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Settling Performance In Wastewater Fed High Rate Algae Ponds, Elliott Blake Ripley

Master's Theses

Although high rate algae ponds (HRAPs) are a proven wastewater treatment technology with numerous environmental, social, and economic benefits, their widespread use has been hindered by inconsistent and unreliable settling performance. Hence, the goal of this thesis is to investigate how specific operational parameters affect the settling performance of HRAPs. Nine HRAPs (30 m² surface area, 0.3 m depth) were operated as three triplicate sets, with each set run on either a 2, 3, or 4 day HRT continuously from January 25, 2012 through April 11, 2013. Settling performance was determined (i) by measuring the TSS of Imhoff cone …

Computational Modeling To Evaluate Helical Electrode Designs For Use In Vagus Nerve Stimulation, Anthony W. Cowley

Master's Theses

An estimated 0.5% of world’s population has been diagnosed with epilepsy. Of these patients 20-30% will be unable to achieve seizure control with anti-epileptic drugs. Vagus nerve stimulation (VNS) may be an appropriate treatment option for some patients with pharmaceutically refractory, partial-onset seizures.

VNS therapy uses a helical electrode to interface between the implantable pulse generator and the vagus nerve. While there have been several studies related to the mechanical and electrical safety of such electrodes, little work has been done toward understanding the effectiveness of the helical electrode in nerve stimulation. A better understanding of the voltage field and …

Beach Wheelchair Project, Rory Aronson, Joshua Marcum, Samuel Coyne, Alex Hayes, Alexa Colburn, Max Hessel, Benedikt Strauss, Marvin Rimmele, Marco Pietsch

Mechanical Engineering

The Beach Wheelchair, Sandcrawler, is a machine intended to help give people with disabilities the full beach experience. The non-profit organization Bridge II Sports sponsored this project, and tasked us with developing the design and fabricating a prototype. This chair has several features including a linkage mechanism that raises and lowers a chair relative to an external frame, hand crank drive with Gates Carbondrive belt and sprockets, buoyant Wheeleez balloon tires, and much more.

Surfactant Formulations For Water-Based Processing Of A Polythiophene Derivative, Cameron Dean Danesh

Master's Theses

Conjugated polymers are semiconducting materials that are currently being researched for numerous applications from chemical and biological sensors to electronic devices, including photovoltaics and transistors. Much of the novel research on conjugated polymers is performed in academic settings, where scientists are working to prepare conjugated polymers for commercially viable applications. By offering numerous advantages, inherent in macromolecular materials, conjugated polymers may hold the key to cheap and environmentally friendly manufacturing of future electronic devices. Mechanical flexibility, and solvent-based coating processes are two commonly cited advantages. Transitions in the backbone conformation of polythiophenes (PT) in organic solvents have been widely observed …

Polymer Fiber Arrays For Adhesion, Shing Chung Josh Wong, Johnny F. Najem, Guang Ji, Shuwen Chen

Mechanical Engineering Faculty Research

The ability of geckos to adhere to vertical solid surfaces comes from their remarkable feet with millions of projections terminating in nanometer spatulae. In this paper, we present a simple yet robust method for fabricating directionally sensitive dry adhesives. By using electrospun nylon 6 nanofiber arrays, we create gecko-inspired dry adhesives, that are electrically insulating, and that show shear adhesion strength of 27 N/cm2 on a glass slide. This measured value is 270% that reported of gecko feet and 97-fold above normal adhesion strength of the same arrays. The data indicate a strong shear binding-on and easy normal lifting-off. Size …

Measurement Of Adhesion Energy Of Electrospun Polymer Membranes Using A Shaft-Loaded Blister Test, Shing Chung Josh Wong, Haining Na, Pei Chen

Mechanical Engineering Faculty Research

This study aims to examine the adhesion work of electrospun polymer nano- and micro-fibers. The adhesion energy at the interface of electrospun membrane and a rigid substrate is characterized by a shaft-loaded blister test (SLBT). By controlling the processing parameters, polyvinylidene fluoride (PVDF) fibrous membranes are prepared with fiber diameters ranging from 201 ± 86 nm to 2,724 ± 587 nm. The adhesion energy between electrospun membrane and rigid substrate increases from 8.1 ± 0.7 mJ/m2 to 258.8 ± 43.5 mJ/m2 by use of smaller fiber diameters. Adhesion energies between electrospun PVDF membranes and SiC substrates made of different grain …

