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The Physicist Engineering is a multidisciplinary profession in which an undergraduate student integrates and applies their knowledge of Physics, Mathematics, and Computing to adapt and innovate all kind of technologies, as well as to development and apply theoretical knowledge to different fields of science and engineering.

A Physicist Engineer, supported by a solid preparation in science and engineering is available to study, analyze, identify, and solve problems in different fields of science and technology for industries, hospitals, research laboratories, institutes and governmental organizations focused on metrology, optics, energy, materials, instrumentation of sophisticated equipment. The Physicist Engineering bachelor degree is a national and international reference to encouraging all those students to apply knowledge through active participation in the operation, planning, and management of projects.

The technological and scientific impact of a Physicist Engineering undergraduate and graduate students, as well as the tutorial of the research professor that are interested in Physics and Physics Engineering, may be found in a biennial event like the International Conference on Physicist Engineering, through the diffusion of both experimental and theoretical research and teaching.

In order to promote and encourage strength academic goals among universities and research institutions, the International Conference on Physics Engineering Committee, integrated by a faculty meeting of the Universidad Autónoma Metropolitana, Campus Azcapotzalco, has decided to grant the VIII International Congress of Physics Engineering to the Universidad Autónoma de Yucatán, which is going to take place on Mérida, November 7^th to 11^th, 2016.

This conference considers different topics as:

Renewables Energies Engineering

Materials Technology

Nanotechnology

Medical Physics

Education in Physics Engineering

Nuclear Engineering

High Precision Instrumentation

Atmosphere Physics

Optics Engineering

Physics History

Acoustics

Related Topics

The conference integrates lectures on top trending topics with pre-congress workshops, which are given by recognized scientists with an outstanding academic record. The lectures and workshops allow to share experiences and create research networks. The Conference also encourages professional mobility among all universities and research institutes.

CIIF2016 Organizing and Editorial Committee

Dr. Ernesto Rodrigo Vázquez Cerón

Dra. Inés Riech Méndez

Dr. Oscar Olvera Neria

Dra. Milenis Acosta Díaz

Dr. Roberto Tito Hernández López

Dr. Cesar Renán Acosta

Prof. Jaime Granados Samaniego

Dr. José Méndez Gamboa

Dr. Anatolio Martínez Jiménez

Dr. Luis Enrique Noreña Franco

All papers published in this volume of Journal of Physics: Conference Series have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

A stationary power plant with two Carnot-like cycles is optimized. Each cycle has the following irreversibilities: finite rate heat transfer between the working fluid and the external heat sources, internal dissipation of the working fluid, and heat leak between reservoirs; is extended to two or more of this combined model. Using the Bellman' Principle, we find the optimal recurrence relations for the allocation of the heat exchangers for this power plant. The optimal allocation or effectiveness of the heat exganchers of power plant is determined by two design rules: internal thermal conductance fixed; or areas fixed. The optimal obtained are invariant to the power and efficiency and to the heat transfer law.

A stationary power plant with two Carnot-like cycles is optimized. Each cycle has the following irreversibilities: finite rate heat transfer between the working fluid and the external heat sources, internal dissipation of the working fluid, and heat leak between reservoirs. The optimal allocation or effectiveness of the heat exchangers for this power plant is determined by applying, two alternating design rules: fixed internal thermal conductance or fixed areas. The optimal relations obtained are substituted in the power and the maximum power, according to the isentropic ratio of each one of the Carnot-like cycles of the power plant, is calculated. Additionally, the efficiency to maximum power is presented.

We analyzes the different stages in the dehydration of fruits and vegetables. It was found to vary from a lettuce: as a sharp drop at low temperature, (arround 150 °C) to five stages in total, with a loss almost continuous to about 300 ° C, such as grapefruit, papaya and fig. The first section in your paper.

The photoluminescence and X ray diffraction of the mixture of ZnO + 1.0% C nanocrystals (NCs) have been studied before and after intensive mechanical processing (MP) with the aim to identify the nature of emission bands and radiative defects. The study reflects the diversity of physical processes occurring during MP: the destruction of primary ZnO NC aggregates, crushing individual ZnO NCs from the size of 250 nm down to 14 nm, the interaction of carbon atoms with oxygen in a treatment chamber and with the surface of ZnO nanoparticles etc. The new PL band peaked at 2.84-2.95 eV has been revealed in PL spectra after 9 min of MP. The origin of this emission in ZnO has not been conclusively established. The new PL band peaked at 2.84-2.95 eV has been studded and its nature is discussed.

This work focuses on a three-dimensional analysis of the deformation of a drop — immersed in a Newtonian fluid— generated by a 2D elongational flow with vorticity. The study of steady-state deformations of the cross-section of the drop shows a prevalent non-circular shape. The axisymmetric idealization of the ellipsoid is not observed nor the linear dependency between capillary number and deformation of the drop, as Taylor and Cox theory predicted. Our numerical results are consistent with experiments and other numerical simulations. However, in the latter cases, measurements of the cross section of the drop are few while a limited class of flows is applied. In this work, deformations induced by general two-dimensional flows upon the 3D drop shape are presented with special emphasis about the length scale along the third axis —perpendicular to the plane of the applied flow field.

The preparation and characterization of titanium dioxide thin films modified with different amounts of bismuth using a two laser ablation plasmas configuration is reported. The plasmas were produced ablating simultaneously two different targets, one of bismuth and other of titanium dioxide, using a Nd:YAG laser with emission in the fundamental line. The elemental composition, together with the vibrational and optical properties of the deposited films were investigated as a function of the parameters of the bismuth plasma. The composition of the thin films was determined from measurements of X-ray photoelectron spectroscopy (XPS) as well as by Rutherford backscattering spectroscopy (RBS). The structural modification of the deposited material, due to the incorporation of Bi, was characterized by Raman spectroscopy. The optical properties were determined from UV-Vis spectroscopy measurements. It is found that bismuth incorporation has an important effect on the optical properties of TiO₂ narrowing the band gap from 3.2 to 2.5 eV.

Aluminium oxide thin films modified with different amounts of carbon were prepared using a parallel laser ablation plasmas configuration. The effect of the amount of carbon incorporated in the films on their compositional, morphological, structural, and thermoluminescent properties was studied. The results showed that films with different C content, from 11 to 33 at. %, were obtained. The structural characterization revealed the growth of an amorphous material. Surface morphology of the obtained thin films showed smooth surfaces. The films were exposed to UV and gamma radiation (Co-60) in order to study their thermoluminescence response. The results tend to indicate that carbon incorporation into the alumina favours the increase of a high temperature TL peak.

We have calculated the dependence of transmittance spectra with wavelength for TE wave at normal incidence in one-dimensional dielectric photonic crystals (1DPC) using the transfer matrix method. We demonstrate that when consider two defects layers spatial breaking periodicity in the 1DPC, the presence of defect modes located within the photonic band gap can be found. Additionally we have calculated the effect on the transmittance spectrum by varying the thickness of the defects in the 1DPC.

In this work an energy and exergy analysis of solar distillation process is presented. The analysis is based on the experimental observation of the simple basin type solar stills for 4 different initial volumes (5.5, 6.5, 7.5 and 8.5 L). Energy and exergy balance equations have been written for all components of the solar still including glass cover, brine and absorber plate. The thermodynamic models for the energy and exergy analysis are presented on the critical heat transfer correlations in literatures for the simple basin type solar still. The results show that maximum values are reached in the energy efficiency of 45.6, 41.5, 35.7 and 31.8%, however exergetic efficiency for maximum values are 7.5, 7.2, 7 and 5.4%, corresponding to volumes 5.5, 6.5, 7.5 and 8.5 L respectively.

In this work an irreversibility analysis for the thermal process of solar distillation of three different substances is presented, for which it employs a solar still of a slope where three experimental tests with 5.5 L of brine, river water and MgCl₂ were performed. Temperature data principally in the glass cover, absorber plate, fluid, environment and the incident solar radiation on the device were obtained. With measurements of temperature, solar radiation and exergetic balance, irreversibilities are found on the device. The results show that the highest values of irreversibilities are concentrated in the absorber plate with an average of 321 W, 342 W and 276 W, followed by the cover glass with an average of 75.8 W, 80.4 W and 86.7 W and finally the fluid with 15.3 W, 15.9 W and 16 W, for 5.5 L of brine, river water and MgCl₂.

