• Title/Summary/Keyword: humid

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Carbon Isotope Analysis for the Climatic Environment Change in South Korea During the Holocene: a Case Study in Yengjong Islands of Yellow Sea (탄소동위원소분석을 이용한 한국 홀로세의 기후환경변화: 서해 영종도지역을 사례로)

  • Jung, Hea-Kyung;Park, Ji-Hoon;Kim, Cheong-Bin
    • Journal of the Korean earth science society
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    • v.31 no.4
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    • pp.313-321
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    • 2010
  • The landform of the study area is defined as a small-scale alluvial plain in the valley bottom adjacent to the coast. By the aggradation of alluvial materials, this valley bottom plain was formed in dissected parts of low hills. For the purpose of reconstructing the palaeo climate environment in this study, $\delta^{13}C$ analysis and soil organic carbon analysis are therefore employed. Main results of this study are as follows: Section I: the period of $6,600{\pm}60yr$ B.P.$-5,350{\pm}60yr$B.P. was mostly in warm and humid climate environment. A little changes of the humid environment are detected as subdry (or sub-humid)${\rightarrow}$humid in terms of the dryness and wetness. Section II: the period of $5,350{\pm}60yr$ B.P.-2,200 yr B.P. was in warm and humid climate environment, which is similar to the present. However, The sediments between $4,720{\pm}60yr$ B.P. and $4,210{\pm}50 yr$ B.P. experienced the most humid climate environment of all studied sedimentary layers. After $4,210{\pm}50 yr$ B.P., the environment started to change from the humid to the sub-humid (or sub-dry) climate. Section III: the period of 2,200 yr B.P.$-210{\pm}60 yr$ B.P. was distinguish from previous two sections as the environmental changes to sub-humid (or sub-dry) climate was apparent.

Evaluation of decontamination factor of radioactive methyl iodide on activated carbons at high humid conditions

  • Choi, Byung-Seon;Kim, Seon-Byeong;Moon, Jeikwon;Seo, Bum-Kyung
    • Nuclear Engineering and Technology
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    • v.53 no.5
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    • pp.1519-1523
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    • 2021
  • Radioactive iodine (131I) released from nuclear power plants has been a critical environmental concern for workers. The effective trapping of radioactive iodine isotopes from the off-gas stream generated from nuclear facilities is an important issue in radioactive waste treatment systems evaluation. Numerous studies on retaining methyl iodide (CH3I131) by impregnated activated carbons under the high content of moisture have been extensively studied so far. But there have been no good results on how to remove methyl iodide at high humid conditions up to now. A new challenge is to introduce other promising impregnating chemical agents that are able to uptake enough radioactive methyl iodide under high humid conditions. In order to develop a good removal efficiency to control radioiodine gas generated from a high humid process, activated carbons (ACs) impregnated with triethylene diamine (TEDA) and qinuclidine (QUID) were prepared. In addition, the removal efficiencies of the activated carbons (ACs) under humid conditions up to 95% RH were evaluated by applying the standard method specified in ASTM-D3808. Quinuclidine impregnated activated carbon showed a much higher decontamination factor above 1,000, which is enough to meet the regulation index for the iodine filters in nuclear power plants (NPPs).

A Study on the Removal Efficiency of a TEDA Impregnated Charcoal Bed for Methyl iodide under Humid Conditions (습윤 조건하에서 TEDA함침탄소층에 의한 Methyl Iodide 제거효율에 관한 연구)

  • Won Jin Cho;Soon Heung Chang
    • Nuclear Engineering and Technology
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    • v.16 no.3
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    • pp.161-168
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    • 1984
  • The adsorption model to predict the time dependent removal efficiency of methyl iodide by triethylenediamine (TEDA) impregnated charcoal bed under humid condition is proposed. Under humid conditions, the reduction of equilibrium adsorption capacity and effective pore diffusivity is considered. The predicted values are compared with the experimental results.

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The Effects of the Annealing Temperature and Environments on Room Temperature Wear Behavior of Plasma-Sprayed Partially Stabilized Zirconia Coatings (플라즈마 용사된 부분안정화 지르코니아 코팅의 상온 마모거동에 미치는 열처리온도 및 분위기의 영향)

  • 김장엽;임대순
    • Journal of the Korean Ceramic Society
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    • v.31 no.10
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    • pp.1176-1180
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    • 1994
  • The sliding wear behavior of the plasma-sprayed zirconia containing 3 mol% yttria was investigated after the annealing at room temperature to 80$0^{\circ}C$ in various concentrations of humid atmosphere as laboratory, humid, dry argon atmosphere. Both of the friction coefficient and the wear loss increased with increasing temperature up to 80$0^{\circ}C$. Surface morphology of the worn samples changed with annealing temperature. The change of monoclinic/tetragonal (m/t) x-ray peak intensity ratio effected the wear behavior. The m/t ratio had maximum value at 20$0^{\circ}C$ and decreased with increased temperature in laboratory and humid atmosphere. In argon atmosphere the m/t ratio had no maximum value and decreased with increasing temperature. At all the annealing temperature humid atmosphere had more the m/t ratio value than any other atmosphere. The change of toughness was showed the inversed result of m/t ratio change. The results indicated that the resudial stress which was induced by the different amount of phase transformation takes a detrimental role in wear behavior.

