This study was attempt to improve the quality of rapid- and low salt-fermented liquefaction of sardine (Sardinops melanoslicta). Effect of pretreatment methods such as water adding, heating, and intermittent NaCl adding on fermented liquefaction of chopped whole sardine were investigated. The divisions of the experimental samples by pretreatment methods were as follows; Sample A (water adding and heating): chopped whole sardine adding 20% water and then adding 3 and 5% NaCl consecutively at the intervals of 3 and 6 hrs during heating for 9 hrs at 50℃ and then fermented at 33℃ for 90 days. Sample B (preheating): chopped whole sardine with 8% NaCl and heating at 50℃ for 9 hrs and then fermented at 33℃ for 90 days. Sample C (control): neither pretreatment methods of water adding nor preheating on chopped whole sardine with 13% NaCl and then fermented at 33℃ for 90 days. Comparison of the appropriate fermentation period, yield of hydrolysate, chemical composition of fermented liquefied products were carried out. The highest content of amino nitrogen appeared at 60 days in the sample A, 75 days in the sample B, and 90 days in the sample C during the fermentation period. The appropriate fermentation period of the sample A was shorten 15 days than the sample B and 30 days than the sample C in the processing of sardine. The product A was lower NaCl (8.5%) and lower histamine content (25mg/100g) than the sample B and C. Possibly, three kinds of pretreatment methods such as water adding, heating, and intermittent NaCl adding, might be recommend as the processing of rapid- and low salt-fermented liquefaction product of chopped whole sardine.
A three-dimensional digital image processing technique is proposed to quantitatively predict the dispersion phenomena of oil droplet onto the surface of the water. This technique is able to get the dispersion rate of an oil droplet three-dimensionally just below the surface of the water over time. The obtained dispersion rate obtained through this technique is informative to the investigation into the relationship among the gravity, surface tensions between oil, water, and air. This technique is based upon the three-dimensional PIV(Particle Imaging Velocimetry) technique and its system mainly consists of a three CCD(Charge Coupled Device) cameras, an image grabber, and a host computer in which an image processing algorithm is adopted for the acquisition of dispersion rate oil an oil droplet.
As a part of investigation to use sardine(Sardinops melanoslicta) more effectively as a food source, this study was undertaken the processing condition of rapid- and low salt-fermented liquefaction of sardine. To prepare rapid fermented products, the chopped whole sardine was added 8% NaCl and then preheating treatment at 40℃, 45℃ and 50℃ in the manufactured fermenter(180L) for 9 hrs, and then fermentation at 33℃ for 90 days. The chemical changes such as amino nitrogen(amino-N), volatile basic nitrogen(VBN), and histamine in the hydrolysates of fermented sardine were analyzed as well as viable cell count and organoleptic evaluation during fermentation to compare the quality between control and preheating samples. During fermenting, the amino-N in the hydrolysates increased rapidly during the first 30 days and slowly thereafter. The highest content of amino-N appeared at 75 days in control sample and 60~75 days in preheating samples. The changes of VBN in the hydrolysates increased rapidly during first 15 days in control samples and 30 days in preheating samples. However they were generally low level in preheating samples. Histamine content in the hydrolysates of the control samples increased markedly after 15 days, but preheating samples were generally low level, and then 75~90 days of fermentation reached to the maximum which was about 2.0~3.0 times lower than that of control samples. As for the organoleptic flavor evaluation, the control and preheating at 40℃ samples were unpleasant odor after 15 and 60 days, respectively. But preheating at 45˚ and 50˚ samples were fresh odor after 90 days fermentation.
In order to establish the processing condition of salt-fermented liquefaction of sardine (Sardinops melanoslicta), effect of temperature, pH value, and concentration of salinity on crude enzyme activity of sardine viscera were investigated. The optimum temperature range of crude enzyme activity in sardine viscera was 45~50℃ and the optimum pH value of it was 9.8. According to the concentration of salinity increased the crude enzyme activity in sardine viscera decreased. The relationship between concentration of salinity (X) and the crude enzyme activity (Y) in sardine viscera is shown as follows; Y=-0.01363X+0.7676 (r=-0.88). For the purpose of processing conditions of rapid- and low salt-fermented liquefaction of sardine, changes of viable cell count, histamine content, and volatile basic nitrogen (VBN) in the chopped whole sardine with 8% NaCl during preheating process at 40˚, 45˚ and 50℃ for 48 hrs were analyzed. During preheating, initial viable cell counts of chopped whole sardine were 104-7/g, but they decreased 101-5/g after 48 hrs. Histamine contents during preheating process at 40˚ and 45℃ were gradually increased, whereas at 50℃ were almost the same level after 48 hrs. VBN contents were continuously increased during preheating, but preheating at 50℃ samples were lower level than that of 40˚ and 45℃ ones. For the purpose to accelerate the fermentation and liquefaction of chopped whole sardine, preheating at optimum temperature of crude enzyme activity for 48 hrs was useful processing method and the contents of viable cell count, histamine, and VBN were safety level for food sanitation.
