• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.11
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• pp.1629-1636
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• 2004

The continuous casting is primarily a heat-extraction process in which the heat transfer at various cooling zones profoundly influences quality of products. So development of numerical model is necessarily needed for more specific and clear investigations upon heat transfer mechanism at mold and secondary cooling zones. In this study, heat transfer coefficients which show the characteristic of heat transfer mechanism in mold are calculated for more exact analysis with temperature measured in bloom mold using optimal algorithm, and finally the validity of cooling conditions at secondary cooling zone actually used at field fur 30 Ton bloom type continuous casting of 0.187%C is investigated. From the results of solidification analysis, the characteristic of bloom mold shows a similar tendency with that of previous studies, and optimized cooling conditions for 0.187%C are presented.

• Journal of Oriental Neuropsychiatry
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• v.22 no.1
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• pp.13-23
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• 2011

Objectives : The aim of this survey study is to analysis clinical symptoms and patterns of dementia patients. The results of this study will be used to support development of the oriental herbal medicine for dementia. Methods : Clinical data were collected from 41 dementia patients and 20 aged persons who have no cognitive impairment in 3 sites including 2 hospitals and 1 sanatorium. 'The instrument of oriental medical evaluation for dementia' is used to evaluate clinical symptoms and patterns of all subjects. Results : 1. Subjects of deficiency syndrome patterns were nearly three times more than subjects of excess syndrome patterns. 2. In dementia patient group, the average rate for 4 clinical symptoms, related with treatment principle of clear heat, was 26.9%. 3. The average rate for 4 clinical symptoms, related with condition of urine and feces, was 15.6%. 4. The average rate for 5 clinical symptoms, related with anger, irritation, anxiety and restlessness, was 40.0%. Conclusions : 1. It is needed to develop new herbal medicine for dementia focuing on clear heat, anger, irritation, anxiety, restlessness, and condition of urine and feces. 2. 'The instrument of oriental medical evaluation for dementia' has strong tendency that excessively reflects general geriatric symptoms, related to deficiency syndrome patterns. so, more clinical symptoms of excess syndrome should be added in this tool.

• Herbal Formula Science
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• v.29 no.4
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• pp.297-310
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• 2021

Objectives : In traditional herbal medicine, as clinical experience increased, the number of herbal formulas also increased. For example, there are 61,739 herbal formulas in Pujifang, and 96,592 in Dictionary of Traditional Chinese Medicine Prescriptions. In chapter of Clear Heat (CH; 淸熱劑) of textbook, the 38 formulas were presented. For enhancing understanding of herbal formula, a large majority of books explained each individual formula with description or figure about interactions between constituent herbs. But there is no study on the interrelationship of each CH herbal formulas. This study investigated the interrelationship of CH herbal formulas. Methods : The CH herbal formula were analyzed with the ingredients, actions and clinical applications by literature study. Results : To improve cognition the interrelationship of CH herbal formulas, we analyzed the formulas and established the 16 interrelations of herbal formulas. Conclusions : Finally, this study established the interrelation of herbal formula as one figure. This result could contribute to improve cognition on the interrelationship of CH herbal formulas.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.10
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• pp.1200-1205
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• 2014

The effect of nanofluids on the heat transfer performance of a pulsating heat pipe has been experimentally investigated. Water-based diamond nanofluid and aluminium oxide ($Al_2O_3$) nanofluid were tested in the concentration range of 0.5-5%. The pulsating heat pipe was constructed using clear Pyrex tubes of 1.85 mm in inner diameter in order to visualize the pulsating action. The total number of turns was eight each for heated and cooled parts. The supply temperatures of heating water and cooling water were fixed at $80^{\circ}C$ and $25^{\circ}C$ respectively. The liquid charging ratio of the nanofluid was 50-70%. The test results showed that the case of 5% concentration of diamond nanofluid showed 18% increase in heat transfer rate compared to pure water. The case of 0.5% concentration of $Al_2O_3$ nanofluid showed 24% increase in heat transfer rate compared to pure water. But the increase of $Al_2O_3$ nanofluid concentration up to 3% did not show further enhancement in heat transfer. It is also observed that the deposited nanoparticles on the tube wall played a major role in enhanced evaporation of working fluid and this could be the reason for the enhancement of heat transfer by a nanofluid, not the enhanced thermal conductivity of the nanofluid.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.51-54
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• 2003

