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Riboflavin and protoporphyrin IX are two molecules that participate in oxidation and reduction reactions in the living cell. Changing some functional groups of riboflavin and protoporphyrin IX can provide compounds with self-assembled monolayer properties with wide applications in designing the molecular electronic devices. In this study, the amphiphilic structure of riboflavin and protoporphyrin IX is resulted from the reaction of stearic acid with riboflavin and phosphatidyl ethanol amine with protoporphyrin IX. The reaction products were purified and analyzed by different spectroscopy techniques such as IR, Uv-Vis, fluorimetry and NMR. The electron transfer ability was confirmed by cyclic voltammetry. The finding approves that the produced amphiphilic compounds have kept theirs intrinsic properties as well.

A bacterial strain (strain PS) was isolated from the textile effluents carrying Serilene Black BNFS® (C.I. Disp. Blk. Mix) disperse dye. The isolate was able to decolorize the dye without the need for any exogenous carbon source. Full sequencing of its 16S rRNA indicated that Bacillus sp strain PS is related to Bacillus cereus groups. Silica- gel-thin layer chromatography of Serilene black dye showed that its main component is a blue dye. FT- IR analysis of this blue fraction showed that its structure corresponds to azoic dyes. Thus Bacillus sp, strain PS was used to decolorize methyl orange as a model azo dye, which it did after 2 days of incubation under aerobic conditions on a shaker incubator (30°C, 140 rpm). Comparing TLC and GC-MS analyses with the authentic sample main showed that its decomposition product is N, N-dimethyl 1, 4- phenylene diamine. Experiments with N, N-dimethyl 1, 4-phenylene diamine as a co-substrate in mineral medium showed that this component disappeared after 7 day incubation. These observations confirm that the decomposition of Serilene dye occurs in a manner similar to that of methyl orange.

This articles is comprised of two parts: a) an experimental investigation on the behavior of an acrylic gel under DC electric field and b) a physico - mathematical description.a) Gel rods made of poly [acrylamide-co-bisacrylamide] were partially hydrolyzed to different extents at pH 12 by teteramethylethylene diamine. Equlibrium properties of the resulting gels rods (water content, number of carboxyl groups and pore size) were determined. Gel rods were then placed in water parallel to planar platinum electrodes. Under the field strengths geater than 2 V/cm the gels gradually bend towards cathode and after reaching a maximum, they traverse a smooth reverse deformation, finally bending towards anode. The speed and extent of these deformations depend on the electric field strergth; length, diameter, charge density (extent of hydrolysis) of the gel rods; temperature, and the pH of the bathing medium. In all cases the bending behavior follows the relation for the tree – point mechanical bending of solid rods. Anodic swelling and bending towards cathode is attributed to the difference in the osmotic pressure between the anodic and the cathodic sides of the gel, while the reverse deformation and bending towards anode is assigned to the migration of H+ ions from the anolyte into the gel and neutralization of COO¯ groups.b) Theoretical analysis: These attributes are quantitatively represented by a proper theoretical formulation based on Donnan and Flory-Huggins theories. The relation obtained for the osmotic pressure within the gels, in the absence of an electric field, is modified to include the ionic flux in response to concentration and electric field gradients. Considering the ionization of water and the network carboxyl groups, together with the principle of charge neutrality, and assuming Donnan equilibrium at the gel boundaries under the applied electric fields, the equations for ionic fluxes are derived and solved by Laplace transform. It is found that the concentration of cations decreases in the anodic side of the gel while it increases in the cathodic side, leading to an osmotic swelling gradient in the gel causing it to bend.

The search for new stationary phases has been one of the predominant concerns in high performance liquid chromatography (HPLC) in order to achieve better resolutions, longer column lives, and reduce the time of analysis. A chromatographic packing for separation of underivatized amino acids (AAs) were prepared by dynamically coating 2-amino tetraphenyl prophyrin (atpp) on a C-18 reversed-phase packing and its properties were examined. The retention characteristics of 20 AAs forming the building blocks of proteins were investigated on the atpp coated C-18 column at pH 7. Results obtained seem to confirm a mixed mechanism of retention involving the hydrophobic interaction between the aromatic porphyrin macrocycle and some of the AAs, p-p interaction between the p-electrons of the porphyrin macrocycle and the p-electrons of analyte, and the hydrogen bonding interactions between Ass and the porphyrin nitrogens.

Slurries of rice-straw cellulose (obtained by delignification and removal of hemicelluloses from the powdered raw material) were subjected to ultrasonic waves at different intensities for various times (constant temperature). Susceptibility of the samples to cellulose-hydrolysis increased initially with pretreatment time, reaching a maximum or a constant level thereafter. Maximum glucose yield (~21%) was obtained under the following conditions: enzyme/substrate ratio 0.1; amplitude 18mm (peak to peak), and exposure time 30 minutes. This yield is 30X that of the starting raw material, 10X that of the untreated rice-straw cellulose and 12-13X that of the value reported by others regarding pretreatment of wheat-straw cellulose by phenol. Changing the enzyme/substrate ratio to 0.4 raises glucose yield to 42% under the same conditions. Removal of temperature control during pretreatment (50-80 °C) increases the yield up to ~30% without increasing the enzyme/substrate ratio.

Fourier transform infrared (FTIR) and gel permeation chromatography (GPC) wre respectively utilized in determining the changes in isocyanate (NCO) concentration and molecular weight (MW) and its distribution (MWD) in polyurethanes during their cure and postcure stages. Samples, originally cured at 45°C, were taken through accelerate aging tests at various temperatures. The FTIR and GPC analytical conditions were optimized, for both molecular weight and molecular weight distribution and NCO group determination. In FTIR spectroscopy Beer's law was obeyed over the ranges: 2.33-22.34 and 0.03-1.61 mmol lit-1. RSD, detection limit and molar absortivity were found to be 1.46%, 4´10-6 mol lit-1 and 1095 lit mol-1 cm-1 respectively. It was found the NCO concentration decreases with the progress of polymerization and at the same time MW of the sol increases, going through a maximum and then decreases to a constant level. The time to reach this level and termination of NCO concentration, i.e., the end of polymerization decreases with the increase in temperature. The results obtained from GPC and FTIR methods in following the different steps of polymerization as well as those from the linear plots of the end time of reaction vs. the 1/T, were in good agreement.

Akin type (asymmetric) reverse osmosis membranes undergo an irreversible osmotic dehydration upon coming into contact (skin side) with salt solutions. The extent of consequent changes (in appearance; decrease in linear dimension, water flux and salt rejection) are dependent on the salt concentration. These observations are correlated with the expected morphological changes taking place during dehydration (drying). It is thus speculated that such phenomena may inadvertently happen during the start-up phase of new RO units treating high salinity waters. To avert such event, it is recommended the start-up phase to be programmed in such a way that feed concentration is gradually elevated to its ultimate level.