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Gateway Decathlon: Cost Estimation of an Offsite Residential Construction Unit
Get PDFThis senior project focused on the cost of the materials used for the shell and structure of the Gateway Decathlon modular residential unit. Collectively, the group on the Gateway Decathlon project decided to design and build the structure using mass timber. A material takeoff of the building was performed, allowing for an accurate measurement of structural materials. After material selection, a final cost estimate was by multiplying the selected materials unit price by the total quantity of the material. The material cost estimate calculations were performed on the current Revit Model allowing for a full-scale analysis of the offsite building. The estimate does not account for labor, strictly materials. The total cost of the structural components of the building was $246,028.13. A large portion of the cost was a result of the use of Cross Laminated Timber (CLT) however prefabrication and efficient building methods could reduce the cost when built. The timber market can also fluctuate which could cause a variety of cost outcomes
Cal Poly Craft Center Wedging Tables
Get PDFThe Craft Center, located on Cal Poly\u27s campus, is where students can unwind from stressful coursework and engage in activities like pottery, surfboard shaping, and stained glass. The pottery studio needed new wedging tables, which are essential for removing air from clay before shaping it. The project involved building two new 7’ x 2.5’ tables that would fit well in the space and be durable. Designed to be 33” tall, these tables are accessible to students of varying heights. They feature a concrete surface that is both durable and porous, helping to absorb some moisture during use. The previous tables were mistakenly discarded during a recent remodel, prompting the need for new ones. This also provided an opportunity to improve the design for better functionality. Enhancements included optimized size, height, and increased storage capacity. The aim is to create tables that withstand the test of time, ensuring that future students can use them for many years. The new tables not only meet the practical needs of the Craft Center but also contribute to a more efficient and enjoyable environment for students to practice their craft
Assessment of Musculoskeletal Disorders (MSDs) Risk During the Framing of a 6\u27 x 8\u27 Wooden Shed Using Traditional Hammers
Get PDFWood-framed construction will almost always use nails as a connector whether it be for different pieces of wall sections or connecting wall sections to the structure. Nails also act in Shear Walls in different nailing patterns to prevent the panel from splitting. Houses in modern times are usually nailed with nail guns, either with a cord or cordless, which reduces their exposure to Musculoskeletal disorders (MSDs). However, smaller jobs may opt to use traditional hammers instead of nail guns. This study aims to numerically quantify the forces and flexions one puts on the body when performing nailing tasks using a traditional hammer. The study is focused on the CM 214, Spring 2024, Section one six feet by eight feet shed. This project was framed during week 5 of the California Polytechnic San Luis Obispo Spring 2024 quarter. Videos of the framing process were taken during construction and then subsequently processed using the VelocityEHS Safety program providing a risk score and flexion graphs. The findings of this paper show the flexions and intensity of said flexion in the neck, back, shoulders, and knees of the framer
Son Care Foundation – Lean to Shade Structure Design and Construction
Get PDFThis paper discusses the design and construction of a lean-to-shade structure built for the Son Care Foundation in San Luis Obispo. The Son Care Foundation is a nonprofit organization that raises guide dogs for veterans and first responders with PTSD. This shade structure is 16 feet long and 6 feet wide, its height slopes from 9 feet in the front down to 8 feet in the back creating a roof pitch of 2:12. The sheet metal roof also has an overhang of approximately 1 foot. As requested by the client, the shade structure was designed to fit the aesthetic of the existing shade structures in the area. After developing a design, with the assistance of architectural engineering students, structural calculations confirmed that the structure was designed adequately for all potential loading conditions. Due to the interdisciplinary collaboration required for the design and construction of this project, the Alliance provided funding for the project through their Hasslein Fund, which provides funding for projects that foster collaboration between different majors. The construction processes included in this project were site layout, excavation, concrete, framing, and roofing
Construction Wellness: Analyzing Mental Health Issues and Solutions for Construction Workers
Get PDFThe construction industry is known for its demanding nature, often leading to significant mental health challenges among its workforces. This study investigates mental health issues prevalent in construction, focusing on identifying key stressors and potential protective factors. A mixed-method approach was employed, combining a systematic literature review with a survey distributed to construction professionals. The survey gathered data on job satisfaction, stress, coping mechanisms, and the availability and utilization of mental health resources. Results indicated high levels of job dissatisfaction and stress, with respondents citing poor communication, excessive work hours, and lack of control over their roles as primary stressors. Additionally, the survey revealed that while some companies offer mental health support programs, awareness and utilization of these resources are limited. Employees reported that their work negatively impacts their personal lives, contributing to mental health issues such as anxiety and depression. The study concludes that there is a critical need for mental health support within the construction industry. Recommendations include improving communication, improving mental health resources, and fostering a supportive work environment to enhance overall well-being among construction workers. This research provides valuable insights for industry stakeholders to develop targeted interventions aimed at improving mental health in the construction sector
