Comparison of two Analytical Methods (ELISA and LC-MS/MS) for Determination of Aflatoxin B1 in Corn and Aflatoxin M1 in Milk

The aim of this paper is to assess the closeness of agreement between results of ELISA and LC-MS/MS methods for determination of aflatoxin B₁ in corn and aflatoxin M₁ in milk. Samples of corn (n=100) and milk (n=250) were simultaneously analyzed using ELISA and LC-MS/MS methods, after the severe drought that affected Serbia in summer 2012 resulting in occurrence of aflatoxin B1 in corn and aflatoxin M₁ in milk. Regression analysis showed higher level of agreement between aflatoxin B₁ samples (R²=0.994), compared to aflatoxin M₁ samples (R²=0.920). However, both techniques were satisfactory in meeting the requirements for official control purposes.     

Antimicrobial residues survey by LC-MS in food-producing animals in Lebanon

ABSTRACT

The treatment of animals with antimicrobial products may lead to the contamination of edible tissues by their residues, which may represent a risk to human health. Therefore, this study aimed to determine the level of antimicrobial residues in food-producing animals (chicken, beef, and milk) in Lebanon. A total of 310 samples were collected and analysed using an LC-MS/MS for the determination of 48 compounds belonging to different families in order to map their compliance according to the European Commission decision 2002/657/EC. Results show that 60% of the analysed samples were not contaminated by any residue, while 12% presented a concentration higher than the MRLs for tetracyclines, sulphonamides, quinolones, and macrolides. Results revealed that chicken were the most contaminated by antimicrobial residues, when compared to beef and milk. The obtained results demonstrate the uncontrolled use of antimicrobials in some Lebanese farms and claim for better management of livestock.     

OTC药品的包装设计

结合儿童OTC(非处方药)药品的包装设计，分析了我国OTC药品包装设计的现状，讨论了OTC药品包装的设计思想及设计步骤。文章指出，在OTC药品包装设计时需要着重研究其设计理念、消费群体及消费定位问题。     

国内外催化裂化降硫助剂研究现状及展望

总结了国内外用于催化裂化装置的具有降低催化裂化汽油硫含量作用的助剂及其材料的研究状况,重点介绍了目前催化裂化过程中使用的降硫助剂的脱硫率及其对催化裂化产品分布的影响等.同时指出,采用高效降硫材料直接添加于催化裂化装置,既不影响裂化产品分布和质量,又能有效地降低催化裂化汽油硫含量,是未来降低汽油硫含量的一个有效途径.     

两两NQD列乘积和的Jamison型强稳定性的一个注记

讨论了不同分布两两NQD列的Jamison型加权乘积和的强稳定性。推广了不同分布独立列部分和和同分布NQD列部分和情形相类似的结论，得到了一些新的结果。     

柴油加氢装置设计和改造问题探讨

论述了产品质量指标的不确定性和产品质量指标越来越严格的趋势,认为柴油加氢新装置设计和老装置改造设计中,确定产品质量指标并根据此指标进行设计是非常必要的;新装置设计应考虑反应部分一步设计、分步实施的可行性,留有进一步脱芳烃和改质的余地;对老装置改造设计应根据其压力等级确定产品的质量目标.介绍了柴油加氢装置的典型流程、工艺流程的特点,对各加工方案工艺流程的选择原则、装置的设计要点进行了探讨.     

加快塑料技术中心建设提高新产品开发水平

对中国石油化工集团公司(简称中国石化)合成树脂生产及加工应用技术的现状进行了分析，指出中国石化应加快建设塑料加工应用技术中心，为塑料产品的加工用户提供高技术水平和快捷周到的技术服务，在合成树脂新产品开发和产品结构调整中发挥积极作用，以提高合成树脂产品的市场竞争力。     

阀门产品图形与数据的计算机管理

阀门产品具有种类、规格多，应用面广的特点。采用产品结构树形式作为系统数据存放结构，用VB套装数据、图形软件，Solidworks软件进行实体造型及参数化设计，3DMAX软件进行渲染、动画，采用ACCESS软件作为产品数据库。根据产品数据模式，建立一个实用的阀门图形与数据的计算机管理系统，帮助用户正确使用阀门产品，为计算机辅助设计提供支持。     

A new approach to modelling of single droplet drying

A model was developed to predict the change in droplet mass and temperature when it is exposed to hot air, as in spray drying of droplets containing solids. The droplet was assumed first to undergo sensible rapid heating with no mass change. Then the droplet experiences some shrinkage, with no temperature change but rapid mass losses, followed by a period of crust formation with a significant change in droplet mass and temperature and finally a short period of sensible heating of the dried particle. The model, unlike previous models, accounts for shrinkage and for the temperature distribution in the droplet. It provided a good prediction for the change in droplet temperature and mass for some of the experimental measurements available in the literatures.     

炼油厂成品油罐区调度优化问题研究

研究了以集合论为基础的调度优化模型。给出了该离散型优化问题的求解算法。根据优化结果，在G2实时智能平台上开发了包含监视子系统和调度子系统的调度支持系统。在中国石化股份有限公司长岭分公司的试用结果表明，该调度系统可以提高炼油厂的生产效率，从而提高炼油厂的经济效益。