La motivación de logro y el rendimiento académico en el área de educación física, I.E.P. “Hno. Noé Zevallos Ortega”, Lima-2019

La presente investigación denominada la motivación de logro y el rendimiento académico en el área de educación física, I.E.P. “Hno. Noé Zevallos Ortega”, Lima- 2019, se ha realizado con la finalidad de determinar la relación entre las dos variables. El estudio corresponde al tipo descriptivo correlacional, con diseño no experimental. Se ha utilizado el método hipotético deductivo con la finalidad de poder indagar sobre estas variables en el área de educación física. La población estuvo conformada por 100 estudiantes, de 3ero, 4to y 5to de secundaria con 35, 33 y 32 alumnos respectivamente. Se ha adaptado el Test de AMPET como instrumento de recolección de información sobre la motivación de logro y para el rendimiento académico los datos se han obtenido de los registros de notas. La adaptación del Test ha sido validada por expertos y sometida a la prueba de confiabilidad de alfa de Cronbach. Se observa que, de la población estudiada, el 52% de los alumnos se encuentran en un nivel de proceso, en lo que corresponde al calificativo de los aprendizajes, el 47% en logro esperado, un 1% en inicio y un 0% en logro destacado. Es decir, que la mayoría de los estudiantes están en un nivel que requiere un seguimiento más detallo del docente para conseguir los objetivos propuestos. Asimismo, se llega a la conclusión que la motivación de logro se relaciona con el rendimiento académico en el área de educación física y así como también con sus dimensiones de esta variable

Stability analysis for dusty plasma under grain charge fluctuations due to non-Maxwellian electron distributions

The most relevant characteristic of a complex plasma is the dust charge as well as the dust charging process itself which controls different collective and individual behaviors of the plasma. The dust charging has been exhaustively studied providing several theoretical approaches that have improved the early Orbital Motion Limited (OML) description [1, 2]. The OML is considered as a suitable model and, at least, it provides a certain perspective of the main plasma parameters involved in the charging processes. Recent works have stressed the importance of the electron and ion velocity distribution functions in addressing the description of plasma stability analysis under the frame of plasma fluid description, including dust charge fluctuations. The consideration of non-Maxwellian distribution functions has been proved to induce plasma departures from the usual Maxwellian equilibrium, specially under the development of intense electric fields that can accelerate charges till superthermal velocities [3]. In these cases, the distribution function tails fit well to a power-law dependence even for electrons. In this communication, we devote attention to the effect of non Maxwellian electron distribution functions on the collective plasma behavior through a linear analysis of perturbed fluid equations. The stability of a partially ionized complex plasma with a non Maxwellian electron population is studied by including this feature on the dust charge fluctuation for infinite and finite dust grain mass

A Low-Cost Modular Platform for Heterogeneous Data Acquisition with Accurate Interchannel Synchronization

Most experimental fields of science and engineering require the use of data acquisition systems (DAQ), devices in charge of sampling and converting electrical signals into digital data and, typically, performing all of the required signal preconditioning. Since commercial DAQ systems are normally focused on specific types of sensors and actuators, systems engineers may need to employ mutually-incompatible hardware from different manufacturers in applications demanding heterogeneous inputs and outputs, such as small-signal analog inputs, differential quadrature rotatory encoders or variable current outputs. A common undesirable side effect of heterogeneous DAQ hardware is the lack of an accurate synchronization between samples captured by each device. To solve such a problem with low-cost hardware, we present a novel modular DAQ architecture comprising a base board and a set of interchangeable modules. Our main design goal is the ability to sample all sources at predictable, fixed sampling frequencies, with a reduced synchronization mismatch (<1 s) between heterogeneous signal sources. We present experiments in the field of mechanical engineering, illustrating vibration spectrum analyses from piezoelectric accelerometers and, as a novelty in these kinds of experiments, the spectrum of quadrature encoder signals. Part of the design and software will be publicly released online

Predictive value and dynamic risk stratification of high sensitive basal or stimulated thyroglobulin assay in a long-term thyroid carcinoma cohort

