• Parasites, Hosts and Diseases
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• 제28권2호
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• pp.85-90
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• 1990

질트리코모나스(Trichomenas vaginalis)에 대한 마우스의 복강 대식세포 및 림포카인으 로 활성화시킨 대식세포의 세포독성을 각각 관찰하였다. 세포독성은 질트리로모나스를 3H-TdR로 label시킨 후 대식세포와 반응시켜 사멸한 원충에서 방출되는 방사능 양을 비교하여 측정하였다. 대식세포의 원충에 대한 비율을 1 : 1, 5 :1, 10 : 1, 20 : 1 및 50 : 1로 증가시키고 반응시간을 12시간 및 24시간으로 변화시켰을 때, 대식세포와 원충의 비율 10 : 1 및 24시간 반응의 경우 가장 놓은 세포독성을 보였다. 마우스 비장세포를 phytohemagglutinin으로 자극시켜 얻은 림포카인으로 활성화시킨 대식세포에서는, 아무 처리를 하지 않은 대조 대식세포와 비교하였을 때 세포독성이 유의하게 증가되었으나 세포독성이 림포카인의 희석정도와는 비례하지 않았다. 또한 질트리코모나스에 세포독성을 나타내는 세포는 주로 플라스틱에 부착하는 대식세포임을 알 수 있었다.

• 한국식품과학회지
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• 제22권2호
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• pp.111-115
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• 1990

원료 성분조성이 다른 시판용 정맥 및 소맥된장의 두 종류 시료를 대상으로 하여 여러 농도의 물 현탁액 (50-200v/w%)을 조제하고 각 현탁액의 리올로지적 거동을 검토하였다. 각 시료 된장 현탁액은 모두 thixotropic 거동을 보였으며, 가수량이 125% 이하인 고농도 현탁액의 경우 전단상승곡선과 하강곡선이 교차하는 Figure-eight 현상을 나타내었다. 시료 모두 가열에 따라 겉보기 점도가 뚜렷한 증가 경향을 보였으며 단백질의 등전점 부근에서 겉보기 점도가 가장 높은점, 가수량 200%의 묽은 현탁액의 경우 $60^{\circ}C$이상으로 가열했을 때 Figure-eight 현상을 보이는 점 등을 종합하여 볼 때 점성거동은 단백질 존재상태와 밀접한 관련을 갖는 것으로 추정되었다.

• Wind and Structures
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• 제23권6호
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• pp.595-613
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• 2016

Large amplitude oscillation of steepled main cables usually presents during construction of a long-span bridge. To study this phenomenon, six typical main cables with different cross sections during construction are investigated. Two main foci have been conducted. Firstly, aerodynamic coefficients of a main cable are obtained and compared through simulation and wind tunnel test: (1) to ensure the simulation accuracy, influences of the numerical model's grid size, and the jaggy edges of main cable's cross section on main cable's aerodynamic coefficients are investigated; (2) aerodynamic coefficients of main cables at different wind attack angles are obtained based on the wind tunnel test in which the experimental model is made by rigid plastic using the 3D Printing Technology; (3) then numerical results are compared with wind tunnel test results, and they are in good agreement. Secondly, aerodynamic coefficients of the six main cables at different wind attack angles are obtained through numerical simulation. Then Den Hartog criterion is used to analyze the transverse galloping of main cables during construction. Results show all the six main cables may undergo galloping, which may be an important reason for the large amplitude oscillation of steepled main cables during construction. The flow structures around the main cables indicate that the characteristic of the airflow trajectory over a steepled main cable may play an important role in the galloping generation. Engineers should take some effective measures to control this harmful phenomenon due to the big possibility of the onset of galloping during the construction period.

