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1
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Mechanochemical Preparation of Organic-Inorganic Hybrid Materials of Drugs with Inorganic Oxides

100%
Shakhtshneider T., Myz S., Dyakonova M., Boldyrev V., Boldyreva E., Nizovskii A., Kalinkin A., Kumar R.
Acta Physica Polonica A
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2011
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vol. 120
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issue 2
272-278
EN
The nanocomposites of piroxicam and meloxicam with alumina were obtained by ball-milling as a result of distribution of the drugs at the surface of oxide with formation of the stable composites. The observed changes in the IR spectra of the ball-milled mixtures suggested the interaction of the drugs with the alumina active surface sites. The functional groups in molecules of piroxicam and meloxicam involved into formation of bonds between the drugs and the surface of the oxide were determined, they are amide, sulfate, enol groups, and pyridyl / thiazolyl nitrogen atoms. It appears that the formation of the new bonds at the contacts of particles in the composite leads to the stabilization of the drugs in metastable state inhibiting their transformation into initial crystalline form.
2
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Core-Shell Mechanocomposites of Drugs with Inorganic Oxides and Hydroxides

100%
Shakhtshneider T., Myz S., Boldyreva E., Nizovskii A., Kumar R.
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vol. 126
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issue 4
1019-1024
EN
The composites of piroxicam and meloxicam with gamma-alumina, aluminium hydroxides (gibbsite and boehmite), alpha and gamma polymorphs of iron(III) oxide having different surface area and morphology were prepared by planetary ball-milling. It has been shown that the initial state of the excipient (specific surface area, particle size and morphology) had a pronounced effect on the formation of the core-shell composites with the drugs and their properties. The X-ray diffraction patterns and IR spectra measured for co-milled samples as well as X-ray photoelectron spectroscopy studies gave evidence that the components of the mixtures interacted with each other and became amorphous, as composites were formed. The drug release from the composites was different as compared with pure drugs, meloxicam and piroxicam behaving differently that can be explained by formation of strong or weak bonds with the active sites of the carriers. In the case of mechanocomposites, the drugs dissolved quickly due to high surface of organic phase in the core-shell composites. The high-porous carriers can serve as the sorbents for the drugs in solution.
3
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On the Flexural Vibration of Pre-Stressed Nanobeams Based on a Nonlocal Theory

100%
Rahmani O.
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vol. 125
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issue 2
532-533
EN
In this study, a model based on a nonlocal theory is proposed to study the effect of external loads on the free vibration of nanobeams. The governing equations for the initially pre-stressed beam are obtained by using the Hamilton principle. Analytical solution of vibration is presented using the Eringen nonlocal theory to bring out the effect of the nonlocal behavior on natural frequencies. The performance of the present model is compared with that of others by the presentation of comparative results. It is suggested that the present model can be used as a benchmark in future studies.
4
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Free Vibrations of a Rotating Single-Walled Carbon Nanotube Embedded in an Elastic Medium Based on Nonlocal Elasticity Theory

63%
Nahvi H., Boroojeni M.
Acta Physica Polonica A
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2013
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vol. 123
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issue 2
304-306
EN
In this paper, a nonlocal beam model is developed and applied to investigate flapwise vibration characteristics of a rotating single-walled carbon nanotube on a Pasternak foundation. Differential quadrature method is used to solve equation of motion. The effects of small-scale factor, angular velocity and elastic foundation on the natural frequencies are examined and discussed. It is shown that small-scale effect plays an important role in the vibration response of a rotating nanotube.
5
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Investigation of Nanoscale TiN/MoN Multilayered Systems, Fabricated Using Arc Evaporation

51%
Pogrebnjak A., Bondar O., Abadias G., Eyidi D., Beresnev V., Sobol O., Postolnyi B., Zukowski P.
Acta Physica Polonica A
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2015
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vol. 128
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issue 5
836-840
EN
Using the vacuum-arc evaporation method we fabricated periodic multilayered TiN/MoN structures with different bilayer periods λ ranging from 8 to 100 nm. We found that molybdenum nitride and titanium nitride layers grown on steel show local partial epitaxy and columnar growth across interfaces. A molybdenum-titanium carbide interlayer was evidenced between the substrate and the multilayer. Molybdenum nitride and titanium nitride layers contain small (5÷30 nm) grains and are well crystallized with (100) preferred orientation. They were identified as stoichiometric fcc TiN and cubic γ-M₂N. Non-cubic molybdenum nitride phases were also detected. The hardness of the obtained structures achieved great values and maximal hardness was 31÷41.8 GPa for the multilayered structure with a 8 nm period. Hardness of the obtained coatings is 25÷45% higher in comparison with the initial single-layer nitride coatings, plasticity index of multilayered structure is 0.075.
6
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Multicomponent (Ti-Zr-Hf-V-Nb)N Nanostructure Coatings Fabrication, High Hardness and Wear Resistance

