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M.A. Prieto-Calvo, M.K. Omer, O. Alvseike, M. López, A. Alvarez-Ordóñez and M. Prieto

bacteria to utilise 95 various carbon sources and assigns unknown strains to a species by mathematically comparing their utilisation pattern (metabolic fingerprint) with the Biolog database ( Odumeru et al ., 1999 ; Kootallur et al ., 2011 ). Fourier transform-infrared (FT-IR) spectroscopy is considered a chemotaxonomic method that is able to provide a great amount of taxonomic data. Spectra obtained from cellular biomass are very characteristic and can be considered as ‘fingerprints’ or molecular patterns distinctive of a particular bacterial strain ( Naumann, 2000

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B.B.V.S. Vara Prasad, K.V. Ramesh and A. Srinivas

Abstract

Co–Zn nanocrystalline ferrites with chemical composition Co0:5Zn0:5Fe2O4 were synthesized by sol-gel and combustion methods. The sol-gel method was carried out in two ways, i.e. based on chelating agents PVA and PEG of high and low molecular weights. In auto-combustion method, the ratio of citric acid to metal nitrate was taken as 1:1, while in sol-gel method the chelating agents were taken based on oxygen balance. All the three samples were studied by thermogravimetric and differential thermal analysis for the identification of phase formation and ferritization temperature. The synthesized samples were characterized by powder X-ray diffraction and FT-IR spectroscopy without any thermal treatment. The measured lattice constants and observed characteristic IR absorption bands of the three samples are in good agreement with the reported values showing the formation of a cubic spinel structure. The crystallite sizes of all samples were determined using high intensity peaks and W-H plot. Size-Strain Plot method was also implemented since two of the samples showed low crystallite sizes. The least crystallite size (5.5 nm) was observed for the sample CZVP while the highest (23.8 nm) was observed for the sample CZCA. Cation distribution was proposed based on calculated and observed intensity ratios of selected planes from X ray diffraction data. All structural parameters were presented using experimental lattice constant and oxygen positional parameter, and they correlated with FT-IR results. Magnetic measurements were carried out using vibrating sample magnetometer at room temperature to obtain the characteristic parameters such as saturation magnetization, coercivity, remanence, squareness ratio and Bohr magnetons. Among all, the sample synthesized via citric acid autocombustion method displayed a remarkably higher magnetization of 53 emu/g and the remaining two samples displayed low magnetization values owing to their smaller crystallite sizes.

Open access

Anna Adamczyk

Abstract

Aluminosilicate materials were obtained by sol-gel method, using different Al2O3 and SiO2 precursors in order to prepare sols based on water and organic solvents. As SiO2 precursors, Aerosil 200TM and tetraethoxysilane TEOS: Si(OC2H5)4 were applied, while DisperalTM and aluminium secondary butoxide ATSB: Al(OC4H9)3 were used for Al2O3 ones. Bulk samples were obtained by heating gels at 500 °C, 850 °C and at 1150 °C in air, while thin films were synthesized on carbon, steel and alundum (representing porous ceramics) substrates by the dip coating method. Thin films were annealed in air (steel and alundum) and in argon (carbon) at different temperatures, depending on the substrate type. The samples were synthesized as gels and coatings of the composition corresponding the that of 3Al2O3·2SiO2 mullite because of the specific valuable properties of this material. The structure of the annealed bulk samples and coatings was studied by FT-IR spectroscopy and XRD method (in standard and GID configurations). Additionally, the electron microscopy (SEM) together with EDS microanalysis were applied to describe the morphology and the chemical composition of thin films. The analysis of FT-IR spectra and X-ray diffraction patterns of bulk samples revealed the presence of γ-Al2O3 and δ-Al2O3 phases, together with the small amount of SiO2 in the particulate samples. This observation was confirmed by the bands due to vibrations of Al–O bonds occurring in γ-Al2O3 and δ-Al2O3 structures, in the range of 400 to 900 cm−1. The same phases (γ-Al2O3 and δ-Al2O) were observed in the deposited coatings, but the presence of particulate ones strongly depended on the type of Al2O3 and SiO2 precursor and on the heat treatment temperature. All thin films contained considerable amounts of amorphous phase.

Open access

Kristīne Kalneniece, Andrejs Bērziņš, Zaiga Petriņa, Kristīne Ruģele, Elīna Salava, Kārlis Švirksts, Māra Grūbe, Vizma Nikolajeva and Olga Mutere

,” Water Research , vol. 13, no. 6, pp. 485–492, Jan. 1979. https://doi.org/10.1016/0043-1354(79)90043-5 [21] M. Grube, J. G. Lin, P. H. Lee, and S. Kokorevicha, “Evaluation of sewage sludge-based compost by FT-IR spectroscopy,” Geoderma , vol. 130, no. 3–4, pp. 324–333, Feb. 2006. https://doi.org/10.1016/j.geoderma.2005.02.005 [22] M. Grube, I. Dimanta, M. Gavare, I. Strazdina, J. Liepins, T. Juhna, and U. Kalnenieks, “Hydrogen-producing Escherichia coli strains overexpressing lactose permease: FT-IR analysis of the lactose-induced stress

