• Bulletin of the Korean Chemical Society
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• v.28 no.9
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• pp.1477-1484
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• 2007

Artificial neural networks (ANNs), for a first time, were successfully developed for the prediction partial molar heat capacity of aqueous solutions at infinite dilution for various polar aromatic compounds over wide range of temperatures (303.55-623.20 K) and pressures (0.1-30.2 MPa). Two three-layered feed forward ANNs with back-propagation of error were generated using three (the heat capacity in T = 303.55 K and P = 0.1 MPa, temperature and pressure) and six parameters (four theoretical descriptors, temperature and pressure) as inputs and its output is partial molar heat capacity at infinite dilution. It was found that properly selected and trained neural networks could fairly represent dependence of the heat capacity on the molecular descriptors, temperature and pressure. Mean percentage deviations (MPD) for prediction set by the models are 4.755 and 4.642, respectively.

• Journal of the Speleological Society of Korea
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• no.71
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• pp.5-11
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• 2006

A theoretical investigation of the solid phase mechanochemical synthesis of nano sized target product on the basis of dilution of the initial powdered reagent mixture by another product of an exchange reaction is presented. On the basis of the proposed 3 mode particle size distribution in mechanically activated mixture, optimal molar ratios of the components in mixture are calculated, providing the occurrence of impact friction contacts of reagent particles and excluding aggregation of the nanosized particles of the target reaction product. Derivation of kinetic equations for mechanochemical synthesis of nanoscale particles by the final product dilution method in the systems of exchange reactions is submitted. On the basis of obtained equations the necessary times of mechanical activation for complete course of mechanochemical reactions are designed. Kinetics of solid phase mechanosynthesis of nano TlCl by dilution of initial (2NaCl+$Tl_2SO_4$) mixture with the exchange reaction product (diluent,$zNa_2SO_4$, z=z*=11.25) was studied experimentally. Some peculiar features of the reaction mechanism were found. Parameters of the kinetic curve of nano TlCl obtained experimentally were compared with those for the model reaction KBr+TlCl+zKCl=(z+1) KCl+TlBr (z=z1*=13.5), and for the first time the value of mass transfer coefficient in a mechanochemical reactor with mobile milling balls was evaluated. Dynamics of the size change was followed for nanoparticle reaction product as a function of mechanical activation time.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.405-406
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• 2005

A theoretical investigation of the solid-phase mechanochemical synthesis of nano-sized target product on the basis of dilution of the initial powdered reagent mixture by another product of an exchange reaction is presented. On the basis of the proposed 3-mode particle size distribution in mechanically activated mixture, optimal molar ratios of the components in mixture are calculated, providing the occurrence of impact-friction contacts of reagent particles and excluding aggregation of the nanosized particles of the target reaction product. Derivation of kinetic equations for mechanochemical synthesis of nanoscale particles by the final product dilution method in the systems of exchange reactions is submitted. On the basis of obtained equations the necessary times of mechanical activation for complete course of mechanochemical reactions are designed. Kinetics of solid phase mechanosynthesis of nano-TlCl by dilution of initial (2NaCl + $Tl_2SO_4$) mixture with the exchange reaction product (diluent, $zNa_2SO_4$, $z=z^*=11.25$) was studied experimentally. Some peculiar features of the reaction mechanism were found. Parameters of the kinetic curve of nano-TlCl obtained experimentally were compared with those for the model reaction KBr + TlCl + zKCl = (z + 1) KCl + TlBr ($z=z_l^*=13.5$), and for the first time the value of mass transfer coefficient in a mechanochemical reactor with mobile milling balls was evaluated. Dynamics of the size change was followed for nanoparticle reaction product as a function of mechanical activation time.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.1
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• pp.62-69
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• 1998

To remove nitrogen from wastewater, ammonia nitrogen has to be oxidized to nitrate nitrogen before denitrification reaction which converts nitrate nitrogen to nitrogen gas. In order to understand nitrification, several mathematical models had been proposed and Monod type model has been accepted internationally. Since Monod type model consists of maximum substrate utilization rate, substrate concentration and half-saturation coefficient, these values have to be addressed before using Monod type model. Several experimental procedures to determine half-saturation coefficient have been developed, however, Infinite dilution method was known to be time saving procedure. In this study, the mathematical equations and experimantal procedures for Infinite dilution method are presented and this method is used to determine half-Saturation coefficient for nitrifying bacteria. As results, Infinite dilution method is proved that this coefficient can be determined within 8 hours and the values of half-saturation coefficient has a range of 0.728 and $0.455gNH_4{^+}-N/m^3$ and the average has $0.580gNH_4{^+}-N/m^3$ through 5 sets of experiments.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.05a
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• pp.5-8
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• 2005

Sound absorbing performance is affected by porosity and continuity of void, therefore it is important to maintain stabilization of foam and to analyze properties of void pore in hardened state. The purpose of this study is to analyze the sound absorption properties and void characteristic of foamed concrete according to dilution ratio of foaming agent. The results of this experiment were as follows. It is determined that an increase in total and continuous void ratio is achieved by increasing of dilution ratio, and a shorter absorbing time was exhibited at a higher continuous void ratio. When the average void size of foamed concrete was below 1.5mm, the tendency of sound absorption coefficient compared with general sound absorber was appeared similarly.

