• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.439-444
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• 1995

Preparative conditions and characteristics of six-vegetable and fruit juice were studied for the effects of mixing ratio, heat treatment and addition of sugar, salt and organic acid. The vegetables and fruit used were carrot(Ct), cabbage(Cg), pear(Pr), cucumber(Cr), celery(Cy) and dongchimi(Di). From the sensory results of mixing ratio of three of binary mixtures of Cg-Pr(1:3):Ct-Di(1:4):Cr-Cy(3:1), two ratios of 5.0:2.5:2.5(V-6A) and 6.0:2.0:2.0(V-6B) were suggested optimal for six-vegetable and fruit juice. Addition of 2% sucrose and 0.3% NaCl improved the preference significantly. The pH 4.0 for V-6A and pH 3.5 for V-6B were more prefered when pH was adjusted by citric acid. Heating the juice at $100^{\circ}C$ for 100 minutes slightly decreased pH and increased the acidity. Total solids and viscosity were also decreased by heating. All of those changes were more significant in V-6B than V-6A, probably due to lower pH. Heating the juice resulted in a slight decrease in L value and an increase in a and b values. Heating at $100^{\circ}C$ caused an increase in moldy flavor and a decrease in fresh vegetable flavor while heating at $80^{\circ}C$ for 20 minutes changed them little.

• Fashion & Textile Research Journal
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• v.12 no.4
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• pp.500-507
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• 2010

In this study, physical properties were studied by using latent stretching yarn in order to develop the texturing yarn technique for super bulky yarn, which is better in bulkiness and handle than natural wool and also adds property of synthetic fiber to natural wool. In order to obtain textured conditions by analysing basic properties for manufacturing DTY yarn with super bulky property, DTY 50d/12 after spinning latent yarn spined POY 80d/12 was obtained under the two conditions of (i) false twist(T/M) level 3 in DTY texturing and (ii) draw ratio level 4 in draw texturing. For DTY texturing yarn, Elongation rate increased as the heat treatment time and temperatures increased. In addition, shrinkage became higher as false twist was higher, so that elongation rate became lower. When annealing became longer in time and higher in temperature, initial modulus increased. In addition, as the count of false twist increased, the initial modulus showed higher values. For draw texturing yarn, under the conditions of heat temperature 180 and heating time 30 minutes, shrinkage rate in draw ratio 1.55 and 1.6 draw ratio was 7%, and that in 1.65 and 1.7 draw ratio was 8.5%. High draw ratio samples' tenacity was much influenced by heating time and temperature, but low draw ratio samples' tenacity was influenced not by treated time, but by treated temperature.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.109-114
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• 2009

The dominant heating system used in Korean residential apartment buildings is a hydronic radiant floor heating system, known as the Ondol system. The most common control strategy applied to this traditional hydronic radiant system is a simple on-off control that intermittently supplies "hot water of a fixed temperature" at a "constant flow rate" to each room. However, the current problems with the aforementioned control are as follows: (1) since the simple on-off control is usually based on a one point measured temperature (a signal from a thermostat installed in a living room) in each dwelling unit, heating energy use for unoccupied rooms as well as a difference in temperatures between spaces (master bedroom, living room, bedroom1, bedroom2) can occur occasionally. (2) the most widely used residential water splitter has static valves, and is thus not able to change the flow rate to each room depending on the space heating load. In other words, the ratio of flow rates to rooms is fixed after construction, resulting in over- or under-heating and an improper use of energy. The aim of this paper is therefore to investigate the differences in the system's performance between control strategies in terms of the flow rate control and sensor location. It is shown that energy savings of control strategies are strongly influenced by occupant schedule.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.5
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• pp.687-694
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• 1999

An experimental study was carried out in two laboratory-scale reactors to investigate the effect of heating rate on the behavior of flame front in a pulverized coal flame. Each. reactors had different heating mechanisms. For reactor A losing large heat through transparent quartz wall. pulverized coal particles were ignited by secondary air of 1050K. Flame front could be visualized through the transparent wall. Reactor B was insulated with castable refractory to minimize the heat loss through the reactor wall and accompanied with secondary air of 573K. Flame front was estimated from the gas temperature and species concentration measured using R-type thermocouple(Pt-Pt/Rh 13%) and gas chromatograph at various coal-air ratios and swirl intensities. The flame front position was closely related with the magnitude of heating rate. The heating rate for lifted flame was of the order of $10^4$ to $10^5K/s$ and for coal Ignition at least over $10^4K/s$. The heating mechanism had little impact on the extinction limits. The weak swirl number of 0.68 forced the flame front to move toward the upstream by the rapid mixing of coal and air. The primary/secondary momentum ratio was an inappropriate variable to distinct the liftoff of flame.

• Journal of Korea Foundry Society
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• v.17 no.6
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• pp.598-607
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• 1997

Fractional melting process involves heating an alloy within its liquid-solid region simultaneously ejecting liquid from the solid-liquid mixture. The extent of the purification obtained is comparable to that obtained in multi-pass zone refining. The new fractional melting process in which centrifugal force was used for separating the liquid from the mixture has been developed and applied to the purification of the metallic grade. Refining ratio depends on partition ratio, cake wetness and diffusion in the solid, and it was controlled by various processing parameters such as rotating speed and heating rate. The new parameter called "refining partition coefficient" has been suggested to estimate the effects of processing variables on the refining ratio. Because major impurities in MG-silicon such as Fe, Al, Ni have a low segregation coefficient, good purification effect is expected. The results of refining MG-silicon(98%) showed that 3N-Si was obtained in refined solid of 50% of the original sample.

