• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.2
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• pp.104-110
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• 2001

Structural, optical and electrical properties of Cd$_{1-x}$ Zn$_{x}$S films deposited by chemical bath deposition(CBD), which is a very attractive method for low-cost and large-area solar cells, are presented. Especially, in order to control more effectively the zinc component of the films, zinc acetate, which was used as the zinc source, was added in the reaction solution after preheating the reaction solution and the pH of the reaction solution decreased with increasing the concentration of zinc acetate. The films prepared after preheating and pH control had larger zinc component and higher optical band gap. The crystal structures of Cd$_{1-x}$ Zn$_{x}$S films was a wurtzite type with a preferential orientation of the (002) plane and the lattice constants of the films changed from the value for CdS to those for ZnS with increasing the mole ratio of the zinc acetate. The minimum lattice mismatch between Cd$_{1-x}$ Zn$_{x}$S and CdTe were 2.7% at the mole ratio of (ZnAc$_2$)/(CdAc$_2$+ZnAc$_2$)=0.4. As the more zinc substituted for Cd in the films, the optical transmittance improved, while the absorption edge shifted toward a shorterwavelength. the photoconductivity of the films was higher than the dark conductivity, while the ratio of those increased with increasing the mole ratio of zinc acetate. acetate.

• Korean Journal of Organic Agriculture
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• v.17 no.2
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• pp.237-251
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• 2009

This study was carried out to evaluate the effect of replacing antibiotics by organic acid mixture on growth performances and blood metabolites in growing pigs. Twenty-five crossbred pigs (Large White${\times}$Landrace) at the age of 79 days were fed five different diets by supplementing organic acid mixture and chlortetracycline. The experimental diets were consisted of diets without antibiotics supplementation (control), diets added 100mg/kg of chlortetracycline to control diet (T1), diets added 100mg/kg of chlortetracycline and 0.1% of $Acidomix^{(R)}$ (comprising formic acid 25%, sorbic acid 10%, fumaric acid 10%) to control diet (T2), diets added 0.1% of $Acidomix^{(R)}$ to control diet (T3), and diets added 0.3% of $Acidomix^{(R)}$ to control diet (T4). The changes in feed conversion ratio, average daily gain and blood metabolites were investigated. Twenty-five pigs were allotted to five treatments with five replications of each and the experiment was conducted on the basis of complete randomized design for 6 weeks. Average daily gain was significantly (p<0.05) different between T4 and control diets. All treatments including diets added $Acidomix^{(R)}$ and chlortetracycline were slightly higher than control diets. The feed intakes did not show a significant difference between the control and other treatments, and did not give change in feed intake by the addition of $Acidomix^{(R)}$. No differences on feed conversion ratio among treatments were observed but T4 and T3 treatments showed lower value than other treatments. The concentrations of blood urea nitrogen, total cholesterol and triglyceride were significantly (p<0.05) different among treatments, but their values were within the normal range representing that effects on blood profile by organic acid or antibiotics supplementation were not found. The results from this study indicated that adding chlortetracycline or organic acid mixtures to diets showed tendency to improve average daily gain and feed conversion ratio in growing pigs. These results showed that antibiotics could be replaced by organic acid mixture in growing pig diets, leading to stimulated growth and improved feed conversion ratio.

• Journal of the Korean Society of Food Culture
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• v.25 no.6
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• pp.779-787
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• 2010

The principal objective of this study was to determine the optimal mixing conditions for three amounts of onion powder, sugar, and butter to prepare onion powder cookies. The experimental design was based on the central composite design methodology of response surface, which included 16 experimental points including two replicates for onion powder, sugar, and butter. The mechanical and sensory properties of the cookies were measured, and these values were applied to the mathematical models. A canonical form and perturbation plot showed the influence of each ingredient on the mixed final product. The results of the spread ratio did not show significant results, but hardness increased with increasing quantities of onion powder and sugar but decreased with butter (p<0.01). The color lightness "L" value increased with increasing quantities of sugar and butter but decreased with added onion powder. In contrast, the redness color "a" value increased with increasing quantities of onion powder and sugar. Sugar did not affect the yellowness color "b" value, but the color b value increased with increasing onion powder and sugar. The results of a sensory evaluation using the predicted model showed significant values for flavor (p<0.01), texture (p<0.05), taste (p<0.05), and overall quality (p<0.01). As a result, the optimum formulation by numerical and graphical methods was calculated as 12.58 g onion powder, 35 g sugar, and 52.38 g butter.

