• 공업화학
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• 제28권4호
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• pp.437-441
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• 2017

본 연구에서는 방화용 실란트의 첨가제로 사용되는 팽창흑연의 부피팽창률과 경도특성을 개선하기 위해 팽창흑연에 다양한 수지를 코팅한 후 그 특성을 고찰하였다. 수지의 코팅률을 나타내는 평균코팅두께는 수지의 건조속도와 점도의 영향으로 초산비닐계수지 > 아크릴수지 > 우레탄수지 > 수용성라텍스의 순으로 크게 나타났다. 또한 수지의 종류에 따라 코팅된 팽창흑연의 부피팽창률은 우레탄수지 > 수용성라텍스 > 아크릴수지 > 초산비닐계수지의 순으로 컸으며, 경도는 초산비닐계수지 > 아크릴수지 > 수용성라텍스 > 우레탄수지의 순으로 증가함을 알 수 있었다. 이는 코팅처리를 하지 않은 팽창흑연에 비해 부피팽창률은 감소하나 경도가 현저하게 증가되어 방화첨가제로 사용이 가능함을 알 수 있었다. 반응표면분석법에 의한 최적화실험 결과 아크릴수지의 최적코팅 조건은 수지의 첨가량 37.6 wt%과 코팅 교반속도 441.4 rpm이었다.

• 한국의류산업학회지
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• 제22권1호
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• pp.66-75
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• 2020

This study helps develop cool-touch functional dance sportswear. We suggest a draft design for dance sportswear that chooses appropriate cool-touch functional materials based on an investigation of the changes of body surface temperature before and after exercise, the physical properties of cool-touch materials on the market, and the preference for cooling tools. The results are as follows. First, cool-touch functional sportswear products on the market utilize materials such as PCM, Delta fabric, high gauge fabric, and ice chips as well as incorporate functions such as UV block and eyelets for enhanced breathability. Polyester and polyurethane fibers are mainly used for cool-touch functional sportswear. Second, the neck area showed the highest surface temperatures (32.7℃ and 32.1℃) before and after exercise. Body surface temperatures measured after exercise were also lower than temperatures measured before exercise when wearing dance sportswear. Third, as for the physical properties of cool-touch materials, material 1 showed amaximum drying speed (130 min), material 3 the best moisture absorption speed (122 × 132 min), and material 4 the best thermal conductivity (0.013 7 w/m·K). Fourth, a draft design for a cool-touch functional dance sportswear was suggested, including a neckband made of removable soft PVC material on the neck area and applying material 4 in F1, B4, S2 and lower arm areas and material 1 in the armpit area. Deodorant tape was also attached to the armpit area for added comfort and antibacterial deodorant effect.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.254-254
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• 2011

The memories with nano-particles are very attractive because they are promising candidates for low operating voltage, long retention time and fast program/erase speed. In recent, various nano-floating gate memories with metal-oxide nanocrystals embedded in organic and inorganic layers have been reported. Because of the carrier generation in semiconductor, induced photon pulse enhanced the program/erase speed of memory device. We studied photo-induced electrical properties of these metal-oxide nanocrystal memory devices. At first, 2~10-nm-thick Sn and In metals were deposited by using thermal evaporation onto Si wafer including a channel with $n^+$ poly-Si source/drain in which the length and width are 10 ${\mu}m$ each. Then, a poly-amic-acid (PAA) was spin coated on the deposited Sn film. The PAA precursor used in this study was prepared by dissolving biphenyl-tetracarboxylic dianhydride-phenylene diamine (BPDA-PDA) commercial polyamic acid in N-methyl-2-pyrrolidon (NMP). Then the samples were cured at 400$^{\circ}C$ for 1 hour in N atmosphere after drying at 135$^{\circ}C$ for 30 min through rapid thermal annealing. The deposition of aluminum layer with thickness of 200 nm was followed by using a thermal evaporator, and then the gate electrode was defined by photolithography and etching. The electrical properties were measured at room temperature using an HP4156a precision semiconductor parameter analyzer and an Agilent 81101A pulse generator. Also, the optical pulse for the study on photo-induced electrical properties was applied by Xeon lamp light source and a monochromator system.

