고상-기상 반응에 의한 질화 알루미늄 휘스커 합성

강종봉,양성구,이성우,정승화 慶南大學校 附設 工業技術硏究所 2003 硏究論文集 Vol.21 No.2

질화알루미늄 휘스커 합성을 위하여, Al원으로는 Al_2O_3, Al(OH)_3, AlOOH를 사용하였고, 환원제로는 카본블랙, 기상반응을 유도하기 위하여 AlF_3, NH_4F, CaF_2를 사용하여 고순도 질소분위기에서 실험을 행하였다. 또한 액상반응 시 미세구조상의 변화를 확인하기 위하여 금속 알루미늄을 첨가하여 실험을 행하였다. 질화알루미늄의 생성과 침상형 휘스커상의 형상은 1600℃의 온도에서 가장 잘 나타났으며 열처리 온도의 상승은 오히려 휘스커상의 형성을 방해하고 있음을 보여주었다. 침상형 휘스커의 합성에 가장 큰 영향을 주는 것은 기상반응을 일으키는 AlF_3 첨가이며, AlF_3 첨가량이 증가함에 따라 침상형 휘스커상의 증가를 확인할 수 있었다. 액상 반응을 위한 금속 알루미늄 첨가는 전체의 15 wt%까지는 침상형 휘스커가 증가하였으나 15 wt%이상으로 첨가하는 경우 오히려 침상형 휘스커가 감소하는 것으로 나타났다. To synthesize aluminium nitride whisker, Al_2O_3, Al(OH)_3, and AlOOH were used for aluminium element. Experiment was done under the high purity nitrogen atmosphere with carbon black as deoxidation agent and AlF_3, NH_4F and CaF as gas phase reactants. Metallic aluminium was used for liquid phase reaction in which microstructural change occured. The AlN with whiskered Phase was formed at 1600℃ and the increase of temperature inhibited the formation of whiskered phase. AlF_3 was the main factor for the formation of needle-shaped whiskers, and the amount of whisker increased with AlF_3 contents. The amount of needle-shaped AlN whiskers increased with the addition of metallic aluminium up to 15 wt% but decreased with aluminium of above 15 wt%.

Headed Reinforcement를 사용한 철근콘크리트 깊은 보의 전단거동

강경훈,이우진,김수봉,서수연,윤승조,김성수 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

Generally, headed reinforcement offers several advantages over straight bar or hooked bar anchorages to develop reinforcement in concrete members. The purpose of this study is to investigate the shear behaviors of reinforced concrete deep beam with headed reinforcement. Five deep beam specimens are designed to study the anchorage capacity of headed reinforcement as well as the contribution of H-bar and V-bar to the shear. Two anchorage types, standard 90-degree anchorage and headed reinforcement, are considered in design. From the tests, it is shown that In the test results, headed reinforcement is able to replace standard 90-degree anchorage as the anchorage method. The evaluation on the contribution of H-bar and V-bar in current design code for deep beam shows that the former is overestimated 75% and the latter is overestimated 17%.

감마선과 Methyl Bromide 처리가 사과의 생리화학적 품질에 미치는 영향

강호진,정헌식,조덕조,변명우,최성진,최종욱,권중호 한국식품저장유통학회 ( 구 한국농산물저장유통학회 ) 2003 한국식품저장유통학회지 Vol.10 No.3

감마선(0, 0.5, 1, 2, 3 kGy) 조사와 methyl bromide(MeBr, 26 g/㎏, 4hr) 훈증 및 이들의 처리시기가 사과의 생리화학적 품질특성에 영향을 비교하여, 검역처리를 위한 ◁그림 삽입▷ (원문을 참조하세요) 감마선 조사의 응용성을 검토하였다. 감마선과 MeBr 처리에 따른 사과의 생리화학적 품질평가에서 2kGy 이상의 감마선 조사와 MeBr 훈증은 사과의 일부 생리화학적 품질특성의 변화를 촉진시키는 것으로 나타났다. 감마선과 MeBr의 처리시기별로는 수확 직후보다는 저온(0℃)에서 40일 정도 보관 후 처리한 대체적으로 품질손상이 적은 것으로 나타났다. 따라서 1kGy 이하의 감마선 조사와 지연조사는 사과 과실의 품질을 비교적 양호한 상태로 유지할 수 있어 검역처리 기술로 활용성이 있는 것으로 생각된다. 'Fuji' apples were treated by gamma irradiation (0∼3 kGy) or methyl bromide fumigation at commercial conditions (MeBr, 25 g/㎏, 4 hr) for quarantine purpose at two different treatment timing after harvest and stored under air a 0℃ for 4 months. Associated with the treatment timing of irradiation or fumigation, after 40 days of storage at 0℃ following harvest was more adequate than immediately after harvest in keeping qualities of stored apples. However, more than 2 kGy irradiation and MeBr fumigation were detrimental to physiological and chemical qualities of the fruits. These results show that less than 1 kGy irradiation at the delayed timing has a possibility to be applied as a quarantine procedure without significant changes in the quality of apples.

