259 research outputs found

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

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    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)

    Effects of sodium lactate and lactic acid on chemical, microbiological and sensory characteristics of marinated chicken

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    This study was undertaken to evaluate the chemical changes, microbiological effects and sensory attributes of marinated chicken thighs treated by lactic acid (LA) at different concentrations (0.2, 0.3, 0.5, 0.6, 0.8 and 1%) and sodium lactate (SL) at 1, 1.5, 2, 2.5 and 3%, stored at 4°C. The results reveal that these additives were efficient (P < 0.05) against the proliferation of various spoilage microorganisms; including aerobic, psychrotrophic populations, Pseudomonas spp., Enterobacteriaceae, Staphylococcus aureus and Salmonella spp. The general order of antibacterial activity of the different additives used was; LA > SL. Chemical analysis revealed a reduction in the pH value and also in the total volatile bases nitrogen contents in treated thigh. Overall, the findings demonstrate that the addition of 1% LA in marinated chicken can delay the proliferation of spoilage microorganisms and the appearance of undesirable chemical. This LA concentration improves the sensory attributes and extends the shelf life of the product during refrigerated storage. The LA additive have strong potential and promising properties that can, therefore, open new pathways and opportunities for the poultry industrial production for using efficient, safe, and cost-effective additives.Key words: Marinated chicken, sodium lactate, Lactic acid, Microbial quality, Sensory evaluation

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

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    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

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

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    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%

    An efficient implicit direct forcing immersed boundary method for incompressible flows

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    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

    17.4 Efficient in vivo gene delivery using chitosan/DNA nanoparticles for applications in cartilage repair

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    Traitement des diplegies laryngees en fermeture: Apport du laser

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    Introduction: Les diplegies laryngees en fermeture sont rares et mal tolerees par les patients. Leur prise en charge therapeutique a connu de nombreuses avancees au cours des dernieres annees. Le but de ce travail est dfetudier la place du laser dans leur prise en charge.Malades et methodes : Notre etude est retrospective a propos de six patients porteurs de diplegie laryngee en fermeture. Lfage moyen etait de 46 ans (16 et 70 ans). Lfetiologie etait une intubation prolongee ou traumatique dans 3 cas, post thyroidectomie totale dans deux autres cas et idiopathique dans 1 cas. Le traitement a consiste en une tracheotomie en urgence dans 5 cas. Tous les patients ont beneficie dans un secondtemps dfun traitement au laser apres 9 mois de surveillance.Resultats : La cordectomie posterieure a ete realisee en premier temps dans 4 cas. Elle etait bilaterale en deux temps dans 2 cas et unilaterale dans 2 cas. Une aryteno.dectomie initiale a ete realisee pour les deux autres patients. Une revision chirurgicale a consiste en une arytenoidectomie dans 2 cas et une cordotomie partielle posterieure controlaterale dans un cas. La decanulation etait bien toleree pour 4 patients. Un seul malade a garde une gene respiratoire sans veritabledyspnee avec une canule parlante fermee et la decanulation a ete refusee. Une voix satisfaisante a ete obtenue pour tous les malades. Des fausses route transitoires ont ete note dans 2 cas.Discussion : Actuellement, le traitement endoscopique au laser constitue le traitement de choix dans la diplegie laryngee et doit etre propose en premiere intension. Deux techniques principales sont decrites :  lfaryteno.dectomie au laser type Ossof et la cordectomie posterieure transverse de kashima. plusieurs series ont defendu chacune des deux techniques. Notre serie a montre que les deux techniques peuvent etre associees pour donner de meilleurs resultats.Mots cles : diplegie laryngee, Laser, aryteno.dectomie, cordectomie posterieure

    Synthesis, spectroscopic, structural and thermal characterizations of [(C7H6NO4)2TeBr6·4H2O]

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    AbstractTellurium (IV) complexes with pyridine-2,6-dicarboxylate ligand were synthesized by slow evaporation from aqueous solutions yielding a new compound: [(C7H6NO4)2TeBr6·4H2O]. The structure of this compound was solved and refined by single-crystal X-ray diffraction. The compound is centrosymmetric P21/c (N°: 14) with the parameters a=8.875(5)Å, b=15.174(5)Å, c=10.199(5)Å, β=94.271° (5) and Z=2. The structure consists of isolated H2O, isolated [TeBr6]2− octahedral anions and (pyridine-2,6-dicarboxylate) [C7H6NO4]+ cations. The stability of the structure was ensured by ionic and hydrogen bonding contacts (N–H⋯Br and O–H⋯Br) and Van-Der Walls interaction. The thermal decomposition of the compound was studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The FTIR and Raman spectroscopy at different temperatures confirm the existence of vibrational modes that correspond to the organic, inorganic and water molecular groups. Additionally, the UV–Vis diffuse reflectance spectrum was recorded in order to investigate the band gap nature. The measurements show that this compound exhibits a semiconducting behavior with an optical band gap of 2.66eV

    Seafood processing, preservation, and analytical techniques in the age of industry 4.0

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    Fish and other seafood products are essential dietary components that are highly appreciated and consumed worldwide. However, the high perishability of these products has driven the development of a wide range of processing, preservation, and analytical techniques. This development has been accelerated in recent years with the advent of the fourth industrial revolution (Industry 4.0) technologies, digitally transforming almost every industry, including the food and seafood industry. The purpose of this review paper is to provide an updated overview of recent thermal and nonthermal processing and preservation technologies, as well as advanced analytical techniques used in the seafood industry. A special focus will be given to the role of different Industry 4.0 technologies to achieve smart seafood manufacturing, with high automation and digitalization. The literature discussed in this work showed that emerging technologies (e.g., ohmic heating, pulsed electric field, high pressure processing, nanotechnology, advanced mass spectrometry and spectroscopic techniques, and hyperspectral imaging sensors) are key elements in industrial revolutions not only in the seafood industry but also in all food industry sectors. More research is still needed to explore how to harness the Industry 4.0 innovations in order to achieve a green transition toward more profitable and sustainable food production systems.José S. Câmara and Rosa Perestrelo acknowledge FCT-Fundação para a Ciência e a Tecnologia through the CQM Base Fund—UIDB/00674/2020, and Programmatic Fund—UIDP/00674/2020, Madeira 14–20 Program, project PROEQUIPRAM—Reforço do Investimento em Equipamentos e Infraestruturas Científicas na RAM (M1420-01-0145-FEDER-000008), and ARDITI—Agência Regional para o Desenvolvimento da Investigação Tecnologia e Inovação, through M1420-01-0145- FEDER-000005—Centro de Química da Madeira—CQM+ (Madeira 14–20 Program) for their support. The research leading to these results was supported by MICINN supporting the Ramón y Cajal grant for M.A. Prieto (RYC-2017-22891); by Xunta de Galicia for supporting the program EXCELENCIAED431F 2020/12; and the pre-doctoral grant of P. Garcia-Oliveira (ED481A-2019/295); and by the program BENEFICIOS DO CONSUMO DAS ESPECIES TINTORERA-(CO-0019-2021).info:eu-repo/semantics/publishedVersio
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