Distributed Multichannel Speech Enhancement Based On Perceptually-Motivated Bayesian Estimators Of The Spectral Amplitude, Marek B. Trawicki, Michael T. Johnson

Electrical and Computer Engineering Faculty Research and Publications

In this study, the authors propose multichannel weighted Euclidean (WE) and weighted cosh (WCOSH) cost function estimators for speech enhancement in the distributed microphone scenario. The goal of the work is to illustrate the advantages of utilising additional microphones and modified cost functions for improving signal-to-noise ratio (SNR) and segmental SNR (SSNR) along with log-likelihood ratio (LLR) and perceptual evaluation of speech quality (PESQ) objective metrics over the corresponding single-channel baseline estimators. As with their single-channel counterparts, the perceptually-motivated multichannel WE and WCOSH estimators are functions of a weighting law parameter, which influences attention of the noisy spectral amplitude through …

Electrospun Plant Protein Scaffolds With Fibers Oriented Randomly And Evenly In Three-Dimensions For Soft Tissue Engineering Applications, Shaobo Cai

Department of Textiles, Merchandising and Fashion Design: Dissertations, Theses, and Student Research

In this work, electrospinnable and water stable soyprotein was extracted by using a reducing agent in mild alkaline condition, and novel 3D zein and 3D pure soyprotein electrospun scaffolds with three-dimensionally and randomly oriented fibers and large interconnected pores were successfully fabricated by reducing surface resistivity of materials. This unique structure is different from most electrospun scaffolds with fibers oriented mainly in one direction. The structure of novel 3D scaffolds could more closely mimic the 3D randomly oriented fibrous architectures in many native extracellular matrixes (ECM). Confocal laser scanning microscope shows that instead of becoming flattened cells when cultured in …

Stent Graft Blush, Vanessa Barrett, Thomas Matzinger, Mike Morelli

Mechanical Engineering

In order to better understand Type IV endoleaks (“blush”), the Cal Poly Senior Project team GraftTest has developed a blush evaluation system able to mimic several of the aorta’s environmental parameters. Capable of both pressure and flow rate control, this bench top system accommodates Medtronic’s wide range of abdominal and thoracic aortic stent grafts. Having researched endoleaks, stent grafts, and numerous other factors affecting stent graft blush, a system was developed with the aim of assessing and comparing the performance of Medtronic’s stent grafts with regard to blush. Furthermore, this system has been designed to provide reliable and repeatable results …

Design And Installation Of A Mobile Agriculture Chemical Mixing Station, Jason Mendes

BioResource and Agricultural Engineering

This senior project encompassed the design and fabrication of a Mobile Agricultural Chemical Mixing System. The design parameters were provided by Mark McKean and McKean Farms from Riverdale, Ca. The project’s objective was to provide safer working conditions for operators by improving their working environment while increasing mixing efficiency. This mobile system will provide storage for materials, as well as, a diversified mixing system at the site of applications.

The major components of the project include two chemical mixers to mix materials, a 2-inch suction pump to supply water from non-powered sources, and a flatbed trailer to encompass the unit …

Dairy Manure Flushwater Treatment By Packed-Bed Anaerobic Digesters, Neal Cary Adler

Master's Theses

Wastewater treatment performance of three pilot-scale packed-bed anaerobic digesters with walnut shell medium was researched for treating dairy freestall barn flushwater. Reciprocation mixing was evaluated as a means to lessen channelization in the media bed and to improve biogas production and organic matter removal at ambient temperatures. Reciprocation has been used in biological nitrogen removal systems to introduce air into the system to repeatedly oxygenate nitrifying biofilm along with mixing (Behrends et al. 2003), but the anaerobic systems benefit from mixing. Two tanks were used in each system, where one was full and one was empty at any given time. …

