• Title/Summary/Keyword: Coupled System

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The Physiological Responses and Subjective Sensation in the Subjects Wearing Dust-free Garment for Semiconductor Industrial Environments (방진복 착용에 따른 인체의 온열생리적 특성 및 주관적 감각)

  • 권오경;이창미
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 1998.04a
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    • pp.255-263
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    • 1998
  • Dust-free garment prevents contamination which otherwise is caused by skin and clothes to protect from dust or dirt. Therefore, it requires high performance and should function as a working clothes. Clothes are a medium between human and thermal environmental system, and it is required to study human enviroment to ensure comfortableness of clothes and to satisfactorily go along with enviroment .This study investigates the physical and physiological features of dust-free garment used in the clean room at a semiconductor factory in oredr to scientifically clarify what the dust-free garmint is as well as to contribute to the design and development of high performance material and clothes. Three kinds of dust-free fabrics (DFG-I, DFG-II, DFG-III) which are being developed by a local company are used to manufacture dust-free garment. These dust-free garments are dressed and tested in such an enviroment as similar to semiconmemts with temperature at 23${\pm}$1$^{\circ}C$ and humidity at 50${\pm}$5%RH in order to investigate the thermo physiological and psychological features of human body. The results of this study are as follows. The results of this study are as follows. 1.The mean skin temperature was significantly different among the clothes, subjects and experimental time. Temperature tends to rise from the time of exercising load. Continuous motion coupled sealed clothes prevents heat transmittance, and temperature rises in the order of DFG-l, DFG-ll and DFG-lll as time course. 2.As for the skin temperature by local timperature is minimun on the head and torso and increares remarkably at the terminal part of human body. 3. As for the body mass loss was significantly higher in DFG-lll than DFG-l and DFG-ll. 4. Though there is no significant difference in the temperature within clothes among the kind of clothes temperature is 1$^{\circ}C$ higher in the back. Temperature within all the dust-free garments 29.7$^{\circ}C$ in the back and 31.3$^{\circ}C$ in the chest which belong to the comfort zone(31-33$^{\circ}C$). The relative humidity is 39.7%RH in the chest and 33.8%RH in the back which is slightly below the comfort zone(40-60%RH) 5. The thermal sensation belong to the comfort zone regardless of the kinds of clothes. The subjects feels a slight fatigue as times goes. As for the subjective sense of subjects the mean skin temperature as well as temperature and humidity within clothes show similar tendency. This means that they relate with each other.

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Allergy Immunity Regulation and Synergism of Bifidobacteria (Bifidobacteria의 allergy 면역 조절과 synergism)

  • Cho, Kwang Keun;Choi, In Soon
    • Journal of Life Science
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    • v.27 no.4
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    • pp.482-499
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    • 2017
  • Allergic diseases have increased over the past several decade worldwide including developing countries. Allergic inflammatory responses are caused by Th (T helper)2 immune responses, triggered by allergen ingestion by antigen presenting cells such as dendritic cells (DCs). Intestinal microorganisms control the metabolism and physiological functions of the host, contribute to early immune system maturation during the early life, and homeostasis and epithelial integrity during life. Bifidobacteria have strain-specific immunostimulatory properties in the Th1/Th2 balance, inhibit TSLP (thymic stromal lymphopoietin) and IgE expression, and promote Flg (Filaggrin) and FoxP3 (Treg) expression to alleviate allergies. In addition, unmethylated CpG motif ODN (oligodeoxynucleotides) is recognized by TLR (toll-like receptors)9 of B cells and plasmacytoid dendritic cells (pDCs) to induce innate and adaptive immune responses, while the butyrate produced by Clostridium butyricum activates the GPR (G-protein coupled receptors)109a signaling pathway to induce the expression of anti-inflammatory gene of pDCs, and directly stimulates the proliferation of thymically derived regulatory T (tTreg) cells through the activation of GPR43 or inhibits the activity of HADC (histone deacetylase) to differentiate naive $CD4^+$ T cells into pTreg cells through the histone H3 acetylation of Foxp3 gene intronic enhancer.