In this work we inform about the results of estimations of the changes of the spinodal decomposition areas and its dependence on the thickness of epitaxial layers. The calculations have been performed using the CALPHAD method and the SGTE data taking into account the elastic energy generated by the lattice mismatch between forming solid solutions and substrate. We have shown that in thin layers the elastic energy may serve both as a stabilizing factor for compositions inside the immiscibility region but lattice matched, or close, to the substrate and, on the contrary, as a reason of instability for the compositions laying in the periphery of the miscible regions.

In this work, an exergy evaluation to determine the energy availability across to glass covers, place where the solar radiation enters toward a solar cooker box-type is done. Considering the heating process of water, the energy not used is quantified by means of exergy. The results allow identifying the glasses in the cover as the zone where the solar cooker could be improved. The conduction heat transfer losses for the glasses is most big than 75%. Because the values for the conduction heat losses are around 90%, which are very important, this allows to identify the cover glass as the area where improvements could be made in this type of solar cookers.

In the present work calculations for the cooking power in three different solar cookers are shown. The designs considered for the solar cookers are square, rectangular and octagonal. Agree to the results, a solar cooker with larger area for the solar radiation inlet has the biggest cooking power. The cooking powers obtained for the solar cookers are 4.04 W (0.49 m²), 2.06 W (0.15 m²) and 0.88 W (0.19 m²) which correspond to square, rectangular and octagonal designs respectively. For the evaluation, the standard ASAE S580 JAN03 was considered to evaluate the cooking power in the solar cookers. Following the method established in this standard was possible to calculate the cooking power and evaluate the solar cookers at the same time. This activity except for what has been done in the standard, have not been done in other works.

The influence on the hydrogen molecule adsorption on a pristine and a defective graphene layer is compared. The different lengths for the C-C bonds on the graphene layer with one vacancy are visualized and compared respect to pristine graphene. The energy of formation of one vacancy is calculated and a comparison of the binding energy for the hydrogen molecule is presented when the molecule is adsorbed on pristine graphene or on the defective graphene layer. The adsorption is studied for a single vacancy and at least for two different pairs of carbon vacancies. The qualitative general result, and contrary to the expected effect of the carbon vacancies on the hydrogen adsorption is that the rearrangement of the carbon atoms on the defective graphene layer allows only a relatively small increase in the magnitude of the binding energy for the hydrogen molecule.

The density of states for adsorbed sulphur atom on a graphene layer system is discussed for pristine graphene layer and for mono and divacancies on the graphene layer. To our knowledge this is the first time that an entire adsorption of the sulphur atom is reported at the plane of the carbon atoms, when there is a pair of closer vacancies at the graphene layer.

We have constructed a low cost fluorescence detector model to determine the presence of some heavy metals in an aqueous medium. In particular, we focus on metals which cause public health problems in our country. We did the first tests with standard samples of Hg (II). The innovative features of this instrument are its small dimensions (9 dm³) and the low cost of materials used in its construction.

We present the influence high heat treatment temperature of a nitrogen austenitic stainless steel, deform by cold compression, in 10 different percentages. The steel contains high chromium (19.25 %), nickel (1.5 %) and nitrogen (0.2 %). The typical applications for this alloy are automobile parts and special valves for his excellent mechanical properties and corrosion resistance. Produced by hot rolling, they were subjected homogenized treatment at 975 °C for 45 minutes. Subsequently, deformed, by cold compression. We get ten different deformations, from 3 % to 22 %. These samples then to a heat treatment at 750 °C for one, 2 and 4 hours respectively. To observe the microstructure all samples were metallographic study and measured also their Rockwell C hardness. The initial sample has an austenitic matrix with a small amount of precipitates with a 42 RC average hardness. The homogenized sample had a 39 RC hardness. The deformed samples increased their hardness with a maximum of 49 RC. The samples with the treatment, showed a lower hardness with longer time with high dispersion. The decreased of hardness is due to the elimination of residual stresses and precipitates increasing size.

The flow of a magnetorheological suspension in the Poiseuille flow is studied in this work. A capillary rheometer was constructed and designated in order to adapt a magnetic field perpendicular to the flow direction covering the entire capillary zone; this restricts the maximum length of the glass capillary. A Newtonian suspension of carbonyl iron in glycerol at 20% in volume was studied at several intensities of magnetic field. The results showed a close-Bingham behavior at lower intensities of magnetic field. But a deviation is seen at higher intensities accompanied with a clearly shear thinning behavior with flow instabilities. These instabilities were evidenced by oscillations in shear rate and increased with the magnetic field and the shear stress.

A set of H13 steels were nitrocarburized with the aim of improving their performance as matrices and pins. The nitrocraburizing process was performed in an ETSA liquid salt bath furnace at 570°C for 45, 60, 90, 120, 150 and 180 minutes in order to evaluate the effect of time during the nitrocarburizing treatment on the quality of the nitrocarburizing layer. Microstructural evolution of the compound and diffusion layers were studied by scanning electron microscopy and by X-ray diffraction analysis. From microstructural characterization, it was observed mainly a continuous nitrocraburizing ε-Fe_2–3(C,N) layer with nitrocraburizing times between 45 to 60 minutes showing better wear performance as compared with specimen with nitrocarburizing times between 90 to 180 minutes.

In this work the analysis of the thermodynamic behavior of heat pumps (HP) which supply the energy needed in the public pool at the Aquatic Center of Azcapotzalco was performed. There are 18 installed HP's but only those needed to provide the energy required are alternately activated. The evaluation was conducted during May and June of 2015. We selected one of the HP to implement temperature and pressure gauges at the inlet and outlet of the compressor. The measurements were made every day at three times, 6:30, 13:00 and 18:00 hours. In a period of 24 hours, 1 000 L evaporated, there was no variation registered overnight, since the pool was covered with plastic to avoid loss of the fluid. The heat pump provided 150 kW to maintain the water temperature at the right level of operation, namely 28 °C. The coefficients of performance (COP) of the HP were 6.39 at 6:30, 7.42 at 13:00 and 7:32 at 18:00 hrs., values which are very close to the one provided by the manufacturer.

The characterization of AlGaAs/GaAs laser structures using surface photovoltage spectroscopy (SPS) is presented. The experiments were carried out at room temperature in the simplified variant of metal–insulator–semiconductor (MIS) configuration by means of a lab-made automated experimental setup. With this technique was possible to identify all the layers forming the heterostructure and important parameters have been extracted. The aluminium composition of the layers, obtained in this way agrees very well with the intentional growth parameters. Also from the surface photovoltage spectra was possible to obtain the lasing wavelength in each structure, which is in a good agreement with the values obtained by measuring the electroluminescence spectra. Results underline the power of SPS in characterization of actual laser devices in a contactless nondestructive way.

A comparison between experimental and numerical results for natural convection flow generated inside a square cavity filled with water, which has internal protuberances, is presented. The cavity is formed by vertical-isothermal and horizontal-adiabatic walls. The built prototype is integrated by: a clear glass square cavity, where internal protuberances are located; a cavity with water which maintains one of its walls at low temperature; an electrical resistance which preserves another wall at high temperature; and an array of mirrors. The experimental flow development was studied with a Particle Image Velocimetry (PIV) device. Furthermore, ANSYS software was used and mass, momentum and energy equations were numerically solved. Results were compared using a system with rectangular, semi-circular, and triangular protuberances versus a system without protuberances; it was found that: a) the maximum positive value of the vertical velocity decreased 7.12, 3.33 and 3.03%, respectively, for the experimental case, and 4.52, 2.26 and 1.27%, respectively, for the numerical case; b) the maximum positive value of the horizontal velocity decreased 18.37, 11.89 and 4.59%, respectively, for the experimental case, and 6.46, 4.75 and 2.47%, respectively, for the numerical case; c) the average Nusselt number decreased 10.52, 7.95 and 6.06%, respectively, for the experimental case, and 12.01, 9.06 and 3.02%, respectively, for the numerical case.

In Colombia, especially in the Atlantic Coast it is produced and marketed the costeño cheese, an indigenous product of the gastronomy of this region, but the prolonged exposure of this product to the environment leads to microbial contamination and non-enzymatic rancidity. For this reason the transmittance of an edible coating based in aloe vera gel and cassava starch to preserve costeño cheese was evaluated using trifurcated optical fibers. The results become a tool for the selection of treatments in making edible films and their subsequent use in coatings for various types of food products.

This paper presents the modelling of hot-water flow at the inlet of a swimming pool in the absence of swimmers, in order to find the option that allowed the best distribution of the fluid with less temperature loss. Two different input velocities, 3 and 4 m/s and two injection-nozzles inclinations, 60° and 30°, were used in the simulation. COMSOL Multiphysics software, with appropriate boundary conditions that were obtained by direct measurements in the pool, was used. The best condition was observed for an input velocity of 4 m/s and an injection-nozzle inclination of 30°, since it presented the best distribution of the fluid at the temperature of 29.86 °C in most of the considered site.

