Biopohjaiset tyydyttymättömät polyesterihartsit

Tiivistelmä. Tyydyttymättömät polyesterihartsit (UPR) ovat synteettisten hartsien luokka, joista voidaan valmistaa kovettamalla kevyitä ja kestäviä kertamuoveja. Tyydyttymättömiä polyesterihartseja ja niiden komposiitteja käytetään nykypäivänä monilla eri aloilla kuten rakennus-, auto- ja lääketeollisuudessa. Valtaosa polymeeriteollisuudessa käytetyistä monomeereista ovat kuitenkin öljynjalostuksesta peräisin olevia petrokemikaaleja. UP-hartsien tuotannon hiilijalanjäljen pienentämiseksi osa tai kaikki komponenteista voidaan teoriassa korvata uusiutuvista luonnonvaroista saatavilla vaihtoehdoilla. Tässä työssä tutkittiin biopohjaisten komponenttien hyödyntämistä tyydyttymättömien polyesterihartsien valmistuksessa. Tarkoituksena oli selvittää kuinka hyvin uusiutuvista luonnonvaroista saadut monomeerit soveltuvat laajasti käytettyjen petrokemikaalijohdannaisten korvikkeeksi. Aineistoa tutkielmalle etsittiin Oulun yliopiston kirjaston tarjoamien tietokantojen avulla. Työssä tarkasteltiin erilaisia UP-esipolymeerien syntetisoinnissa käytettyjä biopohjaisia polyalkoholeja ja dihappoja. Lisäksi tarkasteltiin hartsien valmistamisessa oleellisten reaktiivisten liuottimien biopohjaisia vaihtoehtoja. Biopohjaisten UP-polymeerien soveltuvuutta tarkasteltiin karakterisoimalla niiden fysikaalisia sekä termomekaanisia ominaisuuksia ja vertailemalla näitä kaupallisiin UP-polymeereihin. Tulosten perusteella biopohjaiset UP-polymeerit osoittautuvat ominaisuuksiltaan pääosin samanlaisiksi tai jopa paremmiksi, kuin petrokemikaaleihin pohjautuvat UP-polymeerit

Entry, Descent, and Landing Operations Analysis for the Stardust Re-Entry Capsule

On the morning of January 15, 2006, the Stardust capsule successfully landed at the Utah Test and Training range in northwest Utah returning cometary samples from the comet Wild-2. An overview of the entry, descent, and landing (EDL) trajectory analysis that was performed for targeting during the Stardust Mission Navigation Operations Phase upon final approach to Earth is described. In addition, how the predicted landing location and the resulting overall 99 percentile landing footprint ellipse obtained from a Monte Carlo analysis changed over the final days and hours prior to entry is also presented. The navigation and EDL operations effort accurately delivered the entry capsule to the desired landing site. The final landing location was 8.1 km from the target, which was well within the allowable landing area

Policy instruments and welfare state reform

A core, but so far untested, proposition of the new politics perspective, originally introduced by Paul Pierson, is that welfare state cutbacks will be implemented using so-called ‘invisible’ policy instruments, for example, a change in indexation rules. Expansion should, by implication, mainly happen using ‘visible’ policy instruments, for example, a change in nominal benefits. We have coded 1030 legislative reforms of old-age pensions and unemployment protection in Britain, Denmark, Finland and Germany from 1974 to 2014. With this unique data at hand, we find substantial support for this crucial new politics proposition

Morphology of the spectral resonance structure of the electromagnetic background noise in the range of 0.1?4 Hz at <i>L</I> = 5.2

International audienceContinuous observations of fluctuations of the geomagnetic field at Sodankylä Geophysical Observatory (L = 5.2) were used for a comprehensive morphological study of the spectral resonance structure (SRS) seen in the background electromagnetic noise in the frequency range of 0.1?4.0 Hz. It is shown that the occurrence rate of SRS is higher in the nighttime than in the daytime. The occurrence rate is higher in winter than in summer. The SRS frequencies and the difference between neighbouring eigenfrequencies (the frequency scale) increase towards nighttime and decrease towards daytime. Both frequency scale and occurrence rate exhibit a clear tendency to decrease from minimum to maximum of the solar activity cycle. It is found that the occurrence rate of SRS decreases when geomagnetic activity increases. The SRS is believed to be a consequence of a resonator for Alfvén waves, which is suggested to exist in the upper ionosphere. According to the theory of the ionospheric Alfvén resonator (IAR), characteristics of SRS crucially depend on electron density in the F-layer maximum, as well as on the altitudinal scale of the density decay above the maximum.We compared the SRS morphological properties with predictions of the IAR theory. The ionospheric parameters needed for calculation were obtained from the ionosphere model (IRI-95), as well as from measurements made with the ionosonde in Sodankylä. We conclude that, indeed, the main morphological properties of SRS are explained on the basis of the IAR theory. The measured parameters of SRS can be used for improving the ionospheric models

