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Articles 1 - 29 of 29
Full-Text Articles in Manufacturing
Investigation Of Slective Laser Melting Of Mecanically Alloyed Metastable Al5fe2 Powder, Hugo Montiel
Investigation Of Slective Laser Melting Of Mecanically Alloyed Metastable Al5fe2 Powder, Hugo Montiel
Theses and Dissertations - UTB/UTPA
Selective Laser Melting (SLM), an Additive Manufacturing (AM) technology, enables the production of complex structured metal products. Aluminum alloys are used in SLM as high-strength lightweight materials for weight reduction in structural components. Previous investigations report high laser powers (300 W) and slow scanning speeds (500 mm/s) to process aluminum alloys under SLM. This research investigates the SLM processing of Al-Fe alloy by utilizing metastable Al5Fe2 powder system produced by mechanical alloying. Metastable systems are thermodynamically activated with internal energy that can generate an energy shortcut when processing under SLM. The optimum laser power, scan speeds and scan distances were …
A Study Of The Selective Laser Alloying Of Elemental Titanium And Boron Powder, Yingbin Hu
A Study Of The Selective Laser Alloying Of Elemental Titanium And Boron Powder, Yingbin Hu
Theses and Dissertations - UTB/UTPA
To better understand the selective laser alloying process of elemental titanium and boron powder, theoretic models are created which takes material related, reaction related, laser related, and other affecting factors into consideration. These models do help interpret the corresponding experiment results. In turn, the related experiment results validate the theoretic models created. In practice, the experiments with two different molar ratios of 1:2 and 4:1 between titanium and boron are carried out. The huge amount of energy released because of reaction between titanium and boron during laser irradiation makes it hard to understand and control the alloying process. At the …
A Preventive Maintenance Framework In Dairy Production Operations, Maria F. Vargas
A Preventive Maintenance Framework In Dairy Production Operations, Maria F. Vargas
Theses and Dissertations - UTB/UTPA
Dairy operations suffer frequent stops. Product shrinkage is a consequence of downtime, which includes losses of packaging material, scraped finish product and capacity. This work proposes a troubleshooting methodology to identify causes of downtime, estimation of waste cost, and minimization of operation disruptions by applying a combination of a cost function to assess waste, and performance measurements. The drinkable yogurt process is evaluated to find the principal areas for wasted bottles and yogurt. In order to make a decision about which of those sources to address, a General Cost Function is used to estimate waste cost which include measurements that …
A Study Comparing The Pedagogical Effectiveness Of Virtual Worlds And Of Traditional Training Methods, Benjamin Peters
A Study Comparing The Pedagogical Effectiveness Of Virtual Worlds And Of Traditional Training Methods, Benjamin Peters
Theses and Dissertations - UTB/UTPA
This experiment tests whether a virtual world is a more suitable alternative to classical paper and pen case studies for teaching people how to disarm improvised explosive devices (IED). Following preliminary training, the subjects are separated into a group of 32 and one of 33. The odd-numbered subjects receive case studies while the even-numbered subjects receive training in the virtual world, Second Life. After their training, each subject is put into a simulated test where they attempt to properly disarm a mock IED attached to a victim played by an actor/actress. The results of the experiment show no significant difference …
A Decision Support Model For Process Planning In Remanufacturing Using Fuzzy Set Theory And Genetic Algorithm, Juan C. Martinez
A Decision Support Model For Process Planning In Remanufacturing Using Fuzzy Set Theory And Genetic Algorithm, Juan C. Martinez
Theses and Dissertations - UTB/UTPA
The environmental awareness and resources preservation has boosted the use of remanufacturing processes. Many important studies have been made in this area, but there are still pitfalls and opportunities that have not been explored yet. Specifically, the cleaning processes play a critical role in remanufacturing. It is among the top of most costly processes and it plays a key step in remanufacturing because delivers a free of contaminant product ready for reprocessing. Understanding and selecting the best processes to meet the need and goals of remanufacturers are important for effective and efficient remanufacturing. Due to variables and high uncertainty associated …
A Decision Support System To Measure Product Suitability For Additive Manufacturing Processes, Cynthia De Vasconcellos Barros
A Decision Support System To Measure Product Suitability For Additive Manufacturing Processes, Cynthia De Vasconcellos Barros
Theses and Dissertations - UTB/UTPA
