붉은 Yeast Phaffia rhodozyma로 부터 Astaxanthin의 생산

안길환 이화여자대학교 가정과학대학 식품영양학과 아시아 식품영양연구소 1995 食品營養情報 Vol.- No.6

Astaxanthin(3, 3'-dihydroxy-β, β-carotene-4, 4'-dione)은 연어류의 주요 carotenoid 色素이다. 漁場에서 生産한 연어의 生産은 過去수 십년 동안 빠르게 增加되었고, 1998년에는 연간 70∼80만 톤의 연어가 養殖될 것으로 예상된다. 현재의 astaxanthin의 세계 시장규모는 년간 1200억원이다. Phaffia rhodozyma는 色素의 生物學的 소스로서 바람직한 特性들을 가지고 있지만 自然菌株의 astaxanthin 含量은 200∼300㎍/g yeast에 불과하다. 菌株改良에서 얻은 HT - 계열 菌株는 약 5.5mg carotenoid/g yeast를 生産하지만 보다 높은 色素生産을 위해서는 繼續的인 改良을 必要로 한다. 일본의 기린은 현재 astaxanthin까지의 유전자 cloning을 끝내고 양산체제에 돌입하려 하고 있다. 몇 가지 문제점(많은 유전자를 cloning을끝내고 양상체제에 돌입하려 하고 있다. 몇 가지 문제점(많은 유전자를 cloning하여 수율 증진이 힘든 것, 사용 허가가 오래 걸리는 것 등)들을 해결하면 가장 강력한 competitor가 될 것이다. Flow cytometry의 cell sorting 方式을 사용함으로써 carotenoid 大量生産菌株를 10,000배 까지 濃縮할 수 있었다. 이는 유전적 조작 후에 균주 screening에 유용하게 사용할 수 있을 것이다내. 細胞 內 carotenoid 螢光을 測定한 結果, 일부 細胞는 15mg/g yeast의 色素를 含有하고 있었고 이를 이론적 최대 수율으로 결론 내렸다. P.rhodozyma의 carotenoid 分布를 laser confocal fluorescene microscophy를 가지고 硏究하였는데, carotenoid 脂肪體에 存在하고 endoplastic reticulum이나 mitochondria에는 存在하지 않는 것으로 밝혀졌다. Proline, asparate, asparagine, gultamine, gultamate는 yeast의 成長을 增加시켰지만, 色素의 生産은 減少시켰다. 20개의 아미노산의 同時 過剩供給은 停止期 동안의 carotenoid의 蓄積을 방해하였다. 연구개발 필요부분은 다음과 같다: 1) carotenoid 生合成 經路 確立: 2) bottle-neck 部分 糾明 및 key enzymes의 增幅: 3) regulated 部分 糾明 및 이의 deregulation: 4) 遺傳子 操作 方法 및 vector 確立: 5) fermentation 및 harvesting condition 確立: 그리고 6) 他微生物로 色素 遺傳子 移轉.

성인의 천미추부 종괴

조길환,이백권,장도명,김영진,안상태 大韓成形外科學會 1999 Archives of Plastic Surgery Vol.26 No.3

We developed an animal model to recreate the condition of an open fracture in communication with the maxillary sinus. We then studied wound healing of the sinus wall structures following fracture in the presence of autogenous bone and alloplastic implant. This model is designed to simulate the repair of an orbital floor fracture in humans. The New Zealand White rabbit was used as the animal model. Standardized 8mm defects were made bilaterally in the maxillary sinuses to include bone and mucosa in 36 rabbits. Two different implants and autogenous calvarial bone graft were placed in the soft-tissue pockets to obturate the defects, exposing one surface of the implant to the open sinus. Medpor porous polyethylene, silicone and calvarial bone implant were compared. Animals were killed at 1, 2 and 8 weeks after implantation. Gross examination of the specimens for the amount of mucosal closure and implant tissue fixation was performed. Histological sections were evaluated for bone and soft-tissue morphology juxtaposed to the implant. Complete closure of the mucosal defect was demonstrated with each type of implant. Medpor implants showed both vascular and soft-tissue ingrowth into pores by week 1. Bone ingrowth was seen by week 2. Closure of the Medpor obturated defects occurred more rapidly than in the silicone group. The Medpor implants and calvarial bone demonstrated bone and soft-tissue fixation, callus formation and maturation, while mature overlying mucosa was reconstituted over the defects. Silicone implants demonstrated a fibrous tissue reaction within 1 week of implantation and they never became fixed to bone or soft tissue. Maxillary sinus wall regeneration occurred in all defects. This study supports clinical observations of maxillary sinus wall regeneration in humans. Although sacrococcygeal mass is rare and usually found in infants or children, adolescent or adult patients with protruding mass in sacrococcygeal region occasionally come to us simply for a cosmetic problem. In this situation, even though there is no definite neurological deficit, it should be evaluated whether or not the underlying bony pathology or dural defect exists. Few cases about the sacrococcygeal mass have been reported in adults. We reviewed our cases including preoperative evaluation methods and postoperative diagnosis. From March, 1993 to February, 1997, we experienced 6 adult patients with sacrococcygeal mass and no neurological abnormality. Preoperative evaluation were made by plain X-ray, myelogram, computed tomography(CT), and magnetic resonance imaging (MRI), as needed. Postoperative diagnoses were 2 meningoceles, 2 lipomyelomeningoceles, 1 desmoid tumor, and 1 teratoma. From our experiences, CT or MRI is essential to evaluate the sacrococcygeal mass preoperatively. These methods can visualize the precise anatomic location and extent of the mass, its relation to the spinal cord, and associated bony abnormalities. MRI is superior to CT, especially in defining the nature of the mass and involvement of the spinal cord. Conclusively, even a simple mass in the sacrococcygeal region in adults needs MRI or CT evaluation, and MRI is the most valuable method of evaluating the mass preoperatively and provides important information to establish a treatment plan.

