180 research outputs found
Analysis of optical near-field energy transfer by stochastic model unifying architectural dependencies
We theoretically and experimentally demonstrate energy transfer mediated by
optical near-field interactions in a multi-layer InAs quantum dot (QD)
structure composed of a single layer of larger dots and N layers of smaller
ones. We construct a stochastic model in which optical near-field interactions
that follow a Yukawa potential, QD size fluctuations, and temperature-dependent
energy level broadening are unified, enabling us to examine
device-architecture-dependent energy transfer efficiencies. The model results
are consistent with the experiments. This study provides an insight into
optical energy transfer involving inherent disorders in materials and paves the
way to systematic design principles of nanophotonic devices that will allow
optimized performance and the realization of designated functions
Biologisk mangfold og jernbane : skjøtselsforsøk og kartlegging langs jernbanen i Sør-Norge
Prosjektet ”Biologisk mangfold” pågikk i Jernbaneverket Region Sør fra 2000 til 2005. Hensikten var både å kartlegge biologisk viktige områder langs banen samt å teste ut metoder for skjøtsel av vegetasjon i side terreng. Sluttrapporteringen fra prosjektet er delt i to. Denne rapporten oppsummerer skjøtselsforsøkene langs Sørlandsbanen i 2000-2005 samt registreringer av verdifulle naturtyper i prosjektet. Resultat fra litteratursøk samt en oppsummering av kunnskap om biologisk mangfold og jernbane presenteres i en egen rapport
Octo- and Nonagenarians\u27 Outlook on Life and Death When Living with an Implantable Cardioverter Defibrillator: A Cross-Sectional Survey
Background: Elderly individuals are increasingly represented among patients with implantable cardioverter defibrillators (ICD), but data describing life with an ICD are scarse among octo- and nonagenarians. Moreover, few studies have reported those elderly patients’ perspective on timly discussions concerning what shock deactivation involves, preferences on battery replacement, and their attitudes about turning off the ICD nearing end-of-life. Consequently, the aim of the study was to describe outlooks on life and death in octo- and nonagenarian ICD-recipients.
Methods: Participants were identified via the Swedish Pacemaker- and ICD-registry, with 229 octo- and nonagenarians (82.0 ± 2.2 years, 12% female) completing the survey on one occasion. The survey involved questions on health and psychological measures, as well as on experiences, attitudes and knowledge of end-of-life issues in relation to the ICD.
Results: The majority (53%) reported their existing health as being good/very good and rated their health status as 67 ± 18 on the EuroQol Visual Analog Scale. A total of 34% had experienced shock(s), 11% suffered from symptoms of depression, 15% had anxiety, and 26% reported concerns related to their ICD. About one third (34%) had discussed their illness trajectory with their physician, with those octo- and nonagenarians being more decisive about a future deactivation (67% vs. 43%, p \u3c .01). A minority (13%) had discussed what turning off shocks would involve with their physician, and just 7% had told their family their wishes about a possible deactivation in the future. The majority desired battery replacement even if they had reached a very advanced age when one was needed (69%), or were seriously ill with a life-threatening disease (55%). When asked about deactivation in an anticipated terminal illness, about one third (34%) stated that they wanted to keep the shocks in the ICD during these circumstances. About one-fourth of the octo- and nonagenarians had insufficient knowledge regarding the ethical aspects, function of the ICD, and practical consequences of withdrawing the ICD treatment in the end-of-life.
