• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.7
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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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.874-881
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• 2015

In the food industry, thermal treatment is an important process for extending shelf-life of foods. However, heating process affects the physicochemical, nutritional, and microbial properties of foodstuff such as color, texture, pH, and proximate compositions. This study was conducted to select an optimal thermal treatment by observing physicochemical, nutritional, and microbial effects of shiitake mushrooms with different thermal treatment methods. Shiitake mushrooms were washed and sliced equally ($5cm{\times}0.5cm{\times}0.5cm$) and then heat-treated by three methods. Samples were heated in $100^{\circ}C$ boiling water, steamed for 10 min, or pan fried at $130^{\circ}C$ for 4 min. Total color difference values showed significantly increasing tendency with treatment time. For pH values, boiling water-treated mushrooms showed increasing tendency according to increased thermal treatment. For the results of hardness, boiling water or pan frying-treated mushrooms showed reduced tendency within 1 min. In the case of steam-treated mushrooms, hardness values were maintained for 1 min. Organic acid contents of steam-treated sample showed the lowest value among treatments. For microbial counts, steam-treated samples for 3 min showed the lowest value. Consequently, the results of this study suggest that steam treatment could be the optimal thermal treatment to minimize quality loss of shiitake mushrooms.

• Journal of the Korean Society for Heat Treatment
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• v.13 no.5
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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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.3
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• pp.270-278
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• 1992

Two of the Hard White Winter (HWW) wheats had higher farina yield than mixed Hard Red Winter (HRW) wheat. Optimum steaming time for HRW farina spaghetti was 3min under 86-98$^{\circ}C$. Optimum cooking time decreased after steam treatment. Steam treated spaghetti showed much higher strength of dried spaghetti, lower cooking loss, and cooked weight, less stickiness, and total organic matters (TOM) value than in treated spaghetti after cooking. The rooking qualities except stickiness were significantly different between treated and untreated steam. The quality of hard wheat farina spaghetti was more affected than that of durum spaghetti after steam treatment. HWW farina spaghetti im-roved all the qualities of steam treated and untreated spaghetti than those of HRW farina spaghetti except stickiness. From the observations of scanning electron microscope (SEM), maybe two general principles of steaming can be explained by : i) forming hydrophobic protein film on surface of pasta, ii) higher retrogradation of starch, which cause less swelling of starch.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.5
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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.

• Food Science of Animal Resources
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• v.33 no.1
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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.

• Journal of the Korea Furniture Society
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• v.11 no.2
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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.

• The Korean Journal of Food And Nutrition
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• v.24 no.3
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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.

• Journal of the Korean institute of surface engineering
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• v.42 no.3
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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.

• Journal of the Korean Society of Tobacco Science
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• v.17 no.1
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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.