New hydrogels based on maleilated collagen with potential applications in tissue engineering

New hydrogels based on maleic anhydride (MA) modified collagen were prepared with the aim of overcoming the high degradation rate displayed by collagen that is not otherwise chemically crosslinked. Semi-interpenetrated matrices were obtained by free radical polymerization of maleilated collagen (CM) and 2-hydroxyethyl methacrylate (HEMA) in the presence of ammonium persulfate (APS) and N,N,N′,N′-tetramethylethylenediamine (TEMED) as initiating system. The resulting matrices (CMH) had a sharp decrease in degradation, when compared to pure collagen. FTIR and H¹ NMR spectroscopies were used to confirm the incorporation of MA on the collagen peptide chains. The final composition of CMH was found to be strongly dependent by the concentration of maleilated collagen. The morphology of the hydrogels was studied by Scanning electron microscopy (SEM) and the macro-gel structure was confirmed. Water uptake of the synthetised hydrogels is influenced by both composition and the porosity of the matrices.     

Enhanced colliding bodies optimization for design problems with continuous and discrete variables

Colliding Bodies Optimization (CBO) is a new multi-agent algorithm inspired by a collision between two objects in one-dimension. Each agent is modeled as a body with a specified mass and velocity. A collision occurs between pairs of objects and the new positions of the colliding bodies are updated based on the collision laws. In this paper, Enhanced Colliding Bodies Optimization (ECBO) which uses memory to save some best solutions is developed. In addition, a mechanism is utilized to escape from local optima. The performance of the proposed algorithm is compared to those of standard CBO and some optimization techniques on some benchmark mathematical functions and three standard discrete and continuous structural design problems. Optimization results confirm the validity of the proposed approach.     

浅谈CORBA体系在软件系统集成中的应用

本文介绍了CORBA体系的一些基本知识，着重谈到它针对于在软件系统集成过程中出现的三方通信问题的应用，最后通过一个实例来说明整个设计思路和流程.     

含油饱和度的评价和监测方法

美国KernRiver油田为了用COR测井资料监测和确定含油饱和度 ,对从测井数据采集到资料处理过程中的多个技术环节进行了改进 ,提高了COR测井资料的准确度和精确度 ,形成了一套别具特色的含油饱和度评价和监测方法     

X. Yeast sequencing reports. Revised nucleotide sequence of the cor region of yeast Saccharomyces cerevisiae chromosome X

The COR region, a gene cluster located on chromosome X of Saccharomyces cerevisiae and including genes CYC1, UTR1, UTR3, OSM1, tRNA^Gly and RAD7, was sequenced within the framework of the European Union genome systematic sequencing project. It was compared with previously published sequences to be found in GenBank under the acronym YSCCORA. While some of the discrepancies observed can be readily ascribed to polymorphism, others most probably result from sequencing errors. A revised version of the sequence of the COR cluster is given. The sequence has been deposited in the EMBL Data Library under Accession Number L26347.     

Impact of carbon monoxide on PEFC catalyst carbon support degradation under current-cycled operating conditions

It is well known that, even at ppm levels, the presence of CO in a PEFC anode feed stream has a significant impact on the MEA performance. Numerous work on short-term CO impact on PEFC performance under steady-state current demands has been carried out. However, to the best of our knowledge, the impact of long-term (i.e., >600 h) CO contamination on intrinsic Pt and C support aging (Pt oxidation/dissolution/ripening, C oxidation, …) under current-cycled operating conditions has never been explored. In this paper, on the basis of a combined theoretical and experimental approach, we investigate the long-term CO effect on PEFC performance and degradation. Firstly, on the basis of our previously published PEFC materials degradation models, we suggest that anodic CO poisoning could be used to mitigate the cathodic carbon catalyst-support corrosion phenomena and thus to enhance the MEA durability. Secondly, endurance experiments are performed on single fuel cells with current-cycled protocols representative of transport applications. The impact of CO on electrochemical transient response shows a reasonable agreement with simulated behaviors, and it is experimentally demonstrated that the impact of CO on the cell potential degradation rate is strongly dependent on the current-cycle mode.     

基于CORBA的UML到C++正向转换研究

该文通过对分布式对象技术和CORBA机制、UML可视化建模语言的分析,进行了UML/IDL/C++的正向转换,提供给用户一个包括面向对象建模,生成IDL,形成实际C++代码几步工作在一起的CASE工具。让用户能够方便有效地采用UML建模,并使用CORBA这种软件总线技术来开发C++程序,进而得到需要的CORBA组件。     

采集数据在EPSW98中自动绘图的程序设计

运用Visual Basic 6.0程序开发语言,编程处理全站仪野外采集数据,在EPSW98中自动展绘地物独立符号,同一地物测点自动连线构成图形,野外无需绘制草图,拓展了软件的使用功能,以节约人力物力,提高作业效率。     

Enhancement the solar box cooker performance using steel fibers

The use of fossil fuel and wood for cooking poses health, environmental, and economic challenges, especially with the growing population. This has led to an increase in the trend towards the use of clean and sustainable cooking sources, including solar cookers. This experimental study aims to contribute by enhancing the performance of a solar box cooker (SBC) according to the concept of porous media via adding steel fibers inside the box as a modified SBC and comparing it with a conventional SBC. The stagnation test to determine the first figure of merit and the load test to determine the second figure of merit, standard boiling time, and cooker optothermal ratio were conducted under the outdoor conditions of Baghdad city. Also, an energy and exergy efficiency analysis, and calculating the rate of heat loss by three water loads heating and cooling tests. The results revealed that the modified SBC has a higher thermal performance than the conventional SBC.     

IFM国际能力验证之变压器电阻法的测量

该文主要介绍IFM能力验证中线性变压器绕组温升测量的电阻法的测量方法,以及在对比测试中的注意事项和相关要求。