• 제목/요약/키워드: Natural Standard

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건설폐토석의 식생용토로서의 이화학적 특성 (Physico-Chemical Properties of the Recycled Waste Soils from Construction Site as Planting Soil)

  • 김원태;윤용한;박봉주
    • 한국환경복원기술학회지
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    • 제10권5호
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    • pp.31-39
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    • 2007
  • This study was carried out to evaluation the recycled waste soils from construction site for planting soil. For this purpose, the concentrations of polluted materials and the physico-chemical properties were measured at recycled soil samples of an industrial waste treating company in the Metropolitan landfill area. The concentrations of polluted materials did not exceed to the standard critical levels of soil pollution in all analyzed items. The measures of the samples soil texture (loamy sand), bulk density (1.09~1.32g/$cm^3$), saturated hydraulic conductivity ($1.6{\times}10^{-3}{\sim}1.8{\times}10^{-3}$cm/sec), solid phase distribution (0.4~0.5$m^3/m^3$), porosity (0.5~0.6$m^3/m^3$), Ex. $K^+$ (1.0~1.2cmol/kg), Ex. $Mg^{2+}$ (0.2~0.6cmol/kg) were identified as not worse than those of conventional planting soil. But the sample soils have serious problems for planting soil such as high levels of pH (9.6~11.5), EC (0.78~1.84ds/m) and Ex. $Ca^{2+}$ (25.6~34.5cmol/kg), low level of organic matter (0.2~0.3%). It is required to improve pH, EC and Ex. $Ca^{2+}$ of sample soils. Consequently, the results suggested a high potential of recycling of the wastes soils for planting soil.

Airborne Nicotine Concentrations in the Workplaces of Tobacco Farmers

  • Yoo, Seok-Ju;Park, Sung-Jun;Kim, Byoung-Seok;Lee, Kwan;Lim, Hyun-Sul;Kim, Jik-Su;Kim, In-Shik
    • Journal of Preventive Medicine and Public Health
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    • 제47권3호
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    • pp.144-149
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    • 2014
  • Objectives: Nicotine is a natural alkaloid and insecticide in tobacco leaves. Green tobacco sickness (GTS) is known as a disease of acute nicotine intoxication among tobacco farmers. Until now, GTS has been recognized globally as a disease that results from nicotine absorption through the skin. However, we assumed that GTS might also result from nicotine inhalation as well as absorption. We aimed to measure the airborne nicotine concentrations in various work environments of Korean tobacco farmers. Methods: We measured the nicotine concentrations in the tobacco fields, private curing barns, and joint curing barns of farmers from July to October 2010. All sampling and analyses of airborne nicotine were conducted according to the National Institute for Occupational Safety and Health manual of analytic methods. Results: The airborne nicotine concentrations (geometric mean [geometric standard deviation]) in the tobacco field were $83.4mg/m^3$ (1.2) in the upper region and $93.3mg/m^3$(1.2) in the lower region. In addition, the nicotine concentration by personal sampling was $150.1mg/m^3$. Similarly, the nicotine concentrations in the private curing barn, workers in curing barns, the front yard of the curing barn, and in the joint curing barn were $323.7mg/m^3$(2.0), $121.0mg/m^3$(1.5), $73.7mg/m^3$(1.7), and $610.3mg/m^3$(1.0), respectively. Conclusions: The nicotine concentration in the workplaces of tobacco farmers was very high. Future studies should measure the environmental concentration of nicotine that is inhaled by tobacco farmers.

