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Articles 77611 - 77640 of 196053

Full-Text Articles in Engineering

Developing A Hil-Based Software Platform For Testing Electric And Hybrid Vehicle Powertrains, Daniel Schwartz May 2018

Developing A Hil-Based Software Platform For Testing Electric And Hybrid Vehicle Powertrains, Daniel Schwartz

Graduate Theses and Dissertations

The objective of this thesis is to present a dynamometer test stand with hardware in the loop (HIL) testing capabilities for the evaluation of electric and hybrid vehicle powertrains under realistic driving conditions. The traction inverter and dc/dc converter are two crucial subsystems of the powertrain and new prototypes require significant validation before implementing into production vehicles. As fundamental technologies such as power modules, thermal management systems, and passive components improve; the performance improvements to the overall system must be demonstrated. The plug and play nature of the testbed makes it ideal for making direct comparisons of design iterations under …


Design, Fabrication, And Characterization Of All-Inorganic Quantum Dot Light Emitting Diodes, Ramesh Vasan May 2018

Design, Fabrication, And Characterization Of All-Inorganic Quantum Dot Light Emitting Diodes, Ramesh Vasan

Graduate Theses and Dissertations

Quantum dot light emitting diodes are investigated as a replacement to the existing organic light emitting diodes that are commonly used for thin film lighting and display applications. In this, all-inorganic quantum dot light emitting diodes with inorganic quantum dot emissive layer and inorganic charge transport layers are designed, fabricated, and characterized. Inorganic materials are more environmentally stable and can handle higher current densities than organic materials. The device consists of CdSe/ZnS alloyed core/shell quantum dots as the emissive layer and metal oxide charge transport layer. The charge transport in these devices is found to occur through resonant energy transfer …


Phase Transitions In Monochalcogenide Monolayers, Mehrshad Mehboudi May 2018

Phase Transitions In Monochalcogenide Monolayers, Mehrshad Mehboudi

Graduate Theses and Dissertations

Since discovery of graphene in 2004 as a truly one-atom-thick material with extraordinary mechanical and electronic properties, researchers successfully predicted and synthesized many other two-dimensional materials such as transition metal dichalcogenides (TMDCs) and monochalcogenide monolayers (MMs). Graphene has a non-degenerate structural ground state that is key to its stability at room temperature. However, group IV monochalcogenides such as monolayers of SnSe, and GeSe have a fourfold degenerate ground state. This degeneracy in ground state can lead to structural instability, disorder, and phase transition in finite temperature. The energy that is required to overcome from one degenerate ground state to another …


Characterization Of Bacteriorhodopsin And Halorhodopsin Reconstituted In Lipid Bilayer Membranes, Joel Domkam Kamwa May 2018

Characterization Of Bacteriorhodopsin And Halorhodopsin Reconstituted In Lipid Bilayer Membranes, Joel Domkam Kamwa

Graduate Theses and Dissertations

Motivated to produce electricity with photon activated ion pumps, the main purpose of this work was to characterize the photosynthetic membrane proteins bacteriorhodopsin (proton pump) and halorhodopsin (chloride pump). The proteins were re-suspended in lipid bilayers. For this work, an experimental set-up was built which included: chambers for lipid bilayer formation and characterization, lasers for ion pump activation, and an AxoPatch electrophysiology system for small photocurrent measurement. Lipid bilayer membranes were formed using mostly folding method: folding two monolayers together. The membranes were characterized by their resistance, capacitance, and generated photocurrent. Photocurrent was generated upon illumination of lipid-protein membranes with …


Effect Of Incubation Temperature On Phosphorous Release From Soils To Water, Seth Boles May 2018

Effect Of Incubation Temperature On Phosphorous Release From Soils To Water, Seth Boles

