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1.
Searching for Pair Halos
Serguei Vorobiov, Lisa Fallon, 2010, objavljeni povzetek znanstvenega prispevka na konferenci

Najdeno v: ključnih besedah
Povzetek najdenega: ...system, Cherenkov telescopes, active galaxies, extragalactic background light, electromagnetic cascades, pair halos, ...
Ključne besede: ground based y-ray telescopes, H.E.S.S. system, Cherenkov telescopes, active galaxies, extragalactic background light, electromagnetic cascades, pair halos
Objavljeno: 25.04.2014; Ogledov: 4059; Prenosov: 17
URL Polno besedilo (0,00 KB)

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Bi2O3-BASED PYROCHLORE NANOSTRUCTURES AND THEIR CRYSTALLOGRAPHIC, OPTOELECTRONIC AND PHOTOCATALYTIC PROPERTIES
Metka Benčina, 2015, doktorska disertacija

Opis: Bi2O3-based pyrochlore nanomaterials and their photocatalytic, optoelectronic and crystallographic properties are the research topics of this doctoral dissertation. We synthesized these materials at nanoscale, since they are expected to possess photoactivity in the visible-light spectrum, which is an important target for the high-performance photocatalysts. To prepare nanoparticles that are not agglomerated, different synthesis methods (coprecipitation, coprecipitation followed by the digestion, reverse micelle) and post-treatments (furnace or hydrothermal reactor) were examined. Micrometer size materials were prepared with the solid-state reaction and annealing at high temperature. Bi2Ti2O7 nanoparticles were synthesized with the coprecipitation reaction, followed by annealing at 570 °C in the furnace or in the hydrothermal reactor at 230 °C for 18h in NH4OH medium. UV-Vis diffuse reflectance spectra of the Bi2Ti2O7 samples showed that they exhibit the maximum absorption edge at ~420-440 nm. The UV-Vis diffuse reflectance measurements of Bi2Ti2O7 loaded with 10 wt. % of Ag as a co-catalyst showed an enhanced absorbance in the visible region, presumably due to a contribution of Local Surface Plasmon Resonance. The Bi2Ti2O7 nanoparticles are not photocatalytically active under the visible light irradiation without assistance of a sacrificial reagent. The photocatalytic activity does not increase even with Ag as a co-catalyst under visible light irradiation. All samples are active under UV light irradiation, especially the sample with Ag that is able to decolourize 7 mg/L of metyl orange in just 3 min of exposure to UV light. However, H2O2 as a sacrificial reagent increases the photocatalytic activity of Bi2Ti2O7 under visible light irradiation. Phase pure pyrochlore Bi1.647Nb1.118Fe1.157O7 (BNF) nanoparticles were synthesized with coprecipitation reaction and further annealing in the furnace at 570 °C for 7h or 15h and in the hydrothermal reactor at 160 °C for 18h in 3 M or 6 M NaOH medium. The BNF materials exhibit shift toward longer wavelengths in absorbance of visible light (up to ~550-650 nm). This result confirmed that incorporation of Fe in the pyrochlore structure decreases the band gap. The BNF nanoparticles annealed for 7h showed intense photoactivity under visible light irradiation in the presence of a sacrificial reagent. The improved photoactivity, much better than with BNF, was shown for the composite nanoparticles BiOCl/BNF. They decolourize 100 % of the 7 mg/L methyl orange within only 2h of the visible light irradiation in the presence of H2O2. Phase pure pyrochlore Bi1.9Te0.58Fe1.52O6.87 (BTF) nanoparticles were synthesised by coprecipitation reaction and further annealing in the furnace at 570 °C for 7h. Although the BTF nanoparticles include higher amount of Fe than BNF nanoparticles and exhibit narrower band gap, the photoactivity of these nanoparticles is a bit lower than that of BNF nanoparticles. We assume that Fe at some critical concentration causes formation of mid-band states, which act as recombination centers. The same as BiOCl/BNF, the BiOCl/BTF composite is able to decolourize 100 % of the 7 mg/L MO within 2h of the visible light irradiation in the presence of H2O2. Based on the band gap determination and estimation of valence and conduction band levels, the proposed photodecolourization mechanisms are discussed. The conduction band levels of all synthesized materials lie more positively than O2/O2● redox potential (vs. negative hydrogen electrode potential), but are more close to H2O2/●OH redox potential. Thus, we assume that the photogenerated electrons form ●OH radicals, the species that induce dye decolourization under visible light irradiation. We believe that better performance of composite materials (BiOCl/BNF, BiOCl/BTF) is due to the formation of heterojunction, which facilitates the electron transfer between semiconductors, and O2 vacancy states formation in the BiOCl material.
Najdeno v: ključnih besedah
Povzetek najdenega: ...are expected to possess photoactivity in the visible- light spectrum, which is an important target for...
Ključne besede: nanoparticles, pyrochlore structure, photocatalysis, visible light
Objavljeno: 26.06.2015; Ogledov: 6538; Prenosov: 166
.pdf Polno besedilo (7,29 MB)

