• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.2
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• pp.146-150
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• 2011

A large amount of nitrogenous compounds are found in burley tobacco and are responsible for peculiar aroma during smoking. Excess in nitrogen or its compounds such as total nitrogen and proteins in burley tobacco gives a strong pungency and make its taste bad. The present study has focused on improving quality of Burley tobacco by regulating topping and harvesting time of leaf to reduce nitrogen compounds in Burley tobacco. In addition, the early-stage of flower topping had lower level of nitrogenous compound, such as total nitrogen and protein nitrogen, and total tobacco-specific nitrosamine (TSNA) contents compared to the button-stage and full flower-stage topping. Also, the contents of nicotine got significantly decreased while the ether extract was increased as the period of topping got delayed. Regarding the brightness among the colors of cured leaves, the color at the full flower-stage topping was the brightest, and there was no particular difference in red and yellow colors. The harvesting amount was decreased as the period of topping got delayed and there was no significant difference between the topping treatments in terms of the exterior quality. As the harvesting time delayed, the total nitrogen, protein nitrogen, nitrate nitrogen, and ammonium nitrogen were decreased while the nicotine contents got increased. Also, the total TSNA contents were decreased as the harvesting time delayed. However, ether extract was increased. Among the colors of cured leaves, the brightness and degree of yellow color were significantly increased as the harvesting time delayed, and there was no particular difference in the degree of red color. The harvesting amount was decreased along with the delayed harvesting time; however, the harvest of the matured and mellow leaves was higher in terms of price, compared to that of the immature leaves. For the reduction of nitrogenous compound and TSNA contents in Burley tobacco, the topping was examined to be more effective in terms of improvement in chemical contents and quality regardless of the decreased harvesting amount.

• Journal of Food Hygiene and Safety
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• v.30 no.2
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• pp.178-188
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• 2015

Microbial quality of baked egg products was evaluated by counting the levels of sanitary indicative bacteria (aerobic plate counts, coliforms, and E. coli), L. monocytogenes and Salmonella spp. at the critical control points (CCPs) of manufacturing process. In addition, the survival and growth of foodborne pathogens in various egg products (cheese, tuna, tteokgalbi, pizza omelets, baked egg, and steamed egg) were investigated at 4, 10, and $15^{\circ}C$. The contamination level of aerobic plate counts decreased from 4.67 log CFU/g at CCP 1 to 0.56 log CFU/g at CCP 3 in baked egg products. No coliforms and E. coli were detected at all CCPs. Although L. innocua and Salmonella spp. were identified at CCP 1, no L. monocytogenes and Salmonella spp. were detected in the final products. The contamination levels of aerobic plate counts and coliforms in egg strips and number of aerobic plate counts in Tteokgalbi omelet are higher than the microbiological standard of processed egg products. At $10^{\circ}C$, the growth of all pathogens was not prevented in omelet and baked egg, but the populations of S. Typhimurium and E. coli were reduced in steamed egg at $10^{\circ}C$, regardless of the presence of other pathogens. The growth of L. monocytogenes was faster than that of S. Typhimurium and E. coli in omelet. More rapid growth of S. Enteritidis than S. Typhimurium was observed in egg products, indicating the greater risk of S. Enteritidis than S. Typhimurium in egg products.

• Korean Journal of Ecology and Environment
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• v.44 no.1
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• pp.1-8
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• 2011

We investigated developmental stages of embryo and early life history of the Korean indigenous fish, the northern loach, Cobitis pacifica in 2009 in order to understand fundamental knowledges for conservation of this species. Eggs were obtained after hormones injections (LHRH-a, HCG) and were artificially fertilized by the dry method. The embryo was spherical, separative demersal, faint white, and averaged $1.09{\pm}0.04\;mm$ (n=20) in diameter. The hatching of the embryo took place in about 48 hours after fertilization under water temperature of $21.0{\sim}24.0^{\circ}C$ and the newly hatched larvae averaged $2.87{\pm}0.05\;mm$ (n=20) in total length (TL). Four days after hatching, the larvae grew up to $6.86{\pm}0.10\;mm$ (n=10) in TL and york sac absorption, mouth and anus opening were shown. Fourteen days after hatching, most of fin-rays appeared at $10.71{\pm}0.34\;mm$ (n=10) in TL and color spots on the body surface were attained. Twenty six days after hatching, the larvae grew up to $14.88{\pm}0.45\;mm$ (n=10) in TL, and all their fin-rays were formed. Therefore, according to current study regarding the morphological development of Cobitis pacidica, the conversion from larval to juvenile stages occurred at 26 days after hatching. Eighty days after hatching, the larvae were $33.3{\pm}1.25\;mm$ (n=10), and their body shape and color pattern were similar to adult fish. In this study, embryonic development and early life history of the northern loach, Cobitis pacifica show morphological characteristics of Cobitidae family. We expected that our results can be used as an fundamental knowledges for restoration study of indigenous fish species.

