• 공업화학
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• 제24권5호
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• pp.558-561
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• 2013

본 연구에서는 인 결합 단백질(phosphate-binding protein)이 세포질(cytoplasm)에서 발현되는 재조합 대장균(Escherichia coli)을 제조하였으며, 이를 이용하여 수중에 함유된 인의 제거에 대하여 고찰하였다. 이 균주를 6 h 동안 배양하여 1.0, 1.5, 2.0 mg/L의 인을 처리하였을 때, 각각 90, 49, 41%의 제거효율을 도출하였으며, 우수한 인 제거 능력(specific phosphate removal)을 나타내었다. 또한, 세포의 Optical density를 2.5, 5.0으로 조절하여 운전하였을 때, 인의 제거효율이 향상됨을 알 수 있었으며, 2.0 mg/L 인을 80%까지 제거시킬 수 있었다. 이 연구를 통하여 얻어진 새로운 생물기술은 수계의 부영양화 문제를 해결하는데 효과적으로 사용될 수 있을 것이다.

• 공업화학
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• 제34권4호
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• pp.421-425
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• 2023

Polymethyl methacrylate (PMMA), polycarbonate (PC), polyvinyl chloride (PVC), 그리고 polyacetal을 포함하는 일부 플라스틱류에 대한 연기특성을 조사하였다. 연기밀도는 ISO 5659-2의 기준에 의해 연기밀도시험기를 이용하여 정적인 연기 특성의 관련 값을 측정하였다. 또한 불꽃을 동반하는 연소와 불꽃을 동반하지 않는 연소를 구분하여 측정하였다. 불꽃방식의 복사열 50 kW/m² 의 조건하에서 연기의 최대비광학밀도(D_m) 측정값은 PMMA (401.26)가 최저로, PVC (1345.04)가 최대로 나타났다. 또한 비불꽃방식의 복사열 50 kW/m² 의 조건하에서 연기의 D_m 측정값은 PMMA (262.82) 가 최저로, PVC (1385.43)가 최대로 나타났다. 대상물의 연소 시 연기발생은 복사열 유속의 영향을 상당히 받으며, 탄화성 플라스틱은 연소 시 비탄화성 플라스틱보다 높은 연기 발생량을 나타내었다. 주 고분자 사슬에 방향족 그룹이 있는 폴리머는 열분해로 인해 다량의 숯이 생성되므로 다량의 연기를 발생시켰다.

• 한국의류산업학회지
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• 제15권6호
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• pp.985-992
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• 2013

Polytrimethylene terephthalate(PTT) offers several advantageous properties such as good tensile strength, uniformity, stiffness, toughness, UV stability, resilience, stain resistance, outstanding elastic recovery, and dyeability. The effects of annealing temperature on physical properties and the structure of PTT filaments and yarn were investigated by measuring wide-angle X-ray diffraction (WAXD), density, optical birefringence, dynamic visco elasticity, and tensile testing. The intensity of maximum tan ${\delta}$ decreased and the temperature of maximum tan ${\delta}$ shifted to a higher temperature as the annealing temperature of filaments increased; however, it shifted to a lower temperature when the annealing temperature exceeded $130^{\circ}C$. In addition, crystallinity, density and D-spacing of (010) crystal face increased as the annealing temperature increased. Optical birefringence and specific stress were almost constant up to $100^{\circ}C$ and then decreased above $130^{\circ}C$. The shrinkage of PTT filament is 0 in boiling water when annealed above $130^{\circ}C$; consequently, the use of annealed fiber above $130^{\circ}C$ can remove thermal instability when dyeing PTT fiber. In the case of yarns, the thermal stability and physical properties of yarns showed the best effect when the ply number is less than 5, twist number is less than 400tpm, and the annealing time is 20minutes.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.376-376
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• 2007

In Liquid Crystal Display (LCD) manufacturing, the organic over coat materials over coat materials for insulation layer of color filter with acryl ate was widely used. Therefore, we approach that the organic overcoat material can use to insulation layer for color filter and liquid crystal (LC) alignment layer in this research. The LC aligning capabilities was successful stuided for the first time. The organic overcoat layer and polymer layer was coated by spin-coating. In order to characterize the LC alignment, electric optic and residual DC and atomic force microscopy (AFM) image was used. The good LCD aligning capabilities treated on the organic overcoat thin film surfaces with ion beam exposure of $45^{\circ}$ above ion beam energy density of 1200 eV can be achieved. Also the good LCD alignment capabilities treated polymer on surfaces with ion beam exposure of $45^{\circ}$ above ion beam energy density of 1800 eV can be achieved. Comparing electro-optical characteristics between the Polyimide (PI) and the overcoat, the resultant transmittance of the overcoat considerably matched that of the PI and the residual DC also exhibited similar features with the PI.

• 분석과학
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• 제22권3호
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• pp.247-253
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• 2009

단결정의 실리콘 웨이퍼를 hydrofluoric acid와 ethyl alcohol이 혼합된 용액에 담궈 적정한 전류를 흘려주면 웨이퍼 표면에 수많은 pore를 형성하면서 에칭되어진다. 이러한 pore의 형태와 porosity는 전류 값과 에칭 시간 및 주기를 변화시켜 쉽게 조절할 수 있는데, 이렇게 제작된 다공성 실리콘은 수백 $m^2/cm^3$의 큰 표면적을 가지게 된다. 이때 sin 파와 같은 모양으로 시간대별 가해지는 전류 밀도를 다르게 해주어 pore안쪽의 모양을 변화시켜 주어 가시광선 영역에서 하나의 spectrum을 나타나게 되는 rugate 박막을 제작 한다. 본 연구에서는 법과학적인 목적으로 코드화된 다공성 실리콘의 rugate film을 이용하여 nano particle을 제작한 다음 이 입자들을 페인트에 혼합, 차량에 도포하고, 회수 후에 이를 확인할 수 있는지 조사하였다. 본 연구에서는 또 다양하게 가해지는 전류 값을 변경 또는 혼합하여 다공성 실리콘에 다양한 코드화를 시도하였으며, 사고 시 탈착한 페인트에서 다공성 실리콘 nano particle을 회수 하기위해 다공성 실리콘 안에 magnetite를 삽입하여 자석을 이용한 미량 나노입자 시료를 응집시켜 스펙트럼을 확인하였다.