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Plasma-enhanced ALD deposition of mixed CoNiO[sub]x protective layer for Ta[sub]3N[sub]5 water splitting photoanode
Nadiia Pastukhova, Yanbo Li, 2020, objavljeni povzetek znanstvenega prispevka na konferenci

Najdeno v: ključnih besedah
Povzetek najdenega: ...photoelectrochemical water splitting, light-responsive photoelectrodes, nickel oxides, cobalt oxides...
Ključne besede: photoelectrochemical water splitting, light-responsive photoelectrodes, nickel oxides, cobalt oxides
Objavljeno: 03.11.2020; Ogledov: 1527; Prenosov: 46
URL Polno besedilo (0,00 KB)

5.
Temperature induced de-agglomeration of the polysilane macromolecules
Matjaž Valant, Mattia Fanetti, Artem Badasyan, Andraž Mavrič, 2016, objavljeni povzetek znanstvenega prispevka na konferenci

Najdeno v: ključnih besedah
Povzetek najdenega: ...polysilane, de-agglomeration, dynamic light scattering, differential scanning calorimetry...
Ključne besede: polysilane, de-agglomeration, dynamic light scattering, differential scanning calorimetry
Objavljeno: 05.10.2016; Ogledov: 3779; Prenosov: 0
.pdf Polno besedilo (73,71 KB)

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The Camera Calibration Strategy of the Cherenkov Telescope Array
Marko Zavrtanik, Danilo Zavrtanik, Gabrijela Zaharijas, Lili Yang, Serguei Vorobiov, Samo Stanič, Gašper Kukec Mezek, Andrej Filipčič, M. K. Daniel, 2015, objavljeni znanstveni prispevek na konferenci

Najdeno v: ključnih besedah
Povzetek najdenega: ...Cherenkov Telescope Array (CTA), Cherenkov light intensity, calibration of cameras of CTA telescopes...
Ključne besede: Cherenkov Telescope Array (CTA), Cherenkov light intensity, calibration of cameras of CTA telescopes
Objavljeno: 24.01.2017; Ogledov: 2829; Prenosov: 204
.pdf Polno besedilo (202,93 KB)

8.
Efficient de-agglomeration of polysilane macromolecules in solution and their molecular size
Matjaž Valant, Mattia Fanetti, Artem Badasyan, Andraž Mavrič, 2017, objavljeni povzetek znanstvenega prispevka na konferenci

Najdeno v: ključnih besedah
Povzetek najdenega: ...polysilane, solubility, de-agglomeration, dynamic light scattering...
Ključne besede: polysilane, solubility, de-agglomeration, dynamic light scattering
Objavljeno: 03.07.2017; Ogledov: 3312; Prenosov: 0
.pdf Polno besedilo (1,81 MB)

9.
Portrait of light
Marco Pelos Spagno, 2017, diplomsko delo

Opis: This work aims to research the basic structure of lighting in portraits in a controlled light situation. After providing a brief historical introduction to define where modern lighting comes from, I will describe and analyse the tools used to modify the light in a studio and the procedure to follow before a portrait session. I will present a series of images shot in a studio, and I will touch upon most possible basic lighting setups in a portrait session, from most simple ones to some more complex ones, describing the set of lights, the type of modifiers used, and the effects that the light can have on a viewer. My final aim is to build up a collection of light setups that can be helpful to anyone who wants to approach portrait photography and the studio workflow, not aiming to build a manual, but just providing a report on my personal research and study.
Najdeno v: ključnih besedah
Ključne besede: portrait, light, studio, study, technique, photography, bw, model, modifiers, controloflight, history, paintings, art, exposure
Objavljeno: 29.11.2017; Ogledov: 3658; Prenosov: 280
.pdf Polno besedilo (6,53 MB)

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