비선형 초음파공명 특성을 이용한 미세균열 탐지 (Detection of Micro-Crack Using a Nonlinear Ultrasonic Resonance Parameters)

  • 정용무;이덕현
    • 비파괴검사학회지
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    • 제32권4호
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    • pp.369-375
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    • 2012
  • 기존 비파괴평가 기술의 결함 탐지 한계를 극복하기 위하여 비선형 초음파공명 특성을 이용한 미세 균열 진단 기술을 개발하였다. 가진 전압에 따른 초음파공명 주파수의 천이현상과 정규화 공명 진폭 감소 현상을 비선형 초음파공명 특성 파라미터로 제안하였으며 이를 실험적으로 확인하였다. CT 시편에 피로시험을 통하여 미세한 자연 균열을 생성하였으며 피로 사이클 단계마다 초음파공명주파수와 정규화 공명진폭의 변화를 측정하였다. 무결함 또는 10 ${\mu}m$ 정도의 매우 미세한 균열이 존재하는 시편에서는 초음파공명 주파수 천이현상이나 정규화 공명 진폭의 변화가 나타나지 않는 반면에 30 ${\mu}m$급 이상의 미세 균열 시편에서는 균열 크기가 증가함에 따라 초음파공명주파수의 천이 현상이나 정규화 공명 진폭의 감소량이 증가함을 확인하였다.

고령친화용품 표준화를 위한 분류 (Classification for a Standardization System for the Elderly's Necessities)

  • 김이순;권자연;신순식;문인혁;황이철;김경철
    • 동의생리병리학회지
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    • 제20권2호
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    • pp.328-332
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    • 2006
  • This study aims to provide definitions and standardization for necessities that elderly people can use conveniently and properly in their daily lives and classify necessities for different purposes. First, standard terminologies were defined by reviewing the literature and the relevant laws related to daily necessities for the elders. Secondly, a concept for necessities for the elders was also defined through consultation with experts. Lastly, the elderly's necessities were selected and classified. The elderly's necessities are defined as aids that ordinary elderly people in normal aging process need for the purpose of the convenience of life and aids they wear or use to maintain or improve their health. In this study, the elderly's necessities are divided into three categories: necessities of health, necessities of Oriental medical aids and necessities of daily living. Each category is further classified as follows: Necessities of health include aids for personal medical treatment, aids for personal care and protection and aids for recreation. Necessities of Oriental medical aids include aids for personal medical treatment, aids for personal care and protection and others. Necessities of daily living include aids for personal care and protection, aids for personal mobility, aids for housekeeping, furnishings, aids for communication, information and signalling, aids for handling products and goods and aids for recreation. The classification of the elderly's necessities in this study can be used as basic information for further studies of demand for necessities for the elderly. The results will lay the foundation for a standardization system for the elderly's necessities and the development of silver industry.

국내 음용지하수중 전알파 특성 연구 (Study on Gross-alpha Characteristics of Groundwater for Drinking in Korea)

  • 정도환;이영준;주병규;노회정;유순주;김문수
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제16권5호
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    • pp.67-73
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    • 2011
  • Groundwaters were sampled from 730 wells being used for drinking purposes during 2007-2009. These samples were analysed using a gas-flow type GPC (Gas Proportional Counter) according to the USEPA method (900.0). We obtained a gross-alpha counting TDS (total dissolved solid) efficiency curve (Y = 0.0017X2 - 0.3122X + 19.165, X = TDS, Y = efficiency, $R^2$ = 0.9734) using natural uranium standard to get gross ${\alpha}$ value of the samples. The gross alpha values ranged from MDA (minimum detectable activity) to 14.88 pCi/L and 429 samples showed values higher than MDA (< 0.9 pCi/L). Correlations of the uranium values with the total alpha values and the gross-alpha values indicate that uranium values have high impacts on gross-alpha values. Groundwater samples of study areas were classified into four regions according to the rock types; plutonic (granite) rock region (427 areas), metamorphic rock region (181 aeras), sedimentary rock region (70 areas), volcanic rock region (52 areas). Groundwater of Cretaceous granite presented the highest gross-alpha value. Gross alpha in groundwaters showed no relationship with uranium in terms of the geological ages, rocks and minerals.

