Effect of hydrolysis of AlN particulates on corrosion behavior of Al/AlNp composite in neutral chloride solution

The effects of hydrolysis of the AlN particulates on corrosion behavior of Al/AlN_p composite were examined by analyzing potentiostatic anodic current transient, cyclic voltammetry curves and potentiodynamic cathodic polarization curves. It is found that the degree of hydrolysis of AlN particulates in the composite increase with the pre-hot water treatment time, which increase the occurrence of metastable pits in the composite. In addition, hydrolysis of AlN particulates also affects the electrochemical corrosion behaviors of the composite, and makes Al/AlN_p composite show intergranular corrosion behavior to some extent.     

Computer-aided prototyping of production flows for a virtual enterprise

This paper presents a logistics framework to cope with the problem of planning and control of production flows processed on a set of work cells distributed among component firms of a virtual enterprise (VE). The constraints theory framework is employed to study constraint-based production flow coordination rules. The article discusses relationships linking structural parameters (e.g. buffer capacity, machine tool efficiency, and automated storage/retrieval systems) of VE components with material flow control guaranteeing efficient completion of work orders, and specified by such parameters as batch delivery periods, work-in-process (WIP) and make-span. The results are summarized in the form of a performance evaluation scheme. Examples using a software package that implements the proposed flow coordination methodology are provided.     

Electrodeposition of metals from non-aqueous solutions

Electrodeposition of metals from non-aqueous solutions is reviewed. Attention is paid mainly to surface morphology of deposits and their adhesion. The major reasons for carrying out electrodeposition in non-aqueous electrolytes (such as conventional organic solvents, ionic liquids and molten salts) are the water and air stability and the wide electrochemical window of these media. The following metals have been electrodeposited and investigated for the last 15 years: aluminum, zinc, silver, palladium, tantalum, zirconium, gadolinium, plutonium, nickel, cobalt, and other alloys.     

Constrained approximate boundary controllability

In this paper, constrained approximate boundary controllability for linear disturbed parameter dynamical systems described by partial differential equations of parabolic-type with mixed boundary conditions is considered. Using methods of spectral analysis for linear self-adjoint operators and general constrained controllability results, given by Son (1990), necessary and sufficient conditions for constrained approximate boundary controllability are formulated and proved. Moreover, in illustrative examples the constrained approximate boundary controllability of 1D distributed parameter dynamical systems is investigated. The constrained controllability conditions obtained represent an extension of the unconstrained controllability results given by Glothin (1974)     

Synthesis of rod-shaped LaNi5 alloy via solid reduction method

A novel chemical synthesis technique that a large quantity of rod-shaped LaNi₅ alloy has been successfully synthesized using a solid reduction method was reported. The as-prepared alloy, proven via the XRD spectrum, was single-phased and hexagonal. The SEM and TEM photographs showed that the alloy was rod-shaped with a diameter in the range of 300–500 nm, and length of about 6–10 μm. The SAED pattern of LaNi₅ alloy clearly indicated the orientation alignment along the c-axis.     

Room temperature photoluminescence studies of nitrided InP(100) surfaces

The evolution of thin InN overlayer grown on InP (100) rich In substrate was investigated at room temperature by photoluminescence method versus the duration of nitridation process. The main important parameters were the duration of the process, and the angle of the reactive nitrogen flow. The nitridation was performed by a glow discharge source (GDS). The correlations between the electronic properties, gathered from photoluminescence (PL) measurements, and the chemical composition of InN–InP interfaces, derived from Auger electron spectroscopy (AES) were found. AES revealed that the nitridation process proceeds quickly in time showing self-limiting behavior. It is more effective for grazing nitrogen flux. The interface state density distributions, N_SS(E), were determined via advanced computer-aided analysis of dependencies of band edge PL efficiency, Y_PL, versus excitation light intensity, Φ. The analysis showed that the substrates were well passivated with N_SS(E) minima on the order of 5·10¹¹ cm^− 2 eV^− 1_. The nitrogen flux angle during the nitridation was found to have an influence on Y_PL(Φ) spectra. In all analyzed cases the grazing nitrogen flux generated the interface with slightly improved N_SS(E) distribution. Finally, the behavior of Y_PL versus Φ and N_SS(E) was precisely examined.     

Fractal character of basin boundaries in a tubular chemical reactor with mass recycle

The basin boundaries for two attractors were found for a mathematical model of a chemical tubular reactor with recycle. The basin boundaries were found to be fractal. Their topological dimension and entropy were determined.     

Synthesis and polymerization of a novel oxirane bearing a cyclic acetal of salicylaldehyde chain moiety

The novel compound 2(1,3-dioxolan-2-yl)phenoxymethyloxirane was synthesized and anionically polymerized with potassium hydroxide, potassium hydride and potassium tert-butoxide. Polymers were characterized by ¹H and ¹³C NMR spectroscopy, size exclusion chromatography and electrospray mass spectrometry. Copyright © 2004 Society of Chemical Industry     

Dry-sliding tribological behavior of Fe–Ni alloys

The paper reports the dry-sliding tribological behavior of Fe_100−x–Ni_x (x=20,23,25,30) alloys with various martensite fractions. For all the alloys, the friction coefficient decreased with increasing applied load and increased with increasing sliding speed, but there was nearly no difference between the different alloys. The wear rate of the alloys increased with increasing applied load and decreased slightly with increasing sliding speed. Microstructures had great influence on the wear behavior of these alloys. The Fe₇₇Ni₂₃ alloy with well-proportioned martensite exhibited the best wear resistance.     

Cloning and sequencing of the para-type sodium channel gene from susceptible and kdr-resistant German cockroaches (Blattella germanica) and house fly (Musca domestica)

This paper presents the results of viscosity determinations on aqueous solutions of bovine serum albumin (BSA) at a wide range of concentrations and at temperatures ranging from 5 degrees C to 45 degrees C. On the basis of these measurements a general formula connecting the relative viscosity eta r with temperature T and concentration c of the dissolved proteins was established: [formula: see text] The quantities alpha, beta, B, D and delta E are described in the text below. A simple substantiation of the formula was also given. This relation gives immediately the Mooney approximation and allows the prediction of the values of the parameter S and a self-crowding factor K in this approximation. By applying an asymptotic form of the formula such rheological quantities as the intrinsic viscosity and Huggins coefficient were calculated.