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1

Dielectric and X-ray Studies of Eleventh and Twelfth Members of Two Isothiocyanato Mesogenic Compounds

100%

Jasiurkowska M., Budziak A., Czub J., Urban S.

Acta Physica Polonica A

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2006

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vol. 110

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issue 6

795-805

EN

Results of the dielectric and X-ray studies of the long-alkyl-chain members (n=11, 12) of two homologous series: nBT (4-n-alkyl-4'-isothiocyanato-biphenyl) and nCHBT (4-trans-4'-n-alkyl-cyclohexyl-isothiocyanato-benzene) in their liquid crystalline phases are presented. These compounds exhibit different polymorphisms: the nematic phase for $n$CHBTs and the smectic E and smectic A phases for nBTs. The dielectric measurements were performed in a wide frequency range of 1 kHz-3 GHz. The layer thickness in the smectic E and smectic A phases and the orthorhombic unit cell parameters of the smectic E phase were determined using the small angle X-ray diffraction method. In the smectic E phase the layer-thickness-to-molecular-length ratios are found to be close to 1. The corresponding ratios observed for the smectic A phase of $n$BTs are considerably higher (≈1.24), which indicates that an alternating head-to-tail arrangement of molecules in the layers is favored. The rotational dynamics of molecules in the smectic E phases is discussed in relation to their packing in a unit cell.

2

Calorimetric and Positron Lifetime Measurements οf Hydrogenated Carbon Nanocones

100%

Budziak A., Dryzek J., Krawczyk J., Zieliński P.

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issue 4

574-577

EN

Two carbon nano-structured samples containing 5 and 20% of carbon nanocones in their volume were investigated. Using the Sieverts apparatus the hydrogen was loaded into the samples. The measurements of heat capacity in the temperature range from 100 K to 320 K and the positron lifetime measurements at the room temperature were performed for hydrogenated and non-hydrogenated carbon nanocones. The desorption of hydrogen at the temperature of 230 K is deduced from the heat capacity measurements. The detection of the positronium, the bound state of positron and electron, in the measured samples reveals the presence of open volume defects of ca. 0.198 ± 0.002 nm.

3

Chemical, Magnetic and X-Ray Diffraction Studies of the Sediments from Oil Field in Argentina

76%

Kopeć M., Kąc M., Bałanda M., Budziak A., Kąc S., Perzanowski M., Góra M.

Acta Physica Polonica A

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2012

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vol. 121

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issue 2

566-570

EN

Chemical, magnetic, and phase composition analysis of deposits taken from sedimentation tank from oil plant in Argentina was carried out. Energy dispersive spectroscopy indicates iron as a main sediment component with the site dependent fraction ranging from 11% to 78% (weight percentage). Moreover, large fractions of sulfur (4%-33%), oxygen (8%-28%), calcium (1%-14%), and silicon (1%-11%) were found. The chemical analysis performed with wet chemical methods also indicated Fe as a main component (about 35%), additionally a large fraction ( ≈ 15%) of the sulfur and under 10% fractions of calcium ( ≈ 7%), carbon ( ≈ 6%), and silicon ( ≈ 5%) were found in the sample. The phase composition studies performed using X-ray diffraction showed magnetite - Fe_3O_4, goethite - α-FeOOH, lepidocrocite - γ-FeOOH, siderite - FeCO_3, and iron-sulfur compounds (mackinawite - FeS, stoichiometric FeS, greigite - Fe_3S_4) and other compounds like aragonite - CaCO_3, calcite - CaCO_3, anorthite - CaAl_2Si_2O_8, quartz - SiO_2 and barium sulphate Ba(SO_3)_{0.3}(SO_4)_{0.7}. Studies performed by the Mössbauer spectroscopy, confirmed presence of majority of compounds identified by X-ray diffraction. Magnetic AC susceptibility measurements show that magnetite is a main component of the studied deposit. High concentration of the magnetic compounds deposited in the sedimentation tank points to the advisability to install the magnetic device designed to support water treatment processes, i.e.: flocculation, coagulation, sedimentation, and filtration. This device could simultaneously inhibit microbiological and chemical corrosion.

