Ravikumar Kolekar, Suresh Baburao Kapatkar and Shridhar Narasinhmurthy Mathad
.R.; Shinde, S.S.; Moholkar, A.V.; Bhosale, J.; Kim, H.; Rajpure, K.Y. Physical properties of sprayed antimony doped tin oxide thin films: The role of thickness. J. Semicond . 2011 , 32(5) , 053001–053008.
28. Prabhu, Y.T.; Rao, K.V.; Kumar, V.S.S.; Kumari, B.S. X-ray analysis by Williamson-Hall and size-strain plot methods of ZnO nano particles with fuel variation. World J. Nano Sci. Eng. 2014 , 4 , 21–28.
29. Mathad S.N. Mechanical and structuralproperties of Zn 0.1 Ni 0.4 Cu 0.5 Fe 2 O 4 ferrite, Int. J. Adv. Sci. Eng. 2018 , 5(2) , 911
This paper describes synthesis and structural properties of Ni0.45Cu0.55Mn2O4 nanopowder, obtained by co-precipitation route. XRD pattern reveals cubic structure with lattice parameter 8.305 Å. We report crystallite size (D), micro strain (ε), dislocation density (ρD), and hopping lengths (LA and LB). We also report preferential orientation by texture coefficients [Tc (h k l)]. The Williamson-Hall plot and stress-strain plot also employed to understand the mechanical properties of materials.
Justyna Pawlonka, Grzegorz Słowik, Wojciech Gac and Tadeusz Borowiecki
Microemulsion method was used for preparation of copperzinc mixed oxides. Samples were prepared from the solutions containing zinc and copper nitrates. Sodium carbonate was used as a precipitant and hydrazine as reducing agent. Water-in-oil (W/O) microemulsions were formed by the application of cyclohexane, isopropyl alcohol, and hexadecyltrimethylammonium bromide (CTAB) as surfactant. The aim of the studies was determination of the influence of the sequence of synthesis stages on the formation of materials, their surface and structural properties. Thermal decomposition studies of materials were carried out by infrared spectroscopy. The physicochemical properties were characterized by nitrogen adsorption-desorption method, X-ray diffraction (XRD) and temperature-programmed reduction (TPR).
Barbora Urminská, Ján Derco, Ronald Zakhar and Adriana Korpicsová
Natural or synthetic zeolites have unique physical, chemical and structural properties that predetermine their use in many processes, including wastewater treatment. This study presents the results of our preliminary research in the field of nitrogen and phosphorus removal using adsorption and adsorptive ozonation with natural and modified zeolites. Iron-modified zeolite was the most efficient for the removal of ammonium nitrogen by adsorption. Phosphorus removal efficiency using adsorption was relatively low and natural zeolite was not suitable for the phosphorus removal at all. Ozone had no significant impact on the removal efficiency. Regeneration of loaded zeolites with ozone has also been studied. This method was partly efficient but it needs be further examined.
Ilona Jastrzębska, Wiktor Bodnar, Kerstin Witte, Eberhard Burkel, Paweł Stoch and Jacek Szczerba
In this work spinel series with the general formula Fe1-xMnxAl2O4 (where x = 0, 0.3, 0.5 and 0.7) were synthesized and characterized with respect to their structure and microstructure. X-ray diffractometry (XRD) was used to identify the phase composition that revealed a single phase spinel material. Rietveld refinements of the XRD patterns were carried out in order to determine the lattice and oxygen positional parameters of the spinel compounds. Mössbauer effect measurements were performed at room temperature to determine the local chemical environment of the Fe ions, their valences, and degrees of spinels inversion. It was shown that an increase in the Mn content led to a decrease in the ratio of Fe2+ to Fe3+. The results obtained from Mössbauer spectroscopy (MS) were used to establish the chemical formulas of the synthesized spinels. Finally, the microstructure that was observed using scanning electron microscopy (SEM) showed a compact microstructure with an octahedral crystal habit.
Synthetic carbon adsorbents - the method of their preparation and application in adsorption and chromatography
This paper is devoted to the methods of preparation of the synthetic carbon adsorbents by carbonization of different polymer precursors and the research into the structural and surface properties of the obtained carbon adsorbents. The paper describes the research into the preparation of active carbons by carbonization of: polysufonated cation-exchanged resin, polyvinyl chloride and porous copolymer (4,4-diphenyl sulfone dimethacrylate). The carbonization of polymers was carried out in inactive atmosphere under the supervised conditions. The spherical shape of grains is a result of carbonization. The obtained carbon adsorbents were subjected to additional modification processes, i.e. hydrothermal activation in steam atmosphere, oxidation with nitric acid (6M HNO3) and heated in hydrogen (H2) atmosphere.
