Electrochemical characterization and transport properties of polyvinyl chloride based carboxymethyl cellulose Ce(IV) molybdophosphate composite cation exchange membrane

The polyvinyl chloride (PVC) based carboxymethyl cellulose Ce(IV) molybdophosphate composite membrane are prepared and characterized by the Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Fourier transformed infrared (FTIR), and thermogravimetric analysis (TGA) studies. The inorganic–organic composite membrane was found to be crystalline in nature with consistent arrangement of particles and indicating no sign of visible cracks. The FTIR spectra verify the binding of organic polymer with inorganic component. The membrane was found to be cation-selective. The order of surface charge density for uni-univalent electrolytes solution was found to be KCl > NaCl > LiCl.     

Convergence of multivalued mappings via approximable measurable selectors

We investigate the convergence of measurable selectors for the limit of measurable multivalued maps. The relationship between the convergence of measurable selectors and lower and upper limits of measurable multivalued mappings with closed images is also derived.     

Multi-product selective newsvendor problem with service level constraints and market selection flexibility

We consider a multi-product multi-market newsvendor problem where the decision-maker could select some markets to serve. The considered problem involves the integration of procurement and market selection decisions. The products are procured from an external supplier. We assume that the realised demand for each product should be satisfied. In the case of shortages, the firm procures items at a higher cost. The paper considers the case where the selling prices, market entry costs, and product demand distributions are market dependent. Specifically, we discuss three cases of the Multi-Product Selective Newsvendor Problem: flexible market entry case, full market entry case and partial market entry case. The mathematical models of the above cases result in binary nonlinear programmes. We develop solution algorithms for solving the resulting combinatorial problems. Some managerial insights are provided.     

Effect of deflocculants on hardness and densification of YSZ–Al2O3 (whiskers & particulates) composites

In the present study effect of deflocculants like P-Aminobenzoic Acid (PABA) and Cetyltrimethyl ammonium bromide (CTAB) on densification and hardness of 3 mol.% Yttria-stabilized ZrO₂ (abridged as YSZ) + Al₂O₃ (whiskers or particulates) composite have been studied. Maximum hardness & density were achieved at 1 wt% of CTAB or PABA, while further addition (5, 10 and 15 wt%) had no significant affect on the aforementioned properties. It was also observed that alumina addition in form of particulates only improved the density while its addition in form of whiskers significantly increased the hardness of YSZ + alumina composite. The maximum hardness achieved was more than 14 GPa in case of sample containing alumina in form of whiskers.     

Preparation,characterization, biological activity,and transport study of polystyrene based calcium–barium phosphate composite membrane

Calcium–barium phosphate (CBP) composite membrane with 25% polystyrene was prepared by co-precipitation method. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transformed infrared (FTIR), and Thermogravimetric analysis (TGA) were used to characterize the membrane. The membrane was found to be crystalline in nature with consistent arrangement of particles and no indication of visible cracks. The electrical potentials measured across the composite membrane in contact with univalent electrolytes (KCl, NaCl and LiCl), have been found to increase with decrease in concentrations. Thus the membrane was found to be cation-selective. Transport properties of developed membranes may be utilized for the efficient desalination of saline water and more importantly demineralization process. The antibacterial study of this composite membrane shows good results for killing the disease causing bacteria along with waste water treatment.     

Effect of various processing techniques and different levels of antioxidant on stability of rice bran during storage

Rice bran is a major cereal by‐product available for animal feeding in many parts of the world. It has a good balance of protein, fat, carbohydrates, fiber, vitamins and minerals. The greatest restriction to the use of rice bran is its instability during storage, leading to rancidity and the presence of heat‐labile antinutritional factors. Rice bran was treated to stabilize it by extrusion cooking, roasting, pelleting and adding antioxidant (125, 250 and 375 ppm). The rice bran so treated was stored for 345 days and analyzed every 15 days for free fatty acid, peroxide and iodine values. Heat treatments were effective in stabilizing rice bran by reducing the rancidity and increasing the storage life. Roasting was effective in stabilizing rice bran for only 180 days of storage. Raw and pelleted rice bran behaved similarly with regard to stability during storage for 345 days. Addition of antioxidant in rice bran was not effective for stabilizing FFA, peroxide and iodine values. There was no difference in dose rates of antioxidant of 125, 250 and 375 ppm. Extrusion cooking proved to be the most effective process for stabilizing rice bran for prolonged storage, and roasting would be the next choice. Addition of antioxidant in rice bran was not effective for stabilizing rice bran during storage. Copyright © 2004 Society of Chemical Industry     

Effect of surfactant and heat treatment on morphology,surface area and crystallinity in hydroxyapatite nanocrystals

Hydroxyapatite (HA) powders were synthesized by the wet precipitation method, with and without surfactant, under identical processing parameters. These powders were then heat treated at 900 °C for 3 h in air. The detailed characterization of the powders was done by using SEM, dynamic light scattering, nitrogen adsorption, XRD, Raman spectroscopy, and FTIR techniques. The HA phase, identified by well defined PO₄^3? and OH^? ion peaks in Raman and FTIR spectra, was observed in all the powder samples. The addition of surfactant changed the morphology of the particles from spherical to needle/rod-like structure and increased the surface area up to three times (from 33 to 96 m²/g). Also, suppression in the evolution of β-TCP phase was observed along with decrease in the crystal size and crystallinity of the powder due to the addition of surfactant. Synthesized nano-HA crystals were found to have diameters and lengths in the range 10–25 nm and 75–150 nm, respectively. The heat treatment changed the architecture of the particles, increased the crystallinity and reduced the surface area to ≈7 m²/g. However, the relative increase in crystallinity was much higher for the powder synthesized with surfactant. The ratio of the average crystallite size to the crystallinity degree was about 0.53±0.07 for all the powders. The particle size distribution was bimodal and coarser for the powder synthesized without surfactant. The pore size analysis showed transformation of a predominantly mesoporous structure into a meso- plus macroporous one on heat treatment. The intensity of OH^? group peak in Raman spectra was found to be highly sensitive to the crystalline state of the HA powder and may be used to assess crystallinity.     

A Pareto-based hybrid multiobjective evolutionary approach for constrained multipath traffic engineering optimization in MPLS/GMPLS networks

This paper proposes a hybrid evolutionary algorithm for solving the constrained multipath traffic engineering problem in MPLS (Multi-Protocol Label Switching) network and its extended architecture GMPLS (Generalized MPLS). Multipath traffic engineering is gaining more importance in contemporary networks. It aims to satisfy the requirements of emerging network applications while optimizing the network performance and the utilization of the available resources within the network. A formulation of this problem as a multiobjective constrained mixed-integer program, which is known to be NP-hard, is first extended. Then, we develop a hybrid heuristic algorithm based on combining linear programming with a devised Pareto-based genetic algorithm for approximating the optimal Pareto curve. A numerical example is adopted from the literature to evaluate and compare the performance of six variations of the proposed heuristic. We study the statistical significance of the results using Kruskal–Wallis nonparametric test. We also compare the results of the heuristic approach with the lexicographic weighted Chebyshev method using a variety of performance metrics.     

Security & Privacy in Software Defined Networks,Issues, Challenges and Cost of Developed Solutions: A Systematic Literature Review

International Journal of Wireless Information Networks - Due to fast development in digital systems, the traditional network architecture is becoming inadequate for the requirements of new...