Distributed Control of the Generalized Korteweg-de Vries-Burgers Equation

The paper deals with the distributed control of the generalized Kortweg-de Vries-Burgers equation (GKdVB) subject to periodic boundary conditions via the Karhunen-Loève (K-L) Galerkin method. The decomposition procedure of the K-L method is presented to illustrate the use of this method in analyzing the numerical simulations data which represent the solutions to the GKdVB equation. The K-L Galerkin projection is used as a model reduction technique for nonlinear systems to derive a system of ordinary differential equations (ODEs) that mimics the dynamics of the GKdVB equation. The data coefficients derived from the ODE system are then used to approximate the solutions of the GKdVB equation. Finally, three state feedback linearization control schemes with the objective of enhancing the stability of the GKdVB equation are proposed. Simulations of the controlled system are given to illustrate the developed theory

Turbulent marine bottom boundary layer by V t2-F turbulence model

In this work, we propose to implement the V2- f turbulence model rarely used in the marine environment to study the marine bottom boundary layer (MBBL). This model will complete the series of the turbulence models already implemented in the operational model 1DV-MoSeTT (1D Vertical Model of Sediment Transport and Turbu- lence) developed for the MBBL dynamics analysis . To show the performance of v/2 - f turbulence model first, we give a comparison between this model and q2 - q2σ model. This comparison is based in various laboratory data proposed in the literature and widely used by the scientific community. Second, and in comparison with in-situ suspended sediment transport measurements, we examine the impact of the v/2 - f and the q2 - q2σ turbulence models on the quantification of flux sediment at the bottom and on the estimation of the vertical profile of the suspended particle matter (SPM)

Dynamic estimation of bank-propeller interaction effect on ship maneuvering using CFD method coupled to 6DOF algorithm

This paper presents a numerical investigation of ship maneuvering under the combined effect of the bank and propeller. The incompressible turbulent flow with free surface around the self-propelled hull form is simulated using a commercial CFD software (Fluent). In order to estimate the dynamic effect of bank and propeller, the CFD model with the dynamic mesh setting is coupled to the 6DOF module to compute the ship motion due to hydrodynamic forces. The numerical simulations are carried using the equivalent experiment conditions. The validation of the CFD model is performed by comparing the numerical results to the experimental data

Permeability and tensile strength of concrete with Arabic gum biopolymer

The use of materials of vegetal origin is increasingly being promoted in many industries due to their cost effectiveness and the rising sensitivity to environmental protection and sustainability. Arabic Gum Biopolymer (AGB) is a wild plant byproduct that is abundantly found in Sudan and is also produced in other African countries. It has long been used in various industries. However, its utilization is very limited in the construction sector although there appears to be a significant potential for use of AGB in the building industry. As an example, there is evidence that AGB may be an effective additive to concrete mixes that would improve fresh and hardened concrete properties. The aim of the present work is to provide further experimental evidence on the improvement that can be achieved in the physical and mechanical properties of hardened concrete when AGB is added to the mixture. The experimental results show a significant reduction in permeability for an optimum percentage of AGB and an increase in flexural and tensile strength and in the elastic modulus

Permeability and tensile strength of concrete with Arabic gum biopolymer

The use of materials of vegetal origin is increasingly being promoted in many industries due to their cost effectiveness and the rising sensitivity to environmental protection and sustainability. Arabic Gum Biopolymer (AGB) is a wild plant byproduct that is abundantly found in Sudan and is also produced in other African countries. It has long been used in various industries. However, its utilization is very limited in the construction sector although there appears to be a significant potential for use of AGB in the building industry. As an example, there is evidence that AGB may be an effective additive to concrete mixes that would improve fresh and hardened concrete properties. The aim of the present work is to provide further experimental evidence on the improvement that can be achieved in the physical and mechanical properties of hardened concrete when AGB is added to the mixture. The experimental results show a significant reduction in permeability for an optimum percentage of AGB and an increase in flexural and tensile strength and in the elastic modulus

An efficient implicit direct forcing immersed boundary method for incompressible flows

International audienceA novel efficient implicit direct forcing immersed boundary method for incompressible flows with complex boundaries is presented. In the previous work [1], the calculation is performed on the Cartesian grid regardless of the immersed object, with a fictitious force evaluated on the Lagrangian points to mimic the presence of the physical boundaries. However the explicit direct forcing method [1] fails to accurately impose the non-slip boundary condition on the immersed interface. In the present work, the calculation is based on the implicit treatment of the artificial force while in an effective way of system iteration. The accuracy is also improved by solving the Navier-Stokes equation with the rotational incremental pressure- correction projection method of Guermond and Shen [2]. Numerical simulations performed with the proposed method are in good agreement with those in the literature