3D Modeling of Turbid Density Flow Induced into Daecheong Reservoir with ELCOM-CAEDYM (ELCOM-CAEDYM을 이용한 대청댐 유입탁수의 3차원 모델링)

  • Chung, Se-Woong;Lee, Heung-Soo;Ryoo, Jae-Il;Ryu, In-Gu;Oh, Dong-Geun
    • Journal of Korea Water Resources Association
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    • v.41 no.12
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    • pp.1187-1198
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    • 2008
  • Many reservoirs in Korea and their downstream environments are under increased pressure for water utilization and ecosystem management from longer discharge of turbid flood runoff compared to a natural river system. Turbidity($C_T$) is an indirect measurement of water 'cloudiness' and has been widely used as an important indicator of water quality and environmental "health". However, $C_T$ modeling studies have been rare due to lack of experimental data that are necessary for model validation. The objective of this study is to validate a coupled three-dimensional(3D) hydrodynamic and particle dynamics model (ELCOM-CAEDYM) for the simulation of turbid density flows in stratified Daecheong Reservoir using extensive field data. Three different groups of suspended solids (SS) classified by the particle size were used as model state variables, and their site-specific SS-$C_T$ relationships were used for the conversion between field measurements ($C_T$) and state variables (SS). The simulation results were validated by comparing vertical profiles of temperature and turbidity measured at monitoring stations of Haenam(R3) and Dam(R4) in 2004. The model showed good performance in reproducing the reservoir thermal structure and propagation of stream density flow, and the magnitude and distribution of turbidity in the reservoir were consistent with the field data. The 3D model and turbidity modeling framework suggested in this study can be used as a supportive tool for the best management of turbidity flow in other reservoirs that have similar turbidity problems.

Heavy Metal Analysis of Inhabitants from City of the Seoul, Korea (서울지역 거주 성인 모발의 유해 중금속 함량 분석)

  • Im, Eun-Jin;Ha, Byung-Jo
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.35 no.1
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    • pp.27-32
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    • 2009
  • Human hair is an excretory system for trace metals and thus metal content in human hair can reflect the body status. The investigation of trace elements in human hair has been correlated with the diagnosis of various diseases as well as the monitoring of deficiency statues in nutrition. Many chronic diseases may be related to mineral status, some may be related to toxic mineral. Hair samples were collected from 120 inhabitants of the city of Seoul, Korea. In this study the concentrations of 10 elements (Hg, Pb, Cd, Al, As, U, Bi, Sb, Ba, Be) in hair were determined by inductively coupled plasma mass spectroscopy (ICP-MS). The conclusions showed that people in Seoul, Korea were affected by some kinds of toxic minerals. The Hg concentrations of male are higher than those of female and reference range. The mean concentration of Sb was higher in the female than male and reference range. In age distribution, the mean concentration of Hg was in 40's are higher than 20's and 30's and reference range. The concentrations of Al were the highest in the 20's. After analyzing, we concluded that a compounded treatment should be conducted, which considers the variety of factors related to detoxification.

Analysis of Fatty Acid Composition and Effects of Pumpkin Seed Oil on Human Umbilical Vein Endothelial Cells (호박씨유의 지방산 성분 분석 및 Human Umbilical Vein Endothelial Cell에 미치는 영향 연구)

  • Kim, Kyoung Kon;Kang, Yun Hwan;Kim, Dae Jung;Kim, Tae Woo;Lee, Jeong Il;Choe, Myeon
    • Journal of the East Asian Society of Dietary Life
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    • v.24 no.3
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    • pp.351-358
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    • 2014
  • Pumpkin seed oil (PSO) was investigated for its parasite elimination activity and efficacy in treating disorders of the prostate gland and urinary bladder. We confirmed the composition of PSO and identified its ability to improve vessels. Gas chromatography coupled with mass spectrometric (GC-MS) system was used for PSO composition analysis. Cytotoxicity and cell proliferation were confirmed by Cell Counting Kit-8 (CCK-8) assay. Nitric oxide(NO) production was measured with Griess reagent, and intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 mRNA expression levels were measured by reverse transcription polymerase chain reaction (RT-PCR). As a result, PSO revealed the presence of several components such as linoleic acid, oleic acid, palmitic acid and stearic acid. Cytotoxic effects of PSO were not observed, and PSO increased nitric oxide production in human umbilical vein endothelial cells (HUVEC). Additionally, TNF-${\alpha}$-induced cell proliferation and ICAM-1 expression in HUVEC were inhibited by PSO treatment, whereas VCAM-1 expression was not significantly reduced. Taken together, these results show that PSO is worthy of study as a candidate food material for improvement of vascular disease.

