A multi-item transportation problem with fuzzy tolerance

This paper presents the recently introduced modified subgradient method for optimization and its effectiveness in a fuzzy transportation model. Here a multi-item balanced transportation problem (MIBTP) is formulated where unit transportation costs are imprecise. Also available spaces and budgets at destinations are limited but imprecise. The objective is to find a shipment schedule for the items that minimizes the total cost subjected to imprecise warehouse and budget constraints at destinations. The proposed model is reduced to a multi-objective optimization problem using tolerances, then to a crisp single-objective one using fuzzy non-linear programming (FNLP) technique and Zimmermann's method. The above fuzzy MIBTP is also reduced to another form of deterministic one using modified sub-gradient method (MSM). These two crisp optimization problems are solved by Genetic Algorithm (GA). As an extension, fuzzy multi-item balanced solid transportation problems (STPs) with and without restrictions on some routes and items are formulated and reduced to deterministic ones following FNLP and Zimmermann's methods. These models are also solved by GA. Models are illustrated numerically, optimum results of fuzzy MIBTP from two deductions are compared. Results are also presented for different GA parameters.     

Phase Diagram and Upper Critical Field of Homogeneously Disordered Epitaxial 3-Dimensional NbN Films

We report the evolution of superconducting properties with disorder, in 3-dimensional homogeneously disordered epitaxial NbN thin films. The effective disorder in NbN is controlled from moderately clean limit down to Anderson metal?Cinsulator transition by changing the deposition conditions. We propose a phase diagram for NbN in temperature-disorder plane. With increasing disorder, we observe that as k _F l??1 the superconducting transition temperature (T _c ) and normal state conductivity in the limit T??0 (?? ₀) go to zero. The phase diagram shows that in homogeneously disordered 3-D NbN films, the metal?Cinsulator transition and the superconductor?Cinsulator transition occur at a single quantum critical point, k _F l??1.     

Surface Activation and Adhesion Properties of Wood-Fiber Reinforced Thermoplastic Composites

Four surface activation methods were evaluated on a series of wood-fiber reinforced thermoplastic composites (WPCs) as a means to improve the adhesion of a water-based acrylic coating. Treatments with chromic acid and oxygen plasma performed best, increasing the acrylic coating peel load to WPCs by 170 and 122%, respectively, and yielding adhesion levels equivalent to or higher than those obtained on wood. The benzophenone/ultraviolet and flame treatments also improved the coating adhesion by 100 and 64%, respectively, but did not reach the adhesion levels achieved on wood. For both the chromic acid and oxygen plasma treatments, the WPC formulation impacted the treatment efficacy. Profilometry and scanning electron microscopy (SEM) showed that the chromic acid treatment acted mainly by roughening WPC surfaces. While surface oxidation was not evident from attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), the improved wettability of WPCs with water suggested that the oxygen plasma treatment oxidized WPCs.     

A MATHEMATICAL MODEL FOR MILD HYDROCRACKING:KINETICS AND PRODUCT YIELDS FROM A CRUDE OIL BLEND IN LIGHT GAS OIL OVER HYDROTREATING CATALYST.

Abstract

Mild hydrocracking of 30% crude oil (Indian Crude oil.North Gujarat base)solution in light gas oil is carried out over a commercial hydrotreating catalyst at a temperature range of 300–450°c and pressure of 6. 8–20.OMpa in laboratory reactor. About 30 to 60% of the long residue (365° c+ cut) in the solution is converted to light distillates.

A mathematical model has been developed to predict the yields of products.     

Selective Extraction of (−)Epigallocatechin Gallate from Green Tea Leaves Using Two-Stage Infusion Coupled with Membrane Separation

A novel method for the extraction of (−)epigallocatechin gallate of high purity from green tea leaves is proposed in this study. The method comprised a two-stage water-based extraction followed by successive use of microfiltration and ultrafiltration. Microfiltration was used as a pretreatment to ultrafiltration. The best process conditions of each unit operation were estimated by performing well-planned experimentations. The clarified liquor was dried to powder by freeze drying. Chemical analyses revealed that the tea powder contained about 90% of polyphenols. The purity of (−)epigallocatechin gallate was found to be about 80%, while its average yield was 1.22 g/l. The method outlined in this study may have remarkable importance for the bulk production of high-purity (−)epigallocatechin gallate with potential application in pharmaceutical, cosmetic, and food-processing industries. Besides being a green process, this method can be easily scaled up for the commercial production of (−)epigallocatechin gallate.     

