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The alarming rise of multi-drug resistant (MDR) Pseudomonas aeruginosa has prompted the World Health Organization to consider it a serious threat to human health. Although phage (Phg), an effective...

A review article described the chemistry of 4-thiazolidinones particularly rhodanine ring and different approaches for its reactions which included the modification of the ring. Besides, the reactivity of rhodanine ring which helped in the synthesis of different arylidenes at position 5 and carboxylic acids at position 3 The most reactive positions in 4-thiazolidinone are 3 and 5, which determine the major directions of heterocycle modification. Approaches to the synthesis of 3,5-disubstituted 4-thiazolidinones in general include two pathways. The first one was throughout the synthesis of 3,5-disubstituted 4-thiazolidinones by different reactions in position 3 of the thiazolidinone cycle. The second was the synthesis of 3,5-disubstituted 4-thiazolidinones by diverse reactions in position 5 of the thiazolidinone cycle Modification of 4-thiazolidinone cycle on positions 2, 3, 4 or 5 was successful to achieve synthetic products with a wide spectrum of pharmacological activity Currently 4-thiazolidinones were considered as a new class of antidiabetic (insulinsensitizing) drugs and potent aldose reductase inhibitors, which possess the potential for the treatment of diabetes complications (cataract, nephropathy, neuropathy).

Novel non-sulfonylureas derivatives bearing an acetamide linker between a spirohydantoin scaffold and a phenyl ring were prepared and their hypoglycemic activity was estimated in vivo . Their abilities to discriminate in vitro between aldehyde reductase (ALR1) and aldose reductase (ALR2) were determined. The molecular docking and the in silico prediction studies were performed to rationalize the obtained biological results and to predict the physicochemical properties and drug-likeness scores of the new compounds. N -(2,4-Dichlorophenyl)-2-(2′,4′-dioxospiro[fluorene-9,5′-imidazolidine]-3′-yl)acetamide ( 3e ) displayed an 84% reduction in blood glucose level superior to that of repaglinide 66% and showed an IC 50 value of 0.37 μM against ALR2 that is superior to that of sorbinil 3.14 µM. Compound ( 3e ) was selective 96 fold towards ALR2 which is closely related to serious diabetic complications. Based on the identification of this hit candidate, a new generation of safe and effective antidiabetic agents could be designed.

Novel derivatives of spiroimidazolidinedione were synthesized and evaluated as hypoglycemic agents through binding to sulfonylurea receptor 1 (SUR1) in pancreatic beta-cells. Their selectivity index was calculated against both aldehyde reductase (ALR1) and aldose reductase (ALR2). Aldehyde reductase is a key enzyme in the polyol pathway that is involved in the etiology of the secondary diabetic complications. All structures were confirmed by microanalysis and by IR, 1H NMR, 13C NMR and EI-MS spectroscopy. The investigated compounds were subjected to molecular docking and an in silico prediction study to determine their free energy of binding (ΔG) values and predict their physicochemical properties and drug-likeness scores. Compound 1′-(5-chlorothiophene-2-ylsulfonyl)spiro[cyclohexane-1,5′-imidazolidine]-2′,4′-dione showed IC50 0.47 µM and 79% reduction in blood glucose level with a selectivity index 127 for ALR2.

In the present study, a novel generation of selective aldose reductase ALR2 inhibitors with significant hypoglycemic activities was designed and modulated based on rhodanine scaffold joined to an acetamide linker in between two lipophilic moieties. The synthesis of the novel compounds was accomplished throughout simple chemical pathways. Molecular docking was performed on B-cell membrane protein SUR1, aldehyde reductase ALR1 and aldose reductase ALR2 active sites. Compounds 10B, 11B, 12B, 15C, 16C, 26F and 27F displayed the highest hypoglycemic activities with 80.7, 85.2, 87, 82.3, 83.5, 81.4 and 85.3% reduction in blood glucose levels, respectively. They were more potent than the standard hypoglycemic agent repaglinide with 65.4% reduction in blood glucose level. Compounds 12B and 15C with IC50 0.29 and 0.35 µM were more potent than the standard ALR2 inhibitor epalrestat with IC50 0.40 µM. They were selective towards ALR2 over ALR1 134 and 116 folds, respectively. Molecular docking studies matched with the in-vitro and in-vivo results to elucidate the dual activities of both compounds 12B and 15C as potent antagonists for ALR2 over ALR1 and good agonists for the SUR1 protein.

