Heat loss analysis: An approach toward the revival of parabolic dish type solar cooker

Present work investigates a noble approach toward the heat loss analysis of parabolic dish type solar cooker. Various experiments have been done on cooking pot to get the input parameter for calculation purposes. Cooking pot was kept at the focus of a parabolic dish type concentrator and repeated experiments have been done to measure solar radiation intensity (direct and Indirect) using a pyrometer, temperature at the focus of parabolic dish using a thermocouple and air velocity using hot wire anemometer to investigate the heat losses from the cooking pot. In the present article, a numerical approach has been performed to define the new parameter called performance index of the cooking pot which decides how the useful energy of working fluid inside the cooking pot approaches concentration ratio of the parabolic dish type solar cooker. The present analysis shows that the performance index varies from 15.45 to 17.66 and efficiency varies from 85.83% to 98.10% with the time of the day.     

Enhancing biomass energy use in Kenya

This paper argues that in Kenya, environmental and economic factors will favour the continued use of biomass as a primary fuel for household and institutional cooking for the next decade or longer. The paper describes several successful projects which have improved the efficiency of urban charcoal use and of rural woodfuel use. The Kenya Ceramic Jiko, a more efficient version of the traditional charcoal stove, is a model programme sustained by free market competition, artisans participation, and widespread public acceptance. The Maendeleo stove is the best example of a successful rural woodstove project. The performance attributes of the stove, and its promotion through Kenya's largest women's organization, have resulted in the distribution of an estimated 26 000 Maendeleo stoves. Rural stove efficiency will become important as the cash-based economy expands in those areas. Agroforestry will also be critical to an enhanced use of biomass energy in Kenya. Experience to date shows that successful agroforestry programmes will have to be appropriate to local conditions and crops .     

面向管理的海洋修复工程生态绩效考核指标体系构建研究

目前国内关于海洋修复工程的考核研究多为修复工程的生态效果考核,极少包含成本效益考核,以致无法比较和分析不同类型、不同规模的海洋修复工程的生态绩效,不利于海洋修复工程的考核和验收管理。根据当前自然资源部实施“蓝色海湾”等整治修复工程的检查验收管理的新需求,本文构建了基于海洋生态系统健康恢复、生态系统服务价值增长和单位成本生态效益等理论的海洋修复工程生态绩效考核指标体系。此外,本文以温州海域2014—2016年海洋修复的生态绩效的考核为例,结合考核结果以及直接相关性、独立性、可测量性和业务化等指标选取原则,对指标体系进行了改进。结果表明本指标体系可以在海洋修复工程的检查验收中被用于生态绩效考核,管理部门可根据海洋修复工程的类型和管理需求,有选择性地采纳部分或全部指标进行考核。     

Applying Integrated Urban Water Management Concepts: A Review of Australian Experience

This article explores recent Australian experiences in the application of the concept of integrated urban water management (IUWM) to land development sites through the review of 15 case studies. It discusses lUWM’s emergence and comments on the success or otherwise of Australian experience in its application. The understanding of IUWM is maturing within the Australian water industry, an occurrence that has been facilitated by demonstration sites such as those reviewed. Successes include the translation of IUWM concepts into well-functioning operational urban developments, significant reductions in the impact of the urban developments on the total water cycle, and the increasing acceptance of the concept within the water and land development industries. However, there is still room for greater integration of the water supply, stormwater, and wastewater components of the urban water cycle, improved dissemination of knowledge, enhancement of skills in both public and private organisations, and monitoring the performance of systems and technologies.     

