We demonstrated an effective way of preparing melt spinnable mesophase pitches via catalytic hydrogenation of petroleum residue (fluidized catalytic cracking-decant oil) and their subsequent thermal soaking. The mesophase pitches thus obtained were analyzed in terms of their viscosity, elemental composition, solubility, molecular weight, softening point and optical texture. We found that zeolite-induced catalytic hydrogenation under high hydrogen pressure contributed to a large variation in the properties of the pitches. As the hydrogen pressure increased, the C/H ratio decreased, and the solubility in n-hexane increased. The mesophase pitch with entirely anisotropic domains of flow texture exhibited good meltspinnability. The mesophase carbon fibers obtained from the catalytically hydrogenated petroleum residue showed moderate mechanical properties.
목적 : 본 연구에서는 표전 근전도 신호를 기반으로 기존의 재활로봇 알고리즘의 성능의 개선하기 위한 새로운 특징 요소를 개발 및 검증하였다.
연구방법 : 기존의 선형 재귀 모델을 기반으로 한 실시간 로봇 제어 알고리즘을 수정하여, 2개 이상의 주파수 특징을 가지는 근 전도신호에 그 특징의 수에 맞추어 주파수 영역을 다르게 한 모델을 개발하였다.
결과 : 측정된 결과 개선된 알고리즘의 모델이 기존 모델대비 높은 정확도가 나옮을 확인할 수 있었으며, 향후 이를 적용 한다면, 근전도 기반 재활로봇의 정확도가 향상될 수 있음을 확인할 수 있었다.
결론 : 본 연구에서 제안된 복수의 필터뱅크 특징을 기반으로 한 개선될 선형 재귀알고리즘이 기존 알고리즘보다 높은 성능을 보임을 확인할 수 있었다. 이를 바탕으로 향후 뇌졸중 환자의 치료를 위한 재활 로봇을 제어하는데 활용된다면, 환자의 의지를 더욱 정확히 반영한 재활치료를 통하여 환자의 재활치료효과를 증진시킬 것이라 기대된다.
Plant-parasitic nematodes causes yield losses of more than $100 million per year in the world. Among them, soybeancyst nematode (Heterodera glycines Ichinohe) causes the greatest yield loss to soybean compared to any other pest worldwide.SCN causes yield reductions by feeding on plant nutrients, retarding root growth and inhibiting Bradyrhizobium japonicum(Kirchner) Buchanan nodulation. The primary methods for controlling SCN include planting resistant cultivars and rotationwith nonhost crop. In order to control SCN, we should be breeding resistant soybean cultivars which has resistant genefor this pest. The research that can minimize the damage of the soybean yield is still insufficient, comprehensive andsystematic research is urgently required. Current researches in our lab are discussed.
The entomopathogneic fungal colonization has become an interesting issue in ecological pest management. Plant-orientedfungi induce plant growth promotion and act as natural control agents against insect pest. Herein this work, we evaluatedthe ability of fungal colonization on bark, branches and leaves of pine tree (Pinus densiflora) to select optimal candidatesfor controlling Japanese pine sawyer (Monochamus alternatus), which is the pine wilt disease vector in Korea. As a result,some Beauveria and Metarhizium isolates could colonize on the substrates of P. densiflora and showed pathogenicity againstM. alternatus. This result suggests that the selected entomopathogenic fungi are possibly candidates for long-term managementof M. alternatus in pine tree forest.
Japanese pine sawyer, Monochamus alternatus HOPE (Coleoptera: Cerambycidae) are considered as important pine forestinsect pests in several countries which transmits the pine wood nematode, Bursaphelenchus xylophylus. In this study, wetried to control Japanese pine sawyer using entomopathogenic fungi to prevent the spread of pine wilt disease in Korea.Several entomopathogenic fungi were exposed to the adults of Japanese pine sawyer and mycosis was observed in themembranous cuticles after 6 days. In particular, two isolates showed high virulence against the adults. The selected 2isolates were sprayed to the adults at 1×105, 1×106 and 1×107 conidia/ml. In the concentration of 1×107 conidia/ml, thesurvival rates of insects were 40% and 47%, respectively. Based on these results, the possibility of controlling the Japanesepine sawyer was confirmed.
Community and guild structures were investigated in 5 regions (Cheorwon, Icheon, Buan, Haenam, Ulsan) in 2016.A total of 4,806 spiders were collected and identified as 73 species of 48 genera in 17 families. Species compositionand abundance were high in Linyphiidae, Tetragnathidae and Lycosidae. Average species richness index was 28.27±0.72,abundance was 320.40±28.41 and diversity index was 2.49±0.06. Guild of rice field spiders were categorized 8 ecologicallyfunctional groups; Space web builders, Wandering sheet weavers, Orb weavers, Ground runners, Ambushers, Stalkers, Sheetweb builders and Foliage runners. Their abundance was high in ground runners with 167.00±24.12 and low in sheet webbuilders with 0.73±0.23. In species diversity, ground runners was high with 1.30±0.07 and stalkers was low with 0.31±0.09.
Until recently, molecular detection method for Bursaphelenchus xylophilus (Bx) infesting pine trees and killing themhas been developed several ways such as RFLP, Real-time PCR and LAMP. However, these were not only time-consumingprocess but also could not confirm the result in a short time. Furthermore, these methods also need thermo cycler orthermostat which are not portable and inexpensive. For above reasons, we had been developed the detection method forBx remaining in the pinewood chips without using electronic devices. In this study, we had used DUNT buffer that isable to extract genome DNA from Bx in the pinewood within 10 min and isothermal amplification that could be amplifiedthe specific DNA fragment of Bx at 37 ℃ for 10 min. As a result, our method is able to confirm the presence or absenceof Bx in pine trees within 20 min and could be used in the field as it does not require the electronic devices.