• Journal of the Korean Society of Tobacco Science
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• v.3 no.1
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• pp.20-24
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• 1981

This experiment was carried out to determine the relationships between maturity and content of the chemical components in flue-cured tobacco. The results were as follows : 1) Among the chemical components, the contents of total nitrogen, ammonia nitrogen, total alkaloids, nicotine, total volatile base, petroleum-ether extract, crude fiber, crude ash, water soluble ash, and chlorine decreased significantly, and those of total sugar, reducing sugar, and starch increased as leaf maturity progressed until the stage of ripeness, but, afterwards, a reverse tendency appeared. 2) There was a significant relationship between maturity and the contents of chemical components, such as total nitrogen, protein nitrogen, ammonia nitrogen, total volatile base, and the correlation coefficients of them were -0.743, -0.789, -0.797, and -0.642, respectively.

• Membrane and Water Treatment
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• v.11 no.5
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• pp.345-351
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• 2020

Eutrophication of surface waters is commonly caused by excessive inputs of nutrients such as nitrogen and phosphorus. Nakdong River basin was chosen as the study area to investigate the effect of point and non-point source pollution of nitrogen on eutrophication in water body. Non-point source inputs of nitrogen accounted for approximately 84% in the total nitrogen input of the upper Nakdong river watershed, which mainly consists of agricultural land and forests. However, point source inputs of nitrogen accounted for 58~85% in the total nitrogen input of the middle and lower watersheds, including urban area. Therefore, for watershed near urban area, control of point source inputs of nitrogen may be an optimal method to control eutrophication. In this respect, the enforcing reduction of nitrogen in the final effluent of wastewater treatment facilities is needed. On the other hand, to enact more stringent nitrogen regulations, the LOT (limit of technology) and environmental impact should be considered. In this study nitrogen data were analyzed to propose new nitrogen regulations.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.3
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• pp.313-316
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• 2000

Three Holstein steers, fitted with ruminal and duodenal cannulas, were used in a replicated $3{\times}3$ Latin square design to determine the digestibility of dietary nitrogen in total digestive tract by three methods, 1) mobile nylon bag (MNB); 2) total fecal collection (TFC); and 3) washed fecal sample after freezing and thawing through a sieve with a pore size of $45{\mu}m$ (WFS). A basal diet of oaten hay-barley was supplemented with one of the following protein sources; soybean meal, fish meal or blood meal. Steers were fed at a level of 2% of body weight. The experimental diets were contained approximately 1.85% nitrogen. There were no differences (p>0.05) among the diets on DM, NDF and nitrogen disappearances, and the diet results were pooled to assess the methods. Total tract disappearances of dry matter and neutral detergent fiber were 61.6, 71.1 and 78.9 and 25.3, 63.2 and 64.6 for MNB, TFC and WFS methods, respectively. The lower digestibility of DM and NDF in the MNB method could be a result of low ruminal incubation time. The TFC method had the lower (p<0.05) determination of nitrogen disappearance in the total digestive tract than the MNB and WFS methods. On the other hand, nitrogen disappearance in the total digestive tract determined by the WFS technique was comparable to that in MNB technique, as there was no significant difference (p>0.05) between the methods. It is shown that the disappearance of dietary nitrogen in the total digestive tract could be estimated in the intact animals by using washed fecal sample prior to freezing and thawing.

• Journal of Nutrition and Health
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• v.7 no.2
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• pp.37-51
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• 1974