• 한국산업보건학회지
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• 제31권2호
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• pp.138-146
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• 2021

Objectives: This study aims to compare and evaluate the reduction efficiency of disinfectants used in the domestic meat processing industry to reduce bioaerosol exposure of meat industry workers and to use this as basic data for establishing work environment management measures. Methods: Thirteen disinfectants sold in South Korea were selected for evaluation and the bacterial reduction effect of the disinfectants was investigated. Bacterial suspension and surface disinfection tests were conducted to compare and analyze the antibacterial strength of the disinfectants. Pork carcasses, cutting boards, benches, and conveyor belts were selected for surface sterilization tests. Results: As a result of the bacterial suspension experiment test, all disinfectants had a bacterial reduction efficiency of more than 86%. Among them, the bacterial reduction efficiency of chlorine disinfectants was 99.93% on average. In the results of the pork carcass surface sterilization test, the rate of reduction of disinfectants made of quaternary ammonium compounds (QACs) was the highest. Tests of plastic cutting boards showed that chlorine disinfectants had the best sterilization effect. Experiments on stainless steel benches showed the best bacterial reduction efficiency for chlorine dioxide and QACs disinfectants. In the conveyor belt made of urethane, QACs disinfectants showed excellent sterilization effects. Conclusions: The study evaluated the disinfection power of disinfectants against bacteria occurring in domestic meat processing plants. All disinfectants were found to be effective in bacterial suspension experiments, and chlorine disinfectants were particularly effective. In surface sterilization experiments, sterilizing agents with QACs as the main ingredient were excellent.

• The Plant Pathology Journal
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• 제22권3호
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• pp.283-288
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• 2006

Trichoderma harzianum YC459 (Th 459), isolated from sawdust compost, was effective in controlling cucumber and tomato gray mold caused by Botrytis cinerea under controlled and plastic film tunnel conditions. A water suspension of the wettable powder formulation of Th 459 significantly $(P\leq0.05)$ reduced the severity of cucumber gray mold by foliar spraying at all tested concentrations from $10^5\;to\;10^8$ colony forming unit (cfu)/ml in repeated experiments. The control efficacy was maintained at least seven days with the average control value of 70% in cucumber pot tests. Mixing one to eight grams of the granular formulation ($10^8cfu/g$ dry weight) of Th 459 into one liter nursery potting mix at seeding also significantly $(P\leq0.05)$ reduced the severity of cucumber gray mold by suppression of lesion formation three weeks after treatment. Application of mixing granular formulation at seeding in combination with foliar spraying during cultivation provided a more significant reduction $(P\leq0.05)$ of cucumber gray mold than granule mixing or leaf spray alone. The foliar spraying of the formulated wettable powder of Th 459 significantly $(P\leq0.05)$ reduced the infection of tomato fruits by B. cinerea as effective as the chemical fungicide, dichlofluanid, in three plastic film tunnel experiment trials. It is suggested that effective control of gray mold of cucumber and tomato can be provided by both treatment of Th 459 into potting mix and foliar spray through induction of systemic resistance and direct inhibition of the pathogen.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제12권2호
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• pp.9-20
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• 1990

A series of 19 cases with maxillary hyperplasia and mandibular retrognathia were operated on by simultaneous superior repositioning of the maxilla after Le Fort I osteotomy and anterior repositioning of the mandible after bilateral sagittal split ramus osteotomies with or without osteotomy of the inferior border of the mandible. These were evaluated by retrospective cephalometric and computer analysis for the longitudinal skeletal and dental changes for an average of 17.1 months after surgery. For stabilization of the osteotomized segments, the authors used wire osteosynthesis by means of bilateral infraorbital and zygomatic buttress suspension wire at the maxilla, and direct interosseous wire at the split segments of the mandibular rami. Results show generally good stability after simultaneous maxillary and mandibular surgery with wire osteosynthesis, and a minimal to moderate tendency toward skeletal and dental relapse. This article is a preliminary study to defy the efficiency of the wire osteosynthesis (wo)compared with rigid internal fixation (RIF) for simultaneous maxillary and mandibular surgery. 1. The vertical relapse rate of the A point after superior repositioning of the maxilla is 2.2%. 2. The horizontal relapse rate of the B point after advancement of the mandible is 18.3%. 3. The condyle is distracted inferiorly and slightly posteriorly at the immediate postoperative period. 4. At the long term follow up examination, the condyle presents tendency of return to the preoperative position. 5. Condylar segment angle is decreased at the immediate postoperative period, and at the long term follow up evaluation, the angle is increased. 6. Gonial angle is increased at the immediate postoperative period, and then is decreased at the long term follow up evaluation. 7. The dentition is satisfactory with acceptable movement at the long term follow up evaluation. 8. At the mandibular free body analysis, genioplasty shows good stability. 9. Wire osteosynthesis provides excellent stabilization for the simultaneous maxillary and mandibular surgery.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.741-746
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• 2003