A comprehensive review of the energy efficiency on nano coated fin and tube condenser

The condenser is a piece of equipment used to effectively transfer heat from water to the environment. The fin and tube condenser is the most commonly used in commercial applications. The improved performance of heat transfer in the fin and tube condenser is a significant area of study all over the world because optimizing the efficiency of heat transfer in the condenser will contribute to enhancing the effectiveness of system performance. The vapor deposition, plasma spray, and thermal spray techniques are being used, and it is determined that a heat transfer enhancing coating improves condenser performance. This review discusses the nanomaterial coating over the fin and tube condenser in detail. The various nanomaterial coatings with various propositions and coating methods had been discussed with the evidence of previous researchers. At a 50-degree inclination angle on the condensate plate, the condensate over the coating surface increases by more than 30%. The thermal properties of the working fluid are improved over the condenser, and the overall effectiveness of the condenser is increased by approximately 40% over the non-coated condenser. A 1% volumetric concentration of Nanoparticles in the coated material achieves a maximum efficiency increase of 78.7%.     

HB6783、GB/T5170在温湿度试验箱性能指标验收中的应用

本文简要介绍了环境与可靠性试验领域试验设备系列检定标准HB 6783、GB/T 5170。以本单位某型温湿度试验箱验收为例,详细介绍了HB 6783、GB/T 5170系列温湿度试验设备检定/检验标准在温湿度试验箱性能指标验收中的应用,通过对比应用总结,指出综合比较不同检定标准中温湿度性能指标的检定项目、方法,结合本单位产品试验需求应用,是制定温湿度试验箱性能指标验收方法的最佳途径。     

Creativity enhancement through flotation isolation

Research over the last 25 years on the contribution of aloneness to creativity enhancement has had mixed results. Early studies of sensory deprivation generally found negative effects while more recent research on flotation isolation has reported positive influence. Sports performance, for example, has been improved by means of directed imagery and flotation aloneness. However, there has been only one study which has attempted to enhance creativity through the flotation method and while this study reported positive results, it lacked several control features and was based on a very small sample of highly selected subjects.The present study was designed to evaluate directly the potential contribution of floating to creativity enhancement as measured by the Guilford fluency test and other measures. Subjects were male and female university students, half of whom spent one hour in a float environment and the other half in a darkened room. Each was tested before and after experimental trial on the Guilford and other creativity measures and on two personality/affect scales. Float subjects showed significant increases on the Guilford test from the pre- to post-float and meaningful increases on other thinking measures as compared to non-floating control subjects. Floating was associated with a decrease in anxiety/tension, depression, hostility, and fatigue, but with an increase in vigor and a maintenance of curiosity scores, and it is speculated that the creativity benefits may be a result of these state changes.     

Three-dimensional numerical modeling and characterization of two-stage and multilayer thermoelectric couples

The two-stage thermoelectric couple (TE couple) and the multilayer TE couple are proposed and their output performance is compared with the conventional TE couple in this paper. Three dimensional (3-D) numerical and finite element models are established for these three types of TE couples which are analyzed in the ANSYS Workbench environment. Simulation results show that the output voltage and the current of the two newly designed TE couples increase in a certain extent than those of the conventional device before the load resistance reaches a critical value, however, the multilayer TE couple has the best performance. Similar conclusions can be drawn from the results of comparisons with the maximum output power and the maximum heat conversion efficiency between different types of TE couples. When thicknesses of the intermediate ceramic substrate and the intermediate copper conductor change, the output performance of the two newly-designed types of TE couples can be improved further. The maximum output power and the maximum heat conversion efficiency of the multilayer TE couple increase by 71.15% and 14.87%, respectively, when compared with those for the conventional device under certain conditions. Therefore, the multilayer TE couple has the potential to be one of the future development directions of TE couple structures.     

Review of socio-economic drivers of community acceptance and adoption of decentralised water systems