내시경적 점막절제술로 치험한 식도 과립상 세포종 1례

강혁주,김성욱,최석진,이중현,장재식,서영범,윤병구,박건욱,김성자,김용섭,강승완,이구,양창헌,이창우,김욱년,이광헌,서정일 동국대학교 의학연구소 2000 東國醫學 Vol.7 No.-

과립상 세포종은 Schwann 세포 기원으로 생각되며 인체에 비교적 드물게 발생한다. 과립상 세포종은 전신 어느 곳에서나 발견될 수 있으나 주로 혀, 구강, 피부 혹은 유방 등에서 호발하며 드물게 위장관에서 발견된다. 위장관에서는 식도에서 가장 호발하며 다음으로 위, 대장 순이다. 과립상 세포종은 대부분, 특히 위장관에서는 양성이며 소수의 악성 병변이 보고되었다. 이러한 이유와 함께 수술 전의 진단이 어렵기 때문에 과립상 세포종에 대한 근본적인 치료는 현재까지 외과적 절제술이다. 최근에 시도되는 치료방법들로는 내시경적 레이저 치료, 용종절제술, 내시경적 점막 절제술 등이 있다. 저자들은 상부 소화관 내시경검사를 시행하여 식도 과립상 세포종을 진단하고 내시경적 점막 절제술을 시행하여 합병증 없이 퇴원하여 현재 재발없이 경과 관찰중인 1례를 경험하였기에 보고하는 바이다. Granular cell tumors, which occur infrequently, are probably of Schwann cell origin. They can occur almost anywhere in the body but usually affect the tongue, oral cavity, skin, or breasts and are rarely found in the gastrointestinal tracts. The esophagus is the most frequent gastrointestinal site, followed by the stomach and the colon. Granular cell tumors are generally benign, especially in the gastrointestinal tract, some malignant lesions have been reported. For this reason, and also because preoperative diagnosis is difficult, the standard treatment for granular cell tumor has until now been surgical excision. In recent years, other therapeutic methods is endoscopic laser therapy (ELT), polypectiomy, endoscopic mucosal resection (EMR). We report a case of esophageal granular cell tumor which was diagnosed by an endoscopy and managed using an endoscopic mucosal resection without complication.

새로운 Baculoviurs 전이벡터를 이용한 Escherichia coli β-galactosidase 유전자의 발현

우수동,김우진,김혜성,진병래,강석권 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.1

국내에서 분리된 BmNPV를 이용하여 제작된 새로운 전이벡터 pBmKSK1에 외래 유전자로서 E. coli lacZ 유전자를 클로닝하고 재조합 바이러스를 제작하였다. 재조합 바이러스에 대하여 Southern blotting 분석을 실시하여 lacZ 유전자의 존재를 확인하였으며, 재조합 바이러스가 접종된 세포의 SDS-PAGE 및 Western blotting 분석을 통하여 β-galactosidase의 발현을 확인하였다. 재조합 바이러스의 발현효율을 누에 세포주 및 유충에서 비교 조사한 결과, 유충에서 더욱 높은 발현량을 보임을 확인하였다. To investigate the expression efficiency of new transfer vector of Bombyx mori nuclear polyhedrosis virus (BmNPV), Escherichia coli lacZ gene was inserted into new transfer vector pBmKSK1, under the control of polyhedrin promoter and expressed in BmN-4 cells coninfected with transfer vector pBmKSK1-LacZ and vild type BmNPV genome, and analysed by Southern blotting. The expression of β-galactosidase was characterized by SDS-PAGE, Western blotting and β-galactosidase activity assay. The results showed that the level of expression in silkworn larvae was higher than that of BmN-4 cells.

