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Abdominal aortic aneurysm disease is the local enlargement of the aorta, typically in the infrarenal section, causing up to 200,000 deaths/year. In vivo information to characterize the individual elastic properties of the aneurysm wall in terms of rupture risk is lacking. We used a method that combines 4D ultrasound and direct deformation estimation to compute in vivo 3D Green-Lagrange strain in murine angiotensin II-induced dissecting aortic aneurysms, a commonly used mouse model. After euthanasia, histological staining of cross-sectional sections along the aorta was performed in areas where in vivo strains had previously been measured. The histological sections were segmented into intact and fragmented elastin, thrombus with and without red blood cells, and outer vessel wall including the adventitia. Meshes were then created from the individual contours based on the histological segmentations. The isolated contours of the outer wall and lumen from both imaging modalities were registered individually using a coherent point drift algorithm. 2D finite element models were generated from the meshes, and the displacements from the registration were used as displacement boundaries of the lumen and wall contours. Based on the resulting deformed contours, the strains recorded were grouped according to segmented tissue regions. Strains were highest in areas containing intact elastin without thrombus attachment. Strains in areas with intact elastin and thrombus attachment, as well as areas with disrupted elastin, were significantly lower. Strains in thrombus regions with red blood cells were significantly higher compared to thrombus regions without. We then compared this analysis to statistical distribution indices and found that the results of each aligned, elucidating the relationship between vessel strain and structural changes. This work demonstrates the possibility of advancing in vivo assessments to a micro-structural level ultimately improving patient outcomes.

Although the pour plate method is widely employed in microbiological quality control, it has certain drawbacks, including having to melt the culture medium before seeding. The preparation of the culture media was modified by using a lower concentration of agar (10g/L), which was separated from the nutrients during sterilization. The new protocol was assessed in frequently media used in microbiological quality control of food, cosmetics and pharmaceutical products, with Tryptic Soy Agar (TSA), Sabouraud 4% Dextrose Agar (SDS) and Violet Red Bile Glucose Agar (VRBG). In comparison with the conventionally produced media, the modifications significantly improved the growth of Saccharomyces cerevisiae in SDS, Staphylococcus aureus, Salmonella Salmonella enterica subsp. enterica ser. Typhimurium Typhimurium and Candida albicans in TSA, and Escherichia coli ATCC 8739 and ATCC 25922 and S. Typhimurium Salmonella enterica subsp. enterica ser. Typhimurium in VRBG. The modified VRBG was also more selective for Pseudomonas aeruginosa. Regarding physicochemical properties, a significantly lower pH was observed in TSA and VRBG, and lower strength values in TSA. Sterilizing agar separately from the other media components and reducing the agar concentration to 10g/L can improve microorganism growth and enhance the selectivity of differential media in the pour plate method. These modifications could facilitate the automation of this culture technique.

The present work studies the hydro-gasdynamic analogy between a shock wave, occurring in supersonic internal or external compressible flows, and a hydraulic jump, a sort of normal shock occurring in open-channel flows. It consists of an extensive theoretical framework followed by a practical analysis, the aim of which was to experimentally trigger the hydraulic jump, both normal and oblique, while using a low-cost designed lab prototype. The assembly development, called ‘water table’, arises from the necessity of economical alternatives to expensive supersonic wind tunnels in the experimental study of compressible fluid dynamics. With this objective in mind, a hydraulic canal based on a Laval nozzle was constructed where water flow could accelerate from subcritical to critical to supercritical regime and then return to subcritical regime through a hydraulic jump. In addition, multiple design alternatives were evaluated considering environmental, economic, functional and aesthetics factors. A low-cost implementation was the critical criterion in the design process. The measurements have revealed that the geometry of the nozzle and the wedges designed as obstacles to cause obliquity are the most significant and influential elements in the formation of a hydraulic jump in the experimental set-up. Regarding the experimental variables, the experiments demonstrate the effect of the upstream and downstream heights of the hydraulic jump in the data collection. This experience is a step forward in supporting students in the understanding of compressible flow and its principles by providing an in-house experimental set-up that promotes active learning, motivation and interest in fluid mechanics.

