• Journal of the Korean Society of Radiology
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• v.9 no.4
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• pp.219-225
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• 2015

This study aims to evaluates the image quality of CR and DR that are scanned with the use of the attachable carbon heater X-ray scanner table equipped with heating device by measuring SNR and CNR before and after the attachment of the said table. In the aluminum staircase testing, CR increased SNR and CNR when attached with the table, while DR decreased SNR and CNR. In the human-body model phantom testing, CR increased SNR and CNR only in the low-energy low-dose radiation and the high-energy high-dose radiation, but decreased SNR and CNR under all other conditions. In conclusion, the use of such table can make the patient feel comfortable by removing his or her anxiety, thus helping the testing, but in the actual clinical application thereof, if the thickness and material of the bottom film and the protective film, including the carbon heater, are not considered, it affects the picture quality, thereby requiring continuous research on the use of such table.

• Journal of the Mineralogical Society of Korea
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• v.16 no.2
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• pp.161-169
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• 2003

A phase transformation study on a synthetic amorphous diopside, $(Ca,Mg)SiO_3$has been carried out up to ∼30 GPa, and ∼$1000^{\circ}C$ using a diamond anvil cell and YAG laser heating system, respectively. A starting amorphous material shows a direct transition to cubic $(Ca,Mg)SiO_3$perovskite at high pressure, which contradicts to the crystalline diopside phase transformation sequence disproportionating into mixtures of the orthorhombic$ MgSiO_3$perovskite and the cubic $CaSiO_3$perovskite phases. This discrepancy might be due to the different starting materials as well as the temperature variations at each specific experiment performed. The present phase transfor mation sequence would modify the mineralogical assemblage in the Earth transition region and the lower mantle depending upon the pressure, temperature and the oxygen partial pressure.

• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.673-677
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• 1996

Four low fat ground beef groups containing 10% fat plus 0, 5, 10 and 20% additional cooked old rice and a control ground beef containing 30% fat were prepared and their cholesterol contents, calories and production costs were investigated to find out the appropriateness of addition of cooked old rice. There were no differences in pHs with the variations in fat content and the content of cooked old rice. As the amount of added cooked old rice increased from 5 to 20%, cook yield of ground beef also increased. When the fat content of beef was reduced from 30 to 10%, the cholesterol content of beef was not reduced but with the fat content fixed to 10% and the content of added cooked old rice increased from 5 to 20%, the cholesterol content of ground beef decreased. Calories of ground beef were reduced by approximately 50% with the reduction of fat content from 30 to 10% and production costs decreased with the increase in the content of added cooked old rice.

• Food Science of Animal Resources
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• v.28 no.5
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• pp.567-573
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• 2008

This study investigated the effects of sodium chloride, potassium chloride, potassium lactate and calcium ascorbate on the physico-chemical and sensory characteristics of sodium-reduced pork patties. Pork patties were prepared in 4 ways: T1 (control, 1.0% NaCl), T2 (0.6% NaCl, 0.4% KCl), T3 (0.7% NaCl, 0.3% potassium lactate) and T4 (0.7% NaCl, 0.3% calcium ascorbate). The pH, cooking loss, total plate counts, TBARS (2-thiobarbituric acid reactive substances), surface color (L, a, b) and sensory characteristics were evaluated. The partial substitution of NaCl with KCl and calcium ascorbate decreased the cooking loss and TBARS values, and enhanced microbial stability. The partial substitution of NaCl with potassium lactate significantly decreased TBARS values and enhanced microbial stability, but significantly increased cooking loss compared to the control after 1 and 4 days of storage. However, the surface color and sensory characteristics were not affected by any of the treatments.

• Fire Science and Engineering
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• v.25 no.6
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• pp.64-72
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• 2011

The concrete void slab structure with the existing mushroom slab, is the structure that maximizes the advantages, while minimizing the weakness with removing useless body force of the concrete part, located on the center of the slab cross-section, which does not need to support the structural weight. In this research, a fire test is performed to analyze how the blaze behave according to the thickness of slab cover, with the practical span length of concrete void slab for the slab length 7.5 m. With this heating test, we assumed the uniform-load-model considering fixed loads and live loads, and chose the standard fire test condition. We measured the temperature changes and the deflection character according to the depth from the heat exposure side, and assessed the resisting capability according to the standard KS F 2257-1. The result comes out with the EPS model can secure about 2 hour fire-resisting-capability with 50 mm of cover depth.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.6
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• pp.688-694
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• 2017

The effects of heat treatments on the physicochemical properties and in vitro biological activities of quinoa (Chenopodium quinoa Willd.) were investigated. Quinoa grains were subjected to two different heat treatment methods: boiling and steaming plus roasting (steaming/roasting). Compared with raw quinoa, boiled quinoa samples had slightly lower crude protein, crude fat, crude ash, and starch contents. However, steaming/roasting treatment did not cause significant differences in proximate composition. Heat treatments reduced total phenolic and flavonoid contents in quinoa extracts, and higher reduction was detected upon boiling treatment. Heat treatments also reduced lightness and increased yellowness of quinoa samples. Heat treatments increased water absorption index but decreased water solubility index. In vitro starch hydrolysis increased substantially after both heat treatments, and slightly higher values were observed in the boiled quinoa samples. 1,1-Diphenyl-2-picrylhydrazyl free radical scavenging activity and nitrite scavenging activity were reduced by heat treatments, and the boiled quinoa sample showed the lowest activity likely due to loss of activities in cooking water.

