• Title/Summary/Keyword: ecological systems

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An Evaluation on the Sound Insulation Performance of Drywall for High-Rise Buildings (초고층 건물에 적용 가능한 건식벽체의 차음성능 평가)

  • Lee, Sang-Woo;Yoo, Ho-Chun;Lee, Su-Yeal;Jung, Gap-Chul;Jung, Young-Min
    • KIEAE Journal
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    • v.7 no.2
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    • pp.3-8
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    • 2007
  • Recently, the structural system of public residential buildings has been changed from the reinforced concrete (RC) wall system to the (PC) wall and moment resisting systems. Thus, it is important to develop the suitable wall system in accordance with the trend of the modern structural system. This paper presents the basic study on the suitable boundary wall in high-rise buildings. The research also demonstrates the evaluation results on sound characteristics in the aspect of sound insulation. The evaluation of sound insulation capability for the commercialized wall structure was conducted based on literature survey while the measurement of sound insulation capability for the light-weght EPP concrete was performed in according to KS F2808 in laboratory. The main objective of this research is to propose the most suitable dry wall system as a sound insulation structure through the comparison and analysis of frequency characteristics and weight-acoustic attenuation.

ZERO-EMISSION MATERIALS CYCLE IN PRODUCTION PROCESS AND REGIONAL SCALE

  • FUJIE, Koichi
    • Clean Technology
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    • v.3 no.2
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    • pp.13-24
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    • 1997
  • The present paper aims to give basic information to establish zero emission material cycle including the minimization of emissions from industrial production processes and the area in regional scale. Strategies and methodologies to analyze emissions from the production processes and our human activities and to reduce those emissions by refining and/or replacing the unit process with the alternatives are introduced as well. Quantitative evaluation and management systems of any raw materials and the production process are from vie points of treatment are essential. Estabiishment of a process networking for the recycle of discharged non-products materials by the intra-process, trans-process and the trans-industries are proposed. Procedures and priorities to formulate industrial and regional zero emission system are proposed as well.

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Developing the Light-weight PV Blind System and the Shading Analysis by the Control Conditions (경량 태양광발전 블라인드 개발 및 제어조건에 따른 음영분석)

  • Chung, Yu-Gun
    • KIEAE Journal
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    • v.15 no.1
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    • pp.83-88
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    • 2015
  • This study aims to develope the light-weight PV blinds with windows and to investigate the shading analysis by the control conditions. For the study, the polycarbonate characteristics and coating methods are analyzed and the PV blind design for a small office is suggested. Also, the mock-up model of a suggesting system was made. The field tests were controled based on a solar altitude under clear sky conditions. As results, it is necessary to use a polycarbonate instead of a tempered glass for a light-weight PV. The shading effects of blind systems are high in slat angle $30^{\circ}$ and low in $0^{\circ}$. Also, the shading ratio is more affected by solar latitude than solar altitude. The shading change rate is relevantly constant on the solar altitude.

Alternative Nutrient Cycles for Terrestrial Plants, Positive Feedbacks through Detrital Processes, and Nutrient Use Efficiency (육상식물 중심의 영양소 순환 경로와 부식과정에 의한 양성 되먹임과정, 그리고 영양소 이용효율)

  • Lee, Dowon;Thomas P. Burns
    • The Korean Journal of Ecology
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    • v.16 no.1
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    • pp.115-131
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    • 1993
  • Six nutrient cycles involving terrestrial plants are identified and characterized. Plants affect biotic and abiotic cycles through their effects on soil properties. They determine their internal nutritional status and nutrient concentrations in their environment via internal and external cycles. Contributions of organic matter to mycorrhizal, trophic, and detrital mediated external cycles and alterations of nutrient concentrations by plants can promote positive feedbacks leading to increased availability and retention of soil nutrients in open systems. Recognizing alternative cycles through plants leads to a definition of nutrient use efficiency for ecosystems: the ratio of system production to nutrient content of organic matter. A simple graph model to predict changes of nutrient use efficiency during primary succession is then presented.

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Child Abuse (아동학대)

  • Kim, Choon-Kyung;Lee, Ju-Ok;Song, Young-Joo
    • Korean Journal of Child Studies
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    • v.30 no.6
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    • pp.349-360
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    • 2009
  • During the last ten years, a number of the substantiated child abuse cases, studies, and newspaper articles in relation to child abuse have increased rapidly. Newspaper reports on physical abuse cases decreased, while articles on those of the sexual abuse and negligence increased after the year of 2000. However, the reason of child abuse was less studied, in comparison to the substantial number of research on the policy and the negative effects of child abuse. It is suggested that child abuse studies and policies should be performed from a pre-preventive perspective as well as a pro-protective perspective. The research regarding child abuse has to be conducted in the ecological perspective which includes not only the problems of children and their families, but also sociocultural issues. The results of studies on child abuse should be applied for the actual policy and systems improvement.

