Controlled gas‐phase sulfonation of low‐density polyethylene films

In the current research, a highly controllable system operating at low temperatures and for short reaction times is employed for the surface sulfonation of low‐density polyethylene. This system provides the advantages of short reaction times and low reaction temperatures, as compared with previous methods of surface sulfonation. Low‐density polyethylene films were sulfonated at 40°C for time periods ranging from 5 to 30 min. Subsequently, all films were analyzed by SEM, EDX, horizontal ATR–FTIR, surface roughness, and dynamic contact‐angle measurements. Sulfonation was effected at all reaction times. The degree of surface sulfonation increased through 10 min and reached a maximum between 10‐ and 30‐min reaction times with concomitant changes in the physicochemical properties of the material. At 30 min, the film topography changed substantially, indicating that sulfonation was no longer limited to a strictly surface reaction. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1865–1869, 2000     

Parallel implementation of the Kronecker product technique for numerical solution of parabolic partial differential equations

Using the alternating directional Galerkin technique we show that the approximate solution of the initial boundary value problem of parabolic partial differential equations is equivalent to the least squares solution of the linear system A B = b. In the full rank case, an efficient method for obtaining the solution of the least squares problem suitable for distributive memory computers was presented in (Fausett et al., 1994). This method is extended to solve the rank deficient case using the RRQR factorization of matrices A and B together with the commutatively property of the Kronecker product. Solution algorithm and parallel implementation are discussed. Timing results are presented and compared with previous work.     

Organic geochemistry characterisation of crude oils from Mishrif reservoir rocks in the southern Mesopotamian Basin,South Iraq: Implication for source input and paleoenvironmental conditions

Seven crude oils from Cretaceous Mishrif reservoir rocks in the southern Mesopotamian Basin, South Iraq were studied to describe oil characteristics, providing information on the source of organic matter input and the genetic link between oils and their potential source rock in the basin. This study is based on biomarker and non-biomarker analyses performed on oil samples. The analysed oils are aromatic intermediate oils as indicated by high aromatic hydrocarbon fractions with more that 50%. These oils are also characterized by high sulfur and trace metal (Ni, V) contents and relatively low API gravity values (19.0–27.2° API). The results of this study indicate that these oils were derived from a marine carbonate source rocks bearing Type II-S kerogen that were deposited under sulphate-reducing conditions. This is primary achieved from their biomarkers and bulk carbon isotope and inorganic element contents (i.e., S, Ni and V). The absence of 18a (H)-oleanane biomarker also suggests a source age older than Late Cretaceous. The biomarker characteristics of these oils are consistent with those of the Late Jurassic to Early Cretaceous source rocks in the basin. However, biomarker maturity data also indicate that the oils were generated from early maturity source rocks. This appears to result from the type of kerogen of the source rock, characterized by a high-S kerogen (Type II-S).     

Equation Discovery for Financial Forcasting in Context of Islamic Banking

This paper describes an equation discovery approach based on machine leamng using LAGdtAMGE as an equation discovery tool,with two sources of input,a dataset and model presented in context-free gammar.The approach is searching a large range of potential equations by a specific model.The parameters of the equation are fitted to find the best equations.The The experiments are illustratedwith commodity prices from the London Metal Exchange for the period of January-October 2009.The outputs of the experiments are a large number of equations;same of the equations display that the predicted rakes are following the market trends in perfect patterns.     

Three-dimensional phase-field modeling of martensitic microstructure evolution in steels

In the present work a 3-D elastoplastic phase-field (PF) model is developed, based on the PF microelasticity theory proposed by A.G. Khachaturyan and by including plastic deformation as well as anisotropic elastic properties, for modeling the martensitic transformation (MT) by using the finite-element method. PF simulations in 3D are performed by considering different cases of MT occurring in an elastic material, with and without dilatation, and in an elastic perfectly plastic material with dilatation having isotropic as well as anisotropic elastic properties. As input data for the simulations the thermodynamic parameters corresponding to an Fe-0.3%C alloy as well as the physical parameters corresponding to steels acquired from experimental results are considered. The simulation results clearly show autocatalysis and morphological mirror image formation, which are some of the typical characteristics of a martensitic microstructure. The results indicate that elastic strain energy, anisotropic elastic properties, plasticity and the external clamping conditions affect MT as well as the microstructure.     

Self-assembly of coordination polymers constructed from CuCN and unidentate pyridine bases

The self-assembly of K₃[Cu(CN)₄] and unidentate pyridine bases (L): pyridine (py), 3-methyl pyridine (3-mpy), and 2,4,6-trimethyl pyridine (tmpy) in the presence of Me₃SnCl affords new coordination polymers (CPs) CuCN·0.5(py)] (1), [CuCN·0.5(3-mpy)] (2), and [CuCN·0.5(tmpy)] (3). The syntheses are achieved in H₂O/acetonitrile media at room temperature. The structure of the CP 3 was characterized by X-ray single crystal analysis. It is crystallized as orthorhombic in the space group Pnma, a = 9.1065 (3) ?, b = 8.6669 (3) ?, and c = 12.1998 (5) ? and Z = 8. The CPs 1, 2 were investigated by IR, mass, Uv–visible, and ¹H-NMR spectra, as well as TGA. The CPs 1–3 are 2D-polymers consisting of 1D-(CuCN) _n chain structure while the ligands alternate on both sides of the chain with associated copper atom coordination number of three. Hydrogen bonds play an essential role for developing 2D-network structure. These CPs exhibit strong fluorescent emissions in the solid state.     

