• 제목/요약/키워드: radiation sources

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Distributions and Sources of Dissolved Organic Matter in Seawaters Surrounding Aqua Farms on the Haengwon-ri in Jeju-Island in Summer 2015 (2015년 하계 제주 행원리 일대 양식장주변 해수 중 용존유기물 분포와 기원)

  • Kim, Jeonghyun;Kim, Tae-Hoon
    • Ocean and Polar Research
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    • v.39 no.1
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    • pp.35-43
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    • 2017
  • Concentrations of dissolved organic carbon (DOC), dissolved organic nitrogen (DON), dissolved organic phosphate (DOP), and colored dissolved organic matter (CDOM) were measured in the coastal sea off inland aqua farms in northeastern Jeju Island in summer 2015. The highest concentrations of DOC, DON, and DOP were revealed in the surface water off Hado-ri where the lowest salinity conditions prevailed (31.6). The concentrations of DOC, DON, and DOP in the surface water were lower in the inner stations (SH1-1, 1-2, and 1-3) near the aqua farms of the Haengwon-ri than in the outer stations. The concentrations of DOC, DON, and DOP negatively correlated with salinity. These results indicate that the contribution of dissolved organic matter (DOM) from the aqua farms seems to be not significant. On the other hand, the higher concentrations of DON and DOP in the inner stations of Hado-ri (HD 1-1) seem to be attributed to excrement of migrating birds. The three components of CDOM (T, M, and C peaks) showed no relationship with salinity, perhaps due to various in situ productions by marine organisms and decomposition by ultraviolet radiation. The observed lower C:M ratio, an indicator of terrestrial source, and the higher biological index (BIX) of CDOM in the station off Hado-ri indicate that DOM is produced mainly by biological activity. Based on the higher humification index (HIX) of CDOM and the higher DOC:DON ratio off Haengwon-ri, refractory DOM in the inland aqua farms is likely transported to the coastal sea.

GUI construction for 3D visualization of ocean hydrodynamic models (해수유동모델의 3차원 가시화를 위한 GUI 구축)

  • Lee, Won-Chan;Park, Sung-Eun;Hong, Sok-Jin;Oh, Hyun-Taik;Jung, Rea-Hong;Koo, Jun-Ho
    • Proceedings of KOSOMES biannual meeting
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    • 2006.11a
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    • pp.213-215
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    • 2006
  • This study presents an application of GIS technologies to construct the graphic user interface for 3-dimensional exhibition of the results obtained by ocean hydrodynamic model. In coastal management studies, GIS provide a receptacle for scattered data from diverse sources and an improvement of the 3D visualization of such data. Within the frame of a GIS a variety of analytical, statistical and modeling tools can be applied to transform data and make them suitable for a given application. A 3D hydrodynamic model was driven by time-dependent external forcing such as tide, wind velocity, temperature, salinity, river discharge, and solar radiation under the open boundary condition. The Jinhae Bay was selected as a case study. Here, we have used GeoMania v2.5 GIS software and its 3D Analyst extension module to visualize hydrodynamic model result that were simulated around the Jinhae Bay.

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Spatial and Temporal Variations of Atmospheric Concentrations of Carbonyl Compounds in Seoul Metropolitan Area (수도권 지역 대기 중 카보닐화합물의 시.공간적 농도 분포 특성)

  • Seo, Young-Kyo;Jeong, Eun-Hui;Seo, Seok-Jun;Hwang, Yun-Jeong;Han, Jin-Seok;Bae, Sung-Ok
    • Journal of Korean Society for Atmospheric Environment
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    • v.24 no.2
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    • pp.206-219
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    • 2008
  • The purpose of this study is to evaluate concentrations of carbonyl compounds during summer season in Seoul metropolitan area. The air samples were collected at 7 sites in this area from June 2001 to June 2003. The carbonyl compounds were analyzed by DNPH/HPLC method. The analytical method applied in this study showed good repeatability, linearity, and sensitivity. The most abundant carbonyl was formaldehyde (average 4.48 ppb), and followed by acetone, acetaldehyde, methyl ethyl ketone, butyraldehyde, propionaldehyde and benzaldehyde, respectively. Concentrations of carbonyl compounds in June were higher than those in August. There was not only higher solar radiation but also higher ozone concentration in June than in August. As a result o photochemical reactions, carbonyl compounds from both primary and secondary sources are likely to contribute to the formation of ozone. The contributions to photochemical ozone creation of two carbonyl compounds such as formaldehyde and acetaldehyde were estimated to be about 70%. Ratios of formaldehyde to acetaldehyde in this study ranged from 1.13 to 4.26, which are generally equivalent levels to those of other urban areas in domestic and foreign countries.

