• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.421-424
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• 2006

High nitrogen steels (HNS) exhibit both high strength and ductility during tensile deformation. In the present study the Fe-18Cr-14Mn-4Ni-0.9N high nitrogen steel was heat treated at $1000^{\circ}C$ and $1100^{\circ}C$ to produce $Cr_2N$ precipitates in austenite matrix and full austenite microstructures, respectively. Tensile tests of the heat treated specimens were performed at two different strain rates of 0.05/sec and 0.00005/sec. Each tensile curve of the specimens could be well characterized by the the modified Ludwik equation. Plastic deformation of the steel was adequately represented by the four parameters of the modified Ludwik equation. At 0.05/s strain rate, the specimen with the $Cr_2N$ precipitate exhibited higher strength than the full austenite specimen, while the full austenite specimen showed better mechanical properties at 0.00005/s strain rate. It was found that the $Cr_2N$ precipitates influences deformation behavior of the high nitrogen steel significantly.

• Membrane and Water Treatment
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• v.10 no.4
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• pp.265-275
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• 2019

This study aimed to develop a compact partial nitritation step by forming granules with high Ammonia-Oxidizing Bacteria (AOB) fraction using the Air-lift Granulation Reactor (AGR) and to evaluate the feasibility of treating reject water with high ammonium content by combination with the Anammox process. The partial nitritation using AGR was achieved at high nitrogen loading rate ($2.25{\pm}0.05kg\;N\;m-3\;d^{-1}$). The important factors for successful partial nitritation at high nitrogen loading rate were relatively high pH (7.5~8), resulting in high free ammonia concentration ($1{\sim}10mg\;FA\;L^{-1}$) and highly enriched AOB granules accounting for 25% of the total bacteria population in the reactor. After the establishment of stable partial nitritation, an effluent $NO_2{^-}-N/NH_4{^+}-N$ ratio of $1.2{\pm}0.05$ was achieved, which was then fed into the Anammox reactor. A high nitrogen removal rate of $2.0k\; N\;m^{-3}\;d^{-1}$ was successfully achieved in the Anammox reactor. By controlling the nitrogen loading rate at the partial nitritation using AGR, the influent concentration ratio ($NO_2{^-}-N/NH_4{^+}-N=1.2{\pm}0.05$) required for the Anammox was controlled, thereby minimizing the inhibition effect of residual nitrite.

• Journal of Energy Engineering
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• v.23 no.3
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• pp.174-180
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• 2014

Experimental study of liquid nitrogen pool spread is carried out when it is continuously released. The liquid nitrogen spreads over a cement mortar plate with continuous release. Evaporation rate per unit area of the liquid nitrogen is measured using a digital balance, and a spreading distance of the liquid pool is measured by thermocouples. It is discovered that the evaporation rate per unit area of liquid nitrogen tends to decrease as the liquid pool spreads.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.4
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• pp.369-375
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• 1991

A series of in vitro incubation studies with washed rumen bacteria were conducted to determine the influence of incubation time and concentrations of peptides, alanine, ammonia nitrogen and carbohydrate on the rate of peptide disappearance and on bacterial growth. Disappearance rate of tri-alanine (ala3) under various conditions was between 30.6 and $58.2mg\;hr^-$ per gram bacterial dry matter. Ala3 was removed from the incubation medium in an almost linear fashion as incubation time and ala3 concentration was increased. Washed rumen bacteria utilized ala3 faster than di-l-alanine (ala2) at all concentrations. Adding 9mM carbohydrate significantly increased ala3 disappearance, but level of ammonia nitrogen had no influence on ala3 disappearance. The presence of alanine in the medium significantly lowered ala3 utilization by rumen bacteria. Bacterial dry matter and nitrogen growth yield were not influenced by alanine and peptides when incubation medium already contained a sufficient level of ammonia nitrogen. Increased ammonia nitrogen in the presence of ala3 did not stimulate bacterial growth. Carbohydrate significantly increased bacterial dry matter and nitrogen growth as expected. Results indicate that the rate of peptide utilization by rumen bacteria may be altered by type and concentration of peptides, and energy supply, and this may be mediated through changes in numbers and type of bacteria.

