• 한국재료학회지
• /
• 제13권3호
• /
• pp.185-190
• /
• 2003

Titanium dioxide films were prepared by RF sputtering method on glass for various oxygen partial pressures at power 270 W. The crystal structure, photocatalytic property and the hydrophilicity of $TiO_2$thin film the deposition conditions were investigated. Crystallized anatase phase was observed in $TiO_2$film deposited at the ratio of oxygen partial pressure 10% and 20% for 2 hrs. As the increase of deposition time, the grain size and void size of $TiO_2$film have increased and also $V_2$films have been good crystallinity. The ultraviolet-visible light absorption of $TiO_2$films was increased with increasing of deposition time and occured chiefly at the wavelength between 280 and 340 nm. The absorption band was shifted to a longer wave length as deposition time increased. Water contact angle on the X$TiO_2$film of anatase structure was decreased with increasing ultraviolet illumination time and became lower than $11^{\circ}$ from $83^{\circ}$. When hydrophilic $TiO_2$film changed by enough ultraviolet illumination was stored in the dark, the film surface gradually turned to hydrophobic state.

• Journal of Applied Biological Chemistry
• /
• 제59권3호
• /
• pp.203-206
• /
• 2016

보리나방과 화랑곡나방 성충에 대한 LED 트랩의 곡물보관창고에서 이용가능성을 평가하기 위해 상업적 대조구 BLB 트랩과 비교한 실증실험을 통하여 유인효과를 비교하였다. 그 결과 4일 후 blue LED 트랩은 보리나방, green LED 트랩은 화랑곡나방에 대하여 대조구 BLB 트랩보다 높은 유인활성을 나타내었으며 곡물보관창고 외부에서 진행한 실험은 내부 실험보다 약 1.7배 높은 유인활성을 나타내었다. 이러한 결과를 바탕으로 blue LED와 green LED 트랩이 곡물보관창고에서 화랑곡나방과 보리나방을 방제하기 위한 친환경 저곡해충 방제법으로 적용 가능성을 보여주었다.

• 한국균학회지
• /
• 제9권1호
• /
• pp.1-6
• /
• 1981

Aspergillus parasiticus NRRL 2999에 의한 보리의 aflatoxin생성(生成)에 미치는 코발트-60감마선(線)의 영향(影響)을 조사(調査)하였다. 감마선(線)은 평형수분(平衡水分)된 후(後)(접종(接種) 3일후(日後)), 그리고 10일(日)동안 배양후(培養後) 0, 50, 100, 200 및 400krad로서 조사(照射)하였으며 그 결과(結果)는 다음과 같다. 1. 수분함량(水分含量)이 17%에서 25%로 증가(增加)함으로써 aflatoxin의 생성량(生成量)이 현저(顯著)하게 증가(增加)하였으며, 특히 무조사구(無照射區)에서 크게 증가(增加)하였다. 2. 배양기간(培養期間)을 3일(日)에서 13일(日)로 연장(延長)하여 조사(照射)함으로써 aflatoxin의 생성(生成)이 더욱 증가(增加)하였다. 3. 접종(接種) 13일후(日後) 200krad로 조사(照射)하여 $25^{\circ}C$에서 배양(培養)된 25%수분함량(水分含量)(RH:100%)에서는 50 또는 100krad로 조사(照射)된 것보다 aflatoxin의 생성(生成)이 증가(增加)하였다. 4. Aflatoxin의 종류별(種類別) 축적비율(蓄積比率)은 aflatoxin G가 B보다 현저(顯著)하게 대량(大量)으로 축적(蓄積)되었다.

• Journal of Biosystems Engineering
• /
• 제13권3호
• /
• pp.44-51
• /
• 1988

The objective of this study is to develop a grain handling system for loading, unloading and transporting of rough rice stored at the in-bin drying and storage (IBDS) developed by the Korea Advanced Institute of Science and Technology(KAIST). A mechanized Fain handling system consisted of a portable auger and a gate was developed and tested. The test results can be summarized as the following: 1) The loading capacity of the handling system developed is $16.2m^3/h$ (8.3 ton/h) for the Indica type rice and $13.0m^3/h$(7.3 ton/h) for the Japonica type. It is greater than that of manual handling as much as 2.5 - 2.7 times. 2) The unloading capacity of the handling system developed is $16.0m^3/h$(8.2 ton/h) for the Indica type rice and $12.6m^3/h$(7.0 ton/h) for the Japonica type. It is greater than that of the manual as much as 4.7 - 5.5 times. 3) For 3-ton capacity of the storage, the loading and unloading can be performed for 20 and 30 minutes by one man operation of equipment. while 60 and 120 minute for the manual of 2 men, respectively. 4) The volumetric efficiency of the system developed is 0.42 - 0.54 and the power efficiency is 4.0 - 4.4. 5) The break-even quantity of the handling system developed is about 38.6 ton($68.7m^3$) of rough rice and the initial investment for the system would be returned within five years for the most owners of the KAIST IBDS system.

