• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.206-214
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• 2018

This study was conducted from August 2017 to May 2018. Beer was prepared by different ratio of rice and malt and different types of beer, and quality analysis were conducted. The ratio of rice and malt was divided into 0:100 (S0), 20:80 (S1), 40:60 (S2), 60:40 (S3) and 80:20 respectively. We compared the characteristics of the mashing methods(infusion and decoction method) and investigated the characteristics of different types of beer (lager, ale, wheat beer) using yeast (bottom and top yeast). Even with different ratios of rice and malt, normal infusion time was observed and the iodine test was confirmed to be normal. Also, the mashing proceeded normally and the sugar content of the primary wort was between $21.0{\sim}21^{\circ}brix$. In mashing method, the mash concentration, color and flavor of wort were the highest in the three mash method(decoction method). During the fermentation period of beer, the sugar content, pH and yeast number did not differ significantly depending on the ratio of rice and malt, and the type of yeast. Higher alcohol and esters also had no correlation with the ratio of rice to malt, and wheat beer was somewhat higher. The higher the ratio of rice, the more the color intensity(EBC) decreased, the bitter unit(BU) and the preference decreased. When the rice ratio was higher than the malt rate, the degree of preference decreased significantly. Based on the results of this study, it is expected that the rice ratio will be less than the malt ratio and the flavor of the wort will be improved by using the deccoction method. If the malt is supplemented with the use of the special malt and the various hops according to the beer type, it may be helpful to manufacture rice beer.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.3
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• pp.39-55
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• 1992

In this research, a Three Level Decomposition technique has been developed for configuration design optimization of truss structures. In the first level, as design variables, behavior variables are used and the strain energy has been treated as the cost function to be maximized so that the truss structure can absorb maximum energy. For design constraint of the optimal design problem, allowable stress, buckling stress, and displacement under multi-loading conditions are considered. In the second level, design problem is formulated using the cross-sectional area as the design variable and the weight of the truss structure as the cost function. As for the design constraint, the equilibrium equation with the optimal displacement obtained in the first level is used. In the third level, the nodal point coordinates of the truss structure are used as coordinating variable and the weight has been taken as the cost function. An advantage of the Three Level Decomposition technique is that the first and second level design problems are simple because they are linear programming problems. Moreover, the method is efficient because it is not necessary to carry out time consuming structural analysis and techniques for sensitivity analysis during the design optimization process. By treating the nodal point coordinates as design variables, the third level becomes unconstrained optimal design problems which is easier to solve. Moreover, by using different convergence criteria at each level of design problem, improved convergence can be obtained. The proposed technique has been tested using four different truss structures to yield almost identical optimum designs in the literature with efficient convergence rate regardless of constraint types and configuration of truss structures.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.1
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• pp.90-96
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• 2000

The composition of leachates varies depending on the waste characteristics, landfill age and landfilling method. Generally, leachates contain high dissolved organic substance and ammonia nitrogen whereas phosphorus concentration was very low. Leachate A produced from young landfill is characterized by high BOD5/COD ratio (0.8) whereas leachate C produced from old landfill has lower BOD5/COD ratio (0.1). Maximum biochemical methane potential of leachate A, B (from medium landfill) and C were 271,106 and 4 ml CH4/g-COD, respectively. On the other hand, the maximum biodegradability of leachate A, B, and C were 75,30, and 1%, respectively. These results indicated that anaerobic treatment of leachate from young landfill was effective in removing organic pollutants. In case of leachate C, carbon might reside in the form of large molecular weight organic compounds such as lignins, humic acids and other polymerized compounds of soils, which are resistant to biodegradation. The lag-phase period increased with the increasing organic concentration in leachate. In case of leachate A of concentration greater than 25%, the lag-phase period increased sharply. This implied that the start-up period of anaerobic process using an unacclimated inoculum could be extended due to the higher concentration of leachate. This relatively long lag-phase is probably related to the fact that most of the inhibitory compounds have been diluted beyond their inhibitory concentrations of less than 50%. Furthermore, the ultimate methane yield and methane production rate decreased as leachate concentration increased. It was anticipated the potential inhibition was related with the steady-state inhibition as well as the initial shock load.

