• Korean Journal of Environmental Agriculture
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• v.34 no.2
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• pp.105-110
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• 2015

BACKGROUND: Soy isoflavones, structurally similar to endogenous estrogens, may affect human body through both hormonally mediated and non-hormonally related mechanisms. Heat processing could change chemical compositions. The effects of different thermal processes, boiling and HTHP(high temperature and high pressure) on the composition of isoflavone compounds and total amount of domestic soybeans were investigated in this study. METHOD AND RESULTS: Three different kinds of soybean samples were collected from RDA-Genebank. The samples were extracted using methanol, distilled water, and formic acid based solvent. Also the same solvents were used for mobile phase in UPLC/ToF/MS. All of the isoflavone compounds were analyzed based on the aglycone type of external standard for quantification. The standard calibration curve presented linearity with the correlation coefficient R2 > 0.98, analysed from 1 to 50 ppm concentration. The total isoflavone contents does not change by treatment within the same breed. While "boiling" and "HTHP" processes tend to increase the contents of aglycone and ${beta}$-glucosides, "fresh" soybeans retained the high concentration of malonylglucosides. CONCLUSION: These results have to be considered while developing an effective functional food, from the health while point of view using soybeans.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.18-25
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• 2016

Enhanced tubes are used widely in the evaporators of large tonnage compression-type refrigerators. The evaporators consist of tube bundles, and the refrigerant properties are dependent on the locations in the tube bundles. In particular, the saturation temperatures of low pressure refrigerants (R-11, R-123) are strongly dependent on the locations due to the saturation temperature-pressure curve characteristics. Therefore, for the proper design of evaporators, local property predictions of the refrigerants are necessary. In this study, a computer program that simulates the flooded refrigerant evaporators was developed. The program incorporated theoretical models to predict the refrigerant shell-side boiling heat transfer coefficients and pressure drops across the tube bundle. The program adopted an incremental iterative procedure to perform row-by-row calculations over the specified incremental tube lengths for each water-side pass. The program was used to simulate the flooded refrigerant evaporator of the "T" company operating with R-123, which yielded satisfactory results. The program was extended to predict the performance of the flooded refrigerant evaporator operating with R-11, R-123, and R-134a. The effects of bundle aspect ratio are investigated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.21-27
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• 2018

FRN (Full range Naphtha) is distilled from crude oil in a Naphtha Splitter Unit and is separated into the Light Straight Naphtha, Heavy Naphtha, and kerosene according to the boiling point in sequence. This separation is conducted using a series of binary-like columns. In this separation method, the energy consumed in the reboiler is used to separate the heaviest components and most of this energy is discarded as vapor condensation in the overhead cooler. In this study, the first two columns of the separation process are replaced with the Petlyuk column. A structural design was exercised by a stage to stage computation with an ideal tray efficiency in the equilibrium condition. Compared to the performance of a conventional system of 3-column model, the design outcome indicates that the procedure is simple and efficient because the composition of the liquid component in the column tray was designed to be similar to the equilibrium distillation curve. An analysis of the performance of the new process indicated an energy saving of 12.3% under same total number of trays and with a saving of the initial investment cost.

• Journal of Environmental Science International
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• v.14 no.1
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• pp.61-69
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• 2005

Adsorption characteristics of toluene vapor, which is one of important source of volatile organic compounds (VOCs), by activated carbon were investigated using a fixed bed adsorption column. The operating parameters such as breakthrough curve, adsorption capacity, mass transfer zone (MTZ), and length of unused bed (LUB) were studied. The experimental results showed that the breakthrough time decreased with increasing inlet toluene concentration and gas flow rate. MTZ and LUB increased with the increase of inlet concentration, gas flow rate, and particle size of activated carbon. The adsorption capacity increased with the increase of inlet toluene concentration, while it decreased with increasing particle size. However, it was kept at constant value regardless of the increase of gas flow rate. Adsorption isotherm of toluene vapor could be represented by the Freundlich adsorption equation fairly well. From the adsorption experiments using some VOC gases such as toluene, xylene, butyl acetate. butanol and acetone, it was also found that the adsorption capacity was higher in the case of gas with higher boiling point and lower vapor pressure.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.3
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• pp.520-527
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• 1988

Liquid ejectors are widely used as marine pumps, inducer stage for the boiler feed water pump, boiler recirculating pump, cooling water recirculating pump in boiling water type nuclear reactor and a deep well pump, because of their high working confidence and simplicity. Furthermore, it requires only a modest net positive suction head for cavitation-free operation and it can be installed in remote location from mechanical power source. It is not easy to presume the friction losses, because it is complicately affected by area ratio, flowrate ratio, nozzle spacing, throat length, shape of liquid ejector and so on. Therefore, the optimization of liquid ejector design is still dependent, to a large extent, on the experimental results and empirical procedures. On the design of the liquid ejector, the area ratio and the nondimensional throat length are the most important design factors among the mentioned above. In this experiment, the effects of the area ratio and the nondimensional throat length to ejector efficiency are carried out systematically by the combination of 4 kinds of motive nozzle and 2 kinds of throat length. In this paper, the present experimental results are compared with the calculated ones by the previous computer aided design program based on one dimensional flow equation. And also, an empirical equation for the working limit of liquid ejector is reported.

