• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.7
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• pp.639-644
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• 2006

This study was performed to compare the differences in physicochemical characteristics between head and incomplete kernels separated from Ilpumbyeo, Korean rice cultivar. The contents of mineral and protein were higher in incomplete than head kernels. There was significant difference in composition of fatty acid and amino acids, which affect the taste, between two kernels. The gelatinized head kernel had the higher viscosity than incomplete kernel. The content and chain length of amylose were higher in head than incomplete kernels. Differential scanning calorimeter results revealed that head kernel had lower starting temperature, higher maximum temperature, and higher enthalpy for gelatinization than incomplete kernel. Also we could found that the hydrolysis rate by glucoamylase was higher in the head kernel than incomplete kernel.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1108-1111
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• 2017

The nozzle exit shape is scarfed according to the external shape of missile when the nozzle axis should be canted from missile axis due to missile system application. There is inevitable thrust loss for the scarfed nozzle comparing to non-scarfed nozzle. The numerical analysis is necessary to calculate the thrust loss in design process, and ground tests of rocket motor were performed to verify the calculation results. From the comparison of non-scarfed nozzle and scarfed nozzle experiment results, the thrust loss from calculation was about 16.6% and that from experiments was about 15.0%.

• Journal of Korean Society of Forest Science
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• v.40 no.1
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• pp.63-69
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• 1978

A bark comprises about 10 to 20 percents of a typical log by volume, and is generally considered as an unwanted residue rather than a potential1y valuable resourses, As the world has been confronted with decreasing forest resources, natural resources pressure dictate that a bark should be a raw material instead of a waste. The utilization of the largely wasted bark of genus Pinus, Quercus, and Populus grown in Korea can be enhanced by learning their chemical properties. However, the chemical study of tree bark grown in korea have never been undertaken. In the present paper, the studies on the chemical properties of bark comprise carbohydrates, lignin, and extractives, composition of reducing sugars and five essential elements. The results may be summarized as follows: 1. Bark are much richer in quantity of lignin and extractives than the corresponding wood, and are chiefly consisted of lignin, extractives and carbohydrates orderly. It is the same with ash contents. Alcohol-benzene extractives of populus bark are the highest among three genus. 2. Although glucose constitutes the major sugar in both pine and hardwoods bark, in pinus, arabinose and xylose are the next but in hard woods, the next is xylose. 3. Essential elements, Ca and Kjeldahl-N are higher in the bark than in the wood. Ca content is the highest among others, and N,K followed it. Essential elements are higher in Quercus than in Populus and pinus.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.2
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• pp.164-173
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• 2018

Elevated atmospheric carbon dioxide concentration ($CO_2$) is a major component of climate change, and this increase can be expected to continue into the crop and food security in the future. In this study, Soil-Plant-Atmosphere-Research (SPAR) chambers were used to examine the effect of elevated $CO_2$, temperature, and drought on the canopy architecture and concentration of macronutrients in potatoes (Solanum tuberosum L.). Drought stress treatments were imposed on potato plants 40 days after emergence. Under AT+2.8C700 (30-year average temperature + $2.8^{\circ}C$ at $700{\mu}mol\;mol^{-1}$ of $CO_2$), at maximum leaf area, elevated $CO_2$, and no drought stress, a significant increase was observed in both the aboveground biomass and tuber, and for the developmental stage. Even though $CO_2$ and temperature had increased, AT+2.8C700DS (30-year average temperature + $2.8^{\circ}C$ at $700{\mu}mol\;mol^{-1}$ of $CO_2$ under drought stress) under drought stress showed that the leaf area index (LAI) and dry weight were reduced by drought stress. At maturity, potatoes grown under $CO_2$ enrichment and no drought stress exhibited significantly lower concentrations of N and P in their leaves, and of N, P, and K in tubers under AT+2.8C700. In contrast, elevated $CO_2$ and drought stress tended to increase the tuber Mg concentration under AT+2.8C700DS. Plants grown in AT+2.8C700 had lower protein contents than plants grown under ATC450 (30-year average temperature at $400{\mu}mol\;mol^{-1}$ of $CO_2$). However, plants grown under AT+2.8C700 showed higher tuber bulking than those grown under AT+2.8C700DS. These findings suggest that the increase in $CO_2$ concentrations and drought events in the future are likely to decrease the macronutrients and protein concentrations in potatoes, which are important for the human diet.

