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In this work, a new Physics laboratory experiment on Acoustics beats is presented. We have designed a simple experimental setup to study superposition of sound waves of slightly different frequencies (acoustic beat). The microphone of a smartphone is used to capture the sound waves emitted by two equidistant speakers from the mobile which are at the same time connected to two AC generators. The smartphone is used as a measuring instrument. By means of a simple and free AndroidTM application,arXiv:1605.01370v2 fatcat:bk2fs26cgfdv7fppmmmt6xdv34
more »... sound level (in dB) as a function of time is measured and exported to a .csv format file. Applying common graphing analysis and a fitting procedure, the frequency of the beat is obtained. The beat frequencies as obtained from the smartphone data are compared with the difference of the frequencies set at the AC generator. A very good agreement is obtained being the percentage discrepancies within 1 %.
Marcos H. Giménez received a degree in civil engineering from the Universidad Politécnica de Valencia in 1986. ...doi:10.1002/cae.10025 fatcat:2fhw4ejw5bdhhnmcjmtjrzprxq
We present a simple diffraction experiment with fractal gratings based on the Triadic Cantor Set. Diffraction by fractals is proposed as a motivating strategy for the students of optics about the potential applications of optical processing. The Fraunhofer diffraction patterns were obtained with the standard equipment present in most undergraduate physics labs and compared with that obtained with conventional periodic gratings. It is shown that fractal gratings produce self-similar diffractiondoi:10.1088/0143-0807/32/3/005 fatcat:jdpqikmm6jdjpk7pm6trnfjvxu
more »... atterns which can be evaluated analytically. A very good accuracy is obtained between experimental and numerical results.
The mobile acceleration sensor has been used to in Physics experiments on free and damped oscillations. Results for the period, frequency, spring constant and damping constant match very well to measurements obtained by other methods. The Accelerometer Monitor application for Android has been used to get the outputs of the sensor. Perspectives for the Physics laboratory have also been discussed.arXiv:1212.4403v1 fatcat:poxsre2drvcfhiy637nkxvrg2i
In this paper, we present some learning objects for the study of Kepler's laws that graphically show the orbits and the movements of various planets. One of them shows the orbit of a planet from the point of view of a fixed planet, showing that the orbit is quite difficult. No equations differentials are required, but only elementary vector calculus. The learning object has been implemented in Matlab.doi:10.1002/cae.20446 fatcat:syr7ws6rsjcwlo7csu5eunsm7u
We studied total exchangeable sodium, ion transport activity at maximal rate, and erythrocyte Na + content in response to angiotensin converting enzyme inhibition in mild-to-moderate essential hypertensive patients with normal renal function. Twenty-five patients (mean age 56 years, range 40-62 years) who had abnormal red blood cell Na + -K + -Cl~ cotransport or red blood cell Li + -Na + countertransport were treated with either enalapril (20 mg daily) or hydrochlorothiazide (50 mg daily)doi:10.1161/01.hyp.17.3.334 pmid:1999365 fatcat:ts4mngs4hre4jh6b7mevfdpfa4
more »... a 30 -day period. During the period of enalapril treatment, Na + -K + pump and Na + -K + -Cl" cotransport increased significantly from 4,282±255 to 5,236±325 /tmol/1 red blood cell/hr (;><0.01) and 166±21 to 220±24 jimol/l red blood cell/hr (/7<0.05), respectively. Mean intracellular Na + content in erythrocytes decreased from 11.4+0.40 to 10.0±0J3 mmol/1 (p<0.01) and exchangeable Na + from 39.8±0.6 mmol/kg to 35.6±0.6 mmol/kg (/»<0.001). Sodium reduction correlated with the recovery of Na + -K + -Clc otransport activity (r=-0.65, p<0.01). During treatment, systolic and diastolic blood pressures were reduced significantly (/?<0.01). In 12 patients treated with hydrochlorothiazide,
.; Gimenez Valentin, MH. (2008). Testing theoretical models of magnetic damping using an air track. ...doi:10.1088/0143-0807/29/2/014 fatcat:f24iiz4ztber5dwhm6ryoezg64
El smartphone como barómetro en experimentos de Física Isabel Salinas, Juan Carlos Castro Palacio, Marcos H. Giménez y Juan A. ... El smartphone como barómetro en experimentos de Física Isabel Salinas, Juan Carlos Castro Palacio, Marcos H. Giménez y Juan A. Monsoriu . ...doi:10.4995/msel.2018.9021 fatcat:adcbmsmunvaslbq265xnfzkjzi