개구부가 있는 밀폐공간내 화재의 복합열전달 및 연소가스 분석에 관한 연구 (A Study on the Combined Heat Transfer and Analysis Fire Induced Combustion Gas in a partially Open Enclosure)

  • 박찬국;추병길;김철
    • 한국화재소방학회논문지
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    • 제11권1호
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    • pp.21-35
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    • 1997
  • The natural convection and combined heat transfer induced by fire in a rectangular enclosure is numerically studied. The model for this numerical analysis is partially opened right wall. The solution procedure includes the standard k-$\varepsilon$ model for turbulent flow and the discrete ordinates method (DOM) is used for the calculation of radiative heat transfer equation. In numerical study, SIMPLE algorithm is applied for fluid flow analysis, and the investigations of combustion gas induced by fire is performed by FAST model of HAZARD I program. In this study, numerical simulation on the combined naturnal convection and radiation is carried out in a partial enclosure filled with absorbed-emitted gray media, but is not considered scattering problem. The streamlines, isothermal lines, average radiation intensity and kinetic energy are compared the results of pure convection with those of the combined convection-radiation, the combined heat transfer. Comparing the results of pure convection with those of the combined convection-radiation, the combined heat transfer analysis shows the stronger circulation than those of the pure convection. Three different locations of heat source are considered to observe the effect of heat source location on the heat transfer phenomena. As the results, the circulation and the heat transfer in the left region from heating block are much more influenced than those in the right region. It is also founded that the radiation effect cannot be neglected in analyzing the building in fire. And as the results of combustion gas analysis from FAST model, it is found that O2 concentration is decreased according to time. While CO and CO2 concentration are rapidly increased in the beginning(about 100sec), but slowly decreased from that time on.

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해양플랜트 설비의 비상전원공급을 위한 태양광 발전시스템 연구 (Study of a Photovoltaic System as an Emergency Power Supply for Offshore Plant Facilities)

  • 최군환;이병호;정노택;신규보
    • 한국해양공학회지
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    • 제32권4호
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    • pp.279-286
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    • 2018
  • The use of eco-friendly energy in the offshore plant system is expanding because conventional generators are operated by fossil fuel or natural gas. Eco-friendly energy, which replaces existing power generation methods, should be capable of generating the power for lighting protection equipment, airborne fault indication, parameter measurement, and others. Most of the eco-friendly energy used in offshore plant facilities is solar and wind power. In the case of using photovoltaic power, because the structure must be constructed based as flat solar panels, it can be damaged easily by the wind. Therefore, there is a need for a new generation system composed of a spherical structure that does not require a separate structure and is less influenced by the wind. Considering these characteristics, in this study we designed, fabricated, and tested a unit that could provide the most efficient spherical photovoltaic power generation considering wind direction and wind pressure. Our test results indicated that the proposed system reduced costs because it did not require any separate structure, used eco-friendly energy, reduced carbon dioxide emissions, and expanded the proportion of eco-friendly energy use by offshore plant facilities.

콘크리트 재생 순환골재의 파쇄 효과에 따른 다짐 및 열저항 특성 연구 (Effect of Particle Breakage on Compaction and Thermal Resistivity of Concrete-based Recycled Aggregates)

  • 강성철;김경훈;위지혜;안태봉;이대수;최항석
    • 한국지반공학회논문집
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    • 제31권10호
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    • pp.17-28
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    • 2015
  • 최근 친환경 건설에 대한 엄격한 규제와 가용한 천연골재 자원의 고갈에 따른 대안으로 전력구 되메움재로서 순환골재에 대한 관심이 급증하고 있다. 본 논문에서는 일반적인 되메움재인 강모래와 콘크리트 재생 순환골재를 대상으로 다짐에너지가 가해질 때, 발생하는 골재의 입자파쇄를 실내다짐시험을 통해 규명하였다. 적용된 다짐에너지 수준에서 일반 강모래는 입자파쇄가 미미하여 다짐 전후 골재의 다짐특성과 열저항의 변화가 매우 적었다. 반면에 일반 강모래에 비하여 순환골재는 재생과정에서 이미 입자에 큰 응력이 가해진 상태이므로 추가 다짐에너지에 의한 입자파쇄가 발생했다. 다짐에 의한 순환골재 입자파쇄는 세립분 양을 증가시켜 전반적으로 되메움재의 열저항을 감소시키고 입도곡선의 모양을 변화시켰다. 특히, 순환골재의 입자파쇄는 다짐에너지의 댐핑이 상대적으로 적은 저함수비 구간에서 더 뚜렷하게 발생하였다.

