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Full-Text Articles in Engineering

Dual-Axis Solar Tracker, Alazone Smith Jan 2019

Dual-Axis Solar Tracker, Alazone Smith

All Undergraduate Projects

The global energy crisis and continued supporting evidence of global climate change have begun to shift the world economies towards solutions that solve both challenges. Solar power has become one of the most recognizable and popularized renewable energy methods to date. In comparison to other photovoltaic systems, this project demonstrates the performance advantages of a dual-axis solar tracker. It also addressing its viability on a non-commercial scale. The objective was to improve upon previous solar tracker projects at Central Washington University by adding another axis to the system. This system implements both an actuator and a stepper motor to examine …


Trade-Off Balancing For Stable And Sustainable Operating Room Scheduling, Amin Abedini Jan 2019

Trade-Off Balancing For Stable And Sustainable Operating Room Scheduling, Amin Abedini

Theses and Dissertations--Mechanical Engineering

The implementation of the mandatory alternative payment model (APM) guarantees savings for Medicare regardless of participant hospitals ability for reducing spending that shifts the cost minimization burden from insurers onto the hospital administrators. Surgical interventions account for more than 30% and 40% of hospitals total cost and total revenue, respectively, with a cost structure consisting of nearly 56% direct cost, thus, large cost reduction is possible through efficient operation management. However, optimizing operating rooms (ORs) schedules is extraordinarily challenging due to the complexities involved in the process. We present new algorithms and managerial guidelines to address the problem of OR …


Development And Thermodynamic Analysis Of An Integrated Mild/Partial Gasification Combined Cycle (Impgc) Under Green And Brown Field Conditions With And Without Carbon Capture, Henry A. Long Iii Dec 2018

Development And Thermodynamic Analysis Of An Integrated Mild/Partial Gasification Combined Cycle (Impgc) Under Green And Brown Field Conditions With And Without Carbon Capture, Henry A. Long Iii

University of New Orleans Theses and Dissertations

Coal is a very prominent energy source in the world, but it is environmentally unattractive due to its high sulfur and ash content as well as its alleged contribution towards climate change, but it is affordable, abundant, and has high energy content. Thus, utilizing coal in a cleaner and more efficient way has become necessary. One promising clean coal technology involves fully gasifying coal into synthesis gas, cleaning it, and feeding it into a high-efficiency combined cycle, such as an Integrated Gasification Combined Cycle (IGCC). Inspired by the recent success of warn gas cleanup (WGCU), mild and partial gasification are …


Comparative Study Of Power Semiconductor Devices In A Multilevel Cascaded H-Bridge Inverter, Kenneth Mordi Dec 2018

Comparative Study Of Power Semiconductor Devices In A Multilevel Cascaded H-Bridge Inverter, Kenneth Mordi

Graduate Theses and Dissertations

This thesis compares the performance of a nine-level transformerless cascaded H-bridge (CHB) inverter with integrated battery energy storage system (BESS) using SiC power MOSFETs and Si IGBTs. Two crucial performance drivers for inverter applications are power loss and efficiency. Both of these are investigated in this thesis. Power devices with similar voltage and current ratings are used in the same inverter topology, and the performance of each device is analyzed with respect to switching frequency and operating temperature. The loss measurements and characteristics within the inverter are discussed. The Saber® simulation software was used for the comparisons. The power MOSFET …


A Comparative Analysis Of Regional Productivity Trends, Michael P. Foley Dec 2018

A Comparative Analysis Of Regional Productivity Trends, Michael P. Foley

Construction Management

Throughout recent decades, the construction industry has suffered considerably from its inability to accurately target and measure key aspects of worker output that hinder productivity most. Much research has been conducted to analyze the factors contributing to labor productivity output at the work face, however, this dissertation is primarily focused on discovering key components of the building process that seem to hinder productivity from the perspective of the general contracting team. This paper’s literature review looks to address historical data relating to productivity difficulties specific to the construction industry, laborers’ productivity dilemma at the work face, and the resulting impact …