The adsorption from aqueous solutions of the chosen organic compounds on the modified synthetic active carbons, the adsorption of organic compounds in relation to water as well as structural characteristics of carbon adsorbents are discussed in this paper. The interaction of the organic substances and the synthetic active carbons in aqueous solutions depends on the structural properties of carbons (volume of micro- and meso-pores, distribution of pore sizes, specific surface area) and their chemical properties (i.e. concentration of functional oxygen groups, presence of mineral admixtures).
Marek Wiertel, Zbigniew Surowiec, Mieczysław Budzyński, Jan Sarzyński and Anatoly I. Beskrovnyi
The aim of the presented paper is to study an influence of replacement of Fe atoms by Si atoms in quasibinary Sc(Fe1−xSix)2 Laves phases on their structural and magnetic properties. Powder X-ray diffraction (XRD) and neutron diffraction (ND) measurements carried out at different temperatures from 4.3 K up to about 700 K revealed that samples were single phase with cubic C15 structure for Si concentration x from 0.05 to 0.20 and hexagonal C14 structure for higher concentration. The results of 57Fe Mössbauer measurements showed that the Sc(Fe1−xSix)2 compounds with x ≤ 0.30 are ferrimagnetic at 4.3 K. At temperature 80 K in the samples with x = 0.20 and 0.30, a magnetic cluster spin-glass state has been observed, as ferrimagnetic long-range order disappears. Such picture was supported by the results of ND measurements carried out at 8 K, which confirmed the lack of long-range order for x above 0.10 and an occurrence of hyperfine field distributions in the corresponding Mössbauer spectra. At room temperature, samples with x ≥ 0.20 became paramagnetic. A substitution of Si atoms for Fe ones leads to a decreasing of mean values of hyperfine magnetic fields in samples under investigation. From the neutron diffraction pattern analysis of Sc(Fe0.90Si0.10)2Fe magnetic moment was determined as to be equal to 1.5 μB at 8 K. Combining this result with a value of hyperfine magnetic field on 57Fe probes, the hyperfine coupling constant A in Sc(Fe0.90Cu0.10)2 phases is estimated at about 11.6 T/μB at 8 K.
In studies of individual organisation levels of organisms, the requirement of hollistic expression of structure and function is traditional despite the fact that structural direction prevails in studies. Less attention is paid to the place where function activity occurs in connection with the structure. This place is the surface - the medium where physical, chemical, biological and synergic processes interact. These surfaces are called ecologically active surfaces (EAS). From this standpoint, the surface is a place for energy exchange, which appears as mean studies of function and structural properties of the biological object.
The quantification of these areas taking into account the functional activities - (developed surface, the functional characteristics) to the desktop, or to the volume is the methodological starting point in the assessment of the country, or of its componens after the assessment of the energy potential of the environment. This ratio can be considered as the degree of heterogeneity of the conditions after taking into account the gradient of the environment.
We have achieved partial results related to EAS during the solution of tasks connected with the environmental evaluation of biotic components of a landscape, mainly during the investigation of aquatic biotopes, which are demonstrated on some examples.
Mechanical alloying method was applied to prepare nanocrystalline iron-based Fe1−xZnx solid solutions with x in the range 0.01 ≤ x ≤ 0.05. The structural properties of the materials were investigated with the Mössbauer spectroscopy by measuring the room temperature spectra of 57Fe for as-obtained and annealed samples. The spectra were analyzed in terms of parameters of their components related to unlike surroundings of the iron probes, determined by different numbers of zinc atoms existing in the neighborhood of iron atoms. The obtained results gave clear evidence that after annealing process, the distribution of impurity atoms in the first coordination spheres of 57Fe nuclei is not random and it cannot be described by binomial distribution. The estimated, positive values of the short-range order parameters suggest clustering tendencies of Zn atoms in the Fe-Zn alloys with low zinc concentration. The results were compared with corresponding data derived from Calphad calculation and resulting from the cellular atomic model of alloys by Miedema.