12 research outputs found
The transiting multi-planet system HD3167: a 5.7 MEarth Super-Earth and a 8.3 MEarth mini-Neptune
HD3167 is a bright (V=8.9 mag) K0V star observed by the NASA's K2 space
mission during its Campaign 8. It has been recently found to host two small
transiting planets, namely, HD3167b, an ultra short period (0.96 d)
super-Earth, and HD3167c, a mini-Neptune on a relatively long-period orbit
(29.85 d). Here we present an intensive radial velocity follow-up of HD3167
performed with the FIES@NOT, [email protected], and HARPS-N@TNG spectrographs. We
revise the system parameters and determine radii, masses, and densities of the
two transiting planets by combining the K2 photometry with our spectroscopic
data. With a mass of 5.69+/-0.44 MEarth, radius of 1.574+/-0.054 REarth, and
mean density of 8.00(+1.0)(-0.98) g/cm^3, HD3167b joins the small group of
ultra-short period planets known to have a rocky terrestrial composition.
HD3167c has a mass of 8.33 (+1.79)(-1.85) MEarth and a radius of
2.740(+0.106)(-0.100) REarth, yielding a mean density of 2.21(+0.56)(-0.53)
g/cm^3, indicative of a planet with a composition comprising a solid core
surrounded by a thick atmospheric envelope. The rather large pressure scale
height (about 350 km) and the brightness of the host star make HD3167c an ideal
target for atmospheric characterization via transmission spectroscopy across a
broad range of wavelengths. We found evidence of additional signals in the
radial velocity measurements but the currently available data set does not
allow us to draw any firm conclusion on the origin of the observed variation.Comment: 18 pages, 11 figures, 5 table
K2-60b and K2-107b. A Sub-Jovian and a Jovian Planet from the K2 Mission
We report the characterization and independent detection of K2-60b, as well as the detection and characterization of K2-107b, two transiting hot gaseous planets from the K2 space mission. We confirm the planetary nature of the two systems and determine their fundamental parameters combining the K2 time-series data with FIES @ NOT and HARPS-N @ TNG spectroscopic observations. K2-60b has a radius of 0.683 +/- 0.037 R-Jup and a mass of 0.426 +/- 0.037 M-Jup and orbits a G4 V star with an orbital period of 3.00267 +/- 0.00006 days. K2-107b has a radius of 1.44 +/- 0.15 R-Jup and a mass of 0.84 +/- 0.08 M-Jup and orbits an F9 IV star every 3.31392 +/- 0.00002 days. K2-60b is among the few planets at the edge of the so-called desert of short-period sub-Jovian planets. K2107b is a highly inflated Jovian planet orbiting an evolved star about to leave the main sequence
The transiting multi-planet system HD3167: a 5.7 MEarth Super-Earth and a 8.3 MEarth mini-Neptune
The First Post-Kepler Brightness Dips of KIC 8462852
We present a photometric detection of the first brightness dips of the unique variable star KIC 8462852 since the end of the Kepler space mission in 2013 May. Our regular photometric surveillance started in October 2015, and a sequence of dipping began in 2017 May continuing on through the end of 2017, when the star was no longer visible from Earth. We distinguish four main 1-2.5% dips, named "Elsie," "Celeste," "Skara Brae," and "Angkor", which persist on timescales from several days to weeks. Our main results so far are: (i) there are no apparent changes of the stellar spectrum or polarization during the dips; (ii) the multiband photometry of the dips shows differential reddening favoring non-grey extinction. Therefore, our data are inconsistent with dip models that invoke optically thick material, but rather they are in-line with predictions for an occulter consisting primarily of ordinary dust, where much of the material must be optically thin with a size scale <<1um, and may also be consistent with models invoking variations intrinsic to the stellar photosphere. Notably, our data do not place constraints on the color of the longer-term "secular" dimming, which may be caused by independent processes, or probe different regimes of a single process
The study of drying kinetics of wood chips in laboratory scale rotary drum dryer
Uusiutuvan energian käyttöä tullaan Suomessa lisäämään tulevaisuudessa ja pitkän aikavälin tavoitteena on hiilineutraali energiajärjestelmä, joka pohjautuu vahvasti uusiutuviin energialähteisiin kuten biopolttoaineisiin. Biopolttoaineen termistä lämpöarvoa voidaan kasvattaa alentamalla biopolttoaineen kosteuspitoisuutta kuivauksella.
