• Transactions of the Korean Society of Mechanical Engineers
• /
• v.16 no.10
• /
• pp.1955-1962
• /
• 1992

The purpose of this study is to identify the radiative heat transfer augmentation by a coaxial cylinder introduced in the infinite cylindrical pipe enclosing a participating gas. The gas is either a mixture of water vapor and carbon dioxide or gray. The gas is assumed to be homogeneous at a constant temperature, and has a refractive index of unity. All of the surfaces are opaque and gray, diffusely emitting and reflecting at a constant temperature, The effect of system diameter, diameter ratio, wall emittances, gas and surface temperatures, mixture component on heat transfer augmentation are studied by using the zone method with participating gas radiative properties evaluated from the weighted sum of gray gases model. From the radiative equilibrium condition, the installed wall temperature is formulated and calculated by the iteration method. If the medium is a gray gas, the augmentation observed are negligible. For the range of values studied for a real gas, if the system diameter is larger than about 0.1m the augmentation parameter increases up to about 1.2 as the system diameter increases. The augmentation parameter have a maximum value at a certain diameter ratio. The augmentation parameters decreases as the emittance of the installed wall decreases. If the gas temperature is higher than about 1273 k, the augmentation parameter decreases as the gas temperature increases.

• Journal of the Korean Institute of Gas
• /
• v.11 no.1 s.34
• /
• pp.13-17
• /
• 2007

It is very insecure to treat a butane can for cooking out of door. The human injury from the accidents of butane cans has been getting increased 1.5 times yearly since 2003. In this context, the Institute of Gas Technology Training in Korea Gas Safety Corporation carries out explosion experiment to make trainees to take all possible measures to ensure safe management of gas in the field by fully recognizing the hazards of gas explosion accidents. This study intends to examine the influence of such explosion experiments on the trainees witnessing nearby. The GEN exposed to the active students participating in the experiment away from 25 meters from the explosion site was 57.94 dB and the GEN to the passive students not participating away from 50 meters was 51.92 dB. According to Weber-Fechner's law for the lower value than 65 dB which is the environmental standard, it is safe from the place 15 meter far from the explosion place. The environmental standard of offices is 50 dB, and it is lower than the environmental standard if the office is 65 meter far from the explosion place.

• 연구논문집
• /
• s.28
• /
• pp.111-121
• /
• 1998

Offshore of Sakhalin Island is one of potential oil and gas development fields in Russia. American and Japanese companies are actively participating in the developments. They plan to export the produced oil and gas to East Asia including Korea, Japan and China. So far, offshore oil and gas field developments are mainly concentrated in the Russian Arctic area such as Barents Sea, Kara Sea and Tinman-Pechora Sea. In this article, the projects under development on the Sakhalin Shelf are reviewed and the environmental conditions in this area are summarized. At the end, the future prospects of the Sakhalin developments are reviewed.

• Journal of Sensor Science and Technology
• /
• v.26 no.4
• /
• pp.228-234
• /
• 2017

Gas sensors based on metal-oxide-semiconductors are predominantly used in numerous applications including monitoring indoor air quality and detecting harmful substances such as volatile organic compounds. Nanostructures, e.g., nanoparticles, nanotubes, nanodomes, or nanofibers, have been widely utilized to improve the gas sensing properties of metal-oxide-semiconductors by increasing the effective surface area participating in the surface reaction with target gas molecules. Recently, 1-dimensional (1D) metal oxide nanostructures fabricated using glancing angle deposition (GAD) method with e-beam evaporation have been widely employed to increase the surface-to-volume ratio significantly with large-area uniformity and reproducibility, leading to promising gas sensing properties. Herein, we provide a brief overview of 1D metal oxide nanostructures fabricated using GAD and their gas sensing properties in terms of fabrication methods, morphologies, and additives. Moreover, the gas sensing mechanisms and perspectives are presented.

• Journal of KIISE:Computing Practices and Letters
• /
• v.16 no.12
• /
• pp.1165-1176
• /
• 2010

In order to realistically visualize such participating media as cloud, smoke, and gas, the light transport process must be physically simulated inside the media. While it is known that this process is well described physically through the volume rendering equation, it usually takes a great deal of computation time for obtaining high-precision solutions. Recently, GPU-based, fast rendering methods have been proposed for the realistic simulation of participating media, however, there still remain several problems to be resolved. In this article, we describe our rendering techniques applied to enhance the performances and features of our GPU-assisted participating media renderer, and analyze how such efforts have actually improved the renderer. The presented techniques will be effectively used in volume renderers for creating various digital contents in the special effects industries.