51%
Pogrebnjak A., Beresnev V., Kolesnikov D., Bondar O., Takeda Y., Oyoshi K., Kaverin M., Sobol O., Krause-Rehberg R., Karwat C.
Acta Physica Polonica A
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2013
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vol. 123
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issue 5
816-818
EN
First results in the field of synthesis and research of the multicomponent (Ti-Zr-Hf-V-Nb)N nanostructured coatings are presented in the paper. Influence of processes of spinodal segregation and mass-transfer on single-layered or multilayered crystal boundary (second phase) forming were explored. Superhard nanostructured coatings were investigated before and after annealing at the temperature 600°C using unique methods (slow positron beam, proton microbeam particle induced X-ray emission-μ, Rutherford backscattering-analysis, scanning electron microscopy with energy dispersive X-ray spectroscopy, X-ray diffraction analysis was performed using DRON-4 and nanoindentor). Diffraction spectra were taken point-by-point, with a scanning step 2Θp=0.05 to 0.1°. We detected that positron trapping by defects was observed on the nanograins boundaries and interfaces (vacancies and nanopores which are the part of triple and larger grain's boundary junction). The 3D distribution maps of elements obtained by the proton microbeam (particle induced X-ray emission-μ) together with the results obtained by slow positron microbeam gave us comprehensive information about physical basis of the processes, connected with diffusion and spinodal segregation in superhard coatings.
7
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Effect of Thermal Treatment on the Structure and Mechanical Properties of Coatings Based on (Ti, Hf, Nb, Si)N

51%
Pogrebnjak A., Komarov F., Sobol O., Kaverina A., Shypylenko A., Karwat C.
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vol. 125
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issue 6
1312-1316
EN
Current paper presents the results of investigating of nanostructured cathode arc vacuum evaporation coatings, based on (Ti, Hf, Nb, Si)N. Several methods of the structural and elemental analysis were used: proton microbeam, nano- and micro-electron beam, X-ray diffraction analysis. To determine tribological properties (scratch resistance, adhesive and cohesive strength) of the coatings, scratch testing were conducting. Influence of thermal annealing at temperatures 300, 500, 800, 1000C on elemental composition, microstructure, residual stress, phase composition, profiles of atomic distribution in the coatings were investigated.
8
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Influence of Deposition Parameters and Thermal Annealing on the Structure and Properties of Nitride Coatings (TiHfZrVNb)N

51%
Pogrebnjak A., Abadias G., Chartier P., Bondar O., Yakuschenko I., Takeda Y., Krause-Rehberg R., Kolesnikov D., Beresnev V., Partyka J.
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vol. 125
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issue 6
1296-1299
EN
Results of structure, phase composition, physical and mechanical properties and tribological properties investigations of nitride high-entropy coatings (TiZrHfVNb)N are presented in the paper. Proton microbeam (μ-PIXE), X-ray diffraction method, including method of X-ray strains measurements, energy dispersive X-ray spectroscopy and scanning electron microscopy analysis, microhardness testing and nanoindentation were used. Thermal annealing (t=600°C) influence on defect profiles, structure and element distribution in the coatings was investigated. It was found that thermal treatment of coatings leads to changing of defect profiles and to element redistribution. Also we can say that it influences less on grain size changing. Investigated (TiZrHfVNb)N coatings demonstrate high values of hardness and excellent wear resistance.
9
Content available remote

Structure and Properties of Multilayer Nanostructured Coatings TiN/MoN Depending on Deposition Conditions

51%
Pogrebnjak A., Abadias G., Bondar O., Postolnyi B., Lisovenko M., Kyrychenko O., Andreev A., Beresnev V., Kolesnikov D., Opielak M.
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vol. 125
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issue 6
1280-1283
EN
This work presents the results of TiN/MoN coatings studying. These multilayer nanostructured coatings demonstrate dependence on depositions conditions on nanometer level. The influence of nanosized monolayer thickness on structure changing and properties of nanocomposite multilayer coatings TiN/MoN was found. Multilayer TiN/MoN coatings of the total thickness from 6.8 to 8.2 μm were obtained using C-PVD method. Thicknesses of monolayers were 2, 10, 20, 40 nm. The structure of samples was studied using X-ray diffraction (Bruker D-8 Advance) in Cu K_{α} radiation, high resolution transmission electron microscopy with diffraction CFEI EO Techai F200, scanning electron microscopy with energy dispersive X-ray spectroscopy (JEOL-7001F), and microhardness measurements in dependence on indenter load. Scratch tests (friction, wear, etc.) were also provided using Rockwell-C diamond indenter (CSM Revetest Instruments) with a tip radius of 200 μm. Friction and wear behavior were evaluated using ball-on-plate sliding test on a UMT-3MT tribometer (CETR, USA). With decreasing monolayer thickness the hardness value increases, and the size of nanograins reduces. The values obtained for the friction coefficient of the multilayer system is much smaller than in nanostructured coatings of TiN (nc) or MoN (nc). Annealing showed formation of a (Ti,Mo)N solid solution and small growth of nanocrystals.
10
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Structure and Properties of Nano- and Microcomposite Coating Based on Ti-Si-N/WC-Co-Cr

