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The experimental study of glass multilayer columns using digital image correlation

Demchyna B., Surmai M., Tkach R.

Archives of Materials Science and Engineering

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2019

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Vol. 96, nr 1

32--41

EN

Purpose: The purpose of the research is to study the deformability of glass multilayer columns at the central compression using digital image correlation. It becomes possible to use the method of digital image correlation for the experimental study of load bearing building structures of glass. Design/methodology/approach: The approach which has been used to solve the above problems is to conduct an experimental study of glass columns on central compression, in which deformations were measured using digital image correlation. Findings: The possibility of using load bearing building structures of glass triplex has been discovered. A program of experimental studies was developed. It included the testing of prototype samples on central compression with rigid fastening. On the basis of the obtained results, a graph of dependence of relative deformations on normal tension, graphs of the dependence of the bending of columns on load in different planes, and a modulus of elasticity of triplex glass have been determined. Research limitations/implications: The lack of a calculation methodology and regulatory documents for designing load bearing building structures of triplex glass increases their cost, since each project is individual and requires the experimental research. Practical implications: Using the approaches developed in the paper, the method of digital image correlation, which is to measure deformations when testing glass structures on central compression can be applied. Originality/value: The experimental study is probably the first one in which deformations of glass columns are determined using the method of digital image correlation, so it is new and original. The lack of a calculation methodology and regulatory documents for designing load bearing building structures of triplex glass, increases their cost, since each project is individual and requires the experimental research.

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Carbides Analysis of the High Strength and Low Density Fe-Mn-Al-Si Steel

Sozańska-Jędrasik L., Mazurkiewicz J., Borek W., Matus K.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 1

265--276

EN

The work presents the results of investigations into the structure and phase composition of newly developed high manganese steels of the X98MnAlSiNbTi24-11 and X105MnAlSi24-11 type. The average density of such steels is 6.67 g/cm3, which is 15% lower as compared to typical structural steels. An analysis of phase composition and structure allows to conclude that the investigated steels feature an austenitic γ-Fe(Mn,Al,C) structure with uniformly distributed and elongated α-Fe(Mn,Al) ferrite grains on the boundaries of austenite grains and carbides. Examinations by diffraction of back scattered electrons (EBSD) allow to conclude that high-angle boundaries dominate in such steels, having significant influence on mechanical properties. Three types of carbides with differentiated chemical composition and size were identified in steel X98MnAlSiNbTi24-11 with scanning and transmission electron microscopy. κ-(Fe,Mn)3AlC carbides, having a regular, face-centered cubic lattice (fcc), were identified in austenite. Transmission electron microscopy examinations have enabled to identify M7C3-type carbide in ferrite. Nb- and Ti-based complex carbides were identified in steel X98MnAlSiNbTi24-11, both, in ferrite and austenite. (NbTi)C2 carbide precipitates were confirmed in an X-ray qualitative phase analysis. The size of the above-mentioned carbides is within several to several dozens of μm. An X-ray qualitative phase analysis has confirmed the precipitates of M7C3 carbides in both steels.

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Dializa równowagowa. Metoda badania selektywności oddziaływań ligand.DNA

Czerwińska I., Głuszyńska A., Juskowiak B.

Wiadomości Chemiczne

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2010

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[Z] 64, 1-2

105-122

EN

Equilibrium or competition dialysis is a powerful tool for binding study of ligands that are expected to bind to nucleic acids with selectivity related to their structure or sequence. In the equilibrium dialysis experiment, a set of nucleic acid samples that differ in structure and sequence is dialyzed against a test ligand solution. After equilibration, the concentration of ligand bound to each structure or sequence is determined by UV-Vis absorption or fluorescence spectroscopy in each dialysis unit. Since all nucleic acid samples are in equilibrium with the same free ligand concentration, the amount of bound ligand is directly related to the ligand binding affinity. Thus, equilibrium provides a direct measure of selectivity and identifies the nucleic acid sample, which is preferred by a particular ligand. We describe here the principles and practice of the method. Examples of an application of the method are limited to the discovery of small molecules that selectively recognize the unique structural features of G-quadruplexes. There are proofs for important functional roles of G-quadruplex structures in biology (maintenance of telomeres, transcriptional regulation, and modulation of mRNA translation). G-quadruplex DNA can exist in a variety of structural forms that may possess numerous potential binding sites for small molecules. Therefore equilibrium dialysis provides a useful tool for discovery of new mall-molecule therapeutic agents targeting G-quadruplexes.