| 1. |
- Bordogna, Marco Tito, et al.
(författare)
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MUSCAT experiment : active free falling units for in situ measurements of temperature and density in the middle atmosphere
- 2013
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Ingår i: European Space Agency. - ESTEC, Noordwijk, The Netherlands : ESA Communications. - 9789290922858 ; , s. 575-582
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The main scientific objective of the MUSCAT Experimentis to develop a technique to reconstruct temperatures and density profiles in the middle atmosphere using active spherical probes. The MUSCAT experiment was launched on May 9, 2013 on the REXUS-13 sounding rocket from Esrange, in northern Sweden. The experiment ejected four probes that collected raw GPS signal. The experiment design and preliminary results are presented here.
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| 2. |
- Galván, Ignacio Fdez., et al.
(författare)
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OpenMolcas : From Source Code to Insight
- 2019
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Ingår i: Journal of Chemical Theory and Computation. - : American Chemical Society (ACS). - 1549-9618 .- 1549-9626. ; 15:11, s. 5925-5964
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Tidskriftsartikel (refereegranskat)abstract
- In this Article we describe the OpenMolcas environment and invite the computational chemistry community to collaborate. The open-source project already includes a large number of new developments realized during the transition from the commercial MOLCAS product to the open-source platform. The paper initially describes the technical details of the new software development platform. This is followed by brief presentations of many new methods, implementations, and features of the OpenMolcas program suite. These developments include novel wave function methods such as stochastic complete active space self-consistent field, density matrix renormalization group (DMRG) methods, and hybrid multiconfigurational wave function and density functional theory models. Some of these implementations include an array of additional options and functionalities. The paper proceeds and describes developments related to explorations of potential energy surfaces. Here we present methods for the optimization of conical intersections, the simulation of adiabatic and nonadiabatic molecular dynamics, and interfaces to tools for semiclassical and quantum mechanical nuclear dynamics. Furthermore, the Article describes features unique to simulations of spectroscopic and magnetic phenomena such as the exact semiclassical description of the interaction between light and matter, various X-ray processes, magnetic circular dichroism, and properties. Finally, the paper describes a number of built-in and add-on features to support the OpenMolcas platform with postcalculation analysis and visualization, a multiscale simulation option using frozen-density embedding theory, and new electronic and muonic basis sets.
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| 3. |
- Aquilante, Francesco, et al.
(författare)
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Modern quantum chemistry with [Open]Molcas
- 2020
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 152:21
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Tidskriftsartikel (refereegranskat)abstract
- MOLCAS/OpenMolcas is an ab initio electronic structure program providing a large set of computational methods from Hartree-Fock and density functional theory to various implementations of multiconfigurational theory. This article provides a comprehensive overview of the main features of the code, specifically reviewing the use of the code in previously reported chemical applications as well as more recent applications including the calculation of magnetic properties from optimized density matrix renormalization group wave functions.
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| 4. |
- Bergman Ärlebäck, Jonas, 1972-, et al.
(författare)
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IPAs - ihopparningsaktiviteter : aktiviteter med låg tröskel som tränar elevers begrepps-, procedur-/ metod- och resonemangsförmåga
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Syftet med denna rapport är att på ett beskrivande sätt delge hur arbetet i projektet om IPAs som genomförts HT2014 – VT2015 gått till och vilka erfarenheter och slutsatser som arbetet resulterat i. Den tänkte läsaren är framför allt kommunernas matematiklärare, men vi tror även att andra lärare och skolpersonal kan finna innehållet intressant och användbart. Det är vår förhoppning att rapporten med tillhörande aktiviteter kan inspirera till reflektion och en mer varierad undervisning. När pronomen som vi och oss används i rapporten åsyftats alla som aktivt ingått i IPAprojektets forskande grupp, vilken har bestått av såväl deltagande lärare som forskare:Marcus Claesson (Kungsgårdsgymnasiet, Norrköping), Malin Hällgren (Birgittaskolans vuxenutbildning, Linköping), Sofia Lindh (Hagagymnasiet, Norrköping), Mia Lundell (Djäkneparksskolan, Norrköping), Mattias Nordling (Anders Ljungstedska gymnasiet, Linköping) och Jonas Bergman Ärlebäck (LiU). Huvudansvaret för författandet av rapporten har Jonas haft som medverkande forskare i projektet. De medforskande lärarna har bidragit med analyser, erfarenheter och exempel från sina klassrum, utvecklat, testat och formulerat aktiviteterna som utgjort navet i projektet, samt läst och kommenterat rapporten under dess framställning.Rapporten följer samma logik och uppbyggnad som de rapporter skrivna inom det övergripande samarbetsprojektet Matematikdidaktik för bättre matematikkunskaper av det arbete och den forskning som bedrivits av Lisa Björklund Boistrup (Björklund Boistrup et al. 2013a; 2013b; 2013c; 2014a; 2014b). Vissa delar av texten använder därför, eller bygger till viss del på, Lisas texter, och när så är fallet tydliggörs detta med fotnoter. Andra delar av texten, så som exempelvis beskrivningen av de teoretiska utgångspunkterna, är i stort identiskt i samtliga delprojektsrapporter för de projekt som Jonas medverkat i som forskare (Ärlebäck et. al. 2017a, 2017b, 2017c, 2017d). Rapporten är dock skriven för att kunna läsas helt fristående från de andra rapporterna författade i projektet och förutsätter med andra ord ingen tidigare kunskap eller kännedom om projektet och de perspektiv som används. De läsare som redan tagit del av arbetet inom samarbetsprojektet Matematikdidaktik för bättre matematikkunskaper på olika sätt kommer här och var att känna igen sig, men vi hoppas att de delar som är unikt specifika för just detta delprojekt ska vara intressant och inspirerande.
