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  • Bacillus mycoides  (1)
  • PACS. 63.20.Dj Phonon states and bands, normal modes, and phonon dispersion - 64.70.Kb Solid-solid transitions - 65.40.+g Heat capacities of solids  (1)
  • PACS. 63.20.Dj Phonon states and bands, normal modes, and phonon dispersion - 81.30.Kf Martensitic transformations - 61.12.-q Neutron diffraction and scattering  (1)
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  • 1
    Electronic Resource
    Electronic Resource
    Influence of atomic order on [110] phonon softening [4] and displacive phase transition in Invar alloys (1999)
    Springer
    The European physical journal 10 (1999), S. 641-648 
    Details
    ISSN: 1434-6036
    Keywords: PACS. 63.20.Dj Phonon states and bands, normal modes, and phonon dispersion - 64.70.Kb Solid-solid transitions - 65.40.+g Heat capacities of solids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract: The acoustic phonon dispersions of two Invar crystals , one ordered with the ( ) structure, the other disordered fcc, have been investigated between 3.4 K and 470 K by inelastic and elastic neutron scattering. For the ordered crystal, pronounced softening of the whole phonon branch is observed on cooling below the Curie temperature. Particularly strong phonon softening at the M-point zone boundary of the structure leads to a displacive, antiferrodistortive phase transition at low temperatures. For the disordered crystal, much weaker softening of the phonons is observed and restricted to the region near the Brillouin zone center, where increasing elastic scattering with decreasing temperature indicates the growth of local tetragonal strain. This strain is considered as a typical precursor of the transformation to bct martensite. Specific heat measurements, performed at low temperatures on both crystals confirm the neutron scattering results and reveal considerable enhancement of the low energy phonon density of states in the ordered crystal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100510050896
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  • 2
    Electronic Resource
    Electronic Resource
    Identification of bacterial sources of soil peptidases (2000)
    Springer
    Biology and fertility of soils 31 (2000), S. 219-224 
    Details
    ISSN: 1432-0789
    Keywords: Key words Proteolytic soil bacteria ; Pseudomonas fluorescens ; Bacillus cereus ; Bacillus mycoides ; Metallopeptidases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  Four topsoils and three subsoils from an arable field, two grasslands and a beech forest with different ecophysiological properties were investigated for the most abundant proteolytic bacteria. The number of proteolytic bacteria was estimated with the most probable number (MPN) assay using a gelatin-based medium. Subsequent isolations of bacteria were performed on a gelatin-based agar medium. No coherence was observed between site specific properties, MPN counts of proteolytic bacteria and proteolytic activities at the different sites. In the subsoils proteolytic activity was considerably lower than in the corresponding topsoils. Differences in MPN counts of proteolytic bacteria were only significant for the arable field profile in March, with lower values in the subsoil. Pseudomonas fluorescens was the most abundant proteolytic species in all investigated horizons except for the acidic topsoil of the beech forest. Bacillus cereus and B. mycoides were also prominent especially in the topsoils and were less abundant in the subsoils. Flavobacterium-Cytophaga bacteria were enriched in autumn, but were lacking in the beech forest horizons and in the topsoil of the arable field. The results of inhibition assays suggest that the extracellular peptidases formed by these species were metalloenzymes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003740050648
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  • 3
    Electronic Resource
    Electronic Resource
    phonon dispersion and martensitic phase transition in ordered alloys (1999)
    Springer
    The European physical journal 11 (1999), S. 75-81 
    Details
    ISSN: 1434-6036
    Keywords: PACS. 63.20.Dj Phonon states and bands, normal modes, and phonon dispersion - 81.30.Kf Martensitic transformations - 61.12.-q Neutron diffraction and scattering
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract: In a previous neutron scattering study, we had observed that the TA phonon softening in L12-ordered ferromagnetic Fe72Pt28 Invar is pronounced at the zone boundary M-point and leads to an antiferrodistortive phase transition at low temperatures. Here, we report on similar neutron scattering investigations on two ordered crystals with higher Fe content to investigate the relation between the TA phonon softening and the martensitic transformation, which occurs in Fe-rich ordered Fe-Pt. We find that the TA phonon softening, especially at the M-point zone boundary, does not depend on the composition of the investigated crystals. In Fe74.5Pt25.5, however, the antiferrodistortive phase transition temperature is enhanced due to tetragonal strain preceding the martensitic transition. In Fe77Pt23 a precursor driven premartensitic phase transition is not observed. The structure of the martensite is, however, influenced by the soft mode lattice instability of the austenite. This would explain the origin of structural details found previously for Fe3Pt thermoelastic martensite.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100510050918
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    Paper (German National Licenses)
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