In the study of cosmic rays, measurements of time of flight and momentum have been used to identify incident particles from its physical properties, like mass. In this document we present the design, construction, characterization, and operation of a detector to measure time of flight of cosmic rays. The device is comprised of three small plates of plastic scintillator arranged in vertical straight line, coupled to one photomultiplier tube. The analogical output has been connected to a data acquisition system to obtain the number of digital pulses per millisecond. We present details of design, construction, operation, and preliminary results.

The mechanical and tribological performance of red clay ceramic tiles uncoated and coated by oxy-fuel thermal spraying process from fly ash powders was evaluated. The ceramic tile substrates were manufactured by uniaxial pressing at 26.17 bar pressure, and sintered at 1100 °C. The coating thickness was determined based on the number of projection-cycles oxyacetylene flame over substrate. Coal fly ash coatings were deposited, with average thickness of 56.18±12.18 μm, 180.42±20.32 μm, and 258.26±25.88μm. The mechanical resistance to bending and wear by abrasion deep, were studied using ISO 10545-4 standards and ISO 10545-6 respectively; adhesion was measured using Elcometer equipment Type III according to ASTM D-4541-02 and the average roughness (Ra) was found according to ASTM standard D7127-13, using the profilometer Mitutoyo SJ 201. The surface morphology presented the heterogeneous molten or semi molten splats with average size of 35.262±3.48 micrometers with good adhesion, justifying increased mechanical resistance to bending by 5%, as well as wear by abrasion deep. These results contribute to the development of ceramic products with added value, to be used in various technological applications.

Degradable plastics have been promoted as an option to mitigate the environmental impacts of plastic waste. However, there is no certainty about its degradability under different environmental conditions. The effect of accelerated weathering (AW), natural weathering (NW) and thermal oxidation (TO) on different plastics (high density polyethylene, HDPE; oxodegradable high density polyethylene, HDPE-oxo; compostable plastic, Ecovio ®; metalized polypropylene, PP; and oxodegradable metalized polypropylene, PP-oxo) was studied. Plastics films were exposed to AW per 110 hours; to NW per 90 days; and to TO per 30 days. Plastic films exposed to AW and NW showed a general loss on mechanical properties. The highest reduction in elongation at break on AW occurred to HDPE-oxo (from 400.4% to 20.9%) and was higher than 90% for HDPE, HDPE-oxo, Ecovio ® and PP-oxo in NW. No substantial evidence of degradation was found on plastics exposed to TO. Oxo-plastics showed higher degradation rates than their conventional counterparts, and the compostable plastic was resistant to degradation in the studied abiotic conditions. This study shows that degradation of plastics in real life conditions will vary depending in both, their composition and the environment.

This work shows a method to recover the shape of the surface via randomized algorithms when the null-screen test is used, instead of the integration process that is commonly performed. This, because the majority of the errors are added during the reconstruction of the surface (or the integration process). This kind of large surfaces are widely used in the aerospace sector and industry in general, and a big problem exists when these surfaces have to be tested. The null-screen method is a low-cost test, and a complete surface analysis can be done by using this method. In this paper, we show the simulations done for the analysis of fast conic surfaces, where it was proved that the quality and shape of a surface under study can be recovered with a percentage error < 2.

The numerical simulation of a centrifugal impeller that had previously been designed and manufactured is presented in this paper. The following operating conditions were determined: 0.50 m³/min volumetric flow at a load of 25 m, velocity of rotation of 1750 rpm, and specific velocity of 0. 27. The ANSYS CFX 14.5 software with the k-ε turbulence model was used for simulation with appropriate boundary conditions. The distributions of velocities in the flow field in addition to the distribution of pressures on the entire impeller were obtained. The simulation showed no negative values for the pressure at the entrance of the impeller. The curve of hydrodynamic behaviour of the impeller, which contains the point of operation in which the pump will work was also developed.

This paper describes the implementation and characterization of a displacement sensor according to the strain of a fiber Bragg grating. The system is able to obtain measurements on micrometer scales through heterodyne detection of intensity in a Mach-Zehnder interferometry in fiber optic. For the displacement characterization, the fiber Bragg grating was attached from one end meanwhile at the other end a tension was induced by a high-precision rotation mount. Experimental results are presented for which varying the angular displacement we obtain a linear response in the amplitude of the intensity, determining a sensitivity of 0.77 pW/µm with a displacement size of 48.80 µm in a dynamic range from 0 µm to 488 µm.

We introduce a set of non-linear functions of real, exponential type that can be useful for dealing with some physical problems. We use these functions to find steady states of the one-dimensional non-linear Schrödinger equation for a condensate between an infinite barrier and a step potential in the case where the height of the step is larger than the chemical potential of the condensate.

In the present work, a simple synthetic route for the production of single phase NaA zeolite is demonstrated. Rice husk ash (RHA) as alternative silica source was employed for the synthesis by conventional hydrothermal and non-conventional ultrasound methods. The zeolite was also synthesized using commercially available silicate for comparison. The effect of the reaction time (2, 4 and 6 h) at a fixed temperature of 70 °C was investigated. The elemental, structural and morphological characterization of the ashes and the synthesized zeolites was performed by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and thermogravimetric analysis (TG/DSC).

The results of the first national comparison of pyranometers used in testing laboratories of solar water heating are reported. In the comparison carried out at the facilities of Centro Nacional de Metrología (CENAM-México) participated three testing laboratories, a university and CENAM with seven secondary standards and first class pyranometers. The measurement results for all instruments were adequate, considering that the deviations found in all cases for global irradiance measurements greater than 500 W / m² were in a band of +/- 2.5%, even though pyranometers have different dates of calibration.

Lagrangian trajectory models of atmospheric fluid parcels have been used over a wide range of spatial scales to study the transport and dispersion of pollutants, radioactive materials, ash clouds produced by volcanic eruptions or modeling global carbon cycle. It was pointed out trajectory calculations have three error sources: error in the gridded data from measurements error or from approximations in Eulerian numerical models, error from the spatial and temporal resolution of data, and truncation error from numerical integration of the velocity field. In a recent work we showed that trajectory models can be structurally unstable under perturbations of the mass balance, e.g., the flow can go from hyperbolic to elliptic and vice versa. In this work we propose a mass-consistent approach to correct this structural instability. The orthogonal projection character of this approach guarantees the correction even for large perturbations of the mass-balance. This is illustrated by means of numerical examples. Mass-consistent models have been considered as diagnostic models of the wind field but the results of this work show that such a models can be used for four-dimensional data assimilation of nonstationary flows.

An approach for estimating thermodynamic properties of gases from the speed of sound u, is proposed. The square u², the compression factor Z and the molar heat capacity at constant volume C_V are connected by two coupled nonlinear partial differential equations. Previous approaches to solving this system differ in the conditions used on the range of temperature values [T_min,T_max]. In this work we propose the use of Dirichlet boundary conditions at T_min, T_max. The virial series of the compression factor Z = 1+Bρ+Cρ²+... and other properties leads the problem to the solution of a recursive set of linear ordinary differential equations for the B, C. Analytic solutions of the B equation for Argon are used to study the stability of our approach and previous ones under perturbation errors of the input data. The results show that the approach yields B with a relative error bounded basically by that of the boundary values and the error of other approaches can be some orders of magnitude lager.

There are several sources that produce very energetic cosmic rays that interact with the Earth's atmosphere and create new particles. To detect them there are different methods such as the ionization of a material and Cerenkov radiation, among others. In this work a hybrid cosmic ray detector of 6 channels was designed, built, tested and operated. Being hybrid is possible to validate the signal with the two detection methods. Three Copper bars were used as detection material, each with an ionization and a Cerenkov radiation detection channel. To detect the Cerenkov radiation, Hamamatsu silicon photodiodes were used, and for the ionization channels an RC circuit was developed to measure the signal. The number of signals was counted using discriminator boards, which digitize the signal. With the counts the cosmic rays flux can be measured. The six channels were tested simultaneously. Data collections and analysis were performed. Details of the design, characterization, testing, operation, data analysis and preliminary results are presented.

