Engineering
关键词: 检索项: 二级学科:
 
排列规则 出版时间倒序 出版时间顺序 引用次数 期刊影响因子
 
 Biogass emission prognosis at the landfills
作者  Bicheldey, T.K. & Latushkina, E.
作者单位  
期刊  International Journal of Environment Science and Technology 卷期  Vol. 7, No. 4, 2010 时间  2011.01.17
关键词  Air pollution; Atmosphere; Carbon dioxide; Methane; Solid waste
摘要   The present study aims to estimate biogas potential of two Russian landfills situated in the republic of Tatarstan and in Moscow Region. Due to environmental, economic, social and energetic consideration of biogas for human being, utilization of such a by-product would be of high concern. To date, there are seven biogas utilization projects which have been developed and implemented at municipal solid waste landfills of Russia. The purpose of the research was to determine the biogas potential at the closed landfills. During the studies held in 2008; sampling, transportation, storage of biogas and landfill soil samples, laboratory investigations; physicochemical and analytical methods for measuring of proteins, carbohydrates and fats in the organic part of the soil and the analysis of empirical data by the methods of computer modeling and mathematical statistics were carried out. The obtained results of the research; concentrations of biogas components: methane, carbon dioxide, carbon oxide, nitrogen, hydrogen and oxygen, gas flows, composition of the organic part of the fields and analysis of gas distribution on the surface of the landfills; has shown scientific and practical importance. Results could be used for the assessment of biogas potential at the landfills for further biogas utilization projects implementation with electrical or thermal energy production.
 Computer Simulation System of Stretch Reducing Mill
作者  
作者单位  
期刊  Acta Metallurgica Sinica(English Letters) 卷期  2007, 20(6 时间  2011.01.10
关键词  simulation,tube,stretch reducing mill (SRM),
摘要  
 APPLICATION OF COMPUTER GRAPHICS IN MARTENSITIC TRANSFORMATION
作者  
作者单位  
期刊  Acta Metallurgica Sinica(English Letters) 卷期  1994, 7(2 时间  2011.01.10
关键词  stereograpllic projection, martensitic transformation, computer graphics,
摘要  
 新型长波红外折衍混合消热差系统
作者  郜洪云 Hong-yun GAO
作者单位  
期刊  光子学报 卷期  2010, 39(12 时间  2010.12.25
关键词  光学设计,消热差设计,折衍混合系统,红外光学系统
摘要   为了提高大靶面高分辨率光学系统的性能,本文基于衍射元件独特的温度特性以及热补偿理论,设计了工作波段为8~12um、视场角为16°、F/#为1.9、后工作距为133mm的新型折衍混合消热差系统。系统采用三片式结构,使用锗和硒化锌两种常用的红外材料,仅引入一个二次非球面和一个衍射面,使系统具有结构简单、体积小、重量轻、成本低等优点。结果表明:系统在较大视场内成像质量接近衍射极限,且在-30℃~70℃温度范围内性能稳定,适用于像元尺寸35um,像元数640×480的现代非制冷型焦平面阵列探测器,实现了消热差设计。
 集成式双线阵立体测绘相机光学系统设计
作者  姚罡
作者单位  
期刊  光子学报 卷期  2010, 39(12 时间  2010.12.25
关键词  双线阵CCD相机
摘要   针对双线阵立体测绘相机光学系统设计指标的要求,设计了一种三反离轴光学系统,并针对该光学系统的特点,对像质进行了分析。光学系统设计传递函数在0.6左右(在50lp/mm处),相对畸变小于3×10-4,校正绝对畸变小于20μm ,相机在成像质量方面达到立体测绘的要求。同时,为了使相机在体积尺寸小、结构紧凑及轻量化等方面满足卫星平台的要求,采用了一种新型的光学系统布局,在减小双线阵立体测绘相机的体积、材料及减轻重量等方面,具有独特的优势;光学系统可以安装在同一机械结构体内,以利于采取有效的热控措施,将主镜以一定的交会角在同一基准上支撑、装调,所以它具有尺寸稳定性好,温度敏感度低等优点。
 五层对称人工超常材料结构的表面等离子体激元
作者  张惠芳1,赵玉静2,陶峰2,任海红2,王燕2,白丽华2,戴晔2,阎晓娜1
作者单位  
期刊  光子学报 卷期  2010, 39(12 时间  2010.12.25
关键词  人工超常材料
摘要   研究由左手材料、负介电材料、常规介电材料所构成的几种五层对称结构表面等离子体激元的特性。详细讨论表面等离子体激元的存在区域、色散关系、以及p和s偏振的表面色散曲线枝,发现表面模的性质强烈依赖于系统的组成材料及其组合方式。此外,通过使用衰减全反射方法,探讨激发并观察表面等离子体激元的可能性.
