• Title/Summary/Keyword: International Air Transport

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Study on the Capillary Limitation in Copper-Water Heat Pipes with Screen Wicks

  • Park, Ki-Ho;Lee, Ki-Woo;Noh, Seung-Yong;Rhi, Seok-Ho;Yoo, Seong-Yeon
    • International Journal of Air-Conditioning and Refrigeration
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    • v.12 no.1
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    • pp.21-29
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    • 2004
  • This paper is to study the heat transfer performance of the copper-water heat pipe with screen wicks. Recently, the semiconductor capacity of an electronic unit becomes larger, but its size becomes much smaller. As a result, a high- performance cooling system is needed. Experimental variables are inclination angles, temperatures of cooling waters and the mesh number of screen wicks. The distilled water was used as a working fluid. Based on the experimental results, when the copper-water heat pipe of 6mm diameter is used at the top heat mode, the heat transfer performance of 100 mesh 2 layers heat pipe is better than that of 150 and 200 mesh. The thermal resistance of the two layers with the 100-mesh screen was 0.7-$0.8^{\circ}C$/W.

Integral Analysis of the Effects of Non-absorbable gases on the Heat Mass Transfer of Laminar Falling Film

  • Kim, Byong-Joo
    • International Journal of Air-Conditioning and Refrigeration
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    • v.6
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    • pp.56-66
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    • 1998
  • The absorption process of water vapor in a liquid film is an important process in LiBr-Water absorption system. The composition of the gas phase, in which a non-absorbable gas is combined with the absorbate, influences the transport characteristics. In the present work, the absorption processes of water vapor into aqueous solutions of lithium bromide in the presence of non-absorbable gas are investigated. The continuity, momentum, energy and diffusion equations for the solution film and gas are formulated in integral forms and solved numerically. It is found that the mass transfer resistance in gas phase increases with the concentration of non-absorbable gas. However the primary resistance to mass transfer is in the liquid phase. As the concentration of non-absorbable gas in the absorbate increases, the interfacial temperature and concentration of absorbate in solution decrease, which results in the reduction of absorption rate. The reduction of mass transfer rate is found to be significant for the addition of a small amount of non-absorbable gas to the pure vapor, especially at the outlet of tube where the non-absorbable gas accumulates. At higher non-absorbable gas concentration, the decrease of absorption rate seems to be linear to the concentration of non-absorbable gas.

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COVID-19 Pandemic and Pilot Mental Health Care (코로나19 팬데믹과 조종사 정신건강 관리)

  • Kwon, Young Hwan
    • Korean journal of aerospace and environmental medicine
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    • v.31 no.3
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    • pp.64-67
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    • 2021
  • When the COVID-19 crisis hit air transport, the whole aviation industry was affected. The change in the behavior of passengers following the COVID-19 crisis, travel restrictions and the ensuing economic crisis have resulted in a dramatic drop in demand for airline services. The COVID-19 pandemic, with all its associated consequences, has had a significant impact on the mental health and well-being of pilots, which could impact operational safety. As the number of international flights has decreased, pilots are exposed to high levels of psychological stress such as job instability, reduced income and increased risk of infection during flight work. Psychological stress lowers work performance and threatens aviation safety. The pilot needs mental health management during the COVID-19 pandemic, but psychological support is weak. For pilot mental health management, it is important to raise awareness about mental health and to continuously respond. To this end, it is necessary to foster a safe and trustworthy culture in which mental health issues are discussed freely and solved together without hiding them. They should also support the establishment of a peer support program that is easily accessible and that allows pilots to discuss their issues with confidence.