Analysis of Steady Flow Around a Two-Dimensional Body Under the Free Surface Using B-Spline Based Higher Order Panel Method (B-Spline 기저 고차경계요소법에 의한 자유수면하의 2차원 물체주위 유동해석)

  • Jae-Moon Lew;Yang-Ik Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.39 no.1
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    • pp.8-15
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    • 2002
  • A two-dimensional higher order panel method using B-splines has been developed to overcome the disadvantages of the low order panel method and to obtain more accurate solution. The sources and the normal dipoles are distributed on both the body and the free surface. Instead of applying the upwind finite difference schemes to satisfy the linearized free surface and the radiation condition, the derivatives of the basis functions of the B-splines are directly applied to the linearized free surface condition. Numerical damping in the Dawson's method are avoided in the Present computations. In order to validate the present method, numerical computations are carried out for a submerged cylinder and a two-dimensional hydrofoil steadily moving beneath a free surface. The numerical results show that fast convergence and better accuracies have been achieved by the present method.

PATHWAYS AND GENES OF DNA DOUBLE-STRAND BREAK REPAIR ASSOCIATED WITH HEAD AND NECK CANCER (DNA 이중나선파손의 수복 과정과 이와 연관된 두경부암 발생 유전자)

  • Oh, Jung-Hwan;Lee, Deok-Won;Ryu, Dong-Mok
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.35 no.1
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    • pp.1-6
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    • 2009
  • DNA double-strand breaks (DSBs) occur commonly in the all living and in cycling cells. They constitute one of the most severe form of DNA damage, because they affect both strand of DNA. DSBs result in cell death or a genetic alterations including deletion, loss of heterozygosity, translocation, and chromosome loss. DSBs arise from endogenous sources like metabolic products and reactive oxygen, and also exogenous factors like ionizing radiation. Defective DNA DSBs can lead to toxicity and large scale sequence rearrangement that can cause cancer and promote premature aging. There are two major pathways for their repair: homologous recombination(HR) and non-homologous end-joining(NHEJ). The HR pathway is a known "error-free" repair mechanism, in which a homologous sister chromatid serves as a template. NHEJ, on the other hand, is a "error-prone" pathway, in which the two termini of the broken DNA molecule are used to form compatible ends that are directly ligated. This review aims to provide a fundamental understanding of how HR and NHEJ pathways operate, cause genome instability, and what kind of genes during the pathways are associated with head and neck cancer.

GUI Implementation for 3D Visualization of Ocean Hydrodynamic Models (해수유동모델 결과의 3차원 가시화를 위한 GUI 구현)

  • Choi, Woo-Jeung;Park, Sung-Eun;Lee, Won-Chan;Koo, Jun-Ho;Suh, Young-Sang;Kim, Tae-Hyun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.7 no.3
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    • pp.99-107
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    • 2004
  • This study presents an application of GIS technologies to construct the graphic user interface for 3-dimensional exhibition of the results obtained by ocean hydrodynamic model. In coastal management studies, GIS provide a receptacle for scattered data from diverse sources and an improvement of the 3D visualization of such data. Within the frame of a GIS a variety of analytical, statistical and modeling tools can be applied to transform data and make them suitable for a given application. A 3D hydrodynamic model was driven by time-dependent external forcing such as tide, wind velocity, temperature. salinity, river discharge, and solar radiation under the open boundary condition. The Jinhae bay was selected as a case study. Here, we have used GeoMania v2.5 GIS software and its 3D Analyst extension module to visualize hydrodynamic model result that were simulated around the Jinhae bay.

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Optimum Design of Ring Light for Medical Purpose using High Brightness LED (고휘도 LED 를 이용한 의료용 링 라이트의 최적 설계)

  • Cheon, Min-Woo;Park, Yong-Pil
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.10a
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    • pp.757-758
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    • 2010
  • At the time of medical treatment and surgical operation, halogen lamp and plasma lamp were mainly used as luminous source for lighting. These two luminous sources have drawbacks that the life of lamps are not long, various problems are brought about due to excessive heat generation and its volume is very big because of cooling device. Accordingly, in this research a ring light was developed so that a partial shadowless shooting for the patient's affected area at the medical treatment room and surgical operation room using high luminance LED for which attention is being paid as new lighting parts for medical purpose. LED which was applied to the development used high luminance three color LED for full color for which various color materialization and the adjustment of radiation intensity are possible and we can get white light in order to emphasize the delicate expression for generic tone of shooting object, strong highlight, simple shadow and three dimensional effect at the time of close-up shadowless shooting of the affected area.

