Consulta: subjectFacets:"Mathematical modelling"
Registros recuperados: 11
Data/hora: 08/06/2024 17:27:02

Aide mémoire de dynamique sédimentaire. 7ème édition
Provedor de dados: 5
Autores: Le Hir, Pierre.
This aide-mémoire is not a lesson on sedimentary dynamics but more of a calculation form. Its use implies a good knowledge of the involved processes. This report presents the basic formulations used for the calculation of the hydrodynamic forcings as well as the main sediment behavioural laws, in order to help the reader conduct a basic sediment transportation calculation.
Tipo: Text
Palavras-chave: Bottom shear stress; Boundary layer; Mathematical modelling; Transport rate; Cohesive sediments; Non cohesive sediments; Sediment dynamics; Contrainte de cisaillement au fond; Couche limite; Modélisation mathématique; Fonctions de transport; Sédiments cohésifs; Sédiments non cohésifs; Dynamique sédimentaire.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/rapport-6273.pdf

Optimal control of bacterial growth for the maximization of metabolite production
Provedor de dados: 5
Autores: Yegorov, Ivan; Mairet, Francis; De Jong, Hidde; Gouze, Jean-luc.
Microorganisms have evolved complex strategies for controlling the distribution of available resources over cellular functions. Biotechnology aims at interfering with these strategies, so as to optimize the production of metabolites and other compounds of interest, by (re)engineering the underlying regulatory networks of the cell. The resulting reallocation of resources can be described by simple so-called self-replicator models and the maximization of the synthesis of a product of interest formulated as a dynamic optimal control problem. Motivated by recent experimental work, we are specifically interested in the maximization of metabolite production in cases where growth can be switched off through an external control signal. We study various optimal...
Tipo: Text
Palavras-chave: Optimal control; Nonlinear dynamical systems; Mathematical modelling; Bacterial growth; Biotechnology.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00486/59791/63028.pdf

Dynamical modelling of a reactive extrusion process: Focus on residence time distribution in a fully intermeshing co-rotating twin-screw extruder and application to an alginate extraction process
Provedor de dados: 5
Autores: Baron, Regis; Vauchel, Peggy; Kaas, Raymond; Arhaliass, Abdellah; Legrand, Jack.
The context of this study is the modelling of reactive extrusion process based on an alginate extraction protocol. Residence Time Distribution (RTD) is one important part to predict the kinetics of reactive compounds. A simple model is proposed to predict RTD in fully intermeshing co-rotating twin-screw extruders without reaction. This model, which can be easily extended to reactive case in a future work, is based on the extension of an axial dispersion model, including control parameters (screw speed and flow rate) and geometrical parameters (screw profile and die design). Simulations were performed for various operating and geometrical conditions so as to illustrate possibilities offered by the proposed model. Validation was conducted for two different...
Tipo: Text
Palavras-chave: Alginate; Extraction; Extrusion; Mathematical modelling; Residence time distribution; Simulation; Laminaria digitata.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00005/11592/8985.pdf

Modelling mud transport in a macrotidal estuary
Provedor de dados: 5
Autores: Le Hir, Pierre; Bassoullet, Philippe; L'Yavanc, Jacky.
In order to determine the fate of the fine particles and adsorbed contaminants in·a short macrotidal èstuary, a mathematical modelling system for cohesive suspended mater transport and bottom evolution, including a new consolidation algorithm, is developed. An analysis of successive erosion, transport and deposi~ion processes due to tidal forcing is given and comparisons with field data are provided. A description of mean-term bottom variations has been attempted and is partially validated by differential soundings.
Tipo: Text
Palavras-chave: Dynamique des sédiments cohésifs; Estuaire Morlaix; Tassement des vases; Modèle mathématique; Érosion; Dépôt; Cohesive sediment dynamics; Estuary; Erosion; Deposition; SoiT consolidation; Mathematical modelling.
Ano: 1988
URL: https://archimer.ifremer.fr/doc/00682/79379/81909.pdf

Tracers of physical and biogeochemical processes, past changes and ongoing anthropogenic impacts: The 43rd International Liege Colloquium on Ocean Dynamics, Liege, Belgium, May 2–6, 2011 A joint Liège Colloquium — Geotraces–BONUS–GoodHope meeting
Provedor de dados: 5
Autores: Gregoire, Marilaure; Anderson, Bob; Delille, Bruno; Jeandel, Catherine; Speich, Sabrina.
Tipo: Text
Palavras-chave: Trace elements and isotopes; Tracers of physical and biogeochemical processes; Pollution; Atmospshere-ocean-sediment interactions; Mathematical modelling.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00138/24958/26065.pdf

Synthèse bibliographique sur le rejet en mer de l'effluent mixte urbain-industriel de La Salie. Validation de terrain des résultats obtenus par modélisation mathématique.
Provedor de dados: 5
Autores: Trut, Gilles.
The compilation of data collected during the last decade, as part of the institutional survey of bathing waters, urban wastes, registered protected areas etc, demonstrates that the treated effluent discharged at La Salie Ocean (Bay of Arcachon) can be divided into two distinct types. The first is of urban origin and mainly of microbiological concern. Whilst, the second is due to the chemical treatment of wood for paper making and is rich in dissolved organic matter. The results of a specific survey conducted in the summer of 1997 at 8 stations close to the discharge outlet, confirm a significant impact of the discharges over the southern zone, as previously predicted by mathematical models. These results lead to the reclassification of the water quality on...
Tipo: Text
Palavras-chave: Rejet urbain; Process papetier; Effluent de papeterie; Impact clu rejet; Eau de baignade; Modélisation mathématique; Urban effluent; Paper processing; Paper mill effluent; Impact of effluents; Mathematical modelling; Bathing water quality.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00104/21544/19138.pdf