The WINLAB Network Centric Cognitive Radio Hardware Platform—WiNC2R

This paper presents the design goals and architecture of WiNC2R—the WINLAB Network Centric Cognitive radio hardware platform. The platform has been designed for flexible processing at both the radio physical layer and MAC/network layers with sustained bit-rates of ~10 Mbps and higher. The hardware prototype supports multi band operation with fast spectrum scanning, the ability to dynamically switch between a number of OFDM and DSSS modems and multiple MAC protocols. The radio modems, MAC, and network-layer protocols are implemented in a flexible manner using general-purpose processing engines and a set of dynamically configurable hardware accelerators. An FPGA based platform implementation currently in progress is described in terms of key hardware components including the software-defined modem, the flexible MAC engine and network-level processor. Preliminary prototyping results are reported, and a roadmap for further evolution of the WiNC2R board is provided.     

Stability, Throughput, and Delay of Asynchronous Selective Reject ALOHA

An analytical performance evaluation model is presented for selective reject (SREJ) ALOHA, a recently proposed high-capacity protocol for unslotted channels with high propagation delay. SREJALOHA approaches the theoretical asynchronous multiaccess throughput limit of 0.368 for fixed or variable length message traffic, using subpacketization of messages in conjunction with a selective reject retransmission policy. A finite user flow equilibrium-based model for SREJ-ALOHA with variable length messages is derived and used to characterize stability, throughput, and delay. Particular attention is given to the development of a stability analysis methodology for unslotted ALOHA-type protocols with variable length transmissions. Numerical results based on a satellite channel example are presented to demonstrate the significant performance advantages offered by SREJ-ALOHA, even after accounting for realistic subpacket overheads.     

Models for minimum ignition temperature of organic dust clouds

The minimum ignition temperature of dust clouds is one of the important factors required for the design of preventive measures against dust explosion. The mathematical models available to predict this parameter have been analyzed for thier application to organic dust clouds. A solution of the most general model proposed by Mitsui and Tanaka is presented, together with its comparision with experimental data. It has been found to be quite successful in predicting the minimum ignition temperature for metal dusts but not for organic dusts. Recommendations for the development of a new model to predict the minimum ignition temperature of an organic dust, such as polyethylene, have been given.     

The effect of coagulants on the texture of chhana (an acid and heat coagulated product made from milk)

Chhana (a heat and acid coagulated milk protein mass and an Indian equivalent to cottage cheese) can be used as a raw material for the manufacture of various types of sweets popular all over India. Texture Profile Analysis (TPA), using an Instron Universal Testing Machine, was used to determine the effect of different coagulants on the textural characteristics of chhana. Chhana was made using three different coagulants: citric acid, lactic acid and calcium lactate, at five different concentrations, 0.5, 1, 2, 4 and 8%. Two types of dilution media, distilled water and acid whey, were used. The textural characteristics obtained when aqueous 0.5% citric acid, aqueous 0.5% lactic acid and 4–8% calcium lactate solutions, using acid whey as the solvent, gave similar TPA readings to normal chhana.     

The induction of cytotoxic T cells and tumor regression by soluble antigen formulation

CTLs specific for tumor antigens play a major role in the immunity against cancer. We have shown that class I-restricted CTLs can be induced by injecting soluble antigens mixed in an antigen formulation (AF) that consists of squalane, Tween 80, and Pluronic L121 (S. Raychaudhuri et al., Proc. Natl. Acad. Sci. USA, 89: 8308-8312, 1992). In this study, using ovalbumin and the ovalbumin-expressing transfectoma (EG7) as a tumor model system, we examined the in vivo antitumor effect of antigen-AF mixture. Vaccination of mice with ovalbumin in AF 2 or 3 days after EG7 tumor challenge showed significant inhibition of tumor growth compared to mice vaccinated with ovalbumin in alum or in saline. Depletion of CD8+ cells at the time of immunization completely abrogated the AF-induced tumor protection, indicating that CD8+ T cells are the major effectors in tumor protection in vivo. Depletion of CD4+ cells led to a marginal loss of tumor protection, which may be the result of inhibition of ovalbumin-specific CTL response due to the lack of T-helper activity. Our results demonstrate that AF can be used in subunit vaccines to stimulate CTLs and tumor regression in vivo.