In the present work, a semi-empirical algorithm is proposed for estimating the adiabatic coefficient (c), the isothermal compressibility (js), the heat capacity at constant pressure (cp), and constant volume (cv), for...
详细信息
In the present work, a semi-empirical algorithm is proposed for estimating the adiabatic coefficient (c), the isothermal compressibility (js), the heat capacity at constant pressure (cp), and constant volume (cv), for liquid mixtures of organic compounds as a function of temperature and concentration. The algorithm was applied to the binary systems: 1,6-Dichlorohexene (x) + Dodecane (1-x) and 1,5-Dichloropentane (x) + Dodecane (1-x) reported in literature. The obtaining values for c, cp;cv and js are reported at all concentrations and temperatures. The implementation of the algorithm required experimental data of the adiabatic coefficients of the pure components (c0i ) to 298.15 K, acoustic and volumetric data of the binary mixture in the entire concentration and temperature range between (278.15-328.15) K every 5 K. The results obtained are in excellent agreement with the experimental results. (c) 2021 The Authors. Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://***/licenses/by-nc-nd/4.0/).
In the context of climate change, it is important to take concrete action in terms of energy transition, and it is with this in mind that Hydro-Quebec has developed technological solutions for observing and forecastin...
详细信息
ISBN:
(纸本)9798350360332;9798350360325
In the context of climate change, it is important to take concrete action in terms of energy transition, and it is with this in mind that Hydro-Quebec has developed technological solutions for observing and forecasting global horizontal irradiance (GHI) using GOES satellite data and semi-empirical and deep learning methods. In particular, the solutions developed will meet the company's needs in terms of solar production and demand forecasting (load forecasting), to better balance the different sources of production, as well as better optimize the reduction of demand linked to passive heating. Initial results are encouraging and show definite potential for near-real-time characterization of the solar resource, with RMSEs between 80 and 130 W/m(2) depending on climate type (arid vs. continental) and the method adopted (AI vs. semi-empirical algorithm).
The use of satellite remote sensing to estimate coloured dissolved organic matter (CDOM) and identify its potential sources is important for monitoring lake water quality and implementing management strategies. In thi...
详细信息
The use of satellite remote sensing to estimate coloured dissolved organic matter (CDOM) and identify its potential sources is important for monitoring lake water quality and implementing management strategies. In this study, taking Erhai Lake as an example and based on MODIS/Aqua satellite images and in-situ measured data, we used empirical and semi-empirical methods to develop algorithms for CDOM and the fluorescence index (FI370) from remote sensing reflectance (Rrs(lambda)). The temporal and spatial distributions of the CDOM concentration and FI370 in Erhai Lake during 2013-2019 were retrieved. The results show the following. (1) The band ratio (Rrs (469)+Rrs(645))/Rrs(555) model could estimate the CDOM absorption coefficient at 412 nm (aCDOM(412)) (R2=0.507), and it was relatively stable. Using the band ratio Rrs(645)/Rrs(469) combined with the chlorophylla (Chl-a) APProach by ELimination (APPEL) model, a semi-empirical inversion model of FI370 performed with satisfactory accuracy (R2=0.550) and was more accurate than the empiricalalgorithm (R2=0.505). (2) During the period of 2013-2019, the CDOM concentration in Erhai Lake generally decreased from the northern to the central to the southern parts of the lake, and the CDOM concentration was higher in summer and autumn than in spring and winter. FI370 was higher in the northern and western coastal waters and lower in the central, southern and eastern parts of the lake. FI370 in autumn and winter was higher than that in spring and summer. CDOM was affected by both terrestrial and internal sources, and their relative contributions were not the same in different seasons. (3) For different Chl-a concentrations, different CDOM concentration models had better retrieval effects, i.e., Rrs(645))/Rrs(555) and (Rrs(469)+Rrs(645))/Rrs(555) had the best performance when Chl-a 10 mu g/L and Chl-a 10 mu g/L, respectively. The inversion models established in this study offer improved quantifications of the CDOM concentration
Efficient and accurate modelling of a self-propelled vessel in a large amplitude seaway with CFD-based numerical methods is a challenging task and is prohibitively expensive for most designers and engineers. Viscous C...
详细信息
Efficient and accurate modelling of a self-propelled vessel in a large amplitude seaway with CFD-based numerical methods is a challenging task and is prohibitively expensive for most designers and engineers. Viscous CFD methods can accurately model viscous effects, but the small numerical time step required to analyze the rotating propeller leads to a large computational cost. A method for efficiently and accurately modelling the six degree of freedom force on the propeller is required to feasibly model a self propelled vessel maneuvering in a high amplitude seaway. This paper outlines the framework for developing an unsteady body force propeller model for unsteady conditions. The purpose of this study is to train a semi-empirical algorithm to accurately prescribe the unsteady body force to model the propeller. The MOERI Container ship propeller is analyzed with RANS CFD. Open water data is compared to the BANS CFD results of a steady Moving Reference Frame approach. Unsteady surge and propeller revolution rate are applied to a transient rotating mesh model in open water and behind condition. The predictions of the algorithm match well with the CFD results.
MERIS images (2003-2011) were used to detect algal bloom events in Lake Idro (Northern Italy) applying a semi-empirical algorithm. From the study of an intense phenomenon occurred in late summer 2010, a retrospective ...
详细信息
MERIS images (2003-2011) were used to detect algal bloom events in Lake Idro (Northern Italy) applying a semi-empirical algorithm. From the study of an intense phenomenon occurred in late summer 2010, a retrospective analysis of similar events during late summer/early autumn period was performed. High intra- and inter-annual variability was observed and three additional bloom events were identified on 2003, 2005 and 2008. Hydrological and weather parameters were examined at different temporal intervals (August-October, September-October and monthly from August to October) to investigate the regulating factors of bloom incidence. Rather low temperatures and the persistence of clouds seem to facilitate starting and maintenance of blooms.
For low ambient wind speeds, airflow in deep urban canyons is characterized by a high scatter and important fluctuation as no coupling is established between the undisturbed wind flow and the flow inside the canyon. T...
详细信息
For low ambient wind speeds, airflow in deep urban canyons is characterized by a high scatter and important fluctuation as no coupling is established between the undisturbed wind flow and the flow inside the canyon. Thus, thermal and mechanical forces determine the wind speed characteristics. Existing studies based on experimental comparison have shown that under the above boundary conditions, deterministic models may predict with sufficient accuracy the mean wind speed but not the fluctuation caused by the thermal phenomena. In the present paper, data have been collected through an extensive experimental campaign in seven canyons. Then, data driven techniques, to predict the more probable wind speed in deep urban canyons as a function of the prevailing thermal and inertia phenomena, have been developed. The proposed methodologies are strictly valid inside the limits of the experimental data, i.e. aspect ratios between 1.7 and 3.25, and can be used to estimate the more probable wind speed close to the facades of urban canyons. (c) 2007 Elsevier Ltd. All rights reserved.
In this paper the development of a semi-empirical algorithm for estimating soil moisture content from dual-frequency (C- and X-bands) microwave AMSR data is demonstrated. The algorithm is based on a simplified form of...
详细信息
ISBN:
(纸本)0780379292
In this paper the development of a semi-empirical algorithm for estimating soil moisture content from dual-frequency (C- and X-bands) microwave AMSR data is demonstrated. The algorithm is based on a simplified form of the Radiative Transfer Theory and computes the optical depth through the Polarization Index at X-band. Validation of the algorithm was attempted first with SMMR data collected in Russia in 1979-1981.
暂无评论