• 제목/요약/키워드: V2H

검색결과 6,591건 처리시간 0.042초

Hard TiN Coating by Magnetron-ICP P $I^3$D

  • Nikiforov, S.A.;Kim, G.H.;Rim, G.H.;Urm, K.W.;Lee, S.H.
    • 한국표면공학회지
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    • 제34권5호
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    • pp.414-420
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    • 2001
  • A 30-kV plasma immersion ion implantation setup (P $I^3$) has been equipped with a self-developed 6'-magnetron to perform hard coatings with enhanced adhesion by P $I^3$D(P $I^3$ assisted deposition) process. Using ICP source with immersed Ti antenna and reactive magnetron sputtering of Ti target in $N_2$/Ar ambient gas mixture, the TiN films were prepared on Si substrates at different pulse bias and ion-to-atom arrival ratio ( $J_{i}$ $J_{Me}$ ). Prior to TiN film formation the nitrogen implantation was performed followed by deposition of Ti buffer layer under A $r^{+}$ irradiation. Films grown at $J_{i}$ $J_{Me}$ =0.003 and $V_{pulse}$=-20kV showed columnar grain morphology and (200) preferred orientation while those prepared at $J_{i}$ $J_{Me}$ =0.08 and $V_{pulse}$=-5 kV had dense and eqiaxed structure with (111) and (220) main peaks. X-ray diffraction patterns revealed some amount of $Ti_{x}$ $N_{y}$ in the films. The maximum microhardness of $H_{v}$ =35 GN/ $M^2$ was at the pulse bias of -5 kV. The P $I^3$D technique was applied to enhance wear properties of commercial tools of HSS (SKH51) and WC-Co alloy (P30). The specimens were 25-kV PII nitrogen implanted to the dose 4.10$^{17}$ c $m^{-2}$ and then coated with 4-$\mu\textrm{m}$ TiN film on $Ti_{x}$ $N_{y}$ buffer layer. Wear resistance was compared by measuring weight loss under sliding test (6-mm $Al_2$ $O_3$ counter ball, 500-gf applied load). After 30000 cycles at 500 rpm the untreated P30 specimen lost 3.10$^{-4}$ g, and HSS specimens lost 9.10$^{-4}$ g after 40000 cycles while quite zero losses were demonstrated by TiN coated specimens.s.

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과산화수소를 이용한 V2O5 Xerogel의 합성 및 전기화학적 특성 (The Electrochemical Properties and Synthesis of V2O5 Xerogel using H2O2)

  • 박희구;정재엽;이만호
    • 공업화학
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    • 제16권1호
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    • pp.107-111
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    • 2005
  • $V_2O_5$ 분말을 과산화수소에 용해시켜 $V_2O_5$ 겔을 졸-겔법으로 합성한 후 물성과 전기화학적 특성을 NMR, 선형전압전류법 등을 이용하여 조사하였다. $V_2O_5$ xerogel에 삽입된 $Li^+$ 이온의 량에 따라 NMR 스펙트라의 화학적이동값이 다르게 나타났으며 xerogel 구조 내에서 다른 환경의 리튬이온 자리가 존재함을 알 수 있었다. 합성에 이용한 $V_2O_5$의 초기농도 변화와 pH 변화에 따른 xerogel의 전기화학적 특성은 큰 차이가 나타나지 않았으며, 전지용량은 이온교환수지법으로 제조한 xerogel과 비슷한 140 mAh/g으로 나타났다.

혼합과채쥬스 특성에 미치는 여러 인자의 영향 (Effect of Several Factors on the Characteristics of Six-Vegetable and Fruit Juice)

