• Title/Summary/Keyword: a confined area

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Can relativistic electrons be accelerated in the geomagnetic tail region?

  • Lee, J.J.;Parks, G.K.;Min, K.W.;Lee, E.S.;McCarthy, M.P.;Hwang, J.A.;Lee, C.N.
    • Bulletin of the Korean Space Science Society
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    • 2008.10a
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    • pp.31.1-31.1
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    • 2008
  • While some observations in the geomagnetic tail region supported electrons could be accelerated by reconnection processes, we still need more observation data to confirm electron acceleration in this region. Because most acceleration processes accompany strong pitch angle diffusion, if the electrons were accelerated in this region, strong energetic electron precipitation should be observed near earth on aurora oval. Even though there are several low altitude satellites observing electron precipitation, intense and small scale precipitation events have not been identified successfully. In this presentation, we will show an observation of strong energetic electron precipitation that might be analyzed by relativistic electron acceleration in the confined region. This event was observed by low altitude Korean STSAT-1, where intense several hundred keV electron precipitation was seen simultaneously with 10 keV electrons during storm time. In addition, we observed large magnetic field fluctuations and an ionospheric plasma depletion with FUV aurora emissions. Our observation implies relativistic electrons can be generated in the small area where Fermi acceleration might work.

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A Study on Thermal Characteristics on Polymeric Floorings (고분자물질 바닥재의 열적특성에 관한 연구)

  • Lee, Nae-Woo;Kim, Nam-Seok;Moon, Byoung-Soo
    • Journal of the Korean Society of Safety
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    • v.21 no.6 s.78
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    • pp.38-45
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    • 2006
  • Polymeric floorings mainly consisted of PVC are easily decomposed by many kinds of hot environmental factors, then generate hazardous asphyxiate gases and/or toxic gases etc. Therefore the mechanism of decomposition and quantitative toxic indices of products are very important for preventing safety and health disasters, especially in case of confined area. So we have investigated decomposition kinetics, numbers of process involved, toxicity indices of product and so on, using DSC, TGA, FT-IR and Pyrolyzer-GC/MS. The thermal decomposition process of polymeric floorings can be mainly divided by dehydrochlorinated reaction and polyene decomposition step, and activation energies of those are approximately $53.93{\sim}62.42kcal/mol$. Especially lethal concentration($LC_{50}$), fractional effective dose (FED) are calculated by measuring the amount of decomposition product. The values on $LC_{50}$ of sample G are ranged $2,003{\sim}2,019(mg/m^{3})$ in case of sample K and H are $1,877,\;1,998(g/m^{3})$ respectively. Even if the results are estimated by calculation method without animal test and/or clinical demonstration, these values could be very useful data for occupational health, hygiene and safety control.

The Forms of Man's Wig in Seventeen-Eighteen Century Focused on the movie "Pirates Of The Caribbean: The Curse of the Black Pearl" (17, 18세기 남성의 가발형태 영화 "캐리비안의 해적-블랙펄의 저주-"을 중심으로)

  • Choi, Mi-Ouk;Kim, Sung-Nam
    • Journal of the Korean Society of Fashion and Beauty
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    • v.5 no.3
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    • pp.105-110
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    • 2007
  • With the beginning of seventeenth century, the men in France royal palace began to wear wigs and by eighteenth century wig became sole possession of men. Then, it had been become a satire thing filling one side of the era with the pouf that had been for women. All these things were closely related with the unstable social situation. The bourgeoisie expressed the anger for the privilege that come from the disparity of class consciousness. The reaction against the discriminative treatment by the illuminists stimulated the outbreak of the French Revolution on 14th, July in 1789. This paved way of characterizing the wig styles of the time. The symbolism of cultural-historical meaning in the west is not confined only in Europe. The worship of hair that is different from one cultural area to another had started with their own unique taboo consciousness and had developed to the form speaking for the expression of masculine, the symbol of man power and the extravagance of the privileged class.

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A Numerical Study on the Heat Transfer Characteristics of the Multiple Slot Impinging Jet (다양한 노즐 수 변화에 따른 충돌 제트의 열전달 특성에 관한 수치적 연구)

  • Kim, Sang-Keun;Ha, Man-Yeong;Son, Chang-Min
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.23 no.11
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    • pp.754-761
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    • 2011
  • The present study numerically investigates two-dimensional flow and heat transfer in the multiple confined impinging slot jet. Numerical simulations are performed for the different Reynolds numbers(Re=100 and 200) in the range of nozzles from 1 to 9 and height ratios(H/D) from 2 to 5, where H/D is the ratio of the channel height to the slot width. The vector plots of velocity profile, stagnation and averaged Nusselt number distributions are presented in this paper. The dependency of thermal fields on the Reynolds number, nozzle number and height ratio can be clarified by observing the Nusselt number as heat transfer characteristic at the stagnation point and impingement surface. The Nusselt number at the stagnation point of the central slot shows unsteadiness at H/D=3 and Re=200. The value of Nusselt number at the stagnation point of the central slot decreases with higher Reynolds number and number of nozzle although overall area averaged Nusselt number increases. Hence careful selection of geometrical parameters and number of nozzle are necessary for optimization of the heat transfer performance of multiple slot impinging jet.