The aim of this paper is to highlight key social and economic drivers crucial to understanding community acceptance and adoption of decentralised water systems. The review focused on social science literature pertaining to alternative forms of household water, with an emphasis on research examining decentralised water acceptance. Researchers consistently reported that most communities were open to alternative water sources for domestic applications; however, this was highly dependent upon the level of personal contact with the water. Acceptance and adoption of alternative water technology, such as decentralised systems, was influenced by risk perception, water culture, and threat perception. Motivational drivers were also identified as potentially influencing adoption of decentralised systems. A clear limitation of the literature was found to be an over-reliance on measuring people's intentions to adopt alternative water systems and building a conceptual understanding of acceptance solely on hypothetical water supply scenarios. Further, within the social science literature there appears to be a skewing towards focusing on acceptance of centralised alternative water, such as recycled and desalinated water systems. Although there are some research outcomes that are generalizable to the decentralised water context, it is clear that there is a significant gap in the knowledge base of social drivers specific to the acceptance of decentralised water systems and the factors contributing to its widespread use. It is recommended that future research focus on examining public attitudes relevant to decentralised water systems, as well as adoption behaviours among current users of these systems. This will assist in developing policies specific to domestic decentralised water use.     

Different Shades of Green: A Case Study of Support for Wind Farms in the Rural Midwest

Benton County, in north-central Indiana, USA has successfully sited more than 500 turbines. To understand Benton County’s acceptance of wind farms, a holistic case study was conducted that included a document review, a survey of local residents and interviews with key stakeholders. Survey questionnaires were sent to 750 residents asking questions about attitudes toward the wind farms, perceived benefits and impacts from the wind farms, environmental attitudes, and demographic information. Key stakeholders were also interviewed for a deeper understanding of the historical timeline and community acceptance of the wind farm development. While there is limited opposition to the turbines, on the whole the community presents a front of acceptance. Financial, rather than environmental, benefits are the main reason for the acceptance. Although significant in other case studies, transparency and participation do not play a large role in Benton County’s acceptance. Most residents are not concerned with either visual impacts or noise from the wind turbines. More concrete benefits to the community, such as reduced energy bills for county residents, could help to extend acceptance even further within the community. Although there are concerns about the acceptance of wind farms and the impacts of those farms on local residents in both peer-reviewed literature and popular media, we found little evidence of those concerns in Benton County. Instead, we found Benton County to be a community largely accepting of wind farms.     

A solar hybrid thermoelectric generator and distillation system

A solar still of a single basin-slope coupled with a finned condensing chamber and installed thermoelectric modules at the bottom of the water basin has been presented in this paper. A mathematical model under steady state conditions has been introduced and improved to investigate the system performance. An increase of solar radiation and ambient temperature or a decrease in wind velocity affect positively the distillation rate, the still efficiency, and the system efficiency. Integrating a condenser and finned condenser increases the distillation rate of the proposed system. The results of the simulation have been verified by comparing them with published theoretical and experimental results, and the comparison shows very good agreement.     

Factors affecting alkalinity generation by successive alkalinity-producing systems: regression analysis

Use of successive alkalinity-producing systems (SAPS) for treatment of acidic mine drainage (AMD) has grown in recent years. However, inconsistent performance has hampered widespread acceptance of this technology. This research was conducted to determine the influence of system design and influent AMD chemistry on net alkalinity generation by SAPS. Monthly observations were obtained from eight SAPS cells in southern West Virginia and southwestern Virginia. Analysis of these data revealed strong, positive correlations between net alkalinity generation and three variables: the natural log of limestone residence time, influent dissolved Fe concentration, and influent non-Mn acidity. A statistical model was constructed to describe SAPS performance. Subsequent analysis of data obtained from five systems in western Pennsylvania (calibration data set) was used to reevaluate the model form, and the statistical model was adjusted using the combined data sets. Limestone residence time exhibited a strong, positive logarithmic correlation with net alkalinity generation, indicating net alkalinity generation occurs most rapidly within the first few hours of AMD-limestone contact and additional residence time yields diminishing gains in treatment. Influent Fe and non-Mn acidity concentrations both show strong positive linear relationships with net alkalinity generation, reflecting the increased solubility of limestone under acidic conditions. These relationships were present in the original and the calibration data sets, separately, and in the statistical model derived from the combined data set. In the combined data set, these three factors accounted for 68% of the variability in SAPS systems performance.     

