Vection in depth during treadmill walking

Vection has typically been induced in stationary observers (ie conditions providing visual-only information about self-motion). Two recent studies have examined vection during active treadmill walking--one reported that treadmill walking in the same direction as the visually simulated self-motion impaired vection (Onimaru et al, 2010 Journal of Vision 10(7):860), the other reported that it enhanced vection (Seno et al, 2011 Perception 40 747-750; Seno et al, 2011 Attention, Perception, & Psychophysics 73 1467-1476). Our study expands on these earlier investigations of vection during observer active movement. In experiment 1 we presented radially expanding optic flow and compared the vection produced in stationary observers with that produced during walking forward on a treadmill at a 'matched' speed. Experiment 2 compared the vection induced by forward treadmill walking while viewing expanding or contracting optic flow with that induced by viewing playbacks of these same displays while stationary. In both experiments subjects' tracked head movements were either incorporated into the self-motion displays (as simulated viewpoint jitter) or simply ignored. We found that treadmill walking always reduced vection (compared with stationary viewing conditions) and that simulated viewpoint jitter always increased vection (compared with constant velocity displays). These findings suggest that while consistent visual-vestibular information about self-acceleration increases vection, biomechanical self-motion information reduces this experience (irrespective of whether it is consistent or not with the visual input)

Enhancing selectivity in photocatalytic formation of p-anisaldehyde in aqueous suspension under solar light irradiation via TiO2 N-doping

The photocatalytic partial oxidation of 4-methoxybenzyl alcohol to the corresponding aldehyde (p-anisaldehyde) was performed under simulated solar irradiation by using home prepared N-doped TiO2 catalysts. The photocatalysts were prepared by a sol–gel method, using TiCl4 as TiO2 precursor and NH4Cl, urea or NH4OH as N-doping sources. A commercial TiO2 (Degussa P25) was also used for comparison aims. The prepared catalysts were characterized by BET specific surface area, XRD, ESEM and UV-vis spectroscopy. The reactivity results show that (i) the doped catalysts are predominantly amorphous, and they show selectivity values far higher than those of the corresponding undoped ones and of well crystallized catalysts – even if the last ones show a higher activity – and (ii) exploitation of solar light significantly increases the reaction selectivity. In addition, different light sources were also used in order to investigate the effect of radiation wavelength ranges on the reactivity and selectivity to aldehyde

Overview on oxidation mechanisms of organic compounds by TiO2 in heterogeneous photocatalysis

This review provides the reader with a general overview on heterogeneous photocatalytic oxidation mechanisms in the presence of TiO2, with a special address to conversion of aliphatic and aromatic organic species. The aim was to clarify the steps of the photo-oxidation of the various classes of compounds and to relate them with the properties of the catalysts and the experimental conditions used. Reactions carried out to perform complete degradation and photocatalytic partial oxidations have been deeply discussed. Recent isotopic studies highlighted new reaction pathways concerning partial oxidation of alcohols to aldehyde and oxidation of benzene while EPR investigations confirmed that not only the photogenerated hole but also the OH radicals are involved in the oxidation of the substrates

Sequential biological and photocatalysis based treatments for shipboard slop purification: A pilot plant investigation

This study investigated the treatment of a shipboard slop containing commercial gasoline in a pilot plant scale consisting of a membrane biological reactor (MBR) and photocatalytic reactor (PCR) acting in series. The MBR contributed for approximately 70% to the overall slop purification. More precisely, the biological process was able to remove approximately 40%, on average, of the organic pollution in the slop. Nevertheless, the membrane was capable to retain a large amount of organic molecules within the system, amounting for a further 30% of the influent total organic content removal. However, this affected the membrane fouling, thus resulting in the increase of the pore blocking mechanism that accounted for approximately 20% to the total resistance to filtration (2.85∙10 13 m −1 ), even if a significant restoration of the original membrane permeability was obtained after chemical cleanings. On the other hand, the biological treatment produced a clear solution for the photocatalytic system, thereby optimizing the light penetration and generation of highly oxidizing active oxygen species that enabled the degradation of bio-recalcitrant compounds. Indeed, low total organic carbon (TOC) values (<10 mg L −1 ) were achieved in the output of the photocatalytic reactor by means of only 60 Einstein (E) of cumulative impinging energy after the addition of K 2 S 2 O 8 . Overall, coupling the two processes enabled very high TOC removal (ca. 95%)