Analyzing off-line Noah land surface model spin-up behavior for initialization of global numerical weather prediction model (전지구수치예측모델의 토양수분 초기화를 위한 오프라인 Noah 지면모델 스핀업 특성분석)

  • Jun, Sanghee;Park, Jeong-Hyun;Boo, Kyung-On;Kang, Hyun-Suk
    • Journal of Korea Water Resources Association
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    • v.53 no.3
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    • pp.181-191
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    • 2020
  • In order to produce accurate initial condition of soil moisture for global Numerical Weather Prediction (NWP), spin-up experiment is carried out using Noah Land Surface Model (LSM). The model is run repeatedly through 10 years, under the atmospheric forcing condition of 2008-2017 until climatological land surface state is achieved. Spin-up time for the equilibrium condition of soil moisture exhibited large variability across Koppen-Geiger climate classification zone and soil layer. Top soil layer took the longgest time to equilibrate in polar region. From the second layer to the fourth layer, arid region equilibrated slower (7 years) than other regions. This result means that LSM reached to equilibrium condition within 10 year loop. Also, spin-up time indicated inverse correlation with near surface temperature and precipitation amount. Initialized from the equilibrium state, LSM was spun up to obtain land surface state in 2018. After 6 months from restarted run, LSM simulates soil moisture, skin temperature and evaportranspiration being similar land surface state in 2018. Based on the results, proposed LSM spin-up system could be used to produce proper initial soil moisture condition despite updates of physics or ancillaries for LSM coupled with NWP.

Crystallographic and Interfacial Characterization of Al2O3 and ZrO2 Dielectric Films Prepared by Atomic Layer Chemical Vapor Deposition on the Si Substrate (Si 기판에서 원자층 화학 기상 증착법으로 제조된 Al2O3 및 ZrO2 유전 박막의 결정학적 특성 및 계면 구조 평가)

  • Kim, Joong-Jung;Yang, Jun-Mo;Lim, Kwan-Yong;Cho, Heung-Jae;Kim, Won;Park, Ju-Chul;Lee, Soun-Young;Kim, Jeong-Sun;Kim, Geun-Hong;Park, Dae-Gyu
    • Korean Journal of Materials Research
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    • v.13 no.8
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    • pp.497-502
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    • 2003
  • Crystallographic characteristics and interfacial structures of $Al_2$$O_3$and $ZrO_2$dielectric films prepared by atomic layer chemical vapor deposition (ALCVD) were investigated at atomic scale by high-resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (EDS)/electron energy-loss spectroscopy (EELS) coupled with a field-emission transmission electron microscope. The results obtained from cross-sectional and plan-view specimens showed that the $Al_2$$O_3$film was crystallized by annealing at a high temperature and its crystal system might be evaluated as either cubic or tetragonal phase. Whereas the $ZrO_2$film crystallized during deposition at a low temperature of ∼$300^{\circ}C$ was composed of both tetragonal and monoclinic phase. The interfacial thickness in both films was increased with the increased annealing temperature. Further, the interfacial structures of X$ZrO_2$$O_3$and $ZrO_2$films were discussed through analyses of EDS elemental maps and EELS spectra obtained from the annealed films, respectively.

A Study on Heavy Metal Concentrations in Waste Water Produced in the Casting Pickling Process at Dental Technical Laboratories (치과기공소 주조체 산세척과정에서 발생하는 폐수내 중금속 농도)