• Applied Biological Chemistry
• /
• 제23권3호
• /
• pp.166-172
• /
• 1980

광학 현미경 및 Scanning electron microscopy로 관찰한 녹두 전분 입자는 타원형 및 구형으로서 너비는 $8{\sim}13{\mu}m$, 길이는 $18{\sim}30{\mu}$이었다. X-ray 회절도는 $2{\theta}$가 $16.9^{\circ}$에서 약간의 결정성을 보였다. 전분의 blue value는 0.36, 아밀로스 함량은 22.7%, 알카리 수는 8.52, ferricyanide 수는 1.06물 결함 능력은 81.6%이었다. 전분의 팽윤은 $50^{\circ}C$까지는 큰 변화가 없었고, 이후 급격히 증가하였다. 전분 현탁액(0.3%)의 광 투과도는 $65^{\circ}C$ 이후 급격히 증가하였으며, $65{\sim}90^{\circ}C$에서는 Single stage의 호화 양상을 보였다. 아밀로그래프에 의한 전분의 호화는 농도(건물중으로 6,7 및 8%)에 관계없이 최고 점도는 나타나지 않았다. 전분 gel(건물중으로 40% 농도)의 retrogradation시 시간상수는 $21^{\circ}C$에서 1.99일이었다.

• 한국재료학회지
• /
• 제22권1호
• /
• pp.16-23
• /
• 2012

Research into the development of high strength (1 GPa) and superior formability, such as total elongation (10%), and stretch-flangeability (50%) in hot-rolled steel was conducted with a thermomechanically controlled hot-rolling process. To improve the overall mechanical properties simultaneously, low-carbon steel using precipitation hardening of Ti-Nb-V multimicroalloying elements was employed. And, ideal microstructural characteristics for the realization of balanced mechanical properties were determined using SEM, EBSD, and TEM analyses. The developed steel, 0.06C-2.0Mn-0.5Cr-0.2(Ti + Nb + V), consisted of ferrite as the matrix phase and second phase of granular bainite with fine carbides (20-50 nm) in both phases. The significant factor of the microstructural characteristics that affect stretch-flangeability was found to be the microstructural homogeneity. The microstructural homogeneity, manifest in such characteristics as low localization of plastic strain and internally stored energy, was identified by grain average misorientation method, analyzed by electron backscattered diffraction (EBSD) and hardness deviation between the phases. In summar, a hot-rolled steel having a composition 0.06C-2.0Mn-0.5Cr-0.2(Ti + Nb + V) demonstrated a tensile strength of 998 MPa, a total elongation of 19%, and a hole expansion ratio of 65%. The most important factors to satisfy the mechanical property were the presence of fine carbides and the microstructural homogeneity, which provided low hardness deviation between the phases.

• 한국식품위생안전성학회지
• /
• 제13권1호
• /
• pp.47-52
• /
• 1998

쌀에대하여 afltoxin 생성을 위한 기질로서의 능력을 알아보기 위하여 현미 (청청벼) 시료에 Aspergillus parasiticus를 접종하고 조건을 달리하여 저장하면서 Aflatoxin $B_1$의 생성을 관찰하였다. 시료중의 Aflatoxin $B_1$의 분석은 ELISA를 이용하여 수행하였다. 현미 시료에서 Aflatoxin $B_1$ 생성에 가장 좋은 온도는 $28^{\circ}C$였으며, 시료의 수분함량을 15.8%로 증가시킨 경우 Aflatoxin $B_1$ 의 생성이 유의하게 증가하였고 (P<0.05), 고압증기멸균시킨 시료는 Aflatoxin $B_1$ 생성에 보다 효과적인 기질이 되었다. 실온에서 3개월 동안 저장한 현미에서는 15일 동안 저장 한 경우에 비해 Aflatoxin $B_1$ 생성이 유의한 증가를 보였다(P<0.05). 따라서 저장 온도 및 수분함량이 쌀에서도 Aflatoxin $B_1$ 생성에 영향을 미치는 바를 나타내었으며, 또 시료의 상태 및 저장기간도 쌀에서 Aflatoxin 생성 위험 요인으로 작용할 수 있음이 제시되었다. 이러한 결과로부터 쌀이 aflatoxin 생성에 좋은 기질이 될 수 있는 것으로 평가된다.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제28권1호
• /
• pp.5-9
• /
• 2014

