Influence of surface geometry on the quality of the polishing process of glazed porous ceramic tiles

Comunicació presentada al 23rd International Congress on Project Management and Engineering CIDIP 2019 (Málaga, 10-12 July 2019)Glazed porous ceramic tiles are used for wall tiling due to their high humidity absorption, which produces deformations in them. These tiles have a good surface appearance due to its glazed layer, and polishing is not required. However, some manufacturers proceed to its subsequent polishing, obtaining high-gloss tiles. Nevertheless, the polishing process of these parts is complex because it is very difficult to obtain pieces with the flatness required for polishing, due to different contraction coefficients between the ceramic base and the glazed surface layer. In addition, during the polishing process the parts absorb water used in the process, which produces a change in its geometry, causing a decrease in productivity and a high number of defective parts. In this work a study of the geometry evolution of these pieces according to humidity content and elapsed time is carried out, and a strategy of parts pretreatment prior to polishing is proposed, which allows increasing the productivity by improving the flatness.Las baldosas cerámicas esmaltadas de gres poroso se emplean para el alicatado de paredes dada su elevada absorción de humedad, la cual produce deformaciones en las mismas. Estas baldosas presentan un buen aspecto superficial debido a la capa cristalina de esmalte, no siendo necesario su pulido. Sin embargo, algunos fabricantes proceden a su posterior pulido, obteniendo piezas de muy alto brillo. Sin embargo, el proceso de pulido de estas de piezas es muy complejo debido a que es muy difícil obtener a la salida del horno piezas con la planicidad requerida para su pulido, debido a los muy diferentes coeficientes de contracción entre la base cerámica y capa superficial de esmalte vitrificado. Además, durante el proceso de pulido las piezas absorben parte del agua empleada en el proceso, lo cual origina un cambio de su geometría, provocan un descenso de la productividad y un elevado nivel de defectos. En el trabajo propuesto se realiza un estudio de la evolución de la geometría de estas piezas en función del contenido de humedad y del tiempo transcurrido, y se propone una estrategia de tratamiento de las piezas previo al pulido que permite incrementar la productividad al mejorar la planicida

An approach for the design of infrastructure mode indoor WLAN based on ray tracing and a binary optimizer

This paper presents an approach that combines a ray tracing tool with a binary version of the particle swarm optimization method (BPSO) for the design of infrastructure mode indoor wireless local area networks (WLAN). The approach uses the power levels of a set of candidate access point (AP) locations obtained with the ray tracing tool at a mesh of potential receiver locations or test points to allow the BPSO optimizer to carry out the design of the WLAN. For this purpose, several restrictions are imposed through a fitness function that drives the search towards the selection of a reduced number of AP locations and their channel assignments, keeping at the same time low transmission power levels. During the design, different coverage priority areas can be defined and the signal to interference ratio (SIR) levels are kept as high as possible in order to comply with the Quality of Service (QoS) requirements imposed. The performance of this approach in a real scenario at the author´s premises is reported, showing its usefulness.This work was supported by the Spanish Ministry of Science and Innovation (TEC2008-02730) and the Spanish Ministry of Economy and Competitiveness (TEC2012-33321)

Gemcitabine-Loaded Magnetically Responsive Poly("-caprolactone) Nanoparticles against Breast Cancer

A reproducible and efficient interfacial polymer disposition method has been used to formulatemagnetite/poly("-caprolactone) (core/shell) nanoparticles (average size 125 nm, production performance 90%). To demonstrate that the iron oxide nuclei were satisfactorily embedded within the polymeric solid matrix, a complete analysis of these nanocomposites by, e.g., electron microscopy visualizations, energy dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, electrophoresis, and contact angle goniometry was conducted. The magnetic responsive behaviour of these nanoparticles was quantitatively characterized by the hysteresis cycle and qualitatively investigated by visualization of the colloid under exposure to a 0.4 T magnet. Gemcitabine entrapment into the polymeric shell reported adequate drug loading values ( 11%), and a biphasic and pH-responsive drug release profile ( four-fold faster Gemcitabine release at pH 5.0 compared to pH 7.4). Cytotoxicity studies in MCF-7 human breast cancer cells proved that the half maximal inhibitory concentration of Gem-loaded nanocomposites was two-fold less than that of the free drug. Therefore, these core/shell nanoparticles could have great possibilities as a magnetically targeted Gemcitabine delivery system for breast cancer treatment.FEDER, Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I+D+i), Instituto de Salud Carlos III (FIS, Spain) PI19/0147