Inefficiencies analysis of a point-focus CPV∕T system

In this paper, a point-focus concentrating photovoltaic and thermal (CPV∕T) system, sized for a domestic application, is presented in order to evaluate its inefficiencies and the related costs. The CPV∕T system adopts parabolic concentrator mirrors to reflect the light on triple-junction cells InGaP∕InGaAs∕Ge (indium--gallium phosphide∕indium--gallium arsenide∕germanium) placed on pipes, where the cooling fluid flows; CPV∕T system consists of three modules in parallel linked to a tank that works as hot water storage. The main maintenance problems are due to: moving parts such as the tracking system, cell wear linked to hotspot problems and optics cleaning. In particular, the model presented allows us to evaluate electric and thermal outputs, energy inefficiencies, and maintenance costs of the CPV∕T system. The analysis has been subdivided in several steps and a FMECA (Failure Mode, Effects and Criticality Analysis) approach has been considered to investigate the main failure modes and their relative effects in terms of efficiency losses and intervention costs. So, the inefficiencies analysis has allowed to identify the system malfunction causes, evaluating the impact due to the stops for each type of fault. Hence, an economic analysis has allowed to evaluate the CPV∕T system convenience when inefficiencies and maintenance incidence are also considered.     

Recombinant bovine somatotropin (rbST): Is there a limit for biotechnology in applied animal agriculture?

The intent of this article is to outline, integrate, and interpret relevant scientific, economic, and social issues of rbST technology that have contributed to the acceptance dilemma for this product. The public is divided into social groups, each with its own set of criteria on which they base rbSTs acceptability. Criteria for the scientific community may best be described as physiological. However, for consumers, criteria may be more practical, or procedural, including human health, animal welfare, environmental concerns, and overproduction. Because the business of dairy production depends on demand from the consuming public, the criteria for acceptance of rbST by producers largely reflects those of the consumers. Of necessity, producers are also critical of rbST from a business and animal improvement standpoint. Although this article demonstrates that rbST has met most physiological criteria for acceptance, the consuming public has treated the acceptance issue with forceful skepticism. The question this article addresses is, why? The authors comment that with rbST and other biotechnologies applied to agricultural animal production, it will be the responsibility of government health agencies, scientists, and manufacturers of the products to provide early, adequate, and honest public education. Attention to the concerns of the public may be the only means to prevent hysteria over this and future agricultural products of biotechnology and will, therefore, allow the public to form logical and thoughtful criteria assessments with respect to acceptance or rejection of each product.     

Investigation effect of hydrogen addition on the performance and exhaust emissions of Pongamia pinnata biodiesel fueled compression ignition engine

In the recent decades, the energy demand for transport and industrial sector has increased considerably. Fossil fuels which were the major fuel source for decades are no more sustainable. Biodiesel is an efficient alternative compared to depleting fossil fuels. The prospect of biodiesel as the best alternative fuel is a reliable source compared to depleting fossil fuels. Hydrogen is also considered as an attractive alternative fuel producing low emission with improved engine performance. This paper investigates the performance and emission characteristics of a single cylinder compression ignition engine using hydrogen as an inducted fuel and biodiesel, aka Pongamia pinnata as injected fuel. The experiments are conducted for different quantities of hydrogen induction through the intake manifold in order to improve the performance of the engine. The performance parameters such as brake thermal efficiency, brake specific fuel consumption, exhaust temperature and emission quantities like HC, NO_X, CO, CO₂ of biodiesel fueled CI engine with variable mass flow rate of hydrogen are investigated. The performances of biodiesel combined with hydrogen at varying mass flow rates are also compared. The 10 LPM hydrogen induction with biodiesel provided 0.33% increase of brake thermal efficiency compared with diesel and increase of 3.24% to biodiesel at 80% loading conditions. The emission of HC decreased by 13 ppm, CO decreased by 0.02% by volume and CO₂ decreased by 3.8% by volume for biodiesel with induction of hydrogen at 10 LPM to that of neat biodiesel for 80% load conditions.     