An accurate estimation of porosity and permeability are extremely essential for designing an ideal and efficient program of an oil and gas field development. Numerous methods have been developed to determine the porosity and permeability including laboratory measurements and log derived models. Artificial neural network (ANN) provides an efficient technique that successfully addressed several engineering and geological challenges. In the present study ANN is applied to help in predicting porosity and permeability in carbonate reservoirs using back propagation neural network (BPNN) with high accuracy on well log data from numerous fields worldwide. ANN has the ability to understand a highly non – linear relationship and to perform simulation studies in a rapid manner. The BPNN model of porosity and permeability is developed using a set of well logging data as input layers and core porosity and core permeability as output layers. Two scenarios are considered to develop by ANN. The first scenario considers using all available logging data directly as input for ANN. In the second scenario an additional input, diagenesis parameter, is added as input to ANN which is essentially calculated from logging data. In each scenario two models are developed; the first for porosity prediction and the second predicts permeability in carbonate reservoirs. The optimal learning rate and momentum constant used in the BPNN model are achieved after serial combinative trials. The available data was assigned 80% for training and 20% for verification. The results of the developed porosity and permeability models are well compared to core data in verification. In the first scenario, cross-plot of the actual porosity versus ANN predicted Porosity exhibited a good match with a correlation coefficient equal to 0.97. Cross-plot of the actual permeability versus ANN predicted permeability exhibited a good match with a correlation coefficient equal to 0.80. In the second scenario, cross-plot of the actual porosity versus ANN predicted porosity exhibited a good match with a correlation coefficient equal to 0.97. Cross-plot of the actual permeability versus ANN predicted permeability exhibited a good match with a correlation coefficient equal to 0.98. Such data indicate that the developed models are successful in predicting the porosity and permeability for carbonate reservoirs.

In this study AlSi10 Mg/Al2O3 composite was processed via selective laser melting. The influence of different process parameters namely, laser power, scan speed and hatch spacing was investigated to determine their effect on the physical and mechanical properties of the consolidated powders. Input energy and balling effect, had a major influence on the developed pore morphology. Poor consolidation associated with poor heat diffusion and insufficient melting occurred at the low input energy. Intermediate input energy resulted in the formation of continuous porosity along the building direction separated by consolidated zones of equal width and associated with uniform balling effect. High input energy developed distorted porosity with non-uniform distribution associated with irregular course balling. The formed continuous porosity is attributed to the segregation and migration of alumina particles to the spacing between the deposited successive powder layers followed by their selective melting forming oxide films that acts as a barrier to the complete solidification.

Background Rice (Oryza sativa L.) is one of the leading food crops of the world, the staple food of over half the world's population. The bran, which is an important byproduct obtained during rice milling, constitutes about 1/10 of the weight of the rice grain. Rice bran is the outer brown layer including the rice germ that is removed during the milling process of brown grain. This milling byproduct is reported to be high in natural vitamins and minerals, particularly vitamin E. Objectives The present study was conducted to determine the chemical composition of bran and bran oil of 13 different rice varieties commonly produced in Egypt, to study the utilization of rice bran in bread production, and to assess the quality and acceptance of the rice bran edible oil produced. Methods Rice bran was produced from 13 Egyptian varieties of recently harvested rice as well as from paddy rice stored for 1 year. The extracted bran was immediately stabilized then subjected to chemical analysis (such as moisture content, protein, fat, carbohydrates, fiber, and ash) as well as trace and heavy metals determination (P, K, Na, Ca, Fe, Zn, Cu, and Mg). Bread was produced by adding Giza172 rice bran at three different concentrations to wheat flour then subjected to chemical analysis, caloric content, and organoleptic examination. Bran oil was extracted from the different varieties of rice bran (recently harvested and stored) then subjected to chemical and organoleptic examinations as well as vitamin E and oryzanol determination. Results The percentage of rice bran of newly harvested Egyptian rice was 11.68% and was 10.97% in stored rice. The analysis showed mean values of 5.91 and 5.53% for moisture, 14.60 and 14.40% for crude protein, 14.83 and 15.20% for fat, 44.77 and 45.40% for carbohydrates, 6.55 and 7.06% for crude fiber, and 8.87 and 8.50% for ash for newly harvested and stored rice bran, respectively. Bread containing 15% rice bran showed the highest score percentages for organoleptic quality compared with the control (100% wheat flour). Rice bran oil showed higher scores of taste, smell, appearance, and texture than corn oil and sunflower oil. Conclusion Rice bran contains high nutritional components as well as phytochemicals such as vitamin E (i.e. tocopherols and tocotrienols) and the γ-oryzanol fraction that have positive effects on human health. Storage of paddy rice before milling resulted in significant effect on all studied rice bran characters and rice bran oil characters under the present investigation except crude protein and carbohydrates characters. Recommendations Substitution of wheat flour with rice bran by 15% in bread production to fortify the bread with vitamin E and to reduce the amount of imported flour is recommended.