The continuous casting is primarily a heat-extraction process in which the heat transfer at various cooling zones profoundly influences quality of products. So development of numerical model is necessarily needed for more specific and clear investigations upon heat transfer mechanism at mold and secondary cooling zones. In this study, heat transfer coefficients which shows the characteristic of heat transfer mechanism in mold are calculated for more exact analysis with temperatures measured in bloom mold using optimal algorithm, and finally the validity of cooling conditions at secondary cooling zone which is actually used at field for 30 Ton bloom type continuous casting of 0.187%C is investigated. From the results of solidification analysis, the characteristic of bloom mold shows good agreements with that of previously studies by other authors and optimized cooling conditions for 0.187%C are presented.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.5
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• pp.511-520
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• 2000

The urban atmosphere is characterized by th difference in surface and atmospheric environment between urban and more natural area. To investigate th climatic effect of land use type and anthropogenic heat of urban on wind field, numerical simulations were carried out under typical summer synoptic condition. The wind model PNU_MCM(Pusan National University Mesoscale Circulation Model) is based on the three-dimensional Boussinesq equations, taking into account the hydrostatic assumption . Since lane-use differs over every subdivision on Pusan the surface energy budget model includes sub0grid parameterization scheme which can calculate the total heat flux over a grid surface composed of different surfaces. The simulated surface wind agrees well with the observed value, and average over 6 days which represent typical summer lan-sea breeze days, August 1998, i.e. negligible gradient winds and almost clear skies. Urbanization makes sea-breeze enhance at day and reduce land-breeze at night. The results show that contribution of land-use type is much larger than that of anthropogenic heat in Pusan.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.11
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• pp.792-798
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• 2012

A general concept on the definition of the second law efficiencies of thermodynamic cycles is introduced. The efficiency is defined to be proportional to the entropy generation divided by the maximum possible entropy generation. This way of definition of the cycle efficiency is clear and concise and, moreover, follows faithfully the concept of the second law of thermodynamics. This definition is applied to heat engine, refrigerator and heat pump. The second law efficiencies of heat engine and refrigeration cycles are derived, which are the same as the existing ones, respectively. The second law efficiency of heat pump, however, finds to be different from the existing one. Discussion is given about the difference and its cause.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.714-719
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• 2002

In The Great Hanshin-Awaji Earthquake, the general yield brittle fractures were observed in beam-column connections of steel building frames. Among many influencing factors which affect the general yield brittle fracture, it can be considered that fracture toughness has substantial effects. Some studies are making clear the required toughness for the base metal and the weld metal, but general values are not proposed. Moreover, it seems that it is also important to pay attention to the toughness decrease in the weld heat affected zone (weld HAZ), because the toughness decrease occurs in the HAZs of mild steel. In this paper, the relationship between toughness of simulated HAZs of "the rolled steels for building structures (SN)" and the weld heat-input limit of the SN steel are investigated, in an attempt to provide the required toughness for HAZs. The relationships between the increase of the hardness value and toughness, and changes of microstructure after weld heat-input are also discussed. The main results are summarized as follows. 1) The SN400B can keep its toughness at higher heat-inputs compare to the SN490Bs. 2) The steel grade, which becomes harder than other steel grades at the same heat-input, has smaller absorbed energy and smaller limit of heat-input. 3) The weld heat-input limit of the SN400B and the SN490B are proposed separately for some required toughness values.

• Journal of Magnetics
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• v.18 no.2
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• pp.86-89
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• 2013

This paper shows a new effective approach to measure crystallization temperature of soft magnetic underlayer (SUL) for next generation of heat assisted perpendicular recording media. This approach uses temperature dependent reflectivity, which shows a clear jump when samples are crystallized. To achieve this measurement, an optical system is set up using hot plate and infrared laser. Reflectivity of SUL $(Co_{70}Fe_{30})_{92}Ta_3Zr_5$ shows a clear jump at its amorphous-crystalline transition temperature. Experiment results show this effect is clear in infrared region, and is weak for visible light.

• Transactions of the Korean hydrogen and new energy society
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• v.12 no.4
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• pp.267-275
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• 2001

To clear the differences of heat transfer coefficient of in-cylinder gas with fuel properties, the transient heat transfer coefficient of hydrogen gas is investigated by using the hydrogen fueled engine. The measured results were also compared with those of gasoline engine and several empirical equations. Transient heat transfer coefficients were determined by measurements of unsteady heat flux and instantaneous wall temperature in the cylinder head. As the main results, it is shown that transient heat transfer coefficients have remarkable differences according to fuel properties, and it's value for hydrogen engine is twice higher than that of gasoline engine. It means that equation of heat transfer coefficient that the effect of fuel properties is considered sufficiently, is needed to analyze or simulate the gas engine performance.