Object recognition is still a major research issue of particular relevance in robotics. The new trend in industrial and mainly in service robotics is to perform manipulation tasks in an unstructured environment working in synergy with humans. To perform tasks in an environment that is not perfectly controlled, robots need adequate perceptual capabilities. Among various types of sensors available for robotic systems, the time-of-flight (ToF) camera is one of the most utilized since it simultaneously provides intensity and depth data at a high frame rate. Our proposal makes use of this technology exploiting both, depth and grey-scale information. Therefore, intensity and geometric features are fused together to allow 3D object recognition in real scenes in presence of partial occlusions. As a case study, an object tracking task for an anthropomorphic robot is presented. Experimental results demonstrate the effectiveness of the proposed method, not only providing reliable visual information about the object to be tracked but also recognizing potential obstacles which should be avoided during the robot arm movement.

This article presents a methodology for predicting the fluid dynamic behavior of a gear pump over its operating range. Complete pump parameterization was carried out through standard tests, and these parameters were used to create a bond graph model to simulate the behavior of the unit. This model was experimentally validated under working conditions in field tests. To carry this out, the pump was used to drive the auxiliary movements of a drilling machine, and the experimental data were compared with a simulation of the volumetric behavior under the same conditions. This paper aims to describe a method for characterizing any hydrostatic pump as a “black box” model predicting its behavior in any operating condition. The novelty of this method is based on the correspondence between the variation of the parameters and the internal changes of the unit when working in real conditions, that is, outside a test bench.

Baby diaper, despite their evolution, still caused serious problems after using on the baby’s skins, as diaper rash or seat dermatitis. To avoid these problems, understanding of the structure of the material in contact with the baby’s skin and its mechanical behavior is necessary. Therefore, the study of the non-wovens fabrics of the top-sheet is compulsory. Our aim is to relate mechanical properties of the tissues to their microstructure. To achieve that goal, the microscopic observation have been performed to study the composition and the structure of the textile, particularly the distribution of the fibers orientation. Also, tensile tests in both longitudinal and transversal directions and compression tests have allowed to mechanically characterize some mechanical properties, as stiffness. Results show that longitudinal directions are favored comparing to the transversal ones and that actual baby diapers are more rigid than others under study.

This work presents a new project based learning methodology focused on solving case studies proposed by companies. The methodology is based on one of the models proposed in the European KA2 Erasmus + Project titled “Smart HEI-Business collaboration for skills and competitiveness” (HEIBus). This project was formed by a consortium of 5 European universities and 7 companies with international activities and was focused on the development and implementation of new models for business-university cooperation. The model of cooperation between university students and companies was implemented using case studies proposed by companies to groups of multidisciplinary students. This model has been adapted to a project based learning methodology that will be applied in several courses in the Electronics and Automation Department of the University of Jaen

This paper outlines a practical intervention aiming to collect the effects of introducing flexible learning in engineering higher education. The work dis- cusses the implementation of the flipped classroom method and the threshold concepts in the Turbomachinery section of Fluid Engineering course in the third year of Mechanical Engineering (Bachelor's degree) at the Universitat Politècnica de Catalunya. Fluid Engineering is traditionally one of the hardest courses involving a complex interaction between understanding concepts and using those concepts in the solution of cases, which also require the devel- opment of a set of skills. This case study is centred on two student cohorts, and the research spans over two consecutive Fall semesters. The study is based on sound pedagogy of educational technologies, in practice, frequent student-to-instructor interaction, academic results, and statistical and survey analyses. A principal conclusion is that overall class performance is much higher than that of the previous courses. The results indicate that learners gained under- standing from semester to semester and no statistical significance was ob- served between group and exam format. Students were satisfied with the level of suitability and the degree of compliance of the new implementation and found it constructive in their learning process, an important educational benefit. This positive experience, in terms of benefit-cost and outcomes, en- courages the intervention without sacrificing any curriculum syllabus, but taking advantage and bringing the benefits of interactivity distance learning technologies and traditional face-to-face lectures. This scholarly research aims to contribute to this area, by abandoning traditional lecturing in favour of active learning

The quality and obtained quantity of Virgin Olive Oil is determined by the influence of the process variables during the production process based on the properties of the olives being processed. Since the quality of the olives evolve during the harvesting season, a relevant question is to systematically suggest when to harvest the olives in order to maximize the profit over the whole season. This work proposes a method to determine an optimal production plan for the whole harvesting season explicitly considering the stochastic nature of the problem, the uncertainty in the problem parameters and the information available at each step, and presents the results obtained in its application to different production scenarios.

