• Journal of Welding and Joining
• /
• 제20권5호
• /
• pp.99-105
• /
• 2002

One of the important advantage of adhesive bonded joint can combine the different materials. The joint that bonded by structural adhesive bond must keep a large force and its strength is affected by some environmental factors such as temperature and submergence time in water. In order to advance the fatigue strength of adhesive bonded joint, mostly put a surface treatment on the surface. This study was researched the effect of air temperature, submergence time, submergence temperature and surface treatment on the fatigue strength. We found that submergence temperature has the most effect and low plasma treatment specimens have the most fatigue strength.

• 한국의류산업학회지
• /
• 제15권3호
• /
• pp.461-466
• /
• 2013

Synthetic fiber materials were developed due the desire of consumers for high-quality, high-performance and comfort. A high functionality of synthetic fiber can be obtained through surface treatment that can improve hydrophilic properties, color depth after dyeing and adhesion properties. These advantages create added-value. Hydrophobic properties are an important feature to create added-value (such as hydrophilic properties). One side processing is a method of imparting to contrary function on the front and rear side. In this study, fluorine-coated Nylon/PU blended fabric was treated on only one side with a low-temperature plasma treatment; subsequently, the contact angles decreased by increasing the time and intensity of the plasma treatment. The contact angle of the untreated surface and the treated surface was different. It a showed a difference in the properties of both surfaces. Tensile strength and stiffness decreased by increasing the time and intensity of the plasma treatment. However, plasma treatment did not significantly change the tensile strength and stiffness on both surfaces of the fabric. SEM photographs showed the surface of fluorine-coated fabric and the etching surface by using plasma treatment on the fabric. Plasma treatment was confirmed not to affect the physical properties of the fabric.

• 한국염색가공학회지
• /
• 제7권3호
• /
• pp.11-14
• /
• 1995

열처리 온도를 각각 다르게 한 Poly(ethylene terephthalate)에 반응기 내의 처리 조건이 서로 다른 두 가지 플라즈마 장치를 사용하여 산소 저온 플라즈마 처리를 했다. 열처리 온도가 플라즈마 감량에 미치는 영향은 열처리 온도가 증가함에 따라 결정화도도 증가하지만 감량율은, 열처리 온도가 16$0^{\circ}C$까지는 감소하다가 16$0^{\circ}C$ 이상에서는 증가하는 경향을 보이며, 분산염료에 의한 Poly(ethylene terephthlate) 섬유의 염색특성과 유사한 거동을 나타냈다.

• 한국재료학회지
• /
• 제21권6호
• /
• pp.303-308
• /
• 2011

The effect of heat treatment on the micro-structures and the mechanical properties of 0.002% boron added low carbon steel was investigated. The tensile strength reached the peak at about $880-890^{\circ}C$ with the rising quenching temperature and then the hardness decreased sharply, but the tensile strength hardly decreased. The tensile and yield strength decreased and the total elongation increased with a rising tempering temperature, but the tensile and yield strength sharply fell and the total elongation prominently increased from above a $400-450^{\circ}C$ tempering temperature. Tempered martensite embrittlement (TME) was observed at tempering condition of $350-400^{\circ}C$. In the condition of quenching at $890^{\circ}C$ and tempering at $350^{\circ}C$, the boron precipitates were observed as Fe-C-B and BN together. The hardness decreased in proportion to the tempering temperature untill $350^{\circ}C$ and dropped sharply above $400^{\circ}C$ regardless of the quenching temperature.

• 소성∙가공
• /
• 제15권8호
• /
• pp.539-543
• /
• 2006

Experimental studies are carried out in order to investigate the effects of heat treatment on the surface machined by W-EDM. In this work, two ways of heat treatment after W-EDM are considered. As a comparison, the machined surface by a traditional method such as milling/grinding is also considered. Thereby, specimens are prepared by four different machining methods. Those are (1) milling and then grinding, (2) wire-cut electric discharge machining (W-EDM), and (3) low temperature heat treatment or (4) high temperature heat treatment after W-EDM. The resulting surface roughness are measured and the changes of surface microstructures are investigated using the scanning electron microscope (SEM) with energy dispersive X-ray spectrometer (EDS). In general, heat treatment after W-EDM result in smoother surface and better chemical composition at the machined surface. Especially, high temperature tempering could remove defects in the thermally affected zone, which cause an overall deterioration of the surface machined by W-EDM.

