2024-03-29T06:29:41Zhttps://bibdigital.epn.edu.ec/oai/requestoai:bibdigital.epn.edu.ec:15000/84242019-04-07T11:52:44Zcom_15000_8421com_15000_7554com_15000_7553com_15000_1col_15000_8422
Repositorio Digital - EPN
author
Díaz Campoverde, Carlos Wime
2014-08-18T20:08:50Z
2014-08-18T20:08:50Z
2007
T-MVE/0059/CD 0817
http://bibdigital.epn.edu.ec/handle/15000/8424
El creciente desarrollo de la sociedad y su entorno ha impulsado la investigación sobre nuevos materiales con propiedades y funciones particulares. Los polvos cerámicos avanzados de dimensiones manométricas están entre estos nuevos materiales ya que, por sus propiedades físicas, químicas y mecánicas, pueden ser utilizados en aplicaciones tecnológicas muy variadas. En este trabajo se sintetizó polvo cerámico de óxido de circonio con calcio por el método de precipitación controlada. Para esta síntesis se utilizó oxicloruro de circonio, acetato de calcio, ácido nítrico e hidróxido de amonio. La cantidad de calcio en el sistema fue de 15 y 20% molar. El polvo cerámico obtenido se sometió a un tratamiento térmico a 900oC durante 2 horas y su caracterización se realizó utilizando espectroscopia de infrarrojo para determinar grupos funcionales, difracción de rayos X para la estructura cristalina, y microscopía electrónica de barrido para determinar el tamaño y la morfología de las partículas obtenidas. De la caracterización de los polvos cerámicos se determinó que se obtuvieron los compuestos Zr0.8Ca0.2O1.8 y Zr0.85Ca0.15O1.85 de estructura cristalina cúbica, con tamaño de partícula de 2 y 3 ?m y aglomerados con tamaño promedio de 40 ?m. El siguiente paso en este trabajo fue la incorporación de nano partículas cerámicas previamente sintetizadas por el método de Pechini a una matriz epóxica, en una proporción de 2 y 4%. Para esto se empleó el método de incorporación in-situ. El objetivo fue formular nanocompuestos que podrían ser usados como revestimiento para proteger superficies metálicas sometidas a un ambiente corrosivo. Estos recubrimientos fueron aplicados sobre placas metálicas que luego fueron introducidas en una solución salina al 5% de NaCl para propósito de ensayo. En el trabajo se evaluó el grado de corrosión producido sobre la superficie metálica de las muestras revestidas y los efectos existentes sobre el revestimiento aplicado.
spa
openAccess
Ciencia e ingeniería de materiales
Materiales nanoestructurados
Obtención de nanopartículas mediante el método de precipitación controlada: caracterización e incorporación en matrices termoestables
masterThesis
Cg==
URL
/var/dspace/bitstream/15000/8424/3/CD-0817.pdf
File
MD5
c729d226b898acefe847f9fbe563de5f
2142822
application/pdf
CD-0817.pdf
URL
/var/dspace/bitstream/15000/8424/4/CD-0817.pdf.txt
File
MD5
79fcb1d3a3c34f857173e83b1b373656
156257
text/plain
CD-0817.pdf.txt
oai:bibdigital.epn.edu.ec:15000/84282019-04-07T11:46:55Zcom_15000_8421com_15000_7554com_15000_7553com_15000_1col_15000_8422
Repositorio Digital - EPN
author
Páez Gallardo, Sergio Antonio
author
Zavala Ruiz, Paulo Cristóbal
2014-08-18T20:25:24Z
2014-08-18T20:25:24Z
2007
T-MVE/0060/CD 0828
http://bibdigital.epn.edu.ec/handle/15000/8428
En este documento se desarrolla una metodología que permite incrementar la productividad de la fabricación de válvulas para cilindros de GLP de 15 kg, de uso doméstico, mediante la automatización del proceso de corte de bronce en la planta Esacontrol S. A. La automatización del proceso de corte de las barras de latón de bronce se realiza mediante el uso de controladores lógicos programables (PLC). Se presentan cuadros y gráficos que muestran la secuencia de operaciones que realizan los diferentes elementos en el transcurso del tiempo hasta conseguir completar un ciclo de corte. Se implementa el programa de control y se realizan las pruebas de funcionamiento respectivas, las cuales evidencian la mejora obtenida. Finalmente se mencionan las respectivas conclusiones y recomendaciones que se derivan del trabajo realizado.
spa
openAccess
Gestión y mejoramiento de la producción
Automatización industrial
Controladores lógicos programables
Incremento de la productividad en la fabricación de válvulas para cilindros de GLP de 15 Kg. De uso doméstico mediante la automatización del proceso de corte de las barras de bronce en la planta ESACONTROL S. A.
masterThesis
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
URL
/var/dspace/bitstream/15000/8428/3/CD-0828.pdf
File
MD5
fc222fb74e60bc5dcf621ced82dd19dd
1272082
application/pdf
CD-0828.pdf
URL
/var/dspace/bitstream/15000/8428/4/CD-0828.pdf.txt
File
MD5
ecb6e84acb86209f295e93506b768144
98239
text/plain
CD-0828.pdf.txt
oai:bibdigital.epn.edu.ec:15000/86582019-04-08T02:57:16Zcom_15000_8421com_15000_7554com_15000_7553com_15000_1col_15000_8422
Repositorio Digital - EPN
author
Flores Tamayo, Leonardo Patricio
2014-10-07T15:24:38Z
2014-10-07T15:24:38Z
2014-10-07
T-MVE / 0081 /CD-ROM 1515
http://bibdigital.epn.edu.ec/handle/15000/8658
La tesis está dividida en seis capítulos. En el primero se realiza una introducción y se definen los parámetros funcionales como capacidad de picado, fuente de poder, estacionalidad y precio. En el segundo capítulo se plantea el modelo para el análisis y se describe el funcionamiento teórico alrededor del cual se basara el desarrollo de la presente tesis. En el tercer capítulo se determina el ángulo ? entre la cuchilla móvil y la cuchilla fija considerando los diferentes parámetros geométricos que intervienen como diámetro del cilindro, longitud de la garganta de alimentación, longitud teórica de corte, capacidad teórica, número de cuchillas y además el par torsor, energía y potencia de corte. El cuarto capítulo comprende el análisis y diseño de todos los componentes del cilindro picador utilizando los modernos sistemas informáticos como el CAD/CAE para realizar tareas de creación, análisis y simulación en cada uno de ellos con el software Autodesk Inventor. El quinto capítulo desarrolla el proceso constructivo usando el CAM con la herramienta informática "MASTERCAM X". En el sexto capítulo se enumera las conclusiones y recomendaciones de la presente tesis.
