Search results for " Capa"
showing 10 items of 1248 documents
Improving High Frequency Transformers behavior for DC-DC Converter Used in Electric Vehicles
2018
The paper presents a design procedure for high frequency transformer windings adopted in the DC-DC converter used in electric vehicles. The output of the design procedure is the integration of a 3D printed plastic case in the transformer windings, with the aim to maximize the output power. The proposal design procedure is entirely based on a finite element analysis approach and on a differential evolution algorithm used for the solution of the optimization problem.
Monitoring soil volume wetness in heterogeneous soils by electrical resistivity. A field-based pedotransfer function.: A field-based pedotransfer fun…
2014
11 pages; International audience; Modern irrigation techniques require accurate, rapid, cost-effective, spatial measurement of soil moisture. Electrical Resistivity Tomography (ERT) meets most of these requirements, but needs to be calibrated for each use because it is very sensitive to differences in soil characteristics. In this study, a pedotransfer function approach is used to remove the need for site-specific calibration, allowing ERT to be used directly to measure soil moisture. The study site was a hillslope vineyard, where eight calcaric-cambisol soil profiles were identified. From 2012 to 2013, 23 000 soil volume wetness measurements were acquired by Time Domain Reflectometry, and …
Photonic nanopatterns of gold nanostructures indicate the excitation of surface plasmon modes of a wavelength of 50-100 nm by scanning near-field opt…
2003
Scanning near-field optical microscopy images of metal nanostructures taken with the tetrahedral tip (T-tip) show a distribution of dark and bright spots at distances in the order of 25-50 nm. The images are interpreted as photonic nanopatterns defined as calculated scanning near-field optical microscopy images using a dipole serving as a light-emitting scanning near-field optical microscopy probe. Changing from a positive to a negative value of the dielectric function of a sample leads to the partition of one spot into several spots in the photonic nanopatterns, indicating the excitation of surface plasmons of a wavelength in the order of 50-100 nm in metal nanostructures.
Scanning probe microscopies applied to the study of the domain wall in a ferroelectric crystal.
2007
Summary Scanning near-field optical microscopy is capable of measuring the topography and optical signals at the same time. This fact makes this technique a valuable tool in the study of materials at nanometric scale and, in particular, of ferroelectric materials, as it permits the study of their domains structure without the need of chemical etching and, therefore, not damaging the surface (as will be demonstrated later). We have measured the scanning near-field optical microscopy transmission, as well as the topography, of an RbTiOPO4 single crystalline slab, which exhibits two different of macroscopic ferroelectric domains. A chemical selective etching has been performed to distinguish b…
Monofloral honeys by Sicilian black honeybee (Apis mellifera ssp. sicula) have high reducing power and antioxidant capacity
2016
Thirty samples from thirteen Sicilian monofloral honeys by the local black honeybee, and two honeydew honeys, were studied to assess phenol content, reducing power and antioxidant capacity as well as correlations among these parameters. Honeys from Apiaceae showed the highest phenol amount and capacity to reduce ferric ion and stable chemical radicals, whereas honeys from Leguminosae the lowest. All honeys were active against myoglobin-derived radicals usually formed in red meat after storage and/or heating and significant correlation (p = 0.023) was found between flavonoid content and deactivation rate of this radical. Dill > almond?> tangerine > thistle?> sulla honeys inhibite…
Impedance and admittance characteristics of Bi2S3 nanowire arrays
2013
Current studies of the electrical impedance and admittance characteristics of the anodised aluminum oxide (AAO) nanoporous arrays and bismuth sulphide (Bi2S3) nanowire within AAO membranes are presented. The influence of potential and frequency scan rate effect produced on the real, imaginary and complex electrochemical impedance and double layer capacitance of the AAO nanopore and the Bi2S3 nanowire arrays were studied.
Influence of SMSI effect on the catalytic activity of a Pt(1%)/ Ce0.6Zr0.4O2 catalyst: SAXS, XRD, XPS and TPR investigations
2004
Abstract The steady-state activity of NO reduction by C3H6, in lean conditions, was studied on a Pt(1%)/Ce0.6Zr0.4O2 catalyst, in a plug-flow reactor, in the temperature range 100–500 °C. The influence of reductive pre-treatments on the catalytic performance at low temperature (250 °C) was investigated. Enhancement of the activity was found for the catalyst pre-treated in hydrogen at 350 °C as compared to the sample pre-treated in H2 at 800 and 1050 °C. Moreover, transient reactivity tests of NO reduction by hydrogen were also carried out. As previously observed, the sample reduced at 350 °C was the most active catalyst. In both types of reactions the temperature and the nature of pre-treat…
Modeling soil cation exchange capacity in multiple countries
2017
Abstract Cation exchange capacity (CEC), as an important indicator for soil quality, represents soil's ability to hold positively charged ions. We attempted to predict CEC using different statistical methods including monotone analysis of variance (MONANOVA), artificial neural networks (ANNs), principal components regressions (PCR), and particle swarm optimization (PSO) in order to compare the utility of these approaches and identify the best predictor. We analyzed 170 soil samples from four different nations (USA, Spain, Iran and Iraq) under three land uses (agriculture, pasture, and forest). Seventy percent of the samples (120 samples) were selected as the calibration set and the remainin…
Evaluation of the SEDD model for predicting sediment yield at the Sicilian experimental SPA2 basin
2007
In this paper a spatially distributed model of the hillslope sediment delivery processes, named the sediment delivery distributed (SEDD) model, is initially reviewed; the model takes into account the sediment delivery processes due to both the hillslope sediment transport and the effects of slope curvature. Then the rainfall and sediment yield events measured at the experimental SPA2 basin, in Sicily, are used both to calibrate the SEDD model and to verify the predictive capability of the distributed sediment delivery approach at event scale. For the SPA2 basin discretized into morphological units and stream tubes, the SEDD model is calibrated at event scale using the measurements carried o…