Deriving bulk materials with ultra-high mechanical strength from nanometer-sized single metalic crystals depends on the consolidation procedure. We present an accurate molecular dynamics study to quantify microstructure responses to consolidation. Aluminum single crystals with an average size up to 10.7 nm were hydrostatically compressed at temperatures up to 900 K and pressures up to 5 GPa. The consolidated material developed an average grain size that grew exponentially with the consolidation temperature, with a growth rate dependent on the starting average grain size and the consolidation pressure. The evolution of the microstructure was accompanied by a significant reduction in the concentration of defects. The ratio of vacancies to dislocation cores decreased with the average grain size and then increased after reaching a critical average grain size. The deformation mechanisms of poly-crystalline metals can be better understood in the light of the current findings.

One of the most important casting defects in Al alloys is thought to be the double-oxide film defect (bifilm) which has been reported to have a deleterious effect on the reproducibility of the mechanical properties of Al castings. Previous research has suggested that the atmosphere inside such bifilms could be consumed by reaction with the surrounding melt, which might decrease the size of the defects and reduce their harmful effect on mechanical properties. In order to follow the change in the composition of the interior atmosphere of a bifilm, analog air bubbles were held inside Al alloy melts, for varying lengths of time, and subjected to stirring, followed by solidification. The bubble contents were then analyzed using a mass spectrometer to determine the changes in their compositions with time. The results suggested that initially oxygen and then nitrogen inside the bubble were consumed, and hydrogen dissolved in the melt diffused into the bubble. The consumption rates of O and N as well as the rate of H diffusion were dependent upon the type of oxide, which was dependent on the alloy composition. The reaction rates were the fastest with MgO (in an Al-5Mg alloy), slower with alumina (in commercial-purity Al alloy), and the slowest with MgAl2O4 spinel (in an Al-7Si-0.3Mg alloy). It was estimated that the times required for typical bifilm defects in the different alloys to lose their entire oxygen and nitrogen contents were about 345 seconds (~6 minutes), in the case of Al-5Mg; 538 seconds (~9 minutes), in the case of a commercial purity alloy; and 1509 seconds (~25 minutes), in the case of the Al-7Si-0.3Mg alloy (2L99) due to the different oxides that the different alloys would be expected to form.

Many Nanoparticles (NPs) were reported to significantly enhance the production of biogas from the anaerobic digestion of organic wastes. Herein, two types of NPs (Ni-Ferrite and Ni-Co-Ferrite) were synthesized using the co-precipitation method and characterized using X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HRTEM) with energy dispersive X-ray spectroscopy (EDS) techniques. Three different concentrations (20, 70 and 130 mg/l) of each type were added to separate biogas reactors to study their effect on the biogas production compared to blank reactor. A pressure-based biogas reactor was designed and manufactured specifically to test the effect of the NPs on the anaerobic digestion process. The pressure of the daily produced biogas was monitored using a pressure transducer and the volume of the biogas was calculated at standard conditions of pressure (1.013 bar) and temperature (15 °C). The results showed an increase in the biogas production of 6.6%, 5.9% and 32.9% upon the use of Ni-Co-Ferrite NPS at concentrations of 20, 70, and 130 mg/l compared to blank reactor, respectively. In addition, the Ni-Ferrite NPs achieved biogas enhancements of 30.8%, 28.5%, and 17.9% at concentrations of 20, 70 and 130 mg/l, respectively.

