This study aimed to identify milling characteristics depending on the number of a cutting roller’s air vent and blowing velocity to remove rice bran by the cutting type milling machine which can minimize the conventional milling process. The level of whiteness was found to be 38±0.5 in all the conditions, showing consistent whiteness levels during milling. The rice temperatures turned out to be 15.4 and 14.6oC which were rather low-level under the conditions of the cutting roller with 3 vents and blowing velocities of 35 and 40 m/s respectively. Cracked rice ratio was 2.13% under the conditions of the cutting roller with 3 vents and a blowing velocity of 35 m/s. Broken rice ratio showed the range of 0.762-0.869%, reflecting a low level. Turbidity after milling was decreased, as blowing velocity became faster. Energy consumption for milled rice production was decreased, as blowing velocity became faster. The optimum milling condition for cutting type milling machine depending on air vent number of cutting roller and blowing velocity was found to be 3 vents and 35 m/s.

The purpose of this study was to verify the drying characteristics of steamed sweet potato and to establish optimal drying conditions for far-infrared drying of steamed sweet potato. 4 kg of steamed sweet potato was sliced to thicknesses of 8 and 10 mm, and dried by a far-infrared dryer until a final moisture content of 25±0.5%. The far-infrared dryer conditions were an air velocity of 0.6, 0.8 m/s and drying temperature of 60, 70, and 80oC. The results can be summarized as follows. The drying time tended to be reduced as temperature and air velocity for drying increased. The Lewis and Modified Wang and Singh models were found to be suitable for drying of steamed sweet potato by a far-infrared dryer. The color difference was 35.09 on the following conditions: Thickness of 8 mm, temperature of 80oC, and air velocity of 0.8 m/s. The highest sugar content (59.11 oBrix) was observed on the conditions of a thickness of 8 mm, temperature of 80, and air velocity of 0.8 m/s. Energy consumption decreased on the conditions of higher temperature, slower air velocity, and thinner steamed sweet potato.

본 연구에서는 파장의 위상차를 변화시켜 균일한 살균을 유도할 수 있고 저전력으로 효과를 높일 수 있는 QRD(quadratic residue diffusor) 마이크로파를 이용하여 챔버 내부의 위치에 따른 온도변화를 측정하여 효율성과 균등성을 분석한 결과는 다음과 같다. 챔버 내부의 수직 35cm, 중앙 위치에서는 7kW 조사시 가장 효율이 높게 나타났고, 좌우측 위치에서는 5kW에서 효율성이 높았다. 그리고 마그네트론 No. 1, 2, 3에서 3kW로 하였을 때, Bar의 위치에 따른 온도 균등성은 1Bar와 2Bar의 위치에서는 거의 비슷하게 나타났다. 마그네트론 No. 3, 4, 5의 3kW로 하였을 경우에는 3Bar에서 온도가 약 10~ 20% 정도 높게 나타났고 마그네트론 용량을 5, 7, 9kW로 하였을 때, 조사 시간에 대한 평균 온도는 Bar의 위치에 무관하게 거의 유사한 형태로 증가하였다. 반면에 챔버의 적정 내용적에 대한 효율성은 조사용량에 반드시 비례하지는 않았다. 마그네트론 3kW를 60, 120, 180초 동안 조사하였을 경우 마그네트론 조사 위치에 따라 구석 부분에서 약 5~10oC 더 높게 상승하였고 수평면의 위치별 온도 분포는 비교적 균일하였으며 부분적으로 구 석부분에서 약간 더 온도가 상승하는 경향이 있었다. 마그네트론 5, 7, 9kW 조사에서는 Bar의 위치와 상관없이 전반적으로 온도가 비교적 균일하게 상승하고 있었다.

This study was to find out the relationships between whiteness, hardness, crack ratio, broken rice ratio, increased grain temperature, moisture content, electric energy consumption, and optimum conditioning of grain temperature for the milled rice efficiency and quality maintenance during the milling process of brown rice at low temperature. There was no significant difference between the whiteness variations of white rice after milling process when the conditioning grain temperatures ranging from 0 to 20oC was used. The crack and broken rice ratios of white rice and the hardness of brown rice decreased with an increased in the conditioning grain temperature. Conditioning grain temperatures of 12, 20oC are applicable to appropriated standard of temperature (15oC) after milling process. In the case of low temperature of grain, there was steadily increase the rate of changing moisture contents because of dew condensation. There was 2.62~14.28% decline of electricity energy for milling process when the temperature of grain was higher than 0oC. Therefore, it needs to control temperature over 10oC for appropriate milling in winter season.

Up to recently building are constructed focusing on the convenience of residential condition. However, environmental-friendly materials is required for construction as people are spending more time inside buildings and causes of many problems like sick-building syndrome are known due to the noxious gases and polluted air originated from construction materials. Although loess(hwangtoh) is an environmental-friendly material, it has limitations in compressive strength far a construction material. The purpose of this study is to suggest the optimal ratio of loess(hwangtoh) mortar by tests of compressive strength comparing with standard strength of floor finishing mortar and evaluate the usability of loess(hwangtoh) mortar for floor finishing material through an impact test, a cracking test and a abrasion test. Based on the results of this study, 86% of loess(hwangtoh) and 14% of inorganic binder is suggested for the optimal mixture ratio of loess(hwangtoh) mortar. Moreover, the characteristics of loess(hwangtoh) is suitable for floor finishing material in impact, crack, abrasion.

원적외선 복사 물질인 세라믹 분말을 벼 기계이앙상토에 혼합하였을 때 벼 유묘의 생장에 미치는 효과를 분석하고, 세라믹 분말의 적정혼합비를 구명하기 위하여 실험을 실시하였다. 공시 품종은 화성벼로 하였고, 세라믹 분말은 Al2 O3 계를 사용하였다. 시험한 결과를 요약하면 다음과 같다. 1. 시험에 사용한 세라믹 분말의 복사파장 범위는 6~11mu extrmm이었다. 2. 세라믹 분말의 혼합처리는 무처리에 비하여 초장이 뚜렷하게 증가하였다. 3. 세라믹 분말의 혼합처리는 모의 건물중을 증가시키는 것으로 나타났다. 4. 벼 유묘의 초장을 증가시키는 세라믹 분말의 추정 적정혼합비는 9.6%(240g)인 것으로 나타났다.