• Title/Summary/Keyword: cold environment

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A Study on Electrostatic Charging Characteristics in Vehicle Fuel Systems (차량 연료시스템에서의 정전기 축적특성 연구)

  • Seo, Joon-Ho;Na, Byung-Chul;Kim, Jin-Young
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.2157-2162
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    • 2004
  • As the friction between two mated materials generates electrostatic voltage, vehicles especially in the cold climate has been accumulated an electrostatic voltage by the reason of fuel flow in the fuel line, air flows out side of vehicle, etc. In this study, investigations of electrostatic discharge characteristics has been carried out in the fuel systems of gasoline engines depending on the environment temperature. For the experiment, conventional fuel filters(paint coated steel case) and specially made testing equipment are prepared. The experimental results shows, an accumulation speed of electrostatic voltage depends on the environmental temperature and new methods of testing procedures are required compare to SAE standards.

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ZigBee Location-based Human Adaptive HVAC System for Intelligent Building System (지능형 빌딩을 위한 ZigBee 위치기반 인간 적응형 HVAC 시스템)

  • Park, Eun-Ju;Lee, Suk;Lee, Kyung-Chang;Kim, Hyun-Hee
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.8
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    • pp.750-757
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    • 2012
  • This paper focuses on human adaptive HVAC system that can regulate the thermal comfort of the resident in intelligent buildings. The thermal comfort is represented in this paper by PMV (Predicted Mean Vote) as defined by ISO 7730. This PMV value indicates how hot or cold a resident feels by considering temperature, humidity, resident's metabolic rate, relative air velocity, and clothing insulation. In order to develop such a system, a location detection system based on ZigBee module was used along with temperature sensors, other environment sensors. The human adaptive HVAC system was evaluated experimentally on a test bed emulating a room.

Evaluation of the Alternatives to Minimize Stack Effect Problems with Elevators in Tall Complex Buildings (초고층 복합건축물 엘리베이터에서의 연돌현상 저감방안 평가)

  • Yu, Jung-Yeon;Song, Kyoo-Dong;Cho, Dong-Woo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.2
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    • pp.118-125
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    • 2009
  • The purpose of this study is to evaluate the stack effect reduction alternatives in tall complex buildings in cold climates. The main problems in tall buildings occur in elevators. Such problems as elevator doors that do not close and exhaust airflows result in excessive pressure differences across elevator doors due to stack effect. Under the expected conditions causing these pressure differences, Field measurements are performed in three tall buildings. Each result of the measurements is analyzed in architectural design aspects. With these analysis, building design guidelines are proposed and analyzed by field measurements and computer simulations.

Studies on the Physiology of Hibernation - with particular reference to blood level of insulin - (동면에 관한 연구 - 혈중 Insulin 농도의 변화 -)

  • Kang, Bok-Soon;Kang, Doo-Hee
    • The Korean Journal of Physiology
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    • v.6 no.1
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    • pp.19-26
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    • 1972
  • Physiological changes in hibernating animals (Manchurian Chipmunk and Hamster) were studied during various phases of the hibernation. The results obtained are summarized as follows. 1. Rectal temperature was declined markedly during hibernation, whereas it remained constant even in exposure of the animals to 0 C environment if the animals were not prepared for hibernation. As body temperature was lowered, heart rate was also markedly reduced as well as respiration and blood pressure. 2. The electrical activity recorded from cortical structure was characterized by replacement of fast wave activity by slow wave activity as body temperature was lowered and became flat at body temperature below 20C. 3. Blood glucose level showed no clear seasonal variations. However, the glycogen contents of the liver were markedly greater during the cold seasons than during the warm seasons. 4. Blood levels of insulin showed no clear seasonal variations.

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Development of High-Frequency Induction Heating Method Using Adhesive Waterproofing Sheet Laminated with Aluminum Sheet (알루미늄 박판 점착 복합 방수시트를 이용한 고주파 유도가열 방수공법 개발 평가 연구)

  • Kim, Yun Ho;Kim, Dong Bum;Park, Jin-Sang;Oh, Sang Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.05a
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    • pp.111-114
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    • 2011
  • Waterprooping Method with sheet need to study technology and multilateral verification considering the arctic conditions as low temperature and humidity, which is the result only considered of material aspects without environmental condition in construction But there are no measures up until now. To solve this problem by using high frequency induction heating method developed waterproof sheets, cold (5 ℃ or less) can be applied in a more stable environment, water-resistant materials and construction methods were studied for development. The results of the test showed that high frequency induction heating method is effective for usability in low temperature condition and securement of proper quality than existing Waterprooping Method with sheet need.

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Characteristics on Big Data of the Meteorology and Climate Reported in the Media in Korea

  • Choi, Jae-Won;Kim, Hae-Dong
    • Quantitative Bio-Science
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    • v.37 no.2
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    • pp.91-101
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    • 2018
  • This study has analyzed applicable characteristics on big data of the meteorology and climate depending on press releases in the media. As a result, more than half of them were conducted by governmental departments and institutions (26.9%) and meteorological administration (25.0%). Most articles were written by journalists, especially the highest portion stems from straight articles focusing on delivering simple information. For each field, the number of cases had listed in order of rank to be exposed to the media; information service, business management, farming, livestock, and fishing industries, and disaster management, but others did rank far behind; insurance, construction, hydrology and energy. Application of big data about meteorology and climate differed depending on the seasonal change, it was directly related to temperature information during spring, to weather phenomenon such as monsoon and heat wave during summer, to meteorology and climate information during fall, and to weather phenomenon such as cold wave and heavy snow during winter.

