Reduction of current harmonics in grid-connected PV inverters using harmonic compensation - conforming to IEEE and IEC standards

This paper deals with the reduction of harmonics generated by Grid-Connected PV Inverters to conform to the harmonic limits set by the IEEE and IEC standards. An analysis of the current harmonics present in the output current of a grid-connected inverter will be presented. The inverter will be current controlled by a Proportional-Resonant (PR) current controller. The design and testing of the PR current controller will be presented. This paper will also deal with the application of harmonic compensation to make the inverter compliant to the standards, by using selective harmonic compensators in addition to the Proportional-Resonant (PR) controller. Both simulation and experimental results will be presented. Testing was carried out on a Grid-Connected PV Inverter which was designed and constructed for this research.peer-reviewe

Human health effects of benzene, arsenic, cadmium, nickel, lead and mercury: Report of an expert consultation

Ana Isabel Cañas Portilla y Argelia Castaño Calvo del Centro Nacional de Sanidad Ambiental (ISCIII) han participado en este informe como expertos proporcionando comentarios técnicos.Benzene, arsenic, cadmium, lead, mercury and nickel are ubiquitous pollutants in ambient air. The main sources are industrial processes, electricity generation and fuel combustion. The main routes of exposure are inhalation for benzene, and diet for arsenic, cadmium, lead, nickel and mercury. Inhalation of benzene, arsenic and cadmium is relevant for exposure in active tobacco smokers and people exposed to second-hand tobacco smoke. Epidemiological studies show that exposure to these pollutants is associated with adverse effects on the cardiovascular (cadmium, lead, mercury); haematological (benzene, lead); immunological, neurological and reproductive (benzene, lead, mercury); respiratory (cadmium, nickel); renal (cadmium, lead); and skeletal (cadmium) systems. Limited epidemiological evidence on ambient air pollution suggests adverse effects on the cardiovascular system (arsenic and nickel). Since benzene, arsenic, cadmium and nickel are classified as carcinogenic, the lowest possible exposure level is suggested to minimize the risk for cancer development in view of the no-effect threshold paradigm. Lead and methylmercury compounds are classified as possibly carcinogenic to humans. However, the available evidence is insufficient to warrant updating the air quality guidelines for these air pollutants. Evidence gaps are identified and these should guide future research efforts.S

A GIS model-based assessment of the environmental distribution of g-hexachlorocyclohexane in European soils and waters

The MAPPE GIS based multimedia model is used to produce a quantitative description of the behaviour of γ-hexachlorocyclohexane (γ-HCH) in Europe, with emphasis on continental surface waters. The model is found to reasonably reproduce γ-HCH distributions and variations along the years in atmosphere and soil; for continental surface waters, concentrations were reasonably well predicted for year 1995, when lindane was still used in agriculture, while for 2005, assuming severe restrictions in use, yields to substantial underestimation. Much better results were yielded when same mode of release as in 1995 was considered, supporting the conjecture that for γ-HCH, emission data rather that model structure and parameterization can be responsible for wrong estimation of concentrations. Future research should be directed to improve the quality of emission data. Joint interpretation of monitoring and modelling results, highlights that lindane emissions in Europe, despite the marked decreasing trend, persist beyond the provisions of existing legislation. An spatially-explicit multimedia modelling strategy was applied to describe the historical distribution of γ-HCH in European soils and surface waters

European union leadership in biofuels regulation: Europe as a normative power?

The rapid emergence of the European Union (EU) as a leader in global environmental politics has led many scholars to argue in favour of the EU being a ‘normative power’ in international relations. This paper critically examines the EU's biofuels policy and evaluates whether its attempts to lead by example and shape international practice in this field could support such arguments. Europe's biofuel policies are evaluated through a sustainable development lens, so as to determine the extent to which it has embraced a holistic approach to sustainability. While not dismissing that the identity of the EU is indeed an explanatory factor and that normative intentions may well be regarded as a motivating force, this study argues that an interest-based perspective on international environmental regulation offers a supplementary view of how an actor's preferences for an international regime are shaped. By erecting barriers aimed at shielding its own inefficient domestic biofuels production the EU is in essence placing trade competitiveness and economic growth above environmental protection, thus permitting sustainability concerns to be addressed only in part

