Organización morfológica y variación del esqueleto axial de víboras: una aproximación morfométrica a la homología seriada

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid. Facultad de Ciencias, Departamento de Biología. Fecha de lectura: 26-04-201

Assessment of air flow distribution and hazardous release dispersion around a single obstacle using Reynolds-averaged Navier-Stokes equations

The flow around a cubical building, with a pollution source at the central point of the top of the cube, is studied. The Reynolds-averaged Navier-Stokes and species concentration equations are solved for Reynolds number, Re = 40,000, is based on the height of the cube. The predictions obtained with the standard, the Kato-Launder, and the low-Reynolds number k-epsilon models are examined with various wall functions for the near wall treatment of the flow. Results are compared against Martinuzzi and Tropea measurements (J. of Fluids Eng., 115, 85–92, 1993) for the flow field and against Li and Meroney (J. of Wind Eng. and Industrial Aerodynamics, 81, 333–345, 1983) experiments and Gaussian models for the concentration distribution. It is found that the present unstructured mesh model performs similarly to the structured mesh models. Results from the Kato-Launder model are closer to the experimental data for the flow patterns and contaminant distribution on the cube's roof. However, the Kato-Launder model has an over-prediction for the recirculation zone and the contaminant distribution windward of the cube. The standard k-epsilon and the low-Reynolds number k-epsilon models predict similar flow patterns and are closer to the experimental data of the cube's windward and side face

Computational assessment of the hazardous release dispersion from a diesel pool fire in a complex building’s area

A hazardous release accident taking place within the complex morphology of an urban setting could cause grave damage both to the population’s safety and to the environment. An unpredicted accident constitutes a complicated physical phenomenon with unanticipated outcomes. This is because, in the event of an unforeseen accident, the dispersion of the hazardous materials exhausted in the environment is determined by unstable parameters such as the wind flow and the complex turbulent diffusion around urban blocks of buildings. Our case study focused on a diesel pool fire accident that occured between an array of nine cubical buildings. The accident was studied with a Large eddy Simulation model based on the Fire Dynamics Simulation method. This model was successfully compared against the nine cubes of the Silsoe experiment. The model’s results were used for the determination of the immediately dangerous to life or health smoke zones of the accident. It was found that the urban geometry defined the hazardous gasses dispersion, thus increasing the toxic mass concentration around the buildings

Variación morfológica y alometría de las vértebras precloacales en el ofidio daboia russelli (viperidae)

Understanding the variation of the ophidian vertebral morphology is an essential tool in snake paleobiology, but so far this field remains hardly investigated. A major problematic is the still scarce knowledge about the basis of homogeneity of intracolumnar shape variation along the vertebrae of the precloacal region in these animals. For instance, this variation can be overwhelmingly low in cases such as in vipers, for which it seems almost impossible to describe a concrete regionalization of the precloacal region without ambiguity. This study has applied geometric morphometrics to analyze if the shape variation of the vertebrae of the precloacal vertebrae of an adult specimen of Daboia russelli allows differentiating any sort of parcellation within the column of this organism. We have also explored if size is associated with the organization of vertebral shape along the axial skeleton. The multivariate analyses showed that the main pattern of vertebral shape variation in D. russelli concerns the neural spine and the hypapophysis, whereas the shape of the vertebral centrum appears to be nearly invariant along the series. Our analysis also showed that the precloacal region can be sudivided into two portions that merge in a transitional boundary of largest vertebrae in the middle of the column. From this middle region towards the distal ends of the column vertebrae become smaller changing their shapes in two antithetical waysFunds provided by the project CGL2009-11838 BTE and a FPU grant (AP2007-00904; MICINN) to I. Sarri

Large eddy simulation of dispersion of hazardous materials released from a fire accident around a cubical building

The turbulent smoke dispersion from a pool fire around a cubical building is studied using large eddy simulation at a high Reynolds number, corresponding to existing experimental measurements both in laboratory and field test scales. Emphasis of this work is on the smoke dispersion due to two different fuel pool fire accident scenarios, initiated behind the building. For the setup of fire in the first case, crude oil was used with a heat release rate of 7.8 MW, and in the second, diesel oil with a heat release rate of 13.5 MW. It is found that in both fire scenarios, the downstream extent of the toxic zone is approximately the same. This is explained in terms of the fact that the smoke concentration and dispersion are influenced mainly by the convective buoyant forces and the strong turbulence mixing processes within the wake zone of the building. It is suggested that wind is the dominating factor in these accident scenarios, which represent the conditions resulting in the highest toxicity levels

