• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.1
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• pp.21-26
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• 2012

Microstructural and mechanical property were evaluated at the medium-sized HT9 (12Cr-1MoWV) forged steel which was considered as primary candidate for the fuel cladding in sodium-cooled fast reactor (SFR). Material was forged at $1170^{\circ}C$ after the induction melting to make round bar as 160mm diameter, 7000mm length then the radial distribution of microstructure as well as microhardness was evaluated. The results showed that overall microstructure exhibited as ferrite-martensite structure, where small amount (2~3%) of delta ferrite was formed throughout the specimen and maximum 15% of transformed ferrite was formed at the center, where it gradually decreased toward the radial direction. Sensitivity analysis of the cooling curve and Time-Temperature-Transformation (TTT) diagram revealed that formation of transformed ferrite could be avoided when the diameter was decreased down to 120mm.

• Korean Journal of Human Ecology
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• v.19 no.4
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• pp.699-707
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• 2010

Catechu is widely used as in natural dyeing as well as in various medicines and tannage. This study investigated the dyeing properties and functionality of Catechu through a series of dyeing experiments using cotton fabric. It was shown that the absorbance of Catechu solution has two peaks at 220nm and 280nm. Thus, it can be concluded that the color constituent of Catechu is a catechol tannin and color tone is YR. The dyeability of Catechu increases as the concentration of the dye is increased. Its variation was shown to be similar to the isothermal absorption curve of the Freundlich. As dyeing time was increases, the dyeability did not change significantly after the 30 minute mark was passed. At high temperatures the dyeability was shown to increase. As the dyeing temperature was increased the color of dyeing fabrics changes from Y and YR to R. Experiments with pre-mordanting method showed that various colors can be obtained using Catechu. Cotton is effective in using K, Cu, Fe mordants, and the dyeability was shown to be improved with low pH. Both washing fastness and light fastness were shown to be low. However, the fabric color gradually changed to red was due to mailard reaction of catechol tannin causing by repeated washing and sunlight. The ultraviolet-cut ability was improved for cotton fabric dyed with Catechu. Also, dyed fabric with Catechu showed very good antimicrobial abilities at 99.9%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.1
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• pp.11-15
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• 1988

Square slices of sea tangle was dried in constant condition of thickness (1.54mm), air temperature $(50^{\circ}C)$, relative humidity $(30\%)$ and air velocity (0.4m/s). The shrunk surface area and the shrinking rate were investigated. The results obtained are summarized as follows : 1) Comparing the shrinking of transverse section with that of vertical section, the transverse section was proceeded more double shrinkage than vertical section. 2) The shrunk surface area curve showed nearly a linear shrinkage up to 90min of drying time. 3) The shrinking rate was rapidly increased in first falling rate period, and was largest in the early period of second falling rate period.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.9
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• pp.740-753
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• 2008

The conventional Split Hopkinson Pressure Bar (C-SHPB) technique with aluminum pressure bars to achieve a closer impedance match between the pressure bars and the specimen materials such as hot temperature degraded POM (Poly Oxy Methylene) and PP (Poly Propylene) to obtain more distinguishable experimental signals is used to obtain a dynamic behavior of material deformation under a high strain rate loading condition. An experimental modification with Pulse shaper is introduced to reduce the nonequilibrium on the dynamic material response during a short test period to increase the rise time of the incident pulse for two polymeric materials. For the dynamic stress strain curve obtained from SHPB experiment under high strain rate, the Johnson-Cook model is applied as a constitutive equation, and we verify the applicability of this constitutive equation to the probabilistic reliability estimation method. The methodology to estimate the reliability using the probabilistic method such as the FORM and the SORM has been proposed, after compose the limit state function using Johnson-Cook model. It is found that the failure probability estimated by using the SORM is more reliable than those of the FORM, and the failure probability increases with the increase of applied stress. Moreover, it is noted that the parameters of Johnson-Cook model such as A and n, and applied stress affect the failure probability more than the other random variables according to the sensitivity analysis.

• Fashion & Textile Research Journal
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• v.16 no.3
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• pp.476-484
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• 2014

The purpose of this study was to investigate the dyeing properties and anti-microbial ability of silk and wool fabrics dyed with Terminalia chebula Retzius(TCR) extract using two extraction solvent, hot water and methanol. Dyeing properties of fabrics were studied by investigating the characteristics of colorant, changes in dye uptake under different dyeing conditions, and by investigating color change when mordants were applied. Also, color fastness, and antimicrobial activity of dyed fabrics were estimated. Regardless of extraction solvent type, colorant showed maximum absorption wavelength at 280 nm and 578 nm, which implied that tannin was the major pigment component of TCR. Also, through FT-IR spectrum result, it was confirmed that tannin of TCR methanol extract was hydrolysable tannin. But for the hot water extract, it was only assumed that its tannin was condenced tannin. Fabric dyed with hot water solvent extract showed higher dye uptake than fabric dyed with methanol solvent extract, dye uptake increasing by higher concentration of the dye, longer dyeing time and higher dyeing temperature. And the absorption curve between TCR extract and protein fiber was shaped in the form of Langmuir adsorption isotherm. Fabric dyed without mordant was yellow in color, and when dyed with mordant, fabric showed various colors depending on mordant types except Sn. Color fastness to washing was generally fine and color fastness to light was moderate. But color fastness to rubbing and dry cleaning was outstanding. Lastly, dyed fabrics showed very good antimicrobial activity of 99.9% against Staphylococcus aureus and Kiebsiella pneumoniae.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.6
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• pp.511-519
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• 1992

