• 제목/요약/키워드: $U_3 O_8$

검색결과 507건 처리시간 0.026초

400-700 $^{\circ}C$의 온도범위에서 모의 핵연료의 산화거동 (Oxidation Behavior of the Simulated Supent Fuel at 400-$700^{\circ}C$)

  • 강권호
    • 한국분말재료학회지
    • /
    • 제6권3호
    • /
    • pp.209-214
    • /
    • 1999
  • The oxidation behavior of the simulated spent fuel of burn up 33 MWD/kgU was investigated to predict that of the spent fuel in the temperature ranges of 400 to $700^{\circ}C$ and was compared with those of $UO_2$. The forms of uranium oxides after the oxidation were conformed by XRD analyses. The oxidation rate at each the temperature and the activation energy were obtained. After complete oxidation, the simulated spent fuel was converted to $U_3O_8$ and pulverized to powder due to the density difference between the simulated spent fuel and uranium oxides. The activation energies were 85.35 and 30.77kJ/mol in the temperature ranges of 400$\leq$T($^{\circ}C$)$\leq$500 and 500$\leq$T($^{\circ}C$)$\leq$700, respectively.

  • PDF

Antioxidant actions of polyphenol QGR and its building blocks on unopsonized zymosan-induced oxidative stress in murine macrophages Raw264.7

  • Kim, Byung-Hak;Reddy, A.M.;Min, Kyung-Rak;Kim, Young-Soo
    • 대한약학회:학술대회논문집
    • /
    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
    • /
    • pp.155.1-155.1
    • /
    • 2003
  • Polyphenol QGR (quercetin 3-O-beta-(2"-galloyl)-rhamnopyranoside) was isolated from Persicaria lapathifolia (Polygonaceae). In this study, we investigated inhibitory effects of QGR and its building blocks (quercitrin, quercetin and gallic acid) on superoxide anion and NO productions in unopsonized zymosan-stimulated murine macrophages Raw264.7. QGR and quercetin showed potent inhibitory effects on unopsonized zymosan-induced superoxide anion production with IC50 values of 3.2 uM and 4.8 uM, respectively. (omitted)

  • PDF

덕평지역(德平地域)의 옥천누층군(沃川累層群)에 분포(分布)하는 변성이질암(變成泥質岩)과 바륨-바나듐 백운모(白雲母)의 지구화학적(地球化學的) 및 광물학적(鑛物學的) 특성(特性) (Geochemistry and Mineralogy of Metapelite and Barium-Vanadium Muscovite from the Ogcheon Supergroup of the Deokpyeong Area, Korea)

  • 이찬희;이현구
    • 자원환경지질
    • /
    • 제30권1호
    • /
    • pp.35-49
    • /
    • 1997
  • The coal formation of the Deokpyeong area are interbedded along metapelites of the Ogcheon Supergroup, which are composed mainly of graphite, quartz, muscovite and associated with small amounts of biotite, chlorite, pyrite and barite. The ratios of $SiO_2/Al_2O_3$, $Al_2O_3/Na_2O$ and $K_2O/Na_2O$ of the coaly metapelite are variable and wide range from 1.80 to 10.21, from 27.8 to 388.8 and from 7.6 to 61.8, respectively. These coal formation were deposited in basin of marine environments, and the REE of these rocks are not influenced with metamorphism and hydrothermal alterations on the basis of $Al_2O_3$ versus La, La against Ce, the ratios of La/Ce (0.19 to 0.99) and Th/U (0.02 to 4.75). These rocks also show much variation in $La_N/Yb_N$ (1.19 to 22.89), Th/Yb (0.14 to 21.43) and La/Th (0.44 to 13.67), and their origin is explained by derivation from a mixture of sedimentary and igneous rocks. The wide range in trace and REE element characteristics as Co/Th (0.12 to 2.78), La/Sc (0.33 to 10.18), Sc/Th (0.57 to 5.73), V/Ni (8 to 2347), Cr/V (0.02 to 0.67) and Ni/Co (1.56 to 32.95) of these coaly metapelites argues for inefficient mixing of the various source lithologies during sedimentation. Deep to pale green barium-vanadium muscovites (vanadium-oellacherite) have been found in this coal formations. Modes of occurrence and grain size of muscovite are heterogeneous, but most of the barium and vanadium-bearing muscovites occur along the boundaries between graphite and quartz grains, ranging from 200 to $350{\mu}m$ in length and from 40 to $60{\mu}m$ in width. Results of X-ray diffraction data of the minerals characterized to be monoclinic system with $a=5.249{\AA}$, $b=8.939{\AA}$, $c=20.924{\AA}$ and ${\beta}=95.894^{\circ}$. Representative chemical formula of the muscovite was $(Na_{0.09}K_{1.44}Ba_{0.46})(Al_{2.75}Ti_{0.07}V_{0.56}Fe_{0.08}Mg_{0.50})(Si_{6.12}Al_{1.88})O_{22}$. The V possibly substitute octahedral Al, and the Ba is coupled substitution of $K^+Si^{4+}=Ba^{2+}Na^+Ca^{2+}$, which compositional ranges of V and Ba are from 0.42 to 0.69 and from 0.34 to 0.56 based on $O_{22}$, respectively. Formation mechanism of the barium-vanadium muscovites in the coaly metapelite is shown that the formed by high pressure and temperature from regional metamorphism origanated during diagenesis at the interface between a basinal brine and organic matter.

