• 제목/요약/키워드: Hot environment

검색결과 921건 처리시간 0.053초

Development of Cooling Garment for Extremely Hot Environment Using a Peltier Device and its Comfort Properties (고온환경 작업을 위한 펠티어 소자 냉각복 개발 및 쾌적성 평가)

  • Jung, Ye-Lee;Chae, Young-Jin;Kim, Eun-Ae
    • Journal of the Korean Society of Clothing and Textiles
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    • 제36권1호
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    • pp.1-11
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    • 2012
  • This paper reports on a prototype cooling garment applying a cooling module. The cooling module was composed of a Peltier device, a cold sink, a heat sink and two fans. A constant box was used to evaluate the cooling effect of the module. Two cooling modules were attached on each side of the garment. The wear trial was conducted using 10 male subjects in an environmental chamber maintained at $30{\pm}0.5^{\circ}C$, $50{\pm}5%$RH. Subjective sensations of thermal, humidity, and comfort were surveyed. Statistical package SPSS12.0 was used for the t-test and the Wilcoxon signed-rank test. The results showed that most effective cooling module decreased the temperature of the constant temperature box by $-4.9^{\circ}C$. The micro-temperature of the cooling garment with a Peltier device was lower than the control garment during the exercise. In particular, the chest skin temperature was $1.5^{\circ}C$ lower with the cooling garment than the control. The maximum temperature difference was $-2.57^{\circ}C$ on the sides of the $1^{st}$ layer. Subjective thermal sensation from wear trials of the Peltier device attached garment was lower than the control garment. Subjects felt more comfortable with the cooling garment in almost all the periods.

Hot spot DBC: Location based information diffusion for marketing strategy in mobile social networks (Hotspot DBC: 모바일 소셜 네트워크 상에서 마케팅 전략을 위한 위치 기반 정보 유포)

  • Ryu, Jegwang;Yang, Sung-Bong
    • Journal of Intelligence and Information Systems
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    • 제23권2호
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    • pp.89-105
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    • 2017
  • As the advances of technology in mobile networking and the popularity of online social networks (OSNs), the mobile social networks (MSNs) provide opportunities for marketing strategy. Therefore, understanding the information diffusion in the emerging MSNs is a critical issue. The information diffusion address a problem of how to find the proper initial nodes who can effectively propagate as widely as possible in the minimum amount of time. We propose a new diffusion scheme, called Hotspot DBC, which is to find k influential nodes considering each node's mobility behavior in the hotspot zones. Our experiments were conducted in the Opportunistic Network Environment (ONE) using real GPS trace, to show that the proposed scheme results. In addition, we demonstrate that our proposed scheme outperforms other existing algorithms.

Effects of Design and Material Change of Firefighter Station Uniform on Thermal Physiological and Subjective Responses (소방 기동복의 디자인과 소재 변화가 착용자의 온열생리 반응 및 주관적 감각에 미치는 영향)

  • Kim, Hee-Eun;Kim, Seong-Suk;Son, Su-Young
    • Journal of the Korean Society of Clothing and Textiles
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    • 제44권4호
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    • pp.776-787
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    • 2020
  • This study investigated physiological and subjective responses to different types of firefighter station uniforms made with various designs and materials. Six healthy males participated in this study that consisted of 20 min of rest, 30 min of treadmill exercise, and 30 min of recovery in a hot and humid environment (34℃ and 65%RH). The experimental clothing conditions were as follows. 1) a fitted T-shirt and trouser made of 100% polyester (FC-Uniform), and 2) flame retardant T-shirts made of acrylic and cotton as well as trousers with aramid and polyester, designed for overfitting (Control). There were no significant differences in the body temperature, and sweat rate between the two conditions; however, the heart rate with the FC-Uniform was significantly lower than Control (p=.025). The clothing microclimate temperature at the chest of the FC-Uniform was significantly lower than the Control (p=.037), and a difference of 1℃ was maintained until the recovery was complete. There were no significant differences in the subjective responses; however, participants experienced a humidity sensation faster with FC-Uniform in the recovery phase. The results indicate that changes in the design and material of firefighter station uniforms may have a positive influence on reducing the thermal stress of firefighters.