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| 5. |
- Bumann, Adrian, et al.
(författare)
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Predicting the spread of invasive marine species with open data and machine learning: Process and Challenges
- 2021
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Ingår i: International Conference on Marine Data and Information Systems (IMDIS) 2021.
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Konferensbidrag (refereegranskat)abstract
- One of the world’s most complex marine challenges is the spread of invasive species. Invasive species cause severe harm to marine ecosystems and the people who depend on them, with economic impact alone amounting to several billion dollars annually. Recent advances in data science and artificial intelligence (AI) along with the increasing availability of free marine and other data online are improving the possibility to tackle these challenges. This paper presents the efforts by Ocean Data Factory Sweden (ODF Sweden), a data-driven innovation consortium in Gothenburg, to apply machine learning (ML) to one use case – the prediction of the spread of the Killer Shrimp, or Dikerogammarus Villosus, into the Baltic Sea (Figure 1). We discuss our process to address this use case as well as some reflections on the process and its challenges, in particular when taking into consideration the FAIR (findable, accessible, interoperable and reusable) principles in data science.
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| 6. |
- Delcey, Mickael G., et al.
(författare)
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Exact semi-classical light-matter interaction operator applied to two-photon processes with strong relativistic effects
- 2020
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Ingår i: Journal of Chemical Physics. - : American Institute of Physics (AIP). - 0021-9606 .- 1089-7690. ; 153:2
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Tidskriftsartikel (refereegranskat)abstract
- X-ray processes involve interactions with high-energy photons. For these short wavelengths, the perturbing field cannot be treated as constant, and there is a need to go beyond the electric-dipole approximation. The exact semi-classical light-matter interaction operator offers several advantages compared to the multipole expansion such as improved stability and ease of implementation. Here, the exact operator is used to model x-ray scattering in metal K pre-edges. This is a relativistic two-photon process where absorption is dominated by electric-dipole forbidden transitions. With the restricted active space state-interaction approach, spectra can be calculated even for the multiconfigurational wavefunctions including second-order perturbation. However, as the operator itself depends on the transition energy, the cost for evaluating integrals for hundreds of thousands unique transitions becomes a bottleneck. Here, this is solved by calculating the integrals in a molecular-orbital basis that only runs over the active space, combined with a grouping scheme where the operator is the same for close-lying transitions. This speeds up the calculations of single-photon processes and is critical for the modeling of two-photon scattering processes. The new scheme is used to model Kα resonant inelastic x-ray scattering of iron-porphyrin complexes with relevance to studies of heme enzymes, for which the total computational time is reduced by several orders of magnitude with an effect on transition intensities of 0.1% or less.
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| 7. |
- Farahani, Pooria, 1985-, et al.
(författare)
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Theoretical study of the dark photochemistry of 1,3-butadiene via the chemiexcitation of Dewar dioxetane
- 2015
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 17, s. 18653-18664
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Tidskriftsartikel (refereegranskat)abstract
- Excited-state chemistry is usually ascribed to photo-induced processes, such as fluorescence, phosphorescence, and photochemistry, or to bio-and chemiluminescence, in which light emission originates from a chemical reaction. A third class of excited-state chemistry is, however, possible. It corresponds to the photochemical phenomena produced by chemienergizing certain chemical groups without light - chemiexcitation. By studying Dewar dioxetane, which can be viewed as the combination of 1,2-dioxetane and 1,3-butadiene, we show here how the photo-isomerization channel of 1,3-butadiene can be reached at a later stage after the thermal decomposition of the dioxetane moiety. Multi-reference multiconfigurational quantum chemistry methods and accurate reaction-path computational strategies were used to determine the reaction coordinate of three successive processes: decomposition of the dioxetane moiety, non-adiabatic energy transfer from the ground to the excited state, and finally non-radiative decay of the 1,3-butadiene group. With the present study, we open a new area of research within computational photochemistry to study chemically-induced excited-state chemistry that is difficult to tackle experimentally due to the short-lived character of the species involved in the process. The findings shall be of relevance to unveil "dark'' photochemistry mechanisms, which might operate in biological systems under conditions of lack of light. These mechanisms might allow reactions that are typical of photo-induced phenomena.
