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Functional Nanocomposite Coatings for Use in Food Packaging
Get PDFPlastics are a class of materials known for their cost and property advantages, increasing significantly in their usage worldwide. Unfortunately, these benefits come with an increasingly concerning environmental impact. A combination of inadequate disposal options and combinations of materials have led to environmental disasters that will impact generations. One of the worst areas for plastic waste is food packaging. Plastic as a material generally excels at durability and longevity, but as food packaging, it outlives its intended purpose by several orders of magnitude. This leads to plastic food packaging materials sitting in landfill or leading to the environment for hundreds of years. Because of this, there is a strong motivation to develop food packaging materials that are biodegradable, yet still maintain the properties that make plastic better than other classes of materials. Food packaging has many forms, but in general, the most important aspects are cost, mechanical, and oxygen and water barrier properties. To achieve an end-product that excels in these aspects, combinations of materials called composites may be developed. Nanocomposites are a subcategory of composites composed of a matrix material and nanomaterials, separate phases that interact with one another in a number of ways. This research is focused on increasing the mechanical and barrier properties of polyvinyl alcohol, the most commercially-viable biodegradable polymer. The nanomaterials used were graphene oxide (GO) and cellulose nanofibers (CNF) for mechanical and barrier reinforcement. Five sample compositions were produced: a control PVA, CNF, 1 wt% GO, 5 wt% GO, and 10 wt% GO, which were drawn down on uncoated paper and cast by themselves. Testing of these nanocomposites included oxygen transmission, mechanical, and thermal property analysis, and various solvent-interaction testing including absorption of water and oil, Cobb testing, and water vapor permeation. With the addition of CNF and GO to PVA, there was an observed increase in barrier properties through a reduction of hydrophilicity and water absorption, and oxygen permeability
The Influence of Myoblast Implantation on Arteriogenesis in Mice with Diet-Induced Obesity
Get PDFPeripheral arterial occlusive disease (PAOD) is characterized by atherosclerosis, which is the buildup of plaque, consisting largely of cholesterol, in the arterial walls. This plaque accumulation eventually blocks blood flow to the limbs, causing symptoms such as intermittent claudication and tissue death in cases of critical limb ischemia. The body compensates for the reduced perfusion by enlarging pre-existing bypass arteries, known as collaterals, in a process called arteriogenesis. However, in many cases, collateral networks constructed through arteriogenesis fail to enlarge sufficiently or function effectively in patients. Therefore, the development of a therapeutic intervention specifically targeting this process would offer a valuable solution for improving blood flow and facilitating tissue perfusion. Obesity and its comorbidities induce PAOD by promoting atherosclerosis, endothelial dysfunction, and impaired vascular function, so it is critical to analyze the degree of collateral remodeling following arteriogenesis in obese subjects to understand if the phenotype impacts the effectiveness of regenerative treatment. This study aims to determine whether myoblast implantation enhances collateral growth after induced ischemia in the hindlimbs of mice with diet-induced obesity (DIO) and in lean mice. PAOD was mimicked in all subjects by occluding blood flow in the femoral artery with a suture-based ligation. A thermally responsive, injectable polymer containing myoblasts, or no cells, was injected under the gracilis anterior, just deep to the targeted collateral. After 7 days post-operation, the polymer was removed and prepared for assessment. To assess the degree of collateral remodeling, perfusion fixation and vascular casting were performed, with subsequent removal of the anterior gracilis muscle for imaging and measuring vessel luminal/abluminal diameters and calculating arterial wall thickness. The analysis of the study revealed that there was no notable difference in collateral remodeling in the subjects that received the cell treatment and no difference in collateral diameters between the phenotypes (DIO and lean). However, the arterial wall thickness was larger in mice with DIO, regardless of the treatment received. Overall, the outcome of the experiment suggests that arteriogenesis was not enhanced by myoblast implantation in obese subjects
The Impact of Employee Position and Company Size on Workplace Stress in the Commercial Construction Industry
Get PDFWhile stress is commonly experienced in the construction field, there is a lack of understanding regarding how employee rank and company size contribute to this phenomenon. This paper investigates the impact of employee rank and company size on stress levels in the construction industry. To address the gap of information, a qualitative survey was conducted among employees of a small commercial company, focusing on stress levels according to employee ranking. This would be part one. The findings shed light on the relationship between employee position and stress. Additionally, an indirect comparative analysis was performed, comparing the results of this study with those of a similar study conducted on a large construction company, for part two. The analysis of each part determines whether company size influences the amount of stress experienced by individuals in the commercial construction industry. The study reveals that generally, Senior Management employees experience a higher level of stress. Additionally, it demonstrates that, overall, large and small commercial construction companies experience similar levels of stress, except for variations within formal management of stress