This Study was carried out to observe the effect of nutritional condition on the change of protein metabolism in the animal body by feeding on imbalanced protein diet. A total 242 growing male albino rats, weighing $115{\sim}120$ gm, were used for the experimental animals. The rats were fed on the standard diet(st), protein flee diet(pf) and imbalanced protein diet(ib) for twelve weeks respectively. Hemoglobin, packed cell volume in blood, and total nitrogen, amino acid nitrogen, urea-nitrogen, creatinine, transaminases(GPT, GOT) in liver and serum, and total nitrogen in small intestine, and total nitrogen, urea-nitrogen In small intestine, and total nitrogen, urea-nitrogen, creatinine, urea-nitrogen/creatinine ratio in urine were measured. The results obtained are as follows; 1. The gained body weight were lower in pf group and ib group than those of st group. The gained body weight fed for 12 weeks, were 80% lower in pf group than those of st group, and the body weight of pf group for $50{\sim}75$ days feeding were $40{\sim}60%$ decreased, compared with the stating weight, and then all of them died. 2. The change of the brain, liver, kidney, spleen and small intestine by feeding on imbalanced diet for 12 weeks were no remarkable difference with the starting weight, but those of protein free diet group were half or more decrease and those were significantly lower in spleen and small intestine especially than the other organ 3. The contents of hemoglobin in pf group for 8 weeks feeding, and the packed cell volume in pf group for 8 weeks feeding and in ib group for 12 weeks feeding were decreased. but those of the other feeding group were almost same value. 4. The total nitrogen in the liver, small intestine and serum of each diet group were no remarkable difference respectively. The contents of amino acid nitrogen in pf group for 2 and 6 weeks feeding were increased. 5. On transaminases: a) The cycle of increase and decrease of GPT activities were come periodically and the interval of cycle were fast in the early stage of feeding and slow there-after. b) The GPT activities were decreased gradually in pf group after feeding and those were increased in ib group for 6 weeks feeding but decreased there-after. The frequency of cycle were more GPT than GOT and specially those of GPT in early stage of feeding were two or three times while GOT was one. c) The interval of increase and decrease in GOT and amino acid nitrogen cycle were similar tendency. 6. The contents of total nitrogen, creatinine and urea-nitrogen of pf group in urine were decreased very sharply from sharting feeding to one week but increased dully from six weeks to eight weeks feeding. The contents of urea-nitrogen of ib group were increased dully by feeding on ten weeks but decreased by feeding on twelve weeks. From the above results, it is concluded that the trend of the metabolic change is maintained equally by homeostatic mechanism using the endogenous protein source during a certain period by imbalanced protein diet feeding. The homeostatic mechanism is come peridically, very fast in early stage of feeing and than slow there-after.

• Korean Journal of Environmental Agriculture
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• v.21 no.1
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• pp.74-79
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• 2002

Two consecutive green house experiments were carried out to examine the effect of Azospirillum spp. inoculation on growth, nitrogen and phosphorus accumulation in maize plants grown in pots. There were eight treatments including an uninoculated control and Azospirillum strains OAD-3, OAD-9, AZ-22, AZ-8, AZ-9, Azospirillum brasilense BR-11001 and Azospirillum lipoferum BR-11080. The inoculated plants showed higher values in each of the following measurements; plant height, total dry mass and nitrogen and phosphorus accumulation in shoot when compared to the uninoculated control plants in two consecutive experiments conducted in the same soil. Among Azospirillum strains, Azospirillum sp. OAD-3 inoculated plants showed higher nitrogen accumulation by 44.5% and 45.1%, total dry mass by 48.6% and 66.9% in two consecutive experiments respectively. The nitrogen concentration in the maize plants was not changed significantly in the first experiment, however it increased significantly in the second experiment due to Azospirillum inoculation. In addition, Azospirillum sp. OAD-9 and A. brasilense BR-11001 also proved to be effective with respect to total dry mass, total nitrogen accumulation and total phosphorus accumulation. The nitrogen concentrations in maize plants were increased in the second experiment due to Azospirillum inoculation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.83-86
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• 1969

The present investigations were made with the purpose of elucidating the seasonal variation in total nitrogen content of Gelidium amansii. Monthly samples were collected from the sea near pusan, from August 1957 to June 1959. The results obtained have been summarized as follows: The maximum total nitrogen content of Gelidium amansii was observed during the months of January and February, and the minimum content was observed in June and July Thus the total nitrogen content of Gelidium amansii exhibited a considerable periodic change throughout the year. The recommended harvest time of Gelidium amansii with regard to total nitrogen content, is from May to October, but on the other hand the proper harvest time is from May to June, with respect to the season of spore-formation and its propagation.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.1
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• pp.5-14
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• 2010

