Search

Your search keyword '"VASANELLI, Lorenzo"' showing total 130 results
Start Over Author "VASANELLI, Lorenzo"

Refine your results

more »

more »

more »
130 results on '"VASANELLI, Lorenzo"'

4. Deposition of SiO2 films with high laser damage thresholds by ion-assisted electron-beam evaporation

Author

Alvisi, Marco, Nunzio, Giorgio De, Giulio, Massimo Di, Ferrara, Maria Christina, Perrone, Maria Rita, Protopapa, Lucia, and Vasanelli, Lorenzo

Subjects
Thin films -- Research, Lasers -- Research, Electron beams -- Research, Ions -- Research, Astronomy, Physics
Abstract

Si[O.sub.2] thin films ([approximately equal to]100 nm thick) with transmittivity and a laser damage threshold nearly equal to those of bulk material are deposited on silica substrates by the technique of ion-assisted electron-beam evaporation. The influence of film packing density on the laser damage threshold is investigated by the technique of photoacoustic probe beam deflection. It is shown that films with lower packing density may have a higher laser damage threshold and as a consequence better heat dissipation.

Published
1999

8. 'Microfluidics systems for radiosynthesis of β-cit'

Author

Masi G. S., Rella R., Manera M. G., Quaranta F., Panichelli P., Martini D., CONGEDO, Paolo Maria, VASANELLI, Lorenzo, VALENTINI, Giovanni, Masi, G. S., Congedo, Paolo Maria, Rella, R., Manera, M. G., Quaranta, F., Vasanelli, Lorenzo, Valentini, Giovanni, Panichelli, P., and Martini, D.

Published
2009

11. Electronic structure of double stacked InAs/GaAs quantum dots: Experiment and theory

Author

PERSANO A, COLA A, TAURINO A, CATALANO M, LOMASCOLO M, CONVERTINO A, LEO G, CERRI L, VASANELLI, Lorenzo, Persano, A, Cola, A, Taurino, A, Catalano, M, Lomascolo, M, Convertino, A, Leo, G, Cerri, L, and Vasanelli, Lorenzo

Subjects
quantum dot
Abstract

An experimental and theoretical investigation on the electronic structure of double layer InAs/GaAs quantum dots (QDs) is presented. In order to evaluate the effects of the quantum coupling between the zero-dimensional states, the spacer separating the two QD layers is varied from 4.5 to 10 nm. The quantitative comparison between experiment and theory is obtained by a previously proposed single band effective masslike model, where the input parameter values are given by a systematic morphological, structural, and spectroscopic investigation of the QD samples. Although the two QDs forming the stacked pairs are not perfectly equal in size, the quantum coupling mechanism is predicted to occur when the spacer is thinner than 8 nm and to increase by reducing the spacer thickness. A good agreement between theory and experiment is found for the S, P, and D shell transitions both in single and double QD layers This result suggests that the model used can be a reliable guide for the design of devices based on double QDs.

Published
2007

13. THE ECODONET PROJECT: DEVELOPMENT OF A MODEL WEB BASED VIRTUAL OBSERVATORY OF ACHERONTAS, KALAMAS AND TORRE GUACETO ECOSYSTEMS AND ITS APPLICATION AS A MOBILE EXHIBIT AND PERMANENT ENVIRONMENTAL KIOSK TOWARDS PUBLIC AWARENESS AND SUSTAINABLE DEVELOPMENT OF COASTAL ECOSYSTEMS

Author

D. KARAMANIS, P. ASSIMAKOPOULOS, K. IOANNIDES, A. KATSIKIS, I. LEONARDOS, C. PAPADOPOULOU, K. STALIKAS, K. STAMOULIS, N. KOTSIOS, A. KOROU, K. GRINIAS, E. MELLOS, MELE, Giuseppe Agostino, MALITESTA, Cosimino, VASANELLI, Lorenzo, VASAPOLLO, Giuseppe, A. Kungolos, K. Aravossis, A. Kargiannidis, P. Samaras, D., Karamani, Mele, Giuseppe Agostino, P., Assimakopoulo, K., Ioannide, A., Katsiki, I., Leonardo, C., Papadopoulou, K., Stalika, K., Stamouli, Malitesta, Cosimino, Vasanelli, Lorenzo, Vasapollo, Giuseppe, N., Kotsio, A., Korou, K., Grinia, and E., Mellos

