305 research outputs found

    Importancia de los conceptos en el aprendizaje de la mecánica

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    The difficulties that students have in the process of learning physics is owing to different factors. We want to emphasize the preponderant role of adequate understanding of concepts in the understanding of the physical world. Physics is based on models, laws, theories, principles, postulates, which have a conceptual outline that, if well understood and applied, will substantially improve the learning of this science.Las dificultades que tienen los estudiantes en el aprendizaje de la Física, se deben a diferentes factores. Queremos hacer hincapié en el papel preponderante que tiene la comprensión adecuada de los conceptos en el entendimiento del mundo físico. La Física se fundamenta en modelos, leyes, teorías, principios, postulados, los cuales tienen anexo un esquema conceptual que, si es bien entendido y aplicado mejorará sustancialmente el aprendizaje de esta ciencia

    Learning of the Object Oriented Paradigm Through Interactive Video-Games Development

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    The Object Orientation Paradigm (OOP) is more than Object Oriented languages. Learning the syntax of a language as C++ or Java is a relatively easy task compared with the understanding of the principles of OO Modeling and Design (OOD), which require a high ability of abstract reasoning. Moreover, it is not enough to teach the artifacts of Computer Aided Software Engineering (CASE) as the Unified Modeling Language (UML) if those principles are not properly understood. We wanted to engage the students in a motivating framework, so both the principles of OOD are properly acquired and put in practice with CASE and programming tools

    Espectroscopia. fundamento de la resonancia magnética nuclear

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    Presentamos una introducción al fenómeno de la espectroscopia, su significado y los principios físicos básicos involucrados en el proceso de absorción y emisión de  radiación que posee una capacidad suficiente para perturbar las condiciones de equilibrio de un átomo. Explicamos  el principio de operación de un espectrómetro sencillo y  analizamos la espectroscopia de resonancia magnética nuclear (RMN) una de las herramientas más poderosas con que cuenta la Medicina moderna para detectar ciertos desequilibrios en la estructura y configuración molecular.AbstractWe present an introduction to the phenomenon of spectroscopy.Its meaning and the basic physical principles involve the process of absorption and emission of radiation that possess enough capacity to perturb the conditions of equilibrium of an atom. We explain the principle of operation of a simple spectrometer and analyze the spectroscopy of nuclear magnetic resonance (NMR). It is one of the most powerful tools available to modern medicine to detect certain imbalances in the structure and molecular configuration

    Advanced data acquisition system implementation for the ITER Neutron Diagnostic use case using EPICS and FlexRIO technology on a PXIe platform

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    In the framework of the ITER Control Breakdown Structure (CBS), Plant System Instrumentation & Control (I&C) defines the hardware and software required to control one or more plant systems [1]. For diagnostics, most of the complex Plant System I&C are to be delivered by ITER Domestic Agencies (DAs). As an example for the DAs, ITER Organization (IO) has developed several use cases for diagnostics Plant System I&C that fully comply with guidelines presented in the Plant Control Design Handbook (PCDH) [2]. One such use case is for neutron diagnostics, specifically the Fission Chamber (FC), which is responsible for delivering time-resolved measurements of neutron source strength and fusion power to aid in assessing the functional performance of ITER [3]. ITER will deploy four Fission Chamber units, each consisting of three individual FC detectors. Two of these detectors contain Uranium 235 for Neutron detection, while a third "dummy" detector will provide gamma and noise detection. The neutron flux from each MFC is measured by the three methods: . Counting Mode: measures the number of individual pulses and their location in the record. Pulse parameters (threshold and width) are user configurable. . Campbelling Mode (Mean Square Voltage): measures the RMS deviation in signal amplitude from its average value. .Current Mode: integrates the signal amplitude over the measurement perio

    Effects of transcranial static magnetic field stimulation over the left dorsolateral prefrontal cortex on random number generation

