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41.
The eutectic 80Au/20Sn solder alloy is widely used in high power electronics and optoelectronics packaging. In this study, low cycle fatigue behavior of a eutectic 80Au/20Sn solder alloy is reported. The 80Au/20Sn solder shows a quasi-static fracture characteristic at high strain rates, and then gradually transforms from a transgranular fracture (dominated by fatigue damage) to intergranular fracture (dominated by creep damage) at low strain rates with increasing temperature. Coffin-Manson and Morrow models are proposed to evaluate the low cycle fatigue behavior of the 80Au/20Sn solder. Besides, the 80Au/20Sn solder has enhanced fatigue resistance compared to the 63Sn/37Pb solder. 相似文献
42.
This paper undertakes an environmental evaluation of bioethanol production, using wheat cultivated in Belgium. Cultivation steps are modelled using Belgian specific data. Wheat transformation in ethanol relies on industrial data. GHG emissions of the whole life cycle are calculated and compared with the default values given by the European Renewable Energy Directive. Belgian wheat bioethanol achieves a 5% higher GHG reduction than the one mentioned in the European directive but impact repartition is different with a higher importance of cultivation step in our case. Belgian wheat bioethanol complies with the current sustainability criteria but is also able to conform to further ones. Sensitivity analyses are performed on the importance of N fertilizers and associated emissions known as main important parameters. These analyses reveal non negligible variations and then a range of available GHG reduction when using wheat bioethanol. 相似文献
43.
Alexander Döß Markus Schubert Michael Wiezorek Uwe Hampel Felix Flegiel Christoph Windmeier Eckhard Schleicher Christoph Schunk 《化学,工程师,技术》2021,93(7):1126-1133
Tailored conditioning and control of flashing feeds in industrial applications requires knowledge of the evolving flow morphology and phase fractions along the feed pipe. Design methods obtained from reference systems (e.g. water-air) are hardly applicable for commercial scales and critical fluid properties (e.g. high vapor densities, low surface tension). In this study, the flow morphology of flashing feeds in a novel refrigerant test rig at critical fluid properties was analyzed using wire-mesh sensors at two locations along the feed pipe and experimental data from the water-air system. 相似文献
44.
Bulin Boonrod Paweena Prapainainar Viganda Varabuntoonvit Kandis Sudsakorn Chaiwat Prapainainar 《International Journal of Hydrogen Energy》2021,46(17):10570-10585
Bio-hydrogenated diesel (BHD) is a second generation biofuel that can be produced from vegetable oil and hydrogen via hydroprocessing. BHD is considered as one of alternative and renewable energy. This work presents evaluation of environmental impacts of BHD produced from palm fatty acid distillate (PFAD) compared to fatty acid methyl ester (FAME). Greenhouse gas emission, energy consumption, and overall environmental impacts are assessed. System boundary is from palm oil cultivation to BHD production. The functional unit is defined as 1 kg of fuel produced at the plant. The results indicate that energy consumption of BHD-PFAD is 1.18 times higher than that of BHD-FAME, while giving GHG emission 13.56 times lower than that of BHD-FAME. The results of overall environmental impacts indicated that BHD-PFAD was 3.58 greater than that of BHD-FAME. 相似文献
45.
Li-Jane Shih Jia-Yu Wang Jing-Yao Jheng An-Ci Siao Yen-Yue Lin Yi-Wei Tsuei Yow-Chii Kuo Chih-Pin Chuu Yung-Hsi Kao 《International journal of molecular sciences》2020,21(23)
Prostate cancer (PCa) is a reproductive system cancer in elderly men. We investigated the effects of betel nut arecoline on the growth of normal and cancerous prostate cells. Normal RWPE-1 prostate epithelial cells, androgen-independent PC-3 PCa cells, and androgen-dependent LNCaP PCa cells were used. Arecoline inhibited their growth in dose- and time-dependent manners. Arecoline caused RWPE-1 and PC-3 cell cycle arrest in the G2/M phase and LNCaP cell arrest in the G0/G1 phase. In RWPE-1 cells, arecoline increased the expression of cyclin-dependent kinase (CDK)-1, p21, and cyclins B1 and D3, decreased the expression of CDK2, and had no effects on CDK4 and cyclin D1 expression. In PC-3 cells, arecoline decreased CDK1, CDK2, CDK4, p21, p27, and cyclin D1 and D3 protein expression and increased cyclin B1 protein expression. In LNCaP cells, arecoline decreased CDK2, CDK4, and cyclin D1 expression; increased p21, p27, and cyclin D3 expression; had no effects on CDK1 and cyclin B1 expression. The antioxidant N-acetylcysteine blocked the arecoline-induced increase in reactive oxygen species production, decreased cell viability, altered the cell cycle, and changed the cell cycle regulatory protein levels. Thus, arecoline oxidant exerts differential effects on the cell cycle through modulations of regulatory proteins. 相似文献
46.
