• Korean Journal of Ecology and Environment
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• v.52 no.3
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• pp.210-220
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• 2019

Population growth and the increase of energy consumption due to civilization caused global warming. Temperature on the Earth rose about $0.7^{\circ}C$ for the last 100 years, the rate is accelerated since 2000. Temperature is a factor, which determines physiological action, growth and development, survival, etc. of the plant together with light intensity and precipitation. Therefore, it is expected that global warming would affect broadly geographic distribution of the plant as well as structure and function ecosystem. In order to understand the effect of global warming on the ecosystem, a study about the effect of temperature rise on germination and growth in the plant is required necessarily. This study was carried out to investigate the effects of experimental warming on the germination and growth of two oak species(Quercus mongolica and Q. serrata) in temperature gradient chamber(TGC). This study was conducted in control, medium warming treatment($+1.7^{\circ}C$; Tm), and high warming treatment ($+3.2^{\circ}C$; Th) conditions. The final germination percentage, mean germination time and germination rate of two oak species increased by the warming treatment, and the increase in Q. serrata was higher than that in Q. mongolica. Root collar diameter, seedling height, leaf dry weight, stem dry weight, root dry weight, and total biomass were the highest in Tm treatment. Butthey were not significantly different in the Th treatment. In the Th treatment, Q. serrata had significantly higher H/D ratio, S/R ratio, and low root mass ratio (RMR) compared with control plot. Q. mongolica had lower RMR and higher S/R ratio in the Tm and Th treatments compared with control plot. Therefore, growth of Q. mongolica are expected to be more vulnerable to warming than that of Q. serrata. The main findings of this study, species-specific responses to experimental warming, could be applied to predict ecosystem changes from global warming. From the result of this study, we could deduce that temperature rise would increase germination of Q. serrata and Q. mongolica and consequently contribute to increase establishment rate in the early growth stage of the plants. But we have to consider diverse variables to understand properly the effects that global warming influences germination in natural condition. Treatment of global warming in the medium level increased the growth and the biomass of both Q. serrata and Q. mongolica. But the result of treatment in the high level showed different aspects. In particular, Q. mongolica, which grows in cooler zones of higher elevation on mountains or northward in latitude, responded more sensitively. Synthesized the results mentioned above, continuous global warming would function in stable establishment of both plants unfavorably. Compared the responses of both sample plants on temperature rise, Q. serrata increased germination rate more than Q. mongolica and Q. mongolica responded more sensitively than Q. serrata in biomass allocation with the increase of temperature. It was estimated that these results would due to a difference of microclimate originated from the spatial distribution of both plants.

• Journal of Nutrition and Health
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• v.9 no.1
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• pp.92-98
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• 1976

The present studies were carried out to observe the nutritional effects of three kinds of locally produced dried infantile formula milk (DFM) and one fermented milk (FM). A feeding trial with 60 male growing albino rats weighing $60{\sim}70$ grams was conducted during 6 weeks to compare the nutritive values and protein qualities of three DFM and a FM. The diet treatments consisted of 100% control diet, 70% control diet plus 30% DFM-A, 70% control diet plus 30% DFM-B, 70% control diet plus 30% DFM-C, 100% control diet with FM and 70% control diet plus 30% DFM-B with FM. The items investigated were body weight gain, feed intake, feed efficiency ratio (FER), various organ weights, protein efficiency ratio (PER), digestibility of nutrients, biological value, utilizability of protein and intestinal microbial changes of albino rats. The results obtained are summarized as follows; 1. Although there was no statistical significance, rats fed diets containing DFMs and FM gained faster than the rats fed control diet. The best growth rate was obtained with the DFM-A and DFM-C groups. In spite of the lower protein contents of the three DFM diets than the control diet, the growth rate of albino rats fed the DFM diets was somewhat improved than rats fed control diet. 2. No statistical significance was found in feed consumption but the trend was that the feed intake of control group was higher than those of the DFM diet group. 3. Feed efficiency was inproved significantly (p<0.01) by feeding DFMs as compared with control diet. DFM-A group showed the best FER, although no statistical significance was found. 4. Rats fed the DFM diets showed significantly (p<0.01) higher PER as compared with those of the control group. But no difference was found anions DFM groups. The significant improvement (p<0.01) of PER due also to the feeding of FM was seemed to be brought about by the beneficial effect of FM. 5. The present data revealed that feeding DFM and FM didn't affect the weights of various organs of rats. 6. The protein digestibility of experimental diets was similar to each other. Although no statistical significance was found among treatments, the DFMs and FM surely tended to improve the biological value and utilizability of protein. 7. Microbial study indicated that among intestinal flora FM fed group, there were more Lactic acid bacteria than E. coli. From the experimental results described above, it may be concluded that the nutritive effects of three kinds of locally produced DFMs are much alike and the growth rate of growing albino rats can be improved by feeding either DFM or FM due to their beneficial effects on the feed efficiency and protein utilization.

