SUSPENDED SEDIMENT AND METALS REMOVAL FROM URBAN RUNOFF BY A SMALL LAKE1

ABSTRACT: A small lake in the Chicago Metropolitan Area was from 91 to 95 percent efficient in removing suspended sediment and from 76 to 94 percent efficient in removing copper, iron, lead, and zinc from urban runoff. Sediments accumulated in the lake in the form of an organic-rich mud at an average rate of 20 millimeters per year; this reduced lake storage and covered potential habitat for aquatic organisms. Copper, lead, and zinc concentrations were closely associated with suspended-sediment concentrations and with silt- and clay-sized fractions of lake sediment. Although concentrations of mercury and cadmium were near detection limits in runoff, measurable concentrations of these metals accumulated in the lake sediments.     

Net value royalties : Practical tool or economist's illusion?

The petroleum industry has traditionally generated substantial revenues for governments. Where governmental power is divided, as in federations like Canada and Australia, a junior level of government normally collects royalties while the senior level levies a variety of imposts (income tax, export duties, excises on production). The combination of recent sharp reductions in prices, more price volatility and an era of freer markets has subjected existing tax and royalty systems to severe strain and has shifted attention to the design of fiscal systems that are more profit- sensitive. For the royalty element, interest focuses on net value royalties (NVRs). This paper deals with the nature and problems of NVRs. It proceeds by looking first at the application of resource rent royalties in Australia. It then focuses on recent megaproject royalty arrangements in Alberta and evaluates the degree to which Alberta's current royalty system is profit- sensitive. Problems associated with NVRs are discussed in the fourth section; concluding remarks are made in the last section.     

吉林省城市紧凑度与城市效率的时空演变及相关性

紧凑城市理念被认为可以有效提高城市经济发展效率,减少城市在开发建设、资源配置等方面的低效率。为探究我国城市紧凑度和城市效率的时空演变及两者间的相关性,本研究以吉林省地级及以上城市为研究对象,研究时间段选择为2000—2013年。研究主要分为三个部分。第一部分,运用熵值法,对吉林省地级及以上城市的紧凑度时空演变特征进行研究,研究发现,吉林省城市紧凑度平均水平较低,并且空间分布极不均衡,受区位和经济发展水平影响较大,高紧凑度城市基本位于哈大城市走廊一线。第二部分运用DEA数据包络模型,对吉林省城市效率演变特征进行研究,结果显示,吉林省城市效率在经过了长期的反复波动后于2012年步入快速增长阶段,受多种因素影响,各城市全要素生产率增长节奏迥异,但都表现出与技术进步一致的变动性,城市经济发展对新技术、新的生产要素投入的依赖较大,资源利用效率整体较低。第三部分运用R语言对吉林省城市紧凑度与城市效率的相关性进行了研究,两者间存在极弱的相关性,接着借助象限图法得出两者在不同时间段内存在一定程度的同步性,紧凑度提升时大部分城市的城市效率会出现提升,紧凑度的下降不一定有效引起城市效率同步下降。     

Stand-alone wind power system with battery/supercapacitor hybrid energy storage

This paper presents a stand-alone wind power system with battery/supercapacitor hybrid energy storage. A stand-alone wind power system mainly consists of a wind turbine, a permanent magnet synchronous generator, hybrid energy storage devices based on a vanadium redox flow battery and a supercapacitor, an AC/DC converter, two bidirectional DC/DC converters, a DC/AC converter and a variable load. Several control strategies for the stand-alone wind power system are involved such as a maximum power point tracking (MPPT) control, a vanadium redox flow battery charge/discharge control and a supercapacitor charge/discharge control. The proposed MPPT control combines a sliding mode control with an extreme search control to capture maximum wind energy. This strategy avoids the necessity of measuring wind velocity, obtaining models or parameters of the wind turbine and calculating the differentials of the power generated from the wind power system and from the speed of the generator. The battery charge/discharge control maintains a constant DC bus voltage. When the battery charging/discharging current reaches the setting threshold, the charge/discharge control of the supercapacitor is triggered to limit the charging/discharging current of the battery. The simulation results show that the proposed method can rapidly respond to variations in wind velocity and load power.     

中国区域能源效率发展演变趋势的R/S分形分析

改革开放以来中国能源效率不断地提高,但是在某些年份存在波动现象.采用非线性分形理论及分形分析R/S方法,科学定量地描述了中国以及各个地区能源效率的演变趋势.首先采用分形理论对1978-2008年的中国能源效率时间序列数据进行研究,结果显示,中国能源效率发展演变存在Hurst现象,具有明显的分形特征.并依照“五年计划”来划分时间序列样本为研究区间,结合“五年计划”详尽地解释说明了中国能源效率变动的原因.然后将数据扩大为样本期为1995-2008年29地区的面板数据,采用面板变系数模型进一步对各个地区的能源效率进行分析,发现除海南外其他地区的能源效率演变过程中具有明显的持续性规律,各个地区能源效率将继续保持增长.西部6个地区以及东北三省的能源效率演变趋势高于全国水平,说明“西部大开发”战略和“振兴东北”战略都已经显效.     

