• Clean Technology
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• v.17 no.4
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• pp.389-394
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• 2011

A compact adsorption-based process for removal of carbon dioxide and nitrogen from natural gas has been discussed. Among the adsorption-based processes, especially, the pressure swing adsorption (PSA) process has been a suitable unit operation for the purification and separation of gas because of low operation energy and cost. A step cycle is made up of pressurization, feed, equalization, blowdown and rinse. In this work, the PSA process is composed of zeolite 13X and carbon molecular sieve (CMS) for removal of carbon dioxide and nitrogen from mixed gas containing $CH_4/CO_2/N_2$ (75:21:4 vol%). A CMS selectively removes carbon dioxide and a zeolite 13X separates nitrogen from methane. CMS is investigated experimentally due to the high throughput of the faster diffusing component ($CO_2$). The gas composition of top, bottom and feed tank was measured with the gas chromatography (GC) using TCD detector, helium as carrier gas and packed column for analysis of methane, carbon dioxide, and nitrogen.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.60-60
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• 2022

As various wheat variety for bread, all-purpose, and cake flour have been developed, suitable cultivation method for the end-use of the new variety need to be revised. This study was conducted to suggest an optimal nitrogen(N) fertilizer method for wheat Variety 'Saekeumgang' and 'Hojoong' with good noodle quality. In order to analyze the yield and quality changes of 'Saekeumgang' and 'Hojoong' as nitrogen fertilizer amount and timing, these varieties were sown on paddy soil in jeunju, Republic of Korea. The amount of N fertilizer was divided into 4 levels (7.1, 9.1 11.1,13.1kg/10a). In each levels, N amount in sowing date fixed as 3.6kg/10a, N amount in 10 days after heading(DAH) were treated 0 or 2kg/10a, and the other N amount was treated in regrowing stage. As N amount in regrowing stage increased, culm length of 'Saekkeumgang' was increased, but culm length of 'Hojoong' was not affected. Spike number/m² was increased when N fertilizer amount in regrowing stage increased as 3.5 to 7.5kg/10a. But, spike number/m² wasn't increased compared N amount 7.1kg/10a conditions when N fertilizer amount 9.1kg/10a. When the N fertilization amount in regrowing stage was increased by 1kg/10a, grain yield increased by 45.7 kg/10a in 'Saegeumgang' and 21.4kg/10a in 'Hojoong', so the fertilizer effect of 'Saegeumgang' was higher, when N fertilizer amount was increased to 2kg/10a at 10DAH, 1000-grain weight increased, but spike number/m2 and grain yield were not affected by N fertilizer at 10 DAH. Protein content and SDS-sedimentation value were increased as increasing N fertilizer amount in regrowing stage and 10 DAH. Among them, N fertilizer amount in 10 DAH had higher impact on protein content and SDS-sedimentation value. As N fertilize in 10 DAH, hardness of noodle was increased and chewiness of noodle was decreased

• Korean Journal of Soil Science and Fertilizer
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• v.4 no.2
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• pp.155-159
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• 1971

1. Based upon an fertilizer experiment done in a farmer's field, with a medium maturity variety, Jinheung, (in 1969) a method of determination of nitrogen to be additionally given, at tillering and reproductive stages was studied. In this experiment, four kilograms of nitrogen per 0.1 ha was applied as basal dressing to all experimental treatments at transplanting time. 2. The application of nitrogen at the reproductive stage of paddy increased the yield remarkably and cut down the amount of nitrogen to be given at the tillering stage. The yield of paddy, 670kg/0.1 ha obtained by the application of 6.82kg N/0.1 ha at the reproductive stage far exceeded the yield, 644kg/0.1ha obtained when over 8kg N/0.1ha of N is applied at tillering stage alone. This emphasizes the importance of nitrogen top dressing at the reproductive stage. 3. As the amount of nitrogen to be given at both stages, reproductive and tillering, would be the reflection of soil fertility of the field, a correlative study between the amount of nitrogen to be given at both stages and soil analysis is suggested to be undertaken. 4. A study on the relationship between the amount of fertilizer to be given at stages different growth and yield components is suggested to be undertaken for the purpose of establishing a better fertilizer use technique.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.4
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• pp.491-500
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• 2010

