Search results for " Thermal"
showing 10 items of 492 documents
Casimir-Lifshitz force out of thermal equilibrium between dielectric gratings
2014
We calculate the Casimir-Lifshitz pressure in a system consisting of two different 1D dielectric lamellar gratings having two different temperatures and immersed in an environment having a third temperature. The calculation of the pressure is based on the knowledge of the scattering operators, deduced using the Fourier Modal Method. The behavior of the pressure is characterized in detail as a function of the three temperatures of the system as well as the geometrical parameters of the two gratings. We show that the interplay between non-equilibrium effects and geometrical periodicity offers a rich scenario for the manipulation of the force. In particular, we find regimes where the force can…
Evaluating the Effectiveness of Modelling-Oriented Workshops for Engineering Undergraduates in the Field of Thermally Activated Phenomena
2017
Two 20-h modelling-based workshops focused on the explanation of ther- mally activated phenomena were held at the University of Palermo, Italy, during the Academic Year 2014–2015. One of them was conducted by applying an inquiry-based approach, while the other, still based on laboratory and modelling activities, was not focused on inquiry. Seventy-two students belonging to the Undergraduate Program for Chemical Engineering attended the two workshops. The related content was focused on an à la Feynman unifying approach to thermally activated phenomena. Question- naires were administered to the students of both groups, before and post instruction. Responses were analysed using k-means cluster…
QPOs expected in rotating accretion flows around a supermassive black hole
2007
It is well known that rotating inviscid accretion flows with adequate injection parameters around black holes could form shock waves close to the black holes, after the flow passes through the outer sonic point and can be virtually stopped by the centrifugal force. We numerically examine such shock waves in 2D accretion flows with 10−5 to 106 Eddington critical accretion rates around a supermassive black hole with 106 M. As the results, the luminosities show QPO phenomena with modulations of a factor 2–3 and with quasi-periods of a few to several hours.
Spatial sharpening of land surface temperature for daily energy balance applications
2008
ABSTRACT Daily high spatial resolution assessment of actual evapotranspiration is essential for water management and crop water requirement estimation under stress conditions. The application of energy balance models usually requires satellite observations of radiometric surface temperat ure with high geometrical and temporal resolutions. By now, however, high spatial resolution (~ 100 m) is available with low time fre quency (approximately every two weeks); at the opposite daily acquisition are characterised by poor spatial resolution. The analysis of vegetation index (VI) and land surface temperature (LST) spatial relationship, shows in substance a scale invariant behaviour [1] ; this con…
Applications of a remote sensing-based two-source energy balance algorithm for mapping surface fluxes without in situ air temperature observations
2012
Abstract The two-source energy balance (TSEB) model uses remotely sensed maps of land–surface temperature (LST) along with local air temperature estimates at a nominal blending height to model heat and water fluxes across a landscape, partitioned between dual sources of canopy and soil. For operational implementation of TSEB, however, it is often difficult to obtain representative air temperature data that are compatible with the LST retrievals, which may themselves have residual errors due to atmospheric and emissivity corrections. To address this issue, two different strategies in applying the TSEB model without requiring local air temperature data were tested over a typical Mediterranean…
Broncalt®, class II medical device, in patients with acute upper airways disease: a survey in clinical practice.
2019
Inflammation is a common pathogenic mechanism involved in many otorhinolaryngological (ORL) disorders. Broncalt® is a class II Medical Device containing: thermal water (Medesano, PR, Italy), hyaluronic acid, and grapefruit seed extract. It has been reported that it exerted a safe and effective anti-inflammatory, washing, and antimicrobial activity by virtue of these components. Therefore, the aim of the current survey, conducted in clinical practice of 84 Italian ORL centers, was to evaluate its safety and efficacy in the treatment of patients with acute upper airways disease. The 3,533 (1,797 males, mean age 43.5 years) patients were evaluated at baseline (T0) and after a 2-week treatment …
Performance Analysis of Innovative Vacuum Insulation Panel
2013
Thermal insulation has become one of the central themes in energy behavior improvement. The use of insulating materials, from the thermal and hydrothermal aspect, allows the reduction of the heat transfer in each of the technical elements increasing their thermal inertia. Even if the research has led to the use of innovative materials with high values of thermal insulation, one of the main problems, which is difficult to resolve, is the thickness of the building envelope to reach levels of transmittance that can allow considerable savings of energy and CO2 emissions. With this objective the VIP (Vacuum Insulation Panel) technology in building applications is an innovative solution to obtain…
A Single-Channel Algorithm for Land-Surface Temperature Retrieval From ASTER Data
2010
This letter presents an adaptation to Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data of the generalized single-channel (SC) algorithm developed by JimE?nez-MuN?oz and Sobrino, also adapted to the Landsat thermal-infrared (TIR) channel (band 6) later by JimE?nez-MuN?oz The SC algorithm relies on the concept of atmospheric functions (AFs), which are dependent on atmospheric transmissivity, upwelling, and downwelling atmospheric radiances. These AFs are fitted versus the atmospheric water-vapor content for operational purposes, despite the fact that other computation options are also possible. The SC algorithm has been adapted to ASTER TIR bands 13 (10.659 ?m) and …
Multisensor comparison of NDVI for a semi‐arid environment in Spain
2009
The joint use of multiresolution sensors from different satellites offers many opportunities to describe vegetation and its dynamics. This paper introduces the concept of a virtual constellation (defined as an ensemble of all Earth Observation satellites in orbit that satisfy common requirements) for agricultural applications and contributes to providing the necessary inter-sensor calibration methodology for spectral reflectances and NDVI. For this purpose, we performed an observational study, comparing reflectances and the Normalized Difference Vegetation Index (NDVI), from near-synchronous image pairs of Landsat 7 Enhanced Thematic Mapper Plus (ETM+), as the reference sensor and Landsat 5…
Improved land surface emissivities over agricultural areas using ASTER NDVI
2006
Abstract Land surface emissivity retrieval over agricultural regions is important for energy balance estimations, land cover assessment and other related environmental studies. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) produces images of sufficient spatial resolution (from 15 m to 90 m) to be of use in agricultural studies, in which fields of crops are too small to be well-resolved by low resolution sensors. The ASTER project generates land surface emissivity images as a Standard Product (AST05) using the Temperature/Emissivity Separation (TES) algorithm. However, the TES algorithm is prone to scaling errors in estimating emissivities for surfaces with low s…