A pilot-scale biological aerated filter (BAF) was operated with an anaerobic, anoxic and oxic zone at $23{\pm}1^{\circ}C$. The influent sCOD and total nitrogen concentrations in the feedwater were approximately 250 mg/L and 35 mg N/L, respectively. sCOD removal at optimum hydraulic retention time (HRT) of 3 hours with recirculation rates of 100, 200 and 300% in the column was more than 96%. Total nitrogen removal was consistently above 80% for 4 and 6 hours HRT at 300% recirculation. For 3 hours HRT and 300% recirculation, total nitrogen removal was approximately 79%. Based on fitting results, the kinetic parameter values on nitrification and denitrification show that as recirculation rates increased, the rate of ammonia and nitrate transformation increased. The ammonium loading rates for maximum ammonium removed were 0.15 and 0.19 kg $NH_3$-N/$m^3$-day for 100% and 200% recirculation, respectively. The experimental results demonstrated that the BAF can be operated at an HRT of 3 hours with 200 - 300% recirculation rates with more than 96 % removal of sCOD and ammonium, and at least 75% removal of total nitrogen.

• KSBB Journal
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• v.24 no.3
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• pp.291-295
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• 2009

This study performed verification experiment for the removal of total nitrogen in sewage from a Town M village sewage treatment plant using YPNR processes. The total nitrogen discharged after the denitrification process was maintained at a level of 8-15 mg/L, which results in the total nitrogen removal efficiency above 68% on average. The total nitrogen components in discharged water consisted of 16% of ammonia nitrogen, 6% of nitrite nitrogen, and 77% of nitrate nitrogen, which reaches a 95% nitrification efficiency. Hence, the YPNR advanced treatment process used in this study can be successfully applied to sewage treatment.

• Journal of Nutrition and Health
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• v.28 no.5
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• pp.406-414
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• 1995

Nitrogen(N) concentration of preterm(PT) and term (T) milk in various fractions, such as total, protein, nonprotein, whey protein and casein were determined at 2-5 days, 1, 2, 4 and 6 weeks of postpartum. The purpose of this study was to investigate the nitrogen concentration of human milk from mothers delivering at preterm and term, and the propriety of preterm milk for premature infants. The concentration of total N, nonprotein N, protein N, whey protein N and casein N in preterm milk was decreased significantly with time postpartum. Total N was 374mg/이 at colostrum, 232mg/dl at mature milk. Whey protein N was decreased from 42mg/dl at 2-5 days to 32mg/dl at 4-6 weeks. Protein N was 332mg/dl at colostrum, 202mg/dl at mature milk. The proportion of whey protein N and casein N were 39:61 at colostrum, 28:72 at mature milk. No difference were found between T and PT milk for total nitrogen excepted 2 weeks. In this report we show that nitrogen concentration except casetpt casein N is smaller in milk from mothers giving birth prematurely than in milk from mothers giving birth at term, over the first two weeks of lactationl But protein N was higher in preterm milk than term milk, whey protein nitrogen was lower. By comparing predicted nitrogen intakes to estimated requirements of preterm infants fed 150 to 200ml/kg/day of their own mother's milk, we predict that the quantities of protein provided would be adequate to meet the requirements of the prematured infants during the early weeks of life.

• Journal of the Korean Applied Science and Technology
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• v.25 no.3
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• pp.355-362
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• 2008

One of the popular domestic sewage treatment process (called step feed oxic-anoxic-oxic process) for nitrogen removal was analyzed in this study by theoretical analysis based on the nitrification and denitrification reaction. Total nitrogen removal efficiency was suggested by considering influent qualities(i.e., ammonia, nitrite, nitrate, alkalinity, and COD). Total nitrogen removal efficiency depends on r (influent allocation ratio). In the case that all influent components are enough, the total nitrogen removal follows equation 100-b/(1+b), when r is 1/(1+b). Finally, it can be concluded that step feed oxic-anoxic-oxic process could be effective for nitrogen removal.