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    OBJECTIVE: Focal application of transcranial static magnetic field stimulation (tSMS) is a neuromodulation technique, with predominantly inhibitory effects when applied to the motor, somatosensory or visual cortex. Whether this approach can also transiently interact with dorsolateral prefrontal cortex (DLPFC) function remains unclear. The suppression of habitual or competitive responses is one of the core executive functions linked to DLPFC function. This study aimed to assess the impact of tSMS on the prefrontal contributions to inhibitory control and response selection by means of a RNG task. METHODS: We applied 20 min of tSMS over the left DLPFC of healthy subjects, using a real/sham cross-over design, during performance of a RNG task. We used an index of randomness calculated with the measures of entropy and correlation to assess the impact of stimulation on DLPFC function. RESULTS: The randomness index of the sequences generated during the tSMS intervention was significantly higher compared to those produced in the sham condition. CONCLUSIONS: Our results indicate that application of tSMS transiently modulates specific functional brain networks in DLPFC, which indicate a potential use of tSMS for treatment of neuropsychiatric disorders. SIGNIFICANCE: This study provides evidence for the capacity of tSMS for modulating DLPFC function

    Proyecto PREDIRCAM 2. Análisis preliminar de uso y valoración de la plataforma

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    En la actualidad, la prevalencia de las enfermedades no transmisibles (Non-communicable diseases NCD) y la cantidad de muertes causadas por éstas es muy elevada, en su mayoría, consecuencia del envejecimiento de la población, el aumento de la obesidad y los hábitos de vida sedentarios. En este trabajo se describen el funcionamiento y los resultados preliminares del proyecto Predircam 2, destinado al desarrollo y validación de una plataforma inteligente de tecnologías biomédicas para la monitorización, prevención y tratamiento personalizados del sobrepeso, la obesidad y la prevención de enfermedades asociadas como la diabetes, hipertensión arterial o alteraciones del metabolismo lipídico. El objetivo de este trabajo es presentar los resultados preliminares del análisis del uso de la plataforma, la evaluación de la usabilidad y la valoración de la atención recibida por los pacientes en relación a los profesionales sanitarios

    Assessing microplastic ingestion and occurrence of bisphenols and phthalates in bivalves, fish and holothurians from a Mediterranean marine protected area

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    Microplastic (MP) ingestion, along with accumulated plasticizers such as bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS), and phthalates represented by diethyl phthalate (DEP), dibutyl phthalate (DBP) and bis (2-ethylhexyl) phthalate (DEHP), were quantified in bivalves, fish, and holothurians collected from a coastal pristine area at the western Mediterranean Sea. MP ingestion in sediment-feeders holothurians (mean value 12.67 ± 7.31 MPs/individual) was statistically higher than ingestion in bivalves and fish (mean 4.83 ± 5.35 and 3 ± 4.44 MPs/individual, respectively). The main ingested polymers were polyethylene, polypropylene, and polystyrene. The levels of BPS, BPF, and DEHP were highest in bivalves' soft tissue; BPA and DBP had the highest levels in the holothurians’ muscle. In addition, the levels of all plasticizers assessed were lowest in fish muscle; only BPA levels in fish were higher than in bivalves, with intermediate values between those of bivalves and holothurians. This study provides data on exposure to MPs and plasticizers of different species inhabiting Cabrera Marine Protected Area (MPA) and highlights the differences in MP ingestion and levels of plasticizers between species with different ecological characteristics and feeding strategies.En prensa3,39

