• 한국식물병리학회지
• /
• 제2권1호
• /
• pp.48-52
• /
• 1986

흰토끼풀에 황색모자이크병징을 나타내는 이병주를 채집하여 병즙액의 지표식물반응과 물리적 성질조사, 풍매전염시험, 바이러스입자의 형태관찰 그리고 항혈청반응 등의 방법으로 병원바이러스의 동정을 시도한 결과 강낭콩황반모자이크바이러스(BYMV)로 밝혀졌다. 공시병원바이러스의 지표식물반응은 명아주에 전체국부반응, 잠두의 접종엽에 국부반응, 줄기와 상위엽에 각각 양저증상과 모자이크반응을 보였으며, 강남콩에는 엽맥양저, 황색모자이크 또는 축엽이 되고 순이 고사하였다. 또한 완두, 녹두, 팥과 red clover에는 모자이크 반응을 나타냈다. 바이러스입자의 형태 및 크기는 740nm정도의 사상입자이며, 복숭아혹진딧물에 의하여 전염이 가능하였다. 바이러스병즙액의 생리적 성질은 내열성이 $60\~65^{\circ}C$, 내희석성이 $10^{-3}\;-\;10^{-4}$, 내보존성이 3일이었다. 순화된 공시바이러스는 일본 식물바이러스 연구소로부터 분양받은 BYMV항혈청과의 혼합침강반응결과 양성반응을 보였다.

• 한국세라믹학회지
• /
• 제48권6호
• /
• pp.537-542
• /
• 2011

Magnesium hydroxide as a non-halogen flame retardant has increasing attention due to its non-toxicity, high decomposition temperature and smoke suppressant ability during combustion. For the application of magnesium hydroxide retardant to the textile by soaking and coating method, the prerequisite for the coating is a small particle size, stable dispersion, and adhesion to the textile. The dispersion of $Mg(OH)_2$ particles and stability of the coating was checked by monitoring the change of transmittance and backscattering by varying the types of dispersion agents, binder, solvent, and $Mg(OH)_2$ source, and their compositions in the coating. The $Mg(OH)_2$ dispersion coating was applied to PET(poly(ethylene terephthalate)) non-woven textile. The physical properties are characterized by surface morphology, amount of coating, particle dispersion, and adhesion test. The flame retardant $Mg(OH)_2$ coated textile has been compared by limited oxygen index(LOI) and thermal gravimetry and differential scanning calorimetry(TG-DSC). It was found that phosphorous additive may give synergistic effect on $Mg(OH)_2$ flame retardant coating to make the flame retardant PET non-woven textile.

• 한국세라믹학회지
• /
• 제45권7호
• /
• pp.387-394
• /
• 2008

The Physical property changes of calcined clay by carburization were investigated studied. The carburization mechanism is the penetration of carbon which occurred during incomplete fuel combustion into crevice of clay structure. The experiments for elasticity and freeze-thaw resistance were conducted, and the results can be summarized as follows: Dynamic modulus of elasticity and also freeze-thaw resistance of calcined clay by carburization treatment increased more than 92% after testing 300 cycle, which was more improved than 88% of calcined clay. Therefore, it can decrease the possibility of winter-sowing, which is one the weakness of calcined clay. It is on the basis of the fact that the porosity of calcined clay by carburization treatment is about 12%, which indicates smaller pore spaces comparing with the 14% of porosity of calcined clay and those values were calculated by apparent porosity show and also supported by SEM images. Infrared emissivity of calcined clay by carburization treatment and calcined clay were respectively 0.92 and 0.9l at $80^{\circ}C$. However, those values were 0.91 and 0.88 at $200^{\circ}C$, which means infrared emissivity of calcined clay by carburization treatment shows 3.6% higher than the calcined clay. Moreover, within the wavelength range from 3 to $7\;{\mu}m$, while the calcined clay had low infrared emissivity, the calcined clay by carburization treatment had increased infrared emissivity. It is inferred that it was affected by carbon element that has high infrared absorptivity within this wavelength range.