spa
openAccess
ganadería
Elementos de máquinas
Diseño de un cilindro picador de forraje
masterThesis
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
URL
/var/dspace/bitstream/15000/8658/3/CD-1515.pdf
File
MD5
2b5fc804e657241c4d30caff71a8e6ae
2257866
application/pdf
CD-1515.pdf
URL
/var/dspace/bitstream/15000/8658/4/CD-1515.pdf.txt
File
MD5
64cb0a4dda800bbb7b295252e9b9fd1a
186785
text/plain
CD-1515.pdf.txt
URL
/var/dspace/bitstream/15000/8658/5/CD-1515.pdf.txt
File
MD5
64cb0a4dda800bbb7b295252e9b9fd1a
186785
text/plain
CD-1515.pdf.txt
URL
/var/dspace/bitstream/15000/8658/6/CD-1515.pdf.txt
File
MD5
64cb0a4dda800bbb7b295252e9b9fd1a
186785
text/plain
CD-1515.pdf.txt
oai:bibdigital.epn.edu.ec:15000/86602019-04-08T10:39:19Zcom_15000_8421com_15000_7554com_15000_7553com_15000_1col_15000_8422
Repositorio Digital - EPN
author
Olmedo Salazar, José Fernando
2014-10-07T15:35:38Z
2014-10-07T15:35:38Z
2014-10-07
T-MVE / 0080 /CD-ROM 1510
http://bibdigital.epn.edu.ec/handle/15000/8660
La presente tesis aborda el problema que supone el análisis de piezas complejas hechas de materiales compuestos y está articulada en desarrollos teóricos y prácticos. Los capítulos 1, 2 y 3 presentan el marco teórico previo que define y permite entender la mecánica de los compuestos. Dentro de la mecánica de los compuestos se parte de la unidad fundamental que es la lámina y se converge al laminado. La mecánica de un laminado se basa en dos teorías básicas: la teoría de Kirchhoff y la teoría de placas de Mindlin - Reissner. Puesto que la teoría presentada no permite analizar más que geometrías simples, se hace necesario acudir al método de los elementos finitos. En el capítulo 4 se revisa la teoría de elementos finitos basada en el principio de energía potencial mínima y su aplicación a compuestos, que permite determinar la matriz de rigidez del elemento finito, y se plantea un problema sencillo para entender el concepto de ensamblaje de varios elementos. Las complejidades verificadas aquí permiten concluir que la manera práctica de analizar una estructura hecha con compuestos es por medio de una herramienta computacional adecuada. Dado que es importante determinar los niveles de esfuerzos que puede soportar un elemento estructural sin perder su funcionalidad, en el capítulo 5 se estudia las teorías de falla. Los capítulos 6 y 7 ilustran la solución de un problema estructural mediante Ansys, para lo cual se escogió un chasis monocasco proveniente de una competición universitaria que es la fórmula SAE. Para ello se diseña las superficies del mencionado chasis y, utilizando las hipótesis de carga típicas para estos prototipos, se determinan desplazamientos y esfuerzos y se evalúan los criterios de falla para cada una de las hipótesis. Los resultados obtenidos dan la certeza de que Ansys se puede utilizar con confianza para resolver una amplia gama de problemas que involucren materiales compuestos.
spa
openAccess
materiales compuestos
elementos finitos
Diseño de estructuras tipo cáscara basadas en materiales compuestos laminares, utilizando el métodod de elementos finitos
masterThesis
URL
/var/dspace/bitstream/15000/8660/3/CD-1510.pdf
File
MD5
1e26336813bee77148539ad59ef4e0aa
6945594
application/pdf
CD-1510.pdf
URL
/var/dspace/bitstream/15000/8660/4/CD-1510.pdf.txt
File
MD5
04d744179e50a2ccf0fe46c31addd264
307627
text/plain
CD-1510.pdf.txt
URL
/var/dspace/bitstream/15000/8660/5/CD-1510.pdf.txt
File
MD5
04d744179e50a2ccf0fe46c31addd264
307627
text/plain
CD-1510.pdf.txt
URL
/var/dspace/bitstream/15000/8660/6/CD-1510.pdf.txt
File
MD5
04d744179e50a2ccf0fe46c31addd264
307627
text/plain
CD-1510.pdf.txt
oai:bibdigital.epn.edu.ec:15000/86642019-04-08T10:29:12Zcom_15000_8421com_15000_7554com_15000_7553com_15000_1col_15000_8422
Repositorio Digital - EPN
author
Soto Aymar, Luis Ricardo
2014-10-07T16:34:12Z
2014-10-07T16:34:12Z
2014-10-07
T-MVE / 0078 /CD-ROM 1497
http://bibdigital.epn.edu.ec/handle/15000/8664
El uso de los engranajes para la transmisión de movimiento se remonta hace cientos de años. Sin embargo el diseño de estos elementos es relativamente nuevo, a pesar de existir muchas investigaciones sobre el tema, es de gran interés el estudio de otros métodos que permitan realizar un análisis de esfuerzos de forma más exacta. El Método de los Elementos Finitos (MEF) constituye una gran herramienta para el diseño, aunque requiere de experiencia y de ciertos cuidados para que los resultados sean confiables. En el trabajo se realiza el análisis por el MEF y se comparan los resultados con los obtenidos mediante las fórmulas de AGMA. Para la simulación mediante el MEF se debe crear la geometría del engrane cilíndrico helicoidal, este es uno de los pasos más complicados. En la modelación se ha tratado de reproducir la geometría del engrane de la manera más exacta posible, para esto se utiliza el programa gratuito "TrueGear" que trabaja en el entorno de "AutoCAD". Con el modelo tridimensional del engrane se realiza el mallado. Para determinar el tamaño óptimo de la malla se crean varios modelos refinando cada vez más la malla, hasta encontrar la convergencia de la solución. Determinados los parámetros para el mallado se procede al análisis por el MEF mediante el programa "Algor". Se realizan múltiples simulaciones con variaciones en: el ángulo de hélice, el ancho de cara y el módulo con el fin de determinar el comportamiento y la validez de los resultados obtenidos.
