Engineering Commons^™

The Effect Of Chlorine And Ozone In Controlling Microbes On Organically Grown Cilantro And Carrots, Adam Holtz

BioResource and Agricultural Engineering

This senior project investigates the relative efficacy of ozonated water and chlorinated water for the purpose of sanitizing freshly-harvested organic produce. The aim of this study was to assist the Cal Poly Organic Farm in deciding whether or not to invest in an ozone generator. The crops used for testing were grown organically in the same field. Carrots and cilantro were harvested and promptly treated with 5 ppm ozone solution or 25 ppm sodium hypochlorite solution. Carrots were sampled at 0, 7, and 14 days storage to determine microbial populations. Cilantro was similarly tested at 0, 6, and 12 days …

Investigation Of Bacillus Subtilis As A Biopesticide Against Botrytis Cinerea, Kenneth K. Ng

Master's Theses

The objective of this thesis was to investigate BiOWiSH^TM-Aqua, a commercial dry solid formulation containing a consortium of bacteria and yeast, as a biopesticide for treatment of Botrytis cinerea, a gray mold that affects strawberries. BiOWiSH^TM-Aqua was compared with another commercial product specifically used as a fungicide and bacteriocide, Serenade® Garden Disease Control Spray (concentrated Bacillus subtilis strain QST 713). Both laboratory tests as well as in vivo lab tests were conducted. BiOWiSH^TM-Aqua results varied widely from plate to plate, regardless of experimental conditions. In some of these plates, inhibition zones were observed …

Design, Acnd Construction Of A Portable Artificial Insemination Chute, Chris Herrera

BioResource and Agricultural Engineering

This senior project report discusses the design, construction, and evaluation of a portable artificial insemination chute for the use of the Cal Poly Beef Department. The design was based on the suggested modifications from operators of several other chutes currently in use.

The main areas considered for the design were; Ergonomics, cattle safety, factors effecting maximum breeding conception rates, and Portability.

The breeding chute proved superior over traditional chutes in a variety of ways. Improvement occurred in the areas of consideration as follows, user operation was simplified, animal stress was decreased, and maximum breeding efficiency was obtained.

Impact Of Collateral Enlargement On Smooth Muscle Phenotype, Alexander Jerome Bynum

Master's Theses

Peripheral Artery Disease is a very serious disease characterized by an arterial occlusion due to atherosclerotic plaques. In response to an arterial occlusion, arteriogenesis occurs, causing smooth muscle cells to transition from a contractile to synthetic state. Also following an arterial occlusion, functional impairment was seen in the collateral circuit. An immunofluorescence protocol was developed in order to assess the impact of collateral enlargement (arteriogenesis) on smooth muscle phenotype at various time points. Smooth muscle α-actin was used to mark all smooth muscle cells, Ki-67 was used to label proliferating smooth muscle cells, and a fluorescent nuclear stain was used …

Impaired Resistance Artery Reactivity Following Arteriogenesis, Michael (Mike) Machado

Biomedical Engineering

No abstract provided.

Oxidation Kinetics Of Silver Thin Films For Antimicrobial Applications In The Health Care Industry, Sean D. Morham

Materials Engineering

To determine if varying city water qualities from around the United States can support a developing “oxidation corrosion of silver thin films” method of creating aqueous ionic silver solutions for the anti-microbial treatment of healthcare linens, a test was devised holding all variables constant with the exception of water quality parameters. This corrosion style test was done in order to assess a pass/fail criteria of 25 ppb ionic silver concentration in the aqueous solutions which resulted from the corrosion of silver thin film coated substrates. Above 25 ppb being a pass, below 25 ppb being a fail. While varying the …

Determining A Method For Rendering Low Cost Cdse(Zns) Core(Shell) Quantum Dots Aqueous Soluble Via Amphiphilic Polymer Wrapping, Patrick Mcbride

Materials Engineering

Herein is described the procedure of two amphiphilic polymer wrapping techniques that may be employed for obtaining aqueous soluble quantum dots (QDs) for use in biological fluorescent imaging applications. The advent of QDs has led to new nanoscale fluorescent materials that exhibit unparalleled quantum yields (QYs), high resistance to photobleaching, tunable emissions, and
absorption over a large optical range. However, the QD synthesis employed here at Cal Poly to obtain bright, photostable CdSe(ZnS) core(shell) QDs involves the use of organic solvents and surfactants, leading to hydrophobic QDs. Since all of biology relies on aqueous solubility, this hydrophobicity creates a major …

