• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.10a
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• pp.42-42
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• 2003

• Journal of Sasang Constitutional Medicine
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• v.29 no.3
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• pp.211-223
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• 2017

Objectives The purpose of this study is to understand the formation of Jogakdaehwang-tang(JD-T)'s patholoy and the compositional change of it in Sasang Constitutional Medicine(SCM). Methods The pathologic condition in which JD-T was used and the change of its composition was studied in SCM Results and Conclusions 1. Jogak and Daehwang in "Dongmuyoogo Haedong" were presented with Ungdam because of the common purpose flowing the energy of lung. Therapeutic method for exogenous Ungibyeong in "Dongyisusebowon sangchobongwon" was subdivided into Hangwul's treated by Ungdam, and the heat pattern featuring contagious cold and constipation, treated by Jogakhwanggeumdaehwang-tang(JHD-T). 2. JD-T in "Dongyisusebowon Gabogubon" was used for Yangdok and Onbyeong which are exogenous disease causing by heat. The composition of JD-T has been completed as it included Mahwang, Gilgyeong, and Seungma derived from prescriptions relevant with Yangdok. 3. JD-T in "Dongyisusebowon Sinchukbon(Sinchukbon)" was included in pathology of Ganyeol, and it substituted Galgeunhaegi-tang(GH-T) for Onbyeong, not for Yangdok, so Galgeun and Seungma became the main drug in JD-T. Galgeunseung-gitang(GS-T) was created for treating heat pattern owing to Daehwang, its main drug, and moreover Jogak's effect is too strong. Therefore, Mahwang, Hwanggeum and Gilgyeong was excluded from the composition of JD-T. 4. The origins of JD-T could be Yiseonggugo-hwan, Daesiho-tang, Jowiseungchung-tang, Heukno-hwan, and GH-T. The change of JD-T went for them throughout JHD-T to JD-T. JD-T in "Sinchukbon" consists of Galgeun and Daehwang which directly gets rid of severe heat from small intestine, and Jogak and Seungma which help to eliminate mild heat existing from small intestine throughout nose to flesh.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.160-160
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• 1999

To reduce the fouling of heat exchangers, the plasma polymerized films was coated on the heat exchangers, and an effect of plasma polymerized film on fouling of heat exchangers was investigated. Monomer and reactive gases were used as the precursors of plasma polymerization. Plasma polymerized films were deposited with process parameters of pressure, power, and ratio of gases. Plasma polymerized films could be served as functional layers of good wettability and high resistance to corrosion. Wettability of plasma polymerized film could be controlled by the ratio change gas mixture. Hydrophilicity of plasma polymerized films on heat exchanger in air conditioner can provide improvement in performance of heat exchanger which results from good water drainage, decrease of pressure drop. DC-plasma polymerized films improve resistance to corrosion whcih is related to deposit formation in heat exchangers. The difference in the build up of fouling deposits between bare substrate and plasma polymerized substrate was investigated by scanning electron microscopy (SEM). An effect of plasma polymerized film on fouling of heat exchangers was discussed in terms of surface properties such as wettability, surface chemical state.

• Journal of Ocean Engineering and Technology
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• v.29 no.6
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• pp.481-487
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• 2015

The effects of the heat input and preheat/interpass temperatures on the tensile strength and impact toughness of multipass welded weld metal were investigated and interpreted in terms of the recovery of the alloying elements and microstructure. Increases in both the heat input and preheat/interpass temperatures decreased the tensile strength of the weld metal. A lower recovery of alloying elements, especially Mn and Si, and smaller area fraction of acicular ferrite in the weld metal were observed in higher heat input welding, resulting in a lower tensile strength. In contrast, only a microstructure difference was observed at a higher preheat/interpass temperature. The impact toughness of the weld metal gradually increased with an increase in the heat input because of the lower tensile strength. However, it decreased again when the heat input was larger than 45 kJ/cm because of the much smaller area fraction of acicular ferrite. No effect of the preheat/interpass temperature on the impact toughness was observed. The formation of a weld metal heat-affect zone showed little effect on the impact toughness of the weld metal in this experiment.

• Journal of the Korean Society for Heat Treatment
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• v.10 no.1
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• pp.1-9
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• 1997

The variation of the mechanical properties and the formation of retained austenite with heat treatment conditions in austempered Si bearing carbon steels has been investigated. In the case of a steel containing 0.35C-1.48Si-0.95Mn, it has been found that a feather shape bainite structure of lath are obtained under a isothermal treated condition at just below the Ms temperature, and the martensite, bainitic ferrite and retained austenite of second phase particles on the ferrite matrix for a isothermal treated steels after intercritical annealing are precipitated in a linked shape. The retained austenite with $2{\mu}m$ size induced as TRIP is found to increase with increasing the formation rate of retained austenite for the intercritical annealing and high Si containing steels. The tensile strength is increased as austempering temperature increases in all isothermal treatment temperature, whereas the elongation is shown to roughly decrease as the tensile strength increases. The values of tensile strength-elongation balance have showed a marked dependence upon the elongation rather than the tensile stregth, and their values are increased for high Si containing steels and intercritical annealing condition. The most optimum result has been shown to be the tensile stregth-elongation balance of $2882.4kgf/mm^2.%$ and the elongation of 33.3% for a "B" steel in the heat treating temperature range of $780{\sim}370^{\circ}C$.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.4
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• pp.407-414
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• 2017

