Assessing the cost-effectiveness of electric vehicles in European countries using integrated modeling

Electric vehicles (EVs) are considered alternatives to internal combustion engines due to their energy efficiency and contribution to CO₂ mitigation. The adoption of EVs depends on consumer preferences, including cost, social status and driving habits, although it is agreed that current and expected costs play a major role. We use a partial equilibrium model that minimizes total energy system costs to assess whether EVs can be a cost-effective option for the consumers of each EU27 member state up to 2050, focusing on the impact of different vehicle investment costs and CO₂ mitigation targets. We found that for an EU-wide greenhouse gas emission reduction cap of 40% and 70% by 2050 vis-à-vis 1990 emissions, battery electric vehicles (BEVs) are cost-effective in the EU only by 2030 and only if their costs are 30% lower than currently expected. At the EU level, vehicle costs and the capability to deliver both short- and long-distance mobility are the main drivers of BEV deployment. Other drivers include each state’s national mobility patterns and the cost-effectiveness of alternative mitigation options, both in the transport sector, such as plug-in hybrid electric vehicles (PHEVs) or biofuels, and in other sectors, such as renewable electricity.     

Energy pricing policies in developing countries

Government energy pricing policies have multiple and often conflicting objectives: economic efficiency, government revenues (for both parastatal supply companies and the treasury), maintenance or improvement of income distribution, promotion of particular sectors (such as industrial exporters and local resource development) demand management and security of supply. It is important to examine the impacts on and the trade-offs between these objectives resulting from alternative policies in order to assist in policy selection. This article discusses the more important objectives and their conflicts and outlines an approach for the quantitative examination of alternative policies.     

Degrees of destitution: a typology of homelessness in developing countries

There is an ongoing attempt to develop a globally acceptable definition of homelessness. Whether such a definition is broad and inclusive of squatters, and those living in particularly poor quality housing, or narrowly focused on street homelessness, it is likely to include a large population. Therefore, we are left with a need to develop criteria for identifying, allocating and prioritising appropriate support. Drawing on a study of homelessness in nine developing countries, this paper presents a new categorisation or typology of homelessness, based on choice and opportunity. It highlights the way in which homeless people, living in identical shelter situations, and for ostensibly similar reasons, might require different responses to support them out of homelessness. This paper does not seek to debate the definition of homelessness but to stimulate discussion on finding a way to identify and prioritise the needs of those included within any given definition.     

Transport and energy in developing countries

The author examines the transport energy consumption of developing countries and compares it with that of developed countries. These figures are found to suggest considerable scope for transport energy savings. Given the need for improved energy efficiency, the author moves on to consider transport in the context of the wider economy. Four broad policy approaches which can affect transport energy consumption are identified — information and training programmes, subsidies; pricing and tax policies; and administrative regulations. The author's primary conclusion is that the energy price changes of the last decade do not hold revolutionary implications for the transport sector. There remains, however, a need to improve efficiency in this sector.     

Fully Developed Turbulence of Power-Law Fluids in Circular Pipe Based on Large Eddy Simulation

幂律流体圆管湍流的大涡模拟

王淑彦^1,2, 李淼¹, 王树青³, 李好婷¹, 陈羽佳¹, 马一玫¹, 孙启冀¹

（1.东北石油大学 石油工程学院, 黑龙江 大庆 163318;

2.提高采收率教育部重点实验室（东北石油大学）, 黑龙江 大庆 163318;

3.中国石油大庆油田股份有限公司第四采油厂, 黑龙江 大庆 163511）

摘 要：本文采用动态亚格子模型,对幂律流体在圆管内的充分发展湍流流动进行了大涡模拟（LES）,得到了不同幂律指数下的湍流流动信息。文中分析了平均轴向速度、脉动速度均方根和雷诺应力等随着幂律指数增加的变化趋势,得出随着幂律指数的增加对数区的平均轴向速度减小,脉动速度均方根和雷诺应力的值增大,模拟结果表明剪切稀化流体比剪切稠化流体的非牛顿特征更明显。同时对湍流流动的高阶统计量（偏斜因子和平坦因子）进行了分析,结果表明随着幂律指数的减小,轴向脉动的偏斜因子和平坦因子在近壁面区增大,随着幂律指数的减小轴向脉动的间歇性和非对称性更强。不同幂律指数下的湍流流动变化明显,进一步说明了幂律指数对幂律流体的湍流流动有重要影响。模拟结果与直接数值模拟结果吻合较好,证实了大涡模拟可以用来预测较大雷诺数情况下幂律流体流动的湍流特性。