Additive Manufacturing (AM) technologies started arising around 1980’s and they are currently considered to be the third industrial revolution. With improvements in computers, materials, and automated machines, manufacturers across several types of industries are becoming more familiar with AM processes, and it has become more common to see products that are being fabricated by using this new technology. However, there are still questions regarding when it is suitable to use Additive Manufacturing or conventional manufacturing processes depending on different factors. The purpose of this thesis is to create a Decision Support System (DSS) that will help users measure product suitability …
Development Of Hydrodynamic Channel Routing Model Of The Lower Rio Grande River To Assist In Flood And Stormwater Management, Andrew W. Leeper
Development Of Hydrodynamic Channel Routing Model Of The Lower Rio Grande River To Assist In Flood And Stormwater Management, Andrew W. Leeper
Theses and Dissertations - UTB/UTPA
Flooding and stormwater management of the Lower Rio Grande River (LRG) has become a major issue throughout the years with local entities along the river. The purpose of this study is to develop a hydrodynamic channel routing model to predict water surface elevation changes due to flooding. The study area consists of the LRG from Los Ebanos to Brownsville, Texas. This hydrodynamic model displays the hydraulics of the water flow through the LRG and determines where potential flood hazards exist. To verify the accuracy of the model a series of calculated output hydrographs were established at the Progreso Bridge and …
A Case Study For Financial Feasibility Of Automated Costing Support In A Small Machine Shop, Benito A. Gonzalez
A Case Study For Financial Feasibility Of Automated Costing Support In A Small Machine Shop, Benito A. Gonzalez
Theses and Dissertations - UTB/UTPA
A knowledge-based cost estimating expert system is chosen by a Mexican machine shop. Differences between the traditional experience-based system employed and the automated system are studied. Data is gathered to analyze time effectiveness, accuracy and payback of the software. Data from seventy part models is recorded to study the time experiment, and data from fifty part models is used to study the accuracy and consistency. Data is analyzed by calculating mean, standard deviation, and test of hypothesis. The results indicate that the software is faster than the traditional quoting system; however, the payback point is high. Also, results show the …
Remanufacturing Cleaning Process Evaluation, Comparison And Planning, Ozan Yagar
Remanufacturing Cleaning Process Evaluation, Comparison And Planning, Ozan Yagar
Theses and Dissertations - UTB/UTPA
This thesis aims to combine previous research on remanufacturing cleaning processes and applications into a single decision-making tool, in the form of software, which a remanufacturer can use to find a cleaning system that matches their specific demands. This thesis will provide an in-depth review of each cleaning process, the chemicals used in those processes, and the contamination types for which they were developed. This research also provides evaluation and comparison that assists remanufacturers in designing their cleaning systems. Finally, there will be a description and demonstration of the software. The ultimate goal is to find correct cleaning process to …
The Evaluation And Analysis Of The Impact Of Variability On The Twelve Workstation Factory, Hernando Garrido
The Evaluation And Analysis Of The Impact Of Variability On The Twelve Workstation Factory, Hernando Garrido
Theses and Dissertations - UTB/UTPA
Presently, there is theory and work examples about factory performance presented in the book ―Optimizing factory Performance‖ by James Ignizio, Ph.D. The theory explains how to determine performance using three fundamental equations by considering the impact and propagation of variability through a 12-Workstation Factory Model, and a number of its variations. The objective of developing a simulation model was to serve as a tool for instructors to illustrate the impact and propagation of variability in the manufacturing industry and to investigate phenomena (i.e., time to reach steady state, impact of variability) in the three dimensions of manufacturing. The validation of …
Characterizing And Optimizing The Molten Salt Cleaning, Yangyang Long
Characterizing And Optimizing The Molten Salt Cleaning, Yangyang Long
Theses and Dissertations - UTB/UTPA
Molten salt cleaning is an important cleaning approach in remanufacturing which can remove a variety of contaminants from metal substrates with high efficiency. Facing the very limited research of this approach in literature, this thesis intends to characterize molten salt cleaning process and optimize its parameters when big parts with complicated shapes are cleaned. Based on the development of molten salt cleaning and studies on contaminations, two experiments are conducted. The first one investigates the influences of the hot salts on three metal substrates and shows the applicable of cleaning carbon steel and grey iron parts with molten salt. The …
An Analytic Hierarchy Process Approach To Assess Health Service Quality, Yan Li
An Analytic Hierarchy Process Approach To Assess Health Service Quality, Yan Li
Theses and Dissertations - UTB/UTPA