Gimenez Valentin, MH.; Riera Guasp, J.; Vidaurre, A. (2005). Measuring coupled oscillations using an automated video analysis technique based on image recognition. ... For the localization of the moving objects, we considered each frame as an input scene, f(x,y), and used a detached image as the filter for the particular object of interest, h(x,y). ... It can be easily proved that  : ) , ( ) , ( ) , ( y x h F y x f F F y x g 1 . ( In this way, the correlation function can be calculated relatively rapidly using the direct and ...doi:10.1088/0143-0807/26/6/023 fatcat:2z3ij72jqfawvalemslmmhxrw4
.; Gimenez Valentin, MH.; Cuenca Gotor, VP.; Seiz Ortiz, R.; Monsoriu Serra, JA. (05-2). Design and evaluation of a three-dimensional virtual laboratory on vector operations. ...doi:10.1002/cae.22108 fatcat:5vlbzs42tvhnhn3i3sp5atv344
.; Gimenez Valentin, MH.; Monsoriu Serra, JA. (2013). Using a mobile phone acceleration sensor in physics experiments on free and damped harmonic oscillations. ...doi:10.1119/1.4793438 fatcat:vw3pbhzchjas7n6gmxion4q6ba
El Proyecto del Parque Turístico Ambiental de Integración (P.T.A.I.), ubicado en el límite internacional en donde con_uyen el punto más oriental de la Argentina continental (Bernardo de Irigoyen, Misiones) y las ciudades brasileras de Dionisio Cerqueira y Barração, fue concebido como un espacio con dos objetivos fundamentales: fomentar la integración de los países y mejorar el control fronterizo, desde un abordaje participativo e interinstitucional, que involucró a todos los actores vinculadosdoi:10.30972/adn.042183 fatcat:jkvaztaxrffypehtl7bgbqynya
more »... la problemática. La propuesta contempló acciones en tres escalas de intervención (estructural, jerárquica y anexa), en función de lograr la articulación del Parque con las tres ciudades involucradas, en una extensión de 3000 metros lineales y 60.000 m2 de área de intervención.
In this work, the normal modes of a two-dimensional oscillating system have been studied from a theoretical and experimental point of view. The normal frequencies predicted by the Hessian matrix for a coupled two-dimensional particle system are compared to those obtained for a real system consisting of two oscillating smartphones coupled one to the other by springs. Experiments are performed on an air table in order to remove the friction forces. The oscillation data are captured by thearXiv:1605.01372v2 fatcat:27e4wif4cbcfnidazfoqrlflfq
more »... tion sensor of the smartphones and exported to file for further analysis. The experimental frequencies compare reasonably well with the theoretical predictions, namely, within 1.7 % of discrepancy.
The Physics Teacher
The Physics Teacher ◆ Vol. 55, OctOber 2017 DOI: 10.1119/1.5003745 Direct Visualization of Mechanical Beats by Means of an Oscillating Smartphone Marcos H. Giménez, Isabel Salinas, and Juan A. ...doi:10.1119/1.5003745 fatcat:pxub7vxd4zddfj3ipi5mwk35dy
The COVID-19 pandemic has had an impact on ischaemic stroke management, with a reported decrease in hospital admissions, and even disruptions in healthcare and increased in-hospital mortality. However, there is a lack of evidence on the impact of the pandemic on functional prognosis. The aim of this study is to analyse the effect of the COVID-19 pandemic on the 3-month functional outcomes of patients hospitalised due to acute ischaemic stroke in Aragon (Spain). We reviewed the data of alldoi:10.1016/j.nrleng.2021.02.001 pmid:34099423 fatcat:pfa6zop36vfqbknrs6qp6hvx2q
more »... ts admitted due to ischaemic stroke to any hospital in our regional healthcare system between 30 December 2019 and 3 May 2020. We compared modified Rankin Scale scores and mortality at 3 months in patients hospitalised before and after the declaration of a state of emergency due to the COVID-19 pandemic. In total, 318 patients with acute ischaemic stroke met our inclusion criteria. No differences were observed between periods in global or specific characteristics, with the exception of a higher proportion of patients older than 80 years during the first period (42.2% vs 29.0%, P = .028). In the comparative analysis, we found no significant differences in mortality (12.3 vs 7.9, P = .465) or in the proportion of patients with modified Rankin Scale scores ≤ 2 (57.7% vs 57.1%, P = .425) at 3 months. To our knowledge, this is the first study to analyse the impact of COVID-19 pandemic on the 3-month functional outcomes of patients with ischaemic stroke. In our region, there has been no increase in rates of mortality or disability at 3 months in patients admitted due to ischaemic stroke during the pandemic.
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