Shooting Type Laplace–Adomian Decomposition Algorithm for nonlinear differential equations with boundary conditions at infinity

In this paper, Shooting Type Laplace–Adomian Decomposition Algorithm (STLADA), is applied to some boundary value problems with one of the boundary conditions at infinity. The analytic solution obtained by using this method converges rapidly, highly effective in terms of accuracy and very close to the exact solution. The solution is compared with the existing results. Shooting Type Laplace–Adomian Decomposition Algorithm is an efficient method for solving these types of problems occurring especially in fluid mechanics.     

Recombinant protein purification using gradient assisted simulated moving bed hydrophobic interaction chromatography. Part II: process design and experimental validation

In the first part of this work adsorption isotherm parameters were acquired to describe the migration of recombinant streptokinase in Butyl Sepharose columns at different salt concentrations. Based on these results, a simulated moving bed (SMB) chromatographic process was designed and realised, which exploits a two-step salt gradient and allows the continuous separation of streptokinase from contaminants present in a clarified Escherichia coli cell lysate solution. This second part describes the design of the three-zone open-loop gradient SMB process applying both equilibrium theory and an equilibrium stage model and presents results of a series of experiments aiming to obtain pure streptokinase. Moreover, the potential of the SMB process and the design approach are evaluated.     

Recombinant protein purification using gradient-assisted simulated moving bed hydrophobic interaction chromatography. Part I: selection of chromatographic system and estimation of adsorption isotherms

The design of gradient simulated moving bed (SMB) chromatographic processes requires an appropriate selection of the chromatographic system followed by the determination of adsorption isotherm parameters in the relevant range of mobile phase conditions. The determination of these parameters can be quite difficult for recombinant target proteins present in complex protein mixtures. The first part of this work includes the estimation of adsorption isotherm parameters for streptokinase and a lumped impurity fraction present in an Escherichia coli cell lysate for a hydrophobic interaction chromatography (HIC) matrix. Perturbation experiments were carried out using a Butyl Sepharose matrix with purified recombinant protein on buffer equilibrated columns as well as with crude cell lysate saturated columns. The Henry constants estimated for streptokinase were found to exhibit in a wide range a linear dependence on the salt concentration in the mobile phase. These parameters were applied in subsequent investigations to design a simulated moving bed (SMB) process capable to purify in a continuous manner recombinant streptokinase from the E. coli cell lysate.     

"Nanocatalyst ∪ reagent-on-a-polymer film": a new polymer-supported system for (electro-)catalytic reactions

Poly(3,4-ethylenedioxythiophene) has been used to immobilize both the metal particle catalyst and the reagent, (cyano-)borohydride, by simple doping and chemical reduction. These films have shown catalytic activity in the hydrogenation of nitrophenol and electro-oxidation of methanol, formic acid and borohydride.     

Study of inclusion complex of β-cyclodextrin and diphenylamine: photophysical and electrochemical behaviors

The photophysical, electrochemical and photoprototropic behaviors of diphenylamine (DPA) in aqueous β-cyclodextrin (β-CD) solution have been investigated using absorption spectroscopy and cyclic voltammetric techniques. Absorption of the neutral and cationic form of DPA is enhanced due to the formation of a 1:1 complex with β-CD. The formation of this complex has been confirmed by Benesi-Hildebrand plot and docking studies by RasMol tool methods. The solid complex of β-CD with DPA is investigated by FT-IR, XRD and AFM methods. The thermodynamic parameters (ΔG, ΔH and ΔS) of inclusion process are also determined. The pK(a) values of neutral-monocation equilibria have been determined with absorption (conjugate acid-base) titrations. A mechanism is proposed to explain the inclusion process.     

Modified TTA method for the determination of plutonium

The spent fuel from Fast Breeder Test Reactor of various burnups from 25 to 155?GWd/te is being reprocessed in CORAL (COmpact Reprocessing of Advanced fuels in Lead shielded cell) using a modified PUREX (Plutonium Uranium Recovery by EXtraction) process. Total plutonium (Pu^{238, 239, 240, 241 & 242}) concentration in the sample is analysed by HTTA (Thenoyl Trifluoro Acetone) extraction method wherever interference from other alpha emitting nuclides (Raffinate) and bulk natural uranium (uranium products) are present "as reported by Milyukov et al. (Analytical chemistry of plutonium, 1967) and Natarajan and Subba Rao (BARC, pp. 38?C43, 2007)". This method requires the addition of corrosive reagents such as NH₂OH.HCl which is a problem in waste disposal for reduction. A salt-free reagent such as Hydroxyurea is studied as a reducing agent which has the ability to reduce both Pu(VI) and Pu(IV) to Pu(III) "as reported by Zhaowu (260(3):601?C606, 2004) and Zhaowu (262(3):707?C711, 2004)". Pu(III) thus formed can be easily oxidised to Pu(IV) by NaNO₂ for the extraction of Pu by HTTA.     

Two-Commodity Inventory System with Individual and Joint Ordering Policies and Renewal Demands

Abstract

This article analyzes a two-commodity continuous review inventory system with renewal demands. The ordering policy is a combination of policies namely ordering individual commodities and ordering jointly both commodities. The steady state probability distribution for the joint inventory levels is computed. Various system performance measures in the steady state are derived. The results are illustrated numerically.     

Structural,electrical, magnetic,elastic, and internal friction studies of Nd1−xCaxMnO3 (x=0.2, 0.33, 0.4, and 0.5) manganites

A series of Nd_1?xCa_xMnO₃ (x=0.2, 0.33, 0.4, and 0.5) manganites was prepared by sol–gel route by sintering at 1300 °C, mainly to understand the correlation between electron, spin, and phonon couplings. The internal friction and longitudinal modulus along with electrical and magnetic properties have been measured. All the samples are found to exhibit anomalies at T_C, T_N, and T_CO transition temperatures. The anomalies in longitudinal modulus and the internal friction peak at T_CO are attributed to Jahn–Teller effect. A strong correlation between the temperature dependent elastic, anelastic, resistivity, and ac susceptibility properties has been observed and an effort has been made to explain the observed anomalous behavior by a qualitative model.