• The Journal of Korean Academy of Prosthodontics
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• v.42 no.1
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• pp.21-29
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• 2004

Statement of problem : Because dental impression can be a cross-infection source, disinfection, such as immersion disinfection is nessecary. However, the disinfection process may change the volume of the impression cast. Purpose : The purpose of this study is to find out the effects on dimensional change of different storage times and methods, of agar-alginate impression when immersed in a 5% idophor disinfectant. Material and Methods : An agar-alginate impression was made from a mandible model and then was disinfected and stored according the experimental conditions and a stone model was produced. Measurements were taken between reference points on the original mandible model and they were compared to measurements taken between reference points on the stone model. The study was divided into 4 groups. In group 1, the impression was stored in a 100% humidor for 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours, 12 hours and 24 hours and stone models were made at each time. In group 2, the impression was immersed in 5% idophor disinfectant and then stored in a 100% humidor for the same length of times as group 1, and stone models were made at each time. In group 3, the impression was stored in extend-A-pourR, a special storage solution for 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours, 12 hours, 24 hours 3 days, and 7 days and stone models were made at each time. In group 4, the impression was immersed in 5% idophor disinfectant and then stored in stored in extend-A-pourR, a special storage solution for the same length of times as group 3, and stone models were made at each time. 5 impressions and stone models were made at each time to make a total of 180. The Student-t test (P < .05) was used to do a statistical analysis of the measurements of the mandible model and stone models. The repeated-measure 2-way analysis of variance (P < .05) was used to do a statistical analysis of the difference in the 4 groups. Results : The percent liner dimensional change was from $0.25{\pm}0.03%$ (group 1, 30 minutes) to $0.34{\pm}0.06%$ (group 4, 7 days). No significant change was noticed between the 4 groups. Conclusion : According to the above study, in both methods, least dimensional change was recorded when the storage times were short and in both methods, immersion in 5% idophor disinfectant did not effect dimensional change in the agar-alginate impression.

• Applied Biological Chemistry
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• v.34 no.3
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• pp.225-230
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• 1991

In this study, several combined effect of KCl addition into bring solution, microwave heating of Chinese radish for 3 minutes and addition of two salt mixtures into half fermented Kakdugi were investigated to compare their improving effects of storage stability of Kakdugi, Kakdugi was prepared by salting in 15% NaCl solution for 2 hours and fermented at $25^{\circ}C$ and determined for the changed in pH, total acidity and reducing sugars. It was found from the result that the combined method of salts addition and heating treatment improved the storage stability by 6.4 folds based on pH change where salts mixture of phosphated, Ca EDTA, and Sod. citrate contributed the most effect. Changed in reducing sugar were greatly reduced by salt mixture addition while microwave heating and KCl addition affected little. Storage of Kakdugi at $4^{\circ}C$ after preparation with combined method could extend the storage life more than 8 folds of those Kakdugi stored at $25^{\circ}C$. However total acidity showed higher values for those prepared by combined method and stored at $4^{\circ}C\;or\;25^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.2
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• pp.260-267
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• 2015

We investigated the applicability of polyethylene glycol (PEG) as a plasticizer in enteric-coated soft capsules based on determination of quality characteristics according to molecular weight and concentration of enteric-coating PEG solution. There was no difference according to molecular weight of PEG, whereas a low PEG concentration in the enteric-coating solution was associated with higher whiteness index and slower disintegration time in pH 6.8 media. Brittleness was observed in the coating film at seam areas in 5% PEG enteric-coating solution after 2 weeks of storage at room temperature. The enteric-coating properties of PEG were compared with those of acetylated monoglyceride (AMG) and triacetin, which are enteric-coating plasticizers. Enteric-coated soft capsule containing PEG as a plasticizer showed a lower whiteness index and faster dissolution profile than AMG and triacetin. Moreover, enteric-coated soft capsule containing AMG and triacetin as plasticizers showed coating film brittleness at seam areas after 2 months of accelerated storage [$40^{\circ}C$, relative humidity (RH) 75%] but no difference at room temperature storage ($25^{\circ}C$, RH 60%). The present study suggests that concentration of PEG is important to determine enteric-coating quality, regardless of the molecular weight of PEG. In conclusion, PEG has potential as a plasticizer due to its transparency and storage stability in enteric-coated soft capsules.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.7
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• pp.46-52
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• 2006

The effects of surface treatment on the hydrogen storage properties of a $Mg_2Ni$ alloy particle were investigated by the microvoltammetric technique, in which a carbon-filament microelectrode was manipulated to make electrical contact with the particle in a KOH aqueous solution. It was found that the hydrogen storage properties of $Mg_2Ni$ at room temperature were improved by the surface treatment with a nickel plating solution. The sodium salts(sodium phosphate and sodium dihydrogen citrate) contained in the nickel plating solution made the alloy form an amorphous-like state, resulting in an improved hydrogen charge/discharge capacity at room temperature as high as about 150[mAh/g] from the original value of 17[mAh/g]. Potential-step experiment was carried out to determine the apparent chemical diffusion coefficient of hydrogen atom($D_{app}$) in the alloy. Since the alloy particle we used here was a dense, conductive sphere, the spherical diffusion model was employed for data analysis. $D_{app}$ was found to vary the order between $10^{-8}{\sim}10^{-9}[cm^2/s]$ over the course of hydrogenation and dehydrogenation process.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.2
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• pp.68-75
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• 2018

