Saengcheonggukjang, known as Natto in Japan, is a soybean fermented food which is made from steamed soybean, Bacillus and water. Demand of Saengcheonggukjang has increased because it does not have much smell compared to Cheonggukjang. Seven varieties of Saengcheonggukjang were investigated and compared in terms of 100 seed weight, quality characteristics, hard seed rate, and water absorption rate in order to determine the suitability of Korean soybeans. In addition, each characteristic of Saengcheonggukjang was compared. ‘Hoseo’ and ‘Haewon’ showed low 100 seed weight with 8.41 g and 8.11 g, respectively. The water absorption rate was higher in ‘Hoseo’ and ‘Pungwon’ than in Japan varieties. The yield of Saengcheonggukjang was significantly different for each variety. No differences were observed in yield and hardness of Saengcheonggukjang with respect to the varieties and sowing date. ‘Haewon’ showed the highest amino nitrogen content with 575.0 mg%. Viscous material content did not appear to differ between varieties. These results suggested that ‘Hoseo’ and ‘Haewon’ can be considered as suitable candidates for yield and quality of Saengcheonggukjang compared to Japan varieties.

In this study, the performance was checked and the optimal conditions were found by machining the inner surface of a round pipe using the magnetic abrasive finishing method. In this experiment, an AL 6063 pipe was used as a sample. To check the performance of magnetic abrasive finising, the machining effect of different abrasive particle mixing ratio, rotation speed, and magnetic pole arrangement was analyzed through surface roughness (Ra) and weight removal measurement. The optimum mixing ratio was 3:1 of electrolytic iron to magnetic abrasive particles, the rotational speed was 1600rpm, and the best surface roughness was obtained in the N-S-N arrangement of magnetic poles.

This study was conducted to investigate changes on the quality characteristics of Prunus davidiana sugar extracts (PSEs) by processing conditions. The PSEs were prepared by extraction with commercial sucrose at 4°C or 25°C for 9 months with or without a pressure plate. The quality characteristics of PSEs were analyzed for Bxo, pH, total acidity, Hunter color value, alcohol content, polyphenol content, DPPH radical scaveging activity, and free sugar content. Bxo increased significantly while pH decreased with increased storage period (p<0.05). The PSEs stored at 4oC scored lower than those stored at 25oC for total acidity, alcohol content, and polyphenol contents. The PSEs with pressure plate possessed lower alcohol content and higher polyphenol content and DPPH free radical scavenging activity than those without pressure plate. The sucrose content in PSEs decreased with increased storage period, while glucose and fructose contents increased. These results indicate that by increasing storage period, sucrose in PSEs is decomposed into glucose and fructose, and the quality characteristics of PSEs such as total acidity, alcohol, and polyphenol content depend on processing conditions.

A commercial AA1070 alloy for electrical wire is severely deformed by drawing process in which a rod with an initial diameter of 9mm into is reduced to a wire of 2mm diameter. The drawn AA1070 wire is then annealed at various temperatures from 200 to 450 oC for 2h. Changes in microstructure, mechanical properties and electrical properties of the specimens with annealing temperature are investigated in detail. The specimen begins partially to recrystallize at 250 oC; above 300 oC it is covered with equiaxed recrystallized grains over all regions. Fiber textures of {110}<111> and {112}<111> components are mainly developed, and {110}<001> texture is partially developed as well. The tensile strength tends to decrease with annealing temperature due to the occurrence of recovery or/and recrystallization. On the other hand, the elongation of the annealed wire increases with the annealing temperature, and reaches a maximum value of 33.3 % at 300 oC. Electric conductivity of the specimens increases with annealing temperature, and reaches a maximum value of 62.6%IACS after annealing at 450 oC. These results are discussed in comparison with those for the other aluminum alloy.

본 연구는 2018년 10월에서 2019년 9월까지 부산지역 유통 판매되고 있는 872건의 다양한 식품을 대상으로 B. cereus 오염도를 분석하였다. 총 872건 중 78건(8.9%)에서 B. cereus 검출되었으며 식품별 B. cereus 검출률은 김치· 절임·조림·젓갈류에서 23.9%, 조미식품 19.4%, 바로 섭취 가능한 농산물 10.5%, 조리식품 7.3%, 즉석섭취식품 5.6%, 신선편의식품 5.0%, 즉석조리식품 0.0% 순으로 분포하였으며 통계적으로 유의한 차이가 있었다. B. cereus 오염 수준은 불검출에서 최대 20,000 CFU/g로 평균 48 CFU/g였으며, 식품별 B.cereus 오염도에는 차이가 없었다. 78건의 검체에서 분리된 113주의 B. cereus의 독소 유전자 확인 시험을 수행하였다. 식품에서 분리된 113주를 대상으로 B. cereus 독소유전자 확인 결과 최소 1종류에서 최대 5종류 의 독소 유전자가 검출되었으며 총 18개 profile로 분류되 었다. 장독소 5종(Cytk-nheA-entFM-bceT-hblC)을 모두 보유한 경우가 34주(30.1%)로 가장 많았다.

