5 research outputs found
The scope of the EU VAT Directive: Transactions carried out via Video Sharing Websites
Video Sharing Websites constitute a rather peculiar situation. On one hand, they are considered as part of what the Commission perceives as online sharing economy: users are eligible to derive income from monetizing their audiovisual content. On the other hand, their business model is reminiscent of what is described as âfree -economyâ: access to the audiovisual content is prima facie provided without any monetary consideration. While the Commission has published guidelines, in an effort to map the potential issues regarding the VAT Treatment of persons who conduct activities via sharing economy online platforms, its assessment focalized more on âdigitalizedâ traditional activities. This inquiry is dedicated to raising the issues concerning the qualification as âsupplies of goods or services for considerationâ, of activities carried out via Video Sharing Websites, and of their provider as âtaxable personâ, for the purposes of EU VAT, in the light of the EU VAT Directive and the CJEUâs interpretation of these concept
Preparation of hydrogen, fluorine and chlorine doped and co-doped titanium dioxide photocatalysts: a theoretical and experimental approach
Titanium dioxide (TiO2) has a strong photocatalytic activity in the ultra-violet part of the spectrum combined with excellent chemical stability and abundance. However, its photocatalytic efficiency is prohibited by limited absorption within the visible range derived from its wide band gap value and the presence of charge trapping states located at the band edges, which act as electron-hole recombination centers. Herein, we modify the band gap and improve the optical properties of TiO2via co-doping with hydrogen and halogen. The present density functional theory (DFT) calculations indicate that hydrogen is incorporated in interstitial sites while fluorine and chlorine can be inserted both as interstitial and oxygen substitutional defects. To investigate the synergy of dopants in TiO2 experimental characterization techniques such as Fourier transform infrared (FTIR), X-ray diffraction (XRD), X-ray and ultra-violet photoelectron spectroscopy (XPS/UPS), UV-Vis absorption and scanning electron microscopy (SEM) measurements, have been conducted. The observations suggest that the oxideâs band gap is reduced upon halogen doping, particularly for chlorine, making this material promising for energy harvesting devices. The studies on hydrogen production ability of these materials support the enhanced hydrogen production rates for chlorine doped (Cl:TiO2) and hydrogenated (H:TiO2) oxides compared to the pristine TiO2 reference
Imaging of a Renal Artery Aneurysm Detected Incidentally on Ultrasonography
Renal artery aneurysms occur with a frequency of less than 1% of the general population. Even if they are usually asymptomatic and incidentally found, they can be complicated with life-threatening conditions like rupture, thrombosis, embolism, or hypertension. Thus, once diagnosed, they should be fully evaluated with further imaging and treated when indicated. We present the case of a patient who was referred for ultrasonography for an unrelated reason. The examination demonstrated a hyperechoic focus near the right kidney. Further imaging workup with MDCT established the diagnosis of a right renal artery aneurysm which was saccular in shape and peripherally calcified. This ring-like calcification was also visible in a KUB radiography which was also performed. After presenting the case, various aspects of this rare entity are discussed
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Simulating the formation of carbonaceous aerosol in a European Megacity (Paris) during the MEGAPOLI summer and winter campaigns
We use a three-dimensional regional chemical transport model (PMCAMx) with high grid resolution and high-resolution emissions (4 Ă 4 km2) over the Paris greater area to simulate the formation of carbonaceous aerosol during a summer (July 2009) and a winter (January/February 2010) period as part of the MEGAPOLI (megacities: emissions, urban, regional, and global atmospheric pollution and climate effects, and Integrated tools for assessment and mitigation) campaigns. Model predictions of carbonaceous aerosol are compared against Aerodyne aerosol mass spectrometer and black carbon (BC) high time resolution measurements from three ground sites. PMCAMx predicts BC concentrations reasonably well reproducing the majority (70âŻ%) of the hourly data within a factor of two during both periods. The agreement for the summertime secondary organic aerosol (OA) concentrations is also encouraging (mean bias = 0.1 ”g mâ3) during a photochemically intense period. The model tends to underpredict the summertime primary OA concentrations in the Paris greater area (by approximately 0.8 ”g mâ3) mainly due to missing primary OA emissions from cooking activities. The total cooking emissions are estimated to be approximately 80 mg dâ1 per capita and have a distinct diurnal profile in which 50 % of the daily cooking OA is emitted during lunch time (12:00â14:00 LT) and 20 % during dinner time (20:00â22:00 LT). Results also show a large underestimation of secondary OA in the Paris greater area during wintertime (mean bias = âŻâ2.3 ”g mâ3) pointing towards a secondary OA formation process during low photochemical activity periods that is not simulated in the model