20 research outputs found

    Surface properties of the clean and Au/Pd covered Fe3_3O4_4(111): a DFT and DFT+UU study

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    The spin-density functional theory (DFT) and DFT+UU with Hubbard UU term accounting for on-site Coulomb interactions were applied to investigate structure, stability, and electronic properties of different terminations of the Fe3_3O4_4(111) surface. All terminations of the ferrimagnetic Fe3_3O4_4(111) surface exhibit very large (up to 90%) relaxations of the first four interlayer distances, decreasing with the oxide layer depth. Our calculations predict the iron terminated surface to be most stable in a wide range of the accessible values of the oxygen chemical potential. The adsorption of Au and Pd on two stable Fe- and O-terminated surfaces is studied. Our results show that Pd binds stronger than Au both to the Fe- and O-terminated surface. DFT+UU gives stronger bonding than DFT. The bonding of both adsorbates to the O-terminated magnetite surface is by 1.5-2.5 eV stronger than to the Fe-terminated surface

    Confirmation of paternity despite three genetic incompatibilities at chromosome 2

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    DNA testing in cases of disputed paternity is a routine analysis carried out in genetic laboratories. The purpose of the test is to demonstrate similarities and differences in analyzed genetic markers between the alleged father, mother, and a child. The existence of differences in the examined loci between the child and the presumed father may indicate the exclusion of biological parenthood. However, another reason for such differences is genetic mutations, including chromosome aberrations and genome mutations. The presented results relate to genetic analyses carried out on three persons for the purposes of disputed paternity testing. A deviation from inheritance based on Mendel’s Law was found in 7 out of 53 STR-type loci examined. All polymorphic loci that ruled out the paternity of the alleged father were located on chromosome 2. Additional analysis of 32 insertion–deletion markers (DIPplex, Qiagen) and sequencing of 94 polymorphic positions of the single nucleotide polymorphism (SNP) type (Illumina, ForenSeq) did not exclude the defendant’s biological paternity. A sequence analysis of STR alleles and their flanking regions confirmed the hypothesis that the alleles on chromosome 2 of the child may originate only from the mother. The results of the tests did not allow exclusion of the paternity of the alleged father, but are an example of uniparental maternal disomy, which is briefly described in the literature

    Budżetowanie działalności jednostek gospodarczych Teoria i praktyka. Część V

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    Z wprowadzenia: "Przekazujemy do rąk Czytelników część monografii dotyczącej budżetowania jednostek gospodarczych. Jej przygotowanie zbiegło się z ukazaniem się manifestu Precz z budżetami Jeremiego Норе’а i Robina Frasera. Autorzy poddają tam ostrej krytyce dotychczasowe praktyki stosowania budżetowania kosztowego. Stąd niniejsza publikacja - między innymi - dlatego różni się istotnie od poprzednich. Od pewnego czasu - także w Polsce - pojawiały się głosy wskazujące na istotne niedoskonałości budżetowania kosztowego, na przykład J. Gierusz [Materiały konferencyjne 2001], G. H. Świderska [Rachunkowośćzarządcza i rachunek kosztów, 2002]. Nie odnosiły one jednak skutku. Nie zauważono też dotąd narastającej listy zarzutów wytaczanych przeciw finansowym jednostkom miary stosowanym w budżetowaniu kosztowym, na przykład G. K. Świderska [jak wyżej], M. Sierpińska, B. Niedbała [Controllingoperacyjny wpnedsiębiorstwie, 2003]. Bez echa pozostało postawione przez autora pytanie: „zmierzch czy rozwój budżetowania?” [„Controlling i rachunkowość zarządcza” 9/2002], gdzie jednoznacznie wskazano, że budżetowanie kosztowe obejmuje jedynie jedną sferę działalności przedsiębiorstwa i tym samym nie może stanowić wystarczającej podstawy do sterowania przedsiębiorstwem. Zwolennicy budżetowania kosztowego nawet zgadzali się ze stawianymi zarzutami, jednak nie reagowali na propozycje zmian w filozofii i metodologii budżetowania."(...

    Binding groups for highly ordered SAM formation : carboxylic versus thiol

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    The structure of analogous SAMs chemisorbed on an Ag substrate via a –SH or –COOH binding group is reported. Our observations indicate that COOH binding groups can be considered as a promising alternative for the current standard based on the sulfur binding groups, particularly when 2D ordering, SAM fabrication time and stability under ambient conditions are of great importance

    Superconductivity in high-entropy alloy system containing Th

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    Abstract Th-containing superconducting high entropy system with the nominal composition (NbTa) 0.67_{0.67} 0.67 (MoWTh) 0.33_{0.33} 0.33 was synthesized. Its structural and physical properties were investigated by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, specific heat, resistivity and magnetic measurements. Two main phases of alloy were observed: major bcc structure and minor fcc. The experimental results were supported by numerical simulation by the DFT Korringa-Kohn-Rostoker method with the coherent potential approximation (KKR-CPA)

    Influence of Nitrided Layer on the Properties of Carbon Coatings Produced on X105CrMo17 Steel Under DC Glow-Discharge Conditions

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    In most cases, machine components, which come in contact with each other, are made of steel. Common steel types include 100Cr6 and X105CrMo17 are widely used in rolling bearings, which are subjected to high static loads. However, more and more sophisticated structural applications require increasingly better performance from steel. The most popular methods for improving the properties of steel is carburisation or nitriding. Unfortunately, when very high surface properties of steel are required, this treatment may be insufficient. Improvement of tribological properties can be achieved by increasing the hardness of the surface, reducing roughness or reducing the coefficient of friction. The formation of composite layers on steel, consisting of a hard nitride diffusion layer and an external carbon coating with a low coefficient of friction, seems to be a prospect with significant potential. The article describes composite layers produced on X105CrMo17 steel and defines their morphology, surface roughness and their functional properties such as: resistance to friction-induced wear, coefficient of friction and corrosion resistance. The layers have been formed at a temperature of 370°C in successive processes of: nitriding in low-temperature plasma followed by deposition of a carbon coating under DC glow-discharge conditions. An evaluation was also made of the impact of the nitrided layers on the properties and morphology of the carbon coatings formed by comparing them to coatings formed on non-nitrided X105CrMo17 steel substrates. A study of the surface topography, adhesion, resistance to friction-induced wear and corrosion shows the significant importance of the substrate type the carbon coatings are formed on
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