• Journal of the Korean Society of Tobacco Science
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• v.1 no.2
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• pp.120-126
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• 1979

The nitrogen contents of some forms in Burley tobacco leaf cultivated in Yaesan, Mokpo and Namwon district were investigated. The rate of each form in total nitrogen contents were as follows ; Protein form nitrogen 30~33 % Nitrate form nitrogen 10~123% Alkaloid form nitrogen 8~16 % Ammonia form nitrogen 6~9% Amide form nitrogen 2~ 3% Other form nitrogen 26~44 % The order of nitrate form nitrogen content on the nitrogen of each tobacco cultivated in three area was Yaesan > Namwon > Mokpo, but that of alkaloid form nitrogen was reverse order of nitrate form nitrogen. As for Quality ( grade ), the orders of alkaloid and ammonia form nitrogen content on total nitrogen were H5> 3> 1> L 1> 3> 5, but that of nitrate form nitrogen was reversed.

• Journal of Bio-Environment Control
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• v.18 no.1
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• pp.40-45
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• 2009

The experiment has investigated the effects of growth, yield, fruit quality and cation absorption of strawberry 'Akihime' in different $NO_3-N:NH_4-N$ ratio in nutrient solution. $NO_3-N:NH_4-N$ ratios were 5.5:0, 4.0:1.5 and $3.0:2.5me{\cdot}L^{-1}$. As the ratio of $NH_4-N$ increased, pH was decreased by $5.0{\sim}6.0$ and EC sustained $0.8{\sim}1.0dS{\cdot}m^{-1}$ during experiment. Though in high $NH_4-N$ ratio of $3.0:2.5me{\cdot}L^{-1}$, the absorption of cations(K, Ca and Mg) was not inhibited. Treatment in contained $NH_4-N$ showed a tendency of increasing of petiole length and leaf width. The fruit length, fruit width, fruit weight and soluble solids were not significantly different. Yield per plant was lowest in $4.0:1.5\;me{\cdot}L^{-1}$, of $NO_3-N:NH_4-N$ ratio. Malformation fruit has not shown during the whole growth period.

• Korean Journal of Microbiology
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• v.26 no.3
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• pp.230-236
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• 1988

The distributions of bacterial numbers and activities were studied bimonthly in 1987, at 3 sites in Lade Paro for elucidating the changes by disturbance of aquatic ecosystem. The total bacterial number was $0.3\times 10^{5}-13.1\times ^{5}$ cells/ml. The geterotrophic bacterial number had the variance from $1.9\times 10^{3}$ CFUs/ml to $3.1\times 10^{4}$CFUs/ml and the variation trend was similar to that of the total bacterial number. The proportions of alpha-glucosidase or beta-glucosidase releasing bacteria showed temporal changes rather than spatial changes. The proportions of phosphatase releasing bacteria had the maximum values, 22.7-83.0%, in July. The electron transpory system activity revealed the variation from $480{\mu}gO_{2}$/l/day to $1696{\mu}gO_{2}$/l/day and hagher values at upper stream and in summer. The degradation fraction by phosphatase was 0.4-9.1%/h and increased with temperature. The maximum value of heterotrophic activity was 8.2%/h in summer. Eventhough the distributions of total bacteria and heterotrophic bacteria were affected by the water disturbance but microbial activities and proportions of the specific enzume releasing bacteria were not affected.

• Korean Journal of Plant Resources
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• v.22 no.5
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• pp.461-466
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• 2009

This study was carried out to evaluate the effects of yam (Dioscorea batatas Dence) extracts on the cell viability, growth and nucleus-DNA damage of tobacco cells which were exposed to $\gamma$-radiation stress. The viability and growth of tobacco cells exposed to 20 Gy of radiation stress were effectively recovered by pretreatment of 10 mg/L ethylacetate (EtOAc) yam extract. Pretreatment of EtOAc extract showed 20% higher cell viability and fresh weight growth than that of cells without pretreatment in 20 Gy radiation treated tobacco cells. Nucleus-DNA damage was measured as the ratio of tail length (T) to head length (H) in individual comet image isolated from tobacco cells. The T/H ratio of control-cells and treated-cells at 20 Gy were 1.05 and 1.68, and % head DNA of those cell were 86.7 and 71.3%, respectively, suggesting that nuclei of tobacco cells were severely damaged in the integrity of DNA by the treatment of $\gamma$-radiation. However, pretreatment of MeOH, EtOAc and n-BuOH extracts decreased radiation induced DNA-damage in the tobacco cells, showing T/H ratio of 1.37, 1.01 and 1.10 and % head DNA of 81.5, 87.6 and 88.7%, respectively.