Toward a Sectorwide Design for Environment Support System for the Rail Industry

Rail has an important role to play in the development toward a sustainable transportation system. In this perspective, the European Brite Euram Project RAVEL (Rail Vehicle Eco-Efficient Design) has developed a rail sectorwide Design for Environment system to be used and standardized throughout the full supply chain. At the core of the system, quantitative environmental performance indicators for rail vehicles and components are used to incorporate environmental performance target levels in the product requirements and to measure and communicate achieved environmental performance. The concept of eco-efficiency is used to integrate both environmental and economical considerations. The methodology further builds on a standardized material list, standardized data formats, and proactive design guidance. To date, first steps are already taken to integrate the RAVEL project results into sector initiatives toward industrywide acceptance and standardization.Published online Note: This version was published online in June 2005 with the cover date of August 2004.     

我国排污权交易政策及完善对策研究

排污权交易在环境管理领域里正受到越来越多的关注。回顾了我国近年来的排污权交易政策,并对排污权交易试点实施效果进行了阐述,同时结合目前排污权交易在我国应用和研究现状,对排污权交易制度在实践过程中仍存在法律政策落后、初始分配公平与效率缺乏保障、市场体制欠缺以及监测监督力度不够等主要问题进行分析,并从排污立法、市场培育、政府监管3个方面提出政策建议。     

The influence of institutions and organizations on urban waste collection systems: an analysis of waste collection system in Accra, Ghana (1985-2000)

Urban waste collection system is a pivotal component of all waste management schemes around the world. Therefore, the efficient performance and the success of these schemes in urban pollution control rest on the ability of the collection systems to fully adapt to the prevailing cultural and social contexts within which they operate. Conceptually, institutions being the rules guiding the conduct of public service provision and routine social interactions, waste collection systems embedded in institutions can only realize their potentials if they fully evolve continuously to reflect evolving social and technical matrices underlying the cultures, organizations, institutions and social conditions they are designed to address. This paper is a product of an analysis of waste collection performance in Ghana under two different institutional and/or organizational regimes; from an initial entirely public sector dependence to a current mix of public-private sector participation drawing on actual planning data from 1985 to 2000. The analysis found that the overall performance of waste collection services in Ghana increased under the coupled system, with efficiency (in terms of total waste clearance and coverage of service provision) increasing rapidly with increased private-sector controls and levels of involvement, e.g. for solid waste, collection rate and disposal improved from 51% in 1998 to about 91% in the year 2000. However, such an increase in performance could not be sustained beyond 10 years of public-private partnerships. This analysis argues that the sustainability of improved waste collection efficiency is a function of the franchise and lease arrangements between private sector group on the one hand and public sector group (local authorities) on the other hand. The analysis therefore concludes that if such franchise and lease arrangements are not conceived out of an initial transparent process, such a provision could undermine the overall sustainability of private sector initiatives in collection services delivery in the long term, as in the case of the Accra example.     

Exergy analysis as a tool for the integration of very complex energy systems: The case of carbonation/calcination CO2 systems in existing coal power plants

A common characteristic of carbon capture and storage systems is the important energy consumption associated with the CO₂ capture process. This important drawback can be solved with the analysis, synthesis and optimization of this type of energy systems. The second law of thermodynamics has proved to be an essential tool in power and chemical plant optimization. The exergy analysis method has demonstrated good results in the synthesis of complex systems and efficiency improvements in energy applications.In this paper, a synthesis of pinch analysis and second law analysis is used to show the optimum window design of the integration of a calcium looping cycle into an existing coal power plant for CO₂ capture. Results demonstrate that exergy analysis is an essential aid to reduce energy penalties in CO₂ capture energy systems. In particular, for the case of carbonation/calcination CO₂ systems integrated in existing coal power plants, almost 40% of the additional exergy consumption is available in the form of heat. Accordingly, the efficiency of the capture cycle depends strongly on the possibility of using this heat to produce extra steam (live, reheat and medium pressure) to generate extra power at steam turbine. The synthesis of pinch and second law analysis could reduce the additional coal consumption due to CO₂ capture 2.5 times, from 217 to 85 MW.