• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.10
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• pp.861-867
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• 2001

In this paper, in order to investigate the catalytic effect of the sludge exhausted from waterworks on NO$_{x}$ removal, we measure NO removal characteristics with and without sludge pellets in BaTiO$_3$-sludge packed-bed reactor of plate-plate geometry. NO initial concentration is 50 ppm balanced with air and a gas flow rate is 5ι/min. Gas temperature is changed from 25 to 10$0^{\circ}C$ to investigate the role of sludge pellet on removing active oxygen species and NO$_2$. BaTiO$_3$pellets is filled for coronal discharge at upstream of reactor and sludge pellets is filled for catalytic effect at downstream of reactor. The volume percent of sludge pellets to BaTiO$_3$pellets is changed from 0% to 100% and AC voltage is supplied to the reactor for discharging simulated gases. In the results, when sludge pellets is put at the downstream of plasma reactor, NO removal rate is slightly increased. However, NO$_2$and $O_3$ as by-products during NO removal is significantly decreased from 51ppm without sludge pellets to 5 ppm with sludge pellets and from 50 ppm without sludge pellets to 0.004ppm with sludge pellets, respectively. Therefore, NO$_{x}$(NO+NO$_2$) removal rate is increased up to 93%. It is thought that sludge pellet maybe react with active oxygen species and NO$_2$ generated by corona discharge in surface of BaTiO$_3$pellets, the then NO$_2$O$_3$as by-products are considerably decreased. When we increase gas temperature from room temperature to 10$0^{\circ}C$, NO removal rate is decreased, while NO$_2$ concentration is independent on gas temperature. These result suggest that the removal mechanism of active oxygen species and NO$_2$in sludge pellet is not absorption, but chemical reaction. Therefore we expect that sludge pellets exhausted for waterworks could be used as catalyst for NO$_{x}$ removal with high removal rate and low by-product.oduct.

• Journal of Conservation Science
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• v.29 no.3
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• pp.197-207
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• 2013

The gas acceleration test was conducted to identify the deterioration of Korean traditional textiles caused by $NO_2$. Total 20 specimens were prepared using 4 different materials (silk, cotton, ramie, hemp) after dyeing with 5 colors (undyed, red, yellow, blue, black). The specimens were exposed to 0.01, 0.1, 1, 10, 100, and 1000 ppm $NO_2$ gas in the test chamber at $20^{\circ}C$, 50% RH for 1 day. Optical, chemical, and physical evaluation was carried out after the exposure. In the case of Korean traditional textile, color difference increased at 1 ppm/day, $NO_3{^-}$ concentration, carbonyl and C-$NO_2$ functional group increased while pH decreased at 10 ppm/day and tensile strength weakened at 100 ppm/day. when it comes to undyed textile, alteration of color difference on silk and hemp cloth, $NO_3{^-}$ concentration and tensile strength on hemp cloth was remarkable. In addition, color difference on blue and yellow textile, $NO_3{^-}$ concentration increase of yellow textile and tensile strength decrease of hemp cloth & ramie cloth were significant. The results suggest that critical $NO_2$ concentration of optical, chemical, and physical damage on Korean traditional textiles are 1ppm/day, 10 ppm/day, 100 ppm/day respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.782-793
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• 1997

To study the physiological adaptation (shift-up) of phytoplankton under the simulated upwelling conditions, nitrate uptake capacity of Dunaliella tertiolecta batch culture was measured in the laboratory using the stable isotope $^{15}N-KNO_3$. Contrary to the expected, there was no significant relationship between the maximum $V_{NO3}$ (nitrogen specific nitrate uptake rate) and the initial nitrate concentration. However, there was a strong relationship between the maximum $\rho_{NO3}$ (nitrate transport rate) and the initial nitrate concentration of $<25\;{\mu}M$, which was also influenced by the physiological status of the culture. The increase in $V_{NO3}$ was mainly due to the increase in PON (particulate organic nitrogen) concentration and partly due to the increase in $V_{NO3}$. When the phytoplankton population was severely shifted-down, the physiological adaptation of nitrate uptake was significantly inhibited at high initial nitrate concentrations. The timing of the maximum $V_{NO3}$ or $\rho_{NO3}$ was related to the initial nitrate concentration. At higher initial nitrate concentrations, maxima in $V_{NO3}$ and $\rho_{NO3}$ occurred 1 or 2 days later than at lower nitrate concentrations. This relationship was the opposite to the prediction from the shift-up model of Zimmerman et al. (1987), The shift-up process is apparently controlled by an internal time sequence and the initial nitrate concentration, but the magnitude of $V_{NO3}$ was affected little by changes in nitrate concentration.

