• 한국기계가공학회지
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• 제11권1호
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• pp.46-49
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• 2012

Gears are reliable and efficient power transmission elements. They have been widely used in all kinds of machinery. Nowadays, resource conservation energy conservation environmental improvements from the request of the compact, light weight, high efficiency, low cost Higher efficiency is required. Tooth root and bottom profiles of cylindrical gears affect bending fatigue life, but they are hard to measure with conventional gear measuring machine(GMM), because GMM is normally customized to measure only gear working flanks. The authors try to develop a new type of GMM by installing an extra 3D scanning probe and control software to measure tooth root and bottom profiles. First, in order to measure in various directions, a 3D scanning probe has been attached to the GMM developed. Next, calibration algorithm has been developed. Deviations of the calibration results are measured and it is found that systematic error must be caused by heat from driving motors. A new alternative GMM with driving motors generating less heat was designed and two GMMs are compared. Finally, 3 Dimension measurement of tooth root and bottom profiles of cylindrical gears is described.

• Nuclear Engineering and Technology
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• 제29권4호
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• pp.336-347
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• 1997

During postulated severe accidents in Light water Reactors, molten corium which was ejected from the reactor vessel bottom, may erode the concrete basemat of the containment and there by threaten the containment integrity. This study experimentally examines the molten core-concrete interaction (MCC) using 20kg of thermite melt (Fe + $Al_2$O$_3$) and the concrete, used in Yonggwang Nuclear Power Plant Units 3 and 4 (YGN 3 & 4) in Korea. The measured data are the downward heat fluxes, concrete erosion rate, gases and particle generation rates during MCCI. Transient results ore compared with those of TURCIT experiment conducted by SNL in USA. The peak downward heat flux to the concrete was measured to be about 2.1㎿/$m^2$. The initial concrete erosion rate was 175cm per hour, decreasing to 30cm per hour. It was shown from the post-test that the erosion was progressed downward up to 18mm in the concrete slug.

• Nuclear Engineering and Technology
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• 제54권3호
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• pp.877-887
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• 2022

A new reactor concept is described that directly couples a supercritical CO₂ (sCO₂) power cycle with a CO₂-cooled, heavy water moderated pressure tube core. This configuration attains the simplification and economic potential of past direct-cycle sCO₂ concepts, while also providing safety and power density benefits by using the moderator as a heat sink for decay heat removal. A 200 MWe design is described that heavily leverages existing commercial nuclear technologies, including reactor and moderator systems from Canadian CANDU reactors and fuels and materials from UK Advanced Gas-cooled Reactors (AGRs). Descriptions are provided of the power cycle, nuclear island systems, reactor core, and safety systems, and the results of safety analyses are shown illustrating the ability of the design to withstand large-break loss of coolant accidents. The resulting design attains high efficiency while employing considerably fewer systems than current light water reactors and advanced reactor technologies, illustrating its economic promise. Prospects for the design are discussed, including the ability to demonstrate its technologies in a small (~20 MWe) initial system, and avenues for further improvement of the design using advanced technologies.

• 한국정밀공학회지
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• 제12권7호
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• pp.46-52
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• 1995

This paper proposes methodologies for the development of radiation thermometer using InSb photo-detector of which spectral sensitivity is excellent over the wave length range of 2 .mu. m .approx. 5 .mu. m. The proposed radiation thermometer has broad measurement range from normal to high, up to more than 1000 .deg. C, with high accuracy, and can measure temperature on the material surface or heat emission noncontactely with high speed. Optical system was consisted of two convex lens with foruslength of 15.2mm for infrared lay focusing, Ge filter to cut the short wave length components and sapphire filter to cut the long wave length components. The cold shielded was installed in the whole surface of the light-absorbing element to remove the error- mometer, calibration using black body furnace which has temperature range of 90 .deg. C .approx. 1100 .deg. C was carried out, and temperature calaibration curve was obtained by exponential function curvefitting. The result shows maximum error less than 0.24%(640K .+-. 1.6K) over the measurement range of 90 .deg. C .approx. 700 .deg. C, and from this result the usefulness of the developed thermometer has been confirmed.