A Comparative Analysis Of Regional Productivity Trends, Michael P. Foley Dec 2018

A Comparative Analysis Of Regional Productivity Trends, Michael P. Foley

Construction Management

Throughout recent decades, the construction industry has suffered considerably from its inability to accurately target and measure key aspects of worker output that hinder productivity most. Much research has been conducted to analyze the factors contributing to labor productivity output at the work face, however, this dissertation is primarily focused on discovering key components of the building process that seem to hinder productivity from the perspective of the general contracting team. This paper’s literature review looks to address historical data relating to productivity difficulties specific to the construction industry, laborers’ productivity dilemma at the work face, and the resulting impact …


Solar Electric Immersion Heating Element Fabrication, Logan V. Kregness Jun 2018

Solar Electric Immersion Heating Element Fabrication, Logan V. Kregness

Industrial and Manufacturing Engineering

Believing that cooking with flame is cheaper and more efficient than cooking with electricity, Ugandan citizens have exposed themselves to several health and safety risks, including major respiratory issues through harmful emissions, pollution, and the burning down of many homes. Even though solar electric cooking is cheaper and healthier than cooking with flames in the long run, many Ugandans lack the resources to invest in cooking with electricity.

The Solar Stove student research team, led by Dr. Pete Schwartz, partnered with Aid Africa to bring solar panels and prototype solar electric cooking units to villages in Uganda. Observing how their …


Improving Efficiencies For The Loading And Packaging Departments At San Luis Sourdough, Alexis Bergstrom, Isabella Pereira, Claudia Robinson Jun 2018

Improving Efficiencies For The Loading And Packaging Departments At San Luis Sourdough, Alexis Bergstrom, Isabella Pereira, Claudia Robinson

Industrial and Manufacturing Engineering

San Luis Sourdough, currently has issues with efficiency and standardization in their packaging department, ergonomics problems in the packaging department, shipment accuracy in their loading department, and lacks an organized layout design. As a result, four objectives were designed within a six month period. The first was to create standard operating procedures for the packaging department. To inform this decision time studies were performed before and after creating these SOPs. It was discovered that there was a clear need for the SOPs due to variation in packaging efficiency among new and experienced associates. The second set of time studies showed …


Reducing Overall Overtime Hours Accumulated By San Luis Sourdough, Marie Scholl, Emily Vallejos, Randall Yonce Jun 2018

Reducing Overall Overtime Hours Accumulated By San Luis Sourdough, Marie Scholl, Emily Vallejos, Randall Yonce

Industrial and Manufacturing Engineering

The packaging department of San Luis Sourdough Company was redesigned to increase bread throughput and decrease overtime hours issued to employees. Time studies were performed to get an accurate representation of the average throughput of bread with the current packaging conveyor system. After collecting data and surveying the employees and management, we came up with three design solutions to improve their current packaging system. The first design recommendation has a low-investment and is quick to implement as it pertains to changing the worker’s schedule to alleviate the employees from working long hour shifts while increasing the bread throughput. The second …


The Design Of A Digital Scheduling Solution For Healing Alternatives, Hailey A. Malin, Krista L. Mcallester, Anne E. Shields Jun 2018

The Design Of A Digital Scheduling Solution For Healing Alternatives, Hailey A. Malin, Krista L. Mcallester, Anne E. Shields

Industrial and Manufacturing Engineering

The focus of this senior project is to assist Healing Alternatives, an acupuncture clinic located in San Luis Obispo, in developing a business management software to fit their needs and boost their overall organization. The approach to finding the right fit for this business included assessing their current system while simultaneously investigating other providers. Once alternatives were found that met all of Healing Alternatives’ initial requirements, trial demos were generated in order to perform user experience testing. The presented final solution, a scheduling software called Acuity Scheduling, was implemented in a three-phase move plan that occurred over the period of …