A PRELIMINARY STUDY OF EFFECT OF THE GREEN FEATURE - WING WALLS ON NATURAL VENTILATION IN BUILDINGS

  • Cheuk Ming Mak;Jian Lei Niu;Kai Fat Chan
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.814-819
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    • 2005
  • There is growing consciousness of the environmental performance of buildings in Hong Kong. The Buildings Department, the Lands Department and the Planning Department of the Hong Kong Government issued the first of a series of joint practice notes [1] to promote the construction of green and innovative buildings. Green features are architectural features used to mitigate migration of noise and various air-borne pollutants and to moderate the transport of heat, air and transmission of daylight from outside to indoor environment in an advantageous way. This joint practice note sets out the incentives to encourage the industry in Hong Kong to incorporate the use of green features in building development. The use of green features in building design not only improves the environmental quality, but also reduces the consumption of non-renewable energy used in active control of indoor environment. Larger window openings in the walls of a building may provide better natural ventilation. However, it also increases the penetration of direct solar radiation into indoor environment. The use of wing wall, one of the green features, is an alternative to create effective natural ventilation. This paper therefore presents a preliminary numerical study of its ventilation performance using Computational Fluid Dynamics (CFD). The numerical results will be compared with the results of the wind tunnel experiments of Givoni.

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A Model of Factors Affecting Entrepreneurial Intention among Information Technology Students in Vietnam

  • VUONG, Bui Nhat;PHUONG, Nguyen Ngoc Duy;HUAN, Dao Duy;QUAN, Tran Nhu
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.8
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    • pp.461-472
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    • 2020
  • In recent decades, the research field of entrepreneurship phenomenon has significantly increased in both quantity and sophistication. In Vietnam, paradoxically, while creating a new business venture has become a tendency, the interest in studying entrepreneurs seems not to be thoroughly investigated. This research aims to evaluate the factors that affect the entrepreneurial intention of information technology (IT) students in Vietnam. The authors make use of mixed methods including both quantitative research method and qualitative research method. The qualitative research method is employed to identify meanings, confirmations, adjustments, and compliments for concept-measurement variables in the conceptual model. Quantitative research is conducted from a sample of 424 IT senior students across many universities in Vietnam. Questionnaires have been sent to students to evaluate the measurement scale and appropriateness of the research model. Results from multiple regression highlighted five independent variables affecting the dependent variable, the entrepreneurial intention, in a descending order as following: entrepreneurial educational environment, personal characteristics, perception of feasibility, entrepreneurial supports, and financial accessibility. In addition, this research has proved that the variable attitudes towards entrepreneurship partially mediated among the interrelationship of the aforementioned variables. From this research, the authors make some recommendations to enhance entrepreneurial intentions of IT students in Vietnam.

A Study on 2010 Beijing Convention for Antiterrorism of International Aviation - Compared Beijing Convention(2010) with Montreal Protocol - (국제항공테러방지 북경협약(2010)에 관한 연구 - 몬트리올협약과의 비교를 중심으로 -)

  • Hwang, Ho-Won
    • The Korean Journal of Air & Space Law and Policy
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    • v.25 no.2
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    • pp.79-112
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    • 2010
  • The Beijing Convention of 2010 taken together effectively establishes a new broader and stronger civil aviation security framework. This adoption would significantly advance cooperation in prevent of the full range of unlawful acting relation to civil aviation and the prosecution and punishment of offenders. First, the Beijing Convention of 2010 will require parties to criminalize a number of new and emerging threats to the safety of civil aviation, including using aircraft as a weapon and organizing, directing and financing acts of terrorism. These new treaties reflect the international community's shared effort to prevent acts of terrorism against civil aviation and to prosecute and punish those who would commit them. Second, this convention will also require States to criminalize the transport of biological, chemical, nuclear weapons and related material. These provisions reflect the nexus between non-proliferation and terrorism and ensure that the international community will act to combat both. Third, this Convention shall not apply to aircraft used in military, customs or police services. As a substitute, International Humanitarian Law will be applied in a case. Moreover, the National Jurisdiction and the application of the law will be extended farther. The treaty promotes cooperation between States while emphasizing the human rights and fair treatment of terrorist suspects.