중등학교 현장 물리교육의 현황과 개선방안

강정우,고영옥,강성진,김규용,박규은 濟州大學校 師範大學 科學敎育硏究所 1996 科學敎育 Vol.13 No.-

To investigete the obstacles of developing physics education in secondary schools and the countermeasure in present situtation, I distributed subject - description style answer sheets to middle & high school teachers in Cheju, which consist of 28 detail subjects under the big 8 themes. The recovery rate is 75%, and now I'm describing the result. According to the themes, total frequency is like this : Derection of Physics Leaming(412), Administration of Physics Facilities and Other Elements(298), Administration of Physics Education(268), Contents of Text( 183), Events of Science(163), Guiding of Students(l23), Grade and Evaluation of Students(101), 6th Education Cumculum(86). It suggests as the improvement that experiment training for teachers be reinforced, programs about new physicse teaching menthod be introduced, teachers try to motivate the students in class, teaching material for students?advanced learning be developed, usage of teaching material be presented, qualified experiment assistant be arranged and no less than two laboratories be provided by school unit and hours of teaching on physics teacher lessen. Besides, science events need to be held for every student by school unit, which should be eximined about when and how they would be he held.

수 종의 도재 수복물에 부착된 세라믹 브라켓의 전단접착강도와 파절양상에 열순환이 미치는 영향

강상욱,손우성,박수병,김성식 대한치과교정학회 2009 대한치과교정학회지 Vol.39 No.4

본 연구는 도재 수복물에 부착된 단결정 세라믹 브라켓의 전단접착강도와 파절양상에 열순환과 도재 수복물의 종류가 어떤 영향을 미치는지 알아보기 위해 시행되었다. 도재전장관에 사용되는 재료들 중 Ceramco 3, Empress II, Zi-ceram/Vintage ZR 세 가지를 선택하여 각 20개씩 총 60개의 시편을 원반형태(두께 2 mm, 직경 12 mm)로 제작하였다. 동일한 접착 술식으로 세라믹 브라켓을 부착한 후 열순환을 시행한 실험군과 시행하지 않은 대조군, 두 군으로 나누어 전단접착강도와 파절양상을 평가하였다. 열순환을 하지 않은 대조군의 전단접착강도는 Ceramco 3는 7.06 ± 1.76 MPa, Empress II는 7.55 ± 2.38 MPa 그리고 Zi-ceram/Vintage ZR은 7.19 ± 1.38 MPa로 추천되는 전단접착강도(6 - 8 MPa)에 적합한 강도를 보였으나 열순환을 시행한 실험군은 전단접착강도가 유의하게 감소하였으며(p < 0.05) 열순환 후의 전단접착강도는 Ceramco 3는 4.88 ± 1.00 MPa, Empress II는 5.46 ± 1.35 MPa 그리고 Zi-ceram/ Vintage ZR은 4.84 ± 1.01 MPa로 임상적으로 추천되는 것보다 다소 낮은 값을 보였다. 도재의 종류에 따른 전단접착강도에는 유의한 차이가 없었다. 파절양상은 대조군에서는 모두 브라켓 기저부와 접착제 사이에서 파절이 일어났으며, 실험군에서는 2개의 시편(Ceramco 3과 Zi-ceram/Vintage ZR군에서 각 1개)만이 접착제내 파절을 보였으며 28개의 시편은 브라켓 기저부와 접착제 사이에서 파절이 일어났다. 이상의 연구 결과에서 보았을 때 도재 수복물의 종류에 따른 차이는 없었으나 열순환에 의해 전단접착강도가 약화되므로 실제 임상에서 고려되어야 할 것이다. Objective: The purpose of this study was to investigate the effect of thermocycling and type of porcelain restoration on shear bond strength (SBS) and mode of failure of monocrystalline ceramic brackets. Methods: A total of 60 porcelain discs were made and divided into three equal groups as follows: Ceramco 3, IPS Empress II, Zi-ceram/Vintage ZR. ceramic brackets were bonded to the prepared porcelain surfaces in the same manner. Each group was divided randomly into two subgroups: thermocycled group and non-thermocycled group (control). All samples were tested in shear mode on an universal testing machine. Results: SBS of the non-thermocycled group was clinically acceptable (Ceramco 3: 7.06 ± 1.76 MPa, IPS Empress II: 7.55 ± 2.38 MPa, Zi-ceram/ Vintage ZR: 7.19 ± 1.38 MPa). But, SBS of the thermocycled group was significantly reduced (Ceramco 3: 4.88 ± 1.00 MPa, IPS Empress II: 5.46 ± 1.35 MPa, Zi-ceram/Vintage ZR: 4.84 ± 1.01 MPa, p < 0.05). There was no difference between the shear bond strength by type of porcelain restoration. All bonding failure occurred between bracket base and adhesive, except for 2 samples. Conclusions: The results of this study suggest that the type of porcelain restoration did not affect SBS, but thermocycling weakened SBS. Therefore, the effect of thermocycling should be considered when using ceramic brackets in practice.

