Manufacturing Commons^™

A Review Of Setup Practices And Procedures For Creating Ieee 802.11 Wireless Community Networks, Jae M. Theobald

Theses and Dissertations

IEEE 802.11 wireless networking equipment has made it possible to bridge the last mile for new broadband internet service providers. Inexpensive wireless networking equipment and high gain antennas enable high speed internet delivery at a fraction of the cost of installing or upgrading land lines for cable or DSL services. Based on this research, a guide of general practices and procedures is proposed for designing, installing, and maintaining a reliable wireless community area network. Included tests have provided performance results for several types of wireless antennas (including wire grid parabolic dishes, Yagi and Vagi styles, and echo backfire), wireless bridges, …

Study Of Ceramic Slurries For Investment Casting With Ice Patterns, Qingbin Liu, Ming-Chuan Leu, Harish Jose, Von Richards

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Ice patterns generated by rapid freeze prototyping or a molding process can be used to make ceramic investment molds for metal castings. Due to the use of ice, the ceramic slurries must be poured around the pattern and cured at sub-freezing temperatures. Success of this process depends greatly on the mold strength after the gelation of the slurries. This paper describes the experimental results of the mold strength after the gelation of the slurries under different compositions. The parameters considered include mixing time, alumino-silicate vs. fused silica ratio, volume of binder, and volume of catalyst. The strength of the gelled …

Experimental Investigation Of Laser Metal Deposition Of Functionally Graded Copper And Steel, Vinay Kadekar, Sashikanth Prakash, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser metal deposition is an emerging technology for producing fully dense metallic parts. This process shows a promising future for the deposition of functionally graded steel - copper alloys. Good thermal conductivity of copper and a high wear resistance of steel can be achieved in dies and cores. However, to accomplish this, there are many issues to be resolved, such as the formation of an undesirable phase, solidification cracking, porosity at the interface and difference in thermal coefficient of expansion between steel and copper. The influences of process variables, such as laser power, laser scan speed, composition, powder flow rate, …

Numerical And Experimental Analysis Of The Powder Flow Streams In The Laser Aided Material Deposition Process, Yogesh D. Thakar, Heng Pan, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Axial powder stream concentration between the nozzle end and the deposition point is an important process parameter in the laser aided material deposition process. The powder concentration is greatly influenced by the nozzle geometry in use. This paper describes the numerical and experimental analysis of this important parameter in relation to the coaxial nozzle. The experiments are performed with the different nozzle geometries to generate various flow patterns of the gravity fed powder in a cold stream. The results of the experimental analysis are compared with the numerical simulation and found justified. These results are used in concluding the significance …

Modeling Of The Metal Powder Flow With Carrier Gas In Coaxial Nozzle For Direct Laser Deposition Process, Heng Pan, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In direct laser deposition process, metal powder is directly fed with carrier gas through the coaxial nozzle into the melt pool created by the laser to form the solid parts. Many operational parameters of the process depend on the characteristic of the powder stream structure below the exit of the coaxial nozzle. In this paper, a computational approach is developed for the simulation of the gas-particle flow in the coaxial nozzle. By taking into account the nozzle geometry and operating parameters, such as width and inclination angle of powder passage and carrier gas velocity, the developed computational code allows the …

Development Of Image Processing Tools For Analysis Of Laser Deposition Experiments, Todd E. Sparks

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Microscopical metallography is a well established field with a long history of techniques for measuring features. Modern computational power allows much more rigorous investigation than simple area fractions and intercept measurements. This paper details the development of image processing tools using GNU Octave, a free, open source numerical computation package. Proposed in the paper is a method for characterizing features within a digital microscope image.

Wire Bonding Challenges In Optoelectronics Packaging, Jianbiao Pan, Patrice Fraud

Industrial and Manufacturing Engineering

Wire bonding has been used in integrated circuit (IC) packaging for many years. However, there are many challenges in wire bonding for optoelectronics packaging. These challenges include bonding on sensitive devices, bonding over cavity, bonding over cantilevel leads and bonding temperature limitations. The optoelectronics package design brings another challenge, which requires wire bonding to have deep access capability. In this paper, the wire bonding technologies are reviewed and ball bonding and wedge bonding are compared. The variables that affect the wire bonding process are then discussed. Finally, the challenges of wire bonding in optoelectronics packaging are presented in detail.