Slm Materials Development, Justin G. Reiner, Michael T. Schembri Jun 2018

Slm Materials Development, Justin G. Reiner, Michael T. Schembri

Industrial and Manufacturing Engineering

The purpose of this project was to create a procedure to efficiently determine a “recipe” of parameter values that create a desired set of mechanical properties. Research was conducted into the laser powder bed fusion process with focus on underdeveloped materials. A design of experiment was used with a set of density correlated parameters to establish a method of producing nearly dense parts. Our methods include SLM printing, metrology, and statistical analysis. An experimental procedure for materials development was designed, but unable to be validated during the scope of this project, due to unforeseen safety issues (exposure to Chromium 6, …


Healing Alternatives Workspace Remodel, Lissandra Ilcyn, Jenifer Astrid Colmenares, Grace E. Kuffner Jun 2018

Healing Alternatives Workspace Remodel, Lissandra Ilcyn, Jenifer Astrid Colmenares, Grace E. Kuffner

Industrial and Manufacturing Engineering

Healing Alternatives is an acupuncture office space located in a repurposed house in San Luis Obispo. Healing Alternatives’ current facility layout does not allow for an additional treatment room or the space to provide additional services because of the wasted space within the facility. Furthermore, patients can be disrupted by noise outside the treatment room causing a negative customer experience. The project team’s objectives are to:

o Design two layout alternatives

o Provide a time estimate for each alternative

o Provide a cost analysis of each alternative

o Implement 5s methodology on the storage room

o Provide a 2D-3D model …


Analysis Of Improved Multiphase Buck Converter, Usamah Riaz Ahmad, Scott Wu Jun 2018

Analysis Of Improved Multiphase Buck Converter, Usamah Riaz Ahmad, Scott Wu

Electrical Engineering

While the number of transistors per microprocessor is rapidly increasing, the power requirements of converters are getting more and more important. The amount of current is increasing, while at the same time the output voltage is steadily decreasing. Today’s boards are exceeding 100A, while the buck converters have their output voltage below 1 V. Due to these new power requirements, multiphase buck converters are becoming more popular. In addition, this topology is usually used with voltage regulator modules (VRM).

The TPS40090EVM-002 board was used as the original multiphase buck with an input voltage of 12 V and output voltage of …


Suitability Of The Kalina Cycle For Power Conversion From Pressurized Water Reactors, Jack Ryan Webster Jun 2018

Suitability Of The Kalina Cycle For Power Conversion From Pressurized Water Reactors, Jack Ryan Webster

Theses and Dissertations

The primary objective of this work is to determine the Kalina cycle's suitability for thermal power conversion from a pressurized water reactor. Several previous papers have examined this application, but these either lack proof of concept or make unfeasible assumptions. This work expands current knowledge by simulating the Kalina cycle and comparing it to current pressurized water reactor Rankine cycles in order to identify which is more efficient. Prerequisite to the modeling is a simulation tool capable of modeling the thermodynamics of ammonia/water mixtures. Instead of using an existing program, a new one called Clearwater is used. This tool is …


Evaluating The Practices Of A Small Business: A Case Study, Madeleine Anne Bernadicou Jun 2018

Evaluating The Practices Of A Small Business: A Case Study, Madeleine Anne Bernadicou

Construction Management

Companies are in constant search to increase profits. The company success is dependent on its standard operational procedures, otherwise known as SOP. Golden State Irrigation and Noack Pump is a non-union merit shop contractor that performs irrigation work in the California’s central valley. This paper researches the utilized methods of the company to see if it is operating at an optimal level. The methodology used in this project is a case study, where multiple jobs, income statements, and cash flows were analyzed, along with conducted interviews. Both qualitative and quantitative data were collected in the investigation of this case study. …


Cal Poly Supermileage Drivetrain, Michael Bolton, Justin Miller, Heather Fields Jun 2018