The identification of olive cultivars is of utmost importance for a multitude of factors affecting both, the olive oil elaboration process and fair trade exchanges. The accurate varietal identification is a time consuming task that requires trained specialists or expensive and specific equipment. When applying the traditional method, a specialist assesses morphological features using the olive endocarp. A proposal to automate this identification method is presented in this paper. Endocarp images, acquired under three different perspectives, are processed to extract the same information that the specialist utilizes. Then, the partial least squares discriminant analysis classifier, with or without feature selection, has been tested on a set of 250 samples from 5 different varieties. Results show that the proposal is an alternative identification method which could also be used in the traditional one in order to assist the specialist in the determination of the variety.

Suppliers of metallic components with high-precision surfaces are facing a trend towards zero-defect tolerance regarding their finishing. Because of the lack of standardization and the difficulty of the task, this inspection is generally done manually. This work aims to detect defects on machined metal parts even if their orientation and shape are very similar to the surface finishing. A machine vision system, performing the detection of flaws on textured surfaces is fully described. One of its main devices, the lighting system, has been carefully designed to ensure the imaging of defects. Hence, multiple images are acquired under different lighting conditions, processed separately, and merged into one. Features extracted from this fused image and the former processing steps establish the feature space for a supervised learning classifier based on artificial neural networks. Results of the automated inspection show that the system works effectively with a low value of false rejections, which makes it suitable for industrial applications.

Supersonic ejectors are used extensively in all kind of applications: compression of refrigerants in cooling systems, pumping of volatile fluids or in vacuum generation. In vacuum generation, also known as zero-secondary flow, the ejector has a transient behaviour. In this paper, a numerical and experimental research of a supersonic compressible air nozzle is performed in order to investigate and to simulate its behaviour. The CFD toolbox OpenFOAM 6 was used, with two density-based solvers: explicit solver rhoCentralFoam, which implements Kurganov Central-upwind schemes, and implicit solver HiSA, which implements the AUSM+up upwind scheme. The behaviour of the transient evacuation ranges between adiabatic polytropic exponent at the beginning of the process and isothermal at the end. A model for the computation of the transient polytropic exponent is proposed. During the evacuation, two regimes are encountered in the second nozzle. In the supercritic regime, the secondary is choked and sonic flow is reached. In the subcritic regime, the secondary flow is subsonic. The final agreement is good with the two different solvers, although simulation tends to slightly overestimate flow rate for large values region.

Over the years, numerous investigations have established the gerotor fundamentals. This work aims to provide a complete review of the literature from the last decade, focusing on the articles published in the past five years on gerotor technology in hydraulic machines. The report gives a catalogue of guidelines based on the trochoidal-envelope definition, a background analysis, the worldwide distribution of articles in each continent and country and the most frequently used keywords in the field. The paper identifies state-of-the-art research, and reports on current mainstream ideas. From the historical background, this literature review reports the current approaches in gerotor pumps (geometry and performance approaches, modeling and numerical simulations), orbital motors and new concepts. The report will serve as a guide and a directory for novel engineers working with gerotor technology in hydraulic machines. Another intention of this paper is to disseminate the works of the researchers who use this technology around the world, and to provide a scenario for future international collaboration. The paper gives an account of the disparity between academia and engineering applications. There is currently very little published literature on design and production methodologies for gerotor pumps and orbital motors. Hence, the future goal is to collect recommendations that combine academia and industry expertise to make better use of these extensive studies in the field.

Thin-wall parts are common in the aeronautical sector. However, their machining presents serious challenges such as vibrations and part deflections. To deal with these challenges, different approaches have been followed in recent years. This work presents the state of the art of thin-wall light-alloy machining, analyzing the problems related to each type of thin-wall parts, exposing the causes of both instability and deformation through analytical models, summarizing the computational techniques used, and presenting the solutions proposed by different authors from an industrial point of view. Finally, some further research lines are proposed. This research was funded by University of Cadiz, UCA/REC01VI/2016.

In recent years, much research has focused on reducing the power consumption of mobile hydraulic machines due to rising fuel costs, regulations on combustion engine emissions and the need to reduce the size and weight of the storage devices in hybrid drives. Current approaches to improve the energy efficiency of a hydraulic system can be classified into four basic groups: reduction of the energy demand, recovery of part of the supplied energy (ERS systems), regeneration of part of the supplied energy and reuse of the recovered and regenerated energy (hybrid systems). Today’s mobile hydraulic systems are often complex, perform different tasks and work under different load conditions, which makes it difficult to analyse energy losses. A study of the energy losses of a hydraulic system from different points of view, such as an energy balance for a complete machine cycle, an analysis of the individual cycle phases and a power analysis for the different operation quadrants of the actuators, can give an global picture of the energy losses, being very useful to rate its energy efficiency, identify main power losses and decide which of the different energy-saving techniques to apply. This paper describes the data collection process, its analysis from various points of view and the summary of the results in easy to understand charts as useful tools to identify and quantify the main energy losses. Only system architecture losses are considered. Losses in the ICE engine or the electric motor, hydraulic pump losses and mechanical losses are outside the scope of this study.

