Revista Mexicana De Fisica最新文献

{"title":"A comparison of viscoelastic behavior of engineering elastomers under different stress and temperature","authors":"Jocelyn Arlet Juárez Hernández, J. A. Sotomayor-del-Moral, O. Susarrey-Huerta, L. Farfán-Cabrera, J. B. Pascual-Francisco","doi":"10.31349/revmexfis.69.031005","DOIUrl":"https://doi.org/10.31349/revmexfis.69.031005","url":null,"abstract":"In this work, a comparison of the viscoelastic creep behavior of five engineering elastomers (Ethylene-Propylene-Diene Monomer, Flouroelastomer, nitrile butadiene rubber, silicon rubber and neoprene/chloroprene rubber) is presented. Creep tests at different stress levels and temperatures were conducted using a “home-built” creep test device. A commercial equipment of Digital Image Correlation technique was implemented for the measurement of the time-dependent strains. The linear viscoelastic behavior regimes were determined by evaluating the creep compliance for each stress and temperature condition. Then, the creep curves obtained were fitted to a characteristic creep model, enabling the calculation of the viscoelastic parameters of each material. It was observed that the tested elastomers exhibited different elastic and viscous parameters, which were found to decrease with temperature. Particularly, it was observed that silicon rubber showed large instantaneous (elastic) strain and a small viscous deformation, whereas the Flouroelastomer rubber exhibited moderate strain curves, even at very high temperatures (100 °C and 120 °C), showing the highest creep resistance and the wider regime of linear viscoelastic behavior.  ","PeriodicalId":21538,"journal":{"name":"Revista Mexicana De Fisica","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49349626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dinámica molecular de grano grueso de la proteína tau","authors":"Luciano Robert-Jimenez, Susana Figueroa-Gerstenmaier, Gustavo Basurto-Islas., Salvador Herrera-Velarde","doi":"10.31349/revmexfis.69.031701","DOIUrl":"https://doi.org/10.31349/revmexfis.69.031701","url":null,"abstract":"Actualmente, a nivel mundial, alrededor de 48 millones de personas padecen la enfermedad de Alzheimer, la forma más común de demencia, para la cual no hay cura. La enfermedad se debe, parcialmente, a las alteraciones postraduccionales que experimenta la proteína tau y que favorecen su polimerización anormal formando fibrillas y marañas neurofibrilares. La tau es una proteína intrínsecamente desordenada, es decir, no posee una estructura bien definida. Una técnica eficaz en el estudio de este tipo de proteínas es la dinámica molecular. En este trabajo se utilizó dinámica molecular empleando el campo de fuerza SIRAH (del inglés: Southamerican Initiative for a Rapid and Accurate Hamiltonian) para modelar dos sistemas distintos de tau, cada uno con dos moléculas de proteína. En el primer sistema las dos proteínas están inmersas únicamente en agua (representada como solvente explícito) y en el segundo sistema, además del solvente, se agregaron iones para investigar la influencia de cargas en la posible agregación de tau. A partir de la trayectoria de 1 µs a una temperatura de 310 K, se analizaron los cambios estructurales que experimentaron los monómeros de tau. En ambos sistemas, las proteínas presentaron cambios importantes respecto a la configuración inicial; existiendo algunas diferencias en la estructura secundaria acorde a la presencia o ausencia de iones. Identificamos que, en ambos sistemas, no hay evidencia de un proceso agregativo. Los resultados validaron el uso del campo de fuerza SIRAH para estudiar proteínas de gran tamaño y la factibilidad de alcanzar escalas temporales y espaciales cercanas a las experimentales. Además, el análisis conformacional de las trayectorias obtenidas ofrece, por primera vez, una perspectiva desde la dinámica molecular de la forma en que interactúan dos proteínas tau completas, lo cual contribuye a la comprensión del fenómeno y a la identificación de las regiones de interacción proteína-proteína.","PeriodicalId":21538,"journal":{"name":"Revista Mexicana De Fisica","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43005811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Water adsorption on rutile titanium dioxide (110): Theoretical study of the effect of surface oxygen vacancies and water flux in the steady state case","authors":"Fatima Bouzidi, Moustafa Tadjine, A. Berbri, A. Bouhekka","doi":"10.31349/revmexfis.69.031004","DOIUrl":"https://doi.org/10.31349/revmexfis.69.031004","url":null,"abstract":"The aim purpose of the present work is highlighting the