Clear understanding of the superior mechanical strength of nanometer-sized metal single crystals is required to derive advanced mechanical components retaining such superiority. Although high quality studies have been reported on nano-crystalline metals, the superiority of small single crystals has neither been fundamentally explained nor quantified to this date. Here we present a molecular dynamics study of aluminum single crystals in the size range from 4.1 nm to 40.5 nm. We show that the ultimate mechanical strength deteriorates exponentially as the single crystal size increases. The small crystals superiority is explained by their ability to continuously form vacancies and to recover them.

Amorphous nanostructure silicon carbide (a-SiC) recently received great attention for its use as protective coating for metallic substrates due to its good mechanical properties and corrosion resistance. In this article, a-SiC thin films were deposited on AISI 304 stainless steel substrates at room temperature for deposition times of 4 and 6 h using pulsed laser deposition technique. The deposition process was stopped every 2 h then resumed for an hour. The effect of interval time during deposition process and substrate type on the properties of the produced films was extensively investigated. The morphological features of the deposited SiC films were investigated using field-emission scanning electron microscope and atomic force microscope. The film structures were determined by transmission electron microscopy, X-ray photoelectron spectroscopy and energy-dispersive X-ray. The mechanical and tribological properties, such as Young’s modulus, hardness and scratch resistance, were determined using nanoindenter. The results showed the formation of uniform monocrystalline nanostructured Si interface between two a-SiC layers after the 2 h of no-deposition time intervals. The formation of crystalline Si interface attributed to the effect of high kinetic energy of the incoming ablated particles deposited on the grown a-SiC layers. The a-SiC films were amorphous having nanostructure grains with dimensions ≤ 100 nm. All films showed smooth surfaces with fine cracks due to the presence of intrinsic stresses. The deposited films showed low mechanical properties due to their amorphous structures.

The mechanical properties of Al castings are reduced by inclusions, particularly double oxide films, or bifilms, which are formed due to surface turbulence of the liquid metal during handling and/or pouring. These defects have been reported not only to decrease the tensile and fatigue properties of Al alloy castings, but also to increase their scatter. Recent research has suggested that the nature of oxide film defects may change with time, as the air inside the bifilm would react with the surrounding melt leading to its consumption, which may enhance the mechanical properties of Al alloy castings. In order to follow changes in the composition of the internal atmosphere of a double oxide film defect within an Al melt, a series of analogue experiments were carried out to determine the changes in gas composition of an air bubble trapped in a melt of commercial purity Al, subjected to stirring. The bubble contents were analysed using a mass spectrometer to determine their change in composition with time. Also, the solid species inside the bubbles solidified in the melt were analysed. The results suggested that first oxygen and then nitrogen inside the bubble were consumed, with consumption rates of 2.5x10-6 and 1.3x10-6 mol m-2s-1, respectively. Also, hydrogen diffused into the bubble from the melt at an average rate of 3.4x10-7 mol m-2s-1, although the rate of H diffusion increased significantly after the consumption of most of the oxygen inside the bubble. Based upon these reaction rates the time required for a typical alumina bifilm to lose all its oxygen and nitrogen was determined to be just under 10 minutes.

Mechanical alloying (MA) is one of the most commonly used methods in preparing metallic materials. We are especially interested in its ability to produce nanostructured materials. MA has rarely been used in producing nanostructured magnesium base alloys due to the process complexity and flammable nature of the alloy. In this work, high energy ball milling of elemental powders, Mg, Zn and Zr, was investigated for the MA of ZK50 alloy. Crystallite size, lattice strain, as a function of total milling energy (required for complete alloying) were characterized using X-ray diffraction. Scanning electron microscopy was employed to determine the influence of milling time on powder morphology. Consolidation of the milled powders into thin sheets was conducted via hot pipe rolling at 0.4 Tm. Results showed that complete alloying was achieved at 45 milling hours which was associated with particle size reduction to 600 nm and crystallite size of 8.8 nm.

