• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.2
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• pp.109-117
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• 2009

In this study, thermodynamic performance of R430A is examined both numerically and experimentally in an effort to replace HFC134a used in the refrigeration system of domestic water purifiers. Even though HFC134a is used predominantly in such a system these days, it needs to be phased out in the near future in Europe and most of the developed countries due to its high global warming potential. To solve this problem, cycle simulation and experimental measurements are carried out with a new refrigerant mixture of 76%R152a124% R600a using actual domestic water purifiers. This mixture is numbered and listed as R430A by ASHRAE recently. Test results show that the system performance with R430A is greatly influenced by the amount of charge due to the small internal volume of the refrigeration system of the domestic water purifiers. With the optimum amount of charge of 21 to 22 grams, about 50% of HFC134a, the energy consumption of R430A is 13.4% lower than that of HFC 134a. The compressor dome and discharge temperatures and condenser center temperature of R430A are very similar to those of HFC134a at the optimum charge. Overall, R430A, a new long term environmentally safe refrigerant, is a good alternative for HFC134a requiring little change in the refrigeration system of the domestic water purifiers.

• Journal of Plant Biotechnology
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• v.5 no.2
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• pp.83-86
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• 2003

A reverse transcription polymerase chain reaction (RT-PCR) protocol was developed using two specific 22-mer primers located in coat protein gene of SPFMV. A 411 bp PCR-product was detected in virus infected plants as well as tissue culture raised sweet potato but not in healthy plants. For optimization of RT-PCR protocol, the optimum crude nucleic acid concentration, annealing temperature, primer concentration and numbers of PCR-cycle for maximum sensitivity and specificity were determined. The optimum condition for RT-PCR was as follows: RT-PCR reaction mixture was one-step mixture, containing 50 pmol of primer, 30 units of reverse transcriptase, 5 units of RNasin, and the crude nucleic acid extracts (200 ng). In RT-PCR, cDNA was synthesized at $42^{\circ}C$ for 45 min before a quick incubation on ice after pre-denaturation at $95^{\circ}C$ for 5 min. The PCR reaction was carried out for 40 cycles at $96^{\circ}C$ for 30 see, $63^{\circ}C$ for 30 sec, $72^{\circ}C$ for 1 min, and finally at $72^{\circ}C$ for 10 min. The viral origin of the amplified product was confirmed by sequencing, with the sequence obtained having $95-98\%$ homology with published sequence data for SPFMV. The benefits of this RT-PCR based detection of SPFMV would be simple, rapid and specific.

• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.68-74
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• 2006

To utilize sea tangle single cell detritus (SCD) as food additive, SCD noodle was developed using mixture model. Flour improved, whereas water decreased texture of SCD noodles. Texture of SCD noodle decreased initially and then increased as SCD content increased. Flour and SCD increased, whereas water decreased $L^*$ and $b^*$ values of dried and cooked noodles. Flour decreased $a^*$ values of dried and cooked noodles, while SCD increased $a^*$ value of cooked noodle. Response constraint coefficient showed SCD influence on texture, and $L^*$ and $b^*$ values of dried and cooked noodles was higher than those of flour and water, whereas water influence on $a^*$ value was higher than those of flour and SCD. Texture and color values fitted nonlinear model with interaction terms for flour-water, flour-SCD, and water-SCD. Optimum mixing ratio value of flour : water : SCD was 63.3 : 31.0 : 3.7%. Sensory evaluation value of SCD noodles was lower than those of industrial and electrolyzed SCD noodles.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.3
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• pp.105-110
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• 2011

Recently, a deep mixture method as a soil improvement method of marine soft ground, which causes less noise and vibration than other methods, are widely used. In this study, for DCM(Deep Cement Mixing) method, one of the deep mixture method, optimum mixing ratio of clay-cement was suggested using uniaxial compression tests on specimens with various mixing ratio of claycement. In addition, the stability of a caisson on tangent circle-type and wall-type DCM treated ground was evaluated using centrifuge tests. As a result, optimum mixing ratio of clay-cement was 28.5% and the stability of the caisson on DCM treated ground was confirmed. However, the lateral displacement of the caisson on the wall-type DCM treated ground was 7% less and the settlement of that was 39% less than the case of the tangent-circle-type DCM method.