  • PDF

개에서 신장결석의 제거를 위한 신절개술 (Removal of Renal Calculi by Nephrotomy in Two Dogs)

  • 정순욱;김진영;최치봉;이경리;최혜정;김지헌;정병현
    • 한국임상수의학회지
    • /
    • 제17권2호
    • /
    • pp.480-484
    • /
    • 2000
  • A 10 years old female Poodle weighing 4.38 kg and a 10 years old female Maltese weighing 4.33kg were referred to veterinary leaching hospital of college of veterinary medicine, Konkuk uni-versity because of hematuria and severa anorexia. Preoperative hematological and srum chemical values revealed that counts of WBC were $78.4{\times}10^3$,/TEX>/ul in the Poodle and $21.6{\times}10^3$in the Maltese, concentrations of BUN 105 and 13 mg/dl, concentrations of creatinine 4.0 and 1.4 mg/dl, concentration of ALKP 542 U/L in the Poodle and concentration of ALF 37 U/L in the Maltese, respectively. Radiographic findings were observed radiopaque bilateral nephroliths in the Poodle and right renal cal- culus in the Maltese. Ultrasonographic findings were showed hyperechoic mass with severe acoustic shadowing, which were ]ocated in the center of both kidneys parenchyma in the Poodle and in right kidney in the Maltese. Bisectional nephrotomy in right kidney for removal of calculus, which had ,sin- gle stone and more large than splitted stones in lets kidney in the Poodle, was performed under isnf- lurane anesthesia in 100% $O_2$. The time from temporary occlusion of blood flow to suture of incisioned kidney after removal of renal calculi was elapsed 12 minutes. During operation and until 24hrs after operation was infusioned mannitol and tranexanic acid solution. There were normal urination with yellow color in the Poodle at 3 days after operation and in the Maltese at 1 day and good appetite after 7 days and 1 day after operation. At 7 days and 9 days after operation, hematolgoical and seam chemical values repealed that counts of WBC were $29.8{\times}10^3/u1 in the Poodle and 13.1 {\itmes}10^3$/ul in the Mal- tese, concentrations of BUN 13 and 10 mg/dl. concentrations of creatinine 1.3 and 1.1 mg/dl, con-centrations of ALT 34 and 97U/L, concentraion of AST 10 U/L in the Poodle, respectively, By ultra-sonographic view there was not observed hyperechoic mass and radippaque calculus in operated kid-ney in radiographic view.

  • PDF

철환원 박테리아에 의한 금속 환원 및 광물형성 (Metal Reduction and Mineral formation by fe(III)-Reducing Bacteria Isolated from Extreme Environments)

  • Yul Roh;Hi-Soo Moon;Yungoo Song
    • 한국광물학회지
    • /
    • 제15권3호
    • /
    • pp.231-240
    • /
    • 2002
  • 미생물에 의한 금속이온의 환원은 탄소와 금속의 생지화학적 순환에 영향을 줄 뿐만 아니라 또한 금속, 방사성원소, 그리고 유기물로 오염된 지하수와 토양의 정화에 있어서 중요한 역할 가능성을 시사하고 있다. 지구의 극한 환경(예: 심해저 퇴적, 알칼리성 호수 등)에서 서식하는 철환원 박테리아를 분리하여 금속이온의 환원과 광물 형성 등의 실험에 이용하여 본 결과에 의하면, 이들 철환원 박테리아는 Fe(III), Mn(IV), Cr(VI), Co(III), and U(VI)이온 등을 환원시킬 뿐만 아니라, 자철석($Fe_3$$O_4$), 능철석($FeCO_3$), 방해석($CaCO_3$), 능망간석($MnCO_3$), 비비아나이트 [$Fe_3$($PO_4$)$_2$ .$8H_2$O], 우라니나이트(UO) 등의 광물을 형성한다. 철 환원 박테리아에 의한 광물 형성과 금속이온의 환원에 영향을 미치는 주요소는 대기의 조성, 화학 조성, 및 박테리아의 종이다. 호열성 철환원 박테리아는 철수화물과 금속이온(Co, Cr, Ni) 등을 동시에 환원시켜 금속 치환된 자철석을 합성하며, 또한 석탄회 등을 이용하여 탄산염 광물을 형성하여 대기 중의 이산화탄소를 고정하는 역할을 하기도 한다. 따라서 미생물에 의한 금속이온이 환원은 자연계에서 철과 탄소의 지화학적인 순환에 영향 미치며, 또한 미생물에 의한 자철석의 합성은 산업적으로 많은 이용가치가 있을 것으로 본다.

