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M. Zajemska, H. Radomiak and A. Poskart

REFERENCES [1] W. Bialik, S. Gil, P. Mocek, Prediction of CFD processes of gaseous pollutants emission in high-temperature combustion chamber, Ęnvironment 11 , 3, 3-12 (2009). [2] R. Bilbao, M.U. Alzueta, A. Millera, V. Cantín, Experimetal study and modeling of the burnout zone in the natural gas reburning process. Chemical Engineering Science 50 , 16, 2579-2587 (1995). [3] A. Bogusławski, A. Tyliszczak, S. Kubacki, Numeryczne modelowanie procesów przepływowych, Materiały dydaktyczne Wydziału Inżynierii Mechanicznej i Informatyki, www

Open access

W. Longa

References W. Longa: The main paradigm used in the theory of calculation of the height and structure of combustion zone and melting zone in coke-fired cupolas. Polish Academy of Sciences Archives of Metallurgy and Materials. 54 , 4, 1207-1222 (2009). W. Longa: Calculation of height and structure of melting zone of coke cupolas. Polish Academy of Sciences Archives of Metallurgy and Materials 55 , 3, 669-682 (2010). W. Longa: Calculation of Combustion Zone Height in a Cupola Working

Open access

A. Poskart, H. Radomiak, P. Niegodajew, M. Zajemska and D. Musiał

REFERENCES [1] R.C. Flagan, J.H. Seinfeld, Fundamentals of air pollution engineering; Prentice-Hall: New Jersey, 2005. [2] D. Vallero, Fundamentals of air pollution. 4th edition. Library of Congress Cataloging-in-Publication Data. Academy Press, 2008. [3] C. Baukal, Oxygen enhanced combustion. Air Products and Chemicals Inc; CRC Press. Allentown: Pensylwania, 1998. [4] O. Marin, F. Châtel-Pélage, G.M. Usman, N.bPerrin, Low-oxygen enrichment in coal-fired utility boilers. Int. Tech. Conf. Coal Util. Fuel Syst., 27th, Clearwater, 2003

Open access

S.H. Choi, B. Ali, S.K. Hyun, J.J. Sim, W.J. Choi, W. Joo, J.H. Lim, Y.J. Lee, T.S. Kim and K.T. Park

Abstract

Combustion synthesis is capable of producing many types of refractory and ceramic materials, as well as metals, with a relatively lower cost and shorter time frame than other solid state synthetic techniques. TiO2 with Mg as reductant were dry mixed and hand compacted into a 60 mm diameter mold and then combusted under an Ar atmosphere. Depending on the reaction parameters (Mg concentration 2 ≤ α ≤ 4), the thermocouples registered temperatures between 1160°C and 1710°C · 3 mol of Mg gave the optimum results with combustion temperature (Tc) and combustion velocity (Uc) values of 1372°C and 0.26 cm/s respectively. Furthermore, this ratio also had the lowest oxygen concentration in this study (0.8 wt%). After combustion, DC plasma treatment was carried out to spheroidize the Ti powder for use in 3D printing. The characterization of the final product was performed using X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and N/O analysis.

Open access

Durga Verma, R. P. Patel and Mohan L. Verma

Abstract

In the present paper, TL and PL study of Dy3+ doped Sr2SiO4:Eu2+ phosphor is reported. A polycrystalline sample of Sr2SiO4:Eu2+, Dy3+ was prepared by combustion method. The obtained phosphor was characterized by powder X-ray diffraction, scanning electron microscopy, UV-Vis spectroscopy, PL and thermoluminescence. The results of the XRD studies obtained for Sr2SiO4:Eu2+, Dy3+ phosphor revealed its monoclinic structure. The average crystallite size was calculated as 12.77 nm. Thermoluminescence study was carried out for the phosphor using UV irradiation and a single glow peak was found. The thermoluminescence glow curves of the samples were measured at various concentrations of co-dopant. The kinetic parameter has been calculated using Chen’s glow curve method. In this paper, the photoluminescence and afterglow behavior of these phosphors are reported.

