Teaching C/C ++ programming using a multimedia system with videos

The C programming language is widely used in computer and industrial engineering. Because of that, such programming language is also widely used as a language to teach programming to industrial engineering students. In Spain, many universities use this language compulsory in the first year, or even in higher courses. Our experience shows that learning computer programming in four months is an arduous task, but curricula require it. Such learning process is also tough by the fact that many students cannot attend classes regularly and, even if they attend, sometimes the class is no longer at the level they require. In this work we develop a series of files in "presentation" format (.ppsx) and videos that allow students to see several explanations about the most complicated programming C topics: functions, arrays, structures, strings, arrays with structures, etc. This multimedia material includes explanations (voice-over), and animations with examples. Students can watch and listen to the explanations whenever and wherever they want (tablet, PC, phone…). Surveys made to students reveal that it is also interesting for students who regularly attend classes, and they prefer to use this course material only at home, outside of regular classes.El lenguaje de programación C se utiliza mucho en informática e ingeniería industrial. Por tanto, dicho lenguaje de programación también se utiliza mucho como lenguaje para enseñar programación a estudiantes de ingeniería industrial. En España, muchas universidades usan este lenguaje de forma obligatoria durante el primer año, o incluso en cursos superiores. Nuestra experiencia indica que aprender programación de computadoras en cuatro meses es una tarea ardua, pero los currículos lo requieren. Tal proceso de aprendizaje también es difícil por el hecho de que muchos estudiantes no pueden asistir a clases regularmente e, incluso si asisten, a veces la clase ya no está en el nivel que requieren. En este trabajo desarrollamos una serie de archivos en formato de "presentación" (.ppsx) y videos que permiten a los estudiantes ver varias explicaciones sobre los temas de programación C más complicados: funciones, matrices, estructuras, cadenas, matrices con estructuras, etc. El material multimedia incluye explicaciones (voz en off) y animaciones con ejemplos. Los estudiantes pueden ver y escuchar las explicaciones cuando y donde quieran (tableta, PC, teléfono, etc.). Las encuestas realizadas revelan que también es interesante para los estudiantes que asisten regularmente a clases, y que prefieren usar este material del curso solo en casa, fuera de las clases regulares

Optimization of the thermal storage system in a solar-driven refrigeration system equipped with an adjustable jet-ejector

[EN] The present paper shows a numerical research about the influence of different thermal storage capacities and thermal power consumption strategies in a solar-driven air-conditioning system operating with refrigerant R1234yf. The computational model is fed with hourly climatic data (solar irradiance and ambient temperature) of the typical meteorological year of a Mediterranean location. A special focus is put on the dynamic response of the refrigeration system, the solar collector, and the sensible heat storage tank. Since the refrigeration needs are nearly synchronized with the sunny hours, small tank volumes are the most convenient architecture to achieve a rapid heating-up after tank discharges. For a parabolic trough collector span of 7.1 m, 13.3 kW of thermal power consumption represents a reasonable trade-off between the main performance indicators, mainly, the refrigeration capacity, COPth (thermal coefficient of performance) and the system's capability to operate properly ensuring an adequate thermal level in the heat reservoir.Authors want to acknowledge to the institution Conselleria dInnovacio, Universitats, Ciencia i Societat Digital de la Generalitat Valenciana for the public aid granted in the research project AICO/2021/124) .Luján, JM.; Galindo, J.; Dolz, V.; Ponce-Mora, A. (2022). Optimization of the thermal storage system in a solar-driven refrigeration system equipped with an adjustable jet-ejector. Journal of Energy Storage. 45:1-12. https://doi.org/10.1016/j.est.2021.1034951124

