32,435 research outputs found

    Defining the Legal and Policy Framework to Stop the Dumping of Environmentally Harmful Products

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    Environmental dumping is a practice historically associated with the export of hazardous product waste from a developed country for irresponsible and often illegal disposal in a developing country. Now, with the industrialization and globalization of China and other developing countries, environmental dumping can involve both developing and developed countries as origin and destination. This dumping can be especially harmful to attempts to control under the Montreal Protocol ozone-depleting and climate-forcing chemical substances and/or products requiring unnecessarily high energy consumption. While developing country Parties to the Montreal Protocol are allowed to delay their phasedown of climate-forcing and ozone-depleting hydrofluorocarbons (HFCs) during a multi-year grace period, there are advantages to earlier implementation when superior alternatives are already available at reasonable costs, as is the case for many uses of HFCs today. Thus, developing countries can benefit under the Protocol from setting controls for environmental dumping. This article aims to give policymakers, especially those in developing countries, a legal and policy “toolkit” that can be used to stop unwanted environmental dumping. It includes an examination of the history of environmental dumping, illustration of such dumping in practice, a detailed explanation and examination of the legal and policy tools, and a summary of the consequences of environmental dumping

    Solar Air Conditioning with Metal Organic Frameworks

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    Air conditioning is responsible for 5% of energy consumption in the United States as is increasingly in demand across the world as the global middle class continues to grow in size. During hotter months, electricity used to power cooling systems becomes taxing on electric grids, constituting approximately 40% of peak power demand. Traditional air conditioning (AC) systems are also associated with harmful environmental impacts. Both refrigerants used for cooling and fossil fuels used in power contribute to global warming by acting as green-house gases (GHG). Due to the negative effects associated with emissions, the ultimate goal of this research is to drastically reduce non-renewable energy consumption associated with AC units. Generations of technologies have been developed to address this ongoing issue. An emerging solution involves the integration of metal-organic frameworks (MOFs) sorbents into a solar air conditioning system. Because of MOF properties, this integration allows for a thermally driven cycle without requiring a non-renewable energy input. This thesis is comprised of six chapters geared towards assisting in the determination of the most efficient and effective means of incorporation of MOFs into AC systems. Primarily by conducting an extensive literature review, the third chapter discusses Metal Organic Frameworks in depth for determining the most suitable candidates for this research project. Specific needs for the system are examined with different MOFs that meet the criteria considered. In chapter four, feasibility of integrating MOFs into a membrane through sorption measurements is tested for candidate MOF CAU-10. Chapter five is centered around modeling a MOF-assisted indirect evaporative cooler using EES: Engineering Equation Solver. Modeling outputs give a preliminary understanding of the cooling process and its effect on temperature. Together, these chapters move toward showing the feasibility of operation and its applicability to the field of renewable AC. The study of MOF attributes in Chapter 3 focused on Relative Humidity (RH) at which the MOFs demonstrated a steep water uptake, water adsorption capacity, temperatures for MOF regeneration, long term stability, and cost to synthesize and fabricate. These investigations showed Co2Cl2(BTDD), MIL-101, MIL-100(M), MOF-841, and CAU-10 to be the most promising applicants. Through sorption measurements of MOF material CAU-10 its isotherm demonstrated a capacity at the adsorption step below 0.30 gH2O/gMOF but a maximum capacity over 0.5 gH2O/gMOF. The EES model results showed 80-90% of recycled air provides a supply temperature necessary for indoor cooling below 21 oC. Chapter six summarizes all results and gives recommendations focused on thermodynamic optimization.No embargoAcademic Major: Mechanical Engineerin

    A multi evaporator desalination system operated with thermocline energy for future sustainability

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    All existing commercial seawater desalination processes, i.e. thermally-driven and membrane-based reverse osmosis (RO), are operated with universal performance ratios (UPR) varying up to 105, whilst the UPR for an ideal or thermodynamic limit (TL) of desalination is at 828. Despite slightly better UPRs for the RO plants, all practical desalination plants available, hitherto, operate at only less than 12% of the TL, rendering them highly energy intensive and unsustainable for future sustainability. More innovative desalination methods must be sought to meet the needs of future sustainable desalination and these methods should attain an upper UPR bound of about 25 to 30% of the TL. In this paper, we examined the efficacy of a multi-effect distillation (MED) system operated with thermocline energy from the sea; a proven desalination technology that can exploit the narrow temperature gradient of 20 °C all year round created between the warm surface seawater and the cold-seawater at depths of about 300–600 m. Such a seawater thermocline (ST)-driven MED system, simply called the ST-MED process, has the potential to achieve up to 2 folds improvement in desalination efficiency over the existing methods, attaining about 18.8% of the ideal limit. With the major energy input emanated from the renewable solar, the ST-MED is truly a “green desalination” method of low global warming potential, best suited for tropical coastal shores having bathymetry depths of 300 m or more