• Korean journal of food and cookery science
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• v.17 no.3
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• pp.255-268
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• 2001

This study aimed for exploring the best recipe of Seosokbyung with different ingredient ratios of glutinous millet flour, sugar, and water added to rice flour. The most desirable recipe was determined by sensory evaluation and mechanical test for measuring texture, moisture content and colorimetry. The best score for each sensory item was obtained in the following condition: Color-245g(70%) of glutinous millet flour, 50g of sugar with 10$m\ell$ of water in 105g of rice flour. Flavor-l75g(50%) of glutinous millet flour with a 80$m\ell$of honey in 175g of rice flour. Graininess and Moistness-245g(70%) of glutinous millet flour with 70$m\ell$ of honey in 105g of rice flour. Chewiness-2I0g(60%) of glutinous millet flour, 60g of sugar with 20$m\ell$ of water in 140g of rice flour. Sweetness-l75g (50%) of glutinous millet flour 7g of sugar with 25$m\ell$ of water in 175g of rice flour. As a result of mechanical examination, the best score for springiness, cohesiveness, chewiness, gumminess, adhesiveness was obtained in the recipe of 175g (50%) of glutinous millet flour with 80$m\ell$ of sugar in 175g of rice flour, and that for hardness in the one of 245g (70%) of glutinous millet flour with 70$m\ell$ of honey in rice flour As the less amount of glutinous millet flour was added, the scores for springiness, cohesiveness, chewiness, gumminess and adhesiveness were increased, and the addition of honey gave higher scores than sugar or oligosaccharide(P<0.05) The best recipe of Seosokbyung was 140g of rice flour, 2 l0g of glutinous millet flour, 60g of sugar, 20$m\ell$ of water and 3.5g of salt. The moisture contents of rice flour and glutinous millet flour were 31.6% and 13.3%, respectively. The content of moisture in the best recipe of the Seosokbyung is approximately 36.101%. The moisture content higher than 36% gave better sensory scores in chewiness and moistness. As a result of colorimetry, the most bright ‘L’value(Lightness) was obtained from 175g of rice flour mixed with 175g (50%) of glutinous millet flour, 70g of sugar and 25$m\ell$ of water. The highest ‘a’ value(Redness) was gained from 175g of rice flour mixed with 175g (50%) of glutinous millet flour and 80$m\ell$ of honey. The best ‘b’ value(Yellowness) was obtained from 140g of rice flour, 210g (60% of rice flour) of glutinous millet flour, 60g of sugar and 20$m\ell$ of water.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.1030-1035
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• 2002

Despite health benefits derived from fish oil, polyunsaturated fatty acids (PUFAs) contained in fish oil are susceptible to lipid oxidation. To determine the optimum condition for maintaining good quality cooked fish during storage, mackerels were broiled with salt or soysauce condiments, and the lipid oxidation during 12 days of storage at refrigerated condition was measured. Peroxide value of broiled mackerel group with salt significantly increased after immediate cooking and maintained higher value throughout the storage period compare to the soysauce-added group, but showed similar value to the control group. Conjugated diene content in the soysauce-group was lower than the control and salt-added groups. Malondialdehyde content of broiled mackerel increased twofold and showed similar values in soysauce-added and the control groups during storage, whereas increased in the salt-added group significantly. Fatty acid compositions of the three mackerel groups changed after cooking, whereas that of the control group was almost stable during storage. In comparison with raw mackerel, the ratio of PUFA and saturated fatty acids decreased significantly, and the content of n-3 family fatty acid decreased from 25.53 to 20.63% in salted broiled mackerel. Soysauce group showed no reduction of PUFA with increasing storage time and showed the highest ratio of n-3/n-6 among the three groups at 10 days storage. Results reveal soysauce condiment protects against lipid peroxidation of broiled mackerel. Maillard reaction products (MRPs) found in soysauce might be responsible for the inhibitory effect and is a good condiment for extending storage life of cooked fish containing high amount of PUFA.

