In this research, a technical study of induction hardening in a grey cast iron used in engine cylinder liners manufactured by LAVCO Ltda., a Colombian foundry company, was carried out. Metallurgical parameters such as austenitization temperature, cooling rate, and quenching sever...
Autor(es): David Alejandro Miranda. E L Castellanos-Leal. A E Coy. J G Barrero. J A González. O P Vesga Rueda.
Molecular and supramolecular systems are essentially mesoscopic in character. The electron self-exchange, in the case of energy fluctuations, or electron transfer/transport, in the case of the presence of an externally driven electrochemical potential, between mesoscopic sites is...
Autor(es): David Alejandro Miranda. Paulo R. Bueno.
El aumento de las propiedades mecánicas (dureza superficial) de las camisas de cilindro es uno de los objetivos de las empresas de fundición especializadas, en miras de aumentar la competitividad de sus productos en el mercado local y extranjero. El objetivo de este estudio se ce...
Autor(es): David Alejandro Miranda. Edgar L. Castellanos-Leal. Ana E. Coy. Jaime A. González. Olga P. Vesga Rueda.
The implementation of the JiTT (Just in Time Teaching) strategy is presented to increase the previous preparation of students enrolled in the subject Physics Laboratory I offered at the Industrial University of Santander (UIS), Colombia. In this study, a laboratory preparation qu...
Autor(es): David Alejandro Miranda. Oscar M. Forero. Melba J. Sanchez.
Hydration occurs when some ionic species are in pure water. In this research study, optical properties of an electrolytic solution with ionic species that emulated the extracellular environment were analyzed. The attenuated total reflection ATR-FTIR spectra and Raman spectra of e...
Autor(es): David Alejandro Miranda. Janeth Fernandez. Sandra Milena Pinto. Eduard Moreno.
The hypothesis being advanced in this paper is that there is a new medical paradigm emerging from the biomedical research carried out in this century, mainly due to the explosion of the so called ?omics? and associated techniques. The main idea is that there is a common pathway f...
Autor(es): David Alejandro Miranda. C.A.Gonzalez-Correa. E.Mulett-Vásquez. C.H.Gonzalez-Correa. P.A.Gómez-Buitrago.
A tetrapolar probe to measure the electrical properties of electrolyte solutions was implemented with gold electrodes according to the van der Pauw method. Electrical impedance spectroscopy (EIS) measurements of different concentrations of phosphate buffer saline (PBS) solution a...
Autor(es): David Alejandro Miranda. Angel Manuel Melendez. L. V. Herrera. C. V. Chaparro.
We herein demonstrate that capacitance spectroscopy (CS) experimentally allows access to the energy associated with the quantum mechanical ground state of many-electron systems. Priorly, electrochemical capacitance, C?[?], was previously understood from conceptual and computation...
Autor(es): David Alejandro Miranda. Paulo R. Bueno.
CuGaSe2 thin films have been synthesized by one-step electrodeposition on titanium and SnO2/glass substrates from aqueous solutions that contain thiocyanate ion as a complexing agent. According to composition, and morphology analysis at deposition potential of -0.55V vs SCE (Stan...
Autor(es): David Alejandro Miranda. L Manfredy. O P Marquez. S A Lopez-Rivera. J Marquez. Y Martínez.
Hg1-xCdxSe are II-VI semiconductors alloys with optoelectronic properties that depend upon the molar fraction x, which can be further controlled by nanostructuring. In this work one electron confined in a zero-dimensional lens-shaped nanostructure of Hg1-xCdxSe surrounded by a ma...
Autor(es): David Alejandro Miranda. J R Herrera. W Gutierrez.
Epidemiological studies have shown that cervical cancer is a public health problem in several countries. Early detection of cervical cancer contributes with a better prognos- tic to the patient. Traditionally, Pap test has been used to screening cervical cancer and its early dete...
Autor(es): David Alejandro Miranda. Lyda V. Herrera. C. Chaparro. Sandra P. Corzo. Sandra M. Pinto. G. Yáñez. Maryen Torres-Mejia. S. C. Méndez-Sanchez.
