149 research outputs found

    Urban Environment Management : an Application of Carrying Capacity to Solid Waste Disposal

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    This section devotes in the first part to the explanations of waste generation and its definition. Solid waste is a part of waste and residential solid waste or refuse is the largest portion of solid waste to be disposed of. The reasons for ever-increasing domestic solid waste which usually enters municipal solid waste management system are given in the later part of the section. The statistical data of solid waste are presented both on the basis of per capita per day and on annual basis. As population increases and more people are concentrated in urban areas, waste problem grows more acute. As standards of living goes up, the public demand better waste disposal service. At the same time, the higher standards of living complicates the problem by increasing the amount of waste produced and the cost of properly disposing of it. In large metropolitan areas particularly the disposal problem has reached serious proportions in recent years due to the steady exhaustion of available landfill areas, the impact of more rigid air, water, and land pollution controls, and the decline of markets for major salvage items such as ferrous metal and paper products (American Public Works Association 1970, P.) Waste comes from human activities of production and consumption. As shown in the following diagram, production activities generate residuals and wastes which are discharged to the environmental resource base, and likewise consumption goods themselves produce or become residuals and are imposed on common pool resources as externalities

    Preliminary Development of a Simultaneous Equation Model of an Urban Housing and Mortgage Market

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    This paper summarizes the state of development of an aggregative simultaneous equation model of the housing and mortgage markets in New Castle County, Delaware. Unfortunately, the development has not been completed at this time. Thus we will simply report on the current status of the model. In the first section we briefly and inadequately indicate the substantial debt we owe to existing theory and previous authors for the theoretical foundations of the model. In the second section the specific approach to modeling the housing and mortage markets in New Castle County is described. Included here are the accommodations with data constraints that have been found necessary. The accounting framework for the model is also clearly specified. The third section briefly describes the results of estimating the model's equations and preliminary results of attempting to use it for simulation experiments. Theoretical Foundations : Ours is an aggregative model of housing and mortgage markets much in the tradition of Muth's work as exemplified in (15). Our focus on the mortgage market differentiates us slightly from muth as does our focus on a small geographic region. In these respects we found ourselves following closely the work of Field and Pfister (6)

    The Political Economy of Energy, Environment and Development

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    This paper examines the environmental implications of the emerging world order of development and underdevelopment. In particular, it considers the prospect that the environment is being socially shaped and, in a specific sense to be examined below, reconstituted by political and economic forces. In our view, what is popularly called "environment," more classically "nature," is undergoing a process of social capture which eventually may make it a "system" subject to political and economic "laws". Although the present energy-environment-development regime is only about 300 years old (dating to the spared of a coal-economy, steam technology and wage labor), it appears to have concurrently institutionalized a world order of social inequality unknown in previous human history and attained a level of technological sophistication that threatens several million years of climate, biological and social evolution. An effort is made below to begin construction of a theoretical framework for conceiving the social origins of this threat and its implications for society and nature. The paper is divided into four sections. The first section reviews the political economy of energy, environment and development which has prevailed since industrialization. The period is characterized as one of expanding commodification of social existence. Nature is seen as successively drawn into the commodification process; but, until recently, its role was limited to serving mainly as a resource mine or a reservoir for the absorption of industrial waste. Under these conditions, it was analytically feasible to focus on the social structure and ignore the possibility that nature was being structurally affected. We argue, however, that commodification has spread to the natural structure-including climate, atmosphere and global temperature-and that conventional distinctions between natural and social structures and laws may now be outmoded. Indeed, the dualistic treatment of society and nature may represent an impediment to conceiving newly evolving relations in the political economy of energy, environment and development. The third section explores the meaning and implications of the social appropriation of natural order. The paper concludes with a discussion of the links between commodification, the appropriation of mature and social inequality

    Linking Lignin Source with Structural and Electrochemical Properties of Lignin-Derived Carbon Materials

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    Valorization of lignin to high-value chemicals and products along with biofuel production is generally acknowledged as a technology platform that could significantly improve the economic viability of biorefinery operations. With a growing demand for electrical energy storage materials, lignin-derived activated carbon (AC) materials have received increasing attention in recent years. However, there is an apparent gap in our understanding of the impact of the lignin precursors (i.e., lignin structure, composition and inter-unit linkages) on the structural and electrochemical properties of the derived ACs. In the present study, lignin-derived ACs were prepared under identical conditions from two different lignin sources: alkaline pretreated poplar and pine. The lignin precursors were characterized using composition analysis, size exclusion chromatography, and 2D HSQC nuclear magnetic resonance (NMR). Distinctive distributions of numerous micro-, meso- and macro-porous channels were observed in the two lignin-derived ACs. Poplar lignin-derived ACs exhibited a larger BET surface area and total mesopore volume than pine lignin-derived AC, which contributed to a larger electrochemical capacitance over a range of scan rates. X-ray photoelectron spectroscopic analysis (XPS) results revealed the presence of oxygen-containing functional groups in all lignin-derived ACs, which participated in redox reactions and thus contributed to an additional pseudo-capacitance. A possible process mechanism was proposed to explain the effects of lignin structure and composition on lignin-derived AC pore structure during thermochemical conversion. This study provides insight into how the lignin composition and structure affect the derived ACs for energy storage applications

    Psychometric Properties of the Hypomania Checklist-32 in Korean Patients with Mood Disorders

