Oxidation of Acid-proof Steel Foil as a Method of Deposition of Phases Active in Nitrogen Oxides Decomposition on Metallic Monolith Walls

2013 ◽  
Vol 651 ◽  
pp. 317-320 ◽  
Author(s):  
E. Bielańska ◽  
J. Camra ◽  
J. Dutkiewicz ◽  
P. Kornelak ◽  
M. Najbar ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Chemical Composition ◽  
Nitrogen Oxides ◽  
Phase Structure ◽  
Air Flow ◽  
Energy Dispersive ◽  
Chemical Compositions ◽  
X Ray ◽  
Metallic Monolith ◽  
Main Factor

Pieces of 1H18N9T acid-proof steel foil were subjected to thermoprogrammed oxidation up to 823K, 873K, 1023K and 1113K in air flow. The phases in the oxide layers were determined by Raman spectroscopy. The chemical compositions of the surface microlayers of oxidized foils were investigated by energy dispersive X-ray spectrometry and the chemical compositions of their surface nanolayers were determined by X-ray photoelectron spectrometry. The affinity to oxygen of the foil components was found to be a main factor determining chemical composition and phase structure of the oxides.

Plasma Electrolytic Carbonitriding of 20CrMnTi Steel

2010 ◽  
Vol 154-155 ◽  
pp. 1393-1396 ◽  
Author(s):  
Xin Min Fan ◽  
Jie Wen Huang ◽  
Qun Yang ◽  
Jun Jie Gan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Composition ◽  
Phase Structure ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Electrolytic ◽  
Scanning Electron ◽  
Microhardness Tester

A carbontirided layer was produced on 20CrMnTi steel by plasma electrolytic carbonitriding (PEC/N). Scanning electron microscopy with an energy dispersive X-ray analysis was employed to study the morphology and chemical composition of the carbonitrided layer. Hardness of the layer was measured using a microhardness tester, and the phase structure was determined by X-ray diffraction. The results show that a compact carbonitrided layer can be obtained on the surface of 20CrMnTi steel. The thickness of the layer increases with carbontriding time. When the sample was treated at 120V for 20min, the thickness is 45μm and the highest microhardness is 766HV0.05. The carbontrided layers are composed of Fe3C, Fe5C2, ε-Fe3N and α-Fe.

Synthesis and Characterizations of Strontium Substituted Hydroxyapatite Thin Films

2010 ◽  
Vol 93-94 ◽  
pp. 231-234
Author(s):  
B. Hongthong ◽  
Satreerat K. Hodak ◽  
Sukkaneste Tungasmita
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Chemical Composition ◽  
Spin Coating ◽  
Phase Structure ◽  
Sol Gel ◽  
Cross Linking ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process

Strontium substituted hydroxyapatite(SrHAp) were fabricated both in the form of powder as reference and thin film by using inorganic precursor reaction. The sol-gel process has been used for the deposition of SrHAp layer on stainless steal 316L substrate by spin coating technique, after that the films were annealed in air at various temperatures. The chemical composition of SrHAp is represented (SrxCa1-x)5(PO4)3OH, where x is equal to 0, 0.5 and 1.0. Investigations of the phase structure of SrHAp were carried out by using X-ray diffraction technique (XRD). The results showed that strontium is incorporated into hydroxyapatite where its substitution for calcium increases in the lattice parameters, and Sr3(PO4)2 can be detected at 900°C. The SEM micrographs showed that SrHAp films exhibited porous structure before develop to a cross-linking structure.

scholarly journals Synthesis and Structural Properties of Nanocomposites Based on Synthetic Opals and Active Dielectrics

2019 ◽  
Vol 12 (1) ◽  
pp. 19
Author(s):  
Bilal Abu Sal
Keyword(s):  
Raman Spectroscopy ◽  
Single Crystals ◽  
Structural Properties ◽  
Raman Spectra ◽  
Phase Structure ◽  
Opal Matrix ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal State ◽  
Synthetic Opals

This work is devoted to generalize and analyze the previouse results of new photonic-crystalline nanomaterials based on synthetic opals and active dielectrics. Data were characterized by X-ray diffraction and Raman spectroscopy. Active dielectrics infiltrated into the pores of the opal from the melt. The phase structure composition of the infiltrated materials into the pores of the opal matrix were analyzed. The results of x-ray diffraction and Raman spectra allowed to establish the crystal state of active dielectrics in the pores of the opal. The Raman spectra of some opal-active dielectric nanocomposites revealed new bands and changes in band intensities compared to the spectra of single crystals of active dielectrics. Further more, differences in band intensities in the spectra were measured at different spots of the sample‘s surface were observed. The revealed changes were attributed to the formation of new crystalline phases due to the injected dielectrics in opal pores.