• Journal of radiological science and technology
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• v.35 no.4
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• pp.345-352
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• 2012

As the breast cancer rate is increasing fast in Korean women, people pay more attention to mammography and number of mammography have been increasing dramatically over the last few years. Mammography is the only means to diagnose breast cancer early, but harms caused by radiation exposure shouldn't be overlooked. Therefore, it is important to calculate the radiation dose being absorbed into the breast tissue during the process of mammography for a protective measure against radiation exposure. Because it is impossible to directly measure the radiation dose being absorbed into the human body, statistical calculation methods are commonly used, and most of them are supposed to simulate the interaction between radiation and matter by describing the human body internal structure with anthropomorphic phantoms. However, a simulation using Geant4 Code of Monte Carlo Method, which is well-known as most accurate in calculating the absorbed dose inside the human body, helps calculate exact dose by recreating the anatomical human body structure as it is through the DICOM file of CT. To calculate the absorbed dose in the breast tissue, therefore, this study carried out a simulation using Geant4 Code, and by using the DICOM converted file provided by Geant4, this study changed the human body structure expressed on the CT image data into geometry needed for this simulation. Besides, this study attempted to verify if the dose calculation of Geant4 interlocking with the DICOM file is useful, by comparing the calculated dose provided by this simulation and the measured dose provided by the PTW ion chamber. As a result, under the condition of 28kVp/190mAs, the Difference(%) between the measured dose and the calculated dose was found to be 0.08 %~0.33 %, and at 28 kVp/70 mAs, the Difference(%) of dose was 0.01 %~0.16 %, both of which showed results within 2%, the effective difference range. Therefore, this study found out that calculation of the absorbed dose using Geant4 Simulation is useful in measuring the absorbed dose in the breast tissue for mammography.

• Journal of Life Science
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• v.19 no.1
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• pp.65-74
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• 2009

The objective of this study was to examine the effects of steam flaking treatment of corn grains imported from USA and India on in vitro gas production, microbial growth and contents of aflatoxin $B_1$ and ochratoxin A. Each treatment was composed of total 4 treatments including (1) USCW (US com-whole type), (2) USCF (US corn-flaked type), (3) IDCW (India corn-whole type) and (4) IDCF (India orn-flaked type) with 4 replications $\times$ 6 incubation times (3, 6, 9, 12, 18 and 24 hr). Mycotoxin (aflatoxin $B_1$ & ochratoxin A) contents in test corns tended to increase gradually with increasing logistics periods from the harbor, hopper, silo to processing line. The contents of aflatoxin $B_1$ in India corn (IDCW) and US corn (USCW) were 11.71 and 1.78 ppb, respectively when measured at the hopper. After steam flaking, both contents of aflatoxin $B_1$ in USCW and IDCW were 0.00 ppb. It means that Aspergillus flavus could be decreased by steam flaking. However, this trend was not observed in ochratoxin content. The gas production rate of USA corns (USCW & USCF) was significantly (p<0.05) higher than India corns (IDCW & IDCF), and that of steam flaked corns (USCF & IDCF) was higher $1.5{\sim}2%$ than whole corns (USCW & IDCW) after 3 hr incubation in in vitro experiment. pH value was optimally maintained for microbial growth during whole incubation times with the value of 6.05 to 6.54, and was not significantly different between treatments, but USCF was somewhat lower than other treatments. pH value decreased following 12 hr of incubation but gas production increased rapidly during the same period. In addition, in vitro microbial growth rates also increased with up to 18 hr of incubation period, thereafter experienced a decrease with extended incubation time. In conclusion, US corn was superior to India corn by origin based on the results of in vitro and mycotoxin contents. And steam flaking process of imported corns tended to decrease mycotoxin contents such as aflatoxin $B_1$ and ochratoxin A as well as improve in vitro gas production and microbial growth rates.