• Korean Journal of Agricultural Science
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• v.16 no.2
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• pp.212-224
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• 1989

This paper reports results of an investigation to determine properties of superplasticizered fly ash concrete. The mixture proportions of fly ash were 0, 10, 20 and 30%, by weight of cement, and superplasticizer was added as a percentage of fly ash, 0, 0.6, 12 and 1.8%. To investigate the effective use of the superplasticized fly ash concrete, the basic data were analyzed. The results obtained were summarized as follows : 1. The unit water content was decreased by 1%, 6% and increased by 2% to the ratio of addition of fly ash 10%, 20%, 30%, respectively, but in case of the superplasticized fly ash concrete, it was decreased by 3~16%, 4~14% and 10~17%, at 0.6, 12, and 1.8% dosage of superplasticizer, respectively. 2. In the properties of the fresh fly ash concrete, the slump loss was reduced with the ratio of replacement of fly ash increased, and with times went by. When using superplasticizer in fly ash substituting concrete, the fludity in the concrete was not decreased. 3. The compressive strength of fly ash concrete at early ages was lower than that of ordinary concrete. At the later age of 28 days, the compressive strength with 20% addition of fly ash was increased than that of ordinary concrete. In cased of 10%, 30% addition of fly ash, the compressive strength were reduced. From this, it was proved that the optimum amount of fly ash appears to be about 20%. The compressive strength at all ages of superplasticized fly ash concrete was significantly higher than that of fly ash concrete, with increasing fly ash content. 4. In case of the tensile strength, the effects of the increasing strength with the ages were similar to those of the compressive strtength, and at the later ages was seen a decreasing tendency of strengths. 5. The correlation between compressive and tensile strength of superplasticized fly ash concrete was highly significant. The multiple regression equations of compressive and tensile strength were obtained on a function of the mixture proportion of fly ash and the addition of superplasticizer. The relation between compressive and tensile strength is higher than for ordinary concrete. The strength ratio is 7~11, and it is higher than that of ordinary concrete, 8~10. 6. Bulk density was decreased by 1~3% compared with ordinary concrete with the mixture proportion of fly ash increased, 10~30%, and decreased by 1~2% with the superplasticizer added 0.6~1.8%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.619-624
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• 2016

Chlorine dioxide ($ClO_2$) gas treatment (75 ppmv, 30 min) has been suggested to improve the microbial safety of postharvest paprika in a previous study. Based on these results, in this study, an additional combined treatment using low-concentration $ClO_2$ gas-generating sticks (3 ppmv) in paprika samples during storage was carried out at $8^{\circ}C$ and 90% relative humidity to further enhance the quality and reduce the decay rate of paprika for the purpose of lengthy storage. After the combined treatment, the initial populations of total aerobic bacteria as well as yeast and molds in the paprika samples decreased by 3.04 and 2.70 log CFU/g, respectively, compared with those of the control samples, and this microbial inactivation was maintained by the low-concentration $ClO_2$ gas-generating sticks during storage. In particular, the decay rate of samples with combined treatment was significantly lower than that of the control. Vitamin C content, hardness, and color quality parameters of paprika samples were not altered by treatment, while weight loss of the samples treated with the combined $ClO_2$ gas was lower than that of the control during storage. These results indicate that the combination of two different $ClO_2$ gas treatments is effective for retaining the quality of paprika during prolonged storage.