Nutrient Removal Using Microalgae In Wastewater-Fed High Rate Ponds, Matthew N. Rodrigues

Master's Theses

This thesis discusses the mechanisms associated with the removal of organic matter, nitrogen and phosphorus in wastewater-fed high rate algae ponds (HRAP) designed to operate as triplicates. Research was conducted at the San Luis Obispo Water Reclamation Facility (SLOWRF) as a pilot-scale study of nine 30-square meter ponds one foot in depth. During period of study, triplicates were operated at hydraulic retention times (HRT) of 4, 3 or 2-days. Main objectives for the study were to determine minimum HRTs required to achieve secondary and tertiary treatment. Experimental conditions such as CO₂ supplementation, nighttime aeration and operation of ponds in …

An Investigation Of Arabinan And Cellulose Based Nano-Composite Fabrication Methods, Marianne Smithfield, Carl Petterson, Robert Miller

Materials Engineering

Microcrystalline cellulose was converted into nanocrystalline cellulose via an acid hydrolysis procedure. Scanning electron microscopy (SEM) was employed to measure the particle size and thus the effectiveness of acid hydrolysis. The nanocrystalline cellulose was poured through a 0.2μm filter to isolate the particles of ideal size. The nanocrystalline cellulose samples were stored in dimethylformamide (DMF) to prevent mold growth and agglomeration upon drying. Numerous composite samples were created by dissolving the arabinan in a solvent, suspending cellulose in the arabinan solution, and then drying the sample. Casting was performed in a silicon mold to allow sample removal without damage. Initial …

Evaluation Of Thermophile Algae In Horizontal Photo-Bioreactor, Olivier Schmied

BioResource and Agricultural Engineering

No abstract provided.

Design, Constuction, And Evaluation Of A Flame Cultivator Attachment, Aaron Evans

BioResource and Agricultural Engineering

This senior project discusses the design, construction, and testing of a flame cultivator attachment. The project used existing torches, a tractor, and a cultivation sled to increase the usability of the farmer’s torches. This project includes two torch clamps, two propane tank brackets, and a removable valve panel. Testing showed that the new system increases the safety and efficiency of the torches.

Algorithms For Library-Based Microbial Source Tracking, Aldrin Montana

Master's Theses

Pyroprinting is a novel, library-based microbial source tracking method developed by the Biology department at Cal Poly, San Luis Obispo. This method consists of two parts: (1) a collection of bacterial fingerprints, called pyroprints, from known host species, and (2) a method for pyroprint comparison. Currently, Cal Poly Library of Pyroprints (CPLOP), a web-based database application, provides storage and analysis of over $10000$ pyroprints. This number is quickly growing as students and researchers continue to use pyroprinting for research. Biologists conducting research using pyroprinting rely on methods for partitioning collected bacterial isolates into bacterial strains. Clustering algorithms are commonly used …

Applying Sustainability From A Systems Perspective:, Timothy Brophy

Master's Theses

Becoming sustainable is no longer an option. Current industry methods will not be able to support the necessary changes our growing society demands. In order to keep up with ever increasing demands industry will be aimed toward making major system changes toward a fully sustainable model. As of right now only basic sustainability actions have been put in place. Industry needs to make a strategic change toward resilient systems with an end goal of evolving into fully biomimic systems. This thesis covers a brief history of production leading to the Industrial Revolution which created a need for increased sustainability efforts. …

The Bicycle-Powered Smartphone Charger, Chris Arntzen

Master's Theses

This thesis entails the design and fabrication of a smartphone charger that is powered by a bicycle dynamo hub. In addition to the design and validation of the charger prototype, this thesis involves the testing and characterization of the dynamo hub power source, the design and construction of specialized test equipment, and the design and prototyping of a handlebar-mounted case for the smartphone and charging electronics. With the intention of making the device a commercial product, price, aesthetics, and marketability are of importance to the design. An appropriate description of the charger circuit is a microcontroller-based energy management system, tailored …

Comparison Of Biofilm Media In Reciprocating Biofilters Treating Dairy Flushwater, Kyle Keoki Tatsuo Fooks

