Performance of PAHs emission from bituminous coal combustion

Carcinogenic and mutagenic polycyclic aromatic hydrocarbons (PAHs) generated in coal combustion have caused great environmental health concern. Seventeen PAHs (16 high priority PAHs recommended by USEPA plus Benzo[e]pyrene) present in five raw bituminous coals and released during bituminous coal combustion were studied. The effects of combustion temperature, gas atmosphere, and chlorine content of raw coal on PAHs formation were investigated. Two additives (copper and cupric oxide) were added when the coal was burned. The results indicated that significant quantities of PAHs were produced from incomplete combustion of coal pyrolysis products at high temperature, and that temperature is an important causative factor of PAHs formation. PAHs concentrations decrease with the increase of chlorine content in oxygen or in nitrogen atmosphere. Copper and cupric oxide additives can promote PAHs formation (especially the multi-ring PAHs) during coal combustion.     

The effect of network size on intra-network knowledge processes

This paper addresses a neglected topic in the knowledge management literature: how the size of a network of actors affects the nature of intra-network social relations and knowledge processes. It makes a theoretical contribution to developing understanding in this area drawing on a range of literatures including practice-based perspectives on knowledge, the literature on the embeddedness of social relations, and relevant knowledge management literature. The central focus of this paper is on the relationship between network size, network density, and how these variables affect intra-network knowledge processes. It suggests that as network size increases network density is likely to decrease (as it becomes problematic for the actors in such networks to retain strong ties with a significant proportion of the network's members), which it will be suggested has significant ramifications for intra-network knowledge processes. This paper concludes by reflecting on the implications of the ideas developed for network-based forms of organizing, and innovation processes.     

Association of Elevated Serum Lipoprotein(a), Inflammation,Oxidative Stress and Chronic Kidney Disease with Hypertension in Non-diabetes Hypertensive Patients

Hypertension is the most common cardiovascular risk factor. Lipoprotein(a) [Lp(a)], inflammation, oxidative stress and chronic kidney disease (CKD) exacerbate the response to tissue injury and acts as markers of the vascular disease, especially in glomerulosclerosis. We compared the clinical characteristics of 138 non-diabetes hypertensive women (ndHT) patients with 417 non-diabetes normotensive subjects and tested the association of hypertension with Lp(a), inflammation, CKD and oxidative stress by using multiple logistic regression. BP, BMI, waist circumference, creatinine, Lp(a), inflammation and malondialdehyde levels were significantly higher and CKD state in the ndHT patients (p < 0.05). Multiple logistic regression showed hypertension associated with increased Lp(a), inflammation, ORs and 95 % CIs were 2.52 (1.33, 4.80), 2.75 (1.44, 5.27) after adjusting for their covariates. Elevated serum Lp(a) and inflammation levels concomitants with increased oxidative stress and CKD were the major risk factors associated with hypertension and implications for the increased risk of HT and vascular disease.     

The effect of extremely high glucose concentrations on 21 routine chemistry and thyroid Abbott assays: interference study

Introduction

Extremely high glucose concentrations have been shown to interfere with creatinine assays especially with Jaffe method in peritoneal dialysate. Because diabetes is the fastest growing chronic disease in the world, laboratories study with varying glucose concentrations. We investigated whether different levels of glucose spiked in serum interfere with 21 routine chemistry and thyroid assays at glucose concentrations between 17-51 mmol/L.

Materials and methods

Baseline (group I) serum pool with glucose concentration of 5.55 (5.44-5.61) mmol/L was prepared from patient sera. Spiking with 20% dextrose solution, sample groups were obtained with glucose concentrations: 17.09, 34.52, and 50.95 mmol/L (group II, III, IV, respectively). Total of 21 biochemistry analytes and thyroid tests were studied on Abbott c8000 and i2000sr with commercial reagents. Bias from baseline value was checked statistically and clinically.

Results

Creatinine increased significantly by 8.74%, 31.66%, 55.31% at groups II, III, IV, respectively with P values of < 0.001. At the median glucose concentration of 50.95 mmol/L, calcium, albumin, chloride and FT4 biased significantly clinically (-0.85%, 1.63%, 0.65%, 7.4% with P values 0.138, 0.214, 0.004, < 0.001, respectively). Remaining assays were free of interference.

Conclusion

Among the numerous biochemical parameters studied, only a few parameters are affected by dramatically increased glucose concentration. The creatinine measurements obtained in human sera with the Jaffe alkaline method at high glucose concentrations should be interpreted with caution. Other tests that were affected with extremely high glucose concentrations were calcium, albumin, chloride and FT4, hence results should be taken into consideration in patients with poor diabetic control.Key words: assay interference, glucose interference, preanalytical phase, creatinine, Jaffe kinetic assay, thyroid function tests     

Critical factors influencing secondary school pupil’s decisions to study computing in tertiary education: Gender differences

This paper aims to determine the factors affecting the decisions of both male and female secondary school pupils whether or not to pursue undergraduate studies in Computing. It is based on research conducted in Greece, on a sample of 248 pupils, 135 of whom were female. All were aged 17 and about to decide on their future undergraduate studies. Questionnaires were used, addressing issues in the following four main categories: a) the reasons pupils chose/rejected Computing, b) how family and friends, the media and the school environment contribute to their decision, c) how pupils perceived their future after studying Computing and d) how pupils perceived the profile of a computer professional in terms of gender.

中学体育课堂教学中准备活动的新尝试

准备活动是体育教学过程中的重要组成部分,正确地认识准备活动的作用,合理地选择安排准备活动的形式、内容和时间,才能有效地提高体育教学的效果和教学质量,并且有利于学生学习和掌握体育基本知识、技术和技能。     

论债务危机背景下欧盟与“金砖四国”的双边经济关系

欧洲债务危机的爆发,使欧盟与＂金砖四国＂的双边贸易额迅速下降,影响了两区域间的贸易结合系数,特别是欧盟与中国的贸易结合度也大幅下降。但是,这对于＂金砖四国＂的一部分出口企业却是一个很好的市场机会,有利于它们打开欧洲内部的高端市场。而从欧盟与＂金砖四国＂的双边资本流动来看,债务危机令这两个区域得到的投资资金急剧下降,这不利于各自的经济增长。     

普洱市教育向周边三国辐射的战略研究

边境民族教育向周边国家的辐射不仅是＂国家较实力＂发展和构建和谐社会的需要,也是邻国的迫切需求,普洱市与缅甸、老挝、越南三国接壤,具有得天独厚的区位优势。在调查分析普洱市与周边三国教育现状及交流的基础上,提出了普洱市加快对外汉语推广的策略与思考。     

基于新课程的物理课堂教学评价体系的完善

对物理课堂教学评价进行理论分析,从课堂教学评价的含义、传统课堂教学评价存在的问题、新课程下课堂教学评价的理念、制定课堂教学评价体系的原则几方面进行了阐述,并结合新课程下中学物理教学特点制定了课堂教学综合评价体系表,尝试对中学物理课堂教学进行试评。