• The Korean Journal of Food And Nutrition
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• v.27 no.6
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• pp.999-1005
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• 2014

This study was performed in order to compare the changes in Korean apples' qualities and antioxidant activity when stored at room temperature, $20^{\circ}C$, for fifteen days. The results showed that the weight, moisture content, soluble solid content, acidity, and hardness levels decreased as the storage period increased. However, pH and color value L increased as the storage period increased. Total phenol contents, total flavonoids contents, DPPH free radical scavenging activity, and vit. C contents of apples significantly decreased with increased storage period. Sensory parameters, such as appearance, sweetness, sourness, crunchiness, and overall acceptability of apples, also decreased as the storage period increased. Based on these results, if, the apple are being stored around $20^{\circ}C$, then, to have the highest quality, the apples should be sold within three days, We also suggested that it is desirable not to store the apples fore more than eight days.

• Korean Journal of Poultry Science
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• v.28 no.3
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• pp.207-213
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• 2001

The objectives or this study were to examine reed value or waste onion in duck. Experimental chicks (Cherry Valley F$_1$, 1day old, 350 chicks) were randomly assigned in 8 treatment groups, each 45 chicks, and man-aged for 7 weeks (3 kg BW, 49 days old). Treatments were control, 3%, 6% of chopped onion-fed, 5%, 10% of onion extract fed, 6% of onion meal, 3%, 6% of fermented onion-fed. Feed intake was significantly (P<0.05) high in control group, but ADG was high in 3% chopped onion-fed group. Feed requirement was very efficient in all treatment groups except 6% fermented onion-fed group. Dressing rate was high in 5% onion extract-fed group, but it was not significant. Abdominal fat was the highest in control and 6% fermented onion-fed group and lowest in 6% chopped onion-fed group. Cholesterol content was lower in all treatment groups than in control group, but it was not significantly different. Stearic acid ($C_{18:0}$) content was significantly low in all treatment group (P<0.05). However, arachidonic acid ($C_{20:4}$) content was higher in treatment group than in control group. In result, onion diet was not significantly effect on palatability, feed intake, ADG in ducks. Duck meat of onion-fed contained low cho-lesterol and high unsaturated fat content.

• Magazine of the Korean Society of Agricultural Engineers
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• v.11 no.4
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• pp.1798-1802
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• 1969

The experiment was carried out as one of the basic studies to improve the alkali-resistance of cement mortars and it was conducted to investigate some propetties of mortars relating to weight losses when exposed to 0.1 N salution of sodium hydroxide. The experiment and the results obtained are summarized as follow; 1. The specimens used in this experiment were made of 5 centi-meter cubes of mortar having such various ratios of mix by weight as 1 : 1, 1 : 3, 1 : 5, 1 : 7 and 1 : 10. 2. Physical tests included compressive strengths at 7 days, 28 days, 3 months, and 6 month, and 5 hour boiling absorption test. 3. In alkali test, every specimen was immersed into 0.1 N solutions of sodium hydroxide. The specimens exposed to the alkali solution were weighed to determine the weight losses of the alkail-corroded at one week interval for 7 week's exposure and the old alkali solutions were also changed to fresh solutions when weighed the weight losses by alkali attack at one week interval. 4. According to the alkail test after 7 week's exposure, no weight losses were observed on ratios of mix 1:1 and 1:3 and slight weight losses occurred on ratios of mix 1:5 and 1:7, but relatively large amount of weight losses were showed by 36.6 per-cent on ratios of mix 1:10. It was also found that the weight losses of the alkali-corroded were extremely lower than those of the acid-corroded at the some concentrations as 0.1 N of solutions. 5. In order to make better quality of alkali-resistant mortar it might recomend that a 1:7 mix or richemixes, use of small amount of mixing water for watertight, 20 per cent or less absorption by 5 hour boiling 1,600 kirogram per cubic meters or denser densities by absolute dry base are available for physical properties of mortar. It could conclude acid-resistant mortars were so high alkali-resistant, that it is expected to make and improve the acid-resistant mortars for getting rid of damages by alkali attack.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1716-1726
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• 2012

