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Aquino, Angel; Santiago, Atzel; Cedeño, José R. Electrical & Computer Engineering, UPR-Mayagüez.
Optimal siting of distributed energy sources on distribution systems
This paper presents the results of studies made on two distribution feeders that were simulated using SKM POWER TOOLS ™. The objective of the studies was to learn about the effects of adding distributed generating units to radial distribution feeders. The simulation results show that the voltage profile improved when generating units were added. Another benefit of adding the generating units to the feeders was that the power losses decreased. Through a trial and error procedure, we were able to find the optimal location to place generating units in order to obtain the best voltage profile. It was also concluded that this same location also minimized losses in the distribution network. The results show the importance of choosing the correct location to place the generating units as well as the benefits of distributed generation. This work is the result of an undergraduate research project at the University of Puerto Rico-Mayagüez (UPRM).
Arocho, Ingrid. Civil and Surveying Engineering Department, UPR-Mayagüez - Estrella, Nery. Mechanical Engineering Department, UPR-Mayagüez - Padilla, Emmanuel. Civil and Surveying Engineering Department, UPR-Mayagüez.
Recycled rubber as an energy absorbent sandwich material for highway guardrails
The raise of waste in Puerto Rico is alarming. Among all the wasted materials, one of the most abundant is the rubber resulting from used vehicle tires. This material cannot be compacted nor melted, only shredded, and because of this it represents a problem for the environment. In addition the rate of accidents in Puerto Rican roads is increasingly alarming. With this abundant material in our hands and in an effort to improve our safety we are suggesting to use it in the highway guardrails. The idea is to use the existing guardrail design and improve it with shredded rubber in the inside enclosed in a steel sheet sandwich structure. With this model in mind, we prepared several sandwiches of different sizes and thickness, and tested them under impact, compression and flexion loads. The results of each of these tests were rewarding, even with our limited resources. We observe that the sandwiches with rubber absorbed more energy than the ones without it. This study is not easy because of all variables involved in the design and the difference in composition of each model. A more viable way to bond the rubber crumb together and to sandwich steel is needed and requires more intensive research.
Atiles, Jose; Jia, Yi. Department of Mechanical Engineering, UPR-Mayagüez.
Wireless strain sensor development
This paper will focus on the validity of a wireless strain gage setup to successfully transmit an adequate signal beholder of the actual strain measured. It reviews the development of the wireless strain sensor that uses strain gages to measure the strain directly. This is a widely researched topic, but in this wireless strain sensor, the strain gages are bonded to the surface of measurement, in this case, a constant-stress cantilever beam, for strain measurement. Also the electronics are mounted at the base of the cantilever for detection and amplification of the strain gage signals. A telemetry system is also built for wireless transmission of signals from the cantilever to a medium of data evaluation and display. The overall objective is to study and develop a reliable, cost-effective technology for making wireless strain micro-sensors for the real-time monitoring of strain in mechanical parts, structures and health devices always allowing the early detection of damage. This will allow the detection of damage and prevent catastrophic failures in aerospace, military and commercial applications. The specific objective of the project can be described as follows: to develop and test a wireless strain micro-sensor based on integrating a semiconductor strain sensing element and Radiometrix„¥ UHF FM Data Transmitter and Receiver Modules in order to monitor the strain variation of moving mechanical components during operation.
Aviles, Abdiel; Santiago, William; Micheri, Jose L. Computer Engineering, UPR-Mayagüez
Digital Class Attendance
Recognizing the value of the instructors time, and bearing the goal of automating the class attendance verification and organization process we present the Digital Class Attendance system. The D. C. A. replaces the old paper attendance lists used by instructors today, with this device students report their attendance by using a magnetic card or their own pin number and the system creates a list with the attendance of all of the students. The instructor can use this device for several of his classes and, a couple of weeks later, download the data on to his computer where a program will generate automatically the attendance report of all of his classes.
Beras-Aulet, Cristina; Milton Mitjans; David S. Hermina; Manuel A. Vega; Yaritza Perez. Electrical Engineering, UPR-Mayagüez.
Microwave feedforward power amplifier
Feed foward amplifiers are used to reduce the noise produced by devices. Our power amplifier is design for frequencies in the 2.4GHz ISM band. These frequencies are used for Wireless LAN Adapters. The signals requiere RF power amplifiers to maintain high levels of spectral effiency to minimize interferance. Amplifiers must maintain linear transfer functions to achieve spectrally efficient operation. The use of feed foward amplifiers helps us to obtain this particular characterisitic.
Bermudez Negron, Nerien; Briano, Julio. Chemical Engineering, UPR Mayagüez.
Synthesis, characterization and kinetic growth of ZnO quantum dots
A water and oil system was used to prepare ZnO nanocrystals (quantum dots) via substitution in reverse micelles. The nanospaces confined in the reverse micelles serve like a nanoreactor where the reaction takes place. The final size of the particles is controlled by changing the dimension of the reverse micelles and by varying the concentration of the reactants. The particular optical properties of these dots are size dependent. The growth of these particles was followed using UV-visible absorption measurements as well as fluorescence. ZnO quantum dots exhibit a quantum size effect show as a blue shift of the light absorption. ZnO quantum dots are of great potential in the developing of chemical and biological sensors.
Briano, Carolina; Fontanez, Jessica; Dukhan, Nihad. Mechanical Engineering Department, UPR-Mayagüez.