    Negative Externalities on Property Values Resulting from Water Impairment: The Case of the Pigeon River Watershed

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    The following hypothesis was tested: Willingness to bear a negative water impairment externality differs between those who do and those who do not receive economic benefit from the impairment source, e.g., a paper mill. The hypothesis was tested using a hedonic analysis of ambient water quality in two discrete housing markets in the Pigeon River Watershed, which have been polluted by the operation of a paper mill. The results suggest that North Carolina residents of the subwatersheds with impaired river, who experience economic benefits from the paper mill in addition to harmful effects, do perceive the pollution as a negative externality, whereas they may have a willingness to bear a similar type of negative externality associated with impaired streams. In contrast, the effects of both degraded river and streams on property values is perceived as a negative externality by residents in the Tennessee side, who experience only harmful effects from the pollution. North Carolina residents may hold greater willingness to bear the harmful effects of pollution as a given condition in their decision-making process because they receive economic benefits from the paper mill, while this internalization of the negative externality is weaker for residents in the Tennessee side.negative Externalities, water quality, spatial hedonic model, Environmental Economics and Policy,

    Health impacts of wind turbines

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    This report presents the results of a rapid, desk based analysis of peer reviewed UK and international literature from the last four years on the effects of wind turbines on human health. The review covers literature specified by the Scottish government, peer-reviewed original studies and recent peer-reviewed literature reviews. Recent original studies consist mostly of cross-sectional studies and case studies on the effects of wind turbines on local residents. All studies present evidence for annoyance due to wind turbine noise and most concur that there is evidence for sleep disturbance in the presence of wind farms but not necessarily from noise. Both results are in agreement with the effects of noise from other environmental sources. Other health effects are increasingly reported in the presence of wind turbines but the reviewed literature does not provide firm scientific evidence of a causal relationship with wind turbines or even more specifically wind turbine noise. The most widely quoted cross-sectional studies show correlations between annoyance and visual impact, economic benefit and attitude related to wind turbines. Wind turbine sound is reported to be comparatively weakly related to annoyance and inseparable from the other contributing factors. Literature on low frequency noise and infrasound (LFIS) can be categorised as reviews, sound level measurements around windfarms and discussion of mechanisms of perception and response. A Swedish review finds no evidence to support ‘wind turbine syndrome’ while another concludes that further research is required. Regarding noise measurements, there are concerns that a new generation of wind turbines will produce a sound with a spectrum shifted down in frequency. However, a study in Australia concluded that infrasound levels near windfarms were no higher than elsewhere and that higher levels in urban areas were probably due to traffic and other human activity rather than wind turbines. Some other studies found measured sound levels near wind farms to conform with a range of criteria for LFIS. Papers by Salt et al. propose that LFIS may differentially stimulate structures in the human inner ear, and may instigate health effects even when inaudible. The authors seek to build a speculative case utilising experimental data gleaned from guinea pigs and some observations on human experiences with specific pathological conditions. Based upon the documents submitted, the proposal is unproven, and would need clear data from hypothesis driven independent research in humans in order to be credible. A proposal by US consultants that motion sickness-like symptoms reported at one wind farm might be caused by acoustic excitation of the balance organs is not new and has previously been discounted as an explanation for similar reported effects not involving wind turbines. Other evidence on acoustic stimulation of the balance organs has been noted but not reviewed. Health effects from other wind turbine related sources such as shadow flicker have been reported in several studies and guidelines to be less of a problem. Careful wind farm design and operational restrictions are suggested to be sufficient to minimise the impact. The mitigation strategies have been found to vary widely internationally with some countries and federal states using fixed noise limits, others using noise limits relative to existing background levels and many like the UK using a combination of both. Set-back distances are also used internationally but have a number of disadvantages. The relevant UK guideline document ETSU-R-97 aims to provide a reasonable degree of protection to noise sensitive listeners; without unduly restricting the development of wind turbine renewable energy resources. In the international comparison the ETSU-R-97 guidelines tends to result in comparatively low noise limits although direct comparisons between fixed and relative noise limits are difficult. ETSU-R-97 has been criticised for its inconsistent implementation and relative complexity. Good practice guidelines by the Institute of Acoustics which aim to address the implementation issues are due to be published in May
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