• Korean Journal of Environmental Agriculture
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• v.28 no.2
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• pp.165-170
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• 2009

The increase in P availability to rice under flooded soil conditions involves the reductive dissolution of iron phosphate and iron (hydr)oxide phosphate. However, since $NO_3^-$ is a more favourable electron acceptor in anaerobic soils than Fe, high$NO_3^-$ loads function as a redox buffer limiting the reduction of Fe. The effect of adding $NO_3^-$ on Fe reduction and P release in paddy soil was investigated. Pot experiment was conducted where $NO_3^-$ was added to flooded soil and changes of redox potential and $Fe_2^+$, $NO_3^-$ and $PO_4^{3-}$ concentrations in soil solution at 10 cm depth were monitored as a function of time. Redox potential decreased with time to -96 mV, but it was temporarily poised at about 330${\sim}$360 mV when $NO_3^-$ was present. Nitrate addition to soil led to reduced release of $Fe_2^+$ and prevented the solubilization of P. Phosphate in pore water began to rise soon after incubation and reached final concentrations about 0.82 mg P/L in the soil without $NO_3^-$ addition. But, in the soil with $NO_3^-$ addition, $PO_4^{3-}$ in pore water was maintained in the range of 0.2${\sim}$0.3 mg P/L. The duration of inhibition in $Fe_2^+$ release was closely related to the presence of $NO_3^-$, and the timing of $PO_4^{3-}$ release was inversely related to the $NO_3^-$ concentration in soil solution. The results suggest that preferential use of $NO_3^-$ as an electron acceptor in anaerobic soil condition can strongly limit Fe reduction and P solubilization.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.736-745
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• 2016

This research was conducted to evaluate the impact of various pre-planting $NH_4{^+}:NO_3{^-}$ ratios on the growth of plug seedlings of 'Bool-am No.3' Chinese cabbage. With fixation of the pre-planting N concentrations to $300mg{\cdot}kg^{-1}$ in a peatmoss+coir dust+perlite (3.5:3.5:3, v/v/v) medium, the $NH_4{^+}:NO_3{^-}$ ratios were varied to 0:100, 27:73, 50:50, 73:27, 100:0. Then, the each of root media containing various ratios of $NH_4{^+}:NO_3{^-}$ as well as equal concentrations of other essential nutrients was packed into 72-cell plug trays. After seeds of 'Bool-am No.3' Chinese cabbage were sown, the seedling growths were measured 2 and 4 weeks after sowing. The weekly analysis of root media and end-crop tissue analysis for mineral nutrients 4 weeks after seed sowing were also conducted. As the seedlings grew up, the pH of the root media increased, however ECs in all treatments of $NH_4{^+}:NO_3{^-}$ ratios decreased. The concentrations of K, Ca and Mg in root media were higher in the treatments of $NH_4{^+}:NO_3{^-}$ (100:0) and $NH_4{^+}:NO_3{^-}$ (73:27) than those of $NH_4{^+}:NO_3{^-}$ (0:100) and $NH_4{^+}:NO_3{^-}$ (27:73) 2 weeks after seed sowing. But the concentrations of K, Ca, Mg and Zn were get lowered in all treatments and the differences among treatments were not significant 4 weeks after sowing. The highest $NH_4{^+}$ and lowest $NO_3{^-}$ concentrations of the root media were observed in the $NH_4{^+}:NO_3{^-}$ (100:0) among all treatments. Contrary to these, the treatment of $NH_4{^+}:NO_3{^-}$ (0:100) had the lowest $NH_4{^+}$ and highest $NO_3{^-}$ concentrations. The seedling growth in terms of fresh and dry weights of aerial part were the highest in the treatment of $NH_4{^+}:NO_3{^-}$ (23:73) at 2 weeks after sowing and those of $NH_4{^+}:NO_3{^-}$ (50:50) at 4 weeks after sowing. The survival rate of seedlings in $NH_4{^+}:NO_3{^-}$ (100:0) treatment were 19% and the growth of aerial part 4 weeks after sowing was the poorest among all treatments tested. The results mentioned above indicate that the pre-planting $NH_4{^+}$ ratio in inert media should not exceed 25% in plug stage 1 through 3 (until 2 true leaf development) and 50% in plug stage 4 (after 2 true leaves to transplant).

