• Restorative Dentistry and Endodontics
• /
• 제19권1호
• /
• pp.124-134
• /
• 1994

The shade of restorative materials is very important for successful restoration esthetically harmonized with the natural tooth. The purpose of this study was to evaluate the color stability and the opacity change of conventional chemical setting and visible light curing glass-ionomer cements for restorative esthetic filling. Specimens of each brand (GC Fuji II and Fuji II LC) were uniformly prepared and divided into three groups: In group l(control group), the specimens received no surface treatment; in group 2, the specimens were coated with varnish and the excess gently blown off; and in group 3. the specimens were coated with light-cured bonding resin and irradiated by a visible light curing unit for 20 seconds on both sides. All specimens were stored in distilled water at $37^{\circ}C$ and checked after for 24 hours. 2 months. 4 months, 6 months. and 8 months. The color characteristics($L^*,\;a^*,\;b^*$) and the opacity(Y%) of all the samples were measured by a spectrocolorimeter and the total color differences(${\Delta}E^*$) and opacity changes(${\Delta}Y%$) were computed. The following results were obtained : 1. The total tolor differences in all groups increased with time. 2. The total color differences of the LC groups after immersion for 8 months in distilled water at $37^{\circ}C$ were lower than those of GC groups(p<0.01), and the total color differences of the varnish or the light-cured bonding resin coated groups were lower than those of the control group with glass-ionomer cements which had no surface treatment(p<0.01). 3. In all groups the translucency decreased with time. 4. In the control group and the varnish coating group. the opacity changes of the GC groups were lower than those of the LC groups(p<0.01) and in the light-cured bonding resin coated group, there was no significant difference between the GC group and the LC group. 5. The opacity changes of the varnish or the light-cured bonding resin coated groups were lower than those of the control group(p<0.01). These results suggest that color change and opacity of conventional chemical setting and light cured glass-ionomer cement were increased with time, and the color changes and the opacity changes of a control group after immersion for 8 months in distilled water at $37^{\circ}C$ were greater than those of the varnish or the light-cured bonding resin coated groups.

• Journal of Plant Biotechnology
• /
• 제49권4호
• /
• pp.347-355
• /
• 2022

제주 용암해수에 함유된 풍부한 미네랄은 노화를 유발하는 활성산소를 제거하는 항산화 효과가 있는 것으로 알려져 있다. 이에 용암해수는 기능성 식품소재로서 상업적 가치가 높은 것으로 알려져 있다. 본 연구에서는 제주산 작물(당근, 블루베리, 감귤)추출물의 항산화 활성을 증류수 추출물과 용암해수 추출물을 이용하여 비교 분석하였다. 블루베리와 감귤의 총폴리페놀 및 플라보노이드 함량은 증류수 추출물보다 용암해수 추출물에서 더 높았다. 또한, 이들 작물의 항산화 효소 활성과 DPPH 라디칼 소거 활성은 증류수 추출물보다 용암해수 추출물에서 더 높았다. 특히, Vero 세포 이용한 블루베리와 감귤의 ROS 소거 효능은 용암해수 추출물에서 더 높게 나타났다. 한편, 당근의 항산화 활성은 총 폴리페놀과 플라보노이드 함량에 차이가 없었음에도 불구하고 용암해수 추출물에서 더 높았다. 이러한 결과는 용암해수가 기능성 식품 산업에서 용매로서의 가능성이 있음을 시사하였으며, 용암해수를 이용한 제주산 작물 추출물은 기능성 식품의 원료로 사용될 수 있는 것으로 판단된다.

