Reduction of Ripple Current Loss by Electromagnetic Coupling of Air‐Core Reactors

To reduce the loss due to ripple current in a multiphase current‐reversible chopper, we investigated electromagnetic coupling of an air‐core reactor. We derived the relationship between the amplitude of the ripple current, the duty factor, and the electromagnetic coupling coefficient, and used the results to estimate the effects of electromagnetic coupling in the design of a train energy storage system. We built reactors with electromagnetic coupling coefficients of 0.93 and 0.60. These reactors employed a new winding structure that provides an optimal electromagnetic coupling coefficient. The mass of the former type of reactor was increased by 4.4% over the conventional design, and that of the latter type of reactor was decreased by 17%. Finally, we tested the new reactors. When the chopper employs the former type of reactor and operates with equal‐phase switching and cumulative coupling, the loss due to ripple current is decreased by 11%. When the chopper employs the latter type of reactor and operates with shift‐phase switching and differential coupling, the loss is decreased to 31%. The test showed that the calculated relationships agreed with the measured values.     

Does the production of Belgian bioethanol fit with European requirements on GHG emissions? Case of wheat

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.     

Hybrid nanocomposite thin films deposited by emulsion-based resonant infrared matrix-assisted pulsed laser evaporation for photovoltaic applications

Emulsion-based, resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) was used to deposit CdSe nanoparticle films and hybrid nanocomposite films comprising colloidal CdSe nanoparticles embedded in a low band gap polymer, poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b′]dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT). We show that, in contrast to traditional MAPLE deposition, the CdSe nanoparticle film deposited by emulsion based RIR-MAPLE is contiguous and uniform, and it maintains the optical properties of the nanoparticle solution. Moreover, we show that the RIR-MAPLE deposited PCPDTBT/CdSe hybrid nanocomposite film exhibits a relatively random and uniform distribution of CdSe nanoparticles without the significant phase segregation that is observed in hybrid nanocomposite films deposited by spin-casting. Finally, hybrid organic solar cells based on nanocomposite films deposited by the RIR-MAPLE technique were fabricated and characterized, showing 0.4% power conversion efficiency. This is the first demonstration of a polymer–nanoparticle hybrid organic solar cell fabricated by a MAPLE-related technique.     

Morphology of Flashing Feeds at Critical Fluid Properties in Larger Pipes

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.     

Environmental impact assessment of bio-hydrogenated diesel from hydrogen and co-product of palm oil industry

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.     

Pure CuBi2O4 Photoelectrodes with Increased Stability by Rapid Thermal Processing of Bi2O3/CuO Grown by Pulsed Laser Deposition

A new method for enhancing the charge separation and photo‐electrochemical stability of CuBi₂O₄ photoelectrodes by sequentially depositing Bi₂O₃ and CuO layers on fluorine‐doped tin oxide substrates with pulsed laser deposition (PLD), followed by rapid thermal processing (RTP), resulting in phase‐pure, highly crystalline films after 10 min at 650 °C, is reported. Conventional furnace annealing of similar films for 72 h at 500 °C do not result in phase‐pure CuBi₂O₄. The combined PLD and RTP approach allow excellent control of the Bi:Cu stoichiometry and results in photoelectrodes with superior electronic properties compared to photoelectrodes fabricated through spray pyrolysis. The low photocurrents of the CuBi₂O₄ photocathodes fabricated through PLD/RTP in this study are primarily attributed to their low specific surface area, lack of CuO impurities, and limited, slow charge transport in the undoped films. Bare (without protection layers) CuBi₂O₄ photoelectrodes made with PLD/RTP shows a photocurrent decrease of only 26% after 5 h, which represents the highest stability reported to date for this material. The PLD/RTP fabrication approach offers new possibilities of fabricating complex metal oxides photoelectrodes with a high degree of crystallinity and good electronic properties at higher temperatures than the thermal stability of glass‐based transparent conductive substrates would allow.     

Betel Nut Arecoline Induces Different Phases of Growth Arrest between Normal and Cancerous Prostate Cells through the Reactive Oxygen Species Pathway

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.     

等离子喷涂与脉冲等离子爆炸复合涂层的氧化组织分析

采用等离子喷涂在镍基高温合金GH4049表面制备了CoNiCrAlY涂层,随后对涂层进行了脉冲等离子爆炸和真空预氧化处理,并对涂层进行了1050℃保温10 h和50 h的恒温静态氧化实验。结果表明:经过脉冲等离子爆炸处理后的涂层表面形貌更加平坦,脉冲等离子爆炸处理使得涂层表面的片层结构转变为致密结构,减少了氧气渗入涂层的通道,有效延缓了涂层的氧化过程,且没有改变涂层的化学成分;在1050℃空气中氧化50 h后,涂层的物相组成与未氧化处理的基本一致。     

高低温循环及对称冲击耦合加载下 炸药的安全性研究

基于一级轻气炮加载装置，研究了高低温循环及对称冲击耦合加载下某黑索今(RDX)基含Al炸药的安全性，计算了缺陷处的内能等参数。结果表明:高低温循环后，炸药试样出现可见的孔隙。对称碰撞加载后，不经高低温循环的试样未发生点火，应力加载峰值为835 MPa，加载时间为35 μs；而经历高低温循环的试样出现点火，点火前应力为242 MPa，加载时间11 μs。高低温循环所产生的缺陷是导致炸药点火的重要原因。