Ambient Vibration Based Damage Diagnosis Using Statistical Modal Filtering and Genetic Algorithm: A Bridge Case Study

The authors recently developed a damage identification method which combines ambient vibration measurements and a Statistical Modal Filtering approach to predict the location and degree of damage. The method was then validated experimentally via ambient vibration tests conducted on full-scale reinforced concrete laboratory specimens. The main purpose of this paper is to demonstrate the feasibility of the identification method for a real bridge. An important challenge in this case is to overcome the absence of vibration measurements for the structure in its undamaged state which corresponds ideally to the reference state of the structure. The damage identification method is, therefore, modified to adapt it to the present situation where the intact state was not subjected to measurements. An additional refinement of the method consists of using a genetic algorithm to improve the computational efficiency of the damage localization method. This is particularly suited for a real case study where the number of damage parameters becomes significant. The damage diagnosis predictions suggest that the diagnosed bridge is damaged in four elements among a total of 168 elements with degrees of damage varying from 6% to 18%

Anatomy of the fruit of the halophyte Crithmum maritimum L. with emphasis on the endosperm structure and histochemistry

The halophytes are plants that can survive and reproduce under high salinity. They show high potentiality as new crops plant for biosaline agriculture. Crithmum maritimum L. (Apiaceae) is one of the promising halophytes. In this paper, the endosperm structure of the fruit of this oilseeds halophyte was investigated using scanning electrons microscopy (SEM), light microscopy (LM) and fluorescence microscopy (FM). The fruit was composed of a spongy outer coat, a secretory envelope, a thin endocarp reduced to a unicellular layer delimiting the endosperm and an embryo. The endosperm cell appeared limited by thick cell wall and filled with numerous reserve globoids. The histochemical test showed that the cell wall of the endosperm was rich of carbohydrates as revealed by PAS (periodic acid-schiffs). Within the endosperm cells, there were mainly lipid bodies and protein bodies. The starch grains were less abundant. The protein bodies enclose crystal globoids. The x-ray microanalysis revealed that the reserve globoids accumulated mostly Mg, K, Ca, S and P. Taken together, these results highlight the structural features, the biochemical composition and confirm the nutritional quality of C. maritimum L. fruit.Keys words: C. maritimum L., crystal globoids, the endosperm cells, histochemical test, protein bodies, x-ray microanalysis

The obstacle problem for water tanks

In this paper we discuss the problem of computing and analyzing the static equilibrium of a non rigid water tank. Specifically, we fix the amount of water contained in the tank, modelled as a membrane. In addition, there are rigid obstacles that constrain the deformation. This amounts to a non convex variational problem. We derive the optimality system and its interpretation in terms of equilibrium of forces. A second order sensitivity analysis, allowing to compute derivatives of solutions and a second order Taylor expansion of the cost function, is performed, in spite of the fact that the cost function is not twice differentiable. We also study the finite elements discretization, introduce a decomposition algorithm for the numerical computation of the solution, ans display numerical results

Inhibition of Fungi and Gram-Negative Bacteria by Bacteriocin BacTN635 Produced by Lactobacillus plantarum sp. TN635

The aim of this study was to evaluate 54 lactic acid bacteria (LAB) strains isolated from meat, fermented vegetables and dairy products for their capacity to produce antimicrobial activities against several bacteria and fungi. The strain designed TN635 has been selected for advanced studies. The supernatant culture of this strain inhibits the growth of all tested pathogenic including the four Gram-negative bacteria (Salmonella enterica ATCC43972, Pseudomonas aeruginosa ATCC 49189, Hafnia sp. and Serratia sp.) and the pathogenic fungus Candida tropicalis R2 CIP203. Based on the nucleotide sequence of the 16S rRNA gene of the strain TN635 (1,540 pb accession no FN252881) and the phylogenetic analysis, we propose the assignment of our new isolate bacterium as Lactobacillus plantarum sp. TN635 strain. Its antimicrobial compound was determined as a proteinaceous substance, stable to heat and to treatment with surfactants and organic solvents. Highest antimicrobial activity was found between pH 3 and 11 with an optimum at pH = 7. The BacTN635 was purified to homogeneity by a four-step protocol involving ammonium sulfate precipitation, centrifugal microconcentrators with a 10-kDa membrane cutoff, gel filtration Sephadex G-25, and C18 reverse-phase HPLC. SDS-PAGE analysis of the purified BacTN635, revealed a single band with an estimated molecular mass of approximately 4 kDa. The maximum bacteriocin production (5,000 AU/ml) was recorded after a 16-h incubation in Man, Rogosa, and Sharpe (MRS) medium at 30 °C. The mode of action of the partial purified BacTN635 was identified as bactericidal against Listeria ivanovii BUG 496 and as fungistatic against C. tropicalis R2 CIP203