scholarly journals Thermoluminescence and dosimetric characteristics study of quartz samples from Seyhan Dam Lake Terraces

2018 ◽  
Vol 96 (7) ◽  
pp. 779-783 ◽  
Author(s):  
Mehmet Yüksel
Keyword(s):  
Dose Response ◽  
Dose Range ◽  
Frequency Factor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Response Range ◽  
Minimum Detectable Dose ◽  
Constant Heating ◽  
Beta Dose ◽  
Seyhan Dam

In the present study, soil samples of Seyhan Dam Lake Terraces were collected and then pure quartz samples were separated using various separation methods. The quartz samples were characterized using X-ray diffraction (XRD) and scanning electron microscopy – energy dispersive X-ray spectroscopy (SEM-EDX) methods. Thermoluminescence (TL) measurements were carried out using lexsyg smart TL – optically stimulated luminescence (OSL) reader with a constant heating rate of 1 °C/s from room temperature to 450 °C. Beta dose response of the samples were investigated in the dose range from 1 to 10 Gy and the linear dose response range was determined as 1–5 Gy. Computerized glow curve deconvolution (CGCD), peak shape, and isothermal decay (ID) methods were used to determine activation energy (E), order of kinetics (b), and frequency factor (s) of the samples. Furthermore, in this study, minimum detectable dose values of the quartz samples were also determined.

scholarly journals Thermoluminescence Characteristics of Terbium Doped Zinc Borates

Crystals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 557 ◽  
Author(s):  
Nil Kucuk
Keyword(s):  
Glow Curve ◽  
Single Phase ◽  
Peak Shape ◽  
X Ray Diffraction ◽  
X Ray ◽  
Initial Rise ◽  
Linear Behavior ◽  
Minimum Detectable Dose ◽  
Xrd Studies ◽  
Dose Responses

In this work, structural and thermoluminescence (TL) characteristics for ZnB2O4:xTb3+ (x = 0.01, 0.02, 0.03, 0.04, 0.05, and 0.10 mole) phosphors were investigated. The phosphors were prepared via synthesis of nitric acid. The X-ray diffraction (XRD) studies show that the synthesized samples can be indexed to nearly single-phase cubic ZnB2O4. The TL characteristics following 90Sr beta irradiation (40 mCi) were studied. TL intensity is found to depend on Tb concentration. The optimal concentration of the doped Tb3+ is 0.03 mol in TL measurements. TL dose responses of the phosphors to beta doses of 0.143, 0.715, 1.43, 15, 30 and 60 Gy showed fairly linear behavior. The minimum detectable dose (MDD) value for ZnB2O4:0.04Tb3+ was found to be 87 mGy. The kinetic parameters of the ZnB2O4:0.03Tb3+ sample were estimated by the glow curve deconvolution, the initial rise, the curve fitting, and the peak shape methods. The results indicate that these phosphors are thought to be promising candidates as TL materials. The results provide valuable knowledge of the characteristics of Tb-doped ZnB2O4 for use in dosimetry research.

scholarly journals Synthesis, Characterization, and Thermal Kinetics of Mixed Gadolinium: Calcium Heptamolybdate System

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
R. K. Koul ◽  
Shivani Suri ◽  
Vishal Singh ◽  
K. K. Bamzai
Keyword(s):  
Grown Crystal ◽  
Frequency Factor ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Relevant Model ◽  
X Ray ◽  
Thermoanalytical Techniques ◽  
Thermal Kinetics ◽  
Symmetry Structure ◽  
Kinetics Of