Computational models are capable of simulating the expected thermal response of biological tissue to laser irradiation. A typical laser tissue model accounts for optical energy deposition, heat transfer, and damage assessment, with the latter often represented by calculation of the Arrhenius integral. Previous studies have successfully employed these methods to predict skin damage thresholds at laser wavelengths with high absorption in water, and usually for single continuous-wave exposures. However, there remains a need for a robust and accurate predictive model in low-absorption, high-scattering cases, such as for exposures in the near-infrared region near 1000 nm. This study presents a framework for modeling laser irradiation of skin tissue at 1070 nm for both continuous-wave and pulsed exposures with durations ranging from 10−2 to 101 s. The authors derive an optical absorption coefficient for the epidermis that agrees with expected chromophore distribution and report the modeled skin thermal responses alongside surface thermography data from in vivo porcine exposures as validation of simulation accuracy. Comparisons of modeled damage thresholds calculated by the Arrhenius integral with documented experimentally determined minimum visible lesion ED50 data exhibit a high degree of agreement. The authors also provide new Arrhenius rate process coefficients of A = 2.74 × 1094 s−1 and Ea = 5.90 × 105 J/mol, determined from experimental thermal profiles with a unique method, that demonstrate more accurate threshold predictions than those used in previous modeling studies. The techniques outlined by this study provide a useful tool in assessing potentially hazardous near-infrared laser exposure scenarios.

Computational models are capable of quantifying the expected thermal response of biological tissue to laser irradiation. A typical laser-tissue model accounts for optical energy deposition, heat transfer, and damage assessment, with the later often represented by calculation of the Arrhenius integral. Previous studies have successfully employed these methods to predict skin damage thresholds at laser wavelengths with high absorption in water, and usually for single continuous-wave exposures. However, there remains a need for a robust and accurate predictive model in low-absorption, high-scattering cases, such as for lasers in the near-infrared (NIR) region near 1 µm, where a large volume of tissue is heated simultaneously. This study presents a framework for modeling laser irradiation of skin tissue at 1070-nm for both continuous-wave and pulsed exposures with durations ranging from 10−2 to 101 seconds. We report the modeled skin thermal responses alongside thermal camera recordings of in-vivo porcine exposures as validation of simulation integrity. Comparisons of modeled damage thresholds calculated by the Arrhenius integral with past experimentally-determined minimum visible lesion ED50 data demonstrate a high degree of accuracy. The techniques outlined by this study provide a useful tool in assessing potentially hazardous near-infrared laser exposure scenarios while informing future investigations into modeling skin laser exposure at these wavelength regions.Computational models are capable of quantifying the expected thermal response of biological tissue to laser irradiation. A typical laser-tissue model accounts for optical energy deposition, heat transfer, and damage assessment, with the later often represented by calculation of the Arrhenius integral. Previous studies have successfully employed these methods to predict skin damage thresholds at laser wavelengths with high absorption in water, and usually for single continuous-wave exposures. However, there remains a need for a robust and accurate predictive model in low-absorption, high-scattering cases, such as for lasers in the near-infrared (NIR) region near 1 µm, where a large volume of tissue is heated simultaneously. This study presents a framework for modeling laser irradiation of skin tissue at 1070-nm for both continuous-wave and pulsed exposures with durations ranging from 10−2 to 101 seconds. We report the modeled skin thermal responses alongside thermal camera recordings of in-vivo porcine exp...