The position dependent mass Schrödinger equation (PDMSE) has a wide range of quantum applications such as the study of semiconductors, quantum wells, quantum dots and impurities in crystals, among many others. On the other hand, the Morse potential is one of the most important potential models used to study the electronic properties of diatomic molecules. In this work, the solution of the effective mass one-dimensional Schrödinger equation for the Morse potential is presented. This is done by means of the canonical transformation method in algebraic form. The PDMSE is solved for any model of the proposed kinetic energy operators as for example the BenDaniel-Duke, Gora-Williams, Zhu-Kroemer or Li-Kuhn. Also, in order to solve the PDMSE with Morse potential, we consider a superpotential leading to a special form of the exactly solvable Schrödinger equation of constant mass for a class of multiparameter exponential-type potential along with a proper mass distribution. The proposed approach is general and can be applied in the search of new potentials suitable on science of materials by looking into the viable choices of the mass function.

In the present work we show the implementation of a learning sequence based on an active learning methodology for teaching Physics, this proposal tends to promote a better learning in high school students with the use of a comic book and it combines the use of different low-cost experimental activities for teaching the electrical concepts of Current, Resistance and Voltage. We consider that this kind of strategy can be easily extrapolated to higher-education levels like Engineering-college/university level and other disciplines of Science. To evaluate this proposal, we used some conceptual questions from the Electric Circuits Concept Evaluation survey developed by Sokoloff and the results from this survey was analysed with the Normalized Conceptual Gain proposed by Hake and the Concentration Factor that was proposed by Bao and Redish, to identify the effectiveness of the methodology and the models that the students presented after and before the instruction, respectively. We found that this methodology was more effective than only the implementation of traditional lectures, we consider that these results cannot be generalized but gave us the opportunity to view many important approaches in Physics Education; finally, we will continue to apply the same experiment with more students, in the same and upper levels of education, to confirm and validate the effectiveness of this methodology proposal.

The use of computers has reported an exponential growth in the last decades, the possibility of carrying out several tasks for both professional and leisure purposes has contributed to the great acceptance by the users. The consequences and impact of uninterrupted tasks with computers screens or displays on the visual health, have grabbed researcher's attention. When spending long periods of time in front of a computer screen, human eyes are subjected to great efforts, which in turn triggers a set of symptoms known as Computer Vision Syndrome (CVS). Most common of them are: blurred vision, visual fatigue and Dry Eye Syndrome (DES) due to unappropriate lubrication of ocular surface when blinking decreases. An experimental protocol was de-signed and implemented to perform thermographic studies on healthy human eyes during exposure to dis-plays of computers, with the main purpose of comparing the existing differences in temperature variations of healthy ocular surfaces.

In this paper we consider the application of the integral transformations for image encryption through optical systems, a mathematical algorithm under Matlab platform using fractional Fourier transform (FrFT) and Random Phase Mask (RPM) for digital images encryption is implemented. The FrFT can be related to others integral transforms, such as: Fourier transform, Sine and Cosine transforms, Radial Hilbert transform, fractional Sine transform, fractional Cosine transform, fractional Hartley transform, fractional Wavelet transform and Gyrator transform, among other transforms. The encryption scheme is based on the use of the FrFT, the joint transform correlator and two RPMs, which provide security and robustness to the implemented security system. One of the RPMs used during encryption-decryption and the fractional order of the FrFT are the keys to improve security and make the system more resistant against security attacks.

We show the design and implementation of an optical polarimeter using electronic control. The polarimeter has a software with a graphical user interface (GUI) that controls the optoelectronic setup and captures the optical intensity measurement, and finally, this software evaluates the Stokes vector of a state of polarization (SOP) by means of the synchronous detection of optical waves. The proposed optoelectronic polarimeter can determine the Stokes vector of a SOP in a rapid and efficient way. Using the polarimeter proposed in this paper, the students will be able to observe (in an optical bench) and understand the different interactions of the SOP when the optical waves pass through to the linear polarizers and retarder waves plates. The polarimeter prototype could be used as a main tool for the students in order to learn the theory and experimental aspects of the SOP for optical waves via the Stokes vector measurement. The proposed polarimeter controlled by a GUI of Matlab is more attractive and suitable to teach and to learn the polarization of optical waves.

An X-pinch experiment using a load made of two 25-μm Tungsten wires was investigated. The X-pinch is a plasma produced by a powerful (~100 kA) current pulse that is applied to two or more slanted wires joined at the centre. The diagnostics employed included PIN diode detection, voltage and current measurement and pinhole X-ray photography. The results show that the X-rays emitted are initially thermal in nature and have energy ~7.7 keV and afterwards there is harder, non-isotropic radiation that can be attributed to a plasma interruption. The radiography shows that there is formation of a jet of plasma at the moment of maximum compression.

In this work we develop a new encryption system for encoded image in phase using the fractional Hartley transform (FrHT), truncation operations and random phase masks (RPMs). We introduce a simplification of the FrHT with the purpose of computing this transform in an efficient and fast way. The security of the encryption system is increased by using nonlinear operations, such as the phase encoding and the truncation operations. The image to encrypt (original image) is encoded in phase and the truncation operations applied in the encryption-decryption system are the amplitude and phase truncations. The encrypted image is protected by six keys, which are the two fractional orders of the FrHTs, the two RPMs and the two pseudorandom code images generated by the amplitude and phase truncation operations. All these keys have to be correct for a proper recovery of the original image in the decryption system. We present digital results that confirm our approach.

In this paper using the Fourier transform of order fractional, the ray transfer matrix for the symmetrical optical systems type ABCD and the formulae by Collins for the diffraction, we obtain explicitly the expression for scaled Fourier transform conventional; this result is the great importance in optical signal processing because it offers the possibility of scaling the size of output the Fourier distribution of the system, only by manipulating the distance of the diffraction object toward the thin lens, this research also emphasizes on practical limits when a finite spherical converging lens aperture is used. Digital simulation was carried out using the numerical platform of Matlab 7.1.

The Cherenkov radiation has been widely studied in transparent materials, and applied to detect and identify elementary particles. But it has not been widely studied in opaque materials. A four channels radiation detector has been designed, built, characterized, and operated; based on four polymaq (UHMW-PE) bars of 2.54 cm X 5.08 cm X 25.4 cm, which is an opaque material to visible radiation to the human eye. Silicon photo detectors, Hamamatsu, avalanche type (APD) are used to detect the radiation produced by the passage of particles in the detector blocks. The design, construction, characterization, operation, and preliminary results of this cosmic ray detector details are presented.

A new nonlinear system for image encryption using the Gyrator transform (GT) and the truncation operations is proposed in this work. The original image is encoded in phase at the beginning of the encryption process. The encryption-decryption system is based on the double random phase encoding (DRPE) in the Gyrator domain (GD). The rotation angle of the Gyrator transform is a new key that increases the security of the encryption system. The amplitude and phase truncation operations are nonlinear and no unitary, these truncation operations allow to select the information of amplitude or phase from a complex-valued image. We apply the truncation operations in the image encryption-decryption system in order to generate two new keys, convert the system in nonlinear and increase the security of the system. To retrieve the original image without error (noise-free) in the decryption system, it is needed all the correct security keys: the two RPMs, the rotation angle of the GT and the two key generated by the amplitude and phase truncation operations. The feasibility of this nonlinear encryption-decryption system is verified and analyzed by numerical simulations.

Information security with optical processing, such as the double random phase encoding and the Gabor transform (GT) has been investigated by various researchers. We present a two-dimensional (2-D) generalization of the one-dimensional GT. This 2-D GT is applied to encrypt digital images in this paper. The scaling factors of the GT can be used as new keys, providing a new encryption system with a high security characteristics. This method can encrypt and protect the information of the digital images with a high security for information processing systems.

Several research groups have proposed the electrical impedance tomography (EIT) in order to analyse lung ventilation. With the use of 16 electrodes, the EIT is capable to obtain a set of transversal section images of thorax. In previous works, we have obtained an alternating signal in terms of impedance corresponding to respiration from EIT images. Then, in order to transform those impedance changes into a measurable volume signal a set of calibration equations has been obtained. However, EIT technique is still expensive to attend outpatients in basics hospitals. For that reason, we propose the use of electrical bioimpedance (EBI) technique to monitor respiration behaviour. The aim of this study was to obtain a set of calibration equations to transform EBI impedance changes determined at 4 different frequencies into a measurable volume signal. In this study a group of 8 healthy males was assessed. From obtained results, a high mathematical adjustment in the group calibrations equations was evidenced. Then, the volume determinations obtained by EBI were compared with those obtained by our gold standard. Therefore, despite EBI does not provide a complete information about impedance vectors of lung compared with EIT, it is possible to monitor the respiration.