Biological and Agricultural Engineering Undergraduate Honors Theses

In recent years, nutrient release into flood waters and runoff has been a major concern within the Illinois River watershed, as well as nationwide. This study investigated whether there was a change in the release rate of soluble reactive phosphorous (SRP) into overlying water from soil cores incubated at different temperatures. Soil cores were incubated at 4.4°C, 20°C, and 32°C. After inundation, water samples were taken periodically over a seven-hour period and SRP measured. Following the drainage of the water, the upper 5 cm soil from each core was dried and analyzed for Mehlich III-extractable and water-extractable P. The results …


Investigating Initial Interactions Between Silver Nanoparticles And Wastewater, Casey Gibson May 2018

Investigating Initial Interactions Between Silver Nanoparticles And Wastewater, Casey Gibson

Biological and Agricultural Engineering Undergraduate Honors Theses

The use of nanoparticles (NPs) has increased exponentially in the last 15-20 years, especially in the consumer market. NPs are currently found in over 1800 commercial products, including cosmetics, clothing, packaging, and toys. As a result, NPs can enter the environment via wastewater (WW) streams, leading to new challenges in WW treatment. This study focuses on the initial fate of silver nanoparticles (AgNPs) in WW. The AgNP interaction including aggregation and dissolution in both synthetic and real WW were studied. Real WW was collected from the primary-clarifier, secondary-clarifier, and effluent WW streams at two local WW treatment plants (Westside and …


Nutrient Limitation Of Algal Growth In Fishery Lakes, Madeline Ludwig May 2018

Nutrient Limitation Of Algal Growth In Fishery Lakes, Madeline Ludwig

Biological and Agricultural Engineering Undergraduate Honors Theses

This study investigated the effect of nutrient addition on algal growth in three United States Forest Service lakes for fishery management in Arkansas. In fishery managed lakes, fertilization works by manipulating algae growth, a basal food resource in lakes, to promote the growth of the fish population. For the nutrient addition experiments, water was collected from each lake in cubitainers and spiked with nutrients; the treatments included the control, nitrogen (+N), phosphorus (+P), and nitrogen and phosphorus (+N +P). When algal growth was visually observed, a water sample was collected from each cubitainer and analyzed for chlorophyll-α. The results showed …


Optimizing Genetic Manipulation Of Methanogens Through Faster Cloning Techniques, Merrisa Jennings May 2018

Optimizing Genetic Manipulation Of Methanogens Through Faster Cloning Techniques, Merrisa Jennings

Biological and Agricultural Engineering Undergraduate Honors Theses

Methanogenesis is the biological production of methane. Only anaerobic archaea known as methanogens are capable of such a metabolic feat. They have strict living conditions and substrate sources which determine their rate of metabolism. This is of particular importance from a greenhouse gas reduction perspective or biogas capturing perspective. One of the best ways to optimize methanogen methane production is via genetic manipulation. The current procedures are timely though, therefore a faster cloning processes should be developed. The objective of this study was to optimize a premade genetic transformation kit known as the Gibson Kit. The Gibson Kit was supposed …


Sustainability Children's Book, Linden Cheek May 2018

Sustainability Children's Book, Linden Cheek

Biological and Agricultural Engineering Undergraduate Honors Theses

As human driven climate change continues to alter our planet, persuading the general public to adopt sustainable living practices has become increasingly important. Storytelling has long been a part of human culture, and recent studies have emphasized the power of storytelling to influence the audience as a means of changing behavior. This project attempted to teach sustainable principles to primary school children through the creation of a scientific children’s book. The book communicated the maxim of “reduce, reuse, recycle” by tracing a fictitious story of a town where children frequently buy new toys and throw the old toys away. The …


Feasibility For An Improved Method Of Deep Bed In-Bin Grain Drying, Ali Ezell May 2018