Three experiments were conducted to investigate the effects of polyurethane coated urea on in vitro ruminal fermentation, ammonia release dynamics and lactating performance of Holstein dairy cows fed a steam-flaked corn-based diet. In Exp. 1, a dual-flow continuous culture was run to investigate the effect of polyurethane coated urea on nutrient digestibility, rumen fermentation parameters and microbial efficiency. Three treatment diets with isonitrogenous contents (13.0% CP) were prepared: i) feedgrade urea (FGU) diet; ii) polyurethane coated urea (PCU) diet; and iii) isolated soy protein (ISP) diet. Each of the diets consisted of 40% steam-flaked corn meal, 58.5% forages and 1.5% different sources of nitrogen. PCU and FGU diets had significantly lower digestibility of NDF and ADF (p<0.01) than the ISP diet. Nitrogen source had no significant effect (p = 0.62) on CP digestibility. The microbial efficiency (expressed as grams of microbial N/kg organic matter truly digested (OMTD)) in vitro of the PCU diet (13.0 g N/kg OMTD) was significantly higher than the FGU diet (11.3 g N/kg OMTD), but comparable with the ISP diet (14.7 g N/kg OMTD). Exp. 2, an in vitro ruminal fermentation experiment, was conducted to determine the ammonia release dynamics during an 8 h ruminal fermentation. Three treatment diets were based on steam-flaked corn diets commonly fed to lactating cows in China, in which FGU, PCU or soybean meal (SBM) was added to provide 10% of total dietary N. In vitro $NH_3-N$ concentrations were lower (p<0.05) for the PCU diet than the FGU diet, but similar to that for the SBM diet at all time points. In Exp. 3, a lactation trial was performed using 24 lactating Holstein cows to compare the lactating performance and blood urea nitrogen (BUN) concentrations when cows were fed PCU, FGU and SBM diets. Cows consuming the PCU diet had approximately 12.8% more (p = 0.02) dietary dry matter intake than those consuming the FGU diet. Cows fed the PCU diet had higher milk protein content (3.16% vs. 2.94%) and lower milk urea nitrogen (MUN) concentration (13.0 mg/dl vs. 14.4 mg/dl) than those fed the FGU diet. Blood urea nitrogen (BUN) concentration was significantly lower for cows fed the PCU (16.7 mg/dl) and SBM (16.4 mg/dl) diets than the FGU (18.7 mg/dl) diet. Cows fed the PCU diet had less surplus ruminal N than those fed the FGU diet and produced a comparable lactation performance to the SBM diet, suggesting that polyurethane coated urea can partially substitute soybean meal in the dairy cow diet without impairing lactation performance.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.223-226
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• 2012