Cal Poly Supermileage Drivetrain, Michael Bolton, Justin Miller, Heather Fields

Mechanical Engineering

The following report details the full design process used by the Cal Poly Supermileage Drivetrain (CPSMD) Senior Project team in designing a new drivetrain system for the Cal Poly Supermileage Vehicle (SMV) Team. Included is the development stages of each component, the manufacturing of our parts, the final solution’s assembly, the testing of the project, and the results from the 2018 Shell Eco-Marathon Competition. After collecting data from several tests, only the final drivetrain efficiency and final sprocket alignment remain unknown. Otherwise, the project came in under budget, within our weight tolerance, and met all the other design objectives. The …


Thermoelectrics And Thermoelectric Devices, Benjamin T. Erck May 2018

Thermoelectrics And Thermoelectric Devices, Benjamin T. Erck

Senior Theses

The field of thermoelectrics has many applications, and more are found in everyday systems. From its current studies, it is apparent that improving the figure of merit zT (which defines a good thermoelectric material) is important in the effectiveness of power generation. Another important part of thermoelectrics is the duality of these devices. They can both move heat and generate power, depending on their role in the system. In this thesis research, a process was made to test these thermoelectric relationships for a few Peltier devices in order to understand their efficiencies and what systems they can be applied to.


Experimental Design, Testing, And Evaluation Of Methods To Improve The Efficiency And Reduce Emissions From A Small Two-Stroke Natural Gas Engine, Christopher Joseph Ulishney Jan 2018

Experimental Design, Testing, And Evaluation Of Methods To Improve The Efficiency And Reduce Emissions From A Small Two-Stroke Natural Gas Engine, Christopher Joseph Ulishney

Graduate Theses, Dissertations, and Problem Reports

Decentralized power generation is a research area of interest due to possible improvements in electrical generation efficiency and grid resilience. Two-stroke engines are simple, inexpensive, power dense systems that could serve as the prime-movers for combined heat and power (CHP) systems. In addition, such systems could be fueled on natural gas (NG) that is readily available to serve as a reliable fuel source in most households. However, most two-stroke engines are inefficient and produce excessive emissions. This research focused on methods to simultaneously improve engine efficiency and decrease emissions from a 34 cc air-cooled, two-stroke engine retrofitted to operate on …


Improving The Efficiency Of Wind Farm Turbines Using External Airfoils, Shujaut Bader Oct 2017

Improving The Efficiency Of Wind Farm Turbines Using External Airfoils, Shujaut Bader

Masters Theses

Wind turbine efficiency typically focuses on the shape, orientation, or stiffness of the turbine blades. In this thesis, the focus is instead on using static fixed airfoils in proximity to the wind turbine to control the airflow coming out of the turbine. These control devices have three beneficial effects. (1) They gather air from “higher up” where the air is moving faster on average (and therefore has more kinetic energy in it). (2) They throw the used (and slowed down air) downwards. This means that any turbines in the wind farm behind the lead turbines do not get “stale” air. …


Design For Waste Reduction And Efficiency Improvement For The Construction Usage Of The Tower Crane, George Merida, Roman Richard Jun 2017

Design For Waste Reduction And Efficiency Improvement For The Construction Usage Of The Tower Crane, George Merida, Roman Richard

Industrial and Manufacturing Engineering

Webcor Concrete Group’s on-site tower crane is currently experiencing unknown forms of inefficiency. The project team used the DMAIC methodology to implement Define, Measure, Analyze, Improve, and Control in order to guide and structure the project. After the project team formulated a problem statement, observations were collected of tower crane deliveries resulting in 470 individual data points. The data was then analyzed using basic statistics, histograms, and lean manufacturing tools in order to identify wastes and inefficiencies. Once the wastes and inefficiencies were identified, root cause analysis was performed. The identified root causes were then used as the basis for …