In this work we performed an electrolytic phan- tom based on an extracellular media containing different ionic species simulating extracellular electrical conductivities to study different cervical neoplastic stage which have been re- ported in the literature (1). An aqueous elec...
Autor(es): David Alejandro Miranda. Sandra M. Pinto. Sandra P. Corzo. Stelia C. Méndez-Sanchez.
Fibromyalgia (FM) is a condition characterized by chronic widespread pain and generalized tenderness, accompanied by fatigue, sleep disturbances and cognitive difficulties. The diagnosis is merely clinical, as no confirmatory objective method is available so far. Several types of...
Autor(es): David Alejandro Miranda. E. Colina-Gallo. C. A. González-Correa.
Until very recently, the colon was a neglected organ in science. During the present century, it has gained much attention, due to its role in health and disease, especially because of the presence of the microbiota. The interaction between the latter and human cells is made basic...
Autor(es): David Alejandro Miranda. Edelberto Mulett-Vásquez. Amilbia Correa-Flórez. Cármen Dussán-Lubert. Carlos-Augusto González-Correa.
Segmental Bioelectrical Impedance Analysis (SBIA) has been proposed as an alternative to overcome some limitations of total BIA measurements for the calculations of body composition. It also has been used in different clinical conditions such as ascites, edema, neuromuscular dama...
Autor(es): David Alejandro Miranda. E. Colina-Gallo. C. A. González-Correa. C. Dussán-Lubert.
La miografía por impedancia eléctrica es una técnica novedosa, rápida, fácil de usar, no invasiva e indolora y que permite obtener información sobre la estructura tisular, que no es posible obtener utilizando otras técnicas de electrodiagnóstico. Si bien, aún se trata de una técn...
Autor(es): David Alejandro Miranda. Evelyn Colina Gallo. Carlos Augusto González Correa.
There are two main methods widely used for CRC screening: Fecal occult blood tests (FOBT) and total colonoscopy (TC). Although not very expensive, the former lacks of good sensitivity and specificity, whereas the latter is expensive and not very well accepted by the general publi...
Autor(es): David Alejandro Miranda. C. Gonzalez-Correa. E. Mulett-Vasquez. M. Osorio-Chica . C. Dussan-Lubert.
An electrodeposition process from an aqueous bath of CdSO4, SeO2 and Hg2Cl2 at pH 2.3 was performed to synthesize two Hg1-xCdxSe alloys with x ? 0.8 onto TiO2. In order to establish an intimate contact between Hg1-xCdxSe and the TiO2 substrate, electrodeposition of Hg1-xCdxSe fil...
Autor(es): David Alejandro Miranda. Angel Manuel Melendez. F A González-Camacho. M Sánchez.
A new test electrochemical cell is described for monitoring the steel microbiologically induced corrosion and numerical simulations were performed using finite element method to demonstrate the suitability of the device. Carbon steel concentric ring-monitoring electrochemical cel...
Autor(es): David Alejandro Miranda. S. Fajardo. S. A. Jaimes. J. M. Bastidas.
A methodology to analyse electrochemical impedance spectroscopy (EIS) data for the study of microbiologically induced corrosion is proposed. The proposed methodology is based on the loss tangent behaviour of EIS spectra for sterile and bacteria-inoculated environments. Loss tange...
Autor(es): David Alejandro Miranda. S. A. Jaimes. J. M. Bastidas.
Early detection of cancer is an important subject to improve patient"s prognostic. Now breast cancer is one of more frequent cause of death in women around the world and new technologies to its early detection are being studied, e.g. optical properties of breast tissue. To contri...
Autor(es): David Alejandro Miranda. Karen Lorena Cristiano. Daniel Andres Triana.
Phonons vibrational frequencies for Hg1-xCdxSeHg1-xCdxSe (x - 0.5) crystalline alloys were theoretical and experimentally studied. Two simple expressions that summarize the optical modes behavior with composition were derived. Such that the behavior of the vibrational propertie...
Autor(es): David Alejandro Miranda. S. A. López R.. A. H. Romero.
