• 생물환경조절학회지
• /
• 제7권2호
• /
• pp.123-129
• /
• 1998

본 실험은 엔디브 양액재배에 적합한 배양액을 조성하고. 새로 조성한 배양액(SCUE)의 효과를 검토하고자 수행하였다. 엔디브 재배에 적합한 배양액을 양수분 흡수율에 의해 조성한 결과 NO$_3$-N 15.0, NH$_4$-N 1.0 PO$_4$-P 3.0. K 10.0, Ca 5.0, Mg 3.5 me.$\ell$$^{-1}$가 적당하였다. 새로 조성한 서울시립대 엔디브액 (SCUE)과 유럽의 엔디브액간의 재배실험 결과, 배양액간의 생육 및 수량은 차이가 없었지만, pH와 EC의 변화폭은 새로 조성한 양액에서 적었다.

• 한국환경보건학회지
• /
• 제13권1호
• /
• pp.47-57
• /
• 1987

Owing to the modification of testing methods of disinfectants or antiseptics, variations of bacteria according to characteristics of regions and resistance changes of bacteria, it is necessary that the bactericidal activities of disinfectants or antiscptics should be reevaluated nowadays. This study was carried out to reevaluate in the vitro bactericidal activity of Chlorhexidine gluconate solution. The results of experiment were summarized as follows. 1. For Chlorhexidine gluconate solution, minimal inhibitory concentrations of total bacteria taken from sewage water and Legionella bozemanii were $2.0\times 10^{-3}$%, $1.0\times 10^{-2}$%, respectively and were comparatively high. Minimal inhibitory concentration of Shigella flexneri was $1.6\times 10^{-4}$%, and was comparatively low. 2. For total bacteria taken from sewage water, it was killed within 15 minute in 0.1% Chlorhexidine gluconate solution when number of cells was $1.6\times 10^7$/ml. 3. For 0.0125% Chlorhexidine gluconate solution, decimal reduction times of Ps. aeruginosa, S. typhi, E. Coli were 45 sec, 25 sec, 18 sec repectively. For 1%, 0.125% Chlorhexidine gluconate solution, decimal reduction times of Legionella bozemanii were 10 sec, 45 sec respectively. 4. There was significant difference in the bactericidal activity of Chlorhexidine gluconate solution according to temperattire. Phenol coefficient of Chlorhexidine gluconate solution as using Staph. aureus was 100 and comparatively higher than that of other disinfectants. In comparison with other disinfectants, Legionella bozemanii was killed within 5 minutes in 0.02% KMnO$_4$ and 0.125% Chlorhexidine giuconate solution but was not killed within 3 minutes in 1% 0-cresol, 1% Phenol.

• 대한의용생체공학회:의공학회지
• /
• 제16권4호
• /
• pp.533-542
• /
• 1995

The present study investigated the effectiveness of pretreatment on dentin bonding. The adhesive resin was 5% 4-methacryloyloxyethyl trimellitate anhydride (4-META) in methyl methacrylate (MMA) combined with poly-MMA powder. Polymerization of this resin was initiated by tri-n-butyl borage (TBB). Ground bovine dentin samples were etched with either an aqueous solution of 10% citric (10-0 solution) (Group I) or aqueous solution of 10% citric acid and 3% ferric chloride(10-3 solution) (Group ll ). After etching, the primer (an aqueous solution of 35% hydroxyethyl methacrylate (HEM- A) and 5% glutaraldehyde was applied on the differently etched surfaces (Group III , Group IV). The 10-0 treatment showed the lowest tensile bond strength, followed by the 10-3 treatment, primer application after the 10-0 treatment and primer application after the 10-3 treatment. The relationship among the surface morphology after pretreatment, fractured surface morphology and tensile bond strength was examined. It revealed that the surface morphology change by different pretreatment influenced the bond strength and the resulting fractured surface morphology. The correlation of tensile bond strength with the fracture morphology was explained.