Subjects
model web
Published
2007

14. Os and Pd Modified Tin Oxide Films for Sensors by the Sol Gel Process

Author

LICCIULLI, ANTONIO ALESSANDRO, S. Mazzarelli, G. De, P. Siciliano, VASANELLI, Lorenzo, R. Rella, Licciulli, ANTONIO ALESSANDRO, S., Mazzarelli, G., De, P., Siciliano, Vasanelli, Lorenzo, and R., Rella

Subjects
Sol-gel, thin film, Pd, sensors
Abstract

Pure, Pd and Os modified SnO2 films were prepared by the sol gel process and used as active materials in gas sensing devices. The films have been prepared starting from tin tetrachloride in alcoholic solution hydrolysed with water. The modifier was added to the sol as inorganic salt. Pd acetate and Os chloride were the Pd and Os precursors respectively. A structural and morphological study was carried out by means of Atomic Force Microscope (AFM), Secondary Ion Mass Spectrometer (SIMS) and x-ray Diffraction (XRD). The electrical resistance variations as a function of various gaseous atmospheres and temperature were measured to evaluate the sensing properties of the films. CO, CH4, CH3OH and C2H5OH gases were used for the tests. Following results were obtained: Pd is present in the form of PdO nanoclusters in the polycrystalline SnO2 matrix as evidenced by XRD spectra whereas Os is a cationic modifier uniformly dispersed as evidenced in SIMS studies. Optimum sensing temperature and the sensitivity variations, with respect to the undoped films, differ according to the gaseous species. It looks therefore promising to use inexpensive, sol-gel derived, array of films in smart gas sensing devices that are able to recognise gas species and concentration.

Published
2001

16. Preparation of uniformly dispersed copper nanocluster doped silica glasses by the sol gel process

Author

MAURO EPIFANI, GOUTAM DE, LICCIULLI, ANTONIO ALESSANDRO, VASANELLI, Lorenzo, Mauro, Epifani, Goutam, De, Licciulli, ANTONIO ALESSANDRO, and Vasanelli, Lorenzo

Subjects
article, chemical analysis, density, differential scanning calorimetry, gel, heat treatment, hydrolysis, infrared spectroscopy, measurement, phase transition, synthesis, temperature dependence, X ray powder diffraction
Abstract

The synthetic mechanism of uniformly dispersed Cu-nanocluster doped (0.05-1.0 wt%) silica glasses (copper ruby glasses) was investigated by UV-VIS and FTIR spectroscopy, DSC, XRD, surface area and density measurements at different stages of drying/densification up to glass formation. The monolithic gels were prepared from Cu(NO3)2, H2N(CH2)2NH(CH2)3Si (OCH3)3 (DAMO) and acid hydrolysed Si(OH2H5)4 (TEOS). DAMO was used to immobilize the Cu2+ ions in the silica matrix. The formation and decomposition of Cu-DAMO complexes in the silica gel monoliths were studied. The doped gels were densified under H2 and He gas atmospheres. A maximum matrix (SiO2) density of 1.70-1.73 g cm-3 (77-79% of the theoretical density) could be achieved in an H2 atmosphere at 900°C. However a density close to silica glass 2.17 g cm-3 (>98.5% of theoretical) was achieved when the gels were densified in H2 up to 800°C followed by He gas at 980°C. The surface area data also confirmed this densification behaviour. Uniformly dispersed Cu metal nanoclusters were formed during the heat-treatment of the gels and as a result a surface plasmon (SP) band of Cu-nanoclusters (563-580 nm) was observed. The increase of heat-treatment temperature caused the growth of nanoclusters and as a consequence the SP band was blue-shifted. XRD data also confirmed this.

Published
2001

18. Nanoscale compositional fluctuations in multiple InGaAs/GaAs quantum wires

Author

M. CATALANO, A. TAURINO, M. LOMASCOLO, M. DE GIORGI, A. PASSASEO, RINALDI, Rosaria, R. CINGOLANI, O. MAURITZ, G. GOLDONI, F. ROSSI, E. MOLINARI, VASANELLI, Lorenzo, M., Catalano, A., Taurino, M., Lomascolo, Vasanelli, Lorenzo, M., DE GIORGI, A., Passaseo, Rinaldi, Rosaria, R., Cingolani, O., Mauritz, G., Goldoni, F., Rossi, and E., Molinari

Published
2000

19. NANOSCALE COMPOSITIONAL FLUCTUATIONS IN MULTIPLE In-GaAs/GaAs QUANTUM WIRES

Author

M. Catalano, A. Taurino, M. Lomascolo, M. DeGiorgi, A. Passaseo, O. Mauritz, G. Goldoni, F. Rossi, E. Molinari, P. Crozier, VASANELLI, Lorenzo, RINALDI, Rosaria, CINGOLANI, Roberto, M., Catalano, A., Taurino, M., Lomascolo, Vasanelli, Lorenzo, M., Degiorgi, A., Passaseo, Rinaldi, Rosaria, Cingolani, Roberto, O., Mauritz, G., Goldoni, F., Rossi, E., Molinari, and P., Crozier

Published
2000

27. 'Tin oxide based gas sensors prepared by the sol-gel process'

Author

RELLA R., SICILIANO P., VASANELLI, Lorenzo, DE G., LICCIULLI, ANTONIO ALESSANDRO, QUIRINI A., SERRA, Antonio, Rella, R., Serra, Antonio, Siciliano, P., Vasanelli, Lorenzo, De, G., Licciulli, ANTONIO ALESSANDRO, and Quirini, A.

Published
1997

30. Structural and optical studies of In/sub x/Ga/sub 1-x/As/GaAs multiple quantum wells

Author

M. DI DIO, M. LOMASCOLO, A. PASSASEO, C. GERARDI, C. GIANNINI, A. QUIRINI, L. TAPFER, P. V. GIUGNO, M. DE VITTORIO, D. GRECO, A. L. CONVERTINO, VASANELLI, Lorenzo, DI DIO, M., Lomascolo, M., Passaseo, A., Gerardi, C., Giannini, C., Quirini, A., Tapfer, L., Giugno, P. V., DE VITTORIO, M., Greco, D., Convertino, A. L., and Vasanelli, Lorenzo

Published
1996

32. Lattice strain determination in MOVPE grown ZnTe epilayers on GaAs by RBS-channeling and reflectance spectroscopy

Author

LOVERGINE, Nicola, MANCINI, Anna Maria, R. Cingolani, G. Leo, VASANELLI, Lorenzo, F. Romanato, A. V. Drigo, Lovergine, Nicola, R., Cingolani, G., Leo, Mancini, Anna Maria, Vasanelli, Lorenzo, F., Romanato, and A. V., Drigo

Subjects
MOVPE, Optical reflectance spectroscopy, ZnTe epitaxy, RBS-channeling, lattice strain, gaA
Abstract

The determination of elastic strain in MOVPE-grown ZnTe epitaxial layers on (100)GaAs by ion channeling Rutherford backscattering spectrometry (RBS) and low temeprature (10K) reflectance spectroscopy is reported in this paper. The crystalline and optical quality of the examined samples is very good as estimated by photoluminescence spectroscopy in conjunction with ion channeling and reflectance measurements. This allowed us to perform meaningful and accurate strain measurements on all investigated samples. The present in-plane strain values obtained by the two techniques are consistent in the range of the epilayer thicknesses examined, showing that the total measured strain increases monothonically with the epilayer thickness. Also, its sign changes from negative (compressive) to positive (tensile) values at around 300 nm. This effect is explained by considering the occurrence of a thickness-dependent residual compressive strain superposed to the expected thermal strain, the latter being caused by the cooling down of the ZnTe/GAs structure from the growth temperature to room temprature.

Published
1992

Catalog

Books, media, physical & digital resources
See catalog results