spa
openAccess
diseño mecánico
elementos finitos
Análisis de esfuerzos de transmisiones de engranes cilíndricos helicoidales mediante el método de los elementos finitos
masterThesis
URL
/var/dspace/bitstream/15000/8664/1/CD-1497.pdf
File
MD5
40464bf1d6c51b701ec093d74654f426
9573717
application/pdf
CD-1497.pdf
URL
/var/dspace/bitstream/15000/8664/3/CD-1497.pdf.txt
File
MD5
be0ad5366d85525930e235b7be8a37df
170027
text/plain
CD-1497.pdf.txt
URL
/var/dspace/bitstream/15000/8664/4/CD-1497.pdf.txt
File
MD5
be0ad5366d85525930e235b7be8a37df
170027
text/plain
CD-1497.pdf.txt
oai:bibdigital.epn.edu.ec:15000/115142019-04-08T02:54:06Zcom_15000_8421com_15000_7554com_15000_7553com_15000_1col_15000_8422
Repositorio Digital - EPN
author
Echeverría Yánez, Luis Manuel
2015-09-15T19:33:28Z
2015-09-15T19:33:28Z
2015-06-18
Echeverría Yánez, L. M. (2015). Diseño y construcción de un flujómetro, tipo obstrucción, con sensor de presión tipo FSR®. 98 hojas. Quito : EPN.
T-MVE/0357/CD 6494
http://bibdigital.epn.edu.ec/handle/15000/11514
Considering that in automation processes, instrumentation is very important and among the instrumentation, the level measurement is critical, being quite onerous level sensors, this paper aims to develop an economic flowmeter, which uses as a secondary sensor, a resistive device type FSR (Force Sensitive Resistor). For the mechanical design, was used easy to get items in a hardware store, as ½ inch Ts and plugs. In the cap, two rubber membranes holding the shaft, in which end plate with a FSR 400 Short from Interlink Electronics is located. Rubber membranes guarantee some flexibility in assembly. Conditioning electronics is performed by means of the amplification circuitry with an LM358 amplifier and data acquisition through a UNO R3 by Arduino. Variable flow line was used for determining the static characteristic, through a compressor DARI Spider 25. To determine the actual flow in the line, a Venturi flowmeter is used with a differential manometer SDE3-D10D-B-HQ4-2P-M and a flowmeter SFAB-1000U. Experimental measurement results determined that the flow has a static characteristic nonlinearity of 7.64% and a hysteresis of 7.2% for a variation of airflow from 10 to 50 GPM.
spa
openAccess
Industria de instrumentación
Automatización industrial
Sensores
Diseño y construcción de un flujómetro, tipo obstrucción, con sensor de presión tipo FSR®
masterThesis
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
URL
/var/dspace/bitstream/15000/11514/1/CD-6494.pdf
File
MD5
eb12634e9c0e69741b61b0ace48c858f
10487829
application/pdf
CD-6494.pdf
URL
/var/dspace/bitstream/15000/11514/3/CD-6494.pdf.txt
File
MD5
34d18d9000aa172edb1b6b89554c1816
214414
text/plain
CD-6494.pdf.txt
URL
/var/dspace/bitstream/15000/11514/4/CD-6494.pdf.txt
File
MD5
34d18d9000aa172edb1b6b89554c1816
214414
text/plain
CD-6494.pdf.txt
oai:bibdigital.epn.edu.ec:15000/131332019-04-07T16:33:29Zcom_15000_8421com_15000_7554com_15000_7553com_15000_1col_15000_8422
Repositorio Digital - EPN
author
Suasti Salazar, José Ricardo
2016-01-12T22:08:47Z
2016-01-12T22:08:47Z
2006-01-01
Suasti Salazar, J. R. (2006). Desarrollo de un procedimiento par la rectificación de matrices en tornos CNC utilizando sistemas CAD/CAM y su aplicación para solucionar un problema industrial. 130 hojas. Quito : EPN.
T-MDES/0034/ CD 0092
http://bibdigital.epn.edu.ec/handle/15000/13133
spa
openAccess
Manufactura
Máquinas CNC
Torno CNC
Sistemas CAD/CAM
Desarrollo de un procedimiento par la rectificación de matrices en tornos CNC utilizando sistemas CAD/CAM y su aplicación para solucionar un problema industrial
masterThesis
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
URL
/var/dspace/bitstream/15000/13133/1/CD-0092.pdf
File
MD5
3986f7b59ec0c7eb0d7eb870b2f831ec
8359420
application/pdf
CD-0092.pdf
URL
/var/dspace/bitstream/15000/13133/3/CD-0092.pdf.txt
File
MD5
9ebcbdb0b3e247f38190dd18ca476ccd
148744
text/plain
CD-0092.pdf.txt
oai:bibdigital.epn.edu.ec:15000/228952022-09-07T13:39:00Zcom_15000_8421com_15000_7554com_15000_7553com_15000_1col_15000_8422
Repositorio Digital - EPN
author
López Alvarado, Queenny Kelly
2022-09-07T13:39:00Z
2022-09-07T13:39:00Z
2022-08
López Alvarado, Q.K.(2022). Caracterización de micro y nanoestructuras quitínicas de alas de mariposas del bosque tropical de Ecuador y su potencial aplicación.52 páginas. Quito : EPN.