Ischemia Impairs Vasodilation In Skeletal Muscle Resistance Artery, Kyle Remington Struthers

Master's Theses

Functional vasodilation in arterioles is impaired with chronic ischemia. We sought to examine the impact of chronic ischemia and age on skeletal muscle resistance artery function. To examine the impact of chronic ischemia, the femoral artery was resected from young (2-3mo) and adult (6-7mo) mice and the profunda femoris artery diameter was measured at rest and following gracilis muscle contraction 14 days later using intravital microscopy. Functional vasodilation was significantly impaired in ischemic mice (14.4±4.6% vs. 137.8±14.3%, p<0.0001 n=8) and non-ischemic adult mice (103.0±9.4% vs. 137.8±14.3%, p=0.05 n=10). In order to analyze the cellular mechanisms of the impairment, a protocol was developed to apply pharmacological agents to the experimental preparation while maintaining tissue homeostasis. Endothelial and smooth muscle dependent vasodilation were impaired with ischemia, 39.6 ± 13.6% vs. 80.5 ± 11.4% and 43.0 ± 11.7% vs. 85.1 ± 10.5%, respectively. From this data, it can be supported that smooth muscle dysfunction is the reason for the observed impairment in arterial vasodilation.

Studying Milk Coagulation Kinetics With Laser Scanning Confocal Microscopy, Image Processing, And Computational Modeling, Richard Joseph Hennessy

Master's Theses

The kinetics of milk coagulation are complex and still not well understood. A deeper understanding of coagulation and the impact of the relevant factors would aid in both cheese manufacturing and also in determining the nutritional benefits of dairy products. A method using confocal microscopy was developed to follow the movement of milk fat globules and the formation of a milk protein network during the enzyme-induced coagulation of milk. Image processing methods were then used to quantify the rate of coagulation. It was found that the texture of the protein network is an indicator of the current status of the …

A Novel Exercise Device For Users In Wheelchairs: A Study Of Abdominal Muscle Activation, Rebecca Jo Campbell

Master's Theses

This study evaluates the use of a wheelchair balance board. The balance board was created as a sensory stimulation tool for users with various disabilities. It was originally designed to create vestibular stimulation for the person after they were loaded on. This study was used as a way to test if the balance board could be used for other things such as physical therapy and exercise. Ten able-bodied individuals were used to show the functionality of the device. They were asked to perform six different abdominal exercises while the muscle activity of their rectus abdominis and external obliques was measured …

Investigating Wood Welding Parameters Using A Prototype Welding Machine, Timothy R. Melin

Master's Theses

Understanding how different processing variables influence wood welded bonds is vital if the technique will ever be used to create engineered lumber without using adhesives. A variation of vibration welding, wood welding uses pressure and friction to bond materials together. During welding, heat causes a softening in the wood, a naturally occurring composite material. This softening leads to fiber entanglement and a bond forms upon cooling.

The goal of this research was to investigate several processing aspects of the wood welding procedure. A prototype wood welding machine, designed and fabricated from the ground up, was used to investigate the effects …

Universal Play Frame Vi, Justin Bazant, Cullen Crackel, Anthony Franceschi

Mechanical Engineering

This design report details the design process utilized by Adaptive Exercise Designs (AED) in creating the sixth design of the Universal Play Frame (UPF). The UPF is an adaptive frame which supports a variety of devices that allows athletes in wheelchairs with limited range of motion to participate in physical activity. The past five frame designs do not meet the needs of the Friday Club due to complications with function and time constraints. To ensure all of Fridays Club's needs were met, the problem was better defined by converting the customer requirements into engineering specifications. The design process our team …

Temperature Influence And Heat Management Requirements Of Microalgae Cultivation In Photobioreactors, Thomas Hagen Mehlitz

Master's Theses

Microalgae are considered one of the most promising feedstocks for biofuel production for the future. The most efficient way to produce vast amounts of algal biomass is the use of closed tubular photobioreactors (PBR). The heat requirement for a given system is a major concern since the best algae growth rates are obtained between 25-30 °C, depending on the specific strain. A procedure to determine temperature influence on algal growth rates was developed for a lab-scale PBR system using the species Chlorella. A maximum growth rate of 1.44 doublings per day at 29 °C (optimal temperature) was determined. In addition, …