Joan Herrero

• Doctor of Engineering
• Associate Professor at Universitat Rovira i Virgili

Analyses of registries and medical imaging suggest that laparoscopic surgery may be penalized with a high incidence of trocar-site hernias (TSH). In addition to trocar diameter, the location of the surgical wound (SW) may affect TSH incidence. The intra-abdominal pressure (IAP) exerted on the abdominal wall (AW) might also influence the appearance...

The effect of the dimensions of the thoracic cage on the resuscitation outcome of cardiopulmonary resuscitation (CPR) maneuvers has long been debated. In this study, the effect of changes in the rib cage dimensions on the achieved compression depth was investigated using finite element simulations. A total of 216 different rib cage geometry models...

Cardiopulmonary resuscitation (CPR) is an emergency procedure performed on patients during cardiac and respiratory arrest. This procedure externally activates the cardiac and respiratory systems via the delivery of chest compression and artificial ventilation. As the main purpose of CPR is to recirculate the blood flow, prediction of the myocardium...

The turbulent flow in the wake of a discontinuous cylinder (DC) was investigated. The DC geometry consisted of cylinder segments $5D$ long (with $D$ being the diameter of the cylinder) separated by gaps of width $2.5D$ . Particle image velocimetry and hot-wire anemometry were used to analyse the flow at two Reynolds numbers, $Re = 4000$ and $10\,00...

Background An accurate knowledge of the relocation of prostate neoplasms during biopsy is of great importance to reduce the number of false negative results. Prostate neoplasms are visible in magnetic resonance images (MRI) but it is difficult for the practitioner to locate them at the time of performing a transrectal ultrasound (TRUS) guided biops...

An ostomy is a surgical procedure by which an artificial opening in the abdominal wall, known as a stoma, is created. We assess the effects of stoma location on the abdominal wall mechanics. We perform three-dimensional finite element simulations on an anatomy model which was generated on the basis of medical images. Our simulation methodology is e...

The biomechanical response of a human rib cage to cardiopulmonary resuscitation maneuvers was investigated by means of finite element simulations. We analyzed the effect of the location where the force was applied on the achieved compression depths and stress levels experienced by the breastbone and ribs. For compression locations on the breastbone...

An ostomy is a surgical procedure by which an artificial opening in the abdominal wall, known as a stoma, is created. We assessthe effects of stoma location on the abdominal wall mechanics. We perform three–dimensional finite element simulations on ananatomy model which was generated on the basis of medical images. Our simulation methodology is ent...

Background: An accurate knowledge of prostate lesions relocation during biopsy is of great importance to prevent mispositioning of the needle and thus reduce the chance of faulty biopsy results (false negatives). Prostate lesions are visible in magnetic resonance images (MRI) but it is difficult for the practitioner to locate them at the time of pe...

The alteration of blood flow around an OPTEASE® inferior vena cava filter with one or two blood clots attached was investigated by means of computational fluid dynamics. We used a patient–specific vein wall geometry, and we generated different clot models with shapes adapted to the filter and vein wall geometries. A total of eight geometries, with...

https://authors.elsevier.com/a/1ZQ~FcV4L381G Background and objective: Abdominal hernia repair is one of the most often performed surgical proce- dures worldwide. Numerical simulations of the abdominal wall mechanics can be a valuable tool to devise actions aimed at preventing hernia formation. A first step towards this goal is the development of...

Computational fluid dynamics was used to simulate the flow of blood within an inferior vena cava (IVC) geometry model that was reconstructed from computed tomography images obtained from a real patient. The main novelty of the present work is that we simulated the implantation of four different filter models in this realistic IVC geometry. We consi...

Deep venous thrombosis (DVT) is a common disease. Large thrombi in venous vessels cause bad blood circulation and pain; and when a blood clot detaches from a vein wall, it causes an embolism whose consequences range from mild to fatal. Walking is recommended to DVT patients as a therapeutical complement. In this study the mechanical effects of walk...

A methodology that might help physicians to establish a diagnostic and treatment tailored for each specific patient with a pathological thrombus is presented. A realistic model for the geometry of a popliteal vein with a thrombus just above the knee was reconstructed from in vivo computed tomography images acquired from one specific patient and the...

