• Title/Summary/Keyword: Na-24

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THE FLUORIDE RELEASING EFFECT OF PVA FLUORIDE-POLYMER ADHESIVE TAPE (불소를 함유한 PVA 고분자 접착 테잎의 불소 유리 효과)

  • Im, Sung-Ok;Lee, Sang-Ho;Lee, Nan-Young;Park, Seung-Hyo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.38 no.4
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    • pp.327-336
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    • 2011
  • The purpose of this study is to investigate the residual fluoride concentration of polymer adhesive tape in oral cavity which is made by spraying NaF on PVA base and to compare with Fluoride varnish(Cavityshiled$^{TM}$). Experimental groups were divided into two according to application methods; Group 1(NaF-PVA tape) and Group 2(Cavityshiled$^{TM}$). Topical fluoride was applied to 20 healthy adults aged from 25 to 30. Fluoride concentration in unstimulated whole saliva was measured by fluoride-sensitive electrode for 72 hours. 1. Until 72 hours after application in every group, significantly higher fluoride concentration was shown in saliva than baseline value(p<0.05). 2. At 2, 3 and 4 hours after application, Group 2 revealed significantly higher fluoride concentration than Group 1(p<0.05). 3. At 24, 48 and 72 hours after application, there was no significance(p>0.05). Although the residual fluoride concentration of saliva and the amount of fluoride of NaF-PVA tape are lower than those of Cavityshield$^{TM}$, NaF-PVA tape is considered to be more effective since it showed almost the same result as Cavityshield$^{TM}$. Therefore, NaF-PVA tape is expected to be a great fluoride application material.

Response Function of HPGe Detector using $^{23}Na$(p, $\gamma$)$^{24}Mg$ and $^{27}Al$(p, $\gamma$)$^{28}Si$ Reaction ($^{23}Na$(p, $\gamma$)$^{24}Mg$$^{27}Al$(p, $\gamma$)$^{28}Si$반응을 이용한 HPGe 검출기의 응답함수)

  • Park, Sang-Tae
    • Journal of Radiation Protection and Research
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    • v.35 no.2
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    • pp.85-90
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    • 2010
  • In the present work, peak relative efficiency for the energy was obtained and response function was worked out. This study was carried out using the high resolution high efficiency HPGe detector(diameter 78.7 mm, length 86.5 mm) and NaI(Tl) detector for anti-compton. The anti-coincidence of the signals from the two detectors could be used to lessen the Compton effect signal; thus, the $\gamma$-ray energy resolution could be improved. The $\gamma$-ray spectrum was measured at $55^{\circ}$ to the direction of the incident proton beam. Reaction spectrum was obtained from the $^{23}Na$(p, $\gamma$)$^{24}Mg$ reaction at $E_p$ = 1424 keV and $^{27}Al$(p, $\gamma$)$^{28}Si$ reaction at $E_p$ = 992 keV. To accelerate the incident proton which creates the (p, $\gamma$) capture reaction, the 3 MeV Pelletron accelerator at the Tokyo Institute of Technology was used. Response function was worked out by a noble technique. We worked out a response function from 1.2 to 9.4 MeV at intervals of 0.75 MeV.

A Study on Urinary Excretions of Sodium and Potassium and the Volume of 24 Hour Urine in Rural Korean Residents (한국 농촌거주자의 24시간 채집 소변중 나트륨, 칼륨의 배설량과 일중 총 소변 배설량에 관한 연구)

  • Sun, Myung-Hoon
    • Journal of agricultural medicine and community health
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    • v.16 no.1
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    • pp.27-32
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    • 1991
  • We measured volume of daily urinary excretion. daily excretion of $Na^+$ and $K^+$, creatinine clearance, blood $Na^+$ and $K^+$ concentration on 34 subjects(12 men. 21 wenen) who live in Hanlim sub-county. Kimhae county. Kyongnam, Korea in December 1990. The data were compared to the data in 9 urban residents(4 men, 5 wemen). Results were as follows. I) Daily mean urinary $Na^+$ excretion of rural residents was $255{\pm}95.6$mEq/day. It is much lower than that of in 1960 but higher than that of students living in urban area(1975) or that of occidentals. 2) Daily mean urinary $K^+$ excretion of rural residents was $45{\pm}15.1$mEq/day. 3) $K^+$ excretion of rural residents was similar to that of urban residents but because of the relatively high $Na^+$ excretion, $K^+/Na^+$ ratio was significantly lower than that of urban residents. In conclusion. salt intake and excretion of rural residents tends to have been decreased progressively and it is thought to be the result of the improvement in dietary life especially increased intake of animal protein.