• 한국식품과학회지
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• 제33권1호
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• pp.55-59
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• 2001

쌀의 팽화에 관한 연구는 팝콘에 관한 연구와 비교하면 매우 미흡한 편이다. 쌀을 팽화시킬 때 대부분 가압식 팽화기나 압출성형기를 이용하고 있다. 대부분의 쌀의 팽화에 관한 연구는 인도에서 이루어져 왔으며, 가공조건(수분함량, 가열온도) 등이 팽화쌀의 물리화학적 성질에 관한 연구가 대부분이다. 팝콘과 같은 인스턴트 팽화쌀의 팽화기작 및 개발에 관한 연구는 극히 제한되어 있다. 압출성형 팽화펠릿의 팽화에서 3일 수침 후 분쇄한 찹쌀을 이용하여 수분함량 $20{\sim}27%$, $CO_2$ 가스주입압력 2.8 MPa, 스크류회전속도 200 rpm으로 제조한 펠릿을 microwave oven에서 팽화시 밀도와 조직감이 비교적 낮게 나타나는 경향을 보였다. 또한 압출성형기로 제조된 펠릿의 팽화시 가장 큰 영향인자는 펠릿의 수분함량과 가스주입압력, 스크류회전속도의 조절에 의해 팽화 및 조직감을 최적화 할 수 있었다.

• 제어로봇시스템학회논문지
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• 제15권9호
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• pp.877-880
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• 2009

A curing process in post-printing section of R2R process is required for an electrical property of the printed pattern when devices such as RFID, Solar cell are printed. PEN as well as heat-stabilized PET which is used as a plastic substrate would be deformed at high temperature due to change of its elastic modulus. And crack in the printed pattern, which is on the plastic substrate is occurred due to the deformation of the substrate. The occurrence of crack causes electrical resistance to increase and the quality of the device to deteriorate. In case of RFID antenna, the range of reading distance is shortened as the electrical resistance of the antenna is increased. Therefore, the deformation of the plastic substrate, which causes the occurrence of crack, should be minimized by setting up low operating tension in R2R process. In low tension, slippage between a moving substrate and a roller would be generated when the operating speed is increased. And scratch would be occurred when slippage is generated due to an air entrainment, which is related to the thickness of the air film. The thickness of the air film is increased when operating speed is increased as shown by simulation based on mathematical model. The occurrence of scratch in conductive pattern printed by roll to roll process is a critical damage because it causes degradation or failure of electrical property of it.

• 한국의류학회지
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• 제36권2호
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• pp.127-137
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• 2012

This study focuses on the optimal washing conditions for dry cleaning recommended fabrics to minimize dimensional changes using wet cleaning. We suggest water-based alternatives to a perchloroethylene based cleaning process. Wool and rayon fabrics were laundered under various washing conditions and then air-dried for 24hrs. All specimens were extended after spinning and shrunk after drying. This is probably because the fibers were swollen and extended by wetting. The wool fabrics were shown to be acutely influenced by washing temperature and mechanical force. The optimal washing conditions for wool fabric to minimize the dimensional change implied a normal washing temperature and minimized mechanical force. For rayon specimens, dimensional change by a hand wash showed a remarkable decrease compared with a machine wash. Rayon fabric seemed to be influenced by the quantity of water contained in the fabric after spinning and washing time. Therefore, the desirable washing conditions for rayon fabric are to reduce the time required for washing and to increase the spin speed.