We analyze the flow and mass transfer in a discontinuous reactor configuration consisting of a pair of corotating enclosed disks with a chemical reaction taking place at the disk surfaces. The calculated mass transfer efficiencies do not follow the expected Sh = Sh(Re,Sc) dependence because the overall mass transfer process is not boundary–layer co...

The current work is focused on the numerical study of mass transport inside a cubical reactor agitated by natural convection. The inner face of the bottom wall is covered with a catalytic layer, where a first order chemical reaction takes place with negligible internal resistance to mass transfer. The reactor operates discontinuously and its time e...

Many challenges in science and engineering are related to the complex dynamics of large scale dy-namical systems. The identification of the invariant objects, such as fixed points, periodic orbits and homoclinic or heteroclinic orbits, and the stability characteristics of these objects are crucial issues in the understanding of the dynamics of any...

The dynamics of a RayleighBnard convection problem in a cubical cavity at moderate values of the Rayleigh number (Ra≤10 5) and a Prandtl number of Pr=0.71 (with extensions to Pr=0.75 and 0.80) was investigated. The cubical cavity was heated from below and had perfectly conducting sidewalls and uniform temperature distributions on the two horizontal...

Fluid particle trajectories for the Rayleigh-Bénard problem in a cube with perfectly conducting lateral walls have been investigated. The velocity and temperature fields of the stationary flow solutions have been obtained by means of a parameter continuation procedure based on a Galerkin spectral method. The rich dynamics of the resulting fluid par...

The effects of a discontinuous cylinder geometry on the near wake structures was investigated experimentally. This ‘discontinuous’ circular cylinder has gaps so that solid segments 5D long are followed by gaps 2.5D long, in a repeating pattern, where D is the diameter of the cylinder. A thin steel plate was used to hold all of the cylinder pieces t...

The mixing process of a solute in a cubical cavity filled with water and heated from below is investigated numerically. The conservation equation of the solute species is discretized by means of a fourth-order accurate finite-volume scheme. The resulting set of ODE's is advanced in time by means of a seventh-eight order Runge- Kutta method with ada...

Fluids in chemical reactors are typically stirred by means of mechanical devices. Impellers provide a fast mixing of reactants and products at the expense of high levels of shear close to the blades. In biological systems reactions are usually slow and less intrusive mixing methods may be adopted. Al-Shannag et al. [1] have recently shown that the...

The two-dimensional momentum and mass transfer in an immobilized enzyme reactor was numerically investigated. The equations of motion and the mass-transport equation of a substrate, consumed at specified boundaries of the reactor, were solved by using fourth-order discretization schemes. A wall-driven cavity of square cross-section was selected to...

Natural convection in a cubical cavity heated from below with perfectly conducting sidewalls is investigated numerically. A parameter continuation procedure based on a Galerkin spectral method was applied to obtain the bifurcation diagrams for steady flow solutions over the region of Rayleigh numbers Ra <= 1.5 x 10(5) at Prandtl numbers Pr = 0.71 a...

The bifurcation diagram of steady convective flow patterns inside a cubical cavity with adiabatic lateral walls heated from below and filled with silicone oil (Pr = 130) was determined for values of the Rayleigh number (Ra) up to 1.5 x 10(5). A continuation procedure based on the Galerkin spectral method was used to determine the steady convective...

An educational model has been designed and implemented at the School of Chemical Engineering (ETSEQ) at Tarragona, Spain, to enable ChE students to acquire and integrate technical and scientific knowledge through the simultaneous and gradual development of competencies encom-passing social and management skills. This model is based on the large-sca...

Universities are becoming increasingly aware of how important it is to equip their students with personal and social competencies such as client orientation or teamwork and cooperation. This paper presents a research project whose aim is to create a comprehensive system of assessment and development of competencies to support the competency-based e...

Fourth-year students in the ChE program of the School of Chemical Engineering (ETSEQ) of the University Rovira i Virgili, Spain, are empowered to assess the competency-based educational model that they have experienced and to prioritize, plan and implement improvements. This assessment and review activity is fully integrated in their role descripti...