Nowadays the analyses of human movement, more specifically of the gait have ceased to be a priority for our species. Technological advances and implementations engineering have joined to obtain data and information regarding the gait cycle in another animal species. The aim of this paper is to analyze the canine gait in order to get results that describe the behavior of the limbs during the gait cycle. The research was performed by: 1. Dog training, where it is developed the step of adaptation and trust; 2. Filming gait cycle; 3. Data acquisition, in order to obtain values that describe the motion cycle canine and 4. Results, obtaining the kinematics variables involved in the march. Which are essential to determine the behavior of the limbs, as well as for the development of prosthetic or orthotic. This project was carried out with conventional equipment and using computational tools easily accessible.

This paper studied experimentally the behavior of a capillary microresonator made from PMMA polymer as a sensor for measuring relative humidity. In the manufactured device, the WGMs modes within the microcavity are excited by the proximity of an optical fiber Taper made from the stretching of a standard optical fiber of silica by the method of scanning flame with waist of the order of 3-5 μm. In the device, the field from a tunable laser system TLS is coupled into the capillary along its cross section where the resonant modes were observed WGMs into the cavity. When the system is subjected to change of the relative humidity of the external environment, the wavelengths of peaks resonances of WGMS modes of the resonant system experience a spectral shift, so that a sensitivity of the microresonator is observed at changes in humidity of the external environment. During the experiment, it was manufactured capillaries with different diameters and different wall thickness obtaining a sensitivity of the order of 0.07 nm/% RH for a capillary thickness 42.1 μm.

Analysis of the influence of void fraction distribution is very important to learn about the fission process and heat produced by the fuel assembly, here in this study several void fraction (VF) values along different burnup values have been considered in order to observe their influence in power distribution, uranium consumption, neutron flux andbehaviour for a GE-12 fuel assembly. For this study, burnups up to 60 MWd/kg and VF values up to 0.8 were considered setting the uranium enrichment at 3.5 weight percent at the start of every VF scenario, results show that higher void fractions reduce the thermal flux decreasing thermal fission and limiting heat production.

Dynamic self-assembly of confined non-Brownian spheres under gravity is investigated in terms of the statistical behavior of the like-gaseous particles closest to oscillating bottom. For strong vibrations, these particles resemble a quasi-two-dimensional gas (qtd-gas) that supports upper particles. By vibrational annealing, wet particles inside a commensurate rectangular container self-assembling into face-centered-cubic (fcc). From high temporal resolution images we study, by means of the associated Radial Distribution Function (RDF), the evolution in time of spatial correlations in the transition: qtd-gas to dense liquid of the vibrating particles closest to the oscillating bottom during self-assembly. As the vibrational annealing advances, the particles closest to the bottom reach this final position and the associated RDF shows a clear increase of the spatial correlation, which is congruent with the fcc crystallization phase.

The paper presents the results obtained from the numerical study of the dynamic properties of a straight channel 50 mm long and 780 μm wide on a 2D model. Numerical simulations were performed by using Navier-Stokes equation. The results showed a good agreement with experiments and other models. Pressure drop and friction factor of water in the channel in the studied ranges of Reynolds number are due to viscosity effects.

We introduce a nonsymmetric version of Jacobian elliptic functions. With these functions, we are able to obtain linear superposition solutions of the non-linear Schrödinger equation for a free condensate. These functions are more general than that of Jacobi and contain them as a special case. The eigenfunctions for a condensate in a box are considered.

The design and construction of an ultrasonic pulser is part of a multichannel ultrasonic system, for the analysis, monitoring and characterization of heterogeneous and highly dispersive materials. The pulser has been built on the FPGA platform and allowed to modify the pulse repetition rate, the pulse width and the number of pulses of a burst. This open architecture is a basic module for a more complex ultrasonic pulser, such as arbitrary pulse generator. The results show the ultrasonic transducer responses under the above parameters.

Numerical and approximate analytical solutions for the compact layer growth kinetics in a pure iron solid cylinder, during a plasma nitriding process, are obtained. The numerical simulations of the model are performed by using a front tracking finite difference scheme and the heat balance integral method. We propose a model where the main assumption is to consider a diffusion zone of constant thickness, which is solved for cylindrical symmetries. We present results for the time evolution of the compound layer, where the obtained solutions from both methods are consistent with the expected behaviour in the asymptotic time limit and experimental data from other authors.

A floating gate dosimeter was designed and fabricated in a standard CMOS technology. The design guides and characterization are presented. The characterization included the controlled charging by tunneling of the floating gate, and its discharging under irradiation while measuring the transistor drain current whose change is the measure of the absorbed dose. The resolution of the obtained device is close to 1 cGy satisfying the requirements for most radiation therapies dosimetry. Pending statistical proofs, the dosimeter is a potential candidate for wide in-vivo control of radiotherapy treatments.

ZnMnO thin films were grown on silicon substrates by pulsed laser deposition (PLD). Pulsed Nd:YAG laser was operated at a wavelength of 1064 nm and 100 mJ. ZnMnO thin films were deposited at the vacuum pressure of 10^-5 Torr and with substrate temperature from room temperature to 600 °C. The effects of substrate temperature on the structural and Optical properties of ZnMnO thin films have been investigated by X-ray diffraction (XRD), Raman spectroscopy and Uv-vis spectroscopy. From XRD data of the samples, it can be showed that temperature substrate does not change the orientation of ZnMnO thin films. All the films prepared have a hexagonal wurtzite structure, with a dominant (002) peak around 2θ=34.44° and grow mainly along the c-axis orientation. The substrate temperature improved the crystallinity of the deposited films. Uv-vis analysis showed that, the thin films exhibit high transmittance and low absorbance in the visible region. It was found that the energy band to 300 ° C is 3.2 eV, whereas for other temperatures the values were lower. Raman reveals the crystal quality of ZnMnO thin films.

In this work we studied experimentally the performance of an solid bottle optical resonator made of PMMA (polymethylmethacrylate) for measure the relative humidity of the medium. In the developed device, the WGMs modes within the microcavity are excited by the proximity of an optical fiber taper with an outer diameter of the order of 3-5 microns made from stretching a standard optical fiber of Silica by the flame brushing technique. In the resonant device, the field produced by a laser system tunable TLS is guided through the fiber taper and is coupled into the microcavity by the approach of the fiber taper to the equatorial zone of the microbottle, causing the excitation of the WGMs resonant modes inside the same. When the device is subjected to changes in relative humidity of the medium, the wavelengths of resonance of WGMs modes that have been coupled in the microresonator are shifted spectrally depending on the external humidity, showing an experimental sensitivity in the resonator due to changes in the relative humidity of the medium.

In the experiment, it was possible to produce different samples of optical resonators with a profile shaped bottle with different maximum diameters achieving a maximum sensitivity of 0.032 nm/% RH for a resonator with equatorial diameter of 1250 μm.

Due to lack of training doctors to identify many of the disorders in the heart by conventional listening, it is necessary to add an objective and methodological analysis to support this technique. In order to obtain information of the performance of the heart to be able to diagnose heart disease through a simple, cost-effective procedure by means of a data acquisition system, we have obtained Phonocardiograms (PCG), which are images of the sounds emitted by the heart. A program of acoustic, visual and artificial vision recognition was elaborated to interpret them. Based on the results of previous research of cardiologists a code of interpretation of PCG and associated diseases was elaborated. Also a site, within the university campus, of experimental sampling of cardiac data was created. Phonocardiography computer-aided is a viable and low cost procedure which provides additional medical information to make a diagnosis of complex heart diseases. We show some previous results.

TiN coatings have been widely studied in order to improve mechanical properties of steels. In this work, thin Ti/TiN films were prepared by plasma based immersion ion implantation and deposition (PBII&D) with a cathodic arc on AISI 1020 steel substrates. Substrates were exposed to the discharge during 1 min in vacuum for the deposition of a Tiunderlayer with the aim of improving the adhesion to the substrate. Then, a TiN layer was deposited during 6 min in a nitrogen environment at a pressure of 3xl0^-4 mbar. Samples were obtained at room temperature and at 300 °C, and with or without ion implantation in order to analyze differences between the effects of each treatment on the tribological properties. The mechanical and tribological properties of the films were characterized. The coatings deposited by PBII&D at 300 °C presented the highest hardness and young modulus, the best wear resistance and corrosion performance.