The host galaxy and late-time evolution of the Super-Luminous Supernova PTF12dam

Super-luminous supernovae of type Ic have a tendency to occur in faint host galaxies which are likely to have low mass and low metallicity. PTF12dam is one of the closest and best studied super-luminous explosions that has a broad and slowly fading lightcurve similar to SN 2007bi. Here we present new photometry and spectroscopy for PTF12dam from 200-500 days (rest-frame) after peak and a detailed analysis of the host galaxy (SDSS J142446.21+461348.6 at z = 0.107). Using deep templates and image subtraction we show that the full lightcurve can be fit with a magnetar model if escape of high-energy gamma rays is taken into account. The full bolometric lightcurve from -53 to +399 days (with respect to peak) cannot be fit satisfactorily with the pair-instability models. An alternative model of interaction with a dense CSM produces a good fit to the data although this requires a very large mass (~ 13 M_sun) of hydrogen free CSM. The host galaxy is a compact dwarf (physical size ~ 1.9 kpc) and with M_g = -19.33 +/- 0.10, it is the brightest nearby SLSN Ic host discovered so far. The host is a low mass system (2.8 x 10^8 M_sun) with a star-formation rate (5.0 M_sun/year), which implies a very high specific star-formation rate (17.9 Gyr^-1). The remarkably strong nebular lines provide detections of the [O III] \lambda 4363 and [O II] \lambda\lambda 7320,7330 auroral lines and an accurate oxygen abundance of 12 + log(O/H) = 8.05 +/- 0.09. We show here that they are at the extreme end of the metallicity distribution of dwarf galaxies and propose that low metallicity is a requirement to produce these rare and peculiar supernovae.Comment: 20 pages, 12 figures, 8 tables, accepted for publication to MNRA

Metabolomic Profiling of Statin Use and Genetic Inhibition of HMG-CoA Reductase

Background Statins are first-line therapy for cardiovascular disease prevention, but their systemic effects across lipoprotein subclasses, fatty acids, and circulating metabolites remain incompletely characterized. Objectives This study sought to determine the molecular effects of statin therapy on multiple metabolic pathways. Methods Metabolic profiles based on serum nuclear magnetic resonance metabolomics were quantified at 2 time points in 4 population-based cohorts from the United Kingdom and Finland (N = 5,590; 2.5 to 23.0 years of follow-up). Concentration changes in 80 lipid and metabolite measures during follow-up were compared between 716 individuals who started statin therapy and 4,874 persistent nonusers. To further understand the pharmacological effects of statins, we used Mendelian randomization to assess associations of a genetic variant known to mimic inhibition of HMG-CoA reductase (the intended drug target) with the same lipids and metabolites for 27,914 individuals from 8 population-based cohorts. Results Starting statin therapy was associated with numerous lipoprotein and fatty acid changes, including substantial lowering of remnant cholesterol (80% relative to low-density lipoprotein cholesterol [LDL-C]), but only modest lowering of triglycerides (25% relative to LDL-C). Among fatty acids, omega-6 levels decreased the most (68% relative to LDL-C); other fatty acids were only modestly affected. No robust changes were observed for circulating amino acids, ketones, or glycolysis-related metabolites. The intricate metabolic changes associated with statin use closely matched the association pattern with rs12916 in the HMGCR gene (R2 = 0.94, slope 1.00 ± 0.03). Conclusions Statin use leads to extensive lipid changes beyond LDL-C and appears efficacious for lowering remnant cholesterol. Metabolomic profiling, however, suggested minimal effects on amino acids. The results exemplify how detailed metabolic characterization of genetic proxies for drug targets can inform indications, pleiotropic effects, and pharmacological mechanisms

The multi-faceted Type II-L supernova 2014G from pre-maximum to nebular phase

We present multi-band ultraviolet, optical, and near-infrared photometry, along with visual-wavelength spectroscopy, of supernova (SN) 2014G in the nearby galaxy NGC 3448 (25 Mpc). The early-phase spectra show strong emission lines of the high ionisation species He II/N IV/C IV during the first 2-3 d after explosion, traces of a metal-rich CSM probably due to pre-explosion mass loss events. These disappear by day 9 and the spectral evolution then continues matching that of normal Type II SNe. The post-maximum light curve declines at a rate typical of Type II-L class. The extensive photometric coverage tracks the drop from the photospheric stage and constrains the radioactive tail, with a steeper decline rate than that expected from the $^{56}$Co decay if $\gamma$-rays are fully trapped by the ejecta. We report the appearance of an unusual feature on the blue-side of H$\alpha$ after 100 d, which evolves to appear as a flat spectral feature linking H$\alpha$ and the O I doublet. This may be due to interaction of the ejecta with a strongly asymmetric, and possibly bipolar CSM. Finally, we report two deep spectra at ~190 and 340 d after explosion, the latter being arguably one of the latest spectra for a Type II-L SN. By modelling the spectral region around the Ca II, we find a supersolar Ni/Fe production. The strength of the O I $\lambda\lambda$6300,6363 doublet, compared with synthetic nebular spectra, suggests a progenitor with a zero-age main-sequence mass between 15 and 19 M$_\odot$.Comment: 24 pages, 14 figure

