scholarly journals Thermogravimetric and Spectroscopic Analysis of 8-Hydroxyquinoline 5-Sulphonic Acid-melamine-formaldehyde Polymer Resin-IV

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Rajesh N. Singru
Keyword(s):  
Activation Energy ◽  
Thermogravimetric Analysis ◽  
Thermal Activation ◽  
Acid Catalyst ◽  
Frequency Factor ◽  
Entropy Change ◽  
Thermal Activation Energy ◽  
Sulphonic Acid ◽  
Continuous Increase ◽  
Using Data

The title terpolymer (8-HQ5-SAMF-IV) synthesized by the condensation of 8-hydroxyquinoline 5-sulphonic acid (8-HQ5-SA) and melamine (M) with formaldehyde (F) in the presence of acid catalyst and using varied 3 : 1 : 5 molar proportions of the reacting monomers. The synthesized terpolymer was characterized by different physicochemical techniques. The thermogravimetric analysis of terpolymer resin prepared in the present study has been carried out by nonisothermal thermogravimetric analysis technique in which sample is subjected to condition of continuous increase in temperature at linear rate. Thermal study of the resin was carried out to determine the mode of decomposition and thermal stability. Thermal decomposition curve was studied carefully with minute details. The Freeman-Carroll and Sharp-Wentworth methods have been used in the present investigation to calculate thermal activation energy and different kinetic parameter of the terpolymer resin. Thermal activation energy () calculated by two above mentioned methods, is in close agreement. The advantage of Freeman-Carroll method is to calculate both the order of reaction (n) and energy of activation in one single stage by keeping heating rate constant. By using data of thermogravimetric analysis, various thermogravimetric parameters like frequency factor (Z), entropy change (ΔS), free energy change (ΔF), and apparent entropy () have been determined using Freeman-Carroll method.

scholarly journals Thermoanalytical Study and Kinetics of New 8-Hydroxyquinoline 5-sulphonic Acid-Oxamide-Formaldehyde Terpolymer Resins

2009 ◽  
Vol 6 (s1) ◽  
pp. S171-S182
Author(s):  
Rajesh N. Singru ◽  
Anil B. Zade ◽  
Wasudeo B. Gurnule
Keyword(s):  
Activation Energy ◽  
Thermogravimetric Analysis ◽  
Thermal Activation ◽  
Acid Catalyst ◽  
Frequency Factor ◽  
Entropy Change ◽  
Thermal Activation Energy ◽  
Sulphonic Acid ◽  
Thermal Stabilities ◽  
Continuous Increase

The terpolymer resins (8-HQ5-SAOF) have been synthesized by the condensation of 8-hydroxyquinoline 5-sulphonic acid (8-HQ5-SA) and oxamide (O) with formaldehyde (F) in the presence of acid catalyst and using varied molar proportion of the reacting monomers. The synthesized terpolymer resins have been characterized by different physico-chemical techniques. Thermogravimetric analysis of all terpolymer resins in present study have been carried out by non-isothermal thermogravimetric analysis technique in which sample is subjected to condition of continuous increase in temperature at linear rate. Thermal study of the resins was carried out to determine their mode of decomposition and relative thermal stabilities. Thermal decomposition curves were studied carefully with minute details. The Freeman-Carroll and Sharp-Wentworth methods have been used in the present investigation to calculate thermal activation energy and different kinetic parameter of the terpolymer resins. Thermal activation energy (Ea) calculated with above two mentioned methods are in close agreement. The advantage of Freeman-Carroll method is to calculate both the order of reaction (n) and energy of activation in one single stage by keeping heating rate constant. By using data of thermogravimetric analysis, various thermodynamic parameters like frequency factor (Z), entropy change (Δ S), free energy change (Δ F) and apparent entropy (S*) have been determined using Freeman-Carroll method.

FADING CORRECTION OF NaCl(I) TLD

2006 ◽  
Vol 20 (09) ◽  
pp. 1077-1086
Author(s):  
B. ARUNKUMAR SHARMA ◽  
R. K. GARTIA ◽  
S. NABADWIP SINGH
Keyword(s):  
Activation Energy ◽  
Theoretical Prediction ◽  
Glow Curve ◽  
Thermal Activation ◽  
Room Temperature ◽  
Storage Period ◽  
Frequency Factor ◽  
Data Acquisition System ◽  
Thermal Activation Energy ◽  
State Of Art

The prediction of fading for the glow peaks relevant to dosimetry of iodised salt has been made using the values of the trapping parameters, namely the thermal activation energy (E), frequency factor (s) and the order of kinetic (b). This theoretical prediction has been checked with experimentally observed glow curves recorded after storage period of 2, 5, 10, 165, 375 and 790 days at room temperature (~21°C). Excellent agreement has been observed between the experimental and theoretical glow curves. This has been possible because of reliable retrieval of the trapping parameters by the use of Computerised Glow Curve Deconvolution (CGCD) as well as state-of-art of data acquisition system. The concept developed in the present paper in principle may be applied to any TLD.