Entropy is a method of non-linear analysis that allows an estimate of the irregularity of a system, however, there are different types of computational entropy that were considered and tested in order to obtain one that would give an index of signals complexity taking into account the data number of the analysed time series, the computational resources demanded by the method, and the accuracy of the calculation. An algorithm for the generation of fractal time-series with a certain value of β was used for the characterization of the different entropy algorithms. We obtained a significant variation for most of the algorithms in terms of the series size, which could result counterproductive for the study of real signals of different lengths. The chosen method was sample entropy, which shows great independence of the series size. With this method, time series of heart interbeat intervals or tachograms of healthy subjects and patients with congestive heart failure were analysed. The calculation of sample entropy was carried out for 24-hour tachograms and time subseries of 6-hours for sleepiness and wakefulness. The comparison between the two populations shows a significant difference that is accentuated when the patient is sleeping.

A single and double layer formed by thin films coatings of aluminium oxide, zirconium oxide and titanium oxide were deposited over 304 stainless steel surface by ultrasonic spray pyrolysis technique. The steel samples were conformed for tensile tests. The purpose of these layers is to reduce hydrogen embrittlement effect in steel. An electrochemical cell was used in hydrogen charged, where a low concentration of sulfuric acid is utilized like electrolytic solution. Tension trials show the change the fracture type in samples with or without coating after hydrogen charged. The embrittlement percent factor and SEM micrographs indicate a reduction of hydrogen permeation for coated samples with double layer.

MEGARA is the new integral-field and multi-object optical spectrograph for the GTC. For medium and high resolution, the dispersive elements are volume phase holographic gratings, sandwiched between two flat windows and two prisms of high optical precision. The prisms are made of Ohara PBM2Y optical glass. After the prisms polishing process, some stains appeared on the surfaces. For this, in this work is shown the comparative study of five different products (muriatic acid, paint remover, sodium hydroxide, aqua regia and rare earth liquid polish) used for trying to eliminate the stains of the HR MEGARA prisms. It was found that by polishing with the hands the affected area, and using a towel like a kind of pad, and polish during five minutes using rare earth, the stains disappear completely affecting only a 5% the rms of the surface quality. Not so the use of the other products that did not show any apparent result.

This work focuses on the incorporation of sugarcane bagasse ash (SCBA) and silica fume (SF) wastes as an alternative raw material into clay bricks, replacing clay by up to 40 wt.%. Fly ash (FA) was used as reference. The plasticity of the batches was determined by Atterberg's consistency limits. Bricks were produced by uniaxial pressing and fired a 900 and 1000°C. Physical properties (fired shrinkage, water absorption, apparent porosity and Initial water absorption rate) and mechanical properties (compressive strength and flexural strength) as function of the firing temperature and type waste were investigated. The results showed that wastes into clay body increase its global plasticity. 80%Clay-20%SCBA mixture has the lower linear shrinkage. After firing process, the brick produced with clay-SCBA show the higher water absorption and apparent porosity, regardless of the firing temperature. The brick produced with 60%clay-40%SF show the water absorption and apparent porosity similar to control bricks. The SCBA waste additions tend to decrease the mechanical strength of the clay bricks, therefore amounts of 40% SCBA waste should be avoided because it reduce the mechanical strength of the red fired bricks. The fired bricks with 40% SF, firing a 900°C show mechanical properties similar control bricks.

Gravimeters are devices that can be used in a wide range of applications, such as mining, seismology, geodesy, archeology, geophysics and many others. These devices have great sensibility, which makes them susceptible to external vibrations like electromagnetic waves.

There are several technologies regarding gravimeters that are of use in industrial metrology. Optical fiber is immune to electromagnetic interference, and together with long period gratings can form high sensibility sensors of small size, offering advantages over other systems with different technologies.

This paper shows the development of an optical fiber gravimeter doped with Erbium that was characterized optically for loads going from 1 to 10 kg in a bandwidth between 1590nm to 1960nm, displaying a weight linear response against power. Later on this paper, the experimental results show that the previous described behavior can be modeled as characteristic function of the sensor.

This work proposes an electrical model that combines homogeneous and filamentary modes of an atmospheric pressure dielectric barrier discharge cell. A voltage controlled electric current source has been utilized to implement the power law equation that represents the homogeneous discharge mode, which starts when the gas breakdown voltage is reached. The filamentary mode implies the emergence of electric current conducting channels (microdischarges), to add this phenomenon an RC circuit commutated by an ideal switch has been proposed. The switch activation occurs at a higher voltage level than the gas breakdown voltage because it is necessary to impose a huge electric field that contributes to the appearance of streamers. The model allows the estimation of several electric parameters inside the reactor that cannot be measured. Also, it is possible to appreciate the modes of the DBD depending on the applied voltage magnitude. Finally, it has been recognized a good agreement between simulation outcomes and experimental results.

Zinc oxide (ZnO) nanostructures with different sizes and morphologies were synthesized using the Controlled Precipitation Method. It follows a standard process, but with different synthesis and washing solvents to modify the features related to the photocatalytic activity. The solid phase evolution during aging step was followed using Infrared Spectroscopy (FTIR) and the solids obtained, after the washing process, were characterized using X-ray diffraction (XRD). The Rietveld refinement indicates a Wurtzite phase (space group P63mc) as majority phase with lattice parameters a = 3.2530 Å and c = 5.2125 Å. Scanning electron microscopy (SEM) image shows a sponge-like morphology for the sample synthesized with ethylene glycol as solvent, acidified with nitric acid and washed with water. The sample synthesized and washed with water shows a needle-like morphology; and the sample synthesized in acetic acid and washed with water shows particles with undefined morphology. The optical properties of the as-prepared ZnO samples were investigated by UV-vis absorption spectroscopy. Finally, the photocatalytic activity of ZnO powders was studied from the initial rate of decomposition of H₂O₂ in aqueous solution. The best results were obtained with samples synthesized and washed with water; the influence of all the solvents on the morphology of ZnO samples and the effect of the morphologies on the photocatalytic activity are discussed.

Density functional theory and molecular dynamics were used to study the interaction of a graphene layer with the surface of lithium niobate. The simulations were performed at atmospheric pressure and 300K. We found that the graphene layer is physisorbed with an adsorption energy of -0.8205 eV/C-atom. Subsequently, the optical absorption of the graphene-(lithium niobate) system was calculated and compared with that of graphene solo and lithium niobate alone, respectively. The calculations were performed using the Quantum Espresso code with the GGA approximation and Vdw-DF2 (which includes long-range correlation effects as Van der Waals interactions).

In order to describe the cell dynamics of T-cells in a patient infected with HIV, we use a flavour of Perelson's model. This is a non-linear system of Ordinary Differential Equations that describes the evolution of healthy, latently infected, infected T-cell concentrations and the free viral cells. Different parameters in the equations give different dynamics. Considering the concentration of these types of cells is known for a particular patient, the inverse problem consists in estimating the parameters in the model. We solve this inverse problem using a Genetic Algorithm (GA) that minimizes the error between the solutions of the model and the data from the patient. These errors depend on the parameters of the GA, like mutation rate and population, although a detailed analysis of this dependence will be described elsewhere.

In this work the estimation of Reynolds number in a 2-dimensional Poiseuille flow is explored employing artificial neural networks (ANNs). The velocity fields of the fluids were generated evaluating the Hage-Poiseuille equation for different Reynolds (Re) from 20 to 2000. The velocity profile obtained for each case is used as input data for the ANNs, which is then trained to predict the Re. The results show an accuracy of at least of 99.5% in all prediction cases. This analysis is the first step towards the construction of a Machine Learning algorithm capable of computing physical parameters in more general scenarios.

The human ribs must be analyzed as long and as curved bones, due to their physiology. For the development of an experimental equipment that simulate the application of loads, over the rib in the moment of a frontal collision in an automobile with seat belt, it was applied a methodology that constituted in the identification of needs and the variables which led the design of 3D model, from this it was used the technique of fused deposition modeling for the development of the equipment pieces. The supports that hold the rib ends were design with two and three degrees of freedom that allows the simulation of rib movement with the spine and the breastbone in the breathing. For the simulation of the seat belt, it was determined to applied two loads over the front part of the rib from the sagittal and lateral plane respectively, for this it was made a displacement through a lineal actuator with a speed of 4mm/s. The outcomes shown a design of an equipment able to obtain the load parameters required to generate fractures in rib specimens. The equipment may be used for the study of specimens with nearby geometries to the rib taken as a reference.

In recent times it has established a debate between experts and academics about the social and economic impact of advances in robotics. The robotic exoskeletons mounted as suits on affected parts of the human body, represent one of the most significant examples of which is oriented towards robotics. With recent technological advances have increased the fields of application of these devices widely with respect to the first applications were teleoperation and increase in strength of a human being for various tasks. The aim of this work is to contribute as much as possible, to start a discussion about the vision of offering future developments in socio-economic terms and its impact resulting from the use of robotic exoskeletons, especially with regard to its application in medical rehabilitation of lower member and especially its use permanent, replacing cumbersome devices such as crutches, walkers, canes. All this, focused on the health sector, which is most affected by different diseases cannot have access to these devices. In this paper, only it proposes a design that could be inexpensive and used for various ailments.