Health Behavior Regarding Liver Flukes among Rural People in Nakhon Ratchasima, Thailand

  • Painsing, Sirinapa;Sripong, Anan;Vensontia, Orramon;Pengsaa, Prasit;Kompor, Pontip;Kootanavanichapong, Nusorn;Kaewpitoon, Soraya J;Kaewpitoon, Natthawut
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권4호
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    • pp.2111-2114
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    • 2016
  • Opisthorchiasis is a health problem in Thailand particularly in northeast and north regions where have been reported the highest of cholangiocarcinoma. Active surveillance is required, therefore a cross-sectional surveyed was conducted in Nong Bunnak sub-district of Nakhon Ratchasima province, Thailand. A total of 367 participants were selected by multistage sampling from 5 villages located near natural water resources. Participants completed a predesigned questionnaire containing behavior questions regarding liver fluke disease, covering reliability and validity knowledge (Kuder-Richardon-20) = 0.80, attitude and practice (Cronbach's alpha coefficient) = 0.82 and 0.79, respectively. Descriptive statistics included frequencies, percentages, means, and standard deviations. The majority of the participants were female (58.3%), age group between 21-30 years old (42.5%), with primary school education (59.9%), occupation in agriculture (38.1%), and married (80.9%). They had past histories of raw fish consumption (88.3%), stool examination (1.4%), anti-parasite medication used (4.6%). Heads of villages, village health volunteers, television, and village newstations were the main sources for disease information. Participants had a moderate level of behavior regarding liver fluke disease. The mean scored of knowledge regarding liver fluke life cycle, transmission, severities, treatment, prevention and control was 10.9 (SD=0.5), most of them had a moderate level, 95.1%. The mean score for attitude regarding liver fluke prevention and control was 45.7 (SD=9.7), and for practice was 30.6 (SD=10.5). Participants had a moderate level of attitude and practice, 94.5% and 47.7, respectively. This study indicates that health education is required in this community including stool examination for liver fluke as further active surveillance screening.

Anti-Cancer Effects of Imperata cylindrica Leaf Extract on Human Oral Squamous Carcinoma cell line SCC-9 in Vitro

  • Keshava, Rohini;Muniyappa, Nagesh;Gope, Rajalakshmi;Ramaswamaiah, Ananthanarayana Saligrama
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권4호
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    • pp.1891-1898
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    • 2016
  • Imperata cylindrica, a tall tufted grass which has multiple pharmacological applications is one of the key ingredients in various traditional medicinal formula used in India. Previous reports have shown that I. cylindrica plant extract inhibited cell proliferation and induced apoptosis in various cancer cell lines. To our knowledge, no studies have been published on the effect of I. cylindrica leaf extract on human oral cancers. The present study was undertaken in order to evaluate the anticancer properties of the leaf extract of I. cylindrica using an oral squamous cell carcinoma cell line SCC-9 as an in vitro model system. A methanol extract from dried leaves of I. cylindrica (ICL) was prepared by standard procedures. Effects of the ICL extract on the morphology of SCC-9 cells was visualized by microscopy. Cytotoxicity was determined by MTT assay. Effects of the ICL extract on colony forming ability of SCC-9 cells was evaluated using clonogenic assay. Cell cycle analysis was performed by flow cytometry and induction of apoptosis was determined by DNA fragmentation assay. The ICL extract treatment caused cytotoxicity and induced cell death in vitro in SCC-9 cells in a dose-dependent manner. This treatment also significantly reduced the clonogenic potential and inhibited cell proliferation by arresting the cell cycle in the G2/M phase. Furthermore, DNA fragmentation assays showed that the observed cell death was caused by apoptosis. This is the first report showing the anticancer activity of the methanol extracts from the leaves of I. cylindrica in human oral cancer cell line. Our data indicates that ICL extract could be considered as one of the lead compounds for the formulation of anticancer therapeutic agents to treat/manage human oral cancers. The natural abundance of I. cylindrica and its wide geographic distribution could render it one of the primary resource materials for preparation of anticancer therapeutic agents.