Characterization of the heat transfer in open-cell metal foam
Material characterization of open-cell aluminum foam in terms of heat transfer is presented. A one-dimensional heat transfer model for the combined convection and conduction in the foam is summarized. The model uses the foam parameters that are usually reported by the manufactures such as: the surface area, the relative densities, the ligament diameters and number of pores per each. The model predicts the temperature profile and the heat transfer in the foam. The model was applied successfully to a sample of aluminum foam having ten pores per inch; and was verified by direct experiment. Excellent agreement between the predictions of the model and the experimental data was obtained. The assumption of a one-dimensional heat transfer was validated. The effect of the flow rate on the heat transfer is also studied in order to further characterize the heat transfer behavior of the foam. The results for an aluminum sample foam of 10 pores per inches are presented at these flow rates.
Calderón, Hermes. Mechanical Engineering, UPR-Mayagüez - Suárez O. Marcelo. General Engineering, UPR-Mayagüez.
A study of heat treatment and mechanical deformation effects on heat-treated aluminum matrix composites through experimental design
Some of the main problems in aluminum matrix composites are: the wettability of the ceramic particles and deterioration of the interphase matrix/ceramic if the reinforcement has a chemical reaction with the liquid aluminum. Using aluminum diboride as reinforcement avoids that chemical reaction as well as it improves the wettability. This new series of metal matrix composites containing borides are prepared through a melting process from aluminum-boron and aluminum-copper alloys. Copper does not react with the reinforcement, but form Al2Cu with the aluminum during the solidification. The low level of copper allows the redissolution of the Al2Cu phase in the aluminum matrix through a solubilization treatment at 540 C. Aging and quenching treatments cause the matrix hardening by intermediate (metastable) phase precipitation. Following an experimental design, the samples are aged and plastically deformed (cold rolled). The experiment analysis has the matrix microhardness as response variable while the boron and copper levels, deformation percent, temperature and time of treatment are the factors. A model to predict the matrix microhardness of the composite is developed based on the process variables as well as in the boron and copper contain. The effect of aging treatment on the hardness is proportional to the copper percent present in the material. The interaction between factors can be predicted based upon hardness and mechanical strength data and can therefore be adjusted through an optimal combination of treatments.
Esquilín, Omar; Caceres, Arsenio. Civil Engineering, UPR Mayagüez.
Parametric studies on the effect of recycled tire rubber in concrete mixes
The objective of this project is to evaluate the use of recycled crushed tire rubber as a substitute of aggregates in concrete. The testing plan consist of generating a series of concrete mixes were rubber particle size, water/cement ratios, and additive content are varied to establish the effect in the overall concrete capacity and durability. The durability of the mix will be evaluated performing permeability tests using the equipment available in the PR Highway and Transportation Authority materials laboratory in Bayamón, PR. A series of parametric plots will be generated to provide guidelines for mix design and proportions.
Feliciano, Christian; O'Neill, Efrain. Engineering, UPR-Mayagüez.
The Virtual Test Bed as an integrating tool in power engineering
This research has as main goal the integration of power electronics simulation tools with the ones used for power system simulations. Specifically, the objective is to take advantage of previous work made in Saber and integrate it with power system simulations done in EMTP. With this merge, the dynamic interaction between power electronics and the power system will be easily study. An option would be a new environment or interface that links ATP and Saber. This new interface could be used to adapt Saber component models in a way that ATP can use them. To accomplish our objective, a complete study of both simulation tools was done by the first two students that were doing the research, including literary review of previous works and learning the basic simulation methods. Once they understood the functionality and capabilities of these tools and analyzed all possible interconnections, Virtual Test Bed (VTB) was selected as our software integration tool. After completion of this stage, it is necessary to learn how to use VTB in order to create an interface between Saber and ATP. To meet our goal, this semester the work was separated in different stages. These stages constituted the scope of this work: Understanding VTB, VTB-Matlab Interface, VTB models using Spice language
Frank, Gustavo E; Jia, Yi. Mechanical Engineering, UPR-Mayagüez Campus - Fregues, Mariela. Electrical Engineering, UPR-Mayagüez Campus.
Novel M.E.M.S multi-hole probe design
Wind sensors are apparatus used for measuring parameters of the wind, because of the existence of different desirable outputs and applications, limitations come along. Leaving to scientist and engineers the quest of the creation of wind sensors for desirable outputs with minimum or none limitations. Through the study and experimentation of the multi-hole probe technique and use of diverse novel probe designs we intend to create a more efficient miniature multi-hole sensor capable of measuring the magnitude and direction of a wind flow in restricted areas.
García, Eduard. Departamento Ingeniería Mecánica, UPR Mayagüez – Silva, Walter. Departamento Ingeniería General, UPR Mayagüez.