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| 8. |
- Giussani, Angelo, et al.
(författare)
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Molecular Basis of the Chemiluminescence Mechanism of Luminol
- 2019
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Ingår i: Chemistry - A European Journal. - : WILEY-V C H VERLAG GMBH. - 0947-6539 .- 1521-3765. ; 25:20, s. 5202-5213
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Tidskriftsartikel (refereegranskat)abstract
- Light emission from luminol is probably one of the most popular chemiluminescence reactions due to its use in forensic science, and has recently displayed promising applications for the treatment of cancer in deep tissues. The mechanism is, however, very complex and distinct possibilities have been proposed. By efficiently combining DFT and CASPT2 methodologies, the chemiluminescence mechanism has been studied in three steps: 1)luminol oxygenation to generate the chemiluminophore, 2)a chemiexcitation step, and 3)generation of the light emitter. The findings demonstrate that the luminol double-deprotonated dianion activates molecular oxygen, diazaquinone is not formed, and the chemiluminophore is formed through the concerted addition of oxygen and concerted elimination of nitrogen. The peroxide bond, in comparison to other isoelectronic chemical functionalities (-NH-NH-, -N--N--, and -S-S-), is found to have the best chemiexcitation efficiency, which allows the oxygenation requirement to be rationalized and establishes general design principles for the chemiluminescence efficiency. Electron transfer from the aniline ring to the OO bond promotes the excitation process to create an excited state that is not the chemiluminescent species. To produce the light emitter, proton transfer between the amino and carbonyl groups must occur; this requires highly localized vibrational energy during chemiexcitation.
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| 9. |
- Guo, Meiyuan, et al.
(författare)
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Fingerprinting Electronic Structure of Heme Iron by Ab Initio Modeling of Metal L-Edge X-ray Absorption Spectra
- 2019
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Ingår i: Journal of Chemical Theory and Computation. - : American Chemical Society (ACS). - 1549-9618 .- 1549-9626. ; 15:1, s. 477-489
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Tidskriftsartikel (refereegranskat)abstract
- The capability of the multiconfigurational restricted active space approach to identify electronic structure from spectral fingerprints is explored by applying it to iron L-edge X-ray absorption spectroscopy (XAS) of three heme systems that represent the limiting descriptions of iron in the Fe-O-2 bond, ferrous and ferric [Fe(P)(ImH)(2)](0/1+) (P = porphine, ImH = imidazole), and Fe-II(P). The level of agreement between experimental and simulated spectral shapes is calculated using the cosine similarity, which gives a quantitative and unbiased assignment. Further dimensions in fingerprinting are obtained from the L-edge branching ratio, the integrated absorption intensity, and the edge position. The results show how accurate ab initio simulations of metal L-edge XAS can complement calculations of relative energies to identify unknown species in chemical reactions.
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| 10. |
- Knudsen, Søren Tang, et al.
(författare)
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Risk factor management of type 2 diabetic patients in primary care in the Scandinavian countries between 2003 and 2015
- 2021
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Ingår i: Primary Care Diabetes. - : Elsevier BV. - 1751-9918 .- 1878-0210. ; 15:2, s. 262-268
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Tidskriftsartikel (refereegranskat)abstract
- Aims: To observe and report population demography, comorbidities, risk factor levels and risk factor treatment in a sample of individuals treated for type 2 diabetes in primary care in Norway, Sweden and Denmark. Methods: Retrospective observational cohort using extraction of data from electronic medical records linked with national health care registries. Results: Sixty primary care clinics participated with annual cross-sectional data (2003 to 2015). In 2015 the sample consisted of 31,632 individuals. Mean age (64.5–66.8 years) and proportion of women (43–45%) were similar. The prevalence of cardiovascular disease in 2015 was 40.7%, 41.6% and 38.0% for Norway, Sweden and Denmark, respectively and 84% to 89% of patients were receiving a pharmacological anti-diabetic treatment. More Danish patients reached targets for HbA1c and LDL cholesterol, while more patients in Sweden and Denmark met the blood pressure target of <130/80 mmHg as compared to Norway. Conclusions: In three comparable public primary health care systems we found a high prevalence of cardiovascular disease and differences in risk factor treatment and attainment of risk factor goals. With recent guideline changes there is potential for further prevention of diabetes complications in primary care in the future.
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