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Synthesis and Properties of Uranium Compounds (I). Salts of Bis(undecatungstophosphato)uranate(Ⅳ) Anion, $[U(PW_{11}O_{39})_2]^{10-}$ (우라늄 화합물의 합성과 성질에 관한 연구 (제1보). 비스(운데카텅스토포스파토)우라늄(IV) 산 이온, $[U(PW_{11}O_{39})_2]^{10-}$의 염)

  • Chul Wee Lee;Hyunsoo So
    • Journal of the Korean Chemical Society
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    • v.26 no.3
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    • pp.160-164
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    • 1982
  • A guanidinium salt of $[U(PW_{11}O_{39})_2]^{10-}$, the solubility of which is adequate for crystal growing, has been synthesized. Using this salt or potassium salt, we have measured the stability of $[U(PW_{11}O_{39})_2]^{10-}$as a function of pH of the solution and found that the anion is stable for the pH range 3~7. We have developed a colorimetric method for determining the concentration of $U^{4+}$. In this method$PW_{11}O_{39}^{7-}$ is added to$U^{4+}$ in such a quantity that the mole ratio $PW_{11}O_{39}^{7-}/ U^{4+}$exceeds 2 and the intensity of the 22.7kK band (${\varepsilon}$1030 M-1cm-1) is measured. In order to develop a continuous method to recover uranium, we have determined the amount of recoverd$PW_{11}O_{39}^{7-}$ after decomposing $[U(PW_{11}O_{39})_2]^{10}$- by adding either a base or an oxidizing agent. The percentage of $PW_{11}O_{39}^{7-}$recovered was approximately 70% when a base was used and approximately 80% when$K_2S_2O_8$ was used. A colorimetric method for determining $PW_{11}O_{39}^{7-}$ has also been developed.

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Cellulolytic Enzymes from Acrophialophora nainiana

  • Punnapayak, Hunsa
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 2005.06a
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    • pp.245-247
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    • 2005
  • A cellulolytic fungus isolated from Agave plantation in northeastern Thailand was identified as Acrophialophora nainiana. The fungus was capable of growing at pH between 3 - 7 and 25 - 45 $^{\circ}C$, with the optimum conditions at pH 5.0 and 40 $^{\circ}C$. The wild isolate produced cellulases, comprising of exoglucanase (0.019 U/mg protein), endoglucanase (0.366 U/mg protein), and ${\beta}$-glucosidase (0.001 U/mg protein). Mutations with UV and NTG produced the UV 10-2 mutant with cellulases activities including exoglucanase (0.093 U/mg protein), endoglucanase (0.585 U/mg protein), and ${\beta}$-glucosidase (0.013 U/mg protein). Purification of the enzymes with ultrafiltration, ammonium sulfate precipitation, and ion-exchange chromatography yielded the maximal cellulase specific activities of 2.736 U/mg protein (exoglucanase), 0.235 U/mg protein (endoglucanase), and 0.008 U/mg protein (${\beta}$-glucosidase). The mutant's cellulases were the most active at pH 5.0 and 60 $^{\circ}C$. Ion-exchange chromatography revealed that A. nainiana UV 10-2 cellulases were comprised of two peaks with one peak showing the single endoglucanase activity while the other peak showed a mixture of the three enzyme activities. Production of A. nainiana UV 10-2 cellulases using banana leaf stalk as the sole carbon source gave comparable yields to that of the pure ${\alpha}$-cellulose. The enzymes were used in the simultaneous saccharification and fermentation (SSF) of plant residue (Coix aquatica) along with Kluveromyces marxianus to produce ethanol. Moreover, when the enzymes were used in the bioscouring process of fabric, the desiravle traits of textile processing including immediate water absorbency, increased in whiteness and reduction of yellowness of the treated fabric were observed.

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Characteristics of Technical Pork Quality Profiles Identified by NPPC Scale (NPPC 기준에 의한 돈육의 품질특성 연구)