Concrete Design: Underwater Concrete Forms in a Saltwater Environment
Get PDFThis following project investigated the effects of salt on the concrete curing process. Concrete possesses numerous strengths, making it extremely versatile. This makes it one of the most utilized construction materials. New improved methods are constantly being developed for concrete’s application as a construction material. While concrete is a flexible material with many strengths, it is not without its flaws. Concrete, while strong in compression is weak in tension. It has long cure times and doesn’t generally handle moisture well. This paper evaluates concrete’s change in strength from letting concrete cure in a salt-based underwater environment. To determine the full effects of saltwater, concrete will be cured in varying amounts of salt and simultaneously testing a batch cured in just water. The study demonstrates a general decrease in compressive strength when the mix is cured in salt water. Despite being an outlier, the implementation of salt did not prove beneficial. The size of the cylinders and inconsistencies in the mix could have also impacted the overall compressive strength of the cylinders. Materials with similar characteristics to salt could prove interesting in future studies involving the strength of concrete
Performance of Multi-Composite Materials with Corrugated and Cell Geometries Under Low-Velocity Impact
Get PDFComposite structures have demonstrated great potential to improve mechanical performance in various applications, including ballistics protection. This study demonstrates that the integration of geometrically optimized composites into core-face sheet assemblies provide great impact resistance. The research investigated the performance of two composite manufacturing methods under low-velocity impact through residual strength and damage comparisons. Corrugated core composites were produced with traditional manufacturing methods, namely compression molding, using twelve stacking sequences. These stacking sequences were chosen to represent four laminate groups, where a unique fiber orientation scheme was employed across three laminate thicknesses (6, 8, and 12 layers). In contrast, honeycomb and auxetic cell cores were produced using continuous fiber-reinforced 3D printing. To maintain consistency, both the corrugated cores and the advanced cell cores were produced with para-aramid fibers, though the matrix differed between the two manufacturing methods. The cores were subjected to a consistent drop-weight impact event under various impact cases where the makeup of the assembly differed. The findings of this testing showed that external damage decreased as layer count increased for the laminates and that the addition of a silica damping material significantly improved post-impact, out-of-plane compressive response. In addition, testing proved that the cross-ply, longitudinally dominant laminates & the honeycomb printed composite exhibit exceptional out-of-plane compressive strength prior to and after impact. The cross-ply core retained 58.0% of its pre-impact stiffness & 68.3% of its pre-impact strength while the honeycomb core retained 88.0% of its pre-impact stiffness and did not fail under the maximum compressive load. Aside from impact testing, theoretical and numerical analyses were performed. Classic Laminate Plate Theory was employed to predict laminate engineering constants, while finite element models were created to simulate the in-plane response of the cores. The theoretical approach roughly approximated the longitudinal modulus, though the error was significant. In contrast, the finite element models developed closely mirrored experimental tensile behavior, with peak stress predicted within 5% of experimental results. The compressive response was also well captured by the model, though the displacement to buckling onset was underpredicted by 38.0%
Finite Element Analysis and Verification of Transverse Mechanical Properties of Generally Cylindrical Orthotropic Constitutive Modeling of 3-Phase Nanocomposite Unit Cell
Get PDFFiber-reinforced composites are increasingly popular due to their specific strength and stiffness, making them ideal for high-performance applications. However, these materials primarily exhibit superior properties in-plane, while their out-of-plane characteristics remain comparatively weaker. Previous research has shown that the most effective method to enhance out-of-plane properties involves the incorporation of carbon nanotubes. Experimental tests have demonstrated significant improvements in properties such as tension, flexural, short beam shear, and fracture toughness. Alongside these experimental studies, analytical equations have been developed to predict the behavior of these composites under various loading conditions, including tension, bending, shear, and fracture. Existing models primarily address axial and radial loads in two-phase composites, with some extending to axial loading in three-phase models. More recently, a three-phase analytical model has been proposed to predict transverse properties under radial load. However, this model has yet to be validated through finite element analysis. To bridge this gap, this study employs Abaqus to develop a finite element model consisting of three orthotropic materials subjected to uniform external radial pressure. This approach allows for the investigation of micro-mechanical behavior and the determination of transverse properties in carbon nanotube composites. A parametric study varying the matrix volume fraction further demonstrates the robustness and potential of the model as a design tool. The results are then compared with analytical solutions to validate the predicted transverse properties under a radial pressure load
Policies and Price Controls on the Research and Development of Orphan Drugs in the United States and the European Union
Get PDFThere is substantive literature surrounding the impact of price controls on the research and development (R&D) of new pharmaceutical products. The European Union (EU) and United States (US) are often studied in contrast to examine the influence of price controls as the US has fewer pharmaceutical price controls than the EU.
