• Title/Summary/Keyword: Face cooling

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Comparing building performance of supermarkets under future climate change: UK case study

  • Agha Usama Hasan;Ali Bahadori-Jahromi;Anastasia Mylona;Marco Ferri;Hexin Zhang
    • Advances in Energy Research
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    • v.8 no.1
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    • pp.73-93
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    • 2022
  • Focus on climate change and extreme weather conditions has received considerable attention in recent years. Civil engineers are now focusing on designing buildings that are more eco-friendly in the face of climate change. This paper describes the research conducted to assess the impact of future climate change on energy usage and carbon emissions in a typical supermarket at multiple locations across the UK. Locations that were included in the study were London, Manchester, and Southampton. These three cities were compared against their building performance based on their respective climatic conditions. Based on the UK Climatic Projections (UKCP09), a series of energy modelling simulations which were provided by the Chartered Institute of Building Service Engineers (CIBSE) were conducted on future weather years for this investigation. This investigation ascertains and quantifies the annual energy consumption, carbon emissions, cooling, and heating demand of the selected supermarkets at the three locations under various climatic projections and emission scenarios, which further validates annual temperature rise as a result of climatic variation. The data showed a trend of increasing variations across the UK as one moves southwards, with London and Southampton at the higher side of the spectrum followed by Manchester which has the least variability amongst these three cities. This is the first study which investigates impact of the climate change on the UK supermarkets across different regions by using the real case scenarios.

Assessment of Occupational Health Risks for Maintenance Work in Fabrication Facilities: Brief Review and Recommendations

  • Dong-Uk Park;Kyung Ehi Zoh;Eun Kyo Jeong;Dong-Hee Koh;Kyong-Hui Lee;Naroo Lee;Kwonchul Ha
    • Safety and Health at Work
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    • v.15 no.1
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    • pp.87-95
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    • 2024
  • Background: This study focuses on assessing occupational risk for the health hazards encountered during maintenance works (MW) in semiconductor fabrication (FAB) facilities. Objectives: The objectives of this study include: 1) identifying the primary health hazards during MW in semiconductor FAB facilities; 2) reviewing the methods used in evaluating the likelihood and severity of health hazards through occupational health risk assessment (OHRA); and 3) suggesting variables for the categorization of likelihood of exposures to health hazards and the severity of health effects associated with MW in FAB facilities. Methods: A literature review was undertaken on OHRA methodology and health hazards resulting from MW in FAB facilities. Based on this review, approaches for categorizing the exposure to health hazards and the severity of health effects related to MW were recommended. Results: Maintenance workers in FAB facilities face exposure to hazards such as debris, machinery entanglement, and airborne particles laden with various chemical components. The level of engineering and administrative control measures is suggested to assess the likelihood of simultaneous chemical and dust exposure. Qualitative key factors for mixed exposure estimation during MW include the presence of safe operational protocols, the use of air-jet machines, the presence and effectiveness of local exhaust ventilation system, chamber post-purge and cooling, and proper respirator use. Using the risk (R) and hazard (H) codes of the Globally Harmonized System alongside carcinogenic, mutagenic, or reprotoxic classifications aid in categorizing health effect severity for OHRA. Conclusion: Further research is needed to apply our proposed variables in OHRA for MW in FAB facilities and subsequently validate the findings.

Study on Multi-stage Hot Forming of A6061 Aluminum Alloy (A6061 알루미늄 합금의 다단 열간성형에 관한 연구)

  • R. H. Kim;M. H. Oh;Y. S. Jeong;S. M. Son;M. Y. Lee;J. H. Kim
    • Transactions of Materials Processing
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    • v.33 no.3
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    • pp.161-168
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    • 2024
  • Aluminum alloy sheets, compared to conventional steel sheets, face challenges in press forming due to their lower elongation. To enhance their formability, extensive research has focused on forming technologies at elevated temperatures, specifically warm forming at around 300℃ and hot forming at approximately 500℃. This study proposes that the formability of aluminum alloy sheets can be significantly enhanced using a multi-stage hot forming technique. The research also investigates whether the strength of the A6061 aluminum alloy, known for its precipitation hardening, can be maintained when formed below the precipitate solid solution temperature. In the experiments, the A6061-T6 sheet underwent heating and rapid cooling between 250 and 500℃. The mechanical properties were evaluated at each stage of the process. The findings revealed that when the initial heat treatment was below 350℃, the strength of the material remained unchanged. However, at temperatures above 400℃, there was a noticeable decrease in strength coupled with an increase in elongation. Conversely, when the secondary heat treatment was conducted at temperatures of 350℃ or lower, the strength remained comparable to that of the initial heat treated material. However, at higher temperatures, a reduction in strength and an increase in elongation were observed.