• Korean Journal of Poultry Science
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• v.43 no.2
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• pp.119-128
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• 2016

This study was conducted to compare nutritional composition and taste-related compounds of breast and thigh meats from four lines of Korean native chickens (KNC) Yeonsan Ogye, Hyunin Black, Hwangbong, and Hoengseong Yakdak. White Leghorn (WL) was used as a control. Fifteen male chickens (three chickens in each line) were grown under same condition and slaughtered at 53 weeks old. The contents of Fe and K in KNC, especially Hwangbong breast meat and thigh meat of Hyunin Black and Hoengseong Yakdak, were higher than WL. The contents of Na were lower in KNC compared with WL regardless of parts (p<0.05). Vitamin A contents were higher in thigh meat of WL and Hyunin Black, and vitamin $B_1$ contents were lower in Hoengseong Yakdak than other lines. Vitamin $B_3$ were higher in breast meat of four lines of KNC and thigh meat of Hoengseong Yakdak than WL. Total amino acid contents were higher in breast meat of KNC than WL. The level of good-tasting amino acids were significantly higher in breast meat of Hoengseong Yakdak and WL, and thigh meat of Hyunin Black and WL than other lines of chickens (p<0.05). The ratio of good-tasting amino acids to bitter tasting amino acids was higher in breast meat of Hoengseong Yakdak and thigh meat of Hyunin Black than WL. IMP contents were higher in Hyunin Black and WL than other lines of chickens. Based on these results, it can be concluded that four lines of KNC may have superior nutritional quality and taste when compared with WL.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.4
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• pp.211-217
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• 1978

Laboratory experiment was conducted to investigate the changes in the amount of inorganic phosphorus forms in soils incubated by preaddition of two kinds of phosphorus fertilizer and to various methods of available soil P. The results are summarized as following. 1. The content of Al-P form was higher in cultivated upland soil than in noncultivated soil and that of Fe-P was higher in clayey soil than in sandy soil. 2. The amount of Al-P was increased greatly by addition of Triple superphosphate and Al-P and Ca-P were increased by addition of Fused phosphate but only a little amount of Fe-P was increased by both two fertilizers. 3. The magnitute of available soil P values of different methods was in order of Bray No. 2-P>Lancaster-P${\fallingdotseq}$Bray No. 1-P>Truog-P>Olsen-P in case of addition of Triple superphosphate, while it was Lancaster-P >Bray No. 2-P>Truog-P>Bray No.1-P>Olsen-P in case of addition of Fused phosphate. 4. Extractability of soil P by variouse extractants for determining avaliable soil p was in order of Al-P>Ca-P>Fe-P but the extractability of Fe-P by Bray No. 1 and Bray No. 2 methods was very slight. 5. Bray No. 1, Bray No. 2 and extractants was more Olsen extractable about Al-P in soil than Ca-P but Lancaster and Truog metho is was more extractable about Ca-P than Al-P.

• Clinical and Experimental Pediatrics
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• v.50 no.3
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• pp.255-261
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• 2007

Purpose : The objective of this study is to observe high-resolution computed tomography (HRCT) findings of lung parenchyme in very low birth weight (VLBW) infants between the corrected age of 38-42 weeks who were treated with oxygen after birth, and to compare them to the clinical severity of bronchopulmonary dysplasia (BPD). Methods : The lungs of fourty-four VLBW infants with gestational ages of less than 32 weeks and birth weights of less than 1,500 g who were treated with oxygen after birth were examined using HRCT taken when the corrected age was between 38-42 weeks. Common findings among the infants and the frequency of their occurrences were noted. Total CT scores obtained by the summation of air trapping and actelectasis scores and the ratio of bronchus-to-pulmonary artery diameter were used to quantitatively evaluate HRCT findings and correlate them with the clinical severity of BPD as defined by Jobe-Bancalari diagnostic criteria. Results : 1) The most common findings in HRCT images of the lungs were air trapping (56%), atelectasis (70.5%), linear opacity (77%), and distortion of the bronchopulmonary bundle (65.9%). These findings were more commonly observed in infants with BPD in a mixed pattern than those without (P<0.05). However, abnormal findings were also found in HRCT images of some infants without BPD. In infants with BPD, air trapping, atelectasis and total CT scores were higher than those without BPD. Also infants with BPD had a lower bronchus-to-pulmonary artery diameter than those without BPD (P<0.05). 2) The total CT scores (r=0.799, P<0.0001) and the ratio of bronchus-to-pulmonary artery diameter (r=0.576, P<0.0001) showed a linear correlation with the clinical severity of BPD. Conclusion : HRCT findings in VLBW infants between the corrected age of 38-42 weeks who had been treated with oxygen after birth are useful in revealing pathologic changes in the lung parenchyme and show a good correlation with the clinical severity of BPD.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.1
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• pp.13-22
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• 1977

