• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.5
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• pp.1104-1112
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• 1988

In this study the structure of a two phase detonation has been numerically investigated through the assumption of a steady and one-dimensional flow in the suspension of carbon particles and pure oxygen. The bow shock formation in front of carbon particles has been taken into consideration when the relative velocity of gas flow with respect to the particle exceeds the local speed of sound. But its effect was found to be very limited to the induction zone only. Furthermore the interior particle temperature distribution has been considered in this work. It was found that the inner temperature gradient was very steep in the region of high relative velocity. On the while the temperature distribution inside the particle was almost uniform in the region of low relative velocity. Overall, the effect of the interior particle temperature distribution has been significant in the two phase detonation.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.11
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• pp.1481-1487
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• 2002

The thin SiC filament technique has been employed to identify the possibility of measuring flame temperature, and especially unstable near-extinction flame temperature in an oxidizer deficient ambience, by comparing the relative visible (non-IR) luminosities of SiC filaments with thermocouple measured temperature in co-flowing, laminar propane/air diffusion flames. The results show good agreement between the digitized relative visible luminosity profiles of the SiC filaments and temperature profiles measured using a thermocouple at temperatures above $700^{\circ}C$, although, a non-linear calibration is probably required far the whole temperature range. The highest radial peak temperature exists near to the nozzle exit. and the centerline temperatures were virtually unchanged with increasing flame height in an oxidizer deficient near-extinction flame.

• Architectural research
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• v.14 no.4
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• pp.153-161
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• 2012

This paper presents an integrated procedure to predict the temperature and moisture distributions in hardening concrete considering the effects of temperature and aging. The degree of hydration is employed as a fundamental parameter to evaluate hydro-thermal-mechanical properties of hardening concrete. The temperature history and temperature distribution in hardening concrete is evaluated by combining cement hydration model with three-dimensional finite element thermal analysis. On the other hand, the influences of both self-desiccation and moisture diffusion on variation of relative humidity are considered. The self-desiccation is evaluated by using a semi-empirical expression with desorption isotherm and degree of hydration. The moisture diffusivity is expressed as a function of degree of hydration and current relative humidity. The proposed procedure is verified with experimental results and can be used to evaluate the early-age crack of hardening concrete.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1989.10a
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• pp.13-18
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• 1989

Temperature distribution of 250W high-pressure mercury lamp has been measured by the spectroscopic method using relative intensities of spectral lines. To obtain radial temperature distribution, the measured intensity which was integrated along the line of sight was transformed into radial line intensity by Abel's inversion. Temperature was determined from relative intensities of spectral lines of the same atomic species. The measured temperature of 250W high-pressure mercury lamp is 6000K at the axis. In this experiment temperature profile of high-pressure arc is papabolic as known.

• Macromolecular Research
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• v.14 no.3
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• pp.354-358
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• 2006

Polybutadiene (BR) was pyrolyzed at $540-860^{\circ}C$ and the effect of pyrolysis temperature on variations in the relative abundance of the major pyrolysis products (C4-, C5-, C6-, C7-, and C8-species) was investigated. Formation of the C4-, C5-, C6-, and C7-species competed with that of the C8-species. Relative intensity of the C8-species decreased with increasing pyrolysis temperature, while that of the C5-, C6-, and C7-species increased. Pyrolysis paths were became more complicated with increasing pyrolysis temperature. We suggested the operation of double bond migration and succeeding rearrangements for the formation of the C5- and C7-species and various rearrangements, including a double bond, for the formation of the C6-species at high temperature. The activation energies for the pyrolysis product ratios of(C5+C6+C7)/C4 and C8/C4 were used to explain the competition reactions to form the pyrolysis products.

• Nuclear Engineering and Technology
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• v.11 no.1
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• pp.21-27
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• 1979

The relative reaction rates were measured in the TRIGA Mark II reactor core and analyzed to obtain the neutron spectrum parameters; relative neutron temperature T$^{n}$ and epithermal index (equation omitted) Measurements were made with the central thimble and the F2 position containing the light water. The relative neutron temperature was represented by the activation ratio of Lu-Mn, and the epithermal index was measured by Au-Mn foil activation. The multichannel analyzer was used to measure the relative ${\gamma}$-rays of the detector foils. The results were compared with the calculated values.

• International Journal of Concrete Structures and Materials
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• v.2 no.2
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• pp.83-90
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• 2008

Permeability to vapor and water among other performances required for finishing materials is dealt with in this study. The relative moisture content of concrete coated/covered with a finishing material was experimentally investigated while changing the environmental conditions including temperature, relative humidity, and rainfall. An organic paint (water-based urethane), organic synthetic resin emulsion-type film coating (film coating E), and inorganic porcelain tiles were selected as the finishing materials. When compared from the aspect of vapor and water permeability, the vapor permeability and water permeability of water-based urethane were high and low, respectively; those of film coating E were high and high, respectively; and those of porcelain tiles were low and low, respectively. This means that the moisture state of concrete structures is governed not only by the environmental conditions but also by the performance of finishing materials. It is therefore of paramount importance to appropriately select a finishing material to address the specific deteriorative factors involved in the concrete structure to be finished.

• Journal of Environmental Science International
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• v.23 no.11
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• pp.1851-1862
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• 2014

It is well known that urban relative humidity has continuous decreasing trend owing to the influence of urbanization. The change of relative humidity is directly influenced by two factors, namely, temperature effect and water vapor effect in various urban effects. In this study, the temperature and the water vapor effects on the relative humidity change were analyzed by using monthly mean relative humidities for a long period(1961~2013) in Busan and Daegu. The major results obtained in this study can be summarized as follows. Firstly, the urban dryness was caused mainly by water vapor effect in summer. But, for the other seasons, the urban dryness is mainly due to the temperature effect. Secondly, the relative humidity in Busan is on the decrease until now. This phenomenon is similar to another Korean huge cities such as Seoul, Daejeon and Incheon.

• Journal of Biosystems Engineering
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• v.23 no.5
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• pp.465-472
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• 1998

In this study short gain rough rice(Chu-cheong) with initial moisture content of around 12%(w.b.) was exposed to 3 levels of relative humidity(70, 80 and 90%) and 3 levels of temperature(20, 25 and 3$0^{\circ}C$) of the air, in order to evaluate the adsorption characteristics of rough rice and the rate of cracked kernels which will serve as the basic data when developing the quality adjusting equipment. The result showed that the moisture content of rough rice increased rapidly during the early stages of moisture adsorption like other grains, and at least 70% of the adsorption occurred within the first 24 hours of exposure to the humid environment. Adsorption rate was more related to relative humidity than the temperature of air stream, and the higher the relative humidity, the higher the adsorption rate. And the Page's equation predicted best the adsorption process of this study. Experimental results for the crack generation during the adsorption process showed that the higher the relative humidity the more the cracked kernels, and that the temperature had little effect. An empirical equation was developed to predict the crack ratio for the conditions of this study, and Nishiyama model predicted better the crack generation than Hoerl model.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.8
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• pp.677-682
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• 2015

We simulate an emulsion system under simple shear rates to analyze its rheological characteristics using the lattice Boltzmann method (LBM). We calculate the relative viscosity of an emulsion under a simple shear flow along with changes in temperature, shear rate, and surfactant concentration. The relative viscosity of emulsions decreased with an increase in temperature. We observed the shear-thinning phenomena, which is responsible for the inverse proportion between the shear rate and viscosity. An increase in the interfacial tension caused a decrease in the relative viscosity of the decane-in-water emulsion because the increased deformation caused by the decreased interfacial tension significantly influenced the wall shear stress.