Alginate dialdehyde (AD)-crosslinked casein films: synthesis,characterization and water absorption behavior

In this work, for the first time, alginate dialdehyde (AD) has been used as a cross linker to prepare casein films. The films, synthesized, have been characterized by Fourier transform infrared spectroscopy, X-ray diffraction analysis and scanning electron microscopy and thermogravimetric analysis. The films were investigated for their water absorption capacity in the physiological fluid of pH 7.4 at 37 °C. The film samples (AD-X-CAS)₁₂, (AD-X-CAS)₂₄ and (AD-X-CAS)₃₆ demonstrated an equilibrium water absorption of 30.86, 26.15 and 11.93 g/g, respectively. Moreover, the swelling exponents for the films were in the range of 0.66–0.75, thus indicating non-Fickian water transport mechanism. The dynamic water uptake data were analysed by various kinetic models. The water vapour transmission rates (WVTR) for the three film samples were found to be 16587, 15900 and 14316 g/m²/day, respectively. The higher values of WVTR, obtained for all the three samples, indicated their suitability for high exudating wounds. The results of expansion study in 4% gelatin medium revealed that the three samples exhibited an almost 2.54, 2.09 and 1.90-fold increase in their diameter in 90, 75 and 60 min, respectively.     

Developing ethylene‐propylene‐diene rubber compounds for industrial applications using a sulfur‐bearing silanized silica nanofiller

The loading of a sulfur‐bearing silanized silica nanofiller in ethylene‐propylene‐diene rubber with 4.5 wt% of ethylidene norbornene diene content was increased progressively to 60 parts per hundred rubber by weight. The rubber compounds were cured via the tetrasulfane groups of the silane by adding sulfenamide accelerator and zinc oxide. The hardness, tensile strength, elongation at break, stored energy density at break, tear strength, Young's modulus, M50–M300, compression set, cyclic fatigue life, and bound rubber content of the rubber vulcanizates were measured. With the exception of the elongation at break and compression set which deteriorated, the remaining properties improved and the rate of cure, optimum cure time, and cross‐link density benefited also when the loading of silica was increased in the rubber. The bound rubber content was unchanged, and the cyclic fatigue life of the rubber vulcanizate enhanced considerably when silica was added. Optimizing the chemical bonding between the rubber and filler via the tetrasulfane groups of bis(3‐triethoxysilylpropyl)‐tetrasulfide reduced the chemical curatives in the rubber. This was a major improvement in health, safety, and environment. POLYM. COMPOS., 34:2019–2025, 2013. © 2013 Society of Plastics Engineers     

Nutritional and Phyto-Therapeutic Potential of Papaya (Carica Papaya Linn.): An Overview

Carica papaya is an economically vivacious plant of tropical and subtropical regions, cultivated in over 50 countries across the world with 6.8 million tons production. Papaya holds a broad spectrum of phytochemicals, including polysaccharides, vitamins, minerals, enzymes, proteins, glycosides, saponins, flavonoids, and phytosterols. These bioactive components are responsible for the pharmacological properties of this auspicious plant and demonstrate its importance in daily intake and alimentation. Additionally, it is an excellent aid to digestion and also hydrolyzing gluten, which is an important aspect for dyspeptic and celiac disease patients. Papaya acts as an antioxidant, antimicrobial, anticarminative, anticancer, and has hepato-protective, immunological, and other therapeutic attributes. The seed and pulp of papaya have bacteriostatic effects against several enteropathogens, such as Bacillus subtilus and E. coli. In the current review, pharmacological attributes, nutritional value of papaya, and medicinal properties of its various parts have been elaborated to provide collective information on this multipurpose commercial plant. Moreover, its role in the production of alcohol and carboxymethyl cellulose is also the limelight of the article. Furthermore, the present review article summarizes the literature pertaining to its pharmakinetics and also allies its health claims. Yet, the authors are still of the view that further research needs to be conducted for meticulousness.     

Prediction of hub corner stall characteristics of a highly loaded low speed single stage fan

In this paper a numerical investigation has been presented on the stall mechanism of a highly loaded Single Stage Low Speed Fan designed for the research test facility to be installed at North Western Polytechnic University (NWPU) Xi’an, China. The results presented are for the design point, near stall and just stall operating conditions at design speed. Design point studies have been found to be an indicative of stall area. Unsteady method of domain scaling has been used to compute the results at near stall and just stall conditions. It has been found that unlike the conventional tip leakage flow of the rotor, stator hub section is mainly responsible for the stall of the fan. The flow mechanism has been discussed with correlation to the design variables and previous investigations. Commercial CFD code NUMECA FINE/Turbo has been used for computations; results have been compared with results obtained from commercial CFD code ANSYS-CFX. The loss prediction of latter code is conservative than the former. The stall mechanism predicted by both codes is analogous.     

密度和纤维取向对炭/炭复合材料烧蚀性能的影响(英文)

采用不同的预制体和致密化方法制备了密度不同的5种炭/炭复合材料(密度范围1.77g/cm3～1.85g/cm3)。用氧-乙炔焰对试样进行了烧蚀试验,并用SEM表征了烧蚀后材料的形貌。结果表明:烧蚀后,与乙炔焰成30o角的纤维变成楔形,而与火焰平行的纤维变成直径为3.5μm～4.5μm的针状,针状纤维更易被火焰烧蚀而钝化。部分宏观孔(直径为1.0mm～1.26mm)、针状微孔及界面裂纹等缺陷处更易被烧蚀而变成烧蚀坑。包裹纤维的沥青炭层由于热解炭基体的不连续而出现了严重的剥蚀。高密度材料(1.85g/cm3)具有良好的抗烧蚀性能。