The foundation of Noksan area is composed of consolidified sediments including clay mineral, quartz, plagioclase and calcite. The mineral compositions vary dependent on the depth. That is, at the depth of 0-15 meters quartz and plagioclase are more abundant than clay mineral, at the depth of 17-39 meters clay minerals and calcite are more than quartz and plagioclase, at the depth deeper than 40 meters, the amounts of quartz and plagioclase increase slightly and that of clay minerals decrease. Clay minerals of the clayey sediments include illite, smectite, kaolinite and chlorite. At the depth 17-39 meters smectite is abundant and kaolinite is little relatively The pH of suspension is various between 3-9 and decrease to 3-5 at the depth deeper than 40 meters. The result of soil test of clay sediments, water content shows that liquid limit, plastic limit, particle size, unconfined compressive strength varies depending on the depth. The variation of mineralogical, geochemical, engineering properties of soil with the depth are probably due the differing sediments of different sedimentary environment. That is, these variations are considered to be correlated with the sedimentary environment change resulting from the change from continental environment to ocean environment due to the transgression of the interglacial period after the regression the latest glacial period.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 춘계학술대회 논문집
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• pp.117-124
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• 2002

The lightness of components required in automobile and machinery industry is requiring high strength of components. In particular, manufacturing process and new materials development for solving the fatigue fracture problem attendant upon high strength of suspension of automobile are actively advanced. In this paper, the effect of compressive residual stress of spring steel(JISG SUP-9) by shot-peening on fatigue crack growth characteristics in high temperatures($100^{\circ}C,\;150^{\circ}C,\;180^{\circ}C$) was investigated with considering fracture mechanics. So, we can obtain followings. (1) Compressive residual stress is decreased in high temperature, that is, with increasing temperature. (2) The effect of compressive residual stress on fatigue crack growth behavior in high temperature is increased below ${\Delta}K=17{\sim}19MPa\sqrt{m}$. The fatigue crack growth rate is increased with increasing temperature. The fatigue life is decreased with increasing temperature. (3) The dependence of temperature and compressive residual stress on the parameters C and m in Paris' law formed the formulas such as equations (3),(4),(5),(6),(7),(8),(9),(10). (4) It was investigated by SEM that the constraint of compress residual stress for plastic zone of fatigue crack tip was decreased in high temperature as compared with room temperature.

• 한국안전학회지
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• 제21권4호
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• pp.1-6
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• 2006

The lightness of components that was required in automobile and machinery industry requires high strength of components. In particular, manufacturing process and new materials development for solving the fatigue facture problem attendant upon high strength of suspension of automobile are actively advanced. In this paper, the effect of compressive residual stress of spring steel(JISG SUP-9)by shot-peening on fatigue crack growth characteristics in high temperature($100^{\circ}C,\;150^{\circ}C,\;180^{\circ}C$)was investigated with considering fracture mechanics. So, we can obtaint the followings. (1) Compressive residual stress is decreased with increasing the test temperature. (2) The effect of compressive residual stress on fatigue crack growth behavior in high temperature is increased below ${\Delta}K=17{\sim}19MPa{\sqrt{m}}$. (3) It was investigated by SEM that the constraint of compress residual stress for plastic zone of fatigue crack tip was decreased in high temperature as compared with room temperature.

• 약학회지
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• 제40권4호
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• pp.411-417
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• 1996

Epidermal growth factor(EGF), a potential healing agent for wounds and burns, has been formulated to topical gels with the hydrophilic polymers, Carbopol 934P. Physicochemical c haracteristics of the aqueous gels were evaluated by rheological properties and pH changes on storage. The gels were relatively stable at $4^{\circ}C$ and room temperature showing no changes in pH for two weeks, and revealed the rheogram of shear thinning plastic flow with the yield values in the range of 40 to 70dyne/$cm^2$. In vivo healing effects of different gel formulations have been compared with water-soluble and oleaginous ointments in full-thickness wound mouse model. The gel systems resulted in better wound healing effects than the other ointments. Furthermore, liposomal Carbopol gel has been developed by the addition of EGF-containing liposomal suspension into the Carbopol gel. The enhanced wound healing effects have been observed in the liposomal gel system, compared to the other gels and conventional ointments.