• Tuberculosis and Respiratory Diseases
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• v.44 no.3
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• pp.592-600
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• 1997

Background : The level of imposed work of breathing (WOB) is important for patient-ventilator synchrony and during weaning from mechanical ventilation. Triggering methods and the sensitivity of demand system are important determining factors of the imposed WOB. Flow triggering method is available on several modern ventilator and is believed to impose less work to a patient-triggered breath than pressure triggering method. We intended to compare the level of imposed WOB on two different methods of triggering and also at different levels of sensitivities on each triggering method (0.7 L/min vs 2.0 L/min on flow triggering ; $-1\;cmH_2O$ vs $-2cm\;H_2O$ on pressure triggering). Methods : The subjects were 12 patients ($64.8{\pm}4.2\;yrs$) on mechanical ventilation and were stable in respiratory pattern on CPAP $3\;cmH_2O$. Four different triggering sensitivities were applied at random order. For determination of imposed WOB, tracheal end pressure was measured through the monitoring lumen of Hi-Lo Jet tracheal tube (Mallincrodt, New York, USA) using pneumotachograph/pressure transducer (CP-100 pulmonary monitor, Bicore, Irvine, CA, USA). Other data of respiratory mechanics were also obtained by CP-100 pulmonary monitor. Results : The imposed WOB was decreased by 37.5% during 0.7 L/min on flow triggering compared to $-2\;cmH_2O$ on pressure triggering and also decreased by 14% during $-1\;cmH_2O$ compared to $-2\;cmH_2O$ on pressure triggering (p < 0.05 in each). The PTP(Pressure Time Product) was also decreased significantly during 0.7 L/min on flow triggering and $-1\;cmH_2O$ on pressure triggering compared to $-2\;cmH_2O$ on pressure triggering (p < 0.05 in each). The proportions of imposed WOB in total WOB were ranged from 37% to 85% and no significant changes among different methods and sensitivities. The physiologic WOB showed no significant changes among different triggering methods and sensitivities. Conclusion : To reduce the imposed WOB, flow triggering with sensitivity of 0.7 L/min would be better method than pressure triggering with sensitivity of $-2\;cm\;H_2O$.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.4
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• pp.107-117
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• 2005

The objective of this study was to investigate the proper operation conditions of fenton oxidation such as initial pH, $H_2O_2/Fe^{2+}$ ratio, $H_2O_2/Fe^{2+}$ dosage amount, and neutralizing agent for pretreatment of the livestock wastewater. Fenton oxidation reagents were reacted with the livestock wastewater for 2 hours at 120 rpm and the settling was performed for 2 hours using jar-tester apparatus under the different experimental conditions. And then the supernatant was sampled and measured for the residual $H_2O_2$, $COD_{Cr}$, and SS. The results are as follows; optimum initial pH=4, optimum $H_2O_2/Fe^{2+}$ ratio=10:1, optimum $H_2O_2/Fe^{2+}$ dosage amount=5,000/500 mg/L and $Ca(OH)_2$ as proper neutralizing agent. The removal efficiency of $COD_{Cr}$ and SS were 43% and 84% under those optimal fenton oxidation conditions.

• Korean Journal of Medicinal Crop Science
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• v.7 no.1
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• pp.1-6
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• 1999

Basic informations for direct somatic embryo formation in Rehmannja glutinosa Lib. were obtained in 500ml erlenmyer flask. The ratio of ammonium to nitrate nitrogen of 825(mg/l) : 1900(mg/l) was proper condition for somatic embryo formation from stem and petiole explants and 3% sucrose was the most effective carbon source. Full strength MS medium with 2mg/l BA was better than LS medium for somatic embryogenesis. The initial pH 5.7 of medium(full strength MS with 2.0mg/l BA and 0.1mg/l NAA) was good for embryo production. Potassium ion was taken up rapidly within 2 weeks. while $Ca^{++}$ and $Mg^{++}$ ion contents were almost constant during culture period. Sucrose hydrolysis occurred throughout the culture, while glucose and fructose were absorbed simultaneously from the third week of culture.

