P. Padilla-Sosa

The ellipse in parabolic motion: An undergraduate experiment

We present a simple method of experimentally studying the elliptic shape of the joined apices of parabolic projectile trajectories in the undergraduate laboratory. The experimental data agrees well with theoretical results, and we find that this experiment provides an interesting twist to the venerable undergraduate experiment on projectile motion.

Analysis of anhydrous glucose and human serum assisted by Raman spectroscopy

Raman spectroscopy has been considered like a potentially important clinical tool for real-time diagnosis of disease and evaluation of living tissue, whit the proposal to development noninvasive glucose measurements in a near future, with lower power than other reported studies, in this work are reported experimental tests made with a excitation source of semiconductor laser of 785 nm and 35 mW power. Measurements were made to different glucose concentrations, with variation from 50 mg/dL to 6000 mg/dL. For this, three intervals with different ranges of concentration were analyzed, these tests were put into plastic sampling cells, making incise the beam vertically on sample. In the same way measurements to serum human are reported, for healthy volunteers had 12 hours fasting and non-fasting conditions, with its corresponding values of glucose taken through a conventional glucometer. Freeze-dried human serum was poured on object-holder, in the case of human serum reconstitute, it was used container in which were previously kept samples. Nine spectra per test were obtained and subsequently average was calculated, the spectra were studied in a range of 500 to 1700 cm-1. This work explores the intensity variation of the bands of glucose in 1065 cm-1 and 1127 cm-1 as a function of glucose concentration. In the obtained results, there observes a behavior with positive slope in both substances, interrelation being observed between the measurements, being promissory for non-invasive measurement.

Microbubble Generation with Tapered Optical Fiber

We present the microbubble generation using tapered optical fibers. We studied the relation of microbubble generation with experimental parameters. We report the relation of these, with size, speed of growing and lifetime of the microbubbles.

Erratum: “The ellipse in parabolic motion: An undergraduate experiment” [Am. J. Phys. 82, 354–356 (2014)]

M. A. Carrillo-Bernal, P. E. Mancera-Pina, H. H. Cerecedo-Nunez, P. Padilla-Sosa, H. N. Nunez-Yepez, and A.L. Salas-Brito Citation: American Journal of Physics 82, 707 (2014); doi: 10.1119/1.4874515 View online: http://dx.doi.org/10.1119/1.4874515 View Table of Contents: http://scitation.aip.org/content/aapt/journal/ajp/82/7?ver=pdfcov Published by the American Association of Physics Teachers Articles you may be interested in Erratum: “The torque on a dipole in uniform motion” [Am. J. Phys. 82, 251–254 (2014)] Am. J. Phys. 82, 354 (2014); 10.1119/1.4869186 The ellipse in parabolic motion: An undergraduate experiment Am. J. Phys. 82, 354 (2014); 10.1119/1.4864291 On the numerical solution of a two dimensional elliptic-parabolic equation AIP Conf. Proc. 1479, 606 (2012); 10.1063/1.4756205 Erratum: “On a fourth order degenerate parabolic equation in higher space dimension” [J. Math. Phys.50, 123524(2009)] J. Math. Phys. 53, 079901 (2012); 10.1063/1.4736991 Comment on “Diamagnetically stabilized magnetic levitation,” by M. D. Simon, L. O. Heflinger, and A. K. Geim[Am. J. Phys. 69, 702 (2001)] Am. J. Phys. 70, 188 (2002); 10.1119/1.1430699

Optical fiber trap: radiation pressure effect on inorganic and organic micro-particles

An optical fiber trap operates by radiation pressure and transverse force gradient while conventional optical trap operates on longitudinal gradient to trap particles. This subtle difference translates into easy setup and many advantages over conventional single-beam optical tweezers. In this work, we present a brief review of the current situation of fiber optic trap and their applications. Subsequently, we discuss the effect of radiation pressure on micro-organic and inorganic particles. Using a single optical fiber, radiation pressure transfers movement to the micro-particles, so velocity and acceleration are quantified. After that, micro particles are trapped, but now using two optical fibers. Finally, we discuss the results and problems involved with this research.

Ultraviolet Light Absorption in Different Photosensitive Optical Fibers, a Comparative Case of Study

A comparative analysis of ultraviolet light absorption is presented for distinct photosensitive optical fibers. Fibers are irradiated by ultraviolet light, coming from a pulsed Nd:YAG Laser (90 mJ, 5-7 ns) at 266 nm. Absorption is analyzed from ultraviolet to infrared region and it is compared for different photosensitive optical fibers. The final goal of this work is to identify absorption spectral regions, which would be useful in order to improve fiber grating printing.

Detection of corrosion by digital speckle pattern interferometry

It has been recently shown that application of Michelson interferometry, is suitable for monitoring of oxide layers growing in metallic structures during preliminary states of oxidation processes in aqueous solutions, without any physical contact with the sample. The qualitative and quantitative interpretation of the observed interferograms allows evaluation of important physical parameters related to specific corrosion processes [1]. Although the using of aluminum samples with surfaces polished to certain optical quality is a necessary requirement to obtain well-built interferograms, it complicates further applications for diffused surfaces typical of industrial conditions. In this work we present preliminary qualitative results obtained by using a simple experimental setup based on Digital Speckle Pattern Interferometry (DSPI) [2], as a proposal to solve this difficulty and on the other hand, to use the benefits of certain powerful tools like low-coherence optical techniques for further applications on monitoring of corrosion through turbid media.