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Short-term Effects of Sodium Hypochlorite (NaOCl) in Marine Fishes (Sodium Hypochlorite(NaOCl)의 해산어류에 대한 단기노출의 영향)

  • 박관하;한조희
    • Environmental Analysis Health and Toxicology
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    • v.17 no.2
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    • pp.135-140
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    • 2002
  • Sodium hypochlorite (NaOCl) has been demonstrated to be effective against algae that cause red tides. To secure the environmental safety of this chemical for practical use, toxic effects of NaOCl were evaluated in two important aquaculture fishes, flounder and rockfish. At concentrations above 2.5 and 5 ppm for 1 hr, mortality occurred in flounder and rockfish, respectively. Flounder, however, did not die at 2 ppm up to an 8 hr exposure, nor did lipid peroxide level change at the same concentration in 1 hr. Plasma glucose level significantly increased in 1 hr with more than 2 ppm exposure. The results indicate that NaOCl may not induce persistent severe toxicity in flounder and rockfish at the algicidal concentration, 0.5 ppm.

Effect of Ginseng Alcohol Extract on Sodium Movements across the Red Cell Membrane (인삼이 적혈구막을 통한 $Na^+$ 이동에 미치는 영향)

  • Lee, Syng-Il;Kang, Doo-Hee
    • The Korean Journal of Physiology
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    • v.12 no.1_2
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    • pp.1-5
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    • 1978
  • In an attempt to explore the effect of Ginseng on the permeability of the biological membrane to cations we have investigated the effect of Ginseng-alcohol extract on the transport of $Na^+$ human red blood cell preprations. The $Na^+$ influx was measured in intact red cells using $^{22}Na$ as a tracer and the efflux in reseated red cells using $^{24}Na$ as a tracer. 1. The influx of $Na^+$ was not apparently changed by the Ginseng-alcohol extract of 20mg% in the incubation medium. 2. Similarly, 20mg% Ginseng-alcohol extract in the cellular space did not alter the efflux of $Na^+$ from the cell. However, 50mg% of Ginseng-alcohol extract in the cell resulted in a significant increase in the $Na^+$ efflux and this effect was magnified when the cell was suspended in the medium containing the Ginseng-alcohol extract in a concentration of 20mg %. The results suggest that Ginseng-alcohol extract over 50mg% increase permeability of red blood cell membrane to $Na^+$ by altering the membrane integrity.

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Characterization of Pretreatment for Barley straw by Alkaline Solutions (염기 용매를 이용한 보릿짚의 전처리 특성)

  • Kim, Kyoung-Seob;Kim, Jun Seok
    • Korean Chemical Engineering Research
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    • v.50 no.1
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    • pp.18-24
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    • 2012
  • Lignocellulose is difficult to hydrolyze due to the presence of lignin and the technology developed for cellulose fermentation to ethanol is not yet economically viable. However, recent advances in the extremely new field of biotechnology for the ethanol production are making it possible to use of Agriculture residual biomass, e.q., Barley straw, because of their several superior aspects as Agriculture residual biomass; low lignin, high contents of carbohydrates. Barley straw consists of 39.78% cellulose (glucose), 22.56% hemicelluloses and 19.27% lignin. Pretreatment of barley straw using NaOH pretreatment solutions concentration with 2%, temperature $85^{\circ}C$ and reaction times 1 hr were investigates. $NH_4OH$ pretreatment condition was solutions concentration with 15%, temperature $60^{\circ}C$, and reaction times 24hr were investigates. Furthermore, enzymatic saccharification using cellulose at $50^{\circ}C$, pH 4.8, 180 rpm for conversion of cellulose contained in barley straw to monomeric sugar. The pretreatment of barley straw using NaOH and $NH_4OH$ can significantly improve enzymatic saccharification of barley straw by extract more lignin and increasing its accessibility to hydrolytic enzymes. The result showed NaOH pretreatment extracted yield of lignin was 24.15%. $NH_4OH$ pretreatment extracted yield of lignin was 29.09%. Shaccharification of barley straw pretreatment by NaOH for 72hr and pH 4.8 result in maximum glucose concentration 15.39g/L (58.40%) and by $NH_4OH$ for 72hr and pH 4.8 result in maximum glucose concentration 16.01g/L (64.78%).