About the Electrical Activation of 1×1020 cm-3 Ion Implanted Al in 4H-SiC at Annealing Temperatures in the Range 1500 - 1950°C

2018 ◽  
Vol 924 ◽  
pp. 333-338 ◽  
Author(s):  
Roberta Nipoti ◽  
Alberto Carnera ◽  
Giovanni Alfieri ◽  
Lukas Kranz
Keyword(s):  
Activation Energy ◽  
Sheet Resistance ◽  
Annealing Time ◽  
Thermal Activation ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Thermal Activation Energy ◽  
Electrical Activation ◽  
Temperature Range ◽  
Annealing Temperatures

The electrical activation of 1×1020cm-3implanted Al in 4H-SiC has been studied in the temperature range 1500 - 1950 °C by the analysis of the sheet resistance of the Al implanted layers, as measured at room temperature. The minimum annealing time for reaching stationary electrical at fixed annealing temperature has been found. The samples with stationary electrical activation have been used to estimate the thermal activation energy for the electrical activation of the implanted Al.

Temperature/Doping-Dependency of the Electrical Properties of the Nickel Doped Copper Oxide Thin Films

2021 ◽  
Vol 16 (2) ◽  
pp. 163-169
Author(s):  
Alaa Y. Mahmoud ◽  
Wafa A. Alghameeti ◽  
Fatmah S. Bahabri
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Electrical Properties ◽  
Thermal Activation ◽  
Doping Concentration ◽  
Energy Gap ◽  
Cupric Oxide ◽  
Electrical Energy ◽  
Thermal Activation Energy ◽  
Ni Doping

The electrical properties of the Nickel doped cupric oxide Ni-CuO thin films with various doping concentrations of Ni (0, 20, 30, 70, and 80%) are investigated at two different annealing temperatures; 200 and 400 °C. The electrical properties of the films; namely thermal activation energy and electrical energy gap are calculated and compared. We find that for the non-annealed Ni-CuO films, both thermal activation energy and electrical energy gap are decreased by increasing the doping concentration, while for the annealed films, the increase in the Ni doping results in the increase in thermal activation energy and electrical energy gap for most of the Ni-CuO films. We also observe that for a particular concentration, the annealing at 200 °C produces lower thermal activation energy and electrical energy gap than the annealing at 400 °C. We obtained two values of the activation energy varying from -5.52 to -0.51 eV and from 0.49 to 3.36 eV, respectively, for the annealing at 200 and 400 °C. We also obtained two values of the electrical bandgap varying from -11.05 to -1.03 eV and from 0.97 to 6.71 eV, respectively, for the annealing at 200 and 400 °C. It is also noticeable that the increase in the doping concentration reduces the activation energy, and hence the electrical bandgap energies.

scholarly journals Pyrolysis Kinetic Parameters of Omari Oil Shale Using Thermogravimetric Analysis

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4060
Author(s):  
Ziad Abu El-Rub ◽  
Joanna Kujawa ◽  
Samer Al-Gharabli
Keyword(s):  
Activation Energy ◽  
Thermogravimetric Analysis ◽  
Kinetic Parameters ◽  
Oil Shale ◽  
Arrhenius Plot ◽  
Frequency Factor ◽  
Coefficient Of Determination ◽  
Assay Method ◽  
Temperature Integral ◽  
Integral Approximation

Oil shale is one of the alternative energies and fuel solutions in Jordan because of the scarcity of conventional sources, such as petroleum, coal, and gas. Oil from oil shale reservoirs can be produced commercially by pyrolysis technology. To optimize the process, mechanisms and rates of reactions need to be investigated. Omari oil shale formation in Jordan was selected as a case study, for which no kinetic models are available in the literature. Oil shale was analyzed using the Fischer assay method, proximate analysis (moisture, volatile, and ash), gross calorific value, elemental analysis (CHNS), and X-ray fluorescence (XRF) measurements. Non-isothermal thermogravimetric analysis was applied to study the kinetic parameters (activation energy and frequency factor) at four selected heating rates (5, 10, 15, and 20 °C/min). When oil shale was heated from room temperature to 1100 °C, the weight loss profile exhibited three different zones: drying (devolatilization), pyrolysis, and mineral decomposition. For each zone, the kinetic parameters were calculated using three selected methods: integral, temperature integral approximation, and direct Arrhenius plot. Furthermore, the activation energy in the pyrolysis zone was 112–116 kJ/mol, while the frequency factor was 2.0 × 107 − 1.5 × 109 min−1. Moreover, the heating rate has a directly proportional relationship with the rate constant at each zone. The three different methods gave comparable results for the kinetic parameters with a higher coefficient of determination (R2) for the integral and temperature integral approximation compared with the direct Arrhenius plot. The determined kinetic parameters for Omari formation can be employed in developing pyrolysis reactor models.

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