• Journal of Nutrition and Health
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• v.9 no.3
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• pp.8-17
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• 1976

This study was carried out to estimate the minimum protein requirement for the Korean college girls, and to see the effect of carbohydrate intake on the minimum protein requirement in the rat. In the first experiment, three students attending Ewha Womans University were given protein free diet for 7 days while caloric intake were adjusted to maintain constant body weight. Endogenous nitrogen excretion was measured to estimate their minimum protein requirement. Second experiment was carried out in 3 parts to find out the effect of carbohydrate intake on the minimum protein requirement using 15 female, 50 days old rats weighing 120g. Inexperiment 2-1, the rats were fed protein free diet for 9 days and endogenous nitrogen excretion was measured to determine the minimum protein requirement of the rats. In experiment 2-2, the minimum casein requirement of the rats needed to maintain nitrogen equilibrium was estimated by the least squares regression method feeding 3 different levels of casein determined from the result of experiment 2-1. Finally, in experiment 2-3, the rats were given the minimum casein requirement for 7 days with 3 different levels of carbohydrate to find out the effect of carbohydrate intake on the nitrogen balance. The results of this study were as follows. Experiment I. Daily endogenous nitrogen losses of 3 college girls were 1.89g in urine, 1.10g in feces and 0.0108g from skin since the total daily endogenous nitrogen loss was 3.0g and the total daily nitrogen intake was 0.52g, the minimum nitrogen requirement of these subjects was about 2.48g/day (15.5g protein/day). Experiment II. Experiment 2-1: daily endogenous nitrogen losses of the rats fed protein free diet were $22.63{\pm}0.48\;mg$ through urine and $13.12{\pm}0.47\;mg$ in feces. The total daily endogenous nitrogen ouput was $35.71{\pm}1.27\;mg$ and the minimum protein requirement of the rats was 225mg/day in this study. Experiment 2-2: the minimum casein requirement needed to maintain the rats in nitrogen equilibrium was determined to be 340mg/day. Experiment 2-3: the rats were given 350mg/day casein with 3 different levels of carbohydrate (12,26 or 46 Cal by sugar-cornstarch mixture). The nitrogen balances were measured to be +0.0021, +0.0073 and +0.0143 respectively and there were significant differences among 3 groups.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2194-2199
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• 2007

An experimental study is performed to investigate the thermal and flow characteristics of subcooled liquid nitrogen in a natural circulation loop. Experimental apparatus is designed and constructed such that a closed loop is cooled at the top by a cryocooler and heated nearly at the bottom by cartridge heaters. Steady state is obtained by controlling the heating power to the cartridge heaters and a thin-film heater to reduce the cooling power of the cryocooler. Temperature is measured at several locations of the loop and the mass flow rate through the loop is estimated from the energy balance in terms of the measured temperatures. Experiment is repeated for various values of the vertical height between the cooling and heating parts. The results show that the heat transfer capability of the loop has a maximum at a certain value of height. The optimal height to maximize the heat transfer is in a good agreement with analytical prediction to take into account the buoyancy and viscous forces in the loop.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.3
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• pp.146-156
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• 2002

The objective of this study was to develop a modified CREAMS model for paddy field conditions. The model simulates daily balance of water and nutrient from irrigated paddies using meteorological, irrigation, and agricultural management data. The model simulates daily evapotranspiration of paddy using Penman equation and determines daily flooding depth changes. Total nitrogen and phosphorus concentrations within flooding water, surface runoff, and leaching water from a paddy field also can be simulated. Parameters of the model were calibrated using observed data of the Agricultural Experiment Station of the Seoul National University in Suwon Korea. The model was applied for the irrigation period of paddy field in Gicheon area when 1,234 mm annual rainfall was occurred. The simulated losses of the total nitrogen and total phosphorous were 11.27 kg/ha and 0.98 kg/ha, respectively. There was a good agreement between observed and simulated data. It was found that CREAMS-PADDY model was capable of predicting runoff and nutrient losses from irrigated paddy fields.

• Carbon letters
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• v.3 no.4
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• pp.187-191
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• 2002

In the present research, we prepared the activated carbon (AC) sorbents to remove gas-phase mercury. The mercury adsorption of virgin AC, chemically treated AC and fly ash was performed. Sulfur impregnated and sulfuric acid impregnated ACs were used as the chemically treated ACs. A simulated flue gas was made of SOx, NOx and mercury vapor in nitrogen balance. A reduced mercury adsorption capacity was obtained with the simulated gas as compared with that containing only mercury vapor in nitrogen. With the simulated gas, the sulfuric acid treated AC showed the highest performance, but it might have the problem of corrosion due to the emission of sulfuric acid. It was also found that the high sulfur impregnated AC also released a portion of sulfur at $140^{\circ}C$. Thus, it was concluded that the low sulfur impregnated AC was suitable for the treatment of flue gas in terms of stability and efficiency.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.6
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• pp.154-162
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• 2001