Producción CientíficaPurpose: To evaluate the predictive value of the rhTSH thyroglobulin stimulation test (rhTSH-Tg) compared to basal high- sensitive thyroglobulin (hs-Tg) under TSH suppressive therapy at 12 months after the completion of initial treatment to predict the long-term response and Dynamic Risk Stratification (DRS) at the last follow-up visit in a long-term DTC cohort. Methods: Prospective study in 114 DTC patients (77.2% women, mean age 46.4 ± 14.1 years old, median/IQR evolution 6.7[3.1–8.0] years) from 2013 to 2020 undergoing total thyroidectomy and radioiodine ablation in whom hs-Tg and rhTSH- Tg was performed 12 months after completing initial treatment. Pearson correlation, receiving operating characteristics (ROC) and DRS at initial and last follow-up visit were analyzed. Results: hs-Tg and rhTSH-Tg show a strong positive linear correlation (r = 0.864, p < 0.001). The diagnostic performance of initial hs-Tg and rhTSH-Tg levels were evaluated via ROC-AUC as a predictor of excellent response (ER) in the last follow-up visit. Hs-Tg showed a better AUC (0.969, 95%CI = 0.941–0.997) than rhTSH-Tg (0.944, 95%IC = 0.905–0.984; p < 0.001). The hs-Tg and rhTSH-Tg cutoff point of highest sensitivity (S) and specificity (E) was 0.110 and 0.815 ng/dl, respectively. Hs-Tg showed a higher diagnostic accuracy than rhTSH-Tg (S = 100% vs 96.8%, E = 84.3% vs 84.3%, NPV = 100% vs 98.6%, PPV = 70.5% vs 69.7%; p < 0.05). The DRS based on initial hs-Tg showed better ability to predict ER (93.3% vs 86.7%) and biochemical incomplete response (53.3%vs13.3%) in the last follow-up visit compared to rhTSH-Tg. Conclusions: Both initial hs-Th and rhTSH-Tg were good predictors of long-term ER. In patients with hs-Tg, the rhTSH-test did not provide relevant prognosis information. An ER after initial treatment was associated with a very high NPV at subsequent follow-up.Publicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL

Detection of eccentricity faults in five-phase ferrite-PM assisted synchronous reluctance machines

Air gap eccentricity faults in five-phase ferrite-assisted synchronous reluctance motors (fPMa-SynRMs) tend to distort the magnetic flux in the air gap, which in turn affects the spectral content of both the stator currents and the ZSVC (zero-sequence voltage component). However, there is a lack of research works dealing with the topic of fault diagnosis in multi-phase PMa-SynRMs, and in particular, focused to detect eccentricity faults. The analysis of the spectral components of the line currents and the ZSVC, allows developing fault diagnosis algorithms to detect eccentricity faults. The effect of the operating conditions is also analyzed, since this paper shows that it has a non-negligible impact on the effectivity and sensitivity of the diagnosis based on the analysis of the stator currents and the ZSVC. To this end, different operating conditions are analyzed. The paper also evaluates the influence of the operating conditions on the harmonic content of the line currents and the ZSVC, and determines the most suitable operating conditions to enhance the sensitivity of the analyzed methods. Finally, fault indicators to detect eccentricity faults, which are based on the spectral content of the stator currents and the ZSVC are derived, and their performance is assessed. The approach presented in this work may be useful to develop fault diagnosis strategies based on the acquisition and subsequent analysis and interpretation of the spectral content of the line currents and the ZSVC.Peer ReviewedPostprint (published version

Simplified sensor design for temperature-strain discrimination using Fiber Bragg Gratings embedded in laminated composites

Several easy-to-manufacture designs based on a pair of Fiber Bragg Gratings structure embedded in Carbon Fiber Reinforced Plastic (CFRP) have been explored. These smart composites can be used for strain and temperature discrimination. A Finite Elements Analysis and Matlab software were used to study the mechanical responses and its optical behaviors. The results exhibited different sensitivity and using a matrix method it is possible to compensate the thermal drift in a real application keeping a simple manufacture process

