Microbial Degradation of Endosulfan by Newly Isolated Strain, Klebsiella pneumoniae KE-1

김동걸 Graduate School Andong National University 2002 국내박사

Laminar flame speeds for n-butanol and methyl decanoate at elevated pressures and temperature

Talukder, Niladri GRADUATE SCHOOL, ANDONG NATIONAL UNIVERSITY 2017 국내석사

Experimental investigations of n-butanol-air and methyl decanoate-air premixed flames have been performed to obtain laminar flame speeds at elevated pressures and temperature for a wide range of equivalence ratios. Shadowgraph technique has been applied to facilitate optical access to the combustion chamber and high-speed camera system has been used to collect images of the flame front propagation for the spherically outward propagating flames, initiated at the center of the chamber. MATLAB image processing code has been used to process data from the images and calculate flame speeds. Similar data trend has been observed for laminar flame speeds against equivalence ratios like other conventional hydrocarbon-air premixed flames. Flame speeds gradually raised from the fuel-lean conditions to the stoichiometric condition. Peaking the value at slightly fuel-rich condition (around φ= 1.1) it gradually went down as the mixtures were made fuel-rich. Like other conventional hydrocarbons, these premixed laminar flame speeds are found to be decreased with the elevation of initial pressures for specific condition.

Electro-Mechanical property evaluation and reliability assessment of Bi-2223 Superconducting Tapes for practical applications

John Ryan C. Dizon Graduate school Andong national University 2005 국내석사

A STUDY ON THE PROCESS PLANNING MODULE FOR FDM 3D PRINTER

MD. OLIOUL ISLAM Graduate School, Andong National University 2017 국내석사

In Additive Manufacturing (AM), 3D printer is becoming one of the key technology to produce physical object. In this technology, a computer aided design (CAD) 3D model is sliced into several 2D cross-sections along the Z-axis, then it produced physically layer-by-layer using 3D printer. However, the manufacturing by 3D printer is divided into three major sections, (a) process planning or slicing the CAD 3D model, (b) actual printing using 3D printer (c) post processing. Process planning is a geometrical work which requires the machine to have much more memories and processing powers than it is used in a 3D printer or any other AM machine. It is the reason the process planning or slicing of the CAD 3D model is done using computer software prior to send the printing command to the 3D printer. Therefore, the process planning section brings the software engineers, and the actual printing and post processing sections bring the mechanical system engineers in 3D printing technology. However, the procedure and output of the process planning varies based on different types of 3D printers and the printing materials. Though the research on 3D printing is aged around 30 years, it still demands much more research to improve the output of the professing planning algorithms. Therefore, the objective of this study is to develop a process planning strategy for fused deposition modeling (FDM) 3D printer which is aimed to slice the CAD 3D model fast and produces better output. Process planning itself includes four main planning tasks; (a) orientation optimization, (b) support design, (c) slicing the CAD 3D model and (d) generating tool path. The first three tasks are almost similar to any other 3D printer. But the tool path generation for a FDM 3D printer is different; it is because of the different printing strategies used in different types of 3D printers. Therefore, this current study started from slicing the CAD 3D model where most of the algorithms for slicing are derived and modified from the previous works in this field. And as the scanning tool path for FDM 3D printer is different, this study includes the development of a suitable tool path for FDM 3D printer. A desktop based slicing software is developed as a part of the research work mentioned above. On that software, slicing layer height, number of shells (offset loops), sharp-corners smoothing factor, infill percentage, extruder diameter and several important parameters are made variable to test the tool path with different parameter sets. Also, the machine settings are kept variable to make the slicing compatible for different size of FDM 3D printers. G-code flavor can also be changed to produce the final output in different kinds of G-code. The research work on the tool path is still being carrying out to make it suitable to use in the FDM 3D printer.

Screening and characterization of chemopreventive properties of lunasin peptide isolated from sybean(Glycine max) : 대두로부터 항암 lunasin peptide 탐색 및 암 예방적 특성