Water Purification in Micromagnetofluidic Devices: Mixing in MHD Micromixers

AbstractThis contribution addresses a possible solution for water purification from heavy metals by magnetic nanoparticles in microfluidic water flow systems. In this technique, the most important component is the micromixer while efficient mixing and particle driving is achieved by external magnetic fields. For the simulation of water flow and nanoparticles, Computational Fluid Dynamics methods are used. The 2D and 3D Navier-Stokes equations are solved for the flow field while trajectories of the magnetic nanoparticles are simulated by the use of a Lagrangian method. Compared to traditional techniques, this method is expected to succeed chemical speed and increased water purification times

Computational Study of the Optimum Gradient Magnetic Field for the Navigation of the Spherical Particles in the Process of Cleaning the Water from Heavy Metals

AbstractThe usage of magnetic spherical nanoparticles, coated with substances and driven to targeted areas in tanks, is proposed for cleaning the water from heavy metals. In the present paper, a computational study for the estimation of the optimum gradient magnetic field is presented in order to ensure the optimum driving of the particles into the targeted area. The optimization of the gradient magnetic field rates’ is verified with the particles’ deviation from a desired trajectory. Using the above mentioned method, it was depicted that with the increase of the optimization parameters number, the particles’ deviation from the desired trajectory is decreased

A Thioredoxin Domain-Containing Protein Interacts with Pepino mosaic virus Triple Gene Block Protein 1

Pepino mosaic virus (PepMV) is a mechanically-transmitted tomato pathogen of importance worldwide. Interactions between the PepMV coat protein and triple gene block protein (TGBp1) with the host heat shock cognate protein 70 and catalase 1 (CAT1), respectively, have been previously reported by our lab. In this study, a novel tomato interactor (SlTXND9) was shown to bind the PepMV TGBp1 in yeast-two-hybrid screening, in vitro pull-down and bimolecular fluorescent complementation (BiFC) assays. SlTXND9 possesses part of the conserved thioredoxin (TRX) active site sequence (W__PC vs. WCXPC), and TXND9 orthologues cluster within the TRX phylogenetic superfamilyclosesttophosducin-likeprotein-3. InPepMV-infectedandhealthyNicotianabenthamiana plants,NbTXND9mRNAlevelswerecomparable,andexpressionlevelsremainedstableinbothlocal and systemic leaves for 10 days post inoculation (dpi), as was also the case for catalase 1 (CAT1). To localize the TXND9 in plant cells, a polyclonal antiserum was produced. Purified α-SlTXND9 immunoglobulin (IgG) consistently detected a set of three protein bands in the range of 27–35 kDa, in the 1000 and 30,000 g pellets, and the soluble fraction of extracts of healthy and PepMV-infected N. benthamiana leaves, but not in the cell wall. These bands likely consist of the homologous protein NbTXND9 and its post-translationally modified derivatives. On electron microscopy, immuno-gold labellingofultrathinsectionsofPepMV-infectedN.benthamianaleavesusingα-SlTXND9IgGrevealed particle accumulation close to plasmodesmata, suggesting a role in virus movement. Taken together, this study highlights a novel tomato-PepMV protein interaction and provides data on its localization in planta. Currently, studies focusing on the biological function of this interaction during PepMV infection are in progress

Dynamo Transition in Low-dimensional Models

Two low-dimensional magnetohydrodynamic models containing three velocity and three magnetic modes are described. One of them (nonhelical model) has zero kinetic and current helicity, while the other model (helical) has nonzero kinetic and current helicity. The velocity modes are forced in both these models. These low-dimensional models exhibit a dynamo transition at a critical forcing amplitude that depends on the Prandtl number. In the nonhelical model, dynamo exists only for magnetic Prandtl number beyond 1, while the helical model exhibits dynamo for all magnetic Prandtl number. Although the model is far from reproducing all the possible features of dynamo mechanisms, its simplicity allows a very detailed study and the observed dynamo transition is shown to bear similarities with recent numerical and experimental results.Comment: 7 page