  • 이규희;최희숙;김우정
    • 한국식품과학회지
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    • 제27권4호
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    • pp.439-444
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    • 1995
  • Preparative conditions and characteristics of six-vegetable and fruit juice were studied for the effects of mixing ratio, heat treatment and addition of sugar, salt and organic acid. The vegetables and fruit used were carrot(Ct), cabbage(Cg), pear(Pr), cucumber(Cr), celery(Cy) and dongchimi(Di). From the sensory results of mixing ratio of three of binary mixtures of Cg-Pr(1:3):Ct-Di(1:4):Cr-Cy(3:1), two ratios of 5.0:2.5:2.5(V-6A) and 6.0:2.0:2.0(V-6B) were suggested optimal for six-vegetable and fruit juice. Addition of 2% sucrose and 0.3% NaCl improved the preference significantly. The pH 4.0 for V-6A and pH 3.5 for V-6B were more prefered when pH was adjusted by citric acid. Heating the juice at $100^{\circ}C$ for 100 minutes slightly decreased pH and increased the acidity. Total solids and viscosity were also decreased by heating. All of those changes were more significant in V-6B than V-6A, probably due to lower pH. Heating the juice resulted in a slight decrease in L value and an increase in a and b values. Heating at $100^{\circ}C$ caused an increase in moldy flavor and a decrease in fresh vegetable flavor while heating at $80^{\circ}C$ for 20 minutes changed them little.

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Evaluation of Electrolyzed Oxidizing Water as a Control Agent of Cucumber Powdery Mildew

  • Lee, Yong-Hwan;Cha, Kwang-Hong;Ko, Sook-Ju;Park, In-Jin;Park, Boung-In;Seong, Ki-Young
    • The Plant Pathology Journal
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    • 제16권4호
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    • pp.206-210
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    • 2000
  • The effect of the electrolyzed oxidizing water on Sphaerotheca fuliginea was investigated with germination and sporulation of the fungal conidia. The sporulation was inhibited by the electrolyzed oxidizing water of pH 2.5, 3.5, and 4.5, but was not inhibited by the distilled water adjusted pH with 1N-HCL solution. However, the electrolyzed oxidizing water did not affect conidial germination. The oxidation-reduction potential at pH 2.5 and pH 3.5 of electrolyzed oxidizing water were 1130 mV and 1060 mV, respectively, but those of distilled water adjusted with HCL solution were 550 mV and 490 mV, respectively. When the electrolyzed oxidizing water of ORP over 1100 mV was sprayed on cucumplanting, the disease severities of powdery mildew were about 8.5% and 19.2%, respectively. Disease severity of a standard control (triflumizole 30% WP, $500\textrm{mg}\textrm{/L}$) was about 3.0%, while that of plants without electrolyzed oxidizing water was to 45.8%.

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Enhanced Ex Vivo Buccal Transport of Propranolol: Evaluation of Phospholipids as Permeation Enhancers

  • Lee, Jae-Hwi;Choi, Young-Wook
    • Archives of Pharmacal Research
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    • 제26권5호
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    • pp.421-425
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    • 2003
  • The aim of the present study was to evaluate the effects of two phospholipid permeation enhancers, lysophosphatidylcholine (LPC) and didecanoylphosphatidylcholine (DDPC), along with a fusidic acid derivative, sodium taurodihydrofusidate (STDHF) and ethanol (EtOH) on the buccal transport of propranolol hydrochloride (PPL) using an ex vivo buccal diffusion model. The permeation rate of [$^3 H$]PPL as measured by steady-state fluxes increased with increasing EtOH concentration. A significant flux enhancement (P<0.05) was achieved by EtOH at 20 and 30 %v/v concentrations. At a 0.5 %w/v permeation enhancer concentration, the buccal permeation of [$^3 H$]PPL was significantly enhanced by all the enhancers studied (i.e., LPC, DDPC and STDHF) compared to the control (phosphate-buffered saline pH 7.4, PBS). LPC and DDPC displayed a greater degree of permeation enhancement compared with STDHF and EtOH-PBS mixtures with an enhancement ratio of 3.2 and 2.9 for LPC and DDPC, respectively compared with 2.0 and 1.5 for STDHF and EtOH:PBS 30:70 %v/v mixture, respectively. There was no significant difference between LPC and DDPC for the flux values and apparent permeability coefficients of [$^3$H]PPL. These results suggest that phospholipids are suitable as permeation enhancers for the buccal delivery of drugs.

