• Title/Summary/Keyword: Heating Pressure

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Development of a PLD heater for continuous deposition and growth of superconducting layer

  • Jeongtae Kim;Insung Park;Gwantae Kim;Taekyu Kim;Hongsoo Ha
    • Progress in Superconductivity and Cryogenics
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    • v.25 no.2
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    • pp.14-18
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    • 2023
  • Superconducting layers deposited on the metal substrate using the pulsed laser deposition process (PLD) play a crucial role in exploring new applications of superconducting wires and enhancing the performance of superconducting devices. In order to improve the superconducting property and increase the throughput of superconducting wire fabricated by pulsed laser deposition, high temperature heating device is needed that provides high temperature stability and strong durability in high oxygen partial pressure environments while minimizing performance degradation caused by surface contamination. In this study, new heating device have been developed for PLD process that deposit and growth the superconducting material continuously on substrate using reel-to-reel transportation apparatus. New heating device is designed and fabricated using iron-chromium-aluminum wire and alumina tube as a heating element and sheath materials, respectively. Heating temperature of the heater was reached over 850 ℃ under 700 mTorr of oxygen partial pressure and is kept for 5 hours. The experimental results confirm the effectiveness of the developed heating device system in maintaining a stable and consistent temperature in PLD. These research findings make significant contributions to the exploration of new applications for superconducting materials and the enhancement of superconducting device performance.

Effects of Change of Wafer Shape through Heating on Chemical Mechanical Polishing Process (가열에 의한 웨이퍼 형상 변화가 CMP에 미치는 영향)

  • 권대희;김형재;정해도
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.1
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    • pp.85-90
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    • 2003
  • Removal rate and Within Wafer Non-Uniformity (WIWNU), the most critical issues in Chemical Mechanical Polish (CMP) process, are related to the pressure distribution, wafer shape, slurry flow, mechanical property of pad and etc. Among them, wafer warp generated by other various manufacturing process of wafer may induce the deviation of pressure distribution on the backside of wafer. In the convex shaped wafer the pressure onto the backside of wafer is higher than that of perfectly flat shaped wafer. Besides, such an added pressure is in proportion to the curvature of wafer. That is, the bigger the curvature of wafer becomes the higher the removal rate goes. And the WIWNU is known to be directly related to the pressure distribution on the wafer as well. In other words, the deviation of pressure distribution is in proportion to the WIWNU. In this paper, it is found that the wafer shape may be modified through heating the backside of it and thus properly changed pressure onto the backside of it may improve the WIWNU.

Simultaneous Consolidation of Titanium Diboride with Self-Propagating High-Temperature Synthesis, Direct Contact-Heating, and Pressure: Modeling of Temperature Distribution and the Relationship between Applied Energy and Densification ($TiB_2$ SHS 및 직접 접촉가열에 의한 동시 가압법 : 온도분포 모델링 및 공급에너지와 치밀화 관계)

  • Chung, G.K.;Cho, K.;Lee, H.B.
    • Journal of the Korean Ceramic Society
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    • v.32 no.7
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    • pp.817-824
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    • 1995
  • TiB2 was simultaneously synthesized and densified with concurrent self-propagating high-temperature synthesis and direct contact-heating by electrcial power input and pressure. Density of TiB2 synthesized by self-propagating high-temperature synthesis and consolidated simultaneously by direct contact-heating and pressure was maximum 80% of the theoretical density (4.52g/㎤). Temperature profile was analyzed by solving heat balance equation with numerical method (FTCS method). The temperature of the sample was sufficiently raised to that temperature sufficient to be densified. It was ascertained that the density of the SHS synthesized TiB2 is exponentially proportinal to the input thermal energy per mass.

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Effect of Heating Rate on Spalling Type of High-Strength Concrete (고강도 콘크리트의 폭렬형태에 미치는 가열속도의 영향)

  • Hwang, Eui-Chul;Kim, Guy-Yong;Son, Min-Jae;Suh, Dong-Kyun;Lee, Yae-Chan;Nam, Jeong-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.05a
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    • pp.237-238
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    • 2021
  • This study evaluated the vapor pressure and thermal stress of high-strength concrete according to spalling type. As a result, it was confirmed that the internal temperature gradient of the concrete varies depending on the heating rate, and the vapor pressure and thermal stress of the concrete are the main factors of spalling. In addition, it was confirmed that spalling type varies depending on the vapor pressure and thermal stress of the concrete.