We find moderate evidence that the US spent more on annual domestic pharmaceutical R&D than the EU between 2004 and 2021, on average, before and after adjusting for GDP growth per capita and year. We find strong evidence that the US increased annual domestic R&D spending at a faster rate than the EU between 2004 and 2021, on average, before and after adjusting for GDP growth per capita.
Prior studies have asserted that increased US R&D spending leads to the production of more pharmaceutical products. Our study aims to quantify the differences in US and EU orphan drug development. Orphan drugs are pharmaceutical products that treat rare diseases. Both the EU and US aim to stimulate orphan drug production with policies including national grants, tax credits, and extended periods of market exclusivity.
Our study gives indication that these policies in the US and EU are effective at spurring rare disease drug creation. We find evidence that orphan drug market authorizations increased annually, on average, in both the US and EU from 2004 to 2021, before and after adjusting for GDP growth rate per capita and the interaction between year and region. We find the same when isolating market authorizations for new orphan drugs.
The US awarded more annual orphan drug market authorizations and market authorizations for new orphan drugs than the EU every year from 2004 to 2021, except in 2007. We find evidence that from 2004 to 2021, the US awarded more annual orphan drug market authorizations and market authorizations for new orphan drugs than the EU, on average, before and after adjusting for GDP growth per capita and year. There is also evidence that the US increased the number of these authorizations at a faster rate annually than the EU, on average, before and after adjusting for GDP growth per capita.
Our results suggest an association between EU price controls and reduced pharmaceutical innovation. This is seen in the form of less annual R&D spending growth, orphan drug market authorizations, and new orphan drugs compared to the US, on average. However, the benefits of this innovation may not reach patients, as US consumers pay higher pharmaceutical prices due to limited price controls. This may contribute to the expansion of existing health inequities in the US. We are also unsure if the quality of US innovation exceeds that of the EU and if increased innovation is truly the result of lower price controls
Development of a Hybrid AC/DC Residential Electrical System
No full textIn pursuit of supporting the global efforts in reducing carbon footprint and reliance on fossil fuels, this thesis seeks to continue the development of a hybrid AC/DC house prototype at Cal Poly State University. In particular, this thesis presents improvements on several aspects of the house. To enhance the power flow to DC loads, a dedicated 48 V DC bus was constructed to replace the impractical multiple DC buses in the previous system. This iteration also added a key feature that enables users to monitor real-time AC and DC powers. Another new functionality involves the provision of a mix of latching and non-latching relays to switch between sources, thus ensuring that both AC and DC loads receive power. This new feature further enables users to conveniently observe the system status and select which sources are utilized from a touchscreen. Other improvements entail the integration of a control system with a Raspberry Pi and Arduino Nano and a touchscreen human-machine interface to control main components in the system. Results from hardware tests revealed that most of the improved components and new features performed well. Design, component selection, and development of the improvement tasks will be discussed in this report, including technical issues encountered. Future work to further improve the system will also be presented. When fully completed, the hybrid AC/DC house will not only serve as a living laboratory to educate students and the community on residential electrical system but will also serve as a demonstration site of a future Net Zero Energy Home