The following results were obtained in this work intended for getting more informations on features of phosphorus in Korean characteristic virgin, upland and paddy soils for knowing the ways how to evaluate the soil phosphorus availability and utilize fertilizers efficiently. 1. A large part of soil phosphorus is occupied by inorganic phosphorus in the soils of which the cultivated soils showed higher accumulation of applied phosphorus as inorganic forms than the uncultivated soils. The accumulation of organic phosphorus was indicated the highest in the paddy soils, and the lowest in the uncultivated soils. Than the cultuivated soil, the uncultivated soils have higher C/P ratio which was estimated to be related to soil fertility status essentially. 2. Iron phosphate was shown to be the most dominant form in soil phosphorus. Difference in parent rocks, from which the soils were originated, was shown to affect the carious distribution of phosphorus forms in the uncultivated soils to a large extent. The paddy soils have almost same distribution pattern of soil phosphorus forms regardless of different parent rocks. 3. The different methods for available phosphorus estimation extracted different amounts of phosphorus from the soils. Close relations between the available phosphours extracted with the different methods and the amounts of seil inorganic phosphorus were shown : e.g. between Fe-P and available-P by Olsen method. 4. Phosphorus absorption coefficient correlated negatively to soil inorganic phosphorus, and also to available phosphorus extracted with the several methods.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.101-109
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• 2004

In this study, the solid-liquid separation characteristics of swine wastewater were investigated for the coagulation and dissolved air flotation (DAF). Coagulation characteristics were studied using jar-tester with the different coagulants and dosage amounts. DAF characteristics were also investigated in terms of the different flotation conditions with the raw swine wastewater, pH adjustment only, and adding coagulants. When the raw swine wastewater was coagulated with the only inorganic coagulants, the proper inorganic coagulants were founded as $FeCl_3$ > PAC > Alum orderly, and the optimal coagulant dosages were founded as $1,000mg/{\ell}$, $1,500mg/{\ell}$, $1,500mg/{\ell}$, respectively. As the raw swine wastewater was treated with the polymer coagulants, the only cationic polymer coagulant showed an effective coagulation and the optimal dosage of cationic coagulant was founded as $200mg/{\ell}$. When the different dosages of cationic polymer was added to each $500mg/{\ell}$ of the inorganic coagulants, the proper inorganic coagulants were founded as $FeCl_3$ > Alum > PAC orderly, and optimal cationic polymer dosages was founded as $25mg/{\ell}$, $25mg/{\ell}$, and $100mg/{\ell}$, respectively. Resulting from the raw swine wastewater experiments using DAF without coagulation, the proper operation conditions of DAF were set to 400% of recycling ratio, 4 atm in air dissolving tank, and under pH 3. But the raw swine wastewater was difficult to successfully operate DAF without pre-coagulation. While the DAF separation after pre-coagulation using inorganic coagulants was not accomplished due to the low intensity of the floc, DAF after pre-coagulation using both the inorganic and cationic polymer coagulants was accomplished very well. Optimal dosage of cationic polymer coagulant in case of $500mg/{\ell}$ Alum dosage was founded as $500mg/{\ell}$.

• Journal of Nutrition and Health
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• v.25 no.2
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• pp.123-131
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• 1992

Concentrations of 5 major minerals(Na, K, Ca, P, Mg) and 3 trace elements(Mn, Mo, Ni) were measured in human milk samples collected from 21 highly selected healty lactating women at 2-5 days and at 1, 2, 4, 6 and 12 weeks postpartum. Significant decrease in contents of the major minerals and trace elements were found with time postpartum. Sodium contents decreased from 293.01ug/N at 2-5 days to 194.27ug/N at 12 weeks. Potassium contents also decreased from 436.18ug/N in colostrum to 358.51ug/N in matured milk at 12 weeks. The Ca/P ratios of colostrum transitional and matured milk were 3.39, 281 and 2.45 respecti-vely. Mean manganese levels of colostrum and transitional were 0.024ug/N and those of matured milk were 0.014ug/N. Molybdenum concentrations in the breast-milk collected at 1, 2, 4 weeks were higher than those in the milk samples at 2-5 days and 12 weeks Nickel content of colostrum was 0.062ug/N and those of trnsitional matured milk were 0.22ug/N and 0.017ug/N, These determinations will provide the basic information on the variability of minerals and trace elements as lactation proceed and the comparison of the components between term and preterm milk.