51%
Pogrebnjak A., Shpak A., Beresnev V., Il'yashenko M., Komarov F., Shypylenko A., Kaverin M., Zukovski P., Kunitskyi Y., Kolesnikov D., Kolisnichenko O., Makhmudov N.
Acta Physica Polonica A
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2011
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vol. 120
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issue 1
100-104
EN
Using the two technologies: plasma-detonation and vacuum-arc deposition, we fabricated two types of coatings: Ti-Si-N/WC-Co-Cr/steel and Ti-Si-N/steel. We found that the top coating of Ti-Si-N was nanostructured one with 12 to 15 nm grain sizes and H = 40 to 38 GPa hardness. A thick coating which was deposited using the pulsed plasma jet, demonstrated 11 to 15.3 GPa hardness, an elastic modulus (E) changing within 176 to 240 GPa, and tungsten carbide grain dimensions varying from 150 to 350 nm to several microns. An X-ray diffraction analysis shows that the coating has the following phase composition: TiN, (Ti,Si)N solid solution, WC, W_2C tungsten carbides. An element analysis was performed using energy dispersive spectroscopy (microanalysis) and scanning electron microscopy, as well as the Rutherford backscattering of ^4He^{+} ion and the Auger electron spectroscopy. Surface morphology and structure were analyzed using scanning electron microscopy and scanning tunnel microscopy. Tests friction and resistance (cylinder-plane) demonstrated essential resistance to abrasive wear and corrosion in the solution. The decrease of grain dimensions ≤ 10 nm occurring in the top Ti-Si-N coating layer increased the sample hardness to 42 ± 2.7 GPa under Ti_{72}-Si_8-N_{20} at.% concentration.
11
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The Effect of Mechanical Alloying on the Microhardness and Fracture Toughness of BaTiO_3

51%
Ertuğ B., Çetiner B., Sadullahoğlu G., Gökçe H., Erkmen Z., Öveçoğlu M.
Acta Physica Polonica A
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2013
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vol. 123
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issue 2
188-190
EN
In this work, the effects of mechanical alloying on the mechanical properties of BaTiO_3 were investigated. In order to examine the milling conditions and sintering parameters on the solid state formation of BaTiO_3, X-ray diffraction technique was used. After mechanical alloying process, nanosized powder mixtures were produced. Sintering temperatures were 600, 700, 800, 900, 1000, and 1200C and sintering duration was 1 h. Besides X-ray diffraction examinations, mechanical properties of the BaTiO_3 samples were determined by Vickers microhardness test.
12
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Surface Magnetostriction Model for MagNEMS

45%
Szumiata T., Gzik-Szumiata M.
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vol. 126
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issue 1
200-201
EN
In this work the influence of surface roughness on magnetostrictive nano-actuator parameters has been analyzed theoretically. A mechanical and magnetoelastic behavior of investigated cantilever bimorphic system has been described in the frame of the simple analytical model. Realistic material parameters have been incorporated into the model for high-magnetostrictive galfenol (Fe-Ga) thin films on silicon substrate. It has been shown that for 5 nm thick galfenol film a flat surface magnetostrictive effects modify the cantilever deflection and force only by 3%, whereas in the case of rough surface this influence increases to about 15%, when dimensions of roughness steps are comparable to the distances between them.
13
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Production and Structural Investigation of Polyethylene Composites with Modified Kaolin

45%
Domka L., Malicka A., Stachowiak N.
Acta Physica Polonica A
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2008
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vol. 114
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issue 2
413-421
EN
The study was undertaken to evaluate the effect of the filler (kaolin) modification with silane coupling agents on the properties of the polyethylene (HDPE Hostalen ACP 5831) composites. Powder mineral fillers are added to polymers to modify the properties of the latter and to reduce the cost of their production. A very important factor is the filler dispersion in the polymer matrix. Kaolin modified with 3-methacryloxypropyltrimethoxysilane and pure kaolin were characterised by surface area, pore size, water absorbing capacity, paraffin oil absorbing capacity, bulk density, scanning electron microscopy observations and X-ray diffraction measurements. Their performance was characterised by determination of the mechanical resistance upon static stretching and tearing, and their structure was observed in scanning electron microscopy images. The results were compared to those obtained for the composites with unmodified filler and pure HDPE.
14
Content available remote

NiTi Shape Memory Marformed Alloy Studied by Electron Beam Precession TEM Orientation Mapping Method

38%
Świec P., Zubko M., Lekston Z., Stróż D.
Acta Physica Polonica A
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2017
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vol. 131
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issue 5
1307-1310
EN
Severe plastic deformation by cold-rolling in martensitic state was applied to Ni_{50.4}Ti_{49.6} shape memory alloy. Received materials with 17, 20, 25, and 35% deformation were further annealed at 450°C for 15 min. After such treatment hardness of this alloy increased significantly reaching 365 HV0.5 for highest deformation degree. Calorimetric studies revealed two-stage and two-step character of martensitic transformation occurring in all specimens. Nanocrystalline structure with average grain size 53, 34, 28, and 24 nm was obtained. In material with 35% of deformation amorphous regions containing a nuclei of B2 parental phase with average size of 5 nm were observed. To determine the crystallographic orientation of observed nanograins and for better phase analysis, electron beam precession transmission electron microscopy orientation mapping was performed.
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