• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 춘계학술대회 논문집
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• pp.344-349
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• 2001

This paper was to investigate of a adhesiveness for the plasma sprayed coating materials did salt spray by acoustic emission method in tensile loadings. The powders used for the coating were nickel aluminum composite powder Ni-4,5wt.%Al and titanium dioxide powder Ti02. These powders were coated on a carbon steel S45C by plasma spray method. The salt solution was a 5% NaCl and the salt spray times were 2, 5 and 10 hours respectively. The salt solution penetrated into the surface of the substrate through pore of the coating layer built in the process of plasma spay. Corrosion productions formed on the surface of substrate. The adhesiveness between the substrate and the coating layer is weaken by corrosion and the exfoliation initiated chiefly at the corrosion surface of the substrate. The AE events and energy of the corroded coating specimens decreased as the salt spray times increased.

• 한국환경보건학회지
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• 제22권1호
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• pp.1-4
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• 1996

I have conducted two testings to find out which water is better for drinking water. First, I made 20 mM L-DOPA solutions by solving L-DOPA (3,4-Dihydroxyphenylalanine) in tap water, Waters' mineral water and reverse osmotic water. Then I measured activities after adding Tyrosinase (purifide enzyme, step 3), which was extracted from Salanum melongena(mad apple), in each L-DOPA solution. Second, I solved 0.1, 0.5 and 0.9% salt in each 20 mM L-DOPA distilled water to measure activity of each salt solution. The results of the testings are as follows: 1. 10 minutes after adding Salanum melongena(mad apple) tyrosinase in each L-DOPA solution, activity of Waters' mineral water was 0.867 tap water 0.777 and reverse osmotic water 0.742. 2. Activity of Waters' mineral water was higher than that of tap water by 10.4% and higher then reverse osmotic by 14.4%. 3. Activity of Waters' mineral water was much higher than that of 0.9% salt water by 41.8%. 4. The optimum pH of Salanum melongena (mad apple) tyrosinase is 9.0. Most enzymes working in the human metabolism are alkaline and body fluids' pH also alkaline. In conclusion, an alkaline water is believed better than an acidic water for drinking.

• 한국세라믹학회지
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• 제27권7호
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• pp.851-860
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• 1990

The hydrolysis-precipitation reaction of mixed aluminum salt solutions of aluminum sulfate, aluminum nitrate, and urea has been investigated to obtain narrow-sized and unagglomerated fine spherical precipitates of aluminum hydroxide required for coating core particles. The hydrolysis-precipitatin reaction could be controlled to be appropriate to coating processes by usign urea as a pH control-agent. As the concetration of total Al3+ ion and the molar ratio of SO42-/Al3+ in starting solutions became smaller and also as the vol. ratio of water/solution for hydrolyzing mixed aluminum salt solution became larger, the morphology of precipitates tended to be more unagglomerated and spherical, while their size(0.5longrightarrow0.05${\mu}{\textrm}{m}$) to be smaller. The optimum hydrolysis condition for coating processes was to hydrolyze the mixed aluminum salt solution, in which the molar ratio of SO42-/Al3+ was 0.75, while the amount of water corresponding to the vol. ratio of water/solution of 15. The precipitate was the aluminum hydroxide which sulfate ions were strongly adsorbed on and the maximum yield in the hydrolysis-precipitation reaction was about 20%.

• Macromolecular Research
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• 제12권3호
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• pp.263-268
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• 2004

We have synthesized a water-soluble polyimide precursor, poly(amic acid) amine salt (PAD), from pyromellitic dianhydride (PMDA), 4,4'-oxydianiline, and N,N -dimethylethanolamine (DMEA) and have investigated in detail its properties with respect to the degree of salt formation (D$\_$sf/). The maximum value of D$\_$sf/ we obtained upon precipitation of the precursor solution into acetone was 79%. We synthesized a PAD having a D$\_$sf/ of 100% (PAD100) by the solid state drying of an organic solution. The precursors showed different solubility depending on the D$\_$sf/ to make up to 4 wt% solutions in water containing a small amount of DMEA. PAD100 is completely soluble in pure water. We investigated the imidization behavior of PAD in aqueous solution using various spectroscopic methods, which revealed that PAD 100 has faster imidization kinetics relative to that of the poly(amic acid)-type precursors. The resulting polyimide films prepared from an aqueous precursor solution possess almost similar physical and thermal properties as those prepared from N-methyl-2-pyrrolidone(NMP) solution. Therefore, we have demonstrated that PAD can be used as a water-based precursor of polyimide; this procedure avoids the use of toxic organic solvents, such as NMP.