Remodeling Office For Growing Grounds, Kyle R. Fawley Jun 2017

Remodeling Office For Growing Grounds, Kyle R. Fawley

Construction Management

This project was my first real re-condition project for a portion of an office space for Growing Grounds Farm here in San Luis Obispo. The purpose of this essay is to look back onto my experience and see how much I struggled and learned, and how I can benefit from it in the future. Throughout my project, I made sure there was constant communication between myself and Craig Wilson, program manager for Growing Grounds Farm, with clarifications and several updates. I made sure to fit and complete the project within my tight schedule and adjust it throughout the process. Throughout …


A Study Of The Sensitivity Of Energy Conversion Efficiency To Load Variation In Class-E Resonant Power Inverter, Richard Samuel Jennings Apr 2017

A Study Of The Sensitivity Of Energy Conversion Efficiency To Load Variation In Class-E Resonant Power Inverter, Richard Samuel Jennings

Electrical & Computer Engineering Theses & Dissertations

In this thesis the sensitivity of energy conversion efficiency (ECE) and output power of a class-E resonant inverter under variable resistive and inductive load assignments is examined for wireless power transfer (WPT) applications. By performing simulation and mathematical analysis, it was found that the on-resistance of the switching device has minor effect on the design’s efficiency. Additional comparisons between the simulation and mathematical analysis show reasonable output power and ECE load variation performance for the design, but with unique load impedances where zero voltage switching (ZVS) and zero derivative switching (ZDS) are achieved. These comparisons also expose inaccurate mathematical assumptions. …


Automatic Power Management For Instructional Computers At Humboldt State University: A Calculation Of Potential Energy Savings And Greenhouse Gas Emissions Reductions, Nicholas F. Flenghi Jan 2017

Automatic Power Management For Instructional Computers At Humboldt State University: A Calculation Of Potential Energy Savings And Greenhouse Gas Emissions Reductions, Nicholas F. Flenghi

Projects

Computers consume an estimated 5,610 GWh per year in California alone. Much of that energy is consumed by computers that are not being used. In this project, detailed user login data are used to estimate the energy consumption of instructional computers at Humboldt State University (HSU) over the course of one semester. The data are also used to estimate the potential energy savings from automating the shutdown process. Potential cost savings and greenhouse gas (GHG) emissions reductions resulting from implementing an automatic-shutdown power management plan are also calculated.

There are approximately 1,000 computers used for teaching and learning purposes at …


Optimization Methodology For Cvt Ratio Scheduling With Consideration Of Both Engine And Cvt Efficiency, Steven Beuerle Dec 2016

Optimization Methodology For Cvt Ratio Scheduling With Consideration Of Both Engine And Cvt Efficiency, Steven Beuerle

Masters Theses

A transmission ratio schedule is developed to optimize the fuel consumption for an automotive continuously variable transmission (CVT) connected to an internal combustion engine (ICE). Although the optimal operating line (OOL) generated from an engine brake specific fuel consumption (BSFC) map can be used to generate a CVT ratio schedule that yields maximum engine efficiency, it was found that OOL-based CVT ratio scheduling does not necessarily offer the best fuel economy because optimal CVT efficiency does not always correspond to OOL tracking. To develop a CVT ratio schedule that can offer the best fuel economy, a novel ratio-scheduling methodology is …


Investigation Of Digital Pump/Motor Control Strategies, Farid El Breidi Aug 2016

Investigation Of Digital Pump/Motor Control Strategies, Farid El Breidi

Open Access Dissertations

A pump is the heart of fluid power systems, it has a significant impact on the efficiency of many fluid power systems. Motors are the most common rotary actuators in fluid power systems. State-of-the-art pump/motor units can achieve efficiencies higher than 90% when operating at maximum displacement; however, as the displacement drops, the efficiency of these units drops to below 50%. A new digital pump/motor design aims at increasing these efficiencies by utilizing two electrically controlled high speed on/off valves per displacement chamber; these valves provide the ability to achieve variable displacement and allow freedom in choosing operating strategies. Such …


Analyzing The Opinion Of Industry Professionals On Model-Based Definition Datasets To Determine The Most Efficient Method, Shawn P. Ruemler Aug 2016

