• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 추계학술발표대회 논문집
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• pp.79-83
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• 2000

Interfacial and microfailure properties of carbon liber/bismaleimide (BMI) composites were evaluated using both tensile fragmentation and compressive Broutman tests with acoustic emission (AE). Since BMI is rather difficult matrix to apply for the conventional fragmentation test because of its too low elongation and too brittle and high modulus properties, dual matrix composite system was applied. After carbon fiber/BMI composite was prepared for rod shape by controlling differing curing stage, composites rod was embedded in toughened epoxy as outer matrix. The typical microfailure modes including fiber break, matrix cracking, and interlayer failure were observed during tensile testing, whereas the diagonal slippage in fiber ends was observed during compressive test. On the other hand, AE amplitudes of BMI matrix fracture were higher than carbon fiber tincture under tensile test because BMI matrix has very brittle and high modulus. The waveform of signals coming from BMI matrix fractures was consistent with AE amplitude result under tensile tests.

• 유변학
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• 제3권1호
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• pp.30-37
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• 1991

제 2세대 bismaleimide의 일종인 Boots Technochemie 사의 Compimide 800을 매트 릭스 수지로 선정하여 여기에 촉매(DABCO 0.2wt%) 및 반응성 내충격성 증진제(TM 120; 15. 30, 60 part)를 첨가하여 Carbon/BMI 적층판($\pm$ 45。)2s를 만들어 인장 시험을 하여 in-plane shear하에서의 파단특성을 조사하였다, 이경우에 전단 탄성율을 망목상구조의 특성 에 의해 좌우되고 전단강도는 파단면의 형태와 밀접합 관계가 있다. TM 120을 30 part 첨 가한 경우의 전단강도가 가장 우수하였다

• 한국재료학회지
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• 제4권8호
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• pp.888-894
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• 1994

bismaleimide취약성을 개선 하기 위하여 toughening agent인 TM120을 첨가하여 carbon/$(\pm 45^\circ)_{2s}$를 제조하고 이들의 파손과 기계적 특성을 인당실험과 음향방출을 통해 자세히 논하였다. 첨가하는 TM120의 비율은 0, 5, 10, 15, 20, 25phr이었고, 1, 4-diazobicyclo-(2, 2, 2)-octane(DABCO) 0.2phr를 경화 촉진제로 사용하였다. 또한, 탄소 섬유는 Toray사의 T300를 사용하였고, 음향방출과 인장실험 결과로 TM120이 적당한 첨가량은 20phr이었으며, TM120은 cabon/$(\pm 45^\circ)_{2s}$의 파손특성과 기계적물성에 많은 영향을 미쳤다.

• Carbon letters
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• 제19권
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• pp.1-11
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• 2016

In efforts to characterize and understand the properties and processing of phenylethynyl-terminated imide (LaRC PETI-5, simply referred to as PETI-5) oligomers and polymers as a high-temperature sizing material for carbon fiber-reinforced polymer matrix composites, PETI-5 imidization and thermal curing behaviors have been extensively investigated based on the phenylethynyl end-group reaction. These studies are reviewed here. In addition, the use of PETI-5 to enhance interfacial adhesion between carbon fibers and a bismaleimide (BMI) matrix, as well as the dynamic mechanical properties of carbon/BMI composites, are discussed. Reports on the thermal expansion behavior of intercalated graphite flake, and the effects of exfoliated graphite nanoplatelets (xGnP) on the properties of PETI-5 matrix composites are also reviewed. The dynamic mechanical and thermal properties and the electrical resistivity of xGnP/PETI-5 composites are characterized. The effect of liquid rubber amine-terminated poly(butadiene-co-acrylonitrile) (ATBN)-coated xGnP particles incorporated into epoxy resin on the toughness of xGnP/epoxy composites is examined in terms of its impact on Izod strength. This paper provides an extensive overview from fundamental studies on PETI-5 and xGnP, as well as applied studies on relevant composite materials.

• Composites Research
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• 제30권2호
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• pp.132-137
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• 2017

본 연구에서는 카본/BMI 면재와 노멕스 허니콤 코어를 가지는 샌드위치 포팅 체결부의 다양한 설계변수에 대한 파손특성 연구를 수행하였다. 샌드위치 시편은 코어 높이, 면재 두께 및 밀도에 따라 총 6종류가 제작되었고, 이중 1종류의 시편에 대해 온/습도 효과를 보기 위해 환경 조건이 가해졌다. 시험 결과 밀도가 $64kg/m^3$ 코어를 제외한 모든 시편에서 코어의 전단좌굴이 초기 파손모드로 나타났으며, 이후 하중을 지지하다 윗면재 파손과 동시에 아랫면재에 볼트가 파고드는 파손형상이 나타났다. 하지만 밀도에 의해 높은 강성을 가지는 시편의 경우 초기 전단좌굴 발생 없이 윗면재와 코어의 계면파손에 의해 낮은 최대파손하중을 나타냈다. 샌드위치 시편의 환경적 영향 평가를 위해 수행된 ETW1($82^{\circ}C$, Wet)과 ETW2($177^{\circ}C$, Wet)의 경우 RTD($24^{\circ}C$, Dry) 조건과 확연히 다른 초기 파손모드를 보였으며, 동일한 습도조건 하에 온도가 상승된 ETW2는 ETW1보다 전단좌굴 하중이 약 18% 감소되는 경향을 보였다.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1993년도 ACT 93
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• pp.617-621
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• 1993

• 한국생활환경학회지
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• 제19권4호
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• pp.479-488
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• 2012

This study investigated the influence of the indoor CO₂concentration level on sleep quality by polysomnography(PSG). One healthy female subject was selected among several subjects based on RI(Risk Indicator) value and BMI(Body Mass Index) value to evaluate judging the risk level of obstructive sleep apnea hypopnea. To get the impact of the indoor carbon dioxide concentration to sleep quality, both CO₂concentration levels were set up using ventilating form with 700~800 ppm and 2000~3000 ppm. Other environments were controlled in the comfortable sleep scope by previous researches. To measure the sleep quality, measurements have carried on polysomnography(PSG). In conclusion, it have shown that high carbon dioxide concentration leads arousal effect about central nervous system and to sustaining dreams and excited condition by bring about REM sleep split phenomenon.