• Korean Journal of Food Science and Technology
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• v.19 no.6
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• pp.480-485
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• 1987

Quick cooking rice was produced by cooking raw, white long grain rice with three different methods which were atmospheric cooking in electric cooker, autoclaving and precooking followed by autoclaving. The drying rate curve showed that cooking methods affected little the drying pattern of the cooked rice except that precooking treatment before autoclaving retarded dehydration. The quick cooking rice prepared by precooking and autoclaving method among three cooking methods showed the fastest rehydration rate and took 7.5 minutes in reaching equilibrium moisture content by soaking in boiling water. And it had less hard and more cohesive texture than the milled rice cooked by conventional method and the quick cooking rice prepared by electric cooking when reconstituted. The microstructure of quick cooking rice was investigated among cooking methods.

• Economic and Environmental Geology
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• v.25 no.4
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• pp.417-433
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• 1992

Lead-zinc-copper deposits of the Jeonheung and the Oksan mines around Euiseong area occur as hydrothermal quartz and calcite veins that crosscut Cretaceous sedimentary rocks of the Gyeongsang Basin. The mineralization occurred in three distinct stages (I, II, and III): (I) quartz-sulfides-sulfosalts-hematite mineralization stage; (II) barren quartz-fluorite stage; and (III) barren calcite stage. Stage I ore minerals comprise pyrite, chalcopyrite, sphalerite, galena and Pb-Ag-Bi-Sb sulfosalts. Mineralogies of the two mines are different, and arsenopyrite, pyrrhotite, tetrahedrite and iron-rich (up to 21 mole % FeS) sphalerite are restricted to the Oksan mine. A K-Ar radiometric dating for sericite indicates that the Pb-Zn-Cu deposits of the Euiseong area were formed during late Cretaceous age ($62.3{\pm}2.8Ma$), likely associated with a subvolcanic activity related to the volcanic complex in the nearby Geumseongsan Caldera and the ubiquitous felsite dykes. Stage I mineralization occurred at temperatures between > $380^{\circ}C$ and $240^{\circ}C$ from fluids with salinities between 6.3 and 0.7 equiv. wt. % NaCl. The chalcopyrite deposition occurred mostly at higher temperatures of > $300^{\circ}C$. Fluid inclusion data indicate that the Pb-Zn-Cu ore mineralization resulted from a complex history of boiling, cooling and dilution of ore fluids. The mineralization at Jeonheung resulted mainly from cooling and dilution by an influx of cooler meteoric waters, whereas the mineralization at Oksan was largely due to fluid boiling. Evidence of fluid boiling suggests that pressures decreased from about 210 bars to 80 bars. This corresponds to a depth of about 900 m in a hydrothermal system that changed from lithostatic (closed) toward hydrostatic (open) conditions. Sulfur isotope compositions of sulfide minerals (${\delta}^{34}S=2.9{\sim}9.6$ per mil) indicate that the ${\delta}^{34}S_{{\Sigma}S}$ value of ore fluids was ${\approx}8.6$ per mil. This ${\delta}^{34}S_{{\Sigma}S}$ value is likely consistent with an igneous sulfur mixed with sulfates (?) in surrounding sedimentary rocks. Measured and calculated hydrogen and oxygen isotope values of ore-forming fluids suggest meteoric water dominance, approaching unexchanged meteoric water values. Equilibrium thermodynamic interpretation indicates that the temperature versus $fs_2$ variation of stage I ore fluids differed between the two mines as follows: the $fs_2$ of ore fluids at Jeonheung changed with decreasing temperature constantly near the pyrite-hematite-magnetite sulfidation curve, whereas those at Oksan changed from the pyrite-pyrrhotite sulfidation state towards the pyrite-hematite-magnetite state. The shift in minerals precipitated during stage I also reflects a concomitant $fo_2$ increase, probably due to mixing of ore fluids with cooler, more oxidizing meteoric waters. Thermodynamic consideration of copper solubility suggests that the ore-forming fluids cooled through boiling at Oksan and mixing with less-evolved meteoric waters at Jeonheung, and that this cooling was the main cause of copper deposition through destabilization of copper chloride complexes.

