• Korean journal of applied entomology
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• v.36 no.3
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• pp.277-282
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• 1997

Chemosterilant effect of chlorpyrifos-methyl (CPM) on the beet armyworm, Spodoptera e.rigua (Hubner) was investigated, using topical application. Egg fecundity and fertility were analyzed in the adults reared from the fifth instar larvae which were treated with sublethal doses of CPM. Though CPM reduced fecundity a little, it gave significant negative effect on egg fertility in a dose-dependent manner. Genetic analysis was performed by reciprocal crosses between treated (100 Wgllarva) and untreated individuals and showed a dominant lethal effect of CPM on egg fecundity and fertility. This results indicate that chlorpyrifos-methyl may act as a chemosterilant as well as a well-known neurotoxicant, and suggest that it can be used in genetic control program.

• Korean journal of applied entomology
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• v.50 no.4
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• pp.315-324
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• 2011

The nematicidal and egg haching inhibitory effects of extracts from 30 herbal plants (total 32 samples) against Meloidogyne hapla J2 juveniles and eggs was tested using the dipping method. At 1,000 ppm, extracts of Daphne genkwa flower buds, Eugenia caryophyllata flowers, Quisqualis indica fruits, and Zingiber officinale rhizomes produced > 80% mortality in J2 juveniles. At 125 ppm, extracts of D. genkwa and Q. indica produced 91 and 99% mortality, respectively. The toxicity of 5 selected plant extracts to M. hapla differed depending on the solvent used (i.e. hexane, methanol, hot water, or cold water). Hot water extracts of Z. officinale and Q. indica produced nematicidal efficacies of 99 and 99%, compared to 36 and 98%, respectively, with cold water extraction. Q. indica extract was highly active against M. hapla regardless of extraction method. The inhibitory effects of Areca catechu, D. genkwa, Desmodium caudatum, Pharbitis nil, Q. indica, and Z. officinale extracts on egg hatching of M. hapla was evaluated. At 1,000 ppm, D. genkwa, P. nil, and Q. indica extracts significantly reduced hatching at 7, 14 and 21 days after treatment. Numbers of juveniles in soil treated with the methanol extract D. genkwa (1,000 ppm) were significantly lower than in untreated soil in trials in pots and in a ginseng (Phanax ginseng) field. These results indicate that Q. indica extracts could be used as an environmental friendly control agent of M. hapla.

• Research in Plant Disease
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• v.26 no.2
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• pp.72-78
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• 2020

Clover cyst nematode, Heterodera trifolii, is one of the most important plant-parasitic nematode on Kimchi-cabbage in highland in Korea. Recently, a demand of soil disinfection machine for fumigants is increasing. This study was conducted to assess the control effects of a newly developed prototype soil disinfection machine to the cyst nematode. Two fumigants, dimethyl disulfide (DMDS) and metam sodium (MNa), were treated using the machine in a field, which was infected with the cyst nematode. After 4 weeks, control effects of fumigants were assessed as eggs hatching rates inside of cysts extracted from the soil, and as a number of females reproduced in roots of Kimchi-cabbage. DMDS (39 l/10 a) suppressed over 99.0% of the eggs hatching rate and the number of females reproduced. On the other hand, MNa (29 l/10 a) controlled the egg hatching rates from minimum 78.3% to maximum 99.4%, and the number of females from 34.7% to 49.3%. The control effects of two fumigants to clover cyst nematode by treated depth were no significant differences statistically. These results showed that DMDS treatment using the soil disinfection machine was expected to have the control effects for the clover cyst nematode.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.1
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• pp.23-30
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• 2007

The ultimate objective of this study is to develop oxygen-enriched combustion techniques applicable to the system of practical industrial boiler. To this end the combustion characteristics of lab-scale LNG combustor were investigated as a first step using the method of numerical simulation by analyzing the flame characteristics and pollutant emission behaviour as a function of oxygen enrichment level. Several useful conclusions could be drawn based on this study. First of all, the increase of oxygen enrichment level instead of air caused long and thin flame called laminar flame feature. This was in good agreement with experimental results appeared in open literature and explained by the effect of the decrease of turbulent mixing due to the decrease of absolute amount of oxidizer flow rate by the absence of the nitrogen species. Further, as expected, oxygen enrichment increased the flame temperatures to a significant level together with concentrations of $CO_2$ and $H_2O$ species because of the elimination of the heat sink and dilution effects by the presence of $N_2$ inert gas. However, the increased flame temperature with $O_2$ enriched air showed the high possibility of the generation of thermal $NO_x$ if nitrogen species were present. In order to remedy the problem caused by the oxygen-enriched combustion, the appropriate amount of recirculation $CO_2$ gas was desirable to enhance the turbulent mixing and thereby flame stability and further optimum determination of operational conditions were necessary. For example, the adjustment of burner with swirl angle of $30\sim45^{\circ}$ increased the combustion efficiency of LNG fuel and simultaneously dropped the $NO_x$ formation.

