Single-color illumination of a copper surface by a red or an ultraviolet femtosecond laser pulse yields a threephoton (red) or a two-photon (UV) photoemission process. A multicolor, multiphoton process is generated when the red and the UV pulses overlap both in space and in time on the photocathode. It is shown that this emission process results from the absorption by an electron of one red and...

Herein we report a one-step, low cost, photocatalytic method for the synthesis of graphene oxide (GO) from commercial graphite using grey TiO2 as photocatalyst. GO formation is achieved by UV-illumination slurry well-dispersed and graphite. Light-induced valence-band holes then lead to an oxidation exfoliation graphite, resulting in visible-light-active GO. An optimal level can be established c...

In the <span>scenario of solid-state lighting (SSL) gradually replacing old standard techniques; pc-LEDs (or diodes based on conversion phosphor) becomes a common method for creating white illumination, SSL. As now, both UV-LEDs and blue LEDs have been still being considered task illumination through phosphor excitation as it hasn’t known which LED type is truly superior. It that when com...

We report light and small-angle neutron scattering measurements that characterize microstructures formed in aqueous surfactant solutions (up to 1.0 wt % surfactant) containing mixtures of sodium dodecyl sulfate (SDS) and the light-sensitive bolaform surfactant, bis(trimethylammoniumhexyloxy)azobenzene dibromide (BTHA) as a function of composition, equilibration time, and photostationary state (...

Experiments have shown that the skyline is an important visual cue for navigating insects. However, the comparison between two snapshots collected at different times of day is a complex task due to possible illumination changes. In this study we examine whether the information from two different color channels (UV and green, which are also available for many insects) can be used to obtain an il...

ABSTRACT. In recent years, the use of light emitting diodes (LEDs) has become commonplace in fluorescence microscopy. LEDs are economical and easy to couple to commercial microscopes, and they provide powerful and stable light that can be triggered by transistor-transistor logic pulses in the range of tens of microseconds or shorter. LEDs are usually installed on the epifluorescence port of the...

A Fourier transform infrared-attenuated total reflection (FTIR-ATR) spectroscopy study of the photodegradation of adsorbed bovine Serum Albumin (BSA) on porous TiO2 films was carried out. The experiments were performed in a flow-through cell in water at concentrations of 10-6 mol/L at room temperature. The curve fitting method of the second derivative spectra allowed us to explore details of th...

We report the use of UV light to control the dynamic surface tensions of mixed surfactant systems containing sodium dodecyl sulfate, SDS, and 4,4′-bis(trimethylammoniumhexyloxy)azobenzene bromide, BTHA. The light influences the dynamic surface tension of these solutions by driving the isomerization of the azobenzene moiety from cis to trans. By combining use of the du Nouy ring, maximum bubble ...

Efficient solar driven photoelectrochemical (PEC) response by enhancing charge separation has attracted great interest in the hydrogen generation application. The formation of one-dimensional ZnO nanorod structure without bundling is essential for high efficiency in PEC response. In this present research work, ZnO nanorod with an average 500 nm in length and average diameter of about 75 nm was ...

The photocatalytic antibacterial properties of anodic titanium oxide (ATO) nanotubes in the anatase structure derived from annealing at 450°C or 550°C N-doping treatment were tested on Escherichia coli under UV-A, visible light illumi-nation, and dark conditions. Under UV-A illumination conditions, most cases, E. cultures containing ATO different treatments showed either no slight differences t...