Effective diffusivity in yacon potato cylinders during drying
Provedor de dados: 91
Autores: Lisboa,Cícera G. C. de; Gomes,Josivanda P.; Figueirêdo,Rossana M. F. de; Queiroz,Alexandre J. de M.; Diógenes,Adelino de M. G.; Melo,João C. S. de.
ABSTRACT The aim of this study was to obtain the effective diffusivity of yacon potato in fixed-bed dryer at different temperatures (50, 60 and 70 ºC) and drying air velocities (1.0, 1.5 and 2.0 m s-1). Non-linear regression analysis was performed by the Quasi-Newton method using the program Statistica 7.0, where the parameters of the models were estimated as a function of the drying air temperature. Approximation of Diffusion, Two Terms, Henderson &amp; Pabis, and Page models fitted well the experimental data. Drying air temperature and speed influenced the drying time of the samples. The effective diffusivity increased with increasing temperature, ranging from 1.18 x 10-9 to 2.15 x 10-9 m2 s-1.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Smallanthus sonchifolia; Mathematical modelling; Diffusion.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662018000800564

DRYING KINETICS OF UNRIPE PLANTAIN CHIPS USING CHARCOAL FUELLED CABINET DRYER.
Provedor de dados: 111
Autores: Famurewa, John Alaba Victor.
This study presents the thin layer drying behavior of unripe plantain slices (Musa paradisiaca) in a developed biomass cabinet dryer. The developed dryer provided an environment with an optimum operating temperature between 50 - 700C meant for drying agricultural materials. The use of thin layer drying mechanisms and equations contribute to better understanding of drying food materials. The thin layer drying behaviour of agricultural products was identified based on the mathematical models which describe the heat and mass transfer phenomena of the products. In order to select a suitable drying model, fourteen different thin layer drying models were fitted to experimental data. Fick’s second law was used to calculate the moisture diffusivity with some...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Food Engineering Thin layer; Mathematical modelling; Diffusion; Drying  biomass fuel.
Ano: 2015
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3028

Modeling of drying thin layer of tomato slices using solar and convective driers
Provedor de dados: 111
Autores: Khama, Réda; Aissani-Benissad, F; Alkama, R; Fraikin, L; Léonard, A.
This paper presents a mathematical modelling of thin layer drying of tomato (Solanum lycopersicum L.). To this end, two different methods are used to dehydrate tomato slices namely the solar drying (in an indirect solar dryer), and the forced convective drying (in a convective dryer). In the solar dryer, the experiments are carried out at a constant air velocity of 1 m/s and average temperatures of 37.2, 39.9, 42.5 °C. In the convective dryer, the experiments are performed with five different temperatures (30, 40, 50, 60 and 70 °C) at a constant air velocity of 1 m/s. In order to estimate and select the appropriate drying curve equation, fifteen different thin layer mathematical drying models available in the literature are applied to the experimental...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Solar drying; Convective drying; Tomato slices; Thin layer; Mathematical modelling; Curve Expert software.
Ano: 2022
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/7407

Development of empirical expression for thin layer groundnut drying under open sun and forced convection modes
Provedor de dados: 111
Autores: Sahdev, Ravinder Kumar; Kumar, Mahesh; Dhingra, Ashwani Kumar.
The thin layer drying behaviour of groundnut was investigated under open sun drying (OSD) and indoor forced convection drying (IFCD) modes. The groundnut samples were dried from initial moisture content of 38% (w.b.) to the safe storage moisture content of 8-10% (w.b.). Four mathematical models were compared for describing the groundnut drying process. The performance of thin layer drying models was investigated by comparing the statistical parameters such as coefficient of correlation (R), reduced chi-square (χ2), root mean square error (RMSE), and mean bias error (MBE) between experimental and predicted moisture ratios. Henderson and Pabis model was observed to give the highest value of R and lowest values of χ2, RMSE and MBE for the groundnut drying...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Groundnut/Peanut; Thin layer; Mathematical modelling; Open sun drying; Indoor forced convection drying; Moisture ratio.
Ano: 2018
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/4216

Dynamic Analysis of the Temperature and the Concentration Profiles of an Industrial Rotary Kiln Used in Clinker Production
Provedor de dados: 42
Autores: RODRIGUES,DIULIA C.Q.; SOARES JUNIOR,ATÍLIO P.; COSTA JUNIOR,ESLY F.; COSTA,ANDRÉA O.S.
ABSTRACT Cement is one of the most used building materials in the world. The process of cement production involves numerous and complex reactions that occur under different temperatures. Thus, there is great interest in the optimization of cement manufacturing. Clinker production is one of the main steps of cement production and it occurs inside the kiln. In this paper, the dry process of clinker production is analysed in a rotary kiln that operates in counter flow. The main phenomena involved in clinker production is as follows: free residual water evaporation of raw material, decomposition of magnesium carbonate, decarbonation, formation of C3A and C4AF, formation of dicalcium silicate, and formation of tricalcium silicate. The main objective of this...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Clinker; Dynamic analysis; Mathematical modelling; Rotary kiln.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652017000603123