 Community Awareness and Preferences on Health Financing Options: The Case of Songea Rural District,
作者  Hussein, Asia K;Mlangwa, MN & Hussein, KN
作者单位  
期刊  East African Journal of Public Health 卷期  Vol. 2, No. 2, 2005 时间  2010.12.20
关键词  Health care financing, community awareness, community preferences, Tanzania
摘要   Objectives:The objectives of this study were to assess community awareness and preferences on the alternative health financing mechanisms that have been introduced in the district. Design:A cross sectional, household survey Setting:Songea Rural District, Ruvuma Region South Western Tanzania Methods:Multistage random sampling procedure was used to select 6 villages that were included in the study. A total of 622 heads of households or their representatives were interviewed using an interviewer administered questionnaire. Computer data entry and analysis were done using EPI Info version 6.0 software programme. Results:Community awareness on the Community Health Fund (CHF) and User Fees were high i.e. 94.9% and 93.2% respectively, while awareness on National Health Insurance Scheme (NHIS) was relatively low at 34.6%. Most of the respondents used User Fees (81.4%) in financing their health care consumption and it was also the most preferred health financing mechanism (38.4%) followed by CHF (30.5%), however almost a fifth of the respondents, the majority of whom were peasants (95.0%) preferred getting "free care". Recommendations:Study recommendations include increasing community awareness on NHIS and ensuring proper identification of individuals who should be given fee waivers/ exemptions.
 Epidemiology of Measles in Tanzania: A Hospital-Based Survey of Measles Morbidity and Mortality
作者  Mnyika, Kagoma S & Akim, Caroline
作者单位  
期刊  East African Journal of Public Health 卷期  Vol. 2, No. 2, 2005 时间  2010.12.20
关键词  
摘要   Objective:To estimate measles morbidity and mortality in selected regions on mainland Tanzania Design:Cross-sectional study Setting:Hospital-based review of existing records on measles morbidity and mortality in the selected district hospitals on mainland Tanzania. Methods:Review of records on measles morbidity and mortality was performed using a standard instrument adopted from the Ministry of Health. The instrument was pre-tested before use. Researchers were recruited from the Muhimbili University College of Health Sciences and were trained on how to collect data from the hospital records. Ethical clearance was obtained from the Ministry of Health in Dar es Salaam. Upon arrival in the respective regions, the researchers recruited and trained local research assistants on methods of data collection. Completed questionnaire forms were entered into a computer and data cleaning was done before data analysis. Results:Measles was found to occur in individuals of over 15 years of age and beyond. Overall 35% (N=2277) of all measles cases were reported from the Iringa region while Mara region had the lowest number of cases. On the other hand Shinyanga had the highest case fatality rate (6%) compared with other regions. Mortality was higher in children below two years of age and among individuals who had no history of measles vaccination. Conclusion:We conclude that despite high measles vaccination coverage, measles is still a public health problem in Tanzania. Efforts should be made to give several booster doses up to the age of 15 years.
