2024-03-28T13:37:35Zhttps://bibdigital.epn.edu.ec/oai/requestoai:bibdigital.epn.edu.ec:15000/165212019-04-07T12:10:59Zcom_15000_16519com_15000_7616com_15000_7613com_15000_18col_15000_16520
Método normalizado ¨pinhole imaging¨ en la determinación del tamaño de foco de un equipo de rayos X para la evaluación de la calidad de imágenes radiográficas de juntas soldadas.
Cely Vélez, Bolívar Mauricio
This paper presents the procedure to determine the size of the focal spot of an X-ray tube and evaluate the quality of radiographic images of welded joints. This paper collects important data of studies related to this project, also it takes into account fundamental aspects of international standards related to Non-Destructive Testing and how to determine focal spots of an industrial radiography tube. The “Pinhole Imaging” method allow to determine the real size of the focal spot of X-ray tubes on a radiographic film. It disclosed the method development, data collection and statistical processing. An experimental statistical analysis was applied to 70 radiographic tests to measure the focal spot of each one. With the results of focal spot sizes obtained it was possible to calculate the geometric unsharpness of welded specimens, later to know the value of the relative error between the reference value of the theoretical focal spot and the experimental focal spot.
Quito, 2016.
2016-07-06
masterThesis
spa
Monar Monar, Willan Leopoldo, director
http://bibdigital.epn.edu.ec/handle/15000/16521
/var/dspace/bitstream/15000/16521/1/CD-7190.pdf
5da6eff4666bf6003fdce669f0019dcc
/var/dspace/bitstream/15000/16521/2/license.txt
8a4605be74aa9ea9d79846c1fba20a33
/var/dspace/bitstream/15000/16521/3/CD-7190.pdf.txt
66867b3919be02912d60bca29bf1ca77
/var/dspace/bitstream/15000/16521/4/CD-7190.pdf.txt
66867b3919be02912d60bca29bf1ca77
openAccess
Radiografías
Rayos X
oai:bibdigital.epn.edu.ec:15000/167792019-04-07T14:04:33Zcom_15000_16519com_15000_7616com_15000_7613com_15000_18col_15000_16520
Diseño, modelación y simulación de un sistema de impresión 3d basado en sistemas de cadena cinemática cerrada con 4 grados de libertad tipo delta
Chang Herrera, Andrés Nikolas
This work proposes an innovating 3D printing system based in closed kinematic chains of 4 degrees of freedom inspired in the Delta robot.Within this work, the system modeling could be found with all the equations of position, velocity and acceleration based in the generalized coordinate’s principle, LaGrange-Euler principle and the Virtual Work principle. The dynamic modeling could be found based in the energy principle and from an analog configuration of the system. The design process in this project begins with the study of the market of the 3D printing systems in order to determine the system requirement and to configure one system based in closed kinematic chains of 4 degrees of freedom. Beginning from the design and the dimensioning of its elements in order to accomplish the stablished requirements, the simulation of the system was made from the equilibrium equations found in the modelling chapter and to stablish a method to evaluate the most important system points and articular variables. Finally, the needed costs to build the designed system are determinate. This investigative project is an important development for future research in the field of Mechatronics within the Faculty of Mechanical Engineering and Ecuador.
Quito, 2016.
2016-08-31
masterThesis
spa
Granja Ramírez, Mario German, director
http://bibdigital.epn.edu.ec/handle/15000/16779
/var/dspace/bitstream/15000/16779/1/CD-7375.pdf
56a75df979faaa9ce1893280ef16b3cf
/var/dspace/bitstream/15000/16779/2/license.txt
8a4605be74aa9ea9d79846c1fba20a33
/var/dspace/bitstream/15000/16779/3/CD-7375.pdf.txt
f8c17a9541a932529d5c03974d205f59
/var/dspace/bitstream/15000/16779/4/CD-7375.pdf.txt
f8c17a9541a932529d5c03974d205f59
/var/dspace/bitstream/15000/16779/5/CD-7375.pdf.txt
f8c17a9541a932529d5c03974d205f59
openAccess
ROBOTICA
DISEÑO DE MAQUINAS
CINEMATICA
oai:bibdigital.epn.edu.ec:15000/167812019-04-07T14:04:39Zcom_15000_16519com_15000_7616com_15000_7613com_15000_18col_15000_16520
Diseño y control automático de una vivienda social sostenible que utilice el hidrógeno como vector energético, generado a partir del aprovechamiento de recursos renovables
Duque Orozco, Mauricio
Llulluna Llumiquinga, Fredy Rafael
The National Government has made great efforts to carry out the project of diversification of the energy matrix, due to pollution and the high fiscal costs it entails; Therefore, the design and automatic control of a sustainable social housing that use hydrogen as an energy vector, generated from the exploitation of renewable resources is proposed. To do this, first a convenient geographical location of housing, the number of people that must be addressed, the average energy consumption and how it should be shaped the renewable energy system (solar or wind) and the storage system was established energy (hydrogen fuel cells or batteries for stationary systems). With the help of software HOMER Energy it was determined that the best option is a home with a solar power system with a battery storage system. Once defined the energy configuration of housing design and control platform for sustainable social housing was conducted in order to monitor and control variables such power.
Quito, 2016.
2016-10-26
masterThesis
spa
Aguinaga Barragán, Álvaro Gonzalo Xavier, director
http://bibdigital.epn.edu.ec/handle/15000/16781
/var/dspace/bitstream/15000/16781/1/CD-7377.pdf
374a5ea0da9b921fa1b89b6e8a34ebd8
/var/dspace/bitstream/15000/16781/2/license.txt
8a4605be74aa9ea9d79846c1fba20a33
/var/dspace/bitstream/15000/16781/3/CD-7377.pdf.txt
005615ad2954de9dac6aba0cb7e5950e
/var/dspace/bitstream/15000/16781/4/CD-7377.pdf.txt
005615ad2954de9dac6aba0cb7e5950e
openAccess
CONTROL AUTOMATICO
ENERGIA RENOVABLE
oai:bibdigital.epn.edu.ec:15000/167852019-04-08T04:01:34Zcom_15000_16519com_15000_7616com_15000_7613com_15000_18col_15000_16520
Evaluación del comportamiento y emisiones en un motor de combustión interna utilizando una mezcla Diésel-Queroseno
Eugenio Pilliza, Cristian Ivan
Montalvo Márquez, Francisco Javier
That research experimentally assesses the effect on performance and emissions of a compression ignition engine using the mixture of diesel with kerosene. Taking advantage of the miscibility between these two fuel, were performed blends in volumetric proportions of 5%, 10%, 15%, 20%, 25% and 30% of kerosene in diesel, identified as D5K, D10K, D15K, D20K, D25K and D30K respectively. To characterize the two fuels and their six mixtures were measured their physicochemical properties in a laboratory guided by a set of norms. To determine the change in the mechanical performance of the vehicle were performed dynamic tests of torque and power based in the norm SAE J-1349 in the chassis dynamometer LPS 3000. While, to assess the effect in the emissions of the polluting gases, were performed static tests of opacity and particulate matter PM2.5 established by the NTE INEN 2202 standard. As experimental result, it was determined that mixtures can be made until a concentration D20K without modifying the fuel supply system and that all mixtures with kerosene allowed reduce the level of opacity and concentration of particulate matter PM2.5, while power and the torque decreases in smaller percentage.
Quito, 2016.
2016-10-12
bachelorThesis
spa
Portilla Aguilar, Ángel Adalberto, director
http://bibdigital.epn.edu.ec/handle/15000/16785
/var/dspace/bitstream/15000/16785/1/CD-7381.pdf
0d643249e6b47da56bf82436aa3672fe
/var/dspace/bitstream/15000/16785/2/license.txt
8a4605be74aa9ea9d79846c1fba20a33
/var/dspace/bitstream/15000/16785/3/CD-7381.pdf.txt
220fafc04129f0b470cc7836c2f78733
/var/dspace/bitstream/15000/16785/4/CD-7381.pdf.txt
220fafc04129f0b470cc7836c2f78733
openAccess
MEDIO AMBIENTE
MOTORES
MOTORES DE COMBUSTION INTERNA
oai:bibdigital.epn.edu.ec:15000/168962019-04-08T04:22:53Zcom_15000_16519com_15000_7616com_15000_7613com_15000_18col_15000_16520
Influencia del tamaño de las discontinuidades en las propiedades mecánicas de las uniones soldadas bajo la Norma API 1104
Castro Revelo, Jonathan Fernando
Serrano Aguiar, Carlos Oswaldo
In this research, the effect of discontinuities mentioned in the API 1104 standard about the mechanical properties of standard test pieces were evaluated. For this purpose, test specimens were obtained with different sizes of defects and those were characterized with the API1104 standard. The obtaining of various defects was performed by metallic inclusions, non-metallic inclusions or machining, depending on the type of discontinuities. The dimensions of external discontinuities were checked by visual inspection, while internal defects were checked through industrial radiography. Due to the difficulty in manufacturing certain sizes of discontinuities, the analysis was completed using simulations with ANSYS 16.1 software. The simulation results were validated with the data obtained from the mechanical tests of standard test specimens. From this comparison, errors of less than 5% were obtained in all cases. From the results obtained it is seen that all sizes of defects have an inversely proportional behavior compared to the tensile strength. According to the API 1104 standard, the most critical defects are the cracks, and the present research confirms that. Following the cracks, in order of criticality we have the inadequate penetration, elongated slag inclusion, incomplete fusion and incomplete fusion due cold lap. Subsequently, the isolated slag inclusions are in conjunction with the pores. Then, the inadequate cross penetration with the undercutting. And finally, the rest of discontinuities as inadequate penetration due high-low, internal concavity and burn-trough.
Quito, 2016.
2016-11-16
bachelorThesis
spa
Barragán Campos, Galo Homero, director
http://bibdigital.epn.edu.ec/handle/15000/16896
/var/dspace/bitstream/15000/16896/1/CD-7475.pdf
569c03c7724c61c8be841066056e964a
/var/dspace/bitstream/15000/16896/2/license.txt
8a4605be74aa9ea9d79846c1fba20a33
/var/dspace/bitstream/15000/16896/3/CD-7475.pdf.txt
8c3232cca8065f1f87a80e30bd379877
/var/dspace/bitstream/15000/16896/4/CD-7475.pdf.txt
8c3232cca8065f1f87a80e30bd379877
/var/dspace/bitstream/15000/16896/5/CD-7475.pdf.txt
8c3232cca8065f1f87a80e30bd379877
/var/dspace/bitstream/15000/16896/6/CD-7475.pdf.txt
8c3232cca8065f1f87a80e30bd379877
/var/dspace/bitstream/15000/16896/7/CD-7475.pdf.txt
8c3232cca8065f1f87a80e30bd379877
openAccess
SOLDADURA
DEFECTOLOGIA
oai:bibdigital.epn.edu.ec:15000/169542019-04-08T00:59:27Zcom_15000_16519com_15000_7616com_15000_7613com_15000_18col_15000_16520
Modelado, simulación y optimización de la producción de hidrógeno en un electrolizador a partir de vapor sobrecalentado de agua mediante la herramienta Labview de National Instruments
Simbaña Guañuna, Julián Alberto
The aim of this paper is to obtain a system to simulate and optimize variables and parameters involved in the production of hydrogen in an electrolyzer through overheated water steam. The study is based on impedance spectroscopy. It allows to understand the physical phenomena because of the electrolysis process by using mathematical models. The hydrogen production process is represented by an electrical circuit for optimization. This circuit establishes a direct relationship between the current generated in the circuit and the hydrogen flow rate using Faraday's law. The mathematical model is obtained from the equivalent circuit, and it allows a connection of the variables that affect the process, such as temperature, area, voltage, frequency, etc. The simulation was performed to design electrolysis equipment to ensure an efficient and economical production of hydrogen, getting and storing relevant information for further analysis by the National Instruments LabVIEW.
Quito, 2016.
2016-11-15
masterThesis
spa
Aguinaga Barragán, Álvaro Gonzalo Xavier, director
http://bibdigital.epn.edu.ec/handle/15000/16954
/var/dspace/bitstream/15000/16954/1/CD-7541.pdf
adb8b757ff0265856eb7f064aa39e6de
/var/dspace/bitstream/15000/16954/2/license.txt
8a4605be74aa9ea9d79846c1fba20a33
/var/dspace/bitstream/15000/16954/3/CD-7541.pdf.txt
33388ad3c47ca954464553cbca90648e
openAccess
CONTROL AUTOMATICO
SIMULACION
oai:bibdigital.epn.edu.ec:15000/169982019-04-08T01:30:48Zcom_15000_16519com_15000_7616com_15000_7613com_15000_18col_15000_16520
Modelado matemático y simulación de la transferencia de calor en un lecho fijo para el núcleo del reactor nuclear “Fixed bed nuclear reactor (FBNR)”
Almachi Nacimba, Juan Carlos
Montenegro Villarreal, Jessica Alexandra
The FBNR reactor constitutes an innovative reactor that bases its operation on this type of structure. Within the study of fixed beds it is important to define the minimum refrigerant flow, the configuration of the fuel elements that make up the bed, the pressure profile in the bed, the profile of the temperature of the coolant and the fuel elements, the parameters. It is of relevant importance to ensure that the thermal limitations of the materials involved in the core and fuel are not exceeded. In order to determine the parameters required for a steady state, a computational bed model was developed in the Comsol Multiphysics software, and Heat combined heat transfer and flow and transfer modules were used. The results of the simulation were validated using a comparison with the data of the theoretical model of heat transfer, which is based on a balance of energy in the bed when considering the fuel spheres as a source of energy generation. A BCC structure was obtained as the best bed configuration, since under this safe operating conditions the optimum refrigerant flow velocity was 0.6 m/s. The selection was made based on the comparative analysis of parameters and due to the ease of construction.
Quito, 2017.
2017-01-05
masterThesis
spa
Portilla Aguilar, Ángel Adalberto, director
http://bibdigital.epn.edu.ec/handle/15000/16998
/var/dspace/bitstream/15000/16998/1/CD-7576.pdf
7cc5d2689fa17163fed499476b531707
/var/dspace/bitstream/15000/16998/2/license.txt
8a4605be74aa9ea9d79846c1fba20a33
/var/dspace/bitstream/15000/16998/3/CD-7576.pdf.txt
c2d278efb9b1c891f2e77731787d63b2
/var/dspace/bitstream/15000/16998/4/CD-7576.pdf.txt
c2d278efb9b1c891f2e77731787d63b2
/var/dspace/bitstream/15000/16998/5/CD-7576.pdf.txt
c2d278efb9b1c891f2e77731787d63b2
/var/dspace/bitstream/15000/16998/6/CD-7576.pdf.txt
c2d278efb9b1c891f2e77731787d63b2
openAccess
TRANSFERENCIA DE CALOR
MODELOS MATEMÁTICOS
oai:bibdigital.epn.edu.ec:15000/170002019-04-08T01:27:37Zcom_15000_16519com_15000_7616com_15000_7613com_15000_18col_15000_16520
Desarrollo de ciclos de conducción en ciudad, carretera y combinado para evaluar el rendimiento real del combustible de un vehículo con motor de ciclo Otto en el Distrito Metropolitano De Quito
Quinchimbla Pisuña, Freddy Eduardo
Solís Santamaría, Javier Milton
This paper proposes the development of driving cycles for obtaining real values of fuel consumption in the Metropolitan District of Quito. The vehicle used was instrumented with a global positioning system and a canister in order to systematically navigate a set of previously selected tracks and to obtain information about distance travelled, travel time, average speed, among others; this information was processed through statistical analysis by the minimization of weighted averages, resulting in representative cycles for the Metropolitan District of Quito. The driving cycles obtained were validated by tests in three real scenarios with different traffic conditions, proving to be statistically repeatable and reproducible, as well as having a high reliability of 99.7% of the measurements taken during each procedure. The results show that city fuel consumption is higher (20,84 MPG), compared to the combined cycle (24,08 MPG) and the extra urban cycle (31,26 MPG). On the other hand, to carry out this study a comparison was performed between the fuel consumption obtained in the cycles of the Metropolitan District of Quito and those indicated by the vehicle manufacturer, resulting in marked differences between the two. On average, the values of the Metropolitan District of Quito cycles are greater in a 36 %.
Quito, 2017.
2017-01-10
masterThesis
spa
Portilla Aguilar, Ángel Adalberto, director
http://bibdigital.epn.edu.ec/handle/15000/17000
/var/dspace/bitstream/15000/17000/1/CD-7578.pdf
ad4c7642eb417bb34b51c4226a167b52
/var/dspace/bitstream/15000/17000/2/license.txt
8a4605be74aa9ea9d79846c1fba20a33
/var/dspace/bitstream/15000/17000/3/CD-7578.pdf.txt
8c746352bd265cb7d9a3f01d8cac4ae1
/var/dspace/bitstream/15000/17000/4/CD-7578.pdf.txt
8c746352bd265cb7d9a3f01d8cac4ae1
/var/dspace/bitstream/15000/17000/5/CD-7578.pdf.txt
8c746352bd265cb7d9a3f01d8cac4ae1
/var/dspace/bitstream/15000/17000/6/CD-7578.pdf.txt
8c746352bd265cb7d9a3f01d8cac4ae1
openAccess
DINAMICA VEHICULAR
VEHICULOS
MOTORES
oai:bibdigital.epn.edu.ec:15000/172272019-04-08T04:27:36Zcom_15000_16519com_15000_7616com_15000_7613com_15000_18col_15000_16520
Obtención y tratamiento digital de imágenes de la huella de contacto neumático – calzada para evaluar las condiciones físicas de los neumáticos en vehículos de tracción delantera
Arauz Estrella, Gustavo David
Llumiquinga Chingay, Ángel Heriberto
The development of this research work born under the need to expand the content of a topic of vital importance such as the tire footprint, from this, along with the contact pressure distribution, it is possible to determine the tire´s behavior, their wear and their influence on the vehicle´s handling, these parameters can´t be obtained directly cause the tire is in contact with the ground. For this a simple equipment capable of obtaining a clear image of the study tire in real time was constructed when the vehicle is stopped. Tests were carried out on three types of tires and images of the tire were obtained at different inflation pressures and with different wear on its tread. Then, from these images, a computer program was developed for its digital treatment to determine parameters of tire operation, contact area, wear type and pressure distribution in the footprint. The results obtained meet the objective of the research since the images obtained were clear and the computer program shows results similar to those obtained manually and to results of previous studies done by the tire manufacturers.
Quito, 2017.
2017-04-10
masterThesis
spa
Suntaxi Guallichico, Segundo Carlos, director
http://bibdigital.epn.edu.ec/handle/15000/17227
/var/dspace/bitstream/15000/17227/1/CD-7732.pdf
eeb7748df6676393ca820a0dce5d4f0e
/var/dspace/bitstream/15000/17227/2/license.txt
8a4605be74aa9ea9d79846c1fba20a33
/var/dspace/bitstream/15000/17227/3/CD-7732.pdf.txt
535b43bc60c447fb4c4458673ec93792
/var/dspace/bitstream/15000/17227/4/CD-7732.pdf.txt
535b43bc60c447fb4c4458673ec93792
openAccess
INGENIERÍA MECÁNICA
NEUMÁTICOS
VEHICULOS
oai:bibdigital.epn.edu.ec:15000/175572019-04-07T13:44:06Zcom_15000_16519com_15000_7616com_15000_7613com_15000_18col_15000_16520
Caracterización de los parámetros de combustión del equipo TVCC instalado en el Laboratorio de Termodinámica de la Facultad de Ingeniería Mecánica de la Escuela Politécnica Nacional
Granja Oramas, María Victoria
Poveda Calderón, Ricardo Andrés
The aim of this work is to characterize the combustion parameters of the Edibon TVCC combustion chamber installed in the Thermodynamics Laboratory of Escuela Politécnica Nacional, using flame image processing. For this purpose, experimental data was obtained under different operating conditions, using LPG and diesel as fuels. The operating conditions were modified regulating the air admission to the burner with an inlet damper. For each operating condition, experimental data was obtained using the following equipment: a gas analyzer, an opacimeter and a digital camera. Combustion parameters such as: air-excess, efficiency, composition of the combustion gases were obtained with the gas analyzer. The opacimeter was used to determine the opacity of the exhaust gases in the chimney; and the camera was used to capture images of the flame, which were then processed and analyzed using Python programming. With the obtained data, characteristic curves were developed to describe the equipment behavior as a function of the percentage of air-excess in the combustion process. In addition, a statistical model was used to develop an equation that enables the prediction of the percentage of air-excess in a LPG combustion process using flame image processing.
Quito, 2017.
2017-08-02
masterThesis
spa
Hidalgo Díaz, Víctor Hugo, director
http://bibdigital.epn.edu.ec/handle/15000/17557
/var/dspace/bitstream/15000/17557/1/CD-8064.pdf
8e6269b74f89f5d1c013fe449c4025bc
/var/dspace/bitstream/15000/17557/2/license.txt
8a4605be74aa9ea9d79846c1fba20a33
/var/dspace/bitstream/15000/17557/3/CD-8064.pdf.txt
60759cfb17813c037d98eb9dec915e89
/var/dspace/bitstream/15000/17557/4/CD-8064.pdf.txt
60759cfb17813c037d98eb9dec915e89
openAccess
TERMODINÁMICA
PROGRAMACION
EFICIENCIA ENERGÉTICA
oai:bibdigital.epn.edu.ec:15000/175822019-04-08T03:46:20Zcom_15000_16519com_15000_7616com_15000_7613com_15000_18col_15000_16520
Análisis del comportamiento del cuello en el efecto latigazo por medio de elementos finitos para obtener los puntos críticos de lesión por medio del análisis dinámico y de fuerzas generadas
Moreno Maza, Geovanny Alfonso
The model seen in the study takes into account ligaments, vertebrae, intervertebral discs of each vertebra and the movement restrictions that exist between each of them. To be able to carry out the study by Finite Elements, a CAD drawing file must be as close as possible to the reality, the drawing is validated from the tomography analysis, it obtained 0.31 mm as the maximum value that indicates that the CAD file has a good approximation with the tomography. There are restrictions that may be mentioned, for example, the restriction of movement in the sagittal plane of the head with the first vertebra C1, and this with the axis or C2 and an additional restriction that is not so true in which the vertebra C7 does not present movement. The values of force obtained from the simulation as can be observed in the document present an error of 29.87% for the analysis of the intervertebral disc that is the vertebra C2 and C3, for the C3 and C4 an error of 13.5% is presented, for the C4 and C5 presents an error of 12.14%, for C5 and C6 an error of 23% The values with which the validation of the results obtained in the study has been made.
Quito, 2017.
2017-08-03
bachelorThesis
spa
Venegas Toro, William Ricardo, director
http://bibdigital.epn.edu.ec/handle/15000/17582
/var/dspace/bitstream/15000/17582/1/CD-8066.pdf
fc466fdc77e0f014e8779df39c5eac8b
/var/dspace/bitstream/15000/17582/2/license.txt
8a4605be74aa9ea9d79846c1fba20a33
/var/dspace/bitstream/15000/17582/3/CD-8066.pdf.txt
034637f64c46c1151a9b8b3b218d0731
openAccess
BIOMECANICA
ELEMENTOS FINITOS
oai:bibdigital.epn.edu.ec:15000/175932019-04-07T13:41:02Zcom_15000_16519com_15000_7616com_15000_7613com_15000_18col_15000_16520
Síntesis de partículas nanométricas y submicrométricas de dióxido de titanio (TiO2) para la formación de películas nanoestructuradas
Baño Morales, Daysi Alexandra
An important application of titanium dioxide (TiO2) nanoparticles is in solar cells, especially in dye-sensitized (DSSC), where TiO2 forms a film that carries the electrons generated by the dye. The intermediate layer must be a film sufficiently porous to come into contact with the pigment and will depend on the ratio of polyethylene glycol /TiO2 in the film. The nanometric and submicron particles of TiO2 were synthesized by the sol-gel method, while the screen printing pastes were made by mixing the particles with polyethylene glycol, water, α-terpineol and acetic acid. The characterization of the particles consisted in the determination of the size and the crystalline structure of the particles of TiO2, while the characterization of the porous TiO2 film consisted of the determination of the morphological characteristics, crystalline structure, absorbance capacity, adhesion of the film to the substrate and the thickness of the deposited layers. The TiO2 films obtained showed high porosity, absence of cracks and cracking, good adhesion and high resistance to current flow.
Quito, 2017.
2017-08-03
masterThesis
spa
Rosas Laverde, Nelly María, director
http://bibdigital.epn.edu.ec/handle/15000/17593
/var/dspace/bitstream/15000/17593/1/CD-8074.pdf
70e4c25a72c5fe0194f93c079630a6e8
/var/dspace/bitstream/15000/17593/2/license.txt
8a4605be74aa9ea9d79846c1fba20a33
/var/dspace/bitstream/15000/17593/3/CD-8074.pdf.txt
98d8d3cb3995f1f506a7afee2bfa7ca0
openAccess
SERIGRAFÍA
NANOPARTICULAS
oai:bibdigital.epn.edu.ec:15000/189302019-04-07T13:18:48Zcom_15000_16519com_15000_7616com_15000_7613com_15000_18col_15000_16520
Selección del tren motriz adecuado para vehículos recolectores de residuos para la ciudad de Quito
Mármol Ruiz, Giovanny Francisco
The propose of the present investigation is describe the correct methodology for the selection of powertrain of trucks, as engine, gear box, clutch for Public Institutions such as; Decentralized Autonomous Governments (GADs), for Institutions that required the public purchasing processes trough terms of reference (TDRs), company of transportation who will be able to clearly specify their requirements and implement this valuable selection. A brief summary of basic powertrain concepts will be carried out, the purpose of each element will be identified, the forces acting on the vehicle movement in addition to the characteristics necessary for the vehicle to be kept in motion will be analyzed. Will present the form of calculation of the transmission ratios, conical torque ratio, external elements involved in the movement such as: aerodynamic force, inertia force, friction force, we make a quickly resume of every element, we make an analysis of every force who interfere with the vehicle move as, Aerodynamic force, Inertial force, Friction force. In order to create a correct way to select a powertrain.
Quito, 2017.
2017-11-17
masterThesis
spa
Portilla Aguilar, Ángel Alberto, director
http://bibdigital.epn.edu.ec/handle/15000/18930
/var/dspace/bitstream/15000/18930/2/license.txt
8a4605be74aa9ea9d79846c1fba20a33
/var/dspace/bitstream/15000/18930/1/CD-8323.pdf
de9e9b7915001d83adeb9e0cb87e6a93
/var/dspace/bitstream/15000/18930/3/CD-8323.pdf.txt
f58ede0d3ac864e0ba728bb7066452ed
openAccess
MOTORES
VEHICULOS
oai:bibdigital.epn.edu.ec:15000/201082019-04-08T11:15:01Zcom_15000_16519com_15000_7616com_15000_7613com_15000_18col_15000_16520
Estudio de la influencia de la incorporación de arenas ferrosas como parte del fundente utilizado en el proceso de soldadura por arco sumergido sobre las propiedades mecánicas y microestructura de juntas soldadas de acero ASTM A572
Acuña Rivera, Marcela Estefanía
This experimental study establishes the influence of replacing part of the flux used in SAW process with ferruginous sand, over, the mechanical properties and microstructure of the weld metal. The aim of this study is to determine the feasibility of incorporating raw ferruginous sand to obtain a welded joint of ASTM A572 steel with comparable properties to one obtained using commercial flux. Weld beads (along the joints) were made using neutral flux, incorporating sand in weight ratios between 0,1 and 0,3. Ultimate tensile strength, toughness, and bending behavior of the welded joints was characterized. Additionally, micrographic analysis and measurements of microhardness on weld metal were performed. The chemical composition of the weld metal samples was analyzed using optical emission spectrometry to verify the variation of alloying elements. The results show that the amount of manganese and silicon is reduced, leading to the formation of nucleate structures different to acicular ferrite. The bending behavior of welded joints obtained when the weight ratio is 0,1 remains unchanged, however, the tensile strength, yielding point, and the percentage of elongation decreases due to the presence of porosity, as a result of the oxygen released from the minerals contained in sand during the process.
Quito, 2019.
2019-02-26
bachelorThesis
spa
Díaz Campoverde, Carlos Wime, director
http://bibdigital.epn.edu.ec/handle/15000/20108
/var/dspace/bitstream/15000/20108/1/CD-9540.pdf
4e361e3b537b7befd5fec284c36e4f11
/var/dspace/bitstream/15000/20108/2/license.txt
8a4605be74aa9ea9d79846c1fba20a33
/var/dspace/bitstream/15000/20108/3/CD-9540.pdf.txt
193035e53fce53dd999091417da1df5d
openAccess
METALURGIA
METAL
SOLDADURA
oai:bibdigital.epn.edu.ec:15000/213732021-02-11T17:15:42Zcom_15000_16519com_15000_7616com_15000_7613com_15000_18col_15000_16520
Exfoliación mecánica de grafito en Vórtices de Taylor y su aplicación en electrodos de dióxido de titanio modificados con grafeno
Escobar Ortiz, Jorge Ismael
This research project shows a development of a methodology to obtain graphene by mechanical exfoliation of graphite in powder. This new methodology presents several advantages comparing with the conventional processes such as low production cost in laboratory, and it is less harmful to the environment. We obtained an adequate mixture of graphite powder, water, and an additive (Tween 80) that increases the viscosity of the solution and generates a toroidal flow (Taylor–Couette flow) which makes a sharp effort over the graphite. This effect was obtained through a mechanical device composed of two concentric and coaxial cylinders in which one of them rotates. As the speed increases, the torque increases rapidly and produces a sharp esforce between two contiguous vortices of Taylor-Couette flow. This force breaks the weak layers of graphite obtaining graphene. It was evaluated the quantity, quality, size, and morphology of the obtened graphene. The results gotten by UV-VIS and RAMAN showed the amount, morphology, and number of layers of the material obtained by exfoliation. With these results we were able to conclude that final product was better quality that the one generated by electrochemical exofoliation.
Quito, 2020.
2019-05-27
masterThesis
spa
Santacruz Terán, Cristian Patricio, director
http://bibdigital.epn.edu.ec/handle/15000/21373
/var/dspace/bitstream/15000/21373/2/license.txt
8a4605be74aa9ea9d79846c1fba20a33
/var/dspace/bitstream/15000/21373/1/CD%2010433.pdf
ab37e62d56b97a780c6b8eead93fecfd
openAccess
EXFOLIACIÓN MECÁNICA
GRAFITO
MECÁNICA