Effect of borax on the thermal and mechanical properties of ethylene‐propylene‐diene terpolymer rubber‐based heat insulator

The effect of Borax on the mechanical and ablation properties of three different ethylene‐propylene‐diene terpolymer (EPDM) compounds containing 20 phr carbon fiber, 20 phr Kevlar or 10 phr/ 10 phr carbon fiber/ Kevlar was investigated. All formulations contained 30 phr fumed silica powder and 10 phr paraffinic oil. It was found that adding Borax to the composite samples containing carbon fiber or Kevlar fiber or their mixture with an equal ratio can increase the tensile strength, elastic modulus and hardness with a slightly decrease in the elongation at break of the rubber samples. The results of thermogravimetry analysis (TGA) on the various samples showed significant increase in the char yield at 670°C by adding Borax to the rubber compounds. Moreover, ablation resistance of samples was also improved by increasing Borax content. Meanwhile, density and thermal conductivity of the insulator were also reduced up to about 10% when the carbon fiber was replaced with the Borax. The results indicated that composites containing Kevlar have high storage modulus and produce compact and stable char. EPDM rubber composite containing Borax (20 phr), carbon fiber (10 phr), and Kevlar (10 phr) showed thermal and ablative properties comparable with those of the asbestos‐ filled EPDM. The thermal conductivity and ablation rate of the above‐ mentioned sample were 0.287 W/m/K and 0.13 mm/s respectively. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41936.     

Investigation of Plasma Power Effect on the Nicraly/8YSZ Coating Properties

In this study, NiCrAlY coating as a bond coat and 8YSZ coating as a top coat were applied on Inconel 718 super alloy substrates by APS method. The plasma power parameter has changed from 24.75 to 34.8 kW. The results show that with increasing the plasma power, the hardness and bond strength increase from 682 to 818 HV and 12.48 to 22.49 MPa, respectively. Also the image analysis shows that the porosity in coatings, decrease from 22.59 percent to 18 percent by increasing the plasma power.     

An Efficient and Facile Synthesis of CL‐20 from TADNO Using HNO3/N2O5 and Optimization of Reaction Parameters by Taguchi Method

Hexanitrohexaazaisowurtzitane (CL‐20) is an outstanding member of a promising new class of energetic compounds, which is applicable in both propellants and explosives. Herein, CL‐20 was synthesized in an efficient method from tetraacetyldinitrosohexaazaisowurtzitane (TADNO) using N₂O₅/HNO₃. The optimization reaction parameters were performed according to the Taguchi OA method. The yield of reaction at the optimized conditions was 97 % with 98.75 % purity.     

Intersymbol interference cancellation in CDMA 1xEVDO network

This paper presents the BER performance of the physical layer of the code division multiple access 1x Evolution Data Only (EVDO) standard for different data transmission formats, and shows the improvement on the BER performance of the EVDO system over intersymbol interference channel by adapting the low complexity turbo equalization scheme at the receiver. The radio frequency, channel condition, and mobile user data speeds were extracted from a mobile user with a drive experiment on a live wireless EVDO network. Then, the real data were utilized to simulate the actual mobile user's data speeds in our simulations to show the overall BER performance of the EVDO system application. The simulation results are shown over Gaussian and Proakis A channels and the results indicate that significant intersymbol interference cancellation is obtained with an adapted code division multiple access system and the advantages of turbo equalization on the EVDO system are discussed in this research. Copyright © 2012 John Wiley & Sons, Ltd.     

Sorption behaviour of Triton X-1OOR surfactant by sand

Dynamic sorption data are reported for the system Triton X-100^R solutions and characterised sands. The sand was in the form of a consolidated sand pack in an attempt to model reservoir conditions. The dynamic isotherms were determined directly for experimental data using the Wilson and DeVault equations. The effect of dispersion was evaluated and the application of the data to enhanced oil recovery discussed. It is shown that the dynamic adsorption isotherm exhibits Langmuir type behaviour up to the c.m.c. whereas results from static measurements of sorption do not. In spite of dispersion being present it was found that the Wilson and DeVault equations predicted the rate of movement of a surfactant band to 1% accuracy.     

Protective effect of Spirulina platensis enriched in phenolic compounds against hepatotoxicity induced by CCl4

Phenolic compounds make up the major secondary metabolites with high pharmaceutical potential. Microalgae were reported to contain low amounts of phenolic compounds. The present study aimed to investigate the hepatoprotective potential of biomass of Spirulina platensis enriched in phenolic compounds. The protective effects of the biomass of S. platensis with low amounts of phenolics (SP1) and with high amounts of phenolics (SP2) against CCl₄-induced acute hepatotoxicity were evaluated in rats. The increased levels of ALT, AST and MDA along with decreased activities of SOD and CAT were significantly (p < 0.01) ameliorated by SP2. Histological examinations revealed that SP2 was more potent than SP1 in protecting the liver from toxic injury of CCl₄ and preserving the hepatocyte ultrastructure. The lesions including necrosis, lymphocyte infiltration, ballooning degeneration and hepatocyte injury as irregular lamellar organisation, dilations in endoplasmic reticulums and the presence of great number of cytoplasmic vacuolization were healed by SP2.     

