Manufacturing Commons^™

Engineered Surface Properties Of Porous Tungsten From Cryogenic Machining, Julius M. Schoop

Theses and Dissertations--Chemical and Materials Engineering

Porous tungsten is used to manufacture dispenser cathodes due to it refractory properties. Surface porosity is critical to functional performance of dispenser cathodes because it allows for an impregnated ceramic compound to migrate to the emitting surface, lowering its work function. Likewise, surface roughness is important because it is necessary to ensure uniform wetting of the molten impregnate during high temperature service. Current industry practice to achieve surface roughness and surface porosity requirements involves the use of a plastic infiltrant during machining. After machining, the infiltrant is baked and the cathode pellet is impregnated. In this context, cryogenic machining is …

Machining Strategies Exploring Reduction In Energy Consumption, Abdullah Al Mamun

All Graduate Theses, Dissertations, and Other Capstone Projects

The main aim of this thesis is to explore machining strategies, analyzing energy consumption using Design of Experiments (DOE) at the material removal rate (MRR), compare to cutting geometrical trajectories according to CNC parameters such as spindle RPM, feed rate, depth of cut per pass and total depth of cut. Spindle RPM, depth of cut per pass, and feed rate are selected as the main three factors and each factor has two levels: low-level (-) and high-level (+). These experiments have been performed at an end-milling machine by using a concept of a constant volume of material removal processes in …

Planning Freeform Extrusion Fabrication Processes With Consideration Of Horizontal Staircase Effect, Amir Ghazanfari, Wenbin Li, Ming Leu, Robert Landers

Faculty Publications, Mechanical Engineering

An algorithm has been developed to estimate the “horizontal” staircase effect and a technique is proposed to reduce this type of geometrical error for freeform extrusion fabrication processes of 3D “solid” parts. The adaptive rastering technique, proposed in this paper, analyzes the geometry of each layer and changes the width of each line of the raster adaptively in order to reduce the staircase error and increase the productivity simultaneously. For each line, the maximum width that results in a staircase error smaller than a predefined threshold is determined for decreasing the fabrication time or increasing the dimensional accuracy, or both. …

Size Effects In Human Visual Inspection For Micro/Meso Scale Parts, Sri Harsha Kavuri

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Visual inspection has been a major method of quality control in conventional manufacturing processes for the last fifty years. Utilizing trained human inspectors to perform this visual inspection has been the most effective means of maintaining quality control. Extensive research has been performed to understand the factors that influence the human inspection process.

In the recent years, there has been a significant emphasis on manufacturing at the smaller end of the size-spectrum such as Micro and Meso scale manufacturing. Quality control at becomes a challenging task due to the extremely small sizes. Several automated visual inspection techniques have been proposed …

Photonic Crystal Fibre Wgm Resonators For Magnetic Field Sensing, Aseel Mahmood, Vishnu Kavungal, Yuliya Semenova, S. S. Ahmed

Conference Papers

Whispering gallery mode (WGM) micro-resonators are remarkable optical devices whose small modevolumes and high Q-factors make them attractive for a wide range of applications such as filters, lasers, modulators and sensors [1]. WGMs can be excited in dielectric structures with circular symmetry, such as microspheres, micro-disks, and optical fibres, and can be imagined as closed-trajectory rays confined within the cavity by almost total reflections from the curved surface of the resonator. The spectral positions of the WGM resonances are highly sensitive to the geometrical dimensions of the resonator and refractive indices of both the resonator itself and its surrounding medium …

Refractive Index Sensor Based On A Silica Microsphere Whispering Gallery Mode Resonator, Arun Mallik, Qiang Wu, Gerald Farrell, Yuliya Semenova

Conference Papers

No abstract provided.

