Synthesis, thermogravimetric analysis and enthalpy determination of lanthanide β-diketonates

2019 ◽  
Vol 107 (12) ◽  
pp. 1173-1184 ◽  
Author(s):  
Shayan Shahbazi ◽  
C. J. Oldham ◽  
Austin D. Mullen ◽  
John D. Auxier II ◽  
Howard L. Hall
Keyword(s):  
Thermogravimetric Analysis ◽  
Linear Trend ◽  
Nuclear Fission ◽  
Lanthanide Chelates ◽  
Melting Point Analysis ◽  
Point Analysis ◽  
Product Separation ◽  
Sublimation Thermodynamics ◽  
Constant Heating

Abstract This work reports thermodynamic characterizations of lanthanide β-diketonates for use in nuclear fission product separation. Adsorption and sublimation enthalpies have been shown to be linearly correlated, therefore there is motivation to determine sublimation thermodynamics. An isothermal thermogravimetric analysis method is employed on fourteen lanthanide chelates for the ligands 2,2,6,6-tetramethyl-3,5-heptanedione and 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedione to determine sublimation enthalpies. No linear trend is seen across the series; values show a cyclical nature, possibly indicating a greater influence of chemisorption for some complexes and less of a role of physisorption in dictating adsorption differences between lanthanides in the same series. This is in line with previous reports in terms of the chromatographic separation order of the lanthanides. The results reported here can be used to manipulate separations parameters and column characteristics to better separate these lanthanide chelates. Fourteen chelates of the ligand 1,1,1-trifluoro-2,4-pentanedione are also thermally characterized but found to not sublime and be undesirable for this method. Additionally, all chelates are characterized by constant heating thermogravimetric analysis coupled with mass spectrometry, melting point analysis, elemental analysis and FTIR.

Characterization of Different Types of Biomass Wastes Using Thermogravimetric and ICP-MS Analyses

2020 ◽  
Vol 70 (12) ◽  
pp. 4594-4600
Keyword(s):  
Thermogravimetric Analysis ◽  
Food Industry ◽  
Wood Waste ◽  
Biomass Ash ◽  
Minor Elements ◽  
Ms Analysis ◽  
Icp Ms ◽  
Different Types

The purpose of this study was to characterize some types of biomass wastes resulted from different activities such as: agriculture, forestry and food industry using thermogravimetric and ICP-MS analyses. Also, it was optimized an ICP-MS method for the determination of As, Cd and Pb from biomass ash samples. The ICP-MS analysis revealed that the highest concentration of metals (As, Cd, Pb) was recorded in the wood waste ash sample, also the thermogravimetric analysis indicated that the highest amount of ash was obtained for the same sample (26.82%). The biomass wastes mentioned in this study are alternative recyclable materials, reusable as pellets and briquettes. Keywords: ash, biomass, ICP-MS, minor elements, TG

scholarly journals Prediction of regional agro-industrial wastes characteristics by thermogravimetric analysis to obtain bioenergy using thermal process

2018 ◽  
Vol 37 (1) ◽  
pp. 544-557 ◽  
Author(s):  
Alejandra Saffe ◽  
Anabel Fernandez ◽  
Germán Mazza ◽  
Rosa Rodriguez
Keyword(s):  
Thermogravimetric Analysis ◽  
Analysis Data ◽  
Proximate Analysis ◽  
Industrial Wastes ◽  
Heating Value ◽  
Application Range ◽  
High Heating Value ◽  
One Step ◽  
Standard Techniques

The use of energy from biomass is becoming more common worldwide. This energy source has several benefits that promote its acceptance; it is bio-renewable, non-toxic and biodegradable. To predict its behavior as a fuel during thermal treatment, its characterization is necessary. The experimental determination of ultimate analysis data requires special instrumentation, while proximate analysis data can be obtained easily by using common equipment but, the required time is high. In this work, a methodology is applied based on thermogravimetric analysis, curves deconvolution and empirical correlations for characterizing different regional agro-industrial wastes to determine the high heating value, the contents of moisture, volatiles matter, fixed carbon, ash, carbon, hydrogen, oxygen, lignin, cellulose and hemicellulose. The obtained results are similar to those using standard techniques, showing the accuracy of proposed method and its wide application range. This methodology allows to determine the main parameters required for industrial operation in only in one step, saving time.

Theoretical Thermogravimetric Analysis at Constant Heating Rates

1980 ◽  
pp. 51-56 ◽  
Author(s):  
C. Comel ◽  
J. Veron ◽  
C. Bouster ◽  
P. Vermande
Keyword(s):  
Thermogravimetric Analysis ◽  
Heating Rates ◽  
Constant Heating

Comparison of Different Methods for the Determination of Phenylalanine Hydroxylase Activity in Rat Liver and Euglena gracilis

1984 ◽  
Vol 39 (7-8) ◽  
pp. 728-733 ◽  
Author(s):  
Rita M. Fink ◽  
Erich F. Elstner
Keyword(s):  
Rat Liver ◽  
Euglena Gracilis ◽  
Phenylalanine Hydroxylase ◽  
Hplc Method ◽  
Enzymic Activity ◽  
Hydroxylase Activity ◽  
Product Separation ◽  
Tyrosine Concentration ◽  
Layer Chromatography

Abstract Three different methods for the determination of phenylalanine hydroxylase activity have been compared: a) Differential photometric assay of the increase in tyrosine concentration in the presence of phenylalanine; b) Product separation by thin layer chromatography and scintillation counting of the [14C]tyrosine formed;c) HPLC separation and spectrofluorometric quantification of derivatized amino acids. A comparison of the activities of phenylalanine hydroxylase in rat liver and Euglena gracilis clearly showed that only rat liver contains this enzymic activity as shown by methods b) and c) although pseudo-activity of Euglena gracilis preparations was found during the spectrophotometric test a). The HPLC method proved to be the fastest, most reliable and convenient method for direct tyrosine determination and thus for measuring phenylalanine hydroxylase activity.

scholarly journals The physical basis of the fission wave reactor

2008 ◽  
Vol 23 (2) ◽  
pp. 3-15 ◽  
Author(s):  
Volodymyr Pavlovych ◽  
Volodymyr Khotyayintsev ◽  
Olena Khotyayintseva
Keyword(s):  
Diffusion Equation ◽  
Main Idea ◽  
Stationary Wave ◽  
Short Review ◽  
Nuclear Fission ◽  
Stationary Processes ◽  
Wave Parameters ◽  
Nuclear Burning ◽  
Fission Wave

The main idea of slow nuclear fission wave reactor is discussed and short review of the existing works is also presented. The aim of this paper is to clarify the physics of processes, which define the stationary wave of nuclear burning, and to develop the approaches determining the wave parameters. It is shown that the diffusion equation for fluence can be used to describe the stationary and non-stationary processes in the nuclear fission wave. Two conditions of stationary wave existence are first formulated in the paper. The rule of determination of wave velocity as the eigenvalue of boundary problem is also formulated.

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