Decoration of graphene films with europium oxide through the R.F. sputtering technique

MRS Advances ◽  
2019 ◽  
Vol 4 (53) ◽  
pp. 2897-2905
Author(s):  
R. Rangel ◽  
V. J. Cedeño ◽  
J. L. Cervantes ◽  
P. Bartolo-Pérez ◽  
J. A. Montes ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Spatial Distribution ◽  
Photoelectron Spectroscopy ◽  
Graphene Film ◽  
Europium Oxide ◽  
X Ray ◽  
Radio Frequency Sputtering ◽  
Graphene Films ◽  
Europium Concentration ◽  
Main Factor

ABSTRACTThe present work is aimed to study a comparison among synthesized graphene films, deposited on copper substrates and commercial graphene films; both decorated with Eu2O3 particles, with the purpose of promoting photoluminescence. The decoration procedure was achieved using the radio frequency sputtering (R.F. Sputtering) technique for the deposition of Eu2O3 on synthesized or commercial graphene films. The SEM obtained images, show differences in morphology when commercial and synthesized graphene films are compared. Our results indicate that the type of surface is the main factor that accounts for the europium oxide spatial distribution that ultimately leads to luminescence enhancing. The x-ray photoelectron spectroscopy (XPS) analyses, showed the trivalent oxidation state of europium and the atomic content of Europium for both; the commercial graphene film and synthesized one, where the first one presented the higher europium concentration. Analysis by Raman spectroscopy reveals that graphene films become disordered after the decoration is achieved. The main Raman bands of the commercial graphene films undergo a remarkable red shift, as a consequence of the presence of europium oxide It was observed that the interaction of Eu2O3 with the sp2 levels of graphene, improves the red photoluminescence of the samples grown on both, commercial and prepared graphene films.

scholarly journals Characterization of the microstructure, microsegregation, and phase composition of ex-situ Fe–Ni–Cr–Al–Mo–TiCp composites fabricated by three-dimensional plasma metal deposition on 10CrMo9–10 steel

2020 ◽  
Vol 20 (4) ◽  
Author(s):  
Łukasz Rakoczy ◽  
Kevin Hoefer ◽  
Małgorzata Grudzień-Rakoczy ◽  
Bogdan Rutkowski ◽  
Marcin Goły ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Composite Coatings ◽  
Thermodynamic Simulation ◽  
Iron Concentration ◽  
Ex Situ ◽  
Chemical Compositions ◽  
Powder Mixtures ◽  
Equivalent Radius ◽  
X Ray ◽  
The Matrix

Abstract Quaternary powder mixtures yNi–20Cr–1.5Al–xTiCp (y = 78.5, 73.5, 68.5; x = 0, 5, 10) were deposited on ferritic 10CrMo9–10 steel to form on plates ex-situ composite coatings with austenitic-based matrix. Plasma deposition was carried out with various parameters to obtain eight variants. The microstructure, chemical composition, phase constitution, phase transformation temperatures, and microhardness of the two reference TiCp-free coatings and six ex-situ composites were investigated by X-ray diffraction, scanning and transmission electron microscopy, energy-dispersive X-ray spectroscopy, thermodynamic simulation, and Vickers microhardness measurements. All composites had an austenite matrix with lattice parameter a = 3.5891–3.6062 Å, calculated according to the Nelson–Riley extrapolation. Microstructural observations revealed irregular distribution of TiCp in the composites. Large particles generally occurred near the external surface due to the acting buoyancy effect, whereas in the interior smaller particles, with an equivalent radius around 0.2–0.6 μm, were present. Due to initial differences in the chemical composition of powder mixtures and also subsequent intensive mixing with the low-alloy steel in the liquid pool, the matrix of the composites was characterized by various chemical compositions with a dominating iron concentration. Interaction of TiCp with matrix during deposition led to the formation of nano-precipitates of M23C6 carbides at the interfaces. Based on the ThermoCalc simulation, the highest solidus and liquidus temperatures of the matrix were calculated to be for the composite fabricated by deposition of 73.5Ni–20Cr–1.5Al–5TiCp powder mixture at I = 130 A. The mean microhardness of the TiCp-free coatings was in the range 138–146 μHV0.1, whereas composites had hardnesses at least 50% higher, depending on the initial content of TiCp.

scholarly journals Hot bubbles of planetary nebulae with hydrogen-deficient winds

2018 ◽  
Vol 620 ◽  
pp. A98 ◽  
Author(s):  
R. Heller ◽  
R. Jacob ◽  
D. Schönberner ◽  
M. Steffen
Keyword(s):  
Chemical Composition ◽  
High Resolution ◽  
Thermal Conduction ◽  
Thermal Structure ◽  
Neutral Hydrogen ◽  
Planetary Nebulae ◽  
Chemical Compositions ◽  
Heat Conducting ◽  
X Ray ◽  
Similar Solutions

