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Towards the automatization of the Foucault knife-edge quantitative test

José de Jesús Villa Hernández JOSE ISMAEL DE LA ROSA VARGAS (2017)

Given the increasing necessity of simple, economical and reliable methods and instruments for performing quality tests of optical surfaces such as mirrors and lenses, in the recent years we resumed the study of the long forgotten Foucault knife-edge test from the point of view of the physical optics, ultimately achieving a closed mathematical expression that directly relates the knife-edge position along the displacement paraxial axis with the observable irradiance pattern, which later allowed us to propose a quantitative methodology for estimating the wavefronterror of an aspherical mirror with precision akin to interferometry.

In this work, we present a further improved digital image processing algorithm in which the sigmoidal cost-

function for calculating the transient slope-point of each associated intensity-illumination profile is replaced for

a simplified version of it, thus making the whole process of estimating the wavefront gradient remarkably more

stable and eficient, at the same time, the Fourier based algorithm employed for gradient integration has been

replaced as well for a regularized quadratic cost-function that allows a considerably easier introduction of the

region of interest (ROI) of the function, which solved by means of a linear gradient conjugate method largely

increases the overall accuracy and e ciency of the algorithm.

This revised approach of our methodology can be easily implemented and handled by most single-board mi-

crocontrollers in the market, hence enabling the implementation of a full-integrated automatized test apparatus,

opening a realistic path for even the proposal of a stand-alone optical mirror analyzer prototype.

Producción Científica de la Universidad Autónoma de Zacatecas UAZ

Conference paper

INGENIERÍA Y TECNOLOGÍA Optical testing Surface measurements

Mediciones de transmisión atmosférica y caracterización de filtros y películas delgadas en longitudes de onda sub-milimétricas y lejano infrarrojo con un espectrómetro de transformada de Fourier

SALVADOR VENTURA GONZALEZ (2011)

We present the first measurements of transmission through the atmosphere

and thin films (SiN and Ti) at sub-millimeter and far-infrared wavelengths using

a Fourier transform spectrometer (FTS) built in the millimeter instrumentation

laboratory at the National Institute of Astrophysics, Optics and Electronics.

The principles of operation and the most important physical components of the

spectrometer are explained by splitting the instrument into four main stages: the

Martin Puplett interferometer, the bolometric detector, the readout electronics

and data acquisition system.

This thesis presents the design of software for the acquisition and subsequent

analysis of data, including control of the mechanical parts, the adequate data

storage of each experiment, frequency calibration and phase correction of the

spectrum, as well as the computation of the transmission in the different mediums

analyzed. These programs and their results are widely described in this

document. In addition, we designed a vacuum chamber to house the FTS in order

to have better control over the humidity environment in which the interferometer

is installed, as well as enabling more sensitive characterizations of different gases

as part of future spectroscopic investigations.

The results show the ability of the FTS to be an instrument that can complement

the astronomical receivers during the operation of the Large Millimeter

Telescope by providing the atmospheric transmission above the site. Furthermore,

the FTS can be used in the development of filters and materials suitable for use

in the fabrication of bolometric detectors.

Se presentan las primeras mediciones de la transmisión en la atmósfera así

como en películas delgadas (SiN y Ti) en longitudes de onda sub-milimétricas y

lejano infrarrojo mediante el uso de un espectrómetro de transformada de Fourier

(FTS, por sus siglas en inglés) construido en el laboratorio de instrumentación

milimétrica del Instituto Nacional de Astrofísica, Óptica y Electrónica.

Los principios de operación y los componentes físicos más importantes del

espectrómetro son explicados, dividiendo al instrumento en cuatro etapas principales:

el interferómetro Martin Puplett, el detector bolométrico, la electrónica de

lectura y el sistema de adquisición de datos.

El presente trabajo se basó principalmente en el diseño de rutinas para la

correcta adquisición y posterior análisis de los datos, incluyendo el control de los

elementos móviles, el adecuado almacenamiento de la información obtenida en

cada experimento, la calibración en frecuencia y la corrección en fase del espectro,

así como el cómputo de la transmisión en los diferentes medios analizados. Estos

programas y los correspondientes resultados son ampliamente descritos en este

documento. Además, se diseñó una caja de purgado con la finalidad de tener

mayor control sobre el medio donde se encuentra instalado el interferómetro, lo que

permitirá la futura caracterización de gases de distintos tipos como una aplicación

útil en investigaciones espectroscópicas.

Los resultados muestran la capacidad del FTS para ser un instrumento que

puede complementar los receptores astronómicos durante la operación del Gran

Telescopio Milimétrico en tanto que permite la caracterización atmosférica del

sitio. Además, el FTS puede ser usado en el desarrollo de filtros y materiales

susceptibles a utilizarse en la fabricación de detectores bolométricos.