CAR FOLLOWING TECHNIQUES: THE ROLE OF THE HUMAN FACTOR RECONSIDERED

[EN] Engineering and psychophysiological car following models emerge in the late 1950s (Saifuzzaman & Zheng, 2014). Such models differ in their ground concepts and explanatory mechanisms, but both assume a fundamental tenet: following each other, drivers invariably attempt to couple, keeping safety distance. More recent models focus on the spontaneous emergence of traffic jams that results from the properties of a system of interacting vehicles (i.e., without bottlenecks). In an experimental setting Sugiyama et al., (2008) have successfully recreated the conditions that allow the observation of the typical soliton wave going backwards through several car clusters. When certain speed, density and inter-vehicular distance join, so do traffic jams. Some of us have built upon these and other factors (e.g., wave movement in nature) exploring the mathematical properties of a system with three incognita that also needs three variables to be solved (Melchor & Sánchez, 2014). Two canonical car-following techniques emerge as a consequence: Driving to keep safety Distance (DD) vs Inertia (DI). Also a basic question: can drivers actually understand and follow either way, or do they stick to a basic normative driving behavior? This paper summarizes the results after three experimental studies done with a driving simulator. Several performance measures from individual drivers (accelerations, decelerations, average speed, distance to leader, and so on) were taken. As an overall indicator, results consistently announce in the three studies that DI trips consume less fuel (about 20%) than DD ones.Blanch Micó, MT.; Lucas Alba, A.; Bellés Rivera, T.; Ferruz Gracia, AM.; Melchor-Galán, Ó.; Delgado Pastor, L.; Ruíz Jimenez, F.... (2016). CAR FOLLOWING TECHNIQUES: THE ROLE OF THE HUMAN FACTOR RECONSIDERED. En XII Congreso de ingeniería del transporte. 7, 8 y 9 de Junio, Valencia (España). Editorial Universitat Politècnica de València. 851-858. https://doi.org/10.4995/CIT2016.2015.3341OCS85185

Optimización heurística de la asignación de canales en redes WIFI

A planning tool that combines the strengths of a propagation prediction tool, CINDOOR, and a particle swarm optimization algorithm (PSO) is presented in this work when applied to optimize wireless networks resources prior to their deployment. For an arbitrary scenario, the approach proposed performs channel allocation, choosing the best set of access points (AP) to be used, including their activation or deactivation to meet a required quality of service (QoS). The CINDOOR software tool provides the heuristic method with data regarding the signal level and delay at each potential receiver point inside a meshed area, associated with any of the potential AP considered. Then, a stochastic binary PSO algorithm is used to meet the following requirements altogether: minimize the interference, maximize the signal-to-interference ratio (SIR) and activate as few AP as possible to maximize the coverage area and reduce interferences. Representative results are included, showing the usefulness of the approach proposed for a real wireless network, considering a certain QoS

Point-of-care lung ultrasound assessment for risk stratification and therapy guiding in COVID-19 patients. A prospective non-interventional study.

Background Lung ultrasound is feasible for assessing lung injury caused by coronavirus disease 2019 (COVID-19). However, the prognostic meaning and time-line changes of lung injury assessed by lung ultrasound in COVID-19 hospitalised patients are unknown. Methods Prospective cohort study designed to analyse prognostic value of lung ultrasound in COVID-19 patients by using a quantitative scale (lung ultrasound Zaragoza (LUZ)-score) during the first 72 h after admission. The primary end-point was in-hospital death and/or admission to the intensive care unit. Total length of hospital stay, increase of oxygen flow and escalation of medical treatment during the first 72 h were secondary end-points. Results 130 patients were included in the final analysis; mean±sd age was 56.7±13.5 years. Median (interquartile range) time from the beginning of symptoms to admission was 6 (4–9) days. Lung injury assessed by LUZ-score did not differ during the first 72 h (21 (16–26) points at admission versus 20 (16–27) points at 72 h; p=0.183). In univariable logistic regression analysis, estimated arterial oxygen tension/inspiratory oxygen fraction ratio (PAFI) (hazard ratio 0.99, 95% CI 0.98–0.99; p=0.027) and LUZ-score >22 points (5.45, 1.42–20.90; p=0.013) were predictors for the primary end-point. Conclusions LUZ-score is an easy, simple and fast point-of-care ultrasound tool to identify patients with severe lung injury due to COVID-19, upon admission. Baseline score is predictive of severity along the whole period of hospitalisation. The score facilitates early implementation or intensification of treatment for COVID-19 infection. LUZ-score may be combined with clinical variables (as estimated by PAFI) to further refine risk stratification

Neck circumference and clustered cardiovascular risk factors in children and adolescents: Cross-sectional study.

