| 1. |
- Carvalho, A., et al.
(författare)
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Identification of the local vibrational modes of small nitrogen clusters in dilute GaAsN
- 2007
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Ingår i: Physica. B, Condensed matter. - : Elsevier BV. - 0921-4526 .- 1873-2135. ; 401-402, s. 339-342
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Tidskriftsartikel (refereegranskat)abstract
- Ultra-high-resolution infra-red local vibrational mode (IR LVM) spectroscopy measurements together with density-functional calculations have been used to identify the signatures of close substitutional nitrogen (NAs) pairs in GaAs1 - x Nx alloys with concentrations of x < 0.025. We show that the presence of sub-peaks close to the NAs absorption band can be attributed to nitrogen pairs up to fourth neighbor position. Additionally, we suggest that the nitrogen pairs which give rise to the deepest levels below the conduction band edge are the first to be removed upon annealing
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| 2. |
- Bhuanantanonoh, K., et al.
(författare)
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MRes Curriculum
- 2005
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Ingår i: 1st Bath University Postgraduate Conference. - Bath : University of Bath.
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Konferensbidrag (refereegranskat)
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| 3. |
- Öberg, Christina, et al.
(författare)
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Changing network pictures : Evidence from mergers and acquisitions
- 2007
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Ingår i: Industrial Marketing Management. - : Elsevier BV. - 0019-8501 .- 1873-2062. ; 36:7 SPEC. ISS., s. 926-940
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Tidskriftsartikel (refereegranskat)abstract
- A merger or acquisition may cause dramatic changes in a business network, which in turn affect managerial cognition as well as managerial activities. We use the concepts of 'network pictures' and 'networking' to illustrate and analyse changes in managerial sense-making and networking activities following a merger or acquisition. The paper focuses on acquiring, acquired or merging parties and those companies with which they have direct customer relationships. Based on three case studies comprising seven acquisitions and one merger, we show that following a merger or acquisition managers may need to adapt their previous network pictures in a radical way, these adaptations are, however, not always realized as shifts in network pictures and adjustments in networking activities by all the managers involved. Whereas the merging parties' network pictures and networking activities are largely driven by their perception of customers' needs and developments, it is not certain that the merger or acquisition is enacted accordingly. The paper contributes to a clearer view on the conceptual interdependence of the constructs of network pictures and networking in multi-actor situations and thus it develops a network perspective on mergers and acquisitions. © 2007 Elsevier Inc. All rights reserved.
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| 4. |
- Bangert, U., et al.
(författare)
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Electron energy loss spectroscopic studies of brown diamonds
- 2006
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Ingår i: Philosophical Magazine. - : Informa UK Limited. - 1478-6435 .- 1478-6443. ; 86:29-31, s. 4757-4779
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Tidskriftsartikel (refereegranskat)abstract
- We investigate both experimentally and theoretically, low-loss electron energy losses in brown type IIa monocrystalline diamonds both before and after high-temperature, high-pressure anneals which remove the brown colouration. We find additional losses within and near the band edge for brown diamond which are significantly reduced after treatment. The additional losses are not associated with dislocations. Graphitic inclusions are detected by EELS as well as TEM studies for some brown diamonds before treatment. These lead to pronounced subgap absorption. However, all brown diamonds exhibit additional losses which are due to point defects lying in the regions between dislocations. First principles theoretical modelling shows that common dislocations are not responsible for the brown colouration but a -bonded vacancy disk lying on {111} planes gives broad bands lying in the diamond band gap, possesses an optical absorption spectrum similar to that of brown diamond, and leads to additional electron energy losses in the band edge region. These and similar defects are suggested to be responsible for the brown colouration. Mechanisms are proposed for their formation and removal.
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| 5. |
- Costa, F., et al.
(författare)
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Management of neuroendocrine tumors : a meeting of experts from Latin America
- 2008
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Ingår i: Neuroendocrinology. - : S. Karger AG. - 0028-3835 .- 1423-0194. ; 88:3, s. 235-42
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Tidskriftsartikel (refereegranskat)abstract
- A panel of experts from Latin America convened in Brazil, in May of 2007, for consensus recommendations regarding the management of neuroendocrine tumors (NETs) of the gastrointestinal tract and pancreas. The recently introduced World Health Organization classification of NETs represents a step forward, but the former classification of carcinoids into foregut, midgut and hindgut is still likely to be useful in the near future. Macroscopic description of the tumor should be followed by light microscopic examination and immunohistochemical staining, whereas other techniques might not be widely available in Latin America. Surgery remains the mainstay of treatment for patients with potentially curable tumors, and adequate selection is paramount in order to optimize treatment results. Regarding systemic therapy, patients with well-differentiated tumors or islet-cell carcinomas may be categorized as having indolent disease, while patients with poorly differentiated, anaplastic, and small-cell carcinomas, or with atypical carcinoids, may be approached initially as having aggressive disease. Somatostatin analogues play a cytostatic role in indolent tumors, and chemotherapy may play a role against other, more aggressive NETs. Obviously, there is an urgent need for novel therapies that are effective against NETs.