Estudio comparativo de ecuaciones de velocidad de la onda variable, en flujo de mezcla gas – líquido, bajo estado transitorio
Flujo de mezcla gas – líquido ocurre muy comúnmente en diferentes tipos de industrias (petróleo, plantas de potencia geotérmicas, tuberías aguas residuales). Cambios rápidos en condiciones de operación o flujo en las fronteras del sistema producen condiciones de flujo transitorio, debido a las fluctuaciones de presión generadas, la velocidad de la onda en la mezcla varía, a diferencia de un líquido puro en la cual permanece constante. Adicionalmente fluctuaciones en frecuencia y magnitud del pulso de presión son observadas, así como formación de ondas de choque por el paso de la onda de presión, limitando el uso de esquemas numéricos de primer orden, tradicionalmente usados en líquidos puros. Es deseable aplicar métodos que permitan predecir las velocidades de la onda y manipular las ondas de choque generadas durante el estado transitorio, como es el caso de esquemas numéricos de segundo orden. Considerando factores como homogeneidad de la mezcla, comportamiento termodinámico del gas, y propiedades elásticas del conducto, entre otros, diferentes autores han desarrollado expresiones para velocidad de la onda variable. En el presente trabajo se compara la validez de distintas ecuaciones para la velocidad de la onda variable, entre si y con data experimental, aplicando un esquema numérico de segundo orden (MacCormack). Resultados preliminares de la simulación, indican predicción aceptable de los primeros pulsos de presión, y menor razón de disipación de la onda, en comparación con los datos experimentales. Fueron observadas algunas restricciones en la aplicación de las ecuaciones para velocidad de onda variable.
García Cortés, Rafael; Agosto Soto, Giselle M.; Colón, Emmanuel; Mercado, Ramón. Electrical and Computer Engineering Department, UPR-Mayagüez.
Digital Checkers Wizard
The Digital Checkers Wizard is a digitized version of one of the most famous board games in the world -- Checkers. This version consists of a transparent board that marks the position of each of the players’ pieces using Light Emitting Diodes (LEDs). A Liquid Crystal Display (LCD) presents a menu from where the player can select to move a piece, draw the game, or resign. When the players choose the movement option, they introduce the coordinates, already set on the board, via a keypad. The system is controlled by a TI - MSP430F149 Microcontroller Unit (MCU). This MCU is responsible of assuring the legality of each play, along with the movement of the pieces. An advantage of this product is the fact that it rids the player from the hassle of losing game pieces and setting up the board before each game. It also represents an alternative to checkers’ fans who would have the opportunity to buy an electronic game intended only for Checkers at a better price.
Gutman Pogoriles, Fernando Ariel; Carlos M. Rinaldi. Chemical Engineering Department, UPR-Mayagüez.
Rheological study of ferrofluid flow in an applied uniform rotating magnetic field
Water based ferrofluids are exposed to the action of a uniform rotating magnetic field to study magnetomechanical coupling in spin-up flow. A sample of ferrofluid, a suspension of superparamagnetic nanoparticles, is placed in the central region of an idealized two-pole magnetic machine stator. A uniform magnetic field, generated by a vertical surface current distribution in the induction machine, perpendicular to the cylinder axis and rotating in the azimuthal direction is applied to induce the magnetically driven flow of the ferrofluid. A solid plastic spindle connected to a digital rheometer is then lowered into the ferrofluid column to measure the viscous torque required to restrain the spindle in a stationary position. These measurements are performed as a function of magnetic field amplitude and frequency. A theoretical model based on solving the coupled vector differential equations describing Ferrofluid flow will be presented and used to describe the experimental observations.
Lassús De Jesús, Marco A; Fernandez Sein, Rafael. Electrical Engineering, UPR Mayagüez Campus.
Image processing techniques applied to multispectral imagery
In the Space Information Laboratory, a component of the Tropical Center for Earth and Space Studies at the UPR – Mayagüez Campus, we acquire image data from the following satellites: Landsat 7, Radarsat, and Terra, among others. The image data is processed with several software applications, such as the ENVI toolbox. Image processing techniques provides several features of the earth surface, for example, the temperature behavior of our atmosphere, image enhancement, vegetation index, spectral analysis, mosaicking, etc. Also, ENVI provides several filtering techniques that will be applied to the images of interest and results will be compared. Another analysis tool that ENVI has is the 3-D modeling of the image surface, providing a feature to measure the surface depth. This project consists of applying image processing techniques to the image data received at the Space Information Laboratory.
Marín, Arturo; Calero, Victoria; Rinaldi, Carlos. Chemical Engineering, UPRM.
Effect of pH on stability of water/AOT/Iso-Octane reverse micelles containing cobalt and iron ions
Magnetic nanoparticles are attractive in developing nanosensors, targeted drug delivery vectors, and magnetocytolysis cancer treatments. Cobalt ferrite is a likely candidate for developing sensors based on binding of the analyte to the nanoparticle surface because of its high magnetic anisotropy. Synthesis in reverse micelles was chosen because final nanoparticle size and polydispersity are important factors in sensor development. The system Water/Aerosol OT/Iso-Octane was used because its phase behavior is well characterized. Reverse micelle solutions with ferrous sulfate heptahydrate (CoSO4ּ7H2O), cobalt chloride pentahydrate (CoCl2·5H2O), and aqueous ammonia 28% (NH4OH) were prepared and subsequently mixed to produce the cobalt ferrite nanoparticles. The effect of varying pH on stability of the reverse micelle nanoreactors, on oxidation of the nanoparticle precursors, and on particle size were studied. Preliminary design considerations for magnetic nanoparticle based sensors will be presented.
Mejias, Marcos. Ingenieria Electrica, UPR-Mayagüez - Diaz, Jose; Del Valle, Jorge; Vega, Dalimar; Martinez, Jesiely. Ingeniería Electrica y Computadoras, UPR-Mayagüez.