• Journal of Microbiology
• /
• 제34권3호
• /
• pp.241-247
• /
• 1996

The stability of the genetically engineered microorganisms and their recombinant plasmids released in natural environments has been regarded as one of the molecular ecological topics. In this study, the recombinant plasmids pCU103 in which the pcbCD genes involved in biodegradation of biphenyl and 4-chlorobiphenyl were cloned in pBluescript SK(+) vector, were examined for their structural and functional stability in different waters at 15 $^{\circ}C$ by the methods of electrophoresis, Southern hybridization, quantification with fluorescent dye, and transformation. The recombinant plamids maintained their stabilities for about 30 days in sterilized distilled water (SDW), 15 days in autoclaved creek water (AW), 25 days in filtered and autoclaved non-sterile creek water (FAW), 4 days in Luria-Bertani (LB) broth, and less than one day in filtered non-sterile creek water (FW). The covalently closed circular (CCC) form of the plasmid was decreased and open circular (OC) form was increased as a function of incubation time, and then linear (L) form was produced to be ultimately degraded out. The degradation rates of the plasmid were proportionally correlated to trophic level of the water, and the biological factor such as DNases was found to be one of the most critical factors affecting structural and functional stability of the plasmid in non-sterile natural water.

• 상하수도학회지
• /
• 제7권2호
• /
• pp.24-33
• /
• 1993

The effects of chlorine dioxide on the oxidation of phenol and disinfection were studied in the various test water conditions. With the 0.3mg/l of chlorine dioxide dose, the spiked phenol(initial concentration: 0.1mg/l) was completely oxidized within 10 minute. The removal rate of phenol was much faster in distilled water than in ground water and filtered water. The applied dose of chlorine dioxide concentrations higher than 0.2mg/l was sufficiently enough for the complete oxidation of phenol. However, with 0.1mg/l of dose, chlorine dioxide can oxidize only 20% of the spiked phenol. The reactive substances present in test water may influence the chlorine dioxide demand in water. pH effect of oxidation rate was also investigated. Increasing the pH, the removal rate of phenol was found to be increased. The disinfection test of chlorine and chlorine dioxide were conducted and compared. The lethal effect for the both disinfectants are similarly powerful. The time for 99% inactivation of E. coli was obtained within 120 sec with the 0.2mg/l of each dose.

• Corrosion Science and Technology
• /
• 제11권4호
• /
• pp.151-156
• /
• 2012

The cavity formed by the ultrasonic generation in the fluid with the application of water cavitation peening collides into the metal surface. At this time, the surface modification effect such as the work hardening presents by the compressive residual stress formed due to the localized plastic deformation. In this investigation, the water cavitation peening technology in the distilled water with the lapse of time was applied to 5052-O aluminum alloy for aluminum ship of a high value. So, the optimum water cavitation peening time on the effect for surface hardening and anti-corrosion property was investigated. Consequently, the water cavitatin peening time on excellent hardness and corrosion resistance characteristic presented 3.5 min. and 5.0 min, respectively. The surface hardness in the optimum water cavitation peening time was improved approximately 45% compared to the non-WCPed condition. In addition, corrosion current density was decreased.

• Environmental Analysis Health and Toxicology
• /
• 제16권1호
• /
• pp.35-41
• /
• 2001

Barley or corn tea, which is usually prepared with municipal chlorinated tap water, is commonly consumed by the public as a substitute for the supplied water itself. This is because most people believe that harmful organic and inorganic compounds can be removed from the tap water by the adsorption mechanism during the tea preparation. In this study, three kinds of commercial grain tea materials-roasted barley grains, a tea bag containing barley grain pieces, and roasted corn grains-were tested for metal removal by preparing 1 liter of tea with deionized/distilled water according the manufacturer's recommended preparation procedures, assuming that the water is contaminated with eight selected metals at levels of 50$\mu\textrm{g}$/l. Of the tested teas, barley tea prepared with roasted grains showed the highest removal efficiency for Cu, As, Ni, Co, Pb, and Cd, ranging from 48 to 71%, followed by corn tea with roasted grains and barley tea with a tea bag. Cr was nearly maintained at the initial concentration in all kinds of tea. The Mn levels. however, were elevated during the tea preparation, particularly in both barley teas, probably because the metal was extracted into the water from the tea materials without significant adsorption. Therefore, it should be considered in the ingestion exposure analysis for metals that their concentrations are altered during the tea preparation with roasted barley or corn grain materials.