The Nile Delta aquifer in Egypt is among the largest groundwater reservoirs in the world. This paper presents main sources causing Fe and Mn pollution to nonconventional drainage and groundwater resources and an applied method to reduce both elements to be safe. The main environmental problems were analyzed to suggest an optimum solution to be implemented in Delta District, Egypt. Raw water samples were collected and analyzed from Gharbia Governorate's study area as it represents most Delta governorates. One of the main problems related to water in Delta is the reddish colour caused by the presence of ferrous and manganese. Iron and manganese concentrations in most samples exceeded World Health Organization and Egyptian Standard for safe water limits. Iron ranges between 0.1 & 1.33, while manganese shows 0.5 & 1.45 (mg/l) in the raw water, respectively. A (GIS) model was developed to access geostatistical analyst and mapping the probability that Fe and Mn concentration exceeds a critical threshold. Results show that the main polluting sources are from chemicals and fertilizers used in fruits farms as well from petrochemical and industrial activities. Treatment process is suggested with percentage removal of Fe & Mn exceeded 92% and 96% with residual concentrations less than 0.1 and 0.05 (mg/l), respectively. These values fulfil the Egyptian guidelines for safe water requirements.

Double-oxide films (bifilms) have been held responsible for the variability in mechanical properties of aluminum castings. It has been suggested that the air entrapped inside a bifilm can react with the surrounding melt, leading to its consumption, which might improve the mechanical properties of the castings. In this work the effect of holding the melt before solidification on the distribution of mechanical properties, and by implication on entrained double oxide films, was investigated for several different aluminum alloys. The Weibull moduli of plate castings were determined under tensile conditions, and their fracture surfaces were examined for evidence of oxide films. The results suggested the occurrence of two competing mechanisms during the holding treatment: (1) the consumption of air inside the bifilms by reaction with the surrounding molten metal that may lead to improvements in mechanical properties and (2) the accompanying diffusion of hydrogen into the bifilms, which would be expected to have a deleterious effect on properties.

Nano-crystalline W-1%Y(2)O(3) (wt.%) powder was produced by a modified solution chemical reaction of ammonium paratungstate (APT) and yttrium nitrate. The precursor powder was found to consist of p ...

High purity W and W-0.9La(2)O(3) (wt.%) nanopowders were produced by a wet chemical route. The precursor was prepared by the reaction of ammonium paratungstate (APT) with lanthanum salt in aqueous ...

Amorphous silicon carbide (SiC) thin films were deposited on silicon substrates by pulsed laser ablation at room temperature. Thicknesses and surface morphology of the thin films were characterized using optical profilers, atomic force and field emission scanning electron microscopy. Nanohardnes, modulus and scratch resistance properties were determined using XP nanoindenter. The results show that crack free, smooth and nanostructured thin films can be deposited using low laser energy densities.

There are many non-linear interaction factors responsible for the performance of the laser cutting process. Identification of the dominant factors that significantly affect the cut quality is important. The present research aims to evaluate the CW ND:YAG laser cutting parameters (the gas pressure, laser power, and scanning speed) for 1.2 mm thick ultra-low carbon steel sheets. The effect of the cutting parameters on the cut quality was then investigated, by monitoring the variation in hardness, oxide layer width and microstructural changes within the heat affected zone (HAZ). Results revealed that good quality cuts can be produced in ultra low carbon steel thin sheets, at a window of laser scanning speed of 1100–1500 mm/min and at a minimum heat input of 337 W under an assisting O2 gas pressure of 5 bar. Higher laser power resulted in either strengthening or softening in the HAZ surrounding the cut kerfs. The oxide layer width is not affected by the energy density input, but is affected by the O2 gas pressure due to exothermal reaction.

This work investigates the influence of the type and wt.% of nanofillers on the tensile strength behaviour and barrier properties of fabricated chitosan (CS) mesoporous membranes and their nanocomposites using graphene (G) and fullerene (F) nanofillers. Non cross-linked chitosan (NCLCS) as well as cross-linked chitosan (CLCS) solutions with sodium tripolyphosphate (TPP) were both mixed with G and F nanofillers with different wt.%. NCLCS membranes displayed yield tensile strength of 24MPa while the CLCS membranes displayed a much lower yield tensile strength of 2.87MPa. The addition of G and F nanofiller enhanced the yield tensile strength of the CS membranes up to 45MPa. However, the increase in % elongation for CLCS membranes was 75% higher than that for NCLCS ones. Furthermore, the results revealed that there was a significant effect of the operating temperature on the membrane pore size, which decreased the tensile strength and the barrier of the produced membranes. The enhancement of the tensile properties of polymer nanocomposites membranes (PNC) membranes is crucial to avoid film fracture or delamination. Moreover, the addition of nanofillers improve the barrier properties of PNC membranes, thus the membranes are used in packaging and current filtration techniques. In this work, experimental as well as statistical analysis of the fabricated CS membranes and their yield tensile strength and % elongation data are presented. This study presents the effect of the filler type, the filler content and the cross-linking of CS membranes on tensile strength behaviour both experimentally as well as theoretically.

