45 research outputs found

    N-Methylimidazole Promotes The Reaction Of Homophthalic Anhydride With Imines

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    The addition of N-methylimidazole (NMI) to the reaction of homophthalic anhydride with imines such as pyridine-3-carboxaldehyde-N-trifluoroethylimine (9) reduces the amount of elimination byproduct and improves the yield of the formal cycloadduct, tetrahydroisoquinolonic carboxylate 10. Carboxanilides of such compounds are of interest as potential antimalarial agents. A mechanism that rationalizes the role of NMI is proposed, and a gram-scale procedure for the synthesis and resolution of 10 is also described

    Lojasiewicz exponent of families of ideals, Rees mixed multiplicities and Newton filtrations

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    We give an expression for the {\L}ojasiewicz exponent of a wide class of n-tuples of ideals (I1,...,In)(I_1,..., I_n) in \O_n using the information given by a fixed Newton filtration. In order to obtain this expression we consider a reformulation of {\L}ojasiewicz exponents in terms of Rees mixed multiplicities. As a consequence, we obtain a wide class of semi-weighted homogeneous functions (Cn,0)(C,0)(\mathbb{C}^n,0)\to (\mathbb{C},0) for which the {\L}ojasiewicz of its gradient map f\nabla f attains the maximum possible value.Comment: 25 pages. Updated with minor change

    Milnor Numbers of Deformations of Semi-Quasi-Homogeneous Plane Curve Singularities

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    The aim of this paper is to show the possible Milnor numbers of deformations of semi-quasi-homogeneous isolated plane curve singularity f. Assuming that f is irreducible, one can write f=∑qα+pβ ≥ pqcαβ xαyβ where cp0c0q≠0, 2≤p<q and p, q are coprime. We show that as Milnor numbers of deformations of f one can attain all numbers from μ(f) to μ(f)−r(p−r), where q≡r(mod p). Moreover, we provide an algorithm which produces the desired deformations

    Structure of capital and the cost of debt in meat procesing industry in Poland

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    Optymalizacja struktury kapitału wciąż stanowi ważne zagadnienie w świecie finansów. Próby stworzenia kompleksowego i transparentnego modelu ekonometrycznego umożliwiającego zwiększanie wartości przedsiębiorstwa przy jednoczesnej optymalizacji kosztu kapitału oraz budowa teorii go objaśniającej trwają nieprzerwanie od połowy XX wieku. Oszacowany w niniejszym opracowaniu model ekonometryczny, objaśniający koszt kapitału obcego na skutek zmian w strukturze kapitałowej badanych przedsiębiorstw branży mięsnej, przeszedł poprawnie weryfikację statystyczną i logiczną, co pozwala na jego dalszą weryfikację na podmiotach spoza próby badawczej oraz implementację do profesjonalnej analizy finansowej.The problem of optimizing the structure of capital is still an unsolved mystery in the financial world. Attempts to create a comprehensive and transparent econometric model allows increasing the enterprise's value while optimizing the cost of capital and the construction of explanatory theory it lasts continuously since the middle of last century. An econometric model estimated in this research explaining the cost of debt due to changes in the capital structure of the surveyed companies in the meat procesing pased correctly statistical and logical verification, which allows for its further verification to entities outside of the research sample and implementation for profesional financial analysis. Built model does not ignore the addition of changes in the parameters of the market economy, which significantly increases its value

    The burden in chosen entity of motoryzation sectors

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    Application of polymer inclusion membranes doped with 1-hexyl-4-methylimidazole for pertraction of zinc(II) and other transition metal ions

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    Transport of Zn(II) from unary aqueous chloride solutions and from solutions which contain mixtures of Cd(II), Co(II) and Ni(II) ions in source phases (cMe = 0.001 mol/dm3, pH = 6.0) across polymer inclusion membranes (PIMs) doped with 1-hexyl-4-methylimidazole as ion carrier was studied. The use of 1-hexyl-4-methylimidazole enables the separation of 98.5% Zn(II) from a unary solution and 96.9% from a quaternary solution of Zn(II)-Cd(II)-Co(II)-Ni(II) after running the process for 24 hours. Using that ion carrier, the metals are transported in the following order: Zn(II) > Cd(II) > Ni(II) > Co(II), and the selectivity coefficients of Zn(II)/Cd(II), Zn(II)/Ni(II), and Zn(II)/Co(II) are 12.9, 23.4 and 40.8, respectively. Findings of atomic force microscopy (AFM) examinations as well as thermograms of a polymer inclusion membrane containing 1-hexyl-4-methylimidazole are also presented. A membrane with 1.0 mol/dm3 of carrier has a porosity of 15.8%, and roughness of 6.6 nm. The membranes remain thermally stable at temperatures up to 200oC. The findings were compared with earlier-reported results for 1-hexylimidazole

    The use of 1-alkylimidzoles for selective separation of zinc ions in the transport process across a polymeric inclusion membrane

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    The transport of Zn(II) ions from different aqueous nitrate(V) source feeding phases (cMe = 0.001 mol/dm3, pH 6.0) across polymer inclusion membranes (PIMs) doped with 1-alkylimidazole as an ion carrier was reported. Alkyl substituents in position 1 of imidazole ring have an effect on hydrophobic properties of the carriers and the initial flux of the transported metal ions. The membranes were characterized by an atomic force microscopy (AFM). The results show that the Zn(II) ions could effectively be separated from other transition metal cations such as Co(II) and Ni(II) from different equimolar ion mixtures. Also, the thermal stability of PIM doped with 1-decylimidazole was studied in replicate experiments. The highest separation coefficients for the Zn(II)/Co(II) and Zn(II)/Ni(II) systems, equal to 9.4 and 11.9 were recorded for the equimolar Zn(II)-Co(II)-Ni(II) mixture for 1-hexylimidazole as a carrier, while using 1-decylimidazole resulted in the highest values of initial flux of the Zn(II) ions transport across the polymeric membrane

    The use of the steric effect of the carrier molecule in the polymer inclusion membranes for the separation of cobalt(II), nickel(II), copper(II), and zinc(II) ions

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    In this study, palladium-modified nickel foam substrate was applied to examine ethanol oxidation reaction (EOR) in 0.1 The transport of cobalt(II), nickel(II), copper(II), and zinc(II) ions from chloride solutions across polymer inclusion membranes (PIMs), which 1-heptylimidazole (1̲) or 1-heptyl-2-methylimidazole (2̲) or 1-heptyl-4-methylimidazole (3̲) as the ion carrier was reported. The steric effect for carriers 2̲&enspand 3̲&enspdecreases the transport of all ions except Cu(II). The initial fluxes of metal ions transport across PIMs with the 1̲- 2̲&enspdecrease in the sequence: Cu(II) > Zn(II) > Co(II) > Ni(II), whereas for 3 they were Cu(II) > Zn(II) > Ni(II) > Co(II). The highest recovery values were obtained for Cu(II), this being 99 and 85% for carrier 1̲&enspand 2̲, respectively. In both membranes the degree of deposition of the Zn(II) ions was comparable. Zn(II), Co(II) and Cd(II) ions, which form complexes with coordination numbers 4 and 6, are more easily recovered with the use of carriers 2̲&enspand 3̲. Ni(II) ions, which form complexes with coordination number 6 only, practically remain in the feeding phase. PIMs with alkylimidazoles were characterized by non-contact atomic force microscopy

    Probabilistic approach to attributes coding in the rough sets theory

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    Questionnaire analysis by decision algorithm generation

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