Sequestration of zinc from zinc oxide nanoparticles and life cycle effects in the sediment dweller amphipod Corophium volutator

We studied the effects of ZnO nanoparticles [ZnO NPs, primary particle size 35 ± 10 nm (circular diameter, TEM)], bulk [160 ± 81 nm (circular diameter, TEM)], and Zn ions (from ZnCl(2)) on mortality, growth, and reproductive endpoints in the sediment dwelling marine amphipod Corophium volutator over a complete lifecycle (100 days). ZnO NPs were characterized by size, aggregation, morphology, dissolution, and surface properties. ZnO NPs underwent aggregation and partial dissolution in the seawater exposure medium, resulting in a size distribution that ranged in size from discrete nanoparticles to the largest aggregate of several micrometers. Exposure via water to all forms of zinc in the range of 0.2-1.0 mg L(-1) delayed growth and affected the reproductive outcome of the exposed populations. STEM-EDX analysis was used to characterize insoluble zinc precipitates (sphaerites) of high sulfur content, which accumulated in the hepatopancreas following exposures. The elemental composition of the sphaerites did not differ for ZnO NP, Zn(2+), and bulk ZnO exposed organisms. These results provide an illustration of the comparable toxicity of Zn in bulk, soluble, and nanoscale forms on critical lifecycle parameters in a sediment dwelling organism.     

Amino acid pattern in eggs as influenced by supplementation of dopamine agonists and antagonists in laying hens

A total of thirty laying hens divided into 3 equal groups was used. The 1st group served as control and was fed a basal ration. The 2nd and 3rd groups received L-Dopa and reserpine, respectively. The goal of the study was devoted to determine the effects of these additives on the rate of egg production, weights of eggs and yolks as well as yolk proteins and their amino acid pattern. In the reserpine-treated hens the rate of egg production was increased whereas in the L-Dopa-treated group, the weights of eggs and yolks, food intake as well as the amino acids aspartate, glutamate, glycine, alanine and methionine were significantly increased. The levels of tyrosine and histidine were decreased in both treatments while methionine was decreased by reserpine only. The addition of dopamine antagonist to a ration containing lysine and leucine in concentrations of 0.55% and 0.9% did not influence their levels in eggs. The increment of methionine, aspartate, glutamate and glycine by the dopamine agonist and their decrease by antagonist revealed that these amino acids are excitatory neurotransmitters in brain.     

Hybrid Solar Dryer for Quality Dried Tomato

A prototype of a hybrid solar dryer was developed for drying of tomato. It consists of a flat-plate concentrating collector, heat storage with auxiliary heating unit, and drying unit. It has a loading capacity of 20 kg of fresh half-cut tomato. The dryer was tested in different weather and operating conditions. The performance of the dryer was compared with an open sun-drying method. Drying performance was evaluated in terms of drying rate, color, ascorbic acid, lycopene, and total flavonoids. Tomato halves were pretreated with UV radiation, acetic acid, citric acid, ascorbic acid, sodium metabisulphite, and sodium chloride. Sodium metabisulphite (8 g L^?1) was found to be effective to prevent the microbial growth at lower temperature (45°C).     

Catalytic performance of organically templated nano nickel incorporated-rice husk silica in hydroconversion of cyclohexene and dehydrogenation of ethanol

Rice husk silica (RHS) was extracted from local rice husk by acid digestion and burning at 650 °C. RHS-Ni catalyst was prepared by dissolving RHS in 1 N NaOH and titrating with 3 N HNO₃ containing 10 wt.% Ni²⁺. The organic modifiers, either p-amino benzoic acid (A) or p-phenylenediamine (PDA) were incorporated in 5 wt.% and reduced in H₂ flow. Investigation of the three catalysts, (RHS-Ni)_R350, (RHS-Ni–A)_R350 and (RHS-Ni–PDA)_R350, confirmed good dispersion of Ni nanoparticles; all catalysts were amorphous. The BET surface areas increased in the order: (RHS-Ni)_R350 < (RHS-Ni–A)_R350 < (RHS-Ni–PDA)_R350 with controlled pore sizes. The as-prepared catalysts were applied for both hydroconversion of cyclohexene with molecular H₂ and ethanol dehydrogenation, using a flow-type reactor, at different temperatures. The activity in cyclohexene hydroconversion and selectivity to cyclohexane depended upon the reaction temperature; at t < 150 °C, the increased hydrogenation activity was referred to the formed SiO₂–Ni–amine complex, pore regulation as a prime requirement for H₂ storage and homogeneous distribution of incorporated Ni nanoparticles. At t > 150 °C, the backward dehydrogenation pathway was more favored, due to unavailability of H₂; the process became structure-sensitive. In ethanol conversion, the prevailing dehydrogenation activity of organically modified catalyst samples was encouraged by improved homogeneous distribution of Ni nanoparticles and created micropre system.