Master's Theses

Reciprocating biofilters known as ReCip is a viable technology to manage nutrients, mainly nitrogen, problems at livestock operations such as swine farms and dairies. Past studies have demonstrated that ReCip is more adept at total nitrogen (TN) removal than traditional subsurface flow wetland systems. The traditional substrate used to attach biomass was rock aggregate; this media may be hard to obtain for some agricultural projects, so alternate substrates are tested and compared with the rock aggregate. The purpose of the study was twofold: first, different biofilm media were tested and compared in terms of treatment performance and, second, the long-term …

Uav Formation Flight Utilizing A Low Cost, Open Source Configuration, Christian W. Lopez

Master's Theses

The control of multiple unmanned aerial vehicles (UAVs) in a swarm or cooperative team scenario has been a topic of great interest for well over a decade, growing steadily with the advancements in UAV technologies. In the academic community, a majority of the studies conducted rely on simulation to test developed control strategies, with only a few institutions known to have nurtured the infrastructure required to propel multiple UAV control studies beyond simulation and into experimental testing. With the Cal Poly UAV FLOC Project, such an infrastructure was created, paving the way for future experimentation with multiple UAV control systems. …

Reconfigurable Threshold Logic Gates Using Memristive Devices, Adrian Rothenbuhler, Thanh Tran, Elisa H. Barney Smith, Vishal Saxena, Kristy A. Campbell

Electrical and Computer Engineering Faculty Publications and Presentations

We present our design exploration of reconfigurable Threshold Logic Gates (TLG) implemented using silver–chalcogenide memristive devices combined with CMOS circuits. Results from simulations and physical circuits are shown. A variety of linearly separable logic functions including AND, OR, NAND, NOR have been realized in discrete hardware using a single-layer TLG. The functionality can be changed between these operations by reprogramming the resistance of the memristive devices.

Exceed: Excellence In Your Engineering Education Summer Transition Program, Stacy Gleixner, Katherine Casey, Jared Tuberty, S. Latic, Patricia Backer, Emily Allen

Faculty Publications

EXCEED: Excellence in Your Engineering Education is a ten day, residential summer transition program that was designed to improve retention and graduation rates at San José State University (SJSU). SJSU is a large, public institution in the West with a very diverse student population. However, the university has lower graduation and retention rates for certain student populations in engineering including underrepresented groups and first generation college students. This transition program was designed to meet five outcomes: acculturate the students to the College of Engineering and the university, enhance math and writing preparation, build community amongst the cohort of students, enhance …

Shelf Life Study Of Electrospun Plga Copolymers, Sean Youra, Nick Hudson

Biomedical Engineering

Poly(lactic-co-glycolic acid) (PLGA) is one of the most commonly used copolymers for electrospinning in tissue engineering applications. However, most research has not focused on the copolymer itself in regards to how long it can be used effectively and if varying the concentrations of polylactic acid (PLA) and polyglycolic acid (PGA) affect the resulting properties. Electrospinning is the method we use to create the three-dimensional constructs, or “scaffolds”, for the blood vessel mimic (BVM) in the tissue engineering lab. The aim of our project was to investigate if the morphology and mechanical properties of the scaffolds changed over time when they …

Analysis Of Acetabular Cup Orientation Effects On Stress Shielding In Total Hip Replacements Using Finite Element Methods, Brogan Mcguire, Jennifer Gemkow, Brad Gausewitz, Alex Georges

Biomedical Engineering

Improper positioning of the acetabular cup has been shown to contribute to issues such as high wear rates and dislocations in total hip replacements. The differences in contact mechanics due to varying orientation of the acetabular cup may also significantly affect strain distribution in the femur. This study examined these effects of acetabular orientation changes and their contribution to stress shielding using finite element analysis. A solid model of a cementless total hip implant was obtained using 3D point scanning and implanted virtually into a femur solid model. The implanted femur model was imported into ABAQUS and loaded with a …