Master thesis

Fourier transform spectrometer Atmospheric spectra Millimetre waves Filters Measurements CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA ASTRONOMÍA Y ASTROFÍSICA

Growth of Ni nanoclusters on irradiated graphene: A molecular dynamics study

Felipe J Valencia ESTHER ELENA HERNANDEZ VAZQUEZ Eduardo M Bringa JOSE LUIS MORAN LOPEZ José Rogan Castillo Rafael I. Gonzalez Francisco Munoz (2018)

"We studied the soft landing of Ni atoms on a previously damaged graphene sheet by means of molecular dynamics simulations. We found a monotonic decrease of the cluster frequency as a function of its size, but few big clusters comprise an appreciable fraction of the total number of Ni atoms. The aggregation of Ni atoms is also modeled by means of a simple phenomenological model. The results are in clear contrast with the case of hard or energetic landing of metal atoms, where there is a tendency to form mono-disperse metal clusters. This behavior is attributed to the high diffusion of unattached Ni atoms, together with vacancies acting as capture centers. The findings of this work show that a simple study of the energetics of the system is not enough in the soft landing regime, where it is unavoidable to also consider the growth process of metal clusters."

Article

Reactive force-field Total-energy calculations Metal-clusters Adatom adsorption Surface Reaxff Diffusion Atoms Simulations interfaces BIOLOGÍA Y QUÍMICA QUÍMICA QUÍMICA

Surface and physicochemical characterization of phosphates vivianite, Fe2(PO4)3 and hydroxyapatite, Ca5(PO4)3OH

DANIEL LUNA ZARAGOZA ELIZABETH TERESITA ROMERO GUZMAN LAZARO RAYMUNDO REYES GUTIERREZ (2009)

"Hydroxyapatite is a calcium phosphate in the apatite group. It has numerous applications due to its particular properties including the sorption of metallic ions. This makes it useful for the treatment of contaminated groundwater and for soil decontamination. The least expensive source of hydroxyapatite for synthesis is bovine bone, since this is a waste material. Vivianite is an iron phosphate which has received little study. Like hydroxyapatite, it has particular properties. This paper describes the method of obtaining these phosphates; calcium phosphate from bovine bone, and iron phosphate by synthesis. Also described are the methods of purifying the materials and characterization of these two phosphates by X-ray diffraction, infrared analysis, thermogravimetric and differential scanning calorimetric analysis, scanning electron microscopy, and surface area by the BET method. Physicochemical characteristics of hydroxyapatite obtained from bovine bone are described, and preliminary results are presented of an investigation into whether hydroxyapatite and iron phosphate are suitable as a permeable reactive barrier for the treatment of metallic and radionuclide contaminants."

Article

Phosphates Surface Site density Mass titration CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA

Magnetic nanocomposites: preparation and characterization of Co-ferrite nanoparticles in a silica matrix

LUIS ALFONSO GARCIA CERDA JOSE ANDRES MATUTES AQUINO OSCAR EDUARDO AYALA VALENZUELA (2004)

Magnetic nanocomposites of Co-ferrite nanoparticles dispersed in silica matrix

(CoFe2O4/SiO2) have been prepared by the sol–gel technique using

tetraethylorthosilicate (TEOS) as precursor of silica, and metallic nitrates as precursors

of ferrite. Samples prepared in powder form have been dried at 100 °C for 3 h and

calcined for 2 h at temperatures between 500 and 1000 °C. Co-ferrite particles were

formed in the matrix pores and the nucleation of these particles was observed with the

increase in the calcining temperature. TEM measurements showed that the

nanoparticles had a fairly uniform morphology and an average particle size of

approximately 5 nm. The combination of different Co-ferrite concentrations and

calcining temperatures allowed to obtain samples with saturation magnetization ranging

from 0.7 to 21.8 emu/g.

Article

Sol–gel process Silica Magnetic measurements CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA OTRAS ESPECIALIDADES FÍSICAS OTRAS

Transmission line characterization on silicon considering arbitrary distribution of the series and shunt pad parasitics

REYDEZEL TORRES TORRES RAFAEL VENEGAS FERRER (2010)

This paper presents an analytical method to simultaneously determine the complex characteristic impedance and the pad parasitics of transmission lines fabricated on silicon. The method uses experimental two-port network parameters of two lines differing in length without the need of a reflect standard such as that required in TRL-like formulations. Furthermore, the losses associated with the silicon substrate are accurately considered using the experimentally determined complex propagation constant of the lines and three different configurations for the pad parasitics can be assumed. When using the extracted parameters in a model to represent transmission lines, excellent agreement between simulated and experimental data was achieved up to 50 GHz even for lines with lengths different to those used in the determination process.

Article

Interconnect De-embedding Transmission lines Microwave measurements CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ELECTRÓNICA ELECTRÓNICA

Human life signs detection using high-sensitivity pulsed laser vibrometer

Feng Jin SERGUEI STEPANOV Jacob Khurgin PONCIANO RODRIGUEZ MONTERO (2007)

We demonstrate experimentally the detection, in

a remote and noncontact manner, of human life signs using a

high-sensitivity pulsed laser vibrometer. The high surface displacement

detection sensitivity of the photo-electromotive-force

(photo-EMF) pulsed laser vibrometer, combined with its tolerance

to the presence and moderate temporal variations of optical

speckles in the light beams, allows the detection of human heartbeats,

breathing, and gross physical movement from essentially

any part of a human subject’s surface, even in the presence of

clothing, all the while without limiting the interrogation points to

specific locations like the chest and carotid areas. In contrast to

conventional Michelson interferometer-based laser vibrometers,

the photo-EMF pulsed laser vibrometer (PPLV) does not require

the use of retroreflective tapes or special electronic filtering to

retrieve vividly the biological subject’s life signs. Experimental

results demonstrating the detection of life signs from various parts

of biological subjects’ bodies, with or without the coverage of

clothing are presented. We also demonstrate the monitoring of a

human subject’s heart movements by interrogating the back of

his/her hand. Results from using PPLV to determine extremity

blood circulation at various levels of proximal occluding pressures

are also presented.