• Journal of the Korean housing association
• /
• v.23 no.4
• /
• pp.11-18
• /
• 2012

The amount of energy consumption in the buildings is approximately 20% of domestic energy consumption. The Carbon Point Program have been published on reduction of greenhouse gas emission in buildings under the paradigm of 'Low Carbon Green Growth'. This study focuses on the effect of 'Carbon Point Program' for residential buildings in Daegu. The amount of electricity and waterwork consumption and information of households were investigated to analyse the effect of carbon point program. The samples are situated in Deagu and are apartment in Bukgu and Suseonggu. The $CO_2$ emission is analysed by factors of energy resource and household organization between before participating and after participating in Carbon Point Program. The participation type has a difference of voluntary participation in Suseonggu and passive participation in Bukgu. Based on this investigation, average amount of $CO_2$ emission was reduced from voluntary participation households but all of them did not. To promote the effect of Carbon Point Program, this study proposes that needing the plans to raise will and activity of reducing carbon and to help participation which have disadvantage against achieving reduction.

• IE interfaces
• /
• v.23 no.3
• /
• pp.213-220
• /
• 2010

As the market becomes increasingly globalized and competition among companies increases in severity, various specialized organizations are participating across the process plant lifecycle, including the stages of design, construction, operation and maintenance, and dismantlement, in order to ensure efficiency and elevate competitiveness. In this regard, it is an important technical issue to develop services or information systems for sharing process plant data among participating organizations. ISO 15926 is an international standard for integration of lifecycle data for process plants including oil and gas facilities. ISO 15926 Part 7, a part of the ISO 15926 standard, specifies an implementation method called a facade that uses Web Services and ontology technologies for constructing plant data repositories and related services, with the aim of sharing lifecycle data of process plants. This paper discusses the ISO 15926-based prototype facade implemented for storing equipment data of nuclear power plants and servicing the data to interested organizations.

• Journal of the speleological society of Korea
• /
• no.5
• /
• pp.53-55
• /
• 1997

In September 1996 I spent 8 days in Kamchatka Oblast of Silberia, speaking at the institute of Volcanic Geology and Geochemistry in Petropavlovsk and participating ina field excursion to the 1740 and 1975 lava beds of Tolbachik volcano. By international standards, the caves of these flows are small. But recently it has appeared that variations in chemistry and gas content of pahoehoe basalts makes profound variations in their lava tube caves. Thus it is important to look at as many speleoliferous regions as possible. This trend continued at Tolbachik.(omitted)

• Bulletin of the Korean Chemical Society
• /
• v.13 no.1
• /
• pp.32-36
• /
• 1992

The gas-phase pyrolysis reactions of 2-alkoxypyrimidines(II), 2-alkoxypyrazines(III), 4-ethoxypyrimidine(IV) and 3-ethoxypyridazine(V) are investigated theoretically using the AM1 MO method. These compounds pyrolyze in a concerted retro-ene process with a six-membered cyclic transition state (TS). The relative order of reactivity if (IV)>(II)>(III)>(V), which can be rationalized by the two effects arising from electron-withdrawing power of the aza-substituent: (ⅰ) Electron withdrawal from the C-O bond accelerates the rate and (ⅱ) electron withdrawal from the $N^1$-atom, that is participating in the six-membered TS, deactivates the reaction. We are unable to explain the experimental result of the greatest reactivity for pyridazine, (V), with our AM1 results. The reactivity increase accompanied by successive methylation of the ethoxy group, ethoxytert-butoxy, is due to a release of steric crowding in the activation process.

• Fire Science and Engineering
• /
• v.33 no.3
• /
• pp.1-8
• /
• 2019

The international standard for FT-IR gas analysis of fire effluents in ISO 5660-1 cone calorimeter has been being developed in ISO TC 92. A comparison of the round-robin test of WD 21397 was conducted with six participating laboratories in 2018. The test specimens were PMMA, rigid PU foam board, and PVC flooring. The measurement quantities were the time-to-ignition, peak heat release rate, total heat release, and effective heat of combustion for a cone calorimeter test and peak gas concentration, gas generation, and gas yield for FT-IR gas analysis. No outliers were identified. For the cone calorimeter quantities, the repeatability and reproducibility were 1.5% and 9.8%, respectively. For FT-IR gas analysis, the repeatability and reproducibility was 12.9% and 27.9%, respectively.