Analyzing The Opinion Of Industry Professionals On Model-Based Definition Datasets To Determine The Most Efficient Method, Shawn P. Ruemler

Open Access Theses

Model-based definition (MBD) has the engineering and manufacturing industries moving towards a model-based enterprise (MBE) where traditional two-dimensional (2D) drawings may one day no longer be needed. With MBD, the product data will be contained in the three-dimensional (3D) computer aided design (CAD) model itself. MBD provides a wealth of benefits to users, including reduced time-to-market, product quality, and task efficiency. Even with all the benefits of MBD, there is still no best practice when it comes to implementing MBD. Different strategies of MBD datasets exist, however none have been compared to see which method is more efficient. This project …


Haas Automation Umc750 5axis Mill Assembly Process Improvement, Mason A. Garcia, Gregory R. Gunion, Juan Pablo Quinonez Weston Jun 2016

Haas Automation Umc750 5axis Mill Assembly Process Improvement, Mason A. Garcia, Gregory R. Gunion, Juan Pablo Quinonez Weston

Industrial and Manufacturing Engineering

The improvement of the current assembly of the motor and casting components for the Haas UMC-750 5-Axis vertical CNC mill includes the evaluation, development and proposal of a new pair of material handling carts. To meet these deliverables, a student team began by assessing the assembly workstation, defining the problem to be solved, researching ergonomics in material handling equipment and drafting the final design of the improved cart models using SolidWorks. The final design considered the initial improvement request from the client, as well as better ergonomic features to enhance the safety of the operators. It was estimated that the …


Efficiency Testing Of An Electronic Speed Controller, Grace Cowell, Matthew Hudson, Marcus Pereira Jun 2016

Efficiency Testing Of An Electronic Speed Controller, Grace Cowell, Matthew Hudson, Marcus Pereira

Mechanical Engineering

This project required the development of a rig that could experimentally determine the efficiency of an Electronic Speed Controller (ESC). The selected design focuses on measuring the losses due to heat from the device and comparing this to its input power. The selected design is a flow rig that utilizes the heat equation q=ṁcpΔT. The rig provides a steady state measurement of the ESC heat output by passing a known mass flow rate of air across the ESC and measuring the temperature difference. It uses a flowmeter to determine ṁ, thermocouples to determine ΔT, and a table lookup to determine …


Mitigating Transients And Azeotropes During Natural Gas Processing, Edris Ebrahimzadeh Apr 2016

Mitigating Transients And Azeotropes During Natural Gas Processing, Edris Ebrahimzadeh

Theses and Dissertations

Cryogenic carbon capture process can be used to efficiently eliminate CO2 emissions from fossil-fueled power plants. The energy-storing embodiment of cryogenic carbon capture (ES-CCC) integrates energy storage with cryogenic carbon capture and uses natural gas as a refrigerant. ES-CCC captures CO2 from slowly varying or steady-state sources even as it absorbs and replaces large amounts of energy on the grid for energy storage. These large transients occur in the LNG generation as the process moves through energy storing to energy recovery operations. Additionally, raw natural gas often includes CO2 that forms an azeotrope with ethane. Breaking this azeotrope and separating …


Towards The Scalability And Hybrid Parallelization Of A Spatially Variant Lattice Algorithm, Henry Roger Moncada Lopez Jan 2016

Towards The Scalability And Hybrid Parallelization Of A Spatially Variant Lattice Algorithm, Henry Roger Moncada Lopez

Open Access Theses & Dissertations

The purpose of this research is to design a faster implementation of the spatially variant algorithm that improves its performance when it is running on a parallel computer system.

The spatially variant algorithm is used to synthesize a spatially variant lattice for a periodic electromagnetic structure. The algorithm has the ability to spatially vary the unit cell orientation and exploit its directional dependencies. The algorithm produces a lattice that is smooth, continuous and free of defects. The lattice spacing remains strikingly uniform when the unit cell orientation, lattice spacing, fill fraction and more are spatially varied. This is important for …