Tässä työssä keskitytään Aalto-yliopistossa olevan laboratoriokokoluokan rumpukuivurin käyttöönottoon ja sen toimintaan. Pilot-rumpukuivurilla tehtiin kuivumiskokeita metsähakkeelle hyödyntäen kuivauskaasuna lämmintä ilmaa sekä käyttämällä kuivausrummun epäsuoraa lämmitystä. Kuivumiskokeiden pohjalta muodostetaan kuivumiskäyriä eri lähtöarvoilla. Lisäksi työssä tutkitaan pilot-rumpukuivurin tilavuutta kohden mitattua lämmönsiirtokerrointa pintalämpötilakokeiden avulla.
Työn ensimmäinen osuus koostuu yleisestä teoriaosuudesta, jossa käsitellään kostean ilman termodynamiikkaa, hakkeen ominaisuuksia, kosteuden määritystä, kuivumista fysikaalisena ilmiönä, rumpukuivurin toimintaa, päästöjä sekä tulipalo- ja räjähdysvaaroja. Toisessa osassa keskitytään kokeelliseen tutkimukseen liittyen pilot-rumpukuivurin käyttöönottoon ja koelaitteistoon, kuivumis- ja kuivumisnopeuskäyrien muodostamiseen sekä tilavuutta kohden mitatun lämmönsiirtokertoimen määritykseen.
Työn tulokset osoittivat, että pilot-rumpukuivuri soveltuu metsähakkeen kuivaukseen, jos sisääntuloilman lämpötila on tarpeeksi korkea, epäsuora lämmitys on käytössä sekä hakkeen sekoittuminen on tarpeeksi tehokasta. Tuloksien epätarkkuuteen vaikuttivat metsähakkeen heterogeeninen koostumus ja palakoon suuri vaihtelu testien välillä.In the future the use of the renewable energy will be increased in Finland and the long-term objective is the carbon neutral energy system, which is based heavily on renewable energy sources such as biofuels. By using drying, the thermal calorific value of the biofuel can be increased by lowering the moisture content of the biofuel.
This study focuses on the commissioning and operation of a laboratory rotary drum dryer in the Aalto University. Drying tests of the wood chips are carried out by using warm air as a drying gas and indirect heating as conductive drying. Based on the drying tests, drying curves are formed with different starting values. In addition, a heat transfer coefficient measured per volume of pilot rotary drum dryer is studied by taking temperature tests from surfaces of wood chips.
The first part of the study concentrates on general theoretical part dealing with thermal dynamics of humid air, wood chips properties, moisture determination, theory of drying, theory of rotary drum dryer, emissions and fire and explosion hazards. The second part of the study focuses on experimental research regarding the commissioning of pilot rotary drum dryer and testing instrumentation, forming drying curves and determining the heat transfer coefficient measured per volume.
The results of the study showed that the pilot rotary drum dryer is suitable for wood chips drying if the inlet air temperature is high enough, indirect heating is used and mixing of chips is efficient enough. The heterogeneous composition of the wood chips and variation of the wood chips size between tests were affected to the uncertainty of the results
Spectroscopic Studies of Fermi LAT Blazars
Blazar research offers a view to one of the most energetic physical processes known
to man. The high-energy end of blazar emission has been probed by the Fermi
satellite mission since 2008, and it has catalogued more than a thousand gamma-
ray bright blazars. However, a large fraction of these sources have no spectroscopic
classification at lower energies.
