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Journal of Thermal Analysis and Calorimetry
Authors: Nopsiri Chaiyo, Rangson Muanghlua, Surasak Niemcharoen, Banjong Boonchom, Panpailin Seeharaj, and Naratip Vittayakorn

analysis of thermogravimetric curves. The calculations, based on multiple rates of thermogravimetric curves, are so-called iso-conversional calculation procedures [ 3 ]. Thermal decomposition of metal oxalates has been the subject of many researches

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Journal of Thermal Analysis and Calorimetry
Authors: Juliusz Leszczynski, Krzysztof T. Wojciechowski, and Andrzej Leslaw Malecki

structure. Phase diagram for the Co-Sb system is well known [ 1 ]. CoSb 3 is the δ phase, which is stable up to 874 °C. Above this temperature it undergoes peritectic decomposition into liquid and CoSb 2 γ phase, stable up to 936 °C. In recent times

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accidents in various plants in the past [ 2 – 6 ]. In contrast to the extensive use of TBP worldwide and the importance of the safety issue of the red oil related explosions, the studies on the thermal decomposition behaviour of TBP are very scarce

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Introduction The kinetics of thermal decomposition of several compounds of the general type have been previously studied using experimental techniques 1 – 4 ]. It has been shown that elimination of molecular hydrogen occurs

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Maximal clique enumeration and maximum clique generation are well known NP-complete discrete optimization problems. Researchers experiment with parallel implementations of known algorithms in order to speed up the resolution process. Parallel implementations are equivalent to divisions of the feasible region that is an implicit decomposition of the original problem. The below study looks for the possible ways of explicit decomposition, which can subsequently serve as bases of parallel algorithms. The paper introduces formally the notion of decomposition, specifies explicit algorithms for different sorts of decomposition, provides and compares decomposition based algorithms for the maximum clique problem.

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Abstract  

Acetohydroxamic acid (AHA) is an important complexant/reductant for Pu(IV) in the UREX process. It decomposes in the presence of nitric acid. In literature, its decomposition kinetics in nitric acid is traditionally reported as pseudo-first order reaction. In this study, new experimental data were reported for kinetics experiments under wide consecration conditions. It was found that the decomposition reaction was first order with respect to both the components hence overall second order.

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Abstract  

Thermal analysis of fusion and decomposition processes was carried out on organosulphur and organoselenium compounds in order to establish thermal stability criteria. Degradation and fusion temperatures of 20 biological active compounds, synthesized by our research group were determined using thermogravimetry (TG) and differential scanning calorimetry (DSC). Analysis of the thermal data indicated that: (a) in general, sulphur compounds are more stable than selenium compounds; (b) the pyridine ring diminished stability of sulphur and selenium compounds much more than the carbocyclic aromatic rings did (6a > 9a; 2b > 3b); (c) selenomethyl derivatives are more stable than selenoethyl and selenoisopropyl compounds; (d) a chlorine atom on selenocompounds has surprising effects.

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The consequences of decline in biodiversity for ecosystem functioning is a major concern in soil ecology. Recent research efforts have been mostly focused on terrestrial plants, while, despite their importance in ecosystems, little is known about soil microbial communities. This work aims at investigating the effects of fungal and bacterial species richness on the dynamics of leaf litter decomposition. Synthetic microbial communities with species richness ranging from 1 to 64 were assembled in laboratory microcosms and used in three factorial experiments of decomposition. Thereafter, the functionality of the different microcosms was determined by measuring their capability to decompose materials with different chemical properties, including two species of litter (Quercus ilex L. and Hedera helix L.), cellulose strips and woody sticks. Incubation was done in microcosms at two temperatures (12°C and 24°C) for 120 days. The number of microbial species inoculated in the microcosms positively affected decomposition rates of Q. ilex and H. helix litters, while relationships found for cellulose and wood were not statistically significant. Diversity effect was greater at higher incubation temperature. We found lower variability of decay rates in microcosms with higher inoculated species richness of microbial communities. Our study pointed out that the relationships between inoculum microbial diversity and litter decomposition is dependent on temperature and litter quality. Therefore, the loss of microbial species may adversely affects ecosystem functionality under specific environmental conditions.

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Abstract  

It is shown that metal oxide composites CuO–ZnO–CeO2/Al2O3 and Cu–ZnO/Al2O3, supported by cordierite monoliths, catalyze the production of hydrogen with selectivity and yield close to 90% and above for the decomposition and the partial oxidation of methanol. In methanol decomposition on CuO–ZnO–CeO2/Al2O3/cordierite, nanosized ceria acts as a key component stabilizing catalyst operation by suppressing carbonization of a surface, facilitating hydrogen production with a yield of 85–96%. At the same time, copper and zinc oxides are shown to act as modifying/promoting additives reducing the temperature of full conversion of the alcohol as well as minimizing the formation of methane as a by-product. Concerning partial oxidation of methanol over Cu–ZnO/Al2O3/cordierite, zinc oxide (as a constituent of ZnAl2O4 aluminate) is shown to be a “self-sufficient” catalytic component playing a key role in the high-yield H2 producing. A non-additive effect of decrease in selectivity concerning CO (as a by-product) on the binary Cu–ZnO catalyst, as compared with the samples derived from individual components Cu and ZnO, is found.

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such as clay, plaster, limes, gypsum and cements, among others [ 1 – 5 ]. In addition, this technique enables the quantification of the minerals present determining the mass loss by the different decomposition reactions that may occur, such as

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