关键词：大涡模拟;幂律流体;充分发展湍流

     

中亚国家电解铝厂总图布置的特点

通过对中亚国家电解铝厂的设计,并与国内同类项目进行比较,指出因社会、自然环境、人文环境和管理体制的不同,而致使总图设计方案有较大的差异,针对这些差异,提出了改进的措施及应注意的问题,可供国内同行参考。     

中东及周边主要国家和地区乙烯工业发展对我国的影响

对中东及周边国家和地区的石化工业总体情况做了简要介绍，并对主要国这和地区的乙烯工业现状、发展趋势及特点进行了分析和预测，同时就其对我国的影响提出了建议和对策。     

近两年我国锆英砂及其精矿进口情况分析

介绍了2005年、2006年及2007年1￣4月我国锆英砂及其精矿的进口情况。2006年,我国累计进口锆英砂374649t,与2005年的340995t相比增长了9.9%,主要从澳大利亚、南非、越南和印尼等国家进口。2006年,我国从印尼进口锆英砂的量急剧增加,达到124855t,进口量仅次于澳大利亚。进口的港口主要集中在上海、海口、南宁、湛江等口岸。从2007年1￣4月的进口情况看,进口量呈上升趋势,增幅达到22.8%。预计2007年我国锆英砂的进口量(折合成精矿量)将比2006年增加(3.0￣3.5)×10~4t。     

Electric cooperatives and the political economy of rural electrification in Africa: Insights from Uganda

Rural electrification is a crucial process of enhancing the modern energy access of rural communities which is an important global development goal. Electric cooperatives have played an important role as drivers of rural electrification worldwide, both historically and contemporaneously. The emerging role of cooperatives in rural electrification is yet to be examined in the context of East Africa, a region that experiences serious infrastructure deficits alongside widespread rural poverty. This study adopts a political economy perspective to explore the roles and challenges of cooperatives in rural electrification in Uganda. Through a high-level case study of two electric cooperatives, we show that while the cooperatives can deliver rural electrification, they face a series of political and economic challenges in fulfilling their mission. To enhance rural electrification through cooperatives, the challenges should be addressed by policy solutions: (1) providing more support to rural households that cannot afford electricity; (2) providing further support to cooperatives to avoid overburdening the community; (3) enhancing investment to upgrade the grid and extend its geographical coverage; and (4) exploring new financial and technological options for rural electrification. We expect the findings of this study to be useful to policymakers, implementers, cooperatives, and international donors currently working in rural electrification in Africa and beyond.     

Can twice weekly hemodialysis expand patient access under resource constraints?

The convention of prescribing hemodialysis on a thrice weekly schedule began empirically when it seemed that this frequency was convenient and likely to treat symptoms for a majority of patients. Later, when urea was identified as the main target and marker of clearance, studies supported the prevailing notion that thrice weekly dialysis provided appropriate clearance of urea. Today, national guidelines on hemodialysis from most countries recommend patients receive at least thrice weekly therapy. However, resource constraints in low‐ and middle‐income countries (LMIC) have resulted in a substantial proportion of patients using less frequent hemodialysis in these settings. Observational studies of patients on twice weekly dialysis show that twice weekly therapy has noninferior survival rates compared with thrice weekly therapy. In fact, models of urea clearance also show that twice weekly therapy can meet urea clearance “targets” if patients have significant residual function or if they follow a protein‐restricted diet, as may be common in LMIC. Greater reliance on twice weekly therapy, at least at the start of hemodialysis, therefore has potential to reduce health care costs and increase access to renal replacement therapy in low‐resource settings; however, randomized control trials are needed to better understand long‐term outcomes of twice versus thrice weekly therapy.