Tenebrio molitor is a major pest of stored grain, although its larvae have potential for use as food. However, little is known about the characteristics of individual larval instars of this species, and the number of instars remains disputed. Therefore, we assessed T. molitor for the average number of instars and its characteristics at different larval stages. The focus of this study was to establish a foundation for further studies on the characteristics of each larval instar. All of the T. molitor larvae showed incubation periods of 7 to 8 d and a period of 3 to 4 d for the $1^{st}$ instar. Beyond the $1^{st}$ instar, there were relatively large variations in the number of days in each instar period. Before emergence, most of the larvae had typically gone through 15 to 17 instars. The highest rate of pupae formation, 28.32%, was observed in the $17^{th}$ instars. The body length gradually increased with each successive instar, reaching its maximum at the 17th instar. Beyond the $17^{th}$ instar, however, the body length decreased. The larvae were white in the first instar, and gradually turned brown after the $2^{nd}$ instar.

• 한국미생물·생명공학회지
• /
• 제10권4호
• /
• pp.297-305
• /
• 1982

한국산 미곡 밀양 25호의 저장중에 출현한 균류의 생육환경조건을 조사하고, 이들 균류에 의한 미곡의 부패를 억제하기 위하여 선정된 훈연제의 최적처리조건을 검토하여 다음과 같은 결과를 얻었다. 1. 대부분의 균류는 수분함량 19%, 상대온도 80% 이상의 미곡에서는 10~30일 이내에 잘 생육하였다. 그러나 수분함량 12.5~l3.0 %의 미곡에서는 Aspergillus candidus, Asperillus versicolor, Penicillium chrysogenum 및 Trichothecium roseum만 2개월 이내에 육안으로 생육이 확인되었고, 기타의 균류는 현미경하에서 균계의 생육만 관찰 할 수 있었다. 2. 10종류의 공시훈엽제중에서 저장균류의 생육을 억제하는데 가장 효과가 있었던 것은 ethylene oxide였으며 그 최저처리농도 및 시간은 16mg/$\ell$와 48시간이었다. 동일처리시간에서 methylbromid는 32mg/$\ell$, acrilonitrile과 methyl iodide는 64mg/$\ell$가 최저처리농도였으며, ammonia, methyl formate, ethyl formate, carbon dioxide 및 propionic acid는 주어진 처리조건에서 거의 효과가 없었다.

• Journal of Biosystems Engineering
• /
• 제26권5호
• /
• pp.469-474
• /
• 2001

Milling the rice with low moisture requires more energy, produces more cracked rice, and results in reducing taste of cooked rice. Accordingly, it is necessary to add moisture to the rice with low moisture to obtain optimum moisture level for milling and taste of rice. This study was performed to evaluate the influence of initial moisture content and absorption rate on rice crack, milling energy and whiteness of milled rice and to obtain the information for design of rewetting system mounted on stirring device in grain bin. The tests were conducted for the four levels of initial moisture content in the range of 11.4 to 14.5%(w.b.) and six levels of absorption rate in the range of 0.04 to 1.0%, w.b./hr. In the case of lower moisture content below 12%(w.b.), crack ratios of brown rice were remarkably high regardless of initial moisture contents. Therefore, it was found that rough rice below 12%(w.b.) in initial moisture content could not rewetted by spraying water without crack generation of low level. Absorption rate must be below 0.3%, w.b./hr to maintain crack ratio increase of less than 1% regardless of initial moisture contents. In the case of allowable crack ratio increase of 2% and 5%, it was found that the maximum absorprion rate was respectively 0.6%, w.b./hr and 1.0%, w.b./hr in the initial moisture content of above 13.5%(w.b.). Rewetting the rough rice in moisture content of 11.4 to 14.5%(w.b.) to 14.3 to 16.9%(w.b.) decreased milling energy consumption by 15.9 to 22.3%. The effect of energy saving was higher in the samples of higher initial moisture content. Whiteness of milled rice was decreased by 0.5 to 1.5.