Feasibility For An Improved Method Of Deep Bed In-Bin Grain Drying, Ali Ezell

Biological and Agricultural Engineering Undergraduate Honors Theses

In-bin grain drying reduces the moisture content of field harvested grain down to a level suitable for profitable storage. The traditional method for in-bin deep bed grain drying is conducted in a cylindrical grain bin with an approximate height to diameter aspect ratio of 1:2, a stirring mechanism, a bottom plenum, a fan, and a heating element. This method poses problems by having a drying front that can move through the grain bed too slowly causing over or under drying leading to losses. This method also requires a stirring mechanism with significant capital costs and the inability to use sensing …


In-Cage Surface Wetting System For Cooling Poultry In Transport, Ryan Clark May 2018

In-Cage Surface Wetting System For Cooling Poultry In Transport, Ryan Clark

Biological and Agricultural Engineering Undergraduate Honors Theses

Abstract

Poultry health and mortality rates are important considerations in poultry production, as companies can minimize product loss and appeal to a consumer base whose concern for animal welfare continues to grow. Although animal welfare is a consideration for the entire poultry production process, this project focuses on the live-haul phase of the process, specifically during transport from grow houses to processing facilities. During the summer months, broiler chickens being transported can suffer from heat stress that can lead to death. This project consists of the designing and testing of an in-cage surface wetting system to minimize heat stress incidents …


Assessing Auto-Flocculation Of Microalgae In Wastewater Treatment, Alexander Parr May 2018

Assessing Auto-Flocculation Of Microalgae In Wastewater Treatment, Alexander Parr

Biological and Agricultural Engineering Undergraduate Honors Theses

Biofuels produced from algae have the prospect to provide a cheap, carbon neutral alternative to fossil fuels. However, the high cost for harvesting algae limits its wide application, as the preferred algae strains for biofuel production are typically unicellular microalgae that do not settle in water very well. Recently, researchers have been focusing on developing a biological method to achieve the sedimentation of algae through flocculation. A recent study has concluded that introducing microalgae that self-flocculates increases the recovery of the desired microalgae, similar to the effect of using coagulant to flocculate the algae. This option can potentially be more …


Performance Assessment Of Solid State Anaerobic Digestion Of Poultry Litter, Mason Puckett May 2018

Performance Assessment Of Solid State Anaerobic Digestion Of Poultry Litter, Mason Puckett

Biological and Agricultural Engineering Undergraduate Honors Theses

The disposal of poultry litter can exert an economic and environmental burden to the agriculture community. As a result, it is desirable to reduce the amount of waste and recover resources from the waste. This study focuses on the construction and preliminary testing of a laboratory scale (20 L) solid state anaerobic digester (AD) fed with dry poultry litter. Glucose was added in addition to the poultry litter to achieve the appropriate C:N ratio to support the growth of anaerobic microorganisms. The AD was first fed every 4 days at 4 g VS/L/feeding for 24 days, rested (no feeding) for …


Chloride Salt Inhibition On Lipid Production In Wastewater-Grown Algae For Biofuel Production, Will Richardson May 2018

Chloride Salt Inhibition On Lipid Production In Wastewater-Grown Algae For Biofuel Production, Will Richardson

Biological and Agricultural Engineering Undergraduate Honors Theses

Algae are increasingly being recognized as useful organisms for many applications in today’s world. Their ability to remove nitrogen, phosphorus, and trace metals from water while adding oxygen to water makes them an attractive tertiary treatment technology in municipal wastewater treatment facilities. At the same time, algae produce lipids and carbohydrates that are useful for biofuel production, and they are not a human food crop unlike many biofuel feedstocks. In this study the effect of increased chloride concentrations in wastewater was assessed on the ability of two species of algae, Chlorella vulgaris and Scenedesmus dimorphus, to function as a …


Automated Control System Design Manual For Plant Growth And Support, Brooke Benham May 2018

Automated Control System Design Manual For Plant Growth And Support, Brooke Benham