• 환경위생공학
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• 제9권2호
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• pp.88-100
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• 1994

A study on the recovery of useful components from waste tire. This study was carried out investigate the recovery of fuel oil condensed from gases formed in the pyrolysis of waste tire. Energy to require the pyrolysis of waste tire was used the heat that was produced by the combustion of the gases from the pyrolysis of waste tire itself. The results are as follows; 1. Energy to require forming the fuel oil by the pyrolysis of waste tire was used only 1/6 quantities of waste tire for forming fuel oil. 2. The formed fuel oil were light oil, Kerosene and gasoline 3. The pollutants of combustion gas of patronizable gases was lower than standard Value.

• Archives of Plastic Surgery
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• 제32권4호
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• pp.408-415
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• 2005

Following a transverse rectus abdominis musculocutaneous(TRAM) flap breast reconstruction, denervated state of the flap causes the flap skin prone to thermal injury, calling for special attention. During the last 5 years, 69 breast reconstruction with 72 free TRAM flaps, were performed. Four out of thesse 69 patients sustained burn injury. Heat sources were a warm bag(n=2), heating pad(n=1) and warming light (n=1). The thermal injuries occured from 2 days to 3 months following the reconstruction. Three patients healed with conservative treatment, but one patient required debridement and skin graft. Initially 3 out of 4 patients with the burn had shown superficial 2nd degree burn with small blebs or bullae. However all 4 patients healed with scars. Mechanism of burn injuries of the denervated flap are known to be resulting from; 1) loss of behavioral protection due to denervation of flap with flap elevation and transfer, 2) loss of autonomic thermoregulatory control with heat dissipation on skin flap vasculature contributing to susceptibility of burn injury. 3) changes of immunologic and normal inflammatory response increasing thromboxane, and a fall in substance P & NGF (nerve growth factor). Including the abdominal flap donor site, sensory recovery of the reconstructed breast varies individually from 6 month even to 5 years postoperatively. During this period, wound healing is delayed, resulting in easier scarring compared to that observed in the sensate skin. Patients should be carefully informed and warned of possible burn injuries and taught to avoid exposure to heat source at least until 3 years postoperatively.

• Archives of Plastic Surgery
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• 제32권4호
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• pp.403-407
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• 2005

Following a transverse rectus abdominis musculocutaneous(TRAM) flap breast reconstruction, denervated state of the flap causes the flap skin prone to thermal injury, calling for special attention. During the last 5 years, 69 breast reconstruction with 72 free TRAM flaps, were performed. Four out of thesse 69 patients sustained burn injury. Heat sources were a warm bag(n=2), heating pad(n=1) and warming light (n=1). The thermal injuries occured from 2 days to 3 months following the reconstruction. Three patients healed with conservative treatment, but one patient required debridement and skin graft. Initially 3 out of 4 patients with the burn had shown superficial 2nd degree burn with small blebs or bullae. However all 4 patients healed with scars. Mechanism of burn injuries of the denervated flap are known to be resulting from; 1) loss of behavioral protection due to denervation of flap with flap elevation and transfer, 2) loss of autonomic thermoregulatory control with heat dissipation on skin flap vasculature contributing to susceptibility of burn injury. 3) changes of immunologic and normal inflammatory response increasing thromboxane, and a fall in substance P & NGF (nerve growth factor). Including the abdominal flap donor site, sensory recovery of the reconstructed breast varies individually from 6 month even to 5 years postoperatively. During this period, wound healing is delayed, resulting in easier scarring compared to that observed in the sensate skin. Patients should be carefully informed and warned of possible burn injuries and taught to avoid exposure to heat source at least until 3 years postoperatively.