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Effect of Joule Heating and Hydrostatic Pressure on Reduction of Total Aerobes and Spores of Bacillus cereus in Sauces Prepared with Traditional Korean Fermented Foods (장류를 이용하여 제조한 소스류의 총균 및 Bacillus cereus 포자에 대한 줄가열 및 초고압 처리 효과)

  • Jo, Eun-Ji;Oh, Se-Wook;Hur, Byung-Serk;Hong, Sang-Pil
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.10
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    • pp.1619-1626
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    • 2014
  • This study was conducted to evaluate the effects of Joule heating and hydrostatic pressure on reduction of total aerobes and spores of Bacillus cereus in four kinds of sauces prepared with traditional Korean fermented foods. Total aerobes and inoculated spores of B. cereus in sauces were assayed after treatment or during storage at $30^{\circ}C$ after 4 or 8 weeks. Joule heating ($85^{\circ}C$), hydrostatic pressure (550 Mpa, 5 min), and antimicrobial additive (3% ethanol) were separately applied or combined as a hurdle technique. A 1.0~2.0 log reduction in total aerobes of Doenjang and Gochujang sauce was observed upon Joule heating at 80, 85, and $95^{\circ}C$. Significant reductions (0.92~1.21 log/0.5~1.38 log and 1.26~1.7 log/0.47~3.45 log) of total aerobes/spores of B. cereus in Doenjang and Gochujang sauce, respectively, occurred upon JA (Joule+additive), JP (Joule+hydrostatic pressure) or JAP (Joule+additive+ hydrostatic pressure). Effects of each treatments were maintained or increased during storage for 8 weeks at $30^{\circ}C$, suggesting that total aerobes and spores of B. cereus in Doenjang and Gochujang sauce can be controlled through Joule heating or hydrostatic pressure treatment.

Thermodynamic Analysis on the Feasibility of Turbo Expander Power Generation Using Natural Gas Waste Pressure (천연가스 폐압발전 활성화의 당위성에 대한 열역학적 분석)

  • Ha, Jong Man;Hong, Seongho;Kim, Kyung Chun
    • Journal of the Korean Institute of Gas
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    • v.16 no.6
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    • pp.136-142
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    • 2012
  • Thermodynamic equations for the electric power and temperature in a turbo expander generator (TEG) using pressure energy in a natural gas line are derived. From the equations, it was shown that dominant factor is not the pressure difference but the pressure ratio. The high energy level in the inlet of TEG can be made from nearly no expense of electric energy input, which means TEG can be treated as one of newly available clean energy source. If a post heating method is chosen to heat up expanded natural gas, the usage of cold energy is possible without a refrigeration cycle. The combined TEG and refrigeration system enhances economic benefit much more.

The Analysis of Physicochemical and Sensory Characteristics in Brown Stock - Comparison of Traditional Method and High-Pressure Extracted Method - (갈색 육수의 이화학적 및 관능적 특성 분석 - 전통 방식과 고압 가열 방식 비교 -)

  • Choi, Soo-Keun;Jang, Hyuk-Rae;Rha, Young-Ah
    • Culinary science and hospitality research
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    • v.14 no.3
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    • pp.196-209
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    • 2008
  • This study was conducted to mass-produce brown stock optimized by using a high-pressure heating extractor and to use brown stock as a material for developing various products. For these purposes, we attempted to produce standardized brown stock by extracting brown stock using a high-pressure heating extractor and compared it with brown stock extracted by the traditional method in terms of general elements and mechanical and sensory characteristics. With regard to how to prepare optimal brown stock, the best brown stock was that extracted seven times repeatedly by the traditional method, but the method had a large economic loss in terms of material consumption and took a long time in extraction. Thus, considering time and labor, it was concluded that extraction at 120$^{\circ}C$ for 15 hours using a high-pressure heating extractor is the optimal extraction condition in terms of economic efficiency and quality. The results of this study are expected to be useful as a practical material for making brown stock production process more convenient, applying cooks' traditional cooking techniques to mass production, maintaining standardized superior quality and taste, and improving shelf life.