  • Jeong, Da-i;Sakong, Joon
    • Journal of Environmental Health Sciences
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    • v.44 no.1
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    • pp.55-62
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    • 2018
  • Objectives: This study set out to measure the heavy metal concentrations in waste water produced in the casting pickling process at dental technical laboratories and examine the actual state of its treatment. Methods:The investigator measured the concentrations of each heavy metal at 55 dental technical laboratories using an inductively coupled plasma optical emission system. Results: The annual usage of electrolytes was under 10 L in 50 (90.9%), and was 10L or more in five (9.1%) laboratories. Among the laboratories, 15 (27.3%) commissioned the treatment of waste,12 (21.8%) treated the waste with general sewage,and 28 (50.9%) treated the waste in aseptic tank. The arithmetic $mean{\pm}standard$ deviation and the geometric mean of chrome(Cr) were $75.3{\pm}50.9$ and 58.3 mg/L; those of cobalt (Co) were $112.3{\pm}106.7$ and 66.1 mg/L; those of nickel (Ni) were $62.9{\pm}83.5$ and 8.9 mg/L; those of molybdenum (Mo) were $17.1{\pm}13.4$ and 12.0 mg/L; those of iron (Fe) were $31.5{\pm}44.1$ and 6.2 mg/L; those of lead (Pb) were $0.3{\pm}0.3$ and 0.3 mg/L; those of beryllium (Be) were $3.6{\pm}3.6$ and 2.0 mg/L. The hydrogen ion concentration was under pH 2 across all the samples. Conclusions: The findings show that the dental technical laboratories were not doing well with the separation, storage, collection, and treatment of the electrolytes they discarded, and that most of the electrolytes were introduced through the general sewage or aseptic tank. The causes of this include alack of perception among the practitioners at dental technical laboratories and contracted companies avoiding collection for economic reasons. There is a need for education to improve the perceptions of waste water treatment among the practitioners at dental technical laboratories. Environment-related departments should be stricter with legal applications in the central and local governments. It is also required to provide proper management of commissioned treatment.

A Study on the Design of Wideband Microstrip Cross Slot Array Antennas with Circular Polarization (원편파용 광대역 마이크로스트립 크로스 슬롯 어레이 안테나의 설계에 관한 연구)

  • Min, Kyeoung-sik;Ko, Jee-Won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.4
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    • pp.894-900
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    • 2004
  • There are many types of circularly polarized(CP) microstrip antenna elements, which are used as a good unit radiator. Since an advantage of CP antenna is no strict alignment requirements between Rx and Tx system, the printed antennas with circular polarization are very often used in numerous satellite and mobile radio systems. In order to realize the broad bandwidth of 3 dB axial ratio and impedance of CP microstrip antenna, complex feed structure and tri-plate patch element have been researched. This paper describes a design of wideband microstrip cross slot array antennas with circular polarization. The proposed antenna is composed of an open-ended microstrip feed line as a feeder and a cross slot as a radiator for circular polarization. To realize the wide bandwidth, tri-plate structure are considered and cross slot is electromagnetically coupled with feed line. Optimum parameters of 1-element cross slot antenna are analyzed and designed by method of moments. These parameters are also applied to may antennas design considered the mutual coupling between radiating elements. Right hand circular polarization(RHCP) and left hand circular polarization(LHCP) of the proposed antenna are easily controlled by asymmetrical cross slot structure and slot position. In 1-element and 15-element cross slot array antenna, the good axial ratio of 1 dB below and the broad bandwidth characteristics of antenna are obtained.

A Study on Numerical Calculations of Hybrid Air Pollution Control System Coupled with SDR and Bag Filter(II) -Structural Improvement (반건식 반응기와 백필터를 결합한 하이브리드 대기오염제어 시스템의 수치해석적 연구(II) -구조개선을 중심으로)

  • Kim, Jin-Uk;Jung, Yu-Jin;Yoo, Jeong-Kun;Shon, Byung-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.2
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    • pp.985-992
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    • 2011
  • The 3D computational fluid dynamics (CFD) was performed in relation to the internal fluid characteristics and flow distribution for the development of the most optimal model in the complex post-disposal device. As it is expected that a channeling (drift) would be made by the semi-dry reactor due to the large difference in the flow distribution by the compartment in the bag filter, a structural improvement should be urgently made for more uniformed flow distribution in the bag filter. Three types of modifications such as i) changing the plenum shape, ii) orifice install in the exit part of cleaned gas, iii) increasing the plenum number were established. From the results of computational fluid dynamics, it was revealed that the changing of plenum shape and orifice install in the exit part of cleaned gas was more reasonable than the increasing the plenum number because of the difficulties of retrofit. The complex post-disposal device, modified and supplemented with this analysis, integrated the semi-dry reactor and the bag filter in a single body, so it follows that the improvement can make the device compact, save the installation area, save the operation fee, and management more convenient.