The effects of short carbon fibers on static and dynamic properties of thermoplastic elastomeric blends of natural rubber (NR) and high density polyethylene (HDPE) have been studied. Both mechanical and dynamic properties are dependent on fiber concentration. The fiber aspect ratio ranges from 20 to 30. Adhesion between fiber and matrix is evident from the SEM photomicrographs of the failed composites and from variation of relative damping properties. Fiber orientation occurring during processing causes anisotropy in the physical properties. In composites with longitudinally oriented fibers, tensile failure occurs by both fiber pullout and breakage, while in composites with transversely oriented fibers, matrix failure dominates. The incorporation of fibers into the matrix lowers the tan δmax value, but no change in glass transition temperature is observed. 相似文献
Various softwood and hardwood bark residues, primary sludges and softwood sawdust residues were processed by vacuum pyrolysis in a laboratory scale batch reactor. The pyrolysis oil, water, charcoal, and gas were recovered and analyzed. The pyrolysis oils were analyzed in details for their content in phenolic compounds after derivatization to their acetyl derivatives. The influence of temperature, heating rate, feedstock bed thickness, particle size and feedstock water pretreatment on the yield of phenols was investigated. The highest yield of phenols was obtained when hardwood bark was soaked in water for 48 hours and pyrolyzed at a temperature of 450°C and a heating rate of 10°C/min. Pyrolysis performance was evaluated in terms of total phenolic yield and composition. 相似文献
Experimental investigations have been carried out for spherical and non-spherical particles using beds comprised of single-sized particles and mixtures in the size and particle density ranges of 439 to 1524 μm and 1303 to 4948 kg/m3, respectively. Five conical fluidizers with varying apex angles of 8.86, 14.77, 19.60, 32.0 and 43.2 degrees were used. Experimental values of minimum velocity and bed pressure drop with air as the fluidizing medium have been compared with their respective values obtained from different models available in the literature. Deviations for each chosen model have been presented. 相似文献
The gasification of biomass derived char obtained via vacuum and atmospheric pyrolysis of Populus tremuloides has been studied in the ranges of 725–960°C and 0.1 to 6 MPa. CO2 was used as the oxidizing gas. The results show that char reactivity is influenced by the preheating rates and that pressure effects are significant between 850°C and 950°C. A correlation based on the expression: df/dt = k0{exp(-E/RT)}(1 - f)afβPyCO2 was used to fit the experimental data. In general, vacuum pyrolysis derived char showed a higher reactivity than atmospheric pyrolysis chars. An explanation based on a higher oxygen content of the vacuum pyrolysis char is suggested. 相似文献
Nocturnal intragastric feeding has been shown to be an effective means to improve clinical and biochemical features in glycogen
storage disease type I (GSD-I). In this study, we investigated the fatty acid patterns in a whole plasma and in circulating
lipoproteins in patients on this therapy. The results demonstrated massive concentration of total fatty acids coupled with
higher levels of triglycerides, free cholesterol, cholesterol ester and phospholipids. This hyperlipidemia involved all fatty
acids without distinction of carbon or bond numbers. However, the increase was more pronounced for saturated than polyunsaturated
fatty acids, as was demonstrated by the ratios of both oleic acid to linoleic acid (1.91±0.40 vs 0.80±0.09 in controls) and
of ω3+ω6 to ω9 fatty acid families (0.92±0.11 vs 1.66±0.08 in controls). The fatty acid patterns in very low (VLDL), low (LDL)
and high (HDL) density lipoprotein showed substantial differences in composition, reflecting an association between an abnormal
lipoprotein pattern and essential fatty acid deficiency. Furthermore, GSD-I patients exhibited a significant increase in VLDL
(17±2 vs 47±7 mg/dl) and LDL cholesterol (124±7 vs 206±24 mg/dl), coupled with a decrease in HDL cholesterol (49±4 vs 28±3
mg/dl). These data documenting high LDL cholesterol and low HDL cholesterol associated with an increased concentration and
proportion of saturated fatty acids suggest that GSD-I patients on nocturnal intragastric feeding are at high risk for atherosclerosis
and its complications. 相似文献
The role of solid state epitaxy in the crystallization of nanocomposite cordierite glass to glass ceramic was investigated. The use of isostructural (-cordierite) seeds in cordierite glass led to a lowering in the crystallization temperature to form glass ceramic by about 50 °C compared to the unseeded glass. The use of non-isostructural seeds such as ZrO2 and TiO2 did not lower the crystallization temperature of cordierite glass to glass ceramic, and in the case of the TiO2-seeded glass the crystallization temperature increased by about 50 °C compared to the unseeded-cordierite glass. The lowering in crystallization temperature by-cordierite seeding can be attributed to the nucleation and epitaxial growth mechanism. 相似文献
Multimedia Tools and Applications - Present era is marked by exponential growth in transfer of multimedia data through internet. Most of the Internet-of-Things(IoT) applications send images to... 相似文献
A novel image encryption framework is proposed in this article. A new chaotic map and a pseudorandom bit generator are proposed. Apart from this, a novel image encryption system is designed based on the proposed map and the proposed pseudorandom bit generator. These three are the major contributions of this work that makes a complete cryptosystem. The proposed new chaotic map is proposed which will be known as the ‘RCM map’ and its chaotic property is studied based on Devaney’s theory. The proposed pseudorandom bit generator is tested using the NIST test suite. The proposed method is simple to implement and does not involve any highly complex operations. Moreover, the proposed method is completely lossless, and therefore cent percent of data can be recovered from the encrypted image. The decryption process is also simple to implement i.e. just reverse of the encryption procedure. A scrambling algorithm is also proposed to further enhance the security of the overall system. The simulation, detailed analysis, and comparative studies of the proposed overall image encryption framework will help to understand the strengths and weaknesses of it. The experimental results are very promising and show the prospects of chaos theory and its usage in the field of data security.