impact of surface oxygen vacancies and H2O flux on the behavior of water adsorption at the rutile titanium dioxide (110). Therefore, a theoretical model, based on molecular and dissociation mechanisms at different surface atomic sites, was formulated in a system of partial differential coupled equations. The proposed model used to study, in an atomic scale, this complex phenomenon of adsorption governed by several factors including surface vacancies defects and water flux. The findings of the solution of the system of equations in the steady state case, presented in this paper, strongly indicated that the rate coverage of surface oxygen vacancies has an important role in the dissociation of H2O as well as the flux which is a key factor in the behavior of water adsorption on the TiO2 (110) and the rate coverage of OH groups.","PeriodicalId":21538,"journal":{"name":"Revista Mexicana De Fisica","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46817449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crystalline native defects in ZnO analyzed by photoluminescence applying Maxwell-Boltzmann statistics in the visible region","authors":"M. A. Vicencio Garrido, O. R. Portillo Araiza, M. Chavez Portillo, O. Portillo, M. Lozano Espinoza","doi":"10.31349/revmexfis.69.021304","DOIUrl":"https://doi.org/10.31349/revmexfis.69.021304","url":null,"abstract":"Zinc oxide (ZnO (s) ) is prepared by Chemical Bath Deposition. This manuscript continues with previous research examining the Photoluminiecence  at UV-Vis-region.   According to emission bands situated at Vis-region by means of Photoluminescence, green (GE) and yellow emission (YE) bands are discussed, which are associated with native intrinsic crystalline defects. The Photoluminescence dependence with the trap density and the surface recombination velocity in the light of the Maxwell-Boltzmann theoretical model (MBM) results associated with the electronic transitions related to the native intrinsic defects situated at9 Vis-region are investigated. The trap density (cm -1 ) of nanocrystals located at range ~8.9-9.9  An approximate a theoretical-experimental kinetic model is presented, considering that the coordination complex ion is a key parameter in the crystal growth of ZnO (s) nanocrystals. The optimized geometry of [Zn(NH 3 ) 4 ] 2+ molecule was obtained with the DFT method using the functional of H-GGA B3LYP.","PeriodicalId":21538,"journal":{"name":"Revista Mexicana De Fisica","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43911336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flavor changing flavon decay ɸ→tc (ɸ = HF, AF ) at the high luminosity large hadron collider","authors":"M. Arroyo-Ureña, A. Fernández-Téllez, G. Tavares-Velasco","doi":"10.31349/revmexfis.69.020803","DOIUrl":"https://doi.org/10.31349/revmexfis.69.020803","url":null,"abstract":"We present a study of the flavor changing decays φ → tc (φ = HF, AF ) of the CP-even and CP-odd scalar flavons at the large hadron collider and its next stage, the high-luminosity large hadron collider. The theoretical framework is an extension of the standard model that incorporates an extra complex singlet and invokes the Froggatt-Nielsen mechanism with an Abelian flavor symmetry. The projected exclusion and discovery regions in terms of the model parameters are reported. We find that AF could be detected at the LHC by considering a reasonable scenario of the model parameter space. As far as HF is concerned, we also found promising results that could be verified experimentally at the high-luminosity LHC.","PeriodicalId":21538,"journal":{"name":"Revista Mexicana De Fisica","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44968231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Artificial neural network for the single-particle localization problem in quasiperiodic one-dimensional lattices","authors":"Gustavo Alexis Dominguez Castro, Rosario Paredes Gutiérrez","doi":"10.31349/revmexfis.69.020502","DOIUrl":"https://doi.org/10.31349/revmexfis.69.020502","url":null,"abstract":"The use of machine learning algorithms to address classification problems in several scientific branches has increased over the past years. In particular, the supervised learning technique with artificial neural networks has been successfully employed in classifying phases of matter. In this article, we use a fully connected feed-forward neural network to classify extended and localized single-particle states that arise from quasiperiodic one-dimensional lattices. We demonstrate that our neural network achieves to correctly uncover the nature of the single-particle states even when