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Characteristics of Fine Particle Concentration and Case during Haze Days in Busan (부산 지역 연무 발생일의 미세먼지 농도와 사례별 특성)

  • Jeon, Byung-Il
    • Journal of Environmental Science International
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    • v.26 no.6
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    • pp.751-765
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    • 2017
  • This research investigates the characteristics of meteorological variation and fine particles ($PM_{10}$ and $PM_{2.5}$) for case related to the haze occurrence (Asian dust, long range transport, stationary) in Busan. Haze occurrence day was 559 days for 20 years (from 1996 to 2015), haze occurrence frequency was 82 days (14.7%) in March, followed by 67 days (12.0%) in February and 56 days (10.0%) in May. Asian dust occurred most frequently in spring and least in winter, whereas haze occurrence frequency was 31.5% in spring, 29.7% in winter, 21.1% in fall, and 17.7% in summer. $PM_{10}$ concentration was highest in the occurrence of Asian dust, followed by haze and haze + mist, whereas $PM_{2.5}$ concentration was highest in the occurrence of haze. These results indicate that understanding the relation between meteorological phenomena and fine particle concentration can provide insight into establishing a strategy to control urban air quality.

Recent Development of Shipping and Logistics in Mongolia

  • Boldbaatar, Tumenjargal;Yoon, Dae-Gwun;Yim, Jeong-Bin
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2011.06a
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    • pp.417-418
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    • 2011
  • Mongolia is an inland country contained between East and Central Asia. I t borders Russia to the north and China to the south, east and west. Mongolia uses as international port for transit Xindang/Qingdao by railway. For domestic transport, our options are varied, which include road, railway and air modes. Mongolia's government enacted some shipping ways to develop logistics around the world. ${\cdots}\;{\cdots}$ (omit).

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Evaluation of Creative Space Efficiency in China' Provinces Based on AHP Method

  • Hu, Shan-Shan;Kim, Hyung-Ho
    • International journal of advanced smart convergence
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    • v.9 no.4
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    • pp.52-61
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    • 2020
  • The AHP method was used in 30 provinces of China to construct the index system of creative space efficiency evaluation and determine the weight of each index. The fuzzy comprehensive evaluation method was further used to score the indexes at all levels, and then the total efficiency score was sorted. The purpose of this study is to adjust the regional layout of creative space reasonably and implement financial policies accurately through the evaluation of the efficiency of creative space. The results is ranking top in weight of several indicators, which include the number of incubated Startups, the number of innovation and entrepreneurship mentors, the survival rate of incubator, the innovative training activities, etc. It was also found that Beijing, Shanghai, Jiangsu, Guangdong and Zhejiang ranked first in the score of creative space efficiency. This study is meaningful in that it was In order to effectively solve the problem of the imbalance of the creative space efficiency in China's province, by coordinating the regional pattern, establishing a sound service system and improving the efficiency evaluation system.

TIPEX (Tropical Indo-Pacific water transport and ecosystem monitoring EXperiment) Program (태평양-인도양 해양순환 연구 프로그램)

  • Jeon, Dongchull;Kim, Eung;Shin, Chang Woong;Kim, Cheol-Ho;Kug, Jong Seong;Lee, Jae Hak;Lee, Youn-Ho;Kim, Suk Hyun
    • Ocean and Polar Research
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    • v.35 no.3
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    • pp.259-272
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    • 2013
  • One of the factors influencing the climate around Korea is the oceanic-atmospheric variability in the tropical region between the eastern Indian and the western Pacific Oceans. Lack of knowledge about the air-sea interaction in the tropical Indo-Pacific region continues to make it problematic forecasting the ocean climate in the East Asia. The 'Tropical Indo-Pacific water transport and ecosystem monitoring EXperiment (TIPEX)' is a program for monitoring the ocean circulation variability between Pacific and Indian Oceans and for improving the accuracy of future climate forecasting. The main goal of the TIPEX program is to quantify the climate and ocean circulation change between the Indian and the Pacific Oceans. The contents of the program are 1) to observe the mixing process of different water masses and water transport in the eastern Indian and the western Pacific, 2) to understand the large-scale oceanic-climatic variation including El Nino-Southern Oscillation (ENSO)/Warm Pool/Pacific Decadal Oscillation (PDO)/Indian Ocean Dipole (IOD), and 3) to monitor the biogeochemical processes, material flux, and biological changes due to the climate change. In order to effectively carry out the monitoring program, close international cooperation and the proper co-work sharing of tasks between China, Japan, Indonesia, and India as well as USA is required.