT and increasing conjugation length leads to a bathochromic series (,max(n+1),,max(n)) with a fast saturation of ,max (n). The effective conjugation length nECL=4 corresponds to ,, 349,nm. These results are discussed in the context of other oligo(para -phenylene)s (OPPs). [source] Optimal use of high-resolution topographic data in flood inundation modelsHYDROLOGICAL PROCESSES, Issue 3 2003P. D. Bates Abstract In this paper we explore the optimum assimilation of high-resolution data into numerical models using the example of topographic data provision for flood inundation simulation. First, we explore problems with current assimilation methods in which numerical grids are generated independent of topography. These include possible loss of significant length scales of topographic information, poor representation of the original surface and data redundancy. These are resolved through the development of a processing chain consisting of: (i) assessment of significant length scales of variation in the input data sets; (ii) determination of significant points within the data set; (iii) translation of these into a conforming model discretization that preserves solution quality for a given numerical solver; and (iv) incorporation of otherwise redundant sub-grid data into the model in a computationally efficient manner. This processing chain is used to develop an optimal finite element discretization for a 12 km reach of the River Stour in Dorset, UK, for which a high-resolution topographic data set derived from airborne laser altimetry (LiDAR) was available. For this reach, three simulations of a 1 in 4 year flood event were conducted: a control simulation with a mesh developed independent of topography, a simulation with a topographically optimum mesh, and a further simulation with the topographically optimum mesh incorporating the sub-grid topographic data within a correction algorithm for dynamic wetting and drying in fixed grid models. The topographically optimum model is shown to represent better the ,raw' topographic data set and that differences between this surface and the control are hydraulically significant. Incorporation of sub-grid topographic data has a less marked impact than getting the explicit hydraulic calculation correct, but still leads to important differences in model behaviour. The paper highlights the need for better validation data capable of discriminating between these competing approaches and begins to indicate what the characteristics of such a data set should be. More generally, the techniques developed here should prove useful for any data set where the resolution exceeds that of the model in which it is to be used. Copyright © 2002 John Wiley & Sons, Ltd. [source] Review modeling the free solution and gel electrophoresis of biopolymers: The bead array-effective medium modelBIOPOLYMERS, Issue 2-3 2007Stuart A. Allison Abstract Free solution and gel electrophoresis is an extremely useful tool in the separation of biopolymers. The complex nature of biopolymers, coupled with the usefulness of electrophoretic methods, has stimulated the development of theoretical modeling over the last 30 years. In this work, these developments are first reviewed with emphasis on Boundary Element and bead methodologies that enable the investigator to design realistic models of biopolymers. In the present work, the bead methodology is generalized to include the presence of a gel through the Effective Medium model. The biopolymer is represented as a bead array. A peptide, for example, made up of N amino acids is modeled as 2N beads. Duplex DNA is modeled as a discrete wormlike chain consisting of touching beads. The technical details of the method are placed in three Appendices. To illustrate the accuracy and effectiveness of the approach, two applications are considered. Model studies on both the free solution mobility of 73 peptides ranging in size from 2 to 42 amino acids, and the mobility of short duplex DNA in dilute agarose gels are discussed. © 2007 Wiley Periodicals, Inc. Biopolymers 87: 102,114, 2007. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] Kinematic and dynamic analysis of open-loop mechanical systems using non-linear recursive formulationINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 12 2006Yunn-Lin Hwang Abstract In this paper, a non-linear recursive formulation is developed for kinematic and dynamic analysis of open-loop mechanical systems. The non-linear equations of motion are developed for deformable links that undergo large translational and rotational displacements. These equations are formulated in terms of a set of time invariant scalars and matrices that depend on the spatial co-ordinates as well as the assumed displacement field, and these time invariant quantities represent the dynamic coupling between the rigid-body modes and elastic deformations. A new recursive formulation is presented for solving equations of motion for