Three-dimensional porous graphene materials for environmental applications

  • Rethinasabapathy, Muruganantham;Kang, Sung-Min;Jang, Sung-Chan;Huh, Yun Suk
    • Carbon letters
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    • 제22권
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    • pp.1-13
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    • 2017
  • Porous materials play a vital role in science and technology. The ability to control their pore structures at the atomic, molecular, and nanometer scales enable interactions with atoms, ions and molecules to occur throughout the bulk of the material, for practical applications. Three-dimensional (3D) porous carbon-based materials (e.g., graphene aerogels/hydrogels, sponges and foams) made of graphene or graphene oxide-based networks have attracted considerable attention because they offer low density, high porosity, large surface area, excellent electrical conductivity and stable mechanical properties. Water pollution and associated environmental issues have become a hot topic in recent years. Rapid industrialization has led to a massive increase in the amount of wastewater that industries discharge into the environment. Water pollution is caused by oil spills, heavy metals, dyes, and organic compounds released by industry, as well as via unpredictable accidents. In addition, water pollution is also caused by radionuclides released by nuclear disasters or leakage. This review presents an overview of the state-of-the-art synthesis methodologies of 3D porous graphene materials and highlights their synthesis for environmental applications. The various synthetic methods used to prepare these 3D materials are discussed, particularly template-free self-assembly methods, and template-directed methods. Some key results are summarized, where 3D graphene materials have been used for the adsorption of dyes, heavy metals, and radioactive materials from polluted environments.

Sand particle-Induced deterioration of thermal barrier coatings on gas turbine blades

  • Murugan, Muthuvel;Ghoshal, Anindya;Walock, Michael J.;Barnett, Blake B.;Pepi, Marc S.;Kerner, Kevin A.
    • Advances in aircraft and spacecraft science
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    • 제4권1호
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    • pp.37-52
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    • 2017
  • Gas turbines operating in dusty or sandy environment polluted with micron-sized solid particles are highly prone to blade surface erosion damage in compressor stages and molten sand attack in the hot-sections of turbine stages. Commercial/Military fixed-wing aircraft engines and helicopter engines often have to operate over sandy terrains in the middle eastern countries or in volcanic zones; on the other hand gas turbines in marine applications are subjected to salt spray, while the coal-burning industrial power generation turbines are subjected to fly-ash. The presence of solid particles in the working fluid medium has an adverse effect on the durability of these engines as well as performance. Typical turbine blade damages include blade coating wear, sand glazing, Calcia-Magnesia-Alumina-Silicate (CMAS) attack, oxidation, plugged cooling holes, all of which can cause rapid performance deterioration including loss of aircraft. The focus of this research work is to simulate particle-surface kinetic interaction on typical turbomachinery material targets using non-linear dynamic impact analysis. The objective of this research is to understand the interfacial kinetic behaviors that can provide insights into the physics of particle interactions and to enable leap ahead technologies in material choices and to develop sand-phobic thermal barrier coatings for turbine blades. This paper outlines the research efforts at the U.S Army Research Laboratory to come up with novel turbine blade multifunctional protective coatings that are sand-phobic, sand impact wear resistant, as well as have very low thermal conductivity for improved performance of future gas turbine engines. The research scope includes development of protective coatings for both nickel-based super alloys and ceramic matrix composites.

Study on the Measurement of GHG Emissions and Error Analysis in Form the MSW Incineration Plant Equipment with the Recovery Heat System (2009~2013) (폐열회수시설이 설비된 생활폐기물 소각자원화시설 온실가스 배출량 산정 시 오차분석 (2009~2013))

