The purpose of this study is to improve the mechanical properties and develop manufacturing technology through self-soluble alloy powder flame spray coating on the surface of a run-out table roller for hot rolling. The roller surface of the run-out table should maintain high hardness at high temperatures and possess high wear, corrosion, and heat resistances. In addition, sufficient bonding strength between the thermal spray coating layer and base material, which would prevent the peel-off of the coating layer, is also an important factor. In this study, the most suitable powder and process for roll manufacturing technology are determined through the initial selection of commercial alloy powder for roll manufacturing, hardness, component analysis, and bond strength analysis of the powder and thermal spray coating layer according to the powder.
Destruxins (Dtxs) are insecticidal cyclic hexadepsipeptides produced by the entomopathogenic fungus Metarhizium anisopliae. Media composition for dtxs production was optimized with industrial grade media. Glycerol and casein peptone were selected as a carbon source and a nitrogen source, respectively. Dtxs production varied with C/N ratios. High yields of dtxs were observed at C/N ratios ranging 0.3 to 1.5, with concentrations mostly higher than 800 mg/L. Low yields were caused by high C/N ratio ranging from 3.0 to 8.0, resulting in less than 500 mg/L. The highest yield of Dtxs was obtained with 2% glycerol and 3% casein peptone, showing 192.2 mg/L of dtx A, 911.1 mg/L of dtx B, and 113.3 mg/L of dtx E, respectively. These results indicated that dtxs production is highly influenced by C/N ratio, especially the content of nitrogen source.
The entomopathogenic fungus Metarhizium anisopliae B is a powerful biological control agent against Monochamusalternatus, a crucial mediator of the pinewood nematode Bursaphelenchus xylophilus. In this study, production of destruxins(dtxs), insecticidal cyclic hexadepsipeptides, was monitored in the submerged culture of M. anisopliae B. Three typesof dtxs, i.e., destruxin A, B, and E, were produced during the culture. Among the three dtxs, the production yield ofdestruxin A was best, followed by destruxin B and E. Destruxin A production was increased when pH was controlledat 6.0, whereas production of destruxin E was not affected by the pH control. The highest yield of dtxs A, B, and Ewere 16.4, 7.3, and 6.1 mg L-1, respectively. Considering that process for dtxs production has not been optimized, M.anisopliae B has more powerful implication as a biocontrol agent.
The entomopathogenic fungus Metarhizium anisopliae is one of potent biological control agents against a variety ofinsect pests. In this study, we investigated enzyme production of M. anisopliae strains A and B. They produced extracellularenzymes for degrading the epidermis of Monochamus alternatus, a crucial mediator of the pinewood nematode Bursaphelenchusxylophilus. With Q-TOF MS/MS analysis, 29 kDa protein, a major band on a SDS-PAGE gel, was identified as subtilisin-likeserine protease PR1A. M. anisopliae A produced an extracellular enzyme more efficiently than M. anisopliae B: however,enzyme activities targeted for the cuticle were comparable. Our results suggest that the two strains of M. anisopliae havethe biological potential against M. alternatus with insecticidal protease production.
The present study was carried out to revise the species of Chlaeniini in Carabidae from Korea, using both classic taxonomy and molecular analysis. Another aim is to decide the taxonomic position of Chlaenius micans Fabricius of which subgeneric status in the genus has been in question. As a part of the results, Chlaenius spathulifer Bates, 1873 was newly recognized to Korean insect fauna. With this new addition Korean Chlaeniini contains now in total 34 species and two genera. This study provids a key to species, photos of adult habitus, photos of male genitalia and redescriptions of 28 Korean species in Chlaeniini.
Oxalic acid has a nematicidal activity against the root-knot nematode Meloidogyne incognita. High producer of oxalic acid was isolated, and then named as Aspergillus niger F22. Oxalic acid production was investigated under various temperatures from 20 – 33oC and rotational speeds in 5 L jar fermenters. Yield of oxalic acid increased with decreasing temperature. The highest yield was obtained at 23oC, showing the yield of oxalic acid of 8.7 g/L, whereas oxalic acid production was least at 33oC. At 20oC, the yield was lower than that of 23oC. At a rotational speed of 300 rpm, serious oxygen depletion was present from 48 - 72 h, resulting in low productivity of 26.2 mg /L·h. When a rotational speed was set at 600 rpm, dissolved oxygen tension was over 40% and oxalic acid production increased up to approximately 55%. Viscosity during the culture differed with temperatures. Viscosity increased with the increment of temperatures. When A. niger F22 was cultured at 23oC, viscosity was 810 cP, which was favorable for oxalic acid production.
수평 배향 액정 모드는 양의 유전율 이방성과 음의 유전융 이방성 액정을 사용한 프린지 필드
스위칭과 양의 유전율 이방성 액정을 사용한 인플래인 스위칭 모드가 대표적이다 . 이 대표적인 세 구동
방식의 화질 특성을 비교하기 위하여 각각의 최척화된 위상지연 값 조건하에서 밝기, 명암대비율과 색
특성을 조사하였다. 그 결과 양액정과 음액정을 사용한 프린지 필드 스위칭 모드가 밝기와 명암대비율
면에 있어서 인플래인 스위칭 모드보다 우수한 특성을 보인다. 또한 양액정을 사용한 프린지 필드 스위
칭 모드는 시야각 방향에서 적은 색 변이 특성을 보인다.