  • Kim, D.H.;Park, B.Y.;Kim, I.S.;Lee, M.;Kim, Y.K.;Lee, J.M.
    • Journal of Animal Science and Technology
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    • v.45 no.5
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    • pp.835-840
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    • 2003
  • Two hundreds and twenty three pork carcasses of commercial breeds were studied for comparing to technical quality characteristics of pork identified by National Pork Producers Council(NPPC) scale. pH and conductance(C) were taken in 1(pH$_1$, C$_1$), 3(pH$_3$, C$_3$), 6(pH$_6$, C$_6$) and 24hr(pHu, Cu) postmortem on 4~5th thoracic vertebrae. Visual color and CIE value were estimated in longissimus dorsi(LD) muscle in 24hr postmortem on the two sites(4~5th thoracic vertebrae and last vertebrae) using National Pork Producers Council(NPPC) scale and color difference meter. Significant differences were observed in pH$_1$, pHu, Cu, CIE L$^{*}$ value, water holding capacity(WHC) and juiciness at all scales(p〈0.05). But, pH and CIE L$^{*}$value were considerably affected by postmortem time and measuring site. NPPC scale was highly related with CIE L$^{*}$(R$^2$=0.77) and WHC(R$^2$=0.66), and moderately related with C$_{u}$(R$^2$=0.59) and pH$_{u}$(R$^2$=0.54), and poorly related with pH$_3$(R$^2$=0.32), pH$_6$(R$^2$=0.28) and C$_1$~C$_6$(R$^2$=0.03~0.18).

MULTIPLE EXISTENCE OF SOLUTIONS FOR A NONHOMOGENEOUS ELLPITIC PROBLEMS ON RN

  • Hirano, Norimichi;Kim, Wan Se
    • East Asian mathematical journal
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    • v.34 no.5
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    • pp.703-713
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    • 2018
  • Let $N{\geq}3$, $2^*=2N/(N-2)$ and $p{\in}(2,2^*)$. Our purpose in this paper is to consider multiple existence of solutions of problem $$-{\Delta}u-{\frac{\mu}{{\mid}x{\mid}^2}}+{\alpha}u={\mid}u{\mid}^{p-2}u+{\lambda}f\;u{\in}H^1({\mathbb{R}}^n)$$, where a, ${\lambda}$ > 0, ${\mu}{\in}(0,(N-2)^2/4)f{\in}H^{-1}({\mathbb{R}}^N)$, $f{\geq}0$ and $f{\neq}0$.

Properties of Urea-Formaldehyde Resin Adhesives with Different Formaldehyde to Urea Mole Ratios

  • Park, Byung-Dae
    • Journal of the Korean Wood Science and Technology
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    • v.35 no.5
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    • pp.67-75
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    • 2007
  • As a part of abating the formaldehyde emission of urea-formaldehyde (UF) resin adhesive by lowering formaldehyde to urea (F/U) mole ratio, this study was conducted to investigate properties of UF resin adhesive with different F/U mole ratios. UF resin adhesives were synthesized at different F/U mole ratios of 1.6, 1.4, 1.2, and 1.0. Properties of UF resin adhesives measured were non-volatile solids content, pH level, viscosity, water tolerance, specific gravity, gel time and free formaldehyde content. In addition, a linear relationship between non-volatile solids content and sucrose concentration measured by a refractometer was established for a faster determination of the non-volatile solids content of UF resin. As F/U mole ratio was lowered, non-volatile solids content, pH, specific gravity, water tolerance, and gel time increased while free formaldehyde content and viscosity were decreased. These results suggested that the amount of free formaldehyde strongly affected the reactivity of UF resin. Lowering F/U mole ratio of UF resin as a way of abating formaldehyde emission consequently requires improving its reactivity.

SOME RESULTS OF p-BIHARMONIC MAPS INTO A NON-POSITIVELY CURVED MANIFOLD

  • HAN, YINGBO;ZHANG, WEI
    • Journal of the Korean Mathematical Society
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    • v.52 no.5
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    • pp.1097-1108
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    • 2015
  • In this paper, we investigate p-biharmonic maps u : (M, g) $\rightarrow$ (N, h) from a Riemannian manifold into a Riemannian manifold with non-positive sectional curvature. We obtain that if ${\int}_M|{\tau}(u)|^{{\alpha}+p}dv_g$ < ${\infty}$ and ${\int}_M|d(u)|^2dv_g$ < ${\infty}$, then u is harmonic, where ${\alpha}{\geq}0$ is a nonnegative constant and $p{\geq}2$. We also obtain that any weakly convex p-biharmonic hypersurfaces in space formN(c) with $c{\leq}0$ is minimal. These results give affirmative partial answer to Conjecture 2 (generalized Chen's conjecture for p-biharmonic submanifolds).

M2M Standard Model and Advanced Machine Concept for u-Manufacturing (u-Manufacturing을 위한 M2M 표준화 및 진보된 Machine Concept)

  • Kim D.H.;Song J.Y.;Cha S.K.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.345-346
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    • 2006
  • In the future, a machine will be more improved in the form of advanced concept with collaborative ability in M2M(Machine to Machine, Mobile to Machine) environment for u-Manufacturing system. This paper tried to standardize M2M and design advanced concept machine. The M2M is front-end system for implementing autonomous ubiquitous environment. The advanced machine in M2M will be a collaborative machine with knowledge-evolutionary ability such as u-Machine(Ubiquitous machine), Vortal(Vertical Portal) machine and P2P(Peer to Peer) machine. Such advanced concept machines will be the key subject for M2M cooperation.