While improving quality in health care is currently at the forefront of professional, political, and managerial attention, the key dimensions constituting health-care quality have not been fully understood. Also, few valid approaches have been proposed to the measurement of health-care quality. In this research, the Analytic Hierarchy Process (AHP) approach is applied to study the structure of health-care quality and deducted relative importance weights for each of the quality elements. A statistical quality model is derived to assess medical equipment quality which is an important part constituting the general health-care quality. Finally, the application of the AHP model to assess …
A Stochastic Product Priority Optimization Method For Remanufacturing System Based On Genetic Algorithm, Xiong Xiong
A Stochastic Product Priority Optimization Method For Remanufacturing System Based On Genetic Algorithm, Xiong Xiong
Theses and Dissertations - UTB/UTPA
Increasing number of manufacturers are developing remanufacturing facilities to recover end-of-life products for product/component reuse and material recycling while the high uncertainty pattern of returned products complicates the production planning. In this thesis a stochastic production priority optimization method, considering various priority concerns for remanufacturing systems is developed. Priority ranking and matching algorithm is developed to determine the priority rule, using thirteen weighting factors. Queueing models are developed to formulate the objective function, a genetic algorithm is then developed to search optimal solution under different business configurations. Result of this research will provide insights to priority assignment mechanism, which in …
An Information Technology Suitability Index For Mass Customization, Oscar Leonardo Barrenechea
An Information Technology Suitability Index For Mass Customization, Oscar Leonardo Barrenechea
Theses and Dissertations - UTB/UTPA
In today’s manufacturing world, high competitive markets are pushing companies to find better ways to satisfy their customer’s needs using several Mass Customization (MC) approaches. Consequently, new Information Technologies (IT) have taken a very important role in order to manage the increasing amount of data generated from those customers. The purpose of this thesis is to develop an IT suitability index for MC that would help to identify the critical IT factors to be addressed in order to efficiently support MC. A linear programming regression model was utilized to generate index values. Finally, the results of this model could be …
Gas-Assisted Powder Injection Molding: A Comparison Of Residual Wall Thickness Between Metal Cavity Vs. Sla Cavity And Effect Of Mold Temperature On Residual Wall Thickness, Donghan Kim
Theses and Dissertations - UTB/UTPA
The effects of processing variables on gas penetration depth and Residual Wall Thickness (RWT) in an aluminum (Al) cavity of Gas-Assisted Injection Molding (GAIM) were investigated with Polypropylene (PP) and Stainless Steel Powder Feedstock (SSPF). The selected processing variables were melt temperature, shot size, gas pressure, and gas delay time. By using a Taguchi L9 array, the results were compared with previous work. For PP, there were no significant differences on gas penetration depth. However, the significance of gas delay time was relatively higher in an Al cavity as compared to a Stereolithography (SLA) cavity from previous work with SSPF. …
A Study On Gas Penetration And Fingering Behavior In Injection Molding Of Polymer And Powder Metal Feedstock, Edna I. Orozco
A Study On Gas Penetration And Fingering Behavior In Injection Molding Of Polymer And Powder Metal Feedstock, Edna I. Orozco
Theses and Dissertations - UTB/UTPA
The effect of processing variables on the level of gas penetration in parts fabricated by gas-assisted injection molding from two different materials was compared. The materials used were polypropylene and stainless steel powder metal/thermoplastic feedstock. Software simulation and physical experiments were conducted. Taguchi analysis was used to reduce the number of experiment trials and to find the optimum processing conditions. Four different variables were changed using nine different combinations. The processing variables are the pressure, the delay time before gas is injected, the temperature of the material injected, and the amount of the material injected. The results showed that the …
A Stochastic Production Cost Model For Remanufacturing Systems, Gaurang S. Patel
A Stochastic Production Cost Model For Remanufacturing Systems, Gaurang S. Patel
Theses and Dissertations - UTB/UTPA
Growing environmental concern throughout this decade coupled with enforced legislation, customer expectations and economic incentives have forced increasing number of manufacturers to take back their products from end user. Managing this reverse flow of products is called reverse logistics. The stochastic nature of returned products complicates the production planning for remanufacturing systems in reverse logistics. In this thesis a stochastic production cost model, considering various costs associated under different situations for remanufacturing systems of returned products is developed. A search algorithm method is recommended to determine optimal production run size, production rate and space for remanufacturing systems in reverse logistics. …
The Use Of Confidence Intervals For The Control Limits Of X¯ And S Control Charts, Daniel A. Lopez
The Use Of Confidence Intervals For The Control Limits Of X¯ And S Control Charts, Daniel A. Lopez