Synthesis of mixed gadolinium calcium heptamolybdate (GdCaHM) system in silica gel medium using single gel single tube technique has been successfully achieved. The grown crystal exhibits various morphologies, which includes spherulites, multifaceted, and square platelets. The nature of the grown material was established by X-ray diffraction (XRD) studies. Fourier transform infrared spectroscopy (FTIR) study signifies the presence of heptamolybdate (Mo7O24) and water symmetry structure, whereas energy dispersive X-ray analysis (EDAX) establishes the stoichiometric of the grown crystal as GdCaMo7O24·8H2O. The thermal behaviour was studied using the thermoanalytical techniques, which include thermogravimetry (TG), differential thermal analysis (DTA), and differential scanning calorimetry (DSC). Results obtained on the application of TG based models, namely, Horowitz-Metzger, Coats-Redfern, and Piloyan-Novikova, suggest the contracting cylindrical model as the relevant model for the thermal decomposition of the material. The kinetic parameters, namely, the order of reaction (n), activation energy (Ea), frequency factor (Z), and entropy (ΔS*), were also calculated using these three models.

scholarly journals Dye-Sensitized Solar Cells Based onBi4Ti3O12

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Zeng Chen ◽  
Shengjun Li ◽  
Weifeng Zhang
Keyword(s):  
Solar Cells ◽  
Dye Sensitized Solar Cells ◽  
Visible Region ◽  
X Ray Diffraction ◽  
Photovoltaic Properties ◽  
X Ray ◽  
Glass Substrates ◽  
Dye Sensitized ◽  
Response Range ◽  
Sensitized Solar Cells

Bismuth titanate (Bi4Ti3O12) particles were synthesized by hydrothermal treatment and nanoporous thin films were prepared on conducting glass substrates. The structures and morphologies of the samples were examined with X-ray diffraction and scanning electron microscope (SEM). Significant absorbance spectra emerged in visible region which indicated the efficient sensitization of Bi4Ti3O12with N3 dye. Surface photovoltaic properties of the samples were investigated by surface photovoltage. The results further indicate that N3 can extend the photovoltaic response range of Bi4Ti3O12nanoparticles to the visible region, which shows potential application in dye-sensitized solar cell. As a working electrode in dye-sensitized solar cells (DSSCs), the overall efficiency reached 0.48% after TiO2modification.

scholarly journals Kinetic Analysis of the Thermal Decomposition of a Synthetic Mercury Jarosite

Minerals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 200 ◽  
Author(s):  
Mizraim Flores ◽  
Iván Reyes ◽  
Elia Palacios ◽  
Francisco Patiño ◽  
Julio Juárez ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Thermal Decomposition ◽  
Environmental Concern ◽  
Frequency Factor ◽  
X Ray Diffraction ◽  
Thermal Decomposition Process ◽  
X Ray ◽  
The Third ◽  
Mercury Oxide

Jarosites are widely used in the hydrometallurgical industry of zinc to eliminate iron and other impurities contained in the concentrates. However, these compounds can also incorporate elements of significant environmental concern such as Tl+, Hg2+, Pb2+, Cd2+, Cr(VI), and As(V). In this work, the characterization of a synthetic mercury jarosite and its thermal decomposition kinetics are reported. XRD and FTIR analyses confirm that a mercury jarosite—Hg0.40(H3O)0.2]Fe2.71(SO4)2.17(OH)4.79(H2O)0.44—was successfully synthesized. Four mass loss events were observed by thermogravimetric analysis at 290 °C, 365 °C, 543 °C, and 665 °C. The third event corresponds to mercury decomposition into mercury oxide, whilst the forth is related to the jarosite to hematite transformation determined by X-ray diffraction starting at around 600 °C. According to the kinetic parameters (activation energy and frequency factor) of the thermal decomposition process, the fourth stage required the highest energy (Ea = 234.7 kJ∙mol−1), which corresponds to elimination of sulfur and oxygen from the jarosite lattice. Results show that jarosite-type compounds have the capability to incorporate heavy metals into their structure, retaining them even at high temperatures. Therefore, they can be used as a remediation strategy for heavy metals, such as mercury and others elements of environmental concern.