Conclusions: Increasing numbers of elderly persons receive an ICD and geriatric care must involve assessments of life expectancy as well as the patient’s knowledge and attitudes in relation to generator changes and deactivation
Application of the multiple-scattering method to analysis of systems with semi-infinite photonic waveguides
We propose a technique of compensating the spurious reflections implied by
the multiple-scattering (MS) method, commonly used for analyzing finite
photonic crystal (PC) systems, to obtain exact values of characteristic
parameters, such as reflection and transmission coefficients, of PC functional
elements. Rather than a modification of the MS computational algorithm, our
approach involves postprocessing of results obtained by the MS method. We
derive analytical formulas for the fields excited in a finite system, taking
explicitly into account the spurious reflections occurring at the artificial
system boundaries. The intrinsic parameters of the investigated functional
element are found by fitting the results of MS simulations to those obtained
from the formulas derived. Devices linked with one and two semi-infinite
waveguides are analyzed explicitly; possible extensions of the formalism to
more complex circuits are discussed as well. The accuracy of the proposed
method is tested in a number of systems; the results of our calculations prove
to be in good agreement with those obtained independently by other authors.Comment: 8 pages, 5 figure
Implementering av forskningsbasert bacheloreksamen i sykepleie – prosess og erfaring
Implementation of a research-based bachelor thesis in nursing – process and experiencesBackground: Ability to ensure quality and to evaluate own practice of nursing, is essential in order to practice a research based health care. An increase of research skills among future nurses, are thus central. The aim of this paper is to describe experiences connected with implementation of a new research-based model for examination of bachelor thesis in bachelor degree in nursing at Molde University College, Norway.Results: The curriculum has gained a clearer focus on science and research, and informative guidelines have been developed. The final bachelor thesis is now consisting of a systematic literature review based on scientific articles. The auditorium as a learning arena in the form of a thesis defence contributes to awareness of importance of research for nursing.Conclusion: The introduction of a new research based model for the bachelor thesis has strengthened the academic environment. Currently, Bachelor of Nursing has a clear focus on research and development. Newly qualified nurses are well placed to work knowledge based and to participate in development of clinical practice
Use of near infrared reflectance spectroscopy to predict nitrogen uptake by winter wheat within fields with high variability in organic matter
In this study, the ability to predict N-uptake in winter wheat crops using NIR-spectroscopy on soil samples was evaluated. Soil samples were taken in unfertilized plots in one winter wheat field during three years (1997-1999) and in another winter wheat field nearby in one year (2000). Soil samples were analyzed for organic C content and their NIR-spectra. N-uptake was measured as total N-content in aboveground plant materials at harvest. Models calibrated to predict N-uptake were internally cross validated and validated across years and across fields. Cross-validated calibrations predicted N-uptake with an average error of 12.1 to 15.4 kg N ha-1. The standard deviation divided by this error (RPD) ranged between 1.9 and 2.5. In comparison, the corresponding calibrations based on organic C alone had an error from 11.7 to 28.2 kg N ha-1 and RPDs from 1.3 to 2.5. In three of four annual calibrations within a field, the NIR-based calibrations worked better than the organic C based calibrations. The prediction of N-uptake across years, but within a field, worked slightly better with an organic C based calibration than with a NIR based one, RPD = 1.9 and 1.7 respectively. Across fields, the corresponding difference was large in favour of the NIR-calibration, RPD = 2.5 for the NIR-calibration and 1.5 for the organic C calibration. It was concluded that NIR-spectroscopy integrates information about organic C with other relevant soil components and therefore has a good potential to predict complex functions of soils such as N-mineralization. A relatively good agreement of spectral relationships to parameters related to the N-mineralization of datasets across the world suggests that more general models can be calibrated
Nonlinear optics and saturation behavior of quantum dot samples under continuous wave driving
The nonlinear optical response of self-assembled quantum dots is relevant to the application of quantum dot based devices in nonlinear optics, all-optical switching, slow light and self-organization. Theoretical investigations are based on numerical simulations of a spatially and spectrally resolved rate equation model, which takes into account the strong coupling of the quantum dots to the carrier reservoir created by the wetting layer states. The complex dielectric susceptibility of the ground state is obtained. The saturation is shown to follow a behavior in between the one for a dominantly homogeneously and inhomogeneously broadened medium. Approaches to extract the nonlinear refractive index change by fringe shifts in a cavity or self-lensing are discussed. Experimental work on saturation characteristic of InGa/GaAs quantum dots close to the telecommunication O-band (1.24-1.28 mm) and of InAlAs/GaAlAs quantum dots at 780 nm is described and the first demonstration of the cw saturation of absorption in room temperature quantum dot samples is discussed in detail
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