• 한국물환경학회지
• /
• 제35권4호
• /
• pp.299-307
• /
• 2019

The purpose of this study was to investigate the effect of low temperature thermal pre-treatment on biodegradation of waste activated sludge for anaerobic digestion as a countermeasure for increasing sludge generation. The experimental condition was accomplished in 2 %, 4 %, and 6 % TS concentration, and $70^{\circ}C$, $80^{\circ}C$, $90^{\circ}C$ of temperature for a maximum of 120 minutes retention time. Then, it was followed by analysis of physical/chemical properties, BMP test and composition of biogas. The biogas characteristic was evaluated by applying the modified Gomperz model. As a result, solubility of dissolved substrate, such as $SCOD_{Cr}$, soluble carbohydrate, and soluble protein, and biogas production increased as temperature increased. Solubilization efficiency at $90^{\circ}C$ was 18.4 %, 17.03 % and 16.88% in 2 %, 4 %, and 6 % TS concentration respectively. Also, solubilization rates of carbohydrate and protein similarly increased. BMP test results also showed that methane production in excess sludge increased to 0.194, 0.187 and $0.182m^3/kg$ VS. respectively, and lag phase decreased to 0.145, 0.220, 0.351 day due to acceleration of the hydrolysis step. Consequently, low-temperature thermal pre-treatment could increase biodegradability of sludge, positively affecting biogas production and sludge reduction.

• 한국자원식물학회:학술대회논문집
• /
• 한국자원식물학회 2023년도 임시총회 및 춘계학술대회
• /
• pp.23-23
• /
• 2023

The Hairy labrador tea (Ledum palustre L. var. diversipilosum Nakai) is a evergreen small shrub, belonging to the Ericaceae and mainly distributed along the alpine areas of Hamgyeong-do in North Korea. Through seed physiological research on North Korean plants, we intend to obtain basic data for the development of mass propagation methods and use them for vegetation restoration. The internal and external morphological characters of the seed were observed using scanning electron microscopy or stereoscopy, and full seeds were selected through X-ray test. Seeds were cultured on a growth condition at 15/6℃ and 25/15℃ to examine the germination response according to temperature, and the number of germinated individuals was examined every 24 hours to calculate germination percentage and mean germination time. Low-temperature treatment (4℃) and hormone treatment (GA3) were performed to investigate the effect of dormancy breaking, and analysis of variance (ANOVA) was performed on the experimental results using SAS 9.4. The seeds of the Hairy labrador tea were elliptical-narrow in shape, and the epidermal cell wall pattern was reticulated. The final germination rate (FGP) was the highest at 58.9% under the condition of low temperature treatment at 25/15℃. The average number of days to germination (MGT) was the highest at 25.1 days without treatment at 15/6℃, and the average of the last germination days was confirmed to be about 13 days. As a result of low temperature treatment, it was confirmed that the final germination rate (FGP) increased by 43.3%. The significance of the final germination rate (FGP) was verified according to the pretreatment at 25/15℃.

• 한국염색가공학회지
• /
• 제6권4호
• /
• pp.27-33
• /
• 1994

Wool fabrics were treated with low temperature oxygen plasma and/or protease, and examined for their mechanical and dyeing properties. By plasma-treatment the strength of wool fabric increased and higher rate of weight loss for protease treatment was obtained. When dyed by levelling type acid dye equilibrium dye uptake appeared same, but rate of dyeing increased by the plasma treatment, while, with milling type acid dye, both of them increased greatly in the order of untreatedplasma/protease-treated. It was assumed from the above results that plasma affects the surface of fiber, and enzyme attacks mainly the inner part of fiber. This was confirmed again by scanning electron microscope.

• Elastomers and Composites
• /
• 제35권4호
• /
• pp.296-302
• /
• 2000

신발 중창용 EVA 발포체의 수용성 폴리우레탄계 접착제에 대한 접착력을 증가시키기 위하여 발포체 표면을 저온 플라즈마 처리하였다. 플라즈마 처리기체 종류, 플라즈마 처리시간, 전극과 시료와의 거리등의 조건에 따른 발포체의 표면형태, 접촉각 및 수성폴리우레탄에 대한 접착력 등을 주사전자현미경, 접촉각 측정기, 인장강도시험기 등을 사용하여 측정하였다. 플라즈마 처리시간이 증가함에 따라 플라즈마 에칭에 의한 표면 형태의 변화가 더욱 뚜렷하게 나타났으며, 물로 측정한 발포체의 표면 접촉각은 현저히 감소하였다. 플라즈마 처리시간이 증가함에 따라 접착력은 현저히 증가하였다.

• 한국염색가공학회지
• /
• 제17권5호
• /
• pp.26-36
• /
• 2005

This study was carried to evaluate mechanical characteristics of Poly(ethylene terephthalate) fabrics (by Kawabata evaluation system(KES)) which was systematically treated with $O_2$ low temperature plasma and chitosan acetate solution. Furthermore, surface structure was investigated by SEM, AFM, air permeability and wettability. Tensile energy(WT), shear rigidity(G) and surface roughness(MIU) properties calculated by KES-FB have increased with increasing plasma treatment time, while bending rigidity(G) and energy of compression(WC) value were decreased compared with those of the untreated. SEM photographs showed the identification of chitosan coating but did not confirm the plasma etching structure. Air permeability was decreased according to plasma treatment time with increasing concentrations of chitosan. The water absorption rate made rapid progress by chitosan treatment.