Human biomonitoring. Basics: educational course

Ana Isabel Cañas Portilla, Argelia Castaño, Susana Pedraza Diaz y Marta Esteban López del Centro Nacional de Sanidad Ambiental (ISCIII) han contribuido en el desarrollo de este curso.Human biomonitoring (HBM) is an instrument for measuring the internal dose of exogenous substances/chemicals that enter a body during a certain period of exposure from a range of sources. It contributes to reducing uncertainties in the assessment of health risks from chemicals and provides information for decision-making on the prevention of negative impacts of chemicals on human health and the environment. Promoting the use of HBM is a recognized priority of chemical safety globally and in the WHO European Region. Given the complexity of HBM, relevant capacities should be built at the national level to explore its benefits. This educational course on HBM, presented in the form of slides with accompanying notes and references, compiles scientific information on HBM as well as practical examples. It was developed to support the training of public-health and health-care professionals; students of medical, biological and other allied sciences; and professionals and decision-makers in the health, environment and other relevant sectorsThis course was developed with financial support from the German Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection and the German Federal Ministry of Health.S

Patriotic values for public goods: transnational trade-offs for biodiversity and ecosystem services?

The natural environment is central to human well-being through its role in ecosystem service (ES) provision. Managing ES often requires coordination across international borders. Although this may deliver greater conservation gains than countries acting alone, we do not know whether the public supports such an international approach. Using the same questionnaire in three countries, we quantified public preferences for ES in home countries and across international borders. In all three countries, the people were generally willing to pay for ES. However, our results show that there is a limit to the extent that environmental goods can be considered global. ES with a use element (habitat conservation, landscape preservation) attracted a patriotic premium, such that the people were willing to pay significantly more for locally delivered services. Supranational management of ES needs to be balanced against the preferences that people have for services delivered in their home countries

The potential impact of reforms to the essential parameters of the council tax

Council Tax was introduced in Britain in 1993 and represents a unique international property tax. There is a growing belief that it is time to reform the number and structure of council tax bands but such views have a minimal empirical base. This paper sets out to assess the impact on personal and local government finances, and extends the analysis to the role of the tax multipliers linked to each band. The research is based on the experience of a representative sample of local authorities in Scotland. A statistical revaluation for 2000 is estimated for the existing eight band system, and from this base a ten band system is calculated. Financial implications are then simulated for each local authority taking account of central resource equalisation mechanisms. The results indicate that increases in bands will have little impact on the burden of the council tax compared with regular revaluations. Changing the tax multiplier range has the greatest impact on local authority finances and council tax payments

Governing culture: legislators, interpreters and accountants

Cultural policy has become dominated by questions of how to account for the intangible value of government investments. This is as a result of longstanding developments within government’s approaches to policy making, most notably those influenced by practices of audit and accounting. This paper will outline these developments with reference to Peter Miller’s concept of calculative practices, and will argue two central points: first, that there are practical solutions to the problem of measuring the value of culture that connect central government discourses with the discourses of the cultural sector; and second, the paper will demonstrate how academic work has been central to this area of policy making. As a result of the centrality of accounting academics in cultural policy, for example in providing advice on the appropriate measurement tools and techniques, questions are raised about the role academia might take vis-à-vis public policy. Accounting professionals and academics not only provide technical expertise that informs state calculative practices, but also play a surveillance role through the audit and evaluation of government programmes, and act as interpreters in defining terms of performance measurement, success and failure. The paper therefore concludes by reflecting on recent work by Phillip Schlesinger to preserve academic integrity whilst allowing accounting scholars and academics influence and partnership in policy

Prospects for radical emissions reduction through behaviour and lifestyle change

Over the past two decades, scholars and practitioners across the social sciences, in policy and beyond have proposed, trialled and developed a wide range of theoretical and practical approaches designed to bring about changes in behaviours and lifestyles that contribute to climate change. With the exception of the establishment of a small number of iconic behaviours such as recycling, it has however proved extremely difficult to bring about meaningful transformations in personal greenhouse gas emissions at either the individual or societal level, with multiple reviews now pointing to the limited efficacy of current approaches. We argue that the majority of approaches designed to achieve mitigation have been constrained by the need to operate within prevailing social scientific, economic and political orthodoxies which have precluded the possibility of non-marginal change. In this paper we ask what a truly radical approach to reducing personal emissions would look like from social science perspectives which challenge the unstated assumptions severely limiting action to date, and which explore new alternatives for change. We emphasise the difficulties likely to impede the instituting of genuinely radical societal change regarding climate change mitigation, whilst proposing ways that the ground could be prepared for such a transformation to take place