제주공항 항공등화 제어시스템의 고효율 운전대책

이길수,김일환 濟州大學校 産業技術硏究所 2000 산업기술연구소논문집 Vol.11 No.2

This paper presents the new control method of aeronautical ground lighting conrol system at Jeju airport. In the computer simulation. it is shown how to make a design for high efficiency aeronautical ground lighting control system using PWM inverter and active power filter with PI control. To verify the theoretical analysis. the conventional aero lighting control system using SCR and the proposed control system are built. Results of computer simulation are presented to support discussion.

Increased Carotenoid Production in Petite Mutants of Phaffia rhodozyma

안길환,박병순 선문대학교 자연과학대학 1998 자연과학대학 논문집 Vol.1 No.-

마이토콘드리아의 돌연변이는 Phaffia rhodozyma에서 carotenoid의 생산을 증대시켰다. 마이토콘드리아의 호흡 돌연변이는 acriflavine과 ethidium bromide를 이용하여 유도되었다. 총 9개의 시험된 호흡 돌연변이주 중 7개가 모 균주에 비하여 증대된 carotenoid를 생산하였다. 호홉 돌연변이주에서 활성산소의 생산이 증대되고 이것이 carotenoid의 생산을 증대시킨 것으로 사료된다. Mitochondrial mutation increased carotenoid production in Phaffia rhodozyma. Mitochondrial petite mutants were selected after treatment with acriflavine and ethidium bromide. Seven out of nine petite mutants, tested, produced increased carotenoid compared to their parent strain. Increased reactive oxygen species might be produced in the petite mutants, and this caused carotenoid production.