Hydrogen/methanol production in a novel multifunctional reactor with in situ adsorption: modeling and optimization

This work proposes a novel multifunctional reactor for simultaneous production of hydrogen and methanol in which zeolite 4A is considered as water adsorbent. For this purpose, in the exothermic side of the proposed configuration, a gas‐flowing solid‐fixed bed reactor (GFSFBR) is used. The remarkable advantage of GFSFBR over the conventional sorption‐enhanced reaction process is the continuous adsorbent regeneration in this novel reactor. MR takes the advantages of adsorption and couple technique simultaneously. The new configuration is designed as a double pipe reactor where highly exothermic methanol synthesis reactions in the exothermic side are coupled with dehydrogenation of cyclohexane. A one‐dimensional, steady‐state heterogeneous model is used to simulate the proposed reactor configuration. Simulation result demonstrates that selective adsorption of water in the exothermic side leads to 22.5%, 9.85% and 7.1% enhancement in methanol, benzene and hydrogen production, respectively, compared with the zero solid mass flux condition. Subsequently, the aforementioned reactor is optimized using differential evolution algorithm to maximize the hydrogen mole fraction in the endothermic side as well as the methanol yield in the exothermic side. Copyright © 2013 John Wiley & Sons, Ltd.     

Numerical Study of the Collision and Coalescence of Water Droplets in an Electric Field

The coalescence of binary water droplets in oil exposed to an external electric field is simulated using a model including both electrostatic and hydrodynamic sections. Available mathematical models for electric dipole‐dipole force are presented in the first part of the model. Volume of Fluid approach is applied in the second part of the model. The simulation results were in good agreement with the published experimental observations. The results indicated that an improvement in electrocoalescence speed could be achieved. It was also revealed that the skew angle of the electric field, the oil viscosity, and the initial drops distance influence the electrocoalescence. Moreover, a correlation was developed to predict electrocoalescence kinetic as a function of the participant parameters.     

Plant oil supplements reduce methane emissions and improve milk fatty acid composition in dairy cows fed grass silage-based diets without affecting milk yield

Four lipid supplements varying in chain length or degree of unsaturation were examined for their effects on milk yield and composition, ruminal CH₄ emissions, rumen fermentation, nutrient utilization, and microbial ecology in lactating dairy cows. Five Nordic Red cows fitted with rumen cannulas were used in a 5 × 5 Latin square with five 28-d periods. Treatments comprised total mixed rations based on grass silage with a forage-to-concentrate ratio of 60:40 supplemented with no lipid (CO) or 50 g/kg of diet dry matter (DM) of myristic acid (MA), rapeseed oil (RO), safflower oil (SO), or linseed oil (LO). Feeding MA resulted in the lowest DM intake, and feeding RO reduced DM intake compared with CO. Feeding MA reduced the yields of milk, milk constituents, and energy-corrected milk. Plant oils did not influence yields of milk and milk constituents, but reduced milk protein content compared with CO. Treatments had no effect on rumen fermentation characteristics, other than an increase in ammonia-N concentration due to feeding MA, RO, and SO compared with CO. Lipid supplements reduced daily ruminal CH₄ emission; however, the response was to some extent a result of lower feed intake. Lipids modified microbial community structure without affecting total counts of bacteria, archaea, and ciliate protozoa. Dietary treatments had no effect on the apparent total tract digestibility of organic matter, fiber, and gross energy. Treatments did not affect either energy secreted in milk as a proportion of energy intake or efficiency of dietary N utilization. All lipids lowered de novo fatty acid synthesis in the mammary gland. Plant oils increased proportions of milk fat 18:0, cis 18:1, trans and monounsaturated fatty acids, and decreased saturated fatty acids compared with CO and MA. Both SO and LO increased the proportion of total polyunsaturated fatty acids, total conjugated linolenic acid, and cis-9,trans-11 conjugated linoleic acid. Feeding MA clearly increased the Δ⁹ desaturation of fatty acids. Our results provide compelling evidence that plant oils supplemented to a grass silage-based diet reduce ruminal CH₄ emission and milk saturated fatty acids, and increase the proportion of unsaturated fatty acids and total conjugated linoleic acid while not interfering with digestibility, rumen fermentation, rumen microbial quantities, or milk production.