Structure, Annealing Characteristics and Mechanical Properties of Mg60Cu30-yY10Siy Bulk Amorphous Alloys

2002 ◽  
Vol 754 ◽  
Author(s):  
U. Wolff ◽  
B. Yang ◽  
N. Pryds ◽  
J.A. Wert
Keyword(s):  
Mechanical Properties ◽  
Amorphous Alloys ◽  
Simple Technique ◽  
Partial Substitution ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Glass Forming ◽  
Si Content ◽  
Constant Heating

ABSTRACTThe effect of different Si contents on the glass forming ability (GFA) and the amorphous-to-crystalline transformation has been investigated for the Mg-Cu-Y-Si system. Four Mg60Cu30-yY10Siy (y = 1–5 at.%) alloys were prepared using a relatively simple technique of rapid cooling of the melt in a copper mould. Crystallization was induced by heat treatment of the alloys and the samples were then characterized concerning their microstructure and thermal stability by X-ray diffraction (XRD), optical (OM) and scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) at a constant heating rate. Partial substitution of Cu by Si leads to a transition of the as-cast structure at a constant cooling rate from amorphous to crystalline with increasing Si content. Furthermore, the glass transition temperature (Tg) of the Mg-Cu-Y-Si alloy is lower compared to the Mg-Cu-Y system. The mechanical properties of the bulk Mg-Cu-Y-Si alloys have been investigated and found to vary with the Si content.

scholarly journals Исследование приповерхностного слоя германия, имплантированного ионами кобальта

2019 ◽  
Vol 45 (20) ◽  
pp. 36
Author(s):  
В.В. Базаров ◽  
В.А. Шустов ◽  
Н.М. Лядов ◽  
И.А. Файзрахманов ◽  
И.В. Янилкин ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ion Implantation ◽  
Dose Range ◽  
Implantation Dose ◽  
X Ray Diffraction ◽  
Cobalt Ions ◽  
X Ray ◽  
Germanium Surface ◽  
Scanning Electron

The results of investigation of germanium surface nanostructured by ion implantation are presented. Single-crystal plates of germanium (c Ge) were irradiated by cobalt ions with an energy of 40 keV in the dose range (2 × 1016 - 8 × 1016) Co + / cm2. The method of scanning electron microscopy (SEM) has been used to study the evolution of the morphology of germanium surface with an increase of implantation dose. It has been found that with increasing dose of implantation, a layer of spherical formations with diameter of ~ 150 nm gradually forms on the surface of implanted germanium. The analysis of X-ray diffraction spectra indicated the appearance of nano-sized cobalt germanide (CoGe) particles in the implanted layer.

In situ and Ex situ Measurements of Stress Evolution in the Cobalt-Silicon System

2000 ◽  
Vol 611 ◽  
Author(s):  
G. Lucadamo ◽  
C. Lavoie ◽  
C. Cabral ◽  
R. A. Carruthers ◽  
J.M.E. Harper
Keyword(s):  
Room Temperature ◽  
Biaxial Stress ◽  
Ex Situ ◽  
Silicide Formation ◽  
Stress Evolution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bending Force ◽  
Constant Heating

ABSTRACTThe biaxial stress in Co thin-films has been investigated in situ by measuring changes in substrate curvature that occurred during deposition and annealing.Films of Co, 35 to 500 nm in thickness, were deposited by UHV magnetron sputtering at room temperature on Si (100) and poly-Si substrates.Results show that during Co deposition the bending force increased linearly with film thickness; a signature of constant stress.In addition, the stress evolution during silicide formation was measured under constant heating rate conditions from room temperature up to 700°C. The stress-temperature curve was correlated with Co2Si, CoSi, and CoSi2 phase formation using in situ synchrotron X-ray diffraction measurements.The room temperature stress for the CoSi2 phase was found to be ∼0.8 GPa (tensile) in the films deposited on Si (100) and ∼1 GPa (tensile) on the films deposited on poly-Si.The higher tensile stress in the poly-Si sample could be a result of Si grain growth during annealing.

scholarly journals Infrared stimulated luminescence (IRSL) properties of natural aluminum corrosion