• 대한기계학회논문집A
• /
• 제25권7호
• /
• pp.1082-1088
• /
• 2001

Nowadays study on recycling disused plastics for automobiles was lively progressed. Rubber and talcum powder was added to retrieve degradation of physical properties caused by recycling disused polypropylene. The effect of the temperature, the fatigue load and the loading speed on DEN(double edged notch) specimen which was made by the pp-rubber composites during fracture was studied by. DEN specimen was made on PP-rubber composites through the injection molding. With increasing temperature the fracture strength was linearly decreased and the fracture energy was increased by $0^{\circ}C$ and after that decreased. In the same temperature the fracture strength during increasing the notch radius was hardly increased. The fracture behaviour at low and high loading speed was different entirely. At high loading speed plastic region was small and fracture behaviour was seen to brittle fracture tendency. With increasing fatigue load fracture energy was first rapidly decreased and subsequently steady when radius of notch tip was 2mm, but Maximum load during fracture scarcely varied. The deformation mechanism of polypropylene-rubber composites during fracture was studied by SEM fractography. A strong plastic deformation of the matrix ahead of the notch/crack occurred. The deformation seem to be enhanced by a thermal blunting of the notch/crack.

• 한국재료학회지
• /
• 제9권5호
• /
• pp.503-508
• /
• 1999

We have investigated the physical and diffusion barrier property of Ti-Si-N film for Cu metallization. The ternary compound was deposited by using reactive rf magnetron sputtering of a TiSi$_2$target in an Ar/$N_2$gas mixture. Resistivities of the films were in range of 358$\mu$$\Omega$-cm, to 307941$\mu$$\Omega$-cm, and tended to increase with increasing the $N_2$/Ar flow rate ratio. The crystallization of the Ti-Si-N compound started to occur at 100$0^{\circ}C$ with the phases of TiN and Si$_3$N$_4$identified by using XRD(X-ray Diffractometer). The degree of the crystallization was influenced by the $N_2$/Ar flow ratio. The diffusion barrier property of Ti-Si-N film for Cu metallization was determined by AES, XRD and etch pit by secco etching, revealing the failure temperature of 90$0^{\circ}C$ in 43~45at% of nitrogen content. In addition, the very thin compound (10nm) with 43~45at% nitrogen content remained stable up to $700^{\circ}C$. Furthermore, thermal treatment in vacuum at $600^{\circ}C$ improved the barrier property of the Ti-Si-N film deposited at the $N_2$(Ar+$N_2$) ratio of 0.05. The addition of Ti interlayer between Ti-Si-N films caused the drastic decrease of the resistivity with slight degradation of diffusion barrier properties of the compound.

• 한국강구조학회 논문집
• /
• 제12권2호통권45호
• /
• pp.197-207
• /
• 2000

본 연구는 유한요소법을 이용해서 시간이력 열전도해석과 열탄성해석을 통해 필렛용접 이음부에서의 잔류응력분포를 측정하였다. 필렛용접은 1패스 용접이며, 경계조건으로는 표면유속조건과 온도에 의존하는 재료의 특성치를 고려하여 잔류응력을 평가하였다. 여기서, 용접입열양을 변수로 하였다. 그리고, 열탄성해석에 의해 잔류응력 평가할 때 중요한 문제로 언급되고 있는 cut-off 온도 설정에 대해 조사하였다. 또한, 시험체에서 구멍뚫기 방법에 의해 잔류응력분포를 측정하여 유한요소법에 의한 잔류응력분포와 비교하였다. 그 결과, 용접부에서는 재료의 항복강도 수준에 해당하는 인장잔류응력이 측정되었으며, 유한요소해석에 의한 수치해석 결과는 구멍뚫기 방법에 의한 측정치 및 다른 연구자의 측정치와 비교적 일치하는 것으로 나타났다. 그리고, Cut-off 온도는 재료의 항복강도가 나타나는 온도로 설정하는 것이 효과적임을 알 수 있었다.

