Scientific blog
PhD report September 2013 (A.Mzyk) 
Sunday, 13 October, 2013, 08:24
Posted by Aldona Mzyk
This month the zeta potential analysis of HA/Chi multilayer coatings on glass slides with 14 mm x 10 mm size was performed. The pH dependence of zeta potential and the isoelectric point derived there from do not enable a differentiation of the PEM with different terminal layers. Neither does an effect of cross-linking become visible by the zeta potential results. We conclude that an intermixing between adjacent HA and Chi layers at a higher number of polysaccharide bilayers makes the outermost surface indistinguishable in terms of surface functional groups. Such behavior is already reported in the literature for weak polyelectrolytes such as hyaluronic acid or chitosan.
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September report (K. Glowinski) 
Friday, 11 October, 2013, 13:49
Posted by Krzysztof Glowinski
In September I was trying to finish an article
on various methods for identification of symmetric
and quasi-symmetric boundaries.
These studies will complete the previous work
on characterization of tilt and twist boundaries.
Since symmetric boundaries are also used as
reference boundaries in quantitative studies of
boundary networks, efficient
tools are also needed for this class of grain boundaries.
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September report 
Friday, 11 October, 2013, 07:47
Posted by Zbigniew Starowicz
In the end of the last month I was on the internship within the Erasmus programe. The internship was conducted in TUBITAK MAM in Gebze in Turkey.Main topic of this period was organic solar cells : the cell formation technology and addition of matal nanoparticles to the hole transporting layer from PEDOT:PSS. For first we tried 70nm particles solution from ICSC PAS but the results were worse for sample with particles than for reference cell. U to 20% of efficiency enhancement was obtained for gold nanoparticles. But the efficiency increase was caused by the Voc increase rather than photocurrent, which was decreased. Thus we explain this results as a series resistance drop due t the nanoparticles presence
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Conference report (SIM 2013) J.Poplewska  
Tuesday, 8 October, 2013, 11:11
Posted by Jagoda Poplewska
I participated in 'The 41th School of Materials Science and Engineering' in 24-27.09.2013 in Krynica (Poland). The conference was organized by AGH University of Science and Technology. The scope of the conference covered fields of materials science such as: iron-based alloys, non-ferrous alloys, surface engineering, welding engineering, oxidation and corrosion, ceramics, composites and polymers, plastic deformation, functional materials. In this conference around 130 participant were attended.

My participation in the 41th school was related to the presentation of research results of AA1050 aluminium alloy and delivered in a 10 minutes presentation titled: ‘ Microstructure and texture evolution during annealing of AA1050 aluminium alloy pre-deformed in ECAP ’.
One of the goal of this conference was integration PhD students involved in the field of ‘Materials Science’.

In the conference papers was published my article (in polish):
- J. Poplewska, H. Paul, A. Tarasek, K. Berent: Zmiany mikrostruktury i tekstury podczas wyzarzania stopu AA1050 wstepnie odksztalconego w procesie ECAP. Materialy Konferencyjne XLI Szkoly Inzynierii Materialowej, Krakow-Krynica 2013, s. 444÷449.

Below the abstract of this article:

MICROSTRUCTURE AND TEXTURE EVOLUTION DURING ANNEALING
OF AA1050 ALUMINIUM ALLOY PRE-DEFORMED IN ECAP

Abstract The main aim of the experiment was to analyze the microstructure and texture evolution during recrystallization of commercial AA1050 aluminum alloy. The samples were processed by ECAP in six passes along route A and then annealed for 1 hour at temperatures ranging from 100°C to 350°C. Studies carried out using scanning electron microscopy equipped with local orientation system and X-ray diffractometer. The obtained results showed that at lower annealing temperatures, the material retains ultra-fine grain structure formed by ECAP. At higher temperatures rapid grain growth appears and transformation of flattened grains into nearly equiaxed was observed. The results showed that obtaining the fine-grained and homogeneous structure of equiaxed grains, is problematic.

Keywords: AA1050 Aluminium alloy; ECAP; Recrystallization; Grain growth; EBSD
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September 
Tuesday, 8 October, 2013, 09:39
Posted by Piotr Drzymala
With regard to process the data from the various improvements made &#8203;&#8203;EBSD . First cut off background for calculating pole figures , which was not as significant to the quality of these figures , but significantly accelerated the calculation. Cut-off backgrounds , however, it is always advisable because it can contribute to the formation of certain artifacts in the calculation of intergranular relationships . An example might be if only the angle of disorientation , but more on that in later reports . Secondly entered the correct scaling pole figures - now scaled is not every pole figure separately, but all have a common scale , which determines the maximum of the most intense pole figure . This allows for an unambiguous assessment of the texture on the basis of a statement such as the three pole figures - in the case study of alloy AZ31 is the dominant component (0001 ) < 11-20 > . Thirdly, efforts were made to improve the calculation of pole figures at the expense of a reduction in accuracy. For this purpose, a histogram of all orientations dividing the space orientation of the cube and assigning each cube orientation in the middle of such a cube and a strength associated with the number of counts orientation that went to the ankles. This whole operation takes place quite rapidly , and the restoration of the pole figure as sorted data . Qualitatively goes under , but not enough for symmetrical structures - eg ortorombowych - is a problem with playing these figures. As we know the structure of orthorhombic symmetry operators have four , but they do not work well in comparison with eg Labotexem . Diffraction measurement introduces an additional symmetry associated with the indiscernibility planes hkl and - hkl . It was found that the multiplication of the symmetry operators results in the correct symmetry of the pole figures . Perhaps this is the solution to this problem .
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