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Abstract. Dust samples from rainfall residues have been collected in southeast Italy (40 • 20 N, 18 • 6 E) during dust outbreaks occurred from April to June 2002 to characterize morphological and elemental particle composition by different techniques, and investigate the dependence of particle properties on source regions. Four-day analytical back trajectories and satellite images have been used to infer source regions of the investigated dust samples.It has been found that the TOMS absorbing aerosol index was in the range 0.7-2.2 over Southern Italy when samples have been collected. The particle-size and -shape analysis by a scanning electron microscope (SEM) has revealed either that the particle-diameter distribution was between 0.3 and 30 µm with median-diameter values between 1.7-2.4 µm, and that the particles were characterized by a roundness factor varying from 0.8 to 2.5. The infrared transmission spectra have allowed recognizing that all dust samples contained a significant amount of illite. The X-ray energy dispersive (EDX) measurements have revealed that the Al/Si ratio of the transported dust varies from 0.41 to 0.50, and that the Al/Si,

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A simple and rapid vapor deposition route has been developed for the growth of trigonal phase selenium microtubes in a horizontal tubular furnace under argon flow gas. Selenium powder was evaporated by heating at 300 °C, and the vapors were condensed on different quartz substrates located at 70−140 °C. It was found that the morphologies of the products were strongly affected by small variations of the temperatures of the deposition zones. It was observed that the growth of microtubes was initiated by formation of nearly spherical microparticles with smooth surfaces; the smooth microspheres were first covered by a rough layer and then they slowly became empty. The additional selenium atoms transported from the heated part of the furnace or coming from the consumption of the inner core of the rough microparticles continued to adsorb on the empty microspheres, allowing two possible growth mechanisms. If the additional Se atoms preferentially went to the circumferential edges of the empty microspheres, crystalline microtubes with no defects were formed; however, Se atoms could also follow a spiral growth mechanism starting from the empty shells. This second growth mechanism led to the formation of semiclosed tubular structures with irregular surfaces, which developed into the relatively completed uniform microtubes with smooth surfaces. The morphology, microstructure, and chemical composition of the microtubes were characterized by various means (X-ray diffraction, energy-dispersive X-ray spectroscopy, Raman spectroscopy, UV−vis spectroscopy, scanning electron microscopy, and transmission electron microscopy). The as-grown Se microtubes may find application as rapid response photosensors and photocells.