Effect Of Chromium-Gold And Titanium-Titanium Nitride-Platinum-Gold Metallization On Wire/Ribbon Bondability, Jianbiao Pan, Robert M. Pafchek, Frank F. Judd, Jason Baxter

Industrial and Manufacturing Engineering

Gold metallization on wafer substrates for wire/ribbon bond applications require good bond strength to the substrate without weakening the wire/ribbon. This paper compares the ribbon bondability of Cr/Au and Ti/TiN/Pt/Au metallization systems. Both chromium and titanium are used to promote adhesion between substrates and sputtered gold films. Both can diffuse the gold surface after annealing and degrade the wire/ribbon bondability. Restoring bondability by ceric ammonium nitrate (CAN) etch was investigated. Experiments were conducted to investigate the effect of Cr/Au and Ti/TiN/Pt/Au, annealing, and CAN etch processes on 25.4 times; 254 μm (1 × 10 mil) ribbon bonding. All bonds were …

Pressure Distribution Around Spherical Distal Ball-Tip In Ultrasound Angioplasty, Graham Gavin, Garrett B. Mcguinness, Finbar Dolan, M.S. J. Hashmi

Conference Papers

INTRODUCTION Ultrasound Angioplasty has been shown to be effective in the removal and re-canalising of blockages in arteries (Siegel RJ, 1993). By delivering therapeutic ultrasound to the blockage, via a wire waveguide to a ball-tip, the lesion or thrombus is affected by pressure waves, micro streaming, cavitation and direct contact with the oscillating ball-tip. Most work to date has concentrated on a spherical ball-tip geometry at the distal end of the wire waveguide (Steffen, 1994 and Rosenschein, 1996). Tip displacements usually lie between 10 - 100m (peak-to peak) and ball tip diameters between 1 - 2mm (Atar, 1999 and Yock, …

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 …

Critical Variables Of Solder Paste Stencil Printing For Micro-Bga And Fine-Pitch Qfp, Jianbiao Pan, Gregory L. Tonkay, Robert H. Storer, Ronald M. Sallade, David J. Leandri

Industrial and Manufacturing Engineering

Stencil printing continues to be the dominant method of solder deposition in high-volume surface-mount assembly. Control of the amount of solder paste deposited is critical in the case of fine-pitch and ultrafine-pitch surface-mount assembly. The process is still not well understood as indicated by the fact that industry reports 52-71% surface-mount technology (SMT) defects are related to the solder paste stencil printing process. The purpose of this paper is to identify the critical variables that influence the volume, area, and height of solder paste deposited. An experiment was conducted to investigate the effects of relevant process parameters on the amount …

Using Stiffeners For Improved Geometric Fidelity Of Flexible Elements, Ankit Kapoor

Masters Theses

Flexible hoses play an important role in safe operation of a transportation vehicle in automotive and aerospace field. Due to lack of accurate and efficient modeling techniques for such flexible elements with large deformation, most Computer Aided Engineering system do not address the problem in their solution methods.

In this thesis a method is presented to improve the geometric fidelity of flexible element models by using off-axis bi-linear stiffeners (spring) into a discrete linear beam model. Resulting deflection of a hose were compared with the digital scans of an actual deflection of the hose. Though the method is computationally expensive, …

Comparing Refractory Coatings On Shell Sand Utilizing Elevated Temperature And Collapsibility Testing, Suet Fong Cheah

Masters Theses

This research study examines the effects of refractory coatings on a shell sand using laboratory testing equipment as opposed to the more laborious and time consuming processes of molding, melting, filling, shakeout, and obtaining dimensions of actual castings. As of today, there have not been any such laboratory test methods. This research project focused on quantifying distortion, mass change, and impact strength found in refractory coated shell sand. The equipment used was the thermal distortion tester (TDT) and a modified impact tester. The thermal distortion curves (TDC), mass change, and impact strength are provided and compared for all systems studied. …

The Contextable: Building And Testing An Intelligent, Context-Aware Kitchen Table, Daniel Matthew Hoopes

Theses and Dissertations

The purpose of this thesis was to design and evaluate The ContexTable, a context-aware system built into a kitchen table. After establishing the current status of the field of context-aware systems and the hurdles and problems being faced, a functioning prototype system was designed and built. The prototype makes it possible to explore established, untested theory and novel solutions to problems faced in the field.