• The Korean Journal of Zoology
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• v.33 no.3
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• pp.322-329
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• 1990

The effects of retinoic acid (RA) on the regenerating limbs of Korean newt (Hynobius leechii) larvae have been studied. Intraperitoneal injection of RA at 4 days post-amputation caused the proximalization of regenerate structures in the proximodistal (PD) axis of the limbs amputated through either the distal zeugopodium or the distal stylopodium. The mean level of proximalization (MLP) increased as a dose-dependent manner, and the MLP was also dependent on the level of amputation at a given dose of RA. At the dose of 150 $\mu$ g/g body wt., MLP's in either amputation level reached close to a peak value, and an increasing number of inhibition of regeneration or duplication in the transverse plane occurred at the dose of 200 $\mu$ g/ g body wt. and above. The changes induced by RA treatment suggest that positional values in the cells of the regenerating limbs have been modified in the three cardinal axes including PD and transverse axes in a graded mode. Furthermore, from the comparison of data in two different amputation levels, it can be speculated that the sensitivity of cells to RA effect along the PD axis might not be linear.

• Health and Mission
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• s.4
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• pp.26-38
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• 2005

최근 성체줄기세포도 배아줄기세포처럼 자신이 속한 조직이나 장기가 아닌 다른 배엽의 줄기세포로 부화할 수 있는 교차분화 능력이 알려지면서 여러 질환에서 이식치료가 활발하게 진행되고 있다. 특히 가톨릭대학교 외신경계 유전테연구센터에서는 난치성 혈관질환 중 놔경색, 버거씨병 등 환자 64명에게서 현저한 치료 효과를 보았다.

• Korean Journal of Poultry Science
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• v.33 no.3
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• pp.225-231
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• 2006

To investigate the effect of feeding rare earth (RE) on the performance of breeder hens a feeding trial with sixteen thousands of 158 day old Ross broiler breeder hens was conducted for thirty weeks. A mixture of RE- chlorides containing mainly La, Ce, and Pr was mixed into corn-soy based diet at two levels, 300 and 600 mg/kg, All the hens were housed in flat layer houses and the ratio of male to female was maintained at one to ten. Dietary supplementation of the of RE at a level of 300 mg/kg made the hens reach egg production peak higher by about 6% and earlier by about two weeks. As a result, it made higher hatchable egg production by 3.5%. It also reduced dramatically the mortality of both male and female breeders(P<0.05). Egg weight was slightly increased but egg qualify was not much influenced by dietary supplementation of RE. Egg albumin hight and Haugh unit were significantly improved while egg shell thickness, egg breaking strength and yolk color were similar to those of the control. Experimental results appeared to show a good possibility that egg fertility and hatchability were improved by feeding RE. Dietary supplementation of RE at a level of 300 mg/kg should be acceptable but not the 600 mg/kg level for breeder hens. Further studies on the effect of RE on egg fertility and hatchability appears to be necessary.

• Korean journal of applied entomology
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• v.60 no.1
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• pp.99-103
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• 2021

This study was conducted to investigate the hatching rate of Pochazia shantungensis according to the treatment method of machine oil and the effect on apple quality by spawning. In the effect of machine oil treatment, when 20 times of the machine oil was spread by brush, the average hatching rate was 0.57%, and the sprayed branches showed an average hatching rate of 1%. When the machine oil agent was applied 50 times, the hatching rate was about 35% to spread by brush, whereas the spray treatment showed about 77%, so there were no difference from the non-treatment considering the deviation. There was no statistically significant difference in the quality of fruit even when apple fruits were fruited in the following year in the results of spawning and non-spawning of P. shantungensis in Hongro and Fuji varieties. In addition, there was no statistical significance in the difference between branch breakage and growth caused by spawning of P. shantungensis.

• 한국연소학회:학술대회논문집
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• 2003.05a
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• pp.241-246
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• 2003

Numerical simulations are performed at atmospheric pressure in order to understand the effect of additives on flame speed and the NOx formation in freely propagating $H_{2}/O_{2}/N_{2}$ flames with oxygen enrichments. A chemical kinetic mechanism is developed, which involves 26 gas-phase species and 99 reactions. Under several equivalence ratios and oxygen enrichments, flame speeds are calculated and compared with those obtained from the experiments, the results of which is in good agreement. As hydrogen chloride as additive is added into $H_{2}/O_{2}/N_{2}$ flames with low oxygen enrichments, its chemical effect causes the decrease of flame speed, radical concentration, and the NO production rate. It is found that the chemical effect of additive has much more influence on the reduction of EINO than its physical effect. However, in flames with very high flame temperature the physical effect rather than the chemical effect becomes more important on the reduction of EINO.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.06a
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• pp.268-270
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• 2014

본 논문은 FME (Fractional Motion Estimation)의 선택적 수행을 통한 HEVC (High Efficiency Video Coding)의 부호화 고속화 방법을 제안한다. HEVC 는 H.264/AVC 에 비해 약 2 배의 압축 효율을 보이지만, 쿼드트리 구조의 재귀적 호출은 복잡도를 크게 증가시켰다. 이러한 이유로 인하여 HEVC 부호화기의 고속 모드 결정 및 고속화 연구가 활발히 진행되고 있다. 본 논문에서는 HEVC 부호화기 중 가장 높은 복잡도를 갖는 화면 간 예측 모드의 부화소 움직임 추정 (FME: Fractional Motion Estimation)의 선택적 수행을 통하여 부호화기를 고속화하는 방법을 제안한다. 제안하는 방법을 HEVC 레퍼런스 소프트웨어인 HM-12.0 에 적용하여 평균 2.0%의 BD-BR 가 증가하였으나, 평균 36.0%의 부호화 시간 감소 효과를 얻을 수 있었다.