Aims. With this paper we want to investigate the highly variable afterglow light curve and environment of gamma-ray burst (GRB) 060526 at z = 3.221.Methods. We present one of the largest photometric datasets ever obtained for a GRB afterglow, consisting of multi-color photometric data from the ultraviolet to the near infrared. The data set contains 412 data points in total to which we add additional data from the literature. Furthermore, we present low-resolution high signal-to-noise spectra of the afterglow. The afterglow light curve is modeled with both an analytical model using broken power law fits and with a broad-band numerical model which includes energy injections. The absorption lines detected in the spectra are used to derive column densities using a multi-ion single-component curve-of-growth analysis from which we derive the metallicity of the host of GRB 060526.Results. The temporal behaviour of the afterglow follows a double broken power law with breaks at t = 0.090 ± 0.005 and t = 2.401 ± 0.061 days. It shows deviations from the smooth set of power laws that can be modeled by additional energy injections from the central engine, although some significant microvariability remains. The broadband spectral-energy distribution of the afterglow shows no significant extinction along the line of sight. The metallicity derived from S ii and Fe ii of [S/H] = –0.57 ± 0.25 and [Fe/H] = –1.09 ± 0.24 is relatively high for a galaxy at that redshift but comparable to the metallicity of other GRB hosts at similar redshifts. At the position of the afterglow, no host is detected to F775W(AB) = 28.5 mag with the HST, implying an absolute magnitude of the host M(1500 Å) > –18.3 mag which is fainter than most long-duration hosts, although the GRB may be associated with a faint galaxy at a distance of 11 kpc.

Laser induced breakdown spectroscopy (LIBS) was demonstrated in stand-off mode as a detection technique for polydisperse liquid aerosols. The goal of this work was to assess the possibility of producing optical breakdown in an aerosol at 10 meters of distance, and to detect the analytical signal resulting from the optical discharge. The doublet characteristic of Na in the spectral region 588.6 nm – 589.5 nm was examined. For data analysis a method is proposed based on the study of the standard deviation of the acquired signal resulting from successive laser shots on the aerosol. This method rests on the high variability of the LIBS signal characteristic in aerosols systems (the percentage of spectra collected with analytical signal was around 30%). The standard deviation method was compared with the more traditional methods of ensemble-average and single-shot data analysis. The limit of detection (L.O.D.) was estimated for each method using a linear approximation, resulting in a value of 55 ppm for standard deviation method while in the case of the ensemble-average method calculation was unsuccessful due to the large uncertainty of the data. The principal advantage of the standard deviation method is that it allows the real-time elemental analysis from highly variable LIBS signals without the need of a priori knowledge of the sample which it is particularly suited for aerosol analysis in stand-off mode of detection.

A study on the variation of the spectral bidirectional reflectance distribution function (BRDF) of four diffuse reflectance standards (matte ceramic, ${\mathrm{BaSO}}_4$, Spectralon, and white Russian opal glass) is accomplished through this work. Spectral BRDF measurements were carried out and, using principal components analysis, its spectral and geometrical variation respect to a reference geometry was assessed from the experimental data. Several descriptors were defined in order to compare the spectral BRDF variation of the four materials.