• 한국식품영양과학회지
• /
• 제21권6호
• /
• pp.701-705
• /
• 1992

수리취의 삶는 방법을 달리하여 조리한 후 그들의 이화학적 특성을 생수리취와 비교 분석하였다. 조리수는 물, 1%소금, 1%중조를 첨가하여 사용하였으며 삶는 시간은 물과 소금 첨가 조리수에서 30분, 중조첨가 조리수에서 10분으로 하였다. 삶는 수리취액의 pH는 중조를 조리수에 이용한 것이 8.21로 가장 높았고, 수리취잎의 색도 중 녹색도(a)의 경우 중조처리구가 생수리취(-10.50)와 가장 유사한 값을 나타내었으며, 클로로필 및 비타민 C의 함량 또한 중조의 경우가 다른 처리구에 비해 조리방법에 따른 변화의 정도가 적었다. 생수리취의 무기질은 Mg, K, Ca의 순으로 그 함량이 높았으며, 삶은 후에는 조리수에 따라 그들의 함량에 다소 차이가 있었고, 소금, 중조 처리구의 경우 Na의 함량이 증가하였다. 생수리취의 가용성 단백질은 70%가 albumin으로 구성되어 있었으나, 조리에 의해 albumin은 감소한 반면 glutelin, globulin 및 prolamin의 함량은 증가하였다. 수리취에서 분리 정제한 알콜 불용성 물질의 식이섬유 함량은 조리방법에 따라 NDF, ADF, cellulose, lignin값이 감소한 반면 hemicellulose값은 증가하였다.

• 대한본초학회지
• /
• 제34권2호
• /
• pp.1-14
• /
• 2019

Objective : This study was designed to evaluate the protective effect of Rehmanniae Radix Crudus (RC) in 150 mM HCl/ethanol induced acute gastritis mice. Methods : ICR mice were divided into 5 groups (normal group, control group, 10 mg/kg sucralfate treated group, 50 mg/kg RC treated group, 100 mg/kg RC treated group, n=8). Normal group was not take any treatment. Control group induced gastritis 1 hour after ingestion of distilled water. 10 mg/kg sucralfate induced group was induced gastritis 1 hour after ingestion of distilled of sucralfate 10 mg/kg. 50 mg/kg and 100 mg/kg RC treated groups were induced gastritis 1 hour after ingestion of distilled of RC 50 mg/kg and 100 mg/kg. After 1 hour of gastritis induction, removed the stomach tissue. We examined histological observations, oxidative stress biomarkers, antioxidant proteins, inflammatory mediators and cytokines. Results : In this study, the RC treatment group showed gastritis and gastric ulcer inhibition, and the area of injury decreased. The oxidative stress biomarkers such as reactive oxygen species (ROS) and peroxy nitrite ($ONOO^-$) in the serum were reduced in the RC treated group. Inaddition, antioxidant proteins (nuclear factor erythroid 2-related factor 2, Heme oxygenase 1) were increased in RC treated group, and the expression of inflammatory mediators and cytokines induced by nuclear factor-kappa B activation was inhibited. Conclusion : According to the results, RC may have an excellent inhibitory effect on acute gastritis and gastric ulcer.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집D
• /
• pp.572-578
• /
• 2001

This study is to research the heat transfer characteristics in copper-water heat pipes with screen wick, #100. Recently, the semiconductor capacity of an electronic unit has been larger, on the contrary, its size is smaller than before. As a result, a high-performance cooling system is needed. Experimental variables are inclination angle and temperature of cooling water. The distilled water was used for the working fluid. At a inclination angle ${-6}^{\circ}$, #100 2layer screen mesh is shown the best heat transfer performance.

• 설비공학논문집
• /
• 제12권5호
• /
• pp.525-532
• /
• 2000

Evaporation heat transfer characteristics have been investigated experimentally when distilled water is sprayed on the outside wall of horizontal tubes in a evaporator. This problem is of particular interest in the design of evaporator of an absorption system. Hydrophilic surface treatment was employed to increase the wettability on copper tubes. The results indicate that evaporation heat transfer with hydrophilic tubes is shown to be 25-44% higher than that with bare tubes at evaporation pressure of 31.8 Torr(evaporation temperature$ 30^{\circ}C). Evaporation heat transfer rates of hydrophilic treatment tubes are improved substantially, comparing with those of conventional copper tubes in the wide range of operating parameters, such as water inlet temperatures, water mass flow rates and evaporation pressures.