Meristem culture (MC) is a technique for producing virus-free garlic plants with high vigor and productivity. We assessed the changes in the agronomic traits of “Namdo” garlic over several generations after the cultivation of MC-induced bulbils. We examined the plant height, leaf sheath length and diameter, leaf number, bulb weight and diameter, clove number, and bulb size distribution. Compared with that of the control, bulb weights of the first-generation bulbils cultivated for three and two years and the second-generation bulbils cultivated for one year increased by 8.7–27.2, 13.9–30.4, and 36.6–46.9%, respectively. In three and two-year cultivation of the firstgeneration bulbils and one-year cultivation of the second-generation bulbils, the proportions of extra-large-sized bulb weight in meristem-cultured plants were 16.2–38.6, 24.0–35.8, and 27.1–51.1%, respectively, whereas that of the control was 7.6%. Thus, the first-generation bulbils can be cultivated for three years to renew the seed bulbs while maintaining productivity.

본 연구는 새만금 간척지와 주산지인 무안에서 재배하였을 때 양파의 생육과 퀘르세틴 등 기능성 성분을 분석하였다. 양파는 중생종 품종인 ‘맵시황’, 중만생 품종인 ‘선파워’, ‘헬시큐’를 사용하였다. 전남 무안에 9월 상순 파종 후 육묘하여 간척지와 무안에 각각 11월 상순에 정식하고 이듬해 6월 초순에 수확하였다. 중만생종 품종인 ‘선파워’와 ‘헬시큐’가 간척지에서 구중 336.5g, 248.3g으로 생육이 우수하였다. 피루브산은 ‘헬시큐’, ‘맵시황’, ‘선파워’ 순으로 높았고 지역 별로는 ‘헬시큐’, ‘맵시황’ 품종이 간척지 재배 시 각각 48.3μmol·g-1, 41.1μmol·g-1으로 무안에서 재배하였을 때보다 높았다. 총 퀘르세틴은 품종 별로 비교하였을 때 ‘헬시큐’가 219.1μg·g-1으로 가장 높았고 ‘선파워’, ‘맵시황’의 순이었으며 재배지역에 따른 차이는 확인되지 않았다. 또한 총 페놀은 총 퀘르세틴 함량과 유사한 경향을 보였으며, ‘헬시큐’의 함량이 853.7μg·mL-1으로 가장 높았고, ‘선파워’는 무안에서 재배할 경우 페놀 함량이 높은 것으로 나타났다. 결과적으로, 피루브산, 총 퀘르세틴, 총 페놀의 함량은 재배지역 보다는 품종에 따른 영향이 큰 것으로 판단되었다.

엔드라인 폭연방지기는 수직 환기장치에 폭연방지와 함께 대기방출을 하도록 한다. 엔드라인 폭연방지장치는 선박과 같은 산업현장의 다양한 분야에 적용된다. 폭연방지기에서 스프링은 스프링 부하와 스프링의 탄성이 후드 개방 모멘트를 결정하므로 필수 부품 이다. 더욱이, 장치 내 스프링은 고온의 상태에서도 작동해야 한다. 따라서, 폭연이 나타나기 시작할 때 스프링의 기계적 하중과 탄성을 분석할 필요가 있다. 이 연구에서는 엔드라인 폭연방지기의 작동 프로세스의 시뮬레이션을 기반으로 열 및 구조해석을 수행하으며, 스프링의 3차원 모델은 CFD 시뮬레이션을 이용하였다. CFD 해석은 FEM 시뮬레이션 값을 입력하여 스프링 구조를 분석한다. 본 연구에서는 스프링 부하의 43 kg, 93 kg 및 56 kg 세 가지 경우 즉, 150 mm 스프링 디플렉션에 부합하도록 집중적으로 관찰하였다. 결과적으로, 1,000℃ 가열조건 하에서 5분 후에 스프링 부하가 10 kg 감소했다. 시뮬레이션 결과는 연소 시간 변화에 따라 스프링의 부하와 탄성을 예측하고 추정할 수 있었다. 또한, 연구의 결과는 폭연방지기의 제조자들에게 역화방지장치뿐만 아니라 스프링의 설계를 최적화하기 위한 참고 자료로 활용할 수 있다.

Flame arrestor as end of line flame arrester for endurance burning prevents a light-back at deflagration and stabilized burning (during and after endurance burning) of potentially explosive vapor-air and gas-air mixtures at the end of vent pipes. In a flame arrestor, spring is an important part. The spring load as well as the spring's elasticity determine when the hood is opened. In addition, the spring have to work in high temperature condition due to gas burning. Therefore, it is necessary to analyze mechanical load and elasticity of spring when gas is burned. Based on the dynamic calculation on working process of a specific flame arrestor, analysis of spring is taken. A three dimensional model for spring burned in flame arrestor by using CFD simulation. Results of the CFD analysis are input in FEM simulation to analyze structure of the spring. The simulation results can predict and estimate the spring’s load and elasticity at variation of the spring’s deflection. Moreover, the obtained result can provide makers with references to optimize design of spring as well as flame arrestor.

This experimental study was performed to investigate wake flow and unsteady flow characteristics using a model for actual shape of a wind breaker and visualization of flow through the particle image velocimetry. Three control angle of flap were selected and instantaneous velocity distributions and flow characteristics were experimently investigated. It is found that as the control angle increases, the flows are characterized by the appearance of the growth of recirculation region.

Two sugary mutants, Hwacheong sugary-1 (Hsu1) and Hwacheong sugary-2 (Hsu2) were obtained by chemical mutagenesis from japonica cultivar, Hwacheongbyeo. Sugary mutants exhibited wrinkled and translucent grain with high soluble sugar content. In addition, amber-colored endosperm of sugary mutants was loosely packed due to abnormal starch granules compared to densely packed wild-type. Especially, the grain of Hsu2 mutant was less wrinkled than that of Hsu1, thus Hsu2 can be polished easily. Previous studies reveal that su1 mutant was resulted from mutation in gene for a debranching enzyme, isoamylase but the sequence of the mutated gene has not been identified. To identify the sequence of sugary genes, the map-based cloning strategy was applied. The genetic study revealed that the phenotype of Hsu2 mutant was controlled by two recessive genes. Interestingly, one of the genes was located on chromosome 8 at the position of isoamylase which was known as su-1. This indicates that mutation in isoamylase gene causes sugary endosperm characteristics. However we found different mutation points between the Hsu1 and Hsu2. The point mutation in Hsu1 was occurred at 10th exon whereas the other mutation related with Hsu2 was occurred at 15th exon. As mentioned above, the Hsu2 mutant has less wrinkled shape and less soluble sugar content than the Hsu1 mutant. Thus, we hypothesize that the other gene controlling Hsu2 mutant phenotype may have a role in weakening the effect of the su-1. Further study on the other gene associated with the Hsu2 phenotype is in progress.