• 한국치위생학회지
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• 제8권4호
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• pp.11-18
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• 2008

The purposes of this study were to examine the effect of 35% Carbamide Peroxide(CP) bleaching agent on the changes in physical and chemical characteristics of tooth. The effect of bleaching agent on enamel was analyzed using Hardness test, SEM and EDS. The microhardness between bleached groups after bleaching showed statistically significant difference according to the paired t-test. The bleached enamel surface showed apparent morphological changes compared to the enamel, which was stored in distilled water only. The difference of the total mineral contents for the distilled water and Carbamide Peroxide did not show statistical significance. These results demonstrated that bleaching using 35% Carbamide Peroxide were adversely affects application time of experimental group and may the safety of using these agents for a short time in dentist-monitored bleaching.

• 한국축산식품학회지
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• 제21권3호
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• pp.246-255
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• 2001

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of muscles extracted with distilled water, saline solution, SDS or Trition X-100 showed simular protein patterns between Hanwoo and Holstein meat, indicating that SDS-PAGE technique may not be useful for the identification between Hanwoo and Holstein meat. Lectine blot analysis of muscle extracted with distilled water demonstrated that Hanwoo and Holstein meat had similar affinities for concanavalin A (Con A), ricinus communis agglutinin (RCA-120), ulex europaeus agglutinin (UEA-1) or peanut agglutinin (PNA) lectins. However, approximately 32.1 kDa component of Hanwoo meat showed high affinity for dolichos biflorus agglutinin (DBA) lectin. On the contrary, high molecular weight components of Holstein meat had the specific affinity for wheat germ agglutinin (WGA) lectin. Hanwoo meat-specific components were observed by lectin staining of heat-denatured meat at 100$^{\circ}C$ for 30 sec. Also, the component of heat-denatured meat at 100$^{\circ}C$ for 30 sec, which was slightly smaller than Hanwoo meat-specific component, was concentrated specifically in Holstein meat.

• Restorative Dentistry and Endodontics
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• 제16권1호
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• pp.1-5
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• 1991

The purpose of this study was to investigate the color stability of 2 light - polymerized veneer resins and 3 heat - polymerized veneer resins. Five specimen discs of each brand were immersed in distilled water at $37^{\circ}C$, in darkroom for 120 days. The distilled water was changed on every third day to prevent contamination from micro - organisms. The color characteristics of all the samples were measured by computer controlled spectrophotometer. The appearence was characterized by means of the $L^*$, $a^*$ and $b^*$ uniform color space(CIELAB) and total color difference was calculated. The following results were obtained 1) ${\Delta}E^*ab$ - value in all brand except IS is were greater than 1 perceptable in visual evaluation. 2) ${\Delta}E^*ab$ - value in VI, IS and VG were lower than upper limit of acceptablilty(3.3 in ${\Delta}E^*ab$). DC was the worst in color stability and was changed into yellow color.

• 전기학회논문지
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• 제59권7호
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• pp.1272-1275
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• 2010

The Cu powder was prepared in distilled water. It has a wide range of size distribution. The submicron-sized particles in the Cu powder were removed by using continuous type centrifugal separator. The average particle size after classification was approximately 50nm. The XRD analysis showed that pure Cu phase and oxide phase ($Cu_2O$)weremixedinthepowderpreparedbythismethod.

• Elastomers and Composites
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• 제47권2호
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• pp.156-161
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• 2012

공기와 증류수에서 노화시킨 천연고무 복합체의 원형 변형으로부터의 회복 거동의 차이를 연구하였다. 공기에서 노화시킨 시험편의 회복률이 증류수에서 노화시킨 것보다 더 컸다. 충진제로 보강한 시험편의 회복속도가 비충진 시험편보다 더 빨랐다. 카본블랙으로 보강한 시험편의 회복속도가 실리카로 보강한 시험편보다 더 빨랐다. 노화 매질에 따른 회복 거동의 차이는 가교밀도 변화와 아닐링 효과로 설명하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.343-346
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• 2002

The chemical compatibility of leachate with the two natural materials was analyzed by performing the hydraulic conductivity test. The selected liner materials were natural marine clay and weathered soil sampled from Kimpo wastefill and Daehwa Dong, Kyonggi Do, respectively. PARAFIX, which is mainly composed of paraffin, cement, stearic acid, PVA etc., was used as solidifying agent. The chemical solutions used in the test were 10% acetic acid, 10% methanol, and real leachate from Kimpo wastefill and the results of tests were compared with that of distilled water. The results of tests show that hydraulic conductivity of solidified clay was increased slightly with permeation of acetic acid, methanol and the increase of hydraulic conductivity was not shown with permeation of leachate, distilled water and in case of weathered soil. Based on the tests, it is ascertained that the tested liner materials can be stable with the solution of low concentration.