A study on the Theory of 'Ja-Yeol(刺熱)' in 32nd Chapter of 'So Moon(素問) Yellow Emperior's Nei-Ching(黃帝內經)' (황제내경(黃帝內經) 소문(素問) 자열론(刺熱論)에 대한 연구(硏究))

  • Kwon, Kun-Hyuck;Hong, Won-Sik
    • Journal of Korean Medical classics
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    • v.3
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    • pp.151-217
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    • 1989
  • In this thesis, I intend to study the translational and clinical interpretation through the theory of Ja-Yeol, and reached the following conclusions. 1. Liver-Heat-Disease due to absess of the function of expelling and lifting off, that Liver-Yang cannot lift up to upper-warmer, and stagnate liver. I think the symptoms of yellowish urine, abdominal pain, somnolence, fever belong to the syndrome of 'Gi-Bun(氣分)', and the symptoms of ravings with surprising, distending pain of hypochondrium, restless involuntary movement of the limbs, unable to lie flat belong to the syndrome of 'Hyeol-Bun(血分)'. 2. Heart-Heat-Disease due that 'Eum-Gi(陰氣)' in heart cannot lay down and reach to stagnate at heart, inner part. I think the symptoms of unjoy, acute cardiac pain, fidgetiness, well-nausea, headeche, reddish face, anhidrosis, etc. reveal with Heart-Heat-Disease. 3. Spleen-Beat-Disease due that 'Eum-Gi' in spleen cannot lay down and Yin of spleen changs heat. I think the symptoms of heaviness of head, cheek pain, fidgetiness, cyanosis, well-nausea, fever, not to let flex and reflex with back pain, diarrhea with abdominal pain, left and right cheek pain reveal with Spleen-Heat-Disease. I think symptoms of fever, diarrhea with abdominal pain belong to the syndrome of Yin-exhausion. 4. Lung-Heat-Disease due to that 'Eum-Gi' in lung cannot lay down. When 'Wi-Gi(衛氣)' stagnates at external part, I think, the symptoms of intolerance to wind and cold, yellowish fur, fever reveal. When Wi-Gi stagnates at lung, inner part, I think, the symptoms of dispnea with cough, pain on chest and back, unable to breath deeply, hydrosis and chilling reveal. 5. Kidney-Heat-Disease, in that the symptoms of back pain, leg aching, extreme thirst and frequently drink, fever, pain and stiffness of nape, cooling and aching leg, heat on plantar pedis, not trying to speak reveal is regarded external heat disease of 'Tai-Yang-Gyeong's(太陽經)' disease that asthenic fever open 'Tai-Yang-Gyeong' and lift by not enough of 'Yang-Gi(陽氣)' lifeing up from Kidney space, the water space of five elements.

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Power Module Packaging Technology with Extended Reliability for Electric Vehicle Applications (전기자동차용 고신뢰성 파워모듈 패키징 기술)

  • Yoon, Jeong-Won;Bang, Jung-Hwan;Ko, Yong-Ho;Yoo, Se-Hoon;Kim, Jun-Ki;Lee, Chang-Woo
    • Journal of the Microelectronics and Packaging Society
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    • v.21 no.4
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    • pp.1-13
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    • 2014
  • The paper gives an overview of the concepts, basic requirements, and trends regarding packaging technologies of power modules in hybrid (HEV) and electric vehicles (EV). Power electronics is gaining more and more importance in the automotive sector due to the slow but steady progress of introducing partially or even fully electric powered vehicles. The demands for power electronic devices and systems are manifold, and concerns besides aspects such as energy efficiency, cooling and costs especially robustness and lifetime issues. Higher operation temperatures and the current density increase of new IGBT (Insulated Gate Bipolar Transistor) generations make it more and more complicated to meet the quality requirements for power electronic modules. Especially the increasing heat dissipation inside the silicon (Si) leads to maximum operation temperatures of nearly $200^{\circ}C$. As a result new packaging technologies are needed to face the demands of power modules in the future. Wide-band gap (WBG) semiconductors such as silicon carbide (SiC) or gallium nitride (GaN) have the potential to considerably enhance the energy efficiency and to reduce the weight of power electronic systems in EVs due to their improved electrical and thermal properties in comparison to Si based solutions. In this paper, we will introduce various package materials, advanced packaging technologies, heat dissipation and thermal management of advanced power modules with extended reliability for EV applications. In addition, SiC and GaN based WBG power modules will be introduced.

Developed an output device for high-frequency cosmetic medical equipment using micro multi-needle (마이크로 멀티니들을 이용한 고주파 피부미용 의료기기를 위한 출력 장치 개발)

  • Kim, Jun-tae;Joo, Kyu-tai;Cha, Eun Jong;Kim, Myung-mi;Jeong, Jin-hyoung
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.14 no.5
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    • pp.394-402
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    • 2021
  • The entry of an aging society and the extension of human life expectancy, the increasing interest in women's social advancement and men's appearance, and the natural interest in K-culture through media media, while receiving worldwide attention, Focus on K-Bueaty. Recently, looking at the occupation of the medical tourism field, in the case of aesthetic medicine tourism such as molding and dermatology, it has gained popularity not only in Asia such as China and Japan, but also in North America and Europe. The first external confirmation of human aging is the wrinkles on the skin of the face. Clean, wrinkle-free, elastic and healthy skin is a desire of most people. Skin condition and condition such as focused ultrasonic stimulation (HIFU: High Intensity Focused Utrasound) and low frequency, high frequency (RF: Radio Frequency), galvanic therapy using microcurrent, cryotherapy using rapid cooling, etc. Depending on the method of management, the effect of the treatment differs depending on the output and the stimulation site, etc., even in the treatment of medical equipment and beauty equipment using the same mechanism. In this research, in order to develop invasive high-frequency dermatological devices using a large number of beauty medical devices and microneedles of beauty devices, the international standards IEC 60601-2 (standards for individual medical devices) and MFDS (Ministry of) We designed and developed a high-frequency output device in compliance with the high-frequency stimulation standard announced in the Food and Drug Safety (Ministry of Food and Drug Safety). The circuit design consists of an amplifier (AMP: Amplifier) using Class-A Topology and a power supply device using Half-Bridge Topology. As a result of measuring the developed high-frequency output device, an average efficiency of 63.86% was obtained, and the maximum output was measured at 116.7W and 50.67dBm.