Wyniki wyszukiwania - BazTech

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Krystalografia wysokich ciśnień, czyli jak zobaczyć strukturę materii…głębiej

Olejniczak A., Dziubek K., Paliwoda D., Zieliński W., Podsiadło M., Katrusiak A.

Wiadomości Chemiczne

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2014

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[Z] 68, 5-6

487--505

EN

During recent decades the number of high-pressure crystallographic studies has rapidly increased. This has been possible owing to the diamond-anvil cell, a small, relatively cheap and save apparatus breaking all records of static pressure. The diamond-anvil cell is suitable for diffraction structural studies, optical and IR spectroscopy and many other types of physical measurements; it can be also applied as a microscopic chemical reaction chamber. High pressure is now often used for synthesizing super-hard materials, new polymorphs and solvates with unique properties required in high-tech applications as well as in food processing and pharmaceutical industry.

2

Wzór Scherrera : stulecie błędnych praktyk

Tomaszewski P. E.

Wiadomości Chemiczne

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2013

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[Z] 67, 9-10

929--942

EN

We present the sources of uncertainty in the evaluation of grain size in nanomaterial. The calculations are made for the same diffraction pattern using Scherrer and Williamson-Hall methods. As an example we use the CoCr2O4 nanocrystal. The comparison of results from different calculations, methods and programs is made just to show how important is the (correct) choice of a method and its internal parameters. The data from well known Scherrer formula, show that the difference in obtained results exceeds 100% up to even about 350%. This indicates that in any case the Scherrer formula could not give the correct and reliable value for crystallite size. As a consequence, the wide use of this formula is a great error providing the incorrect results.

3

Porównawcze elektrochemiczne badania korozyjne stopu magnezu AZ91D poddanego wygrzewaniu w różnych temperaturach

Rogowska R., Rogowski A.

TTS Technika Transportu Szynowego

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2012

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R. 19, nr 9

1031--1042, CD

PL

W pracy przedstawiono wyniki badań wpływu wygrzewania w piecu próżniowym w temperaturach 360°C, 380°C, 400°C, 420°C, 450°C przez okres 330 minut na odporność korozyjną stopu AZ91D. Badania odporności korozyjnej w 0,5M NaCl próbek nie wygrzewanych oraz obrobionych cieplnie przeprowadzono metodami elektrochemicznymi (badania stało- i zmiennoprądowe). Wykonano także badania dyfrakcyjne oraz morfologię powierzchni próbek. Wykazano, że wygrzewanie w piecu próżniowym powoduje zmniejszenie odporności korozyjnej stopu AZ91D.

EN

This paper presents the influence of annealing in a vacuum furnace at temperatures of 360° C, 380° C, 400° C, 420° C, 450° C for 330 minutes on corrosion resistance of AZ91D alloy. The corrosion resistance of the heat treated samples had been investigated in 0.5 M NaCl by the electrochemical methods (research fixed-and variable-current). The surface morphology and diffraction studies of the samples were performed. It was shown that heat treatment in a vacuum decreases the corrosion resistance of the samples made of AZ91D alloy.