Theses and Dissertations - UTB/UTPA
This research focuses on the variation observed on the control limits of X¯ and S control charts, due to the sampling schemes. In previous studies it has been shown that the estimated control limits derived by a small number of subgroups does not help in setting up reliable control limits. It has also been shown that estimating control limits from a large number of subgroups is not a feasible option. In this research quantile tables will be derived by sampling from the standard normal distribution and used to explain the effects of sampling on the control limits. The tables will …
Extension Of Stereolithography Mold Life Using Gas-Assisted Injection Molding, Dilip Bose Ramalingam Nagarajan
Extension Of Stereolithography Mold Life Using Gas-Assisted Injection Molding, Dilip Bose Ramalingam Nagarajan
Theses and Dissertations - UTB/UTPA
Stereolithography (SL) molds show great promise for injection molding of limited number of parts, greatly reducing the time to product and production cost. However, they present challenges to designers because of their strength, thermal characteristics and shorter lifetimes compared to metal molds. Gas-assisted injection molding (GAIM) has been used to alleviate the problems of distortion and thermal damage. The use of GAIM makes it possible to produce a large number of parts compared to conventional injection molding in epoxy molds with higher quality. In this research solid models of the mold with different part geometry were created using CAD and …
The Development Of Web-Based Aerobic And Anaerobic And Muscle Static Work Capacity Modules Using Legacy Cycle Approach, Anant Ravindra Deshpande
The Development Of Web-Based Aerobic And Anaerobic And Muscle Static Work Capacity Modules Using Legacy Cycle Approach, Anant Ravindra Deshpande
Theses and Dissertations - UTB/UTPA
The Legacy cycle is an instructional model that emphasizes inquiry. Learners are faced with progressively complex challenges. For each challenge, learners generate initial thoughts on how they might react to the challenges. In this thesis, a web based instructional method that evaluates interactivity and motivation is presented. The system presented in the thesis helps student to integrate the use of legacy cycle approach in the regular study of aerobic and anaerobic and muscle static work capacity modules. The thesis also focuses on developing modules which contain challenges encompassing various sections, which helps student as an asynchronous learning tool, intended for …
The Effects Of Nationality In The Intercultural Relationship In A Maquila Environment, Cultural Dimensions A Practical Approach, Daniel Martin Reynoso Ortiz
The Effects Of Nationality In The Intercultural Relationship In A Maquila Environment, Cultural Dimensions A Practical Approach, Daniel Martin Reynoso Ortiz
Theses and Dissertations - UTB/UTPA
The Maquiladora Industry has enhanced economic development in the U.S. and Mexico border region. Initially, investors came to set up assembly lines requiring a small amount of technical skill; however, increases in the technological level of products have created the need for companies to require more technical expertise from their staff. Today, the requirement is for the design or redesign of some of their products and the manufacturing processes required to make these products. This brings managerial problems in dealing with technical people in cross cultural environments. These problems deal with staffing issues such as getting the right people and …
Analysis Of Performance Capacity Of Hand Grip Through An Integrated Learning Curve Model, Miguel Torres
Analysis Of Performance Capacity Of Hand Grip Through An Integrated Learning Curve Model, Miguel Torres
Theses and Dissertations - UTB/UTPA
There are few activities or work task in the manufacturing industry that does not involve grip strength. That is why it is in the best interest of the manufacturing industry to have an understanding of the optimum grip strength gain capacity over time that would lead to better performance, accuracy and most of all prevent hand grip related injuries. For that reason, this thesis was concentrated in discovering a possible basic working model for estimating grip strength over time for a specific grip strength activity. The first step was to observe the trend characteristics of the strength gain data over …
Expert System Development For Hard Disk Drive Failure Analysis, Fernando Rodriguez Rosas
Expert System Development For Hard Disk Drive Failure Analysis, Fernando Rodriguez Rosas
Theses and Dissertations - UTB/UTPA
The Computer's Hard Disk Drive is a complex high technology device, diagnosis of a failure is difficult even using sophisticated test equipments. These Drives are expensive and returning a new one when it fails within the warranty period is not an option. The failed drive must be tested and repaired. In the repair process the analysis and diagnosis of the failures is a key point in the process where decisions regarding the repair process that the failed Drive will follow. Therefore, there is a requirement to perform an effective analysis and provide an accurate diagnosis. The standard system utilized for …
Human Reliability Analysis In The Performance Of Advanced Cardiac Life Support Tasks, Lucia Veronica Rosas