• Composites Research
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• v.35 no.3
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• pp.134-138
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• 2022

In this study, Ti powder/Polymer concrete composites were processed by adding the PZT powder, one of the piezoelectric materials, to improve the vibration damping effect of Polymer concrete. Ti powder was added at a constant ratio in order to maximize the vibration damping effect using the piezoelectric effect. Three types of composite material specimens were prepared: a specimen without PZT powder, specimens with 2.5 wt% and 5 wt% of PZT powder. The vibration characteristics and compression properties were analyzed for all specimens. As a result, it was confirmed that as the addition ratio of PZT powder increased, the Inertance value at the resonant frequency decreased due to the piezoelectric effect when the vibration generated from Ti powder/polymer concrete was transmitted. Especially, the Inertance value was decreased by about 19.3% compared to the specimen without PZT at the resonant frequency. The change in acceleration with time also significantly decreased as PZT powder was added, confirming the effect of PZT addition. In addition, through the compression strength test, it was found that the degree of deterioration in compression properties due to the addition of PZT up to 5 wt% was insignificant, and it was confirmed that the powder was evenly dispersed in the composites through the cross-sectional analysis of the specimen.

• Korean Journal of Veterinary Research
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• v.31 no.4
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• pp.491-500
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• 1991

This study was conducted to detect the serum antibodies in the experimentally toxoplasma infected dogs and street dogs by use the of an enzyme-linked immunosorbent assay (ELISA). And this test was performed on the polystylene microplate by coating with the tachyzoites soluble antigen of T gondii (RH strain), incubated with sera diluted then, added with HPO-conjugated rabbit anti-dog IgG and o-phenylenediamine used as a substrate. Tachyzoites of T gondii harvested from mouse peritoneal cavity were purified by 30, 40 and 50% Percoll density gradient centrifugation and used as the source of antigen. The results obtained were summarized as follows; 1. The highest ratio of positive to negative (P/N ratio) was obtained at the level of $l{\mu}g/ml$ protein concentration of antigen with the 1/4000 dilution of the conjugate measured by checker-board titration. It was regarded as the optimum concentration of the antigen and conjugate. 2. Cut-off value in this IgG ELISA was 0.375 that was determined by mean absorbance (at 492nm) of IFA negative serum added with the dauble value of the standard deviation $(mean{\pm}2S.D.)$. 3. Serum ELISA IgG antibodies to T gondii in the exyerimentally infected dogs were detected firstly at the Week 3 after inoculation and the highest titer was recognized at the Week 4, 5 and 6 after inoculation. 4. Stability of the antigen absorbed in the microplates that were preserved at $4^{\circ}C$ and $-25^{\circ}C$ separately were prolonged up to 3 weeks and 10 weeks at $4^{\circ}C$ and $-25^{\circ}C$, respectively. However the reproducibility was not reliable after the preservation of 4 weeks and longer. 5. Positive rate of the specific antibodies in 312 test sera was 28.5% and there was no significant differences between the male (27.8%) and female (29.5%), respectively. 6. The IgG ELISA was proved to be a specific procedure for the detection of antibodies to canine toxoplasma infection and also evaluated as a screening test for the large scale of test samples in laboratory.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.8
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• pp.1181-1188
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• 2014