A Supply Chain Management Tool For Linking Courses In Manufacturing Engineering , Daniel Waldorf, Sema E. Alptekin

Industrial and Manufacturing Engineering

A Recent Society of Manufacturing Engineers (SME) grant received by Manufacturing Engineering Program at Cal Poly has provided funds to strengthen its curricular focus on supply chain management, flexibility, business skills, quality, and process controls. New courses and laboratories are developed in electronics manufacturing, information technology, and supply chain management. A functioning supply chain environment has been developed to provide vertical integration among several courses. A software tool being developed in-house integrates the activities of the students who play the roles of customers and suppliers. Details of the various components of this comprehensive project are presented in this paper.

Understanding Manufacturing Energy Use Through Statistical Analysis, J. Kelly Kissock, John Seryak

Mechanical and Aerospace Engineering Faculty Publications

Energy in manufacturing facilities is used for direct production of goods, space conditioning, and general facility support such as lighting. This paper presents a methodology for statistically analyzing plant energy use in terms of these major end uses. The methodology uses as few as 60 data points that are relatively easy for most plants to obtain. Multivariable change-point models of electricity and natural gas use as functions of outdoor air temperature and production data are then developed. The statistical models can be used to predict energy use for energy budgeting, measure savings, determine cost structures, and diagnostic purposes. Moreover, in …

Tool Management In Flexible Manufacturing Systems, Ahmet Soylemezoglu

Masters Theses

"In this study, impact of cutting tool life and tool slot size on tool management in Flexible Manufacturing Systems (FMS) is investigated. A conceptual tool management framework, which has been proposed by Buyurgan, Saygin, and Kilic (2003), is modified and implemented in a simulation environment in order to assess its performance. This model, namely LS Model (LS stands for Life and Size), makes decisions by considering both tool life and tool slot size. An alternative tool management model that makes decisions based only on tool life, namely LO Model (LO stands for Life Only), is developed in order to make …

Automated Casting Cleaning, Chris Anderson

Graduate Research Papers

The dilemma facing all foundries today is finding a cost effective, efficient, and safe manner in which to clean castings. At the same time produce a cleaned casting that meets consistent quality and delivery expectations. Today nearly 90% of all casting produced are cleaned by the use of manual labor via chipping an grinding. This manual method has proved to be very labor intensive, costly, lacking consistent quality, and carry high rates of injuries. The use of automation to clean castings is in its embryo stage in the foundry industry. The use of automation in the foundry industry, products currently …

Why Toyota And Honda Topped The 2002 J.D. Power Quality Study, Susan Lightle, Kenneth Yale Rosenzweig, John Talbott

Accounting Faculty Publications

Toyota again topped the annual J. D. Power and Associates quality study released in late May of 2002. Toyota scored the highest mark ever with l 07 defects per l 00 vehicles, while Honda came in second with 113 defects. The study was based on responses of approximately 65,000 new car owners queried during their first 90-days of ownership.