Human Reliability Analysis In The Performance Of Advanced Cardiac Life Support Tasks, Lucia Veronica Rosas
Theses and Dissertations - UTB/UTPA
Error reduction in the performance of medical emergency situations is an area of great concern in today's society. This is specially the case when the situation involves a cardiac arrhythmia. These situations are generally categorized as Advanced Cardiac Life Support (ACLS) events. The American Heart Association provides the proper procedures that practitioners of ACLS should follow to provide care to patients presenting heart arrhythmia problems. These situations occur inside and outside the hospital, outside the hospital being the most critical ones considering the limitation of equipment and availability of qualified care. Errors made by the practitioners of ACLS in this …
Analysis Of Lifting Performance Capacity Through An Integrated Learning Curve Model, Jose Roel Flores
Analysis Of Lifting Performance Capacity Through An Integrated Learning Curve Model, Jose Roel Flores
Theses and Dissertations - UTB/UTPA
Physical fitness specific to job demands is necessary for jobs that require moderate or heavy effort. Fitness training is needed not just when a new job is learned but also when an individual has been away from the job for a few weeks and returns to perform the task. The basic problem is to have a good understanding of the dynamics of performance capacities to establish training and retraining regimes to prevent overexertion. To obtain this, a better understanding of the behavior of performance capacity over time is necessary. A performance capacity training regimen was designed for tasks that required …
The Rheological Behavior Of Carbon Nanofiber-Reinforced Thermoplastic Composites, Qiang Zeng
The Rheological Behavior Of Carbon Nanofiber-Reinforced Thermoplastic Composites, Qiang Zeng
Theses and Dissertations - UTB/UTPA
A rheological study of the thermoplastic HDPE filled with vapor grow carbon nanofiber (VGCNF) has been performed with a RheoStress 150 Tester. VGCNF having average 50 nm diameter were used. These nanofibers were purified to provide for an open network of high purity nanofibers. A rheomixer was used to disperse the nanofibers uniformly in the polyethylene matrix because of shear working conditions. The influence of fiber loading, frequency and temperature on the rheology was investigated. Studies were carried out in the temperature range of 160 to 210°C and frequency range of 0.062 to 628.3 rad/s. The rheological measurements show that …
Automated Robotic Inspection System For Electronic Manufacturing, Roberto Alejandro Balderas
Automated Robotic Inspection System For Electronic Manufacturing, Roberto Alejandro Balderas
Theses and Dissertations - UTB/UTPA
An automated robotic inspection system for electronic manufacturing has been developed to identify pin defects of IC packages mounted on printed circuit boards using surface mount technology. The automated robotic inspection system consists of two robots, a computer, a CCD camera with frame gabber for image acquisition, and a customized windows program using neural network for on-line defect identification. Gray scale images of the pins on IC packages are acquired using ambient light. The images are filtered and formatted to appropriate size, so that Matlab neural network tool could be used. The images are used to train neural networks using …
A Neural Network-Based Vision System For Automated Separation Of Onion From Clod Using Mechanical Harvester, Demian Morquin
A Neural Network-Based Vision System For Automated Separation Of Onion From Clod Using Mechanical Harvester, Demian Morquin
Theses and Dissertations - UTB/UTPA
A neural network classifier for separating clods from onions during harvesting has been developed. The separator consists of a multi-layer feedforward network that maps textural features computed from gray-scale images of onions and clods into the correct object. Texture features were computed from co-occurrence matrices that specify the spatial relationship of pixel values in an image. The textural features selected for this application consist of homogeneity, contrast, variance, and energy. The network was trained using the back-propagation algorithm. Based on the textural features classification, the effect of changing the network configuration on separation effectiveness was investigated. Factors including network topology …
Modeling Of A Meat Cooking Process For On-Line Monitoring And Control, Oralia Garcia
Modeling Of A Meat Cooking Process For On-Line Monitoring And Control, Oralia Garcia
Theses and Dissertations - UTB/UTPA
A heat transfer model is developed to predict cooking time of meat patties given the initial temperature of meat, oven temperature, and meat properties to monitor and control a cooking process on-line. Experiments were performed to find the cause of variability in cooked weight and raw temperature effects in forming and final cooked temperature. Advanced charting techniques concluded that only common causes of variability were present in the process. Thermal conductivity experiments were performed to determine the thermal conductivity of meat (k), which was compared with the properties of meat published in literature to validate the experiment. Oven design analysis …