• Journal of Embryo Transfer
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• v.16 no.1
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• pp.47-51
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• 2001

This study was done to examine the relationship between serum chemical values (urea nitrogen, glucose, total protein and cholesterol) of recipients and pregnancy rate following embryo transfer. Blood samples were taken from 184 Holstein heifers or cows on Day 6 or 7 (Day 0=day of estrus) to analysis for serum urea nitrogen, glucose, total protein and cholesterol concentrations. After selection of recipients, frozen Holstein embryos were thawed and directly transferred to recipients non-surgically. The average serum concentrations of urea nitrogen, glucose, total protein and cholesterol were 13.8 mg/dl, 56.5 mg/dl, 7.2 mg/dl, 124.8 mg/dl, respectively. The average concentrations of serum urea nitrogen and cholesterol were lower (P<0.05) in pregnant recipients (10.7 mg/dl, 99.2 mg/dl) than in non-pregnant recipients (13.0 mg/dl, 122.2 mg/dl), respectively, although the concentrations of glucose and total protein were not different. These results show serum urea nitrogen and cholesterol concentrations can be used important factors for selection of recipients in Holstein.

• Journal of Environmental Science International
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• v.13 no.7
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• pp.661-665
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• 2004

As the concentration of ammonium nitrogen could be reached 2～3 mg/L in the winter in the river. It was clear that the excessive concentration of chlorinated organics could be produced with the increase of chlorine addition to remove ammonium nitrogen. In the innovative ammonium nitrogen removal process, zeolite adsorption is very efficient as substitute for rapid sand filtration without other adverse quality change in the water. This study is conducted to evaluate the feasibility of ammonium nitrogen removal and regeneration by zeolite adsorption in drinking water treatment. Also, the reuse possibility of zeolite is evaluated to change the removal efficiency of ammonium nitrogen through several times of regeneration. The ammonium nitrogen was not removed in sand filter, but it was almost removed in zeolite filter during 7 days. The sand and zeolite filters have a similar result of turbidity removal. Therefore, zeolite filtration was confirmed the removal of turbidity and ammonium nitrogen as a media. When compared KCl with NaCl as a chemical for zeolite regeneration, it is demonstrated that KCl was more efficient than NaCl in the ability of zeolite regeneration. The adsorption rate of ammonium nitrogen was almost not decreased in the results of several times of regeneration. It is indicated that both zeolite and regeneration solution were possible to reuse without variation of regeneration rate through this study.

• Food Science and Preservation
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• v.5 no.2
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• pp.123-126
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• 1998

This study was carried out investigate to optimum levels of nitrogen and phosphate fertilizer to get a higher yield and a quality of an onion(Allium Cepa L.) from 1993 to 1994. Three fertilizer levels were applied with 120, 240 and 360kg/ha of nitrogen and 100, 200 and 300kg/ha of P2O5 during the onion growing season. After harvesting the onion, it was storaged at given deposit. The growth and yield of the onion were better at the fertilizer levels of both 240 and 360kg/ha of nitrogen and of both 200 and 300kg/ha of P2O5 than at the level of 120kg/ha in nitrogen and 100kg/ha of P2O5. The content of total nitrogen and P2O5 in plant was decreased with reduced application levels of nitrogen and phosphate fertilizer. The rotting rate was higher at the levels of both 360kg/ha in nitrogen and 300kg/ha in P2O5 than the other treatment during the storage period. The sprouting rate tended to be high at 240kg/ha of nitrogen and 100kg/ha of P2O5.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.527-533
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• 2003