• 한국축산식품학회지
• /
• 제32권5호
• /
• pp.627-634
• /
• 2012

This study was carried out to investigate the physical and thermal properties of ${\kappa}$-carrageenan (${\kappa}$-car) gel added whey protein isolate (WPI) as a cryoprotectant. The concentration of ${\kappa}$-carrageenan was fixed at 0.2 wt%. The mean ice crystal size of the WPI/${\kappa}$-car was decreased according to increasing whey protein isolate concentration. The temperature of gel-sol (Tg-s) and sol-gel (Ts-g) transition of WPI/${\kappa}$-car maxtrix was represented in the order of 3.0, 0.2, 5.0 and 1.0 wt%. In addition, the transition temperature of gel-sol of WPI in sucrose solution were showed in order of 1.0, 5.0, 0.2 and 3.0 wt% depending on whey protein isolate concentration. The shape of ice crystal was divided largely into two types, round and rectangular form. 1.0 wt% WPI/${\kappa}$-car matrix at pH 7 and 9 showed minute and rectangular formation of ice crystals and whey protein isolate in sucrose solution at a concentration of 1.0 wt% WPI/${\kappa}$-car matrix at pH 3 and 5 showed relatively large size and round ice crystals. The ice recrystallization characteristics and cryprotective effect of ${\kappa}$-carrageenan changed through the addition of different concentrations of whey protein isolate. It seems that the conformational changes induced interactions between whey protein isolate and ${\kappa}$-carrageenan affected ice recrystallization.

• 방사성폐기물학회지
• /
• 제14권2호
• /
• pp.135-147
• /
• 2016

심지층 처분시스템에서 완충재는 지하수 유입으로부터 처분용기를 보호하고, 방사성 핵종 유출을 저지하기 위한 중요한 방벽의 하나이다. 이에 완충재는 장기 건전성, 낮은 수리전도도, 낮은 유기물의 함량, 높은 핵종저지능, 높은 팽윤성, 높은 열전도도 등 기술적 요건을 충족시켜야 하며 이는 정량적 분석결과를 바탕으로 결정될 수 있다. 국내의 경우 한국원자력연구원에서는 1997년부터 경주지역에서 생산되는 벤토나이트를 완충재 후보물질로 연구를 지속하고 있다. 본 논문에서는 최근 동일 지역에서 생산된 벤토나이트(KJ-II)의 7가지 물리적 및 화학적 특성을 평가하였다. 분석 결과, 국내산 벤토나이트의 몬모릴로나이트 함량은 약 65% 정도이며, 벤토나이트는 Ca형 벤토나이트이다. 본 논문을 통해 완충재 후보물질의 성능평가 항목과 분석 방법에 대한 기준을 제시하고자 하였다.

• 한국의류학회지
• /
• 제16권3호
• /
• pp.335-344
• /
• 1992

This study was conducted to investigate the influence of addition of cetyl trimethyl ammo­nium bromide (CTAB), and amine [ethylamine (EA) or ethylene diamine (EDA)] to aqueous sodium hydroxide (NaOH) solution on polyester alkaline hydrolysis, The experimental vari­ables such as CTAB concentration, EA or EDA concentration, NaOH concentration, tempera­ture and time were compared, and the changes in physical and chemical properties of alkaline­hydrolyzed PET fabrics depending on their treated conditions were measured, The results are as follows: 1. By adding CTAB and amine in aqueous NaOH solution, increasing effect on weight loss of PET fabrics was obtained in simultaneous addition of CTAB and EDA, but not in CTAB and EA. 2. By adding CTAB & EDA simultaneously, increasing effect on weight loss was obtained regardless of EDA concentration, time and temperature, and it was more effective at lower NaOH concentration. :l. The increase of void space (or irregularly grooved surface), of softness, of wickability, of dyeability on PET fabric, and the decrease of tensile strength, of molecular weight were observed according to the weight loss on the PET fabrics. These changes were equal to all alkaline-hydrolyzed PET fabrics regardless of addition of CTAB and amine. l. There was little changes on crystallinity, thermal behavior when PET fiber was treated with ,aqueous NaOH solution with CTAB and EDA. These results supported that increasing effect on weight loss take place without inducing of fine structural change of PET fibers.

• 한국산학기술학회논문지
• /
• 제16권4호
• /
• pp.2958-2965
• /
• 2015

공중합체인 PLGA는 생분해성 고분자로서 의료용 이식재료로 사용되고 있으며, 이를 이용한 멤브레인은 양호한 생분해 특성 및 지속적 약물 전달체로서 치조골 유도제로 적용할 수 있다. 본 연구는 락티드, 글리콜리드 합성 및 공중합과정을 거쳐 상전이법을 이용하여 PLGA 멤브레인을 제조하였으며, 멤브레인의 광학적(NMR, IR), 기계적(인장강도), 열적(DSC)특성을 조사하였다. 또한 PLGA 멤브레인의 생분해 특성은 PBS (Phosphate Buffered Solution)이 담긴 항온조($60^{\circ}C$) 내에서 분해시간에 따른 표면분해 정도, 멤브레인의 질량변화 및 용액의 pH 변화로 측정하였다.