In this study, to solve the problems of the conventional crack repair and injection method, high elasticity latex was used as the material of the storage tube to withstand the high pressure in the center part differently from the general port. When the repair solution was injected into the crack part, The TPS method was developed so that the air existing in the TPS can be discharged. In addition, a new infusion port in which a valve blocking the backflow of the remediation solution was installed at the injection port was developed and the physical characteristics of the port were analyzed. As a result of the evaluation, it was found that the filling rate of the remedial solution was improved compared to the existing ordinary injector method, and the cracks were completely filled in the test conditions. Compressive strength and tensile strength after repair showed about 20% decrease after repair in case of using ordinary injector method, while TPS method showed about 2~7% increase after repair. The results of this study showed that the injection port method using the elastic storage tube increased the injection performance and the quality after repair compared to the conventional injector method. The result of this study is expected to be utilized as the basic data for application and commercialization of the result to the practical structure.

• The Journal of Engineering Geology
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• v.25 no.1
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• pp.1-8
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• 2015

Deep geological disposal is the preferred storage method for high-level radioactive waste, because it ensures stable long-term storage with minimal potential for human disruption. Because of the risk of groundwater contamination, a buffer of steel and bentonite layers has been proposed to prevent the leaching of radionuclides into groundwater. Quartz is one of the most common minerals in earth's crust. To understand how deformation and dissolution phenomena affect waste disposal, here we study quartz samples at pressure, temperature, and pH conditions typical of deep geological disposal sites. We perform a dissolution experiment for single quartz crystals under different pressure and temperature conditions. Solution samples are collected and the dissolution rate is calculated by analyzing Si concentrations in a solution excited by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). After completing the dissolution experiment, deformation of the quartz sample surfaces is investigated with a confocal laser scanning microscope (CLSM). An empirical formula is introduced that describes the relationship between dissolution rate, pressure, and temperature. These results suggest that bentonite layers in engineering barrier systems may be vulnerable to thermal deformation, even when exposed to higher temperatures on relatively short timescales.

• Journal of Hydrogen and New Energy
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• v.19 no.6
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• pp.482-489
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• 2008

Ti-Cr alloys consist of BCC solid solution, C36, C14 and C15 Laves phase at high temperature. Among others, the BCC solid solution phase was reported to have a high hydrogen storage capacity. However, activation, wide range of hysteresis at hydrogenation/dehydrogenation, and degradation of hydrogen capacity due to hydriding/dehydriding cycles must be improved for its application. In this study, to improve such problems, we added a Nb. For attaining target materials, Ti-10Cr-xNb(x=1, 3, 5wt.%) specimens were prepared by arc melting. The arc melting process was carried out under argon atmosphere. As-received specimens were characterized using XRD(X-ray diffraction), SEM(Scanning Electron Microscopy) with EDX(Energy Dispersive X-ray) and TG/DSC(Thermo Gravimetric Analysis/Differential Scanning Calorimetry). In order to examine hydrogenation behavior, the PCI(pressure-Composition-Isotherm) was performed at 293, 323, 373 and 423K.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.2 no.2
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• pp.29-38
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• 1982

Nonlinear hydrological model containing the nonlinearity of effective rainfall, lag time and runoff is presented. In the evaluation of rainfall excess, the polynomial fitting method for total rainfall, 5 day antecedant rainfall and direct runoff is developed. In the application to actual watershed, the estimated model parameters of nonlinear lag model reflecting the nonlinearity of lag time are compared with the parameters, by both the fitting method and the correlation, model which are the modified version of the storage function model. The Successive Approximation Method in mathematical solution and Newton-Rhapson method in numerical solution are found to be superior to the conventional numerical graphic method in the analysis of nonlinear processes.

• The Korean Journal of Community Living Science
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• v.21 no.1
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• pp.71-79
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• 2010

This study was conducted to develop fresh-cut and processed pears. After treatment of citric acid (1%) or N-acetylcysteine (0.2 M), and co-treatment of citric acid (1%) and N-acetylcysteine (0.2 M) into the pears c.v. 'Wonhwang', the quality changes of pears during cold storage ($1^{\circ}C$) for 10 days were investigated respectively. Pear quality and the taste of pears increased much more in those treated with anti-browning agents than those in the control group at 10 days after anti-browning treatment and cold storage. Changes in Hunter b values of pears treated with 0.2 M N-acetylcysteine were insignificant. Those with Polyphenol oxidase (PPO) activity and ethylene production were had the most decreased effects and those with the phenolics compound contents were the most lowered. Firmness of fruits increased in treatment of 0.2 M N-acetylcysteine + 1% citric acid solution. The amount of respiration decreased in the application of 1% citric acid solution. Consequently, fruit freshness can be maintained more effectively by the treatment of the anti-browning agent compared to non-treatment, even if the effectiveness were different among different kinds of anti-browning agents.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.2
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• pp.33-43
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• 2012

Digital signage is referred to as a smart electronic display system that delivers multimedia-based information and advertisements to customers. Typically, the digital signage starts its playback after downloading a list of multimedia contents from network storage to its local disk. However, a way of downloading the entire contents before its playback entails a long initial delay time. In this paper, we formulate a problem of the initial delay time and provide a solution to compute a minimally demanded initial delay time according to a given network bandwidth and qualities/sizes of the multimedia contents. In addition, we analyze the performance of the proposed solution with various multimedia contents on digital signage.