Physical dispersion and disappearance of bacteria in the Golfo di Palermo: the results of two surveys.

This paper reports on some results of two surveys at sea carried out in the surroundings of a urban wastewater discharge on the coast of the Golfo di Palermo, western Sicily (Italy). At the time of the surveys (year 2005) the stretch of water lying before the central part of the capital town received the untreated wastewater originating from about 200 000 inhabitants, which was discharged on-shore without any prior treatment by the free-surface outfall of “Porta Felice main sewer”. This outfall has crucial importance in the water quality; indeed, the Municipality is steadily implementing a plan featuring an intercepting main sewer along the coast and some pumping stations to connect all the main sewers to the main wastewater treatment plant, located in the SE boundary area of the town. At the moment of the surveys, however, no mitigation measure had been applied yet and the quality of the Gulf was still largely affected by it. Part of the Sanitation Plan was the characterization of the seawater; to this aim, in August and November, 2005, the Università degli Studi di Palermo - on behalf of the Municipality’s Ufficio del Centro Storico - carried out two survey cruises in which the most important seawater quality features were investigated. What will be reported on herein is the part dealing with microbiological indicators, taking the salinity field as background

Properties of compositionally graded Ba(1-x)SrxTiO(3) thick films

Compositionally graded thick films (0.4 mm) have been fabricated using the airflow deposition method. Films were made of five layers with different composition Ba1-xSrxTiO(3) (BST, x=0, 0.1, 0.2, 0.3 and 0.4). The layers presented different thicknesses, ranging from 80 to 30 microns, but similar Vickers microhardness. The average particle size of deposited layers was below 500 nm and the density of asdeposited films was about 80% of theoretical. After sintering at 1350 ?C samples presented increaseddensity (>90%) and maintained a compositional gradient. When compared to single-composition BST ceramics, permittivity of graded films was much less dependent on temperature over a wide range, from -50 to 250 ?C. In addition, the films displayed polarisation offset when driven by an alternating field and heated above 50?C

Dense dielectric ceramics with local graded structure from core-shell particles: preparation and properties

The modification of the surface properties of particles by coating with a different material, resulting in the formation of core-shell structures, is a well-known process. However, the consolidation of core-shell particles in bulk ceramics has not been extensively investigated yet, mainly because of the difficulty in controlling interdiffusion and interface reactions. In this study, we have coated BaTiO(3) spherical templates with SrTiO(3) and BaZrO(3) using a precipitation process from inorganic precursors. The size of the particles as well as the overall composition can be tailored over a wide range. Densification of the resulting core-shell particles was accomplished either using conventional sintering or spark plasma sintering. Dense ceramics with a graded composition at the level of the single grains could only be obtained by careful choice of the sintering conditions. The final ceramics show strongly modified dielectric properties in comparison to both the parent compounds and the homogeneous solid solutions. The proposed approach is quite generic and suggests new possibilities for the realization of polycrystalline materials with local graded structure by the controlled sintering of core-shell particles

Inter-related magnetic and ferroelectric domain structures in BaTiO(3) - (Ni(0.5)Zn(0.5))Fe(2)O(4) multiferroic ceramics

Multiferroic ceramics (1-x)BaTiO(3)-x(Ni(0.5)Zn(0.5))Fe(2)O(4) with various compositions x are investigated in the present work. The processing parameters were adapted in order to obtain pure diphasic ceramics without reactions at the interfaces. The macroscopic ferroelectric behaviour was proved by the existence of the ferroelectric-paraelectric dielectric and calorimetric anomaly of BaTiO(3) around 125-130?C. The magnetic activity with a concentration influence ("dilution" effect) due to the presence of the non-magnetic phase was found by measuring the M(H) loops at various temperatures. The existence of both magnetic and ferroelectric domain structure and their interdependence was proved by local MFM/AFM-piezoresponse experiments

Preparation and characterisation of the Ba(Zr,Ti)O(3) ceramics with relaxor properties