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    OBJECTIVE The aim of this study was to examine the validity of the Korean version of the Hypomania Checklist-32, second revision (HCL-32-R2) in mood disorder patients. METHODS A total of 454 patients who diagnosed as mood disorder according to Structured Clinical Interview for DSM-IV Axis I Disorders, clinician version (SCID-CV) (bipolar disorder [BD] I, n=190; BD-II, n=72; and major depressive disorder [MDD], n=192) completed the Korean module of the HCL-32-R2 (KHCL-32-R2). RESULTS The KHCL-32-R2 showed a three-factorial structure (eigenvalue >2) that accounted for 43.26% of the total variance. Factor 1 was labeled "active/elated" and included 16 items; factor 2, "irritable/distractible" and included 9 items; and factor 3 was labeled "risk-taking/indulging" and included 9 items. A score of 16 or more on the KHCL-32-R2 total scale score distinguished between BD and MDD, which yielded a sensitivity of 70% and a specificity of 70%. MDD and BD-II also could be differentiated at a cut-off of 15 with maximized sensitivity (0.67) and specificity (0.66). Cronbach's alpha of KHCL-32-R2 and its subsets (factors 1, 2, and 3) were 0.91, 0.89, 0.81 and 0.79, respectively. Correlations between KHCL-32-R2 and Montgomery- Asberg Depression Rating Scale, Young Mania Rating Scale and Korean version of Mood Disorder Questionnaire were -0.66 (p=0.41), -0.14 (p=0.9), and 0.61 (p<0.001), respectively. CONCLUSION The KHCL-32-R2 may be a useful tool in distinguishing between bipolar and depressive patients in clinical settings

    Greenhouse Gas Reduction Potential for South Korea

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    South Korea's energy policies over the past 40 years have focused on securing stable energy supplies from fossil fuels and nuclear power. In 2000, imported energy, mainly coal, oil, natural gas and uranium, accounted for 97.2% of national energy supply. The country's energy intensity has been much above the world average and is still increasing. The energy consumption per capita grew from 2.17 tons of oil equivalent(TOE) in 1990 to 4.10 tons of oil equivalent(TOE) in 2000, higher than in Japan and Germany. South Korea was the tenth largest source of carbon dioxide(C02) emissions in the world as of 1999(World Bank, 1999). South Korea has suffered environmental problems because of its heavy reliance on energy-intensive economy. South Korea's anthropogenic emissions of greenhouse gases in 1997 are shown in Table 1

    An Institutional Approach to River Basin Management : Conflict Resolution in the U. S. and South Korea

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    We juxtapose river basin management practices in both the U.S. and South Korea to learn how multi-stakeholder conflicts are resolved under varying policy contexts. The cross-cultural comparison likewise enables an evaluation of conflict resolution as a means for producing socio-politically acceptable, economically sound, technologically feasible and environmentally viable delivery of safe drinking water. It is argued that conflict resolution enhances opportunities to achieve sustainability in river basin management despite very different policy and cultural circumstances. Two U.S. cases reviewed: the Delaware River Basin Commission (established in 1961) and the Susquehanna River Basin Commission (established in 1973). The two South Korean river basin cases under review are the Han and Nakdong Rivers

    Enterovirus 71-associated hand, foot and mouth diseases with neurologic symptoms, a university hospital experience in Korea, 2009

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    PurposeHand-foot-mouth disease (HFMD) is a common viral illness in children, which is usually mild and self-limiting. However, in recent epidemics of HFMD in Asia, enterovirus 71 (EV71) has been recognized as a causative agent with severe neurological symptoms with or without cardiopulmonary involvement. HFMD was epidemic in Korea in the spring of 2009. Severe cases with complications including death have been reported. The clinical characteristics in children with neurologic manifestations of EV71 were studied in Ewha Womans University Mokdong Hospital.MethodsExaminations for EV71 were performed from the stools, respiratory secretion or CSF of children who presented neurologic symptoms associated with HFMD by realtime PCR. Clinical and radiologic data of the patients were collected and analyzed.ResultsEV71 was isolated from the stool of 16 patients but not from respiratory secretion or CSF. Among the 16 patients, meningitis (n=10) was the most common manifestation, followed by Guillain-Barré syndrome (n=3), meningoencephalitis (n=2), poliomyelitis-like paralytic disease (n=1), and myoclonus (n=1). Gene analysis showed that most of them were caused by EV71 subgenotype C4a, which was prevalent in China in 2008.ConclusionBecause EV71 causes severe complications and death in children, a surveillance system to predict upcoming outbreaks should be established and maintained and adequate public health measures are needed to control disease

    Pyruvate Dehydrogenase Kinase 4 Promotes Vascular Calcification via SMAD1/5/8 Phosphorylation

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    Vascular calcification, a pathologic response to defective calcium and phosphate homeostasis, is strongly associated with cardiovascular mortality and morbidity. In this study, we have observed that pyruvate dehydrogenase kinase 4 (PDK4) is upregulated and pyruvate dehydrogenase complex phosphorylation is increased in calcifying vascular smooth muscle cells (VSMCs) and in calcified vessels of patients with atherosclerosis, suggesting that PDK4 plays an important role in vascular calcification. Both genetic and pharmacological inhibition of PDK4 ameliorated the calcification in phosphate-treated VSMCs and aortic rings and in vitamin D3-treated mice. PDK4 augmented the osteogenic differentiation of VSMCs by phosphorylating SMAD1/5/8 via direct interaction, which enhances BMP2 signaling. Furthermore, increased expression of PDK4 in phosphate-treated VSMCs induced mitochondrial dysfunction followed by apoptosis. Taken together, our results show that upregulation of PDK4 promotes vascular calcification by increasing osteogenic markers with no adverse effect on bone formation, demonstrating that PDK4 is a therapeutic target for vascular calcification
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