• Journal of Life Science
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• v.29 no.12
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• pp.1305-1313
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• 2019

Licochalcone (LC), isolated from the roots of Glycyrrhiza inflata has multiple pharmacological effects including anti-inflammatory and anti-tumor activities. To date, Licochalcone C (LCC) has induced apoptosis and inhibited cell proliferation in oral and bladder cancer cells, but lung cancer has not yet been studied. In addition, no study reported LCC-induced autophagy in cancer until now. The present study was designed to investigate the effect of LCC on gefitinib-sensitive and -resistant lung cancer cells and elucidate the mechanism of its action. The 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay data showed that LCC significantly inhibited cell viability in non-small cell lung cancer (NSCLC) HCC827 (gefitinib-sensitive) and HCC827GR (gefitinib-resistant) cell lines. Interestingly, Annexin V/7-aminoactinomycin D double staining and cell cycle analysis showed an apoptosis rate within about 20% at the highest concentration of LCC. LCC induced G2/M arrest by reducing the expression of the cell cycle G2/M related proteins cyclin B1 and cdc2 in NSCLC cell lines. Treatment of LCC also induced autophagy by increasing the expression of the autophagy marker protein microtubule-associated protein 1 light chain 3 (LC3) and the protein autophagy-related gene 5 involved in the autophagy process. In addition, LCC increased the production of reactive oxygen species (ROS), and the cell viability was partially restored by treatment with the ROS inhibitor N-acetyl-L-cysteine. In western blotting analysis, the expression of cdc2 was increased and LC3 was decreased by the simultaneous treatment of NAC and LCC. These results indicate that LCC may contribute to anti-tumor effects by inducing ROS-dependent G2/M arrest and autophagy in NSCLC. In conclusion, LCC treatment may be useful as a potential therapeutic agent against NSCLC.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.4
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• pp.343-356
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• 2016

The Korea Radioactive Waste Agency (KORAD) has developed a dual-purpose metal cask for the dry storage of spent nuclear fuel that has been generated by domestic light-water reactors. The metal cask was designed in compliance with international and domestic technology standards, and safety was the most important consideration in developing the design. It was designed to maintain its integrity for 50 years in terms of major safety factors. The metal cask ensures the minimization of waste generated by maintenance activities during the storage period as well as the safe management of the waste. An activation evaluation of the main body, which includes internal and external components of metal casks whose design lifetime has expired, provides quantitative data on their radioactive inventory. The radioactive inventory of the main body and the components of the metal cask were calculated by applying the MCNP5 ORIGEN-2 evaluation system and by considering each component's chemical composition, neutron flux distribution, and reaction rate, as well as the duration of neutron irradiation during the storage period. The evaluation results revealed that 10 years after the end of the cask's design life, $^{60}Co$ had greater radioactivity than other nuclides among the metal materials. In the case of the neutron shield, nuclides that emit high-energy gamma rays such as $^{28}Al$ and $^{24}Na$ had greater radioactivity immediately after the design lifetime. However, their radioactivity level became negligible after six months due to their short half-life. The surface exposure dose rates of the canister and the main body of the metal cask from which the spent nuclear fuel had been removed with expiration of the design lifetime were determined to be at very low levels, and the radiation exposure doses to which radiation workers were subjected during the decommissioning process appeared to be at insignificant levels. The evaluations of this study strongly suggest that the nuclide inventory of a spent nuclear fuel metal cask can be utilized as basic data when decommissioning of a metal cask is planned, for example, for the development of a decommissioning plan, the determination of a decommissioning method, the estimation of radiation exposure to workers engaged in decommissioning operations, the management/reuse of radioactive wastes, etc.