Liquid livestock manure (LLM) has been used as a nitrogen fertilizer source for horticulture plants. LLM contains organic nitrogen (N), ammonium, nitrate, and nitrite. The amount of nitrate and nitrite in LLM are usually small compared to the amount of ammonium in it and so they can be negligible if total nitrogen (N) concentration in LLM is higher than $1,000mg\;L^{-1}$. However, if total N concentration in LLM is less than $1,000mg\;L^{-1}$, the amount of nitrate and nitrite may affect total N concentration in LLM. Currently, Kjeldahl digestion method is mainly used for ammonium-N in LLM. Therefore, it is ineffective to analyze nitrate-N and nitrite-N. The objective of this study was to evaluate whether the total N concentrations are affected by the amount of nitrate-N and nitrite-N with diverse LLMs by Kjeldahl method (with and without Devarda's alloy after Conc. sulfuric acid digestion). Five liquid livestock manure samples were collected at swine farms in Ansung and Icheon. All LLM samples were stored at $25^{\circ}C$, subsampled at every $15^{th}$ day for 90 days, and analyzed for total N, ammonium-N, and nitrate-N. At the $90^{th}$ day, LLM samples were analyzed with and without Devarda's alloy after Conc. sulfuric acid digestion. Potassium nitrate, ammonium nitrate, and ammonium chloride were used to determine the N recovery percentages. Total N concentration ranged from 560 to $4,230mg\;L^{-1}$. Nitrate-Ns were found in all LLM samples, ranged from 21 to $164mg\;L^{-1}$. N recovery percentages with potassium nitrate were 0 % without Devarda's alloy and 100% with Devarda's alloy because adding Devarda's alloy facilitated nitrate-N into ammonium-N conversion. Total Ns were significantly different between two methods, with and without Devarda's alloy. Total N concentrations were $210mg\;L^{-1}$ at LLM 4 and $370mg\;L^{-1}$ at LLM 5 without Devarda's alloy and $290mg\;L^{-1}$ at LLM 4 and $490mg\;L^{-1}$ at LLM 5 with Devarda's alloy. These results suggest that if total N of LLM is less $1,000mg\;L^{-1}$, additional procedure such as adding Devarda's alloy can be used to estimate the total N and inorganic N better.

• Korean Journal of Environmental Agriculture
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• v.26 no.4
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• pp.306-312
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• 2007

To investigate the effect of N fertigation on the growth, yield, and water and nitrogen use efficiencies during tomato cultivation, seedlings were transplanted in a sandy loam soil under plastic film house condition. 0, 88, 132, 176, $220\;kg\;ha^{-1}$ N rates, which correspond to 0 (NF0), 40 (NF40), 60 (NF60), 80 (NF80), 100% (NF100) N level of soil test-based N fertilization, were injected weekly through drip irrigation system for 15 weeks in N fertigation system, and the control (conventional N treatment) was installed for comparison. Herein, nitrogen was applied by top-dressing with 60% as a basal and 40% as additional fertilizer. There was little different in stem diameter growth among N fertigation treatments, but plant height and dry matter increased with increasing N fertigation rates as well as in N conventional treatment. Tomato yield was increased with increasing the number of marketable fruits in N fertigation treatments, and the fruit yield was maximized in NF 80 treatment ($176\;kg\;ha^{-1}$ N supply or $96.6\;mg\;L^{-1}$ N injection). Dry matter productivity and nitrogen uptake amount were significantly increased with increasing N fertigation rates. The ratio of fruits to the dry weight of whole plant was decreased with increasing N fertigation rates, but this ratio was $2.6{\sim}5.3%$ higher in N fertigation treatments than in the control. In addition, the ratios of nitrogen distributed toward fruits in N fertigation treatments were $3.7{\sim}21.7%$ higher than that of control. The apparent N recovery percentages showed significantly higher values as $71.8{\sim}102.3%$ in N fertigation treatments, compared to 45% in N conventional treatment. Water use efficiency was significantly increased by fertigation system with the maximum $361\;kg/ha\;cm^{-1}$ in NF 80, which is comparable to $324\;kg/ha\;cm^{-1}$ of the conventional treatment. Conclusively, N fertigation system was effective on increasing tomato productivity and nutrient efficiency as well as 20% reduction of N fertilization level.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.3
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• pp.6-13
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• 2000

Ultra-thin gate oxide was grown on nitrogen implanted silicon substrates. For nitrogen implantation, the energy was fixed at 25keV, but the dose was split into 5.0$\times$10$^{13}$ /c $m^{2}$ and 1.0$\times$10$^{14}$ /c $m^{2}$. The grown gate oxide thickness were 2nm, 3nm and 4nm. The oxidation time to grow 3nm was increased by 20% and 50% for the implanted wafers of 5.0$\times$10$^{13}$ /c $m^{2}$ and 1.0$\times$10$^{14}$ /c $m^{2}$ doses, respectively, when it was compared with control wafers which were not implanted by nitrogen. The value of charge-to-breakdown ( $Q_{BD}$ ) is decreased with increasing nitrogen doses. If an annealing process( $N_{2}$, 85$0^{\circ}C$, 60min.) is peformed after nitrogen implantation, $Q_{BD}$ is increased. It is indicated that nitrogen implantation damage affect gate oxide reliability and the damage can be removed by post-implantation annealing process.

