해상 탄성파 반사법을 이용한 포항 인접 해역의 지구조 연구

강익범 연세대학교 1984 국내석사

대미 감귤 수출단지에서 감귤궤양병 역학 연구

강익범 제주대학교 대학원 1999 국내석사

To understand biology of Citrus canker(Xanthomonas axonopodis pv. citri(Hasse) Vauterin et al.) and relationship between disease occurrence and the number of bacteriophages on the designated mandarin groves for fruit export to USA, disease severities and detections of bacteriophage plaques at different stages in the three designated export areas were determined. The results obtained are as follows : 1. There were differences in disease severities on the overwintering leaves of Citrus unshiu among the designated export areas, but, no difference between chemical treatment and no chemical treatment due to drop of infected leaves during winter. Disease severity on the Citrus natsudaidai was much higher than on Citrus unshiu. 2. Disease occurred from early July to early August on the newly produced spring leaves of Citrus unshiu. In July, disease severities ranged from 1.5% to 1.8% on the chemical treatment, and 3.6% to 4.9% on no chemical treatment fields. However, in August, disease severities were increased from 2.1% to 3.8% on chemical treatment, and from 4.8% to 6.3% on the no chemical treatment fields. On summer leaves of Citrus unshiu, disease Severities ranged from 6.4% to 7.4% on chemical treatment, and from 6.3% to 13.7% on the no chemical treatment fields Disease severities on Citrus natsudaidai which ranged from 10.9% to 14.6% were higher than those of Citrus unshiu. 3. Bacteriophage plaques could detected on the overwintering leaves in early June. Populations of bacteiophage per 1g of leaves were counted 10¹ plaques on the healthy and diseased leaves from the healthy and chemical treatment fields. However, bacteriophage plaques were populated 10² to 10³ on the leaves from no chemical treatment and Citrus natsudaidai fields which were as much as 10 to 100 folds of bacteriophage populations from the leaves chemical treatment field. Detections of bacteriophage population greatly decreased on the overwintering leaves from late June. 4. Populations of bacteiophage on the spring leaves in June were detected 10¹, 10² and 10³ plaques at the fields of healthy, chemical treatment and no chemical treatment and Citrus natsudaidai, respectively. However, in early July, populations of bacteriophage on the healthy leaves at healthy and chemical treatment fields were counted 10¹ plaques, and counted 10² on the leaves at chemical treatment and Citrus natsudaidai fields. They were rapidly decreased from late July. On the diseased leaves, bacteriophage plaques were detected 10³ at all fields which were maintained until september due to the typhoon in early August. 5. At the healthy field, bacteriophage plaques were populated 10² on summer leaves. Bactriophage plaques were detected 10³ in August, and detected 10⁴ and 10^5 at september on the healthy leaves at chemical treatment and no chemical treatment fields, respectively. But, on the diseased leaves bacteriophage plaques were increased 10⁴ and 10^5 in August at chemical treatment and no chemical treatment fields, respectively. They were also detected 10^7 and 10^8 plaques in September. 6. Disease severalties on the overwintering leaves were significantly related to bacteriophage populations on the spring leaves in June which had no canker disease yet, and high significantly related to bacteriophage populations on the diseased spring leaves in July. 7. Disease severities on the spring leaves in July were significantly related to bacteriophage population on the healthy and diseased spring leaves in early July, and high significantly related on the healthy and diseased summer leaves in August and September. 8. Disease severities on the spring leaves in August were only significantly related to bacteriophage populations on the diseased spring leaves in August and september. But, disease severities were significantly related to all detections of bacteriophage plaques on the summer leaves. 9. Disease severities on the summer leaves at September were also significantly related to detections of the diseased and healthy spring leaves and the diseased summer leaves in September.