• International Journal of Air-Conditioning and Refrigeration
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• 제17권4호
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• pp.123-128
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• 2009

In this paper, effective ways to produce distilled water with solar radiation was investigated. Four different boxes of condensation systems were compared. The bottoms of the boxes were identical, but the angles of the top collecting plates were different. During the solar radiation, condensation did not occur. Condensation started when solar radiation was decreased. The maximum condensation was found when the temperatures of the top and bottom parts were equal. The condensation was continued until sunrise with gradually reduced rate. When the collecting plate angle was $45^{\circ}$, condensation was the highest compared with other angles.

• KEPCO Journal on Electric Power and Energy
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• 제4권1호
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• pp.39-45
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• 2018

Ammonia Adsorbed Fly Ash (AAFA) samples produced from coal fired plants equipped with SNCR (Selective Non-Catalytic Reduction) of nitrogen oxides with urea have been chemically analyzed, and their physical and dissolution properties have been investigated. XRD results for the ammonia component in AAFA ascertained that ABS (ammonium bisulfate) and AS (ammonium sulfate) were deposited on fly ash as $SO_3$ reacted with unreacted ammonia at SNCR. SEM and EDS images showed that fine ashes on large fly ash surface of sphere type were agglomerated, due to adhesive role of ammonium salts attached fly ashes. Dissolution test results of ammonium salts absorbed on AAFA in distilled water or sea water showed that the proportion of un-ionized $NH_3$ to $NH_4{^+}$ were primarily a function of pH and temperature. Increasing pH and temperature causes an increase in the fraction of un-ionized $NH_3$. At pHs of 9.6 and 10.7, un-ionized $NH_3$ and $NH_4{^+}$ ions are present in equal amounts at distilled water and sea water, respectively.

• Environmental Analysis Health and Toxicology
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• 제14권3호
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• pp.75-79
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• 1999

Due to increasing marine pollution there is a great possibility that seaweed is contaminated with polycyclic aromatic hydrocarbons (PAHs). To investigate the effect of processing on PAM removal from Porphyra tenera (laver) contaminated PAH, laver was contaminated with fluoranthene known to have a strong photoinduced toxicity, followed by washings and drying, which are usual processes for dried laver preparation. Sample at each step was collected and its toxicity was evaluated using cultured animal cells as well as analyzing PAH contents. Fluoranthene level in laver was significantly lowered by sequential washings with sea water and distilled water, but not by drying. Fluoranthene content in raw laver right after contamination was 221 ppm and decreased to 130 ppm by washings with seawater plus distilled water while its level was not lurker lowered by drying process. Cytotoxicity and photoinduced cytotoxicity in mammalian cells were significantly elevated in laver extracts containing fluoranthene. Cellular arylhydrocarbon hydroxylase (AHH), one of the biomarkers for cellular accumulation of PAH, was greatly induced by laver extract contaminated with fluoranthene. These results suggest that photoinduced toxicity and AHH activity can be used to monitor contamination of seafood by PAHs. Fluoranthene accumulated in laver was efficiently removed by sequential washings with seawater and tap water for 24 hrs and 12 hrs, respectively.

• 한국수소및신에너지학회논문집
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• 제12권2호
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• pp.129-136
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• 2001

An investigation on the A/V(ampere/volt) gradient according to the concentration and the kind of solution in a electrolyzer is carried out to obtain the basic data on the ultrasonic application for the efficiency elevation of the hydrogen fuel production. KOH is selected as an electrolyte and concentrations are 0%, 10%, 20% and 30%. The solutions are city water, city water with nitrogen. distilled water and distilled water with nitrogen. The Electrochemical analyzer(BAS Co.) is used as a measuring device to observe the A/V gradient. And the limit of volt is from -3000mV to +3000mV. The 28kHz magnetic transducer is selected to give them ultrasonic forcing. In results, it is clarified that ultrasonic influences the A/V gradient in the electrolytic solution.