City Farm SLO ‘Garden for All’ – Shade Structure
Get PDFLocal non-profit, City Farm SLO, recently presented an opportunity for four Cal Poly Construction Management students to complete senior projects to construct their vision of a “Garden for All.” This paper will focus on the design, preconstruction, and construction processes necessary to complete the shade structure. The project will provide much needed shade to an outdoor classroom area where City Farm SLO hosts farm based education programs all year round. The completion of this senior project required thorough design, estimating, coordination, and construction efforts, while keeping safety and sustainable building practices at the forefront of every decision. This was particularly important since the site was open to active educational and agricultural spaces throughout the course of construction. Special consideration was given for the structural design as well, given the undesirable soil conditions and high wind loads found in the area. Funding was acquired as a joint effort by all four students participating in Garden for All projects. Although coordination between these projects was integral, the design, estimate, and construction of each project was executed by each student independently. Offsite prefabrication of several components was essential to turnover the final product in a quick and seamless manner
French Drain Construction for Woods Humane Society
Get PDFThe Woods Humane Society is a prominent animal care facility that aims to rehabilitate, rescue, and assist in the adoption of dogs and cats in the greater San Luis Obispo area. The property contains multiple dog playpen areas which consist of a concrete slab surrounded by a chain link fence, designed for the animals to have an open space to run around throughout the day. Employees are required to hose down the slab hourly to maintain a clean environment for the animals. When employees hose down the playpen areas, a considerable amount of water runs off the slab and into the soil on the outside of the playpen, resulting in the overgrowing of weeds and shrubbery, diminishing aesthetics, and producing potential hazards towards the dogs. To mediate this issue, the installation of a French drain was proposed. The 173 ft drain, 6” deep x 18” wide broken down into three sections, would border all dog playpen areas preventing further water runoff and weed growth. The French drain consisting of significant excavation, pressure treated lumber, gopher wire, weed barrier, and 2-3” Noiyo cobble stone was the work completed for this project
The Sonoma Developmental Center Redevelopment Project: A Stakeholder Salience and Conflict Analysis Case Study
Get PDFThis analytical case study is an experimental exploration into the utilization of stakeholder salience research to analyze land redevelopment projects from a managerial perspective. The study attempted to develop and apply a simple and approachable research model to a real redevelopment project. The research design is derived from an existing mathematical model designed to quantitatively measure stakeholder salience. Stakeholder salience theory and Pawlak’s conflict theory are the fundamental concepts used to create the research design model. The objective of this research was to assess its effectiveness when applied to a rural land redevelopment setting in the United States. The Sonoma Developmental Center (SDC) redevelopment project is the rural land redevelopment project that is the focus of the study. Stakeholders pertaining to the SDC redevelopment project were identified, grouped based on interest, and surveyed for data collection. Data that was gathered from stakeholder groups of the selected case was used with the developed model to determine the perceived salience value and attitudes toward project concerns of such groups. Data analysis draws comparable results between the case at hand and prior studies while also assessing the feasibility and robustness of the developed research model
The Viability of Electrification for Industrial Off-Road Vehicles in Construction
Get PDFFederal and State legislation has been passed limiting the prospective propulsion options for heavy industrial off-road vehicles that general contractors can operate on the jobsite. The interest behind this research project is the viability of introducing fully electric off-road construction vehicles into the heavy civil construction industry and if the timeline for implementation is realistic or optimistic. As new rules and regulations pertaining to the future emissions requirements of civilian and commercial vehicles effect the country, the construction industry is spending billions in order to develop (and are currently developing) fully electric off-road industrial vehicles (dozers, front loaders, scrappers, dump trucks, etc.) to meet the emissions goals set forth by our governing bodies. In the heavy civil/industrial industry, general contractors rely on their vehicles to be reliable, cheap, and easy to maintain. In this study, six respondents from five different general contractors were interviewed to assess the attitude of the industry from the perspective of the people who purchase, operate, and utilize these vehicles. The results of each interview demonstrate the current questions and concerns regarding the actual viability of an EV replacement paired with the accompanying charging stations and actual impact on national emissions