• Korean Journal of Ecology and Environment
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• v.41 no.spc
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• pp.50-60
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• 2008

We performed the experiment to evaluate the effect of different DO concentrations (0.5, 4.5 and 9.0 $mgO_2L^{-1}$) and water depths (20, 50 and 80 cm) on the filtering rate, mortality, and pseudifeces production of Unio douglasiae against the cyanobacterial bloom (mainly Microcystis aeruginosa). A solitary-living bivalve U. douglasiae was collected in the upstream region of the North Han River (Korea). The harvested mussels were carefully transferred to the laboratory artificial management system, which was controlled temperature $(18{\pm}2^{\circ}C)$, flow rate (10L $h^{-1}$), food $(Chlorella^{TM})$, sediment (pebble and clay), light intensity (ca. $20{\mu}mol$ photons), and photocycle (12 L : 12 D). In the field observation, the mussel mortality was significantly correlated with water temperature, pH and DO concentration (P<0.05). The mortality was decreased with water depth; 65, 90, 80% of mortality at 20, 50, 80 cm water-depth, respectively. Filtering rate (FR) showed the highest value at 50 cm water depth, and thereby the concentration of chlorophyll-${\alpha}$ decreased continuously by 94% of the control at the end of the experiment. In contrast, FR decreased by 34% of the initial concentration at 20 cm water depth. Over the given water-depth range, the mussel FR ranged from $0.15{\sim}0.20L\;gAFDW^{-1}hr^{-1}$ during the 18hrs of experiment, and thereafter, they appeared to be approximately 0.11, 0.26 and 0.30 L $gAFDW^{-1}hr^{-1}$ at 20, 50 and 80cm water depth, respectively. FR was highest with the value of 0.46L $gAFDW^{-1}hr^{-1}\;at\;0.5mgO_2 L^{-1}$ at the early stage of the experiment, while it increased with DO concentration. Maximum pseudofaeces production was 11.2 mg $gAFDW^{-1}hr^{-1}\;at\;9.0mgO_2L^{-1}$. Our results conclude that U. douglasiae has a potential to enhance water quality in eutrophic lake by removing dominant cyanobacteria, but their effects vary with environmental parameters and the water depth at which they are located.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.4
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• pp.239-244
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• 2005

This study was conducted to investigate the effect of the planting densities and nitrogen levels on the growth characteristics, dry matter yield and nutritive value of corn for silage in alpine area(altitude 800m a.s.1.) of National Livestock Research Institute from 2001 to 2002. The experiment was arranged in a split plot design with three replications. Main plots consisted of three planting densities, low(67,000 plants/ha), medium(89,000 plants/ha) and high(95,000 plants/ha). Sub plots consisted of three nitrogen levels, 150 kg/ha, 200 kg/ha, and 250 kg/ha. Tassel height of corn was increased with decreasing planting density, and nitrogen level of 200 kg/ha in all main plots. Ear height of corn was decreased with increasing planting density, and 150 kg/ha of three nitrogen levels. But there were no significant differences among treatment in tassel and ear height. Although dry matter ear ratio of whole com was increased with decreasing planting density, there were no significant differences among treatments. But there were significant differences among nitrogen levels(P<0.05). Dry matter yield of com was high with increasing planting density, but there were no significant differences among treatments. And DM yield of corn was significant difference among nitrogen levels(P<0.05). Crude protein content of corn was the highest with high planting density and low nitrogen level. NDF and ADF content of com was the highest with low planting density and nitrogen levels of 200 kg/ha in all main treatments. These results indicate that low planting density(67.000 plants/ha) and nitrogen of 150-200 kg/ha would be the optimum level fur dry matter yield and nutritive value of silage com in alpine area.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.4
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• pp.271-280
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• 1994

