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In this study, an analysis was conducted on the seismic response of three archaeological structures located in the Chichén Itzá area. The objective of this analysis was to gather relevant information that may be utilized to monitor and ensure the preservation of these monuments. Ambient seismic noise measurements were conducted over three days using broad-band seismographs. The objective was to assess the vibration frequencies of three buildings, namely Las Monjas, El Caracol and El Castillo or Kukulkan Pyramid, using HVSR method. The findings indicate that the dominant frequency of the El Caracol building is 1.3 Hz. Nevertheless, it is noteworthy that within the Las Monjas and El Castillo structures, an observable fundamental frequency of 5.1 Hz is present, accompanied by a relative amplification of around 6. The findings of this study indicate the behavior of the two pyramids can be likened to that of a soil layer overlaying a stiff stratum. The noise recorded by a seismograph at the base of El Castillo enables the observation of a kinematic interaction phenomenon resulting from the disparate stiffness properties of the soil and the structure. No directional effect was observed on the HVSR ratios due to internal irregularities in the pyramids. Considering the half-width of the base of each pyramid and that the site response is of topographic origin, the calculus of shear velocity is 255 m/s. This velocity relates to non-compact materials resting on competent rocks with velocities more than 1000 m/s, materials subject to stress changes that may eventually lead to structural degradation. The findings of this study indicate the need for continuous monitoring and instrumentation of lower levels to assess the influence of substructures during preconstruction stages and determine whether there are any other effects due to the karstic nature of the subsurface. [ABSTRACT FROM AUTHOR]

This work is carried out with the purpose of studying theoretically the measurement of the diffusion coefficient (DC) in liquid substances using double exposure holographic interferometry (DEHI). Diffusion has been defined, throughout history, as the phenomenon in which matter moves in a system, from regions with high concentrations to those regions where the concentration is lower, as a consequence of the random movements of its molecules. Diffusion proceeds gradually in the mixture of substances, ending just when the concentrations are equalized; in the case of liquid phase substances, the diffusion of a solute in a solvent. For the study of this process, multiple techniques have been used, among which the optical ones stand out, specifically holographic interferometry, which associates the precision of interferometric measurements with the advantages of holography; by implementing IHDE, it is possible to compare the wavefronts, which in principle were separated in time, thus allowing any type of variation in the analyzed object, however small, to be determined by knowing the characteristic wavelength of the light used. In this article, the theoretical development is presented to obtain the mathematical expression from which the CD in liquids can be calculated, using IHDE, highlighting that this is found through the comparison between interferential fringes of the same order recorded at different times, taking into account the distances, measured from the interface between the two liquids, at which they appear. Finally, an analysis of the expression found and how it is applied from experimentally obtained data is carried out. [ABSTRACT FROM AUTHOR]

Currently, catastrophic failures have occurred in tailings deposits that have demonstrated the importance of continuous monitoring of the constructive and operational status of these structures to improve their understanding and reduce risk. In many cases, dam failures are preceded by a series of anomalies such as: excessive deformation on the surface, the appearance of stress cracks or acceleration trends. If these are captured in time, they can be of great support for early warning systems or for activating risk mitigation procedures, which can ultimately lead to avoiding failures. Synthetic aperture radar differential interferometry (DInSAR) techniques measure surface deformation by processing the radar phase difference of at least two complex SAR images acquired at different times over the same area. These techniques are very useful for measuring deformations in tailings deposits since they provide high-precision periodic information over large areas, and can even be used in adverse weather conditions, unlike optical satellites. This article shows the results of the application of interferometric analysis of surface deformations in tailings dams, which allow the detection of outstanding deformations, acceleration trends and estimates of the moment of failure in its structures. The processing tools are applied by studying some important international failure cases of tailings deposits that have occurred in recent years. Advanced DInSAR techniques of persistent scatterers (PS InSAR) are used for the study. The results obtained are compared with complementary geotechnical studies carried out on these case studies. [ABSTRACT FROM AUTHOR]

Subsidence is a highly destructive natural hazard, which can be caused by both natural and anthropogenic causes. Its impacts include the creation of cracks and fissures, damages to buildings and infrastructures, a decrease in storage capacity of aquifer systems, and an increase of the susceptibility to flooding. In this study, Persistent Scattered Interferometry (PSI) has been used to process Synthetic Aperture Radar (SAR) images, for the detection and analysis of ground deformation and subsidence processes in the island of Mallorca. The study database is composed of 120 images captured by the Sentinel 1A and 1B satellites (between May 2016 and December 2019), from which we derived a map of accumulated displacement rates occurred during a 3 years and a half period. The results show important subsidence processes of up to 30 mm year-1 in large areas of the sedimentary basin of Palma, and of lesser magnitude (between 10 and 20 mm year-1) in locations of the Central Depression and in basins in the Serra de Tramuntana, such as the Torrent Major at Sóller and the Torrent de Gorg Blau. A significant relationship has also been observed between the thickness of the Quaternary sediment and the observed subsidence rates. The results highlight the high degree of geomorphological dynamism at very short time scales that characterizes Mallorca, and the vulnerability of certain urban areas, such as the city of Palma (? 400000 inhabitants), and agricultural areas, such as the Central Depression, facing the risk of subsidence and associated damages. [ABSTRACT FROM AUTHOR]