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.120-130
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• 1996

Crisphead lettuce(Lactuca sativa L.) was grown in NFT to investigate the effects of NO$_3$-N and NH$_4$-N ratio in nutrient solution and elevated $CO_2$ treatment in the crisphead lettuce growth. This experiment has been conducted under three different ratios of NO$_3$-N:NH$_4$-N(100:0, 75:25, 50:50) with two $CO_2$ concentration (control, 1500ppm ). The results are as follows; 1. In the case of not controlling pH and EC in nutrient solution, pH was gradually increased in NO$_3$-N:NH$_4$-N=100:0 treatment but rapidly decreased in the nutrient solution 2. Daily changes of NO$_3$-N and NH$_4$-N were observed without controlling the nutrient solution. In the treatments of NO$_3$-N:NH$_4$-N ratios were 75:25 and 50:50, NO$_3$-N absorption rates were 27.7% and 26.1%, while NH$_4$-N absorption rates were 87.9% and 71.2%, respectively. 3. There was little differences in total nitrogen of leaves. However phosphorus, potassium, calcium and magnesium contents were highly shown in the treatment of $CO_2$ 1500ppm and 100:0 ratio of NO$_3$-N:NH$_4$-N. 4. Higher $CO_2$ assimilation rate was shown in plants grown under $CO_2$ 1500ppm and 100:0 ratio of NO$_3$-N:NH$_4$-N. It dropped significantly with the increase of NH$_4$- N rates in nutrient solution. 5. Fresh weight, leaf number, root length and root weight of crisphead lettuce were far better in the treatment of $CO_2$ 1500ppm and 100:0 ratio of NO$_3$-N:NH$_4$-N. Growth differences by $CO_2$ elevation were not shown in other NO$_3$-N:NH$_4$-N treatments. 6. The highest nitrate contents of leaves were shown in NO$_3$-N single treatment but shown the lowest vitamin C contents. Nitrate contents of leaves were decreased by $CO_2$ but the effect was slight treatment.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.1
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• pp.10-19
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• 1993

This study reports the influence of nitrogen application on the yield and the accumulation of $NO_3{^-}$ in edible parts of major vegetables in a pot experiment treated with five levels(0, 1, 2, 4, 8g N/pot) of nitrogen. In the $NO_3{^-}$ accumulation of chinese cabbage the outer leaf were superior to the inner leaf. The $NO_3{^-}$ contents of the midrib in outer and inner leaf were higher than those of the leaf blade. By increasing the nitrogen application, the accumulationsgap in $NO_3{^-}$ accumulation between midrib and leaf blade in a leaf, became larger. The difference ratio of $NO_3{^-}$ accumulation in the outer leaf reached 4.8:1 at 8g N/pot treatment. In theradish, the $NO_3{^-}$ accumulation in the aerial root parts is higher than those of the underground root parts, and it is higher in the leaf than in the petiole. The accumulation of $NO_3{^-}$ in sarcocarp of cucumber was increased along with the added amount of nitrogen, but contents of $NO_3{^-}$ in the core of the cucumber showed no differences in the treatment levels. The $NO_3{^-}$ accumulation differences of outer sarcocarp vs. inner core parts in cucumber was increased along with the higher nitrogen levels, and its difference ratio of $NO_3{^-}$ accumulation reached 13.1:1 at 8g N/pot treatment. The highest $NO_3{^-}$ accumulation in edible parts of chinese cabbage, radish and cucumber were found at the 8g N/pot treatment, and were 3,664ppm in the outer leaf midrib of chinese cabbage, 3,449ppm in the aerial part of root of radish, and 484ppm in sarcocarp part of cucumber. Compared with the control each 130 times, 40.8 times, 20.9 times, respectively. There are positive correlation coefficients between the amount of nitrogen fertilization, $NO_3{^-}$ accumulation in the edible parts, yield, and yield components of edible parts.

• the MEAT Journal
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• s.36 summer
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• pp.61-71
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• 2009

The aim of this work was to analyze the effects of salt and NaNO2 on weight loss, proximate compositions, chemical parameters and texture characteristics of dry-cured ham processed using Korean methods. Four different treatments were considered: The H8 group of 3 hams (11.30 kg) was salted with 9.2 g/kg salt (w/w) (high salt batch), the HS+NaNO2 group of 3 hams (10.65 kg) was salted same as HS group and added 100 ppm NaNO2. The LS group of 3 hams (11.42 kg) was salted with 6.2 g/kg salt (w/w) (Low salt batch), the LS+NaNO2 group of 3 hams (10.62 kg) was salted same as L8 group and added 100 ppm NaNO2. The highest weight losses took place at the drying stage (27.46, 28.25, 26.99, and 28.42%). However, there were no significant differences in the weight losses between treatments (p>0.05). The moisture content was significantly affected with addition of NaNO2 (p<0.05), the L8 hams had significantly higher moisture content than HS + NaNO2 and L8 + NaNO2 (p<0.05). The level of salt and NaNO2 did not affect the fat, protein and ash contents. The hardness and chewiness in biceps femoris muscle from L8 hams were significantly lower than in the muscles from HS + NaNO2 hams (p<0.05). The NaNO2 did not affect the texture characteristics of dry-cured hams. The processing conditions significantly affected the chemical parameters of biceps femoris muscle (p<0.05). The water activity in biceps femoris muscle from L8 hams was significantly higher than in muscles from HS and H8+NaNO2 hams (p<0.04). The salt content in biceps femoris muscles from LS + NaNO2 hams was significantly lower than in the muscles from HS and HS + NaNO2 hams (p<0.05). The NaNO2 treatment did not affect the NaNO2 content in biceps femoris muscles (p>0.05). The processing conditions did not significantly affect the lightness (L), redness (a), and $h^{\circ}$ of biceps femoris muscles (p>0.05). The yellowness (b) and chroma in biceps femoris muscle from HS + NaNO2 hams were significantly higher than in the muscles from HS and LS hams.