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Numerical Study on the Thermal Environment of a Natural Light Based Multi-layered Plant Factory (자연광 기반 적층형 식물공장의 열환경에 대한 수치해석 연구)

  • Park, Dong Yoon;Jang, Seong-Teak;Chang, Seong-Ju
    • KIEAE Journal
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    • v.13 no.5
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    • pp.43-50
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    • 2013
  • Recent researches on plant factory system deal with the convergence of lighting technology, agricultural technology inclusive to the high-tech industries worldwide in order to respond to the decreasing crop harvest due to global warming and abnormal weather phenomena. However, the fundamental performance standard is not currently being introduced in the case of plants factory and its commercialization is not activated because of high initial investment and operating cost. Large portion of the initial investment and operating cost of a plant factory is ascribed to artificial light sources and thermal control facilities, therefore, innovation should be provided in order to improve the economics of the plant factory. As an alternative, new plant factory could harness solar thermal and geothermal systems for heating, cooling and ventilation. In this study, a natural light dependent multi-layer plant factory's thermal environment was analyzed with two-dimensional numerical methods to elicit efficient operation conditions for optimized internal physical environment. Depending on the supply air temperature and airflow rate introduced in the facility, the temperature changes around the crops was interpreted. Since the air supplied into the plant factory does not stay long enough, the ambient temperature predicted around the plating trays was not significantly different from that of the supplied air. However, the changes of airflow rate and air flow pattern could cause difference to the temperature around the planting trays. Increasing the amount of time of air staying around the planting trays could improve energy performance in case the thermal environment of a natural light based multi-layer plant factory is considered.

Dose Distribution&Calibration in HDR Intracavitary Irradiation for Uterine Cervical Cancer (자궁경부암의 강내치료를 위한 선량측정)

  • 김진기;김정수;김형진;권형철
    • Progress in Medical Physics
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    • v.6 no.1
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    • pp.13-18
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    • 1995
  • Dose distribution of HDR-RALS source represents an inverse square law as the distance. Difference of measurement value and calculation value according of brachytherapy. Therefore, in HDR-RALS dose calibration and calculation have an important effect in treatment of uterine cervical cancer and absorbed dose of interesting points. In intracavitary therapy, particula attention is paid for precise determination of the doses to be applied. In this report, we have discussed that the calibration of a HDR-RALS, differences between calculation dose use of isodose chart and measurement in rectum. Dose rate calibration of radiation sources are obtained from air kerma and Г factor with calibraed ion chamber for cobalt source. and used semiconductor detector for compared with measurement in phantom. Eighteen patients were treated with a HDR-RALS for intrcavitarty irradiation (ICR) using a cobalt-cesium source. Repoductivity of dose measurements were 0.3 -1.1% in phantom. The means of dose distribution was -6- +21% between calculation of isodose chart and measurement of recyum, and was same mean value upper 6.3% in measurement value than calculation does.

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Effects of Gamma Irradiation on the Decontamination of Animal Feeds: Sterilization of Carbohydrate Sources (배합사료 원료에 대한 방사선 살균 효과 ; 탄수화물의 살균)

  • 조한옥;변명우;권중호;이재원;김영배
    • Journal of Food Hygiene and Safety
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    • v.2 no.3
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    • pp.97-102
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    • 1987
  • The effects of gamma irradiation on microbiological and physicochemical qualities in raw ingredients (thirteen kinds of cereal grain and their by-product) of mixed feeds were investigated. The total aerobic bacteria counts in the samples were $10^2\;to\;10^6/g$. They were sterlllzed to a undetectable level by 5 to 7 kGy irradiation. Coliforms were contaminated in high levels in all sample, ranging from $10^2\;to\;10^6/g$. They were radiation-llensitive and completely eliminated by irradiation with 3 to 5 kGy. Total fungi, ranging from $10^2\;to\;10^4/g$, mainly osmophiles were identified as Aspergillus and Penicillium. They were eliminated below identification limit by 5 to 7 kGy irradiation. Seven kinds of species, including Aspergillus IkrlJUB. were identified as a potential mycotoxin producers. Physicochemical qualities, such as total amino acid content, total sugar content. TBA value and color difference showed that an optimum dose of irradiation was less detrimental than ethylene oxide fumigation.

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