The gerotor pump has many advantages over other hydraulic pumps, such as high reliability, compactness, lower noise in running conditions etc. Considering the increasingly stringent regulations in the field of environmental protection, one of the main goals in the industrial applications of gerotors is to improve their design by using light materials and optimize their performance. This paper will give an overview of modern research that focuses on improving the performance of gerotor pumps. A joint publication of three university centers, namely of Wroclaw, Terrassa and Kragujevac, presents their original approaches to the problem of designing gerotor and orbital systems. The presentations have been prepared in separate parts, but according to similar rules. The first part of the paper focuses on meshing between internal and external gear of gerotor. Analysis for both cases, moved axis and fixed axis, will be provided in accordance to their working characteristics and their application. The second part of the paper provides the design of a gerotor pump strikes a balance between volumetric efficiency, manufacturability and mechanical efficiency. The third part of the paper defines the methodology for selecting the best combination of geometric form parameters of the trochoidal gearing in relation to the reduction of contact stresses and improving other characteristics of the pump. All three parts provide manufacturing and application review in the fluid power machines. Paper concludes with presented theoretical and experimental review of the authors and their practice achievements.

This is a copy of the author 's preprint version of an article published in the journal Experimental techniques. The final publication is available at Springer via http://dx.doi.org/10.1007/s40799-016-0017-9 This article provides a technical description of a flexible hinge for wind tunnel rigs. For academic purposes, the device was integrated into several rod flexures to build a home-made external wind balance system. The cylindrical elastic element incorporates several notches, and the flexure linkage is able to transmit force in the main axial direction without hindering perpendicular movement. The flexural element described here is simple and easily manufactured, and can also be used with other types of wind balance. The flexure described in this article has similar functionality to those mentioned in the reference section, but has a more compact element. The project's effectiveness was demonstrated in a series of experimental comparisons of forces and moments measured on a wing using the N.A.C.A. Clark-Y airfoil profile.

We propose an on-line system to be applied in olive oil industry.We employ hyperspectral images for the prediction of olive oil parameters.Optimal wavelengths have been selected with different methods.We show the regression lines and the validation results. The analysis of the quality of virgin olive oil involves the determination of a series of properties, such as chemical indexes and organoleptic characteristics. In addition, the determination of these properties in real-time could be useful in order to improve the olive oil extraction process since the process parameters could be regulated with the real-time moisture information.In this paper, the feasibility of using a non-invasive hyperspectral device, in order to determine on-line three parameters of the olive oil (free acidity, peroxide index and moisture) is studied. In order to study the correlation between these parameters and the information obtained by the hyperspectral sensor (absorption level), three different methods were applied: genetic algorithms (GA), least absolute shrinkage and selection operator (LASSO), and successive projection algorithm (SPA). From the experimental results, reduced values in cross validation were obtained and the optimal wavelengths were pointed out.

The fatigue of a hydraulic component inherently varies due to various factors that can be divided into two categories: structural and load spectrum variability. The effects of both variabilities must be considered when determining fatigue life. Compared with the structural variability, determining the variability in the load spectrums is more difficult because the service conditions are complicated and the measurements of the load parameters are slow and expensive. The problem that arises when studying the fatigue behaviour of such components is the transferability of short data samples from real-life load histories, which are application-dependant, to laboratory test methods. Derived from the experimental background and know-how of the authors, this paper proposes a methodology that allows the definition and establishment of the hydraulic cylinder design specificactions, while taking into account the probabilistic characterisation of the load spectrum variability. This methodology could be extrapolated to other hydraulic or mechanical components.

© 2017. This version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ All positive displacement pumps produce a pulsating flow. The present paper reports the experimental measurement of steady flow pulsations in the outlet of the internal wheeled pump. In the measured flow, the manufacturing tolerance are responsible of part of the spectra of the whole pulsation. Time-Resolved Particle Image Velocimetry technique has been used for this purpose. The flow pulsation measurement from a direct visualization of the velocity profile was carried out. The flow rate signal is derived from ad-hoc integration algorithm of the radial velocity profile, where the area discretization is a constant parameter that is relevant to minimize PIV errors by velocity gradients regions near the wall. Spectrographic analysis on the experimental data reveled low frequency components related with manufacturing tolerances. Measurements of this non-invasive procedure are compared with detailed CFD numerical results obtained from an improved gerotor model where manufacturing tolerances have been included. To be compared, cross-power spectral density analysis has been applied. The results reported in the paper show a method to provide a fast non-invasive flow pulsation measurement not only for pumps but also could be extended to compare aging effects of other kind of fluid power devices.