• 대한화학회지
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• 제19권2호
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• pp.142-146
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• 1975

황산제일철을 원료로 해서 함수산화철 안료를 제조하기 위한 실험이다. 황산제일철을 암모니아로 중화해서 Mohr's salt(ferrous ammonium sulfate)을 만들고 Mohr's salt의 농도를 Fe(II) 이온농도, 14${\sim}$72g/l, 수소이온농도를 pH3 또는 6으로 조절한뒤, 반응온도는 $90{\sim}100^{\circ}C$로 일정하게 유지하고 반응시간 2시간, 3기압으로 공기 가압한 결과는 다음과 같다. Mohr's salt의 농도가 진하고, 중성으로 갈수록 함수산화철의 수득율이 증가되며, Mohr's salt 농도가 Fe(II) 이온농도, 42.81g/l 일때, 91.5% 이상의 수득율을 얻었다. 이렇게하여 생성된 함수산화철의 결정형은 $\alpha$-goethite형이며, 색상도 천연 ${\alpha}$-goethite와 유사하였다. 이것을 $500^{\circ}C$로 하소(calcination)하니 미려한 적갈색을 띤 ${\alpha}-Fe_2O_3$가 생성되었다.

• The Korean Journal of Ecology
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• 제2권1호
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• pp.31-37
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• 1978

The salt accumulation on the soil surface can be mathematically described. Although the movement of salts in soil solution is expressed in terms of mathematical model, which has certain limitations in practical application, except the exchangeable and absorbable state salts in soil solution. This model is illustrated by analyticl experiments in which evaporation from the bare soils, transpiration of plants and rainfall are required. Agreement between the model and the measured data was satisfactory, which validating the salt accumulation theory on the soil surface.

• Journal of Nutrition and Health
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• 제16권1호
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• pp.21-26
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• 1983

For the purpose of study on optimal gustation of salt 108 patients with hypertension(61 cases of male, 47 cases of female) were studied. And also 48 patients with non-hypertensive heart diseases and pulmonary diseases (20 cases of male, 28 cases of female ) and apparently healthy subjects (107 cases of male, 20 cases of female) were studied as control group. By adding salt into 3% rice boiled powder solution the 0.1%, 0.25% 0.5%, 0.75% and 1 % salt solutions were prepared respectively. Allowed subject to taste all above solution in landed and to point out the optimal salty taste of each subject. There were no significant difference in optimal gustation of salt among the hypertensive patients and control group. The optimal salt gustation of hypertensive patients with low salt diet was slightly lower than those with free diet The optimal salt gustation was higher in old aged persons regardless of diseases.

• 한국분말재료학회지
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• 제10권2호
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• pp.136-141
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• 2003

In the present study, $TiO_2$ imbedded copper matrix powders have been successfully prepared from the ($CuSO_4+TiO_2+Zn$) composite salt solution. The composite $Cu/TiO_2$ powders were formed by drying the solution at $200{\sim}~400^{\circ}C$ in the hydrogen atmosphere. Photocatalytic characteristics was evaluated by detecting TOC (total organic carbon) amount with TOC analyzer (model 5000A Shimadzu Co). Phase analysis of $Cu/TiO_2$ composite powders was carried out by XRD, DSC and powder size was measured with TEM. The mean particle size of composite powders was about 100 nm and a few zinc and copper oxide phases was included. The reduction ratio of TOC amount was 60% by the composite $Cu/TiO_2$ powders under the UV irradiation for 8 hours.

• 한국토양비료학회지
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• 제28권3호
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• pp.233-240
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• 1995

Ficks의 확산 편미방을 Laplace 변환을 적용하여 초기 및 경계조건과 함께 종속 대수 함수로 변환하고 Burington의 역변환표를 활용하여 복귀하는 방법으로 Ficks의 확산 편미방의 해를 구하였다. 적용된 초기 및 정계조건은 일정깊이의 담수에로 무한 깊이의 일정 염농도의 균일한 간척지 토양에서 상향 염분확산 이동에 대한 것이었다. 유도된 해는 특이 조건에서의 비교법으로 오.등 및 Kirkham, 등이 보고 한 간단한 초기 빛 경계조건에서의 해와 일치함을 확인했다. Ficks의 확산식의 해로 계산된 완만한 제염 속도를 근거로하여 담수 제염 방법별 제염 속도와 토양중 염분분포를 추정할수있는 모형식을 제시하였다.

• 한국축산식품학회지
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• 제31권4호
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• pp.497-505
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• 2011

The objective of this study was to examine the effect of hot-boning and soy sauce as a curing agent on the processing properties of beef jerky. Beef jerky was prepared under the following four treatment conditions; Beef jerky with cold-boned beef and salt solution, beef jerky with cold-boned beef and soy sauce solution, beef jerky with hot-boned beef and salt solution, and beef jerky with hot-boned beef and soy sauce solution. Cured meat and jerky containing hot-boned beef had a significantly higher pH, water holding capacity (WHC), moisture content, Myofibrillar fragmentation index (MFI), processing yields, tenderness, and sensorial scores than samples containing cold-boned beef (p<0.05). Regardless of the raw materials, the jerky containing soy sauce had a significantly lower pH, WHC, moisture content, salt content, TBA, CIE $L^*$ and $b^*-$ values, and significantly higher MFI, mechanical tenderness, and sensorial scores (p<0.05). Based on these findings, we concluded that the use of hot-boned meat and soy sauce was the most effective boning method and curing agent during beef jerky processing.