Effect of Defined KSOM Medium on the Development of 1-antitrypsin Transgenic Nuclear Transfer Bovine Embryos

  • M.M.U. Bhuiyan;J.K. Cho;G. Jang;Park, E.S.;S.K. Kang;Lee, B.C.;W.S. Hwang
    • 한국수정란이식학회:학술대회논문집
    • /
    • 한국수정란이식학회 2002년도 국제심포지엄
    • /
    • pp.74-74
    • /
    • 2002
  • Production of u 1-antitrypsin ($\alpha$AT) in transgenic cows has a great value in the field of medicine. The present study was conducted to determine the effect of chemically defined KSOM media on in vitro development of bovine transgenic nuclear transfer (NT) embryos. An expression plasmid for human $\alpha$AT was constructed by inserting a bovine beta-casein promoter, a green fluorescent protein (GFP) marker gene, and a human $\alpha$AT target gene into a pcDNA3 plasmid. Cumulus cells as donor nuclei in NT were collected from a Holstein cow and transfected by lipid-mediated method using FuGene6 (Roche Molecular Biochemicals, USA) as reagent. GFP expressed cumulus cells were introduced into recipient oocytes under DIC microscopy equipped with FITC filter set. After electrical fusion and chemical activation, reconstructed embryos were cultured in 1) SOF + 0.8% BSA, 2) KSOM + 0.8% BSA, 3) KSOM + 10% FBS and 4) KSOM +0.01% PVA for 192 h at 39$^{\circ}C$ with 5% $CO_2$, 5% $O_2$ and 90% $N_2$in humidified condition. The development of the embryos was recorded and the GFP expression in blastocyst was determined under FITC filter. The average fusion rate was 73.8% (251/340; n=8). The development rates to 2-4 cells, morula, blastocysts and expression rates in blastocysts varied from 70.3 to 76.5%, 30.2 to 33.8%, 25.4 to 33.8% and 11.8 to 15.6%, respectively. The difference in development and expression rates of embryos among 4 culture groups was not significant (P>0.05). This study indicates that chemically defined KSOM medium is also able to support development of bovine transgenic NT embryos at similar rate of SOF or KSOM supplemented with BSA or serum.

  • PDF

급속응고법을 이용한 Bi 계 고온초전도체 전류도입선 제조 (Current Leads Fabrication of High $T_c$ Bi System Superconductor Using Rapid Cooling Method)

  • 박용민;한진만;류운선;류운선
    • 한국전기전자재료학회논문지
    • /
    • 제13권3호
    • /
    • pp.254-258
    • /
    • 2000
  • Current leads of high $T_{c}$ superconductor were fabricated with Bi excess B $i_{2.2}$/S $r_{1.8}$/C $a_{1}$/C $u_{2}$/ $O_{x}$ composition by rapid cooling method. The dimensions of final samples were fixed 3 mm and 8 mm diameter with 50 mm length each To control uniform density the samples were preformed by CIP(Cold Isostatic Press) process and followed by partial or full melting process after raising up to 90$0^{\circ}C$ for 30min. Plate shaped microstructure was clearly observed adjacent to the Ag tube wall and the size of plate was about 100$\mu$m. However the severe destruction of growth orientation was shown in the inner growth part. critical temperature ( $T_{c}$) was about 53~71K after directional growth while Tc was decreased about 77~80 K before directional growth. After directional growth critical current( $I_{c}$) and critical current density( $J_{c}$) in the specimen of 8 mm diameter at 50 K were about 110 A and 280 A/c $m^2$ respectively.pectively.ely.

  • PDF

핵연료분말 제조공정 여액으로부터 Uranyl-peroxide 화합물의 제조 (Uranyl Peroxide Compound Preparation from the Filtrate for Nuclear Fuel Powder Production Process)