• Geomechanics and Engineering
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• v.28 no.3
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• pp.255-263
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• 2022

Lime stabilization has conventionally been listed amid the key techniques of chemical stabilization. Replacing lime with sustainable agro-based by-products have gained prominence in recent decades. Bagasse ash (BA) is one such potential alternatives, an industrial waste with abundance in production, and industries exploring sustainable solutions for its safe disposal. Supplementing BA with lime could be an ideal approach to reduce lime consumption. However, suitability of BA and lime for the stabilization of expansive clays, such as black cotton (BC) soil is yet to be explored. This paper therefore aims to investigate the suitability of BA-lime mixtures to stabilize BC soil with emphasis to compaction behaviors and unconfined compressive strength (UCS) using standard laboratory procedures. Suitability of BA-lime mixture is then assessed against addition of calcium sulphate which, from previous experience, is detrimental with lime stabilization. Experimental outcomes nominate 15% BA as the optimum value observed from both compaction and UCS data, while addition of 4% lime to 15% BA showed the best results. Mineralogical and microstructural analysis show the presence of cementitious compounds with addition of lime and calcium sulphate with curing periods. While, formation of Ettringite needles were noted with the addition of calcium sulphate in BA-lime mixtures (at optimum values) after 90-day curing, and UCS results showed a decrease at this point. To this end, addition of BA in lime stabilization showed encouraging results as assessed from the compaction and UCS results. Nonetheless usage of calcium salts, with utmost emphasis on calcium sulphate and equivalent should be avoided.

• Journal of the Korean Geotechnical Society
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• v.26 no.10
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• pp.5-14
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• 2010

The slope stability method using the soil stabilizer is a way to ensure that the slope stability from reinforcing method is environmentally friendly. However, the reinforcing method does not ensure slope stability for lack of research on the reinforcement effect of the mixture with soil. So the application of this method implies difficult technical issues. In this research, reinforcement effect is investigated according to the different ratio of mixture. And the optimum reinforcement depth is proposed according to the height of slope from numerical analysis. The results show that approximately the soil strength increases from two to three times. From numerical analysis, it is possible to estimate the optimum height according to the height of slope. It is anticipated that the use of soil stabilizer will increase the slope stability.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.585-595
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• 2023

This study was conducted to optimize the rice paper roll processing conditions with frozen rainbow trout Oncorhynchus mykiss meat (RPR-FRT) treated with polysaccharide and TGase using a response surface methodology and to examine their quality characteristics. The RSM results for the RPR-FRT showed that the optimum condition for the garlic-pepper mixture was 21.2 g and that for starch was 22.6 g based on 150 g of RPR-FRT. The RPR-FRT contained 58.47 g/100 g of moisture, 8.57 g/100 g of crude protein, 3.28 g/100 g of crude lipid, and 1.00 g/100 g of ash. The vitamin E content was 1,010.91 ㎍/100 g. Based on their contents, the samples could be considered good supplements for P, Cr, and Se. The RPR-FRT contained unsaturated fatty acids (75.84%), DHA (10.33%), and EPA (2.56%). Anserine, arginine, glycine, and taurine accounted for 41.93%, 11.27%, 7.13%, and 7.00% of free amino acids in the RPR-FRT, respectively. The sulfur compounds in the RPR-FRT constituted 73.16% of the total flavor compounds. The RPR-FRT prepared using the optimum conditions was superior in masking off-flavor and showed improved nutritional content.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.480-485
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• 2014