• 한국식품영양학회지
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• 제20권2호
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• pp.173-178
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• 2007

In this study we manufactured mulberry fruit tea(MFT) to be used as an anti-inflammatory agent. Here, MFT was consumed by thirty middle-aged women with symptoms of rheumatoid arthritis for 4 weeks. The anthropometric measurements and serum inflammatory factors were measured before and after consumption of the MFT. For the anthropometric measurements, BMI and body fat decreased after 4 weeks of tea consumption although there were no significant differences. The serum inflammatory factors(uric acid and homocysteine) as well as serum amino transferase activity(aspartate trans-aminase and alanine transaminase) showed a decreasing trend. In addition, serum carbon reactive protein(CRP) decreased significantly decreased after MFT consumption 4 weeks. It's concluded that this MFT is helpful to for rheumatyroid arthritis patients in order to decrease serum inflammatory factors such as CRP.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.44-45
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• 2010

We are currently conducting studies on culturing and biocompatibility assessment of various cells such as neural stem cells and induced pluripotent stem cells(IPS cells) on carbon nanotube (CNT), on nerve regeneration electrodes, and on silicon wafers with a focus on developing nerve integrated CNT based bio devices for interfacing with living organisms, in order to develop brain-machine interfaces (BMI). In addition, we are carried out the chemical modification of carbon nanotube (mainly SWCNTs)-based bio-nanosensors by the plasma ion irradiation (plasma activation) method, and provide a characteristic evaluation of a bio-nanosensor using bovine serum albumin (BSA)/anti-BSA binding and oligonucleotide hybridization. On the other hand, the researches in the case of "novel plasma" have been widely conducted in the fields of chemistry, solid physics, and nanomaterial science. From the above-mentioned background, we are conducting basic experiments on direct irradiation of body tissues and cells using a micro-spot atmospheric pressure plasma source. The device is a coaxial structure having a tungsten wire installed inside a glass capillary, and a grounded ring electrode wrapped on the outside. The conditions of plasma generation are as follows: applied voltage: 5-9 kV, frequency: 1-3 kHz, helium (He) gas flow: 1-1.5 L/min, and plasma irradiation time: 1-300 sec. The experiment was conducted by preparing a culture medium containing mouse fibroblasts (NIH3T3) on a culture dish. A culture dish irradiated with plasma was introduced into a $CO_2$-incubator. The small animals used in the experiment involving plasma irradiation into living tissue were rat, rabbit, and pick and are deeply anesthetized with the gas anesthesia. According to the dependency of cell numbers against the plasma irradiation time, when only He gas was flowed, the growth of cells was inhibited as the floatation of cells caused by gas agitation inside the culture was promoted. On the other hand, there was no floatation of cells and healthy growth was observed when plasma was irradiated. Furthermore, in an experiment testing the effects of plasma irradiation on rats that were artificially given burn wounds, no evidence of electric shock injuries was found in the irradiated areas. In fact, the observed evidence of healing and improvements of the burn wounds suggested the presence of healing effects due to the growth factors in the tissues. Therefore, it appears that the interaction due to ion/radicalcollisions causes a substantial effect on the proliferation of growth factors such as epidermal growth factor (EGF), nerve growth factor (NGF), and transforming growth factor (TGF) that are present in the cells.

• 한국산업보건학회지
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• 제17권2호
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• pp.144-152
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• 2007

Diesel vehicles are a significant source of fine carbon particle emissions including polynuclear aromatic hydrocarbons (PAHs). Urinary 1-hydroxypyrene (1-OHP) is firmly established as a useful biomarker of PAHs uptake in human. To investigate the exposure effect of PAHs in miners according to using diesel truck which was for transportation of ore, we measured urinary 1-OHP as the PAHs exposure biomarker, and analyzed the relationship between urinary 1-OHP concentration and using diesel truck. The study was performed on 118 workers (56 miners in factories using diesel truck, 62 miners in factories non-using diesel truck) and 21 controls. Urine samples were obtained at the end of shift on the survey day. There was no significance in comparison with the mean concentrations on urinary 1-OHP by age, BMI, work duration, smoking, drinking and ventilation type. But significant difference were found among urinary 1-OHP concentrations on factories according to using diesel truck (p=0.000). The urinary 1-OHP mean concentration on underground miners using diesel truck ($0.54{\mu}mol/mol$ creatinine) was higher than those of surface miners using diesel truck ($0.33{\mu}mol/mol$ creatinine, p=0.028), underground miners non-using diesel truck ($0.32{\mu}mol/mol$ creatinine, p=0.001) and controls ($0.22{\mu}mol/mol$ creatinine, p=0.000). In comparison with using status diesel truck, the urinary 1-OHP mean concentration of underground miners using diesel trucks was higher than those of other mine status. The study results would be beneficial to future environmental and biological studies of PAHs exposure to diesel exhaust in mines.