• Title/Summary/Keyword: boiling effect

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Effect of Parameters in Evaporative Removal Process by Absorption of a CW Laser (연속 레이저 흡수에 의한 증발제거 과정의 관련 인자 영향 고찰)

  • 김진윤;송태호
    • Journal of Biomedical Engineering Research
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    • v.16 no.1
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    • pp.67-76
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    • 1995
  • Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd: YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as BrJ, and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased. To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained.

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A Study on the Stability of Carpet by Thermal Decomposition (열분해에 의한 카펫의 안정성에 관한 연구)

  • Park, Keun-Ho;Lee, Ki-Cheol
    • Journal of the Korean Applied Science and Technology
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    • v.23 no.2
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    • pp.147-152
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    • 2006
  • The accidents occurred by unstable material which is easily exploded or burnt up were caused by heat and collision under the condition of relatively low temperature without oxygen, have been reported frequently. However, the amount of the unstable material is getting higher by development of fine ceramic research area even though its dangerous characteristic is disregarded. This research studied a heat stability and measured boiling point of various carpet material. Carpet has been used in home as well as general indoor usage. Now a day, carpet material which is hardly burnt has been on commercial, but its detailed unstable conditions is not mentioned. This research reports the measurement of the initial temperature of generation heat and heat-radiation change on differential scanning calorimeter (DSC). The DSC data of nylon bulked continuous filament (N-BCF) yam 100%, nylon (NY), poly propylene (PP), and a new material named polytrimethylene terephthalate (PTT) are studied and researched about the effect of them using TGA, furnace, and direct-burning experiment.

IMPROVEMENTS OF CONDENSATION HEAT TRANSFER MODELS IN MARS CODE FOR LAMINAR FLOW IN PRESENCE OF NON-CONDENSABLE GAS

  • Bang, Young-Suk;Chun, Ji-Ran;Chung, Bub-Dong;Park, Goon-Cherl
    • Nuclear Engineering and Technology
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    • v.41 no.8
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    • pp.1015-1024
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    • 2009
  • The presence of a non-condensable gas can considerably reduce the level of condensation heat transfer. The non-condensable gas effect is a primary concern in some passive systems used in advanced design concepts, such as the Passive Residual Heat Removal System (PRHRS) of the System-integrated Modular Advanced ReacTor (SMART) and the Passive Containment Cooling System (PCCS) of the Simplified Boiling Water Reactor (SBWR). This study examined the capability of the Multi-dimensional Analysis of Reactor Safety (MARS) code to predict condensation heat transfer in a vertical tube containing a non-condensable gas. Five experiments were simulated to evaluate the MARS code. The results of the simulations showed that the MARS code overestimated the condensation heat transfer coefficient compared to the experimental data. In particular, in small-diameter cases, the MARS predictions showed significant differences from the measured data, and the condensation heat transfer coefficient behavior along the tube did not match the experimental data. A new method for calculating condensation heat transfer coefficient was incorporated in MARS that considers the interfacial shear stress as well as flow condition determination criterion. The predictions were improved by using the new condensation model.

Development of fillet-type seasoner and mixed powder-type seasoner using smoked mackerel (훈제 고등어를 이용한 필렛형 조미료 및 복합 분말조미료의 개발)

  • 오영주;오혁수
    • Culinary science and hospitality research
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    • v.7 no.3
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    • pp.145-161
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    • 2001
  • In odor to develop fillet-type seasoner and mixed powder-type seasoner using smoked mackerel as primary material, processing conditions of the mackerel meat and flavoring extract from various materials were examined. The approximate composition of mackerel meat and mixed powde-type seasoner using mackerel as primary material were 10.9 and 11.7%, for moisture 79.1 and 57.2% for crude protein, 5.3 and 2.9% for crude lipid, and 4.3 and 24.6% for crude ash, respectively. It was suitable to simmer raw mackerel in 3% chitooligosaccaride solution at 8$0^{\circ}C$ for 10 min., for the enhancement of reaction their meat and chitooligosaccharide. Considering effect of type of woodsmoke on organoletic properties of mackerel after smoking, oak and mixture(oak wood + citrus wood = 1 : 1) were superior to another woodsmoke, the smoking conditions favoring the most overall preference were 8$0^{\circ}C$, 25min. for smoking time, 20$0^{\circ}C$, 20min. for baking, and 10$0^{\circ}C$. 4hrs. for drying. The optimal material mixing ratio for mixed powder-type seasoner was powder of smoked mackerel 60%, dried anchovy 15%, dried sea tangle 10%. The most appropriate extraction condition of mixed powder seasoner with packing tea bag(10g/bag) was 98$^{\circ}C$ for 5min. in the boiling water.

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Geometric Optimization of a Microchannel for the Improvement of Temperature Gradient Focusing (온도기울기 농축(TGF) 향상을 위한 미세채널 형상 최적화 연구)

  • Han, Tae-Heon;Kim, Sun-Min
    • The KSFM Journal of Fluid Machinery
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    • v.14 no.2
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    • pp.17-24
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    • 2011
  • Temperature gradient focusing (TGF) of analytes via Joule heating is achieved when electric field is applied along a microchannel of varying width. The effect of varying width of the microchannel for the focusing performance of the device was numerically studied. The governing equations were implemented into a quasi-1D numerical model along a microchannel. The validity of the numerical model was verified by a comparison between numerical and experimental results. The distributions of temperature, velocity, and concentration along a microchannel were predicted by the numerical results. The narrower middle width and wider outside width of the channel having the fixed length contribute to improve the focusing performance of the device. However, too narrow middle width of the channel generates a higher temperature which can cause the problems including sample denaturation and buffer solution boiling. Therefore, the channel geometry should be optimized to prevent these problems. The optimal widths of the microchannel for the improvement on TGF were proposed and this model can be easily applied to lab-on-a-chip (LOC) applications where focusing is required based on its simple design.