Open access

J. Cheng, X.P. Zou, G. Zhu, M. F. Wang, Y. Su, G.Q. Yang and X. M. Lü

In this paper, the effects of position of substrates in flames, preparation time, stability of flames and catalyst precursors on the synthesis of carbon nanofibers (CNFs) by ethanol catalytic combustion (ECC) were investigated. For investigating the effects of these influence factors on the synthesis of CNFs, several sets of controlled experiments were performed, such as preparation experiments with different position of substrates in flames, different preparation time, stable and unstable flames, and different catalyst precursors. In our experiments, the catalyst precursors were iron nitrate, cobalt nitrate, nickel nitrate, and iron chloride, cobalt chloride, nickel chloride. The as-synthesized products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. Our results indicate that the optimal position of substrates in flames is more than 1cm and less than 2.5cm, the optimal preparation time is more than 5min and less than 30min for massive yield, stable flames would be tent to synthesize CNFs with mainly single-type morphology and could improve the graphitization of CNFs, and the catalyst precursors obviously have effects on the synthesis of CNFs.

Open access

Francisco Granados-Correa and Juan Bonifacio-Martínez

Abstract

A rapid, safe and simple technique for the production of high purity strontium oxide powders via a chemical combustion process is reported. The combustion reactions were performed to optimize the fuel to oxidizer ratios in the reaction mixtures required to obtain pure SrO powders by varying the molar ratio of chemical precursors and the temperature. The synthesized powders were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectrometry, infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and N2-physisorption measurements. The results indicate that crystalline SrO was obtained using a 1:1 strontium nitrate: urea molar ratio at 1000 °C after 5 minutes. In addition, high-purity, homogeneous and crystalline SrO powders were easily produced in a short time via a chemical combustion process.

Open access

Guiyang Liu, Kong Xin, Lili Zhang, Baosen Wang and Ying He

Abstract

Spinel LiMn2O4 has been synthesized by a glycerol-assisted combustion synthesis method. The phase composition and morphologies of the compound were ascertained by X-ray diffraction (XRD) and scanning electron microscope (SEM). The electrochemical characterization was performed by using CR2032 coin-type cell. XRD analysis indicates that single phase spinel LiMn2O4 with good crystallinity has been obtained as a result of 5 h treatment at 600 °C. SEM investigation indicates that the average particle size of the sample is 200 nm. The initial discharge specific capacity of the LiMn2O4 is 123 mAh/g at a current density of 30 mA/g. When the current density increased to 300 mA/g, the LiMn2O4 offered a discharge specific capacity of 86 mAh/g. Compared with the LiMn2O4 prepared by a conventional solution combustion synthesis method at the same temperature, the prepared LiMn2O4 possesses higher purity, better crystallinity and more uniformly dispersed particles. Moreover, the initial discharge specific capacity, rate capability and cycling performance of the prepared LiMn2O4 are significantly improved.

Open access

J Mlnařík and J Hruška

References ZareNezhad, B.; Aminian, A. Accurate prediction of the dew points of acidic combustion gases by using an artificial neural network model. Energy Conversion and Management   2011 52 , 911-916. Huijbregts, W.; Leferink, R. Latest advances in the understanding of acid dewpoint corrosion: Corrosion and stress corrosion cracking in combustion gas condensates. Anti-Corrosion Methods and Materials   2004 51 (3), 173-188. Ganapathy, V. Calculating dew points of various acid

Open access

Yogesh Chaudhari, Chandrashekhar Mahajan, Ebrahim Abuassaj, Prashant Jagtap, Pramod Patil and Subhash Bendre

Abstract

Nanocrystalline multiferroic BiFeO3 ceramics was prepared by a novel solution combustion method (SCM). The X-ray diffraction (XRD) studies on structural properties of the synthesized ceramics reveal that the BiFeO3 ceramics has rhombhohedral perovskite structure with an average crystallite size of 15 nm. The ferroelectric P-E hysteresis loop measurement at room temperature shows unsaturated behavior with a partial reversal of polarization. Investigations on temperature dependence of dielectric constant in BiFeO3 demonstrate a clear dielectric anomaly at approximately around 380 °C, which corresponds to antiferromagnetic to paramagnetic phase transition (TN) and also evidences a possible coupling among the electric and magnetic dipoles of BiFeO3. A room temperature variation of dielectric constant “ɛ” and dielectric loss “tan δ” as a function of frequency in the range of 100 Hz — 1 MHz, confirms that both dielectric constant and loss are strong functions of frequency.