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The Secondary Succession and Species Diversity at the Burned Area of the Pine Forest (소나무 수림의 산화적지의 이차천이와 종다양성)

  • Kim, Weon
    • The Korean Journal of Ecology
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    • v.12 no.4
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    • pp.285-295
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    • 1989
  • This report is results of an investigation on the secondary succession and species diversity of the burned area. Fifty hectares of pine forest was burned by the crown fire of the spring (April 6) 1986. The results obtained from spring 1989 were summarized as follows: In the burned area , site and unburned area (U), the vascular plant fo 69 kinds, 49 kinds and 24 kinds were lsted respectively. The life form spectrum of burned area was H---e type, which is common type in most burned area and that unburned area, H---e type. The species diversity (H)and evenness index (e) of burned area (, site) were H=2.51, 1.65 and e=0.59, 0.44 and those of unburned area (U) were H=1.28 and e=0.40. The similarity index was the value of 0.594 in - and 0.236 in -U site. The similarity between and site was greater than between site and U site, and that between and U-site, The dominance index (c) of , and U-site was 0.16, 0.39 and 0.42 respectively. The succession degree (DS) of , and U-site was 244.0, 227.6 and 854.4 respectively. Soil pH, available phosphorous, and exchangeable potassium in the burned area were higher than those in the unburned area, and total nitrogen, organic carbon, and C/N ratio in the burned area were higher than those in the unburned area, and organic matter in the burned area was higher than that in the unburned area.

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Removal of Uranium by an Alkalization and an Acidification from the Thermal Decomposed Solid Waste of Uranium-bearing Sludge (알카리화 및 산성화에 의한 우라늄 함유 슬러지의 열분해 고체 폐기물로부터 우라늄 제거)

  • Lee, Eil-Hee;Yang, Han-Beom;Lee, Keun-Young;Kim, Kwang-Wook;Chung, Dong-Yong;Moon, Jei-Kwon
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.11 no.2
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    • pp.85-93
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    • 2013
  • This study has been carried out to elucidate the characteristics of the dissolution for Thermal Decomposed Solid Waste of uranium-bearing sludge (TDSW), the removal of impurities by an alkalization in a nitric acid dissolving solution of TDSW, and the selective removal (/recovery) of uranium by an acidification in an carbonate alkali solution, respectively. TDSW generated by thermal decomposition of U-bearing sludge which was produced in the uranium conversion plant operation, was stored in KAERI as a solid-powder type. It is found that the dissolution of TDSW is more effective in nitric acid dissolution than oxidative-dissolution with carbonate. At 1 M nitric acid solution, TDSW was undissolved about 30wt% as a solid residue, and uranium contained in TDSW was dissolved more than 99%. In order to the alkalization for the nitric acid dissolving solution of TDSW, carbonate alkalization is more effective with respect to remove the impurities. At the carbonate alkali solution controlled to about 9 of pH, Al, Ca, Fe and Zn co-dissolved with U in dissolution step was removed about $98{\pm}1%$. On the other hand, U could be recovered more than 99% by an acidification at pH about 3 in a carbonate alkali solution, which was nearly removed the impurities, adding 0.5M $H_2O_2$. It was found that uranium could be selectively recovered (/removed) from TDSW.

HAUSDORFF OPERATORS ON WEIGHTED LORENTZ SPACES

  • Sun, Qinxiu;Fan, Dashan;Li, Hongliang
    • Korean Journal of Mathematics
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    • v.26 no.1
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    • pp.103-127
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    • 2018
  • This paper is dedicated to studying some Hausdorff operators on the Heisenberg group ${\mathbb{H}}^n$. The sharp bounds on the strong-type weighted Lorentz spaces ${\Lambda}^p_u(w)$ and the weak-type weighted Lorentz spaces ${\Lambda}^{p,{\infty}}_u(w)$ are investigated. Especially, the results cover the classical power weighted space $L^{p,q}_{\alpha}$. The results are also extended to the product spaces ${\Lambda}^{p_1}_{u_1}(w_1){\times}{\Lambda}^{p_2}_{u_2}(w_2)$, especially for $L^{p_1,q_1}_{{\alpha}_1}{\times}L^{p_2,q_2}_{{\alpha}_2}$. Our proofs are quite different from those in previous documents since the duality principle, and some well-known inequalities concerning the weights are adopted. The results recover the existing results as well as we obtain new results in the new and old settings.