These results do not surprise us, as we have been fortunate to make numerous sojourns to the Toyota plant in Georgetown, Kentucky, and observe the manufacturing processes. These trips were normally facilitated by a former Japanese student of ours, Minako Yanke, …

Riser Design For Green Sand And Ductile Iron Castings, K. Michael Kuebler

Graduate Research Papers

Shrinkage defects in ductile iron riser contacts has long been one of the most frustrating defects to eliminate for the foundry engineer. While process variation can definitively contribute to the occurrence of these defects most can be prevented if the risers are properly designed and/or applied to the castings to be fed. There are several proven methods for the designing risers some of which go back over 40 years ago. There are also new methods available today with the advancements of simulation software. Four of these riser design methods were evaluated for their ability to produce an internally sound casting …

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 …

A Descriptive Performance Model Of Small, Low Cost, Diskless Beowulf Clusters, Curtis R. Nielson

Theses and Dissertations

Commodity supercomputing clusters known as Beowulf clusters, have become a low cost alternative to traditional supercomputers. Beowulf clusters combine inexpensive computers and specialized software to achieve supercomputing power. The processing nodes in a diskless Beowulf cluster do not have a local hard disk unlike the nodes in most commodity clusters. Research has provided performance information for diskless clusters built with expensive, high performance equipment. Beowulf clusters use commodity off-the-shell hardware, and little information is available about their performance. This research includes the construction of several diskless Beowulf clusters. Using the NAS Parallel Benchmarks, the performance of these clusters was measured. …

Modeling For The Control Of The Laser Aided Manufacturing Process (Lamp), Mallikharjuna R. Boddu, Vishnu P. Thayalan, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Many state-of-the-art Rapid Prototyping (RP) technologies adopt lasers to fabricate 3-D solid parts by material deposition in layers. The ability of these RP technologies to control the process requires a thorough understanding of the process mechanics. This paper presents the analysis of an analytical, dynamic model explaining the complex phenomenon of Laser Aided Manufacturing Process (LAMP). The equilibrium of the dynamic model is analyzed and dynamic simulations are performed to determine its stability characteristics. This model forms the basis for the real-time control of the LAMP.

Process Control Of Laser Metal Deposition Manufacturing -- A Simulation Study, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The laser metal deposition process is a rapid manufacturing operation capable of producing functional prototypes with complex geometries and thin sections. This process inherently contains significant uncertainties and, therefore, extensive experimentation must be performed to determine suitable process parameters. An alternative is to directly control the process on-line using feedback control methodologies. In this paper, a nonlinear control strategy based on feedback linearization is created to automatically regulate the bead morphology and melt pool temperature. Extensive simulation studies are conducted to validate the control strategy.

Application Of A Diagnostic Tool In Laser Aided Manufacturing Processes, Sashikanth Prakash, Mallikharjuna Rao Boddu, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Lasers play a vital role in producing parts with high dimensional accuracy, strength and quality in today's rapid prototyping industry. In the process of Laser Metal Deposition, many problems are encountered where the part quality does not meet the required standards. This could be due to the nonconformity of control parameters or unnecessary interactions between the control factors. This paper discusses the implementation of Dr. Genichi Taguchiï's optimization techniques using Design of Experiments (DOE) where a series of fractional factorial experiments are performed on the laser deposition process. The results from these experiments are evaluated with respect to the rate …

Comparison Study Of Cooling Fins And Chills Effectiveness In Aluminum Sand Mold Casting, Vladimir E. Kouznetsov

Graduate Research Papers

Besides proper design of gating and risering systems, there are several methods used to control and modify solidification behavior of cast alloys. Within these methods, the most widely used are local cooling aids employing cooling fins (thin segments attached to problematic areas of casting) or external chills (metal inserts placed into mold walls to accelerate heat withdrawing from potential hot spot). The later helps to promote directional solidification when traditional methods are not possible to use due to limitations related to the casting design. Despite relatively wide application in aluminum foundries, there are no specific recommendations on cooling aids parameters …

Universal Mounting Bracket For Laser Targeting And Feedback System, Richard J. Kelin Ii

Patents (University of Northern Iowa)

A support bracket for mounting a device such as a laser targeting and feedback system to a spray gun. The bracket includes a bolt having a threaded end, a first collar disposed on the bolt opposite the threaded end and a second collar threadably engaged with the threaded end of the bolt. A compressible member is disposed on the bolt between the collars. Opposite the compressible member, a support arm used to support the device is attached to the second collar. The bracket is engageable with a portion of the spray gun body and is engaged therewith by deflecting the …

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 …

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 …

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 …