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Evaluation of Failure Mechanism of Flexible CIGS Solar Cell Exposed to High Temperature and Humid Atmosphere (플렉서블 CIGS 태양전지의 고온고습 환경 고장 기구 분석)

  • Kim, Hyeok-Soo;Byeon, Jai-Won
    • Journal of Applied Reliability
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    • v.16 no.1
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    • pp.41-47
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    • 2016
  • Purpose: The purpose of this study was to evaluate electrical and structural degradation of flexible CIGS sollar cell exposed to high temperature and humid atmosphere. Method: Accelerated degradation was performed for various time under $85^{\circ}C/85%RH$ and then electrical and structural properties were analyzed by 4-point probe method, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). Results: Sheet resistance of the top ITO layer increased with exposure time to the high temperature and humid atmosphere. Blunting of the protrusion morphology of ITO layer was observed for the degraded specimen, while no phase change was detected by XRD. Oxygen was detected at the edge area after 300 hours of exposure. Conclusion: Increase in electrical resistance of the degraded CIGS solar cell under high temperature and humid environment was attribute to the oxygen or water absorption.

A Study on the Relationship between the Climate and Space Organization of India Courtyard Housing - Focused on the Courtyard housings in Hot-dry Region and Hot-humid Region - (인도 중정형 주택의 공간 구조와 기후의 연관성에 관한 연구 - 고온 건조 지역과 고온 다습 지역의 중정형 주택을 중심으로 -)

  • Choi, Siein;Lee, Yoonhie
    • Korean Institute of Interior Design Journal
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    • v.23 no.6
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    • pp.3-13
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    • 2014
  • The purpose of this study is to compare and analyse the difference between courtyard housings of hot-humid region and hot-dry region in India, in order to identify the affection of climate on the space arrangement of housing. The study starts from the curiosity about similar space structure of Indian housings at different climate area. Indian housings usually have courtyard at the center of its plan, though the 'Courtyard housing' is typical form of dry region's house type. Research method is comparative analysis of traditional houses of India, and the samples are selected from hot-dry city, Ahmedabad and hot-humid city, Bangalore. The conclusion is drawn through comparing main houses with traditional houses of other dry city - Jaipur - and humid cities - Trivandrum and Nilambur. It shows that both dry and humid region's housings has courtyard in common, but their spatial structures are not same at all. Houses of dry region shows organically connected spatial form, in order to maximize the cooling effect of ventilation. In contrast, the plan of houses in humid region shows opened, but can be closed in any time to prevent the penetration of moisture. Both Parekh house(Ahmedabad) and Koramangala house(Bangalore) left inconvenience of its arrangement, though the ventilation of air is the most important point of sustainability in hot region. The study could be the practical reference data for advanced sustainable housings of India which may built in the future.

Effect of evaporation-induced osmotic changes in culture media in a dry-type incubator on clinical outcomes in in vitro fertilization-embryo transfer cycles

  • Chi, Hee-Jun;Park, Jun-Sang;Yoo, Chang-Seok;Kwak, Su-Jin;Son, Ho-Jeong;Kim, Seok-Gi;Sim, Chae-Hee;Lee, Kyeong-Ho;Koo, Deog-Bon
    • Clinical and Experimental Reproductive Medicine
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    • v.47 no.4
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    • pp.284-292
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    • 2020
  • Objective: This study investigated whether adding outer-well medium to inhibit osmotic changes in culture media in a dry-type incubator improved the clinical outcomes of in vitro fertilization-embryo transfer (IVF-ET) cycles. Methods: In culture dishes, the osmotic changes in media (20 µL)-covered oil with or without outer-well medium (humid or dry culture conditions, respectively) were compared after 3 days of incubation in a dry-type incubator. One-step (Origio) and G1/G2 (Vitrolife) media were used. Results: The osmotic changes in the dry culture condition (308 mOsm) were higher than in the humid culture conditions (285-290 mOsm) after 3 days of incubation. In day 3 IVF-ET cycles, although the pregnancy rate did not significantly differ between the dry (46.2%) and humid culture (51.0%) groups, the rates of abortion and ongoing pregnancy were significantly better in the humid culture group (1.5% and 49.5%, respectively) than in the dry culture group (8.3% and 37.8%, respectively, p<0.05). In day 5 IVF-ET cycles, the abortion rate was significantly lower in the humid culture group (2.2%) than in the dry culture group (25.0%, p<0.01), but no statistically significant difference was observed in the rates of clinical and ongoing pregnancy between the dry (50.0% and 25.0%, respectively) and humid culture groups (59.5% and 57.3%, respectively) because of the small number of cycles. Conclusion: Hyperosmotic changes in media occurred in a dry-type incubator by evaporation, although the medium was covered with oil. These osmotic changes were efficiently inhibited by supplementation of outer-well medium, which resulted in improved pregnancy outcomes.