  • Choi, Won-Geun;Seo, Ran-Sug;Park, Seung-Chul
    • Journal of Environmental Science International
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    • 제25권2호
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    • pp.239-246
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    • 2016
  • This study aims to analyze region-specific trends in changing greenhouse gas emissions in incineration plants of local government where waste heat generated during incineration are reused for the recent five years (2009 to 2013). The greenhouse gas generated from the incineration plants is largely $CO_2$ with a small amount of $CH_4$ and $N_2O$. Most of the incineration plants operated by local government produce steam with waste heat generated from incineration to produce electricity or reuse it for hot water/heating and resident convenience. And steam in some industrial complexes is supplied to companies who require it for obtaining resources for local government or incineration plants. All incineration plants, research targets of this study, are using LNG or diesel fuel as auxiliary fuel for incinerating wastes and some of the facilities are using LFG(Landfill Gas). The calculation of greenhouse gas generated during waste incineration was according to the Local Government's Greenhouse Emissions Calculation Guideline. As a result of calculation, the total amount of greenhouse gas released from all incineration plants for five years was about $3,174,000tCO_2eq$. To look at it by year, the biggest amount was about $877,000tCO_2eq$ in 2013. To look at it by region, Gyeonggido showed the biggest amount (about $163,000tCO_2eq$ annually) and the greenhouse gas emissions per capita was the highest in Ulsan Metropolitan City(about $154kCO_2eq$ annually). As a result of greenhouse gas emissions calculation, some incineration plants showed more emissions by heat recovery than by incineration, which rather reduced the total amount of greenhouse gas emissions. For more accurate calculation of greenhouse gas emissions in the future, input data management system needs to be improved.

A Study on the Civil Costume in Genre of Hong-Do Kim (단원(檀園) 김홍도(金弘道)의 풍속화첩(風俗畵帖)에 나타난 서민복식(庶民服飾) 연구)

  • Jo, Oh-Soon
    • Journal of Fashion Business
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    • 제4권3호
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    • pp.91-102
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    • 2000
  • As an economy approach new state of affairs under the influence of the Shil-Hak philosophy, the Joshun society at 18th century gave common people to a chance to impress and to patronize the Arts. This social environment made an artist to drawing see and feel, this is a genre picture. Hong Do Kim(1745-1816 or 1818) was a typical genre picturer of Joshun, his picture reflected the time truthly and honestly and described vividly a life of common people, so expressed Realism what based on the actual. Therefore the purpose of this study is to analyze and to study costume of common people and their life style. The costume in a genre picture books are summarized. Man's basic dresses were Jugori and Baji uniformity, but based on the job or situation those had a little variation. People of a blacksmith shop wore that to enlarge sleeve of Bagi and Jugori and wore Strow Sandle exactly, in that way prepared for danger of treating hot iron. On the side, in the summer, Soikojambangiee and Deungguri jucksam wore at grain. The majority of hair style was Minsangtoo that Manggun not to be surrounded a head. Womam's basic dresses were Chima and Jugori, it was not to be different in compare with a woman of the aristocratic class, extremely appeal simplicity. But it was not to be of no accent on fashion even if common people, they wore a shot Dangko jugori that busts were seen below Jugori. A hair style was simple hair that her braid placed aboved a head, different with very richful hair style, Gachae that one‘s braid hair placed above a head, a hair style of woman of the aristocratic class and Kinuer. Because of common people's costume are not a special thing expect for basic dress-Jugori, Baji, Chima, many historical books or articles about costume are not existed. As the results of this study on costume of common people's life, we found that basic dresses appeared to a various types based on the job and the situation.

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Water vapor in high-mass star-forming regions and PDRs: the Herschel/HIFI view