T-MVE/0970/CD 12352
http://bibdigital.epn.edu.ec/handle/15000/22895
The nanostructures that make up butterfly wings are complex physical arrangements whose optical, thermal and mechanical properties are of interest in the field of materials science and engineering for the development of new materials. In this work, the characterization of wing nanostructures of 12 species of butterflies from the tropical forest of the Ecuadorian Chocó was carried out, which have a predominant flight in a defined vertical stratum of the forest (canopy, middle stratum and understory) with specific characteristics of light and temperature. For the characterization, microscopy, spectroscopy and thermogravimetry tests were used to identify particularities of the nanostructures of the species according to the forest stratum where they live. The results indicate that the chemical composition of the wings is similar for all species, however, there are significant differences in the predominant nanostructures and their response to the electromagnetic spectrum in the UV, visible and NIR ranges. The analyzed species, belonging to the Nymphalidae family, show higher light absorbance in the UV range followed by the NIR and the visible range, in addition, butterflies with predominant flight in the understory stratum show higher absorbance in the visible than those in the canopy and middle stratum, which also show a general nanostructural arrangement of the wings with fewer empty spaces and greater prominence of ridges and lamellae. This characterization is a first step to analyze opportunities for the development of biomimetic technologies whose performance could have more efficient and innovative results in relation to the electromagnetic spectrum ranges analyzed.
spa
openAccess
MICROSCOPÍA
ALAS DE MARIPOSA
BIOFÍSICA
ÓPTICA
Caracterización de micro y nanoestructuras quitínicas de alas de mariposas del bosque tropical de Ecuador y su potencial aplicación.
bachelorThesis
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
URL
/var/dspace/bitstream/15000/22895/1/CD%2012352.pdf
File
MD5
641cf4ec11430441429de2e35985d144
2389859
application/pdf
CD 12352.pdf
oai:bibdigital.epn.edu.ec:15000/236502023-03-06T15:53:14Zcom_15000_8421com_15000_7554com_15000_7553com_15000_1col_15000_8422
Repositorio Digital - EPN
author
García Vélez, David Giancarlo
2023-03-06T15:53:14Z
2023-03-06T15:53:14Z
2023-01
García Vélez, D.G.(2023). Síntesis limpia de nanopartículas magnéticas de óxido hierro y análisis de citotoxicidad.197 páginas. Quito : EPN.
T-MVE/1002/CD 12960
http://bibdigital.epn.edu.ec/handle/15000/23650
Magnetic iron oxide nanoparticles (MNPs-Fe) are nanomaterials that have gained attention in various bioapplications. Among them, antibacterial photothermal therapy (PTT) is an alternative to the problem that multi-drug resistant bacteria represent. The biocompatibility, stability, and functionalization of MNPs-Fe, among others, are properties of interest in antibacterial PTT. It was shown that orange waste from the local sale of orange juice could be incorporated into the circular economy. This is by taking advantage of its organic molecules through green synthesis, which allows obtaining MNPs-Fe in a fast and environmentally friendly way. This green approach provides for expanding the range of bioapplications in Fe-MNPs. Because its stability in solution was improved, aggregates were reduced, and cytotoxicity was enhanced (negligible at 250 µg/mL of MNPs-Fe) in mouse macrophages. The MNPs-Fe exhibited superparamagnetic behavior (SPM) over 60 K, surpassing their analogs obtained by coprecipitation and microwaves. Fe-MNPs inhibited gram-positive bacteria, such as S. aureus. and partially gram-negative bacteria, such as E. coli. The photothermal effect allowed reaching temperatures above 50 ⁰C, suggesting Fe-MNPs as photothermal agents (PTAs) comparable to broad-spectrum antibiotics. Due to the ease of being magnetically guided, the MNPS-Fe SPM proposes them as potential targeted drug delivery agents. Also, they can efficiently convert magnetic energy into heat. They do not have remanent magnetization and coercive field, ideal for cancer therapies.
spa
openAccess
NANOPARTÍCULAS SUPERPARAMAGNÉTICAS
TERAPIA FOTOTÉRMICA
CITOTOXICIDAD DE NANOPARTÍCULAS
MICROSCOPÍA CUANTITATIVA
