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Träfflista för sökning "WFRF:(Hietala H.) srt2:(2020-2024)"

Sökning: WFRF:(Hietala H.) > (2020-2024)

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1.
  • Telloni, D., et al. (författare)
  • Study of two interacting interplanetary coronal mass ejections encountered by Solar Orbiter during its first perihelion passage Observations and modeling
  • 2021
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 656
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. Solar Orbiter, the new-generation mission dedicated to solar and heliospheric exploration, was successfully launched on February 10, 2020, 04:03 UTC from Cape Canaveral. During its first perihelion passage in June 2020, two successive interplanetary coronal mass ejections (ICMEs), propagating along the heliospheric current sheet (HCS), impacted the spacecraft.Aims. This paper addresses the investigation of the ICMEs encountered by Solar Orbiter on June 7-8, 2020, from both an observational and a modeling perspective. The aim is to provide a full description of those events, their mutual interaction, and their coupling with the ambient solar wind and the HCS.Methods. Data acquired by the MAG magnetometer, the Energetic Particle Detector suite, and the Radio and Plasma Waves instrument are used to provide information on the ICMEs' magnetic topology configuration, their magnetic connectivity to the Sun, and insights into the heliospheric plasma environment where they travel, respectively. On the modeling side, the Heliospheric Upwind eXtrapolation model, the 3D COronal Rope Ejection technique, and the EUropean Heliospheric FORecasting Information Asset (EUHFORIA) tool are used to complement Solar Orbiter observations of the ambient solar wind and ICMEs, and to simulate the evolution and interaction of the ejecta in the inner heliosphere, respectively.Results. Both data analysis and numerical simulations indicate that the passage of two distinct, dynamically and magnetically interacting (via magnetic reconnection processes) ICMEs at Solar Orbiter is a possible scenario, supported by the numerous similarities between EUHFORIA time series at Solar Orbiter and Solar Orbiter data.Conclusions. The combination of in situ measurements and numerical simulations (together with remote sensing observations of the corona and inner heliosphere) will significantly lead to a deeper understanding of the physical processes occurring during the CME-CME interaction.
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2.
  • Norrman, AE, et al. (författare)
  • Salivary Biomarkers and Oral Health in Liver Transplant Recipients, with an Emphasis on Diabetes
  • 2021
  • Ingår i: Diagnostics (Basel, Switzerland). - : MDPI AG. - 2075-4418. ; 11:4
  • Tidskriftsartikel (refereegranskat)abstract
    • Salivary biomarkers have been linked to various systemic diseases. We examined the association between salivary biomarkers, periodontal health, and microbial burden in liver transplant (LT) recipients with and without diabetes, after transplantation. We hypothesized that diabetic recipients would exhibit impaired parameters. This study included 84 adults who received an LT between 2000 and 2006 in Finland. Dental treatment preceded transplantation. The recipients were re-examined, on average, six years later. We evaluated a battery of salivary biomarkers, microbiota, and subjective oral symptoms. Periodontal health was assessed, and immunosuppressive treatments were recorded. Recipients with impaired periodontal health showed higher matrix metalloproteinase-8 (MMP-8) levels (p < 0.05) and MMP-8/tissue inhibitor of matrix metalloproteinase 1 (TIMP1) ratios (p < 0.001) than recipients with good periodontal health. Diabetes post-LT was associated with impaired periodontal health (p < 0.05). No difference between groups was found in the microbial counts. Salivary biomarker levels did not seem to be affected by diabetes. However, the advanced pro-inflammatory state induced by and associated with periodontal inflammation was reflected in the salivary biomarker levels, especially MMP-8 and the MMP-8/TIMP-1 molar ratio. Thus, these salivary biomarkers may be useful for monitoring the oral inflammatory state and the course of LT recipients.
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5.