Electronic Structures of ANb2PS10 (A=Ag, Na) and AuNb4P2S20

  • Jung, Dong-Woon;Kim, Sung-Jin
    • Bulletin of the Korean Chemical Society
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    • v.24 no.6
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    • pp.739-743
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    • 2003
  • New quaternary compounds $ANb_2PS_{10}$ (A = Na, Ag) and $AuNb_4P_2S_{20}$ were synthesized and characterized. The structures of three compounds consist of one-dimensional infinite chains built by [$Nb_2S_{12}$] and [$PS_4$] units. Cation atoms are occupied within the van der Waals gap of sulfur atoms between infinite chains to make -S…$M^+$…S- contacts. There is only one Au atom site and so crystallographically a unit cell contains four equivalent Au atoms in $AuNb_4P_2S_{20}$. This is only the half of the numbers of Na or Ag atoms in $NaNb_2PS_{10}$ or $AgNb_2PS_{10}$. The ratio between $Nb_2PS_{10}$ matrix vs the cation is, therefore, 1 : 1 for Ag and Na, but it is 2 : 1 for Au. Mixed valency in Au or Nb was expected to balance the charge in the latter compound. The electronic structures calculated based on the extended Huckel tight-binding method show that $ANb_2PS_{10}$ (A = Ag, Na) are semiconducting, while $AuNb_4P_2S_{20}$ is metallic, which is not consistent with the experimental results of these three compounds that all exhibit semiconducting property. The result of calculation suggests that $AuNb_4P_2S_{20}$ might be a magnetic insulator. Magnetic measurement experiment exactly proved that the compound is a Slater antiferromagnetic material with the Neels' temperature of 45 K. It is recognized, therefore, that electronic structure analysis is very useful to understand the properties of compounds.

Electrical Conductivity in oxide glasses subjected to a sodium silver ion-exchange treatment (산화물유리에서의 $Na^{+}$이온과 $Ag^{+}$이온 교환에 따른 전기전도도 변화에 관한 연구)

  • 한준수;강원호;이효경
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.05a
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    • pp.100-105
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    • 1995
  • Bulk glasses in the system $Na_2O$-CaO-$Al_2O_3$-$B_2O_3$-$SiO_2$ containing 20 to 30 mol% sod-ium hav been subjected to a sodium silver ion-exchange reaction for 0, 24, 36, 48 jr were analysed by electrical characterization Ion-exchanged glasses exhibit resistivity and activation energy values lower than those of the untreated ones. The electrical conductivity increase with sodium content and ion-exchanged time. In this experiment the electrical conductivity exhibit a maximum value of 1.78${\times}$10$^{-4}$S/cm at $200^{\circ}C$ which contains 30 mol% sodium and subjects ion-exchange reaction for 48hr.

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Gas Sensing Characteristics and Preparation of SnO2 Nano Powders (SnO2 나노 분말의 합성 및 가스 감응 특성)

  • Lee, Ji-Young;Yu, Yoon-Sic;Yu, Il
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.7
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    • pp.589-593
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    • 2011
  • [ $SnO_2$ ]nano powders were prepared by solution reduction method using tin chloride($SnCl_2{\cdot}2H_2O$), hydrazine($N_2H_4$) and NaOH. The $SnO_2$ thick films for gas sensors were fabricated by screen printing method on alumina substrates and annealed at $300^{\circ}C$ in air, respectively. XRD patterns of the $SnO_2$ nano powders showed the tetragonal structure with (110) dominant orientation. The particle size of $SnO_2$ nano powders at the ratio of $SnCl_2:N_2H_4$+NaOH= 1:6 was about 60 nm. The sensing characteristics were investigated by measuring the electrical resistance of each sensor in a test box. Sensitivity of $SnO_2$ gas sensor to 5 ppm $CH_4$gas and 5 ppm $CH_3CH_2CH_3$ gas was investigated for various $SnCl_2:N_2H_4$+NaOH proportion. The highest sensitivity to $CH_4$ gas and $CH_3CH_2CH_3$ gas of $SnO_2$ sensors was observed at the $SnCl_2:N_2H_4$+NaOH= 1:8 and $SnCl_2:N_2H_4$+NaOH= 1:6, respectively. Response and recovery times of $SnO_2$ gas sensors prepared by $SnCl_2:N_2H_4$+NaOH= 1:6 was about 40 s and 30 s, respectively.

Inhibitory Effects of Some Treatments on Browning During Yam(Discorea batatas Decne) Tuber Processing (가공과정중(加工過程中) 마 괴근조직(塊根組織)의 갈변억제처리(褐變抑制處理) 효과(效果))

  • Kang, Dong-Kyoon;Kim, Sang-Kuk;Chung, Sang-Hwan;Lee, Seong-Phil;Choi, Boo-Sull
    • Korean Journal of Medicinal Crop Science
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    • v.6 no.1
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    • pp.33-37
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    • 1998
  • Browning index rised rapidly within 15 hrs to 83% of total browning in Jang - ma (Dioscorea batatas Decne) tissues at $40^{\circ}C$ while 37% in Dan - ma. Therefore, the degree of browning process of Jang - ma was faster than that of Dan - ma. Browning in Jang - ma was inhibited by treatments of NaCl which showed 48 and 39% inhibition, respectively, after 48 hrs of incubation. Also the treatment of $80^{\circ}C$ heating showed excellent inhibition within 24 hrs. In the case of Dan - ma, browning process was inhibited by treatments of 1 and 0.5M NaCl and $70^{\circ}C$ heating, which showed 43, 26 and 23% inhibition, respectively, after 48 hrs of incubation.

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