We demonstrate the fabrication by anodization of niobium oxide microcones, several microns long, from aqueous solutions of 1 wt% hydrogen fluoride (HF) with varied sodium fluoride (NaF) concentration (0–1 M). Raman spectroscopy and x-ray diffractometer analysis revealed the as-grown microcones to be crystalline Nb_2O_(5−x) with preferred (1 0 0) and (0 1 0) orientations. The overall Nb_2O_(5−x) formation rate increased with the increasing NaF concentration, and structures as tall as 20 μm were achieved in just 20 min of anodization at 1 M NaF. Rapid formation of niobia microcones was even observed in the absence of HF at this NaF concentration. Photocatalytic activity for water oxidation was highest for microcones grown under the highest NaF concentration.

The AA6061 is reinforced by adding SiC at various volume fractions and, the mixture is hot compacted at different processing temperatures. The influences of such parameters are investigated on the product relative density along with its relevant Vickers hardness using quantitative and qualitative formulation approach. Empirical relationships are established to relate each of the controlling (independent) parameters (SiC% and hot compaction (HC) temperature), to the composites relative density and the hardness, as dependent variables. The developed models are examined for its adequacy and significance using several statistical criteria. Response surface and contour graphs are established to reflect the relevant function interrelations and, to provide a data base source for the prior design stage. Within the specified experimental domain, first order and nonlinear models are found independently adequate and significant to grasp the functional dependence between the relative density and both SiC and HC temperature. However, second order multiple model with quadratic components of SiC percent is found to best suit the hardness-SiC%-temperature functional relationship. Increasing SiC content is found to reduce the relative density of the composites regardless the hot compaction temperature while, up to about 18 vol.% SiCp relative ratio, it enormously and nonlinearly increases the composite hardness. Further increase in SiC% addition seems not to affect the composite hardness. Relative density of the resulting composite is decreased by increasing HC temperature.

Background Fluoride is a well-determined nonbiodegradable and moderate pollutant, which at high levels causes serious health problems. Aim The present study was designed to investigate the histopathological changes in liver as a result of exposure to sodium fluoride in albino rats and the possible therapeutic effect of both vitamins E and C. Materials and methods Eighteen adult albino mice were divided into three groups (six rats per each group). The first group served as control. The second group was treated with 3.6 mg/kg body weight sodium fluoride for 30 days, and the third group received 3.6 mg/kg body weight of sodium fluoride for 30 days followed by vitamins E and C for the next 13 days. At the end of the treatment period, the animals were sacrificed by means of cervical dislocation and the liver was dissected out. Blood samples were taken for the assessment of serum glutamic-pyruvic transaminase and serum glutamic oxaloacetic transaminase. Results Liver tissue was cleared and used for assessing the histopathological changes. Liver tissue homogenate was used for the assessment of malondialdehyde and glutathione peroxidase levels. The histopathological results in the present study indicated that exposure to sodium fluoride for 30 days caused degenerative changes in the liver. Light microscopic examination revealed the degenerative changes in the liver, such as disorganization of the cell plates, dilation of the central vein, pyknotic nucleus, ballooned hepatocytes and hepatocytes with empty nuclei, and disturbed mucopolysaccharide metabolism in liver cells. Biochemical examination revealed elevated serum glutamic-pyruvic transaminase, serum glutamic oxaloacetic transaminase, and malondialdehyde and decreased glutathione peroxidase level. Conclusion Administration of vitamins E and C during the first 13 days of the recovery period of sodium fluoride intoxication revealed minimal improvement, which was detected at the biochemical and metabolic level.