OBJECTIVE: Early detection of cardiovascular disease (CVD) risk factors, such as obesity, is crucial to prevent adverse long-term effects on individuals' health. Therefore, the aims were: (1) to explore the robustness of neck circumference (NC) as a predictor of CVD and examine its association with numerous anthropometric and body composition indices and (2) to release sex and age-specific NC cut-off values to classify youths as overweight/obese. DESIGN: Cross-sectional study. SETTING: 23 primary schools and 17 secondary schools from Spain. PARTICIPANTS: 2198 students (1060 girls), grades 1-4 and 7-10. MEASURES: Pubertal development, anthropometric and body composition indices, systolic and diastolic blood pressure (SBP and DBP, respectively), cardiorespiratory fitness, blood sampling triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), glucose and inflammatory markers. Homoeostasis model assessment (HOMA-IR) and cluster of CVD risk factors were calculated. RESULTS: NC was negatively associated with maximum oxygen consumption (R2=0.231, P<0.001 for boys; R2=0.018, P<0.001 for girls) and adiponectin (R2=0.049, P<0.001 for boys; R2=0.036, P<0.001 for girls); and positively associated with SBP, DBP, TC/HDL-c, TG, HOMA, complement factors C-3 and C-4, leptin and clustered CVD risk factor in both sexes (R2 from 0.035 to 0.353, P<0.01 for boys; R2 from 0.024 to 0.215, P<0.001 for girls). Moreover, NC was positively associated with serum C reactive protein and LDL-c only in boys (R2 from 0.013 to 0.055, P<0.05). CONCLUSION: NC is a simple, low-cost and practical screening tool of excess of upper body obesity and CVD risk factors in children and adolescents. Paediatricians can easily use it as a screening tool for overweight/obesity in children and adolescents. For this purpose, sex and age-specific thresholds to classify children and adolescents as normal weight or overweight/obese are provided.This work was supported by the DEP 2010 21662 C04 00 (DEP 2010 21662 C04 01: DEP 2010 21662 C04 02: DEP 2010 21662 C04 03: DEP 2010 21662 C04 04) grant from the National Plan for Research: Development and Innovation (R+D+i) MICINN

Incidencia de la “droga de inicio” en la adicción a otras sustancias

Durante el año 2014, el equipo del IPAD realizó una investigación sobre los efectos del llamado “uso recreativo” de la marihuana. Este trabajo posibilitó nuevos objetivos a investigar: cuál es la incidencia de la droga de inicio, legal o ilegal, en el diagnóstico de trastorno por dependencia a sustancias psicoactivas. Se planteó la necesidad de buscar resultados que nos permitan establecer criterios de prevención a partir de los conocimientos obtenidos. Se realizo una muestreo sobre 109 pacientes con diagnósticos de dependencia y en tratamiento. El 48 % de ellos refieren como sustancias de inicio el alcohol, el 39 % la marihuana y un 9 % la cocaína. El 23% refiere como causal de inicio a “la soledad y a la necesidad de evitar el malestar” (psicológico), como vía alternativa para satisfacer necesidades emocionales y como medio de amortigua rel impacto de una situación vital que no se controla totalmente. Sería una forma de escapar de conflictos familiares o personales, del aislamiento, la pasividad, el aburrimiento, los sentimientos de inferioridad, la depresión, la carencia de apoyos familiares o sociales; mientras que el 55.47%,describe el inicio en el consumo como una forma de repuesta a la sociedad de consumo o presión social; el 21,53% corresponde a otras causas. Estos resultados muestran que los primeros consumos tienen un marcado carácter social, ahí donde lo social desarticula al sujeto transformándolo en objeto. Postulamos a la prevención primaria como una herramienta apropiada y necesaria para restituir lugares de pertenencia, que le posibiliten al hombre un adecuado desarrollo acorde a su cultura, valores y creencias.During 2014 the team of IPAD carried out a research on the effects of the so-called “recreational use” of marijuana. This also enabled to work on new targets to investigate: what is the incidence of initial consumption, legal or illegal, in the diagnosis of substance dependence disorder looking for results that allow us to establish prevention criteria from the knowledge obtained. A sampling of 109 patients in treatment diagnosis of dependence was carried out. 48% of them referred to alcohol as the initial substance, 39% to marijuana and 9% to cocaine. 23% referred to “loneliness and the need to avoid discomfort” (psychological) as the initial cause and as an alternative way to meet emotional needs and as a means to soften the impact of a life situation that is not fully controlled. It would be a way to evade from family or personal conflicts, isolation, passivity, boredom, inferiority feeling, depression, lack of family or social support, while 55,47% describe the initial use as a form of response to the consumer society or social pressure while 21,53% claim other causes.These results show that the first consumption has a strong “social character” where social environment dismantles the subject transforming it into an object. Thus, primary prevention is considered as an appropriate and necessary tool to restore the sense of belonging that will enable a person to reach proper development according to his culture, values and beliefs

Car following: Comparing distance-oriented vs. inertia-oriented driving techniques

The rationale behind most car-following (CF) models is the possibility to appraise and formalize how drivers naturally follow each other. Characterizing and parametrizing Normative Driving Behavior (NDB) became major goals, especially during the last 25 years. Most CF models assumed driver propensity for constant, safe distance is axiomatic. This paper challenges the idea of safety distance as the main parameter defining a unique (or natural) NDB. Instead, it states drivers can adapt to reactive and proactive car following. Drawing on recent CF models close to the Nagoya paradigm and on other phenomena (e.g., wave movement in Nature), we conceived car following by Driving to keep Inertia (DI) as an alternative to Driving to keep Distance (DD). On a driving simulator, three studies (N ¼ 113) based on a repeated-measures experimental design explored the efficiency of these elementary techniques by measuring individual driver performance (e.g., accelerations, decelerations, average speed, distance to leader). Drivers easily grasped and applied either technique and easily switched back and forth between the two. As an overall indicator, all the studies revealed DI trips use about 20% less fuel than DD trips do.Support came from Fundación Universitaria Antonio Gargallo y Obra Social Ibercaja, Spain (grant 2015/B011