Design of an instructional module for hardware description languages
The objective of this project is the creation and dissection of an instructional module for a laboratory on hardware description languages (HDL). To achieve this objective, a design consisting of a simple alarm clock was chosen. This circuit has the capabilities to set both, actual and alarm time, activate or deactivate the alarm, enable a snooze mechanism, change between military and standard time, and display the time or alarm on seven-segment displays. VHDL was chosen as the learning and implementation vehicle. The instructional modules are obtained by dividing the prototype into five main experiments: the Hour Block, the Alarm Block, the Display Driver, the Snooze mechanism, and a final integration experiment combining all the previous parts with an inter-module interface to form a functional system. Each module consists of the functional design, modeling, and synthesis onto a Field Programmable Gate Array (FPGA) of the sub-circuits as well as for the complete system. The list of topics that will be dealt with in this exercise includes sequential and combinational circuit design, design of finite state machines, FPGAs and programmable devices, and modeling and synthesis of VHDL-specified systems. It is expected that students performing the sequence of experiments will develop the skills to specify, design, and develop prototypes of hardware system using HDLs. It is also expected that the students will be able to gain knowledge through practice to carry more complex designs as part of a course integrating this instructional modules, rounding a learning experience in HDLs.
Mercado, Ramón; Pérez, Rocío del Mar; Agosto, Giselle. Electrical and Computer Engineering Department, UPR Mayagüez.
Floating-point support libraries for the WIMS microcontroller
As part of a collaboration project with the Wireless Integrated Microsystems (WIMS) Engineering Research Center of the University of Michigan, Ann Arbor, we will develop a floating-point arithmetic library for the WIMS microcontroller. This microcontroller only supports fixed point arithmetic. This library will be incorporated into the compiler currently under development to enable the computation of floating-point operations. This document includes a description of the microcontroller, information about the compiler, and an overview of the new arithmetic library to be created by our group.
Mercado-Soto, Anibal; Santiago Tirado, Angel; Acosta, Felipe; Santos, Jeannette. Civil Engineering, UPR-Mayagüez.
Polymers, substituting fine and coarse aggregate in a concrete mix
This investigation will provide a summary of all the previous studies performed up to now with polymers substituting the aggregates of concrete. This offers alternatives for recycling materials and the conservation of natural resources such as sand. It also presents a permeability study performed on some of the acrylic samples. The polymers studied so far have been polyvinyl chloride, paper phenolic, polycarbonate, and acrylic. Some polymers were studied with different concentrations and different sizes. Their strength performances are compared considering their mechanical properties. It was observed that polymers with higher Tensile Strength (TS) were the ones that gave the best compression results. This indicates a correlation between the polymer properties and the strength of the concrete. It was also found that the shape and content of the polymer affects the strength of the concrete mix. The optimal percent substitution seems to be a 5% and the best size is the one that substitutes fine aggregates. The last two factors could indicate that too much polymer or too large pieces cause a poor binding between concrete and polymers, which is expected due to the polished surfaces of the polymers. The permeability test helps us describe how easily the ion chloride penetrates in concrete. The presence of polymers increases the permeability of the concrete, which is an undesirable condition. It is concluded that the polymers interrupts the binding between concrete, sand, and stones. Polymers may cause channels where the permeability is increased.
Merced-Gonzalez, Jessenia; Mejias-Rolon, Yaritza. Electrical Engineering, UPR-Mayagüez.
Rain attenuation retrieval using a surface reference technique
Liquid water cloud measurements from 10 GHz radars are affected by attenuation due to atmospheric gases, ice clouds and precipitation. Airborne radars produce reduced attenuations when compared with ground-based radars. This paper describes information recollected by the NASA ER-2 Doppler radar (EDOP). Using the true reflectivity retrieved of the EDOP we can determine the attenuation caused by rain. This paper also describes the use of the Hitschfeld-Bordan Method (HB) and the Surface Reference Technique (SRT) correction for rain attenuation.
Mitjans, Milton; Fernandez Sein, Rafael. Electrical Engineering, UPR-Mayagüez.
Satellite antenna controller using LabView
The Space Information Lab administers three satellite stations: FUSE, SAR and HRPT. All satellites obtain images from the Caribbean and part of the United States. Each station cost more that $1 million dollars and part of our job is to maintain them fully operational. As a way to make easier the search for any problem in one of our station we are developing a satellite antenna controller without the need of depending on critical information from the one’s who developed those stations. What we are working now is to synchronize the controller with one of our satellite antennas to receive data from RadarSat or LandSat satellites. If data is going to be receive a database will be use to store the data. In the next months we are going to move the existing code that we did in LabView to Java in order to make accessible the controller via the Internet. The same process is going to be use for the new software. Some minor changes will be made because of compatibility of Java with the equipment to be use.
Morales Lebron, Cesar; Coutin Rodicio, Sandra; Cabassa Cardenas, David; Rolon, Maria Patricia; Heredia, Tamary. Mechanical Engineering Department, UPR-Mayagüez.
Experimental development for measuring the temperature profile of live cells
An experimental setup is currently under development to measure the transient temperature profile of live cells. Healthy and cancer cells will be studied at human body-like temperatures. Infrared thermography is employed in the measurement of temperatures at various time intervals to observe any typical and atypical thermal behavior in healthy and non-healthy (cancer) cells.
Nuñez-Arzuaga, Melisa. Electrical and Computer Engineering, UPR Mayagüez - Vega, Carlos. Computer Engineering, UPR-Mayagüez - Vera, Juan Carlos; Sanchez, Gustavo. Electrical Engineering, UPR-Mayagüez.
