• Applied Chemistry for Engineering
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• v.30 no.6
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• pp.749-756
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• 2019

Na-X and Na-A zeolites that give high adsorption capacity for heavy metals in an aqueous system were synthesized from the coal fly ash obtained from a thermoelectric power plant using a fusion method. The characteristics and Cu(II) adsorption capacity of the synthetic zeolites were also compared to those of using a commercial zeolite. For the selection of optimum conditions of zeolite synthesis, the effects of major parameters in the fusion method such as a dosage ratio of NaOH, aging time, hydrothermal reaction time, and also the dosage ratio of NaAlO₂ (Na-A) on the characteristics and Cu(II) adsorption capacity of the synthetic zeolites were studied. For the analysis of characteristics of the synthetic zeolites, X-ray diffraction (XRD), cation exchange capacity (CEC), Brunaue-Emmett-Teller (BET) and scanning electron microscopy (SEM) were used. The optimum conditions for the synthesis of zeolites with a high adsorption capacity for cationic heavy metals including Cu(II) were the aging time of 6 h, hydrothermal reaction time of 6 h and NaOH and NaAlO₂ dosage ratio of 1.5 and 0.5 (Na-A), respectively. According to the Langmuir isotherm test, maximum Cu(II) adsorption capacities of the synthetic and commercial Na-X and Na-A zeolites were found to be 90.1, 105.26, 102.05, and 109.89 mg/g, respectively. This indicates that the adsorption capacity of synthetic zeolites was comparable to commercial ones. The results of this study also suggest that the coal fly ash can be potentially used as a raw material for the zeolite synthesis.

• Korean Journal of Environmental Biology
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• v.26 no.3
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• pp.252-263
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• 2008

The purpose of this study was to determine trophic state, based on nutrients (TN, TP), transparency (SD), and chlorophyll-${\alpha}$ (Chl) and identify their empirical relations of TN-Chl, TP-Chl and Chl-SD depending on the dataset used along with dynamics of conductivity and suspended solids. Analysis of trophic states showed that more than half of 36 reservoirs were judged as eutrophic-hypertrophic conditions depending on the trophic variables. Seasonal values of TP varied by nearly 500% and showed greater in August than any other months. In contrast, TN varied within less than 90% and all monthly mean values of TN were never fall less than 1.2 mg L$^{-1}$ indicating low seasonal variations and high ambient concentrations (eutrophic-hypertrophic state). Analysis of empirical relations in the trophic variables showed that transparency had greater functional relations with Chl (R$^2$=0.31, p<0.001) than TP (R$^2$=0.15, p<0.001) and TN (R$^2$=0.20, p<0.001). Ratios of TN : TP in the ambient water indicated that most reservoirs showed a potential phosphorous limitation on the algal growth. Thus, algal biomass, based on Chl values, was more regulated by phosphorous than nitrogen. Analysis of linear regression model, based on log-transformed annual mean values, showed that only 30% in the variation of Chl was explained by TP (R$^2$=0.295, p=0.001, n=36) and 15% by TN (R$^2$=0.151, p=0.019, n=36). However, linear regression model, based on individual system, showed that Chl-TP model had strong positive relations (R$^2$=0.62, p=0.002, n=12), whereas the model had no any relations (p=0.892, n=12). Overall, our data suggested that averaging effect in the empirical model developments may influence the significance in the statistical analysis.

• Childhood Kidney Diseases
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• v.1 no.1
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• pp.17-23
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• 1997

