• Applied Biological Chemistry
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• v.51 no.1
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• pp.1-5
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• 2008

Salt accumulation in soils of greenhouse due to the massive application of nitrogen fertilizers causes salt stress on the various crops, a serious problem in domestic agriculture. Since the majority of the salinity is nitrate, the excess nitrate should be removed; therefore, a bacterial strain having high capacity of nitrate uptake and identified as Enterobacter amnigenus GG0461 was isolated from the soils of greenhouse. Optimum conditions for the bacterial growth and nitrate uptake were investigated. GG0461 was able to grow without nitrate; however, nitrate facilitated the growth. The rate of nitrate uptake increased at alkaline pH and both growth and nitrate uptake were maximal at pH 8-9. When the initial pH of culture medium was increased to pH 8 or 9, it was decreased to neutral upon bacterial growth and nitrate uptake. These results imply that the major factor mediating bacterial nitrate uptake is a nitrate/proton antiporter. The fact was supported by the effect of nitrate addition in the absence of nitrate, since the addition of nitrate greatly increased the nitrate uptake and rapidly decreased pH of media.

• Journal of Environmental Science International
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• v.12 no.8
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• pp.841-846
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• 2003

The ecosystem model was applied to estimate the regional distribution of the net production(or consumption) of phytoplankton and the net uptake(or regeneration) rate of nutrients in Masan Bay for scenario analysis to find a proper management plan. At the surface level, net production of phytoplankton is 200 mgC/㎡/day at the entrance of the bay, and 400∼1000 mgC/㎡/day at the center of the bay. The inner area of the bay showed more than 2000 mgC/㎡/day. All areas of the bottom level have a net consumption, with the center of the bottom level showing more than 600 mgC/㎡/day. For dissolved inorganic nitrogen, the results showed a net uptake rate of 100∼900 mg/㎡/day at the surface level. It showed that the net regeneration is above 50 mg/㎡/day at the bottom level. For dissolved inorganic phosphorus, the net uptake rate showed 10.0∼80.0 mg/㎡/day at the surface level, and the regeneration rate showed 0∼20.5 mg/㎡/day at the bottom level. Therefore, in order to control the water quality in Masan Bay, it is important to consider the re-supplement of nutrients regenerated in the water column.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.4
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• pp.225-233
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• 1978

Uptake and distribution of labelled urea, $NH{_4}^+$, and $NO{_3}^-$ by Tongil and Jinheung rice grown with each nitrogen source until ear formation stage under water culture system were as follows. 1. When the previous nitrogen source was same as one tested the uptake rate ($mg^{15}N/g$ d.w. root 2hrs, at $28^{\circ}C$ light) was great in the order of $NH_4$ >urea> $NO_3$ and higher (especially $NH_4$) in Tongil than in Jinheung. Rate limiting step (slowest) seems to be exist at R (root)${\rightarrow}$LS(leaf sheath) for urea, LS${\rightarrow}$LB(leaf blade) for $NH_4$ and M(medium)${\rightarrow}$R for $NO_3$. The fast step of translocation appeare to be at M${\rightarrow}$R for urea R${\rightarrow}$LS for $NH_4$ and LS${\rightarrow}$LB for $NO_3$. 2. The uptake rate of $NH_4$ by the urea-fed plant increased almost linearly from $18^{\circ}C$ via $28^{\circ}C$ to $38^{\circ}C$ in Tongil ($Q_{10}$=1.21 and 1.32 respectively) while no change in Jinheung ($Q_{10}$=0.99 and 1.00 respectively). It decreased by 12% in Jinheung under dark but uo change in Tongil. 3. The uptake rate of nitrogen source by different source-fed plant was great in the order of $NH_4{\rightarrow}^{15}NO_3$ $NO_3{\rightarrow}^{15}NH_4$, $urea{\rightarrow}^{15}NO_3$ and higher (especially $NH_4{\rightarrow}^{15}NO_3$) in Tongil. In the case of $urea{\rightarrow}^{15}NH_4$ it was same in $NH_4{\rightarrow}^{15}NO_3$ for Tongil and slightly lower than that in $NO_3{\rightarrow}^{15}NH_4$ for Jinheung. It was lower (especially Tongil) in $NH_4{\rightarrow}^{15}NO_3$ than in $NH_4{\rightarrow}^{15}NH_4 $ 4. The uptake rate (in $NH_4{\rightarrow}^{15}NO_3$) was higher during 15 minutes than during 2 hours and always higher in Tongil. 5. $^{15}N$ excess % and content in each part, and uptake rate of root seems to have their own significance relatling with metabolism and translocation respectively. The change of nitrogen nutritional environment and source preference of varieties were discussed in relation to field condition and efficient use of nitrogen fertilizer.