• Economic and Environmental Geology
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• v.28 no.2
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• pp.109-121
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• 1995

The hydrothermal vein type deposits which comprise the Kasihan, Jompong and Gempol mineralized areas are primarily copper and zinc deposits, but they are also associated with lead and/or gold mineralization. The deposits occur within the Tertiary sedimentary and volcanic rocks in the Southern Mountain zone of the eastern Java island, Indonesia. Mineralization can be separated into two or three distinct stages (pre-and/or post- ore mineralization stages and main ore mineralization stage) which took place mainly along pre-existing fault breccia zones. The main phase of mineralization (the main ore stage) can be usually classified into three substages (early, middle and late) according to ore mineral assemblages, paragenesis, textures and their chemical compositions. Ore mineralogy and paragenesis of the three areas in the district are different from each other. Pyrite, pyrrhotite (/arsenopyrite), iron-rich (up to 20.5 mole % FeS) sphalerite and (Cu-)Pb-Bi sulfosalts are characteristic of the deposits in the Kasihan (/Jompong) area. On the other hand, pyrite + hematite + magnetite + iron-poor (2.7 to 3.6 mole % FeS) sphalerite assemblage is restricted to the Gempol area. Fluid inclusion data suggest that fluids of the main ore stage evolved from initial high temperatures (near $350^{\circ}C$) to later lower temperatures (near $200^{\circ}C$) with salinities ranging from 0.8 to 10.1 equiv. wt. percent NaCl. Each area represents a separate hydrothermal system: the mineralization at Kasihan and Jompong were largely due to early fluid boiling coupled with later cooling and dilution, whereas the mineralization at Gempol was mainly resulted from cooling and dilution by an influx of cooler meteoric waters. Fluid inclusion evidence of boiling indicates that pressures of ${\geq}95$ to 255 bars (${\geq}95$ bars for the Gempol area: $\approx$ 120 to 170 bars for the Jompong area: $\approx$ 140 to 255 bars for the Kasihan area) during portions of main ore stage mineralization. Equilibrium thermodynamic interpretation indicates that the evolution trends of the temperature versus fS2 variation of ore stage fluids in the Pacitan district follow two fashions: ore fluids at Kasihan and Jompong changed from the pyrite-pyrrhotite sulfidation stage towards pyritehematite- magnetite state, whereas those at Gempol evolved nearly along pyrite-hematite-magnetite reaction curve with decreasing temperature. The sulfur isotope compositions of sulfide minerals are consistent with an igneous source of sulfur with a ${\delta}^{34}S_{{\Sigma}s}$ value of about 3.3 per mil. The oxygen and hydrogen isotopic compositions of the fluids in each area indicate a progressive shift from the dominance of highly exchanged meteoric water at early hydrothermal systems towards an un- or less-exchanged meteoric water at later hydrothermal systems.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.8
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• pp.1221-1226
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• 2016

This study investigated changes in the S-allyl-L-cysteine (SAC) content of garlic using different cooking methods. Methods for determining SAC were validated by determining specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy using an high-performance liquid chromatography-fluorescence detection system. Results showed high linearity in the calibration curve with a coefficient of correlation ($R^2$) of 0.9999. The LOD and LOQ values for SAC were 0.15 and $0.47{\mu}g/mL$, respectively. The relative standard deviations for intra- and inter-day precision of SAC were less than 5%. The recovery rate of SAC was in the range from 97.35% to 97.47%. The SAC content of raw garlic was 2.77 mg/g, and there was no significant difference in SAC content according to blanching and microwave treatment. However, SAC content upon boiling and autoclaving at $110^{\circ}C$ and $121^{\circ}C$ increased from 3.50~9.16 mg/g, 6.52~16.21 mg/g, and 14.15~50.24 mg/g with increasing cooking temperature and time, respectively.

• Journal of the Korean Institute of Gas
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• v.24 no.1
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• pp.17-22
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• 2020

Light Naphtha is distillated from crude oil unit and separated into the methane, ethylene and propylene by boiling point difference in sequence. This separation is conducted using a series of binary-like columns. This separation method is known that the energy consumed in the reboiler is used to separate the heaviest components and most of this energy is discarded as vapor condensation in the overhead cooler. In this study, the first two columns of the separation process are replaced with the Petlyuk column. A structural design was exercised by the stage computation with ideal tray efficiency in equilibrium condition. Compared with the performance of a conventional system of 3-column model, The design outcome shows that the procedure is simple and efficient because the composition of the liquid component in the column tray was designed to be similar to the equilibrium distillation curve. The performance of the new process indicates that an energy saving of 12.1% is obtained and the cost savings of 44 million won per day based on gross domestic product is reduced under same total number of trays and the initial investment cost is saved.