• 한국재료학회지
• /
• 제22권12호
• /
• pp.706-710
• /
• 2012

The growing conditions of barium nitrate $Ba(NO_3)_2$ single crystals using the aqueous solution method have been studied. Supersaturation can be calculated by measuring the temperature of the solution and its equilibrium temperature. Supersaturation of $Ba(NO_3)_2$ was 0.7% at $32.0^{\circ}C$ and about 3% at $34.0^{\circ}C$. The obtained single crystals have three kind of morphology: tetrahedral, cubic, and, rarely, dodecahedral. The normal growth rate is proportional to the supersaturation; it is necessary to make the solution below 5% supersaturation in order to obtain transparent $Ba(NO_3)_2$ single crystals. The normal growth rate for {1$\bar{1}$1} faces was $2.51{\times}10^{-6}$ mm/s for the 0.7% supersaturation condition ($32.0^{\circ}C$), $6.43{\times}10^{-6}$ mm/s for the the condition of 3.0% supersaturation, and $7.01{\times}10^{-6}$ mm/s for the condition of 5.0% supersaturation. The quality of the grown crystals depends on the nature of the seed, the cooling rate employed, and the agitation of the solution. The faces of the obtained crystals have been identified uising an X-ray diffractometer. The surface diffusion is responsible for the low growth rates of the {1$\bar{1}$1} faces.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제24권1호
• /
• pp.29-35
• /
• 2012

Bumblebees are widely used to pollinate various crops, especially tomato, in greenhouses and fields. Here, we investigated whether different sugar solutions have any effects on the oviposition and colony development of Bombus terrestris queens. The types of sugar solution used were a white sugar solution, brown sugar solution, dark brown sugar solution, and prepared sugar solution; all solution contained with a 40% sugar concentration and 0.3% sorbic acid. Among these sugar solutions, B. terrestris queens reared on the white sugar solution exhibited the best results; the rates of oviposition, colony foundation and progeny-queen production were $75.0{\pm}11.0$, $33.0{\pm}9.6$ and $21.7{\pm}7.3$, respectively, which corresponded to 1.1-33.0-fold increases over the results of other sugar solutions. Queens reared on the prepared sugar solution did not found any colonies. The death rate within one month was lowest for the queens reared on the white sugar solution at $26.1{\pm}10.9%$, which was 1.2-2.0-fold lower than the rate for the other sugar solutions. Furthermore, the numbers of progeny produced by queens reared on the white sugar solution, $131.4{\pm}38.8$ workers and $51.0{\pm}40.6$ queens, were also higher, corresponding to 1.1-1.2-fold increases compared to queens raised on the other sugar solutions. Therefore, the white sugar solution was the favorable sugar solution for the egg-laying and colony developmental characteristics of B. terrestris queens.

• 대한화학회지
• /
• 제10권3호
• /
• pp.114-118
• /
• 1966

The glass electrode was empirically calibrated in dioxane-and ethanol-water mixed solvents, by means of which the pH-meter reading could be converted to stoichiometric hydrogen ion concentration. By the potentiometric titration method, the thermodynamic dissociation constants of hydrogen cupferrate (HCup) with variations of ionic concentration in aqueous solution were determined, and by the extrapolation of the constants the new thermodynamic $pK_a$ value, 3.980${\pm}$0.006, at zero ional concentration was obtained. The thermodynamic dissociation constants of HCup in dioxane-and ethanol-water solution were also potentiometrically determined with the changes in composition of organic solvents at 0.01 and 0.05 of the ionic strength(${mu}$) and 25 $^{\circ}C$. The empirical formula of the constants with mole fraction(n) of the organic solvent are as follow: Dioxane-water solution. $pK_a$= 12.96n + 4.10 at ${\mu}$ = 0.01, n = 0.0228∼0.171 $pK_a$= 12.05n + 4.23 at ${\mu}$ = 0.05, n= 0.0228∼0.171 Ethanol-water solution, $pK_a$= 4.0ln + 4.26 at ${\mu}$= 0.01, n= 0.0395∼0.262 $pK_a$= 3.83n + 4.34 at ${\mu}$= 0.05, n= 0.0395∼0.262

• Journal of Microbiology and Biotechnology
• /
• 제8권2호
• /
• pp.178-181
• /
• 1998

An exopolysaccharide, designated as A49-Pol, was produced from Bacillus polymyxa KCTC 8648P in nitrogen sufficient conditions. The viscosity of the culture broth increased up to $2\times10^4$cP in 38 hours of culture and then decreased to $1.5\times10^4$CP at 48 hours. The $1.0\%$ (w/v) solution of purified A49-Pol represented pseudoplasticity with a viscosity of $2.7\times10^4$cP which was two times higher than xanthan at the same concentration. The viscosity of the A49-Pol solution was also greatly affected by its concentration in comparison with the xanthan solution. The viscosity of $1.0\%$ A49-Pol solution was 930-fold higher than its $0.2\%$ solution, whereas the corresponding viscosities of xanthan solution experienced only l7-fold difference. The viscosity was observed to be maximum at pH 7.0 in both A49-Pol and xanthan solutions, and gradually decreased as the pHs of the polysaccharide solutions went to acidic or alkaline regions. The viscosity of A49-Pol solution was very sensitive to temperature compared to xanthan and decreased with increasing temperature. The viscosity of $0.6\%$ solution of A49-Pol was 8,100 cP at $10^{\circ}C$ and 55 cP at $50^{\circ}C$. The viscosity was also affected by the presence of surfactants such as Span 20 and Triton X-l00 ; with $0.5\%$ Triton X-l00 (v/v), the viscosity of A49-Pol solution increased by $50\%$.