Extruded Expanded Polystyrene Sheets Coated by TiO2 as New Photocatalitic Materials for Foodstuffs Packaging

Nanostructured, photoactive anatase TiO2 sol prepared under very mild conditions using titanium tetraisopropoxide as the precursor is used to functionalise extruded expanded polystyrene (XPS) sheets by spray-coating resulting in stable and active materials functionalised by TiO2 nanoparticles. Photocatalytic tests of these sheets performed in a batch reactor in gas–solid system under UV irradiation show their successful activity in degrading probe molecules (2-propanol, trimethylamine and ethene). Raman spectra ensure the deposition of TiO2 as crystalline anatase phase on the polymer surface. The presence of TiO2 with respect to polymer surface can be observed in SEM images coupled to EDAX mapping allowing to monitor the surface morphology and the distribution of TiO2 particles. Finally thermoforming of these sheets in industrial standard equipment leads to useful containers for foodstuffs

Photocatalytic selective oxidation of 5-(hydroxymethyl)-2-furaldehyde to 2,5-furandicarbaldehyde in water by using anatase, rutile and brookite TiO2 nanoparticles

5-(Hydroxymethyl)-2-furaldehyde (HMF) was selectively oxidized to 2,5-furandicarbaldehyde (FDC) in aqueous medium by using home-prepared (HP) anatase, rutile, and brookite TiO2 nanoparticles. HP samples were prepared via a sol−gel method by using TiCl4 as the TiO2 precursor. Commercial TiO2 catalysts were also used for comparison. All samples were characterized by BET specific surface area, XRD, TGA, and SEM, and the reactivity results showed that HP catalysts are predominantly amorphous and give rise to selectivities toward FDC more than twice that of commercial and well-crystallized catalysts

Glideslope perception during aircraft landing

Ideally, when a pilot approaches a runway on their final approach for landing, they must maintain a constant trajectory, or glideslope, of typically 3°-4°. If pilots misperceive their glideslope and alter their flight path accordingly, they are likely to overshoot or undershoot their desired touch down point on the runway. This experiment examined the accuracy of passive glideslope perceptions during simulated fixed-wing aircraft landings. 17 university students were repeatedly exposed to the following four landing scene conditions: (i) a daylight scene of a runway surrounded by buildings and lying on a 100 km deep texture mapped ground plane; (ii) a night scene with only the side runway lights visible; (iii) a night scene with the side, center, near end and far end runway lights visible and a visible horizon line; or (iv) a night scene with a runway outline (instead of discrete lights) and a visible horizon line. Each of these simulations lasted 2 seconds and represented a 130 km/hr landing approach towards a 30 m wide x 1000 m long runway with a glideslope ranging between 1° and 5°. On each experimental trial, participants viewed two simulated aircraft landings (one presented directly after the other): (a) an ideal 3° glideslope landing simulation; and (b) a comparison landing simulation, where the glideslope was either 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5°. Participants simply judged which of the two landing simulations appeared to have the steepest glideslope. As expected, the daylight landing scene simulations were found to produce significantly more accurate glideslope judgments than any of the night landing simulations. However, performance was found to be unacceptably imprecise and biased for all of our landing simulation scenes. Even in daylight conditions, the smallest glideslope difference that could be reliably detected (i.e. resulted in 75% correct levels of performance) exceeded 2º for 11 of our 16 subjects. It is concluded that glideslope differences of up to 2° can not be accurately perceived based on visual information alone, regardless of scene lighting or detail. The additional visual information provided by the ground surface and buildings in the daytime significantly improved performance, however not to a level that would prevent landing incidents