Search results for "Methods"
showing 10 items of 4526 documents
Analytical results for 2-D non-rectilinear waveguides based on a Green's function
2008
We consider the problem of wave propagation for a 2-D rectilinear optical waveguide which presents some perturbation. We construct a mathematical framework to study such a problem and prove the existence of a solution for the case of small imperfections. Our results are based on the knowledge of a Green's function for the rectilinear case.
Opiskelijoiden motivaatio ja siihen vaikuttavat tekijät selkärangattomien peruslajintuntemuksen kurssilla
2017
Lajintuntemustaidot ovat tärkeä bio- ja ympäristötieteiden alojen ammattilaisten osaamisalue. Lajintuntemuksella on myös merkitys osana laajempaa luonnontuntemusta, sillä esimerkiksi ekosysteemien rakenteen ja toiminnan ymmärtäminen ilman lajintuntemusta olisi hankalaa. Lajintuntemustaitojen on todettu heikentyneen luonnontieteiden korkeakouluopiskelijoilla, minkä lisäksi lajintuntemuksen opiskelu korkeakouluissa on todettu yllättävän vaikeaksi. Kaikki opiskelijat eivät koe lajintuntemustaitojen olevan edes tärkeitä tai kiinnostavia. Lajintuntemuksen opiskelua tulisikin kehittää siten, että opiskelijoiden motivaatio paranisi tieteellisesti, sisällöllisesti ja menetelmällisesti laadukkaalla …
Flexible and Efficient Computer-Aided Design Tool for Advanced Comb-Line Rectangular Waveguide Filters
2015
A very flexible and efficient computer-aided design (CAD) tool, specifically suited for advanced comb-line rectangular waveguide filters, is presented in this work. The developed software tool, which makes use of a full-wave analysis technique based on the Boundary Integral - Resonant Mode Expansion method, permits to load the considered comb-line resonators with any number of radially symmetrical partial-height metallic posts. The implemented CAD tool also allows for dealing with coupling windows of arbitrary cross-section, thus drastically enhancing the flexibility of the computer-aided design process. The excitation of the analyzed components, which is performed by using generalized coax…
Longitudinal Patterns of Ethical Organisational Culture as a Context for Leaders’ Well-Being: Cumulative Effects Over 6 Years
2021
AbstractThe aim of this longitudinal study was to investigate the temporal dynamics of ethical organisational culture and how it associates with well-being at work when potential changes in ethical culture are measured over an extended period of 6 years. We used a person-centred study design, which allowed us to detect both typical and atypical patterns of ethical culture stability as well as change among a sample of leaders. Based on latent profile analysis and hierarchical linear modelling we found longitudinal, concurrent relations and cumulative gain and loss cycles between different ethical culture patterns and leaders’ well-being. Leaders in the strongest ethical culture pattern exper…
Composition and corrosion phases of Etruscan Bronzes from Villanovan Age
2008
A neutron diffraction (ND) and neutron tomography (NT) study of laminated ancient bronzes was performed at the ISIS (Rutherford Appleton Laboratory, UK) neutron source and at the BENSC reactor (Hahn-Meitner Institut, Germany). The samples are part of an 8th century BC Etruscan collection discovered in the necropolises of Osteria-Poggio Mengarelli and Cavalupo in the Vulci area (Viterbo, Italy). The study allowed us to derive-in a totally non-destructive manner-information related to the main composition of the objects, possible presence of alterations and their nature, crusts and inclusions, as well as structure of the bulk. The presence of some components is linked to a variety of question…
The Large Observatory For x-ray Timing
2014
The Large Observatory For x-ray Timing (LOFT) was studied within ESA M3 Cosmic Vision framework and participated in the final down-selection for a launch slot in 2022-2024. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument, LOFT will study the behaviour of matter under extreme conditions, such as the strong gravitational field in the innermost regions of accretion flows close to black holes and neutron stars, and the supra-nuclear densities in the interior of neutron stars. The science payload is based on a Large Area Detector (LAD, 10 m 2 effective area, 2-30 keV, 240 eV spectral resolution, 1 deg collimated field of view) and a WideFi…
The XENON1T Dark Matter Experiment
2017
The XENON1T experiment at the Laboratori Nazionali del Gran Sasso (LNGS) is the first WIMP dark matter detector operating with a liquid xenon target mass above the ton-scale. Out of its 3.2 t liquid xenon inventory, 2.0 t constitute the active target of the dual-phase time projection chamber. The scintillation and ionization signals from particle interactions are detected with low-background photomultipliers. This article describes the XENON1T instrument and its subsystems as well as strategies to achieve an unprecedented low background level. First results on the detector response and the performance of the subsystems are also presented. © 2017, The Author(s).
Search for inelastic scattering of WIMP dark matter in XENON1T
2021
We report the results of a search for the inelastic scattering of weakly interacting massive particles (WIMPs) in the XENON1T dark matter experiment. Scattering off $^{129}$Xe is the most sensitive probe of inelastic WIMP interactions, with a signature of a 39.6 keV de-excitation photon detected simultaneously with the nuclear recoil. Using an exposure of 0.89 tonne-years, we find no evidence of inelastic WIMP scattering with a significance of more than 2$\sigma$. A profile-likelihood ratio analysis is used to set upper limits on the cross-section of WIMP-nucleus interactions. We exclude new parameter space for WIMPs heavier than 100 GeV/c${}^2$, with the strongest upper limit of $3.3 \time…
XENON1T Dark Matter Data Analysis: Signal Reconstruction, Calibration and Event Selection
2019
The XENON1T experiment at the Laboratori Nazionali del Gran Sasso is the most sensitive direct detection experiment for dark matter in the form of weakly interacting particles (WIMPs) with masses above $6\,$GeV/$c^2$ scattering off nuclei. The detector employs a dual-phase time projection chamber with 2.0 metric tons of liquid xenon in the target. A one metric $\mathrm{ton}\times\mathrm{year}$ exposure of science data was collected between October 2016 and February 2018. This article reports on the performance of the detector during this period and describes details of the data analysis that led to the most stringent exclusion limits on various WIMP-nucleon interaction models to date. In pa…
Ymmärrettävyystutkimuksen antia kielenopetukselle : esimerkkinä englanti vieraana kielenä
2022
Nykyaikaisessa vieraiden kielten opetuksessa on tavoitteena helposti ymmärrettävä puhe. Tämä tavoite on kielenopetukselle yhteinen päämäärä oppijoiden iästä tai taitotasosta riippumatta, ja se kulkee täten oppijoiden mukana halki elinikäisen kielenoppimisen. Tässä artikkelissa esitellään soveltavan kielentutkimuksen piirissä virinnyttä ymmärrettävyystutkimusta, joka helpottaa keskittämään kielenopetusta ymmärrettävyyden kannalta olennaisimpiin asioihin. Samalla tiivistetään suomen- ja ruotsinkielisten suomalaisten puhuman englannin ymmärrettävyyttä selvittäneen ICASEF-hankkeen päätulokset. Hankkeen tulosten ja aiemman tutkimustiedon perusteella tunnistetut englannin ymmärrettävyyteen yhdist…