Luz Bertoia Jorge R. Wagner Andrés L. Márquez 《Journal of the American Oil Chemists' Society》2020,97(10):1071-1081
The objective was to study the microstructure and freeze–thaw stability of margarine-like emulsions formulated with vegetable fats using differential scanning calorimetry. Emulsions were prepared with 20% w/w dispersed aqueous phase and a continuous lipid phase composed by coconut oil (CO) and/or palm oil (PO) plus polyglycerol polyricinoleate (PGPR) as emulsifier. Mean temperature (TM) and crystallization enthalpy (ΔHc) were obtained from the exothermic peaks corresponding to freezing of aqueous phase. Successive cooling–heating–cooling cycles were applied to analyze changes in the exothermic peak. The emulsion prepared with CO (without PO) and 1% w/w PGPR in lipid phase showed higher water droplets size (TM = −44.8 ± 0.1 °C) and lower quantity of stabilized aqueous phase (ΔHc = 28.9 ± 1.2 J g−1) prior to application of temperature cycles, while coalescence and (presumably) water transfer processes occurred during the treatment. The use of 2% w/w PGPR was sufficient to accomplish full stabilization of aqueous phase (TM = −45.9 ± 0.1 °C; ΔHc = 42.6 ± 0.3 J g−1) before and after the freeze–thaw treatment. The total or partial (50%) substitution of CO by PO in emulsions with 1% w/w PGPR also improved the stability of the system, exhibiting slight microstructural changes. This enhanced stability would be linked to reduced water droplets size because of more rapid crystallization of lipid phase and immobilization of aqueous phase after emulsion preparation. In conclusion, it is possible to obtain margarine-like emulsions prepared with CO and/or PO using relatively low emulsifier concentration and maintaining a desired microstructure after freeze-thawing if the percentage ratio of both fats is controlled. 相似文献
47.
《Geotextiles and Geomembranes》2022,50(5):845-857
The freeze–thaw cycling damages the soil structure, and the shear performance of soil are degraded. A series of tests on lime–soil(L–S) and fiber–lime–soil(F–L–S), including freeze–thaw test, the triaxial compression test, nuclear magnetic resonance (NMR) test and scanning electron microscope (SEM) test, were completed. The test results showed that fiber reinforcement changed the stress–strain behavior and failure pattern of soil. The cohesion and internal friction angle of soil gradually decreased with the increase of freeze–thaw cycles (F–T cycles). The pore radius and porosity of soil increased, while the micro pore volume decreased, and the small pore volume, medium pore volume and large pore volume increased, and the large pore volume had a little variation after 10 F–T cycles. The number of pores of F–L–S was less than L–S, demonstrating that the addition of fiber helped to reduce the pore volume. The interweaved fibers limited the development and the connection of cracks. By means of the spatial restraint effect of fiber on the soil and the friction action between fiber and soil, the shear performances and freeze–thaw durability of F–L–S better were than that of L–S. 相似文献
48.
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50.
Debojyoti Das Vaneet Bhatia Jayarethanam Pillai Aviral Kumar Tiwari 《Energy Sources, Part B: Economics, Planning, and Policy》2018,13(1):37-45
The authors revisit the relationship between US economic growth and crude oil prices considering Industrial Production Index and West Texas Intermediate crude oil spot prices as respective proxies for a period spanning over January 1986 to June 2017. To capture the asymmetric and time-varying relationship, the authors employ maximum overlap discrete wavelet transform (MODWT)-based quantile regression (QR) analysis. Interestingly, MODWT-based QR analysis provides evidence of supply-driven link between crude oil prices and economic growth in the short run. However, in the medium to long run a demand-driven link is dominant. In addition, the QR results without MODWT also advocate a demand-driven link. Overall, the result of this study adds a new dimension to the literature on the relationship between crude oil prices and economic growth by focusing upon the time-frequency varying business cycle fluctuations. 相似文献