유청배지에서 Propionibacterum Feudenreichii와 Lactobacillus Brebis와의 혼합배양에 의한 프로피온산의 생산

鄭宰顯 충주대학교 1997 한국교통대학교 논문집 Vol.32 No.2

Pure cultures of Propionibacterium freudenreichil did not grow in autoclave-sterilized cheese whey(121℃,15 psi, 20min)at whey concentrations greater than 2% (w/v) spray-dried sweet dairy whey. Propionic acid was produced from autoclave-sterilized whey by growing Propionibacterium freudenreichii in mixed culture with Lactovacillus breves. In medium containing 5-12% autoclaved whey solids and 1% yeast extract, the mixed culture pocuced 1.3-3.0% propoinic acid, 0.5-1.0% acetic acid, and 0.05-0.80% lactic acid.All the lactose was consumed. With pH-controlled fementors (pH=7.0),mixed cultures produced at least 30% more popionic acid than cultures in which pH was not controlled.

Bacillus polymyxa가 生産하는 β- amylase에 關한 硏究

鄭宰顯 忠州大學校 1988 한국교통대학교 논문집 Vol.22 No.-

These experiments were conducted to investigate the purification and the properties of β-amylase producted by Bicallus polymyxa. The results obtained were as follows : 1. The optimum culture time, initial pH and culture temperature were 100hrs., pH7.0 and 30℃, respectively. 2. The crude enzyme was purified by starch absorption, ammonium sulfate fractionation, DEAE-cellulose column chromatography, CM-cellulose column chromatography and Bio Gel p-150 column chromatography. The specific activity of the purified enzyme was 143u/mg. protein and the yield of enzyme activity was 10.1% 3. The purified enzyme showed a single band on polyacrylamide gel electroporesis. Molecular weight of the purified enzyme was estimated to be approximately On the production conditions of α-amylase from Bacillus subtilis MY-1012. 4. The optimum pH, temperature, the stable pH and temperature range of the purified enzyme were pH 7.0∼8.0, 40℃, pH4.0∼9.0 and below 55℃, respectively.

Bacillus Circulans IAM 1112로부터 Maltotetraose와 Maltopentaose를 생산하는 Amylase의 특성

鄭宰顯 忠州大學校 1994 한국교통대학교 논문집 Vol.29 No.2

The maltooligosaccharide producing amylase was extracted from culture broth of Bacillus circulans IAM 1112 and was puried by ammonium sulfate fractionation and DEAE-cellulose column chromatography. The puried anzyme was homogenous on polyacrylamide gel disc electrop-horesis. The optimum temperature and pH of reaction enzyme were 50℃ and 6.0, respectively pH stability range and themal stability of puried enzyme were pH 5.0-10.0 and stable below 55℃. The enzyme was perfectly inhibited by metal ions such as Hg??,Ag?? and not inhibited Ca??.

젖산균발효두유의 기호성

鄭宰顯 충주대학교 1998 한국교통대학교 논문집 Vol.33 No.2

Soy milks have been compared with the fermented soymilk with lactic acid bacteria to determine if a flavor improvement has been achieved. The fermented soymilks had a satisfactory gelatinous curd an acceptable flavor and smooth texture. The fermented soymilks were virtually devoid of objectionable flavor.

장방형내 저온 단일 수평 원관 주위의 동결현상에 관한 실험적 연구

정현철,윤재원,장원택,전승배,이동석,김병철 朝鮮大學校 機械技術硏究所 2007 機械技術硏究 Vol.10 No.1

An experimental study on water in a rectangular cavity with a horizontal cooling tube was carried out to investigate the flow character and thermal behavior in the system. Each experiment was performed with variation of initial temperature and cooling tube temperature. When the cooling tube temperature was -4℃, the supercooling phenomenon was observed regardless of the initial water temperature. And the case of cooling tube temperature was -6℃ with initial temperature was below 4℃, the supercooling phenomenon was also observedin the large region of the test section. When the cooling tube temperature was -10℃, the local region of supercooling phenomenon was observed during the freezing process. And the higher initial temperature was, the higher supercooling degree and the less difference of the ice thickness between upward and downward was observed. It is shown that by controllingthe supercooling phenomena and the cooling tube temperature, it would lead to an increase efficiency of ice making.