The aim of this experiment was to investigate the effects of fertilizing mineral nitrogen on dry matter yield of Reed canarygrass and also to estimate proper levels of fertilizing nitrogen when uncultivated rice paddy rapidly increased these days, was used for the production if Reed canarygrass. \ulcornerhe results are as follows. 1. Relative dry matter according to cutting frequency was appeared the highest at the 2nd cut for 3 and 4 cutting frequencies, and the 3rd cut for 5 cutting frequency. Those were 43.1, 34.0 and 34.1 % respectively. 2. When using only phosphrous and potassium, the average dry matter per year and ha was between 9.0 and 12.0 tons(3, 4 and 5 cutting frequency) and the highest dry matter was shown at 5 cutting frequency. 3. In accordance to the increase in the fertilization of nitorgen, the yield of dry matter was increased and, when 30 kg/ha/cut of mineral nitrogen was added, the biggest increase rate per added nitrogen for dry matter yield per year compared to that of no fe~tilization of nitrogen was recorded and it was 2.7, 3.3, and 3.4 tons/ ha for 3, 4 and 5 cutting frequencies respectively. 4. The efficiencies of mineral nitrogen on dry matter yield(DM kg/N kg) were the highest when 30kg nitrogen was applied particularly in 3, 4 and 5 cutting frequencies(29.7, 27.2, 22.8 DM kg/N kg). It recorded the highest of all the treatments. The efficiency was actually decreased in higher application of mineral nitrogen. The total nitrogen yield efficiency was the highest in 30kg(0.45kg and 0.48kg at 4 and 5 cutting frequency) and 60kg fertilization/ha/cut (0.46kg at 3 cuting frequency) and the decreased efficiencies appeared at fertilization of higher nitrogen. 5. Economical borden of mineral nitrogen fertilization were between 199.2 and 243.3kglha at 3 cutting frequency, between 253.4 and 295.9kg at 4 cutting frequency and between 302.2 and 361.3kg at 5 cutting frequency. 6. Under the condition of this experiment, the cutting frequency leading the potential production at maximum was 3 cutting frequency. At 3 cutting frequency, the efficiency of nitrogen utilization was higher and 15 or 16 tons of dry matter was obtained which is a level of economical border at fertilization between 200 and 240kglha. It wrs possible to obtain the maximal dry matter yield(l7 tonslha) at fertilization of lower level than 400kgl ha.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.495-503
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• 2011

We evaluated the quality characteristics of fresh-cut produce (potato, sweet potato, carrot, radish, zucchini, cucumber, and green bell pepper) washed with sodium hypochlorite, which were vacuum packaged, and stored at 4 and 10$^{\circ}C$. The L-values of the fresh-cut potato and sweet potato decreased during storage. Lower PPO activities of potato and sweet potato were observed at 4$^{\circ}C$ than those at 10$^{\circ}C$ and development of potato and sweet potato browning was delayed at 4$^{\circ}C$. Total aerobic count and coliform increased continuously at 10$^{\circ}C$ during storage. Diced zucchini and shredded sweet potato had the greatest reduction in hardness among the fresh-cut produce during storage. Differences in the rate of quality change were observed according to the kinds and cut types of produce. Thus, a quality maintenance period for each type of fresh-cut produce must be determined, which will lead to the safe use of fresh cut produce in foodservice establishments.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.385-391
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• 2012

The growth of terminal shoots of persimmon (Diospyros kaki) was analyzed during the first two months from the time of bud sprout to understand the dynamics of their early growth. Field-grown, mature 'Fuyu' and 'Nishimurawase' trees were used in a three-year study at two locations in Gyeongnam province. The growth of terminal shoots was most active from late April, about 10 days after foliation, to early May, followed by a gradual decline by late May. The increase in leaf area continued unabated throughout May. The weight of a flower bud increased slowly until early May and rapidly after flowering. Although its extension growth had been ceased by late May, dry weight (DW) of a terminal shoot continued to increase almost linearly throughout May due to shoot thickening and continued growth of leaves and fruits. In late May, the leaves and the stem accounted for more than 60% and less than 20% of total DW of a shoot respectively; fruit proportion increased to 7 to 17% by then. Relative growth rate (RGR) of the terminal shoot was higher than 213 $mg{\cdot}g^{-1}{\cdot}d^{-1}$ in late April, but declined to less than 63 $mg{\cdot}g^{-1}{\cdot}d^{-1}$ in late May. Like the pattern of seasonal changes in RGR, net assimilation rate (NAR) of the shoots decreased from 1.9 to 2 $mg{\cdot}cm^{-2}{\cdot}d^{-1}$ to 0.5 to 0.8 $mg{\cdot}cm^{-2}{\cdot}d^{-1}$. An early-season 'Nishimurawase' did not differ from a late-season 'Fuyu' in RGR and NAR during the first two months of growth. The early growth of the shoots was affected mainly by the reserves redistributed from permanent organs, however, environmental conditions at the time was also involved.