• Bulletin of the Korean Chemical Society
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• v.15 no.7
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• pp.517-519
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• 1994

• Journal of Animal Science and Technology
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• v.62 no.5
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• pp.659-667
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• 2020

This study was conducted to evaluate the effects of different levels of crude protein (CP) and protease on nitrogen (N) utilization, nutrient digestibility, and growth performance in growing pigs. A total of six crossbred ([Landrace × Yorkshire] × Duroc) barrows were individually accepted in 1.2 m × 0.7 m × 0.96 m stainless steel metabolism cages. The pigs (average initial body weight of 27.91 ± 1.84 kg) randomly assigned to six diets with six weeks (6 × 6 Latin square design). The experiment was carried out in an environment with a temperature of 23 ± 1.5℃, a relative humidity of 83 ± 2.3% and a wind speed of 0.25 ± 0.03 m/s. The dietary treatments were arranged in a 2 × 3 factorial design with two levels of CP (15.3% or 17.1%) and three levels of protease (0 ppm, 150 ppm, or 300 ppm). The average daily gain and gain to feed ratio (G:F) tended to increase (p = 0.074) with increasing amounts of protease. The low CP level diet reduced (p < 0.050) urinary and fecal N concentrations, the total N excretion in feces, and increased (p < 0.050) N retention. Different protease levels in the diet did not affect (p > 0.05) at N intake, but supplementation of the diets with 300 ppm protease decreased (p < 0.050) the N concentration in urine and feces and tended to increase (p = 0.061) the percentage of N retention retained of the total N intake. The dietary CP level did not affect (p > 0.050) the apparent total tract digestibility (ATTD) of dry matter, digestible energy (DE), and metabolic energy (ME), but diet supplementation with 300 ppm protease showed higher (p < 0.050) ATTD of DE and ME than in the protease-free diet. Therefore, a low protein diet with protease could improve the utilization of nitrogen, thereby reducing the negative effect of N excretion into the environment while maintaining or increasing growth performance compared to a high protein diet.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.76-82
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• 1986

A laboratory experiment was conducted to find out the denitrification rate upon the levels of nitrogen and source of organic matter in submerged sandy and sandy loam soil. The results obtained were sumarized as follows; 1. Evolution of nitrous oxide was increased at 1st and 10 days after incubation. And dinitrogen was increased at 1st and 30 days after incubation. Applications of green manure was enhanced the evolution of nitrous oxide ($N_2O$) and dinitrogen ($N_2$). 2. The cumulative denitrification rates at 50 days was high in Gyuam sandy loam soil (O-M: 1.52%) than that of Hamchang sandy soil (O-M: 3.81%). On the other hand, the cumulative emission of dinitrogen was high in Gyuam sandy loam soil while nitrous oxide was high in Hamchang sandy soil. The total mount of denitrification rate was high in order of green manure > rice straw > compost > control soil. 3. Increases of fertilizer nitrogen was enhanced the rate of emission of dinitrogen and nitrous oxide during the incubation time. 4. According to Michaelis-Menten kinetic equation, denitrification rates and reaction efficiency were remarkably increased by application of readily decomposable organic matter with in higher organic matter content of soil. 5. The negative relationship was observed between the evolution of dinitrogen and carbon ($CO_2+CH_4$) while the nitrous oxide with carbon was positive. 6. Under the this experiment conditions 1 mg of carbon was required for production of 4 mg N as $N_2O$ and 3 mg of N as $N_2$, respectively.