This study was undertaken to evaluate the antihyperglycemic, antilipid peroxidative, and antioxidant effects of the ethanol extracts of Artemisia iwayomogi (Ai) in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced in Sprague-Dawley rats with a single intravenous injection (45 mg/kg b.w.) of STZ. The diabetic rats were then randomized to the diabetic and Ai extract therapy groups which were treated with Ai extract at doses of 1, 2, and 3 g/kg b.w./day, respectively, for 14 days. Oral administration of Ai (2 g/kg b.w.) significantly decreased their intake of food. Dosage of 2 g/kg of the extract significantly decreased blood glucose levels in the glucose level in diabetic rats after 4 day, there was no significant difference observed at 1 and 3 g/kg. A dose of 2 or 3 g/kg of the Ai extract significantly reduced plasma glucose levels in STZ-induced hyperglycemic rats at 7 days. The hypoglycemic effect of Ai at a dose of 2 g/kg was significantly more effective than that of STZ-control. The effect was more pronounced in 2 g/kg than 1 g and 3 g/kg. A significant reduction in triglycerides (TG) and free fatty acids (FFA), and a significant increase in liver glycogen were observed in treated diabetic rats at doses of 2 g/kg after 14 days of treatment. Administration of Ai extracts to diabetic rats showed a significant decrease in liver malondialdehyde (MDA) levels. The activity of superoxide dismutase (SOD) was significantly increased in the 3 g extract-supplemented groups. The activities of glutathione peroxidase (GSH-px) and catalase (CAT) were significantly increased in the 1 g and 3 g extract-supplemented groups. Ai extract significantly increased glutathione-S transferase (GST) activity in a dose-dependent manner compared with treatment in STZ-control rats. Our result supports the fact that the administration of Ai extract is able to reduce hyperglycemia and hyperlipidemia risk, and also reduce the oxidative stress in diabetic rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.1
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• pp.70-77
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• 2011

This study was conducted to evaluate the efficacy of human milk fortifier (HMF) on growth and nutritional status in growing rats fed infant formula supplemented with HMF. Three week-old male Sprague-Dawley rats were divided into three groups and fed regular formula (RF), premature formula (PF) and regular formula fortified with HMF (RF+HMF) diets for 3 weeks. There was no significant difference in weight gain among groups. However, a significant increase of food intake was observed in PF and RF+HMF groups compared with RF group. With increasing food intake, the intakes of carbohydrate and protein were significantly increased in PF and RF+HMF groups. The weight of perirenal fat was significantly increased in rats fed RF+HMF; however, the weights of liver, kidney and spleen were not significantly different among groups. Although total lipids, total cholesterol, HDL-cholesterol concentrations of serum were not significantly different among groups, triglyceride was significantly increased in PF group. The triglyceride and total-cholesterol of liver were significantly increased in rats fed regular formula fortified with HMF and PF compared with RF group. Glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), creatinine (Cre) and blood urea nitrogen (BUN) in serum showed no significant difference among groups. The concentration of growth hormone was significantly increased in PF group compared with other groups. The concentration of hemoglobin was significantly increased in rats fed PF and RF+HMF. These results suggest that the supplementation of human milk fortifier in growing rats may promote growth as increasing food intake and lipid contents in tissues and prevent the anemia of infants.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.1
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• pp.115-123
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• 1990

The purpose of this study was to examine the uses of coal ash as a type of construction material. The methods of examination were chemical anlysis, soil laboratory test and the soil vibration test. Materials used were coal ash obtained as a by-product from 5 thermal power plants in Yongdong, Yongwol, Sochon(anthracite coal) and in Samchonpo and Honam (bituminous coal). Over 70% of the coal ash consisted of silica and alumina. The fly ash grain size showed a uniform distribution from fine-sand to silt, and that of the bottom ash showed from sand to gravel. The specific gravity and density of the coal ash were low. The long term strength increased gradually due to the self-setting property resulting from pozzolanic activity. The shear strength was higher than that of general soil. Cohesion and optimum moisture content of anthracite coal ash were higher than bituminous coal ash, whereas the maximum dry density was higher in bituminous coal ash. The coal ash dynamic Young's modulous curve range was similar to that of general soil. Of the results from the soil vibration test by car-running, the size relative acceleration level in the ash pond was higher than that of natural ground, but the damping ratio was lower than that of natural ground near the ash pond. The coal ash has more advantageous engineering properties than general soil with particles of the same size. For example, the California Bearing Ratio of the bottom ash at both Yongdong and Yongwol was 77~137%. Therefore we expect that if further study is done, coal ash can be used as a construction material when reclaiming seashore, construction embankments, road construction, making right-weight aggregate, or as a general construction material.