Actively Dealing with Climate Change and Striving to Strengthen the Capability of Sustainable Development

Either from the perspective of the finite supply capacity of global resources and energy,or from the perspective of global environment restrictive conditions,developing countries can not repeat the old development road of developed countries,either in view of the international pressure China is currently facing,or in view of China’s own resources endowment and stages of development,we must actively face such a challenge of climate change.We must recognize that the issue of climate change may be a great restraint to the present and future eco-social development,and may also be an important driving force and new opportunity to push forward the transformation of development pattern,to take a new road of industrialization and to realize sustainable development.This demands us,on the one hand,to take the Scientific Outlook of Development as the guide to make efforts to control the emission of greenhouse gases and continuously increase the capability of adapting to climatic change,and set up the overall plan to respond to climate change of our country,and on the other hand,we should unswervingly take the road of sustainable development,save energy,optimize energy structure and strengthen biological protection in slowing and adapting to climate change.     

Renewable energy potential in India and future agenda of research

ABSTRACT

Demand of electrical energy is exponentially increasing causing environmental problems due to extensive use of fossil fuels. Hence, research has been promoted in renewable energy technologies to mitigate environmental pollution. Indian subcontinent is rich in renewable energy sources (RES). This paper describes potential of RES and region-wise installed capacity in India. Estimated potential of RES is 57 GW which is targeted to be 175 GW by 2022. A logical framework for our future research work has been presented. This includes performance optimisation of solar pumping system and reliability assessments of the designed system using reliability indices.

Abbreviation: RES: Renewable energy resources; SHP: small hydro plants; GOI: Government of India; MNRE: Ministry of New and Renewable Energy; LHP: large hydropower; BCM: billion cubic metres; PEC: per-capita energy consumption; JNNSM: Jawaharlal Nehru National Solar Mission; DNI: direct normal irradiance; SPV: solar photovoltaic; UMPP: ultra mega green solar power project; GIS: geographic information systems; WMS: wind monitoring stations; MPWL: Madhya Pradesh windfarms Ltd.; MIB: mat river basin; SWAT: Soil and Water Assessment Tool; ROR: run of river; SMS: short message service; CDM: clean development mechanism; NIOT: national institute of ocean technology; LOLP: loss of load probability; CSO: Central Statistics Office; CEA: Central Electricity Authority; TERI: The Energy and Resources Institute; WPI: Wind Power India; IEA: International Energy Agency; EAI: Energy Alternatives India; BKP: Biomass Knowledge Portal; IRENA: International Renewable Energy Agency; GAIN: Global Agricultural Information Network; NITI: National Institution for Transforming India; NIWE: National Institute of Wind Energy; UP: Uttar Pradesh; J&K: Jammu and Kashmir; HP: Himachal Pradesh; NR: northern region; MP: Madhya Pradesh; WR: western region; TN: Tamil Nadu; AP: Andhra Pradesh; SR: southern region; ER: eastern region; NER: north eastern region; A&N: Andaman & Nicobar     

Energy consumption,emissions and economic growth in Bahrain

This study examines the Granger causality relationships between economic growth, energy consumption and emissions, from 1980 to 2007 in Bahrain, controlling for capital and urban population using Toda and Yamamoto’s approach. It was found that there is unilateral causality which runs from urban population, economic growth, capital and energy consumption to environment. Further, we found strong support for causality running from economic growth to energy consumption, emissions and capital. The existence of these linkages suggests that the government of Bahrain may pursue energy efficiency strategies and carbon emissions reduction policy in the long run without impeding economic growth. Additionally, the long run pursuit of high economic growth given sustained increases in energy efficiency may also reduce CO₂ emissions intensity per unit of her GDP.     

村级水资源的管理与利用研究--来自南方四个村的案例分析

农村水资源及其相关设施的改革需要更多了解村和户层次上的现实状况和机制安排。以避免改革扭曲和失败。通过对湖北和广西共四个村的村委会、关键知情人及120个农户的调查。在村和农户两个层次上描述水资源及其相关设施的管理与利用，尤其是在干旱年份村和户所采取的策略。并深入分析了农村村级水资源管理与利用的制度安排与问题。得出的结论是。追求水利管理效率的市场化改革需要考虑干旱的威胁，要有基于风险的制度设计和法律保障。     

上海城市污水厂污泥处理与利用系统分析

上海市城市污水处理规划的实施，将在2020年前使该市的城市污水厂污泥产生量从现状的85tDS/d增长至1300－1500tDS/d，将形成可观的污泥消纳压力。预期了该市的污水污泥产生状况，以现有污水污泥处置与利用技术为基础，测算了可行的污泥处置与利用方向及相应的容量，以及满足容量利用的前处理要求。以此为基础，推荐了适宜的容量利用方案，并建议以生物稳定化干化处理为污泥处置与利用前的改性处理步骤，且可在适当的条件下增加厌氧消化环节，提高处理体系的水平与容量宽余度。此污泥处理与利用体系可达到污泥消纳运行的柔性化和可靠性，兼具环境安全性与经济合理性。