This experiment was conducted in 2001 to investigate the effect of four nitrogen levels (0, 5.5, 11, 16.5kg/10a) on the yield and quality of vice especially with respect to eating quality. One early-maturing variety (Daejinbyeo) and two mid-late-maturing varieties (Ilpumbyeo and Chucheongbyeo) were used in this experiment. Rice yields of all varieties were increased by the higher rate of nitrogen application, mainly due to a larger number of panicles per m2. Head rice ratio was reduced significantly with an increased rate of nitrogen, while immature vice ratio was increased significantly. Increasing the nitrogen application rate, a considerable increase of protein content was found in all tested rice varieties. Palatability value of Daejinbyeo and Ilpumbyeo measured by rice taster was not affected by nitrogen application rate ranging from 0 to 11 kg/10a, but it was decreased significantly at the rate of 16.5kg/10a. In contrast, the palatability value of Chucheongbyeo was decreased significantly by increasing nitrogen application at the whole application rate. A positive correlation was found between nitrogen application rate and protein content (r=$0.88^{**}\textrm{-}0.96^{**}$), but head rice (r=$-0.84^{**}$~$-0.91^{**}$) and palatability value (r=$-0.72^{**}$~$-0.85^{**}$) showed a negative correlation with the nitrogen application rate. Regardless of the fact that eleven aroma-active volatile compounds were detected in cooked vice of Chucheongbyeo, it was concluded that the aroma-active volatile compounds of cooked rice was not affected by the different nitrogen application rate. The results of this study showed that the standard nitrogen fertilization rate of 11kg/10a could be appropriate considering both rice yield and palatability.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.37-40
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• 2005

In order to find out better cultivation practices in mid-mountainous area to produce high quality rice, an experiment involving seven nitrogen fertilizer rates and three varieties was carried out, during past two years$(2003\~2004)$. There was an interaction effect on palatability of milled rice between nitrogen fertilizer rate and variety. The palatability of Junambyeo grown by the treatment of nitrogen fertilizer yale wasn't different across the rates significantly, but Hwayongbyeo's palatability grown by 0 kg/ha nitrogen treatment was better than 50, 70,170 kg/ha, and Sangmibyeo's palatability grown by 70 kg/ha nitrogen treatment was better than 90, 110, 140, 170 kg/ha. Amylose content of milled rice was showed without a significant difference between nitrogen fertilizer rate, but in between variety, the amylose content of Sangmibyeo was lower than Hwayongbyeo's, also Hwayongbyeo's amylose content was lower than Junambyeo's. Protein content of milled rice was showed an interaction effect between nitrogen fertilizer rate and variety. The protein content of Hwayongbyeo and Junambyeo grown by the treatment of nitrogen fertilizer rate wasn't different across the fertilizer yale significantly, but Sangmibyeo's protein content grown by 0 kg/ha nitrogen treatment was lower than the rest of treatments, and it's protein content grown by 50, 70, 90 and 110 kg/ha nitrogen treatment was lower than 140 and 170 kg/ha. Bead rice yield of milled rice grown by lower nitrogen fertilizer rate, was lower than that grown by higher nitrogen fertilizer rate. In a conclusion gathering all above the results to produce high quality rice in Mid-mountainous area, the applicative nitrogen fertilizer rate was 70 kg per ha for Sangmibyeo, 110 kg/ha for Hwayongbyeo and 140 kg/ha for Junambyeo, in considering with head rice yield, palatability, amylose${\cdot}$protein content and productivity.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.4
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• pp.203-210
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• 2001

To establish the recycling system of animal manure(AM) for environmental preservation and improve the utilization of AM, this study was to investigate the effects of the types and nitrogen application rate of AM on herbage productivity, efficiency of nitrogen utilization, nutritive value and an increase of soil fertility and in mixed grassland. This sudy was arranged in split plot design. Main plots were the types of AM(Cattle feedlot manure, CFM; Pig manure fermented with sawdust, PMFS; cattle sluny, CS) and subplots were the application rate of animal manure, such as 100, 200 and 300kgNiha. I. DM yields of herbage were the highest with CS and decreased by application over ZOOkgNiha AM. 2. Crude protein(CP) ontent was the highest with CFM and followed by CS, and the lowest with PMFS, and increased as application rate of AM increased. 3. Nitrogen(N) yields of CS treatment was higher than that of CFM and CS. and increased significantly as application rate of AM increased(P<0.05). 4. The contents of NDF, ADF and TDN was hardly influenced by the types and application rate of AM. 5. Organic matter(0M) content in the soil was the highest with PMFS and followed by CFM and the lowest with CS. OM content increased significantly as application rate of AM increased(P<0.05). 6. Total nitrogen content of the soil was not affected by the type of AM, but increased significantly as application rate of AM increased(P<0.05). (Key words : Animal manure, Grassland, Cattle feedlot manure, Pig manure fermented with sawdust, Cattle slurry, Soil fertility)