Chitosan (CS) nanocomposite mesoporous membranes were fabricated by mixing CS with graphene (G) and fullerene (F) nanofillers, and the diffusion properties through CS membranes were studied. In addition, in order to enhance the binding between the internal CS chains, physical cross-linking of CS by sodium tripolyphosphate (TPP) was carried out. F and G with different weight percentages (0.1, 0.5, and 1 wt.%) were added on physically cross-linked chitosan (CLCS) and non-cross-linked chitosan (NCLCS) membranes by wet mixing. Permeability and diffusion time of CLCS and NCLCS membranes at different temperatures were investigated. The results revealed that the pore size of all fabricated CS membranes is in the mesoporous range (i.e., 2–50 nm). Moreover, the addition of G and F nanofillers to CLCS and NCLCS solutions aided in controlling the CS membranes’ pore size and was found to enhance the barrier effect of the CS membranes either by blocking the internal pores or decreasing the pore size. These results illustrate the significant possibility of controlling the pore size of CS membranes by cross-linking and more importantly the careful selection of nanofillers and their percentage within the CS membranes. Controlling the pore size of CS membranes is a fundamental factor in packaging applications and membrane technology.

Carbon nanotube-reinforced polymer composites are being investigated as promising new materials having enhanced physical and mechanical properties. With regards to mechanical behavior, the enhancements reported thus far by researchers are lower than the theoretical predictions. One of the key requirements to attaining enhanced behavior is a uniform dispersion of the nanotubes within the polymer matrix. Although solvent mixing has been used extensively, there are concerns that any remaining solvent within the composite may degrade its mechanical properties. In this work, a comparison is carried out between solvent and “solvent-free” dry mixing for dispersing multiwall carbon nanotubes in polypropylene before further melt mixing by extrusion. Various weight fractions of carbon nanotubes (CNTs) are added to the polymer and their effect on the mechanical properties of the resulting composites is investigated. Enhancements in yield strength, hardness, and Young's modulus when compared with the neat polymer, processed under similar conditions, are observed. Differences in mechanical properties and strain as a function of the processing technique (solvent or dry) are also clearly noted. In addition, different trends of enhancement of mechanical properties for the solvent and dry-mixed extrudates are observed. Dry mixing produces composites with the highest yield strength, hardness, and modulus at 0.5 wt% CNT, whereas solvent mixing produces the highest mechanical properties at CNT contents of 1 wt%. It is believed that this difference is primarily dependent on the dispersion of CNTs within the polymer matrix which is influenced by the processing technique. Field emission scanning electron microscopy analysis shows the presence of clusters in large wt% CNT samples produced by dry mixing. Samples produced by solvent mixing are found to contain homogeneously distributed CNTs at all CNT wt fractions. CNT pull-out is observed and may explain the limited enhancement in mechanical properties. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers

In the current research work reinforcement of a thermoplastic polyurethane (TPU) polymer with graphene powder (G, in the form of particles) as a nanofiller material by in-situ and ex-situ mixing of various weight fractions of G is reported. In addition, investigation on the effect of the weight fraction of G on the mechanical properties of the resulting TPU/graphene (TPU/G) nanocomposites is conducted. A number of different preparation methods have been employed in order to investigate the influence of the preparation process on the resulting TPU/G nanocomposites. Solvent (wet) mixing and mechanical (dry) mixing processes have been used. Significant enhancement in compressive strength, melt flow index and electrical conductivity were observed by employing the different mixing processes when compared with the pure TPU polymer processed under similar conditions. However, dry mixing process has shown enhanced mechanical, viscosity and electrical properties compared to wet mixing process. Moreover, dry mixing process has led to the formation of TPU/G nanocomposites with the highest compressive strength at 0.1 wt% G compared with 0.5, and 1 wt % G. It is believed that the processing technique plays a vital role in producing the desired TPU/G nanocomposites and is also affected by the dispersion of graphene nanofiller particles within the TPU polymer matrix. These results may lead to the development of novel applications of TPU/G nanocomposites across different disciplines.