4

Structural Evolution of Near-Surface Layers in NiTi Alloy Caused by an Ion Implantation

76%

Swiatek Z., Michalec M., Levintant-Zayonts N., Bonarski J., Budziak A., Bonchyk O., Savitskij G.

Acta Physica Polonica A

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2011

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vol. 120

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issue 1

75-78

EN

The results of X-ray diffraction studies on structural changes in the near-surface layers in the NiTi alloy caused by nitrogen-ion implantation with the energy E = 50 keV and the fluence D = 10^{18} cm^{-2} are presented. X-ray diffractometry, using the Philips diffractometer type X'Pert in the Bragg-Brentano geometry, was used to identify the phase composition of NiTi alloy. For layer by layer analysis of structural changes in the near-surface layers, the D8 Discover Bruker diffractometer with polycapilar beam optics was used. The ion-implanted NiTi alloy in the near-surface layer exhibits five phases: the dominating austenite phase, two martensitic phases and a small amount of the Ni_4Ti_3 and NTi phases. Along with the decreasing thickness of the near-surface layer investigated in material an increasing fraction of the Ni_4Ti_3 and NTi phases was observed. With the thickness of this layer about 340 nm, besides still existing the austenite, Ni_4Ti_3 and NTi phases, only one martensitic phase is present in the alloy. Further decrease of the thickness of the near-surface layer to about 170 nm leads to the increasing fraction of the Ni_4Ti_3 and NTi phases.

5

The application of the Mechanochemical Synthesis for the Preparation of Advanced Ceramics Based on Barium Titanate

72%

Garbarz-Glos B., Bąk W., Budziak A., Dulian P., Lisińka-Czekaj A., Czekaj D., Garbarz-Glos B., Bąk W., Budziak A., Dulian P., Lisińka-Czekaj A., Czekaj D.

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6

Investigation of Sediments Causing Damage to Water Meters in a Large Drinking Water Distribution System

52%

Kopeć M., Roman M., Kąc M., Budziak A., Paluszkiewicz C., Zarzycki A., Kąc S., Dutkiewicz E., Cichoń T., Bochnia T., Kwiatek W.

Acta Physica Polonica A

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2018

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vol. 133

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issue 2

296-301

EN

Preliminary studies on the sediments collected from water meters of Krakow water supply system were performed in the cooperation with the Municipal Water Supply and Sewage. Creation and deposition of sediments on the measuring devices installed in the water supply system is a serious technological and economical problem for water companies, defectively operating for this reason water meters must be replaced. It is evident that knowledge of the chemical and phase composition of sediments is an important step towards resolving the problem of impurities in water supply systems. Four different samples of sediments, coming from water meters, were investigated using the proton-induced X-ray emission, the X-ray diffraction, the Fourier transform infrared and Raman spectroscopy. The X-ray methods revealed presence of amorphous and fine-crystalline phases as well as high content of iron-based compounds. As a crystalline phase, the most frequently appeared: goethite, lepidocrocite, iron oxides (hematite, maghemite, magnetite), calcium carbonate, and quartz. In one of the samples, the nanocrystalline phase was found and identified as hydrous iron oxyhydroxide ferrihydrite. Vibrational spectroscopy methods confirmed the composition of crystalline phases as well as enabled to estimate the abundance of amorphous phase in samples.

Refine search results

Dielectric and X-ray Studies of Eleventh and Twelfth Members of Two Isothiocyanato Mesogenic Compounds

Calorimetric and Positron Lifetime Measurements οf Hydrogenated Carbon Nanocones

Chemical, Magnetic and X-Ray Diffraction Studies of the Sediments from Oil Field in Argentina

Structural Evolution of Near-Surface Layers in NiTi Alloy Caused by an Ion Implantation

The application of the Mechanochemical Synthesis for the Preparation of Advanced Ceramics Based on Barium Titanate

Investigation of Sediments Causing Damage to Water Meters in a Large Drinking Water Distribution System