After the first description of IgA nephropathy by Berger in 1968, the prognosis of this disease was considered favourable. However recent studies have revealed that IgA nephropathy result in end stage renal desease in 25-30% by 20 years. Heavy proteinuria, hypertension, histological high class are regarded as poor prognostic factors. In 1996, Yagame et al reported the new histopathologic grading with a strong correlation between the grading, heavy proteinuria, high s-Cr level and renal survival. The aims of this study are to determine whether the pathological grading and other clinical parameters could contribute to predicting the outcome of this disease eventhough pediatric patients. Seventy nine patients (59 males, 20 females) with IgA nephropathy were examined. Patients were 2.08-15.17 years of age ($9.85{\pm}2.83$). The mean follow-up duration were $27{\pm}28$ months. Six of seventy nine patients progressed to chronic renal failure during the follow-up periods. High 24h urinary protein excretion at diagnosis were significantly higher in chronic renal failure patients (p<0.05). Hypertension at diagnosis were the significant associated factors in progression of chronic renal failure (p<0.05). Histological changes of IgA nephropathy in light microscopy were classified into five classes by WHO classification, four grades in Yagame's gradings. Among the seventy nine patients, 24 were as class 1, 30 as class 2, 23 as class 3; 4 as class 4, 0 as class 5 by WHO classification. 23 were classified grade 1, 31 as grade 2, 24 as grade 3, 1 as grade 4 by Yagame's grading. Among six patients who progressed to chronic renal failure, 1 clssified as class 1, 1 as class 2, 3 as class 3, 1 as class 4, 0 as class 5 by WHO Classification. 1 patients were classified as grade 1, 1 as grade 2, 3 as grade 3, 1 as grade 4 by Yagame's grading. (p>0.05) In conclusion, hypertension and heavy proteinuria at initial presentation were significantly associated with progression of chronic renal failure. The classification of WHO & Yagame's grading has no significant association with the progression of chronic renal failure in pediatric patients.

• Korean Journal of Poultry Science
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• v.18 no.1
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• pp.1-8
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• 1991

This study was conducted to estimate heritabilities and genetic correlations on body shape components in Korean Native Ogol fowl , The data analysis were record of 450 pullets producted from 150 dams and 20 sires of Korean Native Ogol fowl raised at Chungnam National University from June 18, 1987 to April 6, 1989. The results obtained are sammarized as follows ； 1. On the body components, shank length at 8, 24 weeks and 300 days of age were $8.717\pm$0.363, $9.576\pm$0.390 and $9.646\pm$0.389cm, the breast width were 3.469$\pm$0.234, $4.310\pm$0.345 and $4.752\pm$0.343cm； the breast girth at 8, 24weeks and 300 days of age were $22.819\pm$1.082, $36.719\pm$1.793 and $39.008\pm$1.709cm； the tibia length at 8, 24weeks and 300days of age were $9.941\pm$0.888, $13.183\pm$0.499 and $13.560\pm$0.552cm. 2. The heritability estimates of body shape components based on the variances of sires, dams and combined components from 8, 24 weeks and 300 days of age were 0.235-0.290, 0.589-0.890 and 0.437-0.565 for shank length ； 0.185-0.237, 0.444-0.536 and 0.314-0.392 for breast width ； 0.218-0.552, 0.499-0.746, 0.486-0.558 for breast girth ； 0.339-0.432, 0.281-0.543 and 0.340-0.446 for tibia length, respectively. 3. The genetic correlation coefficient of body shape components were as follows ； between shank length and breast width, breast girth, tibia length were 0.237-0.836, 0.277-0,729 and 0.378-0.915；between breast width and breast girth, tibia length were 0.637-0.889 and 0.384-0.903；between breast girth and tibia length was 0.905-0.995, respectively.

• Korean Journal of Poultry Science
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• v.42 no.2
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• pp.147-156
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• 2015

This study was conducted to investigate the effects of dietary resveratrol on growth performance, blood biochemical parameters, immunoglobulin, and blood antioxidant activity in broiler chicks. Three hundred twenty one-day old broiler chicks were divided 8 treatments (C(-), basal diet; C(+), basal diet with antibiotics; DL-${\alpha}$-tocopherol 20 IU; DL-${\alpha}$-tocopherol 200 IU; resveratrol 20 ppm; resveratrol 200 ppm; methylated resveratrol 20 ppm; methylated resveratrol 200 ppm) with 4 replicates and 10 birds per replicate. Birds were reared for 35 days, and, at the age of 35 days, eight birds of average weight from each replicate were selected for blood samples collection. There were no significant differences on feed intake and feed conversion ratio. But final body weight and weight gain in antibiotics, resveratrol and methylated resveratrol treatments were significantly higher than no-antibiotics and ${\alpha}$-tocopherol treatments (P<0.05). There were no significant differences on carcass rate and relative organ weights among treatments, however, weights of liver and bursa of februcius in antibiotics, resveratrol and methylated resveratrol treatment were lower than other treatments. Weight of pancreas was high in resveratrol and methylated treatment. On the cecal microflora (total microbes, Coliform bacteria, Salmonella spp., and lactic acid bacteria), these in resveratrol and methylated resveratrol treatments didn't show the differences compared with those in no-antibiotics, antibiotics, and ${\alpha}$-tocopherol treatments. In the serum, there were no significant differences on creatinine, blood urea nitrogen (BUN), total protein, albumin, globulin, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) among treatments, though globulin contents of reseveratrol 200 ppm and methylated resveratrol 20 ppm treatments decreased compared to those of other treatments. Immunoglobulin (IgA, IgG and IgM) were significantly decreased in antibiotics and resveratrol treatments compared to that of no-antibiotics and ${\alpha}$-tocopherol treatments (P<0.05). Superoxide dismutase (SOD) like activity tended to increase in resveratrol groups (P<0.05), however, there was no significant difference on malondiakdehyde (MDA) content among treatments. In conclusion, these results showed that resveratrol derived from mulberry can be used as alternative of antibiotics through improvement of broiler's performance and maintain of health.