Characterization of the WIMS microcontroller
The Wireless Integrated Microsystems (WIMS) Engineering Research Center is dedicated to developing microcontroller technologies aimed at designing cochlear implants and environmental sensor applications. The University of Puerto Rico at Mayagüez is actively collaborating with the University of Michigan, Ann Arbor with the intent to characterize and develop applications for this technology. The biomedical implant and remote environment sensor testbeds both require power-efficient electronics to achieve acceptable size, battery life, and operating temperatures. The goal of this thrust is to develop techniques that will significantly lower the power dissipation of digital and analog circuits. This project will focus on the power characterization of the WIMS microcontroller in order to measure its performance as means of gathering knowledge about its potential behavior as an actual implant. The most relevant aspect of this research is to be able to do a thorough investigation of the low-power capabilities of the WIMS microcontroller by means of application development and testing using an existing simulator of the microcontroller written by the group in the University of Michigan, Ann Arbor. We hope to demonstrate that this custom-designed microcontroller will push sensor technologies to a new, higher level not only regarding electronic design but also application development.
Odeh, Akram; Briano, Julio. Chemical Engineering, UPR Mayagüez.
Synthesis and characterization of CdSe and ZnSe nanoparticles
The control of particle size and surface structure continues to be of interest in the investigation of semiconductor nanoparticles. The synthesis of semiconductor quantum dots of ZnSe and CdSe has been synthesized by the wet chemical route. In this research organically capped quantum dots are obtained using a surfactant that serves as a size stabilizing agent. We focus our investigation toward the reaction that reduces powdered selenium to selenide which is hard to achieve due to the rapid oxidation of the reactants. Absorption, Photoluminescence and Scanning Electron Microscopy (SEM) will be used to perform the structural characterization of CdSe and ZnSe nanoparticles.
Ortiz, Jose; Murphy, Ruben. Computer Engineering, UPR-Mayagüez - Feliciano, Christian. Electrical Engineering, UPR-Mayagüez.
Technology assistance for physically impaired
In this project for undergraduate research, a device will be designed, developed and tested that will allow an impaired person to perform ordinary tasks. Such as opening and closing doors and windows, turn on or off electric home devices. The targetted people are the severely physically impaired with possible cognitive disorders.
Otero, Vivian; Gonzalez, David. Industrial Engineering, UPR Mayagüez.
Process oriented basis estimation in presence of non-orthogonal basis elements
The growth of data-collection technology and the use of online computer for process monitoring have led to an increased interest in the simultaneous observation of several related quality characteristic or process variables (Lowry and Montgomery 1995). Multiple characteristics are being monitored simultaneously, consequently it is important to use and develop techniques for large sets of multivariate process quality data. Multivariate statistical process control techniques monitor such multivariate data to provide a characterization of when irregular behaviors occur in the process, but do not provide any clues as to what caused those irregularities. The challenge consist in extracting meaningful information not only for process monitoring, but also for providing precise process diagnostic to help production personnel in the identification of the most likely process causes, when irregularities are detected. This research is motivated by the need for a multivariate SPC procedure with diagnosis capabilities such as Process Oriented Basis Representations (POBREP) methodology developed by Barton and Gonzalez-Barreto (1996). This methodology identifies the most likely causes of variation in product performance by linking patterns in multivariate data with pattern associated with certain kinds of production problems; this is the process-oriented basis. Although this methodology is effective when orthogonal process-oriented elements are present it is diagnosis capabilities are at risk when the process-oriented basis is not orthogonal or even dependent. Many real problem process deviations may exist that could not be represented with an orthogonal basis. The objective of this research is to evaluate several strategies to work with non-orthogonal process oriented basis and recommend some procedures to solve the problem.
Pagan, Alfredo; Ely X. Colón Jiménez. Mechanical Engineering, UPR Mayagüez.
Composites reinforced with borides and dissolved magnesium and copper to improve mechanical properties
A new series of aluminum matrix composites (AMCs) is proposed in order to eliminate several deleterious effects found in currently available cast AMCs containing ceramic reinforcements such as silicon carbide, graphite, and alumina particulates. By incorporating borides as reinforcers this novel AMC can be produced as a precipitation-hardenable material provided the presence of small amounts of magnesium and/or copper as alloying elements of the matrix. Magnesium and copper boost hardness in precipitation-hardened Al-Mg-Cu-B composites since those alloying elements improve ageing characteristics of the composite. Mg-raisers for the matrix are of the AA 5XXX aluminum alloy series provided by clean used beverage cans. Moreover, the borides add to the mechanical strength in precipitation-hardened Al-Mg-Cu-B composites. To analyze the effects of precipitation hardening on these new composites, all the specimens were heat-treated and ageing. Three different compositions were solutionized at 480ºC to be later quenched in ice water. After the quenching process, the three specimen sets were aged at 170ºC and 190ºC at different times before being quenched in ice water. The experimental microhardness vs. aging time curve of the results demonstrates how these innovative materials and accompanying processing techniques can help adjust the composites to specific hardness values by means of controlled precipitation hardening processes. This is not possible in most AMC produced using conventional techniques, and hence proves the innovative nature of the present investigation. Some of the future work include: scanning electron microscopy (SEM), X-ray diffraction (XRD) and electrical resistivity characterization.
Pagan, Elfred; Lopez, Ana; Rodriguez, Omar; Martinez, Maritere. Computer Engineering, UPR Mayagüez.
