261 research outputs found
Water vapor adsorption on Mars
Near-surface air moisture observations from Phoenix and Curiosity display diurnal adsorption, which appears insensitive to mineralogy of regolith. To study this, adsorptive column model simulations are made for midsummer at Phoenix, validated against recalibrated TECP water vapor pressures p. Two standard-form (= obeying the van't Hoff equilibrium law) adsorption isotherms with quite different specific surface areas A s do produce nearly identical and good matches with the observed p, whereas a widely used non-standard isotherm fails. When made standard, it also produces good results. Adsorbed amounts differ in the three good simulations but their surface fluxes and surface vapor concentrations are nevertheless nearly identical. Properties of regolith except enthalpy are shown to disappear in the model's adsorption term, explaining insensitivity to A(s). The van't Hoff plot of observed In p vs. model's 1/T-g during adsorption and desorption suggests enthalpy of about 22 kJ/mol. Enthalpies of the three standard-form isotherms are close to this, explaining their excellent match with each other and with observations. Hence the low-pressure water vapor adsorption to martian regolith appears essentially nonspecific and is associated with low enthalpy, as is typical for physisorption in general.Peer reviewe
Translatory sequences as collaborative achievements in bilingual workshops for primary school children
Peer reviewe
Measurement of Martian boundary layer winds by the displacement of jettisoned lander hardware
Abstract Martian boundary layer wind speed and direction measurements, from a variety of locations, seasons and times, are provided. For each lander sent to Mars over the last four decades a unique record of the winds blowing during their descent is preserved at each landing site. By comparing images acquired from orbiting spacecraft of the impact points of jettisoned hardware, such as heat shields and parachutes, to a trajectory model the winds can be measured. We start our investigations with the Viking lander 1 mission and end with Schiaparelli. In-between we extract wind measurements based on observations of the Beagle 2, Spirit, Opportunity, Phoenix and Curiosity landing sites. With one exception the wind at each site during the lander’s descent were found to be 20 m s − 1 ), blowing from the north-west was required at a high altitude ( > 2 km) together with a gust close to the surface ( < 500 m altitude) originating from the north. All in all our investigations yielded a total of ten unique wind measurements in the PBL. One each from the Viking landers and one each from Beagle 2, Spirit, Opportunity and Schiaparelli. Two wind measurements, one above about 1 km altitude and one below, were possible from observations of the Curiosity and Phoenix landing site. Our findings are consistent with a turbulent PBL in the afternoon and calm PBL in the morning. When comparing our results to a GCM we found a good match in wind direction but not for wind speed. The information provided here makes available wind measurements previously unavailable to Mars atmosphere modellers and investigators.Peer reviewe
Ortografiset periaatteet Maskun Hemmingin Piae Cantiones -kokoelman suomennoksessa
Die orthographischen Grundsätze in Maskun Hemminkis finnischer Übersetzung der Piae Cantiones (saksa
Sanajärjestystyyppi pääverbi - kieltoverbi viron kielessä
The word order type main verb - negation verb in Estonian (englanti
Yhteisestä toiminnasta yhteiseen kieleen
Marjo Savijärven suomen kielen alaan kuuluva väitöskirja tarkastettiin Helsingin yliopistossa 2. joulukuuta 2011. Vastaväittäjänä toimi tohtori Minna Suni Jyväskylän yliopistostaja kustoksena professori Salla Kurhila. Marjo Savijärvi: Yhteisestä toiminnasta yhteiseen kieleen. Keskustelunanalyyttinen tutkimus toisen kielen oppimisesta kielikylpypäiväkodin arkitilanteissa. Helsinki: Helsingin yliopiston suomen kielen, suomalais-ugrilaisten ja pohjoismaisten kielten jakirjallisuuksien laitos 2011.Kirja on luettavissa myös verkkojulkaisuna: http://urn.fi/URN:ISBN:978-952-10-7309-0
Fakultatiivisten kieltoainesten ja kieltoverbin ellipsin suhteesta itämerensuomalaisissa kielissä
On the relation between optional negation markers and ellipsis of the negation verb in Finnic languages (englanti
- …