박재호 Graduate School, Andong National University 2004 국내박사

Lunasin is a novel and promising chemopreventive peptide from soybean. In this research, to screen lunasin from natural product, we identified lunasin from various plant seeds. We identified lunasin from agronomic crops and vegetables such as wheat, pepper (Capsicum annuum), tomato (Lycopersicum esculentum) and eggplant (Solanum Melongena), wild legumes such as Lespedeza bicolor, Lespedeza cyrtobotrya and Pueraria thunbergiana in another screening from plant seeds. Solanum nigrum and Lycopersicum esculentum were known as anticancer products. Although we did not checked more plant seeds, our results suggest that lunasin existence is associated with current name of scientific name. Also we collected kinds of soybean cultivars and identified lunasin using SDS-PAGE and western blots to compare lunasin content on various soybean cultivars in Korea. The average content of lunasin from thirty-two kinds of soybean cultivars was 0.1086 mg lunasin/g seed. In the result of analysis of lunasin localization, lunasin present in seed among the plant tissue, in cotyledon and embryo from the seed and in cytosol and cell organelles from the cell. Lunasin first appeared at five weeks after flowering and completely disappeared at eight days after soaking. And Its degradation was delayed by three kinds of GA biosynthetic inhibitor such as ancymidole, MC and TNE. To obtain purified lunasin without other anticarcinogen compounds, we purified the crude protein by activated charcoal and ion-exchange column chromatography Colony formation was suppressed in stably ras-transfected cells treated with all soy anticarcinogens such as purified lunasin, synthetic lunasin and BBI. When compared to positive control, purified lunasin, synthetic lunasin and BBI suppressed formation by about 40%, both of the isoflavone such as genistein and daidzein was 38% and 37.7%, respectively. Crude protein suppressed formation by about 24%. The exogenous application of the lunasin, BBI and genstein inhibits acetylation of the N-terminal tails of histone H4 in C3H 10T1/2 cells and MCF-7 cells. To evaluate bioavailability of lunasin peptide in Rat, we identified lunasin from blood and liver after feeding a 8.7 g LES diet in rat a day for 4 week. Lunasin was detected in blood and liver from rat that was fed with LES diet. The amounts of lunasin of rat blood and liver were 17.54 μg lunasin/ml blood and 3.06 μg lunasin/g liver (fresh wt.). In this result, lunasin can be safely absorbed into the liver and may be absorbed into other organs.

Effect of Juvenile Hormone on Metamorphosis and Vitellogenesis of the Beet Armyworm, Spodoptera exigua

김동기 Graduate School Andong National University 2001 국내박사

PART 1 To find out the effect of juvenile hormone (JH) on metamorphosis of Spodoptera exigua, experimants were carried out with applying 3 types of JH, JH analogs and ecdysteroid analog to the 5th instar larvae and pupae. JH II only inhibited pupation while JH I and III did not. PY (a JH analog) treated 5th instar larvae within 2 days after the molting failed in pupation, while those treated after 2 days show no effect. JH I and II inhibited adult emergence when treated with over 1.0 ul per pupa, while those treated with 0.1 ul of JH I and II, and over 10.0 ul of JH III show no effect. FC (JH analog) treated pupae failed in adult emergence with poor development of rectum when treated within a day after the pupatation, while those treated 3 days after the pupation show no effect. RH5992, an ecdysteroid analog, show no effect on inhibition of adult emergence. Therefore, it could be concluded that the effective type of JH(s) in S. exigua would be JH II or JH I, or both, and their effective period in determining to become a pupa or adult would be only one day (or slightly longer) after the molt or pupation. PART 2 To understand the effect of juvenile hormone (JH) on vitellogenesis in S. exigua, experiments were carried out with JH, JH analogs, ecdysteroid and ecdysteroid analog treated to decapitated adults at different times after the emergence. Vitellogenesis in S. exigua seems to start after 4 hours and stop before 48 hours from the emergence. Normal vitellogenesis proceeded in female decapitated right after the emergence if treated with FC, a JH analog, right after the decapitation. Normal vitellogenesis was also observed from decapitated females if treated with JH I and II right after the dacapitation, while JH III produced no effect. Acording to an analysis through electrophoresis, vitellogenin was found from hemolymph of all decapitaed females treated with test hormones (JHs, JH analogs, ecdysteroid and its analog). However, well developed eggs were observed only from those treated with JH I and II, and JH analogs, while those with JH III, ecdysteroids and its analog produced no eggs with yolk inside. JH I, JH II and JH analogs tested induced over 3 degree of follicular patency, while other hormones failed in producing developed eggs induced 2 or 1 degree of gaps between oocytes witin ovarioles. Therefore, it could be concluded that JH I and II are the effective JH on vitellogenesis in S. exigua, while JH III and ecdysteroids are not, because they failed in deposition of yolk in oocytes though they induced to produce vitellogenin. And it could be the explanation, at least partially, that JH III and ecdysteroids are unable to induce enough patency between oocytes within ovariols.

