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M. D. Judd

Bio: M. D. Judd is an academic researcher. The author has an hindex of 1, co-authored 1 publication(s) receiving 13 citation(s).
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Journal ArticleDOI
Abstract: The kinetics of many solid state reactions can best be explained in terms of an order of reaction; this is particularly true in the case of polymer degradation. The methods currently available for the determination ofn andk, from isothermal data, are either limited in the range ofα which can be used or are difference-difference techniques where the data must of necessity be highly accurate. This paper presents a review of these methods and introduces a new approach by whichn andk can be obtained directly, giving results which are unique and objective in that they provide a best fit to the experimental data.

13 citations

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Journal ArticleDOI
Martin Forster1Institutions (1)
Abstract: The conventional Solvay ammonia soda process is a net producer of CO2 and produces large quantities of ecologically doubtful side products. Therefore a possible solution for this problem was investigated. Theoretical and experimental data are given which show the feasibility of a modified ammonia soda process which delivers Na2CO3 and HCl by using exhaust CO2, NaCl and H2O. This modified ammonia soda process would not produce the byproduct CaCl2 as in the conventional Solvay ammonia soda process, would be completely recyclable and could be driven by solar thermal energy. Low maximum reaction temperatures of T ≤ 800 K and an estimated achievable solar efficiency of 10% show that this cycle is not only environmentally friendly but also energetically interesting. Kinetic constants of the main reactions are given which are similar to the ones in the conventional process. The principle of a simple solar thermo-chemical reactor is described. Preliminary economical considerations show that this new process might even be competitive when driven by solar thermal energy instead of using fossil fuels. If this novel process would be implemented worldwide approximately up to 3 × 107 tonne of CO2 could be omitted annually compared with the conventional Solvay ammonia soda process. This would correspond to 0.15% of the annual release of all anthropogenically produced CO2.

11 citations

Journal ArticleDOI
Nicolas Sbirrazzuoli1, D. Brunel1, L. Elegant1Institutions (1)
Abstract: A software is described enabling kinetic analysis under non-isothermal or isothermal conditions from DSC, or from TG data. The program offers thirteen methods of kinetic analysis for DSC, three for isothermal analysis and two for TG, with eight different functions for the choice of the proper mechanism for each of them.

53 citations

Journal ArticleDOI
Abstract: Thermal analysis was used for investigating the effect of the addition of the residue obtained from crude oil vacuum distillation on the carbonization process of brown coal. The kinetic analysis of the experimental TG curves was carried out by using the Coats-Redfern equation and then to select the most likely mechanism (functiong (α)) for particular decomposition stages of brown coal and its mixture with the residue. In the brown coal carbonization process the nucleation of a new solid phase is predominant. In the temperature range of the decomposition of coal (620–820 K) the addition of residue results a change in the mechanism of the thermal decomposition process — in the mixture three-dimensional diffusion processes and one-dimensional diffusion occur, depending on the composition. Above 730 K (secondary carbonation processes) the most likely mechanism involves the nucleation of a new solid phase as well as diffusion processes.

3 citations

Journal ArticleDOI
C. Rózycki1, M. Maciejewski1Institutions (1)
Abstract: Determination of the kinetic parameters of the thermal decomposition of solids usually requires a knowledge of the function describing the mechanism of decomposition. Research was made to obtain a method that enables the selection of one of the 16 functions used in the literature in such a way that it best describes experimental data in the isothermal measurements. The results obtained indicate that the best fit of experimental and calculated data is gained by using the weighted least-squares method with the equation g(α) = kt + b and using criteria based on the minimization of the difference between α exp and α calc

34 citations

Journal ArticleDOI
M.R. Udupa1Institutions (1)

1 citations


Author's H-index: 1

No. of papers from the Author in previous years