본 연구는 개별 메모리를 갖는 소결합 구조의 MIMD형 병렬컴퓨터인 트랜스퓨터시스템 하에서 구조최적화를 위한 병렬처리 과정을 보이고 시험모델에 적용하여 타당성 및 효율성을 검증한다. 전체 최적화과정의 대부분을 차지하는 해석 및 민감도 알고리즘은 영역단위의 병렬성을 갖는 부구조화에 근거하고 하드웨어 구성에 맞춰 변환 재구성한다. 각 노드간 통신은 정적응축과 설계도함수에 한정, 그 횟수를 최소화하고 그들을 동기화하므로써 개별메모리형 연산모델의 약점인 통신비용의 문제를 해소한다. PC를 호스트로 한 수치실험은 고속화 효율성 면에서 고무적인 결과를 보여주고 있으며, 이런 점에서 시스템의 확장성을 함께 고려한다면 트랜스퓨터 시스템에 기초한 병렬처리는 공학 환경의 변화와 요구에 부응하는 좋은 대안이 될 수 있다.
반응생성에 의한 Ti/TiB 복합재료를 제조하기 위한 반응분말(TiB2, B4C), 소결온도, 소결시간을 결정하기 위하여 제조조건에 따른 반응생성상, 미세조직, 상대밀도 등을 조사하였다. 제조된 복합재료의 기계적 성질은 상온 압축항복강도로 평가하였다. 복합재료를 제조하기 위하여 혼합하는 TiB2반응분말의 경우 1300˚C, B4C 반응분말의 경우 1400˚C의 소결온도가 최적조건임을 확인하였다. 본 공정에 의해서 제조된 복합재료의 압축항복강도는 비교재인 Ti-6Al-4V 보다 모두 우수하였다. 또한 TiB2반응분말에 의해서 제조된 복합재료가 B4C 반응분말에 의해서 제조된 복합재료보다 우수한 압축항복강도를 나타내었다. 이는, 압축시험한 복합재료에서의 균열전파양상을 조사한 결과, 강화상과 기지간의 접합특성을 B4C 반응분말에 의한 복합재료의 접합특성보다 우수하였기 때문이었다.
This study was carried out to isolate and identify Salmonella species from poultry slaughterhouses and pork meat processing plants during the period from January 1997 to August 1998, and analyze resistance of antimicrobial agents and plasmid profiles of isolated Salmonella strains. A total of 15 Salmonella strains was isolated from poultry carcasses, swine carcasses, pork meats and cutting boards. Identified Salmonella strains were S. typhimurium, S. heidelberg, S. hilingdon, S. mbandaka, and S. virginia. Ten (66.7%) of 15 Salmonella strains showed resistance to antimicrobial agents and five strains (33.3%) of them were resistant to two or more antimicrobial agents. Plasmids were isolated from three Salmonella isolates which had two or more plasmids.
본 연구에서는 졸-겔공정에 의해 금속 alkoxide용액을 이용하여 강유전성 PMN분말 및 박막을 제조하였다. PMN박막은 dip coating 방법으로 Pt가 피복된 Si 기판 위에 제조하였다. 열처리에 따른 gel 분말의 유기물 분해거동과 제조된 분말 및 박막의 열처리 온도변화에 따른 결정상 발달과정을 열분석, 적외선 및 Rarnan 분광분석과 X-선회절분석을 통하여 규명하였다 또한 과잉의 PbO와 MgO 첨가가 PMN박막의 Perovskite 결정상 생성에 미치는 영향을 고찰하였다. Pt가 피복된 Si기판 위에 5회 코팅으로 제조된 PMN박막의 820˚C에서 1분간 열처리 후 두께는 약 3000 이였다 PMN 박막 제조시, 15% 과잉의 PbO를 첨가하고 1분간 820˚C에서 열처리한 경우에 단일상의 Perovskite상을 얻을 수 있다. 고상반응에서와 같이 액상반응인 sol-gel공정에서도 과잉의 MgO (10mo1% ) 첨가가 Perovskite상의 생성을 증가시키는 것을 확인하였다 Pt가 피복된 Si기판 위에 제조된 PM N박막을 820˚C에서 1분간 열처리하였을 경우에 제조된 PM N박막의 유전상수 값과 손실계수는 10kHz주파수에서 각각 2200~2700 및 -0.33의 값을 나타내었다.