The determination of the content of impurities is a very frequent analysis performed on virgin olive oil samples, but the official method is quite work-intensive, and it would be convenient to have an alternative approximate method to evaluate the performance of the impurity removal process. In this work we develop a system based on computer vision and pattern recognition to classify the content of impurities of the olive oil samples in three sets, indicative of the goodness of the separation process of olive oil after its extraction from the paste. Starting from the histograms of the channels of the Red–Green–Blue (RGB), CIELAB and Hue-Saturation-Value (HSV) color spaces, we construct an initial input parameter vector and perform a feature extraction previous to the classification. Several linear and non-linear feature extraction techniques were evaluated, and the classifiers used were Support Vector Machines (SVMs) and Artificial Neural Networks (ANNs). The best classification rate achieved was 87.66%, obtained using Kernel Principal Components Analysis (KPCA) and a grade-3-polynomial kernel SVM. The best result using ANNs was 82.38%, yielded by the use of Principal Component Analysis (PCA) with the Perceptron.

One of the industrial applications of computer vision is the automated detection and characterisation of surface defects. Some types of surface, such as those that are highly reflective or transparent, require the implementation of custom-made systems for automated inspections. The purpose of this article is to present a machine vision system, with an easily configurable hardware–software structure, for surface quality inspection of transparent parts. This structure permits that different products and part models may be inspected by the system. Its hardware is composed of image-capturing devices and mechanisms for manipulating and holding the part to be inspected. One such mechanism is the lighting system, which has been specifically developed to allow real-time quality control of this type of surfaces. As regards software design, a component-based approach has been adopted in order to increase reusage of the code and decrease the time required for configuring any type of part and adapting it for inspection. To test the efficiency and robustness of the industrial setup, a series of tests using a transparent industrial part, specifically, a commercial model of headlamp lens, have been assessed.

The technology of gerotor pumps is progressing towards cutting-edge applications in emerging sectors, which are more demanding for pump performance. Moreover, recent environmental standards are heading towards leakage-free and noiseless hydraulic systems. Hence, in order to respond to these demands, this study, which will be referred to as the GeroMAG concept, aims to make a leap from the standard gerotor pump technology: a sealed, compact, non-shaft-driven gerotor pump with a magnetically-driving outer rotor. The GeroMAG pump is conceived as a variable-flow pump to accomplish a standard volumetric flow rate at low rotational speed with satisfactory volumetric efficiency. By following the authors’ methodology based on a catalogue of best-practice rules, a custom trochoidal gear set is designed. Then, two main technological challenges are encountered: how to generate the rotational movement of the driving outer rotor and how to produce the guide of rotation of the gear set once there is no drive shaft. To confront them, a quiet magnet brushless motor powers the driving outer rotor through pole pieces placed in its external sideway and the rotational movement is guided by the inner edgewise pads carved on it. Subsequently, GeroMAG pump architecture, prototype, housing, methodology, materials and manufacture will be presented. As a principal conclusion, the GeroMAG proof of concept and pump prototype are feasible, which is corroborated by experimental results and performance indexes.

The trochoidal gear pump, also known as gerotor, owing to its remarkable advantages compared to other hydraulic pumps is chosen for many engineering applications. As each application is unique, the designer ought to be knowledgeable of the required specifications as a first task but need not be an expert in the hydraulic pump design. The review of the existing research reveals significant gaps to develop a new-born project and the work presented in this paper, drawn on existing research work and the authors’ own experience and know-how, aims to overcome them. The objective of the paper is then to provide a summary of the best practice rules to design a trochoidal gear pump from scratch achieving a thorough understanding. In the conceptual stage, making decisions come according to a predetermined set of four parameters known by the designer that will lead to the complete development of the trochoidal gear set. Afterwards, in the design process, the most important characteristics of the pump such as the porting, the pump construction, and the limitations are presented based on the significant explanations, with regard to each feature, selection, effects, and good practices. As a result, the methodology presented compiles the process of engineering in designing a new trochoidal gear pump as a catalogue of guidelines aiming to overcome a vague design due to a lack of knowledge. This collection of best practice rules intends to guide the designer to take good decisions early in the design process that limit design change later in the final stage—the prototype.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The aim of this paper is to study the aerodynamics phenomena of a bass-reflex port that causes noise in the audible frequency range. After discarding structural and mechanical vibration issues, the hypothesis considered is that vortex shedding is the source of the noise. Experimental and numerical evidences of the vortex, an analysis of its noise and the similarities between real and simulated performance are presented. The numerically simulated cases with the original geometry are excited at different frequencies and with modifications of the port geometry. Likewise, the internal performance of an enclosure with a closed port was simulated. The simulations have been performed with axisymmetrical geometries using the open-source OpenFOAM® toolbox. Moreover, experimental measurements were carried out. First, acoustic signal experiments were done to analyse the response of the bass-reflex ports. Secondly, a structure vibration measurement was conducted in order to exclude the cabinet structure vibration as a source of the noise in question. A good agreement was found between numerical and experimental results, especially in the frequency band of the detected noise, i.e. the 1000–1500 Hz range. Despite no remarkable improvement being made with the geometry changes explored, the presented CFD approach has proved a useful and cost-effective tool to address this kind of phenomenon.

