Synthesis and characterization of poly(ethylene aspartate)-metal complexes

Poly(ethylene aspartate) [PEA] was synthesized by the melt condensation of D,L-aspartic acid and ethylene glycol. PEA containing pendent amino and carbonyl groups in its repeating chain was used as the polymeric ligand for complexation with transition metal ions, viz. Co(II), Ni(II), Cu(II), Mn(II), Zn(II), Cd(II), Ca(II), Mg(II), Pb(II) and Hg(II). Complexation was found to be most effective in DMSO. The resulting polyester-metal complexes were solid coloured materials which have been characterized by IR spectroscopy, elemental analysis and magnetic susceptibility measurements. The thermal stability of the polyester-metal complexes was investigated by thermogravimetric analysis (TGA). On the basis of the physico-chemical studies, an oxygen and nitrogen coordinated structure for the polyester-metal complexes is proposed.     

Countercurrent water-heating system with a heat exchanger in a solar energy collector loop

The counter current heat exchanger theory with periodic inlet temperatures has been applied to analyze the thermal performance of a water heating system. The theoretical results obtained are in agreement with the experimental data reported in the literature.     

A scheduling decision aid in glass fiber manufacturing

A decision aid for scheduling production in glass fiber manufacturing industry is described. The methodology combines a linear programming (LP) optimization model with a heuristic model. The LP model determines production goals; the heuristic model then uses the LP output to incorporate system-specific constraints in developing processing sequences.     

Water table fluctuation with a random initial condition

The nonlinear Boussinesq equation is used to understand water table fluctuations in various ditch drainage problems. An approximate solution of this equation with a random initial condition and deterministic boundary conditions, recharge rate and aquifer parameters has been developed to predict a transient water table in a ditch-drainage system. The effects of uncertainty in the initial condition on the water table are illustrated with the help of a synthetic example. These results would find applications in ditch-drainage design.Notation A / tanh t - a lower value of the random variable representing the initial water table height at the mid point - a+b Upper value of the random variable representing the initial water table height at the midpoint - B tanh t - C 4/ - h variable water table height - h mean of the variable water table height - h _m variable water table height at the mid point - h _m mean of the variable water table height at the mid point - K hydraulic conductivity - L half spacing between the ditches - m ₀ initial water table height at the mid point - N Uniform rate of recharge - S specific yield - t time of observation - x distance measured from the ditch boundary - (4/SL)(NK)^1/2 - (L/4)(N/K)^1/2 - dummy integral variable     

Effect of graft chain length of the stabilizer on dispersion polymerization of methyl methacrylate in petrol

To carry out dispersion polymerization of methyl methacrylate (MMA) in petrol, we have used a poly(MMA) grafted-poly(12-hydroxystearic acid) copolymer as the stabilizer. This special copolymer was prepared as a solution in a mixture of ethyl acetate and butyl acetate solvents. We investigated the effect of graft chain length of the stabilizer on the dispersion polymerization in petrol. We synthesized the stabilizer copolymer with n = 1–4 and determined the rate and the molecular weight of the PMMA formed. There is no dispersion polymerization for n = 1. However, for any other n, for a given stabilizer concentration, as the chain length of the graft is increased, the molecular weight as well as the rate of PMMA formation increases. As opposed to this for a given graft length as the concentration of the stabilizer increases, the molecular weight of PMMA first rises, but for a larger concentration, it begins to fall after undergoing a maximum. In this work, we modeled the heterogeneity of the reaction mass and proposed a mathematical model for dispersion polymerization of MMA in petrol. The computer results are found to conform to the experimentally observed molecular weight of the PMMA. © 1993 John Wiley & Sons, Inc.     

Does India need to harmonize the law of patent exhaustion and parallel imports?

