Search results for "Experimental Data"
showing 10 items of 137 documents
Indoor free space optics link under the weak turbulence regime: Measurements and model validation
2015
In this study, the authors present the measurements performed on a free space optics (FSO) communications link using an indoor atmospheric chamber. In particular, the authors have generated several different optical turbulence conditions, demonstrating how even the weak turbulence regime can strongly affect the FSO link performance. The authors have carried out an in-depth analysis of the data collected during the measurements, and calculated the turbulence strength (i.e. scintillation index and Rytov variance) and the important performance metrics (i.e. the Q-factor and bit error rate) to evaluate the FSO link quality. Moreover, the authors have tested, for the first time, an appositely de…
Fuzzy logic and meteorological variables: a case study of solar irradiance
2002
Solar irradiance is an extreme case of an uncertain variable when measured on an hourly, or shorter time interval. In this paper solar irradiance has been considered as a case study for physical fuzzy modelling of a climate variable. The uncertainty of the solar irradiance is treated as a fuzzy uncertainty whilst other variables are considered crisp. The approach is robust as it does not rely on statistical assumptions, and it is a possible alternative to modelling complex systems. To our knowledge, this is the first time that a physical model of a meteorological variable based on fuzzy numbers has been proposed. Previous rule-based fuzzy meteorological models are only descriptive, and cann…
Experimental validation of a customized phase mask designed to enable efficient computational optical sectioning microscopy through wavefront encodin…
2017
In this paper, wavefront-encoded (WFE) computational optical sectioning microscopy (COSM) using a fabricated square cubic (SQUBIC) phase mask, designed to render the system less sensitive to depth-induced aberration, is investigated. The WFE-COSM system is characterized by a point spread function (PSF) that does not vary as rapidly with imaging depth compared to the conventional system. Thus, in WFE-COSM, image restoration from large volumes can be achieved using computationally efficient space-invariant (SI) algorithms, thereby avoiding the use of depth-variant algorithms. The fabricated SQUBIC phase mask was first evaluated and found to have a 75% fidelity compared to the theoretical desi…
Particle flow modelling in slurry-fed stirred vessels
2004
In this paper experimental information on the retention time distribution (RTD) of solid particles in a high-aspect-ratio vessel, stirred by three equally spaced Rushton turbines, is presented. The relevant data were obtained by a special technique named twin system approach (TSA) that greatly simpli+es the handling of particle-laden streams and is therefore particularly suited for investigating particle RTD in 9ow systems. The technique fundamentals are +rst summarized, together with the data analysis procedure. This lastly requires a numerical deconvolution operation that is easily performed with the help of Z-transforms. Two di;erent approaches for excluding the spurious contributions of…
Modelling analysis of centroid curves of olfactory habituation in humans
2020
Indexation en cours.; International audience; Previously published experiments established the time-course of olfactory habituation in humans, and extracted 3 centroid curves from clustering analysis that reflected high, middle and low habituation. The aim of the current theoretical study was to further analyse these previous experimental data by developing a mathematical modelling analysis designed for fitting the 3 curves from a general equation. After adjusting equation parameters for each curve, fitting equation outcomes on experimental data yielded high correlation coefficients of 0.9997 – 0.9995 – 0.9962, respectively. A model-based interpretation of olfactory-habituation centroid cur…
Lattice fluid model generalized for specific interactions: An application to ternary polymer solutions
2011
Abstract The phase diagram of the Poly- l -Lactic-Acid (PLLA), dioxane and water system was derived by using the lattice fluid model generalized for specific interactions. A qualitative analysis of Hansen solubility parameters together with empirical observations were adopted to reduce the number of adjustable parameters. The as-selected model parameters were derived by fitting a set of cloud point curves; consequently, the complete phase diagram of the system was computed. The use of specific interactions between species gave out a quantitative agreement with a set of experimental data, whereas changing the polymer polydispersity the agreement is only qualitative. In principle, the present…
Mechanical And Thermophysical Properties Of Polymers And Chemical Structure: From Computer Simulations To Experimental Data
1988
Chemical structure is related to properties on the basis of results of computer modelling of mechanical behavior. An equation for the shift factor aT,c dependent on temperature T and concentration c is provided, connection to the chain relaxation capability noted, and potential application range of the approach discussed. Constituents of free volume are defined, and effects of individual constituents on mechanical properties.
Biopartitioning micellar chromatography: An alternative high-throughput method for assessing the ecotoxicity of anilines and phenols
2007
An investigation of the use of the chromatographic retention (log k) as an in vitro approach for modelling the toxicity to Fathead Minnows of anilines and phenols is developed. A data set of 65 compounds with available experimental toxicity data was used. Log k data at three pH values were used for the compounds classification and two groups or 'MODEs' were identified. For one 'MODE' a quantitative retention-activity relationship (QRAR) model was calculated. Finally, it was used to estimate the toxicity to Fathead minnows of anilines and phenols for which experimental data are not available. These estimations were compared to those obtained from another toxicity (to Tetrahymena pyriformis) …
Vapor–liquid equilibria in dendrimer and hyperbranched polymer solutions: experimental data and modeling using UNIFAC-FV
2004
Abstract This work evaluates the potential of the group contribution method universal functional activity coefficients-free-volume (UNIFAC-FV) to predict vapor–liquid equilibria (VLE) in dendrimer-solvent and hyperbranched polymer-solvent systems. The VLE of hydroxyl-functional dendritic polymers (polyethers, polyesters, polyamidoamine), dissolved in polar solvents (ethanol and/or water) are studied both experimentally and theoretically. A new approach is suggested to account for the contribution of selected types of polymer structural units (i.e. linear, dendritic and terminal units) to the solvent residual activity. The results of calculations are in a good agreement with experiment. Furt…
Experimental Research on Technological Parameters Optimization of Natural Gases
2015
The paper contains a modeling application with the help of factorial experiments of influence variations of some parameters of natural gases over the hourly flow delivered towards population. In order to completely and correctly draft the experiment we followed and highlighted the objective functions of the process to be analyzed, and then there were identified the factors that influence the objective function to be analyzed. In the end the experimental data was processed and solutions were proposed.