  • Brasseur, Z., et al. (författare)
  • Measurement report: Introduction to the HyICE-2018 campaign for measurements of ice-nucleating particles and instrument inter-comparison in the Hyytiala boreal forest
  • 2022
  • Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 22:8, s. 5117-5145
  • Tidskriftsartikel (refereegranskat)abstract
    • The formation of ice particles in Earth's atmosphere strongly influences the dynamics and optical properties of clouds and their impacts on the climate system. Ice formation in clouds is often triggered heterogeneously by ice-nucleating particles (INPs) that represent a very low number of particles in the atmosphere. To date, many sources of INPs, such as mineral and soil dust, have been investigated and identified in the low and mid latitudes. Although less is known about the sources of ice nucleation at high latitudes, efforts have been made to identify the sources of INPs in the Arctic and boreal environments. In this study, we investigate the INP emission potential from high-latitude boreal forests in the mixed-phase cloud regime. We introduce the HyICE-2018 measurement campaign conducted in the boreal forest of Hyytiala, Finland, between February and June 2018. The campaign utilized the infrastructure of the Station for Measuring Ecosystem-Atmosphere Relations (SMEAR) II, with additional INP instruments, including the Portable Ice Nucleation Chamber I and II (PINC and PINCii), the SPectrometer for Ice Nuclei (SPIN), the Portable Ice Nucleation Experiment (PINE), the Ice Nucleation SpEctrometer of the Karlsruhe Institute of Technology (INSEKT) and the Microlitre Nucleation by Immersed Particle Instrument (mu L-NIPI), used to quantify the INP concentrations and sources in the boreal environment. In this contribution, we describe the measurement infrastructure and operating procedures during HyICE-2018, and we report results from specific time periods where INP instruments were run in parallel for inter-comparison purposes. Our results show that the suite of instruments deployed during HyICE-2018 reports consistent results and therefore lays the foundation for forthcoming results to be considered holistically. In addition, we compare measured INP concentrations to INP parameterizations, and we observe good agreement with the Tobo et al. (2013) parameterization developed from measurements conducted in a ponderosa pine forest ecosystem in Colorado, USA.
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6.
  • Dimmock, Andrew P., et al. (författare)
  • Compiling Magnetosheath Statistical Data Sets Under Specific Solar Wind Conditions : Lessons Learnt From the Dayside Kinetic Southward IMF GEM Challenge
  • 2020
  • Ingår i: Earth and Space Science. - : AMER GEOPHYSICAL UNION. - 2333-5084. ; 7:6
  • Tidskriftsartikel (refereegranskat)abstract
    • The Geospace Environmental Modelling (GEM) community offers a framework for collaborations between modelers, observers, and theoreticians in the form of regular challenges. In many cases, these challenges involve model-data comparisons to provide wider context to observations or validate model results. To perform meaningful comparisons, a statistical approach is often adopted, which requires the extraction of a large number of measurements from a specific region. However, in complex regions such as the magnetosheath, compiling these data can be difficult. Here, we provide the statistical context of compiling statistical data for the southward IMF GEM challenge initiated by the "Dayside Kinetic Processes in Global Solar Wind-Magnetosphere Interaction" focus group. It is shown that matching very specific upstream conditions can severely impact the statistical data if limits are imposed on several solar wind parameters. We suggest that future studies that wish to compare simulations and/or single events to statistical data should carefully consider at an early stage the availability of data in context with the upstream criteria. We also demonstrate the importance of how specific IMF conditions are defined, the chosen spacecraft, the region of interest, and how regions are identified automatically. The lessons learnt in this study are of wide context to many future studies as well as GEM challenges. The results also highlight the issue where a global statistical perspective has to be balanced with its relevance to more-extreme, less-frequent individual events, which is typically the case in the field of space weather.
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7.