• Korean Journal of Poultry Science
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• v.45 no.2
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• pp.119-124
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• 2018

This study was conducted to assess the effect of dietary addition of Germanium (Ge) on performance, egg quality, serum biochemical properties and yolk fatty acid composition in laying hens. At 74 weeks of age, a total of 360 Hy-line brown commercial layers were divided into four treatments with five replicates per treatment. Four dietary levels of Ge (0, 1, 2 and 4%) were added to the basal diets (ME: 2,750 kcal/kg, CP: 16%) and fed corresponding diet for a period of 12 weeks. The effects of these treatments on production performance and egg quality were measured three times at four week intervals, and at the end of the experiment, blood and egg yolk fatty acid were analyzed. The results showed that production performance parameters including egg production rate, feed intake, egg weight, egg mass and feed conversion ratio were non-significant, but dietary addition of 2% Ge tended to increase egg production rate. Eggshell strength was found to be significantly higher in Ge supplemented groups than in the control group (P<0.05), and eggshell thickness was also trended to be improved in Ge treated groups. In serum, triglyceride content was significantly greater (P<0.05), and the highest total cholesterol was found in hens of the control group as compared with that of the Ge supplemented groups. The yolk fatty acid composition including polyunsaturated fatty acid, unsaturated fatty acid and saturated fatty acid were not affected among the treatments but addition of 2 or 4% Ge in basal diet had significantly (P<0.05) increased monounsaturated fatty acid. Therefore, supplementation of Ge in laying hens diet has positive effects on egg quality and triglyceride in serum.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.2
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• pp.87-94
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• 2012

To compare monthly variations of phytoplankton biomass and community composition between in seawater and sediment of the Gomso Bay (tidal flat: approximately 75%), the photosynthetic pigments were analyzed by HPLC every month in 1999 and every two months in 2000. Ambient physical and chemical parameters (temperature, salinity, nutrients, dissolved oxygen, and chemical oxygen demand) were also examined to find the environmental factors controlling structure of phytoplankton community. The temporal and spatial variations of chlorophyll a concentration in seawater were correlated well with the magnitude of freshwater discharge from land. The biomass of microphytobenthos at the surface sediments was lower than that in other regions of the world and 2-3 times lower than phytoplankton biomass integrated in the seawater column. Based on the results of HPLC pigment analysis, fucoxanthin, a marker pigment of diatoms, was the most prominent pigment and highly correlated with chlorophyll a in seawater and sediment of the Gomso Bay. These results suggest that diatoms are the predominant phytoplankton in seawater and sediment of the Gomso Bay. However, the monthly variation of chlorophyll a concentration in seawater at the subtidal zone was not a good correlation with that in sediment of the Gomso Bay. Although pelagic plankton was identified in seawater by microscopic examination, benthic algal species were not found in the seawater. These results suggest that contribution from the suspended microphytobenthos in the tidal flat to the subtidal zone of the Gomso Bay may be low as a food source to the primary consumer in the upper water column of the subtidal zone. Further study needs to elucidate the vertical and horizontal transport magnitude of the suspended microphytobenthos in the tidal flat to the subtidal zone.

• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.155-159
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• 2004

Recently, there are many trials about Artificial neural networks : ANNs structure and studying method of researches for forecasting traffic volume. ANNs have a powerful capabilities of recognizing pattern with a flexible non-linear model. However, ANNs have some overfitting problems in dealing with a lot of parameters because of its non-linear problems. This research deals with the application of a variety of model selection criterion for cancellation of the overfitting problems. Especially, this aims at analyzing which the selecting model cancels the overfitting problems and guarantees the transferability from time measure. Results in this study are as follow. First, the model which is selecting in sample does not guarantees the best capabilities of out-of-sample. So to speak, the best model in sample is no relationship with the capabilities of out-of-sample like many existing researches. Second, in stability of model selecting criterion, AIC3, AICC, BIC are available but AIC4 has a large variation comparing with the best model. In time-series analysis and forecasting, we need more quantitable data analysis and another time-series analysis because uncertainty of a model can have an effect on correlation between in-sample and out-of-sample.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.3
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• pp.220-230
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• 1992

Soil temperature is one of the important environmental factors which control all the physical, chemical and biological processes in soil including germination and root growth of plants and other organisms living in the soil ecosystem. Soil water and nutrient availability and mobility are temperature dependent. Soil temperature change is depended primarily upon energy exchange in soil surface, meteorological variance and physical properties of the soils which are closely related to heat transfer mechanism. In this study physical properties including bulk density, soil texture and organic matter content were measured and thermal diffusivity on the soils was calculated. Soil samples from the 66 meteorological stations under the Korea Meteorology were collected and the physical parameters were measured. To obtain relationship between thermal diffusivity and soil water content a heat probe thermal diffusivity measurement apparatus was designed and used in this experiment. According to the survey on soil physicsal properties on the 66 meteorological stations, the 52% of the surface soil texture were sandy loam and laomy sand or sand, 38% were loam and silty loam, and 10% were clay loam and silty clay loam. The bulk density which was closely related with thermal properties showed average of $1.41g/cm^3$ for sandy soils, $1.33g/cm^3$ for loam and silty loam soils, and $1.21g/cm^3$ for clay loam and silty clay loam soils. The apparent thermal diffusivity of the upper layer from 0 to 30cm ranged from 1.16 to $8.40{\times}10^{-3}cm^3/sec$ with average of $3.53{\times}10^{-3}cm^3/sec$. The apparent thermal diffusivities of the Jeju soils of which organic matter contents were high and the bulk densities were low were near $2{\times}10^{-3}cm^3/sec$. The thermal diffusivity of snow measured in Chuncheon ranged from 0.822 to $2.237{\times}10^{-3}cm^3/sec$. The damping depth calculated from the thermal diffusivity ranged from 5.92 to 13.65cm for daily basis and 124 to 342cm for yearly basis. The significant regression equation to estimate thermal diffusivity with bulk density and soil water content was obtained by the heat probe in laboratory.

• Korean journal of food and cookery science
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• v.11 no.3
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• pp.309-315
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• 1995

This study was conducted to examine the effects of fish sauces from shrimp and anchovy and chitosan on the changes in pH, acidity, texture, and pectin fraction during Kimchi fermentation. Also, we conducted sensory evaluation on the textural properties of various Kimchis. The results were as follows: During fermentation, pH was decreased in the order of fermented anchovy sauce, fermented shrimp and control. And acidify was increased in the same order. But the addition of chitosan retarded the decrease in pH and increase in acidity. The compression force of various Kimchis during fermentation was decreased in the rder of fermented anchovy sauce, fermented shrimp, control and the addition of chitosan. During fermentation, hot water soluble pectin (HWSP) of control, fermented shrimp and fermented anchovy sauce increased whereas HCI soluble pectin (HCISP) in there treatments decreased. On the while, HWSP decreased and HCISP increased by addition of chitosan. Sensory score for the texture parameters such as hardness, crispness and chewiness of various Kimchis after the 3rd and 5th days of fermentation showed that hardness, crispness and chewiness were higher in chitosan treatment than in other treatments. The pH and acidity, compression force of Kimchis were appeared to be most highly correlated with crispness, showing that pH and compression force gave positive correlation and acidity gave negative correlation with crispness respectively. From the above results, chitosan addition was observed to infuluence the textural properties of Kimchi and their pectic substance.