 A Stepwise Regression Analysis on Under-five Diarrhoael Morbidity Prevalence in Nekemte Town, Wester
作者  Eshete, Wondwossen Birke
作者单位  
期刊  East African Journal of Public Health 卷期  Vol. 5, No. 3, 2008 时间  2010.11.20
关键词  Diarrhoea morbidity, Maternal care giving behaviors, Hygiene behaviors, Prevalence, and Under-five children
摘要   Objective:Various studies have addressed the relationship between maternal care giving behaviours including hygiene behaviours and the occurrence of diarrhoea in children. However, very few studies have done in Ethiopia in general and none exist in Nekemte town, western Ethiopia. Therefore, the present study aimed to estimate the prevalence of under-five diarrhoea morbidity in relation to mothers/care takers behaviours including hygiene behavioural determinants. Methods:Community-based cross-sectional study was conducted in Nekemte town, western Ethiopia from October 15- November 26, 2007. 477 mothers/ care takers of index under-five children living in the households selected randomly from sub cities in the town formed the study population. Structured and pre-tested questionnaire was used to collect data. The data were entered into a computer, edited and analyzed using SPSS for windows version 12.01. Stepwise logistic regression model was used to calculate the Odds ratios and 95% confidence interval for the different risk factors was considered. Results:From 477, 461 were participated in the study giving a response rate of 96.6%. The mean ages of the respondents and the index children were about 32.4 (+8.8 SD) years and 25.27(+15.16 SD) months respectively. Diarrhoea morbidity prevalence over a period of two weeks preceding the study was about 28.9%. Although several maternal cares giving and hygiene-related risk factors showed significant association with diarrhoea morbidity on bivariate analysis, the use of cover material during drinking water transportation, faeces seen around the pit-hole and bottle feeding were the only significant variables on multivariate analysis. Conclusion:As diarrhoea morbidity was major problem among under-five children in Nekemte town, appropriate intervention programmes should be formulated focused on identified risk factors.
 KNOWLEDGE, ATTITUDE AND ACCEPTABILITY OF SPERMICIDAL CONTRACEPTION AMONG UNIVERSITY STUDENTS IN DAR
作者  Mwambete, Kennedy D. & Mogasa, C.
作者单位  
期刊  East African Journal of Public Health 卷期  Vol. 4, No. 1, 2007 时间  2010.11.20
关键词  knowledge, attitude, acceptability, spermicides/microbicides and contraception
摘要   Objectives:The aim of this study was to assess the knowledge, acceptability and attitude towards the use of spermicides among students of University of Dar es Salaam (UDSM). Methodology:This was a descriptive cross-sectional study conducted over four-month period among UDSM students. A random sample of students was recruited from all three university campus namely University College of Land and Architectural Studies (UCLAS), Muhimbili University College of Health Sciences (MUCHS) and Mlimani Campus (MC). Questionnaires with both closed and open end-questions were used for data collection in which knowledge, attitude, and acceptability of spermicides were determined. The collected data were analyzed using SPSS/PC+ version 10.0, 1999 computer package. Results:A total of 300 students participated in this study, out of which 154 (51.3%) were females and 146 (48.7%) males. Majority of the students 276 (92%) had poor knowledge of spermicidal products, and out of these, 146 (53%) were absolutely unable to describe the use of spermicides. Ninety-three percent of the students had never used spermicides. Of those who had never used spermicides, 84 (30%) said because they used other contraceptive means, 50 (17.8%) said they are expensive, 29 (10.3%) attributed this to unavailability of the products, 3(1.1%) to fear of "contracting" cancer and 13(4.6%) to the unreliability. Furthermore, a few who had used them didn’t trust the products as ideal means of contraception. Conclusion:The respondents had poor knowledge of spermicides. Spermicides were not accepted by the students because of the presumed side-effects, being very expensive and unreliable for contraception purpose. However, the respondents accepted spermicides usage as an ideal alternative to condom and effective means for a female-controlled method to prevent/reduce unwanted pregnancy and HIV risk. The study recommends that the Government/responsible authorities should encourage spermicides usage, particularly when coupled with microbicides, in reduction of unplanned pregnancies, sexually transmitted diseases (STDs) and HIV infection inclusive.
当前页数:1/总页数:838|首页上一页   下一页 尾页
OPEN ACCESS搜索平台-中国科技论文在线
中国科技论文在线 版权所有
在线首页 | 在线简介 | 服务条款 | 联系我们 | 京ICP备05083805号 | 文保网安备案号:1101080066
主管:中华人民共和国教育部 主办:教育部科技发展中心 技术支持:赛尔网络有限公司