  • Hietala, H., et al. (författare)
  • Benefits Realisation in Post-Implementation Development of ERP Systems: A Case Study
  • 2021
  • Ingår i: CENTERIS 2020 - International Conference on ENTERprise Information Systems / ProjMAN 2020 - International Conference on Project MANagement / HCist 2020 - International Conference on Health and Social Care Information Systems and Technologies 2020, CENTERIS/ProjMAN/HCist 2020. - : Elsevier. ; , s. 419-426
  • Konferensbidrag (refereegranskat)abstract
    • Enterprise Resource Planning (ERP) systems influence organisational performance and business strategies significantly. However, identifying, managing, and realising expected benefits of ERP is challenging. The existing ERP research has largely focused on the implementation phase leaving post-implementation development understudied. Yet, post-implementation development ensures continuing benefits. This paper documents a single-case study on benefits realisation in post-implementation ERP development. The results imply that benefits realisation practices can improve job satisfaction while lack of it can lead to unused solutions. Outdated and evolved business processes, complicated further by workarounds, hinder on-going ERP development. Consequently, benefits realisation is hindered as well. Moreover, when subsidiaries are unable to identify new benefits on their own and while the benefits may even vary from one subsidiary to another, the complexity of benefits realisation increases. Altogether, the article highlights four empirical findings on issues influencing post-implementation benefits realisation and four issues on post implementation ERP development in general.
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8.
  • Hietala, H., et al. (författare)
  • The Challenges and Rewards of Running a Geospace Environment Modeling Challenge
  • 2020
  • Ingår i: Journal of Geophysical Research - Space Physics. - 2169-9380 .- 2169-9402. ; 125:3
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • Geospace Environment Modeling (GEM) is a community-driven, National Science Foundation-sponsored research program investigating the physics of the Earth's magnetosphere and its coupling to the solar wind and the atmosphere. This commentary provides an introduction to a Special Issue collating recent studies related to a GEM Challenge on kinetic plasma processes in the dayside magnetosphere during southward interplanetary magnetic field conditions. We also recount our experiences of organizing such a collaborative activity, where modelers and observers compare their results, that is, of the human side of bringing researchers together. We give suggestions on planning, managing, funding, and documenting these activities, which provide valuable opportunities to advance the field. Plain Language Summary Geospace Environment Modeling (GEM) is a community-driven, National Science Foundation-sponsored research program investigating the physics of the Earth's magnetosphere and its coupling to the solar wind and the atmosphere. An integral part of the program is the so-called "Challenges", which bring people together to compare models and observations in order to advance our understanding of the near-Earth space environment. This commentary provides an introduction to a Special Issue collating recent studies related to one such collaborative effort. We also share our experiences as early-career scientists organizing such an activity, to aid those who might take part in such endeavors in the future. We give suggestions on planning, managing, funding, and documenting the activities.
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9.
  • Lahtinen, M. H., et al. (författare)
  • The impact of thermomechanical pulp fiber modifications on thermoplastic lignin composites
  • 2021
  • Ingår i: Composites Part C: Open Access. - : Elsevier BV. - 2666-6820. ; 6
  • Tidskriftsartikel (refereegranskat)abstract
    • Cellulose and lignin are abundant renewable biopolymers that can be used for the manufacture of new, environmentally friendly materials. The objective of this study was to produce composites of kraft lignin, which were reinforced with cellulosic thermomechanical pulp (TMP) fibers. Furthermore, the fibers were chemically modified resulting in cross-linking or increased hydrophobicity. Ideally, these modifications improve interaction between the components in the composite. The effects of the modifications on the tensile strength and thermal properties of the composites were investigated, and the interactions between components were examined by infrared spectroscopy and scanning electron microscopy. When the fibers were cross-linked with polyethylene glycol diglycidyl ether (PEGDE), the tensile strength properties of the composite were significantly improved. Depending on the amount of PEGDE added, tensile strength was increased by 16–34%, and Young's Modulus by 6–18%, but at the same time the strain at break remained the same. Similarly, by using PEGDE, the amount of free plasticizer (PEG) could be reduced, which also improved the water-resistance of the composite. According to scanning electron microscopy, all chemical treatments improved the compatibility of the fibers with the lignin matrix. However, the increase in compatibility was highest when the fibers were cross-linked with a combination of glyoxal and neopentyl glycol (GL/NPG) or by increasing hydrophobicity through acetylation (AC), although the tensile strength properties were the best in case of cross-linking with PEGDE. 
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