A New Model for Matching Advanced Boosting Systems to Automotive Diesel Engines

[EN] Boosting technologies have been key enablers for automotive engines development through downsizing and downspeeding. In this situation, numerous multistage boosting systems have appeared in the last decade. The complexity arising from multistage architectures requires an efficient matching methodology to obtain the best overall powertrain performance. The paper presents a model aimed to choose the best 2-stage boosting system architecture able to meet required criteria on boosting pressure, EGR ratios for both short and long route loops while respecting the engine thermo-mechanical limits such as in-cylinder pressure, compressor outlet temperature and exhaust manifold temperature. The model includes filling-and-emptying 0D elements together with mean value. The engine model is set in a way that, for given requirements and boosting system layout, calculates in seconds if the requirements will be achieved and the position of variable geometry, waste-gate, EGR and by-pass valves. The model is thus inversed thanks to a new representation of turbine maps that converts the classical iterative matching procedure in straight forward. The model can be also used in a predictive manner to calculate the engine transient response. The model has been calibrated to 3 different turbocharged diesel engines. The model gives good results provided that wave effects are not important. This is the case of compact exhaust manifolds, typically used in turbocharged diesel engines, below 3500 rpm. Tuned intake air lines can be taken into account through a tuning parameter affecting boosting pressure. An example is given in the paper for the matching procedure in a 2-stage, double route EGR, including steady and transient results.This work has been partially financed by the Univeristat Politècnica de València through the Programa de Apoyo a la Investigación y Desarrollo 2012, project PAID-06-2012 DECOAH.Galindo, J.; Luján, JM.; Climent, H.; Guardiola, C.; Varnier, O. (2014). A New Model for Matching Advanced Boosting Systems to Automotive Diesel Engines. SAE International Journal of Engines. 7(1):1-14. https://doi.org/10.4271/2014-01-1078S1147

Las plantas como evidencia legal. Desarrollo de la Botánica Forense en Colombia

La botánica aporta información de gran importancia en el ámbito forense para el estudio de la escena de los hechos en los procesos de investigación judicial. En Colombia, desde comienzos de siglo XX se vienen realizando solicitudes judiciales para determinar, la causa de muerte por ingestión de plantas tóxicas y más recientemente la identificación de elementos materia de prueba procedentes de los cultivos ilícitos. Acá se muestra el estado del tema en el país, con base en los registros oficiales del Instituto Nacional de Medicina Legal y Ciencias Forenses y del Instituto de Ciencias Naturales de la Universidad Nacional de Colombia, que reflejan un incremento de las solicitudes judiciales referentes a plantas de coca, amapola y marihuana. Se presentan algunos avances y perspectivas sobre el tema y se tratan las principales plantas de interés forense y algunos aspectos sobre protocolos de recolección, tratamiento e identificación de muestras.Peer reviewe

Second and higher-order perturbations of a spherical spacetime

The Gerlach and Sengupta (GS) formalism of coordinate-invariant, first-order, spherical and nonspherical perturbations around an arbitrary spherical spacetime is generalized to higher orders, focusing on second-order perturbation theory. The GS harmonics are generalized to an arbitrary number of indices on the unit sphere and a formula is given for their products. The formalism is optimized for its implementation in a computer algebra system, something that becomes essential in practice given the size and complexity of the equations. All evolution equations for the second-order perturbations, as well as the conservation equations for the energy-momentum tensor at this perturbation order, are given in covariant form, in Regge-Wheeler gauge.Comment: Accepted for publication in Physical Review

Validation and sensitivity analysis of an in-flow water condensation model for 3D-CFD simulations of humid air streams mixing

[EN] The mixing of gaseous streams at different humidity and temperature conditions may generate bulk con- densation, which is a particular thermodynamic process that usually implies a great computational effort. A model that provides in-flow condensation predictions without heavily impacting on the simulation time becomes a potential tool for studying situations where the presence of water droplets is a problem. For instance, in a Long- Route Exhaust Gas Recirculation (LR-EGR) system, intake fresh air is mixed with humid and hot exhaust gases, generating water droplets that may impact on the turbo-compressor impeller and produce harmful erosion. Serrano et al. [1] developed a condensation submodel for such purpose. In this work, the 3D CFD methodology is analyzed by means of sensitivity studies on the numerical setup and intake throttle valve angle. Validation of the model is addressed by means of measurements in a fully instrumented continuous flow turbocharger test bench, obtaining quantitative and qualitative agreement. Particularly, a consistent correlation was found between predicted condensation rate and the impeller damage for seven LR-EGR configurations. Moreover, the T-joint geometry is noticed to have a great impact on condensation generation, thus showing the potential of such a 3D model for improving the LR-EGR design.Daniel Tari is partially supported through contract FPI-S2-2015-1095 of Programa de Apoyo para la Investigacion y Desarrollo (PAID) of Universitat Politecnica de Valencia.Galindo, J.; Piqueras, P.; Navarro, R.; Tarí, D.; Meano, CM. (2019). Validation and sensitivity analysis of an in-flow water condensation model for 3D-CFD simulations of humid air streams mixing. International Journal of Thermal Sciences. 136:410-419. https://doi.org/10.1016/j.ijthermalsci.2018.10.043S41041913