the wave functions come from a more complex Hamiltonian than the one used to train the network.","PeriodicalId":21538,"journal":{"name":"Revista Mexicana De Fisica","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47916646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extended Jacobi elliptic function solutions for general boussinesq systems","authors":"Sait San","doi":"10.31349/revmexfis.69.021401","DOIUrl":"https://doi.org/10.31349/revmexfis.69.021401","url":null,"abstract":"In this research paper, we have utilized the Jacobi elliptic function expansion method to obtain the exact solutions of (1+1)- dimensional Boussinesq System (GBQS). The most important difference that distinguishes this method from other methods is the parameters included in the auxiliary equation F’ (ξ) =  Ö P F4(ξ) + QF2(ξ) + R. As far as the authors know, there is no other study in which such a variety of solutions has been given. Depending on P, Q and R, nineteen the solitary wave and periodic wave solutions are obtained at their limit conditions. In addition, 3D and contour plot graphics for the constructed waves are investigated with the computer package program by giving special values to the parameters involved. The validity and reliability of the method is examined by its applications on a class of nonlinear evolution equations of special interest in nonlinear mathematical physics. The results were acquired to verify that the recommended method is applicable and reliable for the analytic treatment of a wide application of nonlinear phenomena","PeriodicalId":21538,"journal":{"name":"Revista Mexicana De Fisica","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47230945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Green chemistry synthesis and structural and optical study of Dy2(CO3)3→ Dy2O3 transition","authors":"O. Portillo, M. Chavez Portillo, H. Juarez Santiesteban, L. Serrano de la Rosa, J. Alvarado Pulido, Y. Ramos Reynoso","doi":"10.31349/revmexfis.69.021302","DOIUrl":"https://doi.org/10.31349/revmexfis.69.021302","url":null,"abstract":"This paper presents preliminary results of Dy2(CO3)3→Dy2O3 transition have been successfully obtained by Chemical Bath Deposition technical and subsequent thermal annealing temperature at ~600 °C. Two different temperatures of ~20°C and ~90 °C ± 2 °C are chosen to carry out the nanocrystalline growth. The crystalline phase is investigated by applying X-Ray Diffraction (XRD) and some optical properties; Transmittance, Reflectivity, Normalized Absorbance, real (n) and imaginary (k) parts refractive index. The crystalline phase of these inorganic nanomaterials for Dy2(CO3)3 is orthorhombic phase, while for Dy2O3 it is cubic. Grain size average values located at ranged ~2.8-3.4 nm for Dy2(CO3)3 and ~6.5-9.6 nm for Dy2O3. Vibrational modes are identified by Raman spectroscopy, modes at ~150-1800 cm-1 frequency range assigned to internal vibrations of  ion: v1-symmetric stretching (~1098 cm-1) v3-asymmetric -C-O stretching situated at ∼1063 cm-1, were observed corresponding to orthorhombic crystalline phase. The Fg+ Ag and A1g modes, corresponding to cubic phase Dy2O3. Multiple absorption bands with different relative intensities are observed at UV-Vis-NIR region, assigned to 4fs→4fs intra-electronic transitions and band gap energy. Absorption measurement were assigned to the transitions from ground state (6H15/2) to different excited states such as 4I13/2→4F7/2, 4I15/2, 6F3/2, 6F5/2, 6F7/2→6H5/2, 6F9/2→6H7/2, 6F11/2→6H9/2 and 6H11/2 of Dy3+ cation. Tauc’s plot reveals band gap situated at range ~4.66-5.17 eV for Dy2(CO3)3 and ~4.26-4.80 eV for Dy2O3 respectively.","PeriodicalId":21538,"journal":{"name":"Revista Mexicana De Fisica","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43391085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal characterization of tropospheric ozone fluctuation in Mexico City","authors":"Sergio Matias Gutierres, Edgar Israel Garcia-Otamendi, L. Morales Ruíz, Leonardo Palacios Luengas","doi":"10.31349/revmexfis.69.021402","DOIUrl":"https://doi.org/10.31349/revmexfis.69.021402","url":null,"abstract":"The air pollution due to tropospheric ozone (O3) is one of the most serious problems of large industrialized cities in the world. The excessive increase in O3 has a negative impact on the population health. Consequently, researchers have focused their efforts establishing measures to characterize the statistical analysis of spatio-temporal data. This work shows a study based on seasonal analysis of spatio-temporal data through second order structure function to and the scale behavior in power law by