天津郊区部分蔬菜地土壤中多环芳烃的污染状况分析

用高压液相色谱法分析了天津市4个郊区菜地中16种多环芳烃（PAHs）的分布，结果表明，菜地土壤中PAHs最大为4105μg／kg，最小为1317μg／kg，绝大部分土壤样品中的∑PAHs含量在2000μg／kg以上．津南、西青两区污染较轻，东丽、北辰两区污染则比较严重。     

磁力传动离心式植物油泵设计研究

植物油厂用泵现场使用表明，大部分泵的失效是由于密封泄漏引起的。文中提出采用磁力传动泵来解决这一问题，并在已有磁力泵的基础上，做了结构上的改进。轴不旋转，内磁钢体与叶轮后盖板直接相连，减少了叶轮后盖板和内磁钢体前端面这两个端面与液体间的圆盘摩擦损失；泵轴不传递扭矩，为轴材料选择和加工提供了方便。     

玉米变性淀粉压裂液稠化剂的研制

对玉米淀粉经化学和物理变性制得变性淀粉。将该变性淀粉与少量植物胶XDF复配制成压裂液稠化剂。并对该稠化剂的理化性能、用量、复配比例以及压裂液的配方、性能和影响凝胶的因素进行了研究。结果表明:用该稠化剂配成的压裂液粘度高、流变性好、摩擦阻力小、易破胶、低残渣、低伤害,是一种适用于80℃以下低温的优良压裂液。     

Psychological and Social Predictors of Changes in Fruit and Vegetable Consumption Over 12 Months Following Behavioral and Nutrition Education Counseling.

This study assessed psychological and social factors predicting 12-month changes in fruit and vegetable consumption achieved by 271 men and women from a low-income population randomized to brief behavioral and nutrition education counseling. Greater increases in fruit and vegetable intake were achieved in the behavioral than in the nutrition education condition (1.49 vs. 0.87 portions per day, p=.021). Increases were predicted by baseline social support for dietary change but not by baseline psychological measures. However, short-term (8-week) changes in dietary self-efficacy, encouragement, anticipated regret, perceived benefits, and knowledge of recommended intake predicted 12-month changes in fruit and vegetable consumption independently of gender, age, ethnicity, income, and baseline intake. These factors accounted for 51% of the superiority of behavioral counseling over nutrition education. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of size and autoclavation of fruit and vegetable wastes on biohydrogen production by dark dry anaerobic fermentation under mesophilic condition

Fermentative hydrogen production from fruit and vegetable wastes (FVWs) through Dry Fermentation Technology (DFT) was studied through three independent experiments in order to find out the effect of particle size and autoclaving pretreatment on bio-hydrogen production from FVWs and as follows: (1) autoclaved FVWs with sizes < 5 cm (experiment I); (2) raw FVWs with sizes < 5 cm (experiment II) and (3) autoclaved FVWs with sizes > 5 cm (experiment III). The assay with autoclaved waste yielded a higher percentage of hydrogen in the headspace of the dry fermenter reaching a maximum value of 44% in experiment I. However, the maximum hydrogen production was obtained in experiment III with 14573 NmL at a yield of 23.53 NmL H₂/gVS. Profiling of the microbial communities by denaturing gradient gel electrophoresis (DGGE) indicated that the most prominent species were the genera Clostridium, Bifidobacterium, and Lactobacillus.     

Effect of straight vegetable oil blends and biodiesel blends on wear of mechanical fuel injection equipment of a constant speed diesel engine

Vegetable oils and biodiesel have emerged as strong alternative fuels worldwide. However use of new fuels in existing engines leads to issues such as wear of vital moving components, and fuel injection equipment (FIE). It is important to ensure that new alternative fuel does not affect the FIE adversely. In this experimental study, a non-firing engine FIE simulator test rig prototype was developed and 250 h endurance test of FIE was performed with an objective to ensure the long-term compatibility and durability of biofuel blends. The components of FIE such as plunger, nozzle needle, valve, and valve holder were investigated for wear. Test fuels used in this study were Karanja blends (K20, K5), Jatropha blends (J20, J5), Biodiesel blends (B20, B5) and baseline mineral diesel in a non-firing engine FIE simulator. The compatibility of FIE with test fuels in terms of dimensional loss, weight loss and surface texture variations using optical microscopy before and after the endurance test was compared. Biodiesel blends showed relatively lower wear compared to mineral diesel however SVO blends showed no definite trend of the wear results compared to baseline mineral diesel.     

Preparation of pressure-sensitive adhesives from tung oil via Diels-Alder reaction

In this study, tung oil was polymerized with a dimaleimide (4,4’-methylene-bis(N-phenylmaleimide) (MPMI) and two diacrylates (poly(propylene glycol) diacrylate (PPGDA) and bisphenol A glycerolate diacrylate (BPAGDA) via Diels-Alder reaction (DA reaction) to prepare pressure-sensitive adhesives (PSAs). On the one hand, the polymer of tung oil and MPMI was readily prepared however it was too rigid to serve as a PSA. On the other hand, the polymerization of tung oil with PPGDA or BPAGDA resulted in PSAs with peel strengths ranging from 0.1 to 0.2 N cm⁻¹ and loop tacks ranging from 0.4 to 0.5 N. Nevertheless, tung oil reacted readily with acrylic acid to form adducts (TOAA) with lower content of conjugated diene groups than those of tung oil. The use of TOAAs instead of tung oil to polymerize PPGDA failed to increase the peel strength of the resulting PSAs. However, polymerizations of TOAAs with BPAGDA resulted in PSAs with much higher peel strengths and much higher loop tacks than the polymerization of tung oil with BPAGDA. In addition, the introduction of a small amount of MPMI in the polymerization of TOAA and PPGDA significantly shortened the curing time.