In this study, a performance evaluation was conducted using a SUS 304 plate applied to low-temperature co-fired coating as a replacement for titanium plates. As a result of computational fluid dynamic analysis, the SUS 304 plate, applied to low-temperature co-fired coating, showed better heat transfer performance than a titanium plate, for 100 micron thickness coating. The result of the experiments using an actual heat exchanger revealed that a coated SUS 304 plate showed better heat transfer performance than a titanium plate. Furthermore, as the degree of corrosion and scale formation of the plate was confirmed through an overhaul inspection, the corrosion resistance of a coated SUS 304 plate was found to be almost the same as that of a titanium plate, and the inhibition effect of scale formation by sea water was better with a coated SUS 304 plate.

• Journal of the Korean Society for Heat Treatment
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• v.2 no.4
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• pp.27-39
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• 1989

The effect of gas mixing ratios during gas nitrocarburizing treatment on the formation of compound layer and the mechanical properties has been studied for hot work tool steel by using a combined heat treating technique. The thickness of compound and diffusion layers has been shown to grow as a parabolic relation with increasing the amount of ammonia at a given flow quantity of $CO_2$ gas. The compound layer consists mainly of ${\varepsilon}-Fe_3$(C, N) with small amounts of ${\gamma}^{\prime}-Fe_4N$ and ${\alpha}$-Fe. The combined heat treated hot work tool steel has shown that the thickness of compound layer increases with increasing nitrocarburizing time, but the rate of growth slows down as gas nitrocarburizing time goes more than two hours. Tensile properties have given a remarkable improvement. In particular, the wear resistance of combined heat treated hot work tool steel has exhibited an improvement of about 165% greater than that obtained from conventional quenching and multi-tempering treatments.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.719-725
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• 1997

This paper presents results of experimental studies on the heat transfer and solidification of the molten metal pool with overlying coolant with boiling. The metal pool is heated from the bottom surface and coolant is injected onto the molten metal pool. As a result, the crust, which is a solidified layer, may form at the top of the molten metal pool. Heat transfer is accomplished by a conjugate mechanism, which consists of the natural convection of the molten metal pool, the conduction in the crust layer and the convective boiling heat transfer in the coolant. This work examines the crust formation and the heat transfer rate on the molten metal pool with boiling coolant. The simulant molten pool material is tin (Sn) with the melting temperature of 232$^{\circ}C$. Demineralized water is used as the working coolant. The crust layer thickness was ostensibly varied by the heated bottom surface temperature of the test section, but not much affected by the coolant injection rate. The correlation beかeon the Nusselt number and the Rayleigh number in the molten metal Pool region of this study is compared against the crust formation experiment without coolant boiling and the literature correlations. The present experimental results are higher than those from the experiment without coolant boiling, but show general agreement with the Eckert correlation, with some deviations in the high and low ends of the Rayleigh number. This discrepancy is currently attributed to concurrent rapid boiling of the coolant on top of the metal layer.

• Korean Journal of Remote Sensing
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• v.26 no.6
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• pp.617-627
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• 2010

Although many researches for heat island study have been developed, there is little attempt to link the findings to actual and hypothetical scenarios of urban developments which would help to mitigate the Urban Heat Island (UHI) in cities. The aim of this paper is to analyze the UHI at urban area with different geometries, land use, and environmental factors, and emphasis on the influence of different geometric and environmental parameters on ambient air temperature. In order to evaluate these effects, the parameters of (i) Air pollution (i.e. Aerosol Optical Thickness (AOT)), (ii) Green space Normalized Difference Vegetation Index (NDVI), (iii) Anthropogenic heat (AH) (iv) Building density (BD), (v) Building height (BH), and (vi) Air temperature (Ta) were mapped. The optimum operational scales between Heat Island Intensity (HII) and above parameters were evaluated by testing the strength of the correlations for every resolution. The best compromised scale for all parameters is 275m resolution. Thus, the measurements of these parameters contributing to heat island formation over the study areas of Hong Kong were established from mathematical relationships between them and in combination at 275m resolution. The mathematical models were then tabulated to show the impact of different percentages of parameters on HII. These tables are useful to predict the probable climatic implications of future planning decisions.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.10
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• pp.1210-1216
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• 2011

The purpose of this study is to establish the analysis method for prediction of temperature during cryogenic heat treatment. Experimental cryogenic heat treatment is conducted to observe the phenomena such as boiling of fluid, ice layer on the material surface and to measure the temperature distribution of Al6061 tube. The CFD analysis considering the observed phenomena in the experiment is performed to predict the temperature distribution and convection heat transfer coefficient at each stage of cryogenic heat treatment, in which the boiling of fluid is considered as the multi-phase condition of vapour and liquid. The formation of ice layer on the tube surface is also modeled between material and fluid. The predicted results are in good agreement with the experimental ones. From the results, it is shown that the analysis method can predict the temperature distribution and convection heat transfer coefficient during cryogenic heat treatment.