8,877 research outputs found
On the polarimetric variability of bright O-type stars
Polarimetric data associated with multi-parameter observational campaigns of selected bright O-type stars and their variable winds, are analysed in relation to the outcomes of the UV and optical spectroscopic studies. For the stars ξ Per and λ Cep, individual measurement uncertainties are Δρ~±0.0002 with nightly mean uncertainties of Δρ~±0.00007. Although variability is apparent on a night-to-night basis, with differences in δρ~0.0002, no correlations are found between these and the periodic behaviours associated with the stellar Si IV and H α lines. Similar polarimetric variability is seen in the data for the standard star ø Cas used as a reference in this observing campaign. It is suggested that all of these low level fluctuations are not intrinsic to the stars but are engendered by structured instrumental polarization in the diffraction pattern and depolarization effects in combination with inconsistent target acquisition and with variable seeing conditions in the Earth's atmosphere. Reassessment of older data for λ Cep from Hayes (1978) also supports this thesis
The impact of boundary conditions on CO2 capacity estimation in aquifers
The boundary conditions of an aquifer determine the extent to which fluids (including formation water
and CO2) and pressure can be transferred into adjacent geological formations, either laterally or vertically.
Aquifer boundaries can be faults, lithological boundaries, formation pinch-outs, salt walls, or outcrop. In
many cases compliance with regulations preventing CO2 storage influencing areas outside artificial
boundaries defined by non-geological criteria (international boundaries; license limits) may be necessary.
A bounded aquifer is not necessarily a closed aquifer.
The identification of an aquifer’s boundary conditions determines how CO2 storage capacity is estimated
in the earliest screening and characterization stages. There are different static capacity estimation methods
in use for closed systems and open systems. The method used has a significant impact on the final
capacity estimate.
The recent EU Directive (2009/31/EC) stated that where more than one storage site within a single
“hydraulic unit” (bounded aquifer volume) is being considered, the characterization process should
account for potential pressure interactions. The pressure interplay of multiple sites (or even the pressure
footprint of just one site) is heavily influenced by boundary conditions
Surface modification of a polyether-urethane with RGD-containing peptides for enhanced cell attachment and signalling
Abstract of article examining the chemical modification of polyurethane with RGD-containing peptides offers a means of encouraging the adhesion, spreading and proliferation of cells cultured on its surface. This study assesses the efficacy of a modification procedure using surface analysis techniques and preliminary cell culture studies
The role of the family in child and adolescent posttraumatic stress following attendance at an emergency department
Objective: To evaluate the role of family factors in posttraumatic stress symptomatology (PTSS) in children and adolescents who have attended an emergency department following assaults or motor vehicle accident. Methods: Children and their parents completed self-report questionnaires and semistructured interviews relating to their psychopathology and cognitive styles at 2-4 weeks and 6 months after trauma. Results: Parental depression was correlated with child PTSS at each assessment point. Less consistent findings were observed for family functioning. Parental endorsement of worry was a correlate of child PTSS at each assessment and a mediator between parental depression and child PTSS. Conclusions: A role for family factors, in particular parental depression and parental endorsement of worry, in the development of child PTSS is supported. Weaknesses of the study are discussed, and suggestions for future research are given
How can paediatric epilepsy services best be delivered in secondary care?
AbstractObjective: To produce practical evidence-based guidelines for the management of paediatric epilepsy in secondary care settings. Design: Question-specific systematic literature review and local service audit. Main outcome measures: Grade of recommendation for specific management issues. Results: There is little good quality research to support many existing epilepsy guidelines for secondary care. Conclusion: Practical guidelines for the provision of children’s epilepsy services can be evidence influenced but until more relevant research is undertaken, not evidence based
Growing Guava for Processing
This bulletin covers the many aspects of growing guava suitable for processing in Hawaii
Transmission Losses in Left-handed Materials
We numerically analyze the origin of the transmission losses in left-handed
structures. Our data confirms that left handed structures can have very good
transmission properties, in spite of the expectable dispersion of their
effective permeability and refraction index. The large permittivity of the
metallic components improves the transmission. High losses, observed in recent
experiments, could be explained by the absorption of the dielectric board
Progress report on the geology of 1:50k sheet 64W (Newtonmore)
This report describes the results of solid geology fieldwork in 1:50 000 sheet 64W
(Newtonmore) resulting from the 2002 summer mapping season. A full revision of the solid
geology at 1:10 000 scale was completed in the north-western part of the sheet (Sheet NN69SE)
while rapid mapping/reconnaissance of the solid geology has been carried out in the remaining
85% of the sheet area The superficial geology of the sheet has been completely revised and will
be described in a separate report.
The north-western part of the sheet contains the transition from the deeper water graded sandy
and silty turbidite deposits of the Corrieyairack Subgroup upwards (and south-eastwards) into
the shallow water sand-dominated deposits of the Strathtummel Subgroup. East of the A9 trunk
road, the Gaick region is confirmed as a single lithostratigraphical package in the Strathtummel
Subgroup recording shallow water depositional conditions, greatly thickened by D2 recumbent
folding. Axial surfaces of these folds dip gently east overall with gently east plunging to subhorizontal fold axes. Axial traces are generally N-S trending. The main regional (biotite)
schistosity is axial planar to these folds and locally, can be seen clearly deforming an earlier
bedding near-parallel biotite fabric. The available evidence for stratigraphical younging is
limited to a few well-washed river sections but shows that regional facing is always to the south
in S2 across the Gaick region. No large-scale F1 folds are recognised with the exception of those
at Crubenmore on the A9. Minor undulations of the main regional fabric mean that the sheet dip
varies between gently north to gently east across open upright north-east-plunging folds, in
marked contrast to the conspicuous pattern of reclined, north-west verging D3 folds deforming
the main regional (S2) schistosity in Glen Truim and farther north-west. There appear to be no
other major fold sets across this part of the Gaick region The Drummochter Dome thus takes the
form of a stack of recumbent D2 folds, modified by steep zones to the north-west (Geal CharnOssian Steep Belt) and south-east (Tummel Steep belt and correlatives). The pattern of early
recumbent folds and later steep belts is similar to that seen in the higher structural levels south of
the Boundary Slide which include the Tay Nappe
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