using the Hurst exponent (H) and analyzing the trend of fluctuations associated with O3 pollution concentration records at four monitoring stations in the Metropolitan Area of Mexico City (MAMC) considering the four season of the year. The records were consulted from the database of the Automatic Atmospheric Monitoring Network (AAMN) in Mexico City from 2010 to 2018. The results show the differences in behavior of ozone according to the seasons of the year in this megacity. The behavior of statistical persistence predominates in spring, with 63.89% of occurrence over the total of the samples analyzed. In winter, the observed regime is antipersistent, with 80.56%. The three regimes: persistence, randomness and antipersistence were observed in summer and autumn, with a similar proportion of occurrence of 33% ± 3%. Given the above, the climatological characteristics of each season could be associated with the regimes of persistent, random and antipersistent behavior of the fluctuation of the concentration of the pollutant O3","PeriodicalId":21538,"journal":{"name":"Revista Mexicana De Fisica","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42865750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detección y estudio de fotones producidos en Aluminio por incidencia de rayos cósmicos","authors":"N. Moreno, J. Félix","doi":"10.31349/revmexfis.69.020802","DOIUrl":"https://doi.org/10.31349/revmexfis.69.020802","url":null,"abstract":"Understanding the interaction between particles and matter is important for the advancement of new detection and particles properties measurement techniques. The result of interaction processes between incident particle and detection material is the production of photons, ions or both. The photon production in metal plaques due to cosmic rays incidence has not been reported to date. We planned, designed, built, characterized and operated an experimental system based on 10 × 10 cm Aluminium plates of various thicknesses and the photodiode Hamamatsu S12572-100P with which we show evidences of photon production in Aluminium due to cosmic rays incidence. We detected signals between violet and infrared with a minimum of dark counts, with approximately the same intensity, the same proportion between the different colors, and we show that they have characteristics that we associate with photons: absorption, reflection, refraction, dispersion and polarization, then we concluded that the detected signals must be produced by photons. The photons are produced inside the material by the incidence of cosmic rays. We observed that the greater the thickness of Aluminium traversed the greater the number of photons produced, in concordance with the very well known result that the greater the thickness of Aluminium traversed by the particle the greater the deposited energy. Some applications of this phenomenon are elementary particles detection, identification of materials, study of cosmic rays, study of ionizing radiation, etc. We present technical details of the experimental system, the physical results obtained, and outline possible explanations of this phenomenon.\u0000 \u0000El entendimiento de la interacción entre partículas y la materia es importante para el avance de nuevas técnicas de detección y medición de propiedades de las partículas. El resultado de los procesos de interacción partícula incidente y material de detección es la producción de fotones, de iones, o de ambos. A la fecha no se ha reportado la producción de fotones en placas metálicas por incidencia de rayos cósmicos. Planeamos, diseñamos, construimos, caracterizamos y operamos un sistema experimental, basado en placas de Aluminio de 10cm x 10cm de varios espesores y el fotodiodo Hamamatsu S12572-100P, con el que mostramos evidencias de la producción de fotones en Aluminio por incidencia de rayos cósmicos. Detectamos señales entre el violeta e infrarrojo, con un mínimo de cuentas oscuras, con aproximadamente la misma intensidad, la misma proporción, entre los diferentes colores, y mostramos que tienen características que asociamos a los fotones: absorción, reflexión, refracción, dispersión, y polarización, por lo que concluimos que deben de ser fotones las señales detectadas. Los fotones se producen en el interior del material por incidencia de rayos cósmicos. Observamos que a mayor espesor de Aluminio atravesado mayor número de fotones producidos, en concordancia con el resultado conocido que a mayor","PeriodicalId":21538,"journal":{"name":"Revista Mexicana De Fisica","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44601454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}