Biological and Agricultural Engineering Undergraduate Honors Theses

The “Automated Control System Design Manual for Plant Growth and Support” project contains a teaching manual for high school students and teachers to use to aid in teaching STEM subjects. Building confidence in students and encouraging the pursuit of STEM related fields is one of the primary functions. This project utilizes low cost instruments and freely available software to teach the construction, installation, programming, and application for an automated control system with emphasis on plant growth and regulation. The end result is a fully automated system that can be controlled wirelessly via an android application to monitor temperature, humidity, and …


Improving Alternative Fuel Efficiency With Water Injection, Connor Strawn May 2018

Improving Alternative Fuel Efficiency With Water Injection, Connor Strawn

Honors Theses

Alternative fuel internal combustion engines (ICEs) have been increasing in popularity as the harmful effects of pollution and the need for a sustainable energy source are becoming more apparent. Two alternative fuels, E85 and hydrogen gas, are considered in this study. These fuels are renewable and have less emissions than traditional fuels, but there are many inherent disadvantages to their use. Water injection could alleviate some of the issues that plague these fuels. To test this, a Briggs and Stratton Baja engine was used, with and without water injection. Gasoline with water injection showed better performance than without: the power …


Real-Time Streaming Video And Image Processing On Inexpensive Hardware With Low Latency, Richard L. Gregg May 2018

Real-Time Streaming Video And Image Processing On Inexpensive Hardware With Low Latency, Richard L. Gregg

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

The use of resource constrained inexpensive hardware places restrictions on the design of streaming video and image processing system performance. In order to achieve acceptable frame-per-second (fps) performance with low latency, it is important to understand the response time requirements that the system needs to meet. For humans to be able to process and react to an image there should not be more than a 100ms delay between the time a camera captures an image and subsequently displays that image to the user.

In order to accomplish this goal, several design considerations need to be taken into account that limit …


Positive Experiences As Countermeasures To Stress In Spaceflight: An Investigation Of The Experiences Of Astronauts, Morgan M. Eudy May 2018

Positive Experiences As Countermeasures To Stress In Spaceflight: An Investigation Of The Experiences Of Astronauts, Morgan M. Eudy

Theses and Dissertations

Long-duration space mission targets such as asteroids, the Moon and Mars in coming years will increase the need to stress management techniques to support crews on increasingly risky, autonomous missions. New stress management approaches may be found by better understanding the reported positive effects resulting from factors in these environments. This study utilized an exploratory case study approach to leverage quantitative and qualitative data to yield research questions for future correlational analysis. This study found that positive experiences and changes in environmental perspectives occurred from viewing Earth from orbit. Furthermore, this study found that personality factors such as extraversion may …


Characterization And Analysis Of Ultrathin Cigs Films And Solar Cells Deposited By 3-Stage Process, Grace Rajan, Krishna Aryal, Shankar Karki, Puruswottam Aryal, Robert W. Collins, Sylvain Marsillac May 2018

Characterization And Analysis Of Ultrathin Cigs Films And Solar Cells Deposited By 3-Stage Process, Grace Rajan, Krishna Aryal, Shankar Karki, Puruswottam Aryal, Robert W. Collins, Sylvain Marsillac

Electrical & Computer Engineering Faculty Publications

In view of the large-scale utilization of Cu(In,Ga)Se2 (CIGS) solar cells for photovoltaic application, it is of interest not only to enhance the conversion efficiency but also to reduce the thickness of the CIGS absorber layer in order to reduce the cost and improve the solar cell manufacturing throughput. In situ and real-time spectroscopic ellipsometry (RTSE) has been used conjointly with ex situ characterizations to understand the properties of ultrathin CIGS films. This enables monitoring the growth process, analyzing the optical properties of the CIGS films during deposition, and extracting composition, film thickness, grain size, and surface roughness which …


Spanish Language Topics Course With An Emphasis On Construction Safety, Austin Changras May 2018

Spanish Language Topics Course With An Emphasis On Construction Safety, Austin Changras

