Blended numerical schemes for the advection equation and conservation laws

In this paper we propose a method to couple two or more explicit numerical schemes approximating the same time-dependent PDE, aiming at creating a new scheme which inherits advantages of the original ones. We consider both advection equations and nonlinear conservation laws. By coupling a macroscopic (Eulerian) scheme with a microscopic (Lagrangian) scheme, we get a new kind of multiscale numerical method

Brócoli envasado en polietileno de baja densidad y policloruro de vinilo

p.191-198La atmósfera modificada con películas plásticas y el control de la temperatura son tecnologías recomendadas para mantener la calidad y extender la vida de almacenamiento de hortalizas. Larespiración natural en brócoli envasado es suficiente para lograr niveles de dióxido de carbono (C 02) y de oxígeno (0 2) en el interior del envase que permitan alargar la vida del producto. Se realizaron tres ensayos a 0ºC, 8ºC y 12ºC en un diseño en parcela dividida con arreglo factorial. Se utilizaron dos películas plásticas: policloruro de vinilo y polietileno de baja densidad, y 4 diseños de paquete: 50, 100, 150 y 200 gramos de brócoli. Se midió la concentración de C 00 y 0 2 del interior de cada envase durante 7 días. Los cambios en la calidad se evaluaron por la pérdida de peso, el color y contenidos de ácido málico y de sólidos solubles durante el período analizado. La selección de la película óptima para el envasado de brócoli depende de la temperatura de almacenamiento y del peso del producto. A 0ºC, con PBD se logra una atmósfera adecuada con muy poca pérdida de peso y cambios químicos. A 8ºC, dado que no hay una variación importante de la calidad, la selección deberá realizarse por la concentración interna del gas lograda en el equilibrio y por la pérdida de peso durante el almacenamiento; así, es conveniente optar por PBD con una masa inferior a 100 gramos para obtener concentraciones óptimas de C 0 2 y de O, y por PVC cuando la masa es superior a 150 gramos para mantener baja la pérdida de peso. A 12ºC ninguna de las dos películas fueron buenas para el envasado de brócoli, porque generan la excesiva perdida de color y de peso (PVC) o la presencia de olores desagradables (PBD)

Two semi-Lagrangian fast methods for Hamilton-Jacobi-Bellman equations

In this paper we apply the Fast Iterative Method (FIM) for solving general Hamilton-Jacobi-Bellman (HJB) equations and we compare the results with an accelerated version of the Fast Sweeping Method (FSM). We find that FIM can be indeed used to solve HJB equations with no relevant modifications with respect to the original algorithm proposed for the eikonal equation, and that it overcomes FSM in many cases. Observing the evolution of the active list of nodes for FIM, we recover another numerical validation of the arguments recently discussed in [Cacace et al., SISC 36 (2014), A570-A587] about the impossibility of creating local single-pass methods for HJB equations

An adaptive POD approximation method for the control of advection-diffusion equations

We present an algorithm for the approximation of a finite horizon optimal control problem for advection-diffusion equations. The method is based on the coupling between an adaptive POD representation of the solution and a Dynamic Programming approximation scheme for the corresponding evolutive Hamilton-Jacobi equation. We discuss several features regarding the adaptivity of the method, the role of error estimate indicators to choose a time subdivision of the problem and the computation of the basis functions. Some test problems are presented to illustrate the method.Comment: 17 pages, 18 figure

Visual control through narrow passages for an omnidirectional wheeled robot

Robotic systems are gradually replacing human intervention in dangerous facilities to improve human safety and prevent risky situations. In this domain, our work addresses the problem of autonomous crossing narrow passages in a semi-structured (i.e., partially-known) environment. In particular, we focus on the CERN’s Super Proton Synchrotron particle accelerator, where a mobile robot platform is equipped with a lightweight arm to perform measurements, inspection, and maintenance operations. The proposed approach leverages an image-based visual servoing strategy that exploits computer vision to detect and track known geometries defining narrow passage gates. The effectiveness of the proposed approach has been demonstrated in a realistic mock-up

Safety of lornoxicam in G-6-PDH deficiency

Objective: To assess the safety of lornoxicam in subjects with G-6-PDH deficiency. Methods: Open controlled 2-week in vivo study on lornoxicam 8 mg bid in subjects with G-6-PDH deficiency suffering from rheumatic diseases. Results: In 8 male patients with the Mediterranean form of G-6-PDH deficiency (mean age ± SD, 54.3 years ± 7.2) lornoxicam showed no influence on red blood cells (RBC) survival curve. The RBC half-life was the same before and after two weeks of treatment. Conclusions: Lornoxicam caused no RBC damage and evidenced favourable safety in subjects with G-6-PDH deficiency, suffering from rheumatic diseases

Potential of native and bioprocessed brewers' spent grains as organic soil amendments

Introduction: The use of novel soil amendments and the exploitation of plant growth-promoting microorganisms are considered promising tools for developing a more sustainable agriculture in times when ensuring high-yield productions with limited resources is essential. Methods: In this study, the potential of brewers' spent grain (BSG), the major by-product of the brewing industry, as organic soil amendment, was investigated. Bioprocessed BSG, obtained by an enzymatic treatment coupled with fermentation, together with native BSG, were used as amendments in a pot-trial. An integrated analytical approach aimed at assessing the modification of the physicochemical properties of a typical Mediterranean alkaline agricultural soil, and the plant growth-promoting effect on escarole (Cichorium endivia var. Cuartana), was carried out. Results: The use of biomasses led to soil organic content and total nitrogen content up to 72 and 42% higher, compared to the unamended soils. Moreover, the lower pH and the higher organic acids content doubled phosphorus availability. Although the number of leaves per plant in escaroles from pots amended with native and bioprocessed BSG did not show any difference compared to plants cultivated on unamended pots, the average fresh weight per escarole head, was higher in pots amended with bioprocessed BSG. Discussion: Hence, the results collected so far encourage BSG application for agricultural purpose, while solving the problem of disposing of such abundant side stream

Repetitive transcranial magnetic stimulation reduces remote apoptotic cell death and inflammation after focal brain injury.

After focal brain injuries occur, in addition to the effects that are attributable to the primary site of damage, the resulting functional impairments depend highly on changes that occur in regions that are remote but functionally connected to the site of injury. Such effects are associated with apoptotic and inflammatory cascades and are considered to be important predictors of outcome. Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive technique that is used to treat various central nervous system (CNS) pathologies and enhance functional recovery after brain damage. OBJECTIVE: This study examined the efficacy of rTMS in mitigating remote degeneration and inflammation and in improving functional recovery in a model of focal brain damage. METHODS: Rats that were undergoing hemicerebellectomy (HCb) were treated with an rTMS protocol for 7 days, and neuronal death indices, glial activation, and functional recovery were assessed. RESULTS: rTMS significantly reduced neuronal death and glial activation in remote regions and improved functional recovery. CONCLUSIONS: Our finding opens up a completely new scenario for exploiting the potential of rTMS as an anti-apoptotic and anti-inflammatory treatment

A Semi-Lagrangian scheme for a modified version of the Hughes model for pedestrian flow

In this paper we present a Semi-Lagrangian scheme for a regularized version of the Hughes model for pedestrian flow. Hughes originally proposed a coupled nonlinear PDE system describing the evolution of a large pedestrian group trying to exit a domain as fast as possible. The original model corresponds to a system of a conservation law for the pedestrian density and an Eikonal equation to determine the weighted distance to the exit. We consider this model in presence of small diffusion and discuss the numerical analysis of the proposed Semi-Lagrangian scheme. Furthermore we illustrate the effect of small diffusion on the exit time with various numerical experiments