Experimental Study of Thermo-electric material using Lithium-Ammonia$(Li(NH_3)_n)$ Solution (리튬-암모니아 $(Li(NH_3)_n)$ 용액을 이용한 열전기적 특성 실험)

  • Park, Han-Woo;Kim, Ji-Beom;Jeon, Joon-Hyeon
    • Korean Chemical Engineering Research
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    • v.49 no.2
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    • pp.263-270
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    • 2011
  • The aim of this paper is, through the experiment of Lithium-Ammonia solutions $(Li(NH_3)_n)$, to analyze and verify a thermoelectric-conversion property at near Ammonia-boiling point ($-40^{\circ}C$). The experiment results show that the solutions with 0.58 MPM~1.87 MPM generate thermoelectric power at temperature difference $({\Delta}T=0{\sim}15^{\circ}C)$ where Current is constantly proportional to Voltage. This paper provides a new insight into the development of a thermoelectric material.

The Experimental Study on Exhaust Emission Characteristics with Oxygen Component Addition in Diesel Engine (디젤기관에서 산소성분 첨가에 의한 배기가스 배출특성의 실험적 연구)

  • Oh, Y.T.;Choi, S.H.;Jang, S.J.
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.800-805
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    • 2001
  • Recently, our world is faced with very serious and hard problems related to the air pollution due to the exhaust emissions of the diesel engine. So, lots of researchers have studied to reduce the exhaust emissions which influenced the environment strong. In this paper, the effect of oxygen component in fuel on the exhaust emissions has been investigated for diesel engine. And, we tried to analysis the quantities of the low and high hydrocarbon among the exhaust emissions in diesel engine. It have been investigated by the quantitative analysis of the hydrocarbon $C_1\simC_6$ using the gas chromatography. This study carried out by comparing the chromatogram with diesel fuel and diesel fuel blended DGM(diethylene glycol dimethyl ether) 5%. The results of this study show that the hydrocarbon $C_1\simC_6$ among the exhaust emissions of the mixed fuels are exhausted lower than those of the diesel fuel at the all load and speed. In particular, high boiling point hydrocarbons such as $C_5$ and $C_6$ were reduced remarkably in high speed and load region.

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A Study on the Heat Transfer Characteristics of Loop Type Capillary Heat Pipe (루프형 세관 히트 파이프의 열전달특성에 관한 연구)

  • Yoon, Suck-Hun;Choi, Jae-Hyuck
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.3
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    • pp.346-353
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    • 2000
  • In this paper, heat transfer characteristics of a loop type capillary heat pipe were experimentally investigated for the effect of several fill charge ratios of working fluid and heat loads. This type of heat pipe consists of a heating section, a cooling section and an adiabatic section. The heat pipe used has a 0.002m internal diameter, a 0.34m length in one turn and consists of 19 turns. Heating and cooling sections each have a length of 70mm. Experiments were performed to measure the temperature distributions and the pressure variation of the heat pipe. Heat transfer performance, effective thermal conductivity, boiling heat transfer and condensation heat transfer coefficients were calculated for various operating conditions of heat pipe and it was found that heat transfer characteristics of this type heat pipe were very excellent. As shown by this experimental study, this type of heat pipe operates by oscillatory flow caused by pressure and temperature oscillations.

Changes in Mineral Content in Several Root Vegetables by Various Cooking Methods (조리 방법에 따른 근채류의 무기질 함량 변화)

  • 오명숙
    • Korean journal of food and cookery science
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    • v.12 no.1
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    • pp.40-45
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    • 1996
  • This study was conducted in order to determine the effect of various cooking methods (boiling, pressure cooking, steaming and microwave heating) on mineral content, color and sensory quality of radish, potato and carrot. It was shown that microwave heating was desirable method in cooking radish on both the acceptability and the retention of mineral content. On the other hand, steaming and pressure cooking were found to be desirable methods for cooking potato. There were not so many differences in both the retention of mineral content and the acceptability of carrot by various cooking methods. The pressure cooking, which was not a proper method for leaf vegetables, could be applied to root vegetables without losing so many mineral contents.

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In order to standarization of Kye-Ji Tang of ${\ulcorner}$Treatise on Febrile Diseases${\lrcorner}$ (계지탕(桂枝湯)의 기미(氣味) 표준화 연구(I))

  • Kim, In-Rak
    • Journal of The Association for Neo Medicine
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    • v.2 no.2
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    • pp.297-314
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    • 1997
  • This study was conducted to standardize the 'Ki-Mi' of Kye-Ji Tang in the basis of ${\ulcorner}$Treatise on Febrile Diseases${\lrcorner}$ and the results were as follows 1. The medicinal plants used are processed with hot water right after picking. 2. One seung(升) of water equals to 10cc. 3. One yang(兩) equals to 6 grams. 4. Medicinal plants are shattered to the size of beans by the process called Boo-Jeor. 5. Kye-Ji Tang, which is composed with 5 medicinal plant(Cortex Cinnamomi : 18g; Radix Paeoniae : 18g; Radix Glycyrrhizae : 12g; Rhizoma Zingiberis : 18g; Fructus Ziziphi Jujubae : 18g), is prepared by adding 490cc water to above 5 medicinal plants and boiled to 210cc. After boiling, the residue is discarded and the extract is taken orally 3 times a day as one dosage of 70cc. It is recommended that 20 minitues after taking of Kye-Ji Tang, the additional uptake of rice porridge might enhance the pharmacological effect of Kye-Ji Tang.

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