• 대한기계학회논문집B
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• 제24권7호
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• pp.994-1001
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• 2000

The dynamic behavior of a single-pressure heat recovery steam generator and turbine system for the combined cycle power plant is simulated on the basis of one-dimensional unsteady governing equations. A water level control and a turbine power control are also included in the calculation routine. Transient response of the system to the variation of gas turbine exit condition is simulated and effect of the turbine power control on the system response is examined. In addition, the effect of the treatment of inertia terms(fluid inertia and thermal inertia of heat exchanger metal) on the simulated transient response is investigated.

• 한국식품영양과학회지
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• 제44권6호
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• pp.874-881
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• 2015

본 연구는 열수 침지, 증기 및 볶음 처리가 표고버섯에 미치는 이화학적 분석 및 영양성분 분석을 통해 최적 열처리 조건을 확립하고자 진행하였다. 소비자들이 상품을 평가할 때 1차적으로 먼저 관찰되는 색도와 경도를 측정하고 추가로 pH 측정 등으로 인한 이화학적 결과로 최적 조건을 선정한 뒤에 그 조건들에 대해서 영양학적 및 미생물 검사를 실시하였다. 색도는 열처리 시간이 길어질수록 색의 변색 정도가 증가하여 뚜렷한 차이를 나타내었다. pH 값은 열수 침지 처리의 경우 pH 증가량이 가장 높았으며 처리 시간이 지속될수록 pH가 증가하는 경향을 나타내었다. 다른 처리군의 경우 일정 시간의 처리 시간 이후에는 유의적인 차이를 보이지 않았다. 경도에서는 열수 침지와 볶음 처리의 경우 1분 이내의 열처리만으로도 경도가 감소하는 경향을 보였으며, 증기 처리의 경우 1분 동안 경도가 유지되는 결과를 보였다. 일반 성분 분석 결과는 증기 처리가 가장 원물에 가까운 결과를 나타냈다. 유기산 함량은 증기 처리에서 유기산 함량 감소율이 가장 낮았다. 또한 3분간 증기 처리를 하였을 때 미생물의 사멸 효과가 가장 높았다. 열수 침지 처리나 볶음 처리의 경우 전체적으로 증기 처리한 시료에 비해서 영양성분 함량이 줄어드는 경향을 나타냈다. 따라서 표고버섯을 증기 처리 방법으로 열처리하는 것이 다른 열처리군에 비해서 최적으로 나타났다. 하지만 본 연구에서는 물리화학 및 영양학적 성분의 변화만을 분석하였기 때문에 실제 식품 산업이나 공정에 적용하기 위해서는 대용량 처리 시에 발생하는 문제들과 관련된 추가적인 연구를 필요로 할 것이다.

• 열처리공학회지
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• 제13권5호
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• pp.330-336
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• 2000

This study deals with the characteristic of refrigerant for heat-treatment deformation control of SM45C steel. The control of heat-treatment deformation must need the progress of production parts for a landing gear. Most of the deformation is occurred on unequal cooling. The unequal cooling is occurred by a property of quenching refrigeration. When a heated metal is deposited in the refrigeration, the cooling speed is so slow in early period of cooling because of occurring a steam-curtain. After more cooling, the steam-curtain is destroyed. In this progress, the cooling speed is very fast. The object of this study is to control the deformation of heat-treatment for landing gear by improving the conditions of quenching. The cooling curves and cooling rates of water, oil and polymer solution are obtained and illustrated. From the characteristics of the quenching refrigerant, the effects of heat-treatments on thermal deformation and fatigue strength are also investigated.

• 한국식품영양과학회지
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• 제21권3호
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• pp.270-278
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• 1992

4종의 제빵용 밀가루를 사용하여 스파게티를 통상의 제조법에 따른 경우는 제품의 질적 저하를 막을 수가 없다. 본 연구에서는 건조직전 즉 압출 직후에 스팀증기 처리를 함으로써 스파게티의 질적 향상을 도모하였다. 스팀처리의 시간은 3분이 가장 적절 하였으며, 이를 제조후 건조된 상태에서의 경도 (breaking stress). 삶은 이후의 질적 관찰에서 적정 조리 시간(optimum cooking time). 조리이후의 손실(cooking loss). 견고성(cutting stress) 점착성(stickiness), 전 유기물 정량(total organic matter) 등에서 거의 대부분의 질적 향상이 뚜렷하였다. 그러나 건조후 면의 굵기 (thickness), 조리후의 무게(cooked weight)는 스팀 처리 이후에 감소함을 알 수 있었다. 또 HWW(Hard White Winter) 밀과 듀럼 (Durum) 밀을 주사현미경 (scanning electro microscope)으로 관찰한 결과 전분이 스파게티 표면에서 단백질과 더욱 단단한 결합을 이루고 있음을 보여 주었으며 이는 아마도 전분이 스파게티 표면에 스팀처리에 의한 소수성 막을 형성하며. 높은 노화 작용에 의하여 조리 후 더 낮은 팽윤을 하는 것으로 보여진다.