• Applied Biological Chemistry
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• v.47 no.3
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• pp.344-350
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• 2004

This study was conducted to develop and assess the applicability of mixed-bed ion exchange resin capsules for water quality monitoring in small agricultural watershed. Recoveries of resin capsules for inorganic N and P ranged from 96 to 102%. The net activation energies and pseudo-thermodynamic parameters, such as ${\Delta}G^{o\ddag},\;{\Delta}H^{o\ddag},\;and\;{\Delta}S^{o\ddag}$ for ion adsorption by resin capsules, exhibited relatively low values, indicating the process might be governed by chemical reactions such as diffusion. However, those values increased with temperature coinciding with the theory. The reaction reached pseudo-equilibrium within 24 hours for $NH_4-N\;and\;NO_3-N$, and only 8 hours for $PO_4-P$, respectively. The selectivity of resin capsules were in the order of $NO_3\;^-\;>\;NH_4\;^+\;>\;PO_4\;^{3-}$, coinciding with that of encapsulated Amberlite IRN-150 resin. At the initial state of equilibrium, the resin adsorption quantity was linearly proportional to the mass of ions in the streams, but the rate of movement leveled off, following Langmuir-type sorption isotherm. The overall results demonstrated that the resin capsule system was suitable for water quality monitoring in small agricultural watershed, judging from the reaction mechanism(s) of the resin capsule and the significance of model in field calibration.

• Radiation Oncology Journal
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• v.25 no.2
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• pp.125-133
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• 2007

[ $\underline{Purpose}$ ]: This study was to design and fabricate a phantom for prostate cancer brachytherapy to validate a developed program applying a 3-film technique, and to compare it with the conventional 2-film technique for determining the location of an implanted seed. $\underline{Materials\;and\;Methods}$: The images were obtained from overlapped seeds by randomly placing a maximum of 63 seeds in the anterior-posterior (AP) position and at $-30^{\circ} to $30^{\circ} at $15^{\circ} intervals. Images obtained by use of the phantom were applied to the image processing procedure, and were then processed into the development program for seed localization. In this study, cases were set where one seed overlapped, where two seeds overlapped and where none of the three views resolved all seeds. The distance between the centers of each seed to the reference seed was calculated in a prescribed region. This distance determined the location of each seed in a given band. The location of the overlapped seeds was compared with that of the 2-film technique. $\underline{Results}$: With this program, the detection rate was 92.2% (at ${\pm}15^{\circ}), 94.1% (at ${\pm}30^{\circ}) and 70.6% (compared to the use of the 2-film technique). The overlaps were caused by one or more than two seeds that overlapped; the developed program can identify the location of each seed perfectly. However, for the third case the program was not able to resolve the overlap of the seeds. $\underline{Conclusion}$: This program can be used to improve treatment outcome for the brachytherapy of prostate cancer by reducing the number of errors in the process of reconstructing the locations of perfectly overlapped seeds.

• Journal of Korea Water Resources Association
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• v.42 no.2
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• pp.141-148
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• 2009

Each river in each country has peculiar channel characteristics at every section. Korea consists of mountains at the rate of 70%. Due to this, the sections that display unique channel form are scattered. One of the typical features is the narrow pass of channel section that presents in the process of the generation of alluvial channel and deformation channel. Around as this narrow pass of channel, it often comes to be regular flood disaster section. Regardless of this situation, investigations and plans that reflect channel characteristics at the narrow pass of channel have been wholly wanting until now. In accordance with this, we have investigated and analysed hydraulic significance and channel form of the narrow pass of channel in Seonsan in this study. The study has found real minute classification of sediment phenomenon at river bed of low flow channel on investigation section which is sand-bed river, but it was vaguely difficult to conclude that classification of sediment arises from explicit natural force. We were able to assume that the phenomenon comes from gentle bed slope, supply of river bed materials which is nearly uniformity. However, classification of sediment would come from collecting an aggregate rather than natural force. And we found that compound cross section conversion has been developing dramatically with channel form of movable bed section referring to movement which was active before at drainage district of the narrow pass of channel. With this, we could find the phenomenon that river width of low flow channel diminished largely. This kind of situation implies that it may cause compound section weighting, flood dimension decreasing, revetment at low flow channel or the local scour at bottom of levee when extraordinary flood occurs.