• Korean Journal of Environmental Agriculture
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• v.23 no.4
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• pp.197-202
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• 2004

The persistence of pendimethalin in soil and ground water has an injurious effect on ecosystem. Pendimethalin-degrading bacterium was isolated from Masan, Gyeongnam province and temporarily identified as Bacillus sp. MS202 by the analysis of API CHB50, kit, FAME, and 16S rDNA sequence. from the analysis of pnedimethalin metabolite using TLC, GC, and GC-MS, we found that the degradation of pendimethalin by Bacillus sp. MS202 did not result in the dealkylated form, but the formation of the reduced compound, 6-amino-2-nitro-N(1-ethylpropyl)-3,4-xylidine or 2- amino-6-nitro-N(1-ethylpropyl)-3,4-xylidine.

• Applied Biological Chemistry
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• v.7
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• pp.53-58
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• 1966

A study was carried out to investigate the microorganisms and their floral changes during the tobacco fermentation. The results were sumarized as follows. I. The molds in the "tobacco leaves" were isolated and identified as follows; Aspergllus flavus Link, A. restrictus G. Smith, A. nidulans (Eidam) Wint, A. awamori, Oidium sp. Edmundmasonia sp. Spicaria sp. II. The bacteria in the tobacco were isolated and identified as follows; Bacillus subtilis, B. subtilis var aterriums. B. licheniformis, B. cereus, B. Pumilus, B. megaterium, Flavobacterium harrisonii, Aerobacter aerogenes. III. The counts of the microorganisms on leaves taken from bulks of the fermenting leaf tobacco revealed the presence of relatively small number on the initial stage of the fermentation. During the tobacco fermentation the number of molds increase gradually to the maximum until the 14 th. day of the fermenation, followed by showing, the plateau, and the bacteria population revealed the maximum on the 7 th. day, then declined slowly.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.765-769
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• 2002

Improvement of hygienic quality of powdered raw grains and vegetables by fermentation was investigated. Luc-tobacillus sp. isolated from kimchi was used as a starter. The cell counts of coliform group and SS enteric bacteria on the SS agar plate in raw grains and vegetables were 2.3$\times$103 cfu/mL and 8.6$\times$10$^3$ cfu/mL, respectively. The starlet, Lactobacillu sp., reached 10$^{7}$ cfu/mL after 48 hr in fermentation. At that time, the coliform group and enteric bacteria on the SS agar plate were gradually inactivated and eliminated after 60 hr of fermentation. During the fermentation process, pH of the suspension was lowered and acidity increased. Antimicrobial activity of the acidic supernatant of fermented raw grains and vegetal]les against the E. coli sp. and Salmonella sp. was higher than that of lactic acid solution or neutralized supernatant. Therefore, it was considered that antimicrobial effect of the fermented raw grains and vegetal]les might be accelerated by tile synergic effect of acid and bacteriocin, and liquid fermentation of powdered raw grains and vegetables will be effective for inactivation of hygienic microorganisms.

• Korean journal of applied entomology
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• v.23 no.2 s.59
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• pp.74-81
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• 1984

The experiments were conducted to study the distribution of wilt of strawberry caused by Fusarium in Korea, the characters of the causal fnngus and its control. The results obtained are summarized as follows. 1. Wilt of strawberry has been found in Gimhae and Samrangjin, Gyeongnam province a few years ago. This disease has been spreading year after year, and observed on farms in most of the strawberry-growing areas in Korea. 2. The fungus was isolated frequently from the crowns and petioles of diseased straw berry plants, and the fungus belonging to Fusariun oxysporum in terms of the morphological characteristics of macroconidia, microconidia, chlamydospore and conidiophore on V-8 Agar. 3. The macroconidia formation of the fungus varied remarkably with the Isolates and kinds of medium tested. However. all isolates abundantly produced macroconidia on V-8 Agar. 4. The cross-inoculation tests with several forma specialis of F. oxysporum to cucumber, tomato, watermelon, luffa, cabbage, melon and strawberry were carried out. The isolates from strawberry viz. Kodama's F. oxysporum f. sp. fragariae and S-1 of the authors were pathogenic to only strawberry. The fungus was also similar in morphology and symptoms to Kodama's and Winks' isolate of F. oxysporum f. sp. fragariae. Therefore, the fungus is identified as Fusarium oxysporum Schl. f. sp. fragariae Winks & Williams. 5. The most effective fungicides were Benomyl and Homai for inhibiting sporulation and mycelial growth of the fungus. 6 The cultivar Kurumae 35, Himiko, Senga gigana and Daehak I were resistant, whereas Hokowase, Instiate Z4, Juspa, Puget beauty and Marshall were susceptible to the fungus with artificial inoculation.