A novel method for the fabrication of highly uniform oxide dispersion-strengthened (ODS) materials made by chemical processing is presented. The powders are fabricated by a two-step route starting with a chemical synthesis at room temperature, producing nanocrystalline yttrium doped tungsten trioxide hydrate precursor powders. Thermogravimetric analysis with evolved gas analysis revealed the presence of ammonium nitrate in the precursors. The second step is the reduction of the precursor in a hydrogen atmosphere at 600 and 800 °C. The reduced powders, containing W-1.2%Y2O3, showed two types of tungsten particles, cube-shaped with a size less than 250 nm and finer particles (

The cyclopentadienyldicarbonyliron complex (I) is photochemically coupled with the chiral diphosphine (II), yielding the optically active complex (V) which reacts with the racemic arsine (±)-(VI) under optical resolution to produce the chiral iron arsine complex (VII).

Question: The function of alveolar macrophages in correlation with immunological stimulation, consequently also in pulmonary transplantation, are a subject of discussion. In this study the alveolar manifestations of rejection following pulmonary homotransplantation are investigated by electron microscopy. Materials and methods: In 20 healthy dogs (body weight between 7 and 19 kg) a left side pulmonary homotransplantation was performed using a standardized method. 2 randomized groups of 10 animals each were formed, one undergoing immunosuppressive therapy, the other none. Needle biopsies (Menghini needles) were taken in both groups at the onset of rejection daily until death of the animals (on the 5th to 12th postoperative day). At death of the animals always total rejection of the homograft was observed. The other animals were subjected to a scheduled immunosuppressive therapy (Kreuzer et al. 1973, Radaszkiewicz et al. 1974). Needle biopsie swere taken only at the stage of a clinically or roentgenologically ascertained crisis of rejection. Before implantation of the homograft and 20 mins after occlusion of anastomoses and onset of circulation in the transplant biopsies were taken, too, to exclude early changes or alterations in the donor. The lung specimens (2 mm in size) obtained by biopsy were fixed in phosphate buffered OsO 4 and buffered phosphate solution by usual alcohol series. After embedding in epon the specimens were studied by electron microscopy. Results: In the group not undergoing immunosuppressive therapy beginning with the 3rd postoperative day perivascular lymphocytic and plasmacellular infiltrates were seen which increased during the course of rejection. In both groups a swelling and vacuolization of endoplasmatic reticulum, cytoplasmic microvilli with with bridge formation accompanied by an increase of alveolar macrophages and by augmentation of lamellar bodies in granular pneumocytes were noted following operation. A correlation between the increase of lamellar bodies and increase of surfactant has been shown previously.

Eight heavy metals were measured seasonally in the sediment of Lake Nasser during 2013. 27 sites were chosen through 9 sectors across the main channel of the lake from Abu-Simbel to Aswan High Dam to assess the levels of the selected metals. The abundance of these metals was in the order of Fe > Mn > Zn > Cr > Ni > Cu > Pb > Cd, with mean concentrations of 12.41 mg/g, 279.56, 35.38, 30.79, 27.56, 21.78, 11.21 and 0.183 μg/g, respectively. Heavy metals are positively correlated with fine particles (mud fractions) and organic matter accumulation. The results showed perspicuous spatial high significant differences (P

The crystal and molecular structure of the title compound, derived by lead tetraacetate oxidation of the bis-p-methoxybenzoylhydrazone of 3,3-dimethylpentane-2,4-dione, is studied by an X-ray crystallographic analysis.

Substituted-3-benzylidenebenzo[b]thiophen-2-ones have been synthesized. 5,6-Dimethoxybenzo[b]-thiophen-2-(3H)one with aniline and triethyl orthoformate gives the 3-anilinomethylene compound, which can be hydrolysed to give the corresponding 3-hydroxymethylene derivative. Dimethoxybenzo[b]thieno[2,3-b]-quinoline has been synthesized.

In field-scale trials at Hamoul in the north of the Nile delta in 1967 and 1968, certain herbicides applied to a soil heavily infested with barnyardgrass (Echinochloa crus-galli) gave very satisfactory results. Taking into account both grass control and increase in rice stand, molinate and propanil at 3-4 Ib/feddan* were shown to be most effective. Molinate used either as a liquid or granular formulation gave excellent results when applied pre-flood (liquid) or post-emergence (liquid and granules). Propanil used post-emergence gave good results provided that the field was drained 24 hours before treatment and flooded again 24 hours after.