  • Choi, Yunhee;van der Tak, Floris F.S.;van Dishoeck, Ewine F.;Bergin, Edwin A.
    • The Bulletin of The Korean Astronomical Society
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    • 제40권2호
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    • pp.42.2-43
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    • 2015
  • Massive stars play a major role in the interstellar energy budget and the shaping of the galactic environment. The water molecule is thought to be a sensitive tracer of physical conditions and dynamics in star-forming regions because of its large abundance variations between hot and cold regions. Herschel/HIFI allows us to observe the multiple rotational transitions of H2O including the ground-state levels, and its isotopologues toward high-mass star-forming regions in different evolutionary stages. Photodissociation regions (PDRs) are also targeted to investigate the distribution of water and its chemistry. We present line profiles and maps of H2O using data from two guaranteed-time key programs "Water In Star-forming regions with Herschel" and "Herschel observations of EXtra-Ordinary Sources". We analyze the temperature and density structures using LTE and non-LTE methods. We also estimate turbulent and expansion velocities, and abundance of water in the inner and outer envelopes using the 1D radiative transfer code. Around high-mass protostars we find H2O abundances of ~10-8-10-9 for the outer envelope and ~10-4-10-5 for the inner envelope, and expansion and turbulent velocities range from 1.0 km s-1 to 2.0 km s-1. The abundances and kinematic parameters of the sources do not show clear trends with evolutionary indicators. The Herschel/HIFI mapping observations of H2O toward the Orion Bar PDR show that H2O emission peaks between the shielded dense gas and the radicals position, in agreement with the theoretical and the observational PDR structure. The derived H2O abundance is ~10-7 and peaks at the depth of AV ~8 mag from the ionization front. Together with the low ortho-to-para ratio of H2O (~1) presented by Choi et al. (2014), our results show that the chemistry of water in the Orion Bar is dominated by photodesorption and photodissociation.

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A Study on the Traditional Korean Special Costumes in Accordance with Climatic Factors of the Korean Peninsula - Focusing on Costumes of the Commoners in the Joseon Dynasty Period - (한반도의 기후적 요인에 따른 한국 전통 특수의상연구 - 조선시대 기층민 복식을 중심으로 -)

  • Hong, Bo Ra;Kan, Ho Sup
    • Journal of the Korean Society of Costume
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    • 제66권3호
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    • pp.107-120
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    • 2016
  • This study examines functions in traditional Korean special costumes in accordance with the climatic factors of the Korean peninsula. The study focused on clothes worn by commoners during the Joseon dynasty. Climate change has been a major global issue in recent times, and it has been a hot topic in social, cultural, scientific, economic, and industrial communities. Studies have been conducted regarding the rapidly changing climate, and finding ways to cope with unusual temperatures. This thesis studies the development of special costumes in preparation for unusual climates, and requirements of the costume in accordance with the climatic factors, as well as the direction of its development. Its biggest significance lies in collecting and organizing the research data on special costume studies, and on costumes of the commoners, which have been fairly insufficient up to this point. After the Little Ice Age, the Joseon Dynasty period faced poor external environment due to unusual temperatures. The results of studying the costumes of the commoners are as follows: The climate of the Korean peninsula displayed different characteristics depending on the season, so the form, material, and appearance of the seasonal clothing items showed clear differences, and the difference in the crops cultivated according to the climate led to difference in material and material preference shown in the costumes. This meant that costumes differed based on region. In addition, difference in social hierarchy, regulations on costume according to class, and farming oriented social background during the period of Joseon dynasty slowed the development of costumes of commoners, but appears to have had a positive effect on the development of special costumes. We anticipate more succeeding studies on costumes of the commoners and special costumes in the future. We hope more costumes that can wisely respond to the approaching changes in temperature in the Korean peninsula can be designed via modernization of traditional Korean special costumes.

Viewing Path Search and Congestion Control Algorithms For Comfortable Museum Viewing (편안한 박물관 관람을 위한 관람 경로 탐색 및 혼잡제어 알고리즘)

  • Seo, Yoon-Deuk;Ahn, Jin-Ho
    • Journal of Internet Computing and Services
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    • 제11권3호
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    • pp.131-137
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    • 2010
  • Today, many museums are changing their forms with ubiquitous environment. Unlike traditional museums providing only static text-based information attached to its corresponding artifacts to visitors, those ubiquitous museums provide not only artifacts' text information, but also many different forms of information such as sound or media through personal digital assistance or cell phones. However, these existing ubiquitous museums still provide each visitor only with artifact-centric information in very simple ways. Also this disadvantageous feature causes high gallery congestion problem resulting from providing a uniform path for every visitor. These limitations may be the biggest barrier to providing more various and useful information about artifacts to visitors through considering each visitor's preference. This paper propose a new optimal viewing path search algorithm to provide comfortable museum viewing for each visitor according to its preference. Also, a new congestion control method is developed to protect visitors from being put in some hot spots on their museum viewing, improving its comfort to a maximum.