Scientific blog
PhD report G. Kulesza (July'13) 
Wednesday, 14 August, 2013, 15:01
Posted by Grazyna Kulesza
The failure of the previous month did not discourage me too much. Reagents cooling in the fridge was failed so I put them into a freezer. All reagents, except water, have a melting point of about -30 degrees C. The result - great! The mixture had cooled to a temperature slightly below zero. Texturization took place in the same reaction mixture during slowly heating in temps: 0, 5, 10, 15, 20, 25. The best result I reached for the wafer etched in solution HF:HNO3:H2O = 8:1:1 in 5 C. Surface was smooth, uniform and black.
In the case of nanoporous layer etching I found that I used too strong solution, 3M KOH instead of a 1M. The experiment should be repeated.
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July 
Wednesday, 14 August, 2013, 14:19
Posted by Piotr Drzymala
Tthe data of EBSD maps of pipe AZ31 magnesium alloy was processed. The purpose of the data analysis was to find evidence to secondary slip systems other special type of locally rebuild lattice inside of grains, called twinning. It was also shown by the way, that used in our laboratory formula of calculation orientation from the (hkl) <uvw> form only works for the cubic network, and therefore the application was written which calculates the matrix in the correct manner for any orientation of the (hkl) <uvw > in the hexagonal system.
To describe any disorientation, one inputs for the two orientations, given eg. by Euler angles, rotation matrices to calculate the passive g1, g2. Then you come up with a lattice symmetry operators. In a hexagonal network of 12, which means that for any orientation, there are 11 consecutive orientation which are set in the configuration of elementary cell indistinguishable in terms of physical properties and also for the human eye. We use left side symmetry operators, call it O. Thus each orientation symmetric matrix is expressed as the overall to get all the combinations of two possible orientations in the hexagonal lattice: O.g1.(O.g2^-1) which is equivalent to O.g1.g2^T.O. Of course we have to add the case: O.g2.g1^T.O to get all 12*2*12 possible combinations. But that's not all, you now need to simplify further considerations, bringing combinations to the area of a given base. This is not a trivial task, as long as we do not know the Rodriguez parametrization and shapeof the fundamental zone of the crystal lattice. In the case of a hexagonal network fundamental zone looks like a piece of cake.

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Problemy z logowaniem 
Wednesday, 14 August, 2013, 13:26
Posted by Administrator
Prosze i maile z informacjami kiedy blog nie dzialal. Prosze podac date godzine oraz usera.
Admin
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PhD report (July 2013) A.Mzyk 
Tuesday, 13 August, 2013, 02:45
Posted by Aldona Mzyk
I spent summer time on developing two parallel paths of my research. I’ve continued studies concerning characteristics of multilayer polyelectrolyte films treated with various concentration of a genipin cross-linking agent. Moreover, I’ve also been working on thermal stability issues. Why? The answer is simple. The surface functionalization of materials intended for contact with blood by polyelectrolyte coatings will be successful, only if we have got the appropriate methodology for their manufacture on a large scale. Furthermore, polyelectrolyte coatings should have a tolerance to allow cryogenic storage and subsequent long-term application at physiological temperature, without any undesirable changes in the structure. Determination of the effect of temperature on the physico-chemical properties of coatings and potential to colonization by endothelial cells should be always a first step in studies on polymer for cardiovascular implant surface modification. Therefore, the aim of this study was to investigate changes in structure and properties of 12 bilayer porous coatings made of poly-L-lysine (PLL) and hyaluronic acid (HA) and subjected to temperature ranging from -50°C to +50°C. Herein, I determined how the post treatment chemical cross-linking of the coating may improve its thermal stability.
This month I carried out comparative analyzes of adhesive properties of silicon discs coated with thin inorganic films (DLC, TiOx, TiCN) in radial flow chamber, using concentrates of human blood erythrocytes.

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Silver nanoislands  
Thursday, 8 August, 2013, 21:35
Posted by Zbigniew Starowicz
I would like to look closer the influence of film thickness and annealing temperature on the obtained microstructure (particles geometry) and optical properties.

For that purpose I prepared poliched silicon wafers and microscope base glass. Those substrates were cut and cleaned with isopropanol and acetone. Next silicon wafers were passivated. Passivation is process of thermal surface oxidation realized in 850 Celsius degrees in oxygen atmosphere. After 15 minutes about 20nm thick layer of silicon dioxide occur at the surface and act as seperation layer between metal nanoparticles and semiconductor surface.

Subsequently on those substrate silver film of thickness 11,14,17 and 20 nm was sputtered. Samples with each thickness was annealed at the 200, 300 and 400 Celsius degrees for 1 hour.

For internal stress determinstion I try to apply XRD methods.

Obtained samples will be examined with SEM and AFM for microstructure description. Optical properties investigation will include diffused and specular reflectance and transmission measurements
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