46 research outputs found
Public Attitudes, Perceptions and Behaviours towards Cabin Safety Communications
Safety Research Grants Program. The ATSB is an operationally independent bureau within the Australian Government Department of Transport and Regional Services. The program funds a number of one-off research projects selected on a competitive basis. The program aims to encourage researchers from a broad range of related disciplines to consider or to progress their own ideas in aviation safety research. The work reported and the views expressed herein are those of the author(s) and do not necessarily represent those of the Australian Government or the ATSB. However, the ATSB publishes and disseminates the grant reports in the interests of information exchange and as part of the overall safety aim of the grants program. © Synovate 2006 ii CONTENTS Acknowledgements............................................................................................... vi
Self-diffusion in a-Fe203 natural single crystals.
Measurements of 180 self-diffusion in hematite (Fe203) natural single crystals have
been carried out as a function of temperature at constant partial pressure ao2 = 6.5"10 -2 in the
temperature range 890 to 1227 ~ The ao2 dependence of the oxygen self-diffusion coefficient at
fixed temperature T = 1150 ~ has also been deduced in the ao2 range 4.5" 10 .4 - 6.5" 10 1. The concentration
profiles were established by secondary-ion mass spectrometry; several profiles exhibit
curvatures or long tails; volume diffusion coefficients were computed from the first part of the
profiles using a solution taking into account the evaporation and the exchange at the surface. The
results are well described by
- 0 26 ( 542 (kJ/mol) ] D o (cm2/s) = 2.7.108 ao2' exp,- ~-
J
From fitting a grain boundary diffusion solution to the profile tails, the oxygen self-diffusion
coefficient in sub-boundaries has been deduced. They are well described by
- 0 4 ( 911 (kJ/mol) /
D" o (cm2/s) = 3.2.1025 ao2' exp,- RT
J
Experiments performed introducing simultaneously 180 and 57Fe provided comparative values of
the self-diffusion coefficients in volume: iron is slower than oxygen in this system showing that
the concentrations of atomic point defects in the iron sublattice are lower than the concentrations
of atomic point defects in the oxygen sublattice. The iron self-diffusion values obtained at T > 940
~ can be described by
DFe (cm2/s) 9.2 101~ -056 (578(kJ/mol) ) = 9 ao~ exp,-
The exponent-1/4 observed for the oxygen activity dependence of the oxygen self-diffusion in
the bulk has been interpreted considering that singly charged oxygen vacancies V~ are involved in
the oxygen diffusion mechanism. Oxygen activity dependence of iron self-diffusion is not known
accurately but the best agreement with the point defect population model is obtained considering
that iron self-diffusion occurs both via neutral interstitals Fe x and charged ones
Impulse control behavior in GBA-mutated parkinsonian patients
Objective: To assess the prevalence and phenomenology of Impulse control behavior (ICB) in Parkinson's disease (PD) patients carrying mutations in the ÎČ-glucocerebrosidase (GBA) gene. Background: GBA mutations are a common genetic factor predisposing to PD. ICB is among the most disabling non-motor complications of PD. The occurrence of ICB in PD patients carrying GBA gene mutations (GBA-PD) has not been yet established. Methods: Forty-six patients with clinically definite PD (23 GBA-PD and 23 non-mutated patients, NM-PD) were screened for ICB. Diagnosis was clinically and rating based on a specific questionnaire (QUIP-RS). Other demographic and clinical variables did not differ between groups. Results: ICB occurred more frequently in GBA-PD patients (52.2%) compared to NM-PD (13%) and the total QUIP-RS score was higher in the GBA-PD group. Hypersexuality and compulsive shopping were the most prevalent ICB types occurring in GBA patients. ICB occurred only in one GBA-PD patient on levodopa monotherapy and in 11 patients taking dopamine agonists, either monotherapy or combined with levodopa (the corresponding figures in NM-PD patients were 0 and 3). Most GBA-PD patients were heterozygous for two common genetic variants, without appreciable difference in their ICB profile. Conclusion: ICB is more common in GBA-PD patients compared to NM-PD. Dopamine agonist therapy may be synergic to GBA carrier status for ICB occurrence
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Effect of fungicide application on soft wheat water productivity
Comprehensive improvement of various features of CuâCd ferrites (Cu0.5Cd0.5Fe2âxCexO4) by cerium (Ce3+) ion substitution
Cerium (Ce3+) substitution in CuâCd spinel nanoferrites with the compositional formula Cu0.5Cd0.5Fe2âxCexO4 (x = 0.0, 0.0125, 0.0250, 0.0375, 0.050) was performed by the hydrothermal route. The structural, morphological, optical, electrical, and dielectric properties of Ce-substituted CuâCd ferrites were explored. X-ray diffraction revealed the single-phase cubic structure of all nanoferrites. The average crystallite size (72.42â11.61 nm) and lattice constant (8.419â8.449 Ă
) were observed for the synthesized ferrites. The surface shapes of particles were determined by scanning electron microscopy. The substitution was also verified by Fourier transform infrared spectroscopy and ultravioletâvisible spectrophotometry. The semiconducting behavior of ferrites was determined from their electrical properties, such as direct current (DC) electrical resistivity. The Curie temperature was observed at 523 K temperature for all nanoferrites. The dielectric constant and dielectric loss significantly indicated the reducing behavior with an increase in the cerium concentration. The sample Cu0.5Cd0.5Fe1.975Ce0.025O4 resulted in the lowest optical bandgap energy, DC resistivity, and dielectric losses. The nature of the electrical resistivity and dielectric constants indicate that the designed materials are highly appropriate for the design of microwave gadgets
Study of oxygen self-diffusion in oxides by ion beam techniques : comparison between nuclear reaction analysis and SIMS.
Oxygen self-diffusion in Fe,_,0 single crystals has been studied by means of the isotope exchange method in Hz/Hzâ0 atmospheres. The â*O concentration profiles were determined by using two different techniques based on ion beams: secondary ion mass spectrometry (SIMS) and nuclear reaction analysis (NRA); the latter by means of the narrow nuclear resonance reaction ââO(p, o)âN at 629 keV, r = 2.1 keV. The diffusion coefficients obtained from the analysis of the measured profiles are in good agreement with those found in the literature. To compare the depth resolution and sensitivity of both techniques, the â0 profiles of implanted Cr,O, single crystals (Erso = 50 keV, fluence = 1.6 X lOI ions/cmâ) were also measured
Unraveling the impact of anthropogenic pressure on plant communities in Mediterranean temporary ponds
Identifying the respective role of environmental, landscape and management factors in explaining the patterns
in community composition is an important goal in ecology. Using a set of 32 temporary ponds in northern Morocco we
studied the respective importance of local (within the pond) and regional (density of ponds in landscape) factors and the impacts of different land uses on the plant species assemblages, separating pond and terrestrial species. The main hypotheses tested were that (1) species assemblages respond to both local and regional environmental factors, (2)anthropogenic pressure has a negative influence on the number of pond species, and that (3) human activities differ in their
impact on pond biodiversity. The results showed that (1) local factors explain most of the variation in plant community composition, and (2) land use impacts the communities through changing local environmental conditions, leading to a loss of typical pond species. Aside from recreation, all other activities (grazing, drainage, agriculture and partial urbanisation) significantly reduced the number of pond species. The conservation strategy for rare pond species should focus on
maintaining networks of oligotrophic ponds, while allowing only low-impact activities.status: publishe