Molecular identification of Cordylobia anthropophaga Blanchard (Diptera: Calliphoridae) larvae collected from dogs (Canis familiaris) in Jos South, Plateau State, Nigeria

This work is licensed under the Creative Commons Attribution License.-- et al.Myiasis-causing larvae were extracted from dogs attending veterinary clinics in Plateau State, Nigeria and subjected to molecular analysis involving polymerase chain reaction amplification of the 28S rRNA gene of blowflies, cloning and sequencing techniques. All larvae were confirmed as Cordylobia anthropophaga Blanchard (Diptera: Calliphoridae) after the initial morphological identification. This is the first molecular identification of any myiasis-causing fly species in Nigeria and may serve as a reliable alternative to morphological identification where samples are not well preserved or difficult to identify to species level.We thank at the Instituto de Investigacion en Recursos Cinegiticos, IREC (CSIC-UCLM-JCCM), Ciudad Real, Spain for providing the facilities to carry out this research.Peer Reviewe

Anxiety as a stigma: The stereotype of the anxious person in the clinical, health-care professional, and general population

El objetivo principal de esta investigación fue la evaluación de la teoría implícita o estereotipo que diferentes grupos de población tienen de las personas con ansiedad clínica. Para ello se administró un listado de adjetivos para la heteroevaluación de la persona ansiosa a un total de 400 participantes, distribuidos en cuatro grupos: pacientes con trastorno de ansiedad, población general, médicos y diplomados en enfermería. A los pacientes ansiosos se les volvió a administrar el listado de adjetivos para su autoevaluación. Se llevó a cabo un estudio descriptivo mediante la prueba de χ2 para determinar las diferencias entre grupos en relación a los adjetivos más utilizados. Seguidamente se realizaron dos ANOVAs para establecer diferencias entre grupos a partir de la hetero-evaluación y para comprobar si había diferencias entre la heteroevaluación y la autoevaluación de las personas con trastornos de ansiedad. Los resultados muestran diferencias en la percepción de las personas ansiosas por parte de los 4 grupos; pero solo en el grupo general se detectan creencias prejuiciosas en el estereotipo que muestran de las personas ansiosas. Dichos hallazgos ponen de manifiesto las diferencias en los estereotipos de cada población referentes a las personas con ansiedad clínicaThe implicit theory or stereotype of anxious personality was assessed in different samples. A list of adjectives was administered for hetero-evaluation to 400 participants, divided into four groups: Patients with anxiety dicorders, general population, doctors, and nurses. Anxious patients were re-administered the list of adjectives for self-evaluation. A descriptive study was conducted using χ2 to discriminate the adjectives used between groups. Two ANOVAs were performed to establish differences between groups from hetero-evaluation and to test the presence of differences between the hetero- and the self-evaluation. Results showed the existence of differences between the clinically anxious group, the group of doctors and the group of nurses in the stereotype of anxious individuals, although no evidence of stigma was found. However, the general population group showed a perceptual bias of anxious individuals, which may indicate readiness to stigmatize these patients

EBSD texture analysis of an AlCuMg alloy for different solidification rates

The 3xx series aluminium alloys are widely used for automotive applications. However, increments in engine power density result in higher alloy mechanical properties requirements for components such as cylinder heads. These alloys should perform better at high temperatures (>200 °C). A good alternative to the traditional Al-Si alloys are the Al- Cu based alloys. However, hot tear tendency is a big obstacle for the widespread use of this family of alloys [1]. The present work focus on determine the relationship between crack occurrence and grain orientation, as a result of the solidification rate. Grain refinement elements such as Ti and Zn are added to the alloy to reduce hot tearing tendency. Two different variants of AlCuMg alloy are evaluated at different solidification rates.Postprint (published version