Article

Biomedical acoustics Biomedical measurements Medical diagnosis Optical velocity measurement Photodetectors Vibration measurement CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ÓPTICA

Preparation of magnetic latexes using styrene monomer

REBECA BETANCOURT GALINDO RUBEN SALDIVAR GUERRERO OLIVERIO SANTIAGO RODRIGUEZ FERNANDEZ LUIS ALFONSO GARCIA CERDA JOSE ANDRES MATUTES AQUINO (2004)

The preparation of magnetic latexes using styrene monomer was carried out via the miniemulsion polymerization technique. Magnetite

(Fe3O4), with an average size of 12 nmwas used as magnetic particles. An organic phasewas prepared dispersing the magnetite in styrene where

bis(2-ethyl, hexyl) sulphosuccinate (AOT) was used as dispersant. The dispersion was then miniemulsified in water using cethyltrimethyl

ammonium bromide (CTAB) as second emulsifier forming a stable emulsion. The miniemulsion polymerization was carried out at 60 ◦C and

was initiated with 2,2-Azobisisobutyronitrile (AIBN). The latexes obtained were characterized by X-ray diffraction (XRD), magnetometry

and transmission electron microscopy.

Article

Magnetic latexes Magnetic materials Magnetic measurements CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA OTRAS ESPECIALIDADES FÍSICAS OTRAS

Permittivity measurements at microwave frequencies using Epsilon-Ear-Zero (ENZ) tunnel structure

Humberto Lobato Morales ALONSO CORONA CHAVEZ JOSE LUIS OLVERA CERVANTES JUAN MARTINEZ BRITO (2011)

A planar epsilon-near-zero (ENZ) tunnel structure implemented on substrate integrated waveguide (SIW) technology is used to evaluate the complex dielectric permittivity of various materials. Design, optimization, and fabrication of the ENZ tunnel structure are explained. Simulations and measurements on various dielectric samples using the cavity perturbation technique of the proposed structure are presented. Measured values of the permittivity are in good agreement with standard values. Sensitivity analyses are performed on the ENZ structure and the conventional SIW cavity techniques. The proposed structure has very high sensitivity, which yields more accurate results when compared to other techniques, such as perturbation of conventional cavities.

Article

Cavity perturbation methods epsilon-near-zero (ENZ) Permittivity measurements substrate integrated waveguide (SIW) CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ELECTRÓNICA ELECTRÓNICA

DEVELOPMENT OF THE PARTICLE IMAGE VELOCIMETRY (PIV) TECHNIQUE FOR THREE DIMENSIONS: TUNNELING VELOCIMETRY

J. Ascención Guerrero Viramontes (2002)

"Conventional velocimetry has an intrinsic limitation because it yields 2D data, neglecting the third velocity component. For this reason, 3D-PIV has recently evolved as an area of research with success at the cost of increasing complexity in its methodology. The increased complexity and the limited optical access found in most industrial applications, meant that many of the 3D-PIV techniques, although of academic interest, cannot be used in practical industrial applications. For practical applications restricted viewing eliminates stereoscopic approaches. Lack of robustness and ease to perform an experiment make of conventional holography an unattractive option due to the fact that it involves a wet developing process, hence is very slow to yield results. However, its large depth of field and storing capacity makes it a technique that should, under the correct environment, be used. Scanning light-sheets are difficult to obtain for restricted optical access and high speeds, so they have not been tried in industrial conditions.

The required capabilities for 3D real-time measurement include the following three aspects: illumination of a volume rather than a plane, particle positioning in 3D from 2D camera information, and positioning calculation at low-magnification. Three-dimensional position and velocity information can be extracted by directly analyzing the diffraction patterns of seeding particles in imaging velocimetry using real-time CCD cameras. The Generalised Lorenz-Mie theory is shown to yield quantitative accurate models of particle position, such that it can be deduced with good accuracy from typical experimental particle images. Tunneling Velocimetry, the proposed technique to perform 3D velocity measurements, is able to provide the means to obtain particle images in a volume of interest rather than on a light sheet. Moreover, with this technique pressure and temperature measurements are feasible from the system background surface. The research reported here is concentrated in the experimental characterization of Tunneling Velocimetry and the problems involved with it. A discussion of the preliminary results is presented."

Doctoral thesis

3D-PIV Velocity measurement Temperature measurements Diffraction Tunneling velocimetry CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA FÍSICA DE FLUÍDOS FÍSICA DE FLUÍDOS