• KSBB Journal
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• v.4 no.2
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• pp.185-190
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• 1989

Semicontinuous alcohol fermentation of Jerusalem Artichoke by K. fragilis CBS 1555 was performed to investigate the effect of the effective dilution rate and influent sugar concentration to the ethanol concentration and alcohol productivity at steady state. When the time interval for the replacement of fresh influent with fermentation broth was less than or equal to 1 hr, the effective dilution rate was found out to be equal to the specific growth rate. Wash out was not occurred until the effective dilution rate, 0.425 hr-1, and the maximum alcohol productivity was around 5.5 g/1·hr. In this case, the effective dilution rate was 0.25 hr-1 and the influent sugar concentration was distributed from 85 g/l to 135 g/1.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.3
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• pp.301-308
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• 2001

Nowadays GPS play a important roles in the navigation system of vehicles, but, it doesn't determine the kinematic positions of vehicles accurately because of few satellites in the urban canyon covered with trees and high buildings. So GLONASS (GLObal Navigation Satellites System), the Russian satellites'system, operated in 1996, was introduced to overcome this drawbacks. Therefore, this study deals with the kinematic positioning of vehicles with Real-time code differential positioning methods. As a result, Real-time DGPS/GLONASS is better than Real-time DGPS in the differential corrected positions and HDOP (Horizontal Dilution of Precision). And it was shown that the combined GPS/GLONASS contributes to the precise kinematic positioning of vehicles.

• Textile Coloration and Finishing
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• v.11 no.2
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• pp.19-26
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• 1999

Strains degrading and decolorizing acid dyes, Nylosan red E-BL 150%. were isolated from natural system, was named as ARK3. The optimal culture conditions of temperature and pH were $35^\circ{C}$, 7.0, respectively. Growth rate of cells in conditions of aerobic shaking more than standing culture conspicuously increased, and optical density of those to strain ARK3 were found as 1.38 and 0.25 after 42 hrs. Decolorization efficiency in batch culture which used as immobilization media to natural zeolite was 15% after 6 hrs, while suspension culture was 5%, also its of immobilization and suspension culture were 90% and 85% after 48 hrs, respectively. Decolorization efficiency of air-lift bioreactor was more than 90% to a dilution rate of $0.038hr^{-1}$, but that was decreased as 70%, when the dilution rate was $0.05hr^{-1}$. Even though at maximum dilution rate of this study, there was not appeared "wash out" phenomienon of biomass. Decolorization efficiency was 97.7% at a dilution rate of $0.025hr^{-1}$, when influent dye concentration was $100mg/\ell$. But if influent dye concentration increased as $150mg/\ell$, even though MLVSS increased, that of treatment water decreased as 93%. Also, when influent dye concentration increased as $200mg/\ell$ and $300mg/\ell$, decolorization efficiencies of treatment water abruptly decreased as 85% and 63%, respectively. Decolorization efficiency was more than 92% to the limit volumetric loading rate of $3.75mg/\ell\cdot{hr}$hr, without regard to variation of influent dye concentration or hydraulic retention time. if volumetric loading rate was more than $3.80mg/\ell\cdot{hr}$, at same condition, decolorization efficiency was lower decrease of retention time than increase of influent dye concentration.entration.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.417-422
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• 2023

In this study, normal saline was diluted with the contrast medium at a certain ratio for the purpose of reducing the image quality poor and side effects caused by the contrast medium during CT examination. At this time, by finding the energy level of DECT that can compensate for the decrease in contrast of the image according to the degree of dilution, the usefulness of applying DECT for compensating the difference in image contrast was investigated through comparative analysis by applying SNR, CNR, and SSIM. As a result, when a dilution ratio of 4 (contrast medium): 6 (normal saline) and the energy level of DECT of 65 keV were applied, the contrast difference was the most similar to that when using the undiluted contrast medium. At this time, SNR was 813.71 ± 37.6, CNR was the highest at 921.87 ± 17.1, and SSIM index was measured at 0.851, which is the most similar to 1. The results of this study are meaningful in providing basic information for finding the appropriate dilution rate and energy level for each examination site through future clinical studies. It is believed that it can be reduced.

• Culinary science and hospitality research
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• v.8 no.2
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• pp.197-206
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• 2002

The present study attempted to obtain a basic data concerning the effect of $\pi$-water, a sort of physiological water, on the maintenance of chicken freshness. The meats were divided into three groups: the control, 20% - dilution, and 5% - dilution groups. In the experiment, the changes of the TBA-values of the meats started to appear on the 3rd day in the control group, and from the 4th day in the 20% - and 5% - dilution groups. The changes of pH didn't appear in the meats as the storage time passed. The number of general bacteria increased rapidly on the 3th day in the control, and on the 5th day in the 20% -, and 5% - dilution groups. As for the color, the meats turned greenish on the 5th day in the control, 7th, in 20% - dilution, and, l0th in the 5%-dilution groups. As for the order, the meats emitted the unpleasant order, such as that of ammonia, on the 3rd day in the control, 5th, in the 20% - dilution, and, 7th, in the 5ft-dilution group.