Removal of Lissamine Red From Wastewater Using Waste Materials

Feasibility of a waste material, flyash, as a material for purification of wastewater containing Lissamine Red has been studied. Effects of time and concentration, temperature and pH on the removal of the dye have been studied. Lower concentrations favour the uptake of dye from water and the maximum removal was observed at a dye concentration of 20 mgL m 1 , 30°C, pH of 7 and adsorbent particle size of 53 µm. Dynamics of the uptake was studied using Lagergren's equation. The mass transfer coefficient was found to be 0.05 cmmin m 1 at a concentration of 20 mgL m 1 , 30°C and 53 µm particle size.     

Stability of Polymer Electrolyte Membranes In Fuel Cells: Initial Attempts To Bridge Physical And Chemical Degradation Modes

In recent years, research on coupled degradation of Nafion^® membrane in polymer electrolyte fuel cell has generated huge interest among the scientific community. The coupled phenomenon behind the premature failure of fuel cell membranes in terms of its degradation is not well established. As the researches on this are in its adolescence, we try to provide some significant answers to the degradation phenomenon in terms of mechanically stimulated chemical degradation of the membrane. While the basic concept heavily relies on accurately modeling the membrane for its mechanical response to obtain molecular chain stretch, the results are utilized by the modified chemical rate equation for unzipping degradation mechanism. This article addresses significant degradation issues such as localized membrane thinning and pinhole formation, and inhomogeneous damage patterns in membrane electrode assembly in terms of mechanically induced accelerated chemical degradation of the membrane.     

Analysis of Leakages in a Solid Oxide Fuel Cell Stack in a System Environment

A solid oxide fuel cell (SOFC) stack can exhibit both anodic and cathodic leakages, i.e. a fuel leak from the anode side and an air leak from the cathode side of the stack, respectively. This study describes the results of an in‐situ leakage analysis conducted for a planar SOFC stack during 2000 hours of operation in an actual system environment. The leakages are quantified experimentally at nominal system operating conditions by conducting composition analysis and flow metering of gases for both fuel and air subsystems. Based on the calculated atomic hydrogen‐to‐carbon ratio of the fuel and air gases, it is found that the fuel leakages are mostly selective by nature: the leaking fuel gas does not have the same composition as the fuel system gas. A simple diffusive leakage model, based on the leakage being driven by concentration differences weighted by diffusion coefficients, is applied to quantify the amount of leakages. The leakage model provides a good correspondence with the experimental results of the gas analysis.     

A regression model for prediction of pipe conveyor belt contact forces on idler rolls

The paper presents design and verification of regression models for prediction of pipe conveyor belt contact forces on idler rolls. Their advantage is in the fact that they have been created according to the real experimental measurement. The obtained models correspond with real operational conditions. The concept of the experimental rig at the Technical University of Košice is designed so that it represents 8 m long section of pipe conveyor. The conveyor belt is an object with action of tension force and at the same time it takes the initiative in the contact force formation. Several criteria have been used to verify the presented regression models. The tensioning force 9000, 12,000 and 15,000 N have MPE of prediction error less than 5%. About 120,000 measured values have been processed during the evaluations which correspond to approximately 15,000 results from experimental measurements.     

海洋资源开发高级专门人才培养实验教学方法探索——以膜集成分离技术为例

专业实验是考查学生掌握理论知识程度及为本科毕业论文的开展奠定基础的一个重要实践教学环节。依托传统优势,着眼于学科交叉,在海洋技术专业实验中开设集成膜分离技术实验,是必要的和可行的。教学实践结果表明,集成膜分离技术实验有助于培养学生的能力,促进学生结合实际生产进行独立思维、团队协作和创新探索。     

11届化学实验技能竞赛的实践与思考

为了激发大学生重视和积极参与化学实验的热情和兴趣,培养大学生严谨的学习态度、科学的研究方法、认真细致的思维方式,掌握化学实验的基本技能,提高大学化学实验课堂教学质量,我校自2001年开始,每年开展一次化学实验技能竞赛活动,至今已举办了11届。竞赛不仅夯实了学生的实验操作技能,锻炼了学生创新意识和初步的科研能力,也促进了实验教学水平提高,为我校探索培养和提高大学生实验能力的思路、途径和方法等方面带来了有益的启示。     

除油型旋流器压降比特性试验研究

在室内试验装置上对单锥除油型水力旋流器的压降比特性进行了试验研究。研究结果表明 ,除油型旋流器压降比的主要影响因素有分流比、入口流量和溢流背压等操作参数 ;溢流背压对压降比的影响存在一“门槛值”。根据试验结果 ,建立了除油型水力旋流器压降比的半经验计算模型     

转化生长因子-β在骨髓间充质干细胞治疗实验性自身免疫性重症肌无力机制中的作用

目的探讨转化生长因子-β(TGF-β)在骨髓间充质干细胞(BMSCs)治疗实验性自身免疫性重症肌无力(EAMG)机制中的作用。方法分离培养健康Lewis大鼠BMSCs,并进行大量体外扩增;以大鼠来源的乙酰胆碱受体(R-AChR)2次免疫Lewis大鼠,建立EAMG模型;第2次免疫的同时,经尾静脉移植BMSCs,1×107个/只,依据Lennon评分标准,进行体重测量和临床体征评定。并通过体外实验进一步探讨TGF-β在治疗EAMG过程中的具体机制。结果BMSCs移植明显缓解了EAMG的临床症状,临床评分及体重变化差异均有统计学意义,表明治疗有效;体外实验结果显示,BMSCs能通过TGF-β的分泌影响AChR特异性Th17/Treg细胞亚群的分布及其相关因子的分泌,以anti-TGF-β抗体封闭后,这种调节作用在一定程度上被抑制。结论BMSCs通过细胞因子TGF-β,能在一定程度上调节AChR特异性Th17/Treg细胞亚群的平衡,从而起到治疗EAMG的作用。