This study investigated the quality characteristics and antioxidant activities of Yukwa added with 'Donganme' sorghum bran powder and its extracts. 'Donganme' variety has the highest antioxidant activity among sorghum varieties in Korea. The added contents of sorghum bran to Yukwa were 1% and 5% bran powder of 'Donganme' (BPD 1% and 5%) as well as 0.1%, 0.5%, and 1% bran powder extracts of 'Donganme' (BED 0.1%, 0.5%, and 1%). The contents of protein, ash, and minerals of BPD 1% and 5% added Yukwa were higher compared to non-added and BED 0.1%, 0.5%, and 1% added Yukwa. The contents of flavonoids of BPD 1% and 5% as well as BED 0.1%, 0.5%, and 1% added Yukwa increased by 1.6~17.1 fold, and DPPH and ABTS radical scavenging activities increased by 1.8~7.4 fold and 2.3~13.6 fold, respectively, compared to non-added Yukwa. Yukwa added with BED 1% showed the highest antioxidant activity among the treatments, followed by BPD 5%, BED 0.5%, BPD 1%, and BED 0.1% added Yukwa. The expansion ratios of BPD 5% and BED 1% added Yukwa remarkably decreased compared to those of non-added and other treatments. The sensory evaluation values corroborated the results of the Yukwa expansion ratio. The acid values of Yukwa under high temperature storage ($60{\pm}1^{\circ}C$) increased rapidly after 20 days in all treatments, and those of BPD 5% and 1% added Yukwa increased slowly compared to non-added Yukwa. ABTS radical scavenging activities of Yukwa showed little change during storage in all treatments. As a results, addition of sorghum bran below BPD 1% and BED 0.5% was suitable for antioxidant activity, quality characteristics and sensory evaluation.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.292-299
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• 2006

Batch experiments were performed to evaluate the effects of the electron donor dosage and the initial biomass on the reductive dechlorination of perchloroethene(PCE) with benzoate as an electron donor. When benzoate was added less than the theoretical requirement for dechlorination(electron donor/acceptor ratio=0.5 and 1), the dechlorination efficiency increased from 71% to 94.3% with the increase in benzoate dosage, but the fraction of electron equivalent utilized for dechlorination decreased from 92.7% to 79.6%. Methane production was observed when the hydrogen concentration was higher than the threshold value(10 nM) after PCE and trichloroethene (TCE) were reduced to cis-1,2-dichloroethene(cDCE). When benzoate was added more than the theoretical requirement, the residual hydrogen converted into methane after the completion of dechlorination. The increase in the seeding biomass shortened the lag time for dechlorination, but it did not affect the maximum dechlorination rate as it was mainly governed by the benzoate fermentation rate. When the seeding biomass concentration was high, active dechlorination during the early period increased dechlorination efficiency while decreasing methane production.

• Korean Journal of Labor Studies
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• v.19 no.1
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• pp.1-34
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• 2013

Labor share of income in Korea has fallen from 90% in 1996 to 79% in 2010. This paper explores the factors driving the movements in the labor share of income based on a panel dataset containing 19 years of data on 18 Korean manufacturing industries. The effects of technical progress, globalization and the bargaining power of labor and capital on the labor share of income are tested for the period of 1991-2009. The main empirical results are as follows. (1) Capital-aug menting technical prog ress measured by capital-labor ratio and R&D intensity has a negative effect on the labor share. (2) Market openness measured by the value of export and import as a ratio to value-added production is found to have a positive impact. (3) Globalization of production measured by inward-FDI and outward-FDI as a ratio to total domestic fixed capital is found to have a negative impact on the labor share. (4) Union density is found to have had a statistically significant effect in 1991-1998. This finding is consistent with the efficient bargain model in which firms and workers bargain over both wages and employment. But union density is insignificant in 2000-2009. This implies that since the financial crisis in 1997, the bargaining institution in Korea has been approaching the right-to-manage model in which firms and unions bargain over wages and then firms set employment unilaterally. (5) Variables for domestic financialization measured by dividend-income ratio and financial-fixed assets ratio have an insignificant effect on labor share.