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381.
This study described the mechanical and thermal properties of hybrid bio‐composites from oil palm empty fruit bunch (EFB) fibers and kaolinite. The polyurethane (PU) used as matrix is formed by reacting palm kernel oil (PKO)‐based polyester with crude isocyanate. The blending ratio of PU to EFB fibers was fixed at 35 : 65 and kaolinite was added at 0, 5, 10, 15, and 20% (by weight). The occurrence of chemical interactions between the hydroxyl terminals in both fillers and the PU system was determined via FTIR spectroscopy. Hybrid bio‐composites showed improved stiffness, strength, and better water resistance with the addition of kaolinite to an extent. At 15% of kaolinite loading, maximum flexural and impact strengths were observed. The interaction between kaolinite with PU matrix and EFB fibers enhanced the mechanical properties of the bio‐composites, which was justified from the FTIR spectrum. However, over‐packing of kaolinite was observed at 20% kaolinite loading, which ruptured the cellular walls and degraded strength of the bio‐composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 相似文献
382.
Zhao-Lin Tan Jing-Xuan Wei Yang Liu Fakhr uz Zaman Wajid Rehman Lin-Rui Hou Chang-Zhou Yuan 《稀有金属(英文版)》2022,(3):775-797
With the continuous development of two-di-mensional(2D)transition metal carbides and nitrides(collectively referred to as MXene).Nowadays,more than 70 MXene mat... 相似文献
383.
Osteochondral defects are still a big challenge for the surgeons because of good biocompatibility and higher mechanical strength requiring issues of the implants. In this study, different concentrations of collagen (dissolved in ionic liquid) up to 60% were blended with polyvinyl alcohol to prepare hydrogels of good mechanical strength, with the best biocompatibility and excellent fluid uptake ability. Ionic liquid was used as a green solvent for dissolution of collagen at a higher concentration as compared to other normal solvents. The prepared hydrogels were characterized with Fourier transform infrared spectroscopy (FTIR) which showed the characteristic peaks assigned to collagen and PVA. The surface morphology was investigated using scanning electron microscopy (SEM) which revealed homogeneity of the composite patches. Thermal gravimetric analysis (TGA) performed for samples show good thermal stabilities. Fluid uptake ability showed the massive uptake of fluid by the hydrogels. Biocompatibility was tested using hemolysis and MTT assay. Electrodynamic fatigue testing system was used for evaluating the mechanical properties and measured the tensile strength in the range of 2.4 to 8.5?MPa. The prepared osteochondral patches show good biocompatibility and mechanical properties. 相似文献
384.
Yah Yun Aw Cheow Keat Yeoh Muhammad Asri Idris Pei Leng Teh Wan Nurshaznie Elyne Khairul Amali Hamzah 《Polymer-Plastics Technology and Engineering》2019,58(1):1-13
Acrylonitrile butadiene styrene (ABS)/zinc oxide(ZnO) composites have been fabricated via fused deposition modelling technique. The effect of filler precoating and printing parameters on mechanical properties of the composites are investigated. The incorporation of precoated fillers and increase of infill density improve the tensile strength, Young’s modulus and hardness of the composites. Printing pattern determines mainly the tensile properties of the composites but has no significant effect on the hardness. Based on experimental results, it is suggested that line pattern printed with precoated fillers at medium dispenser speed and 100% infill density has resulted improved mechanical properties. 相似文献
385.
Richard Ritikos Boon Tong Goh Khairul Anuar Mat Sharif Muhamad Rasat Muhamad Saadah Abdul Rahman 《Thin solid films》2009,517(17):5092-4957
Multilayer thin films consisting of a-CNx:H/nc-Si:H layers prepared by radio-frequency plasma enhanced chemical vapour (r.f. PECVD) deposition technique were studied. High optical reflectivity at a specific wavelength is one of major concern for its application. By using this technique, a-CNx:H/nc-Si:H multilayered thin films (3-11 periods) were deposited on substrates of p-type (111) crystal silicon and quartz. These films were characterized using ultra-violet-visible-near infrared (UV-Vis-NIR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, field effect scanning electron microscopy (FESEM) and AUGER electron spectroscopy (AES). The multilayered films show high reflectivity and wide stop band width at a wavelength of approximately 650 ± 60 nm. The FTIR spectrum of this multilayered structure showed the formation of Si-H and Si-H2 bonds in the nc-Si:H layer and CC and N-H bonds in a-CNx:H layer. SEM image and AES reveal distinct formation of a-CNx:H and nc-Si:H layers in the cross section image with a decrease in interlayer cross contamination with increasing number of periods. 相似文献
386.