Construction Management

The end goal of this research-based project is to evaluate whether a Spanish course with an emphasis on construction site safety would be beneficial to Cal Poly’s Construction Management (CM) program and how it might also benefit the industry. The research orchestrated will be to decipher whether or not there is even a need for this type of class to be included into the curriculum. Along with data research, two separate surveys have been conducted, one administered to the Construction Management student population and the other to industry professionals. Furthermore, George Healy, a fellow CM student, is working on the …


Implementing Bim Management And Process Optimization Tools In Construction Management Curriculum, Jake W. Castillo May 2018

Implementing Bim Management And Process Optimization Tools In Construction Management Curriculum, Jake W. Castillo

Construction Management

As the construction industry rapidly continues to adopt technology and Building Information Modeling practices, we need to ensure that Construction Management curriculum prepares students for what is expected after graduation. Cal Poly’s Construction Management program currently have two Building Information Modeling courses in the curriculum that focus mainly on learning software and while this will be essential for students graduating the Construction Management program, there remains room to improve the courses as the industry adapts. Adding curriculum geared more toward managing the BIM process and learning process optimization skills will not only benefit a higher percentage of students, but will …


Using The Soar Approach To Teach Middle School Students About Math And Science Concepts Found In Engineering, Rachael A. Wagner May 2018

Using The Soar Approach To Teach Middle School Students About Math And Science Concepts Found In Engineering, Rachael A. Wagner

Honors Program: Senior Projects (Public)

In order to address the lack of knowledge about the engineering profession in middle-level students, the project described in this Honors Thesis was developed. Through the creation of an afterschool program centered on engineering, students were able to apply the math and science concepts covered to design, build, and test a bridge. One particular lesson from this after-school program was highlighted in this thesis, the lesson covering the Pythagorean Theorem, to demonstrate the use of SOAR methodology in the lesson’s development and later use in the classroom. The effectiveness of the Pythagorean Theorem lesson was evaluated positively based on the …


Road Diet Feasibility Analysis For Nebraska, Brandon L. Purintun May 2018

Road Diet Feasibility Analysis For Nebraska, Brandon L. Purintun

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Many rural towns and cities throughout Nebraska have experienced consistent population decline over the past 50 years, and the highway system once built to accommodate hoped-for growth is not serving the population as well as it could. These towns and cities would benefit from implementing a road diet conversion on their main highways. Within rural communities, road diets are an increasingly popular method of improving safety along major arterials through the reduction of excess capacity in favor of increasing refuge areas for turning vehicles. A typical application might be the restriping of a four-lane undivided highway into a three-lane highway …


Examination Of Steel Pin And Hanger Assembly Performance: Retrofit To Replacement, Chandana Chickamagalur Balakrishna May 2018

Examination Of Steel Pin And Hanger Assembly Performance: Retrofit To Replacement, Chandana Chickamagalur Balakrishna

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

A number of steel, multi-beam bridges exist in the United States that contain pin and hanger assemblies. Pin and hanger assemblies are fracture critical members whose failure would result in collapse of the bridge or render it unable to perform its expected functions. As these bridges continue to age, many assemblies have deteriorated to a point where retrofit or replacement has to be considered and performed to maintain intended safety and performance. States have taken various approaches to address the pin and hanger assembly retrofit and replacement options. However, there is no single document that summarizes these approaches.

This research …


Optimized Health Monitoring Plans For A Steel, Double-Track Railway Bridge, Ahmed Rageh May 2018

Optimized Health Monitoring Plans For A Steel, Double-Track Railway Bridge, Ahmed Rageh

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Railway bridges are an essential component of any modern society and play a significant transportation role. During the 19th and early 20th centuries steel truss and plate girder bridges were commonly used railway designs, with most of the trusses constructed using pin and eyebar systems and most other load carrying members being riveted, built-up sections.