• Korean journal of food and cookery science
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• v.8 no.1
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• pp.15-20
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• 1992

The changes in color of spinach leaves upon blanching in boiling water and by microwave oven were investigated. The noticible changes in color of leaves were observed above $70^{\circ}C$. The values of L (lightness), a (redness) and b (yellowness) were decreased upon blanching. The value of the under surface of leaves was decreased by 2~3 times compared to that of the upper surface. The noticible color changes occured from 15 sec and the absorbance at 432 nm of water increased rapidly from 2 min of blanching in boiling water. Salt (0.5 and 0.9%) decreased the absorbance at 432 nm of water. The changes of L and b of the under surface of leaves upon heating with a microwave oven were less compared with those in boiling water. Based on the color differences of leaves upon blanching in boiling water, the optimum ratio of spinach to water was 1:4 or 1:5.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.3
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• pp.199-204
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• 2017

We introduced a technology for reducing infrared radiation through the active cooling of hot surfaces by using a thermoelectric refrigerator. Certain surfaces were heated by aerodynamic heating, and the heat generation processes are proposed here. We calculated the temperatures and radiations from surfaces, while using thermoelectric refrigerators to cool the surfaces. The results showed that the contrast between the radiations of certain surfaces and the ambient environments can be removed using thermoelectric refrigerators.

• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.51-59
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• 2005

수소 분리막의 적용 분야는 석탄가스, 천연가스, 메탄가스 혼합기체이며, 고온/고압 및 수소농도가 낮은 혼합기체에서 고순도의 수소를 제조하는 곳이다. 특히 치밀질 세라믹 멤브레인은 고온에서 가스화한 석탄가스나 차세대의 쓰레기 처리 기술인 가스화 용융처리에서 생긴 고온가스로부터 고순도의 수소를 분리할 수 있다. 분리한 수소는 고온을 유지하기 때문에 연료전지 발전에 최적이다. 종래의 연료전지는 발전을 위해서 수소의 가열이 필요했으나 이것이 불필요하게 되어 발전 전체의 효율이 향상된다. 석유화학 산업에서 발생하는 혼합기체에서 수소를 분리하여 사용하고 남은 기체는 연료로 재사용할 수 있다. 분리막의 재질로는 고분자계가 개발되고 있으며 고분자 지지체에 백금이나 로듐과 같은 촉매를 코팅하는 방법이다. 이는 기공의 제어가 용이하고 대량생산이 가능한 장점이 있지만 고온에서 사용이 불가능하고 입자상 물질에 의해 분리막의 손상이 문제가 되고 있다. 이에 비해 치밀질 세라믹 멤브레인은 세라믹의 특성에 의해 고온 및 고압에서도 적용이 가능하며, 실온이나 저압의 조건에서도 적용이 가능한 특징을 가진다. $900^{\circ}C$의 고온에서 적용시 세라믹 멤브레인에는 특성열화가 없어 수명이 긴 장점을 가지게 된다. 수소가 포함되어 있는 기체에서 수소 만을 분리하는 방법은 흡착이나 분리막을 이용하는 방법이 일반적이며 흡착에 의한 방법은 일부 실용화가 진행되고 있다. 고효율의 수소를 분리하는 방법으로 분리막을 이용하는 방법이 있다. 현재 치밀질 수소 분리막의 연구는 외국(미국, 일본 등)에서도 초기 연구 단계이다. 국내에서도 이런 연구가 선행되어 외국과의 기술 격차를 줄이고 에너지 자원에 대한 확보가 필요하기 때문에 이 연구가 수행되었다. 치밀질 멤브레인의 소재로는 proton 및 전자전도가 가능한 소재로서 Ba-Ce-Y계를 기본조성으로 하여 내구성과 전기전도도를 향상시키기 위해 Ca, La, In, Yb를 치환하였다. 제조한 재료의 물리화학적 특성을 평가하였고, 수소여과 장치를 이용하여 여과 효율을 평가하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.61-61
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• 2003

다결정 실리콘 박막은 박막 트랜지스터와 실리콘 태양전지등에 응용되며, 비정질 실리콘을 재결정화 하여 얻어지는 다결정 실리콘 박막이 주로 이용되고 있다. 비정질 실리콘 박막을 금속 원소와 접촉시킨 상태에서 열처리할 경우 결정화 온도가 낮아지고 결정화에 필요한 열처리 시간이 짧아지게 된다. 금속을 실리콘 박막 표면에 가하는 방법은 진공증착법등으로 비정질 실리콘 박막 위에 금속원소 층을 형성하는 방법이 주로 이용되었다. 본 연구에서는 AlCl$_3$와 NiCl$_2$ 금속화합물 분위기에서 LPCVD 비정질 실리콘 박막을 열처리하여 결정화 거동을 관찰하였다. 금속화합물과 결정화할 비정질 실리콘 박막을 각각 다른 온도로 가열해 줄 수 있는 노를 이용하여 열처리를 시행하였다. AlCl$_3$와 NiCl$_2$ 분말을 혼합하여 소스로 이용한 경우 48$0^{\circ}C$ 5시간 열처리로 결정화가 완료되었으며, 박막 전체에 걸친 균일도와 재현성이 우수하였다. AlCl$_3$와 NiCl$_2$를 이용한 결정화 초기 상태에는 박막 전면에 걸쳐 등근 형태의 결정립이 균일한 핵 생성으로 나타났다. 이와 같은 결과는 Al과 Ni이 고상결정화에 동시에 작용하면서 나타난 것으로, Al이 가해진 비정질 실리콘으로 인해 결정화 속도가 빨라지고 결함이 작은 결정립을 얻을 수 있었으며, Ni로 인해 결정화의 균일성과 재현성을 높일 수 있었다.