    LEARNING OF THE OBJECT ORIENTED PARADIGM THROUGH INTERACTIVE VIDEO-GAMES DEVELOPMENT

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    Abstract The Object Orientation Paradigm (OOP) is more than Object Oriented languages. Learning the syntax of a language as C++ or Java is a relatively easy task compared with the understanding of the principles of OO Modeling and Design (OOD), which require a high ability of abstract reasoning. Moreover, it is not enough to teach the artifacts of Computer Aided Software Engineering (CASE) as the Unified Modeling Language (UML) if those principles are not properly understood. We wanted to engage the students in a motivating framework, so both the principles of OOD are properly acquired and put in practice with CASE and programming tools. We found the ideal framework in the development of videogames. Most students are familiar with (even attracted by) them. The existence of powerful yet simple 3D graphical libraries as OpenGL and the portable Window Manager (GLUT), makes very easy the development of quite attractive 3D applications, so the real effort can be done in the OOP. There are two types of games: those with physical simulations (first person shooters, car race, arcade games) and those with logical or reasoning (chess, 4 on a line, etc). Though the second type is interesting, physical systems can be more easily understood and modeled under OOP, because the software and design objects have an equivalent counterpart in the real world. Furthermore physical systems have the added benefit of involving kinematics, dynamics, math, and other disciplines very interesting for the engineering student. At Universidad Politecnica de Madrid, we teach Industrial Informatics which covers both the topics of C++ programming and OOP, starting from a basic knowledge of C language. The subject is taught with 3 hours of C++ theory, 2 hours of OOP theory and 2 hours of practice per week, along a semester, plus a compulsory assignment to be accomplished by the students. We decided to propose the development of a video-game to be carried out along the semester, by groups consisting of two students. Taking into account the required effort, we also decide to restructure the subject around this idea. The practical lessons have been completely modified, leading the student from one practical lesson to the next one in an incremental development of a typical arcade videogame: Pang, in which a player shoots to balls bouncing around the screen. Our focus is the OOP: the application is iteratively built following OOP principles: object creation and destruction, object interaction, relations between classes, GRASP and GOF software patterns, etc. CASE tools and UML are constantly used in this process, in order to support the ideas that motivate our final implementation. The theory and tutorial hours have been also affected: The tutorial time has highly increased, basically overwhelming our capacity. This fact also contributes to the actual understanding of the subject. The theory lessons find the support on the video-games development and practical lessons, making easier for the students to understand the abstract ideas explained in class. We are convinced about the effectiveness of our approach. The motivation of the students has become clearly visible, both in the tutorial lessons and in the high quality of the developed games. The students' grades have clearly improved, not only because of the contribution of the good grades of the game assignment, but also because the understanding of the concepts and the increase of hours dedicated to practical developments

    Local Constraints on the Oscillating G Model

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    We analyze the observational constraints on the effective Brans-Dicke parameter and on the temporal variation of the effective gravitational constant within the context of the oscillating G model, a cosmological model based on a massive scalar field non-minimally coupled to gravity. We show that these local constraints cannot be satisfied simultaneously once the values of the free parameters entering the model become fixed by the global attributes of our Universe. In particular, we show that the lower observational bound for the effective Brans-Dicke parameter and the upper bound of the variation of the effective gravitational constant lead to a specific value of the oscillation amplitude which lies well below the value required to explain the periodicity of 128 Mpc h^{-1} in the galaxy distribution observed in the pencil beam surveys.Comment: PRD, subm., 12 pages, 1 figur

    Evaluation of turbulent dissipation rate retrievals from Doppler Cloud Radar

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    Turbulent dissipation rate retrievals from cloud radar Doppler velocity measurements are evaluated using independent, in situ observations in Arctic stratocumulus clouds. In situ validation data sets of dissipation rate are derived using sonic anemometer measurements from a tethered balloon and high frequency pressure variation observations from a research aircraft, both flown in proximity to stationary, ground-based radars. Modest biases are found among the data sets in particularly low- or high-turbulence regimes, but in general the radar-retrieved values correspond well with the in situ measurements. Root mean square differences are typically a factor of 4-6 relative to any given magnitude of dissipation rate. These differences are no larger than those found when comparing dissipation rates computed from tetheredballoon and meteorological tower-mounted sonic anemometer measurements made at spatial distances of a few hundred meters. Temporal lag analyses suggest that approximately half of the observed differences are due to spatial sampling considerations, such that the anticipated radar-based retrieval uncertainty is on the order of a factor of 2-3. Moreover, radar retrievals are clearly able to capture the vertical dissipation rate structure observed by the in situ sensors, while offering substantially more information on the time variability of turbulence profiles. Together these evaluations indicate that radar-based retrievals can, at a minimum, be used to determine the vertical structure of turbulence in Arctic stratocumulus clouds
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