We studied the possible catalytic effect that a transition metal atom could have after being adsorbed in a surface of hexagonal boron nitride (hBN). We considered platinum and titanium, performing ab-initio calculations, including molecular dynamics at 300K, within the Density Functional Theory. We considered an hBN surface either with a vacancy of a Boron atom, or with a vacancy of a Nitrogen atom, and we found that both titanium and platinum are absorbed at the place of the vacancy for both cases considered. Afterwards, we found that this decoration of the hBN surface indeed has a catalytic effect on the adsorption of a carbon monoxide molecule. Possible desorption was explored, at 800 K. To perform the calculations, the Quantum ESPRESSO package code was used. The generalized gradient corrected Perdew-Burke-Ernzerhof (PBE) approximation was used for the exchange and correlation functional.

The method of growing thin films PLD, is widely used in applications and possesses great potential in thin YBa₂Cu₃O_7-δ films production with outstanding physical properties. However, it is limited in nano and micro technology due to the presence of particles on the surface of the films. This article describes some causes that create these particles. YBa₂Cu₃O_7-δ films have been grown on electrolytic copper used as a variable model the distance target-substrate. The effects are studied through Scanning Electronic Microscopy. It is observed particles with a large variety of shapes and distributions. The results show that ranging the target-substrate distance, the superficial morphology is modified. An evidence of it, is that the evaporation of d_B-S = 7 cm, is more coherent that d_B-S = 3 cm. Therefore, exist a relation between the morphology and the parameters of growing. Also affect, the structural change that exists among the substrate and the film formation, the substrate preparation and it must not be monocrystalline, these factors define a kinetic and a mechanism of growing that promotes a heterogeneous nucleation.

A study of the correlation of lengths of words in large literary texts is presented. We use the statistical tools based on Allan factor and fractal dimension for estimating the fractal indices associated with the presence of correlations in the original sequences. We found that there is a scaling behavior at large scales for Allan factor with an exponent value, which reveals positive correlations. By means of the fractal dimension, we confirmed the presence of memory in the sequences of lengths of words. In addition, when considering a random rearrangement of the lengths of words in the original text, the fractal exponents are consistent with an uncorrelated process.

Nanocavities arrays were synthesized by electrochemical anodization of aluminum using oxalic and phosphoric acids as electrolytes. The morphology and topography of these structures were evaluated by SEM and AFM. Plasmonic properties of Al cavities arrays with different ordering and dimensions were analysed based on specular reflectivity. Al cavities arrays fabricated with phosphoric acid dramatically reduced the optical reflectivity as compared with unstructured Al. At the same time pronounced reflectivity dips were detectable in the 300nm-400nm range, which were ascribed to (0,1) plasmonic mode, and also a colored appearance in the samples is noticeably depending on the observation angle. These changes are not observed in samples made with oxalic acid and this fact was explained, based on a theoretical model, in terms that the surface plasmons are excited far in the UV range.

Inorganic As (V) and As (III) species are commonly found in groundwater in many countries around the world. It is known that arsenic is highly toxic and carcinogenic, at present exist reports of diverse countries with arsenic concentrations in drinking water higher than those proposed by the World Health Organization (10 μg/L). It has been reported that adsorption strategies using magnetic nanoparticles as magnetite (<20 nm) proved to be very efficient for the removal of arsenic in drinking water. Magnetic nanoparticles (magnetite) were prepared using a co-precipitation method with FeCl₃ and FeCl₂ as metal source and NaOH aqueous solution as precipitating agent. Magnetite nanoparticles synthesized were put in contact with As₂O₃ and As₂O₅ solutions at room temperature to pH 4 and 7. The nanoparticles were characterized by FT-IR, DRX, UV-vis, and XRF. The results showed that synthesized magnetite had an average diameter of 11 nm and a narrow size distribution. The presence of arsenic on magnetite nanoparticles surface was confirmed, which is more remarkable when As (V) is employed. Besides, it is possible to observe that no significant changes in the band gap values after adsorption of arsenic in the nanoparticles.

Nowadays, genetic algorithms stand out for airfoil optimisation, due to the virtues of mutation and crossing-over techniques. In this work we propose a genetic algorithm with arithmetic crossover rules. The optimisation criteria are taken to be the maximisation of both aerodynamic efficiency and lift coefficient, while minimising drag coefficient. Such algorithm shows greatly improvements in computational costs, as well as a high performance by obtaining optimised airfoils for Mexico City's specific wind conditions from generic wind turbines designed for higher Reynolds numbers, in few iterations.

Due to the importance of bioactive peptides, proteins and drug for pharmaceutical purpose, there is a growing interest for suitable delivery systems, able to increase their bioavailability and to target them to the desired location. Some of the most studied delivery systems involve encapsulation or entrapment of drugs into biocompatible polymeric devices. A multitude of techniques have been described for the synthesis of nanomaterials from polymers, however, the use of ionizing radiation (γ, e-), to obtain nano- and microgels polymer is characterized by the possibility of obtaining products with a high degree of purity. Although, in the world, electronic radiation is used for this purpose, gamma radiation has not been utilized for these purposes. In this paper is developed the formulation the formulation of Polyvinylpyrrolidone (PVP) nanogels synthesized by gamma radiation techniques, for their evaluation as potential system of drug delivery. Experiments were performed in absence of oxygen using aqueous solutions of PVP (0.05% -1%). Crosslinking reactions were carried out at 25° C in a gamma irradiation chamber with a ⁶⁰Co source (MPX-γ 30). The Viscosimetry, Light Scattering, X-Ray Diffraction and Transmission Electron Microscopy (TEM), were used as characterization techniques.

This paper presents an alternative way to the dynamic modeling of a rotational inverted pendulum using the classic mechanics known as Euler-Lagrange allows to find motion equations that describe our model. It also has a design of the basic model of the system in SolidWorks software, which based on the material and dimensions of the model provides some physical variables necessary for modeling. In order to verify the theoretical results, It was made a contrast between the solutions obtained by simulation SimMechanics-Matlab and the system of equations Euler-Lagrange, solved through ODE23tb method included in Matlab bookstores for solving equations systems of the type and order obtained. This article comprises a pendulum trajectory analysis by a phase space diagram that allows the identification of stable and unstable regions of the system.

In this paper the methodology of the so-called Linear Irreversible Thermodynamics (LIT) is applied; although traditionally used locally to study general systems in non-equilibrium states in which it is consider both internal and external contributions to the entropy increments in order to analyze the efficiency of two coupled processes with generalized fluxes J₁, J₂ and their corresponding forces X₁, X₂. We extend the former analysis to takes into account two different operating regimes namely: Omega Function and Efficient Power criterion, respectively. Results show analogies in the optimal performance between and we can say that there exist a criteria of optimization which can be used specially for biological systems where a good design of the biological parameters made by nature at maximum efficient power conditions lead to more efficient engines than those at the maximum power conditions or ecological conditions.

Diabetic retinopathy is a chronic disease and is the leading cause of blindness in the population. The fundamental problem is that diabetic retinopathy is usually asymptomatic in its early stage and, in advanced stages, it becomes incurable, hence the importance of early detection. To detect diabetic retinopathy, the ophthalmologist examines the fundus by ophthalmoscopy, after sends the patient to get a Retinography. Sometimes, these retinography are not of good quality. This paper show the implementation of a digital tool that facilitates to ophthalmologist provide better patient diagnosis suffering from diabetic retinopathy, informing them that type of retinopathy has and to what degree of severity is find . This tool develops an algorithm in Matlab based on Gabor transform and in the application of digital filters to provide better and higher quality of retinography. The performance of algorithm has been compared with conventional methods obtaining resulting filtered images with better contrast and higher.

An electronic system was designed to acquire tunneling current of a Scanning Tunneling Microscope. A tunneling current originates from the interaction between a conductive tip and a conductive or semiconductor sample. Lower currents than 100 nA were generated and from them, voltages were obtained in the order of 1 volt. Using this mechanism, it is possible to construct images of the atoms positions on the surface of the sample, also other properties of the materials can be studied.