Context. The first high-resolution X-ray spectroscopy of a planetary nebula, BD +30° 3639, opened the possibility to study plasma conditions and chemical compositions of X-ray emitting “hot” bubbles of planetary nebulae in much greater detail than before. Aims. We investigate (i) how diagnostic line ratios are influenced by the bubble’s thermal structure and chemical profile, (ii) whether the chemical composition inside the bubble of BD +30° 3639 is consistent with the hydrogen-poor composition of the stellar photosphere and wind, and (iii) whether hydrogen-rich nebular matter has already been added to the bubble of BD +30° 3639 by evaporation. Methods. We applied an analytical, one-dimensional (1D) model for wind-blown bubbles with temperature and density profiles based on self-similar solutions including thermal conduction. We also constructed heat-conduction bubbles with a chemical stratification. The X-ray emission was computed using the well-documented CHIANTI code. These bubble models are used to re-analyse the high-resolution X-ray spectrum from the hot bubble of BD +30° 3639. Results. We found that our 1D heat-conducting bubble models reproduce the observed line ratios much better than plasmas with single electron temperatures. In particular, all the temperature- and abundance-sensitive line ratios are consistent with BD +30° 3639 X-ray observations for (i) an intervening column density of neutral hydrogen, NH = 0.20-0.10+0.05 × 1022cm−2, (ii) a characteristic bubble X-ray temperature of TX = 1.8 ± 0.1 MK together with (iii) a very high neon mass fraction of about 0.05, virtually as high as that of oxygen. For lower values of NH, we cannot exclude the possibility that the hot bubble of BD +30° 3639 contains a small amount of “evaporated” (or mixed) hydrogen-rich nebular matter. Given the possible range of NH, the fraction of evaporated hydrogen-rich matter cannot exceed 3% of the bubble mass. Conclusions. The diffuse X-ray emission from BD +30° 3639 can be well explained by models of wind-blown bubbles with thermal conduction and a chemical composition equal to that of the hydrogen-poor and carbon-, oxygen-, and neon-rich stellar surface.

scholarly journals Analysis of Chemical Composition of Portland Cement in Ghana: A Key to Understand the Behavior of Cement

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Mark Bediako ◽  
Eric Opoku Amankwah
Keyword(s):  
Chemical Composition ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Chemical Compositions ◽  
Test Results ◽  
Brand Name ◽  
X Ray ◽  
Portland Limestone Cement ◽  
Limestone Cement ◽  
Construction Works

The performance of Portland cement in concrete or mortar formation is very well influenced by chemical compositions among other factors. Many engineers usually have little information on the chemical compositions of cement in making decisions for the choice of commercially available Portland cement in Ghana. This work analyzed five different brands of Portland cement in Ghana, namely, Ghacem ordinary Portland cement (OPC) and Portland limestone cement (PLC), CSIR-BRRI Pozzomix, Dangote OPC, and Diamond PLC. The chemical compositions were analyzed with X-Ray Fluorescence (XRF) spectrometer. Student’st-test was used to test the significance of the variation in chemical composition between standard literature values and each of the commercial cement brands. Analysis of variance (ANOVA) was also used to establish the extent of variations between chemical compositions and brand name of the all commercial Portland cement brands. Student’st-test results showed that there were no significant differences between standard chemical composition values and that of commercial Portland cement. The ANOVA results also indicated that each brand of commercial Portland cement varies in terms of chemical composition; however, the specific brands of cement had no significant differences. The study recommended that using any brand of cement in Ghana was good for any construction works be it concrete or mortar formation.

scholarly journals Origin of Ultraviolet Luminescence from Bulk ZnO Thin Films Grown by Molecular Beam Epitaxy

2011 ◽  
Vol 1 ◽  
pp. 135-139 ◽  
Author(s):  
M. Asghar ◽  
Khalid Mahmood ◽  
Adnan Ali ◽  
M.A. Hasan ◽  
I. Hussain ◽  
...  
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Molecular Beam Epitaxy ◽  
Room Temperature ◽  
Molecular Beam ◽  
Energy Dispersive ◽  
Zno Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Luminescence

Origin of ultraviolet (UV) luminescence from bulk ZnO has been investigated with the help of photoluminescence (PL) measurements. Thin films of ZnO having 52%, 53% and 54% of Zn-contents were prepared by means of molecular beam epitaxy (MBE). We observed a dominant UV line at 3.28 eV and a visible line centered at 2.5 eV in the PL spectrum performed at room temperature. The intensity of UV line has been found to depend upon the Zn percentage in the ZnO layers. Thereby, we correlate the UV line in our samples with the Zn-interstitials-bound exciton (Zni-X) recombination. The results obtained from, x-ray diffraction, the energy dispersive X-ray spectrum (EDAX) and Raman spectroscopy supported the PL results.

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