58 research outputs found

    Atomic and electronic structure of graphene oxide/Cu interface

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    The results of X-ray photoemission (XPS) and valence bands spectroscopy, optically stimulated electron emission (OSEE) measurements and density functional theory based modeling of graphene oxide (GO) placed on Cu via an electrophoretic deposition (EPD) are reported. The comparison of XPS spectra of EPD prepared GO/Cu composites with those of as prepared GO, strongly reduced GO, pure and oxidized copper demonstrate the partial (until C/O ratio about two) removal of oxygen-containing functional groups from GO simultaneously with the formation of copper oxide-like layers over the metallic substrate. OSEE measurements evidence the presence of copper oxide phase in the systems simultaneously with the absence of contributions from GO with corresponding energy gap. All measurements demonstrate the similarity of the results for different thickness of GO cover of the copper surface. Theoretical modeling demonstrates favorability of migration of oxygen-containing functional groups from GO to the copper substrate only for the case of C/O ratio below two and formation of Cu-O-C bonds between substrate and GO simultaneously with the vanishing of the energy gap in GO layer. Basing on results of experimental measurements and theoretical calculations we suggest the model of atomic structure for Cu/GO interface as Cu/CuO/GO with C/O ratio in gapless GO about two.Comment: 22 pages, 14 figures, accepted to Thin Solid Films journa

    LAGUNA in Polkowice-Sieroszowice mine in Poland

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    The Polkowice–Sieroszowice mine in one of the seven candidates for the future pan-European underground laboratory studied in the framework of the LAGUNA project. We review the evidence that from the point of view of geology, long-term plans for the mine and existing infrastructure, and support of the authorities this is a perfect place to host the 100 kton liquid argon detector GLACIER

    Ranolazyna - nowy lek w nawracających opornych na leczenie arytmiach komorowych?

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    Introduction. The pharmacological treatment of ventricular arrhythmias (VA) has significant limitations. Ranolazine is a relatively new drug with documented antianginal and anti-ischaemic mechanisms and where preclinical data provides evidence of additional antiarrhythmic properties. The aim of this article was to evaluate the safety and efficacy of ranolazine in patients with recurrent antiarrhythmic therapy-refractory VA. Material and methods. This prospective evaluation included 30 patients (pts) (male/female: 26/4; mean age: 65 ± 10 years; coronary artery disease/dilated cardiomyopathy: 20/10; New York Heart Association class I/II/III/IV: 2/14/12/2, left ventricular ejection fraction: 27 ± 10%; implantable cardioverter-defibrillator (ICD): 15 pts, implantable cardioverter-defibrillator with cardiac resynchronisation therapy (CRT-D): 14 pts with recurrent significant VA [ventricular fibrillation, sustained ventricular tachycardia (VT) and/or non-sustained VT, multiple ventricular premature complexes > 1,000//day, biventricular stimulation (BiV) < 95%] and where standard treatment options, i.e. pharmacotherapy, coronary revascularisation, and percutaneous ablation, had proved ineffective. The severity of the arrhythmia was assessed by 24-hour electrocardiographic (ECG) Holter monitoring and in ICD/CRT-D memory recording. The patients received, in addition to the standard pharmacotherapy amiodarone: 18 pts, beta-blocker: 26 pts) ranolazine 375 mg twice daily for three months. Baseline data was compared to the data obtained after the three months of ranolazine treatment

    On the electropolishing and anodic oxidation of Ti-15Mo alloy

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    This paper presents research on modifying the surface of Ti-15Mo alloy using electropolishing and anodic passivation. The electropolishing process was carried out in solutions containing sulfuric acid, ethylene glycol, ammonium fluoride and oxalic acid. Whereas a voltage range from 20 to 100 V and a 1 M orthophosphoric acid solution were used during the anodic passivation. The influence of above mentioned processes parameters on the quality of the obtained oxide layer on Ti-15Mo alloy was investigated. The analysis of Ti-15Mo surface after modification was performed using scanning electron microscopy (SEM), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), ellipsometry, and mechanical tests. Moreover, the corrosion resistance was investigated using a potentiostatic method in Ringer's solution. It was found that electropolishing leads to an increase in the surface homogeneity and to the form of an oxide layer, which consisted of TiO2 and MoO3. Whereas the oxide layers obtained during anodic passivation were characterized by different properties depending on the applied voltage. The anodic passivation at various voltages (20-100 V) increased the surface wettability (94.5°-87.6°) in comparison to the electropolished sample (97.5°). Moreover, the obtained oxide layer after anodization exhibited a high hardness. The electrolytic polishing and anodic passivation of Ti-15Mo also improved corrosion resistance of the alloy in contact with Ringer's solution. The sample anodized at 80 V presented the highest corrosion resistance by the smallest corrosion current density (1.4 nA cm-2) and the highest polarization resistance (37.4 MΩ cm2). © 2016 Elsevier Ltd. All rights reserved

    On Discretenes and Continuity in Structural Dialectology

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    Development of the Methods for Testing Mechanical Properties of the Rolling Stock During the 60 Years of History of the Railway Institute

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    W artykule przedstawiono rozwój techniki kolejowej, a w następstwie rozwój możliwości badawczych Laboratorium Badań Taboru Instytutu Kolejnictwa w zakresie własności mechanicznych pojazdów szynowych. Omówiono badania własności wytrzymałościowych gwarantujących bezpieczeństwo bierne obsługi i pasażerów, techniki hamulcowej i dynamicznego oddziaływania pojazdów z torem kolejowym. Zaprezentowano rys historyczny prowadzenia badań oraz stan aktualny. Opisano bazę stanowiskowo-pomiarową wykorzystywaną w czasie badań oraz ich potencjalny zakres.The paper presents the development of railway engineering followed by the development of research capabilities of the Railway Institute's Rolling Stock Testing Laboratory in the field of testing mechanical properties of rail vehicles. Tests of mechanical properties necessary to guarantee passive safety of the staff and the passengers, brake technology and dynamic interaction between vehicle and track are discussed. Historical outline of test procedures as well as current situation are presented. Testing and measuring equipment used for the testing, together with their potential range, are described
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