Application of infrared vision system for potato thermal control

The article proposes a solution to the problem of determining the values of potato tubers tissue thermophysical characteristics. The solution of this problem makes it possible to calculate the optimal regime parameters of potato quality active thermal control, which can be used for automatic sorting. In order to solve this problem, we propose a non-contact non-destructive control method based on a pulsed laser heating of a potato tuber flat surface area and subsequent use of time integral characteristics of temperature and heat flow, as well as a measuring device developed on the basis of physical and mathematical models of the method. The method was used by the authors to determine the thermal conductivity, heat capacity and coefficient of thermal diffusivity of different quality potato tissues: both healthy and affected by phyto-diseases. The studies have shown that the thermal conductivity of plant tissues depends on the presence of structural disturbances in them as a result of phyto-diseases. This fact confirms the possibility of using thermal non-destructive control of potatoes tissues provided the correct choice of power and the duration of the thermal effect on the object of control

Quantitative Nanofriction Characterization of Corrugated Surfaces by Atomic Force Microscopy

Atomic Force Microscopy (AFM) is a suitable tool to perform tribological characterization of materials down to the nanometer scale. An important aspect in nanofriction measurements of corrugated samples is the local tilt of the surface, which affects the lateral force maps acquired with the AFM. This is one of the most important problems of state-of-the-art nanotribology, making difficult a reliable and quantitative characterization of real corrugated surfaces. A correction of topographic spurious contributions to lateral force maps is thus needed for corrugated samples. In this paper we present a general approach to the topographic correction of AFM lateral force maps and we apply it in the case of multi-asperity adhesive contact. We describe a complete protocol for the quantitative characterization of the frictional properties of corrugated systems in the presence of surface adhesion using the AFM.Comment: 33 pages, 9 figures, RevTex 4, submitted to Journal of Applied Physic

Nanoscale roughness and morphology affect the IsoElectric Point of titania surfaces

We report on the systematic investigation of the role of surface nanoscale roughness and morphology on the charging behaviour of nanostructured titania (TiO2) surfaces in aqueous solutions. IsoElectric Points (IEPs) of surfaces have been characterized by direct measurement of the electrostatic double layer interactions between titania surfaces and the micrometer-sized spherical silica probe of an atomic force microscope in NaCl aqueous electrolyte. The use of a colloidal probe provides well-defined interaction geometry and allows effectively probing the overall effect of nanoscale morphology. By using supersonic cluster beam deposition to fabricate nanostructured titania films, we achieved a quantitative control over the surface morphological parameters. We performed a systematical exploration of the electrical double layer properties in different interaction regimes characterized by different ratios of characteristic nanometric lengths of the system: the surface rms roughness Rq, the correlation length {\xi} and the Debye length {\lambda}D. We observed a remarkable reduction by several pH units of IEP on rough nanostructured surfaces, with respect to flat crystalline rutile TiO2. In order to explain the observed behavior of IEP, we consider the roughness-induced self-overlap of the electrical double layers as a potential source of deviation from the trend expected for flat surfaces.Comment: 63 pages, including 7 figures and Supporting Informatio

A robust method for measurement of fluctuation parallel wavenumber in laboratory plasmas

Measuring the parallel wavenumber is fundamental for the experimental characterization of electrostatic instabilities. It becomes particularly important in toroidal geometry, where spatial inhomogeneities and curvature can excite both drift instabilities, whose wavenumber parallel to the magnetic field is finite, and interchange instabilities, which typically have vanishing parallel wavenumber. We demonstrate that multipoint measurements can provide a robust method for the discrimination between the two cases

