Lactic acid production from dining‐hall food waste by Lactobacillus plantarum using response surface methodology

BACKGROUND: Food waste generally has a high starch content and is rich in nutritional compounds, including lipids and proteins. It therefore represents a potential renewable resource. In this study, dining‐hall food waste was used as a substrate for lactic acid production, and response surface methodology was employed to optimise the fermentation conditions. RESULTS: Lactic acid biosynthesis was significantly affected by the interaction of protease and temperature. Protease, temperature and CaCO₃ had significant linear effects on lactic acid production, while α‐amylase and yeast extract had insignificant effects. The optimal conditions were found to be an α‐amylase activity of 13.86 U g^?1 dried food waste, a protease activity of 2.12 U g^?1 dried food waste, a temperature of 29.31 °C and a CaCO₃ concentration of 62.67 g L^?1, which resulted in a maximum lactic acid concentration of 98.51 g L^?1 (88.75% yield). An increase in inoculum size would be appropriate for accelerating the depletion of initial soluble carbohydrate to enhance the efficiency of α‐amylase in dining‐hall food waste fermentation. CONCLUSION: A suitable regression model for lactic acid production was developed based on the experimental results. Dining‐hall food waste was found to be a good substrate for lactic acid fermentation with high product yield and without nutrient supplementation. Copyright © 2008 Society of Chemical Industry     

油气吸收回收系统的研究及工业应用——(Ⅱ)工业试验及效果分析

在油气吸收回收系统中型试验的基础上，开发了常温常压吸收法工业化油气回收系统，并进行了工业应用。结果表明，该油气回收系统平均回收率可达95．13％，每年可回收汽油529t；装车期间装车口周围环境大气中总烃浓度平均降低98．06％。企业通过实施油气回收系统，节能及经济效益明显，且很好地改善了装车场所的作业环境，克服了油气排放带来的安全隐患。     

Preparation and Characterization of Carboxymethyl Chitosan and β-Cyclodextrin Microspheres by Spray Drying

Three kinds of carboxymethyl chitosan/β-cyclodextrin microspheres loaded with theophylline were prepared by spray drying intended for pulmonary delivery. Mucociliotoxicity, permeation rate, and drug release characteristics of the product were investigated. The microspheres obtained by spray drying were found to be spherical with smooth or wrinkled surfaces. The mean particle size was between 3.39 and 6.06 µm. The microspheres demonstrated high product yield (43.7-50.2%), high drug loading (13.7-38.1%), and high encapsulation efficiency (86.9-92.8%). FT-IR indicated that there were interactions of theophylline with carboxymethyl chitosan matrix. Further studies on mucociliotoxicity and permeation confirmed that microspheres had better adaptability and high permeation rate. In vitro drug release from the microspheres was not related to the drug/polymer ratios.     

HSE管理体系认证审核的要点

企业所建立的HSE管理体系已运行多年,大多满足认证的条件,HSE体系认证是体系运行的重要环节,也是体系运行绩效的肯定。审核时要面对大量的体系文件和作业记录,因此把握住审核要点会起到事半功倍的效果。     

我国制造业国有企业的现状与发展

制造业国有企业在我国国民经济中具有非常重要的地位,其发展状况因所处地区、行业的不同而存在很大差别。从总体上看,制造业国有企业在投入产出能力、企业运营能力、盈利能力和偿债能力等方面都有待于提高。制造业中大型国有企业保持了良好增长态势。国家重点企业通过增加研究与开发投入,发展后劲显著增强。制造业中国有企业的数量在大幅度减少,其所占的比重持续下降,在制造业的不少小行业中,非国有企业已经取代了国有企业,成为行业中的主要力量。     

Stability analysis on single-phase natural circulation in Argonne lead loop facility

One-dimensional linear stability analysis was performed for single-phase lead–bismuth eutectic (LBE) natural circulation. The Nyquist criterion and a root search method were employed to find the linear stability boundary of both forward and backward circulations. It was found that the natural circulations could be linearly unstable in a high Reynolds number region. Increasing loop friction makes a forward circulation more stable, but destabilizes the corresponding backward circulation under the same heating/cooling conditions. The characteristic wavelength of an unstable disturbance is roughly equal to the entire loop length.     

关于传统与现代设计理念的思考

中国传统的思维方式深深地影响了中国传统陶瓷艺术设计，中国传统陶瓷艺术设计的历史脉络清晰，深入到设计思维系统的深层，才有助于我们对当前的陶瓷设计作出有效的转化。现代陶瓷设计的观念是对传统陶瓷文化的延续和发展，深入挖掘传统思维方式的源头活水，才是发展中国现代陶瓷设计的关键。     

LD泵浦Nd：YVO4内腔倍频激光器获得120mW绿光连续输出

利用半导体激光器（ＬＤ）端面泵浦Ｎｄ：ＹＶＯ＿４和用ＫＴＰ内腔倍频的绿激光器获得了１２０ｍＷ连续、稳定的５３２ｎｍ绿激光输出。泵浦阈值Ｐ＿（ｔｈ）＝１６０ｍＷ，光－光转换效率η＿ｓ＝８．１％。换用激光腔输出耦合镜，在不加ＫＴＰ晶体倍频时，可连续输出１．０６μｍ的红外激光，输出功率为４５０ｍＷ，光－光转换效率为３１％。     

关于约束方差控制器的评估问题的研究

本文研究当系统的性能指标表现为系统输入及输出的方差约束时一类随机控制器的评价问题，给出了系统反馈输入及输出的辨识算法，该算法可用来评价反馈控制器能否使反馈系统满足既定的方差约束，以便在对实际系统实施控制之前及时调整控制器，从而达到设计目的。