Here we report a simple analytical technique to model a Mach-Zehnder fiber optic interferometric sensors that allow us to predict and calculate via computer simulations parameters that are not easily obtained experimentally. This model was calibrated and compared with experimental data using a 120 mm sensor for measurements of temperature, refractive index and water level. For instance, we were able to calculate the effects on the cladding effective index caused by the variation of those physical parameters. Moreover, this analysis could further our understanding of such sensors and allow us to make predictions about their use in different applications and even their behavior with different sensing lengths. [ABSTRACT FROM AUTHOR]

The objective of this work is the application of an interferometric method for validating the result of wear in a cutting tool insert of hard metal. We describe in this paper the experimental setup for the application of Digital Holography technique, used with digital recording of holograms on a CCD camera. The cutting insert inspected with the optical technique was previously mounted on a support structure and slightly heated with a halogen lamp for evidence of defective regions. For image processing, the software used, ProITec. It was possible to detect, with high resolution and contactless defects that could compromise the structural integrity of the insert analyzed, no defect was found. Analysis of the images obtained, it is verified that the object is deformed as a whole, not to present any visible alteration in their pattern of fringes. [ABSTRACT FROM AUTHOR]

We present an experimental installation for the measurement of deformations of healthy superior premolar teeth implementing the method of projection of fringes. The samples were inserted in polyethylene resin and fixed in support, which has a stem that is responsible for the application of the load, the loads used being of the order of 25 N, 50 N, 75 N and 100 N. Each load was applied along the axis of the tooth by touching its two cusps and then again with the load touching only a cusp. Was developed a computer program supported in MATLAB for the reconstruction of images. The process of digital image reconstruction using the stripe projection method includes: Intensity and phase contrast images and deformation caused by the application of a force on the teeth. For the linearization of the phase was applied the algorithm of Volkov. [ABSTRACT FROM AUTHOR]

Using interferometry and Fourier analysis, the photothermal phase map is obtained from the induced thermal lens effect in a liquid sample with high absorbance at the laser wavelength. The experimental setup consists of an adaptation of two beams thermal lens experiment, where both arms of a Sagnac's interferometer are used as probe beams. The interferograms are recorded with a CCD camera and then processed using Fourier analysis techniques. The results show that the coefficient of thermal diffusivity of a high concentrated water solution of Tartrazine is greater than that of pure water. The technique can be used to study heat transfer in opaque samples to the wavelength of the excitation beam. [ABSTRACT FROM AUTHOR]

The low coherence interferometry in Fourier space (FD-OCT) is a technique to measure distance with typical values of dynamic range in the order of 3 mm and resolution below 10 microns. In this paper we propose to combine the interferometric technique with a technique that measures distances using astigmatic focus signal, allowing lead the resolution limit of less than 10 nm. The experimental scheme shown armed with both techniques and experimental results in displacement of a sample surface, controlled feedback system with a piezoelectric strain gauge which we have used as a reference system. [ABSTRACT FROM AUTHOR]

It is generally assumed that teleost fish lenses are spherically symmetrical. Our purpose is to evaluate this symmetry by means of point diffraction interferometer (PDI) which is an accurately technique to evaluate very aberrated optical elements as eye lenses. Several lenses of two different fish were evaluated in vitro with a PDI, they were placed over a ring inside a glass cell filled with Medium 199. Measurements were performed for ten different positions of the lens, from a position with equatorial plane orthogonally to optical axis of the system to a position with equatorial plane quasi-parallel with optical axis. Based on the assumption of a spherically symmetrical refractive index, they should yield radially-symmetric interferograms regardless of their position. With PDI measurements we are able to test visually and numerically this assumption. We found that only when the fish lens is positioned with equatorial plane orthogonally to the optical axis of the system shows a quasi-spherical symmetry. This technique allows quantify the deviation from the spherical symmetry commonly assumed for teleost fish lenses. [ABSTRACT FROM AUTHOR]

In this work was obtained the influence of the mass ratio of the henequen's fibers as reinforcing over the mechanical properties in traction an impact resistance of the composite with polymeric thermosetting matrix. Was found very similar physics and chemically, fibers from two regions of the country. Was analyzed the samples using digital interferometry searching for defects and was observed the region of rupture using electronic microscopy of sweeping. Was determined that the increase of the inclusion of the fiber as reinforcement in this material cause the increase of the study properties, raising a maximum over the 20 % of the mass ratio in the relation fiber-matrix. Was observed an increasing over the 53 % in the resistance to traction and over 88 % in the impact resistance compare to the matrix alone. [ABSTRACT FROM AUTHOR]

Copyright of Latin-American Journal of Physics Education is the property of Latin-American Physics Education Network and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Educación en Ingeniería is the property of Asociacion Colombiana de Facultades de Ingenieria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of CES Odontología is the property of Universidad CES and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The interference of two or more waves can be described by means of the interaction among them. In this work we present a study of this phenomenon for the case of the Young's experiment of of the double slits using the method of finite differences in the temporal domain. The simulation of the experiment is made by using the technique of Crank-Nicholson, and the spatial propagation of the light that emerges from the slits is analyzed. In the results you can appreciate the behavior that present the light varying the separation between the slits and the wavelength of the source. The exposed method is present in such a way that can be easily adjusted to other cases of interferometry. [ABSTRACT FROM AUTHOR]