Toward the Directions of Landscape Study from the Review of Literatures and the Analysis of Composition of Taek-li-ji (택리지의 경관논적 연구방향 모색 -연구사적 고찰과 구성체계의 분석-)

  • 전미경;정기호
    • Journal of the Korean Institute of Landscape Architecture
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    • v.23 no.1
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    • pp.175-188
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    • 1995
  • Most of studies about Taegni-Ji were searched in the field of geography and history. These are relrealed the conflictin respects of the structure and contents of Taegni-Ji. This study reviewed these studies and searched for limits and inquiries. Thus the parts of overlooking in them were dealt with and interpretated in terms of the characters of the contents and structure of Taegni-Ji. This book is regarded as the subjects of traditional evaluation of landscape. Tractional landscapes were related to Pung-su in many sides. So the contents specialty related to Pung-su which refered used in Taegni-Ji were discussed through the system of Taegni-Ji. As a result the terms of Pung-su used in Taegni-Ji must be researched which were specific term or not. Those studies are bibliographical review. Taegni-Ji contains of many apparent view of rural landscape thug they will be carried to field survey. Research in this area is at an early stage. The Present stuffy was confined to an examination of the characteristics and transformation process of the location of seowons However, it is hoped that this study will offer meaningful guide for further research.

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Retrofitting of squat masonry walls by FRP grids bonded by cement-based mortar

  • Popa, Viorel;Pascu, Radu;Papurcu, Andrei;Albota, Emil
    • Earthquakes and Structures
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    • v.10 no.1
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    • pp.125-139
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    • 2016
  • For seismic retrofitting of masonry walls, the use of fibre reinforced cement-based mortar for bonding the fibre grids can eliminate some of the shortcomings related to the use of resin as bonding material. The results of an experimental testing program on masonry walls retrofitted with fibre reinforced mortar and fibre grids are presented in this paper. Seven squat masonry walls were tested under unidirectional lateral displacement reversals and constant axial load. Steel anchors were used to increase the effectiveness of the bond between the fibre grids and the masonry walls. Application of fibre grids on both lateral faces of the walls effectively improved the hysteretic behaviour and specimens could be loaded until slip occurred in the horizontal joint between the masonry and the bottom concrete stub. Application of the fibre grids on a single face did not effectively improve the hysteretic behaviour. Retrofitting with fibre reinforced mortar only prevented the early damage but did not effectively increase deformation capacity. When the boundaries of the cross sections were not properly confined, midplane splitting of the masonry walls occurred. Steel anchors embedded in the walls in the corners area effectively prevented this type of failure.

A Study on the Characteristics of Penthouse Apartmaent Planning in Korea - Focus on the case analysis of penthouse in Seoul - (국내 펜트하우스(하늘채)의 공간 특성에 관한 연구 - 서울에 위치한 펜트하우스의 평면 계획 분석을 중심으로 -)

  • Choi, Kwang-Min;Hur, Bum-Pall
    • Korean Institute of Interior Design Journal
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    • v.20 no.3
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    • pp.172-181
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    • 2011
  • Many of penthouse apartments began to be built and distributed in Korea from the 2000s. However, we have a transformed definition from the international concept of penthouse. It seems that the penthouse apartments in Korea have a confined definition as a luxury and privileged house-we often find it out from advertisements of newly built apartments. In this thesis, therefore, it needs to make a clear and substantial definition of penthouse. And on the base of this definition, this study is intended to analyze planes of penthouse apartments which are distributed recently. It is in order to find out positive aspects of penthouse apartments and to make practical application of this analysis. The process of this study for plane-planning is as follows. Firstly, it is investigated and analyzed that external factors that have an effect on plane-planning such as locations and types of penthouse apartments. Secondly, an interior of penthouse apartments are divided into a private, public and outward area. And properties of each area through this research show the way of division and arrangement of plane. Thirdly, methods of connection between spaces is analyzed on the base of results of research for the way of partition. Finally, specific characters of penthouse apartments planning is derived from synthesis of research. In conclusion, analysis of plane-planning of penthouse apartments is summarized as follows. The majority of penthouse apartments is arranged to small portions of households and on higher stories in apartment which is situated around Han River or public parks. These external factors influence the plane-planning in both the interior and exterior way. For the exterior planning in space, it becomes important to design bays as many as possible in contact with outside in order to satisfy demands for fine prospects. It is also important to plan extra places naturally such as a terrace in order to provide virtual grounding. In the interior planning, a large size of interior induces to develop space for linking between each area, such as corridors or extra rooms. This makes it possible that the private area is linked to each other, at the same time it has its own distinctiveness according to its usage.