$Y_{2}O_{3}$가 첨가된 $Pr_{6}O_{11}$계 ZnO 바리스터의 d.c. 스트레스에 따른 안정성 (Stability of $Pr_{6}O_{11}$-Based ZnO Varistors Doped with $Y_{2}O_{3}$ under d.c. Stresses)

  • 윤한수;류정선;남춘우
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.551-554
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    • 2000
  • The stability of $Pr_6$$O_{11}$-based ZnO varistors doped with $Y_2$$O_3$ was investigated under various d.c. stresses. The varistors were sintered at $1350^{\circ}C$ for 1h in the addition range of 0.0 to 4.0 mol% $Y_2$$O_3$. The varistors doped with $Y_2$$O_3$ exhibited much higher nonlinearity than that without $Y_2$$O_3$. In Particular, the varistors containing 0.5 mol% $Y_2$$O_3$ showed very excellent V-I characteristics, which the nonlinear exponent was 51.19 and the leakage current was 1.32 $\mu\textrm{A}$. And these varistors also showed an excellent stability, which the variation rate of the varistor voltage and the nonlinear exponent were -0.80% and -2.17%, respectively, under 4th d.c. stress, such as (0.80 $V_ {1mA}$/$90^{\circ}C$/12h)+(0.85 $V_{1mA}$/$115^{\circ}C$/12h)+(0.90 $V_{1mA}$/$120^{\circ}C$/12h)+(0.95 $V_{1mA}$/$125^{\circ}C$/12h). Consequently, since $Pr_ 6$$O_{11}$-based ZnO varistors doped with 0.5 mol% $Y_2$$O_3$ have an excellent stability as well as good nonlinearity, it is expected to be usefully used to develop the superior varistors in future.

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Pharmacokinetics of 11-Hydroxyaclacinomycin X (ID-6105), a Novel Anthracycline, after i.v. Bolus Multiple Administration in Rats

  • Yoo Bo-Im;Ahan Kwang Bok;Kang Min Hee;Kwon Oh-Seung;Hong Young-Soo;Lee Jung Joon;Lee Hong Sub;Ryu Jung Su;Kim Tae Yong;Moon Dong-Cheul;Song Sukgil;Chung Youn Bok
    • Archives of Pharmacal Research
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    • 제28권4호
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    • pp.476-482
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    • 2005
  • We investigated the pharmacokinetics of 11-hydroxyaclacinomycin X (ID-6105), a novel anthracycline, after intravenous (i.v.) bolus administration at a multiple dose every 24 h for 5 days in rats. To analyze ID-6105 levels in biological samples, we used an HPLC-based method which was validated in a pharmacokinetic study by suitable criteria. The concentrations of ID-6105 after the multiple administration for 5 days were not significantly different from the results after the single administration. The $t_{1/2\alpha}, t_{l/2\beta}, V_{dss}, and CL_{t}$ after the multiple administration were not significantly different from the values after the single administration. Moreover, the concentrations of ID-6105 1 min at day 1-5 after i.v. bolus multiple administration did not show the significant difference. Of the various tissues, ID-6105 mainly distributed to the kidney, lung, spleen, adrenal gland, and liver after i.v. bolus multiple administration. ID-6105 concentrations in the kidney or lung 2 h after i.v. bolus administration were comparable to the plasma concentration shortly after i.v. bolus administration. However, the ID-6105 concentrations in various tissues 48 h after i.v. bolus administration decreased to low levels. ID-6105 was excreted largely in the bile after i.v. bolus multiple administration at the dose of 3 mg/kg. The amounts of ID-6105 found in the bile by 12 h or in the urine by 48 h after the administration were calculated to be $14.1\% or 4.55\%$ of the initial dose, respectively, indicating that ID-6105 is mostly excreted in the bile. In conclusion, ID-6105 was rapidly cleared from the blood and transferred to tissues, suggesting that ID-6105 might not be accumulated in the blood following i.v. bolus multiple dosages of 3 mg/kg every 24 h for 5 days. By 48 h after i.v. bolus administration, ID-6105 concentrations in various tissues had decreased to very low levels. The majority of ID-6105 appears to be excreted in the bile.

KURT 지하수 조건에서 셀레늄과 테크네튬의 용해도 및 주요 화학종 (Solubilities and Major Species of Selenium and Technetium in the KURT Groundwater Conditions)

  • 김승수;민제호;백민훈;김계남
    • 방사성폐기물학회지
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    • 제10권1호
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    • pp.13-19
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    • 2012
  • 장수명 핵분열생성물인 $^{79}Se$$^{99}Tc$는 자연수 중에서 용해도가 클 뿐더러 음이온으로 존재하여 방사성폐기물 처분장에서 주요 관심핵종들로 고려되고 있다. 본 연구에서는 KURT 지하수의 다양한 pH와 산화-환원 조건에서 셀레늄과 테크네튬의 Solubility Limiting Solid Phase (SLSP)로 알려진 $FeSe_2$$TcO_2$의 용해도를 측정하였다. 또한, 지화학코드를 이용하여 실험과 유사조건에서 이들의 용해도와 주요 화학종을 계산하였다. 실험 및 계산으로부터 pH 8~9.5와 Eh=-0.3~-0.4 V 조건에서 $FeSe_2$의 용해도는 $1{\times}10^{-6}mol/L$이하이며, 주 용해 화학종은 HSe-로 판단된다. $TcO_2(s)$의 경우는 pH 6~9.5와 Eh<-0.1 V 영역에서 용해도와 주 용해 화학종이 각각 $5{\times}10^{-8}{\sim}1{\times}10^{-9}mol/L$$TcO(OH)_2$로 나타났지만, Eh=-0.35 V조건에서는 주 용해화학종이 pH가 10.5~12와 12이상에서 각각 $TcO(OH)_3^-$$TcO_4^-$로 계산되었다.

취반 가수율에 따른 품종별 쌀밥의 텍스쳐 특성 (Water Addition Ratio Affected Texture Properties of Cooked Rice)

  • 이수정
    • 한국식품영양과학회지
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    • 제25권5호
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    • pp.810-816
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    • 1996
  • 침지온도 $20^{\circ}C$에서 침지 후 30분에서 35분 사이에 대부분의 품종이 평형에 도달했으며, 평형수분 함량은 0.3247~0.3577(g $H_2O/g$ dry matter)로 나타났다. 초기 수분흡수 속도에서는 품종간에 차이를 나타내었으며, 특히 낙동벼의 경우 0.123g $H_2O$/$min^{1/2}$로 가장 높은 값을 나타냈다. 취반 후 밥의 수분 함량은 가수율에 따라 증가하였으며, 가수율이 1.3에서 1.6(v/w)으로 증가함에 따라서 밥의 수분 함량은 품종에 따라 약 6.0~7.0%증가하였다 가수율에 따른 취반 후 밥의 경도는 가수율이 증가할수록 감소하는 경향이었으며 끈기와 끈기대 경도의 비는 대체적으로 증가하였다.

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상수리나무(Querus acutissima)와 굴참나무(Querus vcariabilis) 수피의 추출성분 (Extractives from the barks of Querus acutissima and Quercus variabilis)

  • 김진규;이상극;함연호;배영수
    • 임산에너지
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    • 제21권1호
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    • pp.41-48
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    • 2002
  • 참나무속 상수리나무와 굴참나무 수피를 채취하여 아세톤-물(7:3, v/v) 혼합용액으로 추출하고 유기용매를 제거한 후 hexane, CH₂C1₂, EtOAc 및 수용성으로 분획하여 동결건조하였다. 두 수종의 EtOAc용성 분획물은 MeOH 수용액 및 EtOH-hexane 혼합용액을 사용하여 Sephadex LH-20 칼럼크로마토그래피를 수행하였다. 단리된 화합물의 구조는 ¹H, /sup 13/C 및 2D-NMR spectrum으로 구조를 구명하였다. 화합물의 분자량은 FAB-MS로 측정하였다. 굴참나무에서는 (+)-catechin, caffeic acid, taxifolin-3-O-β-D-glucopyranoside를 단리 하였으며 상수리나무에서는 (+)-catechin, (+)-gallocatechin, gallic acid, taxifolin-3-O-β-D-glucopyranoside를 단리 하였다.

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