Ba(Zr(x)Ti(1-x))O(3) ceramics with various compositions x in the range (0, 0.5) have been prepared via solid state reaction. Optimum parameters for calcination and sintering have been found in order to obtain pure perovskite phase and high density ceramics. The dielectric data showed a transition from ferroelectric towards relaxor state and a shift of the Curie temperature towards lower values with increasing x. Using the modified Landau model for relaxors, the local order parameter has been calculated. Its temperature dependence shows the increasing of the degree of diffuseness of the phase transition with increasing Zr with a maximum for the composition x=0.35. The model also shows that in the relaxor state the local order parameter has non-zero values even at a few hundreds degrees above the temperature corresponding to the maximum of the dielectric constant. Further, the dielectric data obtained for x=0.35 under field cooling (FC) and zero-field cooling (ZFC) conditions shows a splitting characteristic to the relaxors and spin-glass systems

Towards the fabrication of sintered IDEAL-Cells by tape casting, wet powders spraying and screen printing

The realization of complete anode supported cells reproducing the IDEAL-Cell concept was approached by standard and inexpensive ceramic processes like tape casting, screen printing and wet powder spraying. Both commercial and custom powders were employed to build-up layers for button cells (1 inch footprint) and larger (5?5 cm2) substrates. This paper reports the details of the slurries formulation as well as the deposition parameters and sintering conditions. Resulting microstructural features are also presented together with an outlook on future steps of the activit

Perovskite particles and nanostructures by self-assembly

Controlled self-organization of nanocrystals in aqueous media can be a powerful tool to obtain (nano)particles and more complex architectures with well-defined morphology and new modified properties. Aggregation of nanocrystals produces polycrystalline assemblies which can be ordered or disordered. The oriented aggregation of nano buildings blocks overcomes the classic concept of crystal growth, which is typically thought to accur via atom-by-atom or monomer-to-monomer addition of existing nucleous. Secondary nucleation on the surface of existing crystals represents a further mechanism for the growth of particles with some level of internal organization. We will show some examples of self-assembly processes in the synthesis of BaTiO(3) and SrTiO(3) mesocrystals from aqueous suspensions of amorphous titanium hydroxide. The assembly process can be controlled by varying the temperature and the concentration of the solution as well as by introducing suitable organic molecules. Core-shell structures can be obtained when the assembly process occurs at the surface of template particles suspended in the solution. The coating of BaTiO(3) spherical particles with SrTiO(3) and BaZrO(3) nanocrystals and the possible application of this process in the field of dielectric materials will be discussed

Illicit drugs consumption evaluation by wastewater-based epidemiology in the urban area of Palermo city (Italy)

Introduction. A wastewater-based epidemiology approach was performed to estimate the drug consumption in Palermo city, the fifth largest city of Italy with a population of 671 696 inhabitants, and to investigate the monthly variability of drug loads in wastewater from different areas of the city. A seven-months detection campaign was conducted at the two wastewater treatment plants of the city. Methods. Following a pre-treatment, 32 samples of wastewater were analyzed by liquid chromatography-tandem mass spectrometry. Results. We estimated a mean cocaine use in Palermo of 0.19 g/day/1000 people, corresponding to 1.90 doses/1000 people and cannabinoids use of 2.85 g/day/1000 people, corresponding to 35.62 doses/1000 people. Amphetamines residues in wastewater were always recovered in concentrations lower than the limit of quantification. Conclusion. Our findings showed that drugs consumption in Palermo is in line with those of other Italian cities and that no significant differences on prevalence on cocaine and cannabinoids consumption were recorded in the different months of the survey, except for the summer period in a wastewater treatment plant of the city

BaTiO(3)-(Ni(0.5)Zn(0.5))Fe(2)O(4) ceramic composites with ferroelectric and magnetic properties

No abstract availabl

Correlation between microstructure and electric properties in SnO(2) rich enamels

No abstract availabl