23 research outputs found

    The Influence of a Metal Particle Size to Adsorptivity and Reactivity in Hydrogenation of Unsaturated Alcohols on Platinum Catalysts

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    The work is concerned with structure effects exerted by molecules of unsaturated alcohols in heterogeneously catalysed hydrogenation on platinum catalysts. The metod of a competetive hydrogenation was suggested as a suitable kinetic tool for a disscusion on surface complex stability and of a rate of surface in terms of structures of reacting molecules

    Pt(0) alkenové komplexy: vhodný nástroj pro studium povrchových jevů v heterogenní katalýze

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    This work deals with surface phenomena in heterogeneously catalysed hydrogenation

    Determination of thermophysical properties of high temperature alloy IN713LC by thermal analysis

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    The presented paper deals with the study of thermophysical properties of cast and complex alloyed nickel based on superalloy Inconel 713LC (IN713LC). In this work, the technique of Differential Thermal Analysis was selected for determination of the phase transformation temperatures and for the study of the effect of varying heating/cooling rate at these temperatures. The samples taken from as-received state of superalloy were analysed at heating and cooling rates of 1, 5, 10, 20 and 50 °C min−1 with the help of the experimental system Setaram SETSYS 18TM. Moreover, the transformation temperatures at zero heating/cooling rate were calculated. The recommended values for IN713LC after correcting to a zero heating rate, are 1,205 °C (T γ′,solvus), 1,250 °C (solidus) and 1,349 °C (liquidus). Influence of heating/cooling rate on shift of almost all temperatures of phase transformations was established from the DTA curves. Undercooling was observed at the cooling process. The samples before and after DTA analysis were also subjected to the phase analysis by scanning electron microscopy using the microscope JEOL JSM-6490LV equipped with an energy dispersive analyser EDAX (EDS INCA x-act). Documentation of the microstructure was made in the mode of secondary (SEI) and backscattered (BEI) electron imaging. On the basis of DTA analysis and phase analysis it may be stated that development of phase transformations of the alloy IN713LC will probably correspond to the following scheme: melting → γ phase; melting → γ + MC; melting → eutectics γ/γ′; melting → γ + minority phases (e.g. borides); and matrix γ → γ′.Web of Science110121921

    Presence of retinopathy and incident kidney and cardiovascular events in type 2 diabetes with normoalbuminuria – a post-hoc analysis of the PRIORITY randomized clinical trial

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    Aims: Baseline diabetic retinopathy (DR) and risk of development of microalbuminuria, kidney function decline, and cardiovascular events (CVEs) in type 2 diabetes. Methods: Post-hoc analysis of the PRIORITY study including 1758 persons with type 2 diabetes and normoalbuminuria followed for a median of 2.5 (IQR: 2.0–3.0) years. DR diagnosis included non-proliferative and proliferative abnormalities, macular oedema, or prior laser treatment. Cox models were fitted to investigate baseline DR presence with development of persistent microalbuminuria (urinary albumin-creatinine ratio > 30 mg/g); chronic kidney disease (CKD) G3 (eGFR <60 ml/min/1.73m2); and CVE. Models were adjusted for relevant risk factors. Results: At baseline, 304 (17.3 %) had DR. Compared to persons without DR, they were older (mean ± SD: 62.7 ± 7.7 vs 61.4 ± 8.3 years, p = 0.019), had longer diabetes duration (17.9 ± 8.4 vs. 10.6 ± 7.0 years, p < 0.001), and higher HbA1c (62 ± 13 vs. 56 ± 12 mmol/mol, p < 0.001). The adjusted hazard ratios of DR at baseline for development of microalbuminuria (n = 197), CKD (n = 166), and CVE (n = 64) were: 1.50 (95%CI: 1.07, 2.11), 0.87 (95%CI: 0.56, 1.34), and 2.61 (95%CI: 1.44, 4.72), compared to without DR. Conclusions: Presence of DR in normoalbuminuric type 2 diabetes was associated with an increased risk of developing microalbuminuria and CVE, but not with kidney function decline
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