In this thesis, optical spectra for sixteen Fermi blazar candidates are published. The
optical spectroscopic data have been observed with the Nordic Optical Telescope on
the island of La Palma, Spain, during the summer of 2015. The ALFOSC instrument
was used, with exposure times from 800 to 3000 seconds per target, yielding signal-
to-noise ratios from 10 to 38.
All of the sixteen targets show a flat, featureless optical spectrum, characteristic to
BL Lacertae objects. The spectra of two targets contain faint emission features, and
faint absorption features are seen in three targets. However, none of the features
could be reliably identified.
Therefore all of the targets are classified as BL Lacertae objects. This classification
is supported by the statistical distribution of Fermi -selected active galactic nuclei;
more than half of the identified Fermi AGN are BL Lacs. However, the classification
of this sample could be improved further with a new observing campaign. This is
especially true for the objects with uncertain spectral features.Siirretty Doriast
Hiontahuoneen layout-muutos ja 5S-menetelmän käyttöönotto
Opinnäytetyössä oli tavoitteena suunnitella sekä toteuttaa A-tekniikka Oy:n hiontahuoneen layout-muutos, 5S:n käyttöönotto sekä työergonomian ja tulityöturvallisuuden ratkaisut. A-tekniikka Oy on teollisuusyritys, joka on erikoistunut automaattisten nastoituskoneiden valmistukseen.
Työn teoreettisena tietoperustana käsiteltiin layout-suunnittelua, 5S-menetelmää, työergonomiaa sekä tulityöturvallisuutta. 5S-menetelmä on yksi Lean-tuotantofilosofian toteutukseen käytettävä menetelmä, jonka viiden vaiheen avulla saadaan työpaikasta tuottavampi, organisoidumpi, turvallisempi ja laadukkaampi. Työ aloitettiin rajaamalla opinnäytetyön aihe sekä hiontahuoneen parannuskohteet, minkä jälkeen kartoitettiin menetelmät, joilla hiontahuoneen muutokset toteutetaan. Toteutus aloitettiin piirtämällä layout-suunnitelmat, joiden pohjalta pystyttiin suunnittelemaan hiontahuoneeseen työpisteiden ergonomiset ratkaisut, 5S:n toteutus sekä tulityöturvallisuuteen liittyvät ratkaisut. Suunnitelmien pohjalta aloitettiin toteuttamaan hiontahuoneen muutosta käytännössä.
Opinnäytetyön lopputuloksena saatiin suunnitelmiin pohjautuva uudistunut hiontahuone, joka on toimiva, tuottava, viihtyisä sekä turvallinen. Uudistuneessa hiontahuoneessa työntekijöiden on helpompaa ja tehokkaampaa työskennellä, jolloin myös työviihtyvyys ja työn tuottavuus paranevat. Tehtyjen suunnitelmien ja layout-piirustuksien pohjalta hiontahuoneeseen pystytään myös tulevaisuudessa tekemään muutoksia nopeammin ja helpommin.The aim of the Bachelor´s thesis was to plan and implement a layout change, 5S introduction, ergonomics and fire safety solutions for A-Technic Ltd´s grinding room. A-Technic Ltd is an industrial company which is specialized in the manufacturing of automatic studding machines.
The theory section of the thesis deals with theoretical knowledge of the layout-design, the method of 5S, ergonomics and fire safety. The method of 5S is one of the Lean manufacturing philosophies for creating a productive, organized, safe and high-quality workplace with the five steps. Firstly the study was started by defining the topic of the thesis and the improvements of the grinding room. Secondly the methods for the implementation of the modification were decided. The implementation was started by drawing the layout plans. The layout plan formed the basis for the 5S implementation and ergonomic and fire safety solutions. When the plans were ready, the implementation was finally started in practice.
The result of the thesis was a renewed grinding room which was based on the plans. The grinding room is now a functional, productive, comfortable and safe workplace. In the renewed grinding room, working is easier and more efficient and the job satisfaction and productivity have improved. The designs and drawings can be useful in the future if the company wants to improve and update the grinding room again
Faisabilite de controle de production par camera video couplee a un micro-systeme informatique de prise de decision
CNRS AR 12150 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc