Enzymatic enrichment of arachidonic acid from Mortierella single-cell oil

An attempt was made to enrich arachidonic acid (AA) from Mortierella single-cell oil, which had an AA content of 25%. The first step involved the hydrolysis of the oil with Pseudomonas sp. lipase. A mixture of 2.5 g oil, 2.5 g water, and 4000 units (U) Pseudomonas lipase was incubated at 40°C for 40 h with stirring at 500 rpm. The hydrolysis was 90% complete after 40 h, and the resulting free fatty acids (FFA) were extracted with n-hexane (AA content, 25%; recovery of AA, 91%). The second step involved the selective esterification of the fatty acids with lauryl alcohol and Candida rugosa lipase. A mixture of 3.5 g fatty acids/lauryl alcohol (1:1, mol/mol), 1.5 g water, and 1000 U Candida lipase was incubated at 30°C for 16 h with stirring at 500 rpm. Under these conditions, 55% of the fatty acids were esterified, and the AA content in the FFA fraction was raised to 51% with a 92% yield. The long-chain saturated fatty acids in the FFA fraction were eliminated as urea adducts. This procedure raised the AA content to 63%. To further elevate the AA content, the fatty acids were esterified again in the same manner with Candida lipase. The repeated esterification raised the AA content to 75% with a recovery of 71% of its initial content.     

Throughput and delay analysis of free access tree algorithm withminislots

An analysis is made of the throughput and delay performance of two classes of free-access tree algorithms with minislots. In one class, binary feedback information is available in minislots, and in the other, ternary feedback information is available. It is shown that the highest maximum throughput 0.56714 is achieved in the limiting case where the number of minislots in a (large) slot is infinity and minislot overhead is zero. A lower bound of the average transmission delays in these algorithms is analytically derived. The obtained lower bound is also a lower bound of the average delay of the whole class of the free-access algorithms     

Improvement in high temperature stability of Pd coating on Nb by Nb2C intermediate layer

Niobium subcarbide (Nb₂C) was chosen as a material for non-porous intermediate layer to improve the high temperature durability of Pd–Nb composite membranes for hydrogen separation. A layer of Nb₂C was prepared between Nb substrate and thin Pd films (100 nm), and the stability of Pd coating at elevated temperatures (573–773 K) was examined by hydrogen absorption experiments. Hydrogen permeability through the Nb₂C layer appeared to be sufficiently high, and no noticeable deterioration was observed in hydrogen absorption rate under as-prepared conditions. The degradation in coating effect of Pd at elevated temperatures was substantially mitigated by Nb₂C layer. Such improved durability was ascribed to retardation of open porosity development by Nb₂C caused as a consequence of impeded interdiffusion between Pd and Nb.     

Facile fabrication of mesoporous TiO2 electrodes for dye solar cells: chemical modification and repetitive coating

A chemical dispersing technique for preparing a coating paste of TiO₂ nanoparticles is disclosed to fabricate mesoporous electrodes for dye-sensitized TiO₂ solar cells. The suspension of TiO₂ (P-25) powder was stirred in aqueous nitric acid at 80°C, and then evaporated to dryness, giving the nitric acid-adsorbed P-25 powder. The coating paste was obtained by mixing the nitric acid-adsorbed P-25 with PEG (M_w 20,000) as a porosity-controlling agent and cellulosic polymer as a thickener. The mesoporous TiO₂ films were fabricated on conducting glasses by repetitive coating and calcined at 500°C (30 min). The TiO₂ film obtained by the five times repetitive coating (20 μm thickness) resulted in the 1.4 times higher energy conversion efficiency of the dye-sensitized solar cells than that of the one time coating TiO₂ film (V_oc=690 mV, J_sc=12.2 mA/cm², the fill FACTOR=0.71 and η=6.0%).     

基于红外遥感信息的煤矿车辆 异常行为检测研究

为了提升煤矿车辆异常行为检测水平,设计了基于红外遥感信息的煤矿车辆异常行为检测方法。该方法引入清晰度权重以及拉伸系数实现红外遥感图像中目标煤矿车辆部位的局部增强,利用均值漂移算法跟踪增强后的红外遥感图像中目标煤矿车辆,依据煤矿车辆跟踪结果提取煤矿车辆运动方向、运动速度以及运动方向3项异常行为检测参数,采用加权融合方法处理煤矿车辆异常行为检测参数的状态函数,融合结果高于所设定阈值时,煤矿车辆存在异常行为,否则煤矿车辆为正常行驶状态。实验结果表明,该方法可利用煤矿车辆位置、车辆行驶速度以及车辆方向变化检测煤矿车辆异常行为,具有较高的应用性。     

啤酒酵母吸附重金属离子铬的研究

将啤酒酵母自制成生物吸附剂，用于吸附重金属离子铬，考察了啤酒酵母吸附Cr^3＋过程中的影响因素，即pH值、初始Cr^3＋质量浓度、吸附时间、菌体浓度及酸碱预处理方法等因素。结果表 明，啤酒酵母对Cr^3＋的吸附量随pH值的增加而增大，吸附的最佳pH值范围是4～7，当pH7时达到吸附最大值；随着初始Cr^3＋质量浓度增加，吸附量有所提高，当溶液初始Cr^3＋质量浓度为80mg／L吸附效果最佳；最佳吸附时间为1h；菌体的最佳浓度为50mg／L；及啤酒酵母经碱处理后吸附量增大：正交试验确定反应时间为反应过程的显著因素，确定啤酒酵母对Cr^3＋的吸附过程遵循Langmuir方程。     

Leachability and termite resistance of wood treated with a new preservative: ammonium borate oleate

Synthesis of a new chemical compound combining water-repellence of oleic acid and biocidal effect of boric acid linked by ammonia have been followed and validated by fourier transformed infra red (FTIR). This compound named ammonium borate oleate (ABO) has then been studied as a wood preservative. Different molar ratios of oleic acid have been involved in the synthesis of ABO and leachability of those mixes from wood observed according to Japanese industrial standard. The formulation one mole of boric acid and one of ammonia (1:1:4) for four moles of oleic acid has shown the best efficiency compared to formulations 1:1:1, 1:1:2 and 1:1:3 with about 52% of boron remaining after weathering when other formulations retained respectively 10%, 29% and 46% of boron in the case of an impregnation of Cryptomeria japonica. Seven solutions of 1:1:4 ABO in ethanol of different concentrations were then produced and sapwood blocks of C. japonica and Fagus crenata were impregnated. A toxicity threshold of around 2.0 kg/m³ for both species was determined in a termite resistance test to Coptotermes formosanus indicating the positive effect of combining water repellent and biocide. Termite mortality recording and microscopic observations complete this study indicating that the action mechanism of ABO is providing a water resistant inner coating.     

Effect of Risk Information Exposure on Consumers’ Responses to Foods with Insect Contamination

This study explores the impact that scientific information about insect contamination of food has on consumer perceptions. Participants (n = 320, Japanese consumers) were randomly assigned to 1 of 8 information‐type conditions: (1) information about insect type, (2) information about contamination processes, (3) information about the safety of contaminated food, (4, 5, 6) combinations of 2 of (1), (2), and (3) above, (7) all information, and (8) no‐information, and asked to rate their valuation, behavioral intention, and attitude toward food with insect contamination. Results demonstrated that some combinations of scientific information that include the safety of the contaminated food are effective to reduce consumers’ compulsive rejection of insect contamination in food, whereas the single presentation of information about insect type increases consumers’ explicit rejection of both the contaminated product and the manufacturer. These findings have implications for the coordination of risk communication strategies.     

SEMICONTINUOUS ETHANOL FERMENTATION WITH SHOCHU DISTILLERY WASTE*

An effective utilization system using distillery waste discharged from Japanese traditional shochu factory was developed. Mugi (barley) shochu distillery waste discharged from a novel vacuum distillation procedure (35–40°C) contained a large number of viable yeast (7 × 10⁶ cells/ml), glucoamylase activity (19.7 units/ml), acid protease activity (940 units/ml), and neutral protease activity (420 units/ml). Ethanol fermentation was achieved with a mash composed of glucose as the sola carbon source and mugi shochu distillery waste. After ethanol fermentation was completed the fermented broth was again distilled at 35–40°C in vacuo and the non volatile residue used in the next ethanol fermentation. In this way, semicontinuous ethanol fermentation system of more than 10 cycles was developed. Even in the distillate of the mash of the 8th fermentation cycle, 7.9% of ethanol, 33.0 ppm of ethyl acetate, 28.5 ppm of isobutyl alcohol, and other aromatic compounds were present. A semicontinuous ethanol fermentation system has been developed for shochu distillery waste which conventionally is treated as wastewater.     

鳄鱼皮制革工艺的研究

主要从鳄鱼皮的粒面特点、形态结构及应用等方面出发 ,充分考虑了制革过程中机械磨耗对鳄鱼皮的作用 ,加强了对化工材料的选择 ,同时在灰碱烧鳞、漂色、鞣制、复鞣、染色、加脂、整饰等几个技术关键进行了细致的研究 ,提出了制造高档鳄鱼皮革的制革工艺。