Bifurcation diagrams of steady convective flow patterns inside a cubical cavity heated from below and filled with silicone oil (Pr = 130) were determined for adiabatic and perfectly conducting lateral walls. The diagrams were obtained for Rayleigh numbers up to 1.5 10^5 by means of a parameter continuation procedure based on the Galerkin spectral m...

A numerical study of bifurcations and stability of the steady convective flow of air in a cubical enclosure heated from below was carried out using a Galerkin spectral method. The set of basis functions was chosen so that all boundary conditions and the continuity equation were implicitly satisfied. A parameter continuation method was applied to de...

The present work deals with the natural convection flow and heat transfer from a horizontal plate cooled from above. Experiments are carried out for rectangular plates having aspect ratios between φ=0.036 and 0.43 and Rayleigh numbers in the range 290⩽Raw⩽3.3×105. These values of Raw and φ have been selected below those commonly considered in previ...

An analytically-based, computationally simple methodology is presented for calculating the velocity components of air flowing normal and parallel to a pair of suspensions attached to an E-block in a hard disk drive. The analysis allows for arbitrary angular orientation of the E-block/suspensions unit and accounts for the flow blockage due to the po...

The two-dimensional wall-driven flow in a plane rectangular enclosure and the three-dimensional wall-driven flow in a parallelepiped of infinite length are limiting cases of the more general shear-driven flow that can be realized experimentally and modeled numerically in a toroid of rectangular cross section. Present visualization observations and...

The lid-driven incompressible flow in a toroidally shaped cavity of square cross-section (dd) and radius of curvature r c is studied. For discrete values of the curvature ratio (d/r c), the Reynolds number at which the flow becomes three-dimensional (Re c) is determined by means of linear stability analysis. Present results show that both Re c and...

First-year chemical engineering students carry out a horizontally integrated design project working in teams. The teams are each led by two fourth-year students, one taking on the role of team leader and the other of knowledge manager so that the project is also vertically integrated. Team leaders facilitate project and team management while knowle...

Numerical results are obtained for the isothermal laminar flow of air between a pair of disks attached to and rotating with a hub in a fixed cylindrical enclosure. The presence of radial clearances or "gaps" between the rims of the disks and the curved enclosure wall, and the finite thickness of the disks, are considered in the calculations. The ga...

First-year chemical engineering students carry out a horizontally integrated design project working in teams. The teams are each led by two fourth-year students, one taking on the role of team leader and the other of knowledge manager so that the project is also vertically integrated. Team leaders facilitate project and team management while knowle...

Horizontal and vertical integration of engineering education is achieved through an early-design project where students get ac-quainted with Total Quality Management (TQM) principles and design processes from year-one of their University educa-tion. The project is embedded in the undergraduate chemical engineering curriculum as an activity that inv...

The optimisation of the design of printed circuits boards (PCB) for automotive junction boxes is leading the industry towards the inclusion of the numerical prediction of local temperatures at the board and the electrical/electronic components in the initial stages of the design process. The paper shows the modelling and numerical characteristics o...

This is a numerical investigation of the coupled laminar flow and heat transfer in the space between a pair of disks attached to a hub rotating about a vertical axis in a fixed cylindrical enclosure. A temperature variation is imposed in the fluid by setting the disks at different uniform temperatures, the temperature of the bottom disk being highe...

Constant-property laminar flow in the space between two coaxial disks corotating in a fixed cylindrical enclosure is investigated numerically over the Reynolds number range 0 ⩽ Re ⩽ 82 380 for interdisk spacing to disk radius aspect ratios in the range 0.05 ⩽ S ⩽ 0.20. Most of the 3D calculations correspond to regions in the (Re, S) map slightly ab...

The axisymmetric laminar flow and heat transfer in the space between a pair of disks corotating in a cylindrical enclosure is studied by numerical analysis. The effect of buoyancy forces on momentum is modeled through the Boussinesq approximation. In both configurations tested, the bottom disk is at a higher temperature than the top disk.

An improved form of the so-called 'near-wall' k-epsilon turbulence model is proposed. The damping functions accounting for viscous effects at low Reynolds numbers are modified to yield a turbulent viscosity that properly predicts heat transfer rates over a wide range of Prandtl numbers, using a constant turbulent Prandtl number Prt = 0.9. These mod...