Effect Of Oral Lipids On Blood Glucose, Tyler R. Knisley

Biomedical Engineering

Diabetes mellitus is a disease in which insulin hormone is ineffective or no longer produced. Multiple pathophysiologies can cause either insulin dependent diabetes mellitus (IDDM) or insulin independent diabetes mellitus (IIDM), which can lead to chronic hyperglycemia and an array of short and long term health risks. Prior research has shown that IDDM patients have dyslipidemia, and experiments infusing lipids directly into the blood result in heightened insulin resistance. The hypothesis that dyslipidemia increases insulin resistance was tested by performing oral glucose tolerance tests across three treatment conditions. Participants were nondiabetic college-aged students. Data from a control group was gathered …

A Mouse Model Of Aortic Endothelial Denudation And Neointimal Formation, Ashkon C. Nehzati

Biomedical Engineering

More than 385,000 people die from coronary heart disease (CHD) annually and treatment costs $108.9 billion each year including the cost of health care services, medications, and lost productivity. CHD decreases heart function by limiting oxygen and nutrient transport carried through the coronary arteries. A complete block to the coronary arteries causes a myocardial infarction in response to an elimination of blood supply to cardiomyocytes. Partial occlusion results in insufficient blood supply to cardiomyocytes, producing myocardial ischemia and angina, which are usually treated with intravascular stents deployed percutaneously, before myocardial infarction occurs. Stents are the most common ways to expand …

Enzymatic Production Of Biodiesel From Fats Extracted From Lamb Meat Using Supercritical Co2, Hanifa Easa Taher

Theses

Due to the reduction in fossil fuel reserves and associated environmental impacts from using petroleum fuels, biodiesel has been presented as a feasible alternative because it is sustainable and environmentally friendly. In this study, it is proposed to investigate the feasibility of enzymatic production of biodiesel from waste animal fats using supercritical fluid technology for the extraction and reaction. The operating conditions that resulted in the optimum extraction and biodiesel production yield were identified. To the best of my knowledge of the investigators, the waste animal fat extracted by supercritical CO₂ (SC-CO₂) for the production of biodiesel …

Experimental Assessment Of The Impact Of Asymptomatic Gas Emboli On The Vessel Wall, Linxia Gu, Eric L. Cutler

Department of Mechanical and Materials Engineering: Faculty Publications

Quantitative evaluation of shear stress in the vessel wall due to the presence of asymptomatic gas emboli is lacking. The goal of this work was to assess the impact of chronic asymptomatic gas emboli on the risk of atherosclerosis through a custom-built cardiovascular flow simulator. Gas bubbles were created by forced air from a syringe pump. The influences of embolism injection rate, pulse rate, and time-averaged flow rate on the wall mean shear stress were investigated at resting and elevated heart rate conditions. The recorded pressure and volumetric flow rate from 24 experimental settings with four repetitions each were used …

The Effect Of Nanoclays On The Properties Of Aspirin Modified Enteric Polymer Prepared By Hot-Melt Mixing, Nonjaros Chomcharn

Dissertations

Melt mixing in batch equipment or continuous extruders is a technique that recently gained the attention of the pharmaceutical industry. This dissertation investigates two controlled-release drug delivery systems. The first system, namely the enteric matrix, contains an active pharmaceutical ingredient (API) and plasticizer in an enteric polymer while in the second system a nanoclay is added to the enteric matrix, to produce a polymer nanocomposite. The first system employs hot-melt mixing to prepare a modified enteric matrix, as a delayed-release dosage form. Different concentrations of aspirin (ASP) ranging from 10 – 30% w/w are melt-mixed with a plasticized Eudragit® …

Synthesis And Characterization Of Novel Boron-Based Nanostructures And Composites, Rajen B. Patel

Dissertations

A number of nanomaterials have been synthesized by using a method that has been previously utilized to make pure boron nanostructures through the addition of different reactant gases to the process. This method was pioneered by Iqbal-Liu and will be referred to as the IL method in this dissertation. The IL method successfully created boron nanowires, boron nanoflakes, and boron nanotubes. In this dissertation, by adding methane, hydrogen sulfide, and ammonia to the process, an entire family of nanomaterials is prepared. These include nanowires, nano-heterostructures, and thin nanoplatelets of a variety of elemental compositions. These materials can be integrated with …