Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Chemistry  (1)
  • decomposition  (1)
  • decomposition of solids  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Solid-state Decompositions — Stagnation or Progress? (2000)
    Springer
    Journal of thermal analysis and calorimetry 60 (2000), S. 863-877 
    Details
    ISSN: 1572-8943
    Keywords: Arrhenius parameters ; crystolysis ; decomposition of solids ; isothermal kinetics ; non-isothermal kinetics ; reaction mechanisms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract An appraisal of the trends discerned in the recent literature concerned with solid-state decompositions suggests that this research area lacks a general theoretical framework and, hence, order in the subject is difficult to recognize. There have been surprisingly few reviews of the field. Many of the continuing flow of research publications may be of individual value, but most do not contribute to the overall development of the topic. For example, in many studies of reversible dissociations the sensitivity of rate characteristics to prevailing conditions is not discussed so that the fit of data to rate equations and the magnitudes of calculated Arrhenius parameters may be of empirical value only. Some studies report kinetic results without mechanistic discussions supported by complementary observations. Progress forward from an apparent state of stagnation depends upon more critical examination of the existing literature, coupled with better designed experiments to establish the reproducibility and reliability of kinetic conclusions. Techniques capable of providing insights into the bond redistribution steps that occur during reactions in crystals are also urgently needed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010107724523
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The thermal dehydration and decomposition of Ba[Cu(C2O4)2(H2O)]·5H2O (1997)
    Springer
    Journal of thermal analysis and calorimetry 50 (1997), S. 33-50 
    Details
    ISSN: 1572-8943
    Keywords: Ba[Cu(C2O4)2(H2O)]·5H2O ; decomposition ; dehydration ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The thermal behaviour of Ba[Cu(C2O4)2(H2O)]·5H2O in N2 and in O2 has been examined using thermogravimetry (TG) and differential scanning calorimetry (DSC). The dehydration starts at relatively low temperatures (about 80°C), but continues until the onset of the decomposition (about 280°C). The decomposition takes place in two major stages (onsets 280 and 390°C). The mass of the intermediate after the first stage corresponded to the formation of barium oxalate and copper metal and, after the second stage, to the formation of barium carbonate and copper metal. The enthalpy for the dehydration was found to be 311±30 kJ mol−1 (or 52±5 kJ (mol of H2O)−1). The overall enthalpy change for the decomposition of Ba[Cu(C2O4)2] in N2 was estimated from the combined area of the peaks of the DSC curve as −347 kJ mol−1. The kinetics of the thermal dehydration and decomposition were studied using isothermal TG. The dehydration was strongly deceleratory and the α-time curves could be described by the three dimensional diffusion (D3) model. The values of the activation energy and the pre-exponential factor for the dehydration were 125±4 kJ mol−1 and (1.38±0.08)×1015 min−1, respectively. The decomposition was complex, consisting of at least two concurrent processes. The decomposition was analysed in terms of two overlapping deceleratory processes. One process was fast and could be described by the contracting-geometry model withn=5. The other process was slow and could also be described by the contracting-geometry model, but withn=2. The values ofE a andA were 206±23 kJ mol−1 and (2.2±0.5)×1019 min−1, respectively, for the fast process, and 259±37 kJ mol−1 and (6.3±1.8)×1023 min−1, respectively, for the slow process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01979547
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    A temperature-profile Study of the Combustion of Black Powder and its constituent binary mixtures (1989)
    Weinheim : Wiley-Blackwell
    Propellants, Explosives, Pyrotechnics 14 (1989), S. 69-75 
    Details
    ISSN: 0721-3115
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An earlier thermo-analytical study of black powder, using small sample masses and slow heating rates, has been extended to an examination of the behaviour of black powder under the less-controlled conditions of ignition and combustion, by simultaneous measurement of temperature profiles and burning rates.Burning-rate against composition curves for various charcoal/KNO3, mixtures (sulphurless black powder) and for charcoal/KNO3, mixtures with various proportions of sulphur, were concave-down-type curves. The compositions of mixtures with maximum burning rates did not correspond with the compositions of mixtures with maximum enthalpy-of-reaction. Maximum temperatures of ∼1400°C were recorded. Burning rates were found to decrease with increasing particle size of the constituents: with increasing compaction of the mixtures, or when inert diluents or subsidiary fuels were added to the mixtures. Burning rates were also affected by moisture contents above 276, and failure of burning occurred at 〉15% moisture.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prep.19890140205
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...