45 research outputs found
Fabrication, optical characterization and modeling of strained core-shell nanowires
Strained nanowires with varying InAs/InP core-shell thicknesses were grown
using Chemical Beam Epitaxy. Microphotoluminescence spectroscopy, performed at
low temperature, was then used to study the optical properties of single wires.
Emission from the InAs core was observed and its dependence on the shell
thickness/core diameter ratio was investigated. We found that it is possible to
tune the emission energy towards 0.8 eV by controlling this ratio. We have
compared the measured energies with calculated energies. Our findings are
consistent with the wires having a hexagonal crystal structure.Comment: 9 pages, 5 figures, Proceedings of the Eighth International
Conference on Atomically Controlled Surfaces, Interfaces and Nanostructures
and the Thirteenth International Congress on Thin Films - ACSIN-8/ICTF-1
GaN and InN nanowires grown by MBE: a comparison
Morphological, optical and transport properties of GaN and InN nanowires
grown by molecular beam epitaxy (MBE) have been studied. The differences
between the two materials in respect to growth parameters and optimization
procedure was stressed. The nanowires crystalline quality has been investigated
by means of their optical properties. A comparison of the transport
characteristics was given. For each material a band schema was shown, which
takes into account transport and optical features and is based on Fermi level
pinning at the surface.Comment: 5 pages, 5 figure
Growth of unidirectional molecular rows of cysteine on Au(110)-(1x2) driven by adsorbate-induced surface rearrangements
KĂĽhnle A, Molina LM, Linderoth TR, Hammer B, Besenbacher F. Growth of unidirectional molecular rows of cysteine on Au(110)-(1x2) driven by adsorbate-induced surface rearrangements. Physical Review Letters. 2004;93(8):086101.Using scanning tunneling microscopy we have studied the nucleation and growth of unidirectional molecular rows upon adsorption of the amino acid cysteine onto the anisotropic Au(110)-(1x2) surface under ultrahigh vacuum conditions. By modeling a large variety of possible molecular adsorption geometries using density-functional theory calculations, we find that in the optimum, lowest energy configuration, no significant intermolecular interactions exist along the growth direction. Instead the driving force for formation of the unidirectional molecular rows is an adsorbate-induced surface rearrangement, providing favorable adsorption sites for the molecules
Dual diagnosis clients' treatment satisfaction - a systematic review
Background:
The aim of this systematic review is to synthesize existing evidence about treatment satisfaction among clients with substance misuse and mental health co-morbidity (dual diagnoses, DD).
Methods:
We examined satisfaction with treatment received, variations in satisfaction levels by type of treatment intervention and by diagnosis (i.e. DD clients vs. single diagnosis clients), and the influence of factors other than treatment type on satisfaction. Peer-reviewed studies published in English since 1970 were identified by searching electronic databases using pre-defined search strings.
Results:
Across the 27 studies that met inclusion criteria, high average satisfaction scores were found. In most studies, integrated DD treatment yielded greater client satisfaction than standard treatment without explicit DD focus. In standard treatment without DD focus, DD clients tended to be less satisfied than single diagnosis clients. Whilst the evidence base on client and treatment variables related to satisfaction is small, it suggested client demographics and symptom severity to be unrelated to treatment satisfaction. However, satisfaction tended to be linked to other treatment process and outcome variables. Findings are limited in that many studies had very small sample sizes, did not use validated satisfaction instruments and may not have controlled for potential confounders. A framework for further research in this important area is discussed.
Conclusions:
High satisfaction levels with current treatment provision, especially among those in integrated treatment, should enhance therapeutic optimism among practitioners dealing with DD clients
Automatic abstraction in symbolic trajectory evaluation
Symbolic trajectory evaluation (STE) is a model checking technology based on symbolic simulation over a lattice of abstract state sets. The STE algorithm operates over families of these abstractions encoded by Boolean formulas, enabling verification with many different abstraction cases in a single modelchecking run. This provides a flexible way to achieve partitioned data abstraction. It is usually called "symbolic indexing' and is widely used in memory verification, but has seen relatively limited adoption elsewhere, primarily because users typically have to create the right indexed family of abstractions manually. This work provides the first known algorithm that automatically computes these partitioned abstractions given a reference-model specification. Our experimental results show that this approach not only simplifies memory verification, but also enables handling completely different designs fully automatically