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| 6. |
- Coutinho, J., et al.
(författare)
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Donor-vacancy complexes in Ge : cluster and supercell calculations
- 2006
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 73:23, s. 235213-1
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Tidskriftsartikel (refereegranskat)abstract
- We present a comprehensive spin-density functional modeling study of the structural and electronic properties of donor-vacancy complexes (PV, AsV, SbV, and BiV) in Ge crystals. Special attention is paid to spurious results which are related to the choice of the boundary conditions (supercell-cluster approach), the resulting band-gap width, and the choice of the points to sample the Brillouin zone. The underestimated energy gap, resulting from the periodic conditions together with the local-density approximation to the exchange-correlation energy, leads to defect-related gap states that are strongly coupled to crystalline states within the center of the zone. This is shown to produce a strong effect even on relative energies. Our results indicate that in all E centers the donor atom occupies a nearly substitutional site, as opposed to the split-vacancy form adopted by the SnV complex in Si. The E centers can occur in four charge states, from positive to double negative, and produce occupancy levels at E(0/+)=Ev+0.1 eV, E(-/0)=Ev+0.3 eV, and E(=/-)=Ec-0.3 eV.
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| 7. |
- Hounsome, L.S., et al.
(författare)
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Optical properties of vacancy related defects in diamond
- 2005
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Ingår i: Physica Status Solidi (a) applications and materials science. - : Wiley. - 1862-6300 .- 1862-6319. ; 202:11, s. 2182-2187
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Tidskriftsartikel (refereegranskat)abstract
- ‹110› vacancy chains, multi-vacancy clusters and vacancy discs have been modeled using density functional theory within the AIMPRO and DFTB codes. While a connection can be established between the results on vacancy chains and previous EPR experiments, no connection can be made between the point defects and the optical properties of natural type IIa brown diamonds. However, a vacancy disc consisting of a {111} double plane of vacancies is stable and possesses an absorption spectrum similar to that found in brown diamonds.
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| 8. |
- Hounsome, L.S., et al.
(författare)
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Origin of brown coloration in diamond
- 2006
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 73:12, s. 125203-1
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Tidskriftsartikel (refereegranskat)abstract
- Measurements of the absorption spectra of brown natural type IIa diamond as well as brown nitrogen-doped CVD diamond are reported. These are largely featureless and increase almost monotonically from about 1-5.5 eV. It is argued that the brown coloration is due to an extended defect and not to a point defect. First principles modeling studies demonstrate that the spectra could be attributed to vacancy disks lying on {111} planes. Such disks are unstable above about 200 vacancies and should relax to dislocation loops in natural diamond. Hydrogen is shown to passivate the optical activity of the disks.
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| 9. |
- Hounsome, L.S., et al.
(författare)
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Role of extended defects in brown colouration of diamond
- 2007
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Ingår i: Physica Status Solidi. C, Current topics in solid state physics. - : Wiley. - 1610-1634 .- 1610-1642. ; 4:8, s. 2950-2957
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Tidskriftsartikel (refereegranskat)abstract
- The absorption spectrum of brown diamond is broad and featureless, in both natural type IIa and CVD-grown material. It is argued that such an absorption is due to an extended, rather than a point, defect. Ab-initio modelling studies have been conducted on dislocations and extended vacancy-related defects. While certain dislocations could potentially explain the origin of colour, their density is too low to account for experimentally observed absorption magnitudes. It is demonstrated that a vacancy disk lying in the {111} plane has an absorption spectrum similar to that seen in natural and CVD brown diamond. Such disks are unstable above about 200 vacancies and should relax to dislocation loops in natural diamond. Hydrogen is shown to passivate the optical activity of the disks.
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| 10. |
- Jemtå, Lena, et al.
(författare)
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On intimacy, sexual activities and exposure to sexual abuse among children and adolescents with mobility impairment
- 2008
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Ingår i: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227. ; 97:5, s. 641-646
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Tidskriftsartikel (refereegranskat)abstract
- Aim: The aim was to describe experiences of intimacy and sexual activity and exposure to sexual abuse among children and adolescents with mobility impairment, and to relate these experiences to socio-demographic data, disability characteristics and well-being. Methods: This study included semi-structured interviews with 141 children and adolescents aged 7-18 years with mobility impairment. Interpersonal experiences of intimacy and sexuality, socio-demographic data, disability characteristics and well-being were registered. Results: About half of the children and adolescents in the study had been in a boy- or a girlfriend relationship, and about a fifth had an ongoing relationship. Of the adolescents, 15% had at least one experience of a sexual relationship. Whereas no particular sexual dysfunction was reported, 15% had concerns about their future sexual activities, presumably related to mobility impairment. A history of sexual abuse was reported by 7% in the age cohort of 13-18 years. The socio-demographic and disability-related features had a marginal influence on the experiences of intimacy and sexual activities. Conclusion: Several aspects of sexual health are not fully realized for children and adolescents with impaired mobility, and there is a need for specialized sexual health care services to protect the sexual rights of this group.
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