In satsuma mandarin (C. unshiu Marc. cv. Miyagawa), alternate bearing is frequently occurred. It is very difficult to control and maintain the optimum production because satsuma mandarin is a very sensitive citrus cultivar. We carried out the experiment to find out the effects of foliar application of gibberellic acid ($GA_3$) and machine oil emulsion mixture on flowering and fruit quality of satsuma mandarin grown on open field. The treatments were composed of control (no application), $GA_3$ (25, 50 and $100mg{\cdot}L^{-1}$), machine oil emulsion 100 times and mixture of $GA_3$ (25 and $50mg{\cdot}L^{-1}$) with machine oil emulsion 100 times on 16 year-old 'Miyagawa' satsuma mandarin on December 30, 2012. Foliar application of $GA_3$ during winter season led to a reduction of the flowering in the following year. $GA_3$ decreased flowering in dose dependant manner. However, application of $GA_3$ and machine oil emulsion (100 times-diluted mixture) inhibited effectively the flowering compared to $GA_3$ only. Also, flower-leaf ratio was significantly decreased by the application of $GA_3$ 25 (0.54) and $50(0.41)mg{\cdot}L^{-1}$ with machine oil emulsion mixture in comparison to $GA_3$ 25 (0.86) and $50(0.60)mg{\cdot}L^{-1}$ only. The number of leaves per fruit increased in application of $GA_3$ and machine oil emulsion mixture as concentration of $GA_3$ increased. Fruit weight and sugar-acid ratio also increased in comparison to the control whereas fruit size, soluble solid content and acidity remained unchanged. From the results, it was suggested that $GA_3$ application can reduce the number of flowers on the alternate bearing of satsuma mandarin. Moreover, application of $GA_3$ (25 and $50mg{\cdot}L^{-1}$) with machine oil emulsion 100 times mixture can reduce the flowering effectively without altering fruit maturity and soluble solid contents. Therefore, it can be concluded that the application of $GA_3$ 25 and $50mg{\cdot}L^{-1}$ with machine oil emulsion 100 times might be useful in controlling alternate bearing in satsuma mandarin.

• Asian Journal of Turfgrass Science
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• v.23 no.2
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• pp.271-278
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• 2009

This study was conducted to investigate the effect of the mixture ratio of the inorganic soil amendments on the soil physicochemical properties. In this experiment, three kinds of soil amendments which had similar pH, EC and particle size, the A, B and C, were tested. The mixture ratio of soil amendment were 0%, 3%, 5%, 7% and 10% (V/V) incorporated with sand which met to the USGA(United State of Golf Association) particle standard. To analyze the effects of amendment on chemical soil properties, pH, EC(electrical conductivity) and CEC(cation exchangeable capacity) were measured. The porosity, bulk density and hydraulic conductivity also measured to analyze the changes of physical properties. In the chemical properties, pH was significantly related to the mixture ratios of amendments, A and C(P<0.05), CEC and EC also related to the ratios of C(P<0.01). When the results were applied to the USGA standard of the soil physical properties, the optimum mixture ratios of each amendment were 3% in A and B, and 7~10% in C. To analyze the corelation of mixture ratio versus to physical character, volume of porosity was significantly related to the ratio of B (P<0.05), and showed similar corelation in porosity and hydraulic conductivity with ratio of C(P<0.05). These results indicate that types and mixture ratio of inorganic soil amendments should affect on soil physio-chemical properties of root zone on USGA sand green.

• Applied Chemistry for Engineering
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• v.9 no.3
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• pp.394-398
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• 1998

An optimum synthetic condition was studied for the MCS used as a silicone monomer. The contact mixture was made from the four component catalyst system($CuCl/ZnCl_2/Sn/Cd$) and silicon particles. The contact mass was used for a series of experiments with methyl chloride, which were designed and done to explore the optimum condition for MCS synthesis by an experimental design method. The optimum temperature and MeCl flow rate, which were obtained using 50g contact mass at 60rpm and 1 atm, were in the range of $300-305^{\circ}C$ and of 70-80ccm. Also a continuous run was performed to confirm the conditions. The results showed that the average reaction rate and selectivity were 170(g-MCS/hr.kg-Si) and 0.05 respectively at 67% conversion of MeCl and 92% silicon utilization rate. Also the parameters of overall reaction rate equation and a total pressure were estimated on the basis of the results of the continuous run.