Wave-Structure Interaction Processes in Coastal Engineering

Among one of the most challenging engineering problems, fluid-structure interaction processes are complex phenomena that have received much attention over the years [...

Porous Medium Typology Influence on the Scaling Laws of Confined Aquifer Characteristic Parameters

An accurate measurement campaign, carried out on a confined porous aquifer, expressly reproduced in laboratory, allowed the determining of hydraulic conductivity values by performing a series of slug tests. This was done for four porous medium configurations with dierent granulometric compositions. At the scale considered, intermediate between those of the laboratory and the field, the scalar behaviors of the hydraulic conductivity and the eective porosity was verified, determining the respective scaling laws. Moreover, assuming the eective porosity as scale parameter, the scaling laws of the hydraulic conductivity were determined for the dierent injection volumes of the slug test, determining a new relationship, valid for coarse-grained porous media. The results obtained allow the influence that the dierences among the characteristics of the porous media considered exerted on the scaling laws obtained to be highlighted. Finally, a comparison was made with the results obtained in a previous investigation carried out at the field scale

Characteristics of free and submerged hydraulic jumps over different macroroughnesses

AbstractThe present study deals with numerical simulations of the free and submerged hydraulic jumps over different shapes of roughness in various roughness arrangements and different Froude number conditions. The models were studied using three roughness shapes, i.e. triangular, square and semi-oval for 0.2 < T/I < 0.5, where T and I are height and distance of roughness, respectively. The results showed that the numerical model is fairly well able to simulate the free and submerged jump characteristics. The effect of roughness plays a role in the reduction of the relative maximum velocity which is greater in the submerged jump. The thickness of the boundary layer for both free and submerged jumps decreases with increasing the distance between the roughnesses. Triangular macroroughness has a significant effect on the length of the jump and shortest length with respect to the other shapes. The reduction in the submerged depth ratio and tailwater depth ratio depends mainly on the space of the roughnesses. The highest shear stress and energy loss in both jumps occur in a triangular macroroughness (TR) with T/I = 0.50 compared to other ratios and modes. The numerical results were compared with previous studies and relationships with good correlation coefficients were presented for the mentioned parameters

Numerical Simulations of the Flow Field of a Submerged Hydraulic Jump over Triangular Macroroughnesses

The submerged hydraulic jump is a sudden change from the supercritical to subcritical flow, specified by strong turbulence, air entrainment and energy loss. Despite recent studies, hydraulic jump characteristics in smooth and rough beds, the turbulence, the mean velocity and the flow patterns in the cavity region of a submerged hydraulic jump in the rough beds, especially in the case of triangular macroroughnesses, are not completely understood. The objective of this paper was to numerically investigate via the FLOW-3D model the effects of triangular macroroughnesses on the characteristics of submerged jump, including the longitudinal profile of streamlines, flow patterns in the cavity region, horizontal velocity profiles, streamwise velocity distribution, thickness of the inner layer, bed shear stress coefficient, Turbulent Kinetic Energy (TKE) and energy loss, in different macroroughness arrangements and various inlet Froude numbers (1.7 < Fr1 < 9.3). To verify the accuracy and reliability of the present numerical simulations, literature experimental data were considered

Breve Introdução ao Tema

Trabalho apresentado no Simpósio III: “Apoio Diagnóstico e Terapêutico às Atividades de Detecção Precoce na Rede Básica" e publicado nos anais do Seminário Nacional sobre Controle do Câncer Cérvico-Uterino e de Mama", realizado entre 29 e 31 de janeiro de 1985, no Instituto Nacional de Câncer, promovido pela CNCC/INCA, PAISM e Organização Panamericana da Saúde (OPAS)

Quantification of Protein "Biomarkers" in Wheat-Based Food Systems: Dealing with Process-Related Issues