Many of these bridges are still in use and are subjected to increased railway traffic intensity, loads and speeds. The current practice for evaluating the integrity of bridges in the United States, irrespective of use, is primarily via visual inspection, with those inspections …


Peridynamic Modeling Of Dynamic Fracture In Bio-Inspired Structures For High Velocity Impacts, Sneha Akula May 2018

Peridynamic Modeling Of Dynamic Fracture In Bio-Inspired Structures For High Velocity Impacts, Sneha Akula

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

Bio-inspired damage resistant models have distinct patterns like brick-mortar, Voronoi, helicoidal etc., which show exceptional damage mitigation against high-velocity impacts. These unique patterns increase damage resistance (in some cases up to 3000 times more than the constituent materials) by effectively dispersing the stress waves produced by the impact. Ability to mimic these structures on a larger scale can be ground-breaking and could be used in numerous applications. Advancements in 3D printing have now made possible fabrication of these patterns with ease and at a low cost. Research on dynamic fracture in bio-inspired structures is very limited but it is …


Essays On Applications Of Transportation Network Design And Optimization, Amirali Ghaharikermani May 2018

Essays On Applications Of Transportation Network Design And Optimization, Amirali Ghaharikermani

Graduate Theses and Dissertations

In this dissertation, we address different transportation problems. The three main outcomes are: designing a battery swap station network, studying gaps in Empty Container Management literature, designing a model with similar characteristics to the vehicle routing problem as well as implementation scenario for it to be applied for a real-world case.

For the designed battery swap station, a model is developed for customer demand satisfaction that permits construction of different types of BSS in the planning network. Our solution methodology is a Tabu Search algorithm combined with a dynamic programming initialization. Numerous tests showed that the proposed TS approach provides …


Demonstrating Set-Based Design Techniques- A Uav Case Study, Colin Small May 2018

Demonstrating Set-Based Design Techniques- A Uav Case Study, Colin Small

Graduate Theses and Dissertations

The Department of Defense (DoD) and Engineered Resilient Systems (ERS) community seek to improve decision making in the Analysis of Alternatives (AoA) process by incorporating resilience and leveraging the capabilities of model-based engineering (MBE) early in the design process. Traditional tradespace exploration utilizing Point-Based Design (PBD) often converges quickly on a solution with subsequent engineering changes to modify the design. However, this process can lead to a suboptimal solution if an incorrect initial solution is chosen. Enabled by MBE, Set-Based Design (SBD) considers sets of all possible solutions and enables down-selecting possibilities to converge on a final solution. Using a …


Investigation Of Nanomaterial Based Photovoltaic Panel Packaging Materials, Xingeng Yang May 2018

Investigation Of Nanomaterial Based Photovoltaic Panel Packaging Materials, Xingeng Yang

Graduate Theses and Dissertations

In this research, nanomaterial-based packaging materials for photovoltaic (PV) panels are investigated. A hydrophobic/anti-reflective surface coating which not only repels water from the top glass of a PV panel but at the same time reduces its light reflectance is investigated. COMSOL simulation results indicate that taller ellipsoid rod (aspect ratio = 5) reflects less light than shorter rod (aspect ratio = 0.5) in the desired spectrum for solar energy harvest from 400nm-700nm. The addition of a polymer layer on these ellipsoid rods broadens the light incident angle from 23° to 34°, from which light can be efficiently absorbed. Based on …


Low Latency Intrusion Detection In Smart Grids, Israel Zairi Akingeneye May 2018

Low Latency Intrusion Detection In Smart Grids, Israel Zairi Akingeneye

Graduate Theses and Dissertations

The transformation of traditional power grids into smart grids has seen more new technologies such as communication networks and smart meters (sensors) being integrated into the physical infrastructure of the power grids. However, these technologies pose new vulnerabilities to the cybersecurity of power grids as malicious attacks can be launched by adversaries to attack the smart meters and modify the measurement data collected by these meters. If not timely detected and removed, these attacks may lead to inaccurate system state estimation, which is critical to the system operators for control decisions such as economic dispatch and other related functions.

This …