In the last few years, wall shear stress (WSS) has arisen as a new diagnostic indicator in patients with arterial disease. There is a substantial evidence that the WSS plays a significant role, together with hemodynamic indicators, in initiation and progression of the vascular diseases. Estimation of WSS values, therefore, may be of clinical significance and the methods employed for its measurement are crucial for clinical community. Recently, four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) has been widely used in a number of applications for visualization and quantification of blood flow, and although the sensitivity to blood flow measurement has increased, it is not yet able to provide an accurate three-dimensional (3D) WSS distribution. The aim of this work is to evaluate the aortic blood flow features and the associated WSS by the combination of 4D flow cardiovascular magnetic resonance (4D CMR) and computational fluid dynamics technique. In particular, in this work, we used the 4D CMR to obtain the spatial domain and the boundary conditions needed to estimate the WSS within the entire thoracic aorta using computational fluid dynamics. Similar WSS distributions were found for cases simulated. A sensitivity analysis was done to check the accuracy of the method. 4D CMR begins to be a reliable tool to estimate the WSS within the entire thoracic aorta using computational fluid dynamics. The combination of both techniques may provide the ideal tool to help tackle these and other problems related to wall shear estimation.

The trochoidal-gear technology has been growing in groundbreaking fields. Forthcoming applications are demanding to this technology a step forward in the conceiving stage of positive displacement machines. The compendium of the qualities and the inherent characteristics of trochoidal-gear technology, especially towards the gerotor pump, together with scale/size factor and magnetic-driven transmission has led to the idea of a magnet-sleeve-sealed variable flow mini trochoidal-gear pump. From its original concept, to the last phase of the design development, the proof of concept, this new product will intend to overcome problems such as noise, vibration, maintenance, materials, and dimensions. The paper aims to show the technological path followed from the concept, design, and model, to the manufacture of the first prototype, where the theoretical and numerical approaches are not always directly reflected in the prototype performance results. Early in the design process, from a standard-commercial sintered metal mini trochoidal-gear unit, fundamental characteristics and dimensional limitations have been evaluated becoming the strategic parameters that led to its configuration. The main technical challenge to confront is being sealed with non-exterior driveshaft, ensuring that the whole interior is filled and wetted with working fluid and helping the hydrodynamic film formation, the pumping effect, and the heat dissipation. Subsequently, the mini pump architecture, embodiment, methodology, materials, and manufacture are presented. The trend of applications of polymer composite materials and their benefits wanted to be examined with this new mini pump prototype, and a pure polyoxymethylene mini trochoidal-gear set has been designed and manufactured. Finally, both the sintered and the polymer trochoidal-gear units have been experimentally tested in an in-house full-instrumented mini test bench. Although the main goal of the presented work is the development of a new mini trochoidal-gear pump prototype rather than a numerical study, the results have been compared with numerical simulation. Subsequently, the prototype of the mini trochoidal-gear pump is a feasible proof of concept supported by functional indexes and the experimental results.

A new approach based on the open source tool OpenFOAM is presented for the numerical simulation of a mini gerotor pump working at low pressure. The work is principally focused on the estimation of leakage flow in the clearance disk between pump case and gears. Two main contributions are presented for the performance of the numerical simulation. On one hand, a contact point viscosity model is used for the simulation of solid–solid contact between gears in order to avoid the teeth tip leakage. On the other hand, a new boundary condition has been implemented for the gear mesh points motion in order to keep the mesh quality while moving gears with relative velocity. Arbitrary coupled mesh interface (ACMI) has been used both in the interface between clearance disk in inlet/outlet ports and between clearance disk and interteeth fluid domain. Although the main goal of the work is the development of the numerical method rather than the study of the physical analysis of the pump, results have been compared with experimental measurement and a good agreement in volumetric efficiency and pressure fluctuations has been found. Finally, the leakage flow in the clearance disk has been analyzed.