• Journal of the Korean Institute of Rural Architecture
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• v.2 no.1
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• pp.89-100
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• 2000

Recently, according to the increase of population and rapid growth of industry, the amount of effluent pollutant has been rising in natural water. In these pollutant, nutrients such as nitrogen and phosphor are told that these evolve the odor, color and eutrophication in rural housing sewage and lake regulary. Many researches have been carried out to remove these nutrients from effluents and will have to be studied more deeply. Especially, because of the sewage of rural housing and livestock, environmental pollution raises serious problem in a rural community. This method is developed to solve the problem environmentally friendly. Using the natural energy(wasteheat, earthheat, solar engery) and the growth properties of aquatic plants are most efficient method to absorb the nutrients and denitrification and phosphor uptake.

• Textile Coloration and Finishing
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• v.8 no.3
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• pp.59-65
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• 1996

Cotton fabrics were treated by low temperature plasma and/or cellulase, and its physical and dyeing properties were investigated. All the pretreatments of the cotton with low temperature plasma of oxygen, nitrogen and argon slowed down the rate of weight loss of cotton in cellulase solution. Plasma pretreatment did not show any strength retention effect on cotton fiber in the subsequent cellulase treatment. Pretreatment of cotton with low temperature oxygen plasma decreased the rate of dyeing in direct dye bath, while cellulase or plasma/cellulase pretreatment increased the rate. Equilibrium dye uptake of cotton was not changed greatly by the pretreatments except the normal untreated cotton showed more or less high uptake. The pretreatment of cellulase with a water-soluble carbodiimide reduced the enzymatic activity, and did not show any strength retention of cotton in enzymatic weight loss.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.2
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• pp.59-66
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• 2001

In order to determine the influence of nitrogen on agronomic characters, forage yield and quality, a Kenaf was cultured on the volcanic ash soil at the Experimental Farm of Cheju national University under the seven levels of nitrogen rates(0, 50, 100, 150, 200, 250kg/ha) from April 25 to Dec. 25, 1999. The plant height increased by increase of nitrogen rate, showing longest 250kg/ha with 286.6cm and shortest at no application plot with 255.7cm. The difference on leaf number, leaf withering number, stem diameter and branches number by nitrogen rate showed a similar tendency to the plant height. Increasing N rate from 0 to 250kg/ha fresh forage yield form 55.8 to 99.8MT/ha, dry matter (DM) yield from 8.8 to 15.8MT/ha, crude protein(CP) yield form 1.2 to 3.1MT/ha, total digestible nutrients (TDN) yield from 3.8 to 8.6MT/ha. However, no significant differences in these yields were found between 200 and 250kg N/ha. Nitrogen uptake increased form 192.9 to 496.2 kg/ha but N use efficiency decreased form 95.0 to 66.6 kg DM$^{a}$ /kg N with increasing from 0 to 250 kg/ha. As N rate increased from 0 to 250kg/ha, leaf and stem out of CP, crude fat (CF), nitrogen free extract (NFE), TDN contents increased from 20.1% to 25.8% and from 9.7% to 12.4%, from 5.6% to 8.1% and from 3.3% to 4.4%, from 36.1% to 40.2% and from 21.9% to 32.4%, from 59.3% to 75.0% and from 32.2% to 38.2%, respectively, while leaf and stem out of crude fiber decreased from 18.5% to 16.7% and from 51.5% to 39.3%. Based on the these findings, the optimum N rate for forage production of kenaf seems to be about 200 kg/ha in atmospheric phenomena and volcanic ash soils of jeju island.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.1
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• pp.32-40
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• 2006