Peas can replace soybean meal and corn grain in dairy cow diets 总被引:1,自引:0,他引:1
The objective of this experiment was to investigate the effect of a partial substitution of soybean meal and corn grain with field peas in dairy cow diets on intake, milk yield and composition, nutrient digestibility, and urinary and fecal N losses. Twenty-four lactating Holstein cows were blocked into 2 groups based on parity, days in milk, and milk yield at the end of a 2-wk covariate period. Cows within group were randomly assigned to 1 of 2 treatments: control and pea diets. Approximately 45% of the corn grain and 78% of the soybean meal in the control diet were replaced with 15% (dry matter basis) field peas in the experimental diet. The peas used in the trial contained 25% crude protein and an estimated 1.98 Mcal of net energy for lactation/kg. The experiment continued for 70 d. Dry matter intake (25.9 and 26.3 kg/d; control and pea diets, respectively), milk yield (35.4 and 35.6 kg/d), 4% fat-corrected milk yield (33.0 and 34.6 kg/d), milk fat (3.54 and 3.76%) and protein (3.00 and 2.99%) content and yields, and milk N efficiency (26 and 24%) were not affected by diet. Concentration of milk urea nitrogen was also not affected by treatment (14.3 and 15.0 mg/dL, respectively). Intake of organic matter and N were not affected by diet, but intake of neutral detergent fiber was lower and that of starch greater with the control diet. Total tract apparent digestibility of starch was lower (92.1 vs. 88.3%, respectively) and that of dry matter and organic matter tended to be lower with the pea compared with the control diet. Urinary and fecal N losses were not different between the 2 diets. Panel evaluation of milk from the 2 diets indicated no differences in the organoleptic characteristics of milk. This experiment demonstrated that field peas could be safely fed to high-producing dairy cows at a 15% inclusion rate, replacing soybean meal and corn grain. At this inclusion rate, no effects on milk yield or milk composition were observed. 相似文献
387.
A. Mushtaq Massod Iqbal Ishtiaq Hussain Bokhari Tariq Mahmood Tayyab Mahmood Zahoor Ahmad Qamar Zaman 《Annals of Nuclear Energy》2008
Neutronic and thermal hydraulic analysis for the fission molybdenum-99 production at PARR-1 has been performed. Low enriched uranium foil (<20% 235U) will be used as target material. Annular target designed by ANL (USA) will be irradiated in PARR-1 for the production of 100 Ci of molybdenum-99 at the end of irradiation, which will be sufficient to prepare required 99Mo/99mTc generators at PINSTECH and its supply in the country. Neutronic and thermal hydraulic analysis were performed using various codes. Data shows that annular targets can be safely irradiated in PARR-1 for production of required amount of fission molybdenum-99. 相似文献
388.
Weize Xiong Gebara G. Zaman J. Gostkowski M. Nguyen B. Smith G. Lewis D. Cleavelin C.R. Wise R. Shaofeng Yu Pas M. Tsu-Jae King Colinge J.P. 《Electron Device Letters, IEEE》2004,25(8):541-543
Hydrogen anneal is used during FinFET processing to round off the corners of the silicon fins prior to gate oxidation and to smooth the surface of the fin sidewalls. This procedure greatly improves gate leakage and, in addition, reduces the width of the fins, resulting in a lower threshold voltage and improved drain-induced barrier lowering (DIBL) characteristics. Reduction of the leakage current by up to four orders of magnitude is obtained after edge rounding by hydrogen annealing. In addition, a 50% decrease of DIBL is observed, due to fin width reduction. 相似文献
389.
Comments on the article by S. M. Hafeez Zaidi (see record 1960-06828-001), which the current author reports was very precise and to the point, and points out a small omission. While discussing the professional journals, Zaidi has overlooked a professional journal in Pakistan which was in circulation from October 1949 to October 1950. It was a monthly journal called Nafsiyati Jaize. It was entirely devoted to original research in the fields of clinical, social, and applied psychology. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
390.
Summary A constitutive model is proposed to describe creep deformation of polycrystalline materials under complex stress and temperature histories. The concept of piecewise linear effective stress—creep strain rate relationship is utilized. A key assumption in this model is that the back stress under a given stress and temperature reaches a saturation point. This saturation point corresponds to the steady state condition.With 12 Figures 相似文献