Síntesis limpia de nanopartículas magnéticas de óxido hierro y análisis de citotoxicidad.
masterThesis
Tk9URTogUExBQ0UgWU9VUiBPV04gTElDRU5TRSBIRVJFClRoaXMgc2FtcGxlIGxpY2Vuc2UgaXMgcHJvdmlkZWQgZm9yIGluZm9ybWF0aW9uYWwgcHVycG9zZXMgb25seS4KCk5PTi1FWENMVVNJVkUgRElTVFJJQlVUSU9OIExJQ0VOU0UKCkJ5IHNpZ25pbmcgYW5kIHN1Ym1pdHRpbmcgdGhpcyBsaWNlbnNlLCB5b3UgKHRoZSBhdXRob3Iocykgb3IgY29weXJpZ2h0Cm93bmVyKSBncmFudHMgdG8gRFNwYWNlIFVuaXZlcnNpdHkgKERTVSkgdGhlIG5vbi1leGNsdXNpdmUgcmlnaHQgdG8gcmVwcm9kdWNlLAp0cmFuc2xhdGUgKGFzIGRlZmluZWQgYmVsb3cpLCBhbmQvb3IgZGlzdHJpYnV0ZSB5b3VyIHN1Ym1pc3Npb24gKGluY2x1ZGluZwp0aGUgYWJzdHJhY3QpIHdvcmxkd2lkZSBpbiBwcmludCBhbmQgZWxlY3Ryb25pYyBmb3JtYXQgYW5kIGluIGFueSBtZWRpdW0sCmluY2x1ZGluZyBidXQgbm90IGxpbWl0ZWQgdG8gYXVkaW8gb3IgdmlkZW8uCgpZb3UgYWdyZWUgdGhhdCBEU1UgbWF5LCB3aXRob3V0IGNoYW5naW5nIHRoZSBjb250ZW50LCB0cmFuc2xhdGUgdGhlCnN1Ym1pc3Npb24gdG8gYW55IG1lZGl1bSBvciBmb3JtYXQgZm9yIHRoZSBwdXJwb3NlIG9mIHByZXNlcnZhdGlvbi4KCllvdSBhbHNvIGFncmVlIHRoYXQgRFNVIG1heSBrZWVwIG1vcmUgdGhhbiBvbmUgY29weSBvZiB0aGlzIHN1Ym1pc3Npb24gZm9yCnB1cnBvc2VzIG9mIHNlY3VyaXR5LCBiYWNrLXVwIGFuZCBwcmVzZXJ2YXRpb24uCgpZb3UgcmVwcmVzZW50IHRoYXQgdGhlIHN1Ym1pc3Npb24gaXMgeW91ciBvcmlnaW5hbCB3b3JrLCBhbmQgdGhhdCB5b3UgaGF2ZQp0aGUgcmlnaHQgdG8gZ3JhbnQgdGhlIHJpZ2h0cyBjb250YWluZWQgaW4gdGhpcyBsaWNlbnNlLiBZb3UgYWxzbyByZXByZXNlbnQKdGhhdCB5b3VyIHN1Ym1pc3Npb24gZG9lcyBub3QsIHRvIHRoZSBiZXN0IG9mIHlvdXIga25vd2xlZGdlLCBpbmZyaW5nZSB1cG9uCmFueW9uZSdzIGNvcHlyaWdodC4KCklmIHRoZSBzdWJtaXNzaW9uIGNvbnRhaW5zIG1hdGVyaWFsIGZvciB3aGljaCB5b3UgZG8gbm90IGhvbGQgY29weXJpZ2h0LAp5b3UgcmVwcmVzZW50IHRoYXQgeW91IGhhdmUgb2J0YWluZWQgdGhlIHVucmVzdHJpY3RlZCBwZXJtaXNzaW9uIG9mIHRoZQpjb3B5cmlnaHQgb3duZXIgdG8gZ3JhbnQgRFNVIHRoZSByaWdodHMgcmVxdWlyZWQgYnkgdGhpcyBsaWNlbnNlLCBhbmQgdGhhdApzdWNoIHRoaXJkLXBhcnR5IG93bmVkIG1hdGVyaWFsIGlzIGNsZWFybHkgaWRlbnRpZmllZCBhbmQgYWNrbm93bGVkZ2VkCndpdGhpbiB0aGUgdGV4dCBvciBjb250ZW50IG9mIHRoZSBzdWJtaXNzaW9uLgoKSUYgVEhFIFNVQk1JU1NJT04gSVMgQkFTRUQgVVBPTiBXT1JLIFRIQVQgSEFTIEJFRU4gU1BPTlNPUkVEIE9SIFNVUFBPUlRFRApCWSBBTiBBR0VOQ1kgT1IgT1JHQU5JWkFUSU9OIE9USEVSIFRIQU4gRFNVLCBZT1UgUkVQUkVTRU5UIFRIQVQgWU9VIEhBVkUKRlVMRklMTEVEIEFOWSBSSUdIVCBPRiBSRVZJRVcgT1IgT1RIRVIgT0JMSUdBVElPTlMgUkVRVUlSRUQgQlkgU1VDSApDT05UUkFDVCBPUiBBR1JFRU1FTlQuCgpEU1Ugd2lsbCBjbGVhcmx5IGlkZW50aWZ5IHlvdXIgbmFtZShzKSBhcyB0aGUgYXV0aG9yKHMpIG9yIG93bmVyKHMpIG9mIHRoZQpzdWJtaXNzaW9uLCBhbmQgd2lsbCBub3QgbWFrZSBhbnkgYWx0ZXJhdGlvbiwgb3RoZXIgdGhhbiBhcyBhbGxvd2VkIGJ5IHRoaXMKbGljZW5zZSwgdG8geW91ciBzdWJtaXNzaW9uLgo=
URL
/var/dspace/bitstream/15000/23650/1/CD%2012960.pdf
File
MD5
7e350cffb6f5a6bd784124d3480fbfc4
9817306
application/pdf
CD 12960.pdf
oai:bibdigital.epn.edu.ec:15000/236942023-03-27T20:07:28Zcom_15000_8421com_15000_7554com_15000_7553com_15000_1col_15000_8422
Repositorio Digital - EPN
author
Moyano Quishpe, Karla Estefanía
2023-03-27T20:07:28Z
2023-03-27T20:07:28Z
2023-03
Moyano Quishpe, K.E.(2023). Análisis de los efectos causados por irradiación de un haz de electrones de 1 a 10 keV sobre películas de grafeno. 59 páginas. Quito : EPN.
T-MVE 1013/CD 13004
http://bibdigital.epn.edu.ec/handle/15000/23694
Graphene-based materials are currently widely studied due to their unique properties. In the present research work, graphene oxide was synthesized by electrochemical exfoliation of graphite sheets. With the obtained material, thin films were made on glass and irradiated with an electron beam varying the energy from 0.5 keV to 10 keV. A reduction in sheet resistance was observed in the irradiated films when the energy of the electrons increased. In this way, a maximum reduction of 17.28 % of the sheet resistance was obtained when a sample was irradiated with 10 keV for 30 min. The ID/ID' ratio was below 3.5 for all Raman spectra before and after irradiation, which showed the existence of edge defects present in graphene oxide. Whereas, in most cases, the ID/IG ratio is reduced when the irradiation energy is increased. On the other hand, FTIR and XPS spectra showed a reduction of oxygenated functional groups after irradiation. The results suggest that there is a reduction of graphene oxide after irradiation with the electron beam, which increases the conduction of the material.
spa
openAccess
ELECTRONES
ÓXIDO DE GRAFENO
RESISTENCIA LAMINAR
MECÁNICA
Análisis de los efectos causados por irradiación de un haz de electrones de 1 a 10 keV sobre películas de grafeno.
bachelorThesis
Tk9URTogUExBQ0UgWU9VUiBPV04gTElDRU5TRSBIRVJFClRoaXMgc2FtcGxlIGxpY2Vuc2UgaXMgcHJvdmlkZWQgZm9yIGluZm9ybWF0aW9uYWwgcHVycG9zZXMgb25seS4KCk5PTi1FWENMVVNJVkUgRElTVFJJQlVUSU9OIExJQ0VOU0UKCkJ5IHNpZ25pbmcgYW5kIHN1Ym1pdHRpbmcgdGhpcyBsaWNlbnNlLCB5b3UgKHRoZSBhdXRob3Iocykgb3IgY29weXJpZ2h0Cm93bmVyKSBncmFudHMgdG8gRFNwYWNlIFVuaXZlcnNpdHkgKERTVSkgdGhlIG5vbi1leGNsdXNpdmUgcmlnaHQgdG8gcmVwcm9kdWNlLAp0cmFuc2xhdGUgKGFzIGRlZmluZWQgYmVsb3cpLCBhbmQvb3IgZGlzdHJpYnV0ZSB5b3VyIHN1Ym1pc3Npb24gKGluY2x1ZGluZwp0aGUgYWJzdHJhY3QpIHdvcmxkd2lkZSBpbiBwcmludCBhbmQgZWxlY3Ryb25pYyBmb3JtYXQgYW5kIGluIGFueSBtZWRpdW0sCmluY2x1ZGluZyBidXQgbm90IGxpbWl0ZWQgdG8gYXVkaW8gb3IgdmlkZW8uCgpZb3UgYWdyZWUgdGhhdCBEU1UgbWF5LCB3aXRob3V0IGNoYW5naW5nIHRoZSBjb250ZW50LCB0cmFuc2xhdGUgdGhlCnN1Ym1pc3Npb24gdG8gYW55IG1lZGl1bSBvciBmb3JtYXQgZm9yIHRoZSBwdXJwb3NlIG9mIHByZXNlcnZhdGlvbi4KCllvdSBhbHNvIGFncmVlIHRoYXQgRFNVIG1heSBrZWVwIG1vcmUgdGhhbiBvbmUgY29weSBvZiB0aGlzIHN1Ym1pc3Npb24gZm9yCnB1cnBvc2VzIG9mIHNlY3VyaXR5LCBiYWNrLXVwIGFuZCBwcmVzZXJ2YXRpb24uCgpZb3UgcmVwcmVzZW50IHRoYXQgdGhlIHN1Ym1pc3Npb24gaXMgeW91ciBvcmlnaW5hbCB3b3JrLCBhbmQgdGhhdCB5b3UgaGF2ZQp0aGUgcmlnaHQgdG8gZ3JhbnQgdGhlIHJpZ2h0cyBjb250YWluZWQgaW4gdGhpcyBsaWNlbnNlLiBZb3UgYWxzbyByZXByZXNlbnQKdGhhdCB5b3VyIHN1Ym1pc3Npb24gZG9lcyBub3QsIHRvIHRoZSBiZXN0IG9mIHlvdXIga25vd2xlZGdlLCBpbmZyaW5nZSB1cG9uCmFueW9uZSdzIGNvcHlyaWdodC4KCklmIHRoZSBzdWJtaXNzaW9uIGNvbnRhaW5zIG1hdGVyaWFsIGZvciB3aGljaCB5b3UgZG8gbm90IGhvbGQgY29weXJpZ2h0LAp5b3UgcmVwcmVzZW50IHRoYXQgeW91IGhhdmUgb2J0YWluZWQgdGhlIHVucmVzdHJpY3RlZCBwZXJtaXNzaW9uIG9mIHRoZQpjb3B5cmlnaHQgb3duZXIgdG8gZ3JhbnQgRFNVIHRoZSByaWdodHMgcmVxdWlyZWQgYnkgdGhpcyBsaWNlbnNlLCBhbmQgdGhhdApzdWNoIHRoaXJkLXBhcnR5IG93bmVkIG1hdGVyaWFsIGlzIGNsZWFybHkgaWRlbnRpZmllZCBhbmQgYWNrbm93bGVkZ2VkCndpdGhpbiB0aGUgdGV4dCBvciBjb250ZW50IG9mIHRoZSBzdWJtaXNzaW9uLgoKSUYgVEhFIFNVQk1JU1NJT04gSVMgQkFTRUQgVVBPTiBXT1JLIFRIQVQgSEFTIEJFRU4gU1BPTlNPUkVEIE9SIFNVUFBPUlRFRApCWSBBTiBBR0VOQ1kgT1IgT1JHQU5JWkFUSU9OIE9USEVSIFRIQU4gRFNVLCBZT1UgUkVQUkVTRU5UIFRIQVQgWU9VIEhBVkUKRlVMRklMTEVEIEFOWSBSSUdIVCBPRiBSRVZJRVcgT1IgT1RIRVIgT0JMSUdBVElPTlMgUkVRVUlSRUQgQlkgU1VDSApDT05UUkFDVCBPUiBBR1JFRU1FTlQuCgpEU1Ugd2lsbCBjbGVhcmx5IGlkZW50aWZ5IHlvdXIgbmFtZShzKSBhcyB0aGUgYXV0aG9yKHMpIG9yIG93bmVyKHMpIG9mIHRoZQpzdWJtaXNzaW9uLCBhbmQgd2lsbCBub3QgbWFrZSBhbnkgYWx0ZXJhdGlvbiwgb3RoZXIgdGhhbiBhcyBhbGxvd2VkIGJ5IHRoaXMKbGljZW5zZSwgdG8geW91ciBzdWJtaXNzaW9uLgo=
URL
/var/dspace/bitstream/15000/23694/1/CD%2013004.pdf
File
MD5
cf2fca3a7b403859274197ba4aa72fb8
1562583
application/pdf
CD 13004.pdf
oai:bibdigital.epn.edu.ec:15000/247392023-08-09T18:26:18Zcom_15000_8421com_15000_7554com_15000_7553com_15000_1col_15000_8422
Repositorio Digital - EPN
author
Cuadrado Pumalema, Coralía Fabiola
2023-08-09T18:26:18Z
2023-08-09T18:26:18Z
2023-07
Cuadrado Pumalema, C.F. (2023). Evaluación del efecto antimicrobial de amplio espectro de los nanocompósitos magnéticos a base de óxido de grafeno y nanotubos de carbono de pared múltiple basados en la acción bimodal fotodinámico/fototérmico. 106 páginas. Quito : EPN.
T-MVE 1035/CD 13454
http://bibdigital.epn.edu.ec/handle/15000/24739
Throughout history, microbial diseases caused by microorganisms such as bacteria, viruses, fungi, and protozoa, have had a significant impact on humanity, causing millions of deaths and affecting entire communities. For this reason, in recent years there has been a great interest in the development of antimicrobial nanocomposites that can combat this threat. In the present research, magnetic nanocomposites based on multi-walled carbon nanotubes (MWCNT) and graphene oxide (GO) were obtained. These magnetic nanocomposites were synthesized in three steps: first, the coprecipitation synthesis of magnetic nanoparticles in graphene oxide and magnetic nanoparticles in multi-walled carbon nanotubes, obtaining the first two nanocomposites MNPs-GO and MNPs-MWCNTs, respectively; second, functionalization with the photosensitizer Menthol-Zinc Phthalocyanine (ZnMintPc); and finally, the magnetic nanocomposites MNPs-GO and MNPs-MWCNTs carrying ZnMintPc (MNPs-MWCNTs-ZnMintPc and MNPs-GO-ZnMintPc) were dispersed in the biocompatible hydrogel poly(N-vinyl caprolactam-co-poly(ethylene glycol) diacrylate) poly(VCL-co-PEGDA) abbreviated as VCL/PEGDA, thus obtaining the third and fourth magnetic nanocomposite: VCL/PEGDA-MNPs-GO-ZnMintPc and VCL/PEGDA-MNPs-MWCNTs-ZnMintPc. This study addressed the optical, morphological, magnetic, and photophysical properties of nanocomposites. The in vitro antimicrobial effect of the four magnetic nanocomposites obtained on the bacteria Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and the yeast Candida albicans (C. albicans) was evaluated based on the photodynamic/photothermal effect (PTT/PDT) applying a wavelength of 630 nm and a light dose of 65.5 mW·cm−2. The results obtained in the study of the antimicrobial effect showed that the colonies of C. albicans were completely eliminated by the MNPs-GO (MNP=93,3 μg·mL-1, GO=3.47 μg·mL-1) and MNPs-MWCNTs (MNP=93,3 μg·mL-1, MWCNT=3.47 μg·mL-1) nanocomposites based on the bimodal PTT/PDT strategy. Additionally, by the PDT strategy, the E. coli and S. aureus colonies were completely eliminated by the nanocomposite VCL/PEGDA-MNPs-GO-ZnMintPc (MNP=93,3 μg·mL -1, ZnMintPc=8,1 μM, GO=3.47 μg·mL -1), while the three microorganisms were completely eliminated by the nanocomposite VCL/PEGDA-MNPs-MWCNTs-ZnMintPc (MNP=93,3 μg·mL -1, ZnMintPc=8,1 μM MWCNT=3.47 μg·mL -1), therefore, this last magnetic nanocomposite is considered a broad-spectrum antimicrobial agent for PDT.
spa
openAccess
MECÁNICA
NANOMATERIALES ANTIMICROBIANOS
FOTOINACTIVACIÓ
HIDROGEL
NANOPARTÍCULAS MAGNÉTICAS
EFECTO FOTODINÁMICO
EFECTO FOTOTÉRMICO
Evaluación del efecto antimicrobial de amplio espectro de los nanocompósitos magnéticos a base de óxido de grafeno y nanotubos de carbono de pared múltiple basados en la acción bimodal fotodinámico/fototérmico.
masterThesis
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
URL
/var/dspace/bitstream/15000/24739/1/CD%2013454.pdf
File
MD5
6e773d32a5223d17de6471ab4909e89b
4621865
application/pdf
CD 13454.pdf
oai:bibdigital.epn.edu.ec:15000/247782023-09-08T14:25:17Zcom_15000_8421com_15000_7554com_15000_7553com_15000_1col_15000_8422
Repositorio Digital - EPN
author
Paucar Espinosa, Yessenia Ibeth
editor
Pantoja Suárez, Luis Fernando
2023-09-08T14:25:17Z
2023-09-08T14:25:17Z
2023-08-29
Paucar Espinosa, Y.I.(2023). Estudio de la deformación a flexión de un prototipo de sensor obtenido a partir de grafeno inducido por láser. 109 páginas. Quito : EPN.
T-MVE/1053/CD 13493
http://bibdigital.epn.edu.ec/handle/15000/24778
This study investigates the effect of power, focal length and number of engravings on graphene sensors fabricated using a 450 nm diode laser at the upper limit of the UV spectrum. The laser was irradiated over polyimide and the resulting sensors were subjected to deformation by bending at three points. The geometry that best met the requirements was selected to obtain the graphene sensors. These sensors were morphologically characterized by scanning electron microscopy. The material properties were evaluated by Raman spectroscopy and the samples were electrically characterized using the Van der Pauw method. The results showed that it was possible to obtain lowcost graphene whose properties varied according to the variables studied. It was concluded that the power of the laser was critical in the fabrication of graphene vending sensors. It was also highlighted that the focal length had a negligible effect on the laser production of graphene, while increasing the number of etchings reduced the quality of the material and the caliber factor of the sensor. This study shows that it is possible to obtain low-cost graphene by irradiating a commercial laser.
spa
openAccess
GAUGE FACTOR
SÍNTESIS DE MATERIALES AVANZADOS
MATERIALES SÓLIDOS
MECÁNICA
Estudio de la deformación a flexión de un prototipo de sensor obtenido a partir de grafeno inducido por láser.
masterThesis
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
URL
/var/dspace/bitstream/15000/24778/1/CD%2013493%20%282%29.pdf
File
MD5
034b0ada506de16b8be39dcfc0061755
6438491
application/pdf
CD 13493 (2).pdf
oai:bibdigital.epn.edu.ec:15000/250532023-11-10T16:35:41Zcom_15000_8421com_15000_7554com_15000_7553com_15000_1col_15000_8422
Repositorio Digital - EPN
author
Cargua López, Carlos Vinicio
editor
Rosas Laverde, Nelly María
2023-11-10T16:35:41Z
2023-11-10T16:35:41Z
2023-11-10
Cargua López, C.V.(2023).Diseño de aerogeles de óxido de grafeno reducido para la absorción de aceites de motor.92 páginas. Quito : EPN, 2023.
T-MVE 1079/CD 13853
http://bibdigital.epn.edu.ec/handle/15000/25053
Nowadays, water pollution due to oil spills and organic solvents is a matter of great
importance. Physical absorption using reduced graphene oxide aerogels as absorbent
materials has become an effective, environmentally friendly, and user-friendly method for
removing these contaminants from water. This is because aerogels are materials with a
large surface area, a network of pores, and robustness, facilitating the absorption of
contaminant molecules. Although hydrothermal and chemical synthesis methods have been
used to manufacture reduced graphene oxide aerogels, poor results have been found in
terms of motor oil absorption capacity. Therefore, in this research, a lightweight reduced
graphene oxide aerogel with tailored properties for motor oil absorption was fabricated using
a combined reduction synthesis. Variables such as the type of graphene oxide, the type of
reduction (hydrothermal, chemical, and combined), and the freezing process of the hydrogel
at -5°C and -196°C were considered. In addition, a post-synthesis heat treatment at 600°C
was performed. Once the aerogel was synthesized, the morphology, structure, porosity,
and degree of reduction of the aerogels were evaluated using Fourier-transform infrared
spectroscopy, Raman spectroscopy, and scanning electron microscopy techniques. The
characterization results indicated that the type of precursor (graphene oxide), the reduction
type in the hydrogel synthesis, and the freezing temperature influence the morphology,
porosity, and degree of reduction of the aerogel, as well as the motor oil absorption
percentage, speed, and capacity. Finally, the characterization results of the post-synthesis
stage suggested that the resulting aerogel with improved properties was obtained using a
graphene oxide precursor with a higher degree of oxidation through combined reduction
synthesis with a freezing process at -5°C and a heat treatment at 600°C for 1 hour,
presenting a robust three-dimensional structure with low density, a superior absorption
capacity of over 270 g g-1
, and a 94% pore filling.
spa
openAccess
ÓXIDO DE GRAFENO REDUCIDO
SÍNTESIS HIDROTERMAL
ACEITE DE MOTOR
ABSORCIÓN
CIENCIA DE LOS MATERIALES
MATERIALES MULTIFUNCIONALES
Diseño de aerogeles de óxido de grafeno reducido para la absorción de aceites de motor.
masterThesis
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
URL
/var/dspace/bitstream/15000/25053/1/CD%2013853.pdf
File
MD5
1869a0b465a0729a93c2130954db87fc
2482647
application/pdf
CD 13853.pdf
oai:bibdigital.epn.edu.ec:15000/252552023-12-05T13:57:02Zcom_15000_8421com_15000_7554com_15000_7553com_15000_1col_15000_8422
Repositorio Digital - EPN
author
Piarpuezán Enríquez, Marlon Andrés
editor
Pantoja Suárez, Luis Fernando
2023-12-05T13:57:02Z
2023-12-05T13:57:02Z
2023-12-05
Piarpuezán Enríquez, M.A.(2023). Obtención de briquetas obtenidas a partir de residuos del tallo de la papa para su uso como combustible.83 páginas. Quito : EPN.
T-MVE 1095/CD 13888
http://bibdigital.epn.edu.ec/handle/15000/25255
In this study, biomass briquettes were produced from potato stalks to evaluate their potential as a solid biofuel.
Dried potato stalks with a moisture content of 10 % were used and pyrolyzed to obtain carbonised and non carbonised biomass. It was crushed and mixed with potato and achira binders in proportions of 10 % and 20 %.
The briquetting process was carried out at a pressure of 10 MPa and compaction times of 30 and 60 s, followed
by drying. Scanning Electron Microscopy (SEM) characterization revealed a porous structure and adequate
particle and binder distribution, showing good adhesion. Raman spectra of the charred briquettes showed
amorphous carbon characteristics with graphite defects. Thermogravimetric analysis (TGA) showed an ideal
moisture content of 10% for biofuels and high levels of volatiles in the uncharred briquettes. In terms of
compressive strength, the non-carbonised biomass briquettes performed better, withstanding more than 400 N
at 20% deformation and acting effectively as an agglomerate. Finally, the average calorific values of the
carbonised and non-carbonised briquettes were 15 MJ/kg, comparable to sugar cane bagasse and rice husk.
CALII and NCALI stood out with 15.76 and 15.22 MJ/kg respectively, exceeding the threshold of 12.00 MJ/kg
for biomass as biofuel. This study suggests that potato stalk briquettes have promising potential as a sustainable
alternative to non-renewable fuels.n this study, biomass briquettes were produced from potato stalks to evaluate their potential as a solid biofuel.
Dried potato stalks with a moisture content of 10 % were used and pyrolyzed to obtain carbonised and non carbonised biomass. It was crushed and mixed with potato and achira binders in proportions of 10 % and 20 %.
The briquetting process was carried out at a pressure of 10 MPa and compaction times of 30 and 60 s, followed
by drying. Scanning Electron Microscopy (SEM) characterization revealed a porous structure and adequate
particle and binder distribution, showing good adhesion. Raman spectra of the charred briquettes showed
amorphous carbon characteristics with graphite defects. Thermogravimetric analysis (TGA) showed an ideal
moisture content of 10% for biofuels and high levels of volatiles in the uncharred briquettes. In terms of
compressive strength, the non-carbonised biomass briquettes performed better, withstanding more than 400 N
at 20% deformation and acting effectively as an agglomerate. Finally, the average calorific values of the
carbonised and non-carbonised briquettes were 15 MJ/kg, comparable to sugar cane bagasse and rice husk.
CALII and NCALI stood out with 15.76 and 15.22 MJ/kg respectively, exceeding the threshold of 12.00 MJ/kg
for biomass as biofuel. This study suggests that potato stalk briquettes have promising potential as a sustainable
alternative to non-renewable fuels.
spa
openAccess
BIOMASA
PIRÓLISIS
BIOCOMBUSTIBLE SÓLIDO
PODER CALORÍFICO
MATERIALES COMPUESTOS
Obtención de briquetas obtenidas a partir de residuos del tallo de la papa para su uso como combustible.
masterThesis
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
URL
/var/dspace/bitstream/15000/25255/1/CD%2013888.pdf
File
MD5
796d5aa11c697557ed8058d00fb8b95e
3432732
application/pdf
CD 13888.pdf