2단계 醱酵에 의한 人蔘食醋와 市販食醋의 品質比較

鄭宰顯,趙載敏,崔元碩,曺柱鉉 충주대 2003 産業科學論文集 Vol.11 No.-

본 연구는 인삼의 약리성분과 식초의 기능성을 갖는 인삼식초를 제조하기 위하여 시판 식초와 2단계 발효를 거친 인삼식초와의 품질 을 비교 평가하여 다음과 같은 결과를 얻었다. 가. 인삼식초의 산도는 시판식초보다 약간 낮았으며, pH는 3.7정도로 시판식초보다 약간 높았다. 나. 인삼식초 중에는 fructose, maltose, sucrose, glucose등의 유리당이 존재하였으며 시판중인 식초에는 fructose의 양이 많이 함유되어 있었으며 기타 maltose, sucrose 등도 일부 존재하였다. 다. 인삼식초에는 acetic acid, tartaric acid, propionic acid, lactic acid, malic acid, succinic acid 등의 유기산이 함유되어 있었고 일반 시판식초에는 oxalic acid, citric acid, malic acid, acetic acid등을 함유하고 있었다. We producted the ginseng vinegar through two stages fermentation(alcohol fermentation and acetic acid fermentation). At the first stage, ginseng wine contained 17% alcohol was producted at the 11th day. And through the second stage, acetic acid fermentation ginseng vinegar of which total acidity is 5.8% were produced. In comparison with commercial vinegars for physicochemical quality, acidity of ginseng vinegar was lower than those of commercial vinegars and ph was higher than those of commercial vinegars. The major free sugar compositions in ginseng vinegar were fructose, maltose, sucrose and glucose and in commercial vinegar were fructose, sucrose and maltose. The major organic acid compositions were acetic acid, tartaric acid, propionic acid, lactic acid, malic acid and succinic acid and in commercial vinegar were oxalic acid, citric acid, malic acid and acetic acid.

가상 디자인 스튜디오에 의한 도시정보의 공유에 관한 연구

정재희,김능현 경주대학교 건설환경연구소 2000 建設環境論叢 Vol.- No.3

This paper presents a methodology for the development of VRML-based architectual or urban space and a series of projects that speculate on how virtual environments may replace or complement buildings. Virtual design studio allows users from all over the world to access information on any subject, at any time, about almost anyting. In virtual design studio system, we can interactively design and move basic types of three-dimensional objects in a virtual environment with VRML. Moreover, users can share the sample space even if they are geographically separated.

Pseudomonas sp.에 의한 말토올리고당의 최적생성 조건

鄭宰顯 忠州大學校 1995 한국교통대학교 논문집 Vol.30 No.2

The study was carried out to produce the Maltooligosaccharides (G2-G6) directly from the culture broth of Pseudomonas sp.. Optimal production conditions of the maltooligosaccharides were 3% inoculum ratio, pH 8.0, temperature 40℃, incubation time 30hrs, respectively. Optimal medium compositions were most effect at 8% amylose, 1.0% yeast extract, 0.25% KH₂PO₄.

아크릴 부목을 이용한 하악골 골절의 새로운 치료법

정두성,박재현,김진환,최준 大韓成形外科學會 1999 Archives of Plastic Surgery Vol.26 No.3

As modern society becomes increasingly complex, there has been a steady increase in violence, as well as in automobile and industrial accidents. This has resulted in an increased incidence of facial injuries, including mandibular fractures. Many methods have been advocated to achieve reestablishment of normal feature and function. The choice generally depends upon such factors as location of the fractures, displacements, status of the dentition and favorability of the fracture line. Many cases of mandibular fracture are treated by intermaxillay fixation using an arch bar or bite block(acrylic splint)for rapid bone union and minimal displacement. However, there had been some problems, such as discomfort to patients, limitation to eating and weight loss, poor oral hygiene, and temporomandibular joint ankylosis. As a consequence, we have modified the shape of the acrylic splint and method of fixation for circum-mandibular fixation instead of intermaxillary fixation. Acrylic splints are rigid, strong, easily adjusted and repaired, translucent, lightweight and well tolerated by the oral mucosa. The splints are properly secured to each tooth and bind all the teeth together as a single unit. Authors have used modified acrylic splints as tools of circum-mandibular fixation in 12 cases of mandibular symphysis and body fracture from May 1997 to August 1998, achieving the results of very good occlusal relationship, oral hygiene and comfort to patients.

Aspergillus oryzae sp.가 생산하는 amylase에 관한 연구

鄭宰顯 충주대 산업과학기술연구소 1999 産業科學論文集 Vol.7 No.2

These experiments were performed to examined the conditions for the production of amylase of Asp. oryzae sp. on the wheat bran medium and the general properties of amylase. The results obtained were as following : 1.The optimum culture time for the production of amylase on the wheat bran medium was 72 hrs. The optimum adding amount of water for the production of amylase on the wheat bran medium was about 100 %. 2.The optimum pH of amylase was pH 4.5, and the optimum temperture was about 40℃. 3.The additions of Na-oxalate. NaNO2, NaNO3, Na2CO3 and NaHCO3, respectively to the wheat bran medium were effective for the production of amylase. 4.The crude enzyme was activated slightly by the addition of Mg++, Co++, Ba++ and Ca++, but Cu++. Hg++ and Ag++ were inhibited complately.