The work presented in this article demonstrates the use of an empirical and simplified approach based on an optical technique and a home-made ad hoc code that give knowledge of the shape and falling velocity of a free-falling non-submerged liquid stream to predict its typology and flow rate. The visualization photographic technique is a non-intrusive robust technique which can be applied to high-temperature liquids in harsh environments, such as an iron stream in a foundry. This technique allows predicting the liquid stream boundaries and contours without any type of treatment on the fluid. As a result of employing this empirical methodology, three flow typologies for a water stream are proposed and demonstrated experimentally. Comparisons with experimental data reveal satisfactory estimations of mean flow quantities. Finally, the approach used based on experimental visualization is carried out in an iron stream of a foundry, not being disruptive to in-situ foundry operations and showing its potential to improve performance of the cast parts’ properties during the casting phase and revealing to be a useful tool for process optimization.

Decision support systems (DSSs) are a convenient tool to aid plant operators in the selection of process set points. Inputs to these systems for variables that are not easily measured online often come from assessments made by experts, with an associated degree of uncertainty. The application of fuzzy sets and systems as part of DSSs provides a systematic approach to addressing the uncertainty in its variables. This paper builds on prior work on DSSs utilising fuzzy cognitive maps and introduces a non-singleton fuzzification stage which directly addresses uncertainty in system inputs. The motivation of the proposed system is grounded in the real world challenges of producing high-quality olive oil and the paper provides promising application and analysis results as part of the Virgin Olive Oil Production Process.

Resumen Objetivo Evaluar los resultados de un programa de cirugia mayor ambulatoria en pacientes intervenidos quirurgicamente de diversas patologias dermatologicas en nuestro hospital. Metodos Estudio observacional retrospectivo que incluye los pacientes intervenidos de forma programada en el periodo 2004-2007 en un hospital publico realizandose diferentes procedimientos quirurgicos de forma ambulatoria, siendo la cirugia de exeresis de carcinomas basocelulares y espinocelulares, con y sin injerto, la operacion mayoritaria. Se han analizado diversos indices (sustitucion, suspension, ingresos, reingresos), asi como el rendimiento quirurgico y las complicaciones sistemicas que surgieron dentro de las primeras 72 horas tras la cirugia. La medicion de las variables se realizo mediante frecuencias relativas. El analisis utilizado para la evolucion de las complicaciones en el periodo de estudio fue la Chi cuadrado de tendencias. Resultados 2.789 pacientes fueron intervenidos en el periodo indicado, de los que 2.757 se operaron de forma ambulatoria (indice de sustitucion global del 17,99%). El rendimiento quirurgico medio fue 74,36%. El indice de ingresos tras la cirugia fue 2,62% (14 pacientes), siendo ingresos inmediatos en el 85,71% de los casos (12). Nueve pacientes sufrieron complicaciones graves (cardiovasculares, neurologicas, metabolicas e infecciosas), representando un riesgo proporcional de 1:59. En 25 pacientes aparecieron complicaciones de menor gravedad (hipertension arterial, nauseas, vomitos, sincope vasovagal) que requirieron ingreso hospitalario. Conclusiones La cirugia mayor ambulatoria (CMA) es un excelente modelo organizativo de asistencia quirurgica multidisciplinar, que permite tratar pacientes bien seleccionados de una manera efectiva, segura y eficiente. A pesar del cumplimiento de los requisitos optimos, existe un porcentaje pequeno de complicaciones postoperatorias de gravedad variable, aunque afortunadamente la mortalidad es practicamente nula.

Presently, it is quite common, because of their benefits, to find plastic parts as the main elements of diverse commercial products. However, plastic components also present some drawbacks, such as their typical dimensional variations (especially in parts with complex geometry or with considerable size), making difficult, or even impossible, the correct assembly of the parts. This paper introduces a new methodology of dynamic assembly for an industrial application that requires an adaptive positioning of the parts that are to be assembled. In addition, this work presents a successful example of an industrial prototype where different technologies, which aim to solve different problems, have to be analyzed and tested. In particular, different approaches were studied: surface measurement sensors for transparent and deformable objects, actuation systems that could modify the assembly position of the parts, and control algorithms that could carry out this adaptive assembly automatically. The final goal of this work was to obtain a robust industrial prototype for vehicle headlamp assembly that could solve the high dimensional variations of the main plastic parts. To demonstrate the performance of the proposed solution, a wide set of experimental test was carried out in both a research lab and in the assembly line of a vehicle headlamp factory. The new prototype solves the problem of assembling vehicle headlamps, achieves a final product with minimum dimensional errors and offers an example of a solution to the problem of the assembly of pieces with dimensional errors.