D-Frame: A digital picture frame system for personal use
As digital still cameras become more common and the price of printing materials keep rising, a market opens for new technologies that can display digital pictures in a classic manner. Enter D-Frame, a digital picture frame with the ability of displaying digital pictures in the same way you can display normal photography. Using the TI MSP430 microcontroller, a color LCD display and flash memory, D-Frame enables its users to display digital pictures from a device that is not a personal computer, other advantages of D-Frame is the ability to store various pictures in memory and letting its users select which photo they want to display, adding a level of dynamism not available in classic picture frames.
Pérez, Jannette; Resto, Pedro; González, David. Industrial Engineering Department, UPR Mayagüez - Padrón, Mario. Business Administration Department, UPR Mayagüez.
Assessment of Puerto Rico manufacturing readiness with respect to communication and information technology and its impact on productivity
This work will focus on the collection of data from manufacturing companies in five sectors and perform statistical analysis to assess C&IT presence in Puerto Rico’s industries and its impact in productivity.
Rodriguez, Luis; Briano, Julio. Chemical Engineering, UPR-Mayagüez.
Kinetic study of CdS and ZnS quantum dots in w/o systems with AOT
A deep study into CdS and ZnS kinetics was performed in the search of facile preparation methods for semi-spherical structures. The nanoparticles where made in the water/oil system employed in reverse micelles using AOT as a surfactant. Different kinetic behavior in the same w/o system, but supporting highly concentrated aqueous solutions in the process affecting the behavior in the particle and colloidal systems will be discussed. Studies have already been made of the relations of the diameter in the reverse micelle and the particle size using different equations such as the Pileni equation that relates the water/surfactant ratio to the micelle size and other relations between size and absorbance wavelength. These will be of great importance in discussing there optical properties, which are studied in different stop flow experiments involving fluorescence and absorbance to determine the possibilities of different sizes according to different concentration and compositions in the aqueous solutions. The fluorescence measurements that are taken are a definite sign of nanoparticle presence and importance in different applications. Methods for mass production and alteration of fluorescence emissions from these quantum dots are necessary for and even bigger impact in electronics, biological uses and sensors applications.
Rojas, Alejandra. Ingenieria Civil, UPR Mayagüez - Silva, Walter. Ingenieria General, UPR Mayagüez.
Modelacion hidraulica en dos dimensiones para el Rio Grande de Añasco
Los eventos de lluvia de gran magnitud producen inundaciones que generan muchos daños a la infraestructura, agricultura y ganadería de un país. El último huracán que pasó por Puerto Rico fue Georges (1998), donde se estimó pérdidas de dos billones de dólares y cinco pérdidas humanas. Con estos eventos es necesario invertir tiempo y dinero en el modelaje de ríos y plantear medidas de mitigación para zonas inundables. Para este efecto hay que actualizar datos topográficos, la batimetría del río y uso del suelo, parámetros que modifican las características hidráulicas e hidrológicas de la zona. En esta investigación se realizó un estudio comparativo de modelos hidráulicos, FESWMS en dos dimensiones y HEC-RAS en una dimensión en condiciones de flujo permanente. Se modeló en el valle inundable del río Grande de Añasco que tiene condiciones de abanico aluvial en los últimos 8 km a la desembocadura. Es importante utilizar un modelo en dos dimensiones ya que toma en cuenta el cambio en velocidad en la dirección perpendicular al flujo dando mejores resultados. El estudio permitió establecer las zonas de inundación de esta área y se probaron medidas de mitigación como la canalización del cauce, sacar del área inundable las poblaciones del Maní y Tres Hermanos mediante el uso de diques, se probó la reubicación de estas comunidades y el utilizar estos terrenos para otros propósitos sin que estos cambios provoquen un aumento considerable en los niveles de inundación. Además se desarrollaron criterios como diferentes ángulos de abertura, meandreo y relación de ancho de la planicie inundable y ancho del cauce, que permitieron establecer rangos para usar un modelo en una o dos dimensiones.
Rosario-Román, Dennis; Gonzalez-Barreto, David. Industrial Engineering, UPRM.
A tool for functional data analysis, experimentation and control
The technological developments in information processing have made real time process monitoring possible. Today it is possible to analyze a process or a system considering the input or output variables as functions instead of as discrete points. For this type of analysis some techniques have been developed, for example longitudinal data analysis and the functional data analysis (FDA). These analyses are appropriate when each individual is measured repeatedly through time or through a specific signal factor. These techniques are starting to be applied in engineering problems that affect industry. In every manufacturing process is necessary to establish standards, and monitor the performance of the process in order to ensure the highest quality to the customer. But the implementation of a Statistical Process Control (SPC) program is not enough to ensure quality. Sometimes problems occur and it is necessary to have the proper mechanisms to detect the problems. One of the most widely used tools to find the root causes of the problems is Design of Experiments (DOE). DOE provides the mechanisms to find the factors that affect directly the process; it can be used as an optimization tool. For all the reasons mentioned above, it is necessary to develop the proper set of tools to introduce FDA concepts to problems faced by industries. These tools must integrate the analysis of functional data in order to perform successfully experiments and also be able to establish statistical process control when necessary.
Santiago-Tirado, Angel; Mercado-Soto, Anibal. Civil Engineering, UPR Mayagüez - Santos, Jeannette. General Engineering, UPR Mayagüez.