• 펄프종이기술
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• 제33권2호
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• pp.41-48
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• 2001

This paper was made to evaluate the effect of the type of latex for coating on the printability by investigating the structure of pore such as the pore fraction, the number of pores, pore size and distribution of coated paper. The coated structure is mainly depend on the results of interaction between pigment and binder. It means that the structure of pore formed is chiefly affected by the type of latex. This physical properties of pore have a close relation with ink set-off associated with the drying rate, the speed of penetration of ink into base paper and printing gloss. Therefore it was necessary to find out the relationship between pore structure and the performance of printability by modifying the type of latex to vary the pore structure of coated paper. Acrylic latex was superior to S/B latex in the sedimentation volume, compressibility, smoothness, pore fraction and its number, the weight of transferred ink onto the coated paper and ink repellance. In contrast, water retention and ink setting were not good. in the comparison of anionic and amphoteric latex, amphoteric latex showed better performance in the thickness, smoothness, pore fraction and its number, pore size, the weight of ink transmitted and K&N ink receptivity, etc.

• 한국응용과학기술학회지
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• 제10권1호
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• pp.49-55
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• 1993

Ground Calcium Carbonate, among paper coating pigments, will influence less dispersant demand, less binder demand, increase coating solids from 58% to 70%, which means high speed coating, less shrinkage during drying, less energy consumption, more uniform coverage of fibers. The quality point of view of Ground Calcium Carbonate, brightness, particle size, Particle size distribution, hardness, impurities content are important. More important factors of Ground Calcium Carbonate which influence the paper coating process are dispersion mechanisms and their effects. The study was made to investigate the effect of Ground Calcium Carbonate dispersion by sodium salt of polyacrylate dispersant composition and dispersion condition. Basic tests such as physical, optical and chemical were perfumed, and dispersion effects were investigated by different conditions. The results showed that the type of dispersant affected the dispersion effects, and the Ground Calcium Carbonate has critical dispersant demand.

• 펄프종이기술
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• 제36권3호
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• pp.52-59
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• 2004

The greater Increase of the demand for environmental friendly materials especially for packaging industry leads to the larger interest in the reusable and recycable materials such as pulp mold. Although the pulp mold has great characteristics for packaging, some deficiency compared with other packaging material like EPS(Expandable Polystyrene) need to be overcome, for example, the relative higher cost. In this report, since the water drainage rate at the forming zone of a wet pulp mold process could have a great influence on the economical efficiency not only by increasing machine speed but also reducing the drying energy, the optimum ways for increasing drainage were investigated The mechanism of vacuum drainage In pulp mold forming was successfully evaluated by using RDA(Retention and Darinage Analyzer). Since the conditions of stock were greatly affected by the pulping time of low consistency pulper, the optimum pupling time was investigated with considerations of all stock preparation processes. The change of stock temperature and the addition of polyelectrolyte could improve the vacuum drainage rate. It was founded that the wire mesh types of mold former had a little influence on the retention because of the relatively mild vacuum drainage. However, the bigger size of dewatering hole showed better drainage rate and could reduce the plugging and con lamination of mold.

• 한국지역사회생활과학회지
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• 제21권4호
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• pp.551-558
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• 2010

It is a normal circumstance to have high temperature and high humidity in Greenhouses even though these climates are changed by the area, season, climates, the size of the greenhouse, and the crops being raised. Workers in the greenhouses have complained about their uncomfortable work environment and discomfort from the hot conditions, including sunburn. The farmers' ailments are not significantly different between those working in the in greenhouses and those working in the fields. The Farmers' syndrome was almost two times higher for women than those of men for greenhouse workers. This study was developed for functional fatigue clothes for plastic greenhouses which are known for high temperatures and humidity. The ergonomic function and thermal comforts of fatigue clothes were evaluated in the climatic chamber($30.0^{\circ}C$, 70.0%R.H.). The current fatigue clothes which are made of cotton or nylon were purchased at the market. The developed clothes are made of highly absorbent and high speed drying polyester. And these fabrics have excellent elasticity. In this study, the functional fatigue clothes were designed with longsleeved sport shirts and Full length pants. Tre, Tsk, Hcl, HR and the personal subjective sensations such as heat, humidity, and comfortableness were significantly lower when subjects wore the developed clothes made with polyester than the previous attire.