Search results for "HOT"
showing 10 items of 14851 documents
Heterogeneous photocatalysis: guidelines on experimental setup, catalyst characterization, interpretation, and assessment of reactivity
2019
Soon after the publication of the first pioneering works on heterogeneous photocatalysis, the number of papers on this topic continuously increased. This intriguing field of research is very complex as it endows with an interdisciplinary overview that involves different aspects of chemistry, physics, material and environmental sciences. Even if photocatalytic applications in real processes are often difficult to be implemented and scaled-up, investigations at laboratory scale are easy to be performed, and in some cases they may give rise to misconceptions. For this reason, the present work aims to sum up most of the common experimental techniques and procedures generally used in heterogeneo…
The weathering test of polypropylene composites
2000
Polipropylen "Malen P" czysty (a), kompozyty na jego podstawie napełniane (20% mas.) kredą lub talkiem (b) oraz produkty te stabilizowane dodatkowo stabilizatorem UV typu HALS ("Tinuvin 791") (c) poddano badaniom laboratoryjnego starzenia atmosferycznego. Badane próbki poddawano działaniu promieniowania ultrafioletowego w dawkach do 950 MJ/m2, w zaprogramowanych warunkach temperatury, wilgotności oraz nadeszczania. Postęp fotodegradacji polimeru śledzono na podstawie zmian ciężaru cząsteczkowego, jego rozkładu (GPC) oraz wybranych właściwości mechanicznych (wydłużenia względnego, naprężenia zrywającego, udarności z karbem). Określono również odporność próbek badanych białych kompozytów na z…
Vapaus, valtio ja politiikka
2008
Englantilaisen politiikan filosofin Michael Oakeshottin (1901–1990) käsitys vapaudesta ja sen kehittyminen toisen maailmansodan jälkeisistä vuosista aina hänen pääteokseensa On Human Conduct (1975) saakka muodostaa tarinan, jota tässä artikkelissa seurataan. Näinä vuosina hänen tuotantonsa pääpaino oli poliittisessa ajattelussa, joten myös hänen vapauden käsityksensä on suhteutettava tähän. Vapautta voidaan pitää yhtenä politiikan teorian peruskäsitteistä – ideana tai kulmakivenä – ja näin ollen myös Oakeshottia on hyvä verrata aiempiin ja nykyisiin politiikan teorian perinteisiin. peerReviewed
Euclid preparation: XI. Mean redshift determination from galaxy redshift probabilities for cosmic shear tomography
2021
Ilbert, O., et al. (Euclid Collaboration)
A photometric study of Be stars located in the seismology fields of COROT
2007
Context: In preparation for the COROT mission, an exhaustive photometric study of Be stars located in the seismology fields of the COROT mission has been performed. The very precise and long-time-spanned photometric observations gathered by the COROT satellite will give important clues of the origin of the Be phenomenon. Aims: The aim of this work is to find short-period variable Be stars located in the seismology fields of COROT and to study and characterise their pulsational properties. Methods: Light curves obtained at the Observatorio de Sierra Nevada together with data from Hipparcos and ASAS-3 of a total of 84 Be stars have been analysed in order to search for short-term variations. W…
Optical quality of hyperopic and myopic phakic intraocular lenses
2013
Aims: To assess and compare the optical quality of the myopic and hyperopic implantable collamer lens (ICL) from its wavefront aberrations for different powers and pupil diameters. Settings and Design: Prospective study. Material and Methods: The wavefront aberrations of two myopic (−3 and −6 diopters (D)) and two hyperopic V4b ICLs (+3 and +6D) were measured in vitro . To assess and compare the optical quality of different powers of ICLs, we analyzed the root mean square (RMS) of total higher order aberrations (HOAs), trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration at 3- and 4.5-mm pupil. In addition, the point spread functions (PSFs) of each ICL evaluated were ca…
Spin Crossover and Long-Lived Excited States in a Reduced Molecular Ruby.
2020
Abstract The chromium(III) complex [CrIII(ddpd)2]3+ (molecular ruby; ddpd=N,N′‐dimethyl‐N,N′‐dipyridine‐2‐yl‐pyridine‐2,6‐diamine) is reduced to the genuine chromium(II) complex [CrII(ddpd)2]2+ with d4 electron configuration. This reduced molecular ruby represents one of the very few chromium(II) complexes showing spin crossover (SCO). The reversible SCO is gradual with T 1/2 around room temperature. The low‐spin and high‐spin chromium(II) isomers exhibit distinct spectroscopic and structural properties (UV/Vis/NIR, IR, EPR spectroscopies, single‐crystal XRD). Excitation of [CrII(ddpd)2]2+ with UV light at 20 and 290 K generates electronically excited states with microsecond lifetimes. This…
Energy Transport in SiO2 Crystals: Luminescence Excitation Spectra of Stishovite and α-Quartz
2022
The financial support of the Latvian Science Council Grant No lzp-2021/1-0215 and the funding of the University of Latvia as the Centre of Excellence within the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2, are greatly acknowledged.
Photoluminescence and Electron Spin Resonance of Silicon Dioxide Crystal with Rutile Structure (Stishovite)
2018
This work was supported by ERANET MYND. Also, financial support provided by Scientific Research Project for Students and Young Researchers Nr. SJZ/2017/2 realized at the Institute of Solid State Physics, University of Latvia is greatly acknowledged. The authors express our gratitude to R.I. Mashkovtsev for help in ESR signal interpretation. The authors are appreciative to T.I. Dyuzheva, L.M. Lityagina, N.A. Bendeliani for stishovite single crystals and to K. Hubner and H.-J. Fitting for stishovite powder of Barringer Meteor Crater.