• 동의생리병리학회지
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• 제27권5호
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• pp.660-666
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• 2013

The purpose of this study was to investigate the clinical effects of herbal steam therapy on cough. Twenty-eight patients with cough who had treated with herbal steam therapy(chungsang, chungpae) between 3rd of January and 30th of April, 2013 were analyzed. The effects were evaluated the severity and frequency of cough as the modified questionnaire, severity of discomfort using visual analogue scale(VAS), and the patients' subjective satisfaction. Eighteen patients who had been treated herbal steam therapy over 3 times were analyzed improvements before and after therapy. Chungsang and Chungpae steam therapies significantly decreased the severity and frequency of cough. VAS scores also decreased from $7.78{\pm}0.878$ to $4.39{\pm}2.033$. Patients were satisfied with herbal steam therapy. Chungsang and Chungpae steam therapies seem to be effective in the treatment of cough. Further studies with a large number of cases will be needed in the future.

• 한국축산식품학회지
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• 제33권1호
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• pp.103-108
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• 2013

This study was carried out to observe the effect of superheated steam combined with oven heating on the physico-chemical and sensory properties of chicken meat. Specially, chicken breasts and thighs were heated for 40 min in various heating formulations such as oven heating, superheated steam heating or a combination of two kinds of heating. In the physical properties measurement, the shear force was increased as superheated steam heating time and chicken thighs were higher than chicken breasts in all treatments (p<0.05). The highest level of water holding capacity was solely superheated steam treated chicken for 40 min (p<0.05). The $L^*$ value was decreased but $a^*$ value or $b^*$ value were increased after cooking. Chicken breast exhibited a higher colour value than chicken thigh. Superheated heating was effective to reduce heating loss as 22.64% (p<0.05). However, pH was not different depending on the heating formulation or part of the chicken meat (p>0.05). In the sensory test, the combination of 10 min oven heating and 30 min superheated steam heating was effective to create a good flavour of chicken meat. In this study, an optimum formulation was developed which was a combination of 10 min oven heating and 30 min superheated steam heating. It was more effective to improve the quality of chicken meat than the single heat treatment of chicken meat.

• 한국가구학회지
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• 제11권2호
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• pp.1-6
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• 2000

This study was carried out to investigate the effect of steaming on mechanical properties of heat-compressed wood specimens. The specimens for this mechanical strength tests were prepared to super-heated steam treatment after compression to the radial direction of sonamu (Pinus densiflora). The specimen's size is $50(L)mm{\times}20(R)mm{\times}17(T)mm$. Steaming temperature and treatment time is $120^{\circ}C$ and 20, 40, 60, 80, 100 minutes, respectively. Modulus of elasticity(MOE) in compressive test is directly proportional to steaming time. On the other hand, modulus of elasticity in bending test between steaming and not steaming after heat-compressed wood is similar irrespective of steaming time. The reason for this phenomenon is not clear yet.

• 한국식품영양학회지
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• 제24권3호
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• pp.464-470
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• 2011

Thermally processed vegetables have long been considered to have lower nutritional values compared to fresh produce. This consideration is based on the fact that ascorbic acid(vitamin C) or other thermolabile compounds may lose their activity due to oxidation or by consequence of leaching into the water during home cooking or industrial processing, such as by blanching. In this study, major agricultural products such as carrots, broccoli, and potatoes were exposed to steam treatments of different types. Then, changes in color and levels of ascorbic acid, carotene, and moisture in the fresh and steam processed vegetable samples were measured and evaluated. The results clearly showed that steam-processing using a natural convection type method was superior to the other treatments in terms of quality, including color and nutrient retention, among all the vegetables tested.

• 한국표면공학회지
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• 제42권3호
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• pp.139-144
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• 2009

A microwave plasma torch at the atmospheric pressure by making use of magnetrons operated at the 2.45 GHz and used in a home microwave oven has been developed. This electrodeless torch can be used to various areas, including industrial, environmental and military applications. Although the microwave plasma torch has many applications, we in the present work focused on the microwave plasma torch operated in pure steam and several applications, which may be used in future and right now. For example, a high-temperature steam microwave plasma torch may have a potential application of the hydrocarbon fuel reforming at one atmospheric pressure. Moreover, the radicals including hydrogen, oxygen and hydroxide molecules are abundantly available in the steam torch, dramatically enhancing the reaction speed. Also, the microwave plasma torch can be used as a high-temperature, large-volume plasma burner by injecting hydrocarbon fuels in gas, liquid, and solid into the plasma flame. Finally, we briefly report treatment of soils contaminated with oils, volatile organic compounds, heavy metals, etc., which is an underway research in our group.

• 한국연초학회지
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• 제17권1호
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• pp.68-78
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• 1995

A study of expanding tobacco includes the steps of adjusting the moisture content of cut tobacco, without the use of exogenous impregnants by contacting the filler with a high velocity gaseous medium at elevated temperature such that heat is rapidly and substantially uniformly transferred from the medium to the filler for a total contact time sufficient to expand the tobacco leaves. Study is disclosed for drying and expanding cut tobacco by introducing the tobacco into an elongated tubular shaped conduit through which steam high temperature 150-35$0^{\circ}C$ and high velocity above the 18m1sec, super steam is recycled. moisture content of shreded tobacco leaves, immediately before treatment within the range of from 10% to 24% and, most preferably, within the range of from 18% to 21%. Expanding rate showed 70% in NC -82(B.3) and 42% in Burley -21(B.1) which is produced in 1993 under this condition. When expanding tobacco expanded tobacco did not change significally, but they were decreased at 27$0^{\circ}C$ very largely. The curtailment of cost price and physical and chemical properties of various items were improved in cigarettes. Key words : Expanding tobacco, Super steam tobacco expansion, Fast drying tobacco, High temperature treat tobacco, Puffing tobacco.