Modelling shifts in agroclimate and crop cultivar response under climate change

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SNhunt151: An explosive event inside a dense cocoon

Indexación: Scopus.We thank S. Spiro, R. Rekola, A. Harutyunyan, and M. L. Graham for their help with the observations. We are grateful to the collaboration of Massimo Conti, Giacomo Guerrini, Paolo Rosi, and Luz Marina Tinjaca Ramirez from the Osservatorio Astronomico Provinciale di Montarrenti. The staffs at the different observatories provided excellent assistance with the observations.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement No. 267251, ‘Astronomy Fellowships in Italy’ (AstroFIt)’. NE-R acknowledges financial support from MIUR PRIN 2010-2011, ‘The Dark Universe and the Cosmic Evolution of Baryons: From Current Surveys to Euclid’. NE-R, AP, SB, LT, MT, and GP are partially supported by the PRIN-INAF 2014 (project ‘Transient Universe: Unveiling New Types of Stellar Explosions with PESSTO’). GP acknowledges support provided by the Millennium Institute of Astrophysics (MAS) through grant IC120009 of the Programa Iniciativa Cientíifica Milenio del Ministerio de Economía, Fomento y Turismo de Chile. TK acknowledges financial support from the Emil Aaltonen Foundation. CRTS was supported by the NSF grants AST-0909182, AST-1313422, and AST-1413600. AVF is grateful for generous financial assistance from the Christopher R. Redlich Fund, the TABASGO Foundation, the Miller Institute for Basic Research in Science (UC Berkeley), and NASA/HST grant GO-14668 from the Space Telescope Science Institute, which is operated by AURA, Inc. under NASA contract NAS5-26555. The work of AVF was conducted in part at the Aspen Center for Physics, which is supported by NSF grantPHY-1607611; he thanks the Center for its hospitality during the neutron stars workshop in June and July 2017. NE-R acknowledges the hospitality of the ‘Institut de Ciències de l'Espai (CSIC), where this work was completed.This research is based on observations made with the Nordic Optical Telescope, operated by the Nordic Optical Telescope Scientific Association at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofísica de Canarias; the Gran Telescopio Canarias (GTC), installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, on the island of La Palma; the Italian Telescopio Nazionale Galileo (TNG), operated on the island of La Palma by the Fundaci Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias; the Liverpool Telescope, operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias with financial support from the UK Science and Technology Facilities Council; the 1.82-m Copernico Telescope and the Schmidt 67/92 cm of INAF-Asiago Observatory; the Catalina Real Time Survey (CRTS) Catalina Sky Survey (CSS) 0.7-m Schmidt Telescope; and the Las Cumbres Observatory (LCO) network. This work is also based in part on archival data obtained with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute (STScI), which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS5-26555; the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA (support was provided by NASA through an award issued by JPL/Caltech); and the Swift telescope.This work has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA.SNhunt151 was initially classified as a supernova (SN) impostor (nonterminal outburst of a massive star). It exhibited a slow increase in luminosity, lasting about 450 d, followed by a major brightening that reaches M V ≈ -18 mag. No source is detected to M V ≳ -13 mag in archival images at the position of SNhunt151 before the slow rise. Low-to-mid-resolution optical spectra obtained during the pronounced brightening show very little evolution, being dominated at all times by multicomponent Balmer emission lines, a signature of interaction between the material ejected in the new outburst and the pre-existing circumstellar medium. We also analysed mid-infrared images from the Spitzer Space Telescope, detecting a source at the transient position in 2014 and 2015. Overall, SNhunt151 is spectroscopically a Type IIn SN, somewhat similar to SN 2009ip. However, there are also some differences, such as a slow pre-discovery rise, a relatively broad light-curve peak showing a longer rise time (~50 d), and a slower decline, along with a negligible change in the temperature around the peak (T ≤ 10 4 K). We suggest that SNhunt151 is the result of an outburst, or an SN explosion, within a dense circumstellar nebula, similar to those embedding some luminous blue variables like η Carinae and originating from past mass-loss events. © 2017 The Author(s).https://academic.oup.com/mnras/article/475/2/2614/479530