  • 정경채;김태준;최종현;박진호;황성태
    • 공업화학
    • /
    • 제8권3호
    • /
    • pp.430-437
    • /
    • 1997
  • 핵연료 분말제조 공정에서 발생하는 여액중의 미량 우라늄과 과산화수소 용액을 반응시켜 uranyl-peroxide 화합물을 제조하였다. 여액에 $CO_3{^{2-}}$가 공존할 경우에는 용해되어 있는 $UO_2{^{2+}}$가 침전되지 않기 때문에, 여액을 $98^{\circ}C$로 가열하여 $CO_3{^{2-}}$를 우선 제거하였다. Uranyl-peroxide 화합물 제조시 최적조건으로는 암모니아 가스로 여액의 pH를 9.5로 조절한 후 과량의 과산화수소 용액을 10ml/lit.-filtrate로 첨가하여 1시간 ageing시킬 때이며, 처리후 여액중의 우라늄농도는 3ppm 이하로 나타났다. 제조된 uranyl-peroxide 화합물을 FT-IR, X-ray, TG 및 화학분석 등을 통해 분석한 결과 화합물의 조성은 $UO_4{\cdot}2NH_4F$로 나타났으며, 초기 생성된 $1{\sim}2{\mu}m$$UO_4{\cdot}2NH_4F$ 입자들은 반응온도 $60^{\circ}C$ 및 pH 9.5에서 약 $4{{\mu}m}$로 성장하였다. 최적조건에서 제조된 입자들의 고/액 분리효율은 pH의 증가 및 반응온도의 상승에 따라 증가하는 경향으로 나타났다. 한편, 제조된 입자들의 결정형태는 SEM 및 XRD에 의한 분석결과 octahedral 형태로 나타났으며, 이 분말을 공기분위기에서 $650^{\circ}C$까지 열분해한 결과 $U_3O_8$으로 판명되어 핵연료 분말제조 공정으로 재순환이 가능하였다.

  • PDF

액상씨드의 열처리조건에 따라 합성된 나노와이어의 특성변화

  • 김성현;노임준;이경일;신백균;김선민;김종현;조진우
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2010년도 제39회 하계학술대회 초록집
    • /
    • pp.275-275
    • /
    • 2010
  • 나노선의 합성을 위해 필요한 씨드는 기상증착에 경우 값비싼 공정 비용이 요구되지만 액상의 경우 저렴하고 공정이 단순하며 단시간에 공정이 용의하고 대면적이 가능하다는 장점을 가지고 있다. 우리는 zinc acetate, ethylene glycol monoethylethe(C3H8O2), Monoethanolamine을 일정한 비율로 혼합하여 ZnO 나노와이어 합성에 필요한 액상씨드를 만든 후 이것을 기판위에 증착하기 위해 수차례에 걸쳐 스핀코팅을 하였다. 스핀코팅후 퍼니스와 핫플레이트를 이용하여 Soft bake, Hard bake 공정을 통해 각각 열처리 한후 XRD 를 통한 결정성과 방향성 그리고 AFM을 통한 표면거칠기를 관찰하였고 또한 수열합성법을 통하여 제작한 씨드를 기반으로 하는 ZnO 나노와이어를 합성하여 각각의 열처리 조건에 따른 나노와이어의 특성변화를 관찰하였고 향후 나노기반 소자의 적용가능성을 확인하였다.

  • PDF

브라운관의 후면유리 폐기물을 이용한 제올라이트 합성 (Synthesis of Na-A Type of Zeolite from Funnel-Glass Waste)

  • 장영남;배인국;채수천;류경원
    • 자원환경지질
    • /
    • 제34권2호
    • /
    • pp.167-173
    • /
    • 2001
  • 브라운관 후면유리 연마 후 발생되는 고상의 유리폐기물을 재활용을 위해, A형 제올라이트의 최적합성조건을 규명하고 생성된 제올라이트의 제반 특성을 기존의 상용 제올라이트와 비교하였다. 테프론 반응용기에 고규산질 알카리용액, NaAlO$_2$그리고 브라운관 유리폐기물 등 3가지 출발물질을 혼합하고, 80~95$^{\circ}C$ 범위에서 가열하여 제올라이트 Na-A를 열수조건하에서 결정화시켰다. 고규산질 알카리 용액은 자연산 규석을 35$0^{\circ}C$, 1500 기압하에서, NaAlO$_2$는 NaOH와 Al(OH)$_3$시약을 95$^{\circ}C$에서 2~3시간 가열하여 $Na_2$O/Al$_2$O$_3$=1.4, $H_2O$/$Na_2$O=8이 되도록 각각 합성하여 출발물질로 사용하였다. 브라운관 유리 폐기물과 고규산질 알카리 용액의 혼합비율 약 1:10~1:13의 범위에서 Al-공급원으로서 1.5~2.5N의 NaAlO$_2$를 혼합하였을 때 양호한 A-형 제올라이트 결정이 생성되었다. 합성된 Na-A는 하이드록시소달라이트 등과 같은 불순물이 없는 단일상이었으며, 결정형태는 입방 십이면체 (cubo-dodecahedral)형이었고 결정의 1~2 $\mu$의 균질한 입도로 분포하였다. $Ca^{+}$ 양이온교환용량은 215~220 mequivalent/100 g이었다.

  • PDF