Plasma D-dimer Can Effectively Predict the Prospective Occurrence of Ascites in Advanced Schistosomiasis Japonica Patients

  • Wu, Xiaoying;Ren, Jianwei;Gao, Zulu;Xu, Yun;Xie, Huiqun;Li, Tingfang;Cheng, Yanhua;Hu, Fei;Liu, Hongyun;Gong, Zhihong;Liang, Jinyi;Shen, Jia;Liu, Zhen;Wu, Feng;Sun, Xi;Niu, Zhongzheng;Ning, An
    • Parasites, Hosts and Diseases
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    • v.55 no.2
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    • pp.167-174
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    • 2017
  • China still has more than 30,000 patients of advanced schistosomiasis while new cases being reported consistently. D-dimer is a fibrin degradation product. As ascites being the dominating symptom in advanced schistosomiasis, the present study aimed to explore a prediction model of ascites with D-dimer and other clinical easy-achievable indicators. A case-control study nested in a prospective cohort was conducted in schistosomiasis-endemic area of southern China. A total of 291 patients of advanced schistosomiasis were first investigated in 2013 and further followed in 2014. Information on clinical history, physical examination, and abdominal ultrasonography, including the symptom of ascites was repeatedly collected. Result showed 44 patients having ascites. Most of the patients' ascites were confined in the kidney area with median area of $20mm^2$. The level of plasma D-dimer and pertinent liver function indicators were measured at the initial investigation in 2013. Compared with those without ascites, cases with ascites had significantly higher levels of D-dimer ($0.71{\pm}2.44{\mu}g/L$ vs $0.48{\pm}2.12{\mu}g/L$, P=0.005), as well ALB (44.5 vs 46.2, g/L) and Type IV collagen (50.04 vs $44.50{\mu}g/L$). Receiver operating characteristic curve analyses indicated a moderate predictive value of D-dimer by its own area under curve (AUC) of 0.64 (95% CI: 0.54-0.73) and the cutoff value as $0.81{\mu}g/L$. Dichotomized by the cutoff level, D-dimer along with other categorical variables generated a prediction model with AUC of 0.76 (95% CI: 0.68-0.89). Risks of patients with specific characteristics in the prediction model were summarized. Our study suggests that the plasma D-dimer level is a reliable predictor for incident ascites in advanced schistosomiasis japonica patients.

Real-time Monitoring of Ammonia and Hydrogen Sulfide According to Workplace at Swine Farms (양돈장 작업장소별 암모니아 및 황화수소의 실시간 모니터링)

  • Park, Jihoon;Kang, Taesun;Seok, Jiwon;Jin, Suhyun;Heo, Yong;Kim, Kyungran;Lee, Kyungsuk;Yoon, Chungsik
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.23 no.4
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    • pp.402-411
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    • 2013
  • Objectives: This study aims to assess the concentrations of ammonia and hydrogen sulfide according to task unit area at swine farms. Methods: A total of six swine farms were selected for this study. Ammonia and hydrogen sulfide were monitored using a real-time multi-gas monitor which could sample the gases simultaneously. The sampling was done in the pig building, manure storage facility and composting facility of each farm. Results: The concentration of ammonia in the pig buildings(GM 22.6 ppm, GSD 2.3) was significantly higher(p<0.0001) than in the manure storage facilities(GM 10.4 ppm, GSD 2.7) and composting facilities(GM 8.6 ppm, GSD 2.8). The concentration of hydrogen sulfide in the manure storage facilities(GM 9.8 ppm, GSD 3.2) was higher(p<0.0001) than in the pig buildings(GM 2.3 ppm, GSD 2.3) and composting facilities(GM 1.9 ppm, GSD 2.5). In particular, the levels of hydrogen sulfide in the confined manure storage facilities were higher than those in open-type facilities and the peak concentration(98 ppm) in the confined facilities was approximate to 100 ppm, at the value of Immediately Dangerous to Life or Health(IDLH). Conclusions: Suffocation accidents caused by hazardous gases at a swine farm have occurred annually. Real-time monitoring of the hazards should be done in order to protect farm workers and livestock from the sudden accidents.

An Analysis of Groundwater Flow at Bugok Area Using MODFLOW (MODFLOW 모형을 이용한 부곡온천지역 지하수 유동해석)

  • Chung, Sang-Ok;Lee, Young-Dae;Min, Byung-Hyung
    • Water for future
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    • v.27 no.1
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    • pp.79-88
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    • 1994
  • This study was conducted to analyse groundwater flow in the Bugok hot spring area using the MODFLOW model which can simulate three dimensional groundwater flow both in confined and unconfined aquifers. Based on this study the following conclusions were obtained: 1) The hydraulic conductivity and the specific storage of the aquifer were 0.0135 m/day and 0.020, respectively, and the model-predicted groundwater elevation agreed well with the observed one. 2) Simulation results showed that the groundwater level declines at the end of the one-year simulation period when the annual recharge rate is small and the annual pumping rate high, which is the worst combination. Except that combination, the groundwater level does not decline at the end of one-year simulation period indication the pumping rates used were allowable. 3) The safe yield depends upon the magnitudes of the recharge and pumping rates. The pumping rate should not produce excess decline of groundwater level around April when the water level is the lowest in a year.

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