• 제목/요약/키워드: melting

검색결과 3,615건 처리시간 0.03초

Selective Laser Melting을 이용한 코발트-크롬 가철성 국소의치의 수복 증례 (Cr-Co removable partial denture treatment fabricated by selective laser melting: a case report)

  • 임지훈;신수연
    • 구강회복응용과학지
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    • 제37권1호
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    • pp.39-47
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    • 2021
  • 의치의 금속구조물을 selective laser melting을 통하여 제작하는 경우 기존의 제작 방식에 비해 여러 기공 과정이 생략되어 시간이 절약되고 간편해진다. 또한 균질한 밀도의 금속구조물을 얻을 수 있어 우수한 기계적 성질, 특히 피로 파절에 대한 높은 저항성을 기대할 수 있다. 본 증례에서는 부분 무치악 환자에서 기존의 방식으로 최종인상을 채득하여 주모형을 제작하였고 이를 스캔하여 데이터화 하였다. 스캔 데이터 상에서 금속구조물을 디자인한 뒤 selective laser melting 방식으로 가철성 국소의치를 제작하였으며 기능적 및 심미적으로 만족스러운 결과를 보였기에 이를 보고하는 바이다.

MDSC를 이용한 폴리에스테르와 코폴리에테르에스테르의 가역적 융해거동 분석 (Reversible Melting Behaviors of Polyesters and Copolyetheresters studied by MDSC)

  • Kim, Hae-Young;Baik, Doo-Hyun
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 2001년도 가을 학술발표회 논문집
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    • pp.239-242
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    • 2001
  • Melting and crystallization are not reversible because supercooling is always needed for crystal growth. But, recently reversible melting and crystallization phenomena in semi-crystalline polymers, based on modulated differential scanning calorimetry(MDSC) with quasi-isothermal experiment mode were observed in the melting range and continuously proved by others. (omitted)

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Novel Peptide Nucleic Acid Melting Array for the Detection and Genotyping of Toxoplasma gondii

  • Suh, Soo Hwan;Yun, Han Seong;Lee, Sang-Eun;Kwak, Hyo-Sun
    • 한국미생물·생명공학회지
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    • 제47권4호
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    • pp.645-650
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    • 2019
  • Despite differences in virulence between strains of Toxoplasma gondii, rapid and accurate genotyping methods are lacking. In this study, a method was developed to detect and genotype T. gondii in food and environmental samples using PCR and a novel peptide nucleic acid (PNA) melting array. An alignment of genome sequences for T. gondii type I, II, and III obtained from NCBI was generated, and a single nucleotide polymorphism analysis was performed to identify targets for PCR amplification and a PNA melting array. Prior to the PNA melting array, conventional PCR was used to amplify GRA6 of T. gondii. After amplification, the PNA melting array was performed using two different PNA hybridization probes with fluorescent labels (FAM and HEX) and quenchers. Melting curves for each probe were used to determine genotypes and identify mutations. A 214-bp region of the GRA6 gene of T. gondii was successfully amplified by PCR. For all T. gondii strains (type I, II, and III) used to evaluate specificity, the correct genotypes were determined by the PNA melting array. Non-T. gondii strains, including 14 foodborne pathogens and 3 protozoan parasites, such as Giardia lamblia, Cryptosporidium parvum, and Entamoeba histolytica, showed no signal, suggesting that the assay has a high specificity. Although this is only a proof-of-concept study, the assay is promising for the fast and reliable genotyping of T. gondii from food and environmental samples.

Fe-C 공정 온도 고정점의 용융 특성에 대한 연구 (Study on the melting characteristics of the Fe-C eutectic temperature fixed-point)

  • 김용규;양인석;감기술
    • 센서학회지
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    • 제15권4호
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    • pp.257-262
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    • 2006
  • A Fe-C eutectic cell for thermocouple calibration was manufactured and tested to investigate its phase transition characteristics in the thermocouple thermometry. It was observed that the freezing plateaus were strongly affected by the freeze-inducing temperature $T_{f}$. In case of the melting process, the melting plateau was influenced by the previous thermal history. As $T_{f}$. in the previous freezing was lower, the melting plateau became lower with a temperature dependence as small as $-0.0015^{\circ}C/^{\circ}C$. Therefore, it was found that the freeze-inducing temperature should be fixed to obtain a reproducible phase transition temperature in the melting. After fixing $T_{f}$, the melting process was examined and it was found that long and flat melting plateau was obtained within a reproducibility of about ${\pm}0.01^{\circ}C$. Based on the observed results, it was recommended that Fe-C eutectic temperature be best realized for the melting process with a melt-inducing temperature of $+3^{\circ}C$ above the expected liquidus temperature after freezing at $-5^{\circ}C$ below the solidus temperature.