• Journal of Oral Medicine and Pain
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• 제19권1호
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• pp.9-15
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• 1994

This experiment was performed to confirm the hypothesis that LLLT had biostimulation effect for all kinds of cells and there would be differences in the growth of cells among different types of pulsed laser. 360 samples were used in this study. The samples were randomly divided in 6 groups according to the pulse type : quasi continuous type (CW), pulse 1(P1), pulse 7(P7), pulse 9(P9), pulse 15(P15) and shame-irradiated control(Co) groups. Energy fluences of all experimental groups, P1, P7, P9, P15 and CW were 2.12, 2.12, 6.37, 57.32 and 31.85 mj/cm2 respectively. All samples were irradiated for every 1 minute at 0, 12, 24, 36, 48 and 60 hours. Ten samples of each group were sacrificed at 0 and every 12 hours and then the optical density of all samples was measured with the spectrophotometer. As a result, some types of pulses showed significant differences among groups. The increase of cells were markedly stimulated with laser irradiation in P7 and P9 groups, while inhibited in CW, P1, and P15 groups compared with control group. It is therefore, suggested that specific laser pulse should be recommanded to have the biostimulation effects on the specific tissue or cells, although the biostimulation effect is does dependant.

• 대한수의학회지
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• 제25권1호
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• pp.77-89
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• 1985

The agar gel precipitation(AGP), indirect hemagglutination(IHA) and indirect enzyme immunoassay(IEIA) tests were used to detect antibodies in pigs naturally infected with Cysticercus cellulosae in Jeju. The results obtained were summarized as follows: 1. Sera collected from pigs naturally infected with Cysticcrcus cellulosae did not react in AGP test. 2. In the IHA test for swine cysticercosis, the peak titers observed were between 1:20 and 1:160 and non-specific reaction was recognized with a few samples among control sera. 3. In the IEIA test, optical density(OD) values were obtained the best results under the condition of OPD-substrats are reacted at room temperature for 5minutes. The OD values of greater than 0.2 were determined as positive and the high titers in positive sera ranged from 1:40 to 1:1,080. 4. Antibodies to swine cysticercosis were detected by IHA and IEIA tests but the latter was more sensitive and specific than the former. 5. In the preparation of Cystisercus antigens, saline extract which was prepared the precipitate of internal membrane treated ultrasonicator were better results than other antigens for serological tests. 6. Amounts of protein in antigens was not related in direct proportion to results of serological reaction.

• 한국어병학회지
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• 제37권1호
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• pp.9-15
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• 2024

An enzyme-linked immunosorbent assay (ELISA) with two Novirhabdovirus antigens (viral hemorrhagic septicemia virus, VHSV and infectious hematopoietic necrosis virus, IHNV) was used to detect specific antibodies against VHSV from olive flounder (Paralichthys olivaceus) sera. In ELISA plates with VHSV culture supernatants (VHSV-Ag plate), optical density (OD) values for sera from olive flounder with VHS history (VHS sera) ranged from 0.64±0.36, and those of sera from fish without VHS history (non-VHS sera) ranged from 0.26±0.26. In IHNV-Ag plate, the OD values (0.43±0.28) for VHS sera were quite low compared to those in VHSV-Ag plates, while the OD values for non-VHS sera were almost similar. When the OD values for each serum were calculated by subtracting the OD values in the IHNV-Ag plate from those in the VHSV-Ag plate, the corrected OD values were significantly different between VHS sera and non-VHS sera. The results were completely in line with fish histories of VHS epizootics. It was considered that the corrected OD values may represent the true values recognized by VHSV-specific antibodies.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.461-462
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• 2002

Rolling element bearing fatigue life can be significantly reduced by debris particles in lubricants. The debris particles cause raceway surface dents that initiate early fatigue damage. Optical interferometry has been found to be the best method for characterizing bearing raceway debris dent damage. This technique is used to determine the important features, sizes and density of dents. The resulting data file is then used to determine bearing fatigue life. Tests show that bearings manufactured by different processes and material types are affected differently by debris damage and that these differences must be considered by life prediction methodologies. Bearings made by a specific enhanced process can significantly resist the deleterious effects of debris damage and outperform bearings made by other means.

• 한국정밀공학회지
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• 제22권9호
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• pp.34-40
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• 2005

Laser welding of thermoplastics is a new jointing technique with a host of advantages. It is not only another extremely useful welding method but also a cost-effective alternative to traditional techniques involving screws or adhesives. Transmission laser-welding of thermoplastics such as polycarbonate(PC), polypropylene(PP), polyvinyl chloride(PVC), low density polyethylene(LDPE) and acrylic using a high power diode laser has been studied experimentally. The optical transmission of each plastic has been measured at laser wavelength of 808nm. The weld process has been characterized by the specific energy and weld time required for each plastic. The characteristics of laser welding between same plastics have also been analyzed.