사북-고한지역이 탄광폐석에 대한 암석학적 특성 연구

백환조,임길재,서백수,민경원,정연태 강원대학교 석재복합신소재제품연구센터 1996 석재연 논문집 Vol.1 No.-

사북 및 고한 지역에 분포하는 동원탄좌와 삼척탄좌에 적치되어 있는 석탄폐석은 대부분 사암과 흑색 셰일로서, 사북광업소의 경우 약 730만 m³, 정암광업소에는 약 830만 m³의 폐석이 적치되어 있다. 동원탄좌 사북광업소의 석탄폐석중 사암은 대부분 평균 입자의 크기가 0.15∼0.9㎜에 해당하는 등립질 조직을 보이는 이질석영사암으로서, 입자의 모양과 원마도에 따른 분류로는 low sphericity의 subrounded grain에 해당된다. 또한 흑색 셰일은 평균 광물 입자의 크기가 0.05㎜ 이하이고 비교적 물결 모양의 충리를 나타내고 있다. 삼척탄좌 정암광업소의 사암은 대부분 평균 입자의 크기가 0.15∼0.3mm의 범위에 해당하는 등립질의 이질석영사암으로서 대체로 low sphericity의 subrounded grain에 해당되며, 흑색 셰일은 평균 장경이 약 0.03∼0.06㎜에 달하고, 충리가 비교적 잘 발달되어 있다. 주성분 원소들의 화학분석 결과에 따르면 동원탄좌 사북광업소의 사암은 삼척탄좌 정암광업소의 사암에 비해 상대적으로 SiO₂의 평균함량이 약간 더 높은 값을 보이고 있는데, 특히 동원탄좌 사북광업소의 일부 사암(D-4 및 D-5)은 치밀한 조직의 석영으로 구성되어 있고, 소량의 점토광물만이 기질을 이루고 있어 건설재료로서 그 활용가치가 높다고 판단된다. 또한 삼척탄좌의 사암(S-3 및 S-4)은 동원탄좌의 사암보다 상대적으로 낮은 SiO₂ 함량과 높은 Al₂O₃, Fe₂O₃*, K₂O 및 L.O.I. 함량을 보이는데, 이는 기질을 이루는 점토광물의 양이 상대적으로 많음을 반영한다. 삼척탄전의 석탄폐석에 대한 암석학적 및 지구화학적인 특징에 의하면 사암의 경우는 대체로 건설재료로서 활용이 가능하나, 흑색 셰일의 경우는 비교적 탄질물이 많이 함유되어 있어 직접적인 건설재료로의 이용은 비효율적일 것으로 생각된다. The coal mine waste rocks piled in he Sabuk and Gohan district consist mainly of sandstones and black shales, and the estimated volumes of the waste rocks are about 7,300,000m³ and about 8,300,000m³ at the Sabuk mine, Dongwon Coal Co. and the Jeongam mine, Samchok Coal Co., respectively. Sandstones in the waste pile yard of the Sabuk mine are mainly equigranular argillaceous arenites composed of low spherical and subrounded grains of 0.15∼0.9㎜ in size. Black shales show generally wavy lamination and their average grain sizes are less than 0.05㎜. Sandstones in the waste pile yard of the Jeongam mine are also mainly equigranular argillaceous arenite of low spherical, subrounded and 0.15∼0.3㎜ sized grains, and black shales exhibit well developed laminar structure with grains of 0.03∼0.06㎜ in size. Sandstones at the Sabuk mine have higher SiO₂ contents than those at the Jeongam mine, and especially some sandstones (D-4 and D-5) have extremely high SiO₂ contents, reflecting their compact textured quartz grains with small amounts of argillaceous matrix. Compared with those at the Sabuk mine, Sandstones at the Jeongam mine display lower SiO₂ contents but higher abundances of Al₂O₃, Fe₂O₃, K₂O, and L.O.I., reflecting relatively lower amounts of clay minerals. According to their petrological and geochemical properties, sandstones rather than black shales in the Sabuk and Gohan district could be potentially utilized as raw materials for construction and especially for polymer-concrete, which is now under design for mass production in this area.

Decreased Astaxanthin Prduction by Fe+++ in Phaffia rhodozyma

안길환 선문대학교 자연과학대학 1998 자연과학대학 논문집 Vol.1 No.-

Fe^(+++)가 1 mg/L 이상의 농도로 존재할 때 총 carotenoid의 양뿐만 아니라 astaxanthin의 생산비율도 Phaffia rhodozyma에서 심각히 줄었다. Fe^(+++)의 농도가 O.1 ㎎/ℓ 이하에서는 P.rhodozyma의 성장이 저해 받으므로 0.1-1 ㎎/ℓ의 Fe^(+++)를 함유하는 배지가P.rhodozyma의 carotenoid hyperproducer를 이용한 carotenoid 생산에 유리하다. Not only total carotenoid but also the ratio of astaxanthin to the total in Phaffia rhodozyma were significantly decreased at >l ㎎/ℓ ofFe^(+++). Since growth of P. rhodozyma was poor at <0.1 ㎎/ℓ of Fe^(+++), media containing 0.1-1 mg/L of Fe^(+++) are recommended especially for carotenoid hyperproducers of P. rhodozyma.