Acrylic as a fine and coarse aggregates in a concrete mix
Different polymers have been studied as possible substitutes of the aggregates of concrete. Acrylic is one that has performed well in this cause. The main objective of this investigation is to study how the acrylic content will affect the mechanical properties of the concrete. To do this, concrete mixes were made with acrylic substitutions of 5% and 10% as part of the coarse aggregate. Other tested mixes were one with 10% of acrylic as part of the fine aggregate and a control mix. The samples were tested through compression and stress-strain tests. The results showed that the control sample had the best results followed by the sample with five percent of acrylic as coarse aggregate. As for the ten percent substitution mixes of acrylic as fine and coarse aggregate we found that these mixes had the worst resistance to stress. In conclusion, it was determined that the best acrylic material is the fine one, because the coarse acrylic that was used had a surface that was too smooth and flat. These characteristics didn’t fit well with the concrete mix and created failure plans in the samples. The contact surface of the acrylic plays an important role in the behavior of concrete. It was observed that an acrylic material with a rough surface reduces the failure in shear and creates better bonds with the mix.
Torres, Alexis; Fernandez, Rafael. Electrical and Computer Engineering, UPR Mayagüez.
Computer simulation of satellite images
My main efforts are towards learning and making use of the OpenGL Application Programming Interface, and seek how this kind of development tools can be used to address the most immediate needs of the UPRM’s Space Information Laboratory (SIL). My first approach is to seek the way to use OpenGL’s based programs in conjunction with SIL’s existing software to make products of relevance to the database been developed at SIL. To achieve this, I will apply all the knowledge gained so far in the areas of programming and remote sensing. Some of the predicted results that will be implemented are an aerial-like navigation of images captured at the Space Information Laboratory in 2-D and 3-D. Also the documentation of all improvements will serve to others interested in this area of research.
Torres Avila, Nikaulys D.; Avellanet Ruiz, Naomi; Avellanet Ruiz, Tatiana; Galarza, Wilyamir. Electrical and Computer Engineering Department, University of Puerto Rico at Mayagüez.
Smart Soda Vending Machine
This proposal deals with the implementation of a Smart Soda Vending Machine. The machine will have the ability to track real-time inventory and will communicate with the supplier by means of an electronic mail every time the inventory is at a critical level. The email-alert will benefit both the supplier and the customer eliminating or reducing the amount of time in which a given product is not available.
Torres Molina, Luz; Silva Walter. Ingeniería Civil, UPRM.
Modelo cuasi-bidimensional para canales compuestos con meandros
En esta era ambiental, es necesario entender el flujo de los ríos no solo desde el punto de vista de las inundaciones sino también desde el aspecto de calidad de agua. Esto último esta relacionado con el uso del agua, su cantidad y su exposición a agentes contaminantes. Considerando esta situación, los ingenieros en ríos intentan desarrollar métodos efectivos para el control de inundaciones, y que a la vez, conserven el habitad natural, y eviten o prevengan daños a la ecología y la agricultura. Métodos tradicionales como el dragado del fondo de los ríos y el ensanchamiento de sus bancos son opciones poco convenientes debido a la necesidad de frecuente mantenimiento y a la redeposición de sedimentos que sufre el canal. Esta investigación esta encaminada a desarrollar métodos para encontrar soluciones prácticas que consideren la directa relación que existe entre el canal principal y la planicie de inundación. Es así que se está desarrollando un modelo cuasi bidimensional con capacidad para predecir velocidades, profundidades de flujo y distribución de esfuerzos cortantes en canales compuestos donde el problema se complica por el intercambio lateral de cantidad de movimiento entre los esfuerzos cortantes que existen entre los movimientos rápidos del agua en el canal principal y los movimientos lentos en la zona de inundación adyacente.
Vargas, Osvaldo; Acosta, Felipe J. Civil Engineering, UPR Mayagüez.
Mechanical properties of concrete masonry blocks with recycled tire rubber as aggregates
Presently in Puerto Rico more than 4 million automobile tires are rejected and disposed annually, of which approximately 800,000 are recycled. This situation creates serious environmental and health problems, such as the spreading of mosquitoes and other vermin, pose fire hazard, and reduce the life-span of land-fills. Finding alternate uses for the rubber material of both the disposed and recycled tires can greatly alleviate these problems. Therefore, the purpose of this research is to investigate the effect on the mechanical properties of concrete blocks when recycled tire rubber is used to substitute part of the aggregates. This study complements the limited amount of information available in the literature related to the subject. Results from this work will serve as the bases for future investigation to eventually develop design and construction guidelines. The experimental program consists of evaluating the engineering properties of the masonry concrete blocks with the recycled tire rubber by performing compression and flexural test on masonry prisms following the procedures of the ASTM standards. The results are compared with control specimens made of conventional masonry units. An insignificant reduction of the strength is expected since the proportions of the rubber in the mix are not to exceed the 20% to 25% of the total aggregate volume reported by previous works as critical quantities that significantly affect performance.
Velazquez Acevedo, Ruben; Hernandez, William. Ingenieria Industrial UPR RUM.