Establishment of Korea-China joint quality standards and improvement the performance of Non-hardening Waterproofing Material (비경화 방수재의 한·중 공동품질기준 마련 및 성능개선 연구)

  • Choi, Su-Young;An, Hyun-Ho;Choi, Young Hyun;Park, Wan-Goo;Kim, Dong-Bum;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.11a
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    • pp.224-225
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    • 2019
  • The purpose of this study was to develop a technology to prevent leakage of construction structures for the Chinese market. The first key development factor is to establish a joint quality standard that corresponds to all performance criteria set out in Chinese Standard JC / T 2428-2017. The second key development factor is to develop a product capable of exhibiting performance in a low temperature environment of $-30^{\circ}C$ and coping with 15mm structure behavior.

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High Temperature Tensile Properties of Heat-resistant Cast Ferritic Stainless Steels (고내열 페라이트계 스테인레스 주강의 고온인장특성 평가)

  • Jeong, Hyeon Kyeong;Lee, Dong-Geun
    • Journal of the Korean Society for Heat Treatment
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    • v.34 no.1
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    • pp.10-16
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    • 2021
  • Exhaust manifold is a very important component that is directly connected to air environment pollution and that requires strict mechanical properties such as high temperature fatigue and oxidation. Among stainless steels, the ferritic stainless steel with body-centered cubic structure shows excellent resistance of stress-corrosion cracking, ferromagnetic at room temperature, very excellent cold workability and may not be enhanced by heat treatment. The microstructural characteristics of four cast ferritic stainless steels which are high heat-resistant materials, were analyzed. By comparing and evaluating the mechanical properties at room temperature and high temperature in a range of 400℃~800℃, a database was established to control and predict the required properties and the mechanical properties of the final product. The precipitates of cast ferritic stainless steels were analyzed and the high-temperature deformation characteristics were evaluated by comparative analysis of hardness and tensile characteristics of four steels at room temperature and from 400℃ to 800℃.

Diversity of Culturable Bacteria Associated with Hard Coral from the Antarctic Ross Sea

  • Kim, Min Ju;Park, Ha Ju;Youn, Ui Joung;Yim, Joung Han;Han, Se Jong
    • Journal of Marine Life Science
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    • v.4 no.1
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    • pp.22-28
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    • 2019
  • The bacterial diversity of an Antarctic hard coral, Errina fissurata, was examined by isolating bacterial colonies from crushed coral tissue and by sequencing their 16S rRNA gene. From the analyzed results, the bacteria were classified as Actinobacteria (56%), Firmicutes (35%) and Proteobacteria (9%). The thirty-four isolates were cultured in liquid media at different temperatures and their growth was assessed over time. The majority of the isolates displayed their highest growth rate at 25℃ during the first three days of cultivation, even though the coral was from a cold environment. Nevertheless, strains showing their highest growth rate at low temperatures (15℃ and 4℃) were also found. This study reports the composition of an Antarctic hard coral-associated culturable bacterial community and their growth behavior at different temperatures.

Alleviation Technology of Cold Stress of Maize(Zea mays L.) by Low Temperatures Damage

  • Youngchul Yoo;Mi-jin Chae;Jeong Ju Kim;Seuk Ki Lee;AReum Han;Won Tae Jeon;Dae-Woo Lee;Beom-Young Son
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.10a
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    • pp.95-95
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    • 2022
  • Maize is one of the world's three largest crops and has a long cultivation history, and is an important crop used for various purposes such as food, feed, and industrial raw materials. Recently, the agricultural environment is changing, in which the limit of cultivation of crops is shifted to the north due to the rise in temperature due to climate change. This study was conducted in experimental field of Suwon in 2022 by setting a seeding period earlier than the sowing time to establish the North Korean agricultural climatic zone and meteorological conditions. The test cultivars were silage cultivars, Kwangpyeongok and Dacheongok. As a priming test method, it was used to directly plant seeds in the field through immersion using 4mM zinc (Zn) and 2.5mM manganese (Mn), which are trace elements for seeds. The planting season was early on March 15th, April 1st, and April 15th. The number of days from sowing to silk stage of the two cultivars sown on March 15, April 1, and April 15 was 107, 93, and 85 days for Kwangpyeongok and 109, 95, and 87 days for Dacheongok, respectively. The seed priming test did not show any difference from the control group in the growth survey up to the middle stage of growth. In another test, low-temperature recovery was confirmed through nitrogen (2-5%) foliar fertilization after 3 days, 5 days, and 7 days in refrigeration (0 degrees), a selective low temperature treatment for com in the third leaf stage. As a result of this study, it was confirmed that the low-temperature damaged com treated at 0℃ showed the same growth as that of the untreated com through nitrogen foliar fertilization. These results suggest that urea foliar fertilization for low-temperature damage reduction of corn for silage in high-latitude climates will be helpful. In addition, through the results of the study, additional studies are needed on the recovery mechanism and field application through urea foliar fertilization.

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