The concept of crucial experiment is critically revised, on the basis of an historic discussion of the interferometric experiments of Michelson and Morley (1881-87), replied and refined by a couple of physicists in the next decades, on the hypothesis of existence of a material medium or ether for light waves propagation, and developed in an attempt for saving the fitting between the Maxwell's formalism of Electrodynamics and Newtonian Mechanics, via the postulation of an absolute inertial frame. The analysis of the historic context of development of physical theories between 1881 and 1930 show evidences about the insufficiency of the epistemic category of crucial experiment, in connection with rigid logicists interpretations, and rational reconstructions of the change of theories in Physics, in the sense of M. Bunge. The discussion is based on two argumentative ways, respectively the characterisation of the ether notion in the preexistent physical theories by the time of the first Michelson's interferometric measurements as an ad hoc theoretical concept -preserved in the (non relativistic) Maxwell's formulation of the Electrodynamics (1873) because of the necessity of fitting to postulations of Newtonian Physics- and the analysis of the virtual irrelevancy of the interferometric experiments of Michelson and Morley (1881- 87) for the construction of Relativity Theory by Albert Einstein, and consequently for the change of theories/ paradigms between classical Mechanics and Special Theory of Relativity (STR). Some implications of our conclusions are briefly discussed, concerning with science teaching situations and reformulation of Physics curriculum contents in STS (Science, Technology and Society) in Polimodal level (15/17 years) in Argentina. [ABSTRACT FROM AUTHOR]

The use of fringe projection method to obtain the 3D Reconstruction is a technique that has been broadly used in industrial and medical applications. Parallel fringes are projected on the surface either with a conventional system of projection using a diffraction grating or using interferometric fringes. This technique provides discontinuous phase maps and it is necessary to use algorithms of phase correction (unwrapping). Due to the spacial correction, errors can be propagated when erroneous discontinuity points caused by the presence of noise are identified. In this work a methodology is presented that allow to solve the continuous absolute phase distribution without to use spatial procedures. [ABSTRACT FROM AUTHOR]

A Ronchi test for determining the topography of a concave mirror was built. In the experiment, is used a white light source, a diffuser, a grating with a 4 period in a mm, and a digital camera as a detector. By means of a phase analysis method the shape of the mirror is founded. A comparation of the patterns obtained with white light and other quasi-monochromatics sources is presented. Finally, the mirror surface is approximated as a modified Zernike's polinomial function, whose terms are related with the third order aberrations. [ABSTRACT FROM AUTHOR]

In this work fringes patterns axe obtain themselves experimentally that show the deformation that undergoes an object when applying to him a effort of mechanical origin, by means of digital holographic interferometry of double exposure. The experimental assembly for the digital record and the numerical reconstruction of the hologram of the object was made before and after to be deformed for, finally to obtain the deformation fringes. [ABSTRACT FROM AUTHOR]

The article presents a study on the use of Electronic Speckle Pattern Interferometry (ESPI) or holographic technique in measuring the Young modulus in mortars and concrete. It cites that a beam of known dimensions is made for the purpose that is excited with piezoelectric transducer which generates sound waves. The ESPI system captures and digitizes an image from surface of the free end.

The stereoscopy is a technique that allows the observation of three-dimensional images, but it is usually related with the use of special devices to their visualization, such as bi-color or polarized goggles. In medical applications the use of these equipments could restrain their use in surgical procedures, for example. In this work we present the description that shows how to obtain the holographic screen that makes possible a stereoscope without using any other special device to generate three-dimensional images. We describe the optical system of the stereoscope and show the resulting images. [ABSTRACT FROM AUTHOR]

Optical low-coherence reflectometry is a non-destructive interferometric techique, that has several applications such as the characterization of optical components, stress measuring in civil structures and is the basis of optical coherence tomogra-phy (OCT), among others. This paper gives a comprehensive description of a partially coherent interferometer to characterize induced stress and strain in an optical fiber. The work is complemented with computational simulations for getting ready the interferometrer. Finally, are written a series of correct procedures to be applied to reproduce mounting and obtain reliable measurements. [ABSTRACT FROM AUTHOR]

The determination of the Young's module is of great interest in materials science and engineering, because of this property depends on the elastic behavior of them. An alternative form of this amount is inferred from the variation between the speckle patterns registered as occurs deformation. This paper presents the implementation of a speckle interferometer of symmetrical illumination applied to a metal sample subjected to deformation and as a media of recording using a CCD camera. From fringes correlation obtained with the use of image processing routines and extraction of phase values, deformation of the piece is determined, and through this Young's module. [ABSTRACT FROM AUTHOR]

Copyright of Revista Góndola, Enseñanza y Aprendizaje de las Ciencias is the property of Gondola, Ensenanza y Aprendizaje de las Ciencias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)