Search results for "surface"
showing 10 items of 9345 documents
Coexistence of active Brownian disks: van der Waals theory and analytical results
2020
At thermal equilibrium, intensive quantities like temperature and pressure have to be uniform throughout the system, restricting inhomogeneous systems composed of different phases. The paradigmatic example is the coexistence of vapor and liquid, a state that can also be observed for active Brownian particles steadily driven away from equilibrium. Recently, a strategy has been proposed that allows to predict phase equilibria of active particles [Solon et al., Phys. Rev. E 97, 020602(R) (2018)2470-004510.1103/PhysRevE.97.020602]. Here we elaborate on this strategy and formulate it in the framework of a van der Waals theory for active disks. For a given equation of state, we derive the effecti…
Review of thermal infrared applications and requirements for future high-resolution sensors
2016
High-resolution thermal infrared (TIR) remote sensing has a wide range of applications. In this paper, we describe the different applications and requirements identified in a literature review and during a consultation meeting with researcher experts in different fields. As a result, more than 30 applications were identified within three different fields: 1) land and solid Earth; 2) health and hazards; and 3) security and surveillance. A complete set of requirements (spatial, temporal, and radiometric resolution, algorithms used, and supporting data, among others) for each application is also provided. The results presented in this paper provide useful information to enhance the importance …
Minimum configuration of thermal infrared bands for land surface temperature and emissivity estimation in the context of potential future missions
2014
Abstract A number of applications rely on the availability of high resolution TIR data, both in terms of spatial and temporal resolution, as well as in terms of spectral configuration. A consensus exists among the thermal community regarding the lack of such a kind of data, since only one operational sensor is currently providing multispectral TIR data at high spatial resolution (the case of ASTER, at 90 m spatial resolution and a 16-day revisit time). In this paper we propose a minimum multispectral configuration to allow the retrieval of both land surface temperature (LST) and emissivity ( e ) from thermal infra-red (TIR) data. For this purpose, we propose a minimum configuration based on…
Land Surface Temperature Retrieval Methods From Landsat-8 Thermal Infrared Sensor Data
2014
The importance of land surface temperature (LST) retrieved from high to medium spatial resolution remote sensing data for many environmental studies, particularly the applications related to water resources management over agricultural sites, was a key factor for the final decision of including a thermal infrared (TIR) instrument on board the Landsat Data Continuity Mission or Landsat-8. This new TIR sensor (TIRS) includes two TIR bands in the atmospheric window between 10 and 12 $\mu\hbox{m}$ , thus allowing the application of split-window (SW) algorithms in addition to single-channel (SC) algorithms or direct inversions of the radiative transfer equation used in previous sensors on board …
Evaluation of Landsat-8 TIRS data recalibrations and land surface temperature split-window algorithms over a homogeneous crop area with different phe…
2021
Abstract Successive re-calibrations were implemented in Landsat-8 TIRS data since launch. This paper evaluates the performances of both: (1) these re-calibrations, up to the last calibration update announced for TIRS data in the next Landsat Collection 2; and (2) single-channel (SC) corrections and split-window (SW) algorithms to retrieve land surface temperature (LST) from TIRS data. A robust and accurate multi-year (2014–2019) set of reference ground data were used, which included thermal infrared (TIR) radiance measurements taken along transects in a uniform and thermally homogeneous rice paddy area, but also emissivity measurements for the different ground covers at the site through the…
Land surface temperature retrieval from LANDSAT TM 5
2004
In this paper, three methods to retrieve the land surface temperature (LST) from thermal infrared data supplied by band 6 of the Thematic Mapper (TM) sensor onboard the Landsat 5 satellite are compared. The first of them lies on the estimation of the land surface temperature from the radiative transfer equation using in situ radiosounding data. The others two are the mono-window algorithm developed by Qin et al. [International Journal of Remote Sensing 22 (2001) 3719] and the single-channel algorithm developed by Jime´nez-Mun˜oz and Sobrino [Journal of Geophysical Research 108 (2003)]. The land surface emissivity (LSE) values needed in order to apply these methods have been estimated from a…
Experimental Evidence on the Thermal Performance of Opaque Surfaces in Mediterranean Climate
2013
The thermal insulation of buildings, intended as wrap feature which determines the dispersion of heat, the reference parameter is necessary to contain the thermal losses during the winter season. The transmittance of the opaque components, used as an indicator of the energy quality of a casing, together with the overall coefficient of dispersion, represents a proper descriptor of the behavior during the heating season. However, if a strong insulation in winter conditions brings only positive effects, the same cannot be said for the summer conditions. A high value of the insulation in the casing is convenient only when the gains free, either in the form of solar contribution that of endogeno…
Experimental Evidence on the Thermal Performance of Opaque Surfaces in Mediterranean Climate
2013
The thermal insulation of buildings, intended as wrap feature which determines the dispersion of heat, the reference parameter is necessary to contain the thermal losses during the winter season. The transmittance of the opaque components, used as an indicator of the energy quality of a casing, together with the overall coefficient of dispersion, represents a proper descriptor of the behavior during the heating season. However, if a strong insulation in winter conditions brings only positive effects, the same cannot be said for the summer conditions. A high value of the insulation in the casing is convenient only when the gains free, either in the form of solar contribution that of endogeno…
Influence of titanium-vanadium alloys on cell morphology: electron microscopy and ESCA studies
2000
Titanium and its alloys provide optimum metallurgical properties for implants. The formation of an oxide layer favours compatibility with the adjacent hard and soft tissues. Research focuses on further optimizing the passive layer, particularly with respect to minimizing metal ion migration into the tissues. The present study concentrates on two alloys (Ti6A14V and Til.5A125V) coated with oxide layers generated by different techniques: thermal oxidation, anodic oxidation and sol-gel treatment. Only thermal oxidation fails to reduce surface and subsurface concentrations of vanadium, whereas other treatments avoid the element in the outermost surface areas of the alloys. Additionally, the the…
Experimental and Numerical Simulations of Flow and Heat Transfer in Heat Exchanger Elements Using Liquid Crystal Thermography
2004
Experimental and numerical investigation of heat transfer and fluid flow were conducted for classic heat exchanger elements (flat plate with fin-tubes in-line, staggered and with vortex generators) and corrugated-undulated ducts under transitional and weakly turbulent conditions. The dependence of average heat transfer and pressure drop on Reynolds number and geometrical parameters was investigated. Distributions of local heat transfer coefficient were obtained by using liquid crystal thermography and surface-averaged values were computed. Three-dimensional numerical simulations were conducted by a finite-volume method using a low-Reynolds number k-e model under the assumption of fully deve…