• Research in Plant Disease
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• v.20 no.1
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• pp.37-49
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• 2014

A total of 2,714 methanol extracts of 1,677 plant species in 178 families were screened for nemastatic activity against Rhabditis sp. by 96-well microplate bioassay. The plant extracts with a concentration of $5,000{\mu}g/ml$ were mixed with aqueous nematode solution containing about 20 Rhabditis sp. and their activity was examined daily for 7 days. Out of 2,714 plant extracts examined in this test, 2,362 (87.0%) showed no negative influence on the nematode activity, while 187 (6.9%) inhibited nematode activity about 50%, 95 (3.5%) inhibited nematode activity over 90%, and 70 (2.6%) rather enhanced nematode activity. Among those showing over 50% nemastatic activity, 25 extracts were randomly selected for further screening with Rhabditis sp. and with juveniles of Meloidogyne incognita. The screening revealed that 11 extracts (44%) were consistently nemastatic. The 282 extracts with nemastatic activity could be of use in future studies on nematicidal plants.

• Tunnel and Underground Space
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• v.28 no.6
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• pp.584-595
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• 2018

This study conducted direct shear test on about 290 sorts of materials such as sandy soil, clayey soil and gravely soil to present proper standard on shear strength of soil. Shear strength of soil in large scale tends to show that angle of internal friction increases as sand contents grow and it ranges $23.5^{\circ}{\sim}34.9^{\circ}C$ with cohesion of 2.0 kPa~15.7 kPa. Elastic modulus was visibly distinct by load, and which increased approximately 80% as vertical load grows. Angle of internal friction arranging $15.0^{\circ}{\sim}28.6^{\circ}$ on clayey soil decreased as clay contents rises and cohesion increase in regular scale. Elastic modulus tends to increase initial elastic modulus with almost same growing rate. While angle of internal friction on gravely soil indicates $29.9^{\circ}{\sim}36.7^{\circ}$ which hardly shows distinctive features. According to test in detail, cohesion of SW (well-graded sand), SP (poorly-graded sand), SC (clayey sand) and SM (silty sand) indicates value by 94%, 78% and 59% comparing to SC, SW and SP respectively. Angle of internal friction of ML (low-liquid limit silt) and CL (low-liquid limit clay) appears almost same features, and MH (high-liquid limit silt) despite of 88% value of ML. Cohesion among them varies with similar growing rate.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.4
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• pp.370-377
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• 1992