The amendment of patent law of India in 2005 to fulfill her international obligation under the TRIPS Agreement (World Trade Organization Agreement on Trade Related Intellectual Property Rights) was an outcome of an attempt to balance the competing interests of several stakeholders, including indigenous pharmaceutical companies, multi-national pharmaceutical companies, non-governmental organizations and civil society groups concerned with access to affordable drugs. The adverse consequence of this delicate balancing is introduction of some provisions in the Act whose compatibility with the TRIPS Agreement is questionable, and which therefore are prone to litigations. Section 107A(b) of the amended patent law dealing with parallel imports is one such provision, which, if interpreted word for word could have significant connotations for the rights of a patent owner. This article aims to examine the inconsistencies intrinsic in Section 107A(b) and discusses the divergences in the Indian patent law associated with the doctrine of exhaustion and parallel imports. This article also proposes legal amendments with a view to eliminate inconsistencies intrinsic in the section and enlarge the ambit of the exhaustion principle conceptualized therein, while concurrently remaining compliant with the TRIPS Agreement.     

Least squares twin support vector machines for pattern classification

In this paper we formulate a least squares version of the recently proposed twin support vector machine (TSVM) for binary classification. This formulation leads to extremely simple and fast algorithm for generating binary classifiers based on two non-parallel hyperplanes. Here we attempt to solve two modified primal problems of TSVM, instead of two dual problems usually solved. We show that the solution of the two modified primal problems reduces to solving just two systems of linear equations as opposed to solving two quadratic programming problems along with two systems of linear equations in TSVM. Classification using nonlinear kernel also leads to systems of linear equations. Our experiments on publicly available datasets indicate that the proposed least squares TSVM has comparable classification accuracy to that of TSVM but with considerably lesser computational time. Since linear least squares TSVM can easily handle large datasets, we further went on to investigate its efficiency for text categorization applications. Computational results demonstrate the effectiveness of the proposed method over linear proximal SVM on all the text corpuses considered.     

A Petri Net based approach to determine the disassembly strategy of a product

In order to protect the environment and regain value added to products, a process known as disassembly has come into the limelight. This process is to be applied to reuse abandoned goods and materials. Manufacturers are being forced to establish disassembly plants and to develop their products' designs so as to maintain the government's dictate to dispose off their products in an environmentally responsible manner. This research presents a cost-based heuristic analysis for a circuit board assembly. Various components of the product and their assembly relationships are represented by a Petri Net diagram. Firing the transitions of the disassembly Petri Net is integrated with cost-based indices to develop an effective disassembly strategy. The methodology discussed here simplifies the decisionmaking process involved in disassembly planning. A comprehensive disassembly process planning system is proposed here and is exemplified by a case study of circuit board assembly.     

Ultrasonic air-coupled testing of square-shape CFRP composite rods by means of guided waves

In aerospace industry, one of the most important parts of gliders and motor-gliders is a lightweight longeron reinforcement made of carbon fibre reinforced plastics (CFRP) rods, known as Graphlite SM315 composite. During manufacturing, the rods as constructional elements are glued together in epoxy-filled matrix in order to build the arbitrary spar profile. The defects present in single rods such as breakage of fibres, multiple delaminations due to the lack of bonding between fibres and reduction in density affect essentially the strength and the fail-safety of the overall construction.The aim of the present work is to investigate the effects (transmission, reflection, scattering and mode conversion) of guided waves propagation along a square-shape CFRP rod in the case of contactless excitation/reception and interaction with region of multiple delaminations applying the numerical model and performing experiments.The square-shape CFRP composite rods possessing internal artificial delamination type defects have been investigated by numerical modelling and experiments employing the developed air-coupled technique (pitch-catch set-up) for cases of conventional transmission and advanced back-scattering configurations. Numerical predictions of guided wave interaction with a multiple delamination type defect in a CFRP composite rod have been made and the interaction mechanism explained. It is possible to conclude, that the actual sizes of the internal defects have been clearly detected using reception of the back-scattered waves over the edges of the defective regions only.