open-loop chains consisting of interconnected rigid and deformable open-loop mechanical systems. This formulation is expressed by the recursive relationships and the generalized non-linear equations for deformable mechanical systems to obtain a large system of loosely coupled equations of motion. The main processor program consists of three main modules: constraint module, mass module and force module. The constraint module is used to numerically evaluate the relationship between the absolute and joint accelerations. The mass module is used to numerically evaluate the system mass matrix as well as the non-linear Coriolis and centrifugal forces associated with the absolute, joint and elastic co-ordinates. Simultaneously, the force module is used to numerically evaluate the generalized external and elastic forces associated with the absolute, joint and elastic co-ordinates. Computational efficiency is achieved by taking advantage of the structure of the resulting system of loosely coupled equations. The solution techniques used in this investigation yield a much smaller operations count and can more efficiently implement in any computer. The algorithms and solutions presented in this paper are illustrated by using an industrial robotic manipulator system. The numerical results using this formulation are also presented and discussed in this paper. Copyright © 2006 John Wiley & Sons, Ltd. [source] Investigation of the Structural Characterization of Mesoporous Molecular Sieves MCM-41 from SepioliteJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2007Shengming Jin Mesoporous molecular sieves, MCM-41, were synthesized from sepiolite using acid leaching, followed by hydrothermal reconstruction and then calcinations at 540°C for 5 h. The structures and the porosity of MCM-41 were investigated by means of small-angle X-ray diffraction patterns, Brunaer-Emmett-Teller (BET), 29Si MAS NMR, Fourier transform infrared (FTIR), and high resolution transmission electron microscope (HRTEM) methods. The results showed that the hexagonal MCM-41 was formed in an alkaline solution of pH 12, when crystallization was carried out at 100°C for 24 h. The specific surface area, pore diameter, and pore volumes of MCM-41 from sepiolite were 1036 m2/g, 2.98 nm, and 1.06 cm3/g, respectively. 29Si MAS NMR results revealed that amorphous silica decomposed into Si,O chains consisting of two layers of Si atoms, with Q3 configurations resulting in an increase in the fraction of Q3 configuration during the crystallization of post-Mg-extraction sepiolite. The IR results illustrated that the complex of ,,SiO,,CTA+ was formed during the synthesis of MCM-41 from post-Mg-extraction sepiolite. [source] Cellular morphology of rough forms of Listeria monocytogenes isolated from clinical and food samplesLETTERS IN APPLIED MICROBIOLOGY, Issue 4 2000N.J. Rowan Transmission electron microscopy (TEM) studies revealed that rough cell-forms of L. monocytogenes (designated FR variants), isolated from clinical and food samples (and under conditions of sublethal heat stress), consist of either single or paired long-filaments. These FR variants markedly contrast in cell morphology from other previously described avirulent rough-mutants of L. monocytogenes that form long chains consisting of multiple cells of similar size (designated MCR variants). The identity of these Listeria isolates was determined using a commercially available, anti- Listeria polyclonal KPL antibody and by the API Listeria biochemical gallery. This study shows that filamentous rough-forms of L. monocytogenes may occur in clinical and food samples that are of undetermined pathogenicity. [source] Solution Behavior of Temperature-Responsive Molecular Brushes Prepared by ATRPMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 1 2007Joanna Pietrasik Abstract Molecular brushes, with side chains consisting of two copolymers: 2-(dimethylamino)ethyl methacrylate with methyl methacrylate, and N,N -dimethylacrylamide with butyl acrylate were prepared by grafting-from via atom transfer radical polymerization (ATRP). Poly(2-(2-bromoisobutyryloxy)ethyl methacrylate) and poly(2-(2-bromopropionyloxy)ethyl methacrylate) were used as macroinitiators. Dynamic light scattering (DLS) studies were performed for aqueous solutions of molecular brushes below and above the lower critical solution temperature (LCST), and an unusual concentration-dependent LCST was observed. Due to the compact structure of molecular brushes, intramolecular collapse can occur when the average distance between molecules is much larger than the hydrodynamic dimensions of the individual macromolecules. However, if the concentration of the solution of molecular brushes is increased to the level in which the separation distance is comparable with the brush hydrodynamic dimensions, intermolecular aggregation occurs, as typically observed for solutions of linear polymers. [source] | ||||||||||||||||