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Effects of Electric Heating Pad on Abdominal Pain and Anxiety during the Colonoscopy (복부가온패드 적용이 대장내시경 검사 대상자의 통증과 불안에 미치는 영향)

  • Kwon, Tae Jeong;Lee, Hyang Yeon;Lee, Jia
    • Journal of Korean Clinical Nursing Research
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    • v.14 no.2
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    • pp.47-57
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    • 2008
  • Purpose: The purpose of this study was to examine the effects of an electric heating pad on abdominal pain and anxiety during the colonoscopy procedure. Method: Data were collected from 70 adult patients (experimental group (35), control group (35)) who underwent colonoscopy in a general hospital in Seoul, South Korea between January 6 and May 4 2006. For the experimental group the electric heating pad was applied from 20 minutes before the test through the whole procedure. Objective pain was measured during the test, and subjective pain, state anxiety, blood pressure and pulse rate were measured after the procedure. Results: The experimental group with the electric heating pad reported significantly lower subjective pain and anxiety than did the control group. There were no significant differences in objective pain between experimental and control groups. Patients with an electric heating pad showed significantly lower systolic and diastolic pressure than did those in the control group. There was no significant difference in pulse rate between the groups. Conclusion: Use of an electric heating pad was efficient in reducing subjective pain and anxiety among patients undergoing colonoscopy. This is a convenient and useful nursing intervention to reduce anxiety and pain among patients having a colonoscopy.

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Risk evaluation of EVA dust with oxidizer by a pressure vessel (압력용기시험에 의한 EVA분진의 혼촉 위험성 평가)

  • 이창우;김정환;현성호
    • Fire Science and Engineering
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    • v.13 no.4
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    • pp.7-12
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    • 1999
  • Thermal properties of EVA dust and its risks of coexisting with oxidizer were investigated by a pressure vessel. The decomposition of EVA dust with temperature using DSC and the weight loss with temperature using TGA were also investigated to find the thermal hazard of EVA dust. Using the pressure vessel which can estimate ignition and explosion of EVA dust coexisting with oxidizer by bursting of a rupture disc, many experiments have been conducted by varying the orifice diameter, heating rate, the weight ratio of the sample coexisting with oxidizer, and the species of oxidizer. According to the results of the thermal analysis of EVA dust, a little change of the decomposition initiation temperature with the heating rate could be found and the decomposition temperature zone of EVA dust was 250 to 50$0^{\circ}C$. The risk of EVA dust coexisting with oxidizer was increased as the orifice diameter was decreased. On the other hand, it was increased as the heating rate and the weight ratio of the sample coexisting with oxidizer were increased. In addition, the risk of EVA dust coexisting with oxidizer was affected by the decomposition temperature of the sample and oxidizer, respectively, at slow heating rate, but it was affected by the oxygen weight percent of oxidizer at fast heating rate.

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Evaluation of Impact Sound Insulation Properties of Light-Framed Floor with Radiant Floor Heating System

  • Nam, Jin-Woo;Park, Joo-Saeng;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.30 no.3
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    • pp.75-84
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    • 2002
  • In order to find out impact insulation properties, various types of current radiant floor heating systems and light-framed floors that are used in light-framed residential buildings were evaluated for two types of impact sources at the same time. Sound Pressure Level (SPL) was different from each impact sources for those spectrum patterns and peaks. In case of light-framed floor framework, the excitation position and the assumed effective vibrating area have effects on sound pressure level but it is not considerable, and Normalized SPL was reduced for each frequency by increasing the bending rigidity of joist. The mortar layer in the radiant heating system had relatively high density and high impedance, therefore, it distributed much of the impact power when it was excited, and reduced the Normalized SPL considerably. Nevertheless, Increasing a thickness of mortar layer had little influence on SPL. Ceiling components reduced the sound pressure level about 5~25 dB for each frequency. Namely, it had excellent sound insulation properties in a range from 200 to 4,000 Hz frequency for both heavy and lightweight impact sources. Also, there was a somewhat regular sound insulation pattern for each center frequency. The resilient channel reduced the SPL about 2~11 dB, irrelevant to impact source. Consequently, current radiant floor heating systems which were established in light-framed residential buildings have quite good impact sound insulation properties for both impact sources.