The nitrogen (N) absorption and partition of the rice plants are important indicators that can be used to improve the N use efficiency (NUE) of the plants. Improving the plant NUE can help to avoid nutrient waste that may cause environmental pollution. To investigate the N absorption and partition of the rice plants, Hwaseongbyeo (Japonica) and Dasanbyeo (indica/japonica) were applied with N fertilizers at the rates of 60, 120, and 180 kg N per ha in paddy field. Also micro plots of $0.81m^2$ were established inside each plot for application of $^{15}N-labeled$ fertilizer. The differences in N utilization of the rice plants were associated with the total N absorption and partitioning after the heading stage. In the grain filling period, the increase of nitrogen content in the total and leaf blades of Dasanbyeo was higher than that of Hwaseongbyeo. Soil N was the main contributor for the increase of total N of Dasanbyeo during the grain filling period. The N fertilizer uptake rate of Hwaseongbyeo rapidly increased with the increment of N fertilization rate. In Dasanbyeo, N fertilizer uptakes were similar under all rates and times of N application. From heading stage to harvest, Dasanbyeo continued accumulating nitrogen, whereas Hwaseongbyeo had small changes. In conclusion, the difference in nitrogen absorption and partition after heading of the two cultivars was caused by the ability of Dasanbyeo to accumulate and remobilize soil nitrogen to the grains during the grain filling period.

• Journal of Environmental Science International
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• v.6 no.5
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• pp.521-529
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• 1997

In the study, we Investigated the behavior and removal efficiency of organics, nitrogen. phosphorus with operating conditions in SBRs. Substrate used was synthetic wastewater in which the ratio of $COD_{cr}$. : N : P was 100 : 12 : 2. The cycling the in SBRs was adjusted at 6 hours and 8 hours, and then certainly Included anaerobic and aerobic conditions. Also, for each cycling time. we performed 2 series of experiment simultaneously which was set up 10 days and 20 days as SRT. The removal efficiency of $COD_{cr}$. was over 97% in all operating conditions. In the 6 hours cycling time, the removal efficiency of $PO_4^{3-}-P$ reached almost 100% in steady state. And then we could observe a typical phonemena of phosphorus release and uptake, and the removal efficiency of N was 67%, Residual N source was almost TKN and most of the rest remained as $NO_2-N$. Also the difference in both SRTs was not observed practically. In the 8 hours cycling time, dissolution of sludge appeared. and, $PO_4^{3-}-P was not nearly removed but nitrogen was removed up to 75%, And the residual nitrogen was accumulated as $NO_2^--N$.

• Journal of Environmental Science International
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• v.16 no.1
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• pp.45-53
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• 2007

This study was carried out to investigate the variation of organic, nitrogen and phosphorus in $(AO)_2$ SBBR process according to the variation of operating cycle at the high TOC concentration. The operation time in anoxic (anaerobic) time to oxic time was 1:1. Three lab-scale SBBRS were fed with synthetic wastewater based on glucose as carbon source, The variation of total TOC removal was similar each other irrespective of operation time, however, the TOC concentrations in SBBRs showed a little difference according to the operating condition. In SBBR, complete nitrification was not occurred at all reactors, however, R3 showed a higher nitrification than R2. And in SBBR, the variation of operating time more affected at phosphorus removal than nitrogen removal. R2 which had the shortest time at the 1st aeration time showed the lowest phosphorus release and uptake efficacy.

• Carbon letters
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• v.3 no.1
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• pp.13-16
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• 2002

The modification of coal-tar pitch has been carried out by heat treatment of pitch at different temperatures in the range ($300^{\circ}-400^{\circ}C$) for different times (2-5 hrs) in air and nitrogen. The pitch heat treated in air at lower temperature ($300^{\circ}C$) exhibit increase in softening point by $20^{\circ}C$ as compared to only $2^{\circ}C$ when treated in nitrogen. The changes are faster in air than in pure nitrogen. Pitch as such as well as after heat treatment were further treated with metal complexes by solution route. Silver intake has been found to increase from 0.5 to 0.8 % in nitrogen treated pitch while the uptake is found to decrease for pitches treated in air at $350^{\circ}C$ for 5 hrs. Experiments have also been made to incorporate silver into PAN and PAN-ox fibers through solution route. The metal intake has been found to be more in PAN-ox fibers than in PAN as such. Metal loaded carbon composites have been made by using metal loaded fibers as well as cokes. These composites as such exhibit higher surface oxygen complexes but decrease after activation.