The Identification and Insecticidal Mechanisms of Xenorhabdus Nematophilus

박영진 Graduate School Andong National University 2000 국내석사

Xenorhabdus nematophilus is a pathogenic bacterium causing insect haemolymph septicemia, which is believed to be a major insecticidal mechanism of the bacterium. To address the fundamental mechanisms underlying this haemolymph septicemia, we analyzed the host insect immunodepressive response followed by the bacterial infection under the hypothesis that insect immune-mediating eicosanoid pathway blocked by inhibitory action of the bacterium cannot normally develop the immune response. Haemocoelic injection of the bacteria into the fifth instar larvae of Spodoptera exigua reduced the total numbers of live haemocytes with postinjection time and resulted in host death in 16h at 25°C. The lethal efficacy, described by a half lethal bacterial dose (LD50), was estimated as 33 colony-forming units per 5th instar larva of S. exigua. The lethal effect of the bacteria on the infected larvae was reduced significantly by the addition of exogenous arachidonic acid (10mg). In comparison, the injections of dexamethasone (10mg), a specific inhibitor of phospholipase A2, and other eicosanoid inhibitors increased significantly the mortality of the larvae infected with a low dose of the bacteria. Although the larvae injected with the heat-killed X. nematophilus could form the maximal number of nodules after 16h, those infected with live bacteria exhibited much less capacity of nodule formation. Injection of arachidonic acid increased the number of nodule formation significantly in response to live bacterial injection. The treatment of dexamethasone and other inhibitors, however, decreased the nodule formation after injection of the heat-killed bacteria. These results strongly suggest that X. nematophilus inhibit PLA2 activity of S. exigua, which then blocks immune-mediating eicosanoid pathway and finally result in immunodepressive haemolymph septicemia.

Relationship between cold hardiness and diapause in the smaller fruit tortrix, Adoxophyes orana : fischer von roslerstamm

조현미 Graduate school Andong National University 2001 국내석사

The smaller fruit tortrix, Adoxophyes orana (Fischer von Roslerstamm), overwinters as a larva. Cold-hardiness must be expressed during diapause development for successful overwintering. To address this hypothesis, we compared cold tolerance between diapausing and nondiapausing larvae, following overall cold tolerance assays in all stages. Supercooling points (SCPs) varied in relation to developmental stages. The SCPs of adults (-19.8℃) were lower than those of pupae (-17.8℃) and eggs (-15.2℃). It varied from 8.5℃ to 16.8℃ during larval stages. And, in general, cold tolerance increased with age. However, there was no significant difference in SCPs between nondiapausing and diapausing larvae. Field-collected overwintering larvae had rather higher SCPs than did the laboratory-diapausing larvae. Cold tolerance also varied with developmental stages. All the stages died after a few hour exposure to low temperatures above their SCPs. Pupae were the most susceptible to low temperatures. Diapausing larvae were much more tolerant to cold temperatures than the nondiapausing larvae. Nondiapausing larvae acclimated to 0℃ for 2h had higher survival in response to lethal low temperature than did the unacclimated larvae. These cold tolerance differences were related with trehalose contents analyzed by an ion -exchange HPLC. Field-collected overwintering larvae and the laboratory diapausing larvae had significantly higher trehalose contents than did nondiapausing larvae. These results indicate that A. orana is a freeze -susceptible species and that diapause development elevates cold tolerance in this species. These also suggest that trehalose can be the major polyol conferring cold tolerance to the diapausing larvae.

Biological studies of chrysolina aurichalcea Mannerheim : Coleoptera: chrysomelidae

Oliver R. Alaijos Graduate school Andong national University 2005 국내석사

Study on identification of an entomopathogenic nematode, heterorhabditis, and its symbiotic bacterium, photorhabdus temperata subsp. temperata

강상진 Graduate School, Andong National University 2003 국내박사

Heterorhabditis megidis (Rhabditida: Heterorhabditidae) is an entomopathogenic nematode and has potential to be used for insect pest control. Despite of its occurrence in many countries, no isolate has been reported in Korea. This study reports H. megidis indigenous to Korea, where they were collected in two geographically different places. The nematodes were identified by morphological characters of infective juveniles/adult males as well as by host cadaver color/bioluminescence. Two conserved primers flanking internal transcribed spacer (ITS) of ribosomal DNA (rDNA) were used to synthesize ca. 1Kb PCR product. The full sequence (1,047 nucleotide in Andong strain, 1,051 nucleotide in Hwasung strain) of the product gave partial 18S, ITS-1, 5.8S, ITS-2, and partial 26S sequences. The partial ITS (566 bp) including partial 18S, ITS-1, and partial 5.8S sequences showed the highest sequence homology with that of H. megidis among 8 species known in Heterorhabditis genus. Two Korean isolates were similar in morphological characters and identical in the total ITS rDNA sequence except 7 nucleotides. The identified H. megidis had the highest insecticidal activity against the beet armyworm, Spodoptera exigua, among four lepidopteran species tested. The analysis of the nematode life stages in the S. exigua infected with H. megidis showed that the infective juveniles could develop into their hermaphrodite adults, which produced amphimictic sexual stages in the following generation. The production of the infective juveniles varied with the lepidopteran host species in both developmental time and yield.