• Journal of Microbiology and Biotechnology
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• 제18권3호
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• pp.490-496
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• 2008

Symbiobacterium toebii is a commensal symbiotic thermophile that cannot grow without support from a partner bacterium. We investigated the properties of Symbiobacterium growth-supporting factors (SGSFs) produced by the partner bacterium Geobacillus toebii. SGSFs occurred in both the cell-free extract (CFE) and culture supernatant of G. toebii and might comprise multifarious materials because of their different biological properties. The heavy SGSF contained in the cytosolic component exhibited heat- and proteinase-sensitive proteinaceous properties and had a molecular mass of >50 kDa. In contrast, the light SGSF contained in the extracellular component exhibited heat-stable, proteinase-resistant, nonprotein properties and had a molecular mass of <10 kDa. Under morphological examination using light microscopy, S. toebii cultured with the culture supernatant of G. toebii was filamentous, whereas S. toebii cultured with the CFE of G. toebii was rod-shaped. These results strongly suggest that the SGSFs produced by G. toebii comprise two or more types that differ in their growth-supporting mechanisms, although all support the growth of S. toebii. Upon the examination of the distribution of SGSFs in other bacteria, both cytosolic and extracellular components of Geobacillus kaustophilus, Escherichia coli, and Bacillus subtilis had detectable growth-supporting effects for S. toebii, indicating that common SGSF materials are widely present in various bacterial strains.

• 공업화학
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• 제28권4호
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• pp.383-396
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• 2017

광열치료는 빛을 받아 열로 변환하는 광열특성을 가진 광열변환기를 통해 세포의 병변, 특히 암세포를 선택적으로 사멸시키는 치료법이다. 광열특성을 가지는 다양한 물질들이 광열치료에 적용되어왔지만, 그중에서도 금 나노입자는 그 고유한 물리화학적 특성으로 지난 20년 가까이 과학자와 의료인들에게 큰 관심을 받아왔다. 본 총설에서는 금 나노입자를 사용하여 광열치료효과를 향상시키기 위한 전략들을 최근의 광열치료 연구를 중심으로 정리하여 서술하였다. 특히, 광열변환기로서 사용되는 다양한 금 나노입자 구조체의 합성 및 광학 성질 제어를 통해 광열변환 효율 향상을 시도한 연구들과 금 나노입자를 병소에 효과적으로 축적시키기 위한 선별적 전달 방법들을 논의하였으며, 마지막에는 근래에 적극적으로 시도되고 있는 다른 치료법 및 진단기술과의 융합 연구들을 소개했다.

• 대한화장품학회지
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• 제30권1호
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• pp.123-128
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• 2004

최근 기능성 화장품의 대두로 새로운 형태의 미백제들이 많이 출시되고 있다. 본 연구에서는 천화분근, 하고초엽, 위령선근을 이용하여 새로운 미백제를 개발하였다. 그러나 이러한 미백제는 용해성이 좋지 않고 빛, 열, 산소에 의하여 변색 및 함량의 변화를 가져온다. 먼저 천화분근, 하고초엽, 위령선근을 10배수의 50％ 에탄올을 넣어 75∼85도에서 6∼8시간 추출한 후 여과, 농축, 건조하였다. 건조된 추출물을 이용하여 티로시나제 효소 활성 억제효과, 마우스의 색소세포를 이용한 Bl6 멜라닌 생성 억제 효과, brown guinea pig의 동물 피부의 미백효과 결과 다른 비교 샘플에 비하여 매우 우수한 결과가 나왔다. 또한 천화분근, 하고초엽, 위령선근을 안정화시키기 위해서 propylene glycol (PG)/hydrogenated lecithin/middle chain triglycerides (MCT)/glycerin/water를 고압균질화기를 이용하여 30∼50 nm인 리포좀을 만들었다. 이러한 리포좀은 기존의 처리되지 않은 추출물에 비하여 빛과 열에 3∼5배 안정성을 보였다. 이러한 실험을 위하여 particle size analyzer, freeze fracture transmission electron microscopy (FF-TEM), chromameter, HPLC의 분석장비를 사용하였다.