대미 감귤 수출단지에서의 감귤궤양병 연구

강익범 제주대학교 대학원 2002 국내박사

Citrus canker caused by Xanthomonas axonopodis pv. citri (Hasse) (Abb. Xac) is one of the most important diseases of citrus in the world due to severe destruction by the disease. In these studies the citrus canker the pathogen was isolated and identified from the infected leaves and fruits in the citrus (Satsuma mandarin, Citrus unshiu Marc.) cultivating areas for export to USA. Moreover, method of pathogen detection and the disease forecasting were compared between enzyme-linked immunosorbent assay (ELISA) and bacteriophage test (BPT). On the other hand, the efficacies of application with copper and/or antibiotic were also studied in the field in 2001 and 2002. Citrus canker on spring leaves occurred in 196 fields in the six fruit exporting areas in July in 2001. The disease severities of the leaves at Haean, Sangyae, Chongsu, Sangga, Ansung and Eugui were 0.7, 2.6, 5.6, 1.2, 5.4 and 0.2%, respectively. The disease severities of citrus canker were determined in the late July on spring leaves, in early September on summer leaves, and in the late October on autumn leaves in the six areas in 2001. The percentage of diseased plants ranged from 1.3 to 35.3% and that of diseased leaves <0.1 to 15.6% in the late July, 8.7 to 39.3% and 0.6 to 23.1%, respectively, in early September, and 3.4 to 36.3% and <0.1 to 11.5%, respectively, in late October. Six bacterial isolates from the six areas were isolated, and identified genus as Xanthomonas which were characterized gram negative, produced yellow pigment on nutrient-broth yeast extract agar (NBY), no fluorescent pigment on King's B medium (KB) produced, no growth anaerobically, single polar flagellated, rod shaped, and not formed endospore. The isolates were also identified species as Xanthomonas axonopodis pv. citri, which were characterized mucoid growth on yeast extract-dextrose-CaCO_(3) (YDC), growth at 35℃, hydrolized asculin, gelatin liquefaction negative, and produced acid from glucose, but not arabinose and mannose. Isolates also caused the similar symptom with those naturally formed citrus canker when inoculated on citrus leaves by pin prick method. Efficiencies in detecting Xac on fruits were compared between using ELISA and BPT with infected fruits from the fields. ELISA detected Xac by 100%, while BPT by about 44%, indicating that the detection efficiency was improved by 23.5% by ELISA, compared to that of BPT. In addition, ELISA has simpler procedure for testing and is less time-consuming than BPT, suggesting that ELISA may be accurate and simple method to detect Xac on citrus fruits. For the disease forecasting, the four kinds of leaves at four developmental stages were tested by using ELISA and BPT. On overwintered leaves, Xac was detected on 17 May and 30 May by ELISA in the untreated and chemical-treated fields, respectively. However, Xac was not detected by BPT. On spring leaves, Xac was detected in the untreated and chemical-treated fields by ELISA on 30 May and on 7 June, respectively. ELISA detected Xac one week earlier on spring leaves than BPT did. On summer leaves, both ELISA and BPT detected Xac on 27 July in the untreated field and on 3 August in the chemical-treated field. On autumn leaves, Xac detections in the untreated and chemical-treated fields by using ELISA and BPT were on 12 September. The detections of Xac on overwintered leaves were 15 and 20 days faster than the first dates of disease occurrence in the chemical treated and untreated fields, respectively. But the detection of Xac on spring leaves was 7 days earlier than disease appearance in both the treatments. The disease control by chemicals was tested in 2001. Percentages of diseased leaves of the plants treated with chemicals traditionally were 3.1% on spring leaves, 17.3% on summer leaves and 2.5% on autumn leaves, but 8.8% on spring leaves, 78.7% on autumn leaves and 18.0% on autumn leaves for the untreated plants. The efficiencies of disease control on 16 July, 3 September and 24 October were 64.7, 78.5 and 86.1%, respectively. Experiments with different chemicals and times of spraying were carried out in 2002. Percentages of diseased spring leaves on the plants treated with chemicals traditionally, antibiotic, and antibiotic + copper, and untreated plants on 16 July were 0.29, 0.38, 0.04, 0.25 and 1.25%, respectively. Those of diseased summer leaves on plants treated with chemicals traditionally, antibiotic, and antibiotic + copper, and untreated plants on 6 September were 0.67, 0.46, 0.00, 0.41 and 3.13%, respectively. The efficiencies of chemical treatment were 69.6 to 96.8% on 16 July and 78.6 to 100% on 6 September. Especially efficiencies of antibiotic treatment on 16 July and 6 September were highest with 96.8 and 100%, respectively.

Simulation and estimation of viscoelastic and scattering effects in seismic data

강익범 University of Texas at Dallas 1994 해외박사

탄성파 기록지는 P파와 S파의 속도와 밀도뿐만 아니라 P파와 S파의 Q값도 측정될수있다. Q측정 은 주파수의 함수로써 처음에 도착한 P파와 S파로부터의 에너지 손실을직접 측정함으로써 얻어질. North Sea, New Madrid, Turkey, north Texas에서얻어진 탄성파 기록지로 부터 얻어진 결론은 적으로부터도 접근할수 있는 결과를가지며 P파에서는 intrinsic과 scattering 효과 모두 중요하낵��intrinsic효과가 더 중요한 것으로 여겨진다.