Color Removal From Pulp Mill Effluent Using Coal Ash Produced From Georgia Power Coal Combustion Plants, Christopher B. Willett

College of Graduate Studies: Theses & Dissertations

Two environmental concerns currently face Georgia: coal fly ash (CFA) waste from coal power plants, and the effluent generated by pulp mills. Pulp mill effluent discolors surface waters into which it is discharged, and has been proven to negatively impact the dissolved oxygen and carbon necessary for aquatic life. The proposed solution is a cost-effective adsorption treatment using an inexpensive but abundantly available waste material: CFA. CFA possesses beneficial properties that allow it to effectively remove contaminants, and is available at significantly reduced cost. The primary research objective was to define treatment parameters that would result in the maximum removal …

Laser Surface And Sub-Surface Repair During Metal Additive Manufacturing, Prudvi Teja Ravi

Masters Theses

"This study examines the use of laser surface treatment to repair surface and subsurface defects. Numerical analysis was performed on laser surface melting using Gaussian heat distribution equations to analyze the depth of the melt pool created by the phenomena. Concurrently, a process map was developed with a planned set of experiments by varying the ranges of laser power and travel speed to determine the dimensions of the melt pool across the gamut. The data generated from both the process studies and the numerical analysis was then used to determine the ideal operating ranges of the process parameters to repair …

Performance Metrics For Powder Feeder Systems In Additive Manufacturing, Venkata Sivaram Bitragunta

Masters Theses

"In blown powder Direct Metal Deposition (DMD) process, parts are built by adding metal powder on the melt pool created by the laser system. At low feed rates powder feeder systems have perturbations. The study focused on relationship between the perturbation frequencies by inherent powder feeder designs and its impact on deposition quality. Performance metric determine the relation between perturbations in the powder flow and quality of the deposit. To determine performance metric, various powder feeder designs were analyzed. Perturbation frequencies were introduced to the disk feeder design. The quality of the deposit was determined by the surface roughness of …

Parameter Determination And Experimental Validation Of A Wire Feed Additive Manufacturing Model, Kannan Suresh Kumar

Masters Theses

“Laser metal deposition is an additive manufacturing method with great scope and robustness. The wire fed additive manufacturing method has great opportunities in space applications and other zero gravity manufacturing processes. Process parameters play an important role in controlling the complex phenomenon and obtaining an ideal manufactured part. These parameters can be efficiently determined using simulation tools which are highly essential in visualizing real world experiments, therefore saving time and experimental costs. The objective of this study is to develop a transient 3D model of laser aided wire feed metal deposition which realizes the heat transfer and fluid flow behavior …

Process Improvements Of Cilantro Harvesting With Ergonomic Considerations, Eric Penningroth, Branden Shimamoto

Industrial and Manufacturing Engineering

The problems presented by Talley Farms to the team were a lower than desired cilantro harvesting capacity and work health pertaining to lower back problems. The project objectives were to address and improve upon both of these objectives. To increase harvesting capacity, a simulation model was created using standard times from time studies. The simulation model helped to compare the different harvesting methods as well as the effect of the utilization of the on-site manager. The throughputs between each of the models were analyzed. To address ergonomic concerns, a work sampling study was conducted and it was determined that kneeling …

Bikeshare Business Model For Cal Poly- San Luis Obispo, Justin Benson, Andrew Neil Gatchalian

Industrial and Manufacturing Engineering

With the increasing admittance of students into colleges and universities across the nation, the need for alternate modes of transportation is becoming more pressing. College and university campuses, as well as small cities, in which there is a college or university, are being overloaded with student cars. In San Luis Obispo specifically, parking on campus as well as downtown can be extremely difficult to find. Traffic is also getting progressively worse, especially at the hour when class begins/ends and student arrive to or leave campus. Financial reasons are yet another deterrent for students at Cal Poly. Parking permits, gas, and …

Effects Of Patient Factors On Implantation Rates In In Vitro Fertilization, Heidi Richardson, Sofia Soto

Industrial and Manufacturing Engineering

The purpose of this report is to evaluate the effects of patient factors and embryo quality on the implantation rate in In Vitro Fertilization (IVF). For this report, statistical methods are used to test the significance of several patient and embryo characteristics on embryo implantation rate. This project is an analysis of data collected from over 36,000 patients.