sesses the finishing capabilities for application to high-precision machining. Because Ti-6AL-4V (Eli) is widely used in applications where it is exposed to the human body, the industrial grinding oil that is commonly used in the magnetic abrasive finishing process was replaced by vegetable oils; the processing performances of these different grinding oils were compared and verified. The characteristics of magnetic abrasive finishing were also investigated according to the temperature of the material. The experimental results show that olive oil yields a surface roughness improvement of 87%. Also, in terms of the roundness and the amount of material removal, the performance was excellent. This demonstrates the possibility of replacing the conventional industrial oil for grinding. Furthermore, when olive oil was used at different temperatures, the finishing characteristics at room temperature were the most excellent. SEM and EDX analyses of the machined components (before and after processing) showed that the material composition was not changed. Additionally, the magnetic abrasive tool composition was not found on the surface of the finished samples. In conclusion, the possibility of using vegetable oil as the grinding oil for high-precision machining of Ti-6Al-4V (Eli) bars via a magnetic abrasive finishing process at room temperature conditions was verified.

The Carbon Fiber Reinforced Plastic(CFRP) is used in many industrial areas owing to its excellent specific strength. In order to be utilized for machine parts, it is needed to have the hole drilling machining that presents the excellent surface. For the excellent hole machining of CFRP, this study evaluated the cutting force and remaining burr in accordance with changes in temperature by cooling down the temperature of the machining part. It could be used for other machining of composite materials produced by laminating fabric.

우리나라에서 쌀(Rice, Orzya sativa L.)은 주식일 뿐만 아니라 다양한 가공식품원료로서 그의 가치가 높은 식품자원이다. 본 연구는 쌀맥주 제조 시 당화가 잘되는 쌀의 전 처리 방법에 대해 탐색하고자 수행되었다. 쌀을 미세분쇄, 수침처리, 볶음처리, 호화처리, 팽화처리 후 맥아와 함께 당화를 한 결과, 팽화미를 함유한 맥즙이 가장 높은 당도 (°Bx)를 나타내었다. 또한 액화 및 당화효소를 첨가하지 않고, 맥즙을 제조 시 쌀 30% 첨가했을 때 당도가 가장 높은 결과를 나타내었다. 볶은쌀과 팽화미를 이용하여 10, 20, 30% 첨가한 맥주를 제조한 결과 팽화미를 30% 첨가 한 맥즙의 가용성고형분이 15.4 °Bx로 가장 높고 당화도 잘되었으며, 맥주의 알코올함량이 5.0-5.4%로 볶은쌀 첨가 맥주에 비해 높았으며, 탁도가 없었고 쓴맛도 적은 결과를 보였다. 팽화처리는 쌀의 당화를 개선 할 수 있는 좋은 가공방법이라고 생각되며, 팽화미를 첨가한 쌀맥주 제조방법은 편리하고, 좋은 품질의 맥주를 생산 할 수 있는 방법 중의 하나라고 기대된다.

Magnetic abrasive finishing (MAF) process is a surface improvement method, which the magnetic field of permanent magnet or electromagnet is used to control the abrasive particles during the finishing process. The magnetic abrasive tools are filled between the N-pole and S-pole of Nd-Fe-B type permanent magnets. Tungsten carbide bar (WC) is a high hardness material and its compressive strength is much higher than the other materials. Therefore, due to its superior mechanical properties, it has been widely used in cutting or machining process. Because the smooth surface of tungsten carbide is required in cutting tools, thus the magnetic abrasive finishing process was applied for achieving its surface accuracy and dimensional accuracy. The results showed that the surface roughness of tungsten carbide bar was improved from Ra: 0.23㎛ to Ra: 0.02㎛ in 120 sec by magnetic abrasive finishing process.

In this research, the magnetic abrasive finishing process using (Nd-Fe-B) permanent magnet was applied to confirm the performance and to find the optimum conditions. The STS304 bar was used as the specimen in this experiment. In order to confirm the performance of magnetic abrasive finishing process, the surface roughness (Ra) and diameter reduction were measured when the specimens were processed under the conditions of rotational speeds, frequencies, and magnetic pole shapes. The rotational speeds were varied at 8000rpm, 15000rpm, 20000rpm, and 25000rpm. And the frequencies were changed to 0Hz, 4Hz and 10Hz. Also the shapes of the magnetic pole were changed to flat edge, sharp edge and round edge. It can be concluded that the surface roughness (Ra) and diameter reduction were found to be the best at 25000rpm, 4Hz, flat edge.