Distribución de tiempo en actividades de participantes dispersos
Una compañía normalmente tiene varias sucursales a trabes de toda la isla. La misma propone expandir sus facilidades y para esto es necesario hacer una gran inversión de dinero. Para asegurar que esta inversión no se pierda y produzca las ganancias esperadas, se debe entrenar al personal responsable de los servicios en la compañía. Este entrenamiento conlleva a su ves un costo, el cual debe ser el mínimo posible sin afectar el rendimiento del empleado. El caso en que esta investigación se enfoca consiste en varios factores que se encuentran comúnmente en la industria. Los factores principales son tiempo y dinero, al igual que muchos mas mencionados mas adelante. Los factores menos importantes se pueden transformar en términos de tiempo y dinero para de esta forma tener la menor cantidad de variables posible. Estos factores a su vez son restringidos por el tiempo de taller, la cantidad de lugares disponibles para ofrecer los talleres, la capacidad de empleados en estos lugares, la cantidad de empleados a tomar el taller y el lugar de donde provienen. Se debe tener siempre en mente que la idea principal es reducir los costos de inversión de la compañía en talleres de adiestramiento para los empleados. Esto se logra intercambiando los factores económicos entre si, restándole importancia a algunos y multiplicando la de otros. No se puede descartar que mientras se adiestren a los empleados de la mejor manera posible mayor provecho obtendrá la compañía del mismo. Buscar la mejor manera de adiestrar a los empleados se debe considerar como una inversión departe de la compañía. Por la misma razón se debe optimizar el tiempo de un taller para que el flujo del trabajo de los empleados no se afecte de gran manera. Para llegar a una solución estándar se propuso utilizar el método de programación lineal y el programa de optimización LINDO. Se logro cumplir con los objetivos de la investigación y crear un código de programación que bajo leves modificaciones en sus constantes se adapte a cualquier situación. Los resultados de este programa fueron excelentes en las pruebas que se llevaron a cabo. De esta manera se espera que los resultados obtenidos en esta investigación sean de gran beneficio para la industria en Puerto Rico.
Velez, Ivan P. ; Electrical and Computer Engineering, UPR Mayagüez.
Web-based catalog browse system for satellite imagery
The purpose of this project is to design and implement a database system for all the image datasets acquired and processed in the Space Information Laboratory (SIL) in order to present the data in an organized manner so that anyone interested can see the metadata associated with a scene image, and a preview of the satellite image products available at SIL. It also facilitates the request process of satellite imagery that can be obtained through SIL. A graphical user interface is provided for querying and browsing the database through the World Wide Web. The web-based browsing system has been implemented by making use of an Oracle 8i database, in combination with the Apache web server, XML and Java Server Pages technology. Currently, existing Radarsat and Landsat 7 data is being inserted into the database. Most of this data is already available through the Internet at the following URL address: http://rsil.uprm.edu. We are continuing the insertion of the Landsat 7, Radarsat and Terra (Modis) imagery and metadata, and the next stage of the project will be extending the system for a GIS application.
Villalta, Cristhian. Departamento de Ingenieria Civil, UPR-Mayagüez - Silva Walter. Departamento de Ingenieria General, UPR-Mayagüez.
Funciones de transporte de sedimentos para los rios de la bahia de Mayagüez
Ante la falta de mediciones de la cantidad de sedimentos transportados por los ríos es necesaria la búsqueda de métodos alternos para estimar las descargas de sedimentos sin contar con largos períodos de muestreo. Este estudio abarca tres de los rios que desembocan en la bahia de Mayagüez, el Grande de Anasco, el Yaguez y el Guanajibo. Las funciones de transporte de sedimentos (FTS) permiten estimar cuanta cantidad de sedimentos es transportada por un cauce. Esta investigación selecciónó entre 10 de las FTS, aquellas cuyas predicciones cumplen con los criterios hidráulicos y granulométricos para los cuales fueron derivadas. Como metodología se realizó el levantamiento topográfico de cada rio, el muestreo del material de fondo, seguido de un análisis de laboratorio para caracterizar el material. Seguidamente se analizó la geometría de cada sección y la granulometría para determinar velocidades, pendientes y diámetros representativos. Las FTS que se estudiaron son las usadas por el Cuerpo de Ingenieros del Ejército de los Estados Unidos en sus modelos SAM y Hec6 y dentro de las funciones seleccionadas, estas se dividieron en dos grupos, las asociadas a un tramo del rio en donde el material caracteristico es grueso y pendientes altas y otro tramo donde el material es mas fino y con pendientes menores. Posteriormente se modeló en Hec6, un programa unidimensional para el transporte de sedimentos, considerando las FTS seleccionadas y que permitirá obtener estimados del movimiento de sedimentos hacia la bahía de Mayagüez.
Yupa Luna, Jacinto. Mechanical Engineering, UPR Mayagüez - Suárez, O. Marcelo. General Engineering, UPR Mayagüez.
Corrosion effects of aluminum-copper-boron composites in 3.5% Solution
Metal matrix composites are used in many applications aerospace, automobile parts and others. The proposed composite material has good mechanical properties, such as high strength, high hardness. There are further improvement by precipitation hardening that, on the other hand, compromises the corrosion properties of material. This is reason for the present study. The composite was heat treated by solubilization at 540 C for 2 hour; and precipitation at different temperatures and times. The corrosion test was conducted in a computer controlled potentiostat/galvanostat using a 3.5 % NaCl solution for the different sample groups. Every group consisted of nine samples: three were aged at 150 C by 1, 3 and 6 hour; three, at 170 C for the same aging times; and the others, at 190 C and the same times. Results of the corrosion tests indicated that the matrix was affected by corrosion whereas the reinforcing particles acted as cathodes since the matrix/reinforcement interface corrodes like the matrix. The type of corrosion was both pitting and galvanic corrosion in the matrix/reinforcement interface. Corrosion potential (Ecorr ) with aging time decrease when the aging time and temperatures were incremented. The current density (icorr ) varied at different temperatures and times of treatment.