만성 스트레스에 대한 뇌 및 위장관계의 Polyamine반응 : 단일성 및 복합성 스트레스의 차이 Differences between Single and Complex Type Stress

강영우,김희철,이성룡 대한생물치료정신의학회 2001 생물치료정신의학 Vol.7 No.2

Objectives : There is a hypothesis that subject may adapted to same kind repetitive stress. Polyamine(putrescine, spermidine, and spermine) is one of the stress responses in brain and peripheral organs. Therefore, we designed this study to investigate the differences between single and complex type of chronic stresses by examining the changes of polyamine levels in brain and peripheral tissues. Method : There are four groups in this study. 1) control group(n=5) : animals with no stress, 2) immobilization stress group(n=5) : animals with 10 times of immobilization stress, 3) cold-water swimming stress group(n=5) ; animals with 10 times of swimming stress in cold water, 4) complex stress group(n-5) : animals with immobilization and cold-water swimming stress. For immobilization stress(10 days), rats were placed in restrainers once daily, for 3 hours, For cold water swimming stress, rats were placed in ice-cold water once daily for 3min(10 days). For complex stress, rats were alternately underwant immobilization stress and cold swim stress, for 10 days(5 times, respectively). For polyamine analysis, polyamine extracted from brain tissue(frontal cortex and hippocampus) and gastrointestinal tract(gastric and duodenal mucosa) and measured with high performance liquid chromatography and ultraviolet detector at 242nm. Results : Putrescine levels in frontal cortex were significantly decreased by immobilitation stress and complex stress, respectively. Putrescine levels in hippocampus were significantly decreased by immobilization stress. Spermidine levels in duodenal mucosa were significantly decreased by cold swimming stress. However, spermine levels were not changed by any type of stress. There were no differences in polyamine reponses between single type and complex type stresses. Conlusions : Attenuations of putrescine and spermidine levels after chronic stresses seem to be a adaptation process of polyamine responses. In our experimental conditions, there are no differences in polyamine responses between single type and complex type stresses.

조혈모세포이식술이 골수기질세포의 기원 및 조골세포로의 증식 및 분화에 미치는 효과

강무일,조성원,오은숙,백기현,이원영,오기원,김혜수,한제호,윤건호,차봉연,이광우,손호영,강성구,김춘추 대한내분비학회 2000 Endocrinology and metabolism Vol.15 No.4·5

8년간(1992~1999) 산업안전보건연구원에 의뢰된 직업병 심의 사례 분석

강성규,김규상,김양호,최정근,안연순,진영우,최병순,양정선,김은아,채창호,최용휴,김대성,박정선,정호근 대한산업의학회 2000 대한직업환경의학회지 Vol.12 No.2

Objectives : Pneumoconisis and noise-induced hearing loss (NIHL) have been reported as main occupational diseases by the Special Health Examination. The Industrial Accident Compensation Insurance has reported various work-related diseases, however, these two diseases occupied almost a half of compensated cases. Therefore, it was not well known about the status of occupational diseases other than pneumoconiosis, NIHL, and cardio-cerebrovascular accident (CVA). This study was conducted to analyze claimed cases as an occupational disease, that was requested to the Korea Industrial Safety and Health Agency (KOSHA). Methods : The local office of the Korea Labor Welfare Corporation (KLWC) has asked the KOSHA for confirmation of claimed cases as an occupational disease. We analyzed 379 cases requested from KLWC, the Ministry of Labor, employers, unions and occupational health agencies from 1992 to 1999. Results : Male was 80.7 % of the requested cases. Their mean age was 42 years old and 75.5 % of them were more than 35 years old. The requested cases were increased rapidly from 25 cases in 1992 to 108 cases in 1999 and the accept rate was 50.7 %. The majority of requested cases were respiratory diseases(22.4%), cancers(18.5%), Neuropsychiatric problems(14.5%), and musculoskeletal problems(13.5%). The accept rate was high in reproductive, respiratory, musculoskeletal and digestive disorders and low in neuropsychiatric, renal and otologic problems and occupational cancers. 73.6% of them were caused by chemical agents, especially 28.5 % were by organic solvents. 67% of them were clinically confirmed at university hospitals. A half of the cases were from KyongIn area, even the request came from the whole country. Conclusions : A claim was common in workers whose age was over 35 years old and exposure history was over 10 years. The respiratory diseases and neuropsychiatric disorders were still main problems in occupational health and occupational cancers was increasing even though its accept rate was not high yet.