Three pork fabrication processing were examined for isolation and serotyping of Listeria monocytogenes. Three hundred thirty samples were collected from gloves, knife sharpeners, knives, cutting boards, conveyer belts, skinning machines, working room air, pig carcasses, and cut meat. Among the 234 samples taken from processing environment, the isolation rates of Listeria monocytogenes and other Listeria spp. were 17.5%, 34.2% respectively. Isolation rates of Listeria monocytogenes from different specimens during processing were 20.8% in gloves, 21.3% in knife sharpeners, 14.6% in knives, 20.8% in cutting boards, 28.6% in conveyer belts, 16.7% in skinnig machines. Listeria monocytogenes and other Listeria spp. were not detected in working room air. Isolation rate of Listeria monocytogenes 14.6% in pork was increased compared to that of 8.5% in pig carcasses (p$lt;0.05). The serovars of 41 isolates from processing environment were 4b 36.6%, 1/2a 24.4%, 4ab 17.0%, 4a 4.9%, 1/2c 2.4%, and 4c 2.4%. The serovars of 4b, 1/2a, 4ab were detected from carcassess and cut meats.
This study was conducted to investigate the changes in lipid components of red pepper under various processing conditions such as drying, exposing to lights, extraction and storage conditions. The material used in this study were Chungyang cultivars which contained the largest amount of capsaicinoids and Dabok cultivars which is most popular among the various cultivars produced in Korea. Total lipid content of Chungyang was 15.7% and those of Dabok, Udeungsang and Hongilpum were about 17%. The neutral lipid content in free lipid of red pepper was 78.5~80.3% Phospholipid and glycolipid content in bound lipid were 53.8~56.9% and 35.3~38.7% respectively. The major fatty acids of lipid were linoleic, palmitic and oleic acid. Linoleic acid was presented mainly in pericarp, seed and placenta, whereas the most of palmitic acid was presented in stem. Lipid content of cut and whole red pepper were decreased 24.7~28% and 18.1~21.5% by drying for 48hrs at 65℃ and 95℃. And lipid content was also decreased 3.5~3.6% when the red pepper powder was exposed to 15,000 lux of incandescent light for 30 days at 40℃ and 4~4.9% to fluorescent light. The lipid was extracted the highest content of 50.5~51.7% by acid solution(pH2) and the lowest content by neutral solution, and the higher the salt concentration, the greater the lipid was extracted. During storage at 4℃, 25℃, 40℃, for 30 days the lipid content was not much changed but linoleic acid content was decreased during storage at the same conditions.
Chicken carcass microflora were evaluated for aerobic microorganisms after defeathering, evisceration, washing, chilling, and sanitizing during a commercial chicken processing and storage at wholesale and retailsale levels. Sampling was at between December 1997, and March, 1998. Tap water washing and sanitizing with 25 ppm chlorine for 10 sec significantly (P$lt;0.05) reduced aerobic plate counts (APC) and gram-negative bacterial counts (GNC) on chicken carcasses from a commercial chicken-processing plant. After 4 days at 2±2℃, APC and GNC on chicken carcasses in retailsale store rapidly increased compared to those in wholesale store (P$lt;0.05). Chicken wings from retailsale store significantly (P$lt;0.05) decreased generation time (GT) compared to other chicken carcasses.
A new low melting inorganic binder, monoclinic , has been developed for Selective Laser Sintering (SLS) of alumina powder by dehydration process of boron oxide powder in a vacuum oven at . It led to better green SLS parts and higher bend strength far green and fired parts compared to other inorganic binders such as aluminum and ammmonium phosphate. This appeared to be due to its low viscosity and better wettability of the alumina particle surface. A low density single phase ceramic, aluminum borate (), and multiphase ceramic composites, , were successfully developed by laser processing of alumina-monoclinic powder blends followed by post-thermal processing; both and have whisker-like grains. The physical and mechanical properties of these SLS-processed ceramic parts were correlated to the materials and processing parameters. Further densification of the ceramic composites was carried out by infiltration of colloidal silica, and chromic acid into these porous SLS parts followed by heat-treatment at high temperature (). The densities obtained after infiltration and subsequent firing were between 75 and 80% of the theoretical densities. The bend strengths are between 15 and 33 MPa.
반응결합 알루미나(RBAO)-SiC 세라믹스를 AI금속분말/AI2O3/SiC 분말혼합체로부터 제조하였다. 하소알루미나와 용융알루미나를 알루미나 분말공급원으로 사용하였다. 출발원료는 단일구경(3mm)또는 혼합구경(3mm+5mm)의 ZrO2볼로 어트리션 밀링 하였다. 정수압 성형한 시편을 1100˚C까지 1.5˚C/mim로 1차소성한 다음, 1500˚C~1600˚C까지 5˚C/mim으로 2차소성하였다. 용융알루미나와의 분말혼합체가 하소알루미나와의 분말혼합체보다 분쇄가 더욱 잘 되었다. 또한 단일구가 혼합구보다 분쇄에 더욱 효율적이었다. AI2O3 형태에 따른 반응소결거동에는 별 차이가 없었다.