The procedures in Interventional Radiology involve long times of exposure and high number of radiographic images that bring higher radiation doses to patients, staff and environmental than those received in conventional Radiology. Currently for monitoring the dose, the thermoluminescent dosimetry use is recommended. The aim of this work was to carry out the monitoring of the environmental scattered radiation inside the IR room using two types of thermoluminescent dosimeters, TLD-100 (reference dosimeter), CaSO4:Dy (synthesized in our laboratory). The results indicate that the TLD-100 is not effective for the environmental monitoring of low-energy Rx rooms. The CaSO4:Dy presented good behaviour over the 6 months of study. The results will be specific to each room so it is recommended such studies as part of the program of quality control of each Rx room.

Wireless communications have experienced a tremendous development during the last decade. The interaction of the electromagnetic waves as a function of the frequency and intensity with physical objects remains largely unknown. This poses the challenge to study the physical mechanisms involved to actually quantify the impact of the interaction with other objects caused by various electromagnetic waves-emitting sources. Here, we proposed the design of a plane SRR (Split-Ring Resonator) with metamaterial circular rings for S-Band frequency range. To guide the construction of the SRR prototype, simulations of the bandwidth were conducted using the Finite Integral technique. A logarithmic function describes the dependence of the simulated resonant frequency. The maximum simulated bandwidth of the SRR can be reached with an even number of concentric rings.

The Earth's crust is broken into a series of plates, whose borders are the seismic fault lines and it is where most of the earthquakes occur. This plating system can in principle be described by a set of nonlinear coupled equations describing the motion of the plates, its stresses, strains and other characteristics. Such a system of equations is very difficult to solve, and nonlinear parts leads to a chaotic behavior, which is not predictable. In 1989, Bak and Tang presented an earthquake model based on the sand pile cellular automata. The model though simple, provides similar results to those observed in actual earthquakes. In this work the cellular automata in three dimensions is proposed as a best model to approximate a seismic fault. It is noted that the three-dimensional model reproduces similar properties to those observed in real seismicity, especially, the Gutenberg-Richter law.

This paper presents a simple method based on Finite-Time Thermodynamics (FTT) to determine the thermal conductivity of atmospheric air. The method considers an atmospheric heat engine in which the air moves convectively on the border day-night driven by the Sun's energy. The numerical value obtained for the thermal conductivity reasonably accords with the reported value by Van Ness by the number of Rayleigh.

Photothermal systems were used to quantify thermal and optical properties of commercial and natural dairy products. Thermal diffusivity and light absorption coefficient were analyzed. It was found that water content easily alters thermal properties in samples of milk. In addition, all samples showed strong light absorptions at 405 nm, 980 nm and 488 nm, evidencing presence of proteins, fat and vitamins (riboflavin), respectively. Therefore, it was shown that thermo-physical properties measured in this work could be used as complementary parameters for quality evaluation of dairy products.

This work presents a method to calibrate the reference wavefront generated by an IDP. This wavefront is considered for quantitative evaluation of a plano-convex aspheric surface. Preliminary experimental results are presented.

With the purpose of assessing if the epitaxy on vapor phase technique "Close Space Vapor Deposition (CSVT)" is capable of produce thin films with adequate properties in order to manufacture p-n junctions, a study of invert and direct current was developed, in a temperature range of 94K to 293K, to junctions p-n of GaAs grown through the technique CSVT. It is shown that the dominant current, within the range 10^-7 to 10^-2 A, is consistent with a currents model of the type of internal emission form field, which shows these currents are due to the presence of localized states in the band gap.

The measurement of fluid velocity by encoding it in the phase of a magnetic resonance imaging (MRI) signal could allow the discrimination of the stationary spins signals from those of moving spins. This results in a wide variety of applications i.e. in medicine, in order to obtain more than angiograms, blood velocity images of veins, arteries and other vessels without having static tissue perturbing the signal of fluid in motion. The work presented in this paper is a theoretical analysis of some novel methods for multiple fluid velocity encoding in the phase of an MRI signal. These methods are based on a tripolar gradient (TPG) and can be an alternative to the conventional methods based on a bipolar gradient (BPG) and could be more suitable for multiple velocity encoding in the phase of an MRI signal.

Research was conducted to find materials in their natural state at room temperature and exhibit the effects of superconductivity in the volcanic region of deserts Altar in Sonora and Baja California Norte. 100 were collected at random samples of materials from different parts of the region and underwent tests to determine their electromagnetic parameters of electrical resistance, magnetism, temperature and conductivity. Only it has been found that the effects of superconductivity in them is only present at very low temperatures corroborating what has been done in other investigations, however no indication that there is a material or combination of materials that can produce the effects of superconductivity other temperatures so it is suggested to continue the search for such materials and / or develop a technique at room temperature to allow mimic the behavior of atoms when superconductivity occurs at.

The High Altitude Water Cherenkov (HAWC) Observatory is a ground-based air-shower array deployed on the hillside of the Sierra Negra Volcano in the state of Puebla, Mexico. HAWC comprises of 300 water Cherenkov detectors (WCDs), each WCD is equipped with four photomultiplier tubes (PMTs) to detect secondary particles of the air-showers that are produced by the interaction of a primary particle (gamma-rays and cosmic rays) with the atmosphere. HAWC is able to reconstruct gamma-ray showers in the 100 GeV - 100 TeV energy range, but suffers from a lack of sensitivity when the particle showers core develop outside the WCD array. A proposed upgrade to fix this issue is to build an external array of smaller water detectors, called outriggers. A Outrigger comprises a PMT on the bottom of the tank. In this work the instrumentation and characterizing an Outrigger is presented, in order to know the behavior of this detector with as function of threshold voltage.

The thermal and optical properties of selective absorber coatings of a solar cooker have been investigated. Coatings have been prepared using soot from pine resin, wood stove and sugarcane, previously separated by size. Results show that the cooking power and the overall efficiency of these pots are higher than others painted with black primer. Besides, by using an integrating sphere, the diffuse reflectance of absorbers has been obtained. Lower values of the reflectance have been measured for the pots covered with soot, showing a high correlation with the results achieved from the thermal tests, considering the measurement errors.

We present a study of some organizational properties of the oil transport network of the Mexican oil company (PEMEX) in a region of the State of Tabasco. Particularly, the generalized centrality and the distribution of connectivities are calculated in order to evaluate some aspects of the structure of the network. We find that the connectivities (k) are characterized by a degree distribution which follows a power-law function of the form, P(k)~k^−λ, with λ = 2.6. Moreover, our procedure permits to evalute the importance of lines (ducts) and nodes, which can be wells, production headers, separation batteries and petrochemical complexes.

In 1995, De Vos introduced a thermoeconomical analysis for heat engines working in finite time. This analysis was made by the maximization of a benefit function defined as the ratio of the power output and the total costs which are associated to the investment and the fuel consumption. The De Vos methodology has been applied to several heat engine models working at different regimes of performance. In the present work we apply this methodology to a simple model of a chemical engine which works between two reservoirs of constant chemical potential. In this work we take into account a diffusive transport law of particles. From the optimization of the benefit chemical functions defined as the ratio of some characteristic function (power output, efficient power and ecological function) and the total cost involved in the performance of the chemical engine, we obtain the optimal chemical efficiencies under different regimes of performance in an analogous way to the thermo-economic method proposed by De Vos.

The increasing of procedures using fluoroscopy in interventional cardiology procedures may increase medical and patients to levels of radiation that manifest in unintended outcomes. Such outcomes may include skin injury and cancer. The cardiologists and other staff members in interventional cardiology are usually working close to the area under examination and they receive the dose primarily from scattered radiation from the patient. Mexico does not have a formal policy for monitoring and recording the radiation dose delivered in hemodynamic establishments. Deterministic risk management can be improved by monitoring the radiation delivered from X-ray devices. The objective of this paper is to provide cardiologist, techniques, nurses, and all medical staff an information on DR levels, about X-ray risks and a simple a reliable method to control cumulative dose.

The diffusion coefficients characterizing the translational and rotational Brownian motion of a particle in a concentrated suspension were determined in the long time diffusive regime for a ferrofluid suspension with the use of a Langevin equation approach. These dynamical properties depend on the equilibrium micro-structural information of the suspension and take into account the effect of direct anisotropic inter-particle's interactions on self-diffusion. The comparison of this theory with Brownian dynamic simulations results is made in terms of colloid density and dipole interaction strength.

The effective pair interaction potentials of monovalent halide anions and alkali cations in bulk solution of a molecular solvent model were determined using atomistic simulations. These properties result from the microstructure of the ionic liquid which is the main ingredient in the hypernetted chain approach of liquid theory. We used an optimized set of Lennard-Jones parameters that are thermodynamically reliable for bulk phases of the Hofmeister salts.