Selected food proteins may represent suitable markers for assessing either the presence/absence of specific food ingredients or the type and intensity of food processes. A fundamental step in the quantification of any protein marker is choosing a proper protocol for solubilizing the protein of interest. This step is particularly critical in the case of solid foods and when the protein analyte is prone to undergo intermolecular disulfide exchange reactions with itself or with other protein components in the system as a consequence of process-induced unfolding. In this frame, gluten-based systems represent matrices where a protein network is present and the biomarker proteins may be either linked to other components of the network or trapped into the network itself. The protein biomarkers considered here were wheat gluten toxic sequences for coeliac (QQPFP, R5), wheat germ agglutinin (WGA), and chicken egg ovalbumin (OVA). These proteins were considered here in the frame of three different cases dealing with processes different in nature and severity. Results from individual cases are commented as for: (1) the molecular basis of the observed behavior of the protein; (2) the design of procedure aimed at improving the recovery of the protein biomarker in a form suitable for reliable identification and quantification; (3) a critical analysis of the difficulties associated with the plain transfer of an analytical protocol from one product/process to another. Proper respect for the indications provided by the studies exemplified in this study may prevent coarse errors in assays and vane attempts at estimating the efficacy of a given treatment under a given set of conditions. The cases presented here also indicate that recovery of a protein analyte often does not depend in a linear fashion on the intensity of the applied treatment, so that caution must be exerted when attributing predictive value to the results of a particular study

Smoothing of Slug Tests for Laboratory Scale Aquifer Assessment—A Comparison Among Different Porous Media

A filtering analysis of hydraulic head data deduced from slug tests injected in a confined aquifer with different porous media is proposed. Experimental laboratory tests were conducted in a large-scale physical model developed at the University of Calabria. The hydraulic head data were deduced from the records of a pressure sensor arranged in the injection well and subjected to a processing operation to filter the high-frequency noise. The involved smoothing techniques are the Fourier transform and two types of wavelet transform. The performances of the filtered hydraulic heads were examined for different slug volumes and four model layouts in terms of optimal fitting of the Cooper’s analytical solution. The hydraulic head variations in the confined aquifer were analyzed using wavelet transform in order to discover their energy contributions and frequency oscillations. Finally, the raw and smoothed hydraulic heads were adopted to calculate the hydraulic conductivity of the aquifer

Microlaparoscopia em ginecologia: análise de 16 casos e revisão da literatura

Microlaparoscopy represents the development of endoscopic surgery towards a minimally invasive surgical procedure. The advantages include fewer surgical complications, faster return to daily activities, more comfortable postoperative recovery, and satisfactory aesthetic results. The possibility of performing surgery under sedation may result in shorter hospitalization, lower hospital costs, and easier anesthetic procedures. The authors report their preliminary experience with the use of microlaparoscopy, using optics and 2mm instruments, as well as a review of the literature since the introduction of this new technique. The report of these 16 cases demonstrates that microlaparoscopy is a feasible technique with satisfactory results. On the other hand, this new technique requires precise indications and a training period for the development of the skills necessary for performing these surgeries.A microlaparoscopia representa a evolução da cirurgia endoscópica, visando um procedimento cirúrgico minimamente invasivo. As suas vantagens incluem a redução das complicações cirúrgicas, retorno às atividades mais rápido, período pós-operatório mais confortável e resultado estético satisfatório. A possibilidade da realização sob sedação pode resultar em internação hospitalar menor, diminuição dos custos hospitalares, além da simplificação do procedimento anestésico. Os autores relatam sua experiência inicial com a microlaparoscopia, utilizando óptica e instrumentais de 2mm, assim como uma revisão dos trabalhos publicados desde a introdução dessa nova técnica. O relato destes 16 casos mostrou ser a microlaparoscopia exeqüível, apresentando resultados satisfatórios. Por outro lado, o seu uso requer indicações precisas e treinamento para manipular o instrumental

a multi node approach to simulate thin coastal structures in the sph context

We propose an improvement in modeling solid boundary conditions for 2D weakly-compressible Smoothed Particle Hydrodynamics (SPH) simulations for cases in which the thickness of the body is small compared to the desired particle size and the fluid surrounds the body from more than one side. Specifically, the fixed ghost particles technique developed by Marrone et al. (2011), based on interpolation nodes located within the fluid domain, is here extended to a multi-node approach. The fluid domain is thus divided into various sub-areas and an interpolation node for the considered solid particle is associated to every sub-area. Consequently, the solid particles present an array of values interpolated at different sub-areas for the same physical quantity. When a fluid particle located in a specific region interacts with a multi-node fixed ghost particle, the last assumes the field values interpolated in the reference area through the associated node. The present modeling allows to adopt a coarser spatial resolution to model the same physical problem, resulting in a reduction of the computational cost. The proposed solid boundary treatment is applied to horizontal decks and perforated wall-caisson breakwaters subjected to regular waves. In this context, an automatic hybrid diffusive formulation is introduced in order to prevent shock waves during water impacts and preserve the hydrostatic pressure. The formulation is obtained by defining a variable parameter detecting the occurrence of relevant density gradients induced by fluid impacts, resulting in an automatic switch between the two formulations