• Korean Journal of Food Science and Technology
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• v.26 no.1
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• pp.26-30
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• 1994

The purpose of this study was to investigate the effects of heating times of soy protein isolate(SPI) and mixing ratio of coagulants mixture on water holding capacity(WHC) and oil absorption capacity (OAC) of SPI, texture properties and yield of tofu. The effect of heating at $100^{\circ}C$ on the amounts of coagulants required for coagulation showed that the amounts of $CaCl_{2},\;MgCl_{2}$ and GDL decreased as the heating time extended to $6{\sim}9$ minutes while $CaSO_{2}$ was changed little. The tofu yield showed maximum for the tofu prepared by 6 minutes boiling and coagulation with $CaSO_{4}$. The WHC of SPI was significantly reduced by heating at $100^{\circ}C$ while OAC was rather increased until 9 minutes of heating. The textural properties of SPI tofu coagulated with mixed coagulants$(CaSO_{4}-GDL,\;CaSO_{4}-CaCl_{2},\;CaCl_2-GDL)$ showed that softer tofu was obtained as the ratio of $CaSO_{2}$ increased and harder tofu as the ratio of $CaCl_{2}$ and GDL increased. The maximum and minimum tofu yields were prepared from 100% of $CaSO_{2}$ and 100% of GDL, respectively. Organoleptic properties showed that more uniform and tender tofu were obtained with higher portion of $CaSO_{2}$ in the mixed coagulants and higher intensity of sourness and bitterness were scored as the GDL and $CaCl_{2}$ added more.

• Korean Journal of Food Science and Technology
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• v.26 no.1
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• pp.31-36
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• 1994

In order to prepare SPI tofu without compression step, amounts of water added to SPI suspension was studied for textural properties of uncompressed SPI tofu prepared by first heating at $100^{\circ}C$ for 6 minutes and second heating at $75^{\circ}C$ for 25 minutes and use of $CaSO_{4}-GDL$(0.07g, 0.0075 g/g SPI) as coagulants. The hardness and uniformity were gradually increased as the water addition ratio $(gH_{2}O/g\;SPI)$ raised from 6.0 to 8.0 and cohesiveness was rather decreased. The increase in second heating time increased the hardness and gumminess and relativity higher values in hardness were measured for those tofu heated at $85^{\circ}C$ than those at $75^{\circ}C$ or $95^{\circ}C$. A multiple regression equation calculated and RSM figure showed that the effects of water addition ratio was become to be less as the heating time and temperature increased. Addition of 8 g of water per g SPI and second heating at $85^{\circ}C$ for $30{\sim}60$ minutes were found as optimal conditions to prepare uncompressed SPI tofu.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.6
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• pp.645-650
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• 2010

In this research, the problem of combustion and its system in Hyundai Heavy Industries and Sachuan Unison will be analyzed in order to provide some methods of thermal efficiency improvement and help to make a positive influence on fuel savings and their productivity. In forging industries, in order to improve the material properties of the industrial heating elements which are being used, depending on different operation conditions of system equipment and combustion systems, fuel consumption and material properties can get a profound influence. Thus, analyzing about combustion system characteristics of 100 tons heating furnace and heat treatment furnace which are in operation in Hyundai Heavy Industry will be done. In usual, air-fuel ratio is proper for capacity of burner installed in each heating device, otherwise burner gets an automatic turn down ratio. It has a profound influence on heating performance and precision of temperature because it is the fixed characteristics of every industrial furnace. Even if there are some methods to improve the heating performance of a furnace installed with a large capacity burner, it is very difficult to obtain the precision of temperature in maintenance interval. Based on this, performance of burner can be drove to best by improving combustion system. Proper Combustion characteristic for each heating interval was analyzed in heating furnace in Hyundai Heavy Industry. A project plan for improving fuel savings and increasing precision of temperature was presented in this research.

• Applied Chemistry for Engineering
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• v.25 no.5
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• pp.515-519
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• 2014

The fuel properties of biodiesel produced by changing the mixing ratio of methanol and ethanol in trans-esterification of soybean oil and lard were evaluated in this paper. The solubility of oil and fat in ethanol was higher than that in methanol. Also the more homogeneous biodiesel was produced as increasing the mole ratio of ethanol. The conversion characteristics of lard was the best at the mixing mole ratio of methanol and ethanol was 6 : 6 at the reaction temperature of $60^{\circ}C$. On the other hands, the best biodiesel conversion characteristics for soybean oil was obtained at the mixing mole ratio of 3 : 3. The kinematic viscosities of soybean oil and lard based biodiesel were 4.17~4.35 cSt and 4.69~4.93 cSt, respectively. The oxidation stability and higher heating value increased with increasing the mole ratio of ethanol. The oxidation stability satisfied the criteria of biodiesel quality of 6 hours. And finally, the higher heating value was approximately 40 MJ/kg.

• Journal of Energy Engineering
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• v.22 no.2
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• pp.83-89
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• 2013

Energy consumption is closely related to our lives. As Korea has four seasons, heating and cooling system is considered as essential facilities for the residential buildings. Accordingly, the government has continuously strengthened the design criteria to improve energy for new and existing building to save energy. The most important factor in the energy efficiency analysis for apartment is the heat transmission coefficient, and the value is significantly different as the heating energy amount is greatly different according to the window area ratio versus facade area ratio. Therefore, it is time to conduct continuous set-up for goal to enhance efficiency and restriction on window area ratio versus facade area ratio.