Electrical properties of normal and neoplastic cervical tissues in a heterogeneous group of 56 Colombian women were studied by electrical impedance spectroscopy and a model based on the Generalized Effective-Medium Theory of Induced Polarization (GEMTIP). Differences between the ...
Autor(es): David Alejandro Miranda. Sandra Patricia Corzo. C A González Correa.
Phonons and crystalline structures of Hg1?xCdxSe alloys (0 ? x ? 0.5) were studied by Raman spectroscopy and X-ray powder diffraction patterns at 298K. The crystalline alloys were prepared by a special combination of synthesis and the Bridgman method. Experimental data showed a...
Autor(es): David Alejandro Miranda. S. A. López-Rivera. Ch. Power. J. A. Henao.
Electrical Impedance Spectroscopy (EIS) allows the study of the electrical properties of materials and structures such as biological tissues. EIS can be used as a diagnostic tool for the identification of pathological conditions such as cervical cancer. We used EIS in combination...
Autor(es): David Alejandro Miranda. Sandra Patricia Corzo. Carlos-A González-Correa.
Se reportan los resultados de un estudio piloto de las propiedades eléctricas del tejido epitelial de cuello uterino por medio de espectroscopia de impeditividad eléctrica, con el propósito de estudiar la detección temprana de la neoplasia intraepitelial con éste método. Para ell...
Autor(es): David Alejandro Miranda. Sandra Patricia Corzo. Ernesto Garcia. Yolima Estupiñan. Carlos-A. González-C.
Radiative recombination spectra of Hg0.5Cd0.5Se in the temperature range 11?110 K at different excitation power were investigated. A blue shift in the photoluminescence spectra that exposes the peculiarities of the electronic band structure of these alloys was observed. This phen...
Autor(es): David Alejandro Miranda. S. A. López?Rivera. J. J. Prías?Barragan. M. de los Ríos.
La espectroscopia de impeditividad eléctrica (EIE) es una técnica que permite estudiar las propiedades eléctricas de los materiales, como por ejemplo, el tejido humano. El objetivo de esta investigación fue comparar la EIE con la histopatología de cérvix y determinar la capacidad...
Autor(es): David Alejandro Miranda. Elga Johanna Vargas Carreño. Carlos Javier Zamora Rangel.
El estudio del comportamiento de una rata de laboratorio en el laberinto en cruz elevado (LCE) es empleado en la comprensión de algunos estados anímicos y en pruebas de medicamentos ansiolíticos y ansiogénicos. Algunos autores sugieren que el modelado computacional de una rata de...
Autor(es): David Alejandro Miranda. Sandra Patricia Corzo. C. A. Conde. C. C. Celis.
An algorithm is presented to determine the Cole-Cole parameters of electrical impedivity using only measurements of its real part. The algorithm is based on two multi-fold direct inversion methods for the Cole-Cole and Debye equations, respectively, and a genetic algorithm for ...
Autor(es): David Alejandro Miranda. S- A López Rivera.
A Van der Pauw electrolytic conductivimeter was development to calibrate an electrical resistivity probe. This conductivimeter is used in studies of early cancer screening because such studies require a measurement probe, i.e., tetra-polar probe, which needs to be calibrated. The...
Autor(es): David Alejandro Miranda. Samuel Alberto Jaimes. Juan Pablo Valencia Quintero.
Se presenta el análisis teórico de la fuente de corriente Howland con el fin de suministrar un criterio para la selección de los componentes pasivos y activos que la conforman. La metodología de estudio de la fuente de corriente Howland se hace en cuatro partes, primero se analiz...
Autor(es): David Alejandro Miranda. OSCAR ADOLFO AGUILERA ORTIZ. OSCAR JAVIER BAYONA VERGARA.
Se presenta una nueva teoría de muestreo para señales periódicas y aperiódicas de duración finita, y se postula y demuestra el teorema de muestreo por desfase y el teorema de muestreo por desfase generalizado. Además, se presenta la técnica de muestreo por desfase, su análisis d...
Autor(es): David Alejandro Miranda. JAIME GUILLERMO BARRERO PÉREZ.