미소원공결함을 갖는 자동차 전륜구동 축재의 피로수명 예측

이동길,오환교,정재강 朝鮮大學校 機械技術硏究所 1998 機械技術硏究 Vol.1 No.1

본 연구에서는 현재 생산되고 있는 자동차의 전륜 구동축재료 S43C와 S50C를 대상으로 회전굽힘피로시험을 통해 고주파열처리와 온도조건에 따른 피로크랙 전파거동을 고찰하고, Nisitani가 제안한 역학적 변수에 의해 재료상수를 구한 후 그 적용성을 검토해 보았다. 비열처리재 S43C 및 S50C의 피로한도는 각각 98.1MPa, 107.9MPa이었으며, 열처리재는 각각 147.1MPa, 156.9MPa로서 열처리 후 두 재료 모두 피로한도가 약 49MPa씩 증가하였으며, 저온(-30℃)에서의 피로수명은 상온(25℃)에서보다 두 재료 모두 비열처리재는 약 110%, 열처리재는 약 120% 증가하였다. 또한 본 재료에 실험으로부터 얻어진 재료상수를 Nisitani의 피로크랙전파속도 예측식에 적용하여 피로수명을 예측한 결과 고주파 열처리 여부와 실험온도 조건에 관계없이 약 5% 내외의 낮은 오차를 보이며 잘 일치함을 알았다. In this study, the rotary bending fatigue test was carried out with two kinds of materials, S43C and S50C, using in the front engine and front drive shaft of vehicle. The specimens were heat-treated by high frequency induction method and tested at +25℃ and -30℃ in order to look over the influence of the heat treatment and the temperatures. The mechanical factor, C(2a)p, proposed by Nisitani was employed in the present study to compare the results of fatigue life obtained from experiment and prediction. The fatigue limit of the as-received specimens S43C and S50C were 98.1MPa and 107.7MPa, and that of the heat-treated S43C and S50C were shown 147.1MPa and 156.9MPa respectably. It means that the fatigue limit was increased about 49MPa by high frequency heat treatment. Fatigue lifes of the specimens tested at low temperature(-30℃) showed about 110% for as-received, 120% for heat-treated higher than at room temperature(25℃). It was found the crack length at onset or final fracture tested at low temperature was shorter than the crack length at room temperature(+25℃). The fatigue lifes were predicted with an equation of the fatigue crack propagation proposed by Nisitani, d(da/dN)=C(2a)p, the results were found to be within 5.0% error by comparison with experimented results.

高速流에서의 垂直壓力의 定常狀態와 過渡的 特性(1)

鄭吉煥 全北大學校 基礎科學硏究所 1979 基礎科學 Vol.2 No.1

Maxwell model of viscoelasticity is modified to incooperate the Ree-Eyring nonlinear viscosity instead of the linear Newtonian viscosity term. From the solution of the modified Maxwell model we attempted to construct an integral expression of a nonlinear response function.

公共土地開發事業 地方化問題와 代案에 관한 小考

조길환,황의진,김영곤 여수대학교 1998 論文集 Vol.13 No.2

Since 1980 the Korea Land Development Coporation has played a major role in land development by means of a Public Initiated Land Development Scheme. This strategy has attempted to correct the market failure of the generation of large sum of windfall profits. In accordance with reimplementation of the local autonomous ruling system since 1991, the demend for local government initiated land development have increased rapidly as local governments attempt to math the influence of national local development policy. In this regards, it is very useful for urban planners to analyze the merits and dismerits of the local government initiated land development schemes in view of national agency's development. This paper recommends several mitigation measures to improve the settlement of the local government initiated land development scheme.

都市公營開發事業에 對한 考察

조길환,황의진,김영곤 여수대학교 1998 論文集 Vol.13 No.2

This Paper studied the background and characteristics of the adopted public development among the system of housing land development that is executing in our country nowadays And it defined the reasons of problems that is caused by a social change in the Project of public development at the level of city public development toward a service that the public development effects to the City planning. So it would like to propose reform methods in develo-ping housing area to give basic data in establishing system of city public development by the local selfgoverning body as the methods for a construction of effective city space and smooth supply of housing area is presented as follows. First : In order to ensure a legitimacy of an exercise of government power for the business of public development, the gualification of a practical system of public development is to be strengthened. According to the guideline of the policy of city development or nation's housing or land, the condition of Yelated areas, the characteristics of business subject, the system of public development is to be selected. The object of the public development such as the developing business of residential land for the low-incomed class, the suitable business that is developed by the pu-blic, the developing business of land in national basic industries is to be realized and objectified more. Second : A differtial application of distribution price of the residential land according to not only the distribution of residential land related with housing construction business and its use or object but also the storage of public land and reformation of system and distribution object of public development land through an activation of the system of land selling in advance. Third : The idleness one of planning developed land such as a rational management for restriction of privaty ownership of developing profit, the establishment of effective restoration system of the developed profit, and establishment of land developing fund is to be controlled. Fourth : To ensure a reinvestment resources for continuous propulsion of the city developing business, its effective propulsion of developing business by a preaying distribution and induction of land demand and distribution acceleration ncouragement of purchase interest) is to be drived. So the distribution acceleration and fund revulsion is to be smooth with a rational reform of a distribution method by a minimization of dependency degree of outer fund in an early period of development and establishment of inverstment resources by a restoring profit of the public development. Fifth : A method of activation in city developing business is to be considered by a diversity of the developing subject. Sixth : The search for distribution method of space for city environment and the enlargement method of equipment space is to be considered.