Screen Printed Flexible Radiofrequency Identification Tag for Oxygen Monitoring

In this work, a radiofrequency identification (RFID) tag with an optical indicator for the measurement of gaseous oxygen is described. It consists of an O2 sensing membrane of PtOEP together with a full electronic system for RFID communication, all printed on a flexible substrate. The membrane is excited by an LED at 385 nm wavelength and the intensity of the luminescence generated is registered by means of a digital color detector. The output data corresponding to the red coordinate of the RGB color space is directly related to the concentration of O2, and it is sent to a microcontroller. The RFID tag is designed and implemented by screen printing on a flexible substrate for the wireless transmission of the measurement to a remote reader. It can operate in both active and passive mode, obtaining the power supply from the electromagnetic waves of the RFID reader or from a small battery, respectively. This system has been fully characterized and calibrated including temperature drifts, showing a high-resolution performance that allows measurement of very low values of oxygen content. Therefore this system is perfectly suitable for its use in modified atmosphere packaging where the oxygen concentration is reduced below 2%. As the reading of the O2 concentration inside the envelope is carried out with an external RFID reader using wireless communication, there is no need for perforations for probes or wires, so the packaging remains completely closed. With the presented device, a limit of detection of 40 ppm and a resolution as low as 0.1 ppm of O2 can be reached with a low power consumption of 3.55 mA.Junta de Andalucía (Proyecto de Excelencia P10-TIC-5997 and P10-FQM-5974)Project PYR-2012-12, CEI BioTIC (CEB09-0010 and CEI2013-P-2) from CEI program of MICINNEuropean Regional Development Funds (ERDF

Optimization of sulfuric acid hydrolysis conditions for preparation of nanocrystalline cellulose from enzymatically pretreated fibers

NCC preparation using sulfuric acid hydrolysis from cellulase pretreated fibers was optimized in order to obtain the highest possible yield with 62% and 65% wt. sulfuric acid throughout two statistical plans. At optimal conditions (10U/g odp cellulase, 25 min hydrolysis, 47 ºC and 62 % wt. H2SO4) high yields were obtained (=80%) including an increase produced by enzyme of ~9 %. Optimal conditions produced nanosized particles of around ~200 nm with a reduced surface charge and sulfur content. The performed optimization allowed reducing the hydrolysis time in a 44%, and also increasing yield in more than 10% compared to results exposed in previous works. The effects of cellulase pretreatment were noticeable even under aggressive hydrolysis conditions, emphasizing its possibilities. Zeta potential and polydispersity indexes indicated that all studied conditions leaded to good quality final products, with values among -50 mV and 0.2, respectively. TEM analysis confirmed the presence of NCC and suggested morphological differences between samples. Finally FTIR analysis provided evidence that cellulase treatment increased crystallinity of both cellulose fibers and NCC, and also increased accessibility to fibers, supporting data obtained from NCCPostprint (author's final draft

A straightforward bioprocess for a cleaner paper decolorization

A new biotechnological sequence for decolorizing red and black colored paper was developed to reduce the environmental impact of the chemicals used in paper recycling processes. Commercially available low-redox potential laccase from Myceliophthora thermophila, which operates optimally under alkaline conditions, was used in combination with natural mediators to make the process even greener. Based on the optical properties of the resulting decolorized paper, red and black dyes were efficiently removed by all laccase–mediator systems. The best results were provided by the laccase–methyl syringate combination, followed by the laccase–acetosyringone system and the laccase–syringaldehyde system. The decolorization rate for red paper achieved with the laccase–methyl syringate treatment exceeded that obtained with ozone. Red was removed by about 98% by combining two enzymatic stages and hydrogen peroxide stage, and black by 65%, without altering the physical properties of the colored paper in either case. A sequence combining oxidative and reductive (formamidine sulfinic acid) chemical treatments led to comparable optical and physical properties for the two types of paper. The effects of Myceliophthora thermophila laccase and methyl syringate were similar to those of high-redox potential laccase from Trametes villosa combined with either methyl syringate or the synthetic mediator violuric acidPostprint (author's final draft

Potencial de la celulosa en la construcción de nuevos materiales

Actualmente, más de una tercera parte de los tipos de papeles que hoy empleamos son para nuevos usos que hace diez años no existían. Además, la demanda creciente de productos basados en materias primas renovables y la preocupación social hacia el medio ambiente, estimula el desarrollo de productos diferentes con nuevas aplicaciones y alto valor añadido. En los últimos años ha incrementado el interés por la necesidad de buscar alternativas a los materiales derivados del petróleo, que sean más sostenibles y renovables. Los soportes celulósicos son una buena opción siendo un material natural, renovable, reciclable y biodegradable. Uno de los principales campos de investigación en el desarrollo de productos para los sectores del “packaging”, es la obtención de nuevos materiales celulósicos con propiedades avanzadas similares a las que proporcionan los derivados del petróleo. Por otra parte, una de las nuevas aplicaciones del papel que se contempla es en la microfluídica: el uso del papel como material base para construcción de dispositivos microfluídicos y su aplicación de los dispositivos a ensayos para diagnosis médic