Pilot 규모의 열분해 용융 소각 시스템에서의 열분해 및 연소 특성 연구 (A Study on the Pyrolysis and Combustion Characteristics of Solid Waste in a Pilot scale Pyrolysis Melting Incinerator)

  • 류태우;양원;박주원;김봉근;이기방;김희열;박상신;전금하
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2006년도 제33회 KOSCO SYMPOSIUM 논문집
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    • pp.168-174
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    • 2006
  • A pilot scale (200kg/hr) pyrolysis melting incineration system is designed and constructed in Korea Institute of Industrial Technology. The incineration process is composed of pyrolysis, gas combustion, ash melting, gas stabilization, waste heating boiler, and bag filter. For each unit process, experimental approaches have been conducted to find optimal design and operating conditions. Especially, a pyrolysis is very important process in that it is a way of energy recirculation and minimizing the waste products. This paper presents major results of the most efficient operating conditions in a pilot scale pyrolysis melting incinerator.

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고융점 산화물에 대한 고온 증발 (High Temperature Vaporization of the High Melting Point Oxides)

  • 이홍림
    • 한국세라믹학회지
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    • 제15권2호
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    • pp.72-78
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    • 1978
  • The vapor pressure of the high melting point oxides, MgO, $Cr_2O_3$, and $MgCr_2O_4$ were measured over the temperature range 1300 to 175$0^{\circ}C$ under vacuum <$10^{-5}$ torr by the Langmuir and the Knudsen method. The Langmuir vapor pressure was increased with elevating temperature and with increasing porosity of the specimen. The difference between the vapor preseures measured by the Langmuir and the Knudsen method was decreased with elevating temperature and the Langmuir vapor pressure finally reached the Knudsen vapor pressure at the melting point when extrapolated. The vapor pressure of other important oxides with high melting points, i.e., $Al_2O_3$, $ThO_2$, $Yb_2O_3$ and $Y_2O_3$ were cited from the references. The Langmuir and the Knudsen vapor pressure of these oxides also showed the same results, i.e., they showed the same value at their melting points.

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디젤차량 SCR 시스템용 요소수용액의 동결과 해동 현상 (Freezing and Melting Phenomena of Urea-water Solution for Diesel Vehicle SCR System)

  • 최병철;서충길;명광재
    • 동력기계공학회지
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    • 제13권4호
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    • pp.5-10
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    • 2009
  • Urea-SCR system, the selective catalytic reduction using urea as reducing agent, is a powerful technique to reduce nitrogen oxides(NOx) emitted from diesel engines. However, a tank of urea(32.5 wt%)-water solution can be frozen in low ambient temperature levels of below $-11^{\circ}C$. The purpose of this study is to understand freezing and melting phenomena of the urea-water solution, and its can be applied to get the urea-water solution from frozen it within 5 minutes after cold start. Factors considered were the type of heater and the urea tank shape. From the results, it was found that melting volume of cartridge heater B during 5 minutes of heating period was 83ml when supplying electric power of 150W. Horizontal heater B, which was put in the narrow bottom space of the tank T1, had fast melting characteristics.

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수평원관내에서 과냉각 및 자연대류가 융해과정에 미치는 영향 (Effects of Subcooling and Natural Convection on the Melting inside a Horizontal Tube)

  • 서정세;김찬중;노승탁
    • 대한기계학회논문집
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    • 제17권8호
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    • pp.2079-2087
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    • 1993
  • The effects of subcooling and natural convection are studied numerically on the melting process of an initially subcooled phase-change medium filled inside a horizontal circular cylinder. It is postulated that melting continues with the tube wall kept at a constant temperature and with the unmelted solid core fixed. Primary emphasis is placed on the evolution of interface morphology, the local/overall heat transfer rate at the tube wall and at the interface, and the structure of natural convection. The numerical results are mainly presented in terms of the Rayleigh and subcooling numbers. As the degree of subcooling intensifies, the melting rate and the movement of the interface are impeded but the interfaces are of similar shape with the passage of time. The heat transfer characteristics are found to be mostly governed by the formation pattern of natural convection in the liquid phase. Good agreement with available experimental data is found.

인테리어용 인조가죽을 위한 용출형 극세사와 저온 융착사의 제조 (Manufacture of Soluble Micro-fiber and Low Melting Polymer for Interior Synthetic Leather)

  • 안영무
    • 한국생활과학회지
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    • 제12권4호
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    • pp.529-537
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    • 2003
  • This study was conducted to manufacture the soluble micro-fiber and to synthesize low melting polymer for the interior fabric not to use the polyurethane resin causing some problems. Low melting polyester for weft yarn was introduced by adding 30-40 mol% ratio of isophthalic acid to a main chain of polyethylene terephthalate to decrease the melting temperature up to heat setting temperature. Micro-fiber for warp yarn consisted of both soluble and insoluble components with multi-layered structure. When the soluble micro-fiber was treated by alkaline hydrolysis with 3-5% concentration of NaOH, it showed the turning point at 28% weight loss since soluble polyester was hydrolyzed approximate five times faster than regular polyester.

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