This study was performed to examine the rice growth and nutrient change in paddy soil with reclaimed sewage irrigation. Total nitrogen and total phosphorus in the experimental system were analyzed before and after rice culture. The experiment lasted three consecutive years, and this paper presents results of the last year. Additional supply of nutrients to the rice culture by reclaimed sewage irrigation was significant and it increased the yield. Nutrient uptake by rice plant increased with more nutrient supplied, however. there was limit in plant uptake. Nutrient accumulation occurred in the soil and it was more apparent for the phosphorus where most of the remaining quantity was accumulated while substantial amount of nitrogen was lost during the growing season. This study suggested that additional nutrient supply by reclaimed sewage irrigation might be a supplemental benefit to the rice culture, and it can help the fertilization management. However, long term effects of continual reclaimed sewage irrigation should be assessed carefully including nutrient mass balance in the paddy rice culture system.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.398-401
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• 2003

Bacillus species predominantly outgrown in a night soil treatment system were isolated and characterized. Cell interactions took place among them and cell population changed under various culture conditions. Maximum removal of $NH_4\;^+-N$ and cell production occurred under the conditions of 30% DO and C/N ratio of 8. Additions of 0.8% peptone and 0.3% yeast extract to a basal medium influenced the growth of isolates and the removal of $NH_4\;^+-N$ in flask culture, and metal ions such as Ca, Fe and Mg also did. During the flask experiment of nitrogen removal under an aerobic condition, active nitrification by the isolates occurred largely in 1 h with the decrease of COD and alkalinity destructed was only 74.6% of theoretical value. From the nitrogen balance, the percentage of nitrogen lost in the flask culture was estimated to be 29.0%. This conversion of ammonia to $N_2$ under an aerobic condition was confirmed by GC analysis. The B3 process using the Bacillus species seemed to have some economic advantage.

• BMB Reports
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• v.45 no.6
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• pp.342-347
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• 2012

Plant mitochondria possess alternative respiratory pathways mediated by the type II NAD(P)H dehydrogenases and alternative oxidases. Here, E3 SUMO ligase was shown to regulate alternative respiratory pathways and to participate in the maintenance of carbon and nitrogen balance in Arabidopsis. The transcript abundance of the type II NAD(P)H dehydrogenases NDA2 and NDB2 and alternative oxidases AOX1a and AOX1d genes was low in siz1-2 mutants compared to that in wild-type. The addition of nitrate or ammonium resulted in a decrease or an increase in the expression of the same gene families, respectively, in both wild-type and siz1-2 mutants. The amount of free sugar (glucose, fructose and sucrose) was lower in siz1-2 mutants than that in wild-type. These results indicate that low nitrate reductase activity due to the AtSIZ1 mutation is correlated with an overall decrease in alternative respiration and with a low carbohydrate content to maintain the carbon to nitrogen ratio in siz1-2 mutants.

• Progress in Superconductivity
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• v.10 no.2
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• pp.149-154
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• 2009

We measured and analyzed the quench development in coated conductor(CC) tapes. The CC was grown on hastelloy substrates and has an Ag protection layer. The tapes were subjected to simulated AC fault currents for quench development measurement. They were immersed in liquid nitrogen during the experiment. The quench resistance increased rapidly first, and the increase slowed down afterwards. It increased linearly with applied voltage at lower voltages, and depended less strongly on applied voltage at higher voltages. The resistance was compared with that of Au/YBCO films grown on sapphire substrates, and found to increase more monotonously than the latter. Data were analyzed quantitatively with the concept of heat transfer within the tape and the surrounding liquid nitrogen. A heat balance equation was derived and solved, taking into consideration temperature dependence of thermal parameters of the tapes. Solutions, together with values of thermal parameters taken from the literature, explained the data well. Cooling by liquid nitrogen affected the quench development considerably at lower applied voltages. Dependence on applied voltages could be also understood quantitatively.

• Korean journal of food and cookery science
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• v.23 no.5
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• pp.644-649
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• 2007

In this study a purified protein was prepared from pork meat. The product consisted of 0.5% moisture, 3.0% ash, 5.5% ether extract and 88.7% crude protein. Also, a meat oligopeptide mixture was prepared from a pepsin digest of the protein preparation. The two preparations were colorless and odorless powders with low fat contents. The nutritive values of the pork meat protein and oligopeptide mixture were estimated by two methods, one using biological value(BV) and the other employing net protein utilization(NPU) by the nitrogen balance method. The meat oligopeptide mixture showed an excellent nutritive value by both methods. The true digestibilites of both the pork meat protein and the oligopeptide mixture were more than 98%. The above results indicate that the oligopeptide mixture is an excellent material as a dietary nitrogen source for many purposes.

• Journal of Hydrogen and New Energy
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• v.29 no.5
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• pp.466-472
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• 2018

The investigation of cryogenic liquid pool spreading is an essential procedure to assess the hazard of cryogenic liquid usage. In this experimental study, to measure the evaporation velocity when the pool is spreading, liquid nitrogen was continuously released onto unconfined concrete ground. Almost all of the reported results are based on a non-spreading pool in which cryogenic liquid is instantaneously poured onto bounded ground for a very short period of time. A simultaneous measurement of the pool location using thermocouples and of the pool mass using a digital balance was carried out to measure the evaporation velocity and the pool radius. A greater release flow rate was found to result in a greater average evaporation velocity, and the evaporation velocity decreased with the spreading time and the pool radius.