A microcomputer based control system was constructed to save energy consumption in the thermal sterilizing process. The functional accuracy of system was evaluated through the analysis of the thermal diffusivities of the model solid food, Alaska pollack surimi. The heat penetration curves obtained through the experiments were typical for solid foods. The practical thermal diffusivity calculated from heat penetration curve was a constant value at steady sterilizing temperature, and this was independent of the holding time. At different temperatures, the thermal diffusivity values did not show remarkable differences when compared with those predicted by some experimental equations cited from the literatures. The maximal difference was within the range of $\pm10.0\%$.

• Korean Chemical Engineering Research
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• v.46 no.6
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• pp.1087-1094
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• 2008

This article presents a multi-scale simulation approach starting from the molecular level for the adsorption process development, specifically, in n-hexane adsorption on activated carbon. A grand canonical Monte-Carlo(GCMC) method is used for the prediction of adsorption isotherms of n-hexane on activated carbon at the molecular level. Geometric effects and hydrodynamic properties of the adsorption column are examined by means of the two dimensional CFD(computational fluid dynamics) simulation. The adsorption isotherms from the molecular simulation and the axial diffusivity from the CFD simulation are exploited for the process simulation where the elution curve of n-hexane is obtained. For the first moment(mean residence time) of the pulse-response with respect to temperature and flowrate, the process simulation results obtained from this three-steps multiscale simulation approach show a good agreement with experimental data within 20% of maximum difference. The multi-scale simulation approach addressed in this study will be useful to accelerate the adsorption process development, while reducing the number of experiments required.

• Polymer(Korea)
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• v.37 no.5
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• pp.606-612
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• 2013

Glycidol-poly(lactide) (Gly-PLA) were synthesized via L-lactide ring opening polymerization with glycidol as an initiator and $Al(O-i-Pr)_3$ catalyst. The structure of Gly-PLA was analyzed and successfully confirmed by 1H NMR. The OH group of glycidol in Gly-PLA was absent according to the $^1H$ NMR analysis, indicating that the terminal OH group of glycidol successfully served as an initiator in the L-lactide polymerization. The solution and bulk polymerizations of L-lactide with glycidol were performed to examine the effect of L-lactide/glycidol molar ratio, polymerization temperature and time on the molecular characteristics of Gly-PLA. The conversion and molecular weight increased with an increase in L-lactide/glycidol molar ratio. Gly-PLA showed the bimodal type DSC curve. The low $T_m$ peak of low molecular weight reduced but the high $T_m$ peak of high molecular weight increased as L-lactide/glycidol molar ratio increased.

• Food Science and Preservation
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• v.16 no.5
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• pp.719-725
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• 2009

We investigated the absorption characteristics of protein-bound polysaccharide powders of various molecular weights isolated from the mushroom Agaricus blazei Murill. The monolayer moisture content calculated using the GAB equation showed a higher level of significance than did the BET equation. The higher the water activity, the lower the isosteric heat of sorption. The fitness of the isotherm curve was shown to be in the order of the Khun, Oswin, Caurie and Henderson models. The prediction model equations for moisture content were established by use of ln(time), water activity, and temperature.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2000.11a
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• pp.1-2
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• 2000

In chip plating, several parameters must be taken into consideration. Current density, solution concentration, pH, solution temperature, components volume, chip and media ratio, barrel geometrical shape were most likely found to have an effect to the process yields. The 3 types of barrels utilized in chip plating industry are the onventional rotating barrel, vibrational barrel(vibarrel), and the centrifugal type. Conventional rotating barrel is a close type and is commonly used. The components inside the barrel are circulated by the barrel's rotation at a horizontal axis. Process yield has known to have higher thickness deviation. The vibrational barrel is an open type which offers a wide exposure to electrolyte resulting to a stable thickness deviation. It rotates in a vertical axis coupled with multi-vibration action to facilitate mixed up and easy transportation of components. The centrifugal barrel has its plated work centrifugally compacted against the cathode ring for superior electrical contact with simultaneous rotary motion. This experiment has determined the effect of barrel vibration intensity to the plating thickness distribution. The procedures carried out in the experiment involved the overall plating process., cleaning, rinse, Nickel plating, Tin-Lead plating. Plating time was adjusted to meet the required specification. All other parameters were maintained constant. Two trials were performed to confirm the consistency of the result. The thickness data of the experiment conducted showed thatbthe average mean value obtained from higher vibrational intensity is nearer to the standard mean. The distribution curve shown has a narrower specification limits and it has a reduced variation around the target value. Generally, intensity control in vi-barrel facilitates mixed up and easy transportation of components. However, it is desirable to maintain an optimum vibration intensity to prevent solution intrusion into the chips' internal electrode. A cathodic reaction can occur in the interface of the external and internal electrode. 2H20 + e $\rightarrow$M/TEX> 20H + H2.. Hydrogen can penetrate into the body and create pressure which can cause cracks. At high intensity, the chip's motion becomes stronger, its contact between each other is delayed and so plating action is being controlled. However, the strong impact created by its collision can damage the external electrode's structure there by resulting to bad plating condition.