11 research outputs found
Hybrid simulations of the proton precipitation patterns onto the upper atmosphere of Mars
We study the dependence of proton precipitation patterns onto the Martian upper atmosphere on altitude, proton energy, proton origin, and in a lesser extent, solar zenith angle, using the HYB-Mars model, a 3D quasineutral hybrid model. We find that the flux of precipitating protons has a strong altitude dependence: on the dayside, the flux of precipitating protons decreases substantially when the altitude over Mars decreases. We also find that the contribution of exospheric protons to the deposition is significant and its spatial distribution is not identical to that of the solar wind protons. In addition, the low energy proton population comes mainly from the newborn planetary protons. The energized pick-up protons and solar wind protons contribute to the higher energy proton population. The study also confirms that the proton precipitation is highly asymmetric with respect to the direction of the convection electric field in the solar wind. The study implies that the Martian induced magnetosphere protects the upper atmosphere effectively against proton precipitation
A case study of proton precipitation at Mars:Mars Express observations and hybrid simulations
Using the data from the Analyzer of Space Plasma and Energetic Atoms (ASPERA-3) experiment on board Mars Express and hybrid simulations, we have investigated the entry of protons into the Martian induced magnetosphere. We discuss one orbit on the dayside with observations of significant proton fluxes at altitudes down to 260 km on 27 February 2004. The protons observed below the induced magnetosphere boundary at an altitude of less than 700 km have energies of a few keV, travel downward, and precipitate onto the atmosphere. The measured energy flux and particle flux are 10^8–10^9 eV cm^−2 s^−1 and 10^5–10^6 H^+ cm^−2 s^−1, respectively. The proton precipitation occurs because the Martian magnetosheath is small with respect to the heated proton gyroradius in the subsolar region. The data suggest that the precipitation is not permanent but may occur when there are transient increases in the magnetosheath proton temperature. The higher-energy protons penetrate deeper because of their larger gyroradii. The proton entry into the induced magnetosphere is simulated using a hybrid code. A simulation using a fast solar wind as input can reproduce the high energies of the observed precipitating protons. The model shows that the precipitating protons originate from both the solar wind and the planetary exosphere. The precipitation extends over a few thousand kilometers along the orbit of the spacecraft. The proton precipitation does not necessarily correlate with the crustal magnetic anomalies
Matalalentoverkosto : Selvitys toteuttamisvaihtoehdoista
Matalalentoverkostossa on kyse satelliittipaikannukseen perustuvasta reittiverkostosta sekä mittarilähestymismenetelmistä, jotka mahdollistaisivat tehokkaan lentotoiminnan myös näkösääolosuhteita huonommissa sääolosuhteissa. Matalalentoverkosto koos-tuisi kahdesta toisiinsa liittyvästä kokonaisuudesta; reittiverkostosta koko valtakunnan alueella sekä lähestymismenetelmistä valituille lentopaikoille.
Tarve matalalentoverkoston perustamiseen Suomeen on tullut viranomaistoimijoilta, jotka näkevät verkostolle voimakkaan yhteiskunnallisen tarpeen. Näiden lisäksi on tunnistettu yleisilmailun kiinnostus mittarilentotoimintaan valvomattomilla lentopaikoil-la. Yleistä kansainvälisesti määriteltyä konseptia matalalentoverkostosta ei ole, joten kansallisesti voidaan tiettyjen reunaehtojen puitteissa arvioida mahdollisimman tarkoi-tuksenmukainen malli. Selvityksen aikana tehtiin yleisen tason turvallisuusvaikutusten arviointi, joka pohjautuu Eurocontrolin tekemiin kahteen yleistason turvallisuustarkaste-luun koskien erikseen matalalentoreittiverkostoa ja lähestymismenetelmiä. Tässä tar-kastelussa ei ilmennyt kynnyskysymyksiä hankkeen toteutukselle.
Tämä selvitys kuvaa kartoitetut toteuttamisvaihtoehdot. Selvityksen tehnyt työryhmä suosittelee perustettavaksi Suomeen ensivaiheessa viranomaiskäyttöistä, asteittain laajennettavaa matalalentoverkostoa. Reittiverkosto olisi yksinomaan helikoptereille ja lähestymismenetelmät tarpeen mukaan myös lentokoneille. Alailmatilaan odotetaan kohdistuvan tulevina vuosina useita muutoksia ja matalalentoverkosto toteutuessaan olisi näistä yksi keskeisiä
Steering of Foreign Subsidiaries : an Analysis of Steering System Development in Six Finnish Companies
A bibliometric analysis of battery research with the BATTERY 2030+ roadmap as point of departure
In this bibliometric study, we analyze the six battery research subfields identified in the BATTERY 2030+ roadmap: Battery Interface Genome, Materials Acceleration Platform, Recyclability, Smart functionalities: Self-healing, Smart functionalities: Sensing, and Manufacturability. In addition, we analyze the entire research field related to BATTERY 2030+ as a whole, using two operationalizations. We (a) evaluate the European standing in the subfields/the BATTERY 2030+ field in comparison to the rest of the world, and (b) identify strongholds of the subfields/the BATTERY 2030+ field across Europe. For each subfield and the field as a whole, we used seed articles, i.e. articles listed in the BATTERY 2030+ roadmap or cited by such articles, in order to generate additional, similar articles located in an algorithmically obtained classification system. The output of the analysis is publication volumes, field normalized citation impact values with comparisons between country/country aggregates and between organizations, co-publishing networks between countries and organizations, and keyword co-occurrence networks. For the results related to (a), the performance of EU & associated (countries) is similar to China and the aggregate Japan-South Korea-Singapore and well below North America regarding citation impact and with respect to the field as a whole. Exceptions are, however, the subfields Battery Interface Genome and Recyclability. For the results related to (b), there is a large variability in the EU & associated organizations regarding volume in the different subfields. For citation impact, examples of high-performing EU & associated organizations are ETH Zurich and Max Planck Society for the Advancement of Science.This is an open-access publication distributed under the terms of the Creative Commons Attribution 4.0 International License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. To view a copy of this license, please visit https://creativecommons.org/licenses/by/4.0</p
The use of optical biosensor for high-throughput detection of veterinary drug residues in foods.
BATTERY 2030+ and its Research Roadmap : A Bibliometric Analysis.
In this bibliometric study, we analyze two of the six battery research subfields identified in the BATTERY 2030+ roadmap: Materials Acceleration Platform and Smart functionalities: Sensing. In addition, we analyze the entire research field related to BATTERY 2030+ as a whole. We (a) evaluate the European standing in the two subfields/the BATTERY 2030+ field in comparison to the rest of the world, and (b) identify strongholds of the two subfields/the BATTERY 2030+ field across Europe. For each subfield and the field as a whole, we used seed articles, i. e. articles listed in the BATTERY 2030+ roadmap or cited by such articles, in order to generate additional, similar articles located in an algorithmically obtained classification system. The output of the analysis is publication volumes, field normalized citation impact values with comparisons between country/country aggregates and between organizations, co-publishing networks between countries and organizations, and keyword co-occurrence networks.QC 20231009</p