• Clean Technology
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• v.2 no.1
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• pp.96-108
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• 1996

$NO_x$ is mainly emitted from mixed acid pickling process in the stainless industry and its impact to the environment has been worried over. This study which may be considered as one of the development of clean technologies, differing from the traditional end pipe technology is about how to reduce $NO_x$ emission through the modification of corresponding process. This study consists of two parts. First, the influence of various reaction parameters in a acid pickling process on $NO_x$ emission was investigated. Second, the influence of hydrogen peroxide on $NO_x$ formation, which is known as inhibitor of $NO_x$ emission, was investigated. Major findings in this study are as follows. The important reaction parameters which have a great influence on $NO_x$ emission are the reaction temperature and the concentration of fluoric acid. The concentration of nitric acid, some of which results in $NO_x$ compound is not as important as the concentration of fluoric acid. Synthetic mixed acid of nitric acid and fluoric acid itself in absent of pickling plate contributed the $NO_x$ emission, however, its impact was negligible in terms of quantity. The addition of hydrogen peroxide to the acid pickling process significantly contributed to the reduction of $NO_x$ emission and successfully achieved 80% reduction of $NO_x$ emission at the condition of $9.51{\times}10^{-2}mole\;hydrogen\;peroxide/m^2$ pickling area. This result was compared to literature value from Avesta steel process, indicating a sixth of hydrogen peroxide addition of Avesta's in achieving a same amount of $NO_x$ reduction. The region of the economic hydrogen peroxide addition per unit area of plate to be pickled from the result of this study was established.

• Food Science of Animal Resources
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• v.28 no.4
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• pp.493-498
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• 2008

The aim of this work was to analyze the effects of salt and $NaNO_2$ on weight loss, proximate compositions. chemical parameters and texture characteristics of dry-cured ham processed using Korean methods. Four different treatments were considered: The HS group of 3 hams (11.30 kg) was salted with 9.2 g/kg salt (w/w) (high salt batch), the HS+$NaNO_2$ group of 3 hams (10.65 kg) was salted same as HS group and added 100 ppm $NaNO_2$. The LS group of 3 hams (11.42 kg) was salted with 6.2 g/kg salt (w/w) (Low salt batch), the LS+$NaNO_2$ group of 3 hams (10.62 kg) was salted same as LS group and added 100 ppm $NaNO_2$. The highest weight losses took place at the drying stage (27.46, 28.25, 26.99, and 28.42%). However, there were no significant differences in the weight losses between treatments (p>0.05). The moisture content was significantly affected with addition of $NaNO_2$ (p<0.05), the LS hams had significantly higher moisture content than HS+$NaNO_2$ and LS+$NaNO_2$ (p<0.05). The level of salt and $NaNO_2$ did not affect the fat, protein and ash contents. The hardness and chewiness in biceps femoris muscle from LS hams were significantly lower than in the muscles from HS+$NaNO_2$ hams (p<0.05). The $NaNO_2$ did not affect the texture characteristics of dry-cured hams. The processing conditions significantly affected the chemical parameters of biceps femoris muscle (p<0.05). The water activity in biceps femoris muscle from LS hams was significantly higher than in muscles from HS and HS+$NaNO_2$ hams (p<0.05). The salt content in biceps femoris muscles from LS+$NaNO_2$ hams was significantly lower than in the muscles from HS and HS+$NaNO_2$ hams (p<0.05). The $NaNO_2$ treatment did not affect the $NaNO_2$ content in biceps femoris muscles (p>0.05). The processing conditions did not significantly affect the lightness (L), redness (a), and $h^{\circ}$ of biceps femoris muscles (p>0.05). The yellowness (b) and chroma in biceps femoris muscle from HS+$NaNO_2$ hams were significantly higher than in the muscles from HS and LS hams.