2,631 research outputs found

    Charging NOx Emitters for Health Damages: An Exploratory Analysis

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    We present a proof-of-concept analysis of the measurement of the health damage of ozone (O3) produced from nitrogen oxides (NOx = NO NO2) emitted by individual large point sources in the eastern United States. We use a regional atmospheric model of the eastern United States, the Comprehensive Air Quality Model with Extensions (CAMx), to quantify the variable impact that a fixed quantity of NOx emitted from individual sources can have on the downwind concentration of surface O3, depending on temperature and local biogenic hydrocarbon emissions. We also examine the dependence of resulting ozone-related health damages on the size of the exposed population. The investigation is relevant to the increasingly widely used "cap and trade" approach to NOx regulation, which presumes that shifts of emissions over time and space, holding the total fixed over the course of the summer O3 season, will have minimal effect on the environmental outcome. By contrast, we show that a shift of a unit of NOx emissions from one place or time to another could result in large changes in the health effects due to ozone formation and exposure. We indicate how the type of modeling carried out here might be used to attach externality-correcting prices to emissions. Charging emitters fees that are commensurate with the damage caused by their NOx emissions would create an incentive for emitters to reduce emissions at times and in locations where they cause the largest damage.

    Charging NO x Emitters for Health Damages: An Exploratory Analysis

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    We present a proof-of-concept analysis of the measurement of the health damage of ozone (O 3) produced from nitrogen oxides (NO x = NO + NO 2) emitted by individual large point sources in the eastern United States. We use a regional atmospheric model of the eastern United States, the Comprehensive Air Quality Model with eXtensions (CAMx), to quantify the variable impact that a fixed quantity of NO x emitted from individual sources can have on the downwind concentration of surface O 3, depending on temperature and local biogenic hydrocarbon emissions. We also examine the dependence of resulting ozone-related health damages on the size of the exposed population. The investigation is relevant to the increasingly widely used "cap and trade" approach to NO x regulation, which presumes that shifts of emissions over time and space, holding the total fixed over the course of the summer O 3 season, will have minimal effect on the environmental outcome. By contrast, we show that a shift of a unit of NO x emissions from one place or time to another could result in large changes in resulting health effects due to ozone formation and exposure. We indicate how the type of modeling carried out here might be used to attach externality-correcting prices to emissions. Charging emitters fees that are commensurate with the damage caused by their NO x emissions would create an incentive for emitters to reduce emissions at times and in locations where they cause the largest damage.surface ozone, NO x emissions, point sources, health impacts, mortality, morbidity, cap-and-trade

    Charging NOx Emitters for Health Damages: An Exploratory Analysis

    Get PDF
    We present a proof-of-concept analysis of the measurement of the health damage of ozone (O3) produced from nitrogen oxides (NOx = NO + NO2) emitted by individual large point sources in the eastern United States. We use a regional atmospheric model of the eastern United States, the Comprehensive Air Quality Model with Extensions (CAMx), to quantify the variable impact that a fixed quantity of NOx emitted from individual sources can have on the downwind concentration of surface O3, depending on temperature and local biogenic hydrocarbon emissions. We also examine the dependence of resulting ozone-related health damages on the size of the exposed population. The investigation is relevant to the increasingly widely used “cap and trade” approach to NOx regulation, which presumes that shifts of emissions over time and space, holding the total fixed over the course of the summer O3 season, will have minimal effect on the environmental outcome. By contrast, we show that a shift of a unit of NOx emissions from one place or time to another could result in large changes in the health effects due to ozone formation and exposure. We indicate how the type of modeling carried out here might be used to attach externality-correcting prices to emissions. Charging emitters fees that are commensurate with the damage caused by their NOx emissions would create an incentive for emitters to reduce emissions at times and in locations where they cause the largest damage.surface ozone, NOx emissions, point sources, health impacts, mortality, morbidity, cap-and-trade

    A mathematical model of the evaporation of a thin sessile liquid droplet : comparison between experiment and theory

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    A mathematical model for the quasi-steady diffusion-limited evaporation of a thin axisymmetric sessile droplet of liquid with a pinned contact line is formulated and solved. The model generalises the theoretical model proposed by Deegan et al. [Contact line deposits in an evaporating drop, Phys. Rev. E, 62 (2000) 756-765] to include the effect of evaporative cooling on the saturation concentration of vapour at the free surface of the droplet, and the dependence of the coefficient of diffusion of vapour in the atmosphere on the atmospheric pressure. The predictions of the model are in good qualitative, and in some cases also quantitative, agreement with recent experimental results. In particular, they capture the experimentally observed dependence of the total evaporation rate on the thermal conductivities of the liquid and the substrate, and on the atmospheric pressure

    M. Riesz Theorem on Conjugate Harmonic Functions for Octonion-Valued Monogenic Functions

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    The classical theorem of M. Riesz about the conjugate harmonic functions is extended onto octonion-valued monogenic functions

    Acute small bowel obstruction secondary to intestinal endometriosis, an elusive condition: a case report

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    <p>Abstract</p> <p>Background</p> <p>Endometriosis is a benign condition affecting females of reproductive age. Although intestinal endometriosis is common it is rare for the condition to manifest as an acute bowel obstruction secondary to ileocaecal and appendicular endometriosis. This case is important to report as it highlights the diagnostic difficulty this particular condition presents to an emergency surgeon.</p> <p>Case presentation</p> <p>We present the case of a 33 year old female of Asian origin who presented with symptoms and signs of an acute small bowel obstruction. A right hemicolectomy for suspected malignancy was performed with an ileocolic anastomosis. Histological examination demonstrated extensive endometriosis of the appendix and ileocaecal junction.</p> <p>Conclusion</p> <p>Enteric endometriosis should be considered as a differential diagnosis when assessing females of reproductive age with acute small bowel obstruction. A high index of suspicion is required to arrive at a diagnosis of this elusive condition.</p
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