The analysis concluded several findings. There was enough statistical evidence to conclude that age was significant in regards to implantation rate and FSH levels. As the patient ages, the amount of FSH levels found in their blood increases. A patient with high …

Redesign Of Talley Farm's "Fresh Harvest" Produce Program, Nicole Bordwell, John Rivera, Jared Toboni

Industrial and Manufacturing Engineering

Fresh Harvest, a Central Coast Community Supported Agriculture (CSA) program run by Talley Farms located in Arroyo Grande, CA, has a rapidly growing customer base. They harvest, package, and deliver boxes of fresh quality produce to almost 3000 subscribers. However, Talley Farms’ space for production and processing is limited and at times required for other aspects of business. This results in a problem where Talley Farms current processing system of produce for the Fresh Harvest program is not suitable for the forecasted growing demand. This report addresses the need to prepare for continued significant growth to the demand for Fresh …

Analysis And Improvement Of The Security Building At Pg&E Diablo Canyon Nuclear Power Plant, Alyssa Carter, Natalie Christa, Phuong Anh Pham Dinh

Industrial and Manufacturing Engineering

A new Security building was recently designed and built at the Pacific Gas and Electric (PG&E) Diablo Canyon Power Plant (DCPP).This building’s staff and equipment are responsible for performing routine inspections on all personnel entering the facility in order to prevent security-related incidents from occurring at the nuclear power plant. Similar to airport security procedures, the DCPP security building routine inspections include the use of x-ray machines, metal detectors, and explosive detectors.

The Power Plant periodically experiences pre-planned, preventive maintenance outages, that last 4-6 weeks. During an outage, a power plant reactor is shut down for maintenance, repair, and re-fueling. …

Cold Roll Extrusion Machine Redesign Final Design Report, Foja Bains, Bryan Cyr, David Van Schooten

Mechanical Engineering

This report is a comprehensive review of a redesign of subsystems for a Cold Roll Extrusion Machine, a forging operation, for PCC Rollmet. Three subsystems were addressed in this project: A new Loading system, Feed system, and Lubrication system. The Loading system, and support system during developmental design stages, addressed the timely loading process of pipes onto the forging machine. After two quarters of design iteration, the group decided on a lever arm, hydraulic actuated, loading design. In the final quarter of the project, a quarter scale model of this lever arm was constructed to prove the concept of the …

Cal Poly India Project, Derek Babine, Austen Hibler, Alex Hernandez

Mechanical Engineering

This report documents the research, ideation, and development of a solution, implemented by the Cal Poly India Sanitation Team per the request of Mr. Harish Bhutani, to solve the problem of hazardous human waste management in poor villages in India. The sponsor envisioned a universal design that would give each household in those villages access to a private toilet system because the current solution is open defecation in water sources and farming fields. The initial constraints required the project be low cost, not use of electricity or water, have the ability to cater to an 8-10 person household, and be …

Machine Shop Learning Kits, Samantha Kelley, Ellen Chambers

Mechanical Engineering

Currently in the Cal Poly Machine shops, students are struggling to find ways to fulfill the 10 hours of shop experience required to gain their Yellow Tag certification. Red Tag is the first level of certification students generally achieve their freshman year. It allows them to use basic machine tools such as drills, shears, benders, etc. Then after completing 10 hours of shop experience they can take the Yellow Tag test, which gains them access to use a welder, mill, and lathe. The heads of the machine shop, the shop technicians, and the mechanical engineering students will all have different …

Semi-Automated Glass Mat Splice Operation For Asphalt Shingle Line, Justin Bracci, Harry Zhao, Chad Linafelter

Mechanical Engineering

The following report details the senior project sponsored by GAF Materials Corporation, Shafter, CA in regards to semi-automating a glass-mat splicing table for asphalt roofing shingle production. Herein includes details, research, design, and analysis regarding the semi-automation of the gluing processes for the splicing table. A working prototype was manufactured and tested for the future implementation onto GAF’s production line or further senior project involvement.

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 …