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Changes in ROS-Scavenging Enzyme Activity in Rice (Oryza sativa L.) Exposed to High Salinity

  • Koo, Jeung-Suk;Choo, Yeon-Sik;Lee, Chin-Bum
    • Journal of Ecology and Environment
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    • v.30 no.4
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    • pp.307-314
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    • 2007
  • We studied changes in the biochemical and physiological status and ROS-scavenging enzyme (superoxide dismutase, catalase and peroxidase) activity in leaves and roots of rice (Oryza sativa L.) plants exposed to high salinity. Under salt stress, the reduction in RWC (relative water content) in leaves was relatively severe in comparison with that of roots. The proline content was also significantly higher in leaves of rice plants following salt treatment. The activities of CAT and POX in roots increased with increasing NaCl concentration, but the activity of SOD decreased. These results suggest that the increase of endogenous proline is closely associated with the increase of CAT and POX activities, which may play important roles in salt tolerance. Therefore, we conclude that the alleviation of oxidative damage and increased resistance to salinity may result from the presence of efficient antioxidative systems.

Enzyme Based Biosensors for Detection of Environmental Pollutants-A Review

  • Nigam, Vinod Kumar;Shukla, Pratyoosh
    • Journal of Microbiology and Biotechnology
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    • v.25 no.11
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    • pp.1773-1781
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    • 2015
  • Environmental security is one of the major concerns for the safety of living organisms from a number of harmful pollutants in the atmosphere. Different initiatives, legislative actions, as well as scientific and social concerns have been discussed and adopted to control and regulate the threats of environmental pollution, but it still remains a worldwide challenge. Therefore, there is a need for developing certain sensitive, rapid, and selective techniques that can detect and screen the pollutants for effective bioremediation processes. In this perspective, isolated enzymes or biological systems producing enzymes, as whole cells or in immobilized state, can be used as a source for detection, quantification, and degradation or transformation of pollutants to non-polluting compounds to restore the ecological balance. Biosensors are ideal for the detection and measurement of environmental pollution in a reliable, specific, and sensitive way. In this review, the current status of different types of microbial biosensors and mechanisms of detection of various environmental toxicants are discussed.

Gene Expression Profiling in the Nematode Caenorhabditis elegans, as a Potential Biomarker for Soil Ecotoxicology (잠재적 생체지표 발굴을 위한 토양선충 Caenorhabditis elegans에서의 유전자 발현 연구)

  • Roh, Ji-Yeon;Choi, Jin-Hee
    • Environmental Analysis Health and Toxicology
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    • v.25 no.1
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    • pp.1-10
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    • 2010
  • Monitoring toxicity levels in specific biological compartments is necessary to evaluate the ecotoxicological risk associated with soil environmental pollution. Gene expression, as potential biomarker, is increasingly used as rapid early warning systems in environmental monitoring and ecological risk assessment procedures. Various representative species are currently used for the purpose of assessing soil toxicity, however, investigations on toxicological assessments using endpoint based on gene-level have been limited. In this review, we will present the current trends in organisms and endpoints used in soil toxicity study and report gene expression related to toxicity using soil organism, and C. elegans as promising organisms for this approach.

The Study on Optimization of HVAC Systems Design in Tall Buildings (초고층 건축물의 최적화된 설비시스템 설계를 위한 기초연구)

  • Yu, Jung-Yeon;Cho, Dong-Woo;Yu, Ki-Hyung
    • KIEAE Journal
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    • v.5 no.1
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    • pp.11-18
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    • 2005
  • The optimized HVAC system design in tall buildings enable owners to save unnecessary energy consumption and residents to have comfort environments. The purpose of this study is to develop design process for optimized HVAC system design in tall buildings. As basic researches, literature researches and case studies of HVAC system design in tall buildings were performed. Survey was processed among expert in the field and key considerations on HVAC system design were drew as conclusions. With these conclusions, studies were performed on effects of wind velocity, outdoor air temperature, and solar radiation that are main factors of load calculation in tall buildings. Finally, air-tightness and stack effect were analyzed and estimated by literature studies, field measurements and computer simulations.

Feasibility study of ground source heat pump system according to the local climate condition (지역 기후 특성에 따른 지열시스템의 도입경제성 차이에 관한 연구)

  • Nam, Yujin
    • KIEAE Journal
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    • v.14 no.4
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    • pp.127-131
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    • 2014
  • The ground source heat pump (GSHP) system is a kind of the temperature differential energy system using relatively stable underground temperature as heat source of space heating and cooling. This system can achieve higher performance of system than it of conventional air source heat pump systems. However, its superiority of the system performance is different according to installation location or local climate, because the system performance depends on the underground condition which is decided by annual average air temperature. In this study, in order to estimate the feasibility of the ground source heat pump system according to the local climate, numerical simulation was conducted using the ground heat transfer model and the surface heat balance model. The case study was conducted in the condition of Seoul, Daejeon, and Busan, In the result, the heat exchange rate of Busan was 34.33 W/m as the largest in heating season and it of Seoul was 40.61 W/m as the largest in cooling.