• Corrosion Science and Technology
• /
• 제10권2호
• /
• pp.71-75
• /
• 2011

Corrosion properties of Al-0.3Ga-0.3Sn, Al-0.3Mn-0.3Ga, and Al-0.3Mn-0.3Sn alloys were examined to develop an anode material for Al-air battery with alkaline aqueous or ethanol electrolyte. The results of potentiodynamic polarization tests showed that the electrode potential of the Al alloys were lower than the pure Al, implying the cell voltage can be increased by using one of these alloys for an anode in 4 M KOH aqueous solution. The corrosion rate appeared to be increased by alloying Ga but to be reduced by Sn and Mn in the aqueous solution. The ethanol solution is expected to improve the cell performance in that the electrode potential and the corrosion rate of Al were lower in ethanol solution than in aqueous solution. However the Al-(Ga, Sn, Mn) alloys are not favorable in ethanol solution because of the high potential and corrosion rate.

• Reproductive and Developmental Biology
• /
• 제28권3호
• /
• pp.173-179
• /
• 2004

본 연구는 돼지 미성숙 난포란의 유리화 동결액에 노출시 독성과 삼투압 스트레스가 가장 적은 유리화 동결액을 조사하기 위하여 실시하였으며, 그 결과를 요약하면 다음과 같다. 미성숙 난포란을 EFS(40% ethylene glycol +18% ficoll +0.3 M sucrose) 용액, ES(5.5 M ethylene glycol +1.0 M sucrose) 용액, GE(10% glycerol +20% ethylene glycol) 용액에 각각 노출하고 대조구로 아무 처리하지 않은 난포란을 체외성숙하여 관찰한 체외성숙율은 ES 용액과 대조구 에서 EFS 용액과 GE 용액보다 유의적으로 높았으며(P<0.05), 유리화 동결액의 독성에 의한 난포란의 퇴화율은 대조구, ES 용액, EFS 용액, GE 용액 순으로 유의적으로 낮은 퇴화율을 나타내었다(P<0.05). 미성숙 난포란을 EFS 용액, ES용액, GE용액에 각각 노출하고 대조구로 아무 처리하지 않은 난포란을 체외성숙, 체외수정하여 관찰한 정상 수정율은 대조구가 세 종류의 유리화 동결액보다 유의적으로 높았고(P<0.05), 유리화 동결액 간에는 유의적인 차이가 없었다. 다정자 침입율과 난자당 침입한 평균 정자수는 모든 처리구간에 유의적인 차이가 없었다. 미성숙 난포란을 EFS 용액, ES 용액, GE 용액에 각각 노출하고 대조구로 아무 처리하지 않은 난포란을 체외성숙, 체외수정, 체외 배양하여 관찰한 수정 3 일째의 분할율은 ES 용액과 대조구가 EFS 용액과 GE 용액보다 유의적으로 높았으며(P<0.05), 수정 7일째의 배반포 형성율은 모든 처리구간에 유의적인 차이가 없었다. 배양기간 동안 나타난 퇴화율은 대조구가 세 가지 유리화 동결액에 비해 유의적으로 낮았고(P<0.05), ES 용액은 EFS 용액과 GE 용액보다 유의적으로 낮은 퇴화율을 나타내었다(P<0.05).

• 한국유기농업학회지
• /
• 제4권2호
• /
• pp.79-85
• /
• 1995

This experiment was carried out to broadcating effect of chitosan solution levels on dry matter production in Ladino clover(Trifolium repens). Chitosan solution was applie at 6 levels, 0%, 0.01%, 0.05%, 0.1%, 0.5% and 1.0%, respectively. The results obtained were summarized as follows ; 1. The dry matter yields of chitosan treatment plot were about 30%~63% more than the dry matter yield of control plot in all cuts. 2. Total dry matter yield was produced by 659.7kg/10a at levels of 0.05%, it was significantly higher than other chitosan solution levels. 3. The predictable highest yield and economic yield of Ladino clover could be obtained at 0.05% and 0.01% solution levels, respectively. 4. The relative dry matter yields for total dry matter yield were 66.7%, 18.3% and 15.0% at 1st, 2nd and 3rd cut, respectively. Chitosan application at early spring was affected to increasing the dry matter yield of 1st cut.