• Tuberculosis and Respiratory Diseases
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• v.43 no.5
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• pp.693-700
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• 1996

Background : Antituberculous therapy is set a short-term therpy used isoniazid(INH), rifampin(RFP), ethambutol(EMB), pyrazinamide(PZA) from 1970s' and treatment rate has been very improved. But drug interruption or irregular medication due to side effects and resistance of drug are serious problem to retreatment cases, specially. Ofloxasine(OFX), developed from Quinolone at 1980's is effective not only other respiratory infectious disease but also pulmonary tube rculosis. And this is useful drug instead of injection agents for retreatment patients who have side effects to other drugs, lived far distance from medical clinics. So, we will evaluate theffectiveness as four oral drugs involving OFX. Method : A retrospective study was made through the regular follow up of smear positive cases,who treated by four drug, namely, prothionamide (PTA) cycloserine(CS), OFX, paraminosalicylic acid(pAS). Results: 1) Out of 66case with positive sputum AFB smear, 42(64%)cases achieved the negative conversion. 2) Considering the negative conversion in all group, 34 case (52%) of sputum conversion occured within first 6 months, on the extent of diease was minimal, moderate, far advanced pulmonary tuberculosis, sputum AFB smear negative response to treatment was 100%, 78%, 46% respectively. 3) The roentgenological improvement occured in 38(58%), extent of diease was minimal, moderately, far advanced pulmonary tuberculosis, Roentgenological improvement to retreatment was 75%, 64%, 46%. 4) When the drnation of patients illness was less than 1 year, 1 to 3 years, 3 10 5 years and more than 5 years, sputum AFB smear negative response to retreatment was 100%, 88%, 80%, 52 %. 5) On side effects, major problems are gastrointestinal troubles, mild liver function abnormality, psychotic problemes, and skin problem(urticaria, itching sensation). Conclusion : The duration & extents of patients illness was shorter & minimal, sputum AFB smear negative response rate was better. Radiologic response is better as shorter duration and minimal extent of diease. But, as diease is longer duration & far advanced, sputum negative conversion & Roentgenological improvement is poor and limited. The adverse reaction was mainly observed gastrointestinal troubles(indigestion, abdominal pain, nausea, vomiting, diarrhea) and are well controled by symptomatic management in most patients, as regard to tolerance to the secondary drugs.

• Journal of the Korean Ceramic Society
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• v.40 no.1
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• pp.24-30
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• 2003

A formation and conversion of AFm phases decisively play role in the hydration, hardening and corrosion processes of various cement. In this study, the conversion of Alumino-Ferrite Monohydrates(AFm) phases under the addition of $CaCO_3,;CaCl_2;and;CaSO_4{cdot}2H_2O$was investigated by the XRD quantitative analysis. The thypical AFm phases are $M_S(monosulfoaluminate),;M_C(monocarboaluminate);and;M_{Cl}(monochloroaluminate and also Called Friedel's salts)$in this cementitious system, The conversion reaction were not occurred in $M_C-CaCO_3,;M_{Cl}-CaCO_3$ and $M_{Cl}-CaCl_2$system. However, in $M_S-CaCO_3$ system, ettringite and $monocarboaluminate(M_C)$ were formed. In $M_S-CaCl_2;system;M_S$ was transformed to Friedel's $salts(M_{Cl})$ and ettringite was formed. In the case of $CaSO_4{cdot}2H_2O$ addition, all AFm $phases(M_S,;M_C;and;M_{Cl})$ were transformed to ettringite. The order of stabilization of AFm phases under $CaCO_3,;CaCl_2;and;CaSO_4{cdot}2H_2O$ was as follows : $M_S< M_C