A series of field and laboratory experimentes were conducted to find out the effects of kinds of crops residues and the different amount of fertilizer to the microbial interaction, chemical properties, plant growth and their interaction under continous cultivation of hot pepper, soybean, sesame and upland rice. The results obtained were summerized follows : 1. Total number of bacteria and actinomycetes were enhanced by cultivation of upland rice and soybean while no appreciable effects were obtained by the cultivation of hot pepper and sesame. 2. The number of bacteria, actinomycetes and fungi were increased by return of crop residues when the cultivation of hot pepper, soybean, sesame and upland rice. Specially, actinomycetes was remarkably increased by upland rice cultivation. 3. Increased amount of fertilizer were remarkably affected to decrease of number of soil microorganisms. Specially, actinomycetes succession was appearently affects while plant growing time. 4. The number of identified soil bacterial species were obtained high in order of Bacillus sp.>Rhizobium sp.>Agrobacterium sp.>Pseudomonas sp. The number of Gram positive bacteria were superior than that of Gram negative bateria. 5. Interaction between microbial succession and crops cultivation, the number of Bacillus sp. was increased in hot pepper, Rhizobium sp. was in soybean, and sesame, and Agrobacterium sp. were increased in soybean, respectively. 6. Survival and habitate of soil microorganisms were differ with kinds of crop, application of residue and fertilizers. Most high number of Bacillus sp. Rhizobium sp. and Pseudomonas sp. were obtained on the rhizoplane and rhizosphere while Agrobacterium sp. and Fusarium sp. were high in rhizosphere. 7. Factors in relation to change of soil microbial population was obtained high in order of climates>crops>organic>matter>fertilizer.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.67-72
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• 2014

Minimal broth containing nicotine as a sole carbon source (MB/N) was used to isolate novel nicotine-degrading bacterial strains from tobacco plants and field soils. Comparative analysis of 16S rRNA gene sequence, phenotypic test and morphological tests showed that the position of these isolates were in the genus Arthrobacter of the family Micrococcaceae. The highest 16S rRNA gene sequence similarity of the isolate NU11 and NU15 to type strains in the genus Arthrobacter were Arthrobacter equi (98.2%) which was presumably a novel strain and Arthrobacter nicotinovorans (99.8%), respectively. Both strain NU11 and NU15 showed rod shaped, Gram-positive characteristics and catalase activity, but did not show oxidase activity. The novel strain NU11 was found to degrade efficiently nicotine in MB/N medium by the analysis of UV absorption spectra and could be used as an organism in bioremediation technique.

• Korean Journal of Food Science and Technology
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• v.15 no.4
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• pp.326-332
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• 1983

Acorn wine was manufactured experimentally with koji inoculated the strain producing acorn tannin hydrolyzing enzyme in order to apply fungal tannase to food processing. Starch value of several Korean acorns was found to be 72.84 and the acorns were worthy of use as a carbohydrate food. Mixed koji was prepared by combination of rice and acorn powder at a ratio of 50to 50 and inoculation of Aspergillus oryzae producing amylase and Aspergillus sp. AN-11 producing tannase into the mixture in order to hydrolyze efficiently acorn tannin inhibiting alcohol fermentation in the medium, and then the mixed koji was used as a suitable koji to manufacture acorn wine. Acorn wine brewed with medium of the acorn powder treated with water and cooked and the mixed koji prepared was superior about two times to that brewed with medium of untreated acorn powder and general koji with respect to the rate of alcohol production and sugar fermentation during the 1st and 2nd brewing.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.4
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• pp.1123-1132
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• 1996

It has been reported that high temperature structural components represent the phenomenon of material degradation according to a long term service under high temperature and pressure. Especially, fossile power plant components using the fossil fuel and heavy oil are affected by dewpoint corrosion of $H_2SO_4$produced during a combustion. Therefore, the service materials subjected to high temperature and pressure may occur the stress corrosion cracking. The object of this paper is to investigate SCC susceptibility according to the material degradation of the high temperature structural materials in dewpoint corrosive environment-$H_2SO_4$.The obtained results are summarized as follows : 1) In case of secondary superheater tube, the fractograph of dimple is observed at the concentration of $H_2SO_4$-5%. When the concentration of $H_2SO_4$ is above 10%, the fracture mode is shifted from a transgranular fracture to an quasi-intergranular fracture according to the increment of concentration. 2) In the relationship between [$\Delta$DBTT]$_sp$ and SCC susceptibility, it is confirmed that the greater material degradation degree is, the higher SCC susceptibility is. In addition, it can be known that SP test is useful test method to evaluate SCC susceptibility for high temperature structural components. 3) When [$\Delta$DBTT]$_sp$ is above 17$17^{\circ}C$ the SCC fracture behavior is definitely observed with SCC susceptibility of above 0.4.