• Journal of Animal Science and Technology
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• v.47 no.5
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• pp.789-804
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• 2005

This study was conducted to determine effects of supplementation levels of aqueous direct-fed microbials (DFM; Bacillus spp.) to TMR(exp. 1.) and aqueous DFM addition under the various ratios of starch and cellulose(exp. 2.) on ruminal fermentation and fibrolytic enzyme activity. In experiment 1, ruminal fluids taken from rumen-cannulated Holstein cows were incubated during 24 hr by using TMR as substrates. Aqueous DFM was applied at a rate of 0, 0.025 and 0.05%, respectively. The pH of 0.025% treatment was not significantly different from that of control at 6 and 9 hr, but it was significantly lower (P<0.05) than 0.05% treatment. Concentrations of ammonia-N and VFAs were not affected by supplementing aqueous DFM. The A:P ratio of 0.05% treatment was significantly increased(P<0.05) by supplementation of aqueous DFM as compared with that of control at 24 hr. Although overall fibrolytic enzyme activities were not significantly affected by supplementing aqueous DFM, CMCase(carboxymethylcellulase) activity showed significant increase(P<0.05) compared to control at 6hr. However, the xylanase activity of 0.05% treatment significantly decreased(P<0.05) at 12 hr due to the application of aqueous DFM. There was no significant difference for in vitro dry matter disappearance among treatments. In experiment 2, ruminal fluids were incubated under the condition of various ratios of starch to cellulose(90:10, 70:30, 50:50, 30:70 and 10:90) with or without aqueous DFM(0.025%). Ruminal pH was unaffected by the addition of aqueous DFM, however, as increased level of starch, ruminal pH partially showed significant decrease(P<0.05). Ammonia-N concentration was not affected by aqueous DFM and ratio of starch and cellulose. On 9 hr incubation, DFM addition at a ratio of 70:30 showed significantly (P<0.05) lower value of ammonia-N(35.65 mg/dL) than that(65.05 mg/dL) of control. Concentrations of VFAs were significantly increased(P<0.05) by aqueous DFM addition compared with control at the same ratio on 6 hr incubation. The overall CMCase activity was not affected by aqueous DFM addition. However, the xylanase activity by aqueous DFM partially showed significant differences at the ratios of 90:10, 30:70 and 10:90. Our results indicated that supplementation of aqueous DFM did not significantly improve in vitro fermentation and fibrolytic enzyme activity. In addition, the DFM utilized in this study did not show consistent results by having various effects on ruminal fermentation under different feeding regimens.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.9
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• pp.542-549
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• 2015

The bioelectrochemical anaerobic digestion for sewage sludge was attempted at different applied voltages ranged from 0.2 V to 0.4 V. At 0.3 V of the applied voltage, pH and VFAs were at 7.32 and 760 mg COD/L, respectively, which were quite stable. The methane production rate was $1.32L\;CH_4/L.d$, and the methane content in biogas was 73.8%, indicating that the performance of the bioelectrochemical anaerobic digestion could be considerably improved by applying a low voltage. At 0.4 V of the applied voltage, however, the contents of the minor VFA components including formic acid and propionic acid were increased. The methane production rate was reduced to $1.24L\;CH_4/L.d$ and the biogas methane content was also reduced to 72.4%. At 0.2 V of the applied voltage, the pH was decreased to 6.3, and VFAs was accumulated to 5,684 mg COD/L. The contents of propionic acid and butyric acid in the VFAs were considerably increased, The performances in terms of the methane production rate and the biogas methane content were deteriorated. The poor performance of the bioelectrochemical reactor at 0.2 V of the applied voltage was ascribed to the thermodynamic potential lack for the driving of the carbon dioxide reduction into methane at cathode.

• Journal of Animal Science and Technology
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• v.45 no.5
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• pp.841-846
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• 2003

Landrace(L), Largewhite(Lw), Korean Native Pig(KNP) and commercial hybrid were experimented to determine holothane sensitivity, RYR gene mutation and quality profiles. In the results of halothane test, the incidence of halothane positive pigs was similar between L and Lw. But, the rate of dubious halothane positive type was higher in L than Lw. In hal-gene analysis, halothane-positive pigs(nn) were not found in any tested breed and heterotype(Nn) appeared only in one pig of L. Of the breed effect on the quality profiles, there were no differences in pH$_1$(pH at 1hr postslaughter), but pH$_{u}$(pH at 24hr postslaughter) was significantly higher in commercial hybrid and KNP than other breeds(p〈0.05). Color assessed by National Pork Producers Council(NPPC) and CIE L$^{*}$ was significantly paler in L breed than other breeds(p〈0.05). Significant differences were found in water holding capacity(WHC) and cooking loss in KNP(p〈0.05).