Open access

Ioana A. Gorodea

6 and Ca2MnWO6: a neutron diffraction study. J. Phys. Condens. Mat. 2002, 14, 38, 8817-8830. 15. Lavat, A. E., Baran, E. J. IR-spectroscopic characterization of A2BB’O6 perovskites. Vib. Spectrosc. A. 2003, 32, 167-174. 16. Martinez-Lope, M. J., Alonso, J. A., Casais, M. T., Garcia-Hernandez, M., Pomjakushin, V. Preparation, structural study from neutron diffraction data and magnetism of the disordered perovskite Ca(Cr0.5Mo0.5)O3. J. Solid State Chem. 2006, 179 ,8, 2506-2510

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Inga Zinicovscaia, Alexey Safonov, Varvara Tregubova, Victor Ilin, Liliana Cepoi, Tatiana Chiriac, Ludmila Rudi and Marina V. Frontasyeva

Abstract

Spirulina platensis biomass is widely applied for different technological purposes. The process of lanthanum, chromium, uranium and vanadium accumulation and biosorption by Spirulina platensis biomass from single- and multi-component systems was studied. The influence of multi-component system on the spirulina biomass growth was less pronounced in comparison with the single-component ones. To trace the uptake of metals by spirulina biomass the neutron activation analysis was used. In the experiment on the accumulation the efficiency of studied metal uptake changes in the following order: La(V) > Cr(III) > U(VI) > V(V) (single-metal solutions) and Cr(III) > La(V) > V(V) > U(VI) (multi-metal system). The process of metals biosorption was studied during a two-hour experiment. The highest rate of metal adsorption for single-component systems was observed for lanthanum and chromium. While for the multi-component system the significant increase of vanadium and chromium content in biomass was observed. In biosorption experiments the rate of biosorption and the Kd value were calculated for each metal. Fourier transform infrared spectroscopy was used to identify functional groups responsible for metal binding. The results of the present work show that spirulina biomass can be implemented as a low-cost sorbent for metal removal from industrial wastewater.

Open access

G. Bhuvaneswari, L. Guru Prasad and N. Prabhavathi

References [1] CHEMLA D.S., ZYSS J., Nonlinear optical properties of organic molecules and crystals, Academic Press, New York, 1987. [2] PRASAD P.N., WILLIAMS D.J., Introduction to nonlinear optical effects in organic molecules and polymers, Wiley, New York, 1991. [3] HARI SINGH NALWA, SEIZO MIYATA, Nonlinear optics of organic molecules and polymers, CRC Press, Boca Raton, 1997. [4] MOHAN J., Organic Spectroscopy, principles and applications, Alpha Science International Ltd, Harrow, 2004

Open access

Tomasz Szmechtyk, Natalia Sienkiewicz, Katarzyna Koter, Agnieszka Kobierska and Krzysztof Strzelec

). Fibres, films, plastics and rubbers: a handbook of common polymers. Elsevier. 24. Lee, J., Kim, J., Kim, H., Bae, Y.M., Lee, K.H. & Cho, H.J. (2013). Effect of thermal treatment on the chemical resistance of polydimethylsiloxane for microfluidic devices. J. Micromech. Microengin. 23(3), 035007. DOI: 10.1088/0960-1317/23/3/035007. 25. Holland, B.J. & Hay, J.N. (2002). The thermal degradation of PET and analogous polyesters measured by thermal analysis–Fourier transform infrared spectroscopy. Polymer 43(6), 1835–1847. DOI: 10.1016/S0032

Open access

Zenon Sarbak

The effect of supports on coke deposition on supported platinum and platinum-tin catalysts investigated by FT-IR spectroscopy

Coke deposit is produced from ethylene on the surface of the platinum and platinum-tin catalysts supported on two various Al2 O3, SiO2 and SiO2 -Al2O3. The coke amount and the structure depend on the type and the amount of the components introduced onto the catalyst support and on the type of the support. It has been found that the surface area of the support has no significant effect on the type of species in the coke deposit. The analysis of the FT-IR spectra has shown the presence of different species on the surface of the catalysts, including carboxyl groups, pseudo-graphite (polyaromatic) structures, polyphenylene groups, acetyl groups, carbonyl groups of acetone and formate type, enol species.

Open access

Maroš Sirotiak and Alica Bartošová

–718. LARIDE, W.A. (2015): Infrared Spectra of Humic Acid and Metal Humates Precipitated from Groundwater. Journal of Water Resource and Hydraulic Engineering , 4, 1, p. 105-110. LIU, X.; RYAN, D.K. (1997): Analysis of Fulvic acids using HPLC/UV coupled to FT.IR Spectroscopy. Environmental Technology , 18. p 417-424. NAIDJA, A.; HUANG, P.M.; ANDERSON, W.; KESSEL, C. (2002): Fourier Transform Infrared, UV-Visible, and X-ray Diffraction Analyses of Organic Matter in Humin, Humic Acid, and Fulvic Acid Fractions in Soil Exposed to Elevated CO 2 and N Fertilization