Changes in Blood Constituents of Rabbits Subjected to Transportation under Hot, Humid Tropical Conditions

  • Nakyinsige, K.;Sazili, A.Q.;Aghwan, Z.A.;Zulkifli, I.;Goh, Y.M.;Fatimah, A.B.
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.6
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    • pp.874-878
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    • 2013
  • Unlike Europe (particularly, Italy and Spain), where a number of studies have been conducted on the stressful effects of transport on rabbit welfare, few studies have been conducted on transportation of rabbits under hot, humid tropical conditions experienced in countries like Malaysia. We studied the effects of transportation in hot humid tropical conditions of Malaysia on physiometabolic changes in New Zealand white rabbits. Eighty experimental animals were divided into two groups of 40 bucks each and transported for either 3 or 1 h. Transportation caused a significant upsurge of aspartate aminotransferase, alanine aminotransferase and creatine kinase activities (p<0.001) though did not significantly affect lactate dehydrogenase (LDH) activity (p = 0.0706). Both transportation periods caused elevation in plasma glucose levels, lactic acidosis and dehydration as evidenced through elevated packed cell volume and plasma protein concentration. It was concluded that regardless of the duration, transport of rabbits under hot humid tropical conditions, resulted in heat distress since the rabbits showed hyperglycemia, hypercalcemia, lactacidemia, lymphocytopenia, dehydration and increase in blood enzyme activities.

The Paleoenvironment(the LGM time) of the Western Coastal Area of the Korean Peninsula (eastern margin of the yellow sea)based on characteristic Cryoburtation Evidence from the kanweoldo Deposit Cheonsoo Bay West Coast of Korea. (천수만 간월도층의 퇴적후 변형상(cryoturbation)으로 해석되는 제4기 최후빙기의 한 반도 서해안의 고환경)

  • 박용안
    • The Korean Journal of Quaternary Research
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    • v.9 no.1
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    • pp.43-60
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    • 1995
  • The Kanweoldo Deposit in the Cheonsoo Bay western coast of Korean Peninsula is considered to be influenced by severe freezing condition under cold humid environment of the last glacial age. The evidence of severe freezing in the some upper part of the fine-grained Kanweoldo Deposit is characteristically irregular wavy la-mellar structure with the interval of 2∼8mm. In particular lamina show very compacted fabrics composed of rounded or spheroidal discrete aggregates covered by silt caps. Such laminar structure and associated micro-fabrics might owe to soil freezing such as ice segregation in lens form cryophoresis pressure from growing ice and disturbance by frost-creep. Furthermore pedogenesis of cold-humid type such as gleyzation or peseudo-gleyzation also might af-fect the kanweoldo Deposit in the priod of severe cold-humid cli-mate of the Wrm. The Kanweoldo sediment and organic remnant(16,708 B.P. with error limit of 250 years) affected by severe cryogenic activities sug-gest that the paleoclimate of Late Wrm in Korea might be so cold and humid as to engender the cryogenic structure in subaerial silty and sandy silt deposits.

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Humidity Sensor of Polymethacrylate with 4th Ammonium Salt (4차 암모늄 염을 포함하는 폴리메타크릴레이트 습도센서)

  • Hong, Chae-Hwan;Kim, Se-Hoon;Nam, Byeong-Uk
    • Polymer(Korea)
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    • v.31 no.3
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    • pp.255-262
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    • 2007
  • In this work, two types of copolymers are manufactured by a radical polymerization to develop a material for humid membrane. Each copolymer contains three monomers that have functions to improve humid-resistance, membrane stability, flexibility, impedance, and adhesion to the electrode. MDBAB (N,N'-dimethyl-2-methacryloxyethyl-3-bromopropyl ammonium bromide) having a salt form decreases the impedance of the humid membrane and reacts with amines to produce a cross-linking structure. HEMA (2-hydroxyethyl methacrylate) has an important role which reduces the impedance and increases the adhesion strength to the electrode. The other monomers are DAEMA (N,N'-dimethylamino ethyl methacrylate), 4-VP(4-vinyl pyridine), and 2-EHA(2-ethylhexyl acrylate) and all the monomers are formulated with several compositions to make a humid membrane. At specific composition, we could attain a satisfactory results having good performance and long term durability.