2012 ◽  
Vol 39 (3) ◽  
pp. 227-232 ◽  
Author(s):  
Eren Şahiner ◽  
Niyazi Meriç
Keyword(s):  
Dose Response ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Infrared Stimulated Luminescence ◽  
Retrospective Dosimetry ◽  
Aluminum Corrosion

Abstract In this paper, the infrared stimulated luminescence (IRSL) property of naturally corroded aluminum and its possible applications in retrospective dosimetry have been briefly studied. Results are interesting, in particular with regard to the efforts of finding new and widely available materials for accident dosimetry. For aluminum corrosion, the dose response was found to be approximately linear between 2–80 Gy and to reach saturation before 300 Gy. The signal also showed good repro-ducibility without significant fading over storage durations of up to four mounts at room temperature. In addition to the luminescence, the corrosion samples were also analysed by X-ray Fluorescence (XRF) and X-ray Diffraction (XRD), but conclusive identification of the luminescent phase could not be made. It is concluded that the IRSL signals of this material can be favourable for dosimetry research.

Magnetite and Anti-Microbial Properties of Ag2O-CaO-Fe2O3-SiO2 Glass-Ceramic by Sol-Gel Method

2011 ◽  
Vol 399-401 ◽  
pp. 869-872
Author(s):  
Bin Li ◽  
Hai Feng Chen ◽  
Li Hua Wen ◽  
Chen Ma
Keyword(s):  
Glass Ceramic ◽  
Crystallization Process ◽  
Sol Gel ◽  
Frequency Factor ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Heat Treated

Ag2O-CaO-Fe2O3-SiO2glass-ceramic was prepared by the sol-gel method. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) were used to investigate crystallization process of Ag2O-CaO-Fe2O3-SiO2glass. The kinetic results show that the values of the activation energy and frequency factor of the glass are 441.991 KJ/ mol and 1.58×1020, respectively. And the dimensionality of crystal growth, n, decreases as the heating rate increases. The crystalline phases of the glass-ceramic are magnetite, wollastonite and minor hematite. The saturation magnetization and coercive force of the heat-treated glass are 0.08 Wb/m2and 14 KA/m at room temperature. The glass-ceramic has some capacity of anti-microbial.

scholarly journals Thermoluminescent and X-ray diffraction methods in dating of ceramics from archaeological excavations of the Orikti monument (Almaty region)

2020 ◽  
pp. 4-10
Author(s):  
Askar Bakhadur ◽  
Nadezhda Aluker ◽  
Galymzhan Bekseitov ◽  
Yerbolat Ospanov ◽  
Bolat Uralbekov
Keyword(s):  
Dose Rate ◽  
Dose Range ◽  
Sampling Site ◽  
Absorbed Dose ◽  
Average Dose ◽  
Preparation Technique ◽  
X Ray Diffraction ◽  
Absorbed Dose Rate ◽  
X Ray ◽  
Ceramic Samples

In this work, the ages of archaeological ceramics were determined by the thermoluminescent method after X-ray diffraction analysis (XRD) of ceramic samples, which confirms that quartz is the main component phase of the products. This allowed to use the sample preparation technique without isolating the quartz phase from the ceramic sample. Silicon oxide based soil-equivalent thermoluminescent detectors were used to determine the annual absorbed dose rate at the sampling site. The average dose rate at sampling site was 0.62 ± 0.02 cGy/year. Calculation of the ceramics ages was carried out after checking the linearity of lightsums accumulation for samples in the dose range up to 2000 cGy. Based on the performed studies, the ages of the ceramic products were determined that do not contradict to archaeologists dating of these products. It is proposed to use the procedure for determining ceramic samples by the thermoluminescent method after their phase composition identification by XRD. In the case of the predominant mineral composition of quartz phase (the proportion of quartz is more than 60% of the total composition of ceramics), the measurements can be carried out without the quartz isolating; while presence of clay mineral fractions commensurate with quartz levels can lead to the separation of the quartz.

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