SIMPLIFIED PARAMETERS FOR THE EVALUATION OF SITE EFFECTS IN THE

After the 2002 earthquakes, that struck the southern Italy provinces of Campobasso (Molise) and Foggia (Apulia), the safety assessment of buildings has allowed to evaluate, for different building typologies, the damage level caused by the seismic event; in particular, the survey of the damaged cultural heritage was carried out by the Task Cultural Heritage of the Mixed Operating Centre (COM) in Larino (a village in the epicentral area), coordinated by the “Working Group for the Safeguard of the Cultural Heritage from Natural Risks” (Italy’s Gazzetta Ufficiale n. 116, 21 May 2001 - PCM-DPC Decree, 3 May 2001)”. For this survey activity, the churches were investigated with a specific form proposed by the same Working Group (Ministerial Decree n. 133, 23th January 2001), adopting different forms for other kinds of buildings. The surveyors were organized in teams, called NOPSA (Nuclei Operativi Patrimonio Storico Artistico), composed by officials of the Regional board of the Ministry of Cultural Heritage and Environmental Conservation (architects and art historians), an engineer and a Fire Brigade technician. The first phase of the safety assessment has been developed on the basis of the warnings received by the Larino COM, and most of the surveyed buildings were churches. The damage assessment of public or private buildings began, initially, near the earthquake epicentre (area 1 - IMCS between 6 and 8.5) and subsequently was carried out for all the villages from which inspection requests arrived. At the same time a vulnerability survey was carried out for the churches, using the II level form (Lagomarsino et al., 2004) proposed in the SAVE Project (“Updated Tools for the Seismic Vulnerability Evaluation of the Italian Real Estate and of Urban Systems” – http://gndt.ingv.it). The damage and vulnerability survey has allowed to verify and optimize the procedures for damage assessment immediately after a seismic event (emergency phase) and to obtain useful indications for the reconstruction phase. On the whole 379 monumental buildings in 101 Molise villages and 207 monumental buildings in 44 Apulia villages were investigated. Figure 1 shows the number of monumental buildings surveyed after the earthquakes for each Molise village, subdividing the region according to the seismic classification proposed by the recent Italian Seismic Code (OPCM n. 3274, 2003 – http://zonesismiche.mi.ingv.it)

Effetti di amplificazione topografica osservati sul patrimonio monumentale

La ricerca ha avuto l’obiettivo di indagare gli effetti di amplificazione sismica, per cause topografiche, che possono aver interessato le chiese danneggiate da alcuni terremoti storici italiani. La novità di questo studio consiste nell’aver messo a punto una metodologia di analisi che, partendo dall’osservazione degli effetti del terremoto sull’edificio, confronta il danno osservato ed il danno atteso, calcolato attraverso modelli basati su dati statisticamente affidabili, prevede una fase di rilevo delle caratteristiche geologiche, geomorfologiche, geotecniche e geofisiche dei siti di ubicazione delle chiese, arriva a quantificare, anche attraverso modellazioni numeriche della risposta sismica locale, l’influenza che la morfologia di questi siti può aver avuto nel determinare l’incremento dell’input sismico e conseguentemente del danno osservato

Correlation between local amplification effects and damage mechanism for monumental buildings

The damage and vulnerability survey of the monumental buildings, damaged by the 2002 earthquake in the Molise Region, has allowed singling out of a correlation between the observed damage of the churches and their morphological site conditions. The vulnerability model connected to the survey methodology provides an evaluation of the expected mean damage. Comparison with the observed damage determined the introduction of a local morphological behaviour modifier, able to take into account the vulnerability increase due to the site effects. In order to validate the previous results, a numerical 2-D analysis of the seismic local response has been performed. In particular, a numerical code, working with boundary elements, has been applied to the analyzed situations. The results, in terms of pseudo-acceleration response spectra and amplification factors, allow one to compare the numerical and the observed analyses. This comparison shows good agreement and allows one to find some correlations between the geometric characteristics of the sites, the values of the amplification coefficients and the damage mechanism activated

Correlation between local amplification effects and damage mechanisms for monumental buildings

The damage and vulnerability survey of the monumental buildings, damaged by the 2002 earthquake in the Molise Region, has allowed singling out of a correlation between the observed damage of the churches and their morphological site conditions. The vulnerability model connected to the survey methodology provides an evaluation of the expected mean damage. Comparison with the observed damage determined the introduction of a local morphological behaviour modifier, able to take into account the vulnerability increase due to the site effects. In order to validate the previous results, a numerical 2-D analysis of the seismic local response has been performed. In particular, a numerical code, working with boundary elements, has been applied to the analyzed situations. The results, in terms of pseudo-acceleration response spectra and amplification factors, allow one to compare the numerical and the observed analyses. This comparison shows good agreement and allows one to find some correlations between the geometric characteristics of the sites, the values of the amplification coefficients and the damage mechanism activated

Low Cohomogeneity and Polar Actions on Exceptional Compact Lie Groups

We study isometric Lie group actions on the compact exceptional groups E6, E7, E8, F4 and G2 endowed with a biinvariant metric. We classify polar